Analysis of the internal short-circuit conditions of the Acceleration Grid Power Supply of the MITICA experiment

Analisi della situazione di guasto interno del sistema di alimentazione delle griglie di accelerazione dell'esperimento MITICA,il quale è un prototipo di NBI, un sistema di riscaldamento ausiliario, per reattori a fusione. Viene analizzato il guasto per valutare l'utilizzo di alcuni sistemi di protezione e verificarne l'efficacia. Per fare ciò è stato sviluppato un modello circuitale del sistema e sono state effettuate le simulazioni del guastoope

Identification of novel 2-benzoxazolinone derivatives with specific inhibitory activity against the HIV-1 nucleocapsid protein

In this report, we present a new benzoxazole derivative endowed with inhibitory activity against the HIV-1 nucleocapsid protein (NC). NC is a 55-residue basic protein with nucleic acid chaperone properties, which has emerged as a novel and potential pharmacological target against HIV-1. In the pursuit of novel NC-inhibitor chemotypes, we performed virtual screening and in vitro biological evaluation of a large library of chemical entities. We found that compounds sharing a benzoxazolinone moiety displayed putative inhibitory properties, which we further investigated by considering a series of chemical analogues. This approach provided valuable information on the structure-activity relationships of these compounds and, in the process, demonstrated that their anti-NC activity could be finely tuned by the addition of specific substituents to the initial benzoxazolinone scaffold. This study represents the starting point for the possible development of a new class of antiretroviral agents targeting the HIV-1 NC protein

Editorial: deep carbon science

SZ was supported by Australian Research Council grant IH130200012, a University of Sydney Robinson Fellowship, and Alfred P. Sloan grants G-2017-9997 and G-2018-11296.Publisher PDFPeer reviewe

Boosting D3FEND: Ontological Analysis and Recommendations

Formal Ontology is a discipline whose business is to develop formal theories about general aspects of reality such as identity, dependence, parthood, truthmaking, causality, etc. A foundational ontology is a specific consistent set of these ontological theories that support activities such as domain analysis, conceptual clarification, and meaning negotiation. A (well-founded) core ontology specifies, under a foundational ontology, the central concepts and relations of a given domain. Foundational and core ontologies can be seen as ontology engineering frameworks to systematically address the laborious task of building large (more specific) domain ontologies. However, both in research and industry, it is common that ontologies as computational artifacts are built without the aid of any framework of this kind, favoring the occurrence of numerous modeling mistakes and gaps. Through a case study, here we show an exemplar of such a case in the domain of cybersecurity by providing an ontological analysis of D3FEND, an OWL knowledge graph of cybersecurity countermeasure techniques proposed by the MITRE Corporation. Based on the Reference Ontology for Security Engineering (ROSE), a core ontology of the security domain founded in the Unified Foundational Ontology (UFO), our investigation reveals a number of semantic deficiencies in D3FEND, including missing concepts, semantic overload of terms, and a systematic lack of constraints that renders that model under-specified. As a result of our ontological analysis, we propose several suggestions for the appropriate redesign of D3FEND to overcome those issues.</p

A strategy to identify breakdown location in MITICA test facility: results of high voltage test campaign

The Acceleration Grid Power Supply of the MITICA test facility in Padova (Italy) is currently under commissioning. The power conversion system, the DC generator, and the High Voltage equipment have been individually commissioned, whereas the integration tests are ongoing. It is a challenging process due to the unconventional application, to the variety of different electrical technologies involved and to the complexity of the interfaces. During the integrated tests of the power supplies the achievement of 700kV stable operation has been demonstrated for the first time in a Neutral Beam Injector, but an unexpected event occurred, most likely a breakdown in the HV part, which resulted in a fault of the DC generator. A subsequent test using an auxiliary power supply was performed to check the voltage withstanding capability of the HV plant, but another breakdown occurred at around 1MV. This paper describes the activity performed to identify the location of the breakdowns affecting the integrated tests. A test campaign has been devised with increased diagnostic capabilities and specific strategy conceived to trigger intentional breakdowns in specific locations and collect measurement patterns for different cases. The results of the campaign will be presented and the current understanding of the issue will be described, with a view on future tests and further improvements of diagnostics

A review and meta-analysis of the effects of climate change on Holarctic mountain and upland bird populations

Mountain regions are globally important areas for biodiversity but are subject to multiple human-induced threats, including climate change, which has been more severe at higher elevations. We reviewed evidence for impacts of climate change on Holarctic mountain bird populations in terms of physiology, phenology, trophic interactions, demography and observed and projected distribution shifts, including effects of other factors that interact with climate change. We developed an objective classification of high-elevation, mountain specialist and generalist species, based on the proportion oftheir breeding range occurring in mountain regions. Our review found evidence of responses of mountain bird populations to climate (extreme weather events, temperature, rainfall and snow) and environmental (i.e. land use) change, but we know little about either the underlying mechanisms or the synergistic effects of climate and land use. Long-term studies assessing reproductive success or survival of mountain birds in relation to climate change were rare. Few studies have considered shifts in elevational distribution over time and a meta-analysis did not find a consistent direction in elevation change. A meta-analysis carried out on future projections of distribution shifts suggested that birds whose breeding distributions are largely restricted to mountains are likely to be more negatively impacted than other species. Adaptation responses to climate change rely mostly on managing and extending current protected areas for both species already present, and for expected colonizing species that are losing habitat and climate space at lower elevation. However, developing effective management actions requires an improvement in the current knowledge of mountain species ecology, in the quality of climate data and in understanding the role of interacting factors. Furthermore, the evidence was mostly based on widespread species rather than mountain specialists. Scientists should provide valuable tools to assess the status of mountain birds, for example through the development of a mountain bird population index, and policy-makers should influence legislation to develop efficient agri-environment schemes and forestry practices for mountain birds, as well as to regulate leisure activities at higher elevations.Peer reviewe

Partial Discharges detection in 1 MV power supplies in MITICA experiment, the ITER Heating Neutral Beam Injector prototype

MITICA (Megavolt ITER Injector & Concept Advancement), the full scale prototype of ITER Heating Neutral Beam, is under realization at the Neutral Beam Test Facility (Padova, Italy). It is designed to deliver 16.5 MW to ITER plasma, obtained by accelerating negative Deuterium ions up to 1 MeV for a total ion current of 40 A and then neutralized. MITICA Acceleration Power Supply is composed of several non-standard equipment, beyond industrial standard for insulation voltage level (-1 MVdc) and dimensions. Voltage withstand tests (up to 1.265 MVdc) have been performed in five subsequent steps (from 2018 to 2019), according to the installation progress, after connecting equipment belonging to different procurements. During integrated commissioning, started in 2021, two breakdowns occurred in a position of the HV plant not still identified, so they could be occurred either in air or in SF6. To identify the locations of possible weak insulation points, the existing diagnostics for partial discharge detection (the precursor of breakdowns) as a first step have been improved on air-insulated parts by consisting in a set of instrumentation, like capacitive probes and off-the-shelf instruments for AC application (acoustic and electromagnetic sensors). The paper deals with the instruments qualification to assess their suitability for DC usage and then with the investigation performed in MITICA, in particular: 1) sensitivity assessment campaign, with artificially produced corona effect to identify the minimum threshold of each diagnostics 2) voltage application to MITICA plant, moving the instrumentation around equipment and increasing progressively the voltage looking for corona phenomena to identify possible weak insulation points.Comment: Nine pages, twelve figures, accepted manuscript of a paper published in Fusion Engineering and Desig

3D-HST: A wide-field grism spectroscopic survey with the Hubble Space Telescope

We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying the processes that shape galaxies in the distant Universe. 3D-HST provides rest-frame optical spectra for a sample of ~7000 galaxies at 1<z<3.5, the epoch when 60% of all star formation took place, the number density of quasars peaked, the first galaxies stopped forming stars, and the structural regularity that we see in galaxies today must have emerged. 3D-HST will cover 3/4 (625 sq.arcmin) of the CANDELS survey area with two orbits of primary WFC3/G141 grism coverage and two to four parallel orbits with the ACS/G800L grism. In the IR these exposure times yield a continuum signal-to-noise of ~5 per resolution element at H~23.1 and a 5sigma emission line sensitivity of 5x10-17 erg/s/cm2 for typical objects, improving by a factor of ~2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide continuous wavelength coverage from 1.1-1.6 um at a spatial resolution of ~0."13, which, combined with their depth, makes them a unique resource for studying galaxy evolution. We present the preliminary reduction and analysis of the grism observations, including emission line and redshift measurements from combined fits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis yields redshift estimates with a precision of sigma(z)=0.0034(1+z), or sigma(v)~1000 km/s. We illustrate how the generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types of objects, including a quasar at z=4.7, quiescent galaxies at z~2, and the most distant T-type brown dwarf star known. The CANDELS and 3D-HST surveys combined will provide the definitive imaging and spectroscopic dataset for studies of the 1<z<3.5 Universe until the launch of the James Webb Space Telescope.Comment: Replacement reflects version now accepted by ApJS. A preliminary data release intended to provide a general illustration of the WFC3 grism data is available at http://3dhst.research.yale.edu

Dengue Reporter Virus Particles for Measuring Neutralizing Antibodies against Each of the Four Dengue Serotypes

The lack of reliable, high-throughput tools for characterizing anti-dengue virus (DENV) antibodies in large numbers of serum samples has been an obstacle in understanding the impact of neutralizing antibodies on disease progression and vaccine efficacy. A reporter system using pseudoinfectious DENV reporter virus particles (RVPs) was previously developed by others to facilitate the genetic manipulation and biological characterization of DENV virions. In the current study, we demonstrate the diagnostic utility of DENV RVPs for measuring neutralizing antibodies in human serum samples against all four DENV serotypes, with attention to the suitability of DENV RVPs for large-scale, long-term studies. DENV RVPs used against human sera yielded serotype-specific responses and reproducible neutralization titers that were in statistical agreement with Plaque Reduction Neutralization Test (PRNT) results. DENV RVPs were also used to measure neutralization titers against the four DENV serotypes in a panel of human sera from a clinical study of dengue patients. The high-throughput capability, stability, rapidity, and reproducibility of assays using DENV RVPs offer advantages for detecting immune responses that can be applied to large-scale clinical studies of DENV infection and vaccination