651 research outputs found
A brief history of Florentine physics from the 1920s to the end of the 1960s
The history of the Institute of Physics at the University of Florence is
traced from the beginning of the 20th century, with the arrival of Antonio
Garbasso as Director (1913), to the 1960s. Thanks to Garbasso's expertise, not
only did the Institute gain new premises on Arcetri hill, where the
Astronomical Observatory was already located, but it also formed a brilliant
group of young physicists made up of Rita Brunetti, Enrico Fermi, Franco
Rasetti, Enrico Persico, Bruno Rossi, Gilberto Bernardini, Daria Bocciarelli,
Giuseppe Occhialini and Giulio Racah, who were engaged in the emerging fields
of Quantum Mechanics and Cosmic Rays. This {\it Arcetri School} disintegrated
in the late 1930s not only for the transfer of its protagonists to chairs in
other universities but also for the racial laws and the environment created by
the fascist regime. After the war, the legacy was taken up by some students of
this school who formed research groups in the field of nuclear physics and
elementary particle physics. As far as theoretical physics was concerned, after
the Fermi and Persico periods these studies enjoyed a new expansion towards the
end of the 1950s, with the arrival of Giacomo Morpurgo and above all, that of
Raoul Gatto, who created the first real Italian school of Theoretical Physics
at Arcetri.Comment: Latex file, 11 figure
Lo spirito di Arcetri
On 7 November 1921, the new Institute of Physics of the Royal Institute of Higher, Practical and Advanced Studies of Florence was inaugurated in Arcetri. Three years later, with the establishment of the University of Florence, the Degree Course in Physics would start: as such an adventure in research and scientific training began, which would take us to the present day. To mark the centenary of the inauguration of the Institute of Physics in Arcetri, the book takes the opportunity to retrace a part of those years. The period chosen ranged from the arrival of Garbasso in 1913 to the end of the 1960s. The book contains a first part, documenting the history of the Institute of Physics during the above mentioned years. This is followed by a second part, outlining the biographies of some of the protagonists of that history. In the final part, there is an index of the holders of the courses of Physics and Astronomy in Florence from 1876 to 1969. This landscape is the result of research work conducted in the Universityâs Historical Archives of the University
Molecular catalysed Guerbet reaction: Moving to the larger and the Greener through LCA and scale up simulation approaches
Efficient homologation of bio-ethanol can be performed under mild conditions exploiting a catalytic system based of a ruthenium molecular catalyst, benzoquinone and a base as a co-catalysts. Conversions and selectivity can be tuned by changing the head space of the reactor. On this basis, preliminary design of a full-scale process has been developed based on the experimental results. The process has been characterized with specific energy and performance indicators per unit of produced butanol, which have been used as input for the life cycle assessment analysis. The LCA was applied as scientific methodology to address potential burdens of the baseline configuration, 3X catalytic cycles, electricity from Italian grid and heat from natural gas. Hotspots were identified according to a multi-impact approach method (ReCiPe 2016). The usage of dedicated lignocellulosic biomass as a source of EtOH, the synthesis of the catalytic system and the energy requirements were addressed as the major contributors. Thus, further sensitivity scenarios were created. The best configuration was identified in the use of waste biomasses and in an integrated cogeneration unit. In addition, enabling the recovery of the catalytic system up to five cycles to scenario shows a reduction in the impacts higher than 50% for the categories of global warming potential, â41% for the mineral resource scarcity and around â16% for the fine particulate matter formation. The results were also confirmed by an uncertainty analysis with the Monte Carlo method, which demonstrated the major environmental sustainability of the Guerbet route compared to the oxo synthesis from propylene
Substrate-borne vibrations produced during the interaction with natural enemies alter aphids probing behavior
The âecology of fearâ, i.e., physiological and behavioral alterations displayed by pests in response to predation risk, has recently been proposed as a sustainable alternative to chemicals for pest control. However, the development of such a strategy requires a detailed understanding of the signals and cues underlying the pest-antagonist interaction and eliciting the prey behavioral alteration. Here, we characterized the substrate-borne vibrations produced during the interaction between the green peach aphid Myzus persicae and its antagonists, the parasitoid wasp Aphidius colemani and the ladybug Adalia bipunctata. Thereafter, coupling the electrical penetration graph (EPG) with a stimulus controller, we evaluated whether the playback of the vibrations, alone and in combination with the alarm pheromone, impacted aphid probing behavior and interaction with the host plant. Aphids responded to vibrations exhibiting longer non-probing, shorter intracellular probes, i.e. the behavior through which the insect evaluates host plant quality, delay in accessing the phloem vessels and decrease of the frequency of phloem salivation events. In contrast, on plants treated with the alarm pheromone, insects displayed longer intracellular probes. We hypothesize that the alarm pheromone, signaling a distant threat, might induce a careful evaluation of the host plant in order to decide the magnitude of the reaction. On the other hand, vibrations might indicate a closely approaching threat pushing the aphid to rush the host evaluation process and the whole feeding process. The possible repercussion of the behavioral alterations observed on the dynamics of aphid-borne plant virus transmission is also discusse
Docker experience at INFN-Pisa Grid Data Center
Clouds and virtualization offer typical answers to the needs of large-scale computing centers to satisfy diverse sets of user communities in terms of architecture, OS, etc. On the other hand, solutions like Docker seems to emerge as a way to rely on Linux kernel capabilities to package only the applications and the development environment needed by the users, thus solving several resource management issues related to cloud-like solutions. In this paper, we present an exploratory (though well advanced) test done at a major Italian Tier2, at INFN-Pisa, where a considerable fraction of the resources and services has been moved to Docker. The results obtained are definitely encouraging, and Pisa is transitioning all of its Worker Nodes and services to Docker containers. Work is currently being expanded into the preparation of suitable images for a completely virtualized Tier2, with no dependency on local configurations
Astronomia e Fisica a Firenze : dalla Specola ad Arcetri
La Mostra Astronomia e Fisica a Firenze illustra lâevoluzione delle due discipline dal XVIII secolo fino ai primi decenni del Novecento. Teatro cittadino di questo processo, anzi di tutte le scienze, fu lâImperiale e Reale Museo di Fisica e Storia Naturale, dove adesso ha sede la Mostra. Nellâarco di tempo esaminato tutti gli aspetti dellâindagine della natura erano ugualmente pertinenti ad unâunica figura di studioso, ma verso lâinizio del XX secolo alcuni indirizzi subirono una profonda trasformazione e al prevalente approccio tassonomico e fenomenologico subentrĂČ, soprattutto per Astronomia e Fisica, unâindagine specialistica che finĂŹ per differenziare le varie ricerche. Protagonista di questa fase fu lo sviluppo dellâanalisi spettroscopica.
La Mostra, aperta da dicembre 2016 a marzo 2017, Ăš organizzata dallâUniversitĂ di Firenze (Museo di Storia Naturale; Dipartimento di Fisica e Astronomia) e dallâOsservatorio Astrofisico di Arcetri, in collaborazione con la Sezione di Firenze dellâINFN, il Museo Galileo, lâArchivio Storico del Comune di Firenze, lâIstituto Nazionale di Ottica del CNR e la Biblioteca di Scienze dellâUniversit
The first absolute gravity and height reference network in Sicily
The purpose of this work is to provide the methodological and instrumental framework for the establishment of a new absolute gravity and height reference network in Sicily. The aim of the network is to contribute to the new reference systems in the Italian area, useful for the scientific and technological activities related to the gravity field and to the proper definition of a modern height system in this region. The network is composed of 5 stations, evenly distributed to form a large mesh, which roughly covers the entire Sicily. Since four of the five selected stations were measured also in the 1990s, it was also possible to evaluate whether long-term gravity changes occurred at these sites (basic requirement for a reference network) and check the long-term ground deformation patterns, using data from the closest GPS/GNSS stations. The observed gravity changes over a time interval of about 30 years at the absolute stations and in the surrounding areas, confirm the long-term stability of the selected areas/sites
Intruding into a conversation: how behavioral manipulation could support management of Xylella fastidiosa and its insect vectors
Behavioral manipulation (BM) is a multimodal control approach based on the interference with the stimuli mediating insect perception and interaction with the surroundings. BM could represent a winâwin strategy for the management of vector-borne plant pathogens as the bacterium Xylella fastidiosa, since it could reduce the number of vectors alighting on host plants and, consequently, the chances for transmission to occur. In this review, we summarized current knowledge and highlighted gaps in information on (i) how insect vectors of X. fastidiosa in general, and more specifcally the meadow spittlebug Philaenus spumarius, locate and accept the host plant; and (ii) how behavioral manipulation techniques could be applied to disrupt the vectorâhost plant interaction. Finally, we discussed how diverse BM strategies could be combined with other integrated pest management tools to protect olive groves from inoculation with the fastidious bacterium
CERNâs beam instrumentation R&D study for FCC-ee
The Future Circular Collider (FCC) R&D study was started in 2021 as a comprehensive feasibility analysis of CERNâs future accelerator project encompassing technical, administrative and financial aspects. As part of the study, Beam Instrumentation (BI) is a key technical infrastructure that will have to face unprecedented challenges. In the case of electron-positron FCC-ee, these are represented, among others, by the size of the accelerator, the amount of radiation produced along the ring and in machine-detector interaction region, the presence of the top-up booster and collider ring in the same tunnel. In this contribution we will present the current FCC-ee BI study and discuss its status and perspectives
Ruxolitinib in cytopenic myelofibrosis: Response, toxicity, drug discontinuation, and outcome
Background: Patients with cytopenic myelofibrosis (MF) have more limited therapeutic options and poorer prognoses compared with patients with the myeloproliferative phenotype. Aims and methods: Prognostic correlates of cytopenic phenotype were explored in 886 ruxolitinib-treated patients with primary/secondary MF (PMF/SMF) included in the RUX-MF retrospective study. Cytopenia was defined as: leukocyte count <4 Ă 109 /L and/or hemoglobin <11/<10 g/dL (males/females) and/or platelets <100 Ă 109 /L. Results: Overall, 407 (45.9%) patients had a cytopenic MF, including 249 (52.4%) with PMF. In multivariable analysis, high molecular risk mutations (p = .04), intermediate 2/high Dynamic International Prognostic Score System (p < .001) and intermediate 2/high Myelofibrosis Secondary to Polycythemia Vera and Essential Thrombocythemia Prognostic Model (p < .001) remained associated with cytopenic MF in the overall cohort, PMF, and SMF, respectively. Patients with cytopenia received lower average ruxolitinib at the starting (25.2 mg/day vs. 30.2 mg/day, p < .001) and overall doses (23.6 mg/day vs. 26.8 mg/day, p < .001) and achieved lower rates of spleen (26.5% vs. 34.1%, p = .04) and symptom (59.8% vs. 68.8%, p = .008) responses at 6 months compared with patients with the proliferative phenotype. Patients with cytopenia also had higher rates of thrombocytopenia at 3 months (31.1% vs. 18.8%, p < .001) but lower rates of anemia (65.6% vs. 57.7%, p = .02 at 3 months and 56.6% vs. 23.9% at 6 months, p < .001). After competing risk analysis, the cumulative incidence of ruxolitinib discontinuation at 5 years was 57% and 38% in patients with cytopenia and the proliferative phenotype (p < .001), whereas cumulative incidence of leukemic transformation was similar (p = .06). In Cox regression analysis adjusted for Dynamic International Prognostic Score System score, survival was significantly shorter in patients with cytopenia (p < .001). Conclusions: Cytopenic MF has a lower probability of therapeutic success with ruxolitinib as monotherapy and worse outcome. These patients should be considered for alternative therapeutic strategies
- âŠ