Il Nuovo cimento della Societa italiana di fisica. C最新文献

{"title":"Anharmonic activations in proteins and peptide model systemsand their connection with supercooled water thermodynamics","authors":"A. Cupane, null Schirò","doi":"10.1393/NCC/I2016-16305-Y","DOIUrl":"https://doi.org/10.1393/NCC/I2016-16305-Y","url":null,"abstract":"Summary. — Proteins, the nano-machines of living systems, are highly dynamic molecules. The time-scale of functionally relevant motions spans over a very broad range, from femtoseconds to several seconds. In particular, the pico-to nanoseconds region is characterized by side-chain and backbone anharmonic fluctuations that are responsible for many biological tasks like ligand binding, substrate recognition and enzymatic activity. Neutron scattering on hydrated protein powders reveals two main activations of anharmonic dynamics, characterized by different onset temperature and amplitude. Here we review our work on synthetic polypeptides, native proteins, and single amino acids to identify the physical origin of the two onsets —one involving water-independent local dynamics of methyl groups and, to a minor extent, of aromatic side-chains, and the other one, known as “protein dynamical transition”, concerning large scale functional protein fluctuations, most likely induced by a crossover in the structure and dynamics of hydration water connected with the second critical point hypothesis.","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"1 1","pages":"1-12"},"PeriodicalIF":0.0,"publicationDate":"2016-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66581279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trophic factors intervention regenerates the nestin-expressing cell population in a model of perinatal excitotoxicity: Implications for perinatal brain injury and prematurity.","authors":"A Espinosa-Jeffrey, R A Arrazola, B Chu, A Taniguchi, S M Barajas, P Bokhoor, J Garcia, A Feria-Velasco, J de Vellis","doi":"10.15761/imm.1000228","DOIUrl":"10.15761/imm.1000228","url":null,"abstract":"<p><p>We previously showed that TSC1 (a combination of transferrin and IGF-1) is a potent inductor of myelinogenesis in myelin deficient rats and in demyelinated adult mice. More recently, we demonstrated that regeneration of oligodendrocyte progenitors and myelin are possible with a single dose of TSC1 in a mouse model of Premature birth. Here, using the same mouse model of perinatal white matter damage due to glutamate excitotoxicity (GME), we tested the hypothesis that regeneration of endogenous nestin-expressing neural progenitors improves the outcome of prematurity. Treatments: N-methyl-D-aspartate (NMDA), saline, NMDA+TSC1 together or NMDA followed byTSC1 3 days later, were stereotaxically delivered into the corpus callosum of P4 mouse pups. Fluorescence analysis showed an intense enrichment of nestin-expressing cells in groups injected with NMDA+TSC1 from which many were generated by proliferation. Moreover, when TSC1 was injected three days after the primary insult it was still able to reduce ventricular enlargement and extensively rescue nestin-expressing progenitors. Cells co-expressing the proliferation marker Ki67, CNPase and faint nestin label were more abundant in groups injected with MNDA+TSC1 at 35 days after injection. Stereological analysis showed that the number of nestin-expressing cells in the sub-ventricular zone correlated inversely with the volume of the ventricle. A delayed administration of TSC1 after excitotoxicity reduced ventriculomegaly but not as much as, when NMDA and TSC1 were injected simultaneously. Thus, the earliest TSC1 was administered, the more tissue was rescued as shown by reduced ventriculomegaly. Astrocytes responded to GME by upregulating the expression of estrogen receptor and this expression was attenuated in the presence of TSC1 suggesting a decreased inflammation and a lesser need for estrogen-mediated central nervous system (CNS) neuroprotection.</p>","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"1 1","pages":"703-715"},"PeriodicalIF":0.0,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9094396/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88674461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent advances in laser-driven neutron sources","authors":"A. Alejo, H. Ahmed, A. Green, S. R. Mirfayzi, M. Borghesi, S. Kar","doi":"10.1393/NCC/I2015-15188-8","DOIUrl":"https://doi.org/10.1393/NCC/I2015-15188-8","url":null,"abstract":"— Due to the limited number and high cost of large-scale neutron facilities, there has been a growing interest in compact accelerator-driven sources. In this context, several potential schemes of laser-driven neutron sources are being intensively studied employing laser-accelerated electron and ion beams. In addition to the potential of delivering neutron beams with high brilliance, directionality and ultra-short burst duration, a laser-driven neutron source would offer further advantages in terms of cost-effectiveness, compactness and radiation confinement by closed-coupled experiments. Some of the recent advances in this field are discussed, showing improvements in the directionality and flux of the laser-driven neutron beams.","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"38 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2016-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66581150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hints for new sources of flavour violation in meson mixing","authors":"M. Blanke","doi":"10.1393/ncc/i2016-16329-3","DOIUrl":"https://doi.org/10.1393/ncc/i2016-16329-3","url":null,"abstract":"The recent results by the Fermilab Lattice and MILC collaborations on the hadronic matrix elements entering $B_{d,s}-bar B_{d,s}$ mixing show a significant tension of the measured values of the mass differences $Delta M_{d,s}$ with their SM predictions. We review the implications of these results in the context of Constrained Minimal Flavour Violation models. In these models, the CKM elements $gamma$ and $|V_{ub}|/|V_{cb}|$ can be determined from $B_{d,s}-bar B_{d,s}$ mixing observables, yielding a prediction for $gamma$ below its tree-level value. Determining subsequently $|V_{cb}|$ from the measured value of either $Delta M_s$ or $varepsilon_K$ gives inconsistent results, with the tension being smallest in the Standard Model limit. This tension can be resolved if the flavour universality of new contributions to $Delta F = 2$ observables is broken. We briefly discuss the case of $U(2)^3$ flavour models as an illustrative example.","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"39 1","pages":"329"},"PeriodicalIF":0.0,"publicationDate":"2016-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66581331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The DarkSide physics program and its recent results","authors":"C. Aalseth, G. Acconcia, F. Acerbi, P. Agnes, L. Agostino, I. Albuquerque, T. Alexander, A. Alton, P. Ampudia, R. Ardito, K. Arisaka, I. Arnquist, D. Asner, H. Back, B. Baldin, G. Batignani, K. Biery, M. G. Bisogni, V. Bocci, A. Bondar, G. Bonfini, W. Bonivento, M. Bossa, A. Brigatti, J. Brodsky, F. Budano, R. Bunker, S. Bussino, M. Buttafava, A. Buzulutskov, M. Cadeddu, M. Cadoni, Niccolo Calandri, F. Calaprice, J. Calvo, L. Campajola, N. Canci, A. Candela, C. Cantini, H. Cao, M. Caravati, M. Cariello, M. Carlini, M. Carpinelli, A. Castellani, S. Catalanotti, P. Cavalcante, A. Chepurnov, C. Cicalò, M. Citterio, A. Cocco, S. Corgiolu, G. Covone, P. Crivelli, D. D’Angelo, M. D’Incecco, M. Daniel, S. Davini, S. Cecco, M. Deo, G. D. Guido, M. Vincenzi, P. Demontis, A. Derbin, A. Devoto, F. D. Eusanio, G. D. Pietro, C. Dionisi, A. Dolgov, I. Dromia, S. Dussoni, E. Edkins, A. Empl, A. Fan, A. Ferri, C. Filip, G. Fiorillo, K. Fomenko, G. Forster, D. Franco, G. Froudakis, F. Gabriele, A. Gabrieli, C. Galbiati, A","doi":"10.1393/ncc/i2016-16312-0","DOIUrl":"https://doi.org/10.1393/ncc/i2016-16312-0","url":null,"abstract":"Here, DarkSide (DS) at Gran Sasso underground laboratory is a direct Dark Matter search program based on Time Projection Chambers (TPC) with liquid Argon from underground sources. The DarkSide-50 (DS-50) TPC, with 150 kg of Argon is installed inside active neutron and muon detectors. DS-50 has been taking data since November 2013 with Atmospheric Argon (AAr) and since April 2015 with Underground Argon (UAr), depleted in radioactive 39Ar by a factor ~1400. The exposure of 1422 kg d of AAr has demonstrated that the operation of DS-50 for three years in a background free condition is a solid reality, thanks to the superb performance of the Pulse Shape Analysis. The first release of results from an exposure of 2616 kg d of UAr has shown no candidate Dark Matter events. We have set the best limit for Spin-Independent elastic nuclear scattering of WIMPs obtained by Argon-based detectors, corresponding to a cross-section of 2 10–44 cm2 at a WIMP mass of 100 GeV. We present the detector design and performance, the results from the AAr run and the first results from the UAr run and we briefly introduce the future of the DarkSide program.","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"39 1","pages":"312-320"},"PeriodicalIF":0.0,"publicationDate":"2016-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66581647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast-ion measurements with neutron and gamma-ray spectroscopy in thermonuclear plasmas: recent results and future prospects","authors":"M. Nocente","doi":"10.1393/NCC/I2016-16289-6","DOIUrl":"https://doi.org/10.1393/NCC/I2016-16289-6","url":null,"abstract":"— A high-performance thermonuclear plasma is a strong source of nuclear radiation, which includes neutron emission from the main fusion reactions and gamma-rays born from the interaction of supra-thermal ions and plasma impurities. Spectroscopic measurements of both types of radiation are an indirect probe of the distribution function of the fast ions leading to nuclear emission. In this paper we present a selection of recent results obtained with neutron and gamma-ray spectroscopy as a means to study the energy distribution of supra-thermal particles in high-performance thermonuclear plasmas. We focus in particular on the advancements made possible by the combination of dedicated instrumentation and detailed models based on the nuclear physics behind the emission. Future developments are finally addressed, especially regarding the availability of compact detectors with spectroscopy capabilities, which open up to a full tomographic reconstruction of the fast-ion velocity space.","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"21 1","pages":"289"},"PeriodicalIF":0.0,"publicationDate":"2016-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66581216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of a reflective pedagogy to encourage pre-service physics teachers to explore argumentation as an aid to conceptual understanding","authors":"G. Lancaster, Rebecca Cooper","doi":"10.1393/ncc/i2015-15102-6","DOIUrl":"https://doi.org/10.1393/ncc/i2015-15102-6","url":null,"abstract":"— An emerging focus of recent science education research advocates the benefits of using argumentation as an approach in which teachers can better engage students in a more authentic experience of the epistemic work of scientists (Bricker and Bell, 2008). Logical argument and critical thinking are considered essential skills for an effective and successful undertaking of scientific inquiry and analysis. Early research suggests the practise of encouraging students to engage in scientific discourse in the classroom (Kuhn, 2010) can provide rich experiences for students and teachers to hone their cognitive abilities. This paper explores the use of critical ‘discussion problems’ purposefully designed for pre-service physics teachers to investigate their own alternative conceptual understandings of key physics ideas. It also discusses how these problems are then used to generate classroom discourse which focuses on the importance of developing effective pedagogical content knowledge (See Shulman, 1986 for a detailed explanation of pedagogical content knowledge) rather than just mastery of scientific content and its mathematical applications. Further, the paper will detail a preliminary study in which pre-service physics teachers were introduced to a number of discussion problems via an online learning environment and asked to first consider the problem and post a solution in isolation from their peers. A considerable challenge was persuading the pre-service teachers to resist the common practice of “Googling the answer” via the internet before posting their solution attempt. Although most students initially appeared to believe that posting “the correct” answer was the main task objective, the vast majority eventually came to realise that discussing the range of unresearched solutions was much more beneficial for their conceptual understanding and professional practice. Over time, this approach generally encouraged students to post original ideas and to be less influenced by the arguments or analysis of other students. Following the completion of the online posts, the range of ideas included in the postings were then explored during a face to face workshop where the ideas were debated and frequently defended and the implications for pedagogy and their students learning discussed. The initial feedback from the pre-service teachers during this preliminary study is encouraging and suggests there is merit in exploring the benefits of argumentation for pre-service teachers and their students in a subsequent expanded study.","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"24 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2016-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66580940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"16O+65Cu and 19F+62Ni at 16 AMeV reaction mechanisms comparison: Pre-equilibrium vs. clustering","authors":"J. Mabiala, D. Fabris, F. Gramegna, T. Marchi, M. Cicerchia, M. Cinausero, M. Degerlier, O. Fotina, V. Kravchuk, M. D'Agostino, L. Morelli, G. Baiocco, M. Bruno, S. Barlini, M. Bini, Giovanni Casini, N. Gelli, A. Olmi, G. Pasquali, S. Piantelli, G. Poggi, S. Valdré, E. Vardaci","doi":"10.1393/NCC/I2016-16381-Y","DOIUrl":"https://doi.org/10.1393/NCC/I2016-16381-Y","url":null,"abstract":"","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"39 1","pages":"381-1-381-5"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66581392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Inquiry-based approach to the Franck-Hertz experiment","authors":"N. Pizzolato, D. P. Adorno, C. Fazio","doi":"10.1393/NCC/I2015-15109-Y","DOIUrl":"https://doi.org/10.1393/NCC/I2015-15109-Y","url":null,"abstract":"The practice of scientists and engineers is today exerted within interdisciplinary contexts, placed at the intersections of different research fields, including nanoscale science. The development of the required competences is based on an effective science and engineering instruction, which should be able to drive the students towards a deeper understanding of quantum mechanics fundamental concepts and, at the same time, strengthen their reasoning skills and transversal abilities. In this study we report the results of an inquiry-driven learning path experienced by a sample of 12 electronic engineering undergraduates engaged to perform the Franck-Hertz experiment. Before being involved in this experimental activity, the students received a traditional lecture-based instruction on the fundamental concepts of quantum mechanics, but their answers to an open-ended questionnaire, administered at the beginning of the inquiry activity, demonstrated that the acquired knowledge was characterized by a strictly theoretical vision of quantum science, basically in terms of an artificial mathematical framework having very poor connections with the real world. The Franck Hertz experiment was introduced to the students by starting from the problem of finding an experimental confirmation of the Bohr’s postulates asserting that atoms can absorb energy only in quantum portions. The whole activity has been videotaped and this allowed us to deeply analyse the student perception’s change about the main concepts of quantum mechanics. We have found that the active participation to this learning experience favored the building of cognitive links among student theoretical perceptions of quantum mechanics and their vision of quantum phenomena, within an everyday context of knowledge. Furthermore, our findings confirm the benefits of integrating traditional lecture-based instruction on quantum mechanics with learning experiences driven by inquiry-based teaching strategies.","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66581000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tulczyjew triples in the constrained dynamics of strings","authors":"J. Grabowski, K. Grabowska, P. Urbański","doi":"10.1393/ncc/i2015-15162-6","DOIUrl":"https://doi.org/10.1393/ncc/i2015-15162-6","url":null,"abstract":"We show that there exists a natural Tulczyjew triple in the dynamics of objects for which the standard kinematic configuration space $TM$, i.e. the tangent bundle, is replaced with its $n$-th exterior power, i.e. the bundle of tangent $n$-vectors. In this framework, which is fully covariant, we geometrically derive phase equations, as well as Euler-Lagrange equations, including nonholonomic constraints into the picture. Dynamics of strings and a constrained Plateau problem in statics are particular cases of this framework.","PeriodicalId":81495,"journal":{"name":"Il Nuovo cimento della Societa italiana di fisica. C","volume":"38 1","pages":"162"},"PeriodicalIF":0.0,"publicationDate":"2015-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66581069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}