Mixing-induced quantum non-Markovianity and information flow

Mixing dynamical maps describing open quantum systems can lead from Markovian to non-Markovian processes. Being surprising and counter-intuitive, this result has been used as argument against characterization of non-Markovianity in terms of information exchange. Here, we demonstrate that, quite the contrary, mixing can be understood in a natural way which is fully consistent with existing theories of memory effects. In particular, we show how mixing-induced non-Markovianity can be interpreted in terms of the distinguishability of quantum states, system-environment correlations and the information flow between system and environment.Comment: 10 pages, 8 figure

Generalized trace distance approach to quantum non-Markovianity and detection of initial correlations

A measure of quantum non-Markovianity for an open system dynamics, based on revivals of the distinguishability between system states, has been introduced in the literature using the trace distance as quantifier for distinguishability. Recently it has been suggested to use as measure for the distinguishability of quantum states the trace norm of Helstrom matrices, given by weighted differences of statistical operators. Here we show that this new approach, which generalizes the original one, is consistent with the interpretation of information flow between the system and its environment associated to the original definition. To this aim we prove a bound on the growth of the external information, that is information which cannot be accessed by performing measurements on the system only, as quantified by means of the Helstrom matrix. We further demonstrate by means of example that it is of relevance in generalizing schemes for the local detection of initial correlations based on the increase of internal information. Finally we exploit this viewpoint to show the optimality of a previously introduced strategy for the local detection of quantum correlations.Comment: 9 pages, 4 figure

Non-averaged regularized formulations as an alternative to semi-analytical orbit propagation methods

This paper is concerned with the comparison of semi-analytical and non-averaged propagation methods for Earth satellite orbits. We analyse the total integration error for semi-analytical methods and propose a novel decomposition into dynamical, model truncation, short-periodic, and numerical error components. The first three are attributable to distinct approximations required by the method of averaging, which fundamentally limit the attainable accuracy. In contrast, numerical error, the only component present in non-averaged methods, can be significantly mitigated by employing adaptive numerical algorithms and regularized formulations of the equations of motion. We present a collection of non-averaged methods based on the integration of existing regularized formulations of the equations of motion through an adaptive solver. We implemented the collection in the orbit propagation code THALASSA, which we make publicly available, and we compared the non-averaged methods to the semi-analytical method implemented in the orbit propagation tool STELA through numerical tests involving long-term propagations (on the order of decades) of LEO, GTO, and high-altitude HEO orbits. For the test cases considered, regularized non-averaged methods were found to be up to two times slower than semi-analytical for the LEO orbit, to have comparable speed for the GTO, and to be ten times as fast for the HEO (for the same accuracy). We show for the first time that efficient implementations of non-averaged regularized formulations of the equations of motion, and especially of non-singular element methods, are attractive candidates for the long-term study of high-altitude and highly elliptical Earth satellite orbits.Comment: 33 pages, 10 figures, 7 tables. Part of the CMDA Topical Collection on "50 years of Celestial Mechanics and Dynamical Astronomy". Comments and feedback are encourage

Nuclear Magnetic Resonance Reveals Molecular Species in Carbon Nanodot Samples Disclosing Flaws

Carbon nanodots are currently one of the hot topics in the nanomaterials world, due to their accessible synthesis and promising features. However, the purification of these materials is still a critical aspect, especially for syntheses involving molecular precursors. Indeed, the presence of unreacted species or small organic molecules formed during solvothermal treatments can affect the properties of the synthesized nanomaterials. To illustrate the extreme importance of this issue, we present two case studies in which insufficient purification results in misleading conclusions regarding the chiral and fluorescent properties of the investigated materials. Key to identify molecular species is the use of nuclear magnetic resonance, which proves to be an effective tool. Our work highlights the need to include nuclear magnetic resonance as a standard characterization technique for carbon-based nanomaterials, to minimize the risk of observing properties that arise from molecular species, rather than the target carbon nanodots

IGHV mutational status of nodal marginal zone lymphoma by NGS reveals distinct pathogenic pathways with different prognostic implications

The precise B cell of origin and molecular pathogenesis of nodal marginal zone lymphoma (NMZL) remain poorly defined. To date, due to the rarity of NMZL, the vast majority of already-published studies have been conducted on a limited number of samples and the technical approach to analyze the immunoglobulin genes was of amplifying rearranged variable region genes with the classical direct sequencing of the PCR products followed by cloning. Here, we studied the B cell Ig heavy-chain repertoires by next-generation sequencing (NGS) in 30 NMZL cases. Most of the cases were mutated (20/28; 71.5%) with homologies to the respective germ line genes ranging from 85 to 97, 83%, whereas 8/28 (28.5%) were unmutated. In addition, our results show that NMZL cases have a biased usage of specific immunoglobulin heavy-chain variable (IGHV) region genes. Moreover, we documented intraclonal diversity in all (100%) of the mutated cases and ongoing somatic hypermutations (SHM) have been confirmed by hundreds of reads. We analyzed the mutational pattern to detect and quantify antigen selection pressure and we found a positive selection in 4 cases, whereas in the remaining cases there was an unspecific stimulation. Finally, the disease-specific survival and the progression-free survival were significantly different between cases with mutated and unmutated IGHV genes, pointing out mutational status as a possible new biomarker in NMZL

ISMD, a Web Portal for Real-Time Processing and Dissemination of INGV Strong-Motion Data

In Italy, strong-motion monitoring started in the early 1970s, when the Rete Accelerometrica Nazionale (RAN, the Italian National Strong Motion Network; http://www.protezionecivile. gov.it/jcms/it/ran.wp;seeData and Resources for a complete listing of all websites listed in this article) was designed and installed by the Agenzia Nazionale per le NuoveTecnologie, l’Energia e lo Sviluppo Economico Sostenibile (ENEA) and ENEL (an Italian power company). The aim was to evaluate the seismic risk in connection with the construction of nuclear power plants. Since 1997, the RAN (Gorini et al.,2010) has been run by the Dipartimento della Protezione Civile (DPC). At present, the RAN includes about 500 digital strong-motion stations. The contribution of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) to Italian strong-motion monitoring started some years later. Through the 2004–2006 agreement between the INGV and the DPC (Strong-Motion Stations Project), the INGV began the phase of strong-motion monitoring (Augliera et al., 2010, 2011). Since 2006, a complete renewal of the (velocimetric) Rete Sismica Nazionale (RSN; Amato and Mele, 2008) was made by installing accelerometers to sites where broadband RSN velocimeters were already present. Altogether, the current∼150 high-dynamics digital strong-motion stations that cover the Italian territory constitute the INGV strong-motion network. The first channel chosen by the INGV to disseminate the recorded waveforms was through the European Integrated Data Archive (EIDA;http://eida.rm.ingv.it/;http://www.orfeus -eu.org/eida/eida.html), a web portal devoted to seismic data exchange that was developed in the framework of the Network of Research Infrastructures for European Seismology (NERIES) European project (www.neries-eu.org, Networking Activity 3 [NA3]). Since 2008, the INGV raw signals have been downloadable in the Standard for the Exchange of Earthquake Data (SEED) format from the continuous data archive of the INGV National Earthquake Centre (Centro Nazionale Terremoti, CNT). However, the EIDA web portal is devoted in particular to expert end users, and it provides raw data without further information about the waveform metadata and recording sites, which is fundamental for engineering purposes. The recorded RAN strong-motion data from 1972 to 2007 have been available to the scientific community only through specific data requests to the DPC. This changed in 2007, when the RAN data were also disseminated online through the ITalian ACcelerometric Archive (ITACA; Pacor et al., 2011), a static databank that arose in the framework of the S6 Seismological Project (Luzi et al., 2008), with the aim of periodically (usually every 1 year) distributing highquality corrected (i.e., manually processed by expert operators) data to the scientific community. Now, in the last release of ITACA version 2.0 (http://itaca.mi.ingv.it), users can find the RAN strong-motion corrected data up to the end of 2013. Even if the periodic publication of an updated version of ITACA provides new data for the scientific community, within the time span of two subsequent versions, significant earthquakes generally shake the Italian territory. Increasing demands for strong-motion data come from the scientific community soon after an important earthquake, in particular, and the INGV needed to homogeneously organize and disseminate the strongmotion data recorded by its own stations through a new dedicated channel. This motivated the co-operation of several INGV Working Groups to design and develop INGV Strong-Motion Data (ISMD), the first Italian real-time strong-motion web portal. The main scope of the ISMD is real-time archiving, processing, and distribution of strong-motion data recorded by the INGV and partner networks, complete with all of the necessary side information to correctly use the published data. In particular, the automatic system on which the new web portal is based can do the following: 1. check the quality of the raw accelerograms recorded by the INGV strong-motion network; 2. archive and process the data in real time to provide rapid estimations of the main strong-motion parameters of an earthquake; 3. disseminate high-quality strong-motion waveforms and related metadata in real time; 4. collect and distribute all of the available information about the recording sites (i.e., geological, morphological, geophysical); 5. check, update, and homogenize the information related to the INGV strong-motion stations currently installed throughout the entire Italian territory (e.g., coordinates, instrumentation); and 6. within minutes after an earthquake occurs, publish on the website (http://ismd.mi.ingv.it/) a real-time report of the event (e.g., event and waveform metadata, seismic response of recording sites, comparisons between observed and predicted data), jointly providing the binary–Seismic Analysis Code (SAC) uncorrected data (i.e., the raw SEED signals, converted into a new data format), the American Standard Code for Information Interchange (ASCII) corrected accelerograms (i.e., binary-SAC converted into ASCII format, and then processed), as well as the velocity and displacement time series and the related response spectra. The beta version of the ISMD was published during the May–June 2012 ML 5.9 Emilia (northern Italy) seismic sequence. At present it has archived about 23,500 three- component strong-motion records from∼360 Italian events that occurred from 1 January 2012 to the present update of 15 April 2014 with an ML≥3:0Published863-8774T. Sismologia, geofisica e geologia per l'ingegneria sismicaJCR Journa

Coherent ultrafast charge transfer in an organic photovoltaic blend

Blends of conjugated polymers and fullerene derivatives are prototype systems for organic photovoltaic devices. The primary charge-generation mechanism involves a light-induced ultrafast electron transfer from the light-absorbing and electron-donating polymer to the fullerene electron acceptor. Here, we elucidate the initial quantum dynamics of this process. Experimentally, we observed coherent vibrational motion of the fullerene moiety after impulsive optical excitation of the polymer donor. Comparison with first-principle theoretical simulations evidences coherent electron transfer between donor and acceptor and oscillations of the transferred charge with a 25-femtosecond period matching that of the observed vibrational modes. Our results show that coherent vibronic coupling between electronic and nuclear degrees of freedom is of key importance in triggering charge delocalization and transfer in a noncovalently bound reference system

Passive seismology and deep structure in central Italy

n the last decade temporary teleseismic transects have become a powerful tool for investigating the crustal and upper mantle structure. In order to gain a clearer picture of the lithosphere-asthenosphere structure in peninsular Italy, between 1994 and 1996, we have deployed three teleseismic transects in northern, central, and southern Apennines, in the framework of the project GeoModAp (European Community contract EV5V-CT94–0464). Some hundreds of teleseisms were recorded at each deployment which lasted between 3 and 4 months. Although many analyses are still in progress, the availability of this high quality data allowed us to refine tomographic images of the lithosphere-asthenosphere structure with an improved resolution in the northern and central Apennines, and to study the deformation of the upper mantle looking at seismic anisotropy through shear-wave splitting analysis. Also, a study of the depth and geometry of the Moho through the receiver function technique is in progress. Tomographic results from the northernmost 1994 and the central 1995 teleseismic experiments confirm that a high-velocity anomaly (HVA) does exist in the upper 200–250 km and is confined to the northern Apenninic arc. This HVA, already interpreted as a fragment of subducted lithosphere is better defined by the new temporary data, compared to previous works, based only on data from permanent stations. No clear high-velocity anomalies are detected in the upper 250 km below the central Apennines, suggesting either a slab window due to a detachment below southern peninsular Italy, or a thinner, perhaps continental slab of Adriatic lithosphere not detectable by standard tomography. We found clear evidence of seismic anisotropy in the uppermost mantle, related to the main tectonic processes which affected the studied regions, either NE–SW compressional deformation of the lithosphere beneath the mountain belt, or arc-parallel asthenospheric flow (both giving NW–SE fast polarization direction), and successive extensional deformation ( E–W trending) in the back-arc basin of northern Tyrrhenian and Tuscany. Preliminary results of receiver function studies in the northern Apennines show that the Moho depth is well defined in the Tyrrhenian and Adriatic regions while its geometry underneath the mountain belt is not yet well constrained, due to the observed high complexity.Published479-4934T. Sismicità dell'ItaliaJCR Journa

Structured and shared CT radiological report of gastric cancer: a consensus proposal by the Italian Research Group for Gastric Cancer (GIRCG) and the Italian Society of Medical and Interventional Radiology (SIRM)

Objectives Written radiological report remains the most important means of communication between radiologist and referring medical/surgical doctor, even though CT reports are frequently just descriptive, unclear, and unstructured. The Italian Society of Medical and Interventional Radiology (SIRM) and the Italian Research Group for Gastric Cancer (GIRCG) promoted a critical shared discussion between 10 skilled radiologists and 10 surgical oncologists, by means of multi-round consensus-building Delphi survey, to develop a structured reporting template for CT of GC patients. Methods Twenty-four items were organized according to the broad categories of a structured report as suggested by the European Society of Radiology (clinical referral, technique, findings, conclusion, and advice) and grouped into three "CT report sections" depending on the diagnostic phase of the radiological assessment for the oncologic patient (staging, restaging, and follow-up). Results In the final round, 23 out of 24 items obtained agreement ( >= 8) and consensus ( 0.05). Conclusions The structured report obtained, shared by surgical and medical oncologists and radiologists, allows an appropriate, clearer, and focused CT report essential to high-quality patient care in GC, avoiding the exclusion of key radiological information useful for multidisciplinary decision-making