5,097 research outputs found

    The last ten years of research at Tarquinia

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    The Centro di Ricerca Coordinata ‘ProgettoTarquinia’ of the Università degli Studi di Milano is a LERU (League of European Research Universities) exemplary interdisciplinary research project that involves groups from the Università Statale di Milano (Archaeology, Information and Communication Technologies, Geoarchaeology, Palaeoanthropology), the Politecnico di Milano (Architecture and Topography) and bridges the gap between soft and hard sciences. This project stems from the ‘Progetto Tarquinia’ conceived by Maria Bonghi Jovino in 1982. During the last ten years, our integrated system of tools and services, supported by ICTs (ArchMatrix), through which multidisciplinary domain experts can examine all the typologies of data of a given culture, has made it possible to concentrate on the links between data-sources focusing on the recurrence of association rates within different aspects of material evidence and phenomena. The fields of application of our methodology in the domain of archaeology and epigraphy are multifaceted as regards the inside and outside connections of the Tarquinian heritage, whose necropolis with the famous painted tombs is a UNESCO World Heritage Site. Research includes areas of the Civita plateau: the ‘monumental complex’, the Ara della Regina sanctuary, fortifications, and archaeological sites previously explored. In the past ten years, research in the necropolis (roughly 6,000 tombs, of which 400 are painted) and in the surrounding territory has also been implemented and has produced the complete corpus of the painted tombs of Tarquinia. Our holistic approach encompasses archaeological analysis of small (mobile finds), medium (archaeological contexts) and large scale (territory and landscape) architectural analysis and applications for integrated solutions for the cultural heritage, including the first bilingual Virtual Museum dedicated to an Etruscan city

    Combined quantum state preparation and laser cooling of a continuous beam of cold atoms

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    We use two-laser optical pumping on a continuous atomic fountain in order to prepare cold cesium atoms in the same quantum ground state. A first laser excites the F=4 ground state to pump the atoms toward F=3 while a second pi-polarized laser excites the F=3 -> F'=3 transition of the D2 line to produce Zeeman pumping toward m=0. To avoid trap states, we implement the first laser in a 2D optical lattice geometry, thereby creating polarization gradients. This configuration has the advantage of simultaneously producing Sisyphus cooling when the optical lattice laser is tuned between the F=4 -> F'=4 and F=4 -> F'=5 transitions of the D2 line, which is important to remove the heat produced by optical pumping. Detuning the frequency of the second pi-polarized laser reveals the action of a new mechanism improving both laser cooling and state preparation efficiency. A physical interpretation of this mechanism is discussed.Comment: Minor changes according to the recommendations of the referee: - Corrected Fig.1. - Split the graph of Fig.6 for clarity. - Added one reference. - Added two remarks in the conclusion. - Results unchange

    Unfinished Business: a Review of the Implementation of the Provisions of United Nations General Assembly Resolutions 61/105 and 64/72, Related to the Management of Bottom Fisheries in Areas Beyond National Jurisdiction

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    In 2006 the General Assembly adopted resolution 61/105, based on a compromise proposal offered by deep-sea fishing nations, which committed States and regional fisheries management organisations [RFMOs] to take specific measures to protect vulnerable marine ecosystems [VMEs] from the adverse impacts of bottom fisheries in the high seas and to ensure the longterm sustainability of deep-sea fish stocks. These measures included conducting impact assessments to determine whether significant adverse impacts[SAIs] to VMEs would occur, managing fisheries to prevent SAIs on VMEs, and closing areas of the high seas to bottom fishing where VMEs are known or likely to occur, unless regulations are in place to prevent SAIs and to manage sustainably deep-sea fish stocks. Based on a review in 2009 of the actions taken by States and RFMOS, the UNGA adoptedresolution 64/72 that reaffirmed resolution 61/105 and strengthened the call for action through committing States, inter alia, to ensure that vessels do not engage in bottom fishing until impact assessments have been carried out and to not authorise bottom fishing activities until the measures in resolutions 64/72 and 61/105 have been adopted andimplemented

    Adiabatic and non-adiabatic phonon dispersion in a Wannier function approach

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    We develop a first-principles scheme to calculate adiabatic and non-adiabatic phonon frequencies in the full Brillouin zone. The method relies on the variational properties of a force-constants functional with respect to the first-order perturbation of the electronic charge density and on the localization of the deformation potential in the Wannier function basis. This allows for calculation of phonon dispersion curves free from convergence issues related to Brillouin zone sampling. In addition our approach justify the use of the static screened potential in the calculation of the phonon linewidth due to decay in electron-hole pairs. We apply the method to the calculation of the phonon dispersion and electron-phonon coupling in MgB2_2 and CaC6_6. In both compounds we demonstrate the occurrence of several Kohn anomalies, absent in previous calculations, that are manifest only after careful electron and phonon momentum integration. In MgB2_2, the presence of Kohn anomalies on the E2g_{2g} branches improves the agreement with measured phonon spectra and affects the position of the main peak in the Eliashberg function. In CaC6_6 we show that the non-adiabatic effects on in-plane carbon vibrations are not localized at zone center but are sizable throughout the full Brillouin zone. Our method opens new perspectives in large-scale first-principles calculations of dynamical properties and electron-phonon interaction.Comment: 18 pages, 8 figure

    Drug design and synthesis of first in class PDZ1 targeting NHERF1 inhibitors as anticancer agents

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    Targeted approaches aiming at modulating NHERF1 activity, rather than its overall expression, would be preferred to preserve the normal functions of this versatile protein. We focused our attention on the NHERF1/PDZ1 domain that governs its membrane recruitment/displacement through a transient phosphorylation switch. We herein report the design and synthesis of novel NHERF1 PDZ1 domain inhibitors. These compounds have potential therapeutic value when used in combination with antagonists of β-catenin to augment apoptotic death of colorectal cancer cells refractory to currently available Wnt/β-catenin-targeted agents

    Vortex Entanglement and Broken Symmetry

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    Based on the London approximation, we investigate numerically the stability of the elementary configurations of entanglement, the twisted-pair and the twisted-triplet, in the vortex-lattice and -liquid phases. We find that, except for the dilute limit, the twisted-pair is unstable and hence irrelevant in the discussion of entanglement. In the lattice phase the twisted-triplet constitutes a metastable, confined configuration of high energy. Loss of lattice symmetry upon melting leads to deconfinement and the twisted-triplet turns into a low-energy helical configuration.Comment: 4 pages, RevTex, 2 figures on reques

    Folding mechanisms steer the amyloid fibril formation propensity of highly homologous proteins

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    Significant advances in the understanding of the molecular determinants of fibrillogenesis can be expected from comparative studies of the aggregation propensities of proteins with highly homologous structures but different folding pathways. Here, we fully characterize, by means of stopped-flow, T-jump, CD and DSC experiments, the unfolding mechanisms of three highly homologous proteins, zinc binding Ros87 and Ml153-149 and zinc-lacking Ml452-151. The results indicate that the three proteins significantly differ in terms of stability and (un)folding mechanisms. Particularly, Ros87 and Ml153-149 appear to be much more stable to guanidine denaturation and are characterized by folding mechanisms including the presence of an intermediate. On the other hand, metal lacking Ml452-151 folds according to a classic two-state model. Successively, we have monitored the capabilities of Ros87, Ml452-151 and Ml153-149 to form amyloid fibrils under native conditions. Particularly, we show, by CD, fluorescence, DLS, TEM and SEM experiments, that after 168 hours, amyloid formation of Ros87 has started, while Ml153-149 has formed only amorphous aggregates and Ml452-151 is still monomeric in solution. This study shows how metal binding can influence protein folding pathways and thereby control conformational accessibility to aggregation-prone states, which in turn changes aggregation kinetics, shedding light on the role of metal ions in the development of protein deposition diseases
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