14,857 research outputs found
Dall' "Aeterni Patris" al Concilio Vaticano II: Le direttive del magistero sulla dottrina di San Tommaso
The future (?) of effective protection
This paper aims at a comparative reading of some archaeological remains in the island of Sardinia, starting from a reflection on the UNESCO discipline, which introduces a hierarchy of cultural heritage based on the level of worthiness of protection and provides enhanced protection for the goods that are on its list. The main goal of the study is to investigate in parallel the application of this ‘selective appreciation’ on the actual context of the protection of the so-called ‘real cultural heritage’ (article 9 of the Italian Constitution). The study proceeds by comparing some important sites on the island having similar contextualization, but different strategies for protection: the Archaeological Park of Porto Torres, Su Nuraxi in Barumini, registered since 1997 in the World Heritage List of UNESCO, and the archaeological area of Neapolis (Oristano). From comparisons and analysis carried out in selected areas it was possible to focus attention on some critical aspects of the UNESCO rules and on contradictions between the operational guidelines and the objectives that the organization provides for the protection of property. In the wake of new reforms for the reorganization of the Ministry of Heritage, Culture and Tourism, the critical issues discussed in this paper appear even more evident in Sardinia. The idea of a ‘protection of the exceptional’ appears to reduce the opportunities of intervention, by isolating the evidence from its context and making the action of protection inadequate for the territory and for the same items contained therein
The future (?) of effective protection
This paper aims at a comparative reading of some archaeological remains in the island of Sardinia, starting from a reflection on the UNESCO discipline, which introduces a hierarchy of cultural heritage based on the level of worthiness of protection and provides enhanced protection for the goods that are on its list. The main goal of the study is to investigate in parallel the application of this ‘selective appreciation’ on the actual context of the protection of the so-called ‘real cultural heritage’ (article 9 of the Italian Constitution). The study proceeds by comparing some important sites on the island having similar contextualization, but different strategies for protection: the Archaeological Park of Porto Torres, Su Nuraxi in Barumini, registered since 1997 in the World Heritage List of UNESCO, and the archaeological area of Neapolis (Oristano). From comparisons and analysis carried out in selected areas it was possible to focus attention on some critical aspects of the UNESCO rules and on contradictions between the operational guidelines and the objectives that the organization provides for the protection of property. In the wake of new reforms for the reorganization of the Ministry of Heritage, Culture and Tourism, the critical issues discussed in this paper appear even more evident in Sardinia. The idea of a ‘protection of the exceptional’ appears to reduce the opportunities of intervention, by isolating the evidence from its context and making the action of protection inadequate for the territory and for the same items contained therein
Physical interaction between MYCN oncogene and polycomb repressive complex 2 (PRC2) in neuroblastoma: Functional and therapeutic implications
This article is made available through the Brunel Open Access Publishing Fund. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.CLU (clusterin) is a tumor suppressor gene that we have previously shown to be negatively modulated by the MYCN proto-oncogene, but the mechanism of repression was unclear. Here, we show that MYCN inhibits the expression of CLU by direct interaction with the non-canonical E box sequence CACGCG in the 5′-flanking region. Binding of MYCN to the CLU gene induces bivalent epigenetic marks and recruitment of repressive proteins such as histone deacetylases and Polycomb members. MYCN physically binds in vitro and in vivo to EZH2, a component of the Polycomb repressive complex 2, required to repress CLU. Notably, EZH2 interacts with the Myc box domain 3, a segment of MYC known to be essential for its transforming effects. The expression of CLU can be restored in MYCN-amplified cells by epigenetic drugs with therapeutic results. Importantly, the anticancer effects of the drugs are ablated if CLU expression is blunted by RNA interference. Our study implies that MYC tumorigenesis can be effectively antagonized by epigenetic drugs that interfere with the recruitment of chromatin modifiers at repressive E boxes of tumor suppressor genes such as CLU.SPARKS, The Neuroblastoma Society,
a Wellcome Trust grant (to A. S.), and the Italian Association for Cancer
Research
Many-nodes/many-links spinfoam: the homogeneous and isotropic case
I compute the Lorentzian EPRL/FK/KKL spinfoam vertex amplitude for regular
graphs, with an arbitrary number of links and nodes, and coherent states peaked
on a homogeneous and isotropic geometry. This form of the amplitude can be
applied for example to a dipole with an arbitrary number of links or to the
4-simplex given by the compete graph on 5 nodes. All the resulting amplitudes
have the same support, independently of the graph used, in the large j (large
volume) limit. This implies that they all yield the Friedmann equation: I show
this in the presence of the cosmological constant. This result indicates that
in the semiclassical limit quantum corrections in spinfoam cosmology do not
come from just refining the graph, but rather from relaxing the large j limit.Comment: 8 pages, 4 figure
Spinfoams in the holomorphic representation
We study a holomorphic representation for spinfoams. The representation is
obtained via the Ashtekar-Lewandowski-Marolf-Mour\~ao-Thiemann coherent state
transform. We derive the expression of the 4d spinfoam vertex for Euclidean and
for Lorentzian gravity in the holomorphic representation. The advantage of this
representation rests on the fact that the variables used have a clear
interpretation in terms of a classical intrinsic and extrinsic geometry of
space. We show how the peakedness on the extrinsic geometry selects a single
exponential of the Regge action in the semiclassical large-scale asymptotics of
the spinfoam vertex.Comment: 10 pages, 1 figure, published versio
Design Features and Performance of a 10 T Twin Aperture Model Dipole for LHC
A twin-aperture superconducting (sc) dipole model has been designed in collaboration with Finnish and Swedish Institutions and built at CERN. The cable critical current was attained at a central field of 10.5 T at a temperature of 1.77 K after three training quenches only. This model has shown a very good quench performance as well as a robust mechanical behavior over several thermal cycles. This p aper will discuss the design, the innovations of the mechanical structure, and the results obtained during the intensive campaigns of tests
On the Ultraviolet Behaviour of Newton's constant
We clarify a point concerning the ultraviolet behaviour of the Quantum Field
Theory of gravity, under the assumption of the existence of an ultraviolet
Fixed Point. We explain why Newton's constant should to scale like the inverse
of the square of the cutoff, even though it is technically inessential. As a
consequence of this behaviour, the existence of an UV Fixed Point would seem to
imply that gravity has a built-in UV cutoff when described in Planck units, but
not necessarily in other units.Comment: 8 pages; CQG class; minor changes and rearrangement
Power Test Results of the First LHC Second Generation Superconducting Single Aperture 1m Long Dipole Models
Within the LHC magnet research and development programme, a series of single aperture 1m long models of second generation are presently being built and tested at CERN. The main features of these magnets are: five-block, two layer coils wound from 15mm wide graded NbTi cables, enlarged 56mm aperture and all-polyimide insulation. This paper reviews the power test data of magnets tested to date in both supercritical and superfluid helium. The results of the quench training, the initial location and propagation of quenches and their sensitivity to energy extraction are presented and discussed in terms of the design parameters and the aims of this short dipole model test program
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