1,022 research outputs found
VERNACULAR LANGUAGE WITHIN THE TRADITIONAL BELL TOWERS: BETWEEN STAIRS, LANDINGS AND FLOORS
Abstract. The monumental heritage of European historic centres is characterised by special building types that have drawn, more than others, on the vernacular language of the local traditional architecture. The traditional bell towers, even if built by a specific (but not always known) designer, often have some building elements transliterated from the construction tradition of poor and rural buildings. This language can be found in many examples from different historical periods and in faraway areas, such as Italy and Spain. The external monumentality may not correspond to a complex spatial articulation inside the towers. Instead, it is usual to find belfries in which the vertical connections and any horizontal structures are solved by wooden stairs and floors to reach the bell cell. The used materials and building techniques reveal the design simplicity but also the evidence of a lost "know-how". Due to the nature of the materials, possible damages and lack of maintenance, many of these structures have undergone restoration or transformation works, also whit their replacement for the benefit of most modern construction systems. The research aims to underline the central importance of preventive knowledge of these traditional structures and illustrate some significant cases in Eastern Sicily, a high seismic risk area. These case studies are emblematic for the evidence of several original structures or the extreme effects of the 20th-century interventions. These last works have often compromised the historical and documentary trait of the wooden structures, introducing new vulnerabilities due to the excessive stiffening of the masonry
Velocity Distribution of Topological Defects in Phase-Ordering Systems
The distribution of interface (domain-wall) velocities in a
phase-ordering system is considered. Heuristic scaling arguments based on the
disappearance of small domains lead to a power-law tail,
for large v, in the distribution of . The exponent p is
given by , where d is the space dimension and 1/z is the growth
exponent, i.e. z=2 for nonconserved (model A) dynamics and z=3 for the
conserved case (model B). The nonconserved result is exemplified by an
approximate calculation of the full distribution using a gaussian closure
scheme. The heuristic arguments are readily generalized to conserved case
(model B). The nonconserved result is exemplified by an approximate calculation
of the full distribution using a gaussian closure scheme. The heuristic
arguments are readily generalized to systems described by a vector order
parameter.Comment: 5 pages, Revtex, no figures, minor revisions and updates, to appear
in Physical Review E (May 1, 1997
Editorial: Developing Successful Neuroprotective Treatments for TBI: Translational Approaches, Novel Directions, Opportunities and Challenges
[No abstract available]Scopu
Post-Mortem Immunohistochemical Evidence of β2-Adrenergic Receptor Expression in the Adrenal Gland
The evidence from post-mortem biochemical studies conducted on cortisol and catecholamines suggest that analysis of the adrenal gland could provide useful information about its role in human pathophysiology and the stress response. Authors designed an immunohistochemical study on the expression of the adrenal β2-adrenergic receptor (β2-AR), a receptor with high-affinity for catecholamines, with the aim to show which zones it is expressed in and how its expression differs in relation to the cause of death. The immunohistochemical study was performed on adrenal glands obtained from 48 forensic autopsies of subjects that died as a result of different pathogenic mechanisms using a mouse monoclonal β2-AR antibody. The results show that immunoreactivity for β2-AR was observed in all adrenal zones. Furthermore, immunoreactivity for β2-AR has shown variation in the localization and intensity of different patterns in relation to the original cause of death. To the best of our knowledge, this is the first study that demonstrates β2-AR expression in the human cortex and provides suggestions on the possible involvement of β2-AR in human cortex hormonal stimulation. In conclusion, the authors provide a possible explanation for the observed differences in expression in relation to the cause of death
Molecular random tilings as glasses
We have recently shown [Blunt et al., Science 322, 1077 (2008)] that
p-terphenyl-3,5,3',5'-tetracarboxylic acid adsorbed on graphite self-assembles
into a two-dimensional rhombus random tiling. This tiling is close to ideal,
displaying long range correlations punctuated by sparse localised tiling
defects. In this paper we explore the analogy between dynamic arrest in this
type of random tilings and that of structural glasses. We show that the
structural relaxation of these systems is via the propagation--reaction of
tiling defects, giving rise to dynamic heterogeneity. We study the scaling
properties of the dynamics, and discuss connections with kinetically
constrained models of glasses.Comment: 5 pages, 5 figure
Graph homology: Koszul and Verdier duality
We show that Verdier duality for certain sheaves on the moduli spaces of
graphs associated to Koszul operads corresponds to Koszul duality of operads.
This in particular gives a conceptual explanation of the appearance of graph
cohomology of both the commutative and Lie types in computations of the
cohomology of the outer automorphism group of a free group. Another consequence
is an explicit computation of dualizing sheaves on spaces of metric graphs,
thus characterizing to which extent these spaces are different from oriented
orbifolds. We also provide a relation between the cohomology of the space of
metric ribbon graphs, known to be homotopy equivalent to the moduli space of
Riemann surfaces, and the cohomology of a certain sheaf on the space of usual
metric graphs.Comment: 13 page
Pulsed light beams in vacuum with superluminal and negative group velocities
Gouy's phase of transversally limited pulses can create a strong anomalous
dispersion in vacuum leading to highly superluminal and negative group
velocities. As a consequence, a focusing pulse can diverge beyond the focus
before converging into it. A simple experiment is proposed.Comment: 4 pages, 5 figure
Sull'antagonismo in vivo ed in vitro di Acremonium byssoides, endofita in Vitis vinifera, nei confronti di Plasmopara viticola
Lo studio dell\u2019interazione fra Acremonium byssoides, Vitis vinifera e
Plasmopara viticola, condotto nell\u2019ultimo decennio, ha evidenziato in vitro e in vivo
l\u2019attivit\ue0 antagonistica dell\u2019ifomicete, endofita negli organi verdi di alcune cultivars
di vite, nei confronti del patogeno. In particolare, \ue8 stato accertato che sospensioni
conidiche, filtrati colturali, estratti grezzi e metaboliti di A. byssoides riducono
sensibilmente la germinazione delle spore agamiche e gamiche di P. viticola, limitando
la produzione di propaguli. Inoltre, l\u2019uso di un microscopio laser confocale e l\u2019impiego
di un\u2019opportuna tecnica di decolorazione dei tessuti fogliari, seguita da colorazione
di contrasto, ha consentito di visualizzare l\u2019ifomicete, latente nelle nervature di
foglie sane e iperparassita dell\u2019oomicete in foglie infette. In queste ultime, infatti, A.
byssoides, dopo aver prodotto metaboliti secondari tossici per P. viticola, ne invade e
degrada micelio, rami sporangiofori e spore gamiche.
Tale attivit\ue0 antagonistica, determinando il contenimento sia della diffusione
che della sopravvivenza del patogeno, pu\uf2 assumere, quindi, un ruolo rilevante nella
definizione di strategie di difesa biologica contro la peronospora della vite
Early stage scaling in phase ordering kinetics
A global analysis of the scaling behaviour of a system with a scalar order
parameter quenched to zero temperature is obtained by numerical simulation of
the Ginzburg-Landau equation with conserved and non conserved order parameter.
A rich structure emerges, characterized by early and asymptotic scaling
regimes, separated by a crossover. The interplay among different dynamical
behaviours is investigated by varying the parameters of the quench and can be
interpreted as due to the competition of different dynamical fixed points.Comment: 21 pages, latex, 7 figures available upon request from
[email protected]
Phase Ordering Dynamics of the O(n) Model - Exact Predictions and Numerical Results
We consider the pair correlation functions of both the order parameter field
and its square for phase ordering in the model with nonconserved order
parameter, in spatial dimension and spin dimension .
We calculate, in the scaling limit, the exact short-distance singularities of
these correlation functions and compare these predictions to numerical
simulations. Our results suggest that the scaling hypothesis does not hold for
the model. Figures (23) are available on request - email
[email protected]: 23 pages, Plain LaTeX, M/C.TH.93/2
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