1,606 research outputs found
Books are forever: Early life conditions, education and lifetime income
In this paper we estimate the effect of education on lifetime earnings in Europe, by distinguishing between individuals who lived in rural or urban areas during childhood and between individuals who had access to many or few books at age ten. We instrument years of education using reforms of compulsory education in nine different countries, and find that individuals in rural areas were most affected by the reforms while individuals with many books at home mostly benefited from education. Our main result is that books at home at age ten have had long-lasting beneficial effects on the individuals who were pushed by the reforms to increase their years of education
Explicit characterization of the identity configuration in an Abelian Sandpile Model
Since the work of Creutz, identifying the group identities for the Abelian
Sandpile Model (ASM) on a given lattice is a puzzling issue: on rectangular
portions of Z^2 complex quasi-self-similar structures arise. We study the ASM
on the square lattice, in different geometries, and a variant with directed
edges. Cylinders, through their extra symmetry, allow an easy determination of
the identity, which is a homogeneous function. The directed variant on square
geometry shows a remarkable exact structure, asymptotically self-similar.Comment: 11 pages, 8 figure
ISOGAL-DENIS detection of red giants with weak mass loss in the Galactic Bulge
The ISOGAL project is a survey of the stellar populations, structure, and
recent star formation history of the inner disk and bulge of the Galaxy. ISOGAL
combines 15 and 7micron ISOCAM observations with DENIS IJKs data to determine
the nature of a source and the interstellar extinction. In this paper we report
an ISOGAL study of a small field in the inner Galactic Bulge (l=0deg, b=1.0deg,
area=0.035 sq. deg) as a prototype of the larger area ISOGAL survey of the
inner Galaxy. The five wavelengths of ISOGAL+DENIS, together with the
relatively low and constant extinction in front of this specific field, allow
reliable determination of the nature of the sources. The primary scientific
result of this paper is evidence that the most numerous class of ISOGAL
15micron sources are Red Giants in the Galactic bulge and central disk, with
luminosities just above or close to the RGB tip and weak mass-loss rates. They
form loose sequences in the magnitude-colour diagrams [15]/Ks-[15] and
[15]/[7]-[15]. Their large excesses at 15micron with respect to 2micron and
7micron is due to circumstellar dust produced by mass-loss at low rates. These
ISOGAL results are the first systematic evidence and study of dust emission at
this early stage (''Intermediate'' AGB), before the onset of the large
mass-loss phase. It is thus well established that efficient dust formation is
already associated with such low mass-loss rates during this early phase.Comment: 15 pages, 9 figures, accepted for publication in Astronomy and
Astrophysics Journa
Search for Direct CP Violation in Non-Leptonic Decays of Charged and Hyperons
A search for direct CP violation in the non-leptonic decays of hyperons has
been performed. In comparing the product of the decay parameters,
, in terms of an asymmetry parameter,
, between hyperons and anti-hyperons in the charged and decay sequence, we found no evidence of
direct CP violations. The parameter was measured to be .Comment: Submitted for publication; RevTex, 13 pages, 4 figure
Spectral asymptotics of Euclidean quantum gravity with diff-invariant boundary conditions
A general method is known to exist for studying Abelian and non-Abelian gauge
theories, as well as Euclidean quantum gravity, at one-loop level on manifolds
with boundary. In the latter case, boundary conditions on metric perturbations
h can be chosen to be completely invariant under infinitesimal diffeomorphisms,
to preserve the invariance group of the theory and BRST symmetry. In the de
Donder gauge, however, the resulting boundary-value problem for the Laplace
type operator acting on h is known to be self-adjoint but not strongly
elliptic. The latter is a technical condition ensuring that a unique smooth
solution of the boundary-value problem exists, which implies, in turn, that the
global heat-kernel asymptotics yielding one-loop divergences and one-loop
effective action actually exists. The present paper shows that, on the
Euclidean four-ball, only the scalar part of perturbative modes for quantum
gravity are affected by the lack of strong ellipticity. Further evidence for
lack of strong ellipticity, from an analytic point of view, is therefore
obtained. Interestingly, three sectors of the scalar-perturbation problem
remain elliptic, while lack of strong ellipticity is confined to the remaining
fourth sector. The integral representation of the resulting zeta-function
asymptotics is also obtained; this remains regular at the origin by virtue of a
spectral identity here obtained for the first time.Comment: 25 pages, Revtex-4. Misprints in Eqs. (5.11), (5.14), (5.16) have
been correcte
Probing the quantum-gravity realm with slow atoms
For the study of Planck-scale modifications of the energy-momentum dispersion
relation, which had been previously focused on the implications for
ultrarelativistic (ultrafast) particles, we consider the possible role of
experiments involving nonrelativistic particles, and particularly atoms. We
extend a recent result establishing that measurements of "atom-recoil
frequency" can provide insight that is valuable for some theoretical models.
And from a broader perspective we analyze the complementarity of the
nonrelativistic and the ultrarelativistic regimes in this research area.Comment: LaTex, 13 page
Provisionally Permanent - Keeping Temporary Custody Orders Temporary under the Hague Convention on International Child Abdcution
PROGETTO LIFE11 ENV IT 215 RESILFORMED - RESILIENZA AL CAMBIAMENTO CLIMATICO NELLE FORESTE MEDITERRANEE
Le condizioni climatiche delle regioni mediterranee, caratterizzate da frequenti annate siccitose, contribuiscono all’indebolimento degli ecosistemi forestali. Come risultato le foreste riducono le loro capacità produttive e sono più soggette a fenomeni di degrado secondario. Inoltre i contesti economico-sociali possono acuire il degrado con la diffusione di uno scorretto uso della risorsa (tagli boschivi, pascolamento) e con la diffusione degli incendi boschivi. L’obiettivo generale del progetto è preservare i sistemi forestali in ambiente mediterraneo dai rischi derivanti dai cambiamenti climatici, tramite processi di naturalizzazione, aumento di biodiversità e migliorata reattività, nei processi di recupero, in seguito ad eventi destabilizzanti. Obiettivo specifico è implementare una politica forestale regionale in grado di aumentare la capacità di resilienza delle foreste siciliane, migliorandone l’efficienza ecosistemica e favorendo la salvaguardia della biodiversità. Tra le azioni principali previste dal progetto, che si concluderà alla fine del 2015, si possono citare la classificazione delle categorie forestali siciliane in funzione della sensibilità alla desertificazione, l’indagine diacronica sull’uso e copertura del suolo dei principali paesaggi forestali siciliani, la definizione di prassi selvicolturali specifiche; la realizzazione di 120 ettari di interventi dimostrativi in 6 aree della Sicilia; la realizzazione di 6 piani di indirizzo forestali attraverso processi partecipativi con le popolazioni locali. Nella fase finale del progetto è prevista l’implementazione delle linee strategiche sperimentate con ResilForMed nel Piano Forestale Regionale della Sicilia
ISOGAL: A deep survey of the obscured inner Milky Way with ISO at 7 and 15 micron and with DENIS in the near-infrared
The ISOGAL project is an infrared survey of specific regions sampling the
Galactic Plane selected to provide information on Galactic structure,stellar
populations,stellar mass-loss and the recent star formation history of the
inner disk and Bulge of the Galaxy. ISOGAL combines 7 and 15 micron ISOCAM
observations - with a resolution of 6'' at worst - with DENIS IJKs data to
determine the nature of the sources and theinterstellar extinction. We have
observed about 16 square degrees with a sensitivity approaching 10-20mJy,
detecting ~10^5 sources,mostly AGB stars,red giants and young stars. The main
features of the ISOGAL survey and the observations are summarized in this
paper,together with a brief discussion of data processing and quality. The
primary ISOGAL products are described briefly (a full description is given in
Schuller et al. 2003, astro-ph/0304309): viz. the images and theISOGAL-DENIS
five-wavelength point source catalogue. The main scientific results already
derived or in progress are summarized. These include astrometrically calibrated
7 and 15um images,determining structures of resolved sources; identification
and properties of interstellar dark clouds; quantification of the infrared
extinction law and source dereddening; analysis of red giant and (especially)
AGB stellar populations in the central Bulge,determining luminosity,presence of
circumstellar dust and mass--loss rate,and source classification,supplemented
in some cases by ISO/CVF spectroscopy; detection of young stellar objects of
diverse types,especially in the inner Bulge with information about the present
and recent star formation rate; identification of foreground sources with
mid-IR excess. These results are the subject of about 25 refereed papers
published or in preparation.Comment: A&A in press. 19 pages,10 Ps figures; problems with figures fixe
- …
