146 research outputs found
O mediador social e pessoal nos cursos de educação e formação de adultos
Trabalho de projecto de mestrado, Ciências da Educação (Formação de Adultos), Universidade de Lisboa, Instituto de Educação, 2011Este trabalho de projecto, desenvolvido no âmbito das Ciências de Educação/ Formação
de adultos, na área de especialização Formação de Adultos, teve como principal objectivo a
análise do processo de formação dos mediadores de cursos de Educação e Formação de
Adultos de Nível Secundário. Partindo da premissa de que os mediadores se formam através da
experiência procurou-se com este trabalho identificar este processo e quais as suas práticas.
A informação empírica resultou de entrevistas sobre a prática profissional dos
entrevistados que trabalham num centro de formação profissional, na área da mediação social e
pessoal.
Verificou-se que o processo de formação dos mediadores é essencialmente não formal e
informal sendo as experiências que vivem determinantes para a construção dos seus saberes,
práticas e instrumentos de trabalho.
A informação recolhida deu origem à criação de um projecto de intervenção no meio
estudado com o objectivo de fornecer instrumentos aos novos mediadores e orientá-los nas suas
novas funções, mantendo e potenciando o carácter experiencial deste processo formativo.This project work developed within the Science of Education/ Adults Education,
specialized in adults vocational training, had as main objective the analysis of the learning
process of mediators of the second grade vocational training courses for adults. Based on the
thought that mediators learn their profession through experience, we sought to identify, with this
work, this process and their practices.
The empirical information resulted from interviews on the professional practices of the
interviewed, who work in a vocational training centre, in the area of social and personal
mediation.
Was identified that the mediators’ learning process is essentially non-formal and informal
being the experiences they lived, in professional context, extremely important to the building of
their knowledge, practices and working tools.
The obtained information originated an intervention project, in the studied vocational
training centre, that aims to provide work tools for new mediators and to guide them in their new
roles, maintaining and developing the experiential character of this learning process
PSR J1907+0602: A Radio-Faint Gamma-Ray Pulsar Powering a Bright TeV Pulsar Wind Nebula
We present multiwavelength studies of the 106.6 ms gamma-ray pulsar PSR
J1907+06 near the TeV source MGRO J1908+06. Timing observations with Fermi
result in a precise position determination for the pulsar of R.A. =
19h07m547(2), decl. = +06:02:16(2) placing the pulsar firmly within the TeV
source extent, suggesting the TeV source is the pulsar wind nebula of PSR
J1907+0602. Pulsed gamma-ray emission is clearly visible at energies from 100
MeV to above 10 GeV. The phase-averaged power-law index in the energy range E >
0.1 GeV is = 1.76 \pm 0.05 with an exponential cutoff energy E_{c} = 3.6 \pm
0.5 GeV. We present the energy-dependent gamma-ray pulsed light curve as well
as limits on off-pulse emission associated with the TeV source. We also report
the detection of very faint (flux density of ~3.4 microJy) radio pulsations
with the Arecibo telescope at 1.5 GHz having a dispersion measure DM = 82.1 \pm
1.1 cm^{-3}pc. This indicates a distance of 3.2 \pm 0.6 kpc and a
pseudo-luminosity of L_{1400} ~ 0.035 mJy kpc^2. A Chandra ACIS observation
revealed an absorbed, possibly extended, compact <(4 arcsec) X-ray source with
significant non-thermal emission at R.A. = 19h07m54.76, decl. = +06:02:14.6
with a flux of 2.3^{+0.6}_{-1.4} X 10^{-14} erg cm^{-2} s^{-1}. From archival
ASCA observations, we place upper limits on any arcminute scale 2--10 keV X-ray
emission of ~ 1 X 10^{-13} erg cm^{-2} s^{-1}. The implied distance to the
pulsar is compatible with that of the supernova remnant G40.5-0.5, located on
the far side of the TeV nebula from PSR J1907+0602, and the S74 molecular cloud
on the nearer side which we discuss as potential birth sites
Fermi Large Area Telescope Observations of Gamma-ray Pulsars PSR J1057-5226, J1709-4429, and J1952+3252
The Fermi Large Area Telescope (LAT) data have confirmed the pulsed emission
from all six high-confidence gamma-ray pulsars previously known from the EGRET
observations. We report results obtained from the analysis of 13 months of LAT
data for three of these pulsars (PSR J1057-5226, PSR J1709-4429, and PSR
J1952+3252) each of which had some unique feature among the EGRET pulsars. The
excellent sensitivity of LAT allows more detailed analysis of the evolution of
the pulse profile with energy and also of the variation of the spectral shape
with phase. We measure the cutoff energy of the pulsed emission from these
pulsars for the first time and provide a more complete picture of the emission
mechanism. The results confirm some, but not all, of the features seen in the
EGRET data.Comment: Accepted for publication in ApJ. 45 pages, 12 figures, 11 tables.
Corresponding authors: O. Celik, F. Gargano, T. Reposeur, D.J. Thompso
Fermi LAT Observation of Diffuse Gamma-Rays Produced Through Interactions between Local Interstellar Matter and High Energy Cosmic Rays
Observations by the Large Area Telescope (LAT) on the \textit{Fermi} mission
of diffuse -rays in a mid-latitude region in the third quadrant
(Galactic longitude from 200\arcdeg to 260\arcdeg and latitude
from 22\arcdeg to 60\arcdeg) are reported. The region contains no known
large molecular cloud and most of the atomic hydrogen is within 1 kpc of the
solar system. The contributions of -ray point sources and inverse
Compton scattering are estimated and subtracted. The residual -ray
intensity exhibits a linear correlation with the atomic gas column density in
energy from 100 MeV to 10 GeV. The measured integrated -ray emissivity
is (1.63 \pm 0.05) \times 10^{-26} {\rm photons s^{-1} sr^{-1}
H\mathchar`-atom^{-1}} and (0.66 \pm 0.02) \times 10^{-26} {\rm photons
s^{-1} sr^{-1} H\mathchar`-atom^{-1}} above 100 MeV and above 300 MeV,
respectively, with additional systematic error of . The differential
emissivity in 100 MeV--10 GeV agrees with calculations based on cosmic ray
spectra consistent with those directly measured, at the 10% level. The results
obtained indicate that cosmic ray nuclei spectra within 1 kpc from the solar
system in regions studied are close to the local interstellar spectra inferred
from direct measurements at the Earth within .Comment: accepted for publication in the Astrophysical Journal. Revised
according to the author proof.(correction of typos and minor revisions
Discovery of Pulsed -rays from PSR J0034-0534 with the Fermi LAT: A Case for Co-located Radio and -ray Emission Regions
Millisecond pulsars (MSPs) have been firmly established as a class of
gamma-ray emitters via the detection of pulsations above 0.1 GeV from eight
MSPs by the Fermi Large Area Telescope (LAT). Using thirteen months of LAT data
significant gamma-ray pulsations at the radio period have been detected from
the MSP PSR J0034-0534, making it the ninth clear MSP detection by the LAT. The
gamma-ray light curve shows two peaks separated by 0.2740.015 in phase
which are very nearly aligned with the radio peaks, a phenomenon seen only in
the Crab pulsar until now. The 0.1 GeV spectrum of this pulsar is well
fit by an exponentially cutoff power law with a cutoff energy of 1.80.1 GeV and a photon index of 1.50.1, first errors are
statistical and second are systematic. The near-alignment of the radio and
gamma-ray peaks strongly suggests that the radio and gamma-ray emission regions
are co-located and both are the result of caustic formation.Comment: 20 pages, 3 figures, 2 tables. Accepted for publication in Ap
Fermi-LAT Search for Pulsar Wind Nebulae around gamma-ray Pulsars
The high sensitivity of the Fermi-LAT (Large Area Telescope) offers the first
opportunity to study faint and extended GeV sources such as pulsar wind nebulae
(PWNe). After one year of observation the LAT detected and identified three
pulsar wind nebulae: the Crab Nebula, Vela-X and the PWN inside MSH 15-52. In
the meantime, the list of LAT detected pulsars increased steadily. These
pulsars are characterized by high energy loss rates from ~3 \times 10^{33} erg
s to 5 \times 10 erg s and are therefore likely to power a
PWN. This paper summarizes the search for PWNe in the off-pulse windows of 54
LAT-detected pulsars using 16 months of survey observations. Ten sources show
significant emission, seven of these likely being of magnetospheric origin. The
detection of significant emission in the off-pulse interval offers new
constraints on the gamma-ray emitting regions in pulsar magnetospheres. The
three other sources with significant emission are the Crab Nebula, Vela-X and a
new pulsar wind nebula candidate associated with the LAT pulsar PSR J1023-5746,
coincident with the TeV source HESS J1023-575. We further explore the
association between the H.E.S.S. and the Fermi source by modeling its spectral
energy distribution. Flux upper limits derived for the 44 remaining sources are
used to provide new constraints on famous PWNe that have been detected at keV
and/or TeV energies.Comment: Accepted for publication in Astrophysical Journal, 42 pages, 17
figure
Detection of the energetic pulsar PSR B1509-58 and its pulsar wind nebula in MSH 15-52 using the Fermi-Large Area Telescope
We report the detection of high energy gamma-ray emission from the young and
energetic pulsar PSR B150958 and its pulsar wind nebula (PWN) in the
composite supernova remnant SNR G320.4-1.2 (aka MSH 15-52). Using 1 year of
survey data with the Fermi-Large Area Telescope (LAT), we detected pulsations
from PSR B1509-58 up to 1 GeV and extended gamma-ray emission above 1 GeV
spatially coincident with the PWN. The pulsar light curve presents two peaks
offset from the radio peak by phases 0.96 0.01 and 0.33 0.02. New
constraining upper limits on the pulsar emission are derived below 1 GeV and
confirm a severe spectral break at a few tens of MeV. The nebular spectrum in
the 1 - 100 GeV energy range is well described by a power-law with a spectral
index of (1.57 0.17 0.13) and a flux above 1 GeV of (2.91
0.79 1.35) 10^{-9} cm^{-2} s^{-1}. The first errors represent the
statistical errors on the fit parameters, while the second ones are the
systematic uncertainties. The LAT spectrum of the nebula connects nicely with
Cherenkov observations, and indicates a spectral break between GeV and TeV
energies.Comment: 14 pages, 6 figures, accepted for publication by Ap
Bovine tuberculosis at a cattle-small ruminant-human interface in Meskan, Gurage region, Central Ethiopia
ABSTRACT: BACKGROUND: Bovine tuberculosis (BTB) is endemic in Ethiopian cattle. The aim of this study was to assess BTB prevalence at an intensive contact interface in Meskan Woreda (district) in cattle, small ruminants and suspected TB-lymphadenitis (TBLN) human patients. METHODS: The comparative intradermal test (CIDT) was carried out for all animals involved in the cross-sectional study and results interpreted using a < 4 mm and a < 2 mm cut-off. One PPD positive goat was slaughtered and lymph nodes subjected to culture and molecular typing. In the same villages, people with lymphadenitis were subjected to clinical examination. Fine needle aspirates (FNA) were taken from suspected TBLN and analyzed by smear microscopy and molecular typing. RESULTS: A total of 1214 cattle and 406 small ruminants were tested for BTB. In cattle, overall individual prevalence (< 2 mm cut-off) was 6.8% (CI: 5.4-8.5%) with 100% herd prevalence. Only three small ruminants (2 sheep and 1 goat) were reactors. The overall individual prevalence in small ruminants (< 2 mm cut-off) was 0.4% (CI: 0.03-5.1%) with 25% herd prevalence. Cattle from owners with PPD positive small ruminants were all PPD negative. 83% of the owners kept their sheep and goats inside their house at night and 5% drank regularly goat milk.FNAs were taken from 33 TBLN suspected cases out of a total of 127 screened individuals with lymph node swellings. Based on cytology results, 12 were confirmed TBLN cases. Nine out of 33 cultures were AFB positive. Culture positive samples were subjected to molecular typing and they all yielded M. tuberculosis. M. tuberculosis was also isolated from the goat that was slaughtered. CONCLUSIONS: This study highlighted a low BTB prevalence in sheep and goats despite intensive contact with cattle reactors. TBLN in humans was caused entirely by M. tuberculosis, the human pathogen. M. tuberculosis seems to circulate also in livestock but their role at the interface is unknow
Seroprevalence and Risk Factors Associated to Mycobacterium bovis in Wild Artiodactyl Species from Southern Spain, 2006–2010
The control of bovine tuberculosis (bTB) is at a critical point in the last stage of eradication in livestock. Wildlife species recently have emerged infected with TB in Europe, particularly ungulates in the Iberian Peninsula. Epidemiological information regarding TB in wild ungulates including affected species, prevalence, associated risk factors and appropriate diagnostic methods need to be obtained in these countries
Pulsar-Black Hole Binaries in the Galactic Center
Binaries consisting of a pulsar and a black hole (BH) are a holy grail of
astrophysics, both for their significance for stellar evolution and for their
potential application as probes of strong gravity. In spite of extensive
surveys of our Galaxy and its system of globular clusters, no pulsar-black hole
(PSR-BH) binary has been found to date. Clues as to where such systems might
exist are therefore highly desirable. We show that if the central parsec around
Sgr A* harbors a cluster of ~25,000 stellar BHs (as predicted by mass
segregation arguments) and if it is also rich in recycled pulsar binaries (by
analogy with globular clusters), then 3-body exchange interactions should
produce PSR-BHs in the Galactic center. Simple estimates of the formation rate
and survival time of these binaries suggest that a few PSR-BHs should be
present in the central parsec today. The proposed formation mechanism makes
unique predictions for the PSR-BH properties: 1) the binary would reside within
~1 pc of Sgr A*; 2) the pulsar would be recycled, with a period of ~1 to a few
tens of milliseconds, and a low magnetic field B<~10^10 G; 3) the binary would
have high eccentricity, e~0.8, but with a large scatter; and 4) the binary
would be relatively wide, with semi-major axis a_b~0.1 - >~3 AU. The potential
discovery of a PSR-BH binary therefore provides a strong motivation for deep,
high-frequency radio searches for recycled pulsars toward the Galactic center.Comment: 13 pages, 1 figur
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