223 research outputs found
Manifestações neuropsiquiátricas do hiperparatiroidismo primário no idoso: relato de casos e revisão da literatura
Osteoporosis and neuropsychiatric disorders occur more frequently in elderly than in young people. When they appear together there is a possibility of a common etiology. We report two cases of elderly women at the ages of 75 and 80y with established osteoporosis and neuropsychiatric manifestations (apathy, weakness, depression and loss of memory) caused by hypercalcemia (ionic calcium of 1.43mmol/L and 1.65mmol/L, respectively) due to primary hyperparathyroidism (PHPT). Other laboratory results showed normal levels of the intact fraction of parathormone (iPTH), i.e. 64 and 63pg/ml, respectively. They were submitted to parathyroidectomy and only one tumoral mass was removed from each woman. Pathologic examination showed parathyroid adenoma. Shortly after the surgery they got better of the neuropsychiatric signs and symptoms. Six months later the bone mineral density (BMD) of the second patient increased whereas the other one was unable to have her BMD evaluated due to thoracic deformities. The possibility of PHPT must be always considered, especially in patients with normal but not suppresible parathormone levels. The reason is that some parathyroid adenomas present an abnormal set point to calcium and no significantly increase in parathormone production. It should be emphasized that there is no satisfactory medical treatment for parathyroid adenoma except for surgical excision, which is effective in the majority of cases. We conclude that ionic calcium must be measured in all elderly patients who present neuropsychiatric disorders and/ or osteoporosis.A osteoporose e os distúrbios neuropsiquiátricos surgem com maior freqüência entre os pacientes idosos, quando comparados com as demais faixas etárias. Manifestações concomitantes destas sÃndromes podem apresentar causas comuns. Neste artigo, nós descrevemos os casos de duas mulheres com osteoporose estabelecida e idades de 75 e 80 anos, que desenvolveram sinais e sintomas neuropsiquiátricos (apatia, fraqueza, depressão e perda de memória) associados a hipercalcemia [cálcio iônico de 1,43mmol/L e 1,65mmol/L (1,14 - 1,30mmol/L), respectivamente]. Na investigação laboratorial foi observado que os nÃveis da fração intacta do paratormônio (PTHi) estavam dentro dos limites da normalidade (64 e 63pg/ml, respectivamente) ou não suprimidos. Após exploração cirúrgica cervical foram removidas, de cada paciente, massas tumorais únicas, cujo anátomo-patológico revelou adenoma de paratireóide. As duas pacientes apresentaram melhora dos sintomas e sinais neuropsiquiátricos após a cirurgia e a segunda paciente obteve ganho de massa óssea significativo, sem uso de qualquer droga anti-reabsortiva. A outra paciente não pode ser avaliada através da densitometria óssea, devido à s deformidades na coluna torácica. A possibilidade de HPTP deve ser sempre considerada, principalmente em pacientes com nÃveis de paratormônio dentro da faixa de normalidade, ou não suprimidos apesar de cálcio ionizado elevado. Isso ocorre devido a alguns tumores de paratireóide apresentarem set point alterado em relação aos nÃveis de cálcio mas sem aumento significativo da produção de paratormônio. Outra correlação observada é que quanto menor forem os adenomas, maior a chance de serem hipersecretores e autônomos. Em conclusão, a aferição do cálcio iônico em pacientes idosos com osteoporose e ou sintomas e sinais neuropsiquiátricos deve ser feita de rotina com o objetivo de se excluir doenças que possam ser tratadas prontamente e com bons resultados.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaUNIFESP, EPM, Depto. de MedicinaSciEL
Optical Line Emission from z6.8 Sources with Deep Constraints on Ly Visibility
We analyze a sample of -dropout galaxies in the CANDELS GOODS South and
UDS fields that have been targeted by a dedicated spectroscopic campaign aimed
at detecting their Ly line. Deep IRAC observations at 3.6 and 4.5
m are used to determine the strength of optical emission lines affecting
these bands at z6.5-6.9 in order to i) investigate possible physical
differences between Ly emitting and non-emitting sources; ii) constrain
the escape fraction of ionizing photons; iii) provide an estimate of the
specific star-formation rate at high redshifts. We find evidence of strong
[OIII]+H emission in the average (stacked) SEDs of galaxies both with
and without Ly emission. The blue IRAC [3.6]-[4.5] color of the stack
with detected Ly line can be converted into a rest-frame equivalent
width EW([OIII]+H)=1500 assuming a flat intrinsic
stellar continuum. This strong optical line emission enables a first estimate
of f20% on the escape fraction of ionizing photons from
Ly detected objects. The objects with no Ly line show less
extreme EW([OIII]+H)=520 suggesting different
physical conditions of the HII regions with respect to Ly-emitting
ones, or a larger f. The latter case is consistent with a combined
evolution of f and the neutral hydrogen fraction as an explanation of
the lack of bright Ly emission at z6. A lower limit on the specific
star formation rate, SSFR9.1 for galaxies at these redshifts can be derived from the
spectroscopically confirmed sample.Comment: 10 pages, 7 figures; The Astrophysical Journal in press; matched to
the published versio
Scalar and vector decomposition of the nucleon self-energy in the relativistic Brueckner approach
We investigate the momentum dependence of the nucleon self-energy in nuclear
matter. We apply the relativistic Brueckner-Hartree-Fock approach and adopt the
Bonn A potential. A strong momentum dependence of the scalar and vector
self-energy components can be observed when a commonly used pseudo-vector
choice for the covariant representation of the T-matrix is applied. This
momentum dependence is dominated by the pion exchange. We discuss the problems
of this choice and its relations to on-shell ambiguities of the T-matrix
representation. Starting from a complete pseudo-vector representation of the
T-matrix, which reproduces correctly the pseudo-vector pion-exchange
contributions at the Hartree-Fock level, we observe a much weaker momentum
dependence of the self-energy. This fixes the range of the inherent uncertainty
in the determination of the scalar and vector self-energy components. Comparing
to other work, we find that extracting the self-energy components by a fit to
the single particle potential leads to even more ambiguous results.Comment: 35 pages RevTex, 7 PS figures, replaced by a revised and extended
versio
Hubble imaging of the ionizing radiation from a star-forming galaxy at z=3.2 with fesc>50%
Star-forming galaxies are considered to be the leading candidate sources that
dominate the cosmic reionization at z>7, and the search for analogs at moderate
redshift showing Lyman continuum (LyC) leakage is currently a active line of
research. We have observed a star-forming galaxy at z=3.2 with Hubble/WFC3 in
the F336W filter, corresponding to the 730-890A rest-frame, and detect LyC
emission. This galaxy is very compact and also has large Oxygen ratio
[OIII]5007/[OII]3727 (>=10). No nuclear activity is revealed from
optical/near-infrared spectroscopy and deep multi-band photometry (including
the 6Ms X-ray, Chandra). The measured escape fraction of ionizing radiation
spans the range 50-100\%, depending on the IGM attenuation. The LyC emission is
detected at S/N=10 with m(F336W)=27.57+/-0.11 and it is spatially unresolved,
with effective radius R_e<200pc. Predictions from photoionization and radiative
transfer models are in line with the properties reported here, indicating that
stellar winds and supernova explosions in a nucleated star-forming region can
blow cavities generating density-bounded conditions compatible with optically
thin media. Irrespective to the nature of the ionizing radiation, spectral
signatures of these sources over the entire electromagnetic spectrum are of
central importance for their identification during the epoch of reionization,
when the LyC is unobservable. Intriguingly, the Spitzer/IRAC photometric
signature of intense rest-frame optical emissions ([OIII]+Hbeta) observed
recently at z~7.5-8.5 is similar to what is observed in this galaxy. Only the
James Webb Space Telescope will measure optical line ratios at z>7 allowing a
direct comparison with lower redshift LyC emitters, as reported here.Comment: 6 pages, 5 figures, ApJ submitted (comments welcome
Constraints on the star-formation rate of z~3 LBGs with measured metallicity in the CANDELS GOODS-South field
We analyse 14 LBGs at z~2.8-3.8 constituting the only sample where both a
spectroscopic measurement of their metallicity and deep IR observations
(CANDELS+HUGS survey) are available. Fixing the metallicity of population
synthesis models to the observed values, we determine best-fit physical
parameters under different assumptions about the star-formation history and
also consider the effect of nebular emission. For comparison we determine the
UV slope of the objects, and use it to estimate their SFR_UV99 by correcting
the UV luminosity following Meurer et al. (1999). A comparison between SFR
obtained through SED-fitting (SFR_fit) and the SFR_UV99 shows that the latter
are underestimated by a factor 2-10, regardless of the assumed SFH. Other SFR
indicators (radio, far-IR, X-ray, recombination lines) coherently indicate SFRs
a factor of 2-4 larger than SFR_UV99 and in closer agreement with SFR_fit. This
discrepancy is due to the solar metallicity implied by the usual beta-A1600
conversion factor. We propose a refined relation, appropriate for sub-solar
metallicity LBGs: A1600 = 5.32+1.99beta. This relation reconciles the
dust-corrected UV with the SED-fitting and the other SFR indicators. We show
that the fact that z~3 galaxies have sub-solar metallicity implies an upward
revision by a factor of ~1.5-2 of the global SFRD, depending on the assumptions
about the age of the stellar populations. We find very young best-fit ages
(10-500 Myrs) for all our objects. From a careful examination of the
uncertainties in the fit and the amplitude of the Balmer break we conclude that
there is little evidence of the presence of old stellar population in at least
half of the LBGs in our sample, suggesting that these objects are probably
caught during a huge star-formation burst, rather than being the result of a
smooth evolution.Comment: 16 pages, 13 figures, A&A in press. Matched to the published versio
T-PHOT: A new code for PSF-matched, prior-based, multiwavelength extragalactic deconfusion photometry
We present T-PHOT, a publicly available software aimed at extracting accurate
photometry from low-resolution images of deep extragalactic fields, where the
blending of sources can be a serious problem for the accurate and unbiased
measurement of fluxes and colours. T-PHOT has been developed within the
ASTRODEEP project and it can be considered as the next generation to TFIT,
providing significant improvements above it and other similar codes. T-PHOT
gathers data from a high-resolution image of a region of the sky, and uses it
to obtain priors for the photometric analysis of a lower resolution image of
the same field. It can handle different types of datasets as input priors: i) a
list of objects that will be used to obtain cutouts from the real
high-resolution image; ii) a set of analytical models; iii) a list of
unresolved, point-like sources, useful e.g. for far-infrared wavelength
domains. We show that T-PHOT yields accurate estimations of fluxes within the
intrinsic uncertainties of the method, when systematic errors are taken into
account (which can be done thanks to a flagging code given in the output).
T-PHOT is many times faster than similar codes like TFIT and CONVPHOT (up to
hundreds, depending on the problem and the method adopted), whilst at the same
time being more robust and more versatile. This makes it an optimal choice for
the analysis of large datasets. In addition we show how the use of different
settings and methods significantly enhances the performance. Given its
versatility and robustness, T-PHOT can be considered the preferred choice for
combined photometric analysis of current and forthcoming extragalactic optical
to far-infrared imaging surveys. [abridged]Comment: 23 pages, 20 figures, 2 table
Identification of z~>2 Herschel 500 micron sources using color-deconfusion
We present a new method to search for candidate z~>2 Herschel 500{\mu}m
sources in the GOODS-North field, using a S500{\mu}m/S24{\mu}m "color
deconfusion" technique. Potential high-z sources are selected against
low-redshift ones from their large 500{\mu}m to 24{\mu}m flux density ratios.
By effectively reducing the contribution from low-redshift populations to the
observed 500{\mu}m emission, we are able to identify counterparts to high-z
500{\mu}m sources whose 24{\mu}m fluxes are relatively faint. The recovery of
known z~4 starbursts confirms the efficiency of this approach in selecting
high-z Herschel sources. The resulting sample consists of 34 dusty star-forming
galaxies at z~>2. The inferred infrared luminosities are in the range
1.5x10^12-1.8x10^13 Lsun, corresponding to dust-obscured star formation rates
(SFRs) of ~260-3100 Msun/yr for a Salpeter IMF. Comparison with previous SCUBA
850{\mu}m-selected galaxy samples shows that our method is more efficient at
selecting high-z dusty galaxies with a median redshift of z=3.07+/-0.83 and 10
of the sources at z~>4. We find that at a fixed luminosity, the dust
temperature is ~5K cooler than that expected from the Td-LIR relation at z<1,
though different temperature selection effects should be taken into account.
The radio-detected subsample (excluding three strong AGN) follows the
far-infrared/radio correlation at lower redshifts, and no evolution with
redshift is observed out to z~5, suggesting that the far-infrared emission is
star formation dominated. The contribution of the high-z Herschel 500{\mu}m
sources to the cosmic SFR density is comparable to that of SMG populations at
z~2.5 and at least 40% of the extinction-corrected UV samples at z~4
(abridged).Comment: 33 pages in emulateapj format, 24 figures, 2 tables, accepted for
publication in the ApJ
Nuclear Saturation with in-Medium Meson Exchange Interactions
We show that the assumption of dropping meson masses together with
conventional many-body effects, implemented in the relativistic Dirac-Brueckner
formalism, explains nuclear saturation. We use a microscopic model for
correlated exchange and include the standard many-body effects on the
in-medium pion propagation, which initially increase the attractive
nucleon-nucleon () potential with density. For the vector meson exchanges
in both the and sector, we assume Brown-Rho scaling which---in
concert with `chiral' contact interactions---reduces the attraction at
higher densities.Comment: 5 pages REVTeX, 2 eps-figures included, submitted to Phys. Rev. Let
The Exogravity Project: Using Single Mode Interferometry to Characterize Exoplanets
Combining adaptive optics and interferometric observations results in a considerable contrast gain compared to single-telescope, extreme AO systems. Taking advantage of this, the ExoGRAVITY project is a survey of known young giant exoplanets located in the range of 0.1 to 2 from their stars. The observations provide astrometric data of unprecedented accuracy, being crucial for refining the orbital parameters of planets and illuminating their dynamical histories. Furthermore, GRAVITY will measure non-Keplerian perturbations due to planet-planet interactions in multi-planet systems and measure dynamical masses. Over time, repetitive observations of the exoplanets at medium resolution (R = 500) will provide a catalogue of K-band spectra of unprecedented quality, for a number of exoplanets. The K-band has the unique properties that it contains many molecular signatures (CO, H2O, CH4, CO2). This allows constraining precisely surface gravity, metallicity, and temperature, if used in conjunction with self-consistent models like Exo-REM. Further, we will use the parameter-retrieval algorithm petitRADTRANS to constrain the C/O ratio of the planets. Ultimately, we plan to produce the first C/O survey of exoplanets, kick-starting the difficult process of linking planetary formation with measured atomic abundances
The ALPINE-ALMA [C ii] Survey: Size of Individual Star-forming Galaxies at z = 4-6 and Their Extended Halo Structure
We present the physical extent of [CII] 158um line-emitting gas from 46
star-forming galaxies at z=4-6 from the ALMA Large Program to INvestigate CII
at Early Times (ALPINE). Using exponential profile fits, we measure the
effective radius of the [CII] line (r_e,[CII]) for individual galaxies and
compare them with the rest-frame ultra-violet (UV) continuum (r_e,UV) from
Hubble Space Telescope images. The effective radius r_e,[CII] exceeds r_e,UV by
factors of ~2-3 and the ratio of r_e,[CII]/r_e,UV increases as a function of
M_star. We do not find strong evidence that [CII] line, the rest-frame UV, and
FIR continuum are always displaced over ~ 1-kpc scale from each other. We
identify 30% of isolated ALPINE sources as having an extended [CII] component
over 10-kpc scales detected at 4.1-10.9 beyond the size of
rest-frame UV and far-infrared (FIR) continuum. One object has tentative
rotating features up to ~10-kpc, where the 3D model fit shows the rotating
[CII]-gas disk spread over 4 times larger than the rest-frame UV-emitting
region. Galaxies with the extended [CII] line structure have high
star-formation rate (SFR), stellar mass (M_star), low Lya equivalent-width, and
more blue-shifted (red-shifted) rest-frame UV metal absorption (Lya line), as
compared to galaxies without such extended [CII] structures. Although we cannot
rule out the possibility that a selection bias towards luminous objects may be
responsible for such trends, the star-formation driven outflow also explains
all these trends. Deeper observations are essential to test whether the
extended [CII] line structures are ubiquitous to high-z star-forming galaxies.ERC
STF
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