1,007 research outputs found
Prolonged Thrombocytopenia in a Child with Severe Neonatal Alloimmune Reaction and Noonan Syndrome
Fetomaternal alloimmune thrombocytopenia (FMAIT) caused by maternal antibodies is the leading cause of severe neonatal thrombocytopenia. A 1-month-old Caucasian girl was referred to our Hematology Clinic for persistent thrombocytopenia diagnosed after a bleeding episode. Diagnostic tests suggested FMAIT. Mild thrombocytopenia persisted for 18 months, and subsequent findings of dysmorphic facies, short stature and mild pulmonary stenosis led to the hypothesis of Noonan syndrome (NS), which was confirmed by genetic test. Other hematological abnormalities were excluded and she had no further bleeding episodes. This case illustrates the possibility of different diagnoses with the same clinical manifestations. The persistence of thrombocytopenia longer than expected associated with typical physical features led to the diagnosis of NS.info:eu-repo/semantics/publishedVersio
Accretion-Induced Lithium Line Enhancements in Classical T Tauri Stars: RW Aur
It is widely accepted that much of the stochastic variability of T Tauri
stars is due to accretion by a circumstellar disk. The emission line spectrum
as well as the excess continuum emission are common probes of this process. In
this communication, we present additional probes of the circumstellar
environment in the form of resonance lines of low ionization potential
elements. Using a set of 14 high resolution echelle observations of the
classical T Tauri star (CTTS), RW Aur, taken between 1986 and 1996, we
carefully measure the continuum veiling at each epoch by comparing more than
500 absorption lines with those of an appropriate template. This allows us to
accurately subtract out the continuum emission and to recover the underlying
photospheric spectrum. In doing so, we find that selected photospheric lines
are enhanced by the accretion process, namely the resonance lines of LiI and
KI. A resonance line of TiI and a low excitation potential line of CaI also
show weak enhancements. Simple slab models and computed line bisectors lead us
to propose that these line enhancements are markers of cool gas at the
beginning of the accretion flow which provides an additional source of line
opacity. These results suggest that published values of surface lithium
abundances of classical T Tauri stars are likely to be overestimated. This
would account for the various reports of surface lithium abundances in excess
of meteoritic values among the extreme CTTS. Computing LTE lithium abundances
of RW Aur in a low and then high accretion state yields abundances which vary
by one order of magnitude. The low accretion state lithium abundance is
consistent with theoretical predictions for a star of this age and mass while
the high accretion state spectrum yields a super-meteoritic lithium abundance.Comment: 28 pages, 8 figures, accepted by Ap
Evaluation of Microencapsulation of The UFV-AREG1 Bacteriophage in Alginate-Ca Microcapsules using Microfluidic Devices
The indiscriminate use of antibiotics and the emergence of resistant
microorganisms have become a major challenge for the food industry. The purpose
of this work was to microencapsulate the bacteriophage UFV-AREG1 in a calcium
alginate matrix using microfluidic devices and to study the viability and
efficiency of retention. The microcapsules were added to gel of propylene
glycol for use as an antimicrobial in the food industry. The technique showed
the number of the phage encapsulation, yielding drops with an average 100-250
m of diameter, 82.1 2% retention efficiency and stability in the gel
matrix for 21 days. The gel added to the microencapsulated phage showed
efficiency (not detectable on the surface) in reducing bacterial contamination
on the surface at a similar level to antimicrobial chemicals (alcohol 70%).
Therefore, it was possible to microencapsulate bacteriophages in alginate-Ca
and apply the microcapsules in gels for use as sanitizers in the food industry.Comment: 8 pages, 5 figure
Spherical Harmonics for the 1D Radiative Transfer Equation II: Thermal Emission
Approximate methods to estimate solutions to the radiative transfer equation
are essential for the understanding of atmospheres of exoplanets and brown
dwarfs. The simplest and most popular choice is the "two-stream method" which
is often used to produce simple yet effective models for radiative transfer in
scattering and absorbing media. Toon et al. (1989) (Toon89) outlined a
two-stream method for computing reflected light and thermal spectra and was
later implemented in the open-source radiative transfer model PICASO. In Part~I
of this series, we developed an analytical spherical harmonics method for
solving the radiative transfer equation for reflected solar radiation (Rooney
et al. 2023), which was implemented in PICASO to increase the accuracy of the
code by offering a higher-order approximation. This work is an extension of
this spherical harmonics derivation to study thermal emission spectroscopy. We
highlight the model differences in the approach for thermal emission and
benchmark the 4-term method (SH4) against Toon89 and a high-stream
discrete-ordinates method, CDISORT. By comparing the spectra produced by each
model we demonstrate that the SH4 method provides a significant increase in
accuracy, compared to Toon89, which can be attributed to the increased order of
approximation and to the choice of phase function. We also explore the
trade-off between computational time and model accuracy. We find that our
4-term method is twice as slow as our 2-term method, but is up to five times
more accurate, when compared with CDISORT. Therefore, SH4 provides excellent
improvement in model accuracy with minimal sacrifice in numerical expense.Comment: Submitted ApJ; 17 pages; 7 figures; Code available at
https://github.com/natashabatalha/picaso; Zenodo release at
https://zenodo.org/record/7765171#.ZC3G7uzMI8Y; Tutorials/figure
reproducibility at
https://natashabatalha.github.io/picaso/notebooks/10c_AnalyzingApproximationsThermal.html
Spherical Harmonics for the 1D Radiative Transfer Equation I: Reflected Light
A significant challenge in radiative transfer theory for atmospheres of
exoplanets and brown dwarfs is the derivation of computationally efficient
methods that have adequate fidelity to more precise, numerically demanding
solutions. In this work, we extend the capability of the first open-source
radiative transfer model for computing the reflected light of exoplanets at any
phase geometry, PICASO: Planetary Intensity Code for Atmospheric Spectroscopy
Observations. Until now, PICASO has implemented two-stream approaches to the
solving the radiative transfer equation for reflected light, in particular
following the derivations of Toon et al. (1989) (Toon89). In order to improve
the model accuracy, we have considered higher-order approximations of the phase
functions, namely, we have increased the order of approximation from 2 to 4,
using spherical harmonics. The spherical harmonics approximation decouples
spatial and directional dependencies by expanding the intensity and phase
function into a series of spherical harmonics, or Legendre polynomials,
allowing for analytical solutions for low-order approximations to optimize
computational efficiency. We rigorously derive the spherical harmonics method
for reflected light and benchmark the 4-term method (SH4) against Toon89 and
two independent and higher-fidelity methods (CDISORT & doubling-method). On
average, the SH4 method provides an order of magnitude increase in accuracy,
compared to Toon89. Lastly, we implement SH4 within PICASO and observe only
modest increase in computational time, compared to two-stream methods (20%
increase).Comment: Accepted ApJ; 27 pages; 5 figures; Code available at
https://github.com/natashabatalha/picaso; Zenodo release at
https://zenodo.org/record/7765171#.ZC3G7uzMI8Y; Tutorials/figure
reproducibility at
https://natashabatalha.github.io/picaso/notebooks/10b_AnalyzingApproximationsReflectedLightSH.htm
Importance of Primary Indications for Fetal Echocardiography Proposed by the Portuguese Health Department
Introdução: A malformação congénita mais frequente é a cardíaca, afectando cerca de 5-8 recém-nascidos/mil nados vivos. Actualmente é possível obter um diagnóstico pré-natal destas anomalias através do ecocardiograma fetal (EcoF), porém, porque os recursos em Saúde são limitados, este exame deve ser pedido de acordo com os critérios estabelecidos pela Direcção Geral de Saúde (DGS).
Objectivos: Avaliar a importância dos critérios de referenciação propostos pela DGS para detecção de anomalias cardíacas. Determinar as taxas de prevalência e mortalidade nos fetos com doença cardíaca.
Material e Métodos: Revisão casuística de uma amostra de 733 fetos aos quais foi realizado EcoF em consulta de Cardiologia Pré-natal num centro terciário de Cardiologia Pediátrica, no período de 2006 a 2008. Foram avaliados dados demográficos, motivo de referenciação (MR), resultados da EcoF e evolução. Classificámos os MR em dois grupos: (I) concordantes com as indicações da DGS- causas major (familiar, materna, fetal) e causas minor (outras situações);
(II) não concordantes.
Resultados: Realizaram-se 871 EcoF a 705 grávidas. A mediana da idade materna foi de 32 anos (15-45 anos) e a média da idade gestacional foi de 26 semanas (±4 sem). O grupo I incluiu 89% das grávidas. Identificaram-se 52 fetos (7%) com anomalias cardíacas: 42 estruturais, 8 de ritmo e 2 derrames pericárdicos. Estas anomalias distribuíram-se da seguinte forma:
grupo I - causa familiar (3), causa materna (3), causa fetal (39), causas minor (5) e no
grupo II (2). Observou-se um maior número de anomalias cardíacas no grupo I (6,8% vs 0,3%)
(p> 0.05), sobretudo nos fetos referenciados por causa fetal (p<0,05). Perderam-se no controlo evolutivo 10 casos positivos, realizaram-se 3 interrupções médicas da gravidez e ocorreram 3 mortes. Mantêm-se em seguimento na consulta de Cardiologia Pediátrica 11 casos positivos.
Conclusões: Na maioria dos casos cumpriram-se os critérios de referenciação da DGS, no
entanto não se observou uma diferença estatisticamente significativa na prevalência de anomalias cardíacas fetais nas grávidas com e sem factores de risco. A causa fetal foi a que melhor se correlacionou com a presença de anomalia cardíaca. A prevalência destas anomalias e a
taxa de mortalidade aferida na amostra pode estar subestimada por perda de casos positivos no controlo evolutivo
Uso de ninhos de cupin como fonte de matéria orgânica em sistemas de produção agrosilviculturais na Amazônia
The growth of two annual crops, okra (Abelmoschus escutentus) and egg-plant (Solatium melongena) and one perennial crop, andiroba (Carapa guianensis, a native forest tree of Amazonia) under different treatments with organic manure derived from termite nest material of wood-feeding Nasutitermes species was tested (randomized block design). The use of 25-100 g of nest material gave no significant increase in okra productivity, and 25-200 g gave no significant response in andiroba. The combined use of NPK with 200 g of nest material gave a significant higher production in egg-plant (total number and total fresh weight of fruits) when compared to the control (without fertilizer) and to the treatment with NPK only.The results suggest the possibility to use termite nest material to enhance crop production in Amazonia, particularly in combination with low amounts of mineral fertilizer. Research lines for further investigations are outlined.Foi avaliado crescimento de duas espécies agriculturais anuais, quiabo (Abelmoschus esculentus) e berinjela (Solatium melongena), e de uma espécie perene, andiroba (Carapa guianensis, uma árvore nativa da Amazônia) sob diferentes tratamentos com matéria orgânica derivada de material de cupinzeiro de espécies xilófagas de Nasutitermes (desenho de bloco randomizado). O uso de 25-100 g de material de termiteiro não levou a um incremento significativo da produtividade em quiabo, e 25-200 g não resultou numa resposta significativa em andiroba. O uso combinado de NPK com 200 g de ninho de cupim resultou numa produção significantemente maior em S. melongena (número total e peso fresco total de frutos) se comparado com o controle (sem fertilizante nenhum) e com o tratamento de NPK apenas. Os resultados sugerem a possibilidade de usar material de cupinzeiro para melhorara produção agrossilvicultural na Amazônia, especialmente em combinação com pequenas quantidades de fertilizante mineral Linhas de pesquisa para futuras investigações são apresentadas
Minimizing follow-up for space-based transit surveys using full lightcurve analysis
One of the biggest challenges facing large transit surveys is the elimination
of false-positives from the vast number of transit candidates. We investigate
to what extent information from the lightcurves can identify blend scenarios
and eliminate them as planet candidates, to significantly decrease the amount
of follow-up observing time required to identify the true exoplanet systems. If
a lightcurve has a sufficiently high signal-to-noise ratio, a distinction can
be made between the lightcurve of a stellar binary blended with a third star
and the lightcurve of a transiting exoplanet system. We perform simulations to
determine what signal-to-noise level is required to make the distinction
between blended and non-blended systems as function of transit depth and impact
parameter. Subsequently we test our method on real data from the first IRa01
field observed by the CoRoT satellite, concentrating on the 51 candidates
already identified by the CoRoT team. About 70% of the planet candidates in the
CoRoT IRa01 field are best fit with an impact parameter of b>0.85, while less
than 15% are expected in this range considering random orbital inclinations. By
applying a cut at b<0.85, meaning that ~15% of the potential planet population
would be missed, the candidate sample decreases from 41 to 11. The lightcurves
of 6 of those are best fit with such low host star densities that the
planet-to-star size ratii imply unrealistic planet radii of R>2RJup. Two of the
five remaining systems, CoRoT1b and CoRoT4b, have been identified as planets by
the CoRoT team, for which the lightcurves alone rule out blended light at 14%
(2sigma) and 31% (2sigma). We propose to use this method on the Kepler database
to study the fraction of real planets and to potentially increase the
efficiency of follow-up.Comment: 13 pages, 11 figures, 2 tables. Accepted for publication in A&
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