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The prenatal detection of congenital heart disease or defects (CHD) has improved over the years, though it remains below 50%. Major defects are more readily detectable (57%) than isolated lesions (44%). Given that CHD accounts for nearly one-third of all congenital anomalies, its implications on the neonatal outcome and its financial burden are significant. The incidence of CHD is influenced by the definition of the disease, the associated anomalies, and the timing of diagnosis.
Long-range temporal choices are built into contemporary policy-making, with policy decisions having consequences that play out across generations. Decisions are made on behalf of the public who are assumed to give much greater weight to their welfare than to the welfare of future generations. The paper investigates this assumption. It briefly discusses evidence from sociological and economic studies before reporting the findings of a British survey of people's intergenerational time preferences based on a representative sample of nearly 10,000 respondents. Questions focused on two sets of policies: (i) health policies to save lives and (ii) environmental policies to protect against floods that would severely damage homes, businesses and other infrastructure. For both sets of policies, participants were offered a choice of three policy options, each bringing greater or lesser benefits to their, their children's and their grandchildren's generations. For both saving lives and protecting against floods, only a minority selected the policy that most benefited their generation; the majority selected policies bringing equal or greater benefits to future generations. Our study raises questions about a core assumption of standard economic evaluation, pointing instead to concern for future generations as a value that many people hold in common.
We present a pilot study of using the Atacama Large Millimeter/sub-millimeter Array (ALMA) continuum observations to constrain the density structure in the intermediate wind zone of massive stars, in which the wind is extremely sensitive to clumping.
Psychological models of conversion disorder (CD) traditionally assume that psychosocial stressors are identifiable around symptom onset. In the face of limited supportive evidence such models are being challenged.
Forty-three motor CD patients, 28 depression patients and 28 healthy controls were assessed using the Life Events and Difficulties Schedule in the year before symptom onset. A novel ‘escape’ rating for events was developed to test the Freudian theory that physical symptoms of CD could provide escape from stressors, a form of ‘secondary gain’.
CD patients had significantly more severe life events and ‘escape’ events than controls. In the month before symptom onset at least one severe event was identified in 56% of CD patients – significantly more than 21% of depression patients [odds ratio (OR) 4.63, 95% confidence interval (CI) 1.56–13.70] and healthy controls (OR 5.81, 95% CI 1.86–18.2). In the same time period 53% of CD patients had at least one ‘high escape’ event – again significantly higher than 14% in depression patients (OR 6.90, 95% CI 2.05–23.6) and 0% in healthy controls. Previous sexual abuse was more commonly reported in CD than controls, and in one third of female patients was contextually relevant to life events at symptom onset. The majority (88%) of life events of potential aetiological relevance were not identified by routine clinical assessments. Nine per cent of CD patients had no identifiable severe life events.
Evidence was found supporting the psychological model of CD, the Freudian notion of escape and the potential aetiological relevance of childhood traumas in some patients. Uncovering stressors of potential aetiological relevance requires thorough psychosocial evaluation.
HS 2324+3944 is one of only four “hybrid” PG 1159 stars. The latter objects are a subgroup of DO white dwarfs. The spectra of “hybrids” show an He ii/C iv absorption trough similar to the “classical” PG 1159 stars, but also strong Balmer lines (Napiwotzki & Schönberner 1991).
The ZZ Ceti stars form a class of variable white dwarfs: the hydrogen dominated atmosphere ones, which do pulsate in an instability strip in the effective temperature range 13000K-11500K. We know 22 such ZZ Ceti white dwarfs. Their variations are caused by nonradial g-mode pulsations with periods are in the range 100-1000 seconds.
A subsample of the ZZ Ceti stars shows amplitude variations on time scales of the order of one month. These variations could be driven by nonlinear phenomena.
With a time-series CCD photometry survey, we have demonstrated clearly that the observed red edge for the ZZ Ceti stars instability strip at 11,000 K is not an observational selection effect. Previous surveys for variability among hydrogen atmosphere white dwarfs at around 11,000 K have been carried out using high speed photometry which suffers from variable extinction effects that start becoming important at periods of 15 minutes. In our survey we constantly monitor the sky brightness as well as one or more comparison stars. This is done through the same color filter, therefore minimizing adverse effects of differential extinction. The fact that the theoretical red edge should be around 8,000 K remains, but effects not included in the theory, especially convection-aulsation interaction, could explain it.
We report the analysis of 154 hours of nearly continuous high-speed photometric data on the pulsating DB white dwarf (DBV) GD 358 obtained during the Whole Earth Telescope (WET) run of May 1990. The Fourier transform (FT) of the light curve is dominated by power in the range from 1200 – 1700μHz with more than 180 significant peaks in the total transform. We also see significant power at the sums and differences of the dominant frequencies, indicating the importance of nonlinear behavior. We can use this data to obtain an accurate total stellar mass, and surface He layer mass. The implied surface He layer mass, if correct, provides a significant and surprising challenge to stellar evolution theory, as well as the theory of chemical mixing.
We are searching for pulsations in cool (< 6000 K) white dwarfs (WDs), hoping to apply asteroseismological techniques to improve our understanding of their structure and the physical processes inside them. This information is important as we use cool WDs to estimate the lower limit of the age of the Galactic disk. Within a spectroscopic and photometric survey of 110 cool WDs by Bergeron, Ruiz, & Legget, we find 28 candidates with appropriate effective temperatures, masses, and chemical compositions for possible pulsations in nonradial g modes with periods similar to those we observe in DAVs. So far, we have observed 4 candidates, but have found no evidence of large variation.
We present the preliminary results of our analysis of the precise radial velocity (RV) measurements of the roAp star HR1217. We have obtained over 2000 spectra of this star (54 hours of coverage) covering a complete rotation period using the 2-d coude echelle spectrograph of the McDonald Observatory’s 2.7m telescope. Our RV data show rotational modulation in both the amplitude and phase of the pulsations. The broad-band (covering 110 Å) RV semi-amplitudes of the f2 mode (=2.65 mHz) varied in the range of 25 m s–1 to 200 m s–1.
We have used the 2D-Coudé spectrograph of the 2.7-m telescope at McDonald Observatory at a resolution of 60,000. We use an iodine cell which provides us with permanent wavelength reference.
γ Equ was observed for a period of approximately 6 hours. The signal to noise ratio was variable due to the presence of clouds. A typical value for the “good” spectra is 80.
The use of a large detector provides us with complete spectral coverage from 5,000 to 6,000 Å (the region where I2 lines are most visible and useful as a wavelength reference). This allowed us to expand over our previous work analyzing the pulsations of γ Equulei through the use of spectroscopy.
The rapidly oscillating Ap stars (roAp) are a class of nonradially pulsating stars oscillating in low-degree modes with periods of 4–15 minutes. We have started a program to study the oscillations on several roAp stars using precise radial velocity (RV) measurements. The typical mean RV amplitude for the roAp stars we have observed is 50–400 ms−1, but this amplitude depends on the spectral region used for the measurement of the RV amplitude. A detailed line-by-line analysis reveals that the pulsational amplitude depends not only on atomic species, but on the line strength as well. For a given atomic species weak spectral lines exhibit a pulsational amplitude 10–100 times higher than for strong lines. The elemental effect can be understood in the context of the inhomogeneous distribution of elements known to occur on these stars and that is believed to result from the global dipole magnetic fields that are present. For instance, if an element is concentrated near the magnetic pole then it may have a higher RV amplitude than one that is distributed about the magnetic equator. The line strength effect is interpreted as arising from vertical structure to the pulsations since weaker lines are formed, on average, deeper in the atmosphere than stronger lines. Precise RV measurements may prove to be a powerful tool for probing both the vertical and horizontal structure of the pulsations in roAp stars.
We present precise stellar radial velocity (RV) measurements of the rapidly oscillating Ap (roAp) star 33 Lib taken in rapid succession over a 3-hr time span. A Fourier analysis of the data clearly shows the 8.2 min. pulsation period found previously by photometric investigations and gives a peak-to-peak (2K) amplitude of about 80 ms−1. We find, like in other roAp stars we have studied, that the RV amplitude depends on the spectral region used for measuring the pulsational RV amplitude and is as high as 57 ± 4.7 ms−1 in the region 5411–5500 Å and as low as 7 ± 3 ms−1 in the 5877–5976 Å region. An analysis of individual spectral lines show considerable scatter in the RV amplitude, ranging as high as 320 ms−1 and as low as 7 m−1. There is an overall trend of increasing RV amplitude with decreasing line strength. We also found that spectral lines due to nickel have a higher mean RV amplitude than chromium lines. We believe that the line strength variations result from the vertical atmospheric structure of the pulsations and that the elemental differences are related to the inhomogeneous distribution of elements known to occur on Ap stars. Precise stellar radial velocity studies of roAp stars may be a powerful tool for studying both the spatial (surface) and vertical structure to the pulsational velocity field.
The variability of CD-24 7599 (V=11.48 mag) was discovered by JCC during observing run XCOV7 of the Whole Earth Telescope (WET, Nather et al. 1990) network in February, 1992. The star was observed as an additional target and 117 hours of high-quality temporal spectroscopic observations were obtained.
Our analysis of these data revealed the presence of 7 independent pulsation modes between 27.0 and 38.1 cycles per day (313 – 441 μHz) with semiamplitudes of 2.1 – 10.2 milli-modulation amplitudes (mma). We showed that peaks at linear combination frequencies detected in the power spectra were not due to eigenmodes excited to visible amplitude by resonant mode coupling.
The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a narrow-band imaging, very wide field cosmological survey. It will last 5 years and will observe 8500 sq. deg. of the sky. There will be 54 contiguous narrow-band filters of 145Å FWHM, from 3,500 to 10,000Å. Two broad-band filters will be added at the extremes, UV and IR, plus the 3–g, r, and i– SDSS filters. Thus, J-PAS can be an important tool to search for new planetary nebulae (PNe) at the halo, increasing their numbers, because only 14 of them have been convincingly identified in the literature. Halo PNe are able to reveal precious information for the study of stellar evolution and the early chemical conditions of the Galaxy. The characteristic low continuum and intense emission lines of PNe make them good objects to be searched by J-PAS. Though covering a significantly smaller sky area, data from the ALHAMBRA survey were used to test our J-PAS strategy to search for PNe. Our first results are shown in this contribution.
We are trying to reduce the largest uncertainties in using white dwarf stars as Galactic chronometers by understanding the details of carbon crystalliazation that currently result in a 1–2 Gyr uncertainty in the ages of the oldest white dwarf stars. We expect the coolest white dwarf stars to have crystallized interiors, but theory also predicts hotter white dwarf stars, if they are massive enough, will also have some core crystallization. BPM 37093 is the first discovered of only a handful of known massive white dwarf stars that are also pulsating DAV, or ZZ Ceti, variables. Our approach is to use the pulsations to constrain the core composition and amount of crystallization. Here we report our analysis of 4 hours of continuous time series spectroscopy of BPM 37093 with Gemini South combined with simultaneous time-series photometry from Mt. John (New Zealand), SAAO, PROMPT, and Complejo Astronomico El Leoncito (CASLEO, Argentina).
A new radiation-driven wind solution called δ-slow was found by Curé et al. (2011) and it predicts a mass-loss rate and terminal velocity slower than the fast solution (m-CAK, Pauldrach et al. 1986). In this work, we present our first synthetic spectra based on the δ-slow solution for the wind of B supergiant (BSG) stars. We use the output of our hydrodynamical code HYDWIND as input in the radiative transport code FASTWIND (Puls et al. 2005). In order to obtain stellar and wind parameters, we try to reproduce the observed Hα, Hβ, Hγ, Hδ, Hei 4471, Hei 6678 and Heii 4686 lines. The synthetic profiles obtained with the new hydrodynamical solutions are in good agreement with the observations and could give us clues about the parameters involved in the radiation force.
To assess the effectiveness and safety of coblation in relieving inferior turbinate hypertrophy in children.
An observational cohort study was undertaken. The severity of allergic rhinitis and the severity and degree of nasal obstruction were assessed using subjective and clinical symptom grading tools, a visual analogue scale, and endoscopy. Any post-operative complications were noted at 1 week, and at 1, 3, 6 and 12 months post-operatively. Data from extended follow-up periods were included when available. The statistical significance of changes in parameter values was assessed using the Wilcoxon signed-rank test.
Thirty-two patients were recruited (mean age, 11.28 years; range, 6–17 years). Significant post-operative improvement (p < 0.001) was noted in the severity and degree of nasal obstruction. This improvement was maintained after a mean follow-up period of 10.5 months (range, 1 month to 4 years). No mucosal ulceration or adhesion was encountered. Minimal crusting was noted in 8.57 per cent of patients at 1-week follow up. Allergic rhinitis symptoms improved significantly.
Inferior turbinate reduction by coblation is an effective and safe procedure in children aged six years and older. The positive outcomes seem to be long-lasting.