Search

We report on the detailed characterization of the HD 77946 planetary system. HD 77946 is an F5 (M *  = 1.17 M⊙, R *  = 1.31 R⊙) star, which hosts a transiting planet recently discovered by NASA's Transiting Exoplanet Survey Satellite (TESS), classified as TOI-1778 b. Using TESS photometry, high-resolution spectroscopic data from HARPS-N, and photometry from CHEOPS , we measure the radius and mass from the transit and radial velocity observations, and find that the planet, HD 77946 b, orbits with period P b  =  |$6.527282_{-0.000020}^{+0.000015}$| d, has a mass of M b = 8.38 ± 1.32 M⊕, and a radius of |$R_{\rm b} = 2.705_{-0.081}^{+0.086}$| R⊕. From the combination of mass and radius measurements, and the stellar chemical composition, the planet properties suggest that HD 77946 b is a sub-Neptune with a ∼1  per cent H/He atmosphere. However, a degeneracy still exists between water-world and silicate/iron-hydrogen models, and even though interior structure modelling of this planet favours a sub-Neptune with a H/He layer that makes up a significant fraction of its radius, a water-world composition cannot be ruled out, as with |$T_{\rm eq}~= 1248^{+40}_{-38}~$| K, water may be in a supercritical state. The characterization of HD 77946 b, adding to the small sample of well-characterized sub-Neptunes, is an important step forwards on our journey to understanding planetary formation and evolution pathways. Furthermore, HD 77946 b has one of the highest transmission spectroscopic metrics for small planets orbiting hot stars, thus transmission spectroscopy of this key planet could prove vital for constraining the compositional confusion that currently surrounds small exoplanets. [ABSTRACT FROM AUTHOR]

Ninety eight newborn infants weighing less than 1500 g at birth and with gestational ages from 26 to 32 weeks were followed prospectively. They were grouped according to real time ultrasound scans in the neonatal period: infants in group A (n = 20) had periventricular haemorrhage (PVH) and normal ventricles; infants in group B (n = 26) had PVH and dilated ventricles (none with clinical hydrocephalus); and infants in group C, who formed the control group (n = 52), had no PVH and normal ventricles. At outpatient follow up a static image ultrasound scanner was used to measure the width of the lateral ventricles and brain hemispheres. The three groups of infants showed similar growth in occipitofrontal circumference, biparietal diameter, and brain hemispheres irrespective of a history of PVH or ventricular dilatation. The relation of ventricle size to biparietal diameter was similar in those infants in groups A (PVH alone) and C (controls) who had a good outcome. About a third (n = 8) of the infants in group B had persistent ventricular dilatation in relation to biparietal diameter and a poor outcome associated with developmental delay and cerebral palsy. By contrast, the remaining two thirds (n = 18) of the infants in group B who later had smaller ventricles in relation to biparietal diameter showed fewer neurodevelopmental sequelae. It is suggested that persistent ventricular dilatation in relation to biparietal diameter at follow up carries a bad prognosis, which might be due to brain atrophy. [ABSTRACT FROM AUTHOR]

Umbilical venous blood, and umbilical arterial blood pH, PO2, PCO2, and base excess were determined in 453 term infants at birth. The results indicate that umbilical venous blood pH, and umbilical arterial blood pH are significantly related to each another. Acidosis, as defined by an umbilical venous blood pH less than 7 X 27, is associated with a lower PO2, a raised PCO2, and a reduced buffer base when compared with PO2, PCO2, and buffer base associated with a normal pH (7 X 27-7 X 42), or alkalosis (pH greater than 7 X 42). The infant's condition at birth was recorded using modified Apgar scores, in which the gradings were vigorous (5-6), intermediate (3-4), or depressed (0-2). In the neonatal period, neurological abnormalities occurred in infants who had been in a depressed condition at birth in the presence of acidosis. Other infants, who had been in a depressed condition with a normal pH or alkalosis and the remaining infants who had an intermediate or a vigorous condition at birth, did not manifest neurological abnormalities in the neonatal period. Our findings suggest that measurement of umbilical venous blood pH, whose values correlate well with those of umbilical arterial blood pH, in infants who are in a depressed condition at birth improves the clinical assessment of the severity of asphyxia. [ABSTRACT FROM AUTHOR]

A cohort of 91 children from cryopreserved embryos and 83 control children who were conceived normally had their development assessed using the Griffiths's scales of mental development. The controls (81 singletons and two twins) of a similar age, sex, and social class were selected from siblings, cousins, and peers of the cryopreserved embryo group (68 singleton, 20 twins, and three triplets). Children from cryopreserved embryos had a lower mean birth weight and mean gestational age and a higher proportion were born by caesarean section. One child from the cryopreserved embryo group had Down's syndrome, three had squints, and four had conductive hearing loss while in the control children, six had squints, and nine had conductive hearing loss. In both groups, including the child with Down's syndrome, the mean Griffiths's quotient was greater than the standard 100. In the children from cryopreserved embryos, the singleton and multiple birth subgroups had statistically similar assessment results. The mean (SD) Griffiths's quotient was 105.69 (13.55) in children from cryopreserved embryos and 108.18 (9.80) in controls at a chronological age of 25.08 (12.86) and 29.19 (14.65) months respectively. Overall, the development in children from cryopreserved embryos did not cause concern though formal testing had highlighted small differences compared with other children conceived normally and of a similar social class. [ABSTRACT FROM AUTHOR]

A total of 91 children (68 singletons, 20 twins and three triplets) who were conceived from cryopreserved embryos between 27 December 1989 and 18 January 1994, and 83 normally conceived control children (81 singletons and two twins) of a similar age, sex and social class, were assessed for minor congenital anomalies and major congenital malformations. Their development was assessed using the Griffiths Scales of Mental Development. The incidence of minor congenital anomalies (31.9% in the cryopreserved embryo group and 21.7% in the controls) and major congenital malformations (3.3 and 2.4% respectively) in our two groups of children was statistically similar. The relative risk (odds ratio and 95% confidence interval) in the cryopreserved embryo group compared with the controls was 1.7 (0.8, 3.3) for minor congenital anomalies and 1.4 (0.2, 8.5) for major congenital malformations. The minor congenital anomalies were mostly naevi and haemangiomas. The major congenital malformations included Down's syndrome, Beckwith-Wiedemann syndrome and hypophosphataemic rickets in the cryopreserved embryo group and hydronephrosis and gastroschisis in the controls. The Griffiths assessment showed that children from the cryopreserved embryo group and the controls were functioning at a similar level. The mean Griffiths quotient and subquotient values were greater than the standard 100 in children with or without congenital abnormalities. These results in the cryopreserved embryo group are reassuring in that the minor congenital anomaly and major congenital malformation rates were similar to those in normally conceived children of a similar age, sex and social class and their development was not adversely affected by cryopreservation. [ABSTRACT FROM AUTHOR]