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The astrophysical study of mass loss, both steady-state and transient, on the cool half of the HR diagram has implications both for the star itself and the conditions created around the star that can be hospitable or inimical to supporting life. Stellar coronal mass ejections (CMEs) have not been conclusively detected, despite the ubiquity with which their radiative counterparts in an eruptive event (flares) have been. I will review some of the different observational methods which have been used and possibly could be used in the future in the stellar case, emphasizing some of the difficulties inherent in such attempts. I will provide a framework for interpreting potential transient stellar mass loss in light of the properties of flares known to occur on magnetically active stars. This uses a physically motivated way to connect the properties of flares and coronal mass ejections and provides a testable hypothesis for observing or constraining transient stellar mass loss. Finally I will describe recent results using observations at low radio frequencies to detect stellar coronal mass ejections, and give updates on prospects using future facilities to make headway in this important area.
Soon after the discovery of hot Jupiters, it was suspected that interaction of these massive bodies with their host stars could give rise to observable signals. We discuss the observational evidence for star-planet interactions (SPI) of tidal and magnetic origin observed in X-rays. Hot Jupiters can significantly impact the activity of their host stars through tidal and magnetic interaction, leading to either increased or decreased stellar activity – depending on the internal structure of the host star and the properties of the hosted planet. We provide several examples of these interactions. In HD 189733, the strongest X-ray flares are preferentially seen in a very restricted range of planetary phases. Hot Jupiters, can also obscure the X-ray signal during planetary transits. Observations of this phenomena have led to the discovery of a thin upper atmospheres in HD 189733A. On the other hand, WASP-18 – an F6 star with a massive hot Jupiter, shows no signs of activity in X-rays or UV. Several age indicators (isochrone fitting, Li abundance) point to a young age (~0.5 – −1.0 Gyr) and thus significant activity was expected. In this system, tidal SPI between the star and the very close-in and massive planet appears to disrupt the surface shear layer and thus nullify the stellar activity.
Results of adulthood mental health of those born late-preterm (34 + 0–36 + 6 weeks + days of gestation) are mixed and based on national registers. We examined if late-preterm birth was associated with a higher risk for common mental disorders in young adulthood when using a diagnostic interview, and if this risk decreased as gestational age increased.
A total of 800 young adults (mean = 25.3, s.d. = 0.62 years), born 1985–1986, participated in a follow-up of the Arvo Ylppö Longitudinal Study. Common mental disorders (mood, anxiety and substance use disorders) during the past 12 months were defined using the Composite International Diagnostic Interview (Munich version). Gestational age was extracted from hospital birth records and categorized into early-preterm (<34 + 0, n = 37), late-preterm (34 + 0–36 + 6, n = 106), term (37 + 0–41 + 6, n = 617) and post-term (⩾42 + 0, n = 40).
Those born late-preterm and at term were at a similar risk for any common mental disorder [odds ratio (OR) 1.11, 95% confidence interval (CI) 0.67–1.84], for mood (OR 1.11, 95% CI 0.54–2.25), anxiety (OR 1.00, 95% CI 0.40–2.50) and substance use (OR 1.31, 95% CI 0.74–2.32) disorders, and co-morbidity of these disorders (p = 0.38). While the mental disorder risk decreased significantly as gestational age increased, the trend was driven by a higher risk in those born early-preterm.
Using a cohort born during the advanced neonatal and early childhood care, we found that not all individuals born preterm are at risk for common mental disorders in young adulthood – those born late-preterm are not, while those born early-preterm are at a higher risk. Available resources for prevention and intervention should be targeted towards the preterm group born the earliest.
Sleep disturbances are commonly reported in the psychosis prodrome, but rarely explored in relation to psychotic experiences.
To investigate the relationship between specific parasomnias (nightmares, night terrors and sleepwalking) in childhood and later adolescent psychotic experiences.
The sample comprised 4720 individuals from a UK birth cohort. Mothers reported on children's experience of regular nightmares at several time points between 2 and 9 years. Experience of nightmares, night terrors and sleepwalking was assessed using a semi-structured interview at age 12. Psychotic experiences were assessed at ages 12 and 18 using a semi-structured clinical interview.
There was a significant association between the presence of nightmares at 12 and psychotic experiences at 18 when adjusted for possible confounders and psychotic experiences at 12 (OR = 1.62, 95% CI 1.19–2.20). The odds ratios were larger for those who reported persistent psychotic experiences.
The presence of nightmares might be an early risk indicator for psychosis.
The aetiological pathways to borderline personality disorder (BPD) remain only partly elucidated. Retrospective research indicates that prenatal adversity may be an important early risk factor in the development of BPD. This requires corroboration with prospective longitudinal studies.
A community sample of 6050 mothers and their children (born between April 1991 and December 1992) were assessed. Maternal anxiety and depression and maternal alcohol and tobacco consumption were assessed during pregnancy (18 and 32 weeks gestation). Postnatal risks, including maladaptive parenting (suboptimal parenting and parent conflict), family adversity, maternal anxiety and depression and maternal alcohol and tobacco consumption, were assessed during early childhood. Internalizing and externalizing symptoms were assessed in late childhood. Trained psychologists interviewed children in late childhood to ascertain the presence of BPD (at least five probable/definite symptoms).
In unadjusted analyses, all prenatal risk factors (i.e. maternal alcohol and tobacco consumption and maternal anxiety and depression) were significantly associated with BPD. Following adjustment for sex, birthweight and postnatal exposure to anxiety and depression respectively, maladaptive parenting, family adversity and child's internalizing and externalizing symptoms, prenatal anxiety at 18 weeks gestation [odds ratio (OR) 1.57, 95% confidence interval (CI) 1.18–2.09] and depression at 18 weeks (OR 1.59, 95% CI 1.08–2.32) and 32 weeks (OR 1.57, 95% CI 1.14–2.18) gestation remained significantly associated with BPD.
This study provides prospective evidence of associations between prenatal adversities and BPD at 11–12 years. Prenatal anxiety and depression were independently associated with BPD, suggesting that they may exert direct effects on BPD during the prenatal period. This highlights the importance of programmes to reduce maternal stress during pregnancy.
Victims of bullying are at risk for psychotic experiences in early adolescence. It is unclear if this elevated risk extends into late adolescence. The aim of this study was to test whether bullying perpetration and victimization in elementary school predict psychotic experiences in late adolescence.
The current study is based on the Avon Longitudinal Study of Parents and Children (ALSPAC), a prospective community-based study. A total of 4720 subjects with bullying perpetration and victimization were repeatedly assessed between the ages of 8 and 11 years by child and mother reports. Suspected or definite psychotic experiences were assessed with the Psychosis-Like Symptoms semi-structured interview at age 18 years.
Controlling for child's gender, intelligence quotient at age 8 years, childhood behavioural and emotional problems, and also depression symptoms and psychotic experiences in early adolescence, victims [child report at 10 years: odds ratio (OR) 2.4, 95% confidence interval (CI) 1.6–3.4; mother report: OR 1.6, 95% CI 1.1–2.3], bully/victims (child report at 10 years: OR 3.1, 95% CI 1.7–5.8; mother: OR 2.9, 95% CI 1.7–5.0) and bullies (child report at 10 years: OR 4.9, 95% CI 1.3–17.7; mother: OR 1.2, 95% CI 0.46–3.1, n.s.) had a higher prevalence of psychotic experiences at age 18 years. Path analysis revealed that the association between peer victimization in childhood and psychotic experiences at age 18 years was only partially mediated by psychotic or depression symptoms in early adolescence.
Involvement in bullying, whether as victim, bully/victim or bully, may increase the risk of developing psychotic experiences in adolescence. Health professionals should ask routinely during consultations with children about their bullying of and by peers.
Affective instability (AI) is poorly defined but considered clinically important. The aim of this study was to examine definitions and measures of AI employed in clinical populations.
This study was a systematic review using the PRISMA guidelines. MEDLINE, Embase, PsycINFO, PsycArticles and Web of Science databases were searched. Also five journals were hand searched. Primary empirical studies involving randomized controlled trials (RCTs), non-RCTs, controlled before and after, and observational investigations were included. Studies were selected, data extracted and quality appraised. A narrative synthesis was completed.
A total of 11 443 abstracts were screened and 37 studies selected for final analysis on the basis that they provided a definition and measure of AI. Numbers of definitions for each of the terms employed in included studies were: AI (n = 7), affective lability (n = 6), affective dysregulation (n = 1), emotional dysregulation (n = 4), emotion regulation (n = 2), emotional lability (n = 1), mood instability (n = 2), mood lability (n = 1) and mood swings (n = 1); however, these concepts showed considerable overlap in features. A total of 24 distinct measures were identified that could be categorized as primarily measuring one of four facets of AI (oscillation, intensity, ability to regulate and affect change triggered by environment) or as measuring general emotional regulation.
A clearer definition of AI is required. We propose AI be defined as ‘rapid oscillations of intense affect, with a difficulty in regulating these oscillations or their behavioural consequences’. No single measure comprehensively assesses AI and a combination of current measures is required for assessment. A new short measure of AI that is reliable and validated against external criteria is needed.
Very preterm (VP) children are at particular risk for attention deficit/hyperactivity disorder (ADHD) of the inattentive subtype. It is unknown whether the neurodevelopmental pathways to academic underachievement are the same as in the general population. This study investigated whether middle childhood attention or hyperactivity/impulsivity problems are better predictors of VP adolescents' academic achievement.
In a geographically defined prospective whole-population sample of VP (<32 weeks gestation) and/or very low birth weight (<1500 g birth weight) (VLBW/VP; n = 281) and full-term control children (n = 286) in South Germany, ADHD subtypes were assessed at 6 years 3 months and 8 years 5 months using multiple data sources. Academic achievement was assessed at 13 years of age.
Compared with full-term controls, VLBW/VP children were at higher risk for ADHD inattentive subtype [6 years 3 months: odds ratio (OR) 2.8, p < 0.001; 8 years 5 months: OR 1.7, p = 0.020] but not for ADHD hyperactive-impulsive subtype (6 years 3 months: OR 1.4, p = 0.396; 8 years 5 months: OR 0.9, p = 0.820). Childhood attention measures predicted academic achievement in VLBW/VP and also full-term adolescents, whereas hyperactive/impulsive behaviour did not.
Attention is an important prerequisite for learning and predicts long-term academic underachievement. As ADHD inattentive subtype and cognitive impairments are frequent in VLBW/VP children, their study may help to identify the neurofunctional pathways from early brain development and dysfunction to attention problems and academic underachievement.
Retrospective studies have consistently indicated an association between maladaptive parenting and borderline personality disorder (BPD). This requires corroboration with prospective, longitudinal designs. We investigated the association between suboptimal parenting and parent conflict in childhood and BPD symptoms in late childhood using a prospective sample.
A community sample of 6050 mothers and their children (born between April 1991 and December 1992) were assessed. Mothers' family adversity was assessed during pregnancy and parenting behaviours such as hitting, shouting, hostility and parent conflict across childhood. Intelligence quotient (IQ) and DSM-IV Axis I diagnoses were assessed at 7–8 years. Trained psychologists interviewed children at 11 years (mean age 11.74 years) to ascertain BPD symptoms.
After adjustment for confounders, family adversity in pregnancy predicted BPD probable 1 to 2 adversities: odds ratio (OR)=1.34 [95% confidence interval (CI) 1.01–1.77]; >2 adversities: OR 1.99 (95% CI 1.34–2.94) and definite 1 to 2 adversities: OR 2.48 (95% CI 1.01–6.08) symptoms. Each point increase in the suboptimal parenting index predicted BPD probable: OR 1.13 (95% CI 1.05–1.23) and definite: OR 1.28 (95% CI 1.03–1.60) symptoms. Parent conflict predicted BPD probable: OR 1.19 (95% CI 1.06–1.34) and definite: OR 1.42 (95% CI 1.06–1.91) symptoms. Within the path analysis, the association between suboptimal parenting and BPD outcome was partially mediated by DSM-IV diagnoses and IQ at 7–8 years.
Children from adverse family backgrounds, who experience suboptimal parenting and more conflict between parents, have poor cognitive abilities and a DSM-IV diagnosis, are at increased risk of BPD symptoms at 11 years.
We have observed two local vibrational modes related to H bonded to N acceptors in ZnSe samples grown by metal organic vapor phase epitaxy. The modes have been seen in both infrared and Raman spectroscopy. The new mode seen at 3194 cm-1 is assigned to an N-H stretching vibrational mode and the mode found at 783 cm-1 is tentatively assigned to an N-H wagging vibrational mode. Polarized Raman spectroscopy was used to determine that the symmetry of the defect complex is C3v, which implies that the H atom is in either a bonding or anti-bonding position.
We have investigated the effect of annealing on hydrogen-related donors in crystals of InP using Hall effect, infrared absorption, and photorefractive gain measurements. Hydrogen is believed to be incorporated during growth, forming a donor complex around an indium vacancy with hydrogen saturating all four dangling bonds. By observing the local vibrational mode of the hydrogen complex using infrared absorption at 2316 cm−1 was possible to observe a decrease in the concentration of the hydrogen defect after annealing. In the undoped crystal, the disappearance of this defect is accompanied by a decrease in the free carrier concentration as measured by Hall effect. These changes are correlated with a decrease in the absorption due to Fe2+ centers, which form when donors are compensated by the neutral acceptor Fe3+. The existence of the hydrogen-related donor complex is further substantiated by photorefractive experiments using 1064nm irradiation on the iron doped samples. All of the measurements point to the role of hydrogen as a contributor to the net shallow donor concentration in InP crystals.
In order to explain the effects of hydrogen on the electrical properties of bulk indium phosphide crystals, we have performed a series of high temperature annealing studies with both undoped and iron-doped indium phosphide crystals. Our samples were annealed at 900°C for 6, 36, and 72 hours, respectively, under a phosphorus overpressure of five atmospheres. Samples were characterized at 10 K by Fourier transform infrared absorption spectroscopy which allowed us to measure the concentrations of both the Fe2+ and VIn-H4 defects simultaneously. Undoped samples were further characterized by the Hall effect measurements. We find in the iron-doped samples that the [Fe2+]/[Fe3+] ratio decreases gradually with increasing annealing time, indicating a reduction in the number of donors in the samples. In the undoped samples, annealing leads to a reduction of the free electron concentration accompanied by an increase in the 77 K mobility. The increase of the sample's mobility eliminates the possibility that the reduction of the free electron concentration is due to an increase in the concentration of the compensating acceptors. Our explanation for the observed behavior in all samples is that hydrogen acts as a donor and it diffuses out of the crystal during the annealing process. Based on our experimental data, we propose a calibration equation of [VIn-H4] = 4.2×1016 cm−1 × Absorbance (cm−1) which is used to correlate the hydrogen-vacancy complex concentrations with the changes of the VIn-H4 absorption peak in both the iron-doped and the undoped samples. Our results confirm the donor nature of the hydrogen-vacancy complex and provide strong evidence regarding the reduction mechanism of free carrier concentrations in bulk indium phosphide crystals during high temperature annealing under a phosphorus atmosphere.
Previous studies have suggested that impaired fetal and childhood growth
are associated with an increased risk of schizophrenia, but the
association of pre-adult growth with non-clinical psychotic symptoms
(psychosis-like symptoms) in children is not known.
To explore the associations of body size at birth and age 7.5 years with
childhood psychosis-like symptoms.
Prospective cohort of children followed up from birth to age 12: the
Data on 6000 singleton infants born after 37 weeks of gestation. A one
standard deviation increase in birth weight was associated with an 18%
reduction in the risk of definite psychosis-like symptoms after adjusting
for age and gestation (Odds ratio (OR) = 0.82, 95% CI = 0.73–0.92,
P = 0.001). This association was partly confounded by
maternal anthropometry, smoking during pregnancy, socioeconomic status
and IQ. A similar association was seen for birth length and
psychosis-like symptoms, which disappeared after controlling for birth
weight. There was little evidence for an association of 7-year height or
adiposity with psychosis-like symptoms.
Measures of impaired fetal, but not childhood, growth are associated with
an increased risk of psychosis-like symptoms in 12-year-olds.
Non-clinical psychosis-like symptoms (PLIKS) occur in about 15% of the population. It is not clear whether adverse events during early development alter the risk of developing PLIKS. We aimed to examine whether maternal infection, diabetes or pre-eclampsia during pregnancy, gestational age, perinatal cardiopulmonary resuscitation or 5-min Apgar score were associated with development of psychotic symptoms during early adolescence.
A longitudinal study of 6356 12-year-old adolescents who completed a semi-structured interview for psychotic symptoms in the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Prenatal and perinatal data were obtained from obstetric records and maternal questionnaires completed during pregnancy.
The presence of definite psychotic symptoms was associated with maternal infection during pregnancy [adjusted odds ratio (OR) 1.44, 95% confidence interval (CI) 1.11–1.86, p=0.006], maternal diabetes (adjusted OR 3.43, 95% CI 1.14–10.36, p=0.029), need for resuscitation (adjusted OR 1.50, 95% CI 0.97–2.31, p=0.065) and 5-min Apgar score (adjusted OR per unit decrease 1.30, 95% CI 1.12–1.50, p<0.001). None of these associations were mediated by childhood IQ score. Most associations persisted, but were less strong, when including suspected symptoms as part of the outcome. There was no association between PLIKS and gestational age or pre-eclampsia.
Adverse events during early development may lead to an increased risk of developing PLIKS. Although the status of PLIKS in relation to clinical disorders such as schizophrenia is not clear, the similarity between these results and findings reported for schizophrenia indicates that future studies of PLIKS may help us to understand how psychotic experiences and clinical disorders develop throughout the life-course.
The combination of spatial and spectral resolution allow us to use Chandra in the study regions of massive star formation which had been inaccessible even from the ground until the last decade. IRAC and MIPS data from Spitzer can be combined with the X–ray data to provide insight into the presence of a disk and the activity of the star. The total package allows us to better understand the evolution of the clusters. We have an ongoing program to study several young star forming clusters including distant clusters between 1-3 kpc which support O stars, RCW 38, NGC 281 and RCW 108 and well as clusters within a kpc including IRAS 20050+2720 and NGC 1579, which is a small cluster centered on the Be star LkHα101 and is of uncertain distance although the X-ray data help us refine the current distance estimates. Given the space constraints we only discuss RCW 108 below.
ANCHORS is a web based archive of all the point sources observed during Chandra observations of regions of star formation. It is designed to aid both the X-ray astronomer with a desire to compare X-ray datasets and the star formation astronomer wishing to compare stars across the spectrum. For some 50 Chandra fields, yielding 10000+ sources, the database contains X-ray source properties including position, net count rates, flux, hardness ratios, lightcurve statistics and plots.
Objectives: This study assesses the
implications and cost-effectiveness of extending the role of midwives to
include the routine (24-hour) examination of the healthy newborn usually
carried out by junior doctors.
Forty-seven children with non-organic failure to thrive (NOFT) were identified from a whole-population survey of children's growth and development. A significant proportion (N=17) of these 47 children were found to have oral-motor dysfunction (OMD) identified using a previously validated assessment tool. NOFT children with OMD and those with normal oral-motor function (N=30) were compared in order to ascertain whether there were any neurodevelopmental differences which might explain this finding. We hypothesized that children with OMD might have a subtle neurodevelopmental disorder. Few psychosocial variables discriminated the two groups. However, cognitive stimulation within the home and cognitive-growth fostering during mealtimes was much poorer for children with OMD. Some evidence has suggested that NOFT children with OMD may be ‘biologically’ more vulnerable from birth. We suggest that the continued use of the term ‘non-organic’ to describe failure to thrive in such children is questionable and requires redefining.
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