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Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
Our research group demonstrated that vitamin A restriction affected meat quality of Angus cross and Simmental steers. Therefore, the aim of this study is to highlight the genotype variations in response to dietary vitamin A levels. Commercial Angus and Simmental steers (n = 32 per breed; initial BW = 337.2 ± 5.9 kg; ~8 months of age) were fed a low-vitamin A (LVA) (1017 IU/kg DM) backgrounding diet for 95 days to reduce hepatic vitamin A stores. During finishing, steers were randomly assigned to treatments in a 2 × 2 factorial arrangement of genotype × dietary vitamin A concentration. The LVA treatment was a finishing diet with no supplemental vitamin A (723 IU vitamin A/kg DM); the control (CON) was the LVA diet plus supplementation with 2200 IU vitamin A/kg DM. Blood samples were collected at three time points throughout the study to analyze serum retinol concentration. At the completion of finishing, steers were slaughtered at a commercial abattoir. Meat characteristics assessed were intramuscular fat concentration, color, Warner-Bratzler shear force, cook loss and pH. Camera image analysis was used for determination of marbling, 12th rib back fat and longissimus muscle area (LMA). The LVA steers had lower (P < 0.001) serum retinol concentration than CON steers. The LVA treatment resulted in greater (P = 0.03) average daily gain than the CON treatment, 1.52 and 1.44 ± 0.03 kg/day, respectively; however, there was no effect of treatment on final BW, DM intake or feed efficiency. Cooking loss and yield grade were greater and LMA was smaller in LVA steers (P < 0.05). There was an interaction between breed and treatment for marbling score (P = 0.01) and percentage of carcasses grading United States Department of Agriculture (USDA) Prime (P = 0.02). For Angus steers, LVA treatment resulted in a 16% greater marbling score than CON (683 and 570 ± 40, respectively) and 27% of LVA Angus steers graded USDA Prime compared with 0% for CON. Conversely, there was no difference in marbling score or USDA Quality Grades between LVA and CON for Simmental steers. In conclusion, feeding a LVA diet during finishing increased marbling in Angus but not in Simmental steers. Reducing the vitamin A level of finishing diets fed to cattle with a high propensity to marble, such as Angus, has the potential to increase economically important traits such as marbling and quality grade without negatively impacting gain : feed or yield grade.
Background: There are few published reports on the safety and efficacy of stereoelectroencephalography (SEEG) in the presurgical evaluation of pediatric drug-resistant epilepsy. Our objective was to describe institutional experience with pediatric SEEG in terms of (1) insertional complications, (2) identification of the epileptogenic zone and (3) seizure outcome following SEEG-tailored resections. Methods: Retrospective review of 29 patients pediatric drug resistant epilepsy patients who underwent presurgical SEEG between 2005 – 2018. Results: 29 pediatric SEEG patients (15 male; 12.4 ± 4.6 years old) were included in this study with mean follow-up of 6.0 ± 4.1 years. SEEG-related complications occurred in 1/29 (3%)—neurogenic pulmonary edema. A total of 190 multi-contact electrodes (mean of 7.0 ± 2.5per patient) were implanted across 30 insertions which captured 437 electrographic seizures (mean 17.5 ± 27.6 per patient). The most common rationale for SEEG was normal MRI with surface EEG that failed to identify the EZ (16/29; 55%). SEEG-tailored resections were performed in 24/29 (83%). Engel I outcome was achieved following resections in 19/24 cases (79%) with 5.9 ± 4.0 years of post-operative follow-up. Conclusions: Stereoelectroencephalography in presurgical evaluation of pediatric drug-resistant epilepsy is a safe and effective way to identify the epileptogenic zone permitting SEEG-tailored resection.
Maternal mental health during pregnancy and postpartum predicts later emotional and behavioural problems in children. Even though most perinatal mental health problems begin before pregnancy, the consequences of preconception maternal mental health for children's early emotional development have not been prospectively studied.
We used data from two prospective Australian intergenerational cohorts, with 756 women assessed repeatedly for mental health problems before pregnancy between age 13 and 29 years, and during pregnancy and at 1 year postpartum for 1231 subsequent pregnancies. Offspring infant emotional reactivity, an early indicator of differential sensitivity denoting increased risk of emotional problems under adversity, was assessed at 1 year postpartum.
Thirty-seven percent of infants born to mothers with persistent preconception mental health problems were categorised as high in emotional reactivity, compared to 23% born to mothers without preconception history (adjusted OR 2.1, 95% CI 1.4–3.1). Ante- and postnatal maternal depressive symptoms were similarly associated with infant emotional reactivity, but these perinatal associations reduced somewhat after adjustment for prior exposure. Causal mediation analysis further showed that 88% of the preconception risk was a direct effect, not mediated by perinatal exposure.
Maternal preconception mental health problems predict infant emotional reactivity, independently of maternal perinatal mental health; while associations between perinatal depressive symptoms and infant reactivity are partially explained by prior exposure. Findings suggest that processes shaping early vulnerability for later mental disorders arise well before conception. There is an emerging case for expanding developmental theories and trialling preventive interventions in the years before pregnancy.
Young adults who are not in employment, education, or training (NEET) are at risk of long-term economic disadvantage and social exclusion. Knowledge about risk factors for being NEET largely comes from cross-sectional studies of vulnerable individuals. Using data collected over a 10-year period, we examined adolescent predictors of being NEET in young adulthood.
We used data on 1938 participants from the Victorian Adolescent Health Cohort Study, a community-based longitudinal study of adolescents in Victoria, Australia. Associations between common mental disorders, disruptive behaviour, cannabis use and drinking behaviour in adolescence, and NEET status at two waves of follow-up in young adulthood (mean ages of 20.7 and 24.1 years) were investigated using logistic regression, with generalised estimating equations used to account for the repeated outcome measure.
Overall, 8.5% of the participants were NEET at age 20.7 years and 8.2% at 24.1 years. After adjusting for potential confounders, we found evidence of increased risk of being NEET among frequent adolescent cannabis users [adjusted odds ratio (ORadj) = 1.74; 95% confidence interval (CI) 1.10–2.75] and those who reported repeated disruptive behaviours (ORadj = 1.71; 95% CI 1.15–2.55) or persistent common mental disorders in adolescence (ORadj = 1.60; 95% CI 1.07–2.40). Similar associations were present when participants with children were included in the same category as those in employment, education, or training.
Young people with an early onset of mental health and behavioural problems are at risk of failing to make the transition from school to employment. This finding reinforces the importance of integrated employment and mental health support programmes.
Childhood sexual abuse (CSA) has been shown to be a risk factor for personality disorder (PD). However, no previous studies have examined whether associations exist between sexual abuse and abnormal personality as measured both categorically and dimensionally. Such enquiry would more fully illuminate the impact of CSA on adult personality.
Using a large nationally representative sample, we set out to examine associations between CSA and categorically defined PD. We also examined associations between CSA and the five dimensions of personality (openness to experience, conscientiousness, extraversion, agreeableness and neuroticism). A total of 1520 young adults were interviewed to determine the prevalence of sexual abuse occurring before age 16 years. A dimensional measure of personality was completed by 1469 participants, and 1145 had an informant-based PD assessment.
PD was independently associated with repeated CSA [fully adjusted odds ratio (OR) 1.9, 95% confidence interval (CI) 1.1–3.4]. Repeated sexual abuse was also associated with higher neuroticism and lower agreeableness (p values for both <0.001). Adjusting for the effects of potential confounders and mediators, including earlier symptoms of anxiety and depression, had little impact on the strength of associations.
We conclude that repeated CSA is independently associated with categorically defined PD, and also with higher neuroticism and lower agreeableness. Our findings suggest that if a dimensional classification of PDs is adopted in future classification systems, there might be meaningful continuity with previous aetiological research conducted using the current categorical system.
Background. Adverse life events prior to episodes of depression are assumed to play a causal role. Earlier studies have, however, not adequately controlled for the potential confounding effects of previous depression.
Method. A two-phase study was nested within a six-wave population based cohort study of 1947 adolescents. Interviews at two assessment phases with the CIS-R and CIDI were used to generate ICD-10 diagnoses of depressive disorder. Life events with longer-term contextual threat were reported for the 6 months before first diagnosis and categorized on the basis of participant appraisal as negative and neutral/positive in effects. Previous depressive and anxiety symptoms were measured 6 months earlier.
Results. Pre-existing depressive and anxiety symptoms predicted later events, increasing three-fold the risks for both neutral/positive and negative events in females and increased seven-fold the risk of negative events in males. Life events in turn predicted the onset of depressive disorder independently of previous symptoms. Single negative events held an over five-fold elevated risk and multiple events an almost eight-fold higher risk. Personal threat and loss were associated with disorder in females but not males.
Conclusions. The findings are consistent with a causal role for life events in early episodes of depression. The association also reflects a reciprocal relationship in which earlier symptoms predict later events, perhaps as a result of an individual's attempts to change unfavourable social circumstances.
Conformal epitaxy is an epitaxial growth technique capable of yielding low dislocation density III-V films on Silicon. In this technique, the growth of the III-V material occurs parallel to the silicon substrate, from the edge of a previously deposited III-V seed, the vertical growth being stopped by an overhanging capping layer. As an example, conformal GaAs layers on Silicon, presenting dislocation densities below 105cm−2, have been obtained using selective vapor phase epitaxy. These layers have then been used as high quality GaAs on Si substrates for subsequent vertical MBE regrowth of active structures. In this paper, we report on the integration of surface-emitting microcavity LEDs with their silicon drivers using this conformal growth technique. The global technology concept and the design of the active structures are first presented. The compatibility of the conformal growth technique with CMOS technology is then checked: the impact of the integration process on the performances of the drivers is for example quantified. Characterisations of the high crystalline quality of the conformal layers and of the LEDs structures grown on it are then shown. The electro-optical characteristics of the LEDs on Si are finally compared to those of reference LEDs on GaAs substrates in order to prove the efficiency of the integration procedure.
Background. Reports of adolescent suicidal behaviour have
generally derived from clinical settings but population-based studies are
likely to provide a clearer epidemiological view.
Methods. Non-fatal suicidal behaviours were studied in 1699
15- to 16-year-old secondary school students at 44 schools in the state
Victoria, Australia. Self-reported episodes of
self-harm were characterized using items from the Beck Suicide Intent Scale.
Results. The 12 month weighted prevalence estimate for deliberate
self-harm was 5·1%. The commonest forms were self-laceration (1·7%),
self-poisoning (1·5%) and deliberate recklessness
(1·8%). Self-poisoning and self-laceration were commoner in girls.
prevalence of ‘true
suicide attempts’ was 0·2%. Most self-harmers did not perceive
as likely, plan self-harming episodes at length or inform others of the
Psychiatric morbidity had the strongest association with self-harm, an
which held for all subtypes. Antisocial behaviour
and substance abuse were associated with self-harm in girls but not boys.
activity was independently associated with self-harm in both genders.
Conclusions. Deliberate self-harm was common but the great
of episodes were not ‘true
suicide attempts’. It is, therefore, possible that attributable mortality
and morbidity may be
greater in self-harmers without definite suicidal intent.
The notion of a recursive causal graph is introduced, hopefully capturing the essential aspects of the path diagrams usually associated with recursive causal models. We describe the conditional independence constraints which such graphs are meant to embody and prove a theorem relating the fulfilment of these constraints by a probability distribution to a particular sort of factorisation. The relation of our results to the usual linear structural equations on the one hand, and to log-linear models, on the other, is also explained
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