To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The Children of the Twins Early Development Study (CoTEDS) is a new prospective children-of-twins study in the UK, designed to investigate intergenerational associations across child developmental stages. CoTEDS will enable research on genetic and environmental factors that underpin parent–child associations, with a focus on mental health and cognitive-related traits. Through CoTEDS, we will have a new lens to examine the roles that parents play in influencing child development, as well as the genetic and environmental factors that shape parenting behavior and experiences. Recruitment is ongoing from the sample of approximately 20,000 contactable adult twins who have been enrolled in the Twins Early Development Study (TEDS) since infancy. TEDS twins are invited to register all offspring to CoTEDS at birth, with 554 children registered as of May 2019. By recruiting the second generation of TEDS participants, CoTEDS will include information on adult twins and their offspring from infancy. Parent questionnaire-based data collection is now underway for 1- and 2-year-old CoTEDS infants, with further waves of data collection planned. Current data collection includes the following primary constructs: child mental health, temperament, language and cognitive development; parent mental health and social relationships; parenting behaviors and feelings; and other socioecological factors. Measurement tools have been selected with reference to existing genetically informative cohort studies to ensure overlap in phenotypes measured at corresponding stages of development. This built-in study overlap is intended to enable replication and triangulation of future analyses across samples and research designs. Here, we summarize study protocols and measurement procedures and describe future plans.
This research investigates the self-reported perceptions, readiness and psychological wellbeing of 15 male primary school students prior to transitioning to a secondary boarding school (S1) located away from home and family. A mixed-methods approach was used (i.e., online questionnaire and focus group), and findings indicate that while participants were apprehensive about expectations, study and encountering new technology at boarding school, all viewed the impending transition to S1 as a positive opportunity in their educational journey. Participants reported academic motivation and self-regulation above the norm; however, both questionnaire and focus group data indicated their academic self-perception was low. Levels of reported psychological distress were low, with symptoms associated with emotional problems, conduct problems, hyperactivity, peer problems, prosocial behaviour and overall total difficulties all found to be within the normal range. Indicators of life satisfaction and protective factors associated with resilience were similarly found to be within the normal range. Four major themes and eight subthemes emerged from the qualitative data, including: (1) enthusiasm (i.e., confidence, sadness); (2) opportunity (i.e., new experiences and choices, friendships); (3) anchor points (i.e., older siblings, orientation); and (4) expectations (i.e., study, technology). The findings of this study add to the literature encouraging staff in boarding schools to view transition through the lens of the early to mid-adolescence developmental period and the emergence of co-occurring innate psychological needs – in particular, the desire for competence, autonomy and relatedness. Strengths and limitations of this study are presented.
Around the year 1500, the ancient maritime republic of Venice surpassed all the other states of renais-r sance Italy in wealth and power. For nearly a thousand years, the Venetians had enjoyed continual economic and political success, transforming their original scattered settlements on the lagoon islands into the splendid capital of an empire extending from the Greek islands to the rich cities of Lombardy. The patrician ruling caste of the republic consequently thought of itself as invincible and so was completely unprepared for the disastrous events of the war of the League of Cambrai.
The manuscript diary of the patrician Girolamo Priuli reveals the hidden background of one of the decisive events in the contest between Venice and the great European coalition of Cambrai. The defeat of Agnadello in May 1509 shattered the armies of the republic and threatened the metropolis itself with conquest. One after another the towns of the Veneto voluntarily opened their gates to the invaders, and finally, early in June, Padua fell to the Austrian emperor. Only five weeks after this culminating disaster, however, the Venetians recaptured the city by a sudden coup and so changed the course of the war. When the allies of Cambrai failed to regain Padua by a prolonged siege, the League broke up, and Venice could deal with each of its enemies in turn. By 1515, the republic was able to make peace with its dominions nearly intact.
The deformation of elementary fluid volumes by velocity gradients is a key process for scalar mixing, chemical reactions and biological processes in flows. Whilst fluid deformation in unsteady, turbulent flow has gained much attention over the past half-century, deformation in steady random flows with complex structure – such as flow through heterogeneous porous media – has received significantly less attention. In contrast to turbulent flow, the steady nature of these flows constrains fluid deformation to be anisotropic with respect to the fluid velocity, with significant implications for e.g. longitudinal and transverse mixing and dispersion. In this study we derive an ab initio coupled continuous-time random walk (CTRW) model of fluid deformation in random steady three-dimensional flow that is based upon a streamline coordinate transform which renders the velocity gradient and fluid deformation tensors upper triangular. We apply this coupled CTRW model to several model flows and find that these exhibit a remarkably simple deformation structure in the streamline coordinate frame, facilitating solution of the stochastic deformation tensor components. These results show that the evolution of longitudinal and transverse fluid deformation for chaotic flows is governed by both the Lyapunov exponent and power-law exponent of the velocity probability distribution function at small velocities, whereas algebraic deformation in non-chaotic flows arises from the intermittency of shear events following similar dynamics as that for steady two-dimensional flow.
We study the mixing dynamics of solute blobs in the flow through saturated heterogeneous porous media. As the solute plume is advected through a heterogeneous porous medium it suffers a series of deformations that determine its mixing with the ambient fluid through diffusion. Key questions are the relation between the spatial disorder and the mixing dynamics and the effect of the initial solute distribution. To address these questions, we formulate the advection–diffusion problem in a coordinate system that moves and rotates along streamlines of the steady flow field. The impact of the medium heterogeneity is quantified systematically within a stochastic modelling approach. For a simple shear flow, the maximum concentration of a blob decays asymptotically as
. For heterogeneous porous media, the mixing of the solute blob is determined by the random sampling of flow and deformation heterogeneity along trajectories, a mechanism different from persistent shear. We derive explicit perturbation theory expressions for stretching-enhanced solute mixing that relate the medium structure and mixing behaviour. The solution is valid for moderate heterogeneity. The random sampling of shear along trajectories leads to a
decay of the maximum concentration as opposed to an equivalent homogeneous medium, for which it decays as
We have found that 4 new, bright IRAS quasars, out of 7 observed, have strong, non-variable, wavelength-dependent polarization. Three show degrees of polarization, pλ, increasing from infrared to UV wavelengths (Fig. 1), which implies a combination of a polarized, scattered spectrum and a much redder, unpolarized spectrum. Detailed IR and optical polarimetry and spectrophotometry of one, IRAS 13349+2438 (Wills et al.), shows a polarized flux spectrum, pλxFλ, (continuum and Pa α, Hα, and Hβ broad hydrogen lines) typical of unreddened, luminous quasars. This suggests that the path of scattered light from a central, luminous quasar is low in dust and that the polarization of the scattered spectrum is wavelength independent. The latter is most easily explained by electron scattering although the data do not exclude dust scattering. When this polarized flux spectrum is subtracted from the total spectrum, we are left with a very reddened line and continuum spectrum, E(B-V) = 0.3 to 0.7, which we attribute to the same luminous quasar seen through a thick dusty torus. The angle of polarization is parallel to the major axis of the r-band image, presumed to be that of the host galaxy. If the torus is in the plane of the galaxy, the axial ratio suggests a viewing angle of 40° to the plane of the torus. Fig. 2 illustrates the geometry. The appearance of the quasar at optical and UV wavelengths will depend strongly on viewing angle, suggesting that present samples of quasars selected by colours, optical flux density, or quasi-stellar appearance, may be seriously biased, with important consequences for studies of the space density and evolution of AGN.
This study examined indicators of mental health, as well as strengths and difficulties, as reported by same-age boarding and non-boarding students spanning four time points over a 2-year period as they transitioned from primary to boarding school in Western Australia (i.e., at the end of Grade 7, beginning of Grade 8, end of Grade 8, and end of Grade 9). It presents data taken from a larger longitudinal quantitative study, which included 76 male and 74 female boarding students while they were in Grades 7 to 9. Findings indicate that boarding students and non-boarding students reported significant increases in depression, anxiety, as well as emotional symptoms and hyperactivity over time, and reported significant decreases in prosocial behaviour. However, examining the boarder × time interaction, boarding students reported significantly higher levels of anxiety and stress at the end of Grade 8 compared to non-boarding students. No significant difference over time was found in depressive symptomatology between boarding and non-boarding students, whereas at the beginning of Grade 8 and end of Grade 9, boarding students reported significantly higher emotional symptoms than non-boarding students. These findings are discussed in terms of the boarding school context and possible considerations for prevention and practice are presented.
Anxiety disorders are common, and cognitive–behavioural therapy (CBT) is a first-line treatment. Candidate gene studies have suggested a genetic basis to treatment response, but findings have been inconsistent.
To perform the first genome-wide association study (GWAS) of psychological treatment response in children with anxiety disorders (n = 980).
Presence and severity of anxiety was assessed using semi-structured interview at baseline, on completion of treatment (post-treatment), and 3 to 12 months after treatment completion (follow-up). DNA was genotyped using the Illumina Human Core Exome-12v1.0 array. Linear mixed models were used to test associations between genetic variants and response (change in symptom severity) immediately post-treatment and at 6-month follow-up.
No variants passed a genome-wide significance threshold (P=5×10–8) in either analysis. Four variants met criteria for suggestive significance (P<5×10–6) in association with response post-treatment, and three variants in the 6-month follow-up analysis.
This is the first genome-wide therapygenetic study. It suggests no common variants of very high effect underlie response to CBT. Future investigations should maximise power to detect single-variant and polygenic effects by using larger, more homogeneous cohorts.
We report results from a program of near-infrared spectroscopic observations of the H2 emission from planetary nebulae, being carried out at McDonald Observatory using an InSb array-detector spectrometer. Our observations employ both high spatial resolution (3″ diameter aperture) and high spectral resolution (λ/Δλ = 200–600), thus avoiding potential problems with line blending and spatial registration. These observations provide simultaneous measurements of H I recombination lines and H2 emission lines, thus accurately defining the relative extent and distribution of the ionized vs. molecular material. One-dimensional cuts through the compact planetary nebulae BD+30 3639 and Hubble 12, taken along east-west and north-south axes through the nebular centers, show that the H2 emission is concentrated in a ring or shell outside the ionized nebular core. The angular extent of the H2 emission in Hb 12, with a characteristic diameter of about 8–10″ arc seconds, is strikingly larger than the dimensions of the ionized core, which is less than 2″ in diameter.
Recently, Chang et. al. (1992) and Carlsson, Rutten and Shchukina (1992) (CRS) demonstrated the non-LTE formation mechanism behind the 12 μm Mg I emission lines (6g–7h, 6h–7i) observed in the solar spectrum (Murcray et. al., 1981). CRS stress the generality of this mechanism showing that it is a natural consequence of the recombination flow from the large Mg II reservoir through the Rydberg levels of Mg I. We have noted the close parallel between Mg I in the solar atmosphere and Mg II in the atmospheres of B stars (where Mg III plays the role of the reservoir) and investigated the operation of this mechanism in high-ℓ infrared transitions of Mg II. We have employed a 58 level Mg II atom including all energy levels through n = 25 and a total of 491 linearized radiative transitions. The coupled equations of radiative transfer and statistical equilibrium were solved with the MULTI code in its local operator form (Carlsson, 1992).
Convective motions in the photospheres of the Sun and solar-type stars can be studied using spectral line asymmetries via line bisectors and line shifts. Over the past few years there has been an improvement in the precision of the line positions for Fe I, CO and OH. These improved positions can be combined with recent high resolution infrared spectra of the Sun to examine how their convective line asymmetries behave with respect to observable line parameters, such as wavenumber and depth. We have completed a survey of convective line shifts for over 650 Fe I lines, 1320 CO lines and 80 OH lines, between 0.9 and 11 μm. The behavior of the distributions of these features, with respect to observed characteristics, is examined. The use of different species allows for an exploration of convective motions at different levels in the solar atmosphere. The large size of the sample allows for a more complete statistical understanding of the distributions. This work complements surveys of line asymmetries in the visible region of the Solar spectrum, and provides a foundation for further studies of convective motions in the spectra of other stars.
We compare observed fluxes from the ultraviolet (IUE) through J and K with recent Kurucz model atmospheres to determine a temperature for the F5 lb supergiant α Per. The two most important advances in this study as compared with previous work are the use of well calibrated ultraviolet fluxes and the use of models with an appropriate microturbulence.
We previously reported an association between 5HTTLPR genotype and
outcome following cognitive–behavioural therapy (CBT) in child anxiety
(Cohort 1). Children homozygous for the low-expression short-allele
showed more positive outcomes. Other similar studies have produced mixed
results, with most reporting no association between genotype and CBT
To replicate the association between 5HTTLPR and CBT outcome in child
anxiety from the Genes for Treatment study (GxT Cohort 2,
n = 829).
Logistic and linear mixed effects models were used to examine the
relationship between 5HTTLPR and CBT outcomes. Mega-analyses using both
cohorts were performed.
There was no significant effect of 5HTTLPR on CBT outcomes in Cohort 2.
Mega-analyses identified a significant association between 5HTTLPR and
remission from all anxiety disorders at follow-up (odds ratio 0.45,
P = 0.014), but not primary anxiety disorder
The association between 5HTTLPR genotype and CBT outcome did not
replicate. Short-allele homozygotes showed more positive treatment
outcomes, but with small, non-significant effects. Future studies would
benefit from utilising whole genome approaches and large, homogenous
Diurnal preference is an individual's preference for daily activities and sleep timing and is strongly correlated with the underlying circadian clock and the sleep-wake cycle validating its use as an indirect circadian measure in humans. Recent research has implicated DNA methylation as a mechanism involved in the regulation of the circadian clock system in humans and other mammals. In order to evaluate the extent of epigenetic differences associated with diurnal preference, we examined genome-wide patterns of DNA methylation in DNA from monozygotic (MZ) twin-pairs discordant for diurnal preference. MZ twins were selected from a longitudinal twin study designed to investigate the interplay of genetic and environmental factors in the development of emotional and behavioral difficulties. Fifteen pairs of MZ twins were identified in which one member scored considerably higher on the Horne–Ostberg Morningness–Eveningness Questionnaire (MEQ) than the other. Genome-wide DNA methylation patterns were assessed in twins’ buccal cell DNA using the Illumina Infinium HumanMethylation450 BeadChips. Quality control and data pre-processing was undertaken using the wateRmelon package. Differentially methylated probes (DMPs) were identified using an analysis strategy taking into account both the significance and the magnitude of DNA methylation differences. Our data indicate that DNA methylation differences are detectable in MZ twins discordant for diurnal preference. Moreover, downstream gene ontology (GO) enrichment analysis on the top-ranked diurnal preference associated DMPs revealed significant enrichment of pathways that have been previously associated with circadian rhythm regulation, including cell adhesion processes and calcium ion binding.