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We develop rapid chemical vapor sensors and micro gas chromatography (μGC) analyzers based on the optofluidic ring resonator (OFRR). An OFRR is a micro-sized thin-walled glass capillary; the circular cross-section of the capillary acts as an optical ring resonator while the whispering gallery modes or circulating waveguide modes (WGMs) supported by the ring resonator interact with the vapor samples passing through the capillary. The OFRR interior surface is coated with a vapor-sensitive polymer. The analyte and polymer interaction causes the polymer refractive index (RI) and the thickness to change, which is detected as a WGM spectral shift. Owing to the excellent fluidics, the OFRR vapor sensor exhibits sub-second detection and recovery time with a flow rate of 1 mL/min. On-column separation and detection in the OFRR based μGC system is also demonstrated, showing efficient separation of vapor mixtures and presenting highly reproducible retention time for the individual analyte. Compared to the conventional GC system, the OFRR μGC has the advantage of small size, rapid response, and high selectivity over a short length of column.
Anecdotal evidence suggests the use of bolus tube feeding is increasing in long term home enteral tube feed (HETF) patients. A cross-sectional survey to assess the prevalence of bolus tube feeding and to characterise these patients was undertaken. Dietitians from 10 centres across the UK collected data on all adult HETF patients on the dietetic caseload receiving bolus tube feeding, (n=604, 60% male, age 58years). Demographic data, reasons for tube and bolus feeding, tube and equipment types, feeding method and patients’ complete tube feeding regimens were recorded. Over a third of patients receiving HETF used bolus feeding (37%). Patients were long-term tube fed (4.1years tube feeding, 3.5years bolus tube feeding), living at home (71%) and sedentary (70%). The majority were head and neck cancer patients (22%) who were significantly more active (79%) and lived at home (97%), while those with cerebral palsy (12%) were typically younger (age 31years) but sedentary (94%). Most patients used bolus feeding as their sole feeding method (46%), because it was quick and easy to use, as a top up to oral diet or to mimic meal times. Importantly, oral nutritional supplements (ONS) were used for bolus feeding in 85% of patients, with 51% of these being compact-style ONS (2.4kcal/ml, 125ml). This survey shows that bolus tube feeding is common amongst UK HETF patients, is used by a wide variety of patient groups and can be adapted to meet the needs of a variety of patients, clinical conditions, nutritional requirements and lifestyles.
We describe the design and deployment of GREENBURST, a commensal Fast Radio Burst (FRB) search system at the Green Bank Telescope. GREENBURST uses the dedicated L-band receiver tap to search over the 960–1 920 MHz frequency range for pulses with dispersion measures out to
. Due to its unique design, GREENBURST is capable of conducting searches for FRBs when the L-band receiver is not being used for scheduled observing. This makes it a sensitive single pixel detector capable of reaching deeper in the radio sky. While single pulses from Galactic pulsars and rotating radio transients will be detectable in our observations, and will form part of the database we archive, the primary goal is to detect and study FRBs. Based on recent determinations of the all-sky rate, we predict that the system will detect approximately one FRB for every 2–3 months of continuous operation. The high sensitivity of GREENBURST means that it will also be able to probe the slope of the FRB fluence distribution, which is currently uncertain in this observing band.
A power MOSFET-based push–pull configuration nanosecond-pulse generator has been designed, constructed, and characterized to permeabilize cells for biological and medical applications. The generator can deliver pulses with durations ranging from 80 ns up to 1 µs and pulse amplitudes up to 1.4 kV. The unit has been tested for in vitro experiments on a medulloblastoma cell line. Following the exposure of cells to 100, 200, and 300 ns electric field pulses, permeabilization tests were carried out, and viability tests were conducted to verify the performance of the generator. The maximum temperature rise of the biological load was also calculated based on Joule heating energy conservation and experimental validation. Our results indicate that the developed device has good capabilities to achieve well-controlled electro-manipulation in vitro.
A 2018 workshop on the White Mountain Apache Tribe lands in Arizona examined ways to enhance investigations into cultural property crime (CPC) through applications of rapidly evolving methods from archaeological science. CPC (also looting, graverobbing) refers to unauthorized damage, removal, or trafficking in materials possessing blends of communal, aesthetic, and scientific values. The Fort Apache workshop integrated four generally partitioned domains of CPC expertise: (1) theories of perpetrators’ motivations and methods; (2) recommended practice in sustaining public and community opposition to CPC; (3) tactics and strategies for documenting, investigating, and prosecuting CPC; and (4) forensic sedimentology—uses of biophysical sciences to link sediments from implicated persons and objects to crime scenes. Forensic sedimentology served as the touchstone for dialogues among experts in criminology, archaeological sciences, law enforcement, and heritage stewardship. Field visits to CPC crime scenes and workshop deliberations identified pathways toward integrating CPC theory and practice with forensic sedimentology’s potent battery of analytic methods.
The Erasmus Plus programme ‘Innovative Education and Training in high power laser plasmas’, otherwise known as PowerLaPs, is described. The PowerLaPs programme employs an innovative paradigm in that it is a multi-centre programme where teaching takes place in five separate institutes with a range of different aims and styles of delivery. The ‘in class’ time is limited to four weeks a year, and the programme spans two years. PowerLaPs aims to train students from across Europe in theoretical, applied and laboratory skills relevant to the pursuit of research in laser–plasma interaction physics and inertial confinement fusion (ICF). Lectures are intermingled with laboratory sessions and continuous assessment activities. The programme, which is led by workers from the Technological Educational Institute (TEI) of Crete, and supported by co-workers from the Queen’s University Belfast, the University of Bordeaux, the Czech Technical University in Prague, Ecole Polytechnique, the University of Ioannina, the University of Salamanca and the University of York, has just completed its first year. Thus far three Learning Teaching Training (LTT) activities have been held, at the Queen’s University Belfast, the University of Bordeaux and the Centre for Plasma Physics and Lasers (CPPL) of TEI Crete. The last of these was a two-week long Intensive Programme (IP), while the activities at the other two universities were each five days in length. Thus far work has concentrated upon training in both theoretical and experimental work in plasma physics, high power laser–matter interactions and high energy density physics. The nature of the programme will be described in detail and some metrics relating to the activities carried out to date will be presented.
The Commensal Real-time Australian Square Kilometre Array Pathfinder Fast Transients survey is the first extensive astronomical survey using phased array feeds. Since January 2017, it has been searching for fast radio bursts in fly’s eye mode. Here, we present a calculation of the sensitivity and total exposure of the survey that detected the first 20 of these bursts, using the pulsars B1641-45 and B0833-45 as calibrators. The beamshape, antenna-dependent system noise, and the effects of radio-frequency interference and fluctuations during commissioning are quantified. Effective survey exposures and sensitivities are calculated as a function of the source counts distribution. Statistical ‘stat’ and systematics ‘sys’ effects are treated separately. The implied fast radio burst rate is significantly lower than the 37 sky−1 day−1 calculated using nominal exposures and sensitivities for this same sample by Shannon et al. (2018). At the Euclidean (best-fit) power-law index of −1.5 (−2.2), the rate is
(sys) ± 3.6 (stat) sky−1 day−1 (
(sys) ± 2.8 (stat) sky−1 day−1) above a threshold of 56.6 ± 6.6(sys) Jy ms (40.4 ± 1.2(sys) Jy ms). This strongly suggests that these calculations be performed for other FRB-hunting experiments, allowing meaningful comparisons to be made between them.
In the past few years, there has been an unprecedented increase in the number of forcibly displaced migrants worldwide, of which a substantial proportion is refugees and asylum seekers. Refugees and asylum seekers may experience high levels of psychological distress, and show high rates of mental health conditions. It is therefore timely and particularly relevant to assess whether current evidence supports the provision of psychosocial interventions for this population. We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) assessing the efficacy and acceptability of psychosocial interventions compared with control conditions (treatment as usual/no treatment, waiting list, psychological placebo) aimed at reducing mental health problems in distressed refugees and asylum seekers.
We used Cochrane procedures for conducting a systematic review and meta-analysis of RCTs. We searched for published and unpublished RCTs assessing the efficacy and acceptability of psychosocial interventions in adults and children asylum seekers and refugees with psychological distress. Post-traumatic stress disorder (PTSD), depressive and anxiety symptoms at post-intervention were the primary outcomes. Secondary outcomes include: PTSD, depressive and anxiety symptoms at follow-up, functioning, quality of life and dropouts due to any reason.
We included 26 studies with 1959 participants. Meta-analysis of RCTs revealed that psychosocial interventions have a clinically significant beneficial effect on PTSD (standardised mean difference [SMD] = −0.71; 95% confidence interval [CI] −1.01 to −0.41; I2 = 83%; 95% CI 78–88; 20 studies, 1370 participants; moderate quality evidence), depression (SMD = −1.02; 95% CI −1.52 to −0.51; I2 = 89%; 95% CI 82–93; 12 studies, 844 participants; moderate quality evidence) and anxiety outcomes (SMD = −1.05; 95% CI −1.55 to −0.56; I2 = 87%; 95% CI 79–92; 11 studies, 815 participants; moderate quality evidence). This beneficial effect was maintained at 1 month or longer follow-up, which is extremely important for populations exposed to ongoing post-migration stressors. For the other secondary outcomes, we identified a non-significant trend in favour of psychosocial interventions. Most evidence supported interventions based on cognitive behavioural therapies with a trauma-focused component. Limitations of this review include the limited number of studies collected, with a relatively low total number of participants, and the limited available data for positive outcomes like functioning and quality of life.
Considering the epidemiological relevance of psychological distress and mental health conditions in refugees and asylum seekers, and in view of the existing data on the effectiveness of psychosocial interventions, these interventions should be routinely made available as part of the health care of distressed refugees and asylum seekers. Evidence-based guidelines and implementation packages should be developed accordingly.
Mini-sabbaticals are formal short-term training and educational experiences away from an investigator’s home research unit. These may include rotations with other research units and externships at government research or regulatory agencies, industry and non-profit programs, and training and/or intensive educational programs. The National Institutes of Health have been encouraging training institutions to consider offering mini-sabbaticals, but given the newness of the concept, limited data are available to guide the implementation of mini-sabbatical programs. In this paper, we review the history of sabbaticals and mini-sabbaticals, report the results of surveys we performed to ascertain the use of mini-sabbaticals at Clinical and Translational Science Award hubs, and consider best practice recommendations for institutions seeking to establish formal mini-sabbatical programs.
Anxiety symptoms gradually emerge during childhood and adolescence. Individual differences in behavioral inhibition (BI), an early-childhood temperament, may shape developmental paths through which these symptoms arise. Cross-sectional research suggests that level of early-childhood BI moderates associations between later anxiety symptoms and threat-related amygdala–prefrontal cortex (PFC) circuitry function. However, no study has characterized these associations longitudinally. Here, we tested whether level of early-childhood BI predicts distinct evolving associations between amygdala–PFC function and anxiety symptoms across development.
Eighty-seven children previously assessed for BI level in early childhood provided data at ages 10 and/or 13 years, consisting of assessments of anxiety and an fMRI-based dot-probe task (including threat, happy, and neutral stimuli). Using linear-mixed-effects models, we investigated longitudinal changes in associations between anxiety symptoms and threat-related amygdala–PFC connectivity, as a function of early-childhood BI.
In children with a history of high early-childhood BI, anxiety symptoms became, with age, more negatively associated with right amygdala–left dorsolateral-PFC connectivity when attention was to be maintained on threat. In contrast, with age, low-BI children showed an increasingly positive anxiety–connectivity association during the same task condition. Behaviorally, at age 10, anxiety symptoms did not relate to fluctuations in attention bias (attention bias variability, ABV) in either group; by age 13, low-BI children showed a negative anxiety–ABV association, whereas high-BI children showed a positive anxiety–ABV association.
Early-childhood BI levels predict distinct neurodevelopmental pathways to pediatric anxiety symptoms. These pathways involve distinct relations among brain function, behavior, and anxiety symptoms, which may inform diagnosis and treatment.
The low-frequency polarisation properties of radio sources are poorly studied, particularly in statistical samples. However, the new generation of low-frequency telescopes, such as the Murchison Widefield Array (the precursor for the low-frequency component of the Square Kilometre Array) offers an opportunity to probe the physics of radio sources at very low radio frequencies. In this paper, we present a catalogue of linearly polarised sources detected at 216 MHz, using data from the Galactic and Extragalactic All-sky Murchison Widefield Array survey. Our catalogue covers the Declination range –17° to –37° and 24 h in Right Ascension, at a resolution of around 3 arcminutes. We detect 81 sources (including both a known pulsar and a new pulsar candidate) with linearly polarised flux densities in excess of 18 mJy across a survey area of approximately 6 400 deg2, corresponding to a surface density of 1 source per 79 deg2. The level of Faraday rotation measured for our sources is broadly consistent with those recovered at higher frequencies, with typically more than an order of magnitude improvement in the uncertainty compared to higher-frequency measurements. However, our catalogue is likely incomplete at low Faraday rotation measures, due to our practice of excluding sources in the region where instrumental leakage appears. The majority of sources exhibit significant depolarisation compared to higher frequencies; however, a small sub-sample repolarise at 216 MHz. We also discuss the polarisation properties of four nearby, large-angular-scale radio galaxies, with a particular focus on the giant radio galaxy ESO 422–G028, in order to explain the striking differences in polarised morphology between 216 MHz and 1.4 GHz.
Streamwise velocity profiles and their wall-normal derivatives were used to investigate the properties of turbulent channel flow in the low polymer drag reduction
), as realized via polymer injection at the channel surface. Streamwise velocity data were obtained over a friction Reynolds number ranging from
using the single-velocity-component version of molecular tagging velocimetry (1c-MTV). This adaptation of the MTV technique has the ability to accurately capture instantaneous profiles at very high spatial resolution (
data points per wall-normal profile), and thus generate well-resolved derivative information as well. Owing to this ability, the present study is able to build upon and extend the recent numerical simulation analysis of White et al. (J. Fluid Mech., vol. 834, 2018, pp. 409–433) that examined the mean dynamical structure of polymer drag-reduced channel flow at friction Reynolds numbers up to
. Consistently, the present mean velocity profiles indicate that the extent of the logarithmic region diminishes with increasing polymer concentration, while statistically significant increases in the logarithmic profile slope begin to occur for drag reductions less than
. Profiles of the r.m.s. streamwise velocity indicate that the maximum moves farther from the wall and increases in magnitude with reductions in drag. Similarly, with increasing drag reduction, the profile of the combined Reynolds and polymer shear stress exhibits a decrease in its maximum value that also moves farther from the wall. Correlations are presented that estimate the location and value of the maximum r.m.s. streamwise velocity and combined Reynolds and polymer shear stress. Over the range of
investigated, these effects consistently exhibit approximately linear trends as a function of
. The present measurements allow reconstruction of the mean momentum balance (MMB) for channel flow, which provides further insights regarding the physics described in the study by White et al. In particular, the present findings support a physical scenario in which the self-similar properties on the inertial domain identified from the leading-order structure of the MMB begin to detectably and continuously vary for drag reductions less than
Growth mixture modeling with a sample of 749 Mexican heritage families identified parallel trajectories of adolescents’ and their mothers’ heritage cultural values and parallel trajectories of adolescents’ and their fathers’ heritage cultural values from Grades 5 to 10. Parallel trajectory profiles were then used to test cultural gap-distress theory that predicts increased parent–adolescent conflict and adolescent psychopathology over time when adolescents become less aligned with Mexican heritage values compared to their parents. Six similar parallel profiles were identified for the mother–youth and father–youth dyads, but only one of the six was consistent with the hypothesized problem gap pattern in which adolescents’ values were declining over time to become more discrepant from their parents. When compared to families in the other trajectory groups as a whole, mothers in the mother–adolescent problem gap trajectory group reported higher levels of mother–adolescent conflict in the 10th grade that accounted for subsequent increases in internalizing and externalizing symptoms assessed in 12th grade. Although the findings provided some support for cultural gap-distress predictions, they were not replicated with adolescent report of conflict nor with the father–adolescent trajectory group analyses. Exploratory pairwise comparisons between all six mother–adolescent trajectory groups revealed additional differences that qualified and extended these findings.
Recent studies reveal that at large friction Reynolds number
the inertially dominated region of the turbulent boundary layer is composed of large-scale zones of nearly uniform momentum segregated by narrow fissures of concentrated vorticity. Experiments show that, when scaled by the boundary-layer thickness, the fissure thickness is
, while the dimensional jump in streamwise velocity across each fissure scales in proportion to the friction velocity
. A simple model that exploits these essential elements of the turbulent boundary-layer structure at large
is developed. First, a master wall-normal profile of streamwise velocity is constructed by placing a discrete number of fissures across the boundary layer. The number of fissures and their wall-normal locations follow scalings informed by analysis of the mean momentum equation. The fissures are then randomly displaced in the wall-normal direction, exchanging momentum as they move, to create an instantaneous velocity profile. This process is repeated to generate ensembles of streamwise velocity profiles from which statistical moments are computed. The modelled statistical profiles are shown to agree remarkably well with those acquired from direct numerical simulations of turbulent channel flow at large
. In particular, the model robustly reproduces the empirically observed sub-Gaussian behaviour for the skewness and kurtosis profiles over a large range of input parameters.
This paper aims to advance the scientific understanding of the role of culture, particularly cultural orientation, in development and psychopathology. We advance a theoretical framework that conceptualizes cultural orientation as a developmental construct represented by multiple psychological dimensions and social identities, and influenced by the contexts in which individuals are embedded. This perspective suggests that cultural orientation changes within individuals over time as a function of their experiences with and memberships in multiple groups, including the mainstream and ethnic culture groups, as well as a function of their normative developmental changes (i.e., the development of cognitive, social, and emotional capabilities). In addition, this framework places the development of an ethnic culture social identity (e.g., an ethnic identity) and a mainstream culture social identity in broader developmental perspectives that recognize these as two of the many social identities that are simultaneously embedded within the individual's self-concept and that simultaneously influence one's cultural orientation. To support the successful integration of culture into the study of development and psychopathology, we describe how highly reliable and valid measures of cultural orientation, indexed by individuals’ social identities, are essential for generating a scientifically credible understanding of the role of cultural orientation in development and psychopathology. Further, we detail some best research practices associated with our developmental and contextual framework, and note some important considerations for researchers interested in studying cultural orientation, development, and psychopathology.
Magnetic field measurements in turbulent plasmas are often difficult to perform. Here we show that for
kG magnetic fields, a time-resolved Faraday rotation measurement can be made at the OMEGA laser facility. This diagnostic has been implemented using the Thomson scattering probe beam and the resultant path-integrated magnetic field has been compared with that of proton radiography. Accurate measurement of magnetic fields is essential for satisfying the scientific goals of many current laser–plasma experiments.