We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save 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 saving content to .
To save content items to your Kindle, first ensure coreplatform@cambridge.org
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 saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved 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.
Recent fossil discoveries from New Zealand have revealed a remarkably diverse assemblage of Paleocene stem group penguins. Here, we add to this growing record by describing nine new penguin specimens from the late Paleocene (upper Teurian local stage; 55.5–59.5 Ma) Moeraki Formation of the South Island, New Zealand. The largest specimen is assigned to a new species, Kumimanu fordycei n. sp., which may have been the largest penguin ever to have lived. Allometric regressions based on humerus length and humerus proximal width of extant penguins yield mean estimates of a live body mass in the range of 148.0 kg (95% CI: 132.5 kg–165.3 kg) and 159.7 kg (95% CI: 142.6 kg–178.8 kg), respectively, for Kumimanu fordycei. A second new species, Petradyptes stonehousei n. gen. n. sp., is represented by five specimens and was slightly larger than the extant emperor penguin Aptenodytes forsteri. Two small humeri represent an additional smaller unnamed penguin species. Parsimony and Bayesian phylogenetic analyses recover Kumimanu and Petradyptes crownward of the early Paleocene mainland NZ taxa Waimanu and Muriwaimanu, but stemward of the Chatham Island taxon Kupoupou. These analyses differ, however, in the placement of these two taxa relative to Sequiwaimanu, Crossvallia, and Kaiika. The massive size and placement of Kumimanu fordycei close to the root of the penguin tree provide additional support for a scenario in which penguins reached the upper limit of sphenisciform body size very early in their evolutionary history, while still retaining numerous plesiomorphic features of the flipper.
Reward processing has been proposed to underpin the atypical social feature of autism spectrum disorder (ASD). However, previous neuroimaging studies have yielded inconsistent results regarding the specificity of atypicalities for social reward processing in ASD.
Aims
Utilising a large sample, we aimed to assess reward processing in response to reward type (social, monetary) and reward phase (anticipation, delivery) in ASD.
Method
Functional magnetic resonance imaging during social and monetary reward anticipation and delivery was performed in 212 individuals with ASD (7.6–30.6 years of age) and 181 typically developing participants (7.6–30.8 years of age).
Results
Across social and monetary reward anticipation, whole-brain analyses showed hypoactivation of the right ventral striatum in participants with ASD compared with typically developing participants. Further, region of interest analysis across both reward types yielded ASD-related hypoactivation in both the left and right ventral striatum. Across delivery of social and monetary reward, hyperactivation of the ventral striatum in individuals with ASD did not survive correction for multiple comparisons. Dimensional analyses of autism and attention-deficit hyperactivity disorder (ADHD) scores were not significant. In categorical analyses, post hoc comparisons showed that ASD effects were most pronounced in participants with ASD without co-occurring ADHD.
Conclusions
Our results do not support current theories linking atypical social interaction in ASD to specific alterations in social reward processing. Instead, they point towards a generalised hypoactivity of ventral striatum in ASD during anticipation of both social and monetary rewards. We suggest this indicates attenuated reward seeking in ASD independent of social content and that elevated ADHD symptoms may attenuate altered reward seeking in ASD.
Unsustainable hunting, both illegal and legal, has led to the extirpation of many species. In the last 35 years giraffe Giraffa spp. populations have declined precipitously, with extinctions documented in seven African countries. Amongst the various reasons for these population declines, poaching is believed to play an important role in some areas. Giraffes are primarily hunted for consumption and for the use of their body parts as trophies and in traditional medicine. However, the socio-economic factors that correlate with the use of giraffe body parts are not well understood. We conducted our study in Tsavo Conservation Area, Kenya, which experiences high levels of poaching. We used semi-structured surveys amongst 331 households to document how giraffe body parts are typically acquired and their intended use (i.e. trophy, medicinal or consumptive). We then used logistic regression models to assess the correlations between nine socio-economic factors and the use of giraffe body parts. We found that giraffe body parts had mostly consumptive and trophy uses. One-time suppliers, opportunistic access and widely known markets were the most common means of acquiring giraffe body parts. Results from our models showed that three variables (gender: men, occupation: tourism worker, and land ownership) were correlated significantly and positively with the use of giraffe body parts. We describe the complex links between socio-economic factors and the use of giraffe body parts and highlight the importance of implementing mitigation measures adapted to local contexts to combat a challenge that many species of conservation concern are facing.
Viscoelastic flow instability, which is compelled by elastic effects rather than inertia, can be driven to a chaotic state termed elastic turbulence (ET) manifested as strong velocity fluctuations with an algebraic decay in the frequency spectrum and increased mixing. We report the first spatiotemporally complete description of ET by considering a broad volume within a novel three-dimensional ordered porous medium, reconstructing flow at a micrometre characteristic length scale ($\text {Reynolds numbers} \ll 1$) via time-resolved microtomographic particle image velocimetry. Beyond a critical Weissenberg number of 2, we observe an elastic flow instability accompanied by an enhanced pressure drop with spectral characteristics typical of ET. Polymer chains in the ET flow state are advected along increasingly curved streamlines between pores such that they accumulate strain and generate a local flow instability evaluated per an established instability criterion based on local evaluation of elastic tensile stress and streamline curvature. The onset of ET leads to increased pore-scale resistance and positive feedback on upstream streamline curvature. ET is thus characterized by a continuous evolution between states of laminar and unstable flow: pores with unstable flow flood their adjacent peers and thus encourage straightened streamlines and flow stability across the array, while positive feedback from flow resistance on streamline curvature results in the instability propagating upstream along the array. By employing a geometrically ordered medium, we permit flow state communication between pores, yielding generalized insights highlighting the significance of spatial correlation and flow history, and thus provide new avenues for explaining the mechanisms of ET.
Eating disorders have the highest mortality rate of any psychiatric condition. Since the COVID-19 pandemic, the number of patients who have required medical stabilisation on paediatric wards has increased significantly. Likewise, the number of patients who have required medical stabilisation against their will as a lifesaving intervention has increased. This paper highlights a fictional case study aiming to explore the legal, ethical and practical considerations a trainee should be aware of. By the end of this article, readers will be more aware of this complex issue and how it might be managed, as well as the impact it can have on the patient, their family and ward staff.
Viscoelastic flow through an abrupt planar contraction geometry above a certain Weissenberg number ($Wi$) is well known to become unstable upstream of the contraction plane via a central jet separating from the walls and forming vortices in the salient corners. Here, for the first time, we consider three-dimensional (3-D) viscoelastic contraction flows in a microfabricated glass square–square contraction geometry. We employ state-of-the-art microtomographic particle image velocimetry to produce time-resolved and volumetric quantification of the 3-D viscoelastic instabilities arising in a dilute polymer solution driven through the geometry over a wide range of $Wi$ but at negligible Reynolds number. Based on our observations, we describe new insights into the growth, propagation and transient dynamics of an elastic vortex formed upstream of the 3-D microcontraction due to flow jetting towards the contraction. At low $Wi$ we observe vortex growth for increasing $Wi$, followed by a previously unreported vortex growth plateau region. In the plateau region, the vortex circulates around the jet with a period that decreases with $Wi$ but an amplitude that is independent of $Wi$. In addition, we report new out-of-plane asymmetric jetting behaviour with a phase-wise dependence on $Wi$. Finally, we resolve the rate-of-strain tensor $\boldsymbol{\mathsf{D}}$ and ascribe local gradients in $\boldsymbol{\mathsf{D}}$ as the underlying driver of circulation via strain hardening of the fluid in the wake of the jet.
Liben Lark Heteromirafra archeri is a ‘Critically Endangered’ species threatened by the loss and degradation of grassland at the Liben Plain, southern Ethiopia, one of only two known sites for the species. We use field data from nine visits between 2007 and 2019 and satellite imagery to quantify changes over time in the species’ abundance and in the extent and quality of its habitat. We estimate that the population fell from around 279 singing males (95% CL: 182–436) in 2007 to around 51 (14–144) in 2013, after which too few birds were recorded to estimate population size. Arable cultivation first appeared on the plain in the early 1990s and by 2019 more than a third of the plain had been converted to crops. Cultivation was initially confined to the fertile black soils but from 2008 began to spread into the less fertile red soils that cover most of the plain. Liben Larks strongly avoided areas with extensive bare ground or trees and bushes, but the extent of these did not change significantly over the survey period. A plausible explanation for the species’ decline is that grassland degradation, caused before 2007 by continuous high-pressure grazing by livestock, reduced its rates of reproduction or survival to a level that could not support its previous population. Since 2015, communal kalos (grazing exclosures) have been established to generate forage and other resources in the hope of also providing breeding habitat for Liben Larks. Grass height and density within four grassland kalos in 2018 greatly exceeded that in the surrounding grassland, indicating that the plain retains the potential to recover rapidly if appropriately managed. Improvement of grassland structure through the restitution of traditional and sustainable rangeland management regimes and the reversion of cereal agriculture to grassland are urgently needed to avert the species’ extinction.
The COVID-19 pandemic and mitigation measures are likely to have a marked effect on mental health. It is important to use longitudinal data to improve inferences.
Aims
To quantify the prevalence of depression, anxiety and mental well-being before and during the COVID-19 pandemic. Also, to identify groups at risk of depression and/or anxiety during the pandemic.
Method
Data were from the Avon Longitudinal Study of Parents and Children (ALSPAC) index generation (n = 2850, mean age 28 years) and parent generation (n = 3720, mean age 59 years), and Generation Scotland (n = 4233, mean age 59 years). Depression was measured with the Short Mood and Feelings Questionnaire in ALSPAC and the Patient Health Questionnaire-9 in Generation Scotland. Anxiety and mental well-being were measured with the Generalised Anxiety Disorder Assessment-7 and the Short Warwick Edinburgh Mental Wellbeing Scale.
Results
Depression during the pandemic was similar to pre-pandemic levels in the ALSPAC index generation, but those experiencing anxiety had almost doubled, at 24% (95% CI 23–26%) compared with a pre-pandemic level of 13% (95% CI 12–14%). In both studies, anxiety and depression during the pandemic was greater in younger members, women, those with pre-existing mental/physical health conditions and individuals in socioeconomic adversity, even when controlling for pre-pandemic anxiety and depression.
Conclusions
These results provide evidence for increased anxiety in young people that is coincident with the pandemic. Specific groups are at elevated risk of depression and anxiety during the COVID-19 pandemic. This is important for planning current mental health provisions and for long-term impact beyond this pandemic.
Antarctica's ice shelves modulate the grounded ice flow, and weakening of ice shelves due to climate forcing will decrease their ‘buttressing’ effect, causing a response in the grounded ice. While the processes governing ice-shelf weakening are complex, uncertainties in the response of the grounded ice sheet are also difficult to assess. The Antarctic BUttressing Model Intercomparison Project (ABUMIP) compares ice-sheet model responses to decrease in buttressing by investigating the ‘end-member’ scenario of total and sustained loss of ice shelves. Although unrealistic, this scenario enables gauging the sensitivity of an ensemble of 15 ice-sheet models to a total loss of buttressing, hence exhibiting the full potential of marine ice-sheet instability. All models predict that this scenario leads to multi-metre (1–12 m) sea-level rise over 500 years from present day. West Antarctic ice sheet collapse alone leads to a 1.91–5.08 m sea-level rise due to the marine ice-sheet instability. Mass loss rates are a strong function of the sliding/friction law, with plastic laws cause a further destabilization of the Aurora and Wilkes Subglacial Basins, East Antarctica. Improvements to marine ice-sheet models have greatly reduced variability between modelled ice-sheet responses to extreme ice-shelf loss, e.g. compared to the SeaRISE assessments.
While medical nutrition therapy is an essential part of the care for critically ill patients, uncertainty exists about the right form, dosage, timing and route in relation to the phases of critical illness. As enteral nutrition (EN) is often withheld or interrupted during the intensive care unit (ICU) stay, combined EN and parenteral nutrition (PN) may represent an effective and safe option to achieve energy and protein goals as recommended by international guidelines. We hypothesise that critically ill patients at high nutritional risk may benefit from such a combined approach during their stay on the ICU. Therefore, we aim to test if an early combination of EN and high-protein PN (EN+PN) is effective in reaching energy and protein goals in patients at high nutritional risk, while avoiding overfeeding. This approach will be tested in the here-presented EFFORTcombo trial. Nutritionally high-risk ICU patients will be randomised to either high (≥2·2 g/kg per d) or low protein (≤1·2 g/kg per d). In the high protein group, the patients will receive EN+PN; in the low protein group, patients will be given EN alone. EN will be started in accordance with international guidelines in both groups. Efforts will be made to reach nutrition goals within 48–96 h. The efficacy of the proposed nutritional strategy will be tested as an innovative approach by functional outcomes at ICU and hospital discharge, as well as at a 6-month follow-up.
Children with autism spectrum disorder (ASD) have increased susceptibility to anxiety disorders. Variation in a common ASD symptom, insistence on sameness behaviour, may predict future anxiety symptoms.
Aims
To describe the joint heterogeneous longitudinal trajectories of insistence on sameness and anxiety in children with ASD and to characterise subgroups at higher risk for anxiety.
Method
In a longitudinal ASD cohort (n = 421), insistence on sameness behaviour was measured using the Autism Diagnostic Interview-Revised at approximately ages 3, 6 and 11 years. Anxiety was quantified at 8 time points between ages 3 and 11 years using the Child Behavior Checklist (CBCL) (parent report). Clusters of participants following similar trajectories were identified using group-based and joint trajectory modelling.
Results
Three insistence on sameness trajectories were identified: (a) ‘low-stable’ (41.7% of participants), (b) ‘moderate-increasing’ (52.0%) and (c) ‘high-peaking’ (i.e. increasing then stabilising/decreasing behaviour) (6.3%). Four anxiety trajectories were identified: (a) ‘low-increasing’ (51.0%), (b) ‘moderate-decreasing’ (16.2%), (c) ‘moderate-increasing’ (19.6%) and (d) ‘high-stable’ (13.1%). Of those assigned to the ‘high-peaking’ insistence on sameness trajectory, 95% jointly followed an anxiety trajectory that surpassed the threshold for clinical concern (T-score >65) by middle childhood (anxiety trajectories 3 or 4). Insistence on sameness and anxiety trajectories were similar in severity and direction for 64% of the sample; for 36%, incongruous patterns were seen (e.g. decreasing anxiety and increasing insistence on sameness).
Conclusions
The concurrent assessment of insistence on sameness behaviour and anxiety in ASD may help in understanding current symptom profiles and anticipating future trajectories. High preschool insistence on sameness in particular may be associated with elevated current or future anxiety symptoms.
We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band (
${\sim}60\%$
), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.
The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
Evidence suggests that sub-optimal maternal nutrition has implications for the developing offspring. We have previously shown that exposure to a low-protein diet during gestation was associated with upregulation of genes associated with cholesterol transport and packaging within the placenta. This study aimed to elucidate the effect of altering maternal dietary linoleic acid (LA; omega-6) to alpha-linolenic acid (ALA; omega-6) ratios as well as total fat content on placental expression of genes associated with cholesterol transport. The potential for maternal body mass index (BMI) to be associated with expression of these genes in human placental samples was also evaluated. Placentas were collected from 24 Wistar rats at 20-day gestation (term = 21–22-day gestation) that had been fed one of four diets containing varying fatty acid compositions during pregnancy, and from 62 women at the time of delivery. Expression of 14 placental genes associated with cholesterol packaging and transfer was assessed in rodent and human samples by quantitative real time polymerase chain reaction. In rats, placental mRNA expression of ApoA2, ApoC2, Cubn, Fgg, Mttp and Ttr was significantly elevated (3–30 fold) in animals fed a high LA (36% fat) diet, suggesting increased cholesterol transport across the placenta in this group. In women, maternal BMI was associated with fewer inconsistent alterations in gene expression. In summary, sub-optimal maternal nutrition is associated with alterations in the expression of genes associated with cholesterol transport in a rat model. This may contribute to altered fetal development and potentially programme disease risk in later life. Further investigation of human placenta in response to specific dietary interventions is required.
In recent years, the discovery of massive quasars at $z\sim7$ has provided a striking challenge to our understanding of the origin and growth of supermassive black holes in the early Universe. Mounting observational and theoretical evidence indicates the viability of massive seeds, formed by the collapse of supermassive stars, as a progenitor model for such early, massive accreting black holes. Although considerable progress has been made in our theoretical understanding, many questions remain regarding how (and how often) such objects may form, how they live and die, and how next generation observatories may yield new insight into the origin of these primordial titans. This review focusses on our present understanding of this remarkable formation scenario, based on the discussions held at the Monash Prato Centre from November 20 to 24, 2017, during the workshop ‘Titans of the Early Universe: The Origin of the First Supermassive Black Holes’.
Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
Methods
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
Results
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
Conclusions
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.
A lasting legacy of the International Polar Year (IPY) 2007–2008 was the promotion of the Permafrost Young Researchers Network (PYRN), initially an IPY outreach and education activity by the International Permafrost Association (IPA). With the momentum of IPY, PYRN developed into a thriving network that still connects young permafrost scientists, engineers, and researchers from other disciplines. This research note summarises (1) PYRN’s development since 2005 and the IPY’s role, (2) the first 2015 PYRN census and survey results, and (3) PYRN’s future plans to improve international and interdisciplinary exchange between young researchers. The review concludes that PYRN is an established network within the polar research community that has continually developed since 2005. PYRN’s successful activities were largely fostered by IPY. With >200 of the 1200 registered members active and engaged, PYRN is capitalising on the availability of social media tools and rising to meet environmental challenges while maintaining its role as a successful network honouring the legacy of IPY.
We present Phantom, a fast, parallel, modular, and low-memory smoothed particle hydrodynamics and magnetohydrodynamics code developed over the last decade for astrophysical applications in three dimensions. The code has been developed with a focus on stellar, galactic, planetary, and high energy astrophysics, and has already been used widely for studies of accretion discs and turbulence, from the birth of planets to how black holes accrete. Here we describe and test the core algorithms as well as modules for magnetohydrodynamics, self-gravity, sink particles, dust–gas mixtures, H2 chemistry, physical viscosity, external forces including numerous galactic potentials, Lense–Thirring precession, Poynting–Robertson drag, and stochastic turbulent driving. Phantom is hereby made publicly available.