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We present TreeFrog, a massively parallel halo merger tree builder that is capable comparing different halo catalogues and producing halo merger trees. The code is written in c++11, use the MPI and OpenMP API’s for parallelisation, and includes python tools to read/manipulate the data products produced. The code correlates binding energy sorted particle ID lists between halo catalogues, determining optimal descendant/progenitor matches using multiple snapshots, a merit function that maximises the number of shared particles using pseudo-radial moments, and a scheme for correcting halo merger tree pathologies. Focusing on VELOCIraptor catalogues for this work, we demonstrate how searching multiple snapshots spanning a dynamical time significantly reduces the number of stranded halos, those lacking a descendant or a progenitor, critically correcting poorly resolved halos. We present a new merit function that improves the distinction between primary and secondary progenitors, reducing tree pathologies. We find FOF accretion rates and merger rates show similar mass ratio dependence. The model merger rates from Poole, et al. [2017, 472, 3659] agree with the measured net growth of halos through mergers.
The transition from adolescent to adult mental health services (AMHS) is associated with disengagement, poor continuity of care and patient dissatisfaction. The aim of this retrospective and descriptive study was to describe the ‘care pathways’ in an independent mental health service when adolescents reach age 18 and to investigate the level of engagement of those who transitioned to independent AMHS.
This is a retrospective, naturalistic and descriptive study in design. All patients discharged from the St Patrick’s Adolescent Mental Health Service aged 17 years and 6 months and older, during a 3-year period between January 2014 and December 2016, were included. Electronic records were used to collect socio-demographic and clinical details and to determine engagement rates in adolescents who transferred to independent adult services.
A total of 180 patients aged over 17 years and 6 months were discharged from the adolescent service. Of these, 45.6% were discharged to their GP, 28.9% to public mental health services and 25.6% to independent mental health services. The majority who transitioned to independent AMHS went to a Young Adult Service, which had high engagement rates at 3 and 12 months post-transition.
In this independent mental health service, less than half of adolescents who reach the transition age are referred onto AMHS. Engagement rates were found to be high among those referred on to a specialised young adult service.
We present VELOCIraptor, a massively parallel galaxy/(sub)halo finder that is also capable of robustly identifying tidally disrupted objects and separate stellar halos from galaxies. The code is written in C++11, use the Message Passing Interface (MPI) and OpenMP Application Programming Interface (API) for parallelisation, and includes python tools to read/manipulate the data products produced. We demonstrate the power of the VELOCIraptor (sub)halo finder, showing how it can identify subhalos deep within the host that have negligible density contrasts to their parent halo. We find a subhalo mass-radial distance dependence: large subhalos with mass ratios of ≳10−2 are more common in the central regions than smaller subhalos, a result of dynamical friction and low tidal mass loss rates. This dependence is completely absent in (sub)halo finders in common use, which generally search for substructure in configuration space, yet is present in codes that track particles belonging to halos as they fall into other halos, such as hbt+. VELOCIraptor largely reproduces the dependence seen without tracking, finding a similar radial dependence to hbt+ in well-resolved halos from our limited resolution fiducial simulation.
In Ireland, National Clinical Programmes are being established to improve and standardise patient care throughout the Health Service Executive. In line with internationally recognised guidelines on the treatment of first episode psychosis the Early Intervention in Psychosis (EIP) programme is being drafted with a view to implementation by mental health services across the country. We undertook a review of patients presenting with a first episode of psychosis to the Dublin Southwest Mental Health Service before the implementation of the EIP. This baseline information will be used to measure the efficacy of our EIP programme.
Patients who presented with a first episode psychosis were retrospectively identified through case note reviews and consultation with treating teams. We gathered demographic and clinical information from patients as well as data on treatment provision over a 2-year period from the time of first presentation. Data included age at first presentation, duration of untreated psychosis, diagnosis, referral source, antipsychotic prescribing rates and dosing, rates of provision of psychological interventions and standards of physical healthcare monitoring. Outcome measures with regards to rates of admission over a 2-year period following initial presentation were also recorded.
In total, 66 cases were identified. The majority were male, single, unemployed and living with their family or spouse. The mean age at first presentation was 31 years with a mean duration of untreated psychosis of 17 months. Just under one-third were diagnosed with schizophrenia. Approximately half of the patients had no contact with a health service before presentation. The majority of patients presented through the emergency department. Two-thirds of all patients had a hospital admission within 2 years of presentation and almost one quarter of patients had an involuntary admission. The majority of patients were prescribed antipsychotic doses within recommended British National Formulary guidelines. Most patients received individual support through their keyworker and family intervention was provided in the majority of cases. Only a small number received formal Cognitive-Behavioural Therapy. Physical healthcare monitoring was insufficiently recorded in the majority of patients.
There is a shortage of information on the profile and treatment of patients presenting with a first episode of psychosis in Ireland. This baseline information is important in evaluating the efficacy of any new programme for this patient group. Many aspects of good practice were identified within the service in particular with regards to the appropriate prescribing of antipsychotic medication and the rates of family intervention. Deficiencies remain however in the monitoring of physical health and the provision of formal psychological interventions to patients. With the implementation of an EIP programme it is hoped that service provision would improve nationwide and to internationally recognised standards.
Two flood waves from the terminus of Peyto Glacier occurred as a result of very high precipitation in early July 1983 and a landslide which exposed a large section of ice-cored moraine. The flood waves induced erosion, and subsequent melt, of the moraine and deposited an estimated 6000 m3 of gravel in the valley. The majority of the deposition occurred in an area approximately 200 m × 20 m to depths of 3 m at the site of the National Hydrology Research Institute gauging station 1 km from the glacier terminus. The initial flood washed away most of the equipment from the site and the gravel deposition totally destroyed the rest of the installation. These events appear to be unique in the period that hydrological records have been maintained for Peyto Creek.
Effective transition from child and adolescent mental health services (CAMHS) to adult services is one of the main challenges currently facing child psychiatry today
The Young Adult 1Programme (YAP) based at St. Patrick’s University Hospital Dublin, is a group based day programme especially designed to meet the needs of younger people aged 18–25 and support them through this difficult period.
To examine the effectiveness of participation in YAP for young adults with mental illness. To determine whether participation in particular aspects of the programme prove more beneficial and what factors might be associated with outcome.
All patients enrolled in YAP between 1 September 2011 and 31 August 2012 were included in the study. Each patient was assessed using the Health of the Nation Outcome Scales (HONOS) and Global Assessment of Functioning (GAF) rating scale before beginning the programme and after discharge in order to evaluate improvement. The frequency of attendance at individual group sessions was recorded. Patient and illness variables were also recorded, for example demographics, diagnosis.
A total of 101 service users were in enrolled in YAP during this 12-month period. Eight service users could not be used for analysis, as they did not have a complete data set, mostly due to failure to attend for discharge HONOS/GAF ratings
Using a paired sample t-test, there is a significant reduction in HONOS: Mean df=1.3, s.d.=1.09 (95% CI=1.08–1.53), p<0.001
Using a paired sample t-test, there is a significant increase in GAF: Mean df=9.25, s.d.=7.69 (95% CI=7.66–10.83), p<0.001
Improvements in HONOS and GAF scores are significantly correlated with better attendance at the programme (p<0.04, <0.00 respectively).
More attendance at YAP sessions correlates with better improvement in both HONOS and GAF rating scores.
Major depressive disorder (MDD) is a common and disabling condition with well-established heritability and environmental risk factors. Gene–environment interaction studies in MDD have typically investigated candidate genes, though the disorder is known to be highly polygenic. This study aims to test for interaction between polygenic risk and stressful life events (SLEs) or childhood trauma (CT) in the aetiology of MDD.
The RADIANT UK sample consists of 1605 MDD cases and 1064 controls with SLE data, and a subset of 240 cases and 272 controls with CT data. Polygenic risk scores (PRS) were constructed using results from a mega-analysis on MDD by the Psychiatric Genomics Consortium. PRS and environmental factors were tested for association with case/control status and for interaction between them.
PRS significantly predicted depression, explaining 1.1% of variance in phenotype (p = 1.9 × 10−6). SLEs and CT were also associated with MDD status (p = 2.19 × 10−4 and p = 5.12 × 10−20, respectively). No interactions were found between PRS and SLEs. Significant PRSxCT interactions were found (p = 0.002), but showed an inverse association with MDD status, as cases who experienced more severe CT tended to have a lower PRS than other cases or controls. This relationship between PRS and CT was not observed in independent replication samples.
CT is a strong risk factor for MDD but may have greater effect in individuals with lower genetic liability for the disorder. Including environmental risk along with genetics is important in studying the aetiology of MDD and PRS provide a useful approach to investigating gene–environment interactions in complex traits.
Sudden release of accreted ice in fuel systems could pose a serious challenge in aircraft operation. The resultant snowshower may reach the filter and fuel-oil heat exchanger, causing a restriction in fuel flow to the engine. It is fundamental to have an appreciation of the character and the interface shear strength of the accreted ice in aircraft fuel systems. This helps to recognise factors for the sudden release of the accreted ice and the intensity of the consequential snowshower. An experimental study was carried out to quantify the character and the interface shear strength of accreted ice on subcooled surfaces submerged in jet fuel. Ice was accreted on naked aluminium, painted aluminium and carbon fibre composite surfaces at various subcooled temperatures. The accreted ice was akin to fresh snow and exhibited soft and fluffy attributes. The character may be expressed quantitatively in terms of the porosity and was found to be c. 0·95. The ice weakly adhered to the substrate surfaces, and the interface shear strength was found to be c. 0·36Pa and c. 2·19Pa at the top surface and at the vertical surface of a specimen block, respectively. It was not possible to detect any variation in the porosity and the interface shear strength for different types of surface finishes and differences in water affnity in fuels due to the crude approach in the estimation of these parameters.
Strategies to dissect phenotypic and genetic heterogeneity of major depressive disorder (MDD) have mainly relied on subphenotypes, such as age at onset (AAO) and recurrence/episodicity. Yet, evidence on whether these subphenotypes are familial or heritable is scarce. The aims of this study are to investigate the familiality of AAO and episode frequency in MDD and to assess the proportion of their variance explained by common single nucleotide polymorphisms (SNP heritability).
For investigating familiality, we used 691 families with 2–5 full siblings with recurrent MDD from the DeNt study. We fitted (square root) AAO and episode count in a linear and a negative binomial mixed model, respectively, with family as random effect and adjusting for sex, age and center. The strength of familiality was assessed with intraclass correlation coefficients (ICC). For estimating SNP heritabilities, we used 3468 unrelated MDD cases from the RADIANT and GSK Munich studies. After similarly adjusting for covariates, derived residuals were used with the GREML method in GCTA (genome-wide complex trait analysis) software.
Significant familial clustering was found for both AAO (ICC = 0.28) and episodicity (ICC = 0.07). We calculated from respective ICC estimates the maximal additive heritability of AAO (0.56) and episodicity (0.15). SNP heritability of AAO was 0.17 (p = 0.04); analysis was underpowered for calculating SNP heritability of episodicity.
AAO and episodicity aggregate in families to a moderate and small degree, respectively. AAO is under stronger additive genetic control than episodicity. Larger samples are needed to calculate the SNP heritability of episodicity. The described statistical framework could be useful in future analyses.
Bipolar disorder (BPD) essentially has its onset during adolescence and early adulthood. It has the capacity to be highly disruptive, dislocating individuals from their normal developmental trajectory and potentially causing significant long-term co-morbidity and chronicity. At a societal level the burden created is greater than schizophrenia. This is not helped by the very substantial delays in its diagnosis and appropriate treatment. Thus, there is a clear rationale for intervening earlier and at a younger age. However, the field of early intervention in BPD is in its infancy. One approach that conceptually provides a basis for early intervention is the Clinical Staging Model (used widely in general medicine). This article outlines how this model helps in an understanding of the emerging stages of BPD. It also summarises the interventions that might be appropriately introduced if a person progresses from an early to a late stage of the illness. Early intervention has a well-established record in psychotic disorders. If it can be realised for BPDs, then it may hold out hope of better outcomes for the next generation of young people at risk.
The prevalence of type 2 diabetes mellitus (T2DM) is increasing and it is estimated that by 2030 approximately 366 million people will be diagnosed with this condition. The use of dipeptidyl peptidase IV (DPP-IV) inhibitors is an emerging strategy for the treatment of T2DM. DPP-IV is a ubiquitous aminodipeptidase that cleaves incretins such as glucagon like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), resulting in a loss in their insulinotropic activity. Synthetic DPP-IV drug inhibitors are being used to increase the half-life of the active GLP-1 and GIP. Dietary intervention is accepted as a key component in the prevention and management of T2DM. Therefore, identification of natural food protein-derived DPP-IV inhibitors is desirable. Peptides with DPP-IV inhibitory activity have been identified in a variety of food proteins. This review aims to provide an overview of food protein hydrolysates as a source of the DPP-IV inhibitory peptides with particular focus on milk proteins. In addition, the proposed modes of inhibition and structure–activity relationship of peptide inhibitors are discussed. Milk proteins and associated peptides also display insulinotropic activity and help regulate blood glucose in healthy and diabetic subjects. Therefore, milk protein derived peptide inhibitors may be a unique multifunctional peptide approach for the management of T2DM.