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The causes of the beaching and death of sea turtles have not been fully clarified and continue to be studied. Mild, moderate and severe lesions caused by spirorchiidiosis have been seen for decades in different organs and were recently defined as the cause of death of a loggerhead turtle. In the present study, eyes and optic nerves were analysed in green sea turtles with spirorchiidiosis and no other debilitating factors. Injuries to the optic nerve and choroid layer were described in 235 animals (90%) infected with spirorchiids. Turtles with ocular spirorchiidiosis are approximately three times more likely to be cachectic than turtles with spirorchiidiosis without ocular involvement.
Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
The possibility that life, primitive or advanced, might exist in other places of the Universe has occupied the minds of scientists and lay-people for thousands of years. It is only in the last 25 years, however, that we have finally begun to search for answers to this profound question using experimental techniques. The goal of Astronomy is to understand the origin and evolution of planets, stars, galaxies and of the Universe as a whole. The appearance of life is an integral part of this whole process and our picture of the Universe will never be complete until we will comprehend also the significance of life in the process of Cosmic Evolution.
A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
The National Institute of Health and Care Excellence (NICE) in England and Wales recommends the combination of pharmacotherapy and psychotherapy for the treatment of moderate to severe depression. However, the cost-effectiveness analysis on which these recommendations are based has not included psychotherapy as monotherapy as a potential option. For this reason, we aimed to update, augment and refine the existing economic evaluation.
We constructed a decision analytic model with a 27-month time horizon. We compared pharmacotherapy with cognitive–behavioural therapy (CBT) and combination treatment for moderate to severe depression in secondary care from a healthcare service perspective. We reviewed the literature to identify relevant evidence and, where possible, synthesized evidence from clinical trials in a meta-analysis to inform model parameters.
The model suggested that CBT as monotherapy was most likely to be the most cost-effective treatment option above a threshold of £22 000 per quality-adjusted life year (QALY). It dominated combination treatment and had an incremental cost-effectiveness ratio of £20 039 per QALY compared with pharmacotherapy. There was significant decision uncertainty in the probabilistic and deterministic sensitivity analyses.
Contrary to previous NICE guidance, the results indicated that even for those patients for whom pharmacotherapy is acceptable, CBT as monotherapy may be a cost-effective treatment option. However, this conclusion was based on a limited evidence base, particularly for combination treatment. In addition, this evidence cannot easily be transferred to a primary care setting.
For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
It is paramount to understand the epidemiology of chronic hepatitis B to inform national policies on vaccination and screening/testing as well as cost-effectiveness studies. However, information on the national (Scottish) prevalence of chronic hepatitis B by ethnic group is lacking. To estimate the number of people with chronic hepatitis B in Scotland in 2009 by ethnicity, gender and age, the test data from virology laboratories in the four largest cities in Scotland were combined with estimates of the ethnic distribution of the Scottish population. Ethnicity in both the test data and the Scottish population was derived using a name-based ethnicity classification software (OnoMAP; Publicprofiler Ltd, UK). For 2009, we estimated 8720 [95% confidence interval (CI) 7490–10 230] people aged ⩾15 years were living with chronic hepatitis B infection in Scotland. This corresponds to 0·2% (95% CI 0·17–0·24) of the Scottish population aged ⩾15 years. Although East and South Asians make up a small proportion of the Scottish population, they make up 44% of the infected population. In addition, 75% of those infected were aged 15–44 years with almost 60% male. This study quantifies for the first time on a national level the burden of chronic hepatitis B infection by ethnicity, gender and age. It confirms the importance of promoting and targeting ethnic minority groups for hepatitis B testing.
Earlier clinical studies have suggested consistent differences between anxious and non-anxious depression. The aim of this study was to compare parental pathology, personality and symptom characteristics in three groups of probands from the general population: depression with and without generalized anxiety disorder (GAD) and with other anxiety disorders. Because patients without GAD may have experienced anxious symptoms for up to 5 months, we also considered GAD with a duration of only 1 month to produce a group of depressions largely unaffected by anxiety.
Depressive and anxiety disorders were assessed in a 10-year prospective longitudinal community and family study using the DSM-IV/M-CIDI. Regression analyses were used to reveal associations between these variables and with personality using two durations of GAD: 6 months (GAD-6) and 1 month (GAD-1).
Non-anxious depressives had fewer and less severe depressive symptoms, and higher odds for parents with depression alone, whereas those with anxious depression were associated with higher harm avoidance and had parents with a wider range of disorders, including mania.
Anxious depression is a more severe form of depression than the non-anxious form; this is true even when the symptoms required for an anxiety diagnosis are ignored. Patients with non-anxious depression are different from those with anxious depression in terms of illness severity, family pathology and personality. The association between major depression and bipolar disorder is seen only in anxious forms of depression. Improved knowledge on different forms of depression may provide clues to their differential aetiology, and guide research into the types of treatment that are best suited to each form.
In primary care frequent attenders with medically unexplained symptoms (MUS) pose a clinical and health resource challenge. We sought to understand these presentations in terms of the doctor–patient relationship, specifically to test the hypothesis that such patients have insecure emotional attachment.
We undertook a cohort follow-up study of 410 patients with MUS. Baseline questionnaires assessed adult attachment style, psychological distress, beliefs about the symptom, non-specific somatic symptoms, and physical function. A telephone interview following consultation assessed health worry, general practitioner (GP) management and satisfaction with consultation. The main outcome was annual GP consultation rate.
Of consecutive attenders, 18% had an MUS. This group had a high mean consultation frequency of 5.24 [95% confidence interval (CI) 4.79–5.69] over the follow-up year. The prevalence of insecure attachment was 28 (95% CI 23–33) %. A significant association was found between insecure attachment style and frequent attendance, even after adjustment for sociodemographic characteristics, presence of chronic physical illness and baseline physical function [odds ratio (OR) 1.96 (95% CI 1.05–3.67)]. The association was particularly strong in those patients who believed that there was a physical cause for their initial MUS [OR 9.52 (95% CI 2.67–33.93)]. A possible model for the relationship between attachment style and frequent attendance is presented.
Patients with MUS who attend frequently have insecure adult attachment styles, and their high consultation rate may therefore be conceptualized as pathological care-seeking behaviour linked to their insecure attachment. Understanding frequent attendance as pathological help seeking driven by difficulties in relating to caregiving figures may help doctors to manage their frequently attending patients in a different way.
Observed co-morbidity among the mood and anxiety disorders has led to the development of increasingly sophisticated dimensional models to represent the common and unique features of these disorders. Patients often present to primary care settings with a complex mixture of anxiety, depression and somatic symptoms. However, relatively little is known about how somatic symptoms fit into existing dimensional models.
We examined the structure of 91 anxiety, depression and somatic symptoms in a sample of 5433 primary care patients drawn from 14 countries. One-, two- and three-factor lower-order models were considered; higher-order and hierarchical variants were studied for the best-fitting lower-order model.
A hierarchical, bifactor model with all symptoms loading simultaneously on a general factor, along with one of three specific anxiety, depression and somatic factors, was the best-fitting model. The general factor accounted for the bulk of symptom variance and was associated with psychosocial dysfunction. Specific depression and somatic symptom factors accounted for meaningful incremental variance in diagnosis and dysfunction, whereas anxiety variance was associated primarily with the general factor.
The results (a) are consistent with previous studies showing the presence and importance of a broad internalizing or distress factor linking diverse emotional disorders, and (b) extend the bounds of internalizing to include somatic complaints with non-physical etiologies.
Variable energy positron annihilation and Rutherford backscattering spectroscopy have been used to investigate the evolution of secondary defects during the annealing of self-ion irradiated silicon. Evidence supporting the existence of both vacancy- and interstitially-based defects after high temperature anneals is presented. Dopant type and irradiation temperature have both been shown to influence the structure of the defects whose onset can be manipulated via the implantation flux.
Significant progress has been made in the past year in the use of high energy (MeV) ion irradiation to tune the bandgap and therefore emission wavelengths of single and multiple quantum well structures. These shifts are attributable to compositional mixing across the well and barrier layer interfaces, a process that is driven by the vacancy flux, released during the anneal stage, from radiation defects. We present data from a series of measurements in both GaAs- and InP-based QW structures to demonstrate the importance of the implantation parameters chosen (ion species, energy, flux, fluence and implant temperature). The dramatic difference in the response of these two systems with regard to the implant depth is believed to be associated with the very different diffusivities of the Gp III site vacancies. Prospects for implementing the irradiation approach as a spatially selective, planar process in integrated optoelectronic circuitry look very attractive and are illustrated for both passive and active components by reference to recent results from tuned wavelength lasers.
Significant progress has been realized in the use of quantum well intermixing (QWI) as a method for tailoring the bandgap energies of optoelectronic devices. Intermixing can be driven by an ion implantation process, an approach that appeals because of its simplicity, its planarity and its adaptability to selective area processing. Despite its success, the advantages of irradiation induced QWI need to be tested further and we report here current results of three research activities which address a) the existence or not of a simple scaling relationship which connects intermixing in a given QW structure for any ion species; b) reproducibility of intermixing in identical QW structures which have been obtained from different growth systems; and c) intermixing for above the well versus through the well implantation.
Medium energy ion scattering (MEIS), operated at sub-nm depth resolution in the double alignment configuration, has been used to examine implant and damage depth profiles formed in Si(100) substrates irradiated with 2.5 keV As+ and 1 keV B+ ions. Samples were implanted at temperatures varying between 150°C, and 300°C to doses ranging from 3X1014 to 2X1016 cm-2. For the As implants the MEIS studies demonstrate the occurrence of effects such as a dopant accommodation linked to the growth in depth of the damage layer, dopant clustering, as well as damage and dopant movement upon annealing. Following epitaxial regrowth at 600°C, approximately half of the As was observed to be in substitutional sites, consistent with the reported formation of AsnV complexes (n≤4), while the remainder became segregated and became trapped within a narrow, 1.1 nm wide layer at the Si/oxide interface
MEIS measurements of the B implants indicate the formation of two distinct damage regions each with a different dependence on implant dose, the importance of dynamic annealing for implants at room temperature and above, and a competing point defect trapping effect at the Si/oxide interface. B+ implantation at low temperature resulted in the formation of an amorphous layer due to the drastic reduction of dynamic annealing processes.
Notably different dopant distributions were measured by SIMS in the samples implanted with As at different temperatures following rapid thermal annealing (RTA) up to 1100°C in an oxidising environment. Implant temperature dependent interactions between defects and dopants are reflected in the transient enhanced diffusion (TED) behaviour of As.
We describe a dynamic atomic force microscopy (AFM) method to map the nanoscale elastic properties of surfaces, thin films, and nanostructures. Our approach is based on atomic force acoustic microscopy (AFAM) techniques previously used for quantitative measurements of elastic properties at a fixed sample position. AFAM measurements determine the resonant frequencies of an AFM cantilever in contact mode to calculate the tip-sample contact stiffness k*. Local values for elastic properties such as the indentation modulus M can be determined from k* with the appropriate contact-mechanics models. To enable imaging at practical rates, we have developed a frequency-tracking circuit based on digital signal processor architecture to rapidly locate the contact-resonance frequencies at each image position. We present contact-resonance frequency images obtained using both flexural and torsional cantilever images as well as the corresponding vertical contact-stiffness (k*) image calculated from flexural frequency images. Methods to obtain elastic-modulus images of M from vertical contact-stiffness images are also discussed.
We estimated the excess risk of in-patient hospitalization in a large cohort of persons diagnosed with hepatitis C virus (HCV) infection, controlling for social deprivation. A total of 20 749 individuals diagnosed with HCV in Scotland by 31 December 2006 were linked to the Scottish hospital discharge database, and indirectly standardized hospitalization rates, adjusting for sex, age, year and deprivation were calculated. We observed significant excess morbidity considering episodes for: any diagnosis [standardized morbidity ratio (SMR) 3·4, 95% CI 3·3–3·5]; liver-related diagnoses (SMR 41·3, 95% CI 39·6–43·0); and only non-liver-related diagnoses (SMR 2·14, 95% CI 2·08–2·19). Cox regression analyses of the 2000–2006 data indicated increased relative risks of hospitalization for males [hazard ratio (HR) 1·1, 95% CI 1·0–1·2], older age (per 10 years) (HR 1·55, 95% CI 1·5–1·6), and those testing HIV-positive (HR 1·6, 95% CI 1·3–1·8). This study has revealed substantial excess all-cause and liver-related morbidity in the Scottish HCV-diagnosed population, even after allowing for deprivation.
The extant major psychiatric classifications DSM-IV, and ICD-10, are atheoretical and largely descriptive. Although this achieves good reliability, the validity of a medical diagnosis would be greatly enhanced by an understanding of risk factors and clinical manifestations. In an effort to group mental disorders on the basis of aetiology, five clusters have been proposed. This paper considers the validity of the fourth cluster, emotional disorders, within that proposal.
We reviewed the literature in relation to 11 validating criteria proposed by a Study Group of the DSM-V Task Force, as applied to the cluster of emotional disorders.
An emotional cluster of disorders identified using the 11 validators is feasible. Negative affectivity is the defining feature of the emotional cluster. Although there are differences between disorders in the remaining validating criteria, there are similarities that support the feasibility of an emotional cluster. Strong intra-cluster co-morbidity may reflect the action of common risk factors and also shared higher-order symptom dimensions in these emotional disorders.
Emotional disorders meet many of the salient criteria proposed by the Study Group of the DSM-V Task Force to suggest a classification cluster.
The organization of mental disorders into 16 DSM-IV and 10 ICD-10 chapters is complex and based on clinical presentation. We explored the feasibility of a more parsimonious meta-structure based on both risk factors and clinical factors.
Most DSM-IV disorders were allocated to one of five clusters as a starting premise. Teams of experts then reviewed the literature to determine within-cluster similarities on 11 predetermined validating criteria. Disorders were included and excluded as determined by the available data. These data are intended to inform the grouping of disorders in the DSM-V and ICD-11 processes.
The final clusters were neurocognitive (identified principally by neural substrate abnormalities), neurodevelopmental (identified principally by early and continuing cognitive deficits), psychosis (identified principally by clinical features and biomarkers for information processing deficits), emotional (identified principally by the temperamental antecedent of negative emotionality), and externalizing (identified principally by the temperamental antecedent of disinhibition).
Large groups of disorders were found to share risk factors and also clinical picture. There could be advantages for clinical practice, public administration and research from the adoption of such an organizing principle.
The extant major psychiatric classifications, DSM-IV and ICD-10, are purportedly atheoretical and largely descriptive. Although this achieves good reliability, the validity of a medical diagnosis is greatly enhanced by an understanding of both risk factors and clinical history. In an effort to group mental disorders on the basis of risk factors and clinical manifestations, five clusters have been proposed. The purpose of this paper is to consider the position of bipolar disorder (BPD), which could be either with the psychoses, or with emotional disorders, or in a separate cluster.
We reviewed the literature on BPD, unipolar depression (UPD) and schizophrenia in relation to 11 validating criteria proposed by the DSM-V Task Force Study Group, and then summarized similarities and differences between BPD and schizophrenia on the one hand, and UPD on the other.
There are differences, often substantial and never trivial, for 10 of the 11 validators between BPD and UPD. There are also important differences between BPD and schizophrenia.
BPD has previously been classified together with UPD, but this is the least justifiable place for it. If it is to be recruited to a ‘psychotic cluster’, there are several important respects in which it differs from schizophrenia, so the cluster would have a division within it. The alternative would be to allow it to be in an intermediate position in a cluster of its own.