Anchoring genome sequence to chromosomes of the central bearded dragon (Pogona vitticeps) enables reconstruction of ancestral squamate macrochromosomes and identifies sequence content of the Z chromosome.

BACKGROUND: Squamates (lizards and snakes) are a speciose lineage of reptiles displaying considerable karyotypic diversity, particularly among lizards. Understanding the evolution of this diversity requires comparison of genome organisation between species. Although the genomes of several squamate species have now been sequenced, only the green anole lizard has any sequence anchored to chromosomes. There is only limited gene mapping data available for five other squamates. This makes it difficult to reconstruct the events that have led to extant squamate karyotypic diversity. The purpose of this study was to anchor the recently sequenced central bearded dragon (Pogona vitticeps) genome to chromosomes to trace the evolution of squamate chromosomes. Assigning sequence to sex chromosomes was of particular interest for identifying candidate sex determining genes. RESULTS: By using two different approaches to map conserved blocks of genes, we were able to anchor approximately 42 % of the dragon genome sequence to chromosomes. We constructed detailed comparative maps between dragon, anole and chicken genomes, and where possible, made broader comparisons across Squamata using cytogenetic mapping information for five other species. We show that squamate macrochromosomes are relatively well conserved between species, supporting findings from previous molecular cytogenetic studies. Macrochromosome diversity between members of the Toxicofera clade has been generated by intrachromosomal, and a small number of interchromosomal, rearrangements. We reconstructed the ancestral squamate macrochromosomes by drawing upon comparative cytogenetic mapping data from seven squamate species and propose the events leading to the arrangements observed in representative species. In addition, we assigned over 8 Mbp of sequence containing 219 genes to the Z chromosome, providing a list of genes to begin testing as candidate sex determining genes. CONCLUSIONS: Anchoring of the dragon genome has provided substantial insight into the evolution of squamate genomes, enabling us to reconstruct ancestral macrochromosome arrangements at key positions in the squamate phylogeny, demonstrating that fusions between macrochromosomes or fusions of macrochromosomes and microchromosomes, have played an important role during the evolution of squamate genomes. Assigning sequence to the sex chromosomes has identified NR5A1 as a promising candidate sex determining gene in the dragon.

Frequent callers to the ambulance service: patient profiling and impact of case management on patient utilisation of the ambulance service.

BACKGROUND: A minority of patients make frequent and excessive calls to the ambulance service, placing a significant burden on limited resources at a time when demand on urgent and emergency care systems is steadily increasing. Little is known about the reasons underlying frequent caller behaviour or the best way to manage this group of patients. OBJECTIVES: The present study aimed to (i) profile frequent callers to the ambulance service and (ii) evaluate the impact of a case management interventional approach on frequent caller behaviour. METHODS: A retrospective review of data from a 2-year period (from 1 April 2009 to 31 March 2011) was conducted. Patients were included in the analysis if they had been accepted for case management intervention by the Patient-Centred Action Team during this period and met the study inclusion criteria. RESULTS: The review identified 110 frequent callers who met the study inclusion criteria. The majority of frequent callers (86%) had multiple and complex reasons for calling, including frequent medical need, acute or chronic mental health condition, older age and unmet personal or social care needs. In the majority of cases (82%), multiple interventional strategies were required. A significant reduction in median call volume was observed from preintervention to postintervention (from five calls/month to zero calls/month). CONCLUSIONS: Effective management of this complex patient group requires an individualised case management approach in order to identify and tackle the underlying causes of behaviour.

Does use of the recognition of stroke in the emergency room stroke assessment tool enhance stroke recognition by ambulance clinicians?

BACKGROUND AND PURPOSE: U.K ambulance services assess patients with suspected stroke using the Face Arm Speech Test (FAST). The Recognition Of Stroke In the Emergency Room (ROSIER) tool has been shown superior to the FAST in identifying strokes in emergency departments but has not previously been tested in the ambulance setting. We investigated whether ROSIER use by ambulance clinicians can improve stroke recognition. METHODS: Ambulance clinicians used the ROSIER in place of the FAST to assess patients with suspected stroke. As the ROSIER includes all FAST elements, we calculated a FAST score from the ROSIER to enable comparisons between the two tools. Ambulance clinicians' provisional stroke diagnoses using the ROSIER and calculated FAST were compared with stroke consultants' diagnosis. We used stepwise logistic regression to compare the contribution of individual ROSIER and FAST items and patient demographics to the prediction of consultants' diagnoses. RESULTS: Sixty-four percent of strokes and 78% of nonstrokes identified by ambulance clinicians using the ROSIER were subsequently confirmed by a stroke consultant. There was no difference in the proportion of strokes correctly detected by the ROSIER or FAST with both displaying excellent levels of sensitivity. The ROSIER detected marginally more nonstroke cases than the FAST, but both demonstrated poor specificity. Facial weakness, arm weakness, seizure activity, age, and sex predicted consultants' diagnosis of stroke. CONCLUSIONS: The ROSIER was not better than the FAST for prehospital recognition of stroke. A revised version of the FAST incorporating assessment of seizure activity may improve stroke identification and decision making by ambulance clinicians.

Sequence and gene content of a large fragment of a lizard sex chromosome and evaluation of candidate sex differentiating gene R-spondin 1.

BACKGROUND: Scant genomic information from non-avian reptile sex chromosomes is available, and for only a few lizards, several snakes and one turtle species, and it represents only a small fraction of the total sex chromosome sequences in these species. RESULTS: We report a 352 kb of contiguous sequence from the sex chromosome of a squamate reptile, Pogona vitticeps, with a ZZ/ZW sex microchromosome system. This contig contains five protein coding genes (oprd1, rcc1, znf91, znf131, znf180), and major families of repetitive sequences with a high number of copies of LTR and non-LTR retrotransposons, including the CR1 and Bov-B LINEs. The two genes, oprd1 and rcc1 are part of a homologous syntenic block, which is conserved among amniotes. While oprd1 and rcc1 have no known function in sex determination or differentiation in amniotes, this homologous syntenic block in mammals and chicken also contains R-spondin 1 (rspo1), the ovarian differentiating gene in mammals. In order to explore the probability that rspo1 is sex determining in dragon lizards, genomic BAC and cDNA clones were mapped using fluorescence in situ hybridisation. Their location on an autosomal microchromosome pair, not on the ZW sex microchromosomes, eliminates rspo1 as a candidate sex determining gene in P. vitticeps. CONCLUSION: Our study has characterized the largest contiguous stretch of physically mapped sex chromosome sequence (352 kb) from a ZZ/ZW lizard species. Although this region represents only a small fraction of the sex chromosomes of P. vitticeps, it has revealed several features typically associated with sex chromosomes including the accumulation of large blocks of repetitive sequences.

The Ability of Self-Report Methods to Accurately Diagnose Attention Deficit Hyperactivity Disorder: A Systematic Review.

OBJECTIVE: To identify and analyze all studies validating rating scales or interview-based screeners commonly used to evaluate ADHD in adults. METHOD: A systematic literature search identified all studies providing diagnostic accuracy statistics, including sensitivity and specificity, supplemented by relevant articles or test manuals referenced in reviewed manuscripts. RESULTS: Only 20 published studies or manuals provided data regarding sensitivity and specificity when tasked with differentiating those with and without ADHD. While all screening measures have excellent ability to correctly classify non-ADHD individuals (with negative predictive values exceeding 96%), false positive rates were high. At best, positive predictive values in clinical samples reached 61%, but most fell below 20%. CONCLUSION: Clinicians cannot rely on scales alone to diagnose ADHD and must undertake more rigorous evaluation of clients who screen positive. Furthermore, relevant classification statistics must be included in publications to help clinicians make statistically defensible decisions. Otherwise, clinicians risk inappropriately diagnosing ADHD.

Food for folivores: nutritional explanations linking diets to population density.

Ecologists want to explain why populations of animals are not evenly distributed across landscapes and often turn to nutritional explanations. In seeking to link population attributes with food quality, they often contrast nutritionally positive traits, such as the concentration of nitrogen, against negative ones, such as fibre concentration, by using a ratio of these traits. This specific ratio has attracted attention because it sometimes correlates with the biomass of colobine primates across sites in Asia and Africa. Although empirically successful, we have identified problems with the ratio that may explain why it fails under some conditions to predict colobine biomass. First, available nitrogen, rather than total nitrogen, is nutritionally important, while the presence of tannins is the major factor reducing the availability of nitrogen in browse plant species. Second, tannin complexes inflate measures of fibre. Finally, simple ratios may be unsound statistically because they implicitly assume isometric relationships between variables. We used data on the chemical composition of plants from three continents to examine the relationships between the concentrations of nitrogen, available nitrogen, fibre and tannins in foliage and to evaluate the nitrogen to fibre ratio. Our results suggest that the ratio of the concentration of nitrogen to fibre in leaves does sometimes closely correlate with the concentration of available nitrogen. However, the ratio may give misleading results when leaves contain high concentrations of tannins. The concentration of available nitrogen, which incorporates measures of total nitrogen, dry matter digestibility and tannins, should give a better indication of the nutritional value of leaves for herbivorous mammals that can readily be extrapolated to habitats.

Symptom exaggeration in post-secondary students: preliminary base rates in a Canadian sample.

Recent studies conducted at American post-secondary institutions report that a high proportion of college students seeking evaluations for either attention-deficit/hyperactivity disorder or learning disorders fail symptom validity tests (SVTs), calling into question the validity of their performance on standardized assessment measures. The current study undertook to investigate the rate of SVT failure in a Canadian post-secondary sample, drawing on assessment data from a large regional assessment facility. Evaluating the data from 144 consecutively tested students, the present study found that 14.6% of students failed an SVT, and those who failed returned lower scores on many other assessment measures compared with those who passed. These findings indicate that the rate of symptom exaggeration or low test-taking effort may be lower in Canadian samples than in U.S. samples but still represents a substantial number of students. Recommendations and suggestions for future directions are discussed.

Identifying students feigning dyslexia: preliminary findings and strategies for detection.

When conducting psychological evaluations, clinicians typically assume that individuals being evaluated are putting forth maximal effort and are not exaggerating or magnifying symptom complaints. Recent research, however, suggests that students undergoing post-secondary-level assessments to document learning difficulties may not always put forth their best effort, and may even be motivated to exaggerate or magnify symptoms. This paper presents evidence indicating that symptom exaggeration in this context is not only possible, but is indistinguishable from valid symptomatology when it occurs. We argue that symptom validity assessment should be included in all higher-education assessments for dyslexia and other specific learning disorders, and suggest some preliminary strategies for detection.

Identifying students faking ADHD: Preliminary findings and strategies for detection.

When conducting psychological evaluations, clinicians typically assume that the subject being evaluated is putting forth maximal effort and is not exaggerating or magnifying symptom complaints. While the field of neuropsychology has identified that factors, such as effort and motivation, can significantly interfere with correct interpretation of self-reported symptoms and test scores, evaluation methods for other psychological conditions, such as attention deficit hyperactivity disorder (ADHD) have not addressed effort and motivation as potential factors influencing accurate diagnosis. In analyzing the performance of students simulating ADHD, and comparing it to performance of both non-ADHD and genuine ADHD students, this study clearly demonstrated that the symptoms of ADHD are easily fabricated, and that simulators would be indistinguishable from those with true ADHD. In addition, students motivated to feign ADHD could easily perform poorly on tests of reading and processing speed, thus allowing them access to academic accommodations. Implications of these findings are discussed.

Exercise-related sudden cardiac arrest in London: incidence, survival and bystander response.

OBJECTIVE: The study aimed to (1) establish the incidence of exercise-related sudden cardiac arrest (SCA) in London, (2) investigate survival from exercise-related SCA and (3) examine factors related to survival. METHOD: This retrospective observational study examined 2 years' data from the London Ambulance Service (LAS) cardiac arrest registry for patients in whom resuscitation was attempted following an out-of-hospital cardiac arrest (OHCA), a cardiac cause was presumed and the arrest occurred during or within 1 h of exercise. RESULTS: The incidence of exercise-related SCA in London was estimated to be 0.6 per 100 000 person-years which equated to 0.5% of all OHCA, and 1.5% of all OHCA with presumed cardiac aetiology and resuscitation attempted. The majority of cases were male and the incidence increased from age 40 years. Just under one-third of patients survived to hospital discharge. Survival in the Utstein comparator group (cases with presumed cardiac aetiology, resuscitation attempted, bystander witnessed and a presenting cardiac rhythm of ventricular fibrillation or tachycardia) was higher at 42%. Survival was significantly associated with initial cardiac rhythm (χ(2)=17.5, df=2, p<0.001) and bystander defibrillation (Fisher's exact test, p<0.05). CONCLUSIONS: Incidence of exercise-related SCA in the general population in London is rare. Survival following exercise-related SCA was considerably higher than survival for all OHCA with presumed cardiac aetiology and resuscitation attempted attended by the LAS during the same period. The major limitation of the study is the likely under identification of cases of exercise-related SCA.

Thinking about thinking about pain: a qualitative investigation of rumination in chronic pain.

UNLABELLED: SUMMARY  AIMS: A thinking process central to the etiology of emotional disorders, rumination is commonly observed in chronic pain. However, very little is understood about the characteristics of pain-related rumination and the mechanisms through which rumination impacts on pain perception and disability. This study began investigating this cognitive phenomenon by qualitatively examining chronic pain patients' experience of rumination. METHODS: Semistructured interviews were conducted with 20 chronic pain patients. Themes were extracted from interview transcripts using thematic analysis. RESULTS: Six themes were extracted from interviews with frequent ruminators. These elucidated the pattern of rumination and suggested a reciprocal relationship of rumination with not only pain, but also negative emotions and sleeplessness. Frequent ruminators appeared to hold positive beliefs about rumination and negative beliefs about self in overcoming pain. Two themes were extracted from interviews with infrequent ruminators: implicating negative beliefs about rumination and the flexible use of disengagement strategies in these individuals. CONCLUSION: Rumination occurs frequently and can be easily triggered by pain, negative emotions and sleeplessness in patients who lack alternative coping strategies and believe rumination is a way to problem-solve. A tentative model of pain-related rumination has been proposed, outlining interesting hypotheses for rigorous empirical investigations.

Acid loads induced by the detoxification of plant secondary metabolites do not limit feeding by common brushtail possums (Trichosurus vulpecula).

We fed common brushtail possums artificial diets containing a buffer and the plant secondary metabolite (PSM), orcinol, to test the hypothesis that organic acids, common products of PSM metabolism, limit feeding by common brushtail possums (Trichosurus vulpecula). We introduced several diets containing orcinol and a buffer (urinary alkalising agent) over a course of three experiments. A diet containing 2% orcinol (wet matter) caused possums to reduce their food intake immediately, but feeding returned to normal 1-2 days later. Even though possums excreted strongly acidic urine (pH 5.1) and had perturbed nitrogen metabolism, they maintained their food intake and body mass until the experiment terminated 9 days after the introduction of orcinol. Possums ate 52% less when the basal diet contained 4% orcinol. As expected, the acid loads caused a change in the composition of urinary nitrogen with possums excreting more ammonium than urea and a large amount of unidentified nitrogenous material. Supplementing the diet containing orcinol with buffer neutralised the metabolic acid load and partly restored normal nitrogen metabolism, but did not restore feeding. Also, animals eating orcinol excreted normal amounts of 3-methylhistidine, indicating no increase in muscle protein catabolism. This suggests that a limitation to the rate of detoxification or toxicosis, rather than acid loads, limits the ingestion of acid-inducing PSMs.

An investigation of methods to detect feigned reading disabilities.

No clinically proven method currently exists to determine if a test taker is feigning or exaggerating symptoms of a specific reading disability (RD) for potential secondary gain (i.e., extra time on examinations, access to bursary funds, or tax benefits). Our objective was to examine the utility of previously proposed symptom validity measures (i.e., the Dyslexia Assessment of Simulation or Honesty [DASH] and the resulting Feigning Index [FI]) in discriminating students with genuine RDs from sophisticated simulators given ample time to prepare, who were warned that noncredible performance could be detected. The DASH correctly classified almost 83% of coached simulators with no false positives. The FI accurately classified 86% of post-secondary students feigning RD without misidentifying any students with a genuine RD, resulting in 91.8% overall classification accuracy. These two methods show promise as a means of detecting noncredible performance in the assessment of RD.