The spatial structure of Phanerozoic marine animal diversity.

The global fossil record of marine animals has fueled long-standing debates about diversity change through time and the drivers of this change. However, the fossil record is not truly global. It varies considerably in geographic scope and in the sampling of environments among intervals of geological time. We account for this variability using a spatially explicit approach to quantify regional-scale diversity through the Phanerozoic. Among-region variation in diversity is comparable to variation through time, and much of this is explained by environmental factors, particularly the extent of reefs. By contrast, influential hypotheses of diversity change through time, including sustained long-term increases, have little explanatory power. Modeling the spatial structure of the fossil record transforms interpretations of Phanerozoic diversity patterns and their macroevolutionary explanations. This necessitates a refocus of deep-time diversification studies.

Surface wipe and bulk sampling of household dust: arsenic exposure in Cornwall, UK.

Dust elemental levels can be expressed as concentrations (bulk samples) or surface loadings (wipe samples). Wipe sampling has not been widely adopted for elements other than lead (Pb). In this study, 433 wipe samples from 130 households in south west England - a region of widespread, natural and anthropogenic arsenic contamination linked with previous mining activities-were analysed to (i) quantify loadings of arsenic (As); (ii) assess the quality of wipe data using QA/QC criteria; (iii) estimate, using published ingestion rates, human exposure to As in dust using loadings and concentrations from 97 bulk samples and (iv) comparatively assess the performance of wipe and bulk sampling using associations with As biomonitoring data (urine, toenails and hair). Good QC performance was observed for wipes: strong agreement between field duplicates, non-detectable contamination of field blank wipes and good reference material recoveries. Arsenic loadings exceeded an existing urban background benchmark in 67 (52%) households. No exceedances of tolerable daily As intake were observed for adult exposure estimates but infant estimates exceeded for 1 household. Infant estimates calculated using bulk concentrations resulted in 4 (3%) exceedances. Neither wipe nor bulk As metrics were sufficiently better predictors of As in biospecimens. Sampling strategies, analytical protocols, exposure metrics and assessment criteria require refinement to validate dust sampling methodologies.

A seroprevalence study to determine the frequency of hantavirus infection in people exposed to wild and pet fancy rats in England.

Recent cases of acute kidney injury due to Seoul hantavirus infection from exposure to wild or pet fancy rats suggest this infection is increasing in prevalence in the UK. We conducted a seroprevalence study in England to estimate cumulative exposure in at-risk groups with contact with domesticated and wild rats to assess risk and inform public health advice. From October 2013 to June 2014, 844 individual blood samples were collected. Hantavirus seroprevalence amongst the pet fancy rat owner group was 34.1% (95% CI 23·9-45·7%) compared with 3·3% (95% CI 1·6-6·0) in a baseline control group, 2·4% in those with occupational exposure to pet fancy rats (95% CI 0·6-5·9) and 1·7% with occupational exposure to wild rats (95% CI 0·2-5·9). Variation in seroprevalence across groups with different exposure suggests that occupational exposure to pet and wild rats carries a very low risk, if any. However incidence of hantavirus infection among pet fancy rat owners/breeders, whether asymptomatic, undiagnosed mild viral illness or more severe disease may be very common and public health advice needs to be targeted to this at-risk group.

Urinary arsenic profiles reveal exposures to inorganic arsenic from private drinking water supplies in Cornwall, UK.

Private water supplies (PWS) in Cornwall, South West England exceeded the current WHO guidance value and UK prescribed concentration or value (PCV) for arsenic of 10 µg/L in 5% of properties surveyed (n = 497). In this follow-up study, the first of its kind in the UK, volunteers (n = 207) from 127 households who used their PWS for drinking, provided urine and drinking water samples for total As determination by inductively coupled plasma mass spectrometry (ICP-MS) and urinary As speciation by high performance liquid chromatography ICP-MS (HPLC-ICP-MS). Arsenic concentrations exceeding 10 µg/L were found in the PWS of 10% of the volunteers. Unadjusted total urinary As concentrations were poorly correlated (Spearman's ρ = 0.36 (P < 0.001)) with PWS As largely due to the use of spot urine samples and the dominance of arsenobetaine (AB) from seafood sources. However, the osmolality adjusted sum, U-As(IMM), of urinary inorganic As species, arsenite (As(III)) and arsenate (As(V)), and their metabolites, methylarsonate (MA) and dimethylarsinate (DMA), was found to strongly correlate (Spearman's ρ: 0.62 (P < 0.001)) with PWS As, indicating private water supplies as the dominant source of inorganic As exposure in the study population of PWS users.

Prolonged exposure to arsenic in UK private water supplies: toenail, hair and drinking water concentrations.

Chronic exposure to arsenic (As) in drinking water is an established cause of cancer and other adverse health effects. Arsenic concentrations >10 µg L(-1) were previously measured in 5% of private water supplies (PWS) in Cornwall, UK. The present study investigated prolongued exposure to As by measuring biomarkers in hair and toenail samples from 212 volunteers and repeated measurements of As in drinking water from 127 households served by PWS. Strong positive Pearson correlations (rp = 0.95) indicated stability of water As concentrations over the time period investigated (up to 31 months). Drinking water As concentrations were positively correlated with toenail (rp = 0.53) and hair (rp = 0.38) As concentrations - indicative of prolonged exposure. Analysis of washing procedure solutions provided strong evidence of the effective removal of exogenous As from toenail samples. Significantly higher As concentrations were measured in hair samples from males and smokers and As concentrations in toenails were negatively associated with age. A positive association between seafood consumption and toenail As and a negative association between home-grown vegetable consumption and hair As was observed for volunteers exposed to <1 As µg L(-1) in drinking water. These findings have important implications regarding the interpretation of toenail and hair biomarkers. Substantial variation in biomarker As concentrations remained unaccounted for, with soil and dust exposure as possible explanations.

Variability in the chemistry of private drinking water supplies and the impact of domestic treatment systems on water quality.

Tap water from 497 properties using private water supplies, in an area of metalliferous and arsenic mineralisation (Cornwall, UK), was measured to assess the extent of compliance with chemical drinking water quality standards, and how this is influenced by householder water treatment decisions. The proportion of analyses exceeding water quality standards were high, with 65 % of tap water samples exceeding one or more chemical standards. The highest exceedances for health-based standards were nitrate (11 %) and arsenic (5 %). Arsenic had a maximum observed concentration of 440 µg/L. Exceedances were also high for pH (47 %), manganese (12 %) and aluminium (7 %), for which standards are set primarily on aesthetic grounds. However, the highest observed concentrations of manganese and aluminium also exceeded relevant health-based guidelines. Significant reductions in concentrations of aluminium, cadmium, copper, lead and/or nickel were found in tap waters where households were successfully treating low-pH groundwaters, and similar adventitious results were found for arsenic and nickel where treatment was installed for iron and/or manganese removal, and successful treatment specifically to decrease tap water arsenic concentrations was observed at two properties where it was installed. However, 31 % of samples where pH treatment was reported had pH < 6.5 (the minimum value in the drinking water regulations), suggesting widespread problems with system maintenance. Other examples of ineffectual treatment are seen in failed responses post-treatment, including for nitrate. This demonstrates that even where the tap waters are considered to be treated, they may still fail one or more drinking water quality standards. We find that the degree of drinking water standard exceedances warrant further work to understand environmental controls and the location of high concentrations. We also found that residents were more willing to accept drinking water with high metal (iron and manganese) concentrations than international guidelines assume. These findings point to the need for regulators to reinforce the guidance on drinking water quality standards to private water supply users, and the benefits to long-term health of complying with these, even in areas where treated mains water is widely available.

Towards quantitative, atomic-resolution reconstruction of the electrostatic potential via differential phase contrast using electrons.

Differential phase contrast images in scanning transmission electron microscopy can be directly and quantitatively related to the gradient of the projected specimen potential provided that (a) the specimen can be treated as a phase object and (b) full 2D diffraction patterns as a function of probe position can be obtained. Both are challenging to achieve in atomic resolution imaging. The former is fundamentally limited by probe spreading and dynamical electron scattering, and we explore its validity domain in the context of atomic resolution differential phase contrast imaging. The latter, for which proof-of-principle experimental data sets exist, is not yet routine. We explore the extent to which more established segmented detector geometries can instead be used to reconstruct a quantitatively good approximation to the projected specimen potential.

Preparedness for a major incident: creation of an epidemiology protocol for a health protection register in England.

Large incidents and natural disasters are on the increase globally. They can have a major impact lasting many years or decades; and can affect large groups of people including those that are more susceptible to adverse consequences. Following a major incident, it may be considered necessary to establish a register of those people affected by the incident to provide appropriate advice on relevant immediate and longer-term public health interventions that may be required, provide reassurance to the public that their care is paramount, to reassure the worried well to avoid them inappropriately overwhelming local services, and to facilitate epidemiological investigations. Arrangements for the prompt follow-up of populations after large incidents or disasters have been agreed in England and a protocol for establishing a register of individuals potentially affected by a large incident has been developed. It is important for countries to have a protocol for implementing a health register if the circumstances require one to be in place, and are supported by Public Health Authorities. Health registers facilitate the initial descriptive epidemiology of exposure and provide the opportunity of carrying out long term analytical studies on the affected population. Such epidemiological studies provide a greater understanding of the impact that a large incident can have on health, which in turn helps in the planning of health care provision. Registers can also assist more directly in providing access to individuals in need of physical and mental health interventions. The challenge that still remains is to formally pilot the register in the field and refine it based on that experience.

What are the costs and benefits of patient notification exercises following poor infection control practices in dentistry?

BACKGROUND: Allegations of serious failures in infection control practice were made against a dentist practicing in the South West of England. The dentist (who tested negative for Blood Borne Viruses (BBVs)) was immediately suspended. METHODS: Because inadequate infection control presents a potential risk of transmitting BBVs between patients, a notification exercise was undertaken. Of 7625 patients contacted, 2780 (37%) were tested. RESULTS: Nine cases of Hepatitis B (HBV) and four cases of Hepatitis C (HCV) were identified, of which seven were previously diagnosed. None of these were children. All of the six newly diagnosed cases had recognized risk factors for BBVs. The costs of the notification exercise were estimated at £311,500 of which £165,000 was staff costs, (£51,916 per newly diagnosed case). CONCLUSION: This study did not demonstrate any patient-to-patient transmission of blood-borne viruses but the response rate was relatively low. There are significant costs associated with undertaking notification exercises. These findings should inform future recommendations and practice in this area.

Indoor carbon monoxide: a case study in England for detection and interventions to reduce population exposure.

BACKGROUND: Potential exposure to carbon monoxide (CO) in private homes is largely unquantified. AIM: To estimate prevalence of potential exposure to CO in residential dwellings and describe associated interventions in an inner-city community. METHODS: A housing association in London, Hackney Homes, began fitting CO alarms in the 22,831 local authority homes it is responsible for in January 2010. A gas engineer investigated each alarm activation and recorded the information on a standard form. We undertook a cross-sectional study of all 22,831 homes, using data from these forms. Descriptive analysis was performed, including incidence, monthly variation, cause of alarm activation, and actions taken. RESULTS: Between November 2011 and April 2012, 106 incidents were reported. Of these, 34.6% identified an issue with a gas appliance, and 10.6% identified misuse of cooking methods as the cause of activation. Relevant interventions were put in place, including disconnection of the gas appliance and education around cooking methods. DISCUSSION: Little is known about the burden of CO poisoning in residential dwellings. This study provides important information on the path to quantifying population exposure to CO as well as establishing a possible approach to access this key information and realistic interventions to reduce potential exposure.

The role of conjugated linoleic acid in reducing body fat and preventing holiday weight gain.

OBJECTIVE: The incidence of obesity and overweight in the US has increased considerably during the past two decades and currently affects 65% of the adult population. Research has indicated that small, yet irreversible, gains during the holiday season contribute to increases in weight during adulthood. Conjugated linoleic acid (CLA), a naturally occurring dietary fatty acid, has been found to reduce weight gain and dramatically decrease fat mass in animals. Although research in humans has shown inconsistent results, most studies have been of insufficient duration or have utilized body composition methods that are less accurate than the currently accepted criterion. DESIGN: Randomized, double-blind, placebo-controlled study of 3.2 g/day CLA for 6 months. SUBJECTS: Forty healthy, overweight subjects (age: 18-44 years; body mass index: 25-30 kg/m(2)). MEASUREMENTS: Body composition by the four-compartment model, resting metabolic rate (RMR) by indirect calorimetry, self-reported physical activity and dietary intake, and blood chemistries were determined at baseline and after 6 months. Body weight was measured monthly during the pre-holiday season (August-October), holiday season (November-December) and post-holiday season (January-March). Adverse events were assessed monthly. RESULTS: Compared to CLA, the placebo group showed a greater rate of weight gain during the holiday season (P=0.01). Within the placebo group, holiday weight change was significantly greater compared to the pre-holiday period (August-October) (P=0.03). Six-month change in body composition was improved with CLA compared to placebo (P=0.02), and body fat was significantly reduced within the CLA group (-1.0+/-2.2 kg, P=0.05). CLA had no effect on RMR, physical activity or dietary intake. The rate of reported negative emotions decreased significantly with CLA, although there was no difference in any other category of adverse event. In comparison to the placebo, CLA did not affect insulin resistance, blood lipids and markers of liver function or markers of inflammation, with the exception of a significant decrease in a biomarker of endothelial dysfunction. CONCLUSION: CLA supplementation among overweight adults significantly reduced body fat over 6 months and prevented weight gain during the holiday season. Although no adverse effects were seen, additional studies should evaluate the effect of prolonged use of CLA.

Provenance of a New Zealand brush-tailed rock-wallaby (Petrogale penicillata) population determined by mitochondrial DNA sequence analysis.

Modern molecular genetic techniques provide a valuable means to address questions concerning the origins of naturalized populations. Brush-tailed rock-wallabies (Petrogale penicillata), of unknown provenance, were introduced to New Zealand from Australia in the early 1870s. While the introduced wallabies prospered in New Zealand, their antecedents in Australia experienced widespread local population extinctions as part of a drastic, widespread and ongoing decline. In this study, a polymerase chain reaction-single-strand conformation polymorphism analysis was undertaken of mitochondrial DNA (mtDNA) control region sequences from P. penicillata in New Zealand (n = 18) and throughout the species' native range in southeastern Australia (n = 54). A single mtDNA haplotype was identified in New Zealand, while 17 haplotypes were found in sampled Australian populations. Phylogenetic analysis (583 bp sequence) revealed the presence of three divergent mtDNA groups within Australian P. penicillata, with each group showing distinct geographical circumscription. The New Zealand haplotype consistently clustered within the central New South Wales group and was most similar (0.55% sequence divergence) to a haplotype from Winmalee, just west of Sydney. It seems likely then, that the New Zealand population of P. penicillata was founded by animals captured near Sydney in the late 19th century. Since P. penicillata in this region have experienced widespread population declines and extinctions, the naturalized New Zealand population represents a potentially valuable conservation resource for Australia. However, the unusual history of New Zealand's P. penicillata presents unique challenges to Australian wildlife managers.

Accuracy assessment of layer decomposition using simulated angiographic image sequences.

Layer decomposition is a promising method for obtaining accurate densitometric profiles of diseased coronary artery segments. This method decomposes coronary angiographic image sequences into moving densitometric layers undergoing translation, rotation, and scaling. In order to evaluate the accuracy of this technique, we have developed a technique for embedding realistic simulated moving stenotic arteries in real clinical coronary angiograms. We evaluate the accuracy of layer decomposition in two ways. First, we compute tracking errors as the distance between the true and estimated motion of a reference point in the arterial lesion. We find that noise-weighted phase correlation and layered background subtraction are superior to cross correlation and fixed mask subtraction, respectively. Second, we compute the correlation coefficient between the true vessel profile and the raw and processed images in the region of the stenosis. We find that layer decomposition significantly improves the correlation coefficient.

Reliability of bimanual pelvic examinations performed in emergency departments.

OBJECTIVE: To test the reliability of bimanual pelvic examinations performed in emergency departments by emergency medicine physicians. DESIGN: Prospective observational study; 2 examiners each recorded various pelvic examination findings on 186 patients. SETTING: A private university hospital and a public county hospital staffed by attending emergency medicine physicians who share an emergency medicine residency program. SUBJECTS: Senior resident (3rd or 4th year) and attending emergency physicians. MAIN OUTCOME MEASURES: Percentage of agreement and percentage of positive agreement for cervical motion tenderness, uterine tenderness, adnexal tenderness, adnexal mass, and uterine size (within 2 cm). RESULTS: The agreement ranged between 71% and 84%, but the percentage of positive agreement was much lower, ranging from 17% to 33%. Agreement for uterine size, within 2 cm, was 60%. CONCLUSION: The findings of bimanual pelvic examinations performed by emergency physicians in an emergency department have poor interexaminer reliability.

Tropane alkaloid production by shoot culture of Duboisia myoporoides R. Br.

This work demonstrates the presence of hyoscyamine and scopolamine at different stages of shoot regeneration from non-organogenic and organogenic calli. The 11-week-old non-organogenic calli contained 0.41+/-0.03 and 0.23+/-0.02 microg g(-1) dry wt hyoscyamine and scopolamine respectively. However, no root meristem was found in the calli. The alkaloids were absent in 2-week-old organogenic calli. The shoot-buds induced on the non-organogenic and organogenic calli did not contain these alkaloids. Hyoscyamine and scopolamine contents of the 6-week-old non-rooted shoots regenerated from non-organogenic calli were 7.8+/-0.1 and 6.5+/-0.4 microg g(-1) dry wt respectively and those in the 9-week-old non-rooted shoot regenerated from organogenic calli were 38.5+/-0.4 and 3.6+/-0.1 microg g(-1) dry wt respectively. Hyoscyamine and scopolamine contents of the 4-week-old roots regenerated from non-organogenic and organogenic calli were higher than those in the non-rooted shoots. Since the presence of hyoscyamine and scopolamine in the non-rooted shoot depends on the stage of differentiation, manipulation of culture environment may improve hyoscyamine and scopolamine contents of the non-rooted shoots.

Simulating coronary arteries in x-ray angiograms.

Clinical validation of quantitative coronary angiography (QCA) algorithms is difficult due to the lack of a simple alternative method for accurately measuring in vivo vessel dimensions. We address this problem by embedding simulated coronary artery segments with known geometry in clinical angiograms. Our vessel model accounts for the profile of the vessel, x-ray attenuation in the original background, and noise in the imaging system. We have compared diameter measurements of our computer simulated arteries with measurements of an x-ray Telescopic-Shaped Phantom (XTSP) with the same diameters. The results show that for both uniform and anthropomorphic backgrounds there is good agreement in the measured diameters of XTSP compared to the simulated arteries (Pearson's correlation coefficient 0.99). In addition, the difference in accuracy and precision of the true diameter measures compared to the XTSP and simulated artery diameters was small (mean absolute error across all diameters was < or = 0.11 mm +/- 0.09 mm).

X-ray videodensitometric methods for blood flow and velocity measurement: a critical review of literature.

Blood flow rate and velocity are important parameters for the study of vascular systems, and for the diagnosis, monitoring and evaluation of treatment of cerebro- and cardiovascular disease. For rapid imaging of cerebral and cardiac blood vessels, digital x-ray subtraction angiography has numerous advantages over other modalities. Roentgen-videodensitometric techniques measure blood flow and velocity from changes of contrast material density in x-ray angiograms. Many roentgen-videodensitometric flow measurement methods can also be applied to CT, MR and rotational angiography images. Hence, roentgen-videodensitometric blood flow and velocity measurement from digital x-ray angiograms represents an important research topic. This work contains a critical review and bibliography surveying current and old developments in the field. We present an extensive survey of English-language publications on the subject and a classification of published algorithms. We also present descriptions and critical reviews of these algorithms. The algorithms are reviewed with requirements imposed by neuro- and cardiovascular clinical environments in mind.

Regularization method for scatter-glare correction in fluoroscopic images.

Fluoroscopic images are degraded by scattering of x-rays from within the patient and by veiling glare in the image intensifier. Both of these degradations are well described by a response function applied to either the scatter-free or primary intensity. The response function is variable, with dependence on such factors as patient thickness and imaging geometry. We describe an automated regularization technique for obtaining response function parameters with a minimal loss of signal. This method requires a high-transmission structured reference object to be interposed between the x-ray source and the subject. We estimate the parameters by minimizing residual correlations between the reference object and the computed subject density after a scatter-glare correction. We use simulated images to evaluate our method for both ideal and clinically realistic conditions. We find that the residual root-mean-square (rms) error ideally decreases with an increasing number of independent pixels (N) as (1/N)1/2. In simulated 256x256 angiograms mean normalized rms errors were reduced from 40% to 11% in noise-free images, and from 41% to 17% in noisy images, with a similar improvement in densitometric vessel cross-section measurements. These results demonstrate the validity of the method for simulated images and characterize its expected performance on clinical images.

Comparison of methods for instantaneous angiographic blood flow measurement.

Several different algorithms have been reported for measurement of blood flow rates and velocities from digital x-ray angiograms. We compare four videodensitometric methods: (1) distance-density curve matching (DDCM), (2) distance-density curve matching with curve-fitting (DDCM-F), (3) bolus mass tracking with curve-fitting (BMT-F) and (4) fluid continuity method (FCM). We tested the flow algorithms with simulated angiograms and with images obtained from a programmable flow phantom under clinically realistic flow and contrast injection conditions including imperfect mixing. All methods perform well for simulated angiograms. On phantom angiograms with constant flow, all methods tended to underestimate flow velocities by at least 7% and demonstrate high variability between consecutive measurements. The FCM demonstrated relatively low variability, but a large negative bias. The DDCM method was moderately biased and had the highest variability. The BMT-F method demonstrated the lowest bias (-7.1%) and the lowest variability both within (27%) and between (27%) studies. No method yields reliable measurements near the peak contrast opacification, when little or no gradient of contrast is present. The extrapolating version of the BMT-F method was also the most robust for estimation of interframe displacements longer than the field of view.