Molecular fingerprints resolve affinities of Rhynie chert organic fossils.

The affinities of extinct organisms are often difficult to resolve using morphological data alone. Chemical analysis of carbonaceous specimens can complement traditional approaches, but the search for taxon-specific signals in ancient, thermally altered organic matter is challenging and controversial, partly because suitable positive controls are lacking. Here, we show that non-destructive Fourier Transform Infrared Spectroscopy (FTIR) resolves in-situ molecular fingerprints in the famous 407 Ma Rhynie chert fossil assemblage of Aberdeenshire, Scotland, an important early terrestrial Lagerstätte. Remarkably, unsupervised clustering methods (principal components analysis and K-mean) separate the fossil spectra naturally into eukaryotes and prokaryotes (cyanobacteria). Additional multivariate statistics and machine-learning approaches also differentiate prokaryotes from eukaryotes, and discriminate eukaryotic tissue types, despite the overwhelming influence of silica. We find that these methods can clarify the affinities of morphologically ambiguous taxa; in the Rhynie chert for example, we show that the problematic "nematophytes" have a plant-like composition. Overall, we demonstrate that the famously exquisite preservation of cells, tissues and organisms in the Rhynie chert accompanies similarly impressive preservation of molecular information. These results provide a compelling positive control that validates the use of infrared spectroscopy to investigate the affinity of organic fossils in chert.

Strategic considerations for the sustainable remediation of nuclear installations.

Nuclear sites around the world are being decommissioned and remedial actions are being undertaken to enable the sites or parts of the sites to be reused. Although this is relatively straightforward for most sites, experience has suggested that preventative action is needed to minimise the impact of remediation activities on the environment and the potential burden to future generations. Removing all contamination in order to make a site suitable for any use generates waste and has associated environmental, social and economic detriments and benefits that should be taken into account. Recent experience of OECD Nuclear Energy Agency (NEA) member countries in the remediation of contaminated land, predominantly contaminated soil and groundwater, on nuclear sites during decommissioning has been assessed by an NEA task group. The experience was used to identify strategic considerations for nuclear site remediation, to consider the application of sustainability principles to nuclear site remediation, to describe good practice, and to make recommendations for further research and development. The key aspects that were identified were that 1) site remediation should be sustainable by resulting in an overall net benefit; and 2) an adaptive approach is essential in order to take into account the inherent uncertainty associated with the decommissioning and site remediation timescales. A report describing the findings was published by OECD/NEA in 2016. The conclusions provide insights to decision makers, regulators, implementers and stakeholders involved in nuclear site decommissioning so that they can achieve sustainable remediation of nuclear sites, now and in the future.

Performance measurement of a Canadian provincial tuberculosis programme: Manitoba, 2008-2012.

BACKGROUND: Performance measurement assists tuberculosis (TB) programmes in understanding areas of strength and weakness, and planning for improvements. Canada currently does not have a national comprehensive system for the measurement and analysis of TB programme performance. OBJECTIVE: To analyse the performance of a Canadian provincial TB programme using measures and targets based on those published by the US Centers for Disease Prevention and Control for 2015. DESIGN: Using provincial surveillance data from the Canadian province of Manitoba, we analysed key programme performance outcome measures (treatment completion, early detection, human immunodeficiency virus [HIV] testing, paediatric TB, retreatment, and contact elicitation and assessment) for people diagnosed with TB between 2008 and 2010. RESULTS: Significant outcome variation was found between Indigenous and non-Indigenous populations as well as within populations. The reporting rate of HIV testing was low. High rates of paediatric TB among Indigenous populations, particularly in rural areas, were found. Significantly better performance in HIV testing and reporting as well as in contact investigation was found for rural compared with urban Indigenous populations. Foreign-born persons had the lowest contact assessment rate. CONCLUSION: This study of TB programme performance in Manitoba demonstrates the viability of the approach in the Canadian context, and could help to identify key areas for TB programme improvement.

IFN-γ promoter polymorphisms do not affect QuantiFERON® TB Gold In-Tube test results in a Canadian population.

BACKGROUND: Several studies have shown polymorphisms within the interferon-gamma (IFN-γ) promoter influence cytokine expression. The interferon-gamma release assay (IGRA) relies on the ability to produce IFN-γ in response to tuberculosis (TB) specific antigens. This study determined the relationship between the IFN-γ +874 A/T promoter polymorphism and the performance of the QuantiFERON®-TB Gold In-Tube (QFT-GIT) test in an ethnically diverse Canadian population. METHODS: A total of 190 participants were categorised into three groups based on history of and exposure to TB: active TB (n = 55), TB exposed (n = 55) and presumably TB unexposed controls (n = 80). All participants underwent QFT-GIT testing, and DNA was extracted from whole blood and probed for polymorphism at position +874 (T/A) of intron 1 of IFN-γ. Statistical relationships between the QFT-GIT results, polymorphisms and demographic data were evaluated. RESULTS: IFN-γ +874 genotype frequencies among the entire study population (n = 190) were A/A (45.8%), T/A (39.5%), and T/T (14.7%). Among the three study groups, there was no correlation between QFT-GIT results and the IFN-γ +874 A/T genotype, and no correlation of genotype with IFN-γ production in response to either Mycobacterium tuberculosis antigens or mitogenic stimulation. CONCLUSION: Our results indicate that the IFN-γ +874 promoter polymorphism does not influence QFT-GIT performance in this study population.

Food chain model based on field data to predict westslope cutthroat trout (Oncorhynchus clarkii lewisi) ovary selenium concentrations from water selenium concentrations in the Elk Valley, British Columbia.

Previous studies conducted in the Elk River watershed showed that selenium concentrations are higher in aquatic biota in lentic compared to lotic habitats of the system having similar water selenium concentrations. Studies have also shown that water selenium concentrations have increased over time (~10% per year) and recent annual average concentrations have ranged up to 0.044 mg/L in areas downstream from mine discharges. For the present study, trophic transfer of selenium was characterized in lotic versus lentic habitats using concentrations measured in field-collected samples and assuming a three-step food chain of water to the base of the food web (biofilm), to benthic invertebrates, and then to westslope cutthroat trout (WCT) ovaries. Food chain models were developed for each habitat type (lotic and lentic) by combining linear regression equations for the three transfer relationships, allowing for prediction of fish ovary concentrations from water concentrations. Greater accumulation of selenium in lentic areas was mostly attributable to greater uptake at the base of the food chain compared to lotic areas. Enrichment/trophic transfer factors for selenium at all levels of the lotic and lentic food chains decreased and then became near constant as exposure concentrations increased. The lotic model predicted little increase in WCT ovary selenium concentrations over an eightfold increase in water concentrations (~0.005-0.040 mg/L), accounting for the lack of observed increase in within-area fish tissue concentrations over time despite increasing trends in water concentrations.

Measurement of long lived radioactive impurities retained in the disposable cassettes on the Tracerlab MX system during the production of [18F]FDG.

Using a High- Purity Germanium gamma-ray spectrometer, a number of radioisotopes have been identified within Tracerlab MX radiochemistry system cassettes used to synthesise [18F]FDG. Twenty radiochemistry cassettes were measured and the average total activity of each radioisotope was determined. Using these values and decay correction, the minimum time the cassettes should be left in a decay store before the specific activity falls below 0.4B q/g, the limit for disposal alongside Clinical Waste was found to be 24 months.

[Lipids and their correlation with vitamin D in the indigenous populations of Russia European North].

The aim of our research was to investigate the level of 25-OH vitamin D in blood plasma of indigenous inhabitants of Russia European North. The study showed that there was wide spreading of vitamin D deficiency among northerners especially in teenager. The significant reduction of 25-OH vitamin D3 was revealed in the inhabitants of Far North in March. It is shown that there is correlation of the vitamin D with total cholesterol, apolipoprotein A, high and low density lipoproteins and vitamin A and E.

[Vitamin D level in the indigenous populations of Russia European North].

The aim of our research was to investigate the level of 25-OH vitamin D3 in blood plasma of indigenous inhabitants of Russia European North. The study showed that there was wide spreading of vitamin D deficiency among northerners especially in teenager. The significant reduction of level of 25-OH vitamin D3 was revealed in the inhabitants of Far North in March.

Sex differences in contextual fear conditioning are associated with differential ventral hippocampal extracellular signal-regulated kinase activation.

Although sex differences have been reported in hippocampal-dependent learning and memory, including contextual fear memories, the underlying molecular mechanisms contributing to such differences are not well understood. The present study examined the extent to which sex differences in contextual fear conditioning are related to differential activation of the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK), a protein kinase critically involved in memory formation. We first show that male rats exhibit more long-term retention of contextual fear conditioning than female rats. During a tone test, females spent more time freezing than males, although both sexes exhibited robust retention of auditory fear learning. Using Western blot analysis, we then show that phosphorylated ERK levels in ventral, but not dorsal, hippocampus are higher in males than females, relative to same-sex controls, 60 minutes after fear conditioning. Post-conditioning increases in ERK activation were observed in the amygdala in both males and females, suggesting a selective effect of sex on hippocampal ERK activation. Together, these findings suggest that differential activation of the ERK signal transduction pathway in male and female rats, particularly in the ventral hippocampus, is associated with sex differences in contextual fear.

Above threshold dissociation of vibrationally cold HD+ molecules.

The experimental study of molecular dissociation of H2+ by intense laser pulses is complicated by the fact that the ions are initially produced in a wide range of vibrational states, each of which responds differently to the laser field. An electrostatic storage device has been used to radiatively cool HD+ ions enabling the observation of above threshold dissociation from the ground vibrational state by 40 fs laser pulses at 800 nm. At the highest intensities used, dissociation through the absorption of at least four photons is found to be the dominant process.

Spectroscopic characterization of vacuum ultraviolet free electron laser pulses.

Because of the stochastic nature of self-amplified spontaneous emission (SASE), it is crucial to measure for single pulses the spectral characteristics of ultrashort pulses from the vacuum ultraviolet free electron laser (FLASH) at DESY, Germany. To meet this particular challenge, we have employed both photon and photoelectron spectroscopy. Each FEL pulse is composed of an intense and spectrally complex fundamental, centered at a photon energy of about 38.5 eV, with a bandwidth of 0.5% accompanied by higher harmonics, each carrying an intensity of typically 0.3 to 0.6% of that of the fundamental. The correlation between the harmonics and the fundamental is in remarkable agreement with a simple statistical model of SASE FEL radiation.

Urticaria and large cell undifferentiated carcinoma of lung.

The association of urticaria with internal cancer is known mostly with lymphoreticular system malignancies. Rarely, it occurs with cancer of lung, mostly with adenocarcinoma or small cell carcinoma. We report a unique occurrence of urticaria on a patient who suffered from large cell undifferentiated carcinoma of lung. Only the treatment for malignancy relieved the patient from his long standing cutaneous manifestation.

Evidence for rescattering in intense, femtosecond laser interactions with a negative ion.

It is now well established that energetic electron emission, nonsequential ionization, and high harmonic generation, produced during the interaction of intense, femtosecond laser pulses with atoms (and atomic positive ions), can be explained by invoking rescattering of the active electron in the laser field, the so-called rescattering mechanism. In contrast for negative ions, the role of rescattering has not been established experimentally. By irradiating F- ions with ultrashort laser pulses, F+ ion yields as a function of intensity for both linearly and circularly polarized light have been measured. We find that, at intensities well below saturation for F+ production by sequential ionization, there is a small but significant enhancement in the yield for the case of linearly polarized light, providing the first clear experimental evidence for the existence of the rescattering mechanism in negative ions.

The role of small airways in lung disease.

The small airways constitute one of the least understood areas of the lungs. They play a role in many lung diseases, and small airway pathology results in significant morbidity New approaches to their evaluation may provide insights into this major area of lung disease. Asthma is well recognized as a disease of both large and small airways. Physiological and pathological evidence, from techniques such as post-mortem tissue histological analysis, induced sputum and transbronchial biopsies, has reinforced the concept of the involvement of the entire bronchial tree n the inflammatory process in asthma, In addition to describing the airway pathology in asthma, th s review focuses on the pathogenesis and role of small airway obstruction n other diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), sarcoidosis and obliterative bronchiolitis (OB). COPD is characterized by the presence of airflow obstruction resulting from lesions in the small airways. In addition, features compatible with small airways disease are common in IPF, sarcoidosis and OB. Recent advances in pulmonary imaging, such as high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) with hyperpolarized 3He, have allowed non-invasive reproducible measurements of structure-function relationships to be made for the small airways. These techniques have great potential for diagnosing changes in small airway function and for assessing responses to treatment. New insights into the contribution of small airways to a range of lung diseases may lead to the development of therapies targeted at this part of the bronchial anatomy.

Ingestion of toxic Microcystis aeruginosa by dairy cattle and the implications for microcystin contamination of milk.

Microcystin (MCYST) toxins can be produced by the bloom-forming cyanobacterium Microcystis aeruginosa. They are chemically stable compounds and have both acute and chronic effects on the health of mammals, including cattle and humans. Cattle will drink water containing lethal cell concentrations of M. aeruginosa. When cattle consume sub-lethal doses of microcystins, the fate of those toxins is unknown. We provided drinking water containing 1 x 10(5) cells ml(-1) M. aeruginosa (strain MASH01-A19) to four lactating Holstein-Friesian dairy cattle for 21 days to determine if MCYST-LR produced by the cyanobacteria, could be detected in milk produced by the cattle. Cattle consumed up to 15 mg MCYST-LR at an ingestion rate of 1.21 microg kg (live weight) d(-1). Analysis by HPLC and ELISA indicated that no detectable amounts of microcystin from the cyanobacteria were present in the milk obtained from the treated animals. Based on the level of quantitation of the ELISA analyses, the maximum possible concentration in the milk was less than 2 ng l(-1). This is more than three orders of magnitude less that the concentration that could be considered problematic for milk of 0.86 microg l(-1) which we calculated using the World Health Organization derived tolerable daily intake for MCYST-LR and the per capita daily consumption of milk in Australia.