Validation of an ultra high performance liquid chromatography-tandem mass spectrometry method for detection and quantitation of 19 endocrine disruptors in milk

An endocrine disruptor (ED) is an exogenous compound that interferes with the body's endocrine system. Exposure to EDs may result in adverse health effects such as infertility and cancer. EDs are composed of a vast group of chemicals including compounds of natural origin such as phytoestrogens or mycotoxins and a wide range of man-made chemicals such as pesticides. Synthetic compounds may find their way into the food chain where a number of them can biomagnify. Additionally, processing activities and food contact materials may add further to the already existing pool of food contaminants. Thus, our diet is considered to be one of the main exposure routes to EDs. Some precautionary legislation has already been introduced to control production and/or application of some persistent organic pollutants with ED characteristics. However, newly emerging EDs with bioaccumulative properties have recently been reported to appear at lower tiers of the food chain but have not been monitored at the grander scale. Milk and dairy products are a major component of our diet, thus it is important to monitor them for EDs. However, most methods developed to date are devoted to one group of compounds at a time. The UHPLC-MS/MS method described here has been validated according to EC decision 2002/657/EC and allows simultaneous extraction, detection, quantitation and confirmation of 19 EDs in milk. The method calibration range is between 0.50 and 20.0 μg kg with coefficients of determination above 0.99 for all analytes. Precision varied from 4.7% to 23.4% in repeatability and reproducibility studies. Established CCα and CCβ values (0.11-0.67 μg kg) facilitate fast, reliable, quantitative and confirmatory analysis of sub μg kg levels of a range of EDs in milk.

Impacts of compressed air energy storage plant on an electricity market with a large renewable energy portfolio

Renewable energy generation is expected to continue to increase globally due to renewable energy targets and obligations to reduce greenhouse gas emissions. Some renewable energy sources are variable power sources, for example wind, wave and solar. Energy storage technologies can manage the issues associated with variable renewable generation and align non-dispatchable renewable energy generation with load demands. Energy storage technologies can play different roles in each of the step of the electric power supply chain. Moreover, large scale energy storage systems can act as renewable energy integrators by smoothing the variability. Compressed air energy storage is one such technology. This paper examines the impacts of a compressed air energy storage facility in a pool based wholesale electricity market in a power system with a large renewable energy portfolio.

Impact of offshore wind power forecast error in a carbon constraint electricity market

This paper investigates the impacts of offshore wind power forecast error on the operation and management of a pool-based electricity market in 2050. The impact from offshore wind power forecast errors of up to 2000 MW on system generation costs, emission costs, dispatch-down of wind, number of start-ups and system marginal price are analysed. The main findings of this research are an increase in system marginal prices of approximately 1% for every percentage point rise in the offshore wind power forecast error regardless of the average forecast error sign. If offshore wind power generates less than forecasted (−13%) generation costs and system marginal prices increases by 10%. However, if offshore wind power generates more than forecasted (4%) the generation costs decrease yet the system marginal prices increase by 3%. The dispatch down of large quantities of wind power highlights the need for flexible interconnector capacity. From a system operator's perspective it is more beneficial when scheduling wind ahead of the trading period to forecast less wind than will be generated.

Cryptic introgression into the Kidney saxifrage (Saxifraga hirsuta) from its more abundant sympatric congener Saxifraga spathularis, and the potential risk of genetic assimilation

Background and Aims: Although hybridization can play a positive role in plant evolution, it has been shown that excessive unidirectional hybridization can result in replacement of a species’ gene pool, and even the extinction ofrare species via genetic assimilation. This study examines levels of introgression between the common Saxifraga spathularis and its rarer congener S. hirsuta, which have been observed to hybridize in the wild where they occursympatrically. 
Methods: Seven species-specific single nucleotide polymorphisms (SNPs) were analysed in 1025 plants representing both species and their hybrid, S. polita, from 29 sites across their ranges in Ireland. In addition, species distributionmodelling was carried out to determine whether the relative abundance of the two parental species is likely to change under future climate scenarios. 
Key Results: Saxifraga spathularis individuals tended to be genetically pure, exhibiting little or no introgression from S. hirsuta, but significant levels of introgression of S. spathularis alleles into S. hirsuta were observed, indicatingthat populations exhibiting S. hirsuta morphology are more like a hybrid swarm, consisting of backcrosses and F2s. Populations of the hybrid, S. polita, were generally comprised of F1s or F2s, with some evidence of backcrossing. Species distribution modelling under projected future climate scenarios indicated an increase in suitable habitats for both parental species.
Conclusions: Levels of introgression observed in this study in both S. spathularis and S. hirsuta would appear to be correlated with the relative abundance of the species. Significant introgression of S. spathularis alleles was detectedin the majority of the S. hirsuta populations analysed and, consequently, ongoing introgression would appear to represent a threat to the genetic integrity of S. hirsuta, particularly in areas where the species exists sympatricallywith its congener and where it is greatly outnumbered.

A study of patient attitudes towards fasting prior to intravenous sedation for dental treatment in a dental hospital department

INTRODUCTION: Intravenous sedation is the most commonly used method of sedation for the provision of adult dental care. However, disparity exists in pre-operative fasting times in use for patients throughout the United Kingdom.

AIMS: The aims of the study were to obtain information on the effects of existing extended pre-operative fasting regimens, to canvas patient opinions on the fasting process, and to record their positive and negative experiences associated with it.

METHODS: A prospective cross-sectional descriptive study using survey methodology was conducted of adult patients attending a dental hospital for operative treatment under intravenous sedation. Sixty-four questionnaires were distributed over a four-month period, beginning 2nd October 2007.

RESULTS: The surveyed patient pool consisted of 38 females and 14 males with a mean age of 32.4 years. The response rate achieved was 81.2%. Seventy-one per cent of patients indicated that normally they consumed something for breakfast, the most common items being tea and toast. Fifty-one per cent of patients indicated that they would wish to eat the same as normal prior to their appointment and 59% wished to drink as normal. Only 19% of respondents reported that they did not wish to eat anything, with 8% preferring not to drink anything at all. Seventy-nine per cent of the patients reported that they had experienced at least one adverse symptom after fasting and 42% had experienced two or more such symptoms. In general, those patients with more experience of sedation found fasting less unpleasant than those attending for the first time (P<0.05). In addition, one-quarter of all patients indicated that the fasting process had made them feel more nervous about their sedation appointment.

CONCLUSIONS: The extended fasting regimen prior to intravenous sedation appeared to affect patients' wellbeing, as the majority reported adverse symptoms.

Mechanisms of reduced susceptibility and genotypic prediction of antibiotic resistance in Prevotella isolated from cystic fibrosis (CF) and non-CF patients

OBJECTIVES: To investigate mechanisms of reduced susceptibility to commonly used antibiotics in Prevotella cultured from patients with cystic fibrosis (CF), patients with invasive infection and healthy control subjects and to determine whether genotype can be used to predict phenotypic resistance.

METHODS: The susceptibility of 157 Prevotella isolates to seven antibiotics was compared, with detection of resistance genes (cfxA-type gene, ermF and tetQ), mutations within the CfxA-type β-lactamase and expression of efflux pumps.

RESULTS: Prevotella isolates positive for a cfxA-type gene had higher MICs of amoxicillin and ceftazidime compared with isolates negative for this gene (P < 0.001). A mutation within the CfxA-type β-lactamase (Y239D) was associated with ceftazidime resistance (P = 0.011). The UK CF isolates were 5.3-fold, 2.7-fold and 5.7-fold more likely to harbour ermF compared with the US CF, UK invasive and UK healthy control isolates, respectively. Higher concentrations of azithromycin (P < 0.001) and clindamycin (P < 0.001) were also required to inhibit the growth of the ermF-positive isolates compared with ermF-negative isolates. Furthermore, tetQ-positive Prevotella isolates had higher MICs of tetracycline (P = 0.001) and doxycycline (P < 0.001) compared with tetQ-negative isolates. Prevotella spp. were also shown, for the first time, to express resistance nodulation division (RND)-type efflux pumps.

CONCLUSIONS: This study has demonstrated that Prevotella isolated from various sources harbour a common pool of resistance genes and possess RND-type efflux pumps, which may contribute to tetracycline resistance. The findings indicate that antibiotic resistance is common in Prevotella spp., but the genotypic traits investigated do not reflect phenotypic antibiotic resistance in every instance.

On Publication, Refereeing, and Working Hard

We present a model for academia with heterogeneous author types and endogenous effort to evaluate recent changes in the publication process in Economics. We analyze the implications of these developments on research output. Lowering the precision of refereeing signals lowers effort choices of golden middle authors, but invites more submissions from less able authors. Increasing the number of journals stimulates less able authors to submit their papers. The editor can improve the journal's quality pool of submitted manuscripts by improving the precision of refereeing, but not by lowering acceptance standards. The submission strategy of an author is informative of his ability.

Ecology of testate amoebae in an Amazonian peatland and development of a transfer function for palaeohydrological reconstruction

Tropical peatlands represent globally important carbon sinks with a unique biodiversity and are currently threatened by climate change and human activities. It is now imperative that proxy methods are developed to understand the ecohydrological dynamics of these systems and for testing peatland development models. Testate amoebae have been used as environmental indicators in ecological and palaeoecological studies of peatlands, primarily in ombrotrophic Sphagnum-dominated peatlands in the mid- and high-latitudes. We present the first ecological analysis of testate amoebae in a tropical peatland, a nutrient-poor domed bog in western (Peruvian) Amazonia. Litter samples were collected from different hydrological microforms (hummock to pool) along a transect from the edge to the interior of the peatland. We recorded 47 taxa from 21 genera. The most common taxa are Cryptodifflugia oviformis, Euglypha rotunda type, Phryganella acropodia, Pseudodifflugia fulva type and Trinema lineare. One species found only in the southern hemisphere, Argynnia spicata, is present. Arcella spp., Centropyxis aculeata and Lesqueresia spiralis are indicators of pools containing standing water. Canonical correspondence analysis and non-metric multidimensional scaling illustrate that water table depth is a significant control on the distribution of testate amoebae, similar to the results from mid- and high-latitude peatlands. A transfer function model for water table based on weighted averaging partial least-squares (WAPLS) regression is presented and performs well under cross-validation (r 2apparent=0.76,RMSE=4.29;r2jack=0.68,RMSEP=5.18. The transfer function was applied to a 1-m peat core, and sample-specific reconstruction errors were generated using bootstrapping. The reconstruction generally suggests near-surface water tables over the last 3,000 years, with a shift to drier conditions at c. cal. 1218-1273 AD

Dietary habits of patients undergoing methadone therapy

OBJECTIVE: This study was designed to record the dietary habits of patients undergoing methadone therapy.

BACKGROUND: Numerous studies report that patients undergoing methadone treatment present with high levels of oral disease, especially dental caries. A number of factors have been described to account for this: sugared methadone preparations, prolonged oral retention, associated xerostomia and poor diet.

METHODS: A cross-sectional descriptive study using survey methodology was conducted of patients attending a non-resident drug rehabilitation clinic. A self-completion questionnaire and diet diary were developed and distributed to 66 patients over an 8 week period.

RESULTS: Of the 66 questionnaires distributed, 52 were successfully completed giving a response rate of 79%. 6 patients declined to complete the questionnaire. The surveyed patient pool consisted of 32 females (62%) and 20 males (38%) with a mean age of 32 years. All the participants were taking a prescribed daily dose of methadone when questioned. 68% of respondents consumed convience foods or sugary snacks every day. Of those patients who drank tea or coffee daily, 84% added sugar and 54% added 3 teaspoons or more. The majority of patients (71%) consumed at least one glass of a fizzy soft drink daily. In addition, the majority of respondents indicated that they snacked regularly between meals and 24% stated that they often woke up during the night for a snack. Patients recorded their last intake of food ranging from 5pm to 3am.

CONCLUSIONS: The patients surveyed had poor dietary habits. Respondents consumed a large amount of convience foods and sugars during mealtimes and through regular snacking. Dietary counselling should be considered as part of treatment for patients undergoing methadone therapy.

The Evaluation and Quantitation of Dihydrogen Metabolism Using Deuterium Isotope in Rats

Purpose: Despite the significant interest in molecular hydrogen as an antioxidant in the last eight years, its quantitative metabolic parameters in vivo are still lacking, as is an appropriate method for determination of hydrogen effectivity in the mammalian organism under various conditions.

Basic Procedures: Intraperitoneally-applied deuterium gas was used as a metabolic tracer and deuterium enrichment was determined in the body water pool. Also, in vitro experiments were performed using bovine heart submitochondrial particles to evaluate superoxide formation in Complex I of the respiratory chain.

Main Findings: A significant oxidation of about 10% of the applied dose was found under physiological conditions in rats, proving its antioxidant properties. Hypoxia or endotoxin application did not exert any effect, whilst pure oxygen inhalation reduced deuterium oxidation. During in vitro experiments, a significant reduction of superoxide formation by Complex I of the respiratory chain was found under the influence of hydrogen. The possible molecular mechanisms of the beneficial effects of hydrogen are discussed, with an emphasis on the role of iron sulphur clusters in reactive oxygen species generation and on iron species-dihydrogen interaction.

Principal Conclusions: According to our findings, hydrogen may be an efficient, non-toxic, highly bioavailable and low-cost antioxidant supplement for patients with pathological conditions involving ROS-induced oxidative stress.

Bioavailability of atrazine to soil microbes in the presence of the earthworm Lumbricus terrestrius (L.)

Experiments were conducted to investigate the interactions between an earthworm species (Lumbricus terrestrius) and soil microflora with respect to the bioavailability and mineralisation of ¹⁴C ring-labelled atrazine. Presence of earthworms had no affect on atrazine in soil solution (assayed by soil centrifugation). This soil solution pool was highly time dependent, decreasing considerably as the experiment proceeded. KCl-extractable label was, however, affected by the presence of earthworms, with this pool initially increasing in the presence of the worms. This pool was also highly time-dependent although, the pattern of this dependence did not follow that for label in soil solution. Mineralisation of the atrazine closely followed the KCl exchangeable pool and not that of the soil solution pool. However, label sorbed to the surface of the worms was closely correlated to the soil solution pool. Mineralisation in the presence of earthworms was double that of the controls. By the end of the experiment 6% of added radioactivity was present in the earthworm biomass.

Loss of exudates from the roots of perennial ryegrass inoculated with a range of micro-organisms

To determine the effect of microbial metabolites on the release of root exudates from perennial ryegrass, seedlings were pulse labelled with [¹⁴C]-CO₂ in the presence of a range of soil micro-organisms. Microbial inoculants were spatially separated from roots by Millipore membranes so that root infection did not occur. Using this technique, only microbial metabolites affected root exudation. The effect of microbial metabolites on carbon assimilation and distribution and root exudation was determined for 15 microbial species. Assimilation of a pulse label varied by over 3.5 fold, dependent on inoculant. Distribution of the label between roots and shoots also varied with inoculant, but the carbon pool that was most sensitive to inoculation was root exudation. In the absence of a microbial inoculant only 1% of assimilated label was exuded. Inoculation of the microcosms always caused an increase in exudation but the percentage exuded varied greatly, within the range of 3-34%. © 1995 Kluwer Academic Publishers.

Characterization of NKR+ T-cell subsets in human bone marrow:implications for immunosurveillance of neoplasia

In addition to hematopoietic progenitors, human bone marrow contains mature T/NK lymphocytes. Valpha24Vbeta11 NKT-cells, a subset of NK receptor+ (NKR+) T-cells in humans, are rare in bone marrow, suggesting the presence of other NKR+ T-cells which may contribute to tumor surveillance. NKR+/- T-cells were examined in blood (PB), and bone marrow from donors (DM) and patients with active hematopoietic malignancy (PM), or in remission (PR). T-cells in PR & PM were enriched for CD56+ and CD57+ subsets, compared to DM. All marrow NKR+/- T-cell subsets were more activated than PB. PM and, surprisingly, PR marrow contained more activated cells than DM. CD8+ cells were significantly increased in all patient marrows and there was evidence of the formation of an effector/memory pool in malignant marrow. These data suggest that NKR+ T-cell enrichment in human bone marrow that has been exposed to neoplastic transformation is compatible with a role in localized tumor surveillance/eradication.

Organo-mineral complexation alters carbon and nitrogen cycling in stream microbial assemblages

Inland waters are of global biogeochemical importance receiving carbon inputs of ~ 4.8 Pg C y^-1. Of this 12 % is buried, 18 % transported to the oceans, and 70 % supports aquatic secondary production. However, the mechanisms that determine the fate of organic matter (OM) in these systems are poorly defined. One important aspect is the formation of organo-mineral complexes in aquatic systems and their potential as a route for OM transport and burial vs. their use potential as organic carbon (C) and nitrogen (N) sources. Organo-mineral particles form by sorption of dissolved OM to freshly eroded mineral surfaces and may contribute to ecosystem-scale particulate OM fluxes. We tested the availability of mineral-sorbed OM as a C & N source for streamwater microbial assemblages and streambed biofilms. Organo-mineral particles were constructed in vitro by sorption of ¹³C:¹⁵N-labelled amino acids to hydrated kaolin particles, and microbial degradation of these particles compared with equivalent doses of ¹³C:¹⁵N-labelled free amino acids. Experiments were conducted in 120 ml mesocosms over 7 days using biofilms and streamwater sampled from the Oberer Seebach stream (Austria), tracing assimilation and mineralization of ¹³C and ¹⁵N labels from mineral-sorbed and dissolved amino acids.Here we present data on the effects of organo-mineral sorption upon amino acid mineralization and its C:N stoichiometry. Organo-mineral sorption had a significant effect upon microbial activity, restricting C and N mineralization by both the biofilm and streamwater treatments. Distinct differences in community response were observed, with both dissolved and mineral-stabilized amino acids playing an enhanced role in the metabolism of the streamwater microbial community. Mineral-sorption of amino acids differentially affected C & N mineralization and reduced the C:N ratio of the dissolved amino acid pool. The present study demonstrates that organo-mineral complexes restrict microbial degradation of OM and may, consequently, alter the carbon and nitrogen cycling dynamics within aquatic ecosystems.

EpsinR an AP1/clathrin interacting protein involved in vesicle trafficking

EpsinR is a clathrin-coated vesicle (CCV) enriched 70-kD protein that binds to phosphatidylinositol-4-phosphate, clathrin, and the gamma appendage domain of the adaptor protein complex 1 (AP1). In cells, its distribution overlaps with the perinuclear pool of clathrin and AP1 adaptors. Overexpression disrupts the CCV-dependent trafficking of cathepsin D from the trans-Golgi network to lysosomes and the incorporation of mannose-6-phosphate receptors into CCVs. These biochemical and cell biological data point to a role for epsinR in AP1/clathrin budding events in the cell, just as epsin1 is involved in the budding of AP2 CCVs. Furthermore, we show that two gamma appendage domains can simultaneously bind to epsinR with affinities of 0.7 and 45 microM, respectively. Thus, potentially, two AP1 complexes can bind to one epsinR. This high affinity binding allowed us to identify a consensus binding motif of the form DFxDF, which we also find in gamma-synergin and use to predict that an uncharacterized EF-hand-containing protein will be a new gamma binding partner.