Intercomparison of tritium and noble gases analyses, 3H/3He ages and derived parameters excess air and recharge temperature

International audienceGroundwater age dating with the tritium-helium (3H/3He) method has become a powerful tool for hydrogeologists. The uncertainty of the apparent 3H/3He age depends on the analytical precision of the 3H measurement and the uncertainty of the tritiogenic 3He component. The goal of this study, as part of the groundwater age-dating interlaboratory comparison exercise, was to quantify the analytical uncertainty of the 3H and noble gas measurements and to assess whether they meet the requirements for 3H/3He dating and noble gas paleotemperature reconstruction. Samples for the groundwater dating intercomparison exercise were collected on 1 February, 2012, from three previously studied wells in the Paris Basin (France). Fourteen laboratories participated in the intercomparison for tritium analyses and ten laboratories participated in the noble gas intercomparison. Not all laboratories analyzed samples from every borehole. The reproducibility of the tritium measurements was 13.5%. The reproducibility of the 3He/4He ratio and 4He, Ne, Ar, Kr and Xe concentrations was 1.4%, 1.8%, 1.5%, 2.2%, 2.9%, and 2.4% respectively. The uncertainty of the tritium and noble gas measurements results in a typical 3H/3He age precision of better than 2.5 years in this case. However, the measurement uncertainties for the noble gas concentrations are insufficient to distinguish the appropriate excess air model if the measured helium concentration is not included. While the analytical uncertainty introduces an unavoidable source of uncertainty in the 3H/3He apparent age estimate, other sources of uncertainty are often much greater and less well defined than the analytical uncertainty

Separate episodes of capillary leak syndrome and pulmonary hypertension after adjuvant gemcitabine and three years later after nab-paclitaxel for metastatic disease

Background: Systemic capillary leak syndrome is a rare disease with a high mortality rate. This syndrome is characterised by generalised edema, hypotension, hemoconcentration, and hypoproteinemia. The cause is the sudden onset of capillary hyperpermeability with extravasations of plasma from the intravascular to the extravascular compartment. We present the case of a patient who experienced two episodes of systemic capillary leak syndrome and pulmonary hypertension; the first after gemcitabine in an adjuvant setting and the second three years later after treatment with nab-paclitaxel for metastatic disease.Case presentation: A 65-year-old patient underwent a pancreatectomy in January 2010 for ductal carcinoma (pT3 N0 M0, stage IIa), followed by adjuvant chemotherapy. Seven days after the last cycle, she developed dyspnea associated with orthopnea and cough. A transthoracic cardiac ecocolordoppler was performed, with evidence of pulmonary hypertension (58 mmHg). Blood tests showed an increase in creatinine, pro-BNP and D-Dimer. She began high-dose diuretic therapy combined with cortisone. After a month, the patient was eupneic and the anasarca had resolved. We decided gradually to reduce the steroid and diuretic therapy. After ten days of the reduction, the patient began to re-present the same symptoms after treatment with gemcitabine. Corticosteroid therapy was restored with rapid clinical benefit and decreased pro-BNP after a week of treatment. After two years, the disease returned. As a first line treatment, it was decided to use nab-paclitaxel 100 mg/m2 weekly. After two doses, followed by approximately 14 days of treatment, the patient developed acute respiratory distress syndrome. The clinical suspicion was a relapse of capillary leak syndrome and treatment with a high-dose diuretic (furosemide 250 mg daily) was started combined with cortisone (40 mg methylprednisolone). The patient showed a progressive clinical benefit.Conclusions: In patients treated with gemcitabine and nab-paclitaxel who experience a sudden onset of diffuse edema with respiratory distress, capillary leak syndrome should be suspected. Immediate treatment with corticosteroids may be life-saving. © 2013 Casadei Gardini et al.; licensee BioMed Central Ltd

Origin of fluids and related barite deposits at vent sites along the Peru convergent margin

The venting at the northern Peru convergent margin, unlike at other margins, has produced large barite deposits, which have not been observed outside the vents. The 87Sr/86Sr isotopic ratios of the fluids are more radiogenic than seawater. To explain these elevated values, we propose either the influence of a fluid characterized by a more radiogenic signature originating from the continent, or a reaction between seawater and the underlying continental metamorphic basement. The presence of this nonlocal radiogenic component is marked more strongly on the 87Sr/86Sr ratios measured in the barite deposits. We assume that the fluid sampled at the venting site and the fluid responsible for the barite deposit sampled at the same site originated from the same source, i.e., the Paleozoic metamorphic basement of the Andean continental margin

Scientific Opinion on the safety and efficacy of Urea for ruminants

Urea supplementation to feed for ruminants provides non-protein nitrogen for microbial protein synthesis in the rumen and thus in part replaces other dietary protein sources. Urea supplementation of feed for ruminants at doses up to 1 % of complete feed DM (corresponding to 0.3 g/kg bw/day) is considered safe when given to animals with a well adapted ruminal microbiota and fed diets rich in easily digestible carbohydrates. Based on the metabolic fate of urea in ruminants, the use of urea in ruminant nutrition does not raise any concern for consumers\u2019 safety. Urea is considered to be non irritant to skin and eyes and its topical use suggests that it is not a dermal sensitiser. The risk of exposure by inhalation would be low. The substitution of protein by urea in well balanced feed for ruminants would not result in an increased environmental nitrogen load. Urea is an effective source of non-protein nitrogen substituting for dietary protein in ruminants

A hillslope-scale aquifer-model to determine past agricultural legacy and future nitrate concentrations in rivers

The long-term fate of agricultural nitrate depends on rapid subsurface transfer, denitrification and storage in aquifers. Quantifying these processes remains an issue due to time varying subsurface contribution, unknown aquifer storage and heterogeneous denitrification potential. Here, we develop a parsimonious modelling approach that uses long-term discharge and river nitrate concentration time-series combined with groundwater age data determined from chlorofluorocarbons in springs and boreholes. To leverage their informational content, we use a Boussinesq-type equivalent hillslope model to capture the dynamics of aquifer flows and evolving surface and subsurface contribution to rivers. Nitrate transport was modelled with a depth-resolved high-order finite-difference method and denitrification by a first-order law. We applied the method to three heavily nitrate loaded catchments of a crystalline temperate region of France (Brittany). We found that mean water transit time ranged 10–32 years and Damköhler ratio (transit time/denitrification time) ranged 0.12–0.55, leading to limited denitrification in the aquifer (10–20%). The long-term trajectory of nitrate concentration in rivers appears determined by flows stratification in the aquifer. The results suggest that autotrophic denitrification is controlled by the accessibility of reduced minerals which occurs at the base of the aquifer where flows decrease. One interpretation is that denitrification might be an interfacial process in zones that are weathered enough to transmit flows and not too weathered to have remaining accessible reduced minerals. Consequently, denitrification would not be controlled by the total aquifer volume and related mean transit time but by the proximity of the active weathered interface with the water table. This should be confirmed by complementary studies to which the developed methodology might be further deployed

International forum. an investigation of iron status in blood donors

No abstract availabl

The Interaction of αB-Crystallin with Mature α-Synuclein Amyloid Fibrils Inhibits Their Elongation

αB-Crystallin is a small heat-shock protein (sHsp) that is colocalized with α-synuclein (αSyn) in Lewy bodies—the pathological hallmarks of Parkinson's disease—and is an inhibitor of αSyn amyloid fibril formation in an ATP-independent manner in vitro. We have investigated the mechanism underlying the inhibitory action of sHsps, and here we establish, by means of a variety of biophysical techniques including immunogold labeling and nuclear magnetic resonance spectroscopy, that αB-crystallin interacts with αSyn, binding along the length of mature amyloid fibrils. By measurement of seeded fibril elongation kinetics, both in solution and on a surface using a quartz crystal microbalance, this binding is shown to strongly inhibit further growth of the fibrils. The binding is also demonstrated to shift the monomer-fibril equilibrium in favor of dissociation. We believe that this mechanism, by which a sHsp interacts with mature amyloid fibrils, could represent an additional and potentially generic means by which at least some chaperones protect against amyloid aggregation and limit the onset of misfolding diseases

Safety and efficacy of Axtra® PHY 20000 TPT2 (6‐phytase) as a feed additive for poultry and porcine species

Axtra\uae PHY 20000 TPT2 is a solid preparation that contains a 6-phytase produced with a genetically modified strain of Trichoderma reesei. The production strain and its recombinant DNA were not detected in Axtra\uae PHY 20000 TPT2. From the results obtained in tolerance studies, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive is safe for the target species at 2,000 FTU/kg feed. The studies provided to address the safety for the consumer were performed with the fermentation product that is used to formulate the additive and the results do not indicate any reason for concern for consumer safety arising from the use of the product as a feed additive. The studies provided to address the safety for the user were performed with the fermentation product that is used to formulate the additive and have been assessed in a previous opinion. Considering the results of those studies and the substances used during the formulation of Axtra\uae PHY 20000 TPT2, this formulation is not considered a dermal sensitiser. However, it should be considered a potential irritant to skin, eyes and the respiratory tract, and owing to the nature of the active substance, it should be considered a potential respiratory sensitiser. However, the exposure by inhalation is expected to be negligible. No risks to the environment are expected from the use of Axtra\uae PHY 20000 TPT2 as a feed additive. Based on the results of efficacy studies, the Panel concluded that the additive has the potential to be efficacious at 250 FTU/kg feed

Dementia and detectives: Alzheimer's disease in crime fiction

Fictional representations of dementia have burgeoned in recent years, and scholars have amply explored their double-edged capacity to promote tragic perspectives or normalising images of ‘living well’ with the condition. Yet to date, there has been only sparse consideration of the treatment afforded dementia within the genre of crime fiction. Focusing on two novels, Emma Healey’s Elizabeth is Missing and Alice LaPlante’s Turn of Mind, this article considers what it means in relation to the ethics of representation that these authors choose to cast as their amateur detective narrators women who have dementia. Analysing how their narrative portrayals frame the experience of living with dementia, it becomes apparent that features of the crime genre inflect the meanings conveyed. While aspects of the novels may reinforce problem-based discourses around dementia, in other respects they may spur meaningful reflection about it among the large readership of this genre

Safety and efficacy of fumonisin esterase from Komagataella phaffii DSM 32159 as a technological feed additive for pigs and poultry

Fumonisin esterase produced from a genetically modified strain of Komagataella phaffi is intended to degrade fumonisin mycotoxins contaminants in feeds for pigs and poultry. The production strain and its recombinant genes are not present in the final product. The applicant selected 300 U/kg feed to represent a likely upper limit. This concentration showed to be safe for piglets, chickens and turkeys for fattening and laying hens; the additive is thus safe for those categories. This conclusion is extended to all pigs, chickens reared for laying and turkeys reared for breeding and extrapolated to all other poultry species for growing and laying and to minor porcine species. No evidence of mutagenicity or genotoxicity was detected and no evidence of toxicity from a repeated-dose oral toxicity study; the residue assessment did not identify any concern. The use of the additive is, thus, considered safe for consumers. The additive is not toxic by inhalation and the respiratory exposure is likely to be low; however, a risk of sensitisation via the respiratory route cannot be excluded. The additive is non-irritant to skin and eyes and is not considered a dermal sensitiser. No risks for the environment are expected following the use of the additive in feeds under the proposed condition of use. The additive has the capacity to degrade fumonisin contaminants in feed of marketable quality when used at the minimum recommended dose of 10 U/kg complete feed, as shown in studies with chickens for fattening, laying hens and weaned piglets. Since the mode of action of the additive can be reasonably assumed to be the same in animal species for which the application is made, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) considers the additive efficacious for all poultry and all pigs