Carbon isotope fractionation between amorphous calcium carbonate and calcite in earthworm-produced calcium carbonate

In this study we investigate carbon isotope fractionation during the crystallization of biogenic calcium carbonate. Several species of earthworm including Lumbricus terrestris secrete CaCO3. Initially a milky fluid comprising micro-spherules of amorphous CaCO3 (ACC) is secreted into pouches of the earthworm calciferous gland. The micro-spherules coalesce and crystalize to form millimetre scale granules, largely comprising calcite. These are secreted into the earthworm intestine and from there into the soil. L. terrestris were cultured for 28 days in two different soils, moistened with three different mineral waters at 10, 16 and 20 °C. The milky fluid in the calciferous glands, granules in the pouches of the calciferous glands and granules excreted into the soil were collected and analysed by FTIR spectroscopy to determine the form of CaCO3 present and by IRMS to determine δ13C values. The milky fluid was ACC. Granules removed from the pouches and soil were largely calcite; the granules removed from the pouches contained more residual ACC than those recovered from the soil. The δ13C values of milky fluid and pouch granules became significantly more negative with increasing temperature (p < 0.001). For samples from each temperature treatment, δ13C values became significantly (p < 0.001) more negative from the milky fluid to the pouch granules to the soil granules (-13.77, -14.69 and -15.00 respectively at 10 °C; -14.37, -15.07 and -15.18 respectively at 16 °C and -14.89, -15.41 and -15.65 respectively at 20 °C). Fractionation of C isotopes occurred as the ACC recrystallized to form calcite with the fractionation factor εcalcite-ACC = -1.20 ± 0.52 %0. This is consistent with the crystallization involving dissolution and reprecipitation rather than a solid state rearrangement. Although C isotopic fractionation has previously been described between different species of dissolved inorganic carbon and various CaCO3 polymorphs, this is the first documented evidence for C isotope fractionation between ACC and the calcite it recrystallizes to. This phenomenon may prove important for the interpretation of CaCO3-based C isotope environmental proxies

Pharmaceuticals in drinking water and resources for drinking water

Geneesmiddelen komen in zeer lage concentraties voor in drinkwater en drinkwaterbronnen. De hoeveelheden zijn echter zo laag dat effecten op de volksgezondheid zijn te verwaarlozen. Dit blijkt uit een inventarisatie van RIVM in opdracht van het ministerie van VROM. De meest voorkomende medicijnen in drinkwater en drinkwaterbronnen zijn slecht afbreekbaar in het milieu en/of worden veel gebruikt. De inventarisatie is een vervolg op onderzoek van vier waterinstituten in 2003 (RIVM rapport 703719004). Het RIVM heeft destijds vier geneesmiddelen in drinkwater aangetoond. Nu heeft het RIVM van 22 geneesmiddelen onderzocht in welke hoeveelheden ze voorkomen in drinkwater en drinkwaterbronnen. Hiervoor is een meetprogramma tweemaal uitgevoerd bij 22 drinkwaterproductielocaties. Ondanks de lage concentraties blijkt dat geneesmiddelen waarschijnlijk vaker voorkomen in drinkwater dan enkele jaren geleden. De medicijnen die in 2003 zijn aangetroffen zijn ook in het huidige onderzoek aangetoond. De pijnstillers acetylsalicylzuur (overwegend afkomstig van aspirine) en fenazon en het epilepsiemiddel carbamazepine werden het vaakst aangetroffen. Het synthetisch hormoon van de anticonceptiepil is niet aangetoond. Van het antidepressivum prozac is in enkele gevallen een spoortje aangetroffen. Om de verspreiding van humane en diergeneesmiddelen naar water te verminderen heeft het kabinet begin 2007 een pakket aan beleidsmaatregelen voorgesteld. Voorbeelden van deze maatregelen zijn het beperken van geneesmiddelgebruik, het inzamelen en vernietigen van ongebruikte medicijnen, en het ontwikkelen van geneesmiddelen die beter worden opgenomen in het lichaam en makkelijker worden afgebroken in milieu. Volgens dit onderzoek zijn de aangekondigde beleidsmaatregelen nuttig en nodig om het watermilieu en het drinkwater nu en in de toekomst te beschermen tegen verontreiniging met medicijnen.Pharmaceuticals are present in drinking water and drinking water resources in very low concentrations. However, the amounts are so low that effects on public health are negligible. This was shown in an RIVM investigation performed under the authority of the Dutch Ministry for Housing, Spatial Planning and the Environment (VROM). The most frequently detected medicines in drinking water are almost non-degradable in the environment and/or are frequently used. This investigation represents a follow-up to the research done by four water research institutes in 2003(Report 703719004); at that time RIVM detected four pharmaceuticals in drinking water. Recently, RIVM has investigated 22 pharmaceuticals for amounts present in drinking water and drinking-water resources. For this, a monitoring programme was conducted at 22 drinking-water production sites. In spite of low concentrations, detected pharmaceuticals are probably more frequently found in drinking water compared with several years ago. Medicines detected in 2003 were also found in this current investigation. The analgesics, salicylic acid (mainly from aspirin), phenazon and the anti-epileptic carbamazepin were detected most frequently. The synthetic hormone from the contraceptive pill was not found, while traces of the tranquilizer, prozac, were found in a few samples. At the beginning of 2007 the Dutch government proposed a package of policy measures to decrease the discharge of human and veterinary pharmaceuticals to water. Examples of these measures are reducing the use of pharmaceuticals, collecting and destroying unused pharmaceuticals, and developing pharmaceuticals which are better absorbed in the body and better degradable in the environment. This investigation supports the announced policy measures as being useful and necessary to protect the aquatic environment and drinking water against pollution by pharmaceuticals now and in the future.VROM-Inspecti

Observation of strongly entangled photon pairs from a nanowire quantum dot

A bright photon source that combines high-fidelity entanglement, on-demand generation, high extraction efficiency, directional and coherent emission, as well as position control at the nanoscale is required for implementing ambitious schemes in quantum information processing, such as that of a quantum repeater. Still, all of these properties have not yet been achieved in a single device. Semiconductor quantum dots embedded in nanowire waveguides potentially satisfy all of these requirements; however, although theoretically predicted, entanglement has not yet been demonstrated for a nanowire quantum dot. Here, we demonstrate a bright and coherent source of strongly entangled photon pairs from a position controlled nanowire quantum dot with a fidelity as high as 0.859 +/- 0.006 and concurrence of 0.80 +/- 0.02. The two-photon quantum state is modified via the nanowire shape. Our new nanoscale entangled photon source can be integrated at desired positions in a quantum photonic circuit, single electron devices and light emitting diodes.Comment: Article and Supplementary Information with open access published at: http://www.nature.com/ncomms/2014/141031/ncomms6298/full/ncomms6298.htm

Mapping onto Eq-5 D for patients in poor health

<p>Abstract</p> <p>Background</p> <p>An increasing amount of studies report mapping algorithms which predict EQ-5 D utility values using disease specific non-preference-based measures. Yet many mapping algorithms have been found to systematically overpredict EQ-5 D utility values for patients in poor health. Currently there are no guidelines on how to deal with this problem. This paper is concerned with the question of why overestimation of EQ-5 D utility values occurs for patients in poor health, and explores possible solutions.</p> <p>Method</p> <p>Three existing datasets are used to estimate mapping algorithms and assess existing mapping algorithms from the literature mapping the cancer-specific EORTC-QLQ C-30 and the arthritis-specific Health Assessment Questionnaire (HAQ) onto the EQ-5 D. Separate mapping algorithms are estimated for poor health states. Poor health states are defined using a cut-off point for QLQ-C30 and HAQ, which is determined using association with EQ-5 D values.</p> <p>Results</p> <p>All mapping algorithms suffer from overprediction of utility values for patients in poor health. The large decrement of reporting 'extreme problems' in the EQ-5 D tariff, few observations with the most severe level in any EQ-5 D dimension and many observations at the least severe level in any EQ-5 D dimension led to a bimodal distribution of EQ-5 D index values, which is related to the overprediction of utility values for patients in poor health. Separate algorithms are here proposed to predict utility values for patients in poor health, where these are selected using cut-off points for HAQ-DI (> 2.0) and QLQ C-30 (< 45 average of QLQ C-30 functioning scales). The QLQ-C30 separate algorithm performed better than existing mapping algorithms for predicting utility values for patients in poor health, but still did not accurately predict mean utility values. A HAQ separate algorithm could not be estimated due to data restrictions.</p> <p>Conclusion</p> <p>Mapping algorithms overpredict utility values for patients in poor health but are used in cost-effectiveness analyses nonetheless. Guidelines can be developed on when the use of a mapping algorithms is inappropriate, for instance through the identification of cut-off points. Cut-off points on a disease specific questionnaire can be identified through association with the causes of overprediction. The cut-off points found in this study represent severely impaired health. Specifying a separate mapping algorithm to predict utility values for individuals in poor health greatly reduces overprediction, but does not fully solve the problem.</p

Societal Utilities for Cognitive Impairment in Schizophrenia:Developing a Preference-Based Scoring Algorithm Based on the Schizophrenia Cognition Rating Scale

Introduction: Loss of cognitive function is a common feature in schizophrenia. However, generic measures of health-related quality of life favored by decision-makers, such as the EQ-5D, are not designed to detect changes in cognitive function. We report the valuation of the Schizophrenia Cognition Rating Scale (SCoRS), a schizophrenia-specific measure of cognitive impairment.Methods: Expert opinion and psychometric analysis of the SCoRS from clinical trial data was undertaken to select 5 key items from the measure. These items were combined orthogonally to develop health-state vignettes. Vignettes were valued using composite time trade-off (cTTO) in one-on-one video calls. Several econometric models were fitted to the data to estimate disutilities. Performance of EQ-5D- and SCoRS-based utilities were compared in the trial data. Results: The SCoRS items selected for the valuation study represented attention, learning, processing speed, social cognition and memory. Four hundred respondents participated in the valuation study. The best observed health state was valued at 0.855 [standard deviation (SD) = 0.179] and the worst at 0.152 (SD = 0.575). At the most severe levels, ‘social cognition’ received the largest disutility followed by ‘learning’ and ‘memory’. The final model to estimate utilities had 15 parameters. SCoRS-based utilities were sensitive to change in cognition, but the EQ-5D was not. Conclusion: It is feasible to value different dimensions of cognition separately using a validated instrument for proxy assessment. The resulting utilities indicate loss of quality of life due to reduced cognitive functioning.</p

Health-related quality of life and its determinants in patients with metastatic renal cell carcinoma

__Purpose:__ Based on improvements of progression-free survival (PFS), new agents for metastatic renal cell carcinoma (mRCC) have been approved. It is assumed that one of the benefits is a delay in health-related quality of life (HRQoL) deterioration as a result of a delay in progression of disease. However, little data are available supporting this relationship. This study aims to provide insight into the most important determinants of HRQoL (including progression of disease) of patients with mRCC. __Methods:__ A patient registry (PERCEPTION) was created to evaluate treatment of patients with (m)RCC in the Netherlands. HRQoL was measured, using the EORTC QLQ-C30 and EQ-5D-5L, every 3 months in the first year of participation in the study, and every 6 months in the second year. Participation started as soon as possible following a diagnosis of (m)RCC. Random effects models were used to study associations between HRQoL and patient and disease characteristics, symptoms and treatment. __Results:__ Eighty-seven patients with mRCC completed 304 questionnaires. The average EORTC QLQ-C30 global health status was 69 (SD, 19) before progression and 61 (SD, 22) after progression of disease. Similarly, the average EQ-5D utility was 0.75 (SD, 0.19) before progression and 0.66 (SD, 0.30) after progression of disease. The presence of fatigue, pain, dyspnoea, and the application of radiotherapy were associated with significantly lower EQ-5D utilities. __Conclusions:__ Key drivers for reduced HRQoL in mRCC are disease symptoms. Since symptoms increase with progression of disease, targeted therapies that increase PFS are expected to postpone reductions in HRQoL in mRCC