YREE determination in seawater. Standardization and validation of a new method based on preconcentration techniques

The most interesting attraction of using rare-earth elements and yttrium (YREE) to address geochemical and marine chemical problems consists of their chemical coherence as group of trace elements. These characters allow YREE compositions of rocks and minerals to be extensively used in studies of provenance, petrogenesis and chemical evolution of the geological materials (1). Similarly, YREE compositions in the hydrosphere were used in studies of coagulation, particle-solution reactions and oceanic circulation of water masses (2-4). Unfortunately, very low concentrations of YREE (ng l-1 or sub-ng l-1) associated to high ionic strength of seawater always represented the main difficulty to analyse dissolved YREE in marine environment. The first geochemical investigations of YREE contents in seawater were carried out using neutron activation and isotope dilution mass spectrometry that were almost entirely replaced by inductively coupled plasma supplemented by mass spectrometry (ICP-MS) in recent years. This technique offers many advantages including simultaneous analysis of all the elements of series and their quantitative determination with detection limits of the order of ng l-1 if associated to preconcentration techniques (5). To perform ultra-trace YREE analyses in seawater, we developed a preconcentration method based on CHELEX-100 iminodiacetate resin followed by ICP-MS determination (Ref). In this study the YREE behaviour was quantitatively investigated during interactions with ion chelating resin and estimation of composed measurement uncertainty associated to measurements was evaluated with a rigorous metrological approach based on method validation and quality control of YREE data. These goals were achieved using synthetic seawater where YREE had concentrations as occurring in natural seawater samples. Under these conditions good recovery were obtained along the YREE series, ranging from 75%-85% and 90%-100% for heavy REE and Y and light REE, respectively. Composed measurement uncertainty was expressed in terms of precision, recovery uncertainties, reference material uncertainty and instrumental calibration uncertainty. The obtained results were critically discussed on the basis of the different contributions and confirm the quadrupole ICP-MS technique as highly sensitive to determine very low YREE concentrations. REFERENCES 1. S. R. Taylor, S.M. McLennan, The Continental Crust: its Composition and Evolution. Blackwell Scientific Publications, Oxford, 1985). 2. G.J. Piepgras, G.J. Wasserburg, Science 217 (1982) 207. 3. J. Zhang, Y. Nozaki, Geochim. Cosmochim. Acta 60 (1996) 4631. 4. R.H. Byrne, E. Sholkovitz, In: Gschneidner, J.K.A., Eyring, (Eds.), Handbook on the Physics and Chemistry of Rare Earths. Elsevier, New York, (1996) 498-593. 5. P. M\uf6ller, P. Dulski P., J. Luck, Spectrochim. Acta, 47B, 1379

Splenomegaly impacts prognosis in essential thrombocythemia and polycythemia vera: A single center study

Splenomegaly is one of the major clinical manifestations of primary myelofibrosis and is common also in other chronic Philadelphia-negative myeloproliferative neoplasms, causing symptoms and signs and affecting quality of life of patients diagnosed with these diseases. We aimed to study the impact that such alteration has on thrombotic risk and on the survival of patients with essential thrombocythemia and patients with Polycythemia Vera (PV). We studied the relationship between splenomegaly (and its grade), thrombosis and survival in 238 patients with et and 165 patients with PV followed at our center between January 1997 and May 2019

Bythocaris cosmetops (Decapoda: Caridea: Hippolytidae) in the western Mediterranean Sea

The capture of the species Bythocaris cosmetops in the Alboran Sea (southern Spain, western Mediterranean Sea), previously known from only two specimens from the Atlantic, Sierra Leone (south-west Africa) and the northern Bay of Biscay (north-west Europe), represents the first record of the genus and species in the Mediterranean Sea and Iberian Peninsula (south-west Europe). New data on morphology, biology and habitat are provided and discussed.Postprint0,000

Bayesian geostatistical modelling for mapping schistosomiasis transmission

Progress has been made in mapping and predicting the risk of schistosomiasis using Bayesian geostatistical inference. Applications primarily focused on risk profiling of prevalence rather than infection intensity, although the latter is particularly important for morbidity control. In this review, the underlying assumptions used in a study mapping Schistosoma mansoni infection intensity in East Africa are examined. We argue that the assumption of stationarity needs to be relaxed, and that the negative binomial assumption might result in misleading inference because of a high number of excess zeros (individuals without an infection). We developed a Bayesian geostatistical zero-inflated (ZI) regression model that assumes a non-stationary spatial process. Our model is validated with a high-quality georeferenced database from western Côte d'Ivoire, consisting of demographic, environmental, parasitological and socio-economic data. Nearly 40% of the 3818 participating schoolchildren were infected with S. mansoni, and the mean egg count among infected children was 162 eggs per gram of stool (EPG), ranging between 24 and 6768 EPG. Compared to a negative binomial and ZI Poisson and negative binomial models, the Bayesian non-stationary ZI negative binomial model showed a better fit to the data. We conclude that geostatistical ZI models produce more accurate maps of helminth infection intensity than the spatial negative binomial one

Massive pulmonary embolism as a rare complication of a stab in the inguinal region in a HIV-positive patient: a case report

Venous thromboembolism (VTE) is a severe preventable disease; HIV-infection represents a prothrombotic condition, because of specific factors due to the virus itself, the host response and the antiretroviral therapy. Our aim is to raise awareness of thromboembolic risk when dealing with HIV-positive patients presenting to the Emergency Department for treatment of injuries, even though small

High-resolution Extinction Map in the Direction of the Bulge Globular Cluster NGC 6440

We used optical images acquired with the UVIS channel of the Wide Field Camera 3 on board the Hubble Space Telescope to construct the first high-resolution extinction map in the direction of NGC 6440, a globular cluster located in the bulge of our Galaxy. The map has a spatial resolution of 0.\u20335 over a rectangular region of about 160\u2033 7 240\u2033 around the cluster center, with the long side in the northwest/southeast direction. We found that the absorption clouds show patchy and filamentary substructures with extinction variations as large as \u3b4E(B-V) 3c0.5 mag. We also performed a first-order proper motion analysis to distinguish cluster members from field interlopers. After the field decontamination and the differential reddening correction, the cluster sequences in the color-magnitude diagram appear much better defined, providing the best optical color-magnitude diagram so far available for this cluster

A Computer Aided Detection system for mammographic images implemented on a GRID infrastructure

The use of an automatic system for the analysis of mammographic images has proven to be very useful to radiologists in the investigation of breast cancer, especially in the framework of mammographic-screening programs. A breast neoplasia is often marked by the presence of microcalcification clusters and massive lesions in the mammogram: hence the need for tools able to recognize such lesions at an early stage. In the framework of the GPCALMA (GRID Platform for Computer Assisted Library for MAmmography) project, the co-working of italian physicists and radiologists built a large distributed database of digitized mammographic images (about 5500 images corresponding to 1650 patients) and developed a CAD (Computer Aided Detection) system, able to make an automatic search of massive lesions and microcalcification clusters. The CAD is implemented in the GPCALMA integrated station, which can be used also for digitization, as archive and to perform statistical analyses. Some GPCALMA integrated stations have already been implemented and are currently on clinical trial in some italian hospitals. The emerging GRID technology can been used to connect the GPCALMA integrated stations operating in different medical centers. The GRID approach will support an effective tele- and co-working between radiologists, cancer specialists and epidemiology experts by allowing remote image analysis and interactive online diagnosis.Comment: 5 pages, 5 figures, to appear in the Proceedings of the 13th IEEE-NPSS Real Time Conference 2003, Montreal, Canada, May 18-23 200

Optimal Operation of the Multireservoir System in the Seine River Basin Using Deterministic and Ensemble Forecasts

International audienceThis article investigates the improvement of the operation of a four-reservoir system in the Seine River basin, France, by use of deterministic and ensemble weather forecasts and real-time control. In the current management, each reservoir is operated independently from the others and following prescribed rule-curves, designed to reduce floods and sustain low flows under the historical hydrological conditions. However, this management system is inefficient when inflows are significantly different from their seasonal average and may become even more inadequate to cope with the predicted increase in extreme events induced by climate change. In this work, a centralized real-time control system is developed to improve reservoirs operation by exploiting numerical weather forecasts that are becoming increasingly available. The proposed management system implements a well-established optimization technique, model predictive control (MPC), and its recently modified version that can incorporate uncertainties, tree-based model predictive control (TB-MPC), to account for deterministic and ensemble forecasts respectively. The management system is assessed by simulation over historical events and compared to the no-forecasts strategy based on rule-curves. Simulation results show that the proposed real-time control system largely outperforms the no-forecasts management strategy, and that explicitly considering forecast uncertainty through ensembles can compensate for the loss in performance due to forecast inaccuracy