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Context: Among the numerous varieties of squash that exist, some are edible while other bitter-tasting ones are not fit for human consumption. Cases of confusion seem to be multiplying and are characterized by digestive problems (diarrhea, vomiting, and abdominal pain). Methods: This is a descriptive retrospective study of cases of exposure reported to French Poison Control Centers between 1 January 2012 and 12 December 2016. Results: 353 patients were included, with 71.7% belonging to collective cases of poisoning. The male to female sex ratio was 0.75 for an average age of 38.2 ± 23.6 years. The circumstances of exposure were dietary for 337 patients (95.5%). The majority of the squash consumed was purchased at a store (55.8%) but some also came from the garden (25.5%). 204 patients (57.8%) mostly presented with diarrhea, vomiting, abdominal pain, sometimes with the consequent dehydration, hypotension, tachycardia, headaches, or vertigo. There were no deaths or severe (Poisoning Severity Score (PSS) 3) cases, but there were 14 patients (4.0%) of moderate severity, 190 patients (53.8%) of minor severity (PSS 1), and 149 patients (42.2%) without severity (PSS 0) but among which we include the bitter taste of the squash. The average age of PSS 2 patients was significantly (p = .003) older than that of the PSS <2 patients. Conclusion: As the first consequential series in Europe, our study shows that exposure to non-edible squash is frequent. Usually benign, poisoning could be the consequence of the irritating effect of certain cucurbits, the molecules responsible for the taste and toxicity of the fruits. In terms of prevention therefore, we recommend disposing of any squash with a bitter taste. [ABSTRACT FROM AUTHOR]

Ombrotrophic peatlands are fed uniquely by atmospheric inputs and therefore have much potential as temporal archives of atmospheric microplastic (MP) deposition, yet the recovery and detection of MP within an almost purely organic matrix is challenging. This study presents a novel peat digestion protocol using sodium hypochlorite (NaClO) as a reagent for biogenic matrix removal. NaClO is more efficient than hydrogen peroxide (H 2 O 2). By using purged air-assisted digestion, NaClO (50 vol%) reached 99% matrix digestion compared with 28% and 75% by H 2 O 2 (30 vol%) and Fenton's reagent, respectively. At a concentration of 50 vol% NaClO did however chemically disintegrate small amounts (<10 mass %) of polyethylene terephthalate (PET) and polyamide (PA) fragments in the millimeter size range. Observation of PA6 in natural peat samples, while not found in the procedural blanks, questions whether PA is fully disintegrated by NaClO. The protocol was applied to three commercial sphagnum moss test samples, in which MP particles in the range of 0.8–65.4 μm were detected by Raman microspectroscopy. The MP mass% was determined at 0.012% corresponding to 129 thousand MP particles/g, of which 62% were smaller than 5 μm and 80% were smaller than 10 μm, yet were accountable for only 0.4% (500 ng) and 3.2% (4 μg) of the total mass of MP, respectively. These findings underline the importance of the identification of particles Ø < 5 μm when investigating atmospheric MP deposition. The MP counts were corrected for MP recovery loss and procedural blank contamination. MP spike recovery following the full protocol was estimated at 60%. The protocol offers an efficient way of isolating and pre-concentrating most aerosol sized MPs in large quantities of refractory vegetal matrices and enables the automated μRaman scanning of thousands of particles at a spatial resolution on the order of 1 μm. [Display omitted] • Novel technique 'purged air-assisted digestion' uses NaClO to achieve almost complete digestion of vegetal matrices. • MP mass% in commercial sphagnum moss determined at 0.012% following blank- and recovery correction. • Novel extrapolation method based on the ratio between MPs and the area of generic particles. • NaClO may disintegrate PA and PET but does not affect the plastics that constitute the majority of the global production. [ABSTRACT FROM AUTHOR]

An order picking system in a distribution centre consisting of parallel unidirectional picking lines is considered. The objectives are to minimise the walking distance of the pickers, the largest volume of stock on a picking line over all picking lines, the number of small packages, and the total penalty incurred for late distributions. The problem is formulated as a multi-objective multiple knapsack problem that is not solvable in a realistic time. Population-based algorithms, including the artificial bee colony algorithm and the genetic algorithm, are also implemented. The results obtained from all algorithms indicate a substantial improvement on all objectives relative to historical assignments. The genetic algorithm delivers the best performance. [ABSTRACT FROM AUTHOR]

Chemicalengineering processes need careful monitoring in orderto ensure product specification (i.e., composition, quality, etc.).Physicochemical analytical techniques can be applied for characterization,but those techniques can be time-consuming and become impracticalfor chemical processes for which online monitoring is needed. Calorimetryis frequently used to monitor and control batch and semibatch reactions.State and covariance estimation for batch processes employing advancedtechniques, such as moving horizon estimation (MHE) for state andautocovariance least-squares (ALS) for covariance, have not been studiedtogether. In this paper, the ALS technique is extended for batch processesand validated using laboratory data of three experimental case studies,with focus on polymerization processes. The problem of the simultaneousonline estimation of states and parameters in these systems, employingrecursive, extended Kalman filter (EKF) and unscented Kalman filter(UKF), and optimization-based (MHE) estimators with covariances estimatedby the ALS, is examined. The results of the implementation of theproposed approach show accuracy of the estimated variables for thepolymerization processes considered. Thus, this work provides a systematicprocedure for the successful determination of covariances and statesfor experimental batch cases, including systems under repeated perturbations. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Despite of specific guidelines regarding the treatment of dyslipidemia, therapeutic management of patients is not optimal. The objectives of this study were to describe the time for implementation of hypolipemiant treatment and to identify the determinants. Methods: This was an observational, transversal, prospective, multicenter study carried out in France by general practitioners. Adult patients with dyslipidemia diagnosed since<2 years were eligible for this study. Demographic, diagnosis and disease characteristics, and treatment procedures were collected. Results: Three thousand six hundred and twenty-four patients were enrolled by 1226 physicians, and data from 3268 patients meeting the selection criteria were analyzed. Mean age was 57 years old, 64% were male. More than 45% of the patients were overweight, 26% were obese. Only 12% of the patients had no cardiovascular risk factor at the time of dyslipidemia diagnosis. The most frequent cardiovascular risk factors constisted in arterial hypertension (50%), smoking (43%), family antecedents of coronary disease (28%), HDL-cholesterol less than 0.4g/L (20%); 15% of the patients had personal antecedents of cardiovascular disease. Initial management of dyslipidemia included implementation of lifestyle changes for 98% of the patients. More than 90% of the patients were treated with a statin. The median time for implementation of hypolipemiant treatment was 2.9 months. The hypolipemiant treatment was initiated more than 3 months after dyslipidemia diagnosis for 43% of the patients. The main determinant factor of an early implementation of hypolipemiant treatment (?3 months) was secondary prevention (OR=2.2). The number of cardiovascular risk factors had no significant impact. Conclusion: This study highlights the lack of awareness towards the number of cardiovascular risk factors in the management of dyslipidemia, in primary prevention. [Copyright &y& Elsevier]

Diagnostic features of myelodysplastic syndromes (MDS) are often polymorphic and nonspecific including anemia in most cases. Standard parameters provided by an automated analyzer seldom bring any argument for this diagnosis. The aim of this study was to investigate whether some structural parameters, not routinely provided by Sysmex XE 2100 analyzer, could help diagnose MDS in a simple way, adapted to routine practice. Blood samples from 184 MDS fully annotated cases and 3545 normal blood count controls were performed with XE 2100 Sysmex analyzer. Quantitative and structural parameters were considered. We found that the structural neutrophil parameter, NEUT-X, converted into a semi-quantitative parameter, the granularity index (GI), could be used as a flag for MDS in front of anemia. Negative GI and anemia were able to make otherwise unrecognized MDS stand out in routine practice, increasing the number of slides addressed to review from 67% to 96%, without leading to a large excess of unfounded slide review among non-MDS. Including the GI index in the routine parameters provided by the Sysmex analyzer could be of major help for nonspecialized routine laboratories in detecting MDS. [ABSTRACT FROM AUTHOR]

A person experiencing more than one medical condition may have ambiguous clinical presentation. ITP is a serious autoimmune disease with little epidemiological evidence on its burden, risk factors, and comorbidities. Using the United Kingdom general practice research database, we conducted a 14 years population-based case control-type study to explore medical conditions more likely to cooccur with ITP and their temporal relationship in association with ITP. ITP patients were matched to non-ITP on practice, age, gender, and follow-up period. Potential comorbidities were represented by patients' medical information at the preferred term level of the MedDRA international classification. As well as death (OR = 60.0; 95% CI [4.47-806.0]) and known clinical signs and symptoms of ITP, ITP is associated with considerable number of medical conditions. The association between ITP and some of these conditions is apparent both before and after ITP diagnosis. Specific targeted studies can now be setup to reexamine observed associations. [ABSTRACT FROM AUTHOR]

Le syndrome phalloïdien est le toxidrome mycotoxique survenant après l'ingestion de certaines espèces de macromycètes, des genres Amanita , Lepiota et Galerina. Amanita phalloides est l'espèce la plus souvent en cause, responsable de plus de 90 % des décès dus à la consommation de champignons. L'α-amanitine est responsable de la plupart des effets observés. La présentation clinique est caractérisée par un tableau digestif sévère et de survenue tardive (plus de six heures après l'ingestion). Le foie étant le principal organe cible, l'évolution est marquée par une hépatite aiguë souvent sévère pouvant évoluer vers l'insuffisance hépatique terminale justifiant le recours à la transplantation hépatique orthotopique. Une insuffisance rénale aiguë est souvent observée. Le diagnostic de syndrome phalloïdien repose avant tout sur les données cliniques ; il peut être confirmé biologiquement par la mise en évidence des amatoxines, notamment sur prélèvement urinaire. En l'absence d'antidote, la prise en charge hospitalière précoce est indispensable. Elle repose sur la compensation précoce des pertes hydroélectrolytiques, la décontamination digestive, des traitements épurateurs, et des traitements médicamenteux. La thérapie combinée associant silibinine et N-acétylcystéine est recommandée afin de limiter le transport intra-hépatocytaire des amatoxines et à visée hépatoprotectrice. Le pronostic de cette intoxication grave a grandement profité de l'amélioration des techniques de réanimation. La létalité en France est actuellement inférieure à 10 %. Lors d'un cas suspecté ou avéré, le recours à un centre antipoison est recommandé, afin de pouvoir asseoir le diagnostic et guider la prise en charge médicale des patients de façon précoce et adaptée. Amatoxin-containing mushroom poisoning occurs after consumption of certain mushroom species, of the genera Amanita , Lepiota and Galerina. Amanita phalloides is the most implicated species, responsible for over more than 90% of mushroom-related deaths. The α-amanitin is responsible for most of the observed effects. Symptoms are characterized by severe delayed gastrointestinal disorders (more than six hours after ingestion). The liver being the main target organ, outcome is marked by an often severe hepatitis which can evolve towards terminal liver failure, justifying orthotopic liver transplantation. Acute renal failure is common. Diagnosis of amatoxin-containing mushroom poisoning is based primarily on clinical data; it can be biologically confirmed using detection of amatoxins, especially from urine samples. In the absence of an antidote, early hospital management is essential. It is based on supportive care (early compensation of hydroelectrolytic losses), gastrointestinal digestive decontamination, elimination enhancement, amatoxin uptake inhibitors and antioxidant therapy. Combined therapy associating silibinin and N-acetylcysteine is recommended. Prognosis of this severe poisoning has greatly benefited from improved resuscitation techniques. Mortality is currently less than 10%. In the event of a suspected or confirmed case, referral to a Poison Control Center is warranted in order to establish the diagnosis and guide the medical management of patients in an early and appropriate way. [ABSTRACT FROM AUTHOR]

Wet thermal oxidation of AlAsSb was investigated. The oxidation kinetics was studied as a function of temperature and oxidation duration. An expression to allow accurate determination of the oxide depth for any temperature and time was established. Secondary ion mass spectrometry profiles and x-ray diffraction were used to demonstrate that an interfacial layer, composed of pure Sb and As and textured on InP, is formed during the oxidation process. [ABSTRACT FROM AUTHOR]

Le mot « réglisse » désigne la plante, sa racine et son extrait aromatique. D'un point de vue commercial, Glycyrrhiza glabra est l'espèce la plus importante avec un large éventail d'utilisations (phytothérapie, industrie du tabac, cosmétique, alimentaire et pharmaceutique). La glycyrrhizine, de structure hétérosidique triterpènique, est l'un des principaux constituants de la réglisse. Elle est hydrolysée dans la lumière intestinale par des β-glucuronidases du microbiote en acide 3β-monoglucuronyl-18β-glycyrrhétinique (A3MG) et en acide 18β-glycyrrhétinique (AG), qui sont métabolisés dans le foie. La clairance plasmatique est lente en raison d'un cycle entéro-hépatique. L'A3MG et l'AG sont capables de se lier aux récepteurs des minéralocorticoïdes avec une affinité très faible, et l'A3MG induit un pseudo-hyperaldostéronisme par inhibition dose-dépendante de la 11β-hydroxystéroïde déshydrogénase de type 2 dans le tissu rénal. Les cas rapportés dans la littérature de pseudo-hyperaldostéronisme sont nombreux et parfois graves, voire mortels, le plus souvent en contexte de consommation chronique et à doses importantes. Les intoxications à la glycyrrhizine sont caractérisées par une hypertension artérielle, une rétention hydrosodée, et une hypokaliémie avec alcalose métabolique et kaliurèse augmentée. La toxicité est fonction de la dose, du type de produit consommé, du mode de consommation (aiguë ou chronique) et d'une très grande variabilité interindividuelle. Le diagnostic de pseudo-hyperaldostéronisme par intoxication à la glycyrrhizine repose sur les données de l'anamnèse, de l'examen clinique et d'analyses biochimiques. La prise en charge repose avant tout sur celles des symptômes et l'arrêt de consommation de réglisse. The word "licorice" refers to the plant, its root, and its aromatic extract. From a commercial point of view, Glycyrrhiza glabra is the most important species with a wide range of uses (herbal medicine, tobacco industry, cosmetics, food and pharmaceutical). Glycyrrhizin is one of the main constituents of licorice. Glycyrrhizin is hydrolyzed in the intestinal lumen by bacterial β-glucuronidases to 3β-monoglucuronyl-18β-glycyrrhetinic acid (3MGA) and 18β-glycyrrhetinic acid (GA), which are metabolized in the liver. Plasma clearance is slow due to enterohepatic cycling. 3MGA and GA can bind to mineralocorticoid receptors with very low affinity, and 3MGA induces apparent mineralocorticoid excess syndrome through dose-dependent inhibition of 11β-hydroxysteroid dehydrogenase type 2 in renal tissue. The cases of apparent mineralocorticoid excess syndrome reported in the literature are numerous and sometimes severe, even fatal, most often in cases of chronic high dose consumption. Glycyrrhizin poisonings are characterized by hypertension, fluid retention, and hypokalemia with metabolic alkalosis and increased kaliuresis. Toxicity depends on the dose, the type of product consumed, the mode of consumption (acute or chronic) and a very large inter-individual variability. The diagnosis of glycyrrhizin-induced apparent mineralocorticoid excess syndrome is based on the history, clinical examination, and biochemical analysis. Management is primarily based on symptomatic care and stopping licorice consumption. [ABSTRACT FROM AUTHOR]

Abstract: A high-resolution peat record from Eastern Belgium reveals the chronology of dust deposition for the last 2500years. REE and lithogenic elements in addition to Nd and Pb isotopes were measured in a 173cm age-dated peat profile and provide a continuous chronology of dust source and intensity. Calculated dust flux show pronounced increases c. 300BC, 600AD, 1000AD, 1200AD and from 1700AD, corresponding to local and regional human activities combined with climate change. The Industrial Revolution samples (1700–1950AD) are characterised by a significant enrichment in Sc-normalised REE abundance (sum REE/Sc>25) due to intensive coal combustion. For the pre-Industrial Revolution samples, the Sc-normalised REE abundance (10

A 72-year-old male with a 4-year history of TNFalpha antagonist therapy (infliximab and etanercept) for ankylosing spondylitis was diagnosed with breast cancer. He had a family history of breast cancer. The low incidence and considerable severity of breast cancer in males, genetic risk factors, and potential role for TNFalpha antagonist therapy are discussed. [ABSTRACT FROM AUTHOR]

The band-gap (E[sub gp]) and valence band offset (ΔE[sub v]) energies of pseudomorphic GaAsSb layers on GaAs substrate are determined from temperature-dependent photoluminescence measurements on GaAsSb/GaAs and GaAsSb/GaAlAs quantum wells grown by molecular beam epitaxy. A clear evidence of staggered type-II band alignment of GaAsSb relative to GaAs and a value of 1.05 for the valence band offset ratio (Q[sub v]) are proposed. Finally, through a detailed comparison of these values with those published previously, we have shown that the scatter in Q[sub v] found in the literature (<1 to 2.1) is closely dependent on the exact determination of E[sub gp]. Particularly, we have shown that the strain dependence of the deformation potential is important in the calculation of the strain energy contribution to E[sub gp]. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents a study which considered the growth and characterization of indium[sub x]gallium[sub 1-x]arsenide/indium[sub y]gallium[sub 1-y] strained-layer superlattice on indium phosphide substrate. Discussion of the growth; X-ray characterization; Optical characterization.

Compares kinematic and dynamic approaches of x-ray diffraction for multiple InGaAs/InGaAlAs quantum wells around 002 and 004 reflections as a function of strain and thickness. Simulations performed for 002 and 004 reflections for lattice-matched structures and strained structures; Description on automatic determination of structural parameters of strained multiple quantum wells; Discussion on the experimental results.

Deals with a study which investigated the optical spin orientation of gallium arsenide short-period lattices. Methods; Results; Discussion.

The purpose of this study is to evaluate the contamination in As, Ba, Co, Cu, Mn, Ni, Sr, V, Zn and REE, in a high uranium activity (up to 21,000 Bq ∙ kg − 1 ) area, downstream of a former uranium mine. Different geochemical proxies like enrichment factor and fractions from a sequential extraction procedure are used to evaluate the level of contamination, the mobility and the availability of the potential contaminants. Pb isotope ratios are determined in the total samples and in the sequential leachates to identify the sources of the contaminants and to determine the mobility of radiogenic Pb in the context of uranium mining. In spite of the large uranium contamination measured in the soils and the sediments (EF ≫ 40), trace element contamination is low to moderate (2 < EF < 5), except for Ba (5 < EF < 15), due to the precipitation of barium sulfate resulting from mining activities. Most of the trace elements are associated with the most mobile fractions of the sediments/soils, implying an enhanced potential availability. Even if no Pb enrichment is highlighted, the Pb isotopic signature of the contaminated soils is strongly radiogenic. Measurements performed on the sequential leachates reveal inputs of radiogenic Pb in the most mobile fractions of the contaminated soil. Inputs of low-mobile radiogenic Pb from mining activities may also contribute to the Pb signature recorded in the residual phase of the contaminated samples. We demonstrate that Pb isotopes are efficient tools to trace the origin and the mobility of the contaminants in environments affected by uranium mining. [ABSTRACT FROM AUTHOR]

This study combines in situ gamma spectrometry performed at different scales, in order to accurately locate the contamination pools, to identify the concerned radionuclides and to determine the distribution of the contaminants from soil to bearing phase scale. The potential mobility of several radionuclides is also evaluated using sequential extraction. Using this procedure, an accumulation area located downstream of a former French uranium mine and concentrating a significant fraction of radioactivity is highlighted. We report disequilibria in the U-decay chains, which are likely related to the processes implemented on the mining area. Coupling of mineralogical analyzes with sequential extraction allow us to highlight the presence of barium sulfate, which may be the carrier of the Ra-226 activities found in the residual phase (Ba(Ra)SO 4 ). In contrast, uranium is essentially in the reducible fraction and potentially trapped in clay-iron coatings located on the surface of minerals. [ABSTRACT FROM AUTHOR]

In order to assess the influence of local environment and spatial integration of Trace Metals (TM) by biomonitors, Al, As, Cd, Cr, Cs, Cu, Fe, Mn, Ni, Pb, Sb, Sn, V and Zn and some rare earth element (REE) concentrations have been measured in lichens and mosses collected in three French forest sites located in three distinct mountainous areas, as well as in the local soil and bedrock, and in both bulk deposition (BD) and throughfall (TF). Similar enrichment factors (EF) were calculated using lichens and mosses and local bedrock for most elements, except for Cs, Mn, Ni, Pb, and Cu which were significantly (KW, p < 0.05) more enriched in mosses. Similar REE ratios were measured in soils, bedrock, lichens and mosses at each study sites, indicating a regional integration of atmospheric deposition by both biomonitors. Both TM signature and REE composition of mosses revealed that this biomonitor is highly influenced by throughfall composition, and reflect atmospheric deposition interaction with the forest canopy. This explained the higher enrichment measured in mosses for elements which concentration in deposition were influenced by the canopy, either due to leaching (Mn), direct uptake (Ni), or dry deposition dissolution (Pb, Cu, Cs). [ABSTRACT FROM AUTHOR]

Themodeling, analysis, and simulation validation of an industrial-scaledepropenizer column (Refinaria de Capuava, Mauá, SãoPaulo) owned by Petrobras S.A. are carried out using equation-orientedand sequential modular approaches. The model implemented in the equation-orientedenvironment proved to be suitable for real-time optimization (RTO)applications due to its robustness, fast convergence, and abilityto represent the real process. The analysis of the model allows betterunderstanding of the process and establishment of boundaries to processspecifications and the parameters updated in the RTO cycle; furthermore,it is shown that feed composition and column pressure drop are criticalaspects in the model to represent the actual process. [ABSTRACT FROM AUTHOR]

Abstract: The aims of this present study were to: 1) assess the characteristics of hematological malignancies in polymyositis/polymyositis (PM/DM) patients; and 2) determine predictive variables of hematological malignancies in PM/DM patients. We retrospectively reviewed the medical records of 32 patients (14 PM, 18 DM) associated with hematological malignancies. In our 32 PM/DM patients, hematological malignancy was concurrently identified (18.8%) or occurred during the course of PM/DM (31.2%); although, PM/DM more often preceded hematological malignancy onset (50%). We observed that the types of hematological malignancies varied, consisting of: B-cell lymphoma (n=20), T-cell lymphoma (n=4), Hodgkin''s disease (n=2), multiple myeloma (n=1), myelodysplastic syndrome without excess of blasts (n=3), hairy cell (n=1) and acute lymphocytic leukemia (n=1). In 21 patients of our 32 patients with PM/DM-associated hematological malignancy (65.6% of cases), PM/DM paralleled the course of hematological malignancy. Finally, we observed that patients with PM/DM-associated hematological malignancies had a poor prognosis, the survival status ranging from 96.9%, 78.1% and 51.4% at 1, 3 and 5years, respectively. Interestingly, we found that patients with hematological malignancies, compared with those without were older and more frequently had DM; on the other hand, these patients less commonly exhibited: joint involvement (p=0.017), interstitial lung disease (p=0.06) and anti-Jo1 antibody (p=0.001). Taken together, our study underscores that the association between PM/DM and hematological malignancy, especially lymphoma, should not be ignored. Our findings also suggest that antisynthetase syndrome may be a protective factor of hematological malignancy in PM/DM patients. [Copyright &y& Elsevier]

Abstract: An 80-year soil archive, the 42-plot experimental design at the INRA in Versailles (France), is used here to study long-term contamination by 137Cs atmospheric deposition and the fate of this radioisotope when associated with various agricultural practices: fallow land, KCl, NH4(NO3), superphosphate fertilizers, horse manure and lime amendments. The pertinence of a simple box model, where radiocaesium is supposed to move downward by convectional mechanisms, is checked using samples from control plots which had been neither amended, nor cultivated since 1928. This simple model presents the advantage of depending on only two parameters: α, a proportional factor allowing the historical atmospheric 137Cs fluxes to be reconstructed locally, and k, an annual loss coefficient from the plow horizon. Another pseudo-unknown is however necessary to run the model: the shape of historical 137Cs deposition, but this function can be easily computed by merging several curves previously established by other surveys. A loss of ∼1.5% per year from the plow horizon, combined with appropriate fluxes, provides good concordance between simulated and measured values. In the 0–25cm horizon, the residence half time is found to be ∼18yr (including both migration and radioactive decay). Migration rate constants are also calculated for some plots receiving continuous long-term agricultural treatments. Comparison with the control plots reveals significant influence of amendments on 137Cs mobility in these soils developed from a unique genoform. [Copyright &y& Elsevier]

Abstract: Soils have been sampled in the vicinity of the Tomsk–Seversk facility (Siberia, Russia) that allows us to measure radioactive contaminations due to atmospheric and aquatic releases. Indeed soils exhibit large inventories of man-made fission products including 137Cs (ranging from 33,000 to 68,500Bqm−2) and actinides such as plutonium (i.e. 239+240Pu from 420 to 5900Bqm−2) or 241Am (160–1220Bqm−2). Among all sampling sites, the bank of the Romashka channel exhibits the highest radioisotope concentrations. At this site, some short half-life gamma emitters were detected as well indicating recent aquatic discharge in the channel. In comparison, soils that underwent atmospheric depositions like peat and forest soils exhibit lower activities of actinides and 137Cs. Soil activities are too high to be related solely to global fallout and thus the source of plutonium must be discharges from the Siberian Chemical Combine (SCC) plant. This is confirmed by plutonium isotopic ratios measured by ICP-MS; the low 241Pu/239Pu and 240Pu/239Pu atomic ratios with respect to global fallout ratio or civil nuclear fuel are consistent with weapons grade signatures. Up to now, the influence of Tomsk–Seversk plutonium discharges was speculated in the Ob River and its estuary. Isotopic data from the present study show that plutonium measured in SCC probably constitutes a significant source of plutonium in the aquatic environment, together with plutonium from global fallout and other contaminated sites including Tomsk, Mayak (Russia) and Semipalatinsk (Republic of Kazakhstan). It is estimated that the proportion of plutonium from SCC source can reach 45% for 239Pu and 60% for 241Pu in the sediments. [Copyright &y& Elsevier]

Abstract: Management of a game ranch is an important issue as many game ranches operate on meagre profits, and some even at a loss, as their part-time owners subsidize the ranches from other sources of income. In this paper, we address the sustainable game ranching problem in a South African context through an optimization model. To obtain a faithful picture of reality, the model includes conflicting objective functions, and takes into account the fact that annual rainfall is known only stochastically. An approach for solving the resulting multiobjective integer linear stochastic program is discussed and illustrated by means of a numerical example from a Northern Cape ranch. [Copyright &y& Elsevier]

Abstract: Accumulation of organic matter (OM) was studied in four ombrotrophic peat bogs in Finland: Harjavalta (vicinity of a Cu–Ni smelter), Outokumpu (near a closed Cu–Ni mine), Alkkia (Ni-treated site) and Hietajärvi (a pristine site). At each sampling site, two peat cores (15×15×100 cm) were taken. Age-dating of peat was determined using 210Pb method (CRS model). The local annual temperature sum and precipitation for the past 125 years were modeled. The objective was to compare recent net accumulation rates of heavy metal polluted ombrotrophic peat bogs with those of a pristine bog, and to study the relationship between weather and net accumulation rates. Based on 210Pb age-dating, the upper 16-cm peat layer at Harjavalta, 35 cm at Outokumpu and 25 cm at Hietajärvi represents 125 years of peat formation, yielding the following average peat accumulation rates: Harjavalta 1.3 mm year−1, Outokumpu 2.8 mm year−1 and Hietajärvi 2.0 mm year−1. At the Alkkia site, the Ni treatment in 1962 had completely stopped the peat accumulation. Net accumulation rates were related to precipitation at Outokumpu, Harjavalta and Hietajärvi sites. In addition, emissions released from the nearby located Cu–Ni smelter could have affected negatively net OM accumulation rate at Harjavalta site. [Copyright &y& Elsevier]

Abstract: A monolith representing 5420 14C yr of peat accumulation was collected from a blanket bog at Myrarnar, Faroe Islands. The maximum Hg concentration (498 ng/g at a depth of 4.5 cm) coincides with the maximum concentration of anthropogenic Pb (111 μg/g). Age dating of recent peat accumulation using 210Pb (CRS model) shows that the maxima in Hg and Pb concentrations occur at AD 1954 ± 2. These results, combined with the isotopic composition of Pb in that sample (206Pb/207Pb = 1.1720 ± 0.0017), suggest that coal burning was the dominant source of both elements. From the onset of peat accumulation (ca. 4286 BC) until AD 1385, the ratios Hg/Br and Hg/Se were constant (2.2 ± 0.5 × 10-4 and 8.5 ± 1.8 × 10-3, respectively). Since then, Hg/Br and Hg/Se values have increased, also reaching their maxima in AD 1954. The age date of the maximum concentrations of anthropogenic Hg and Pb in the Faroe Islands is consistent with a previous study of peat cores from Greenland and Denmark (dated using the atmospheric bomb pulse curve of 14C), which showed maximum concentrations in AD 1953. The average rate of atmospheric Hg accumulation from 1520 BC to AD 1385 was 1.27 ± 0.38 μg/m2/yr. The Br and Se concentrations and the background Hg/Br and Hg/Se ratios were used to calculate the average rate of natural Hg accumulation for the same period, 1.32 ± 0.36 μg/m2/yr and 1.34 ± 0.29 μg/m2/yr, respectively. These fluxes are similar to the preanthropogenic rates obtained using peat cores from Switzerland, southern Greenland, southern Ontario, Canada, and the northeastern United States. Episodic volcanic emissions and the continual supply of marine aerosols to the Faroe Islands, therefore, have not contributed significantly to the Hg inventory or the Hg accumulation rates, relative to these other areas. The maximum rate of Hg accumulation was 34 μg/m2/yr. The greatest fluxes of anthropogenic Hg accumulation calculated using Br and Se, respectively, were 26 and 31 μg/m2/yr. The rate of atmospheric Hg accumulation in 1998 (16 μg/m2/yr) is comparable to the values recently obtained by atmospheric transport modeling for Denmark, the Faroe Islands, and Greenland. [Copyright &y& Elsevier]

Single and sequential extractions are current and useful tools for estimating the availability of metals in soils or sediments. Many chemical extraction procedures have been proposed in the literature, making the comparison difficult. This study compares the data consistency of the potential availability given by four chemical extractions commonly found in the literature: ➢ two single procedures (using dilute HCl or EDTA as reactant) ➢ two sequential procedures (the modified standardized 3-steps procedure of the Standards, Measurements and Testing Programme (SMTP), namely BCR-extraction, and the 7-steps procedure of Leleyter and Probst (1999), namely LP-extraction). The leaching procedures are all performed on the reference lake sediment CRM BCR-701, used as a reference to assess the accuracy of the modified standardized procedure of Rauret et al. (1999). The results show similar availabilities between HCl and EDTA single leaches for Zn, Cu, Cr and Pb and between HCl and the BCR procedures for Zn, Cu, Cr and Ni. The LP-extraction is the most aggressive of the four tested procedures (except for Pb extraction), mainly due to a better extraction of the exchangeable fraction, by a better dissolution of the acido-soluble phase and particularly to a better dissolution of the amorphous and crystalline Fe-oxides. The comparison between the four procedures reveals a major problem of Pb extraction, potentially due to the formation of lead precipitates during HCl and the LP-extractions, even if an overestimation of the lead availability by the BCR procedure cannot be excluded. • 4 chemical extractions procedures applied to the same reference material BCR-701. • LP-extraction has a better mineralization of the reducible fraction than the BCR. • LP-extraction should be used to estimate the environmental availability. [ABSTRACT FROM AUTHOR]

Fanconi's anaemia (FA) is an autosomal recessive disorder characterized by progressive bone marrow failure that often evolves towards acute leukaemia. FA also belongs to a group of chromosome instability diseases. Because telomeres are directly involved in chromosomal stability and in cell proliferation capacity, we examined telomere metabolism in peripheral blood mononuclear cells (PBMC). Telomere length was significantly shorter in 54 FA patient samples, compared to 51 controls (P<0.0001). In addition, mean telomere terminal restriction fragment lengths (TRF) in nine heterozygous patient samples did not differ from those of controls. In 14 samples from FA patients with severe aplastic anaemia (SFA), telomere length was significantly shorter than in 22 samples of age-matched FA patients with moderate haematological abnormalities (NSFA) (P<0.001). However, no correlation was found between TRF length and the presence of bone marrow clonal abnormalities in 16 additional, separately analysed, patient samples. Sequential measurement of TRF in six FA patients showed an accelerated rate of telomere shortening. Accordingly, telomere shortening rate was inversely correlated with clinical status. Telomerase, the enzyme that counteracts telomere shortening, was 4.8-fold more active in 25 FA patients than in 15 age-matched healthy controls. A model for the FA disease process is proposed. [ABSTRACT FROM AUTHOR]

InAs/GaAs superlattices with ultra-thin InAs (few monolayer) were grown on GaAs substrates. Nucleation of InAs occurs in a two-dimensional or a three-dimensional way depending on the growth conditions. The physical properties: x ray, transmission electron microscopy, and photoluminescence were used to characterize the different growth processes. [ABSTRACT FROM AUTHOR]

We have investigated intersubband absorptions between the conduction ground state and the first excited state of two AlxGa1-xAs/GaAs/AlxGa1-xAs multiple quantum well structures with x=0.3 and 85 Å well width, and with x=0.57 and 96 Å well width. Small-signal measurements show absorption peaks at 10.45 and 10.15 μm, respectively. Under an intense resonant excitation from a pulsed CO2 laser, saturation of the intersubband absorption occurred. The saturation intensity is estimated to be 340±120 kW/cm2 for the first sample and 375±120 kW/cm2 for the second. From these values, we have deduced subband decay times of the order of 10.6±3.5 ps for the first sample and 15.5±5 ps for the second. [ABSTRACT FROM AUTHOR]

The incorporation of nitrogen in the low percentage range is investigated in a different III-V compound matrix. The materials are grown by molecular-beam epitaxy with a nitrogen radio-frequency plasma source. For equivalent growth conditions, the same rate of N incorporation is found for GaAsN and GaInAsN. However, this N incorporation rate is significantly enhanced in the GaAsSbN alloy. These observations support a discussion on the reactive nitrogen species. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]