Influence de divers facteurs écologiques sur la bioaccumulation d'éléments métalliques (Cd, Cu, Pb, Zn) chez de jeunes palourdes (Ruditapes philippinarum) au cours du prégrossissement en nourricerie

La bioaccumulation des métaux chez les mollusques peut être une conséquence de la désorption des éléments métalliques fixés sur les particules inertes ou vivantes en suspension dans l'eau qui leur servent de nourriture. Les meilleures expériences réalisées jusqu'ici semblent indiquer que les matières en suspension ont un rôle mineur dans la contamination des mollusques. Mais quelles que soient les précautions prises, les expériences ne simulent jamais parfaitement les phénomènes naturels. Aussi, nous avons choisi de reprendre cette question à l'aide d'une expérience en grand volume où le nombre de paramètres contrôlés est restreint mais où les organismes sont dans des conditions aussi proches que possible de la réalité.Au cours d'un prégrossissement expérimental, les jeunes palourdes reçoivent des quantités variables contrôlées de nourriture phytoplanctonique. La fourniture d'une nourriture plus abondante a pour conséquence d'augmenter les quantités de cuivre et de zinc et au contraire de diminuer celles de plomb contenues dans chaque individu. Elle entraîne également une diminution des concentrations en cadmium et plomb traduisant une « dilution biologique » de ces métaux. L'augmentation de la densité de la population expérimentale a un effet négatif sur les quantités de cuivre et de zinc contenues dans les individus. A âge identique, les individus les plus grands présentent des concentrations plus faibles en cuivre et zinc et plus élevées en cadmium et plomb.L'utilisation des eaux marines souterraines présente deux avantages: une production algale intense à un coût économique négligeable et la possibilité par échange thermique de réchauffer en hiver les eaux marines naturelles et ainsi de maintenir une croissance des mollusques toute l'année. L'emploi des eaux de forage n'entraîne aucun effet néfaste dans les phénomènes de bioaccumulation des métaux, du moins pour ceux étudiés ici : cadmium, cuivre, plomb et zinc.Metal bioaccumulation in bivalves may occur as a consequence of the ingestion of inert or living particles with fixed trace elements. The best experiments like those carried out by BORCHARDT (1983, 1985) concerning Cd in mussels have shown that the role suspended matter plays in the contamination of molluscs is insignificant. But, however reliable the experimental methodologies, laboratory conditions never reproduce perfectly natural phenomena. We planned therefore to restudy the problem by using a largescale experiment where the procedure was characterized by a restricted number of controlled parameters and the organisms as close as possible to the real conditions.During an experimental nursing of young carpet shells, we assessed the influence of various controlled quantifies of phytoplankton and of experimental population density on the transfer of metal from their environment to molluscs.Carpet-shell brood (Ruditapes philippinarum) was distributed in several cylindrical containers the bottom of which consisted in a sieve. Food and seawater were renewed continuously by means of an ascending current (BAUD et BACHER, 1990). Nursing assays were carried out during summer over a period of 74 days. Eight groups of carpet shells were constituted according to food supplies (0, lx, 2x and 4x of Skeletonema costatum grown upon underground seawater plus natural phytoplankton) and population density (25 000 or 50 000 individuals per experimental container). Young molluscs were fed according to a cycle of 3 h-feeding periods and 2 h-periods with no food alternately. The average concentrations of algal cells in mollusc breeding seawater were 17.5, 35 and 70.103 cells/L. This seawater was renewed at a flow rate of 3 m3/h.At the end of the nursing period, molluscs exposed to different experimental conditions were separated by using sieves of different mesh-size (6, 8 and 10 mm). Young carpet shells were purged for 36 h in order to limit the overvaluation of bioaccumulated metal levels due to ingested matter (AMIARD-TRIQUET et al., 1984; KENNEDY, 1986). In each experimental and size-related categories, 90 individuals were sampled and divided into 3 groups of 30 specimens.In these groups, soft tissues were separated from the shells and oven-dried at 80 °C for 48 h. The dry samples were powdered and three aliquot parts of about 100 mg each were digested with 1 ml of concentrated nitric acid (HNO3, Suprapur) at 95 °C for 1 h. Then the trace element analyses were performed in this solution diluted with deionized water by dame (Zn) or by flameless (Cd, Cu, Pb) atomic absorption spectrophotometry using the Zeeman effect (AMIARD et al., 1987).The influence of both food supplies and experimental population density on the dry weight of soil tissues of young carpet shells, their metal concentration and body burdens were examined by means of multi-linear regression analysis.Increasing body burdens of Cu (4) and Zn (5) and decreasing body burden of Pb (3), corresponded to more abundant food supplies. The increase of phytoplankton supplies induced a decrease of Cd (6) and Pb (7) concentrations as a consequence of a « biological dilution » of these metals. Increasing density induced a depletion of Cu (4) and Zn (5) body burdens. Among individuals of the same age, the biggest ones exhibited the lowest concentrations of Cu and Zn (8 and 9) and the highest concentrations of Cd and Pb (6 and 7).Increased food supplies induce a biological dilution of Cd and Pb in young carpet-shells. These results are in agreement with previous data concerning Cd, Cu, Pb and Zn in different species (MACKAY et al., 1975; BOYDEN, 1971; PHELPS et al., 1985; BERTHET, 1986). Thus front a sanitary point of view, the use of ground seawater for algal culture is not a risk since metal concentrations in molluscs are not enhanced

Second primary neoplasms among 53 159 haematolymphoproliferative malignancy patients in Sweden, 1958–1996: a search for common mechanisms

The Swedish Family-Cancer Database was used to analyse site-specific risk of second primary malignancies following 53 159 haematolymphoproliferative disorders (HLPD) diagnosed between 1958 and 1996. Standardized incidence ratio (SIR) of a second malignancy was calculated as the ratio of observed to expected numbers of second malignancies by applying site-, sex-, age-, period-, residence- and occupation-specific rates in the corresponding population in the Database to the appropriate person-years at risk. Among 18 960 patients with non-Hodgkin's lymphoma (NHL), there was over a 3-fold significant increase in cancer of the tongue, small intestine, nose, kidney and nervous system, squamous cell carcinoma (SCC) of the skin, NHL, Hodgkin's disease (HD) and lymphoid and myeloid leukaemia. Among 5353 patients with HD, there was over a 4-fold significant increase in cancer of the salivary glands, nasopharynx and thyroid, NHL and myeloid leukaemia, and over a 1.6-fold increase in cancer of the stomach, colon, lung, breast, skin (melanoma and SCC), nervous system and soft tissues and lymphoid leukaemia. Among 28 846 patients with myeloma and leukaemia, there was a significant increase in cancer of the skin, nervous system and non-thyroid endocrine glands and all HLPD except for myeloma. Our findings showed some clustering between first and second primaries among Epstein–Barr virus-, ultraviolet radiation- and immunosuppression-related cancers. © 2001 Cancer Research Campaignhttp://www.bjcancer.co

Run Time Models in Adaptive Service Infrastructure

Software in the near ubiquitous future will need to cope with vari- ability, as software systems get deployed on an increasingly large diversity of computing platforms and operates in different execution environments. Heterogeneity of the underlying communication and computing infrastruc- ture, mobility inducing changes to the execution environments and therefore changes to the availability of resources and continuously evolving requirements require software systems to be adaptable according to the context changes. Software systems should also be reliable and meet the user's requirements and needs. Moreover, due to its pervasiveness, software systems must be de- pendable. Supporting the validation of these self-adaptive systems to ensure dependability requires a complete rethinking of the software life cycle. The traditional division among static analysis and dynamic analysis is blurred by the need to validate dynamic systems adaptation. Models play a key role in the validation of dependable systems, dynamic adaptation calls for the use of such models at run time. In this paper we describe the approach we have un- dertaken in recent projects to address the challenge of assessing dependability for adaptive software systems

Household Exposure to Paint and Petroleum Solvents, Chromosomal Translocations, and the Risk of Childhood Leukemia

BackgroundFew studies have examined the association between home use of solvents and paint and the risk of childhood leukemia.ObjectivesIn this case-control study, we examined whether the use of paint and petroleum solvents at home before birth and in early childhood influenced the risk of leukemia in children.MethodsWe based our analyses on 550 cases of acute lymphoblastic leukemia (ALL), 100 cases of acute myeloid leukemia (AML), and one or two controls per case individually matched for sex, age, Hispanic status, and race. We conducted further analyses by cytogenetic subtype. We used conditional logistic regression techniques to adjust for income.ResultsALL risk was significantly associated with paint exposure [odds ratio (OR) = 1.65; 95% confidence interval (CI), 1.26-2.15], with a higher risk observed when paint was used postnatally, by a person other than the mother, or frequently. The association was restricted to leukemia with translocations between chromosomes 12 and 21 (OR = 4.16; 95% CI, 1.66-10.4). We found no significant association between solvent use and ALL risk overall (OR = 1.15; 95% CI, 0.87-1.51) or for various cytogenetic subtypes, but we observed a significant association in the 2.0- to 5.9-year age group (OR = 1.55; 95% CI, 1.07-2.25). In contrast, a significant increased risk for AML was associated with solvent (OR = 2.54; 95% CI, 1.19-5.42) but not with paint exposure (OR = 0.64; 95% CI, 0.32-1.25).ConclusionsThe association of ALL risk with paint exposure was strong, consistent with a causal relationship, but further studies are needed to confirm the association of ALL and AML risk with solvent exposure

Genomic Organization, Tissue Distribution and Functional Characterization of the Rat Pate Gene Cluster

The cysteine rich prostate and testis expressed (Pate) proteins identified till date are thought to resemble the three fingered protein/urokinase-type plasminogen activator receptor proteins. In this study, for the first time, we report the identification, cloning and characterization of rat Pate gene cluster and also determine the expression pattern. The rat Pate genes are clustered on chromosome 8 and their predicted proteins retained the ten cysteine signature characteristic to TFP/Ly-6 protein family. PATE and PATE-F three dimensional protein structure was found to be similar to that of the toxin bucandin. Though Pate gene expression is thought to be prostate and testis specific, we observed that rat Pate genes are also expressed in seminal vesicle and epididymis and in tissues beyond the male reproductive tract. In the developing rats (20–60 day old), expression of Pate genes seem to be androgen dependent in the epididymis and testis. In the adult rat, androgen ablation resulted in down regulation of the majority of Pate genes in the epididymides. PATE and PATE-F proteins were found to be expressed abundantly in the male reproductive tract of rats and on the sperm. Recombinant PATE protein exhibited potent antibacterial activity, whereas PATE-F did not exhibit any antibacterial activity. Pate expression was induced in the epididymides when challenged with LPS. Based on our results, we conclude that rat PATE proteins may contribute to the reproductive and defense functions

A Theory Agenda for Component-Based Design

The aim of the paper is to present a theory agenda for component-based design based on results that motivated the development of the BIP component framework, to identify open problems and discuss further research directions. The focus is on proposing a semantically sound theoretical and general framework for modelling component-based systems and their properties both behavioural and architectural as well for achieving correctness by using scalable specific techniques. We discuss the problem of composing components by proposing the concept of glue as a set of stateless composition operators defined by a certain type of operational semantics rules. We provide an overview of results about glue expressiveness and minimality. We show how interactions and associated transfer of data can be described by using connectors and in particular, how dynamic connectors can be defined as an extension of static connectors. We present two approaches for achieving correctness for component-based systems. One is by compositional inference of global properties of a composite component from properties of its constituents and interaction constraints implied by composition operators. The other is by using and composing architectures that enforce specific coordination properties. Finally, we discuss recent results on architecture specification by studying two types of logics: 1) interaction logics for the specification of sets of allowed interactions; 2) configuration logics for the characterisation of architecture styles

Protection and consolidation of stone heritage by self-inoculation with indigenous carbonatogenic bacterial communities

Enhanced salt weathering resulting from global warming and increasing environmental pollution is endangering the survival of stone monuments and artworks. To mitigate the effects of these deleterious processes, numerous conservation treatments have been applied that, however, show limited efficacy. Here we present a novel, environmentally friendly, bacterial self-inoculation approach for the conservation of stone, based on the isolation of an indigenous community of carbonatogenic bacteria from salt damaged stone, followed by their culture and re-application back onto the same stone. This method results in an effective consolidation and protection due to the formation of an abundant and exceptionally strong hybrid cement consisting of nanostructured bacterial CaCO3 and bacterially derived organics, and the passivating effect of bacterial exopolymeric substances (EPS) covering the substrate. The fact that the isolated and identified bacterial community is common to many stone artworks may enable worldwide application of this novel conservation methodology.This work was supported by the Spanish Government (Grants MAT2012-37584, CGL2012-35992 and CGL2015-70642-R), the Junta de Andalucía through Proyecto de excelencia RNM-3493 and Project P11-RNM-7550, the Research Groups BIO 103 and RNM-179, and the University of Granada (Unidad Científica de Excelencia UCE-PP2016-05). Additional funds were provided by the Molecular Foundry (Lawrence Berkeley National Laboratory, LBNL, University of California, Berkeley, CA) for a research stay of M.S. (project #1451; User Agreement No. NPUSR009206)

Roles of genetic polymorphisms in the folate pathway in childhood acute lymphoblastic leukemia evaluated by bayesian relevance and effect size analysis.

In this study we investigated whether polymorphisms in the folate pathway influenced the risk of childhood acute lymphoblastic leukemia (ALL) or the survival rate of the patients. For this we selected and genotyped 67 SNPs in 15 genes in the folate pathway in 543 children with ALL and 529 controls. The results were evaluated by gender adjusted logistic regression and by the Bayesian network based Bayesian multilevel analysis of relevance (BN-BMLA) methods. Bayesian structure based odds ratios for the relevant variables and interactions were also calculated. Altogether 9 SNPs in 8 genes were associated with altered susceptibility to ALL. After correction for multiple testing, two associations remained significant. The genotype distribution of the MTHFD1 rs1076991 differed significantly between the ALL and control population. Analyzing the subtypes of the disease the GG genotype increased only the risk of B-cell ALL (p = 3.52x10(-4); OR = 2.00). The GG genotype of the rs3776455 SNP in the MTRR gene was associated with a significantly reduced risk to ALL (p = 1.21x10(-3); OR = 0.55), which resulted mainly from the reduced risk to B-cell and hyperdiploid-ALL. The TC genotype of the rs9909104 SNP in the SHMT1 gene was associated with a lower survival rate comparing it to the TT genotype (80.2% vs. 88.8%; p = 0.01). The BN-BMLA confirmed the main findings of the frequentist-based analysis and showed structural interactional maps and the probabilities of the different structural association types of the relevant SNPs especially in the hyperdiploid-ALL, involving additional SNPs in genes like TYMS, DHFR and GGH. We also investigated the statistical interactions and redundancies using structural model properties. These results gave further evidence that polymorphisms in the folate pathway could influence the ALL risk and the effectiveness of the therapy. It was also shown that in gene association studies the BN-BMLA could be a useful supplementary to the traditional frequentist-based statistical method

Haplotypes of DNA repair and cell cycle control genes, X-ray exposure, and risk of childhood acute lymphoblastic leukemia

[[abstract]]Background: Acute leukemias of childhood are a heterogeneous group of malignancies characterized by cytogenetic abnormalities, such as translocations and changes in ploidy. These abnormalities may be influenced by altered DNA repair and cell cycle control processes. Methods: We examined the association between childhood acute lymphoblastic leukemia (ALL) and 32 genes in DNA repair and cell cycle pathways using a haplotype-based approach, among 377 childhood ALL cases and 448 controls enrolled during 1995-2002. Results: We found that haplotypes in APEX1, BRCA2, ERCC2, and RAD51 were significantly associated with total ALL, while haplotypes in NBN and XRCC4, and CDKN2A were associated with structural and numerical change subtypes, respectively. In addition, we observed statistically significant interaction between exposure to 3 or more diagnostic X-rays and haplotypes of XRCC4 on risk of structural abnormality-positive childhood ALL. Conclusions: These results support a role of altered DNA repair and cell cycle processes in the risk of childhood ALL, and show that this genetic susceptibility can differ by cytogenetic subtype and may be modified by exposure to ionizing radiation. To our knowledge, our study is the first to broadly examine the DNA repair and cell cycle pathways using a haplotype approach in conjunction with X-ray exposures in childhood ALL risk. If confirmed, future studies are needed to identify specific functional SNPs in the regions of interest identified in this analysis