332 research outputs found
Etude hydrobiologique de la riviĂšre du Grand Carbet, Basse-Terre, Guadeloupe : rapport final
Asymptotically Good Multiplicative LSSS over Galois Rings and Applications to MPC over Z/ pkZ
We study information-theoretic multiparty computation (MPC) protocols over rings Z/ pkZ that have good asymptotic communication complexity for a large number of players. An important ingredient for such protocols is arithmetic secret sharing, i.e., linear secret-sharing schemes with multiplicative properties. The standard way to obtain these over fields is with a family of linear codes C, such that C, Câ„ and C2 are asymptotically good (strongly multiplicative). For our purposes here it suffices if the square code C2 is not the whole space, i.e., has codimension at least 1 (multiplicative). Our approach is to lift such a family of codes defined over a finite field F to a Galois ring, which is a local ring that has F as its residue field and that contains Z/ pkZ as a subring, and thus enables arithmetic that is compatible with both structures. Although arbitrary lifts preserve the distance and dual distance of a code, as we demonstrate with a counterexample, the multiplicative property is not preserved. We work around this issue by showing a dedicated lift that preserves self-orthogonality (as well as distance and dual distance), for pâ„ 3. Self-orthogonal codes are multiplicative, therefore we can use existing results of asymptotically good self-dual codes over fields to obtain arithmetic secret sharing over Galois rings. For p= 2 we obtain multiplicativity by using existing techniques of secret-sharing using both C and Câ„, incurring a constant overhead. As a result, we obtain asymptotically good arithmetic secret-sharing schemes over Galois rings. With these schemes in hand, we extend existing field-based MPC protocols to obtain MPC over Z/ pkZ, in the setting of a submaximal adversary corrupting less than a fraction 1 / 2 - Δ of the players, where Δ> 0 is arbitrarily small. We consider 3 different corruption models. For passive and active security with abort, our protocols communicate O(n) bits per multiplication. For full security with guaranteed output delivery we use a preprocessing model and get O(n) bits per multiplication in the online phase and O(nlog n) bits per multiplication in the offline phase. Thus, we obtain true linear bit complexities, without the common assumption that the ring size depends on the number of players
Biotic and abiotic predictors of potential N2O emissions from denitrification in Irish grasslands soils: A national-scale field study
Publication history: Accepted - 18 March 2022; Published - 25 March 2022.Large-scale information regarding nitrous oxide (N2O) emissions is needed as an evidence base to underpin land
use policy and mitigation approaches. However, the highly variable rates of denitrification make the prediction
of N2O emission demanding. Here, we evaluated the role of abiotic and biotic factors on the potential denitrification
of Irish soils, in order to identify the key factors regulating potential N2O emissions at a large scale. To do
so, we collected 136 soil samples from 32 sites across Ireland, and characterised the soil physico-chemical
properties, the prokaryotic and fungal community composition, the abundance of N-cycling genes and evaluated
the soil potential nitrification, denitrification and end product N2O/(N2O + N2). We found large differences
in soil potential denitrification between sites (up to 41.5 mg N2OâN kg 1 soil day 1) with most of the emissions
released in the form of N2O rather than N2. Soils with highest potential nitrification rates also exhibited the
highest potential denitrification rates, and similar parameters were linked to both processes. The factors most
predictive of soil potential denitrification were soil physico-chemical properties and the prokaryotic community
composition. Soil phosphorus content was as important for predicting potential denitrification as was pH and
total nitrogen. Soil microbial community structure, rather than denitrifier abundance, was an important predictor
of the potential denitrification and the end-product N2O/(N2O + N2). The prokaryotic community
composition was more strongly associated with denitrification rates and the resulting end-products than fungal
communities. Increased relative abundance of the prokaryotic phyla Actinobacteriota and Crenarchaeota, were
positively correlated to complete denitrification. Altogether, these results lay the foundation for a better understanding
of the key factors regulating the potential denitrification in soils and identify important properties
that enhance prediction of the potential denitrification at larger scales.This research and CD, JR and PRP were financially supported under
the National Development Plan, through the Research Stimulus Fund,
administered by the Irish Department of Agriculture, Food and the
Marine (Grant number 15S655: MINE project)
Detectability of testosterone esters and estradiol benzoate in bovine hair and plasma following pour-on treatment
The abuse of synthetic esters of natural steroids such as testosterone and estradiol in cattle fattening and sports is hard to detect via routine urine testing. The esters are rapidly hydrolysed in vivo into substances which are also endogenously present in urine. An interesting alternative can be provided by the analysis of the administered synthetic steroids themselves, i.e., the analysis of intact steroid esters in hair by liquid chromatography tandem mass spectrometry (LC/MS/MS). However, retrospective estimation of the application date following a non-compliant finding is hindered by the complexity of the kinetics of the incorporation of steroid esters in hair. In this study, the incorporation of intact steroid esters in hair following pour-on treatment has been studied and critically compared with results from intramuscular treatment. To this end animals were pour-on treated with a hormone cocktail containing testosterone cypionate, testosterone decanoate and estradiol benzoate in different carriers. The animals were either treated using injection and pour-on application once or three times having 1 week between treatments using injection and pour-on application. Animals were slaughtered from 10â12 weeks after the last treatment. Both hair and blood plasma samples were collected and analysed by LC/MS/MS. From the results, it is concluded that after single treatment the levels of steroid esters in hair drop to CCÎČ levels (5â20 ”g/kg) after 5â7 weeks. When treatment is repeated two times, the CCÎČ levels are reached after 9â11 weeks. Furthermore, in plasma, no steroid esters were detected; not even at the low microgramme per litre level butâin contrast with the pour-on applicationâafter i.m. injection, significant increase of 17ÎČ-testosterone and 17ÎČ-estradiol were observed. These observations suggest that transport of steroid esters after pour-on application is not only performed by blood but also by alternative fluids in the animal so probably the steroid esters are already hydrolysed and epimerized before entering the blood
PFAS levels and determinants of variability in exposure in European teenagers - Results from the HBM4EU aligned studies (2014-2021)
Background: Perfluoroalkyl substances (PFAS) are man-made fluorinated chemicals, widely used in various types of consumer products, resulting in their omnipresence in human populations. The aim of this study was to describe current PFAS levels in European teenagers and to investigate the determinants of serum/plasma concentrations in this specific age group. Methods: PFAS concentrations were determined in serum or plasma samples from 1957 teenagers (12-18 years) from 9 European countries as part of the HBM4EU aligned studies (2014-2021). Questionnaire data were post-harmonized by each study and quality checked centrally. Only PFAS with an overall quantification frequency of at least 60% (PFOS, PFOA, PFHxS and PFNA) were included in the analyses. Sociodemographic and lifestyle factors were analysed together with food consumption frequencies to identify determinants of PFAS exposure. The variables study, sex and the highest educational level of household were included as fixed factors in the multivariable linear regression models for all PFAS and each dietary variable was added to the fixed model one by one and for each PFAS separately. Results: The European exposure values for PFAS were reported as geometric means with 95% confidence intervals (CI): PFOS [2.13 ÎŒg/L (1.63-2.78)], PFOA ([0.97 ÎŒg/L (0.75-1.26)]), PFNA [0.30 ÎŒg/L (0.19-0.45)] and PFHxS [0.41 ÎŒg/L (0.33-0.52)]. The estimated geometric mean exposure levels were significantly higher in the North and West versus the South and East of Europe. Boys had significantly higher concentrations of the four PFAS compared to girls and significantly higher PFASs concentrations were found in teenagers from households with a higher education level. Consumption of seafood and fish at least 2 times per week was significantly associated with 21% (95% CI: 12-31%) increase in PFOS concentrations and 20% (95% CI: 10-31%) increase in PFNA concentrations as compared to less frequent consumption of seafood and fish. The same trend was observed for PFOA and PFHxS but not statistically significant. Consumption of eggs at least 2 times per week was associated with 11% (95% CI: 2-22%) and 14% (95% CI: 2-27%) increase in PFOS and PFNA concentrations, respectively, as compared to less frequent consumption of eggs. Significantly higher PFOS concentrations were observed for participants consuming offal (14% (95% CI: 3-26%)), the same trend was observed for the other PFAS but not statistically significant. Local food consumption at least 2 times per week was associated with 40% (95% CI: 19-64%) increase in PFOS levels as compared to those consuming local food less frequently. Conclusion: This work provides information about current levels of PFAS in European teenagers and potential dietary sources of exposure to PFAS in European teenagers. These results can be of use for targeted monitoring of PFAS in food.This work was supported by the European Unionâs Horizon 2020 research and innovation programme under Grant agreement No 733032 HBM4EU (www.HBM4EU.eu), and received co-funding from the authorsâ organizations: Riksmaten Adolescents: Riksmaten Adolescents was performed by the Swedish Food Agency with financial support from the Swedish Environmental Protection Agency and the Swedish Civil Contingencies Agency. NEB II: The Norwegian Institute of Public Health (NIPH) has contributed to funding of the Norwegian Environmental Biobank (NEB). The laboratory measurements have partly been funded by the Research Council of Norway through research projects (275903 and 268465) PCB cohort follow-up: PCB cohort follow-up received additional funding from the Ministry of Health of the Slovak Republic, program 07B0103. BEA: BEA study was funded by the Spanish Ministry of Agriculture, Fisheries and Food and the Instituto de Salud Carlos III (SEG 1321/15) SLO-CRP: The Slovenian SLO-CRP study was co-financed by the Jozef Stefan Institute program P1- 0143, and a national project âExposure of children and adolescents to selected chemicals through their habitat environmentâ (grant agreement No. C2715-16-634802). CROME: CROME study was co-funded by the European Commission research funds of Horizon 2020. ESTEBAN: ESTEBAN study was funded by SantĂ© Publique France and the French ministries of Health and the Environment. GerES V-sub: The funding of the German Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection is gratefully acknowledged. FLEHS IV: The Flemish Center of Expertise on Environment and Health is funded by the Government of Flanders, Department of Environment & Spatial Development.S
Construction and characterization of two BAC libraries representing a deep-coverage of the genome of chicory (Cichorium intybus L., Asteraceae)
<p>Abstract</p> <p>Background</p> <p>The Asteraceae represents an important plant family with respect to the numbers of species present in the wild and used by man. Nonetheless, genomic resources for Asteraceae species are relatively underdeveloped, hampering within species genetic studies as well as comparative genomics studies at the family level. So far, six BAC libraries have been described for the main crops of the family, <it>i.e</it>. lettuce and sunflower. Here we present the characterization of BAC libraries of chicory (<it>Cichorium intybus </it>L.) constructed from two genotypes differing in traits related to sexual and vegetative reproduction. Resolving the molecular mechanisms underlying traits controlling the reproductive system of chicory is a key determinant for hybrid development, and more generally will provide new insights into these traits, which are poorly investigated so far at the molecular level in Asteraceae.</p> <p>Findings</p> <p>Two bacterial artificial chromosome (BAC) libraries, CinS2S2 and CinS1S4, were constructed from <it>Hin</it>dIII-digested high molecular weight DNA of the contrasting genotypes C15 and C30.01, respectively. C15 was hermaphrodite, non-embryogenic, and <it>S</it><sub>2</sub><it>S</it><sub>2 </sub>for the <it>S</it>-locus implicated in self-incompatibility, whereas C30.01 was male sterile, embryogenic, and <it>S</it><sub>1</sub><it>S</it><sub>4</sub>. The CinS2S2 and CinS1S4 libraries contain 89,088 and 81,408 clones. Mean insert sizes of the CinS2S2 and CinS1S4 clones are 90 and 120 kb, respectively, and provide together a coverage of 12.3 haploid genome equivalents. Contamination with mitochondrial and chloroplast DNA sequences was evaluated with four mitochondrial and four chloroplast specific probes, and was estimated to be 0.024% and 1.00% for the CinS2S2 library, and 0.028% and 2.35% for the CinS1S4 library. Using two single copy genes putatively implicated in somatic embryogenesis, screening of both libraries resulted in detection of 12 and 13 positive clones for each gene, in accordance with expected numbers.</p> <p>Conclusions</p> <p>This indicated that both BAC libraries are valuable tools for molecular studies in chicory, one goal being the positional cloning of the <it>S</it>-locus in this Asteraceae species.</p
Time Trends of Acrylamide Exposure in Europe: Combined Analysis of Published Reports and Current HBM4EU Studies
More than 20 years ago, acrylamide was added to the list of potential carcinogens found in many common dietary products and tobacco smoke. Consequently, human biomonitoring studies investigating exposure to acrylamide in the form of adducts in blood and metabolites in urine have been performed to obtain data on the actual burden in different populations of the world and in Europe. Recognizing the related health risk, the European Commission responded with measures to curb the acrylamide content in food products. In 2017, a trans-European human biomonitoring project (HBM4EU) was started with the aim to investigate exposure to several chemicals, including acrylamide. Here we set out to provide a combined analysis of previous and current European acrylamide biomonitoring study results by harmonizing and integrating different data sources, including HBM4EU aligned studies, with the aim to resolve overall and current time trends of acrylamide exposure in Europe. Data from 10 European countries were included in the analysis, comprising more than 5500 individual samples (3214 children and teenagers, 2293 adults). We utilized linear models as well as a non-linear fit and breakpoint analysis to investigate trends in temporal acrylamide exposure as well as descriptive statistics and statistical tests to validate findings. Our results indicate an overall increase in acrylamide exposure between the years 2001 and 2017. Studies with samples collected after 2018 focusing on adults do not indicate increasing exposure but show declining values. Regional differences appear to affect absolute values, but not the overall time-trend of exposure. As benchmark levels for acrylamide content in food have been adopted in Europe in 2018, our results may imply the effects of these measures, but only indicated for adults, as corresponding data are still missing for children
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