1,284 research outputs found
Mid-ocean ridge eruptions as a climate valve
Seafloor eruption rates and mantle melting fueling eruptions may be influenced by sea level and crustal loading cycles at scales from fortnightly to 100âkyr. Recent mid-ocean ridge eruptions occur primarily during neap tides and the first 6âmonths of the year, suggesting sensitivity to minor changes in tidal forcing and orbital eccentricity. An ~100âkyr periodicity in fast-spreading seafloor bathymetry and relatively low present-day eruption rates at a time of high sea level and decreasing orbital eccentricity suggest a longer-term sensitivity to sea level and orbital variations associated with Milankovitch cycles. Seafloor spreading is considered a small but steady contributor of CO2 to climate cycles on the 100âkyr time scale; however, this assumes a consistent short-term eruption rate. Pulsing of seafloor volcanic activity may feed back into climate cycles, possibly contributing to glacial/interglacial cycles, the abrupt end of ice ages, and dominance of the 100âkyr cycle
Exploring Neutral Hydrogen and Galaxy Evolution with the SKA
One of the key science drivers for the development of the SKA is to observe
the neutral hydrogen, HI, in galaxies as a means to probe galaxy evolution
across a range of environments over cosmic time. Over the past decade, much
progress has been made in theoretical simulations and observations of HI in
galaxies. However, recent HI surveys on both single dish radio telescopes and
interferometers, while providing detailed information on global HI properties,
the dark matter distribution in galaxies, as well as insight into the
relationship between star formation and the interstellar medium, have been
limited to the local universe. Ongoing and upcoming HI surveys on SKA
pathfinder instruments will extend these measurements beyond the local universe
to intermediate redshifts with long observing programmes. We present here an
overview of the HI science which will be possible with the increased
capabilities of the SKA and which will build upon the expected increase in
knowledge of HI in and around galaxies obtained with the SKA pathfinder
surveys. With the SKA1 the greatest improvement over our current measurements
is the capability to image galaxies at reasonable linear resolution and good
column density sensitivity to much higher redshifts (0.2 < z < 1.7). So one
will not only be able to increase the number of detections to study the
evolution of the HI mass function, but also have the sensitivity and resolution
to study inflows and outflows to and from galaxies and the kinematics of the
gas within and around galaxies as a function of environment and cosmic time out
to previously unexplored depths. The increased sensitivity of SKA2 will allow
us to image Milky Way-size galaxies out to redshifts of z=1 and will provide
the data required for a comprehensive picture of the HI content of galaxies
back to z~2 when the cosmic star formation rate density was at its peak.Comment: 25 pages, 5 figures, 3 tables. Contribution to the conference
'Advancing Astrophysics with the Square Kilometre Array', June 8-13, 2014,
Giardini Naxos, Ital
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BRCA1 and BRCA2 mutation predictions using the BOADICEA and BRCAPRO models and penetrance estimation in high-risk French-Canadian families.
INTRODUCTION: Several genetic risk models for breast and ovarian cancer have been developed, but their applicability to specific populations has not been evaluated. We used data from French-Canadian families to evaluate the mutation predictions given by the BRCAPRO and BOADICEA models. We also used this data set to estimate the age-specific risks for breast and ovarian cancer in BRCA1 and BRCA2 mutation carriers. METHODS: A total of 195 families with multiple affected individuals with breast or ovarian cancer were recruited through the INHERIT (INterdisciplinary HEalth Research International Team on BReast CAncer susceptibility) BRCAs research program. Observed BRCA1 and BRCA2 mutation status was compared with predicted carrier probabilities under the BOADICEA and BRCAPRO models. The models were assessed using Brier scores, attributes diagrams and receiver operating characteristic curves. Log relative risks for breast and ovarian cancer in mutation carriers versus population risks were estimated by maximum likelihood, using a modified segregation analysis implemented in the computer program MENDEL. Twenty-five families were eligible for inclusion in the BRCA1 penetrance analysis and 27 families were eligible for the BRCA2 penetrance analysis. RESULTS: The BOADICEA model predicted accurately the number of BRCA1 and BRCA2 mutations for the various groups of families, and was found to discriminate well at the individual level between carriers and noncarriers. BRCAPRO over-predicted the number of mutations in almost all groups of families, in particular the number of BRCA1 mutations. It significantly overestimated the carrier frequency for high predicted probabilities. However, it discriminated well between carriers and noncarriers. Receiver operating characteristic (ROC) curves indicate similar sensitivity and specificity for BRCAPRO and BOADICEA. The estimated risks for breast and ovarian cancer in BRCA1 and BRCA2 mutation carriers were consistent with previously published estimates. CONCLUSION: The BOADICEA model predicts accurately the carrier probabilities in French-Canadian families and may be used for counselling in this population. None of the penetrance estimates was significantly different from previous estimates, suggesting that previous estimates may be appropriate for counselling in this population.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Cytokine-related genes identified from the RIKEN full-length mouse cDNA data set
To identify novel cytokine-related genes, we searched the set of 60,770 annotated RIKEN mouse cDNA clones (FANTOM2 clones), using keywords such as cytokine itself or cytokine names (such as interferon, interleukin, epidermal growth factor, fibroblast growth factor, and transforming growth factor). This search produced 108 known cytokines and cytokine-related products such as cytokine receptors, cytokine-associated genes, or their products (enhancers, accessory proteins, cytokine-induced genes). We found 15 clusters of FANTOM2 clones that are candidates for novel cytokine-related genes. These encoded products with strong sequence similarity to guanylate-binding protein (GBP-5), interleukin-1 receptor-associated kinase 2 (IRAK-2), interleukin 20 receptor alpha isoform 3, a member of the interferon-inducible proteins of the Ifi 200 cluster, four members of the membrane-associated family 1-8 of interferon-inducible proteins, one p27-like protein, and a hypothetical protein containing a Toll/Interleukin receptor domain. All four clones representing novel candidates of gene products from the family contain a novel highly conserved cross-species domain. Clones similar to growth factor-related products included transforming growth factor beta-inducible early growth response protein 2 (TIEG-2), TGFbeta-induced factor 2, integrin beta-like 1, latent TGF-binding protein 4S, and FGF receptor 4B. We performed a detailed sequence analysis of the candidate novel genes to elucidate their likely functional properties
Sea surface temperature changes in the southern California borderlands during the last glacial-interglacial cycle
A variety of evidence suggests that average sea surface temperatures (SSTs) during the last glacial maximum in the California Borderlands region were significantly colder than during the Holocene. Planktonic foraminiferal Ύ18O evidence and average SST estimates derived by the modern analog technique indicate that temperatures were 6°-10°C cooler during the last glacial relative to the present. The glacial plankton assemblage is dominated by the planktonic foraminifer Neogloboquadrina pachyderma (sinistral coiling) and the coccolith Coccolithus pelagicus, both of which are currently restricted to subpolar regions of the North Pacific. The glacial-interglacial average SST change determined in this study is considerably larger than the 2°C change estimated by Climate: Long-Range Investigation, Mapping, and Prediction (CLIMAP) [1981]. We propose that a strengthened California Current flow was associated with the advance of subpolar surface waters into the Borderlands region during the last glacial
The impact of the new CHAMP and GRACE Earth gravity models on the measurement of the general relativistic Lense--Thirring effect with the LAGEOS and LAGEOS II satellites
Among the effects predicted by the General Theory of Relativity for the
orbital motion of a test particle, the post-Newtonian gravitomagnetic
Lense-Thirring effect is very interesting and, up to now, there is not yet an
undisputable experimental direct test of it. To date, the data analysis of the
orbits of the existing geodetic LAGEOS and LAGEOS II satellites has yielded a
test of the Lense-Thirring effect with a claimed accuracy of 20%-30%. According
to some scientists such estimates could be optimistic. Here we wish to discuss
the improvements obtainable in this measurement, in terms of reliability of the
evaluation of the systematic error and reduction of its magnitude, due to the
new CHAMP and GRACE Earth gravity models.Comment: LaTex2e, 6 pages, no figures, no tables. Paper presented at 2nd CHAMP
science meeting, Potsdam, 1-4 September 200
Statement on a study proposal prepared by the UC to support a future derogation request from the EU import requirements for wood packaging material originating in the US and used to pack and transport military ammunition. Scientific Opinion.
Following a request from the European Commission, the EFSA Panel on Plant Health was asked to deliver a statement on a study proposal prepared by
the US to support a future derogation request from the Community import requirements for wood packaging material (WPM) originating in the US and
used to pack and transport military ammunition. The Panel reviewed the submitted study proposal and based its conclusions on the shortcomings
identified in the study proposal. It was concluded that, due to these shortcomings, the evaluation of the methodological approach described in this study proposal with regard to: 1.the determination of the likelihood that live pinewood nematode (Bursaphelenchus xylophilus) and other harmful organisms relevant for the Community are present in the WPM used by the US Department of Defense to pack and transport military ammunition (Pest survey component), 2. the assessment of the likelihood that harmful organisms may be introduced into the Community through the WPM pathway (Pathway Risk Analysis component) cannot be conducted
Statement on the dossier for a derogation request for the US authorities concerning cold-treated strawberry plants intended for planting.
Following a request from the European Commission, the EFSA Panel on Plant Health examined the report âEvaluation of Strawberry Nursery Plant Cold Treatments on Survival of the Whitefly, Bemisia tabaciâ, submitted to the European Commission by the United States Department of Agriculture (USDA). The report serves as technical justification for a derogation from requirements listed in Annex IV, Part A, Section 1, point 46 of the Council Directive 2000/29/EC. The Panel concluded that due to shortcomings in the report itself and in the experimental design of the study, this report does not demonstrate the effectiveness of the cold treatment proposed for the elimination of B. tabaci from strawberry plant consignments prepared for shipment to the EU. In addition, the Panel conducted a preliminary review of the available literature on viruses of strawberry and concluded that no B. tabaciâtransmitted viruses are currently known to infect strawberry and that no viruses of Fragaria listed in European Council Directive 2000/29/EC are known to be transmitted by B. tabaci. However, adult whiteflies of B. tabaci on strawberry consignments can carry plant viruses irrespective of whether strawberry is a host plant for these viruses and thus represent a pathway for the introduction of nonâEuropean viruses. There is also some uncertainty concerning the extent to which known or unknown B. tabaciâtransmitted viruses could infect strawberry. Irrespective of the presence of B. tabaci, strawberry transplants from the US may represent a pathway for the introduction of any nonâEuropean virus (and other potentially harmful organisms) of Fragaria
Scientific Opinion on the assessment of the risk of solanaceous pospiviroids for the EU territory and the identification and evaluation of risk management options.
Following a request from the EU Commission, the EFSA PLH Panel conducted a risk assessment for the EU territory of pospiviroids affecting solanaceous crops, identified and evaluated risk reduction options and evaluated the EU provisional emergency measures targeting Potato spindle tuber viroid (PSTVd). The risk assessment included PSTVd, Citrus exocortis viroid, Columnea latent viroid, Mexican papita viroid, Tomato apical stunt viroid, Tomato chlorotic dwarf viroid, Tomato planta macho viroid, Chrysanthemum stunt viroid and Pepper chat fruit viroid. Four entry pathways were identified, three involving plant propagation material, with moderate probability of entry, and one involving plant products for human consumption, with low probability of entry. The probability of establishment was considered very high. Spread was considered likely within a crop and moderately likely between crop species, with exception of spread to potato, rated as unlikely. The probability of long distance spread within vegetatively propagated crops was estimated as likely/very likely. The direct consequences were expected to be major in potato and tomato, moderate in pepper, minimal/minor in other vegetables and minimal in ornamentals. Main risk assessment uncertainties derive from limited knowledge on pospiviroids other than PSTVd, although all pospiviroids are expected to have similar biological properties. Management options to reduce risk of entry, spread and consequences were identified and evaluated. No management options can prevent establishment. Examples of successful PSTVd eradication are linked to timely and strict implementation of measures. Uncertainty exists on the effectiveness of risk reduction strategies targeting only one pathway. The EU provisional emergency measures appeared to have significantly reduced PSTVd incidence in Solanum jasminoides and Brugmansia sp., even though eradication from the EU is so far incomplete. The low PSTVd incidence in food crops did not permit to conclude whether the reduction in PSTVd prevalence in ornamentals led to a reduction in outbreaks in food crops
Scientific Opinion on a technical file submitted by the US Authorities to support a request to list a new opinion among the EU import requirements for wood of Agrilus planipennis host plants.
This document presents the scientific opinion of the Panel on Plant Health on the technical file submitted by the US Authorities to support a request to list a new option among the EU import requirements for wood of Agrilus planipennis host plants. The option under consideration is a heat treatment at 60 °C for 60 min to liminate
possible infestations of the wood by the emerald ash borer (EAB). The experiments leading the US Authorities to propose this option are presented in a scientific peer reviewed publication, Myers et al. (2009). The analysis of the aggregated data published by Myers et al. (2009) and based on a Probit regression model showed that the proposed treatment cannot guarantee a control level of 99 % or higher. The analysis of the individual data either from the original measurements or from a corrected dataset, using a Probit regression model, showed that it is likely to observe one live EAB out of an infestation of 100 after the proposed heat treatment of 60 °C /60 min. To ensure a control level of 99 % the temperature of the heat treatment of 60 min should be higher than 70 °C. Results obtained with a Poisson log linear model based on individual data showed that the estimated probability that one insect or more per m2 survive the proposed heat treatment was higher than 0.6 and that there is a 0.1 probability that three insects or more per m2 survive the proposed heat treatment. Based on these results, the Panel concludes that A.
planipennis is likely to survive the proposed heat treatment of 60 °C/60 min with a low uncertainty, and that the alternative option proposed in the technical file submitted by the US Authorities for wood does not guarantee the wood to be free of A. planipennis
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