1,018 research outputs found
Golfoverslag bij dijken en de mogelijke gevolgen bij overslagdebieten tot 10 l/s per meter
No full text1. In opdracht van Rijkswaterstaat is een oriënterende studie uitgevoerd naar de effecten voor het binnentalud van een dijk bij gemiddelde overslagdebieten van 0,1 l/s/m1, 1 1/s/m' en 10 1/s/ra'. Er werd uitgegaan van golfcondities welke in het Benedenrivierengebied kunnen optreden. Tijdens de studie werd speciale aandacht besteed aan de eventuele effecten van golfoverslag bij de combinatie paralleldijk/bestaande dijk. 2. De ervaringen met beschadigingen aan en afschuiven van binnentaluds van dijken stammen grotendeels uit de stormnacht van 1 februari 1953. Deze ervaringen zijn beschreven in hoofdstuk 2 en kunnen als volgt worden samengevat. - In vele dijkvakken waar belangrijke schade aan de binnentaluds is opgetreden moet de gemiddelde hoeveelheid overslag enkele tientallen liters per seconde per meter dijk tot zelfs aanzienlijk meer zijn geweest. De totale transportcapaciteit tijdens de storm is bij deze dijkvakken zeer groot geweest. - Binnentaludbeschadigingen zijn op grote schaal opgetreden. Karakteristieke kenmerken zijn een langsscheur bovenin het binnentalud en afschuivingen in het talud. Er kan vanuit worden gegaan dat de afschuivingen in het algemeen met de langsscheur zijn begonnen. - Uit de waargenomen beschadigingen is de indruk verkregen dat erosie van de met gras beklede toplaag niet of slechts sporadisch de oorzaak is geweest van schade van betekenis. 3. Een grondmechanische evaluatie heeft tot de conclusie geleid dat de scheurvorming en afschuiving in het binnentalud het gevolg moet zijn geweest van een zich in de bovenlaag ingesteld potentiaalbeeld met stroomlijnen evenwijdig aan het binnenbeloop (hoofdstuk 2). Dit potentiaalbeeld ontstaat na volledige verzadiging door penetratie van water in de relatief doorlatende toplaag. Dit mechanisme in combinatie met de in het algemeen steile taluds (gemiddeld 1:1,5 tot 1:1,75) heeft met grote waarschijnlijkheid tot stabiliteitsverlies geleid.TAW/EN
Label-free detection of uptake, accumulation, and translocation of diesel exhaust particles in ex vivo perfused human placenta
No full textBackgroundPregnant women and developing fetuses comprise a particularly vulnerable population as multiple studies have shown associations between prenatal air pollution exposure and adverse pregnancy outcomes. However, the mechanisms underlying the observed developmental toxicity are mostly unknown, in particular, if pollution particles can cross the human placenta to reach the fetal circulation.ResultsHere, we investigated the accumulation and translocation of diesel exhaust particles (DEPs), as a model particle for combustion-derived pollution, in human perfused placentae using label-free detection by femtosecond pulsed laser illumination. The results do not reveal a significant particle transfer across term placentae within 6 h of perfusion. However, DEPs accumulate in placental tissue, especially in the syncytiotrophoblast layer that mediates a wealth of essential functions to support and maintain a successful pregnancy. Furthermore, DEPs are found in placental macrophages and fetal endothelial cells, showing that some particles can overcome the syncytiotrophoblasts to reach the fetal capillaries. Few particles are also observed inside fetal microvessels.ConclusionsOverall, we show that DEPs accumulate in key cell types of the placental tissue and can cross the human placenta, although in limited amounts. These findings are crucial for risk assessment and protection of pregnant women and highlight the urgent need for further research on the direct and indirect placenta-mediated developmental toxicity of ambient particulates.This work received fnancial support from the Flemish Scientifc Research Foundation (Grant no 1150920N, G082317N, and 12P6819N) and the Swiss National Science Foundation (Grant no 31003A_179337 and IZSEZ0_193948). The detection equipment was funded by the Interuniversity Attraction Poles Program (P7/05) initiated by the Belgian Science Policy Ofce and the INCALO project (ERC-PoC).
Acknowledgements
The authors would like to acknowledge all participants of the study. In addition, we owe special thanks to the nurses, midwives, and doctors involved in placenta collection.The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request
Evolution in the genus Arum: a comparative analysis of morpohological and genetic variation.
No full textTesting the correlation of morphological and genetic marker variation enables the investigation of evolutionary processes. Knowledge of evolutionary processes can be used
to identify those morphological characters that could be used to produce evolutionary meaningful taxonomies. This thesis aims to test the correlation between morphological and genetic marker variation to further understand the evolution of species within the genus Arum and identify those morphological characters that correspond with evolutionary groups. The investigation is carried out at the intraspecific level, intrageneric level and in a
putative hybrid zone. At the intraspecific level, genetic (ISSR) and morphological variation was quantified in
populations of the morphologically similar species A. maculatum and A. italicum. Populations of A. maculatum showed evidence of isolation by distance, presumably a result of pollinator behaviour and seed dispersal. Leaf patterning in A. maculatum did not correspond to evolutionary lineages. However, similar leaf patterning characters in A. italicum are used to classify the two subspecies neglectum and italicum and the ISSR analysis confirmed that these taxa are genetically distinct. These two subspecies were shown to be interbreeding in sympatric populations. The interbreeding has created a morphological and genetic difference between subsp. neglectum in sympatric populations compared with allopatric populations.
At the intrageneric level, a phylogenetic analysis of Arum (using trnL and ITS 1 sequences) indicated that both vegetative and reproductive characters are convergent within the genus. The apparent convergent evolution of reproductive and vegetative characters indicates that
both have been important during the diversification of the genus. These convergent characters are not useful for producing classifications that reflect evolutionary groups as the groups they produce are polyphyletic. In the putative hybrid zone, ISSR markers confirmed the presence of A. creticum and A. idaeum hybrids. There appears to be introgression of the A. idaeum genome into A. creticum; this could have implications for the future genetic integrity of A. creticum. Within this hybrid zone, continuous characters were found to be representative of genetic variation, however categorical characters were not.
In conclusion, this thesis has shown that even within a single genus, the correlation between morphological and genetic marker variation is influenced by both the taxa being studied and the nature of the morphological trait. In particular, if morphological characters are found to be adaptively important, their correspondence to genetic groups should be tested before their use in taxonomies. The findings of this thesis also suggest there is great value in the complementary use of genetic and morphological analysis for taxonomic studies as well as evolutionary studies. For example, the importance of reproductive characters in the diversification of Arum species has produced a wide range of morphological variation, with
limited taxonomic utility due to a tendency for homoplasy. Vegetative characters were also found to need careful testing before use in taxonomies as leaf patterning was found to correspond to sub-species status for one species of Arum but not another. Finally, this thesis has shown that, if closely related taxa are hybridising, variation of continuous reproductive characters may be used as an indicator of hybridisation, even if the morphological
characters are potentially polygenic
Big Data, Big Libraries, Big Problems?: the 2014 LibTech Anti-talk?
No full textThe desire to create automatons is a familiar theme in human history, and during the age of the Enlightenment mechanical automatons became not only an “emblem of the cosmos”, but a symbol of man’s confidence that he would unlock nature’s greatest mysteries and fully harness her power. And yet only a century later, automatons had begun to represent human repression and servitude, a theme later picked up by writers of science fiction. Man’s confidence undeterred, the endgame of the modern scientific and technological mindset, or MSTM, seems to be increasingly coming into view with the rise of “information technology” in general and “Big data” in particular. Along with those who wield them, these can be seen as functioning together as a “mechanical muse” of sorts – surprisingly alluring – and, like a physical automaton can serve as a symbol – a microcosm – of what the MSTM sees (at the very least in practice) as the cosmic machine, our “final frontier”. And yet, individuals who unreflectively participate in these things – giving themselves over to them and seeking the powers afforded by the technology apart from technology’s rightful purposes – in fact yield to the same pragmatism and reductionism those wielding them are captive to. Thus, they ultimately nullify themselves philosophically, politically, and economically – their value increasingly being only the data concerning their persons, and its perceived usefulness. Likewise libraries, the time-honored place of, and symbol for, the intellectual flowering of the individual, will, insofar as they spurn the classical liberal arts (with the idea that things are intrinsically good, and in the case of humans, special as well) in favor of the alluring embrace of MSTM-driven “information technology” and Big data - unwittingly contribute to their irrelevance and demise as they find themselves increasingly less needed, valued, wanted. Likewise for the liberal arts as a whole, and in fact history itself, if the acid of a “science” untethered from what is, in fact, good (intrinsically), continues to gain strengt
Observation of H→bb¯ decays and VH production with the ATLAS detector
No full textA search for the decay of the Standard Model Higgs boson into a bb¯ pair when produced in association with a W or Z boson is performed with the ATLAS detector. The data, corresponding to an integrated luminosity of 79.8fb−1 were collected in proton–proton collisions during Run 2 of the Large Hadron Collider at a centre-of-mass energy of 13TeV. For a Higgs boson mass of 125GeV, an excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.9 (4.3) standard deviations. A combination with the results from other searches in Run 1 and in Run 2 for the Higgs boson in the bb¯ decay mode is performed, which yields an observed (expected) significance of 5.4 (5.5) standard deviations, thus providing direct observation of the Higgs boson decay into b-quarks. The ratio of the measured event yield for a Higgs boson decaying into bb¯ to the Standard Model expectation is 1.01±0.12(stat.)−0.15 +0.16(syst.). Additionally, a combination of Run 2 results searching for the Higgs boson produced in association with a vector boson yields an observed (expected) significance of 5.3 (4.8) standard deviations. © 2018 The Author(s
BETA-ADRENOBLOCKERS IN XXI CENTURY: EPOCH END OR IMMORTALITY BEGINNING? A VIEW OF ORDINARY CARDIOLOGIST
No full textUsage of β-blockers (BB) for treatment of patients with cardiovascular diseases is discussed. Results of the basic clinical trials with BB (LIFE, ASCOT, etc.) are analyzed. The role of sympathetic system in different stages of cardiovascular continuum as well as forecast of BB clinical efficacy is surveyed. Author presents a review of data about selective β1-blocker, metoprolol succinate (Betalok ZОК), in patients with cardiovascular diseases
Measurement of sigma (pp -> bbX) at √s=7 TeV in the forward region
No full textDecays of b hadrons into final states containing a D-0 meson and a muon are used to measure the bb; production cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC. In the pseudorapidity interval 2 < eta < 6 and integrated over all transverse momenta we find that the average cross-section to produce b-flavoured or b-flavoured hadrons is (75.3 +/- 5.4 +/- 13.0) mu b
Weak decays of the axial-vector tetraquark Tbb;(u)over-bar(d)over-bar(-)
No full textAzizi, Kazem (Dogus Author)The weak decays of the axial-vector tetraquark T-bb;(u) over bar(d) over bar(-) to the scalar state Z(bc;(u) over bar(d) over bar)(0) are investigated using the QCD three-point sum rule approach. In order to explore the process T-bb;(u) over bar(d) over bar(-) -> Z(bc;(u) over bar(d) over bar)(0)l (nu) over bar (l), we recalculate the spectroscopic parameters of the tetraquark T-bb;(u) over bar(d) over bar(-) and find the mass and coupling of the scalar four-quark system Z(bc;(u) over bar(d) over bar)(0), which are important ingredients of calculations. The spectroscopic parameters of these tetraquarks are computed in the framework of the QCD two-point sum rule method by taking into account various condensates up to dimension ten. The mass of the T-bb;(u) over bar(d) over bar(-) state is found to be m = (10035 +/- 260) MeV, which demonstrates that it is stable against the strong and electromagnetic decays. The full width Gamma and mean lifetime tau of T-bb;(u) over bar(d) over bar(-) are evaluated using its semileptonic decay channels T-bb;(u) over bar(d) over bar(-) -> Z(bc;(u) over bar(d) over bar)(0)l (nu) over bar (l), l = e, mu, and tau. The obtained results, Gamma = (7.17 +/- 1.23) x 10(-8) MeV and tau = 9.18(-1.34)(+1.90) fs, can be useful for experimental investigations of the doubly-heavy tetraquarks
An illustration of different two-SNP interaction models. SNP 1 has genotype AA, Aa and aa; SNP 2 has genotype BB, Bb, and bb. A and B are the major alleles for SNP1 and 2, respectively.
No full text<p>Each entry in the tables represents the risk of the corresponding genotype combination relative to the baseline (AA/BB). (a) Multiplicative interaction model; (b) Unrestricted interaction model; (c) Average Risk Due to Interaction (ARDI) model.</p
Equivariant Tamagawa numbers, fitting ideals and Iwasawa theory
No full textLet L/K be a finite Galois extension of number fields of group G. In [4] the second named author used complexes arising from etale cohomology of the constant sheaf bb Z to define a canonical element T Omega (L/K) of the relative algebraic K-group K-0(Z[G], R). It was shown that the Stark and Strong Stark Conjectures for L/K can be reinterpreted in terms of T Omega (L/K), and that the Equivariant Tamagawa Number Conjecture for the bb Q[G]-equivariant motive h(0)(Spec L) is equivalent to the vanishing of T Omega (L/K). In this paper we give a natural description of T Omega (L/K) in terms of finite G-modules and also, when G is Abelian, in terms of (first) Fitting ideals. By combining this description with techniques of Iwasawa theory we prove that T Omega (L/Q) vanishes for an interesting class of Abelian extensions L/Q
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