726 research outputs found
Rapidity-rank structure of p anti-p pairs in hadronic Z0 decays
No full textThe rapidity-rank structure of pp̄ pairs is used to analyze the mechanism of baryon production in hadronic Z0 decay. The relative occurrence of the rapidity-ordered configuration p M p̄, where M is a meson, and that of pp̄ adjacent pairs is compared. The data are found to be consistent with predictions from a mechanism producing adjacent-rank pp̄ pairs, without requiring 'string-ordered' p M p̄ configurations. An upper limit of 15% at 90% confidence is determined for the p M p̄ contribution. (C) 2000 Elsevier Science B.V.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
pi+-, K+-, p and anti-p production in Z0 ---> q anti-q, Z0 ---> b anti-b, Z0 ---> u anti-u, d anti-d, s anti-s
No full textThe DELPHI experiment at LEP uses Ring Imaging Cherenkov detectors for particle identification. The good understanding of the RICH detectors allows the identification of charged pions, kaons and p rotons, covering the full momentum range from \mbox{0.7\!<\!p\!<\! 45.6~\gevc}. The \pipm,~\kapm, p and \pbar normalised production rates, their differential cross sections, multiplicities a nd the maxima \xipst of the \mbox{\xip=\ln(1/\xp)} distributions are measured for three event samples \zqqbar, ~\zbbbar and \zudsbar, selected from \mbox{}~\zzero deca ys collected by \delphi in 1994. The results are compared to the predictions of the \jetset string fragmentation model and the \herwig cluster fragmentation model. The Modified Leading Logarithm Ap proximation with Local Parton-Hadron Duality is tested. The \xipst dependence on the primary quark flavour is investigated and quantified for the different particle distributions. The \pipm, \kapm, p and \pbar multiplicities are measured with precisions from \%~to~\%. For the \zqqbar and \zbbbar event samples, these improve on previous measurements. The \pipm, \k apm, p and \pbar multiplicities for \zudsbar are presented for the first time
Determination of P(c -> D*(+)) and BR(c -> l(+)) at LEP 1
No full textThe probability P(c --> D*(+)) that a charm quark fragments into a D*+ meson and the c --> l(+) semileptonic branching fraction were measured in Z(0) decay into c (c) over bar events. From the analysis of 3.5 Million Z(0) events collected from 1992 to 1995, a sample of charm meson decays with 81% c (c) over bar purity was selected. The product of the c --> D*(+) fragmentation probability times the D*(+) --> D(0)pi(+) branching fraction was measured to be: P(c --> D*(+)).BR(D*(+) --> D(0)pi(+)) = 0.174 +/- 0.010(stat) +/- 0.004(syst). Using the world averaged value for BR(D*+ --> D(0)pi(+)), the fragmentation probability is inferred: P(c --> D*(+)) = 0.255 +/- 0.015(stat) +/- 0.006(syst) +/- 0.005(syst.BR). From the same sample, 1828 +/- 51 identified leptons in the opposite hemisphere were selected. From this sample, the charm semileptonic branching fraction was measured to be: BR(c --> l(+)) = 0.0958 +/- 0.0042(stat) +/- 0.0028(syst)
Rapidity-rank structure of p(p)over-bar pairs in hadronic Z(0) decays
No full textThe rapidity-rank structure of pa pairs is used to analyze the mechanism of baryon production in hadronic Z(0) decay. The relative occurrence of the rapidity-ordered configuration p M p, where M is a meson, and that of pp adjacent pairs is compared. The data are found to be consistent with predictions from a mechanism producing adjacent-rank pp pairs, without requiring ‘string-ordered’ p M p configurations. An upper limit of 15% at 90% confidence is determined for the p M p contribution. (C) 2000 Elsevier Science B.V. All rights reserved
Polyunsaturated fatty acids in various macroalgal species from north Atlantic and tropical seas
No full textBackground - In this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated. Methods - The fatty acid (FA) composition in lipids from seven sea weed species from the North Sea (Ulva lactuca, Chondrus crispus, Laminaria hyperborea, Fucus serratus, Undaria pinnatifida, Palmaria palmata, Ascophyllum nodosum) and two from tropical seas (Caulerpa taxifolia, Sargassum natans) was determined using GCMS. Four independent replicates were taken from each seaweed species. Results - Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs), were in the concentration range of 2-14 mg/g dry matter (DM), while total lipid content ranged from 7-45 mg/g DM. The n-9 FAs of the selected seaweeds accounted for 3%-56% of total FAs, n-6 FAs for 3%-32% and n-3 FAs for 8%-63%. Red and brown seaweeds contain arachidonic (C20:4, n-6) and/or eicosapentaenoic acids (EPA, C20:5, n-3), the latter being an important "fish" FA, as major PUFAs while in green seaweeds these values are low and mainly C16 FAs were found. A unique observation is the presence of another typical "fish" fatty acid, docosahexaenoic acid (DHA, C22:6, n-3) at ˜ 1 mg/g DM in S. natans. The n-6: n-3 ratio is in the range of 0.05-2.75 and in most cases below 1.0. Environmental effects on lipid-bound FA composition in seaweed species are discussed. Conclusion - Marine macroalgae form a good, durable and virtually inexhaustible source for polyunsaturated fatty acids with an (n-6) FA: (n-3) FA ratio of about 1.0. This ratio is recommended by the World Health Organization to be less than 10 in order to prevent inflammatory, cardiovascular and nervous system disorders. Some marine macroalgal species, like P. palmata, contain high proportions of the "fish fatty acid" eicosapentaenoic acid (EPA, C20:5, n-3), while in S. natans also docosahexaenoic acid (DHA, C22:6, n-3) was detected
Distribution pattern-driven development of service architectures
No full textDistributed systems are being constructed by composing a number of discrete components. This practice is particularly prevalent within the Web service domain in the form of service process orchestration and choreography. Often, enterprise systems are built from many existing discrete applications such as legacy applications exposed using Web service interfaces. There are a number of architectural configurations or distribution patterns, which express how a composed system is to be deployed in a distributed environment. However, the amount of code
required to realise these distribution patterns is considerable. In this paper, we propose a distribution
pattern-driven approach to service composition and architecting. We develop, based on a catalog of patterns, a UML-compliant framework, which takes existing Web service interfaces as its input and generates executable Web service compositions based on a distribution pattern chosen by the software architect
Measurement of prompt photon production in √sNN=8.16 TeV p + Pb collisions with ATLAS
No full textThe inclusive production rates of isolated, prompt photons in p + Pb collisions at √sNN = 8.16 TeV
are studied with the ATLAS detector at the Large Hadron Collider using a dataset with an integrated
luminosity of 165 nb−1 recorded in 2016. The cross-section and nuclear modification factor RpPb are
measured as a function of photon transverse energy from 20 GeV to 550 GeV and in three nucleon–
nucleon centre-of-mass pseudorapidity regions, (−2.83,−2.02), (−1.84, 0.91), and (1.09, 1.90). The
cross-section and RpPb values are compared with the results of a next-to-leading-order perturbative QCD
calculation, with and without nuclear parton distribution function modifications, and with expectations
based on a model of the energy loss of partons prior to the hard scattering. The data disfavour a large
amount of energy loss and provide new constraints on the parton densities in nuclei
Dijet azimuthal correlations and conditional yields in pp and p+Pb collisions at sNN=5.02TeV with the ATLAS detector
No full textThis paper presents a measurement of forward-forward and forward-central dijet azimuthal angular correlations and conditional yields in proton-proton (pp) and proton-lead (p+Pb) collisions as a probe of the nuclear gluon density in regions where the fraction of the average momentum per nucleon carried by the parton entering the hard scattering is low. In these regions, gluon saturation can modify the rapidly increasing parton distribution function of the gluon. The analysis utilizes 25pb-1 of pp data and 360μb-1 of p+Pb data, both at sNN=5.02 TeV, collected in 2015 and 2016, respectively, with the ATLAS detector at the Large Hadron Collider. The measurement is performed in the center-of-mass frame of the nucleon-nucleon system in the rapidity range between -4.0 and 4.0 using the two highest transverse-momentum jets in each event, with the highest transverse-momentum jet restricted to the forward rapidity range. No significant broadening of azimuthal angular correlations is observed for forward-forward or forward-central dijets in p+Pb compared to pp collisions. For forward-forward jet pairs in the proton-going direction, the ratio of conditional yields in p+Pb collisions to those in pp collisions is suppressed by approximately 20%, with no significant dependence on the transverse momentum of the dijet system. No modification of conditional yields is observed for forward-central dijets
The angiogenic response to Bradykinin "in vitro" : the role of Bradykinin receptors in hypoxic hearts and tumors
No full textEnd organ damage resulting from hypertension is a leading
cause of morbidity and mortality worldwide. In
hypertension, left ventricular mass increases resulting in
left ventricular hypertrophy (LVH). LVH increases the risk
of heart failure and sudden cardiac death. This is due to
the decreased supply of oxygen and nutrients (ischemia) to
the myocardium because of vascular rarefaction. Research
has focused on inducers of angiogenesis such as basic
fibroblast growth factor and vascular endothelial growth
factor to improve myocardial oxygenation and function.
However, recently components of the Renin-Angiotensin-
Aldosterone System (RAAS), which contributes to blood
pressure control, have been shown to affect angiogenesis.
Angiotensin-converting-enzyme (ACE) inhibitors are used to
treat high blood pressure and congestive heart failure.
These block the conversion of physiologically inactive
angiotensin I to active vasoconstrictive angiotensin II and
inhibit the breakdown of Bradykinin (BK), a potent
vasodilator and mediator of inflammation. ACE inhibitors
increased capillary density in ischemic tissue by the
induction of new microvessels in ischemic rat limbs in
vivo. Several lines of evidence suggest Bradykinin to
possess significant angiogenic activity. Hence, Bradykinin
may mediate the effect of ACE inhibitors. Still, it is
unclear through whether Bradykinin promotes vascularization
of the ischemic heart via the Bradykinin receptor subtype 1
or 2. On the other hand, blocking angiogenesis could be a
strategy to arrest tumor growth, since tumor growth and
metastasis depend on angiogenesis. However, it is yet to be
fully elucidated whether and through which mechanisms
Bradykinin induces angiogenesis in tumors. Therefore, the aim of this thesis was in the first line to
clarify the angiogenic potential of Bradykinin in the
ischemic heart in vitro, especially the roles of the two
Bradykinin receptor subtypes in the regulation of
Bradykinin-induced angiogenesis. In second line, the thesis
aims to comparatively assess the role of Bradykinin and
requirement of Bradykinin receptors in cancer, i.e.
melanomas.
To do so, we used an in vitro model of angiogenesis of the
murine heart under moderate hypoxic conditions (3% O2).
Pilot experiments showed decreased angiogenic potential of
hypertrophied rodent hearts compared to normal healthy
controls. When using ACE inhibitors, angiogenesis in vitro
of hypoxic normal and hypertrophied hearts increased, and,
interestingly, Bradykinin showed a potent induction of
capillary like sprout formation.
This angiogenic effect was induced at low (10nM) but not at
high concentrations of Bradykinin (1mM). RT-PCR showed
expression of both Bradykinin receptor subtypes in hypoxic
mouse hearts. The angiogenic response to Bradykinin was
inhibited by a specific Bradykinin receptor 2 (BKR2)
inhibitor, but not by an inhibitor of Bradykinin receptor 1
(BKR1). A specific BKR1 agonist reduced angiogenesis.
Bradykinin-induced angiogenesis was not impaired in BKR1 (-
/-) mouse hearts. Different nitric oxide synthase
inhibitors (L-NAME, L-NIL, NIO) almost completely abrogated
the in vitro mouse heart angiogenesis response to
Bradykinin. Bradykinin did not induce angiogenesis in
hearts of iNOS (-/-) mice. Thus, in mouse hearts in vitro
Bradykinin at low nanomolar concentrations is angiogenic
under conditions of prolonged hypoxia. This angiogenic
effect is mediated by BKR2 activation and depends on iNOS. To assess the involvement of Bradykinin in cancer
angiogenesis, melanomas were injected and grown in the ear
of wildtype and BKR1 (-/-) mice, which acquired a BKR1 (-/-
) phenotype vasculature. In contrast to the findings in
hearts, we found that in melanomas from BKR1 (-/-) mice
angiogenesis in vitro was significantly lower as compared
to wildtype control. This suggests that melanomas in
contrast to hearts require vasculature with functional BKR1
to develop new microvessels.
In summary the key findings of this thesis are the
following: Bradykinin potently induces angiogenesis in
vitro of the hypoxic heart at nanomolar concentrations via
BKR2. At high Bradykinin concentrations or using specific
BKR1 agonists the angiogenic effect appears to be blocked.
Furthermore, functional iNOS is required for Bradykinin to
induce angiogenesis in vitro of the heart. In contrast to
the heart endothelial sprouting and angiogenesis, hypoxic
melanomas in vitro require BKR1.
Thus, specific stimulation of the BKR2 of the heart
vasculature may be a target to reduce tissue ischemia by
angiogenesis in the ischemic and/or hypertrophied heart
pi(+/-), K-+/-, p and (p)over-bar production in Z(0)-> q(q)over-bar, Z(0)-> b(b)over-bar, Z(0)-> u(u)over-bar,d(d)over-bar,s(s)over-bar
No full textThe DELPHI experiment at LEP uses Ring Imaging Cherenkov detectors for particle identification. The good understanding of the RICH detectors allows the identification of charged pions, kaons and protons, covering the full momentum range from 0.7 < p < 45.6 GeV/c. The pi(+/-), K+/-, p and (p) over bar normalised production rates, their differential cross sections, multiplicities and the maxima xi(p)* of the xi(p) = In(1/X-p) distributions are measured for three event samples Z(0) –> q (q) over bar, Z(0) –> b (b) over bar, Z(0) –> u (u) over bar, d (d) over bar, s (s) over bar, selected from similar to 1400000 Z(0) decays collected by DELPHI in 1994. The results are compared to the predictions of the JETSET string fragmentation model and the HERWIG cluster fragmentation model. The Modified Leading Logarithm Approximation with Local Parton-Hadron Duality is tested. The xi(p)* dependence on the primary quark flavour is investigated and quantified for the different particle distributions. The pi(+/-), K+/-, p and (p) over bar multiplicities are measured with precisions from +/-4% to +/-6%. For the Z(0) –> q (q) over bar, and Z(0) –> b (b) over bar, event samples, these improve on previous measurements. The pi(+/-), K+/-, p and (p) over bar multiplicities for Z(0) –> u (u) over bar, d (s) over bar, s (s) over bar are presented for the first time
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