64,398 research outputs found
Management of diabetes from preconception to the postnatal period: summary of NICE guidance
Diabetes in pregnancy is associated with risks to the
woman (for example, higher rates of miscarriage, preeclampsia, and preterm labour) and to the developing
fetus and baby (for example, higher rates of congenital
malformations, macrosomia, birth injury, and perinatal mortality).
This article summarises the most recent
guidance from the National Institute for Health and
Clinical Excellence (NICE) on how to manage diabetes
and its complications from preconception to the
postnatal period
Decays of b hadrons and a possible new four-quark interaction
A possibility is considered of explaining the low experimental value of the
ratio of the lifetimes tau(Lambda_b)/tau(B_d) by a new `centiweak' four-quark
interaction, i.e with a strength on the order of 10^{-2}G_F. It is noted that
the considered interaction can also improve agreement with the data on low
semileptonic branching ratio B_{sl}(B) in B meson decays with a simultaneous
slight decrease in the prediction for the average charm yield in those decays.
The proposed new interaction modifies within the present experimental limits
the predictions for differences of lifetimes among B mesons, and can thus be
probed by more precise data on these differences. A sample model is briefly
discussed, where the new interaction arises through a weak SU(2) singlet scalar
field with quantum numbers of a diquark.Comment: 10 page
Sum rules for total hadronic widths of light mesons and rectilineal stitch of the masses on the complex plane
Mass formulae for light meson multiplets derived by means of exotic
commutator technique are written for complex masses and considered as complex
mass sum rules (CMSR). The real parts of the (CMSR) give the well known mass
formulae for real masses (Gell-Mann--Okubo, Schwinger and Ideal Mixing ones)
and the imaginary parts of CMSR give appropriate sum rules for the total
hadronic widths - width sum rules (WSR). Most of the observed meson nonets
satisfy the Schwinger mass formula (S nonets). The CMSR predict for S nonet
that the points form the rectilinear stitch (RS) on the complex
mass plane. For low-mass nonets WSR are strongly violated due to
``kinematical'' suppression of the particle decays, but the violation decreases
as the mass icreases and disappears above . The slope of
the RS is not predicted, but the data show that it is negative for all S nonets
and its numerical values are concentrated in the vicinity of the value -0.5. If
is known for a nonet, we can evaluate ``kinematical'' suppressions of its
individual particles. The masses and the widths of the S nonet mesons submit to
some rules of ordering which matter in understanding the properties of the
nonet. We give the table of the S nonets indicating masses, widths, mass and
width orderings. We show also mass-width diagrams for them. We suggest to
recognize a few multiplets as degenerate octets. In Appendix we analyze the
nonets of mesons.Comment: 20 pages, 3 figures; title and discussion expanded; additional text;
final version accepted for publication in EPJ
Analysis of decays in the perturbative QCD approach
Within the framework of perturbative QCD approach, we study the charmless
two-body decays . Using the decays constants
and the light-cone distribution amplitudes for these mesons derived from the
QCD sum rule method, we find the following results: (a) Our predictions for the
branching ratios are consistent well with the QCDF results within errors, but
much larger than the naive factorization approach calculation values. (b) We
predict that the anomalous polarizations occurring in the decays also happen in the decays , while do not happen in
the decays . Here the contributions from the annihilation diagrams
play an important role to explain the lager transverse polarizations in the
decays , while they are not sensitive to the polarizations in
decays . (c) Our predictions for the direct CP-asymmetries agree
well with the QCDF results within errors. The decays have larger direct CP-asymmetries, which
could be measured by the present LHCb experiments.Comment: 12pages, 1figures. arXiv admin note: substantial text overlap with
arXiv:1203.5913, arXiv:1203.591
Analytical and Numerical Flash-Algorithms for Track Fits
Flash-algorithm track-reconstruction routines with speed factors 3000-4000 in
excess those of traditional iterative routines are presented.
The methods were successfully tested in the alignment of the Test Beam setup
for the ATLAS Pixel Detector
MCM-D modules yielding a
60 fold increase in alignment resolution over iterative routines, for the
same amount of alocated CPU time.Comment: 6 pages, 3 figure
On the Parity Degeneracy of Baryons
The gross features of the observed baryon excitation spectrum below 2 GeV are
well explained if the spectrum generating algebra of its intrinsic orbital
angular momentum states is o(4)*su(2)_I. The spins of the resonances are
obtained through the coupling of a Lorentz bi-spinor (1/2,0)+ (0,1/ 2) to a
multiplet of the type (j,j) in its O(4)/O(3) reduction. The parities of the
resonances follow from those of the O(3) members of the (j,j) multiplets. In
this way relativistic SL(2,C) representations are constructed. For example, the
first S11, P11, and D13 states with masses around 1500 MeV fit into the (1/2,
1/2)* [(1/2,0)+(0,1/2)] representation. The observed parities of the resonances
correspond to natural parities of the (1/2,1/2) states. The second P11, S11,
D13- together with the first P13, F15, D15, and (a predicted) F17 -resonances,
centered around 1700 MeV, are organized into the (3/2,3/2)*[(1/2,0)+(0,1/2)]
representation. I argue that the members of the (3/2,3/2) multiplet carry
unnatural parities and that in this region chiral symmetry is restored. In the
N(939)- N(1650) transition the chiral symmetry mode is changed, and therefore,
a chiral phase transition is predicted to take place.Comment: 9 pages, LaTex, 1 figure; published in Mod.Phys.Lett. A12 (1997)
2373; minor misprints corrected, no statement change
Observations of transients and pulsars with LOFAR international stations
The LOw FRequency ARray - LOFAR is a new radio telescope that is moving the
science of radio pulsars and transients into a new phase. Its design places
emphasis on digital hardware and flexible software instead of mechanical
solutions. LOFAR observes at radio frequencies between 10 and 240 MHz where
radio pulsars and many transients are expected to be brightest. Radio frequency
signals emitted from these objects allow us to study the intrinsic pulsar
emission and phenomena such as propagation effects through the interstellar
medium. The design of LOFAR allows independent use of its stations to conduct
observations of known bright objects, or wide field monitoring of transient
events. One such combined software/hardware solution is called the Advanced
Radio Transient Event Monitor and Identification System (ARTEMIS). It is a
backend for both targeted observations and real-time searches for millisecond
radio transients which uses Graphical Processing Unit (GPU) technology to
remove interstellar dispersion and detect millisecond radio bursts from
astronomical sources in real-time using a single LOFAR station.Comment: To appear in the proceedings of the Electromagnetic Radiation from
Pulsars and Magnetars conference, Zielona Gora, 2012. 4 pages, 1 figur
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