4,939 research outputs found
The size-star formation relation of massive galaxies at 1.5<z<2.5
We study the relation between size and star formation activity in a complete
sample of 225 massive (M > 5 x 10^10 Msun) galaxies at 1.5<z<2.5, selected from
the FIREWORKS UV-IR catalog of the CDFS. Based on stellar population synthesis
model fits to the observed restframe UV-NIR SEDs, and independent MIPS 24
micron observations, 65% of galaxies are actively forming stars, while 35% are
quiescent. Using sizes derived from 2D surface brightness profile fits to high
resolution (FWHM_{PSF}~0.45 arcsec) groundbased ISAAC data, we confirm and
improve the significance of the relation between star formation activity and
compactness found in previous studies, using a large, complete mass-limited
sample. At z~2, massive quiescent galaxies are significantly smaller than
massive star forming galaxies, and a median factor of 0.34+/-0.02 smaller than
galaxies of similar mass in the local universe. 13% of the quiescent galaxies
are unresolved in the ISAAC data, corresponding to sizes <1 kpc, more than 5
times smaller than galaxies of similar mass locally. The quiescent galaxies
span a Kormendy relation which, compared to the relation for local early types,
is shifted to smaller sizes and brighter surface brightnesses and is
incompatible with passive evolution. The progenitors of the quiescent galaxies,
were likely dominated by highly concentrated, intense nuclear star bursts at
z~3-4, in contrast to star forming galaxies at z~2 which are extended and
dominated by distributed star formation.Comment: 6 pages, 4 figures, accepted for publication in Ap
Efficacy of non-surgical periodontal therapy in reducing periodontal indexes in kidney-transplant patients
Efficacy of non-surgical periodontal therapy in reducing periodontal indexes in kidney-transplant patients.
I. Casula, L. Zanardini*, M. Bianchi, V. Spotti, E. Marchesini
Department of Medical and Surgical Specialties and Public Health Dentale - Dental School – University of Brescia, Italy
Aim: kidney-transplant patient must take cyclosporine-A and calcium channel blockers chronically. Both medicines involve a gingival overgrowth (G.O.) as a collateral effect and this is due to their dosage: it appears 1-3 months after the beginning of the therapy. The prevalence of the G.O. is 84%. The G.O. originates from anterior interdental papilla and it appears as a red and soft tumefaction, that becomes more fibrinous as time goes by. The G.O. takes place in apical-coronal verse and also in vestibular-lingual verse and it looks like a gingival hypertrophy and hyperplasia, which is due to an abnormal increase of the number of fibroblasts into gingival connective tissue. The G.O. involves a great aggregation of extracellular Matrix, or less degradation of it, or both these processes simultaneously. The G.O. leads to the formation of pseudopockets, which interfere with the correct oral hygiene practices. This condition gives rise to mature plaque retention , that leads to infection, inflammation and the increase of the G.O. This condition becomes worse because of bad pre-transplant oral hygiene state. The aim of this study is to estimate the efficacy of non-surgical periodontal therapy in reducing the G.O. in kidney-transplant patient.
Materials and methods: a sample of 32 simple random kidney transplant subjects was enrolled in this study (mean age: 58,44; range: 33-81, 21 m., 11f.). All of them were taking cyclosporine A and calcium channel blockers. Patients taking idantoine, pregnant women, patients suffering from diabetes mellitus or people who have undergone gingival surgery were excluded. The study started on November 2012 and finished on September 2013. Periodontal indexes and Professional oral hygiene practices were performed by the same dental hygienist. The plaque, calculus, bleeding, G.O. and probing depth indexes were evaluated at T0, T1, T2, T3 (at 0, 2, 4, 6 months respectively). Every time the same oral hygiene protocol was applied: non-surgical periodontal therapy with ultrasonic instruments above and below the gum. Results: 787 teeth analysed and 4722 periodontal sites probed. Plaque index (PI), calculus index (CI) and bleeding index (BoP) show significant statistical reduction (p<0,0001). T-test was used for statistic analysis. PI at T0=82,09%, at T3=29,89%/ CI at T0=53,44%, at T3=23,70%/ BoP at T0=71,98%, at T3=26,18%. Probing depth (PD), at six-monthly control , shows a significant statistical reduction (p<0,0001). PD 1-3 mm at T0=16,58%, at T3=30,45%. PD 4-6mm at T0=74,06%, at T3=64,70%. PD 7-9 mm at T0=9,36%, at T3=4,85%. G.O. At T0=54,93%, at T3=44,98%, with a significant statistical reduction (p<0,0001). Conclusions: the applied oral hygiene protocol is simple but effective in reducing drug-induced gingival overgrowth in kidney-transplant patient taking Cyclosporine-A. These clinic results assure a better oral health, improving the quality of life form an aesthetic and functional point of view
Holographic analysis of diffraction structure factors
We combine the theory of inside-source/inside-detector x-ray fluorescence
holography and Kossel lines/x ray standing waves in kinematic approximation to
directly obtain the phases of the diffraction structure factors. The influence
of Kossel lines and standing waves on holography is also discussed. We obtain
partial phase determination from experimental data obtaining the sign of the
real part of the structure factor for several reciprocal lattice vectors of a
vanadium crystal.Comment: 4 pages, 3 figures, submitte
Spatially Extended Low Ionization Emission Regions (LIERs) at
We present spatially resolved emission diagnostics for eight
galaxies that demonstrate extended low ionization emission-line regions (LIERs)
over kpc scales. Eight candidates are selected based on their spatial extent
and emission line fluxes from slitless spectroscopic observations with the
HST/WFC3 G141 and G800L grisms in the well-studied GOODS survey fields. Five of
the candidates (62.5%) are matched to X-ray counterparts in the \textit{Chandra
X-Ray Observatory} Deep Fields. We modify the traditional
Baldwin-Philips-Terlevich (BPT) emission line diagnostic diagram to use
[SII]/(H+[NII]) instead of [NII]/H to overcome the blending of
[NII] and H+[NII] in the low resolution slitless grism spectra. We
construct emission line ratio maps and place the individual pixels in the
modified BPT. The extended LINER-like emission present in all of our
candidates, coupled with X-Ray properties consistent with star-forming galaxies
and weak [OIII]5007\AA\ detections, is inconsistent with purely
nuclear sources (LINERs) driven by active galactic nuclei. While recent
ground-based integral field unit spectroscopic surveys have revealed
significant evidence for diffuse LINER-like emission in galaxies within the
local universe , this work provides the first evidence for the
non-AGN origin of LINER-like emission out to high redshifts.Comment: 11 pages, 1 table, 6 figures, accepted for publication in the
Astrophysics Journal (ApJ
Fully Unintegrated Parton Correlation Functions and Factorization in Lowest Order Hard Scattering
Motivated by the need to correct the potentially large kinematic errors in
approximations used in the standard formulation of perturbative QCD, we
reformulate deeply inelastic lepton-proton scattering in terms of gauge
invariant, universal parton correlation functions which depend on all
components of parton four-momentum. Currently, different hard QCD processes are
described by very different perturbative formalisms, each relying on its own
set of kinematical approximations. In this paper we show how to set up
formalism that avoids approximations on final-state momenta, and thus has a
very general domain of applicability. The use of exact kinematics introduces a
number of significant conceptual shifts already at leading order, and tightly
constrains the formalism. We show how to define parton correlation functions
that generalize the concepts of parton density, fragmentation function, and
soft factor. After setting up a general subtraction formalism, we obtain a
factorization theorem. To avoid complications with Ward identities the full
derivation is restricted to abelian gauge theories; even so the resulting
structure is highly suggestive of a similar treatment for non-abelian gauge
theories.Comment: 44 pages, 69 figures typos fixed, clarifications and second appendix
adde
INCLUSIVE PARTICLE PRODUCTION IN \pbp COLLISIONS
We calculate the inclusive production of charged hadrons in \pbp collisions
to next-to-leading order (NLO) in the QCD improved parton model using a new set
of NLO fragmentation functions for charged pions and kaons. We predict
transverse-momentum distributions and compare them with experimental data from
the CERN S\pbpS Collider and the Fermilab Tevatron.Comment: the file containing the figures has been replaced: we correct a
mistake in the uuencoding procedure and we give the real Fig 4 instead of the
spurious one which was accidentally included in the previous file. the text
is unchanged
The underlying event and fragmentation
A good fit to the CDF underlying event is obtained in the multiple parton
scattering picture using HERWIG, after modifying the cluster hadronization
algorithm as suggested by our previous study and adopting a larger maximum
cluster size. The number of scatters per event is generated simply as a Poisson
distribution. If our picture is correct, the baryon yield should be enhanced in
the underlying event. This effect may be studied by measuring the
proton-to-pion ratio.Comment: 23 pages, 8 figure
Deep-Inelastic Final States in a Space-Time Description of Shower Development and Hadronization
We extend a quantum kinetic approach to the description of hadronic showers
in space, time and momentum space to deep-inelastic collisions, with
particular reference to experiments at HERA. We follow the history of hard
scattering events back to the initial hadronic state and forward to the
formation of colour-singlet pre-hadronic clusters and their decays into
hadrons. The time evolution of the space-like initial-state shower and the
time-like secondary partons are treated similarly, and cluster formation is
treated using a spatial criterion motivated by confinement and a
non-perturbative model for hadronization. We calculate the time evolution of
particle distributions in rapidity, transverse and longitudinal space. We also
compare the transverse hadronic energy flow and the distribution of observed
hadronic masses with experimental data from HERA, and find encouraging results.
The techniques developed in this paper may be applied in the future to more
complicated processes such as eA, pp, pA and AA collisions.Comment: 44 pages plus 14 postscript figure
Transverse momentum spectra of identified particles in high energy collisions with statistical hadronisation model
A detailed analysis is performed of transverse momentum spectra of several
identified hadrons in high energy collisions within the framework of the
statistical model of hadronisation. The effect of the decay chain following
hadron generation is accurately taken into account. The considered
centre-of-mass energies range from ~ 10 to 30 GeV in hadronic collisions (pi+
p, pp and Kp) and from ~ 15 to 45 GeV in e+e- collisions. A clear consistency
is found between the temperature parameter extracted from the present analysis
and that obtained from fits to average hadron multiplicities in the same
collision systems. This finding indicates that in the hadronisation, the
production of different particle species and their momentum spectra are two
closely related phenomenons governed by one parameter.Comment: Talk given by F. Becattini in "Correlations and Fluctuations 2000",
12 pp., 11 figure
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