2,978 research outputs found
A J^PG=1++ Charged Resonance in the Y(4260) to pi+pi- J/psi Decay?
New BES and Belle data show a peak in the Y(4260) decay into J/psi plus one
charged pion. We point out that the peak might correspond to a charged
resonance at about 3880 MeV predicted time ago within a tetraquark model. The
same tetraquark model predicts another peak at about 100 MeV below the observed
one. We discuss the possibility of having it in present data. On the other hand
we expect that if the molecular picture were the correct one, a peak
corresponding to a D* D*bar state should appear at about 4020 MeV.Comment: 8 pages, 3 figures. Includes more recent Belle dat
Sarna sarcóptica dos suínos: estratégia de ação no controle e avaliação econômica.
bitstream/item/58756/1/CUsersPiazzonDocuments172.pd
Resistance of European spring 2-row barley cultivars to Pyrenophora graminea and detection of associated loci
Pyrenophora graminea is the seed-borne pathogen causal agent of barley leaf stripe disease.
In this work, we screened a collection of 206 spring two-row barley cultivars from Europe for their
resistance to the fungal pathogen. Artificial inoculation with the highly virulent isolate Dg2 revealed
a continuous variation for the incidence of infection, with few highly resistant or highly susceptible
genotypes. On average, old cultivars showed higher resistance than the more modern ones. Genome-
Wide Association Scan was performed by exploiting available molecular data for >4000 SNP markers
and revealed a single, highly significant association on the short arm of chromosome 6H, in a genomic
position where quantitative trait loci (QTL) for barley resistance to P. graminea were not detected
before. Based on the last version of the reference barley genome, genes encoding for proteins with a
kinase domain were suggested as candidates for the locus
A Methodology for Continuous Monitoring of Rail Corrugation on Subway Lines Based on Axlebox Acceleration Measurements
Rail corrugation is a degradation phenomenon that manifests as a quasi-periodic irregularity on the running surface of the rail. It is a critical problem for urban railway lines because it induces ground-borne vibrations transmitted to the buildings near the infrastructure, causing complaints from the inhabitants. A typical treatment to mitigate the rail corrugation problem is the periodic grinding of the rails, performed by dedicated vehicles. The scheduling of rail maintenance is particularly critical because it can be performed only when the service is interrupted. A procedure for the continuous monitoring of rail corrugation is proposed, based on axlebox acceleration measurements. The rail irregularity is estimated from the measured acceleration by means of a frequency domain model of vertical dynamics of the wheel–rail interaction. The results obtained by using two different methods (a state-of-the-art method and a new one) are compared. Finally, the study of the evolution of the power content of the rail irregularity enables the identification of the track sections where corrugation is developing and rail grinding is necessary
Extended calibration range for prompt photon emission in ion beam irradiation
Monitoring the dose delivered during proton and carbon ion therapy is still a
matter of research. Among the possible solutions, several exploit the
measurement of the single photon emission from nuclear decays induced by the
irradiation. To fully characterize such emission the detectors need
development, since the energy spectrum spans the range above the MeV that is
not traditionally used in medical applications. On the other hand, a deeper
understanding of the reactions involving gamma production is needed in order to
improve the physic models of Monte Carlo codes, relevant for an accurate
prediction of the prompt-gamma energy spectrum.This paper describes a
calibration technique tailored for the range of energy of interest and
reanalyzes the data of the interaction of a 80MeV/u fully stripped carbon ion
beam with a Poly-methyl methacrylate target. By adopting the FLUKA simulation
with the appropriate calibration and resolution a significant improvement in
the agreement between data and simulation is reported.Comment: 4 pages, 7 figures, Submitted to JINS
A Uniform Description of the States Recently Observed at B-factories
The newly found states Y(4260), Y(4361), Y(4664) and Z(4430) stir broad
interest in the study of spectroscopy in a typical charmonium scale. The
Y(4260) which was observed earlier has been interpreted as hybrid, molecular
state, and baryonium, etc. In this note we show for the first time that these
new structures, which are hard to be interpreted as charmonium states, can be
systematically embedded into an extended baryonium picture. According to this
assignment, the so far known characters of these states are understandable.
And, in the same framework, we make some predictions for experimenters to
measure in the future.Comment: 6 pages in Latex. to appear in J.Phys.
The contribution of faint AGNs to the ionizing background at z~4
Finding the sources responsible for the hydrogen reionization is one of the
most pressing issues in cosmology. Bright QSOs are known to ionize their
surrounding neighborhood, but they are too few to ensure the required HI
ionizing background. A significant contribution by faint AGNs, however, could
solve the problem, as recently advocated on the basis of a relatively large
space density of faint active nuclei at z>4. We have carried out an exploratory
spectroscopic program to measure the HI ionizing emission of 16 faint AGNs
spanning a broad U-I color interval, with I~21-23 and 3.6<z<4.2. These AGNs are
three magnitudes fainter than the typical SDSS QSOs (M1450<~-26) which are
known to ionize their surrounding IGM at z>~4. The LyC escape fraction has been
detected with S/N ratio of ~10-120 and is between 44 and 100% for all the
observed faint AGNs, with a mean value of 74% at 3.6<z<4.2 and
-25.1<M1450<-23.3, in agreement with the value found in the literature for much
brighter QSOs (M1450<~-26) at the same redshifts. The LyC escape fraction of
our faint AGNs does not show any dependence on the absolute luminosities or on
the observed U-I colors. Assuming that the LyC escape fraction remains close to
~75% down to M1450~-18, we find that the AGN population can provide between 16
and 73% (depending on the adopted luminosity function) of the whole ionizing UV
background at z~4, measured through the Lyman forest. This contribution
increases to 25-100% if other determinations of the ionizing UV background are
adopted. Extrapolating these results to z~5-7, there are possible indications
that bright QSOs and faint AGNs can provide a significant contribution to the
reionization of the Universe, if their space density is high at M1450~-23.Comment: Accepted for publication on A&A, 16 pages, 22 figure
Superparamagnetic iron oxide nanoparticle-loaded polyacrylonitrile nanofibers with enhanced arsenate removal performance
Novel nanocomposite sorbents of superparamagnetic iron oxide nanoparticles (SPION) supported onto electrospun polyacrylonitrile nanofibers were synthesized by a simple and scalable method. The influence of both nanofiber size and SPION loading on As(V) adsorption capacity was studied and optimization was conducted. A maximum uptake capacity of 32.5 mmol As(V) per gram SPION in batch mode tests using an extremely low loading of only 2.9 mg of SPION per gram of adsorbent was achieved. This represents a remarkable improvement of 36 times compared with SPION in suspension. The optimal material was tested in continuous flow operation mode, reaching an adsorption capacity of 851.7 mg As(V) per gram of adsorbent at pH 3.8. It is also demonstrated that the new adsorbents can retain high performance when tested under real conditions using polluted wastewater from a lixiviation dump containing a large amount of competing anions (Cl- and F- ) and interfering cations (K+, Na+, Mg2+, and Ca2+). Furthermore, there was no release of nanoparticles observed during the operation and the spent porous material can be compressed, generating a small amount of solid waste that can be easily treated or stored
Otoacaríase psoróptica dos caprinos-Infestação subclínica
Naturally occuring subclinical psoroptic otoacariasis in goats is reported in Pernambuco and Rio de Janeiro State. Infestation rates of 59.3% and 46% were observed in goats for about twelve months of age in the States of Pernambuco and Rio de Janeiro, respectively.A otoacaríase psoróptica subclínica dos caprinos é assinalada nos Estados de Pernambuco e Rio de Janeiro. Índices de infestação de 59,3% e 46% foram observados em animais com idade aproximada de doze meses, criados no Estados de Pernambuco e Rio de Janeiro, respectivamente.
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