Hard core attraction in hadron scattering and the family of the Ds meson molecule

We study the discovered Ds(2317) at BABAR, CLEO and BELLE, and find that it belongs to a class of strange multiquarks, which is equivalent to the class of kaonic molecules bound by hard core attraction. In this class of hadrons a kaon is trapped by a s-wave meson or baryon. To describe this class of multiquarks we apply the Resonating Group Method, and extract the hard core kaon-meson(baryon)interactions. We derive a criterion to classify the attractive channels. We find that the mesons f0(980), Ds(2457), Bs scalar and axial, and also the baryons with the quantum numbers of Lambda, Xi_c, Xi_b and also Omega_cc, Omega_cb and Omega_bb belong to the new hadronic class of the Ds(2317).Comment: 5 pages, 1 figure, 2 tables, contribution to the X International Conference on Hadron Spectroscopy, HADRON 2003, August 31 - September 6, 2003, Aschaffenburg, German

The Theta+ (1540) as an overlap of a pion, a kaon and a nucleon

We study the very recently discovered $\Theta^+$ (1540) at SPring-8, at ITEP and at CLAS-Thomas Jefferson Lab. We apply the same RGM techniques that already explained with success the repulsive hard core of nucleon-nucleon, kaon-nucleon exotic scattering, and the attractive hard core present in pion-nucleon and pion-pion non-exotic scattering. We find that the K-N repulsion excludes the Theta+ as a K-N s-wave pentaquark. We explore the Theta+ as heptaquark, equivalent to a N+pi+K borromean boundstate, with positive parity and total isospin I=0. We find that the kaon-nucleon repulsion is cancelled by the attraction existing both in the pion-nucleon and pion-kaon channels. Although we are not yet able to bind the total three body system, we find that the Theta+ may still be a heptaquark state.Comment: 5 pages, 3 figures, 1 table, contribution to the X International Conference on Hadron Spectroscopy, HADRON 2003, August 31 - September 6, 2003, Aschaffenburg, German

Roper Electroproduction Amplitudes in a Chiral Confinement Model

A description of the Roper using the chiral chromodielectric model is presented and the transverse $A_{1/2}$ and the scalar $S_{1/2}$ helicity amplitudes for the electromagnetic Nucleon--Roper transition are obtained for small and moderate $Q^2$. The sign of the amplitudes is correct but the model predictions underestimate the data at the photon point. Our results do not indicate a change of sign in any amplitudes up to $Q^2\sim1$ GeV$^2$. The contribution of the scalar meson excitations to the Roper electroproduction is taken into account but it turns out to be small in comparison with the quark contribution. However, it is argued that mesonic excitations may play a more prominent role in higher excited states.Comment: 10 pages, 8 figures, uses World Scientific macros. Talk presented at EMI2001 in Osaka, Japa

N^* electroproduction amplitudes in a model with dynamical confinement

The Roper resonance is described in a chiral version of the chromodielectric model as a cluster of three quarks in radial-orbital configuration (1s)$^2$(2s)$^1$, surrounded by $\pi$ and $\sigma$-meson clouds and by a chromodielectric field which assures quark dynamical confinement. Radial profiles for all fields are determined self-consistently for each baryon. Transverse $A_{1/2}$ and scalar $S_{1/2}$ helicity amplitudes for the nucleon-Roper transition are calculated. The contribution of glueball and $\sigma$-meson vibrations is estimated; although small for N(1440), the $\sigma$ contribution can be large for N(1710).Comment: 12 pages, 6 figures, uses elsevier macro

Schwinger-Dyson equations and the quark-antiquark static potential

In lattice QCD, a confining potential for a static quark-antiquark pair can be computed with the Wilson loop technique. This potential, dominated by a linear potential at moderate distances, is consistent with the confinement with a flux tube, an extended and scalar system also directly observable in lattice QCD. Quantized flux tubes have also been observed in another class of confinement, the magnetic confinement in type II superconductors. On the other hand the solution of Schwinger Dyson Equations, say with the Landau gauge fixing and the truncation of the series of Feynman diagrams, already at the rainbow level for the self energy and at the ladder level for the Bethe Salpeter equation, provides a signal of a possible inverse quartic potential in momentum space derived from one gluon and one ghost exchange, consistent with confinement. Here we address the successes, difficulties and open problems of the matching of these two different perspectives of confinement, the Schwinger-Dyson perspective versus the flux tube perspective.Comment: 12 pages, 18 figures; talk presented at QCD-TNT, Trento, 7-11 sep 200

Family farming in the agricultural census of 2006: the legal mark and the options for their identification.

(Agricultura familiar no censo agropecuário 2006: o marco legal e as opções para sua identificação). Visando delimitar a agricultura familiar no Censo Agropecuário 2006, o Ministério do Desenvolvimento Agrário (MDA) e o Instituto Brasileiro de Geografia e Estatística (IBGE) elaboraram metodologia para construção de uma variável identificando os estabelecimentos agropecuários recenseados e que se ajustam ao conceito previsto na Lei n.11.326, de 24 de julho de 2006. O texto apresenta os passos metodológicos utilizados e alguns resultados

Factors Associated with Readmission of Patients with Congenital Heart Disease in a Swiss University Hospital.

Congenital heart defects (CHD) lead to extensive use of healthcare resources. Still, there is little information available regarding readmission rates or associated factors. We sought to evaluate readmission rates and their determinants among patients with CHD hospitalized in a Swiss university hospital. We conducted a retrospective study using data from all non-adult (<18 years) patients hospitalized between 2002 and 2014 at the University Hospital of Lausanne with an International Classification of Diseases version 10 code Q20-Q25. Overall, 996 patients (460 girls, 332 undergoing surgery, mean age 2.7 years) were assessed, 96 of whom (9.6%) were readmitted within 30 days after discharge. Among the 96 readmissions, 83 (86.5%) were related to the CHD. Median time to readmission was 10 days (interquartile range 6-20) and median length of readmission was 12 days (interquartile range 6-20). After multivariate adjustment, foreign nationality, greater distance to hospital and length of index hospitalization <14 days predisposed to readmission. Patients who underwent surgery were less likely to be readmitted (8.7%). We conclude that readmissions were frequent, almost 1 in 10 patients, and associated with several socio-clinical factors. Providing patients who live far from hospital with specialized care closer to home may help reduce the rate of readmission

Electrooxidation as the anaerobic pre-treatment of fats: Oleate conversion using RuO2 and IrO2 based anodes

Electrochemical treatment of oleate using RuO2 and IrO2 type dimensionally stable anodes in alkaline medium was performed to develop a feasible anaerobic pre-treatment of fatty effluents. The results showed that the pre-treated solutions over RuO2 were faster degraded by anaerobic consortium than the raw oleate solutions or the electrolysed solutions using IrO2. In batch experiments carried out with pre-treated solutions over RuO2 (100–500 mg/L), no lag phases were observed before the methane production onset. On the other hand, raw oleate and pre-treated oleate over IrO2 had originated lag phases of 0–140 and 0–210 h, respectively. This study demonstrated that it is advantageous to apply the electrochemical treatment carried out on the RuO2 type DSA in order to achieve a faster biodegradation of lipid-containing effluent and consequently to obtain a faster methane production.ELTECH Systems Corporation.Fundação para a Ciência e Tecnologia (FCT