EXPERIMENTAL STUDY OF THE ORIENTATION OF THREE JET EVENTS IN e+ e- ANNIHILATION AT PETRA

The full TASSO data have been used to study the orientation of three-jet events ine+e− annihilation. The polar angle distributions of the normal to the three-jet plane as well as the polar angle distribution of the most energetic jet have been measured as a function of the thrust cut-off used to select the three-jet sample. The data corrected for radiation and detector effects are compared to QCD predictions and fair agreement is found. As a consistency check we also present measurements of the azimuthal correlations between the lepton and hadron planes. A significant azimuthal dependence is found, consistent again with the QCD predictions

Experimental study of the orientation of three-jet events in e+e−e^+ e^- annihilation at PETRA

The full TASSO data have been used to study the orientation of three-jet events ine+e− annihilation. The polar angle distributions of the normal to the three-jet plane as well as the polar angle distribution of the most energetic jet have been measured as a function of the thrust cut-off used to select the three-jet sample. The data corrected for radiation and detector effects are compared to QCD predictions and fair agreement is found. As a consistency check we also present measurements of the azimuthal correlations between the lepton and hadron planes. A significant azimuthal dependence is found, consistent again with the QCD predictions

PARTICLE CORRELATION OBSERVED IN E+E- ANNIHILATIONS INTO HADRONS AT CM ENERGIES BETWEEN 29 AND 37 GEV

We have studied the correlations between charged particles produced in e+e- annihilations into hadrons at c.m. energies between 29 and 37 GeV. We have analysed the correlations between the charged multiplicities of the jets and the two particle rapidity and charge correlations. No evidence for correlations between the multiplicities of the two jets is found. Two particle short range rapidity and charge correlations are observed, indicating that particles cluster in rapidity and that their charges compensate locally. An extensive study of these correlation effects by QCD Monte Carlo calculations was performed. Evidence for charge correlations due to Bose-Einstein statistics is also observed. © 1985 Springer-Verlag

PARTICLE CORRELATION OBSERVED IN e+ e- ANNIHILATIONS INTO HADRONS AT C.M. ENERGIES BETWEEN 29-GeV AND 37-GeV

We have studied the correlations between charged particles produced in e+e- annihilations into hadrons at c.m. energies between 29 and 37 GeV. We have analysed the correlations between the charged multiplicities of the jets and the two particle rapidity and charge correlations. No evidence for correlations between the multiplicities of the two jets is found. Two particle short range rapidity and charge correlations are observed, indicating that particles cluster in rapidity and that their charges compensate locally. An extensive study of these correlation effects by QCD Monte Carlo calculations was performed. Evidence for charge correlations due to Bose-Einstein statistics is also observed. © 1985 Springer-Verlag

SEARCH FOR SPINLESS BOSONS IN E+E- ANNIHILATION

We have measured the cross sections for e+e- → e+e-, e+e- → μ+μ-, e+e- → γγ and e+e- → hadrons in an energy scan at center of mass energies between 39.79 and 46.72 GeV in 30 MeV steps. New spinless bosons, whose existence has been postulated as a possible means to explain the anomalously large radiative width of the Z0 found at the CERN SPS pp collider, are ruled out in the scan region. The data are used to set limits on the couplings to lepton, photon and quark pairs of bosons with masses above 46.72 GeV. © 1985

A STUDY OF THREE JET EVENTS IN e+ e- ANNIHILATION INTO HADRONS AT 34.6-GEV center-of-mass ENERGY

Three-jet events produced by e+e- annihilation into hadrons at 34.6 GeV c.m. energy were studied by comparing them with 2nd order QCD and two different models of fragmentation. The distribution of low energy particles in the 3-jet plane is found to be better described by the LUND color string model than by the independent jet model. The opposite is true for more energetic particles flowing between the 3 jets. The average transverse momenta in jets can be described with values of σq between 350 and 500 MeV/c for the gluon jet. © 1985 Springer-Verlag

Jaburetox, peptídeo derivado de ureases : efeitos sobre as vias enzimáticas da barata Nauphoeta cinerea

Jaburetox é um peptídeo recombinante (~11 kDa) derivado de uma das isoformas de ureases da planta Canavalia ensiformis, popularmente conhecida como feijão-de-porco. O peptídeo induz efeitos variados em diferentes ordens de insetos, incluindo interferência na contração muscular em baratas da espécie Nauphoeta cinerea, ativação do sistema imunitário do vetor da doença de Chagas, Rhodnius prolixus e também, modula a atividade da enzima UDP-N-acetilglicosamina pirofosforilase (UAP) e da óxido nítrico sintase (NOS) no sistema nervoso central de R. prolixus e Triatoma infestans. Além disso, quando injetado, o Jaburetox é letal para ninfas de R. prolixus e insetos adultos de T. infestans. No presente trabalho foi avaliado o efeito inseticida do Jaburetox em baratas adultas da espécie N. cinerea, assim como, exploramos os efeitos induzidos pelo peptídeo no sistema nervoso central, focando na atividade enzimática das enzimas UAP, NOS, fosfatases ácidas (ACP) e acetilcolinesterase (AChE). Os ensaios enzimáticos foram realizados após tratamentos in vivo e in vitro com o Jaburetox, utilizando homogenatos de sistema nervoso central. Técnicas espectrofotométricas foram utilizadas para mensurar a atividade enzimática e a expressão proteica foi avaliada através de Western blot. Para o ensaio inseticida, Jaburetox foi administrado via oral e via injeção no inseto, utilizando uma dose de 50 μg de Jaburetox por g de inseto, ou o mesmo volume de tampão como controle. Em N. cinerea, ambos os tratamentos, in vivo e in vitro, inibiram parcialmente a atividade da NOS, sem modificar os níveis proteicos da mesma. Nenhuma alteração foi observada nos níveis da ACP após tratamentos com Jaburetox. A enzima UAP apresentou diminuição da atividade após 18 h de tratamento in vivo com o Jaburetox. Além disso, em todos os tratamentos in vivo com o peptídeo foi observado um aumento da atividade da AChE, sugerindo um possível mecanismo de resposta aos inseticidas. Contudo, mesmo após injeção e ingestão de Jaburetox as baratas adultas não tiveram taxas de mortalidade significativas, indicando resistência ao efeito inseticida do peptídeo. Em suma nossos resultados sugerem que o Jaburetox afeta as vias nitrinérgica, assim com a atividade da UAP e da AChE na barata. O fato do peptídeo afetar diferentemente as atividades enzimáticas dos R. prolixus e da N. cinerea podem explicar o porquê as baratas não são susceptíveis ao Jaburetox.Jaburetox is a recombinant peptide (~11 kDa) derived from one of the Canavalia ensiformis (Jack bean) urease isoforms. The peptide induces several effects on insects of different orders, including the interference on muscle twitch tension in the cockroach Nauphoeta cinerea, the activation of the immune system in the Chagas’ disease vector Rhodnius prolixus, and the modulation of the enzyme activities of the UDP-N-acetylglucosamine pyrophosphorylase (UAP) and nitric oxide synthase (NOS) in the central nervous system of R. prolixus and the related triatomine Triatoma infestans. Moreover, when injected, the peptide is lethal for R. prolixus nymphs and T. infestans adults. Here, we evaluated the insecticidal effect of Jaburetox on N. cinerea adult cockroaches and explored the effects induced by Jaburetox on the central nervous system, focusing on the enzymatic activities of UAP, NOS, acid phosphatases (ACP), and acetylcholinesterase (AChE). The enzymatic experiments were performed after in vitro and in vivo treatments with Jaburetox using central nervous system homogenates from adult cockroaches. Spectrophotometric assays were employed to measure the enzyme activities and the protein expression of UAP and NOS was evaluated by Western blot. The insecticidal assay was conducted by injection and ingestion of 50 μg of Jaburetox per g of insect or the same volume of buffer for the controls. In N. cinerea, both in vivo and in vitro treatments with the peptide partially inhibited the activity of NOS, without modifying the protein levels. No alterations on ACP activity were observed upon Jaburetox treatment. In addition, the enzyme activity of UAP only had its activity affected at 18 h after injection. The peptide increased the AChE activity, suggesting a possible mechanism involved in overcoming the toxic effects of the insecticide. Moreover, the cockroaches did not die after Jaburetox injection and ingestion, indicating resistance to the toxic action of the peptide. Taken together, our findings indicate that Jaburetox alters the nitrinergic signaling as well as the AChE and UAP activities. The fact that Jaburetox affects differently the enzyme activities in R. prolixus and N. cinerea may explain why the cockroach is not susceptible to the lethal effect of the peptide

SEARCH FOR TWO PHOTON PRODUCTION OF RESONANCES DECAYING INTO K anti-K AND K anti-K pi

An analysis of the production of KS0KS0 and K±Ks0π∓ by two quasi-real photons is presented. The cross section for γγ→K0 {Mathematical expression}, which is given for the γγ invariant mass range from K {Mathematical expression} threshold to 2.5 GeV, is dominated by the f′(1525) resonance and an enhancement near the K {Mathematical expression} threshold. Upper limits on the product of the two-photon width times the branching ratio into K {Mathematical expression} pairs are given for Θ(1700), h(2030), and ξ(2220). For exclusive two-photon production of K±Ks0π∓ no significant signal was observed. Upper limits are given on the cross section of γγ→K+ {Mathematical expression}π- or K-K0π+ between 1.4 and 3.2 GeV and on the product of the γγ width times the branching ratio into the K {Mathematical expression}π final states for the ηc(2980) and the ι(1440), yielding Γ(γγ)→i(1440))·BR(i(1440)→K {Mathematical expression}π<2.2 keV at 95% C.L. © 1985 Springer-Verlag

MEASUREMENT OF THE RADIATIVE WIDTH OF THE A(2) (1320) IN TWO PHOTON INTERACTIONS

The reaction e+e-→e+e- A2 (1320) has been observed by detecting the decay A2→π+,π-π0. The two-photon width of the A2 has been measured to be G{cyrillic}(A2→γγ)=(0.09±0.27 (stat)±0.16 (syst)) keV. The cross section σ(γγ→π+,π-π0 has been determined outside the A2 resonance region. © 1986 Springer-Verlag