Efeito de espécies vegetais em bordadura em cebola sobre a densidade populacional de tripes e sirfídeos predadores.

Analisou-se a relação entre o efeito do plantio de diferentes espécies vegetais, em bordadura, na cultura da cebola, Allium cepa L, na incidência de Thrips tabaci Lind. e sirfídeos predadores, Toxomerus spp. O experimento foi conduzido na Epagri, EE de Ituporanga, de agosto a dezembro de 1998. Os tratamentos foram cebola em monocultivo; cebola + trigo mourisco (Fagopyrum esculentum Moench); cebola + nabo forrageiro (Raphanus sativus L. var. oleiferus Metzg.); cebola + cenoura (Daucus carota L., cv. Nantes e cv. Brasília); cebola + milho (Zea mays L.); cebola + rúcula (Eruca sativa L.) + vegetação espontânea. O plantio de diferentes espécies vegetais em bordadura não provocou diferenças significativas na incidência de tripes e sirfídeos predadores. A produtividade comercial de bulbos de cebola foi similar em sistema de monocultivo e diversificado, sugerindo ser possível adotar tais sistemas sem perdas em rendimento

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

We present the first results of the Fermilab Muon g-2 Experiment for the positive muon magnetic anomaly $a_\mu \equiv (g_\mu-2)/2$. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency $\omega_a$ between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ${\tilde{\omega}'^{}_p}$ in a spherical water sample at 34.7$^{\circ}$C. The ratio $\omega_a / {\tilde{\omega}'^{}_p}$, together with known fundamental constants, determines $a_\mu({\rm FNAL}) = 116\,592\,040(54)\times 10^{-11}$ (0.46\,ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both $\mu^+$ and $\mu^-$, the new experimental average of $a_\mu({\rm Exp}) = 116\,592\,061(41)\times 10^{-11}$ (0.35\,ppm) increases the tension between experiment and theory to 4.2 standard deviationsComment: 10 pages; 4 figure

Higgs Boson Studies at the Tevatron

We combine searches by the CDF and D0 Collaborations for the standard model Higgs boson with mass in the range 90--200 GeV$/c^2$ produced in the gluon-gluon fusion, $WH$, $ZH$, $t{\bar{t}}H$, and vector boson fusion processes, and decaying in the $H\rightarrow b{\bar{b}}$, $H\rightarrow W^+W^-$, $H\rightarrow ZZ$, $H\rightarrow\tau^+\tau^-$, and $H\rightarrow \gamma\gamma$ modes. The data correspond to integrated luminosities of up to 10 fb$^{-1}$ and were collected at the Fermilab Tevatron in $p{\bar{p}}$ collisions at $\sqrt{s}=1.96$ TeV. The searches are also interpreted in the context of fermiophobic and fourth generation models. We observe a significant excess of events in the mass range between 115 and 140 GeV/$c^2$. The local significance corresponds to 3.0 standard deviations at $m_H=125$ GeV/$c^2$, consistent with the mass of the Higgs boson observed at the LHC, and we expect a local significance of 1.9 standard deviations. We separately combine searches for $H \to b\bar{b}$, $H \to W^+W^-$, $H\rightarrow\tau^+\tau^-$, and $H\rightarrow\gamma\gamma$. The observed signal strengths in all channels are consistent with the presence of a standard model Higgs boson with a mass of 125 GeV/$c^2$