Parameter Neraca Hayati Dan Pertumbuhan Populasi Kutu Putih Phenacoccus Manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) Pada Dua Varietas Ubi Kayu

The life history and population growth parameters of mealybug Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on two cassava varieties. The development, reproduction, and population growth parameters of the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on two cassava varieties were studied in laboratory. The varieties tested were UJ-5 with high cyanide content (>100 mg per kg) dan Adira-1 with low cyanide content (27.5 mg per kg). Our research revealed that P. manihoti performances were highly affected by cassava varieties. Incubation period of eggs of P. manihoti were 7.93 ± 0.09 and 8.33 ± 0.11 days, nymphal development periode 12.32±0.13 and 15.67 ± 0.13 days, respectively on UJ-5 and Adira-1. Fecundity averaged 386.37 ± 5.83 on UJ-5 and 318.67±2.81 eggs on Adira-1. Intrinsic rate of increase (rm) were 0.258 ± 0.001 on UJ-5 and 0.220 ± 0.001 on Adira-1. Mean generation time (T) on UJ-5 and Adira-1 were 22.795 ± 0.050 and 25.532 ± 0.047 days, repectively. Our findings showed that variety UJ-5 was more suitable for development and population growth of the cassava mealybug

Quasi-free Compton Scattering from the Deuteron and Nucleon Polarizabilities

Cross sections for quasi-free Compton scattering from the deuteron were measured for incident energies of 236--260 MeV at the laboratory angle -135 degrees. The recoil nucleons were detected in a liquid-scintillator array situated at 20 degrees. The measured differential cross sections were used, with the calculations of Levchuk et al., to determine the polarizabilities of the bound nucleons. For the bound proton, the extracted values were consistent with the accepted value for the free proton. Combining our results for the bound neutron with those from Rose et al., we obtain one-sigma constraints of alpha_n = 7.6-14.0 and beta_n = 1.2-7.6.Comment: 4 pages, 3 figures, accepted in PR

Measurement of Nuclear Transparency for the A(e,e' pi^+) Reaction

We have measured the nuclear transparency of the A(e,e' pi^+) process in ^{2}H,^{12}C, ^{27}Al, ^{63}Cu and ^{197}Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum transfer squared range Q^2 = 1.1 - 4.7 (GeV/c)^2. The nuclear transparency was extracted as the super-ratio of $(\sigma_A/\sigma_H)$ from data to a model of pion-electroproduction from nuclei without pi-N final state interactions. The Q^2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations, and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.Comment: 5 pages, 3 figs Changes to figure 2 and 3 (error band updated and theory curves updated

Scaling study of the pion electroproduction cross sections and the pion form factor

The $^{1}$H($e,e^\prime \pi^+$)n cross section was measured for a range of four-momentum transfer up to $Q^2$=3.91 GeV$^2$ at values of the invariant mass, $W$, above the resonance region. The $Q^2$-dependence of the longitudinal component is consistent with the $Q^2$-scaling prediction for hard exclusive processes. This suggests that perturbative QCD concepts are applicable at rather low values of $Q^2$. Pion form factor results, while consistent with the $Q^2$-scaling prediction, are inconsistent in magnitude with perturbative QCD calculations. The extraction of Generalized Parton Distributions from hard exclusive processes assumes the dominance of the longitudinal term. However, transverse contributions to the cross section are still significant at $Q^2$=3.91 GeV$^2$.Comment: 6 pages, 3 figure

Study of the A(e,e'π+\pi^+) Reaction on 1^1H, 2^2H, 12^{12}C, 27^{27}Al, 63^{63}Cu and 197^{197}Au

Cross sections for the p($e,e'\pi^{+}$)n process on $^1$H, $^2$H, $^{12}$C, $^{27}$Al, $^{63}$Cu and $^{197}$Au targets were measured at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) in order to extract the nuclear transparencies. Data were taken for four-momentum transfers ranging from $Q^2$=1.1 to 4.8 GeV$^2$ for a fixed center of mass energy of $W$=2.14 GeV. The ratio of $\sigma_L$ and $\sigma_T$ was extracted from the measured cross sections for $^1$H, $^2$H, $^{12}$C and $^{63}$Cu targets at $Q^2$ = 2.15 and 4.0 GeV$^2$ allowing for additional studies of the reaction mechanism. The experimental setup and the analysis of the data are described in detail including systematic studies needed to obtain the results. The results for the nuclear transparency and the differential cross sections as a function of the pion momentum at the different values of $Q^2$ are presented. Global features of the data are discussed and the data are compared with the results of model calculations for the p($e,e'\pi^{+}$)n reaction from nuclear targets.Comment: 28 pages, 19 figures, submited to PR

Nuclear transparency and effective kaon-nucleon cross section from the A(e, e'K+) reaction

We have determined the transparency of the nuclear medium to kaons from $A(e,e^{'} K^{+})$ measurements on $^{12}$C, $^{63}$Cu, and $^{197}$Au targets. The measurements were performed at the Jefferson Laboratory and span a range in four-momentum-transfer squared Q$^2$=1.1 -- 3.0 GeV$^2$. The nuclear transparency was defined as the ratio of measured kaon electroproduction cross sections with respect to deuterium, ($\sigma^{A}/\sigma^{D}$). We further extracted the atomic number ($A$) dependence of the transparency as parametrized by $T= (A/2)^{\alpha-1}$ and, within a simple model assumption, the in-medium effective kaon-nucleon cross sections. The effective cross sections extracted from the electroproduction data are found to be smaller than the free cross sections determined from kaon-nucleon scattering experiments, and the parameter $\alpha$ was found to be significantly larger than those obtained from kaon-nucleus scattering. We have included similar comparisons between pion- and proton-nucleon effective cross sections as determined from electron scattering experiments, and pion-nucleus and proton-nucleus scattering data.Comment: 7 pages, 5 figure

Soil application of Bacillus thuringiensis Berliner isolates against root-knot nematode (Meloidogyne javanica (Treub) Chitwood) in okra (Abelmoschus esculentus (L.) Moench)

Bacillus thuringiensis (B.t) is well known for its biocontrol potential against a variety of insects. Nematicidal potential of ten B.t isolates was tested against root-knot nematodes (Meloidogyne javanica (Treub) Chitwood) in vitro, under greenhouse as well as in field conditions. Eggs and second stage juveniles (J2) were exposed to 5 and 25% concentrations of bacterial cell-free aqueous extracts up to 96 h. B.t isolates showed lesser degrees of nematicidal activity at 5% concentration. However, some B.t isolates (B.t-14, B.t-16 and B.t-64) greatly reduced egg hatching and increased J2. All B.t isolates revealed suppressed egg hatching and increased mortality of J2 at 25% concentration. Soil applications with most of the B.t isolates under greenhouse and field conditions significantly improved height and fresh weights of root-knot nematode parasitized okra (Abelmoschus esculentus (L.) Moench). Some isolates, including B.t-64 reduced the number of galls and egg masses. B.t-64 reduced gall formation up to 70% under greenhouse conditions. However, 29% of decrease was observed in field conditions. Similarly, B.t-64 treated plants showed a 56% decreased in eggs/egg mass in a field experiment. Population of root-knot nematodes in the rhizosphere was decreased up to 61% in the field experiment as compared to control

Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely-polarized 3 GeV electrons from unpolarized protons at Q^2 = 0.15, 0.25 (GeV/c)^2. The results are inconsistent with calculations solely using the elastic nucleon intermediate state, and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A_n provides a direct probe of the imaginary component of the 2-gamma exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.Comment: 5 pages, 3 figures, submitted to Physical Review Letters; shortened to meet PRL length limit, clarified some text after referee's comment

Strange Quark Contributions to Parity-Violating Asymmetries in the Forward G0 Electron-Proton Scattering Experiment

We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < Q^2 < 1.0 GeV^2. These asymmetries, arising from interference of the electromagnetic and neutral weak interactions, are sensitive to strange quark contributions to the currents of the proton. The measurements were made at JLab using a toroidal spectrometer to detect the recoiling protons from a liquid hydrogen target. The results indicate non-zero, Q^2 dependent, strange quark contributions and provide new information beyond that obtained in previous experiments.Comment: 5 pages, 2 figure

Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 $< p_{\rm{T}, assoc} < p_{\rm{T}, trig} <$ 5.0 GeV/$c$ is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range $|\eta|<0.9$. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161