Pengaruh Biosin Dan Ekstrak Cente Terhadap Perkembangan Aphis Glycines (Homoptera : Aphididae)

A study was conducted at Engineering of protein and Immunology. Division, Research Institute for Agricultural Biotechnology and Genetic Resources Bogor during 2000, to determine the effect of Biosin and Lantana camara seed extracts on development of Aphis glycines A. completely randomized design was used with four replications. Treatment consisted of three concentrations of Biosin and two concentrations of L camara seed extracts and untreated (control). Thirty days old soybean plant in plastic pots were applied according to its treatments. Biosin and L camara seed extracts were used as foliar spray. Volume of spray solution was 7.5 ml/pot. Half an hour after application, soybean plants were infested by 20 third instar A. glycines each pot. The result showed that Biosin and L. camara seed extracts decreased the development of A. glycines populations, especially Biosin and L camara seed extracts 0.4%

Host Preference Fruit Flies Bactrocera Carambolae (Drew & Hancock) and Bactrocera Dorsalis (Drew and Hancock) (Diptera: Tephritidae)

Host plant preference amongst several fruit species was studied for two fruit fly species i.e. Bactrocera carambolae (Drew & Hancock) and Bactrocera dorsalis (Drew & Hancock), which both belong to B. dorsalis species complex. Both fruit fly species are known to be polyphagous and cause significant economic losses as pests of fruit crops. The aim of this research was to assess the host range of these major pests in Indonesia. The research was conducted at the Entomology Laboratory and Insect Specimen Collection Laboratory, Indonesian Center for Agriculture Biotechnology and Genetic Resource Research and Development, Bogor, West Java, Indonesia from June 2011 to March 2012. Comparative host preference for both species was studied with regard to malaya varieties of star fruit (Averrhoa carambolae), manalagi varieties of mango (Mangifera indica), guava aka water apple (Psidium guajava), citra water guava (Eugenia aquae), Jamaica bol guava (Eugenia malaccenensis), and california papaya (Carica papaya). Our results suggest the strongest preference for malaya star fruit by B. carambolae followed by manalagi mango; and for california papaya followed by manalagi mango by B. dorsalis. The study also found that welahan variety star fruit is least preferred by both species of fruit fly

Axiomatic geometrical optics, Abraham-Minkowski controversy, and photon properties derived classically

By restating geometrical optics within the field-theoretical approach, the classical concept of a photon (and, more generally, any elementary excitation) in arbitrary dispersive medium is introduced, and photon properties are calculated unambiguously. In particular, the canonical and kinetic momenta carried by a photon, as well as the two corresponding energy-momentum tensors of a wave, are derived from first principles of Lagrangian mechanics. As an example application of this formalism, the Abraham-Minkowski controversy pertaining to the definitions of these quantities is resolved for linear waves of arbitrary nature, and corrections to the traditional formulas for the photon kinetic energy-momentum are found. Several other applications of axiomatic geometrical optics to electromagnetic waves are also presented

Fractional and unquantized dc voltage generation in THz-driven semiconductor superlattices

We consider the spontaneous creation of a dc voltage across a strongly coupled semiconductor superlattice subjected to THz radiation. We show that the dc voltage may be approximately proportional either to an integer or to a half- integer multiple of the frequency of the applied ac field, depending on the ratio of the characteristic scattering rates of conducting electrons. For the case of an ac field frequency less than the characteristic scattering rates, we demonstrate the generation of an unquantized dc voltage.Comment: 6 pages, 3 figures, RevTEX, EPSF. Revised version v3: corrected typo

Langmuir wave linear evolution in inhomogeneous nonstationary anisotropic plasma

Equations describing the linear evolution of a non-dissipative Langmuir wave in inhomogeneous nonstationary anisotropic plasma without magnetic field are derived in the geometrical optics approximation. A continuity equation is obtained for the wave action density, and the conditions for the action conservation are formulated. In homogeneous plasma, the wave field E universally scales with the electron density N as E ~ N^{3/4}, whereas the wavevector evolution varies depending on the wave geometry

A flare in the optical spotted in the changing-look Seyfert NGC 3516

We present observations from the short-term intensive optical campaign (from Sep2019 to Jan2020) of the changing-look Seyfert NGC 3516. This active galactic nucleus is known to have strong optical variability and has changed its type in the past. It has been in the low-activity state in the optical since 2013, with some rebrightening from the end of 2015 to the beginning of 2016, after which it remained dormant. We aim to study the photometric and spectral variability of NGC 3516 from the new observations in U- and B-bands and examine the profiles of the optical broad emission lines in order to demonstrate that this object may be entering a new state of activity. NGC 3516 has been monitored intensively for the past 4 months with an automated telescope in U and B filters, enabling accurate photometry of 0.01 precision. Spectral observations were triggered when an increase in brightness was spotted. We support our analysis of past-episodes of violent variability with the UV and X-ray long-term light curves constructed from the archival Swift data. An increase of the photometric magnitude is seen in both U and B filters to a maximum amplitude of 0.25mag and 0.1 mag, respectively. During the flare, we observe stronger forbidden high-ionization iron lines than reported before, as well as the complex broad Ha and Hb lines. This is especially seen in Ha which appears to be double-peaked. It seems that a very broad component of ~10,000 km/s in width in the Balmer lines is appearing. The trends in the optical, UV, and X-ray light curves are similar, with the amplitudes of variability being significantly larger in the case of UV and X-ray bands. The increase of the continuum emission, the variability of the coronal lines, and the very broad component in the Balmer lines may indicate that the AGN of NGC 3516 is finally leaving the low-activity state in which it has been for the last ~3 years.Comment: 7 pages, 6 figures, accepted in A&A (corrected after receiving comments from the language editor