Acorns as Breeding Sites for \u3ci\u3eChymomyza Amoena\u3c/i\u3e (Loew) (Diptera: Drosophilidae) in Virginia and Michigan

Chymomyza amoena is the only chymomyzid fly emerging from white oak acorns in Virginia. An average of 2-3 adult flies emerged from a single acorn in July while emergence declined to 0.4 adults/acorns in September. In fall, Drosophila melanogaster was also present. The incidence of drosophilid (Drosophila, Chymomyza) larvae in parasitized acorns in Virginia (400/0) in autumn was significantly greater than in Michigan (14%). The Chymomyza larvae present in the parasitized acorns in Michigan most likely were C. amoena, from the known adaptation of this species in Michigan to frass-breeding

Drosophilidae (Diptera) Collected in Spring in Michigan

Drosophilids in mid-Michigan overwinter in a preadult stage. One hun- dred twenty-two individuals (84 f, 38 m) representing 14 species were collected over bait in April and May 1992. All appeared recently emerged and had entire wings. This agrees with earlier reports in Michigan and Massachusetts that Drosophila affinis group species overwinter as preadults. Among the species overwintering as preadults in Michigan, Drosophila affinis, D. algonquin, D. athabasca, D. robusta, D. falleni and D. recens have been found to overwinter as adults in New York Latitude and climate may play a role in drosophilid overwintering stage

Burst Populations and Detector Sensitivity

The F_T (peak bolometric photon flux) vs. E_p (peak energy) plane is a powerful tool to compare the burst populations detected by different detectors. Detector sensitivity curves in this plane demonstrate which burst populations the detectors will detect. For example, future CZT-based detectors will show the largest increase in sensitivity for soft bursts, and will be particularly well-suited to study X-ray rich bursts and X-ray Flashes. Identical bursts at different redshifts describe a track in the F_T-E_p plane.Comment: 4 pages, 4 figures. To appear in the proceedings of the 2003 GRB Conference (Santa Fe, NM, 2003 Sep 8-12

Intensity Distributions of Gamma-Ray Bursts

Observations of individual bursts chosen by the vagaries of telescope availability demonstrated that bursts are not standard candles and that their apparent energy can be as great as 10^54 erg. However, determining the distribution of their apparent energy (and of other burst properties) requires the statistical analysis of a well-defined burst sample; the sample definition includes the threshold for including a burst in the sample. Thus optical groups need to the criteria behind the decision to search for a spectroscopic redshift. Currently the burst samples are insufficient to choose between lognormal and power law functional forms of the distribution, and the parameter values for these functional forms differ between burst samples. Similarly, the actual intensity distribution may be broader than observed, with a low energy tail extending below the detection threshold.Comment: For the proceedings of GAMMA 2001 (Baltimore, April 4-6, 2001), 5 page

Big consequences of small changes (Non-locality and non-linearity of Hartree-Fock equations)

It is demonstrated that non-locality and non-linearity of Hartree-Fock equations dramatically affect the properties of their solutions that essentially differ from solutions of Schr?dinger equation with a local potential. Namely, it acquires extra zeroes, has different coordinate asymptotic, violates so-called gauge-invariance, has different scattering phases at zero energy, has in some cases several solutions with the same set of quantum numbers, usually equivalent expressions of current and Green's functions became non-equivalent. These features result in a number of consequences for probabilities of some physical processes, leading e. g. to extra width of atomic Giant resonances and enhance considerably the ionization probability of inner atomic electrons by a strong field.Comment: 16 pages, 3 figure

The High Time Resolution Spectral Evolution of Gamma-Ray Bursts

Previous studies of the evolution of gamma-ray burst spectra have generally relied on fitting sequences of spectra. These studies usually were confined to bright bursts and often lacked sufficient temporal resolution. We have developed techniques which sacrifice spectral resolution for temporal resolution. First, the crosscorrelations between intensity lightcurves in different energy bands allow for the classification of the spectral evolution of a large burst sample. Second, the energy correlation of pairs of counts places limits on short-duration, narrowband emission.Comment: 5 pages, 2 figures, AIPPROC LaTeX, to appear in "Gamma-Ray Bursts, 4th Huntsville Symposium," eds. C. Meegan, R. Preece and T. Koshu

Universality of the momentum band density of periodic networks

The momentum spectrum of a periodic network (quantum graph) has a band-gap structure. We investigate the relative density of the bands or, equivalently, the probability that a randomly chosen momentum belongs to the spectrum of the periodic network. We show that this probability exhibits universal properties. More precisely, the probability to be in the spectrum does not depend on the edge lengths (as long as they are generic) and is also invariant within some classes of graph topologies

Quantum Graphs via Exercises

Studying the spectral theory of Schroedinger operator on metric graphs (also known as quantum graphs) is advantageous on its own as well as to demonstrate key concepts of general spectral theory. There are some excellent references for this study such as a mathematically oriented book by Berkolaiko and Kuchment, a review with applications to theoretical physicsby Gnutzmann and Smilansky, and elementary lecture notes by Berkolaiko. Here, we provide a set of questions and exercises which can accompany the reading of these references or an elementary course on quantum graphs. The exercises are taken from courses on quantum graphs which were taught by the authors