645 research outputs found
Host and Habitat Use by Parasitoids (Hymenoptera: Pteromalidae) of House Fly and Stable Fly (Diptera: Muscidae) Pupae
House fly and stable fly pupae were collected during the summer from a dairy farm in northern Illinois. Spalangia nigroaenea accounted for most of the parasitoids recovered from house flies. Spalangia nigra, S. endius, Muscidifurax spp., and S. nigroaenea accounted for most of the parasitoids from stable flies. The majority of flies were house flies late in the summer and stable flies early in the summer. Higher percentages of house flies tended to be in samples containing lower substrate moisture and higher substrate temperature. Parasitism of stable flies started earlier and peaked weeks before that of house flies, with overall parasitism highest from mid-to late-summer. Parasitism of house flies, but not stable flies, differed significantly among habitats, being greater in calf hutches than in edge samples. Hymenopterous parasitoids from house flies tended to include a greater percentage of S. nigroaenea (and a lower percentage of Muscidifurax spp.) in calf hutches versus drainage or edge habitats and in sub- strates consisting of mostly wood shavings versus mostly manure. Within samples, differential parasitism of fly species was not detected for S. nigroaenea, S. endius, or Muscidifurax spp.; but S. nigra preferentially parasitized stable flies
Three-flavor chiral effective model with four baryonic multiplets within the mirror assignment
We study three-flavor octet baryons by using the so-called extended Linear
Sigma Model (eLSM). Within a quark-diquark picture, the requirement of a mirror
assignment naturally leads to the consideration of four spin-
baryon multiplets. A reduction of the Lagrangian to the two-flavor case leaves
four doublets of nucleonic states which mix to form the experimentally observed
states , , and . We determine the
parameters of the nucleonic part of the Lagrangian from a fit to masses and
decay properties of the aforementioned states. By tracing their masses when
chiral symmetry is restored, we conclude that the pairs , and
, form chiral partners.Comment: Based on the presentation given at FAIRNESS 2016, Workshop for young
scientists with research interests focused on physics at FAIR, 14-19 February
2016 Garmisch-Partenkirchen, Germany. 5 page
Host and Habitat Use by Parasitoids (Hymenoptera: Pteromalidae) of House Fly and Stable Fly (Diptera: Muscidae) Pupae
House fly and stable fly pupae were collected during the summer from a dairy farm in northern Illinois. Spalangia nigroaenea accounted for most of the parasitoids recovered from house flies. Spalangia nigra, S. endius, Muscidifurax spp., and S. nigroaenea accounted for most of the parasitoids from stable flies. The majority of flies were house flies late in the summer and stable flies early in the summer. Higher percentages of house flies tended to be in samples containing lower substrate moisture and higher substrate temperature. Parasitism of stable flies started earlier and peaked weeks before that of house flies, with overall parasitism highest from mid-to late-summer. Parasitism of house flies, but not stable flies, differed significantly among habitats, being greater in calf hutches than in edge samples. Hymenopterous parasitoids from house flies tended to include a greater percentage of S. nigroaenea (and a lower percentage of Muscidifurax spp.) in calf hutches versus drainage or edge habitats and in sub- strates consisting of mostly wood shavings versus mostly manure. Within samples, differential parasitism of fly species was not detected for S. nigroaenea, S. endius, or Muscidifurax spp.; but S. nigra preferentially parasitized stable flies
A varactor tuned low-cost 24 GHz harmonic VCO
We present a low-cost 24 GHz VCO that is based on a microstrip design combined with discrete packaged devices. The output frequency is generated by a harmonic oscillator. The tunabilty was reached using a varactor diode. Two versions of the VCO were built, one has a wide tuning range of 1.1 GHz and the other one has a high output power of 3.7 dBm
The limits of filopodium stability
Filopodia are long, finger-like membrane tubes supported by cytoskeletal
filaments. Their shape is determined by the stiffness of the actin filament
bundles found inside them and by the interplay between the surface tension and
bending rigidity of the membrane. Although one might expect the Euler buckling
instability to limit the length of filopodia, we show through simple energetic
considerations that this is in general not the case. By further analyzing the
statics of filaments inside membrane tubes, and through computer simulations
that capture membrane and filament fluctuations, we show under which conditions
filopodia of arbitrary lengths are stable. We discuss several in vitro
experiments where this kind of stability has already been observed.
Furthermore, we predict that the filaments in long, stable filopodia adopt a
helical shape
Tuning of structure inversion asymmetry by the -doping position in (001)-grown GaAs quantum wells
Structure and bulk inversion asymmetry in doped (001)-grown GaAs quantum
wells is investigated by applying the magnetic field induced photogalvanic
effect. We demonstrate that the structure inversion asymmetry (SIA) can be
tailored by variation of the delta-doping layer position. Symmetrically-doped
structures exhibit a substantial SIA due to impurity segregation during the
growth process. Tuning the SIA by the delta-doping position we grow samples
with almost equal degrees of structure and bulk inversion asymmetry.Comment: 4 pages 2 figure
Photoexcitation of valley-orbit currents in (111)-oriented silicon metal-oxide-semiconductor field-effect transistors
We demonstrate the injection of pure valley-orbit currents in multivalley semiconductors and present the phenomenological theory of this effect. We studied photoinduced transport in (111)-oriented silicon metaloxide-semiconductor field effect transistors at room temperature. By shining circularly polarized light on exact oriented structures with six equivalent valleys, nonzero electron fluxes within each valley are generated, which
compensate each other and do not yield a net electric current. By disturbing the balance between the valley fluxes, we demonstrate that the pure valley-orbit currents can be converted into a measurable electric current
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