Some Notes on Heteropteran Trichobothria

Excerpt: There has been much recent interest in the comparative morphology of the Heteroptera. This work has emphasized the land bugs, or Geocorisae, and has been concerned with working out the relationships and taxonomic placement of the higher categories (categories above the genus), and with the phylogenetic lines and sequences of these higher categories. The geocorisine groups with which I have been most concerned are in the closely related superfamilies Lygaeoidea, Pyrrho- coroidea, and Coreoidea (see Schaefer, 1964, for a discussion of the relationships among these groups). Another superfamily, the Pentatomoidea, is less closely related. All four of these superfamilies have arolia and pseudarolia, and all four have trichobothria. Because they possess this last character in common, the four are grouped together under the name Heteroptera Trichophora (Tullgren, 1918), aname of no nomenclatorial standing but nevertheless convenient. Trichobothria are long hairs arising from often darkened sockets on the relatively bald abdominal venter. They are usually easy to distinguish from other hairs, because they are longer, have a darkened base, and are arranged symmetrically in a distinctive pattern on each segment. These patterns and the number of trichobothria in them are characteristic of the higher categories of the Trichophora. Since the trichophoran families are closely related, and since this close relation- ship has been established on evidence from other morphological features than trichobothria, one might look for phylogenetic significance in the variety of patterns. However, very little is known about the function and phylogenetic origin of trichobothria. I shall speculate here on their function and their phylogenetic significance, but more must be learned about trichobothria before speculation becomes knowledge

Chemical evolution of the early Martian hydrosphere

The chemical evolution of the early Martian hydrosphere is discussed. The early Martian ocean can be modeled as a body of relatively pure water in equilibrium with a dense carbon dioxide atmosphere. The chemical weathering of lavas, pyroclastic deposits, and impact melt sheets would have the effect of neutralizing the acidity of the juvenile water. As calcium and other cations are added to the water by chemical weathering, they are quickly removed by the precipitation of calcium carbonate and other minerals, forming a deposit of limestone beneath the surface of the ocean. As the atmospheric carbon dioxide pressure and the temperature decrease, the Martian ocean would be completely frozen. Given the scenario for the chemical evolution of the northern lowland plains of Mars, it should be possible to draw a few conclusions about the expected mineralogy and geomorphology of this regions

Quark condensate in two-flavor QCD

We compute the condensate in QCD with two flavors of dynamical fermions using numerical simulation. The simulations use overlap fermions, and the condensate is extracted by fitting the distribution of low lying eigenvalues of the Dirac operator in sectors of fixed topological charge to the predictions of Random Matrix Theory.Comment: revtex, 18 pages, 4 postscript figures. V.2, the published version, corrects an error for the shape facto

Annotated Checklist of the Pentatomidae (Heteroptera) of Connecticut

We provide town data for the Pentatomidae in Connecticut. Although this state has been much collected, most sampling has been limited to only a few lo- cations. Species newly recorded for Connecticut are: Halyomorpha halys (Stål), Hymenarcys nervosa (Say), Banasa euchlora Stål, B. sordida (Uhler), and Perillus bioculatus (Fabricius). Podisus neglectus (Westwood) may occur in the state. Other species found in neighboring states may eventually be found in Connecticut: Picromerus bidens (Linnaeus), Rhacognathus americanus Stål, Mcphersonarcys aequalis (Say), Thyanta custator custator (Fabricius), T. custator acerra McAtee, and Amaurochrous brevitylus (Barber and Sailer). We briefly analyze these data, recognizing some faunal elements. More collecting needs to be conducted in the state, so that distribution patterns outlined here can be more broadly understood, and so that species of potential conservation concern can be identified

Aero-acoustic performance comparison of core engine noise suppressors on NASA quiet engine C

The relative aero-acoustic effectiveness of two core engine suppressors, a contractor-designed suppressor delivered with the Quiet Engine, and a NASA-designed suppressor was evaluated. The NASA suppressor was tested with and without a splitter making a total of three configurations being reported in addition to the baseline hardwall case. The aerodynamic results are presented in terms of tailpipe pressure loss, corrected net thrust, and corrected specific fuel consumption as functions of engine power setting. The acoustic results are divided into duct and far-field acoustic data. The NASA-designed core suppressor did the better job of suppressing aft end noise, but the splitter associated with it caused a significant engine performance penality. The NASA core suppressor without the spltter suppressed most of the core noise without any engine performance penalty

Integral lift engine preliminary design

A preliminary mechanical design of a complete lift fan engine system is reported. A description of the lift fan engine, layout drawings of the components and complete engine, and a discussion of the design analyses and results are presented. The design features and areas of analysis include fan and compressor rotor blades of composite construction, a combustor folded over the compressor, relatively high-temperature blades in the high-pressure turbine, the first stage of the low-pressure turbine used for bearing support and ducting of lubricant to the bearings, a complete lubrication system, critical speeds of the shafting, and vibration and flutter of the blading

Evidence for the coexistence of low-dimensional magnetism and long-range order in Ca3CoRhO6

We report the results of neutron powder diffraction studies on the spin-chain compound Ca3CoRhO6 in the temperature range 3 to 293 K. Bragg peaks due to magnetic ordering start appearing below about 100 K. The most interesting observation is that there is a diffuse magnetic peak superimposed over the strongest magnetic Bragg peak. The diffuse magnetic intensity is observed below as well above 100 K. This finding provides a new insight into the physics of this compound as though the low-dimensional magnetic interaction coexists with long range magnetic order - a novel situation among quasi one-dimensional oxides.Comment: accepted by Eur. Phys. Let