Life history of Monocystis parasites and genetic diversity of their hosts, the invasive Amynthas earthworms

Monocystis is a parasites in the phylum Apicomplexa that infects nearly 100% of earthworms; however, the parasites have low survivorship, low production of transmissible gametocysts, and seemingly lack schizogony. The purpose of this study was to investigate the improbable lifecycle and life history traits of a Monocystis species of the invasive Asian earthworms, Amynthas agrestis and A. tokioensis in Vermont. Preliminary data suggested that Monocystis sp. vary in life history traits between three sites sampled; therefore, it was necessary to investigate the genetic diversity and the mating system of its host, as the mating system is responsible for genetic variation. Random Amplified Polymorphic DNA (RAPD) markers revealed genetic variation within and among sites of both Amynthas spp. which appear to employ a mixed-mating system of both sexual and asexual reproduction demonstrated by the presence of both clonal and unique genotypes. The life history and life cycle of Monocystis sp. in A. agrestis was described by using microscopy to measure phenology and parasite stages and numbers. Amynthas spp. at Audubon had a shorter season and the parasites produced gametocysts earlier than at the other two sites. The parasite success rate at Audubon, Hort Farm, and Centennial Woods were 113.8%, 73.6%, and 0%, repectively. Audubon worms had higher numbers of gametocyts but a lower mean number of sporocysts per gametocyst (127.0) than did hosts at Hort Farm (145.8). Monocystis sp. has different life history traits and schedules to compensate for the length of the season and the genetic variation of its host

Aluminum foil interconnects for solar cell panels

Commercially available sonic welding system and a specially-designed tip bonds aluminum foil interconnects to titanium-silver solar cell contacts

Interference Aspects of Adaptive Modems over Slow Rayleigh Fading Channels

Adaptive modulation can achieve channel capacity gains by adapting the number of bits per transmission symbol on a burst-by-burst basis, in harmony with channel quality fluctuations. This is demonstrated in the paper for target bit error rates of 1 and 0.01%, respectively, in comparison to conventional fixed modems. However, the achievable gains depend strongly on the prevalent interference levels and hence interference cancellation is invoked on the basis of adjusting the demodulation decision boundaries after estimating the interfering channel’s magnitude and phase. Using the modem-mode switching levels of Table X and with the aid of interference cancellation, target BERs of 1 and 0.01% can be maintained over slow-fading channels for a wide range of channel Signal-to-noise ratios (SNR) and Signal-to-interference ratios (SIR), as seen in Figs. 20 and 21, respectively. Index Terms—Burst-by-burst adaptive modulation (modems), cochannel interference, interference cancellation

High-voltage pulse generator developed for wide-gap spark chambers

Low-inductance, high-capacitance Marx pulse generator provides for minimization of internal inductance and suppression of external electromagnetic radiation. The spark gaps of the generator are enclosed in a pressurized nitrogen atmosphere which allows the charging voltage to be varied by changing the nitrogen pressure

Determination of physical and chemical states of lubricants in concentrated contacts, part 3

Solid and liquid thin films were analyzed by infrared emission Fourier microspectrophotometry. The apparatus used is a commercial absorption instrument modified to an emission instrument, comprising a rotating polarizing device, a miniature blackbody temperature reference adjustable in temperature and radiant flux and a microscope lens with a high numerical aperture in the entrance system for increased sensitivity and resolution. Studies of lubricant behavior in a simulated ball bearing showed the alignment of the fluid molecules in the Hertzian area. Polyphenyl ether plus 1% 1,1,2-trichloroethane (TCE) required lower shear rates for the same degree of alignment than without TCE. The experiment was run with 440 C stainless steel balls coated with TiN, a chemically inert material. In both cases, the alignment was strongly influenced by the presence of TCE. The results showed (1) the dependence of alignment of fluid molecules on flow and not on adsorption at metallic surfaces, (2) phase separation between lubricant and additive under high pressure which results in two phase flow and (3) reduction in traction of torque transmitting (traction) fluids

Loadcell supports for a dynamic force plate

An apparatus was developed to accurately measure components of force along three mutually perpendicular axes, torque, and the center of pressure imposed by the foot of a subject walking over its surface. The data obtained were used to supplement high-speed motion picture and electromyographic (EMG) data for in-depth studies of normal or abnormal human gait. Significant features of the design (in particular, the mechanisms used to support the loadcell transducers) are described. Results of the development program and typical data obtained with the device are presented and discussed

Recurrence spectrum in smooth dynamical systems

We prove that for conformal expanding maps the return time does have constant multifractal spectrum. This is the counterpart of the result by Feng and Wu in the symbolic setting