Cryogenic seal remains leaktight during thermal displacement

Cryogenic seals protect the surfaces of a plastic member in a low-pressure system subjected to extreme temperature changes. The outer seal is an aluminum expansion ring bonded to the lens outer surface and the inner seal consists of a resin-filled aluminum U-ring bonded to the inner surface

A comparison of the effect of two diatomaceous earth formulations on Plodia interpunctella (Hübner) and the effect of different commodities on diatomaceous earth efficacy

The efficacy of two diatomaceous earth formulations was tested on five commodities; maize, wheat, birdseed, sunflower and barley, against Plodia interpunctella (Lepidoptera: Pyralidae). Exposure to DE began at either the egg stage or 3rd instar stage and the reduction in emergence to adult was noted. There was no significant difference between the freshwater and marine (Protect-It) DE. When eggs were placed on treated diet, the LD90 was 135, 143 and 805 ppm for maize, wheat and birdseed, respectively. When 3rd instars were placed on diet, LD90 was 382, 444, and 1156 ppm for maize, sunflower and birdseed respectively. Keywords: DE, Wheat, Maize, Birdseed, Sunflower, Indian meal mot

The effect of diapause, cold acclimation and ice-nucleating bacteria on the coldhardiness of Plodia interpunctella.

Laboratory tests showed that over 50 d at 0°C, over 10 d at -5°C or 1 d at -10°C were required to control non cold-acclimated 5th instar larvae of Plodia interpunctella (Lepidoptera: Prylidae) (Indian meal moth). To control the most cold-hardy stage, diapausing cold-acclimated 5th instar larvae over 14 d at -10°C or 1 d at - 15°C were required. A freeze-out of a single floor of a seed warehouse was carried out from 23 December 1993 until 2 January 1994 by shutting off the heat and opening the windows. The lowest temperatures achieved varied with the size and location of the seed bulk. Seed packets, that had a few grams of seed, reached -17°C, whereas, the middle of a bag stack with forty 50-kg bags of maize only reached -9°C. By the end of the 10-d freeze-out all non cold-acclimated P. interpunctella larvae were killed in the packets, 90% of the diapausing cold-acclimated larvae were killed in a single bag and 65% were killed middle of the stack. Mortality in the freeze-out was higher than we would have predicted from the laboratory data. The supercooling points (temperature at which freezing begins) of the P. interpunctella larvae range from -7°C for the non-diapausing non-acclimated to -13°C for the diapausing acclimated. Keywords: Indian meal moth, Warehouse, Larvae, Supercooling poin

Ecology of anthocorid (Hemipt.: Anthocoridae) predators of the pear psylla (Homopt.: Psyllidae) in the Okanagan Valley, British Columbia

The supposition is not valid that the disappearance of the native <i>Anthocoris melanocerus</i> from pear orchards late in the summer is because of competitive displacement by the introduced <i>A. nemoralis</i>. It is because <i>A. melanocerus</i> migrates to where prey are most abundant whereas <i>A. nemoralis</i> remains on pear. <i>A. melanocerus</i> is concentrated on willows in the spring, moves to pear when <i>Psylla pyricola</i> becomes abundant, and moves to cottonwood when aphids on it become abundant and the numbers of <i>P. pyricola</i> on pear have become low

Testing the Relation Between the Local and Cosmic Star Formation Histories

Recently, there has been great progress toward observationally determining the mean star formation history of the universe. When accurately known, the cosmic star formation rate could provide much information about Galactic evolution, if the Milky Way's star formation rate is representative of the average cosmic star formation history. A simple hypothesis is that our local star formation rate is proportional to the cosmic mean. In addition, to specify a star formation history, one must also adopt an initial mass function (IMF); typically it is assumed that the IMF is a smooth function which is constant in time. We show how to test directly the compatibility of all these assumptions, by making use of the local (solar neighborhood) star formation record encoded in the present-day stellar mass function. Present data suggests that at least one of the following is false: (1) the local IMF is constant in time; (2) the local IMF is a smooth (unimodal) function; and/or (3) star formation in the Galactic disk was representative of the cosmic mean. We briefly discuss how to determine which of these assumptions fail, and improvements in observations which will sharpen this test.Comment: 14 pages in LaTeX (uses aaspp4.sty). 5 postscript figures. To appear in the Astrophysical Journa

Heat treatment: A viable methyl bromide alternative for managing stored-product insects in food-processing facilities

Heat treatment involves raising and maintaining temperatures of grain storage structures, warehouses, and food-processing facilities between 50 to 60°C to manage stored-product insect species. The duration of heat treatment is application-specific and may vary from 6 h for an empty storage facility to 24 h for an entire food-processing facility. Laboratory and commercial trials with high temperatures during the last decade, especially with forced air gas heaters, have resulted in a wealth of information on (1) understanding responses of insect species and life stages to heat, (2) heat distribution within a treated area, and (3) techniques necessary for gauging effectiveness of commercial heat treatments. Insect responses vary with the temperature, among species, and within a species among life stages. Air movement and strategic placement of fans are important for eliminating cool spots.Keywords: Heat, Forced air, Flour mills, Methyl bromide alternativ

Structurally specific thermal fluctuations identify functional sites for DNA transcription

We report results showing that thermally-induced openings of double stranded DNA coincide with the location of functionally relevant sites for transcription. Investigating both viral and bacterial DNA gene promoter segments, we found that the most probable opening occurs at the transcription start site. Minor openings appear to be related to other regulatory sites. Our results suggest that coherent thermal fluctuations play an important role in the initiation of transcription. Essential elements of the dynamics, in addition to sequence specificity, are nonlinearity and entropy, provided by local base-pair constraints

A Simple Model for r-Process Scatter and Halo Evolution

Recent observations of heavy elements produced by rapid neutron capture (r-process) in the halo have shown a striking and unexpected behavior: within a single star, the relative abundances of r-process elements heavier than Eu are the same as the same as those of solar system matter, while across stars with similar metallicity Fe/H, the r/Fe ratio varies over two orders of magnitude. In this paper we present a simple analytic model which describes a star's abundances in terms of its ``ancestry,'' i.e., the number of nucleosynthesis events (e.g., supernova explosions) which contributed to the star's composition. This model leads to a very simple analytic expression for the abundance scatter versus Fe/H, which is in good agreement with the data and with more sophisticated numerical models. We investigate two classes of scenarios for r-process nucleosynthesis, one in which r-process synthesis events occur in only \sim 4% of supernovae but iron synthesis is ubiquitous, and one in which iron nucleosynthesis occurs in only about 9% of supernovae. (the Wasserburg- Qian model). We find that the predictions in these scenarios are similar for [Fe/H] \ga -2.5, but that these models can be readily distinguished observationally by measuring the dispersion in r/Fe at [Fe/H] \la -3.Comment: AASTeX, 21 pages, includes 4 figure

Towards cyber-physical systems as services: the ASIP protocol

The development of Cyber-Physical Systems needs to address the heterogeneity of several components that interact to build a single application. In this paper we present a model to enable easy integration and interaction of micro-controllers. Specifically, we describe the Arduino Service Interface Protocol (ASIP), we provide an implementation and client libraries for Java, Racket and Erlang, together with the description of a practical example