The Role of the Comstock-Kellogg Glands in Egg Tanning in Romalea guttata

FreshIy laid eggs of the Eastern Lubber grasshopper, Romalea guttata, are yellow and soft-shelled, but within several hours the eggs become hardened and dark brown. In a similar process, calyx and oviduct secretions, which from the egg pod, become frothy, darkened, hardened, and water insoluble during oviposition. It has been suggested that secretions from the paired Comstock-Kellogg glands accelerate tanning of both the eggs and egg pod foam. I investigated the effects of Comstock-Kellogg gland secretions on the rate of egg and egg pod tanning during egg pod production in the female Eastern Lubber grasshopper, R. guttata. Eggs streaked with Comstock-Kellogg gland secretions, macerated CK gland, mac rated intersegmental membrane, or hemolymph took significantly less time to tan than non-streaked egg or eggs streaked with deionized water. Females lacking CK glands laid eggs that took significantly longer to tan than eggs from sham-operated or unoperated females. These results suggest that the Comstoc -Kellogg glands do serve to accelerate tanning, but the chemical composition of the CK secretions may be common to other grasshopper tissues

Light Ions Response of Silicon Carbide Detectors

Silicon carbide (SiC) Schottky diodes 21 mum thick with small surfaces and high N-dopant concentration have been used to detect alpha particles and low energy light ions. In particular 12C and 16O beams at incident energies between 5 and 18 MeV were used. The diode active-region depletion-thickness, the linearity of the response, energy resolution and signal rise-time were measured for different values of the applied reverse bias. Moreover the radiation damage on SiC diodes irradiated with 53 MeV 16O beam has been explored. The data show that SiC material is radiation harder than silicon but at least one order of magnitude less hard than epitaxial silicon diodes. An inversion in the signal was found at a fluence of 10^15 ions/cm^2.Comment: 20 pages, 16 figures, submitted for publication to Nuclear Instruments and Methods in Physics Research

A study of smoke formation from wood combustion

Aerosol time of flight mass spectrometry (ATOFMS) was used to analyse the particles emitted during the flaming and smouldering phases of the combustion of samples of hard and soft woods. Eugenol and furfural were also burned and using results from previous work of the authors, they have been shown to be useful proxies for initial wood combustion products. The ratios of elementary carbon to total carbon in the particles were similar for both the woods and for eugenol. The ATOFMS spectra of most of the particles were consistent with the presence of soot precursor constituents along with oxygen containing fragments. Most particle diameters were less than 2.5. μm, with the greatest concentration of <. 0.12. μm

Altered Composition of Liver Proteasome Assemblies Contributes to Enhanced Proteasome Activity in the Exceptionally Long-Lived Naked Mole-Rat

The longest-lived rodent, the naked mole-rat (Bathyergidae; Heterocephalus glaber), maintains robust health for at least 75% of its 32 year lifespan, suggesting that the decline in genomic integrity or protein homeostasis routinely observed during aging, is either attenuated or delayed in this extraordinarily long-lived species. The ubiquitin proteasome system (UPS) plays an integral role in protein homeostasis by degrading oxidatively-damaged and misfolded proteins. In this study, we examined proteasome activity in naked mole-rats and mice in whole liver lysates as well as three subcellular fractions to probe the mechanisms behind the apparently enhanced effectiveness of UPS. We found that when compared with mouse samples, naked mole-rats had significantly higher chymotrypsin-like (ChT-L) activity and a two-fold increase in trypsin-like (T-L) in both whole lysates as well as cytosolic fractions. Native gel electrophoresis of the whole tissue lysates showed that the 20S proteasome was more active in the longer-lived species and that 26S proteasome was both more active and more populous. Western blot analyses revealed that both 19S subunits and immunoproteasome catalytic subunits are present in greater amounts in the naked mole-rat suggesting that the observed higher specific activity may be due to the greater proportion of immunoproteasomes in livers of healthy young adults. It thus appears that proteasomes in this species are primed for the efficient removal of stress-damaged proteins. Further characterization of the naked mole-rat proteasome and its regulation could lead to important insights on how the cells in these animals handle increased stress and protein damage to maintain a longer health in their tissues and ultimately a longer life

Almstedt: Diegueño Curing Practices

Diegueno Curing Practices. Ruth Farrell Almstedt. San Diego: San Diego Museum Papers No. 10, 1977. 38 pp

Design and application of a polyclonal peptide antiserum for the universal detection of leptin protein

An epitope-specific polyclonal antiserum was produced in rabbits immunized against a synthetic 15 amino acid peptide (QRVTGLDFIPGLHPV) derived from the coding sequence reported for the porcine leptin gene (GenBank Accession No. U59894). This peptide contains a core sequence comprised of eight amino acids (GLDFIPGL) that is totally conserved in all leptin proteins studied to date. Purified recombinant human, mouse, rat, pig, and chicken leptin proteins were separated by polyacrylamide gel electrophoresis (SDS-PAGE) and electro-blotted onto PVDF membranes. Western blots were developed employing the leptin-specific peptide antiserum with an alkaline-phosphatase-conjugated anti-rabbit IgG second antibody chromogenic system. The peptide antiserum was found to be highly specific for leptin which exhibited an estimated molecular weight of about 16 kDa for all species analyzed. The sensitivity of the Western blot assay was not sufficient to permit the direct detection of leptin in chicken serum or plasma. However, with this assay we were able to detect native leptin protein in an enriched fraction prepared from chicken plasma using a combination of gel filtration and ion exchange column chromatography. Slot blots indicated a potential application of the immunostaining technique for quantitative analysis of leptin protein. Finally, the peptide antiserum was successfully employed to localize leptin protein by immunohistochemical staining of thin sections prepared from adipose (chicken and pig) and liver (chicken) tissue samples. This study is the first to report a polyclonal peptide antiserum that apparently recognizes intact leptin protein, both native and recombinant, regardless of the species of origin