Chemical heterogeneity of soldier defensive secretions in the desert subterranean termite, Amitermes wheeleri

Soldier defensive secretions were analyzed by GC/MS in eight spatially separated groups of Amitermes wheeleri collected in Arizona and California. Eleven sesquiterpenoids, four of known structure, were isolated. Quantitative and qualitative differences among the groups of termites were extensive; composition of the defensive secretions among colonies varied from one to six components. Intraspecific differences between pairs of sympatric colonies at six sites were much less pronounced. The variability found in A. wheeleri suggests that soldier defensive secretions in the genus Amiterines are not reliable markers for interspecific systematic comparisons.     

How reproducible are flow cytometry data from paraffin-embedded blocks?

The purpose of this technical report is to determine the reproducibility of flow cytometry data for ploidy and cell cycle kinetics using paraffin-embedded blocks of breast cancer tissue. One block from each of 39 tumors was studied in this report with each block having multiple sections analyzed independently. All of these sections gave ploidy analyses, while only 34 gave cell kinetic values. The standard deviation for the DNA index value in the multiple analysis study was less than 0.1 in all but three cases. The cell kinetic values gave larger variability, and the actual values were dependent on the method of analysis. Comparison of the variability for each method of analysis could not predict which procedure was superior. These results would indicate that ploidy is a reproducible value, while cell kinetic parameters should only be used as an indicator of proliferative activity that has been normalized to the mean or median of a large set of observations processed and analyzed by the same procedure.     

Population genetics of the endangered Maugean skate (<Emphasis Type="Italic">Zearaja maugeana</Emphasis>) in Macquarie Harbour,Tasmania

The Maugean skate (Zearaja maugeana) has only been recorded in two remote and isolated estuaries on the west coast of Tasmania, Australia. While the population status in one of these estuaries (Bathurst Harbour) is uncertain, it is likely that Macquarie Harbour now represents the sole remaining habitat for this species. Environmental conditions, in particular dissolved oxygen levels and benthic biodiversity, in Macquarie Harbour have deteriorated in recent years, impacted by increased nutrient inputs from an expanding salmonid aquaculture industry. These environmental changes are believed to pose a threat to the persistence of the Maugean skate. In assessing the risks for this rare and range-restricted species, it is vital to consider genetic information when developing management strategies. Both mitochondrial and microsatellite markers showed that the species has low genetic diversity; with no detectable genetic diversity in over 3000 base pairs surveyed from the mitochondrial genome, low average microsatellite heterozygosity (0.35?±?0.11), a low average number of alleles per locus (2.1?±?0.4) across eight microsatellite loci and no overall population structure within the microsatellite loci (Fst = ? 0.002, p?=?0.718?±?0.012). There was also evidence of a recent bottleneck or founder event, which may explain the low observed genetic diversity. While the species may have existed with low genetic diversity for many generations, the results of this study represent a flag for conservation concern for the Maugean skate. Given that Macquarie Harbour may be its last remaining habitat, any threats to the species resulting in local extinction could equate to global loss of this unique skate species.     

Association of shiftwork and leukocytes among national health and nutrition examination survey respondents

Shift workers may experience disrupted sleep-wake or circadian cycles which, in turn, may lead to major health problems such as hypertension, obesity, and diabetes. Research indicates that shift workers have increased levels of leukocytes. Data from the National Health and Nutrition Examination Survey (2005–2010) examined the relationship between self-reported current shiftwork and leukocytes with adjustment for important confounders. Using linear regression, we found no association between shiftwork and leukocyte counts. Those not working had elevated levels compared to day workers but values in both groups were still within normal ranges. Additional research is needed to fully understand how shiftwork influences changes in leukocyte counts.     

Restoring Native Perennial Grasses to Rural Roadsides in the Sacramento Valley of California: Establishment and Evaluation

Along rural roadsides of the Sacramento Valley of California, we seeded native and non-native perennial grasses to gauge their potential value in roadside vegetation management programs. In trial I (polycultures), three seeded complexes and a control (resident vegetation only) were tested. Each seeded plant complex included a different mix of perennial grasses seeded into each of several roadside topographic zones. The seeded levels of plant complex were: native perennial grasses 1 (8 species); native perennial grasses 2 (13 species); and non-native perennial grasses (3 species). In trial II, plots were seeded to monocultural plots of 15 accessions of native Californian and three cultivars of non-native perennial grasses. Plots in both trials were seeded during January 1992 and evaluated for three successive years.     

Replication of Coliphage M-13 I. Effects on Host Cells After Synchronized Infection

Techniques have been described for synchronization of bacteriophage M-13 infection of host cells. The latent period in infected cells was 10 min, and no appreciable number of intracellular phage was observed. Phage production proceeded in three phases after release of the starvation block: an initial rapid exponential rate of progeny phage release without cell lysis, a period of rate transition accompanying the resumption of host cell division, and a second, slower exponential rate of phage production which paralleled the rate of host cell division. The size of infected cells was not affected by infection, but the generation time was increased by 25%. Starved infected cells exhibited a much longer lag in attaining an exponential rate of growth upon the addition of nutrients than did an uninfected control culture.     

Amino acid sequence of lysozyme from baboon milk

Reduced alkylated baboon milk lysozyme was subjected to digestion with trypsin. The resulting peptides were purified by a combination of Dowex 1 (X2) and chromatography and electrophoresis on paper. The amino acid sequence of these peptides was determined in detail chiefly by the Edman procedure. Alignment of the tryptic peptides into a single chain containing 130 amino acids was established chiefly by homology with human milk lysozyme; 14 replacements were noted between the two enzymes. Baboon milk lysozyme was devoid of methionine and contained six basic amino acids (arginine residues) less than human milk lysozyme.