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Item 1: Sample descriptions and U-Pb age. Item 2: Zircon analytical procedures. Item 3: Lu-Hf isotope calculations. Item 4: U-Pb age plots. Item 5: Whole-rock chemistry of samples. Item 6: U-Th-Pb isotopic analyses. Item 7: Lu-Hf isotopic analyses.

The contribution of grain protein to the malting quality of barley (Hordeum vulgareL.) was investigated by comparing the hordein composition and the malting quality in barley produced under a range of field conditions. Two malting cultivars, Schooner and Arapiles, and one feed cultivar, Galleon, were grown under five nitrogen regimes in each of two years. Hordein composition of the grain was determined at maturity using a combination of sodium dodecyl sulphate-polacrylamide gel electrophoresis and laser densitometry. Malt extract was determined on all samples after micromalting. Variation in growth conditions resulted in a wide range of grain protein contents and malt extract values, as well as variation in the proportions of the individual B, C and D hordeins in the grain. D hordein in particular varied over a 10-fold range. High levels of all protein fractions were associated with low malt extract. Total protein, as expected, displayed a strong, negative correlation with malt extract. The relationship was cultivar specific and separate regression lines were generated for each cultivar. Of the individual hordein fractions, D hordein displayed the strongest negative correlation with malt extract and its relationship to malt extract was independent of cultivar. A consistent relationship between D hordein and malt extract was observed across seasons, treatments and cultivars that was indicative of a causal relationship between D hordein and malting quality. D hordein therefore offers an alternative measurement to total protein for the prediction of malting quality over a wide range of environmental conditions and cultivars.

A range of fluorescent polystyrene microparticles (0.15, 0.5, 1.0, 3.0 and 10.0 μm) were administered intraduodenally to Wistar rats to provide an assessment of the levels of absorption of microparticles. Coupling a surgical procedure for the cannulation of the superior mesenteric lymph duct and the removal of Peyer's patches and mesenteric lymph nodes, with a sensitive flow cytometric assay it was possible to quantify microparticle absorption across the intestine. Absorption occurred after 5 min and was temporally variable, for all sizes of microparticles, over the time period studied. The 0.5-μm microparticles were found to be absorbed in significantly greater numbers to the Peyer's patches (P < 0.01) and the mesenteric lymph (P < 0.05) than other sizes and the 3.0-μm microparticles were found to be retained in the mesenteric lymph nodes in greater numbers than particles of other sizes. The 10.0-μn microparticles were retained in the mesenteric lymph nodes in low numbers. The levels of absorption, retention and extravasation of some sizes of microparticles suggests that the delivery of microencapsulated vaccines may allow the controlled delivery of antigens to the gut-associated lymphoid tissue (GALT) and their subsequent systemic dissemination.

The absorption of polystyrene microparticles across the intestine of rats was examined as a preliminary assessment of the efficacy of particles as vaccine delivery systems. The superior mesenteric lymph ducts of groups (n = 5) of Wistar rats were cannulated and the lymph analysed by flow cytometry. This allowed direct quantification of the numbers of particles absorbed. The 0.15 and 1.0 μm particles were absorbed rapidly (after 5 min) in a temporally complex manner, with maximal absorption occurring 65 min after delivery, for both sizes of particles. Microparticles were absorbed in approximately equal numbers over 90 min (5.0 × 104 0.15 μm and 4.9 × 104 1.0 μm particles, respectively). The levels of particle absorption in the current study indicate that microparticulate delivery of vaccines may be a realistic possibility.

Bal31 deletion experiments on clones of the PaeR7 restriction-modification system from Pseudomonas aeruginosa demonstrate that it is arranged as an operon, with the methylase gene preceding the endonuclease gene. The DNA sequence of this operon agrees with in vitro transcription-translation assays which predict proteins of 532 amino acids, Mr = 59,260 daltons, and 246 amino acids, Mr = 27,280 daltons, coincident with the methylase and endonuclease genes, respectively. These predicted values coincide with the measured molecular weights of the purified, denatured PaeR7 endonuclease and methylase proteins. The first twenty amino acids from the amino-terminus of the purified endonuclease exactly match those predicted from the DNA sequence. Finally, potential regulatory mechanisms for the expression of phage restriction are described based on the properties of several PaeR7 subclones.

The Peach Springs Tuff of Young and Brennan (1974) is a voluminous ash-flow tuff of early Miocene age that has been identified in western Arizona and the Mojave Desert of southeastern California. The tuff was recognized and described in the areas of Peach Springs and Kingman, Arizona, on the western Colorado Plateau by Young (1966), and Young and Brennan (1974). Glazner et al. (1986) and Wells and Hillhouse (1986) have recently proposed that the Peach Springs Tuff may correlate with ash-flow tuff occurring to the west across the Mojave Desert as far as the area of Barstow, California. If the correlation is correct, the Peach Springs Tuff would be the only Miocene unit of wide areal extent in this region and would cover an area of approximately 35,000 km 2. Thus, the Peach Springs Tuffwould be invaluable for use as a stratigraphic marker and for determining the timing and amount of Tertiary crustal extension. However, ash-flow tuffs are commonly difficult to correlate due to lateral and vertical variations in welding, mineralogy, and chemistry, complex depositional mechanisms, and other complicating factors (Hildreth and Mahood, 1985). Proposed identification of the Peach Springs Tuff over this extensive area has been based primarily on field relations such as its lower Miocene stratigraphic position, and phenocryst assemblage which includes abundant sanidine and lesser amounts of biotite, hornblende, plagioclase and sphene. Additional criteria used for correlation include phenocryst composition and paleomagnetic directions ( Glazner et al., 1986; Wells and Hillhouse, 1986). Inconsistent K-At dates from localities of the Peach Springs Tuff and its proposed equivalents have left nagging uncertainties regarding this correlation. The source of the tuff is not known. In addition, correlation of some localities has been uncertain because of limited and widely scattered outcrop preservation, and the varied stratigraphic relations of the tuff within the numerous isolated Tertiary stratigraphic sections. We report the results of a study of relative abundances of heavy minerals to characterize and distinguish ash-flow

A U.S. Geological Survey Geologic map of the eastern parts of the Cadiz Lake and Cadiz Valley 15-minute quadrangles, San Bernardino and Riverside Counties, California is presented.

DdeI, a Type II restriction-modification system from the gram-negative anaerobic bacterium Desulfovibrio desulfuricans, recognizes the sequence CTNAG. The system has been cloned into E. coli in two steps. First the methylase gene was cloned into pBR322 and a derivative expressing higher levels was constructed. Then the endonuclease gene was located by Southern blot analyses; BamHI fragments large enough to contain the gene were cloned into pACYC184, introduced into a host containing the methylase gene, and screened for endonuclease activity. Both genes are stably maintained in E. coli on separate but compatible plasmids. The DdeI methylase is shown to be a cytosine methylase. DdeI methylase clones decrease in viability as methylation activity increases in E. coli RR1 (our original cloning strain). Therefore the DdeI system has been cloned and maintained in ER1467, a new E. coli cloning strain engineered to accept cytosine methylases. Finally, it has been demonstrated that a very high level of methylation was necessary in the DdeI system for successful introduction of the active endonuclease gene into E. coli.

The complement system is an important effector within the innate immune system as a defence against pathogens and maintaining homeostasis. Detection of pathogen- and damage-associated molecular patterns triggers the proteolytic cascade in complement. In healthy self-tissues effector proteins are tightly controlled by proteins acting as regulators of complement activation, and absence or malfunction of these regulators contribute to pathogenesis in a number of disease conditions in humans. Complement is highly relevant to nanomedicine due its role in adverse reactions on polymers and nanoparticle drug carriers, but also since complement hyperactivation contributes to pathogenesis in many disease conditions that are frequently addressed within nanomedicine. We review here the regulatory mechanisms that modulate complement activation and some of the most prominent cases linking complement dysregulation/deficiencies to pathogenesis as well as the strategies that have been considered for the development of therapeutic complement inhibitors and modulators to alleviate complement-mediated detrimental effects. In addition, this chapter summarizes the wealth of strategies adopted by pathogens to evade complement, such as inhibition of the proteolytic cascade, degradation of complement effector molecules and interference with transmembrane signaling by effectors, and highlights how structural and functional insight into their mode of function now provides leads for the development of novel complement therapeutics.