Best Selling Books by Jason Peter

The HPr proteins were characterized as folding by a two-state folding mechanism. Here, we present a comparison of the equilibrium and kinetic folding for the HPr protein from Bacillus subtilis, E coli and a key variant from these proteins. For the wild-type protein we find that GHX is greater than GUDC, suggesting that the HPr does not fold by a simple two-state mechanism. This discrepancy is revealed by testing the two-state nature of the folding reaction of HPr with mutation. We show that removing a single charge side chain (Asp 69) converts the HPr protein back to a simple two-state mechanism. Ribonuclease Sa and two charge-reversal variants can be converted into amyloidin vitro by the addition of 2,2,2-triflouroethanol (TFE). We report here amyloid fibril formation for these proteins as a function of pH. The pH at maximal fibril formation correlates with the pH dependence of protein solubility, but not with stability, for these variants. Additionally, we show that the pH at maximal fibril formation for a number of ivwell-characterized proteins is near the pI, where the protein is expected to be the least soluble. This suggests that protein solubility is an important determinant of fibril formation.

This dissertation describes the modified role of oxygen content and order in stressed YBa2Cu3O7-delta superconducting systems. Materials or multilayer structures not comprised of optimally oxygenated, single crystal YBa2Cu3O7-delta are considered as stressed YBa2Cu3O7-delta systems. Cation doped thin films and thin film microstructures comprised of YSr2Cu2.75Mo0.25Oz and YBa 2(Cu1-xCOx)3Oz are the first category of stressed YBa2Cu3O7-delta systems examined. Three types of Josephson tunnel junctions were investigated; superconducting-normal layer-superconducting ramp edge junctions with cation doped YBa2Cu3O7-delta normal layers, grain boundary junctions, and interface engineered Josephson junctions where the interface layer between two superconducting electrodes is modified to yield a tunnel barrier. In all cases enhanced oxidation techniques including electromigration and ozone annealing were employed to produce previously unattained levels of oxygenation in each system. For cation doped materials this enhancement is demonstrated by an increase in the superconducting transition temperature, Tc, from 21 to 75 K for YBa2(Cu0.9Co 0.1)3Oz. Other electrical transport measurements, microRaman spectroscopy, and X-ray diffraction analysis also demonstrate the optimal level of oxygenation achieved by these two techniques. The enhancement of Tc for bulk film cation doped materials following ozone anneals at 500°C, or room temperature electromigration, translates into an elevation in operating temperature for ramp edge junctions utilizing doped materials as a normal metal layer. This is demonstrated by similar resistively shunted junction behavior observed at 35 K before ozone annealing, and at 80 K afterwards. In contrast, the changes induced in grain boundary and interface engineered Josephson junctions by enhanced oxidation are consistent with a simple increase in the effective area of the junction. This is attributed to the crystal stress in the vicinity of the grain boundary or engineered interface. Oxygen loss induced by this stress is overcome by the enhanced partial pressure of atomic oxygen provided by ozone and electromigration, thus increasing the volume of well oxygenated YBa2Cu3O 7-delta. In conclusion, we find that the optimal oxygenation of stressed YBa2Cu3O7-delta systems requires enhanced oxidation techniques beyond the standard 500°C O 2 anneals successfully employed for the parent material.

How could I be? I lived under death''s shadow every day. When you swallow eighty Vicodin, twenty sleeping pills, drink a bottle of vodka, and still survive, a certain sense of invulnerability stays with you. When you continually use drugs with the kind of reckless determination that I did, the limit to how much heroin or crack you can ingest is not defined in dollar amounts, but in the amounts your body can withstand without experiencing a seizure or respiratory failure. Yet at the end of every binge, every night of lining up six, seven, eight crack pipes and hitting them one after the other bam! bam! bam! every night of smoking and snorting bag after bag of heroin ... after all of that, when you still wake up to see the same dirty sky over you as the night before, you start to think that instead of dying, maybe your punishment is to live--to be stuck in this purgatory of self-abuse and misery for an eternity. Sometimes you start to think that death would come as a blessed relief. Toward the end, I found myself contemplating death again. Only this time I wasn''t going to leave it to chance. I was going to buy a gun, load the thing, place the barrel in my mouth, and blow my fucking brains out. And then all-- of my problems-- would be solved.

Occupational exposure limits -- Pesticides -- Metals -- Dusts -- Fibres -- South Africa -- Developed countries -- Organisations -- Hazardous chemical substances -- Beroepsblootstellingsdrempels -- Pestisiede -- Metale -- Stof -- Vesels -- Suid Afrika -- Ontwikkelde lande -- Organisasies -- Gevaarlike chemiese substanse.

Investigates the basic biology of the toothy flathead, Neoplatycephalus aurimaculatus. Parameters such as age and growth, reproduction and diet were studied. In eastern Bass Strait, toothy flathead feed mainly on eels and school whiting, breed in late spring and early summer, and are moderately long lived.

We identify all translation covers among triangular billiards surfaces. Our main tools are the J-invariant of Kenyon and Smillie and a property of triangular billiards surfaces, which we call fingerprint type, that is invariant under balanced translation covers.

During soft ground tunnel construction, if the face pressure of a tunnel boring machine is not strictly controlled, excessive ground movements will propagate vertically upwards causing significant damage to adjacent buried infrastructure and surface structures. In order to investigate the face pressure - ground deformation relationship for tunnels in sands, the construction process was modelled using the technique of geotechnical centrifuge modelling and the resulting ground deformations were recorded using digital image correlation. In these tests a unique tunnel face boundary condition was developed which allowed the boundary condition to be initially set as a zero strain condition before it was transformed into a load-controlled boundary to investigate the instability of the face. Tests were preformed at four different burial depths in dry sand, corresponding to cover depths of 0.5, 1, 1.5, and 2 times the tunnel diameter. These results indicate that the face pressure at failure is largely independent of burial depth over the values tested. The ground deformation at the onset of tunnel face instability was found to be very small, and once initiated, the zone of ground deformations was observed to propagate upwards in a narrow chimney in front of the tunnel until it reached the ground surface causing subsidence. Further tests investigated the variation in ground deformations to be expected if a tunnel were to be passing through more complex ground conditions, including unsaturated sand, saturated sand, and the unique case of sand / clay mixed ground conditions. Ground deformations at tunnel face instability were much lower for the case of unsaturated sand, than for either the saturated or dry cases which showed broadly similar responses. In the mixed ground condition of a clay layer over topping a sand layer, the clay layer was found to only influence the tunnel face pressure - deformation response if the bottom of the clay layer was closer than 0.5 diameters above the tunnel crown.

In this dissertation I address the related problems of expertise and long-distance control in the context of British navigation and the bureaucratic practices of the English East India Company. Expertise, in particular, is used as a framework from which I build outward to establish a stronger understanding of commercial trade, the circulation of knowledge and, most crucially, the place of the metropole. The first half of this dissertation introduces expertise and long-distances control and puts the concepts into historical context through the example of navigation between 1673 and 1755. Navigation is illustrative of the problem of expertise because it was a contentious subject at the time and, therefore, the contemporary debates can be followed. Expertise is a crucial problem because it directly addresses power and who controls knowledge. Thus, the question of navigational expertise ties directly to the problem of long-distance control. Therefore, my dissertation begins by moving outward from navigational instruction at the Royal Mathematical School to the practice of navigation on Edmond Halleys first Paramore voyage. In the context of global commercial exchange, long-distance control became an increasing priority for those who sought to assert such control from a presumed centre onto agents around the globe. As such, the second half of the dissertation continues to follow actors further away from London with the setting moving to India and China where I contrast the idea of long-distance control with the reality. In practice the East India Company had little ability to impose itself on either its own employees or on the peoples with whom the Company wished to trade. Instead, the Companys efforts often drew attention to its ignorance of Asian trade and served to underline its weakness in the first part of the eighteenth century. The dissertation concludes by questioning the notion of the metropole and the periphery in the history of science and suggests an inversion of the traditional locations, with London now a periphery rather than centre, a state of affairs more in line with the situation at the time.