Long-term water movements in the southern trough of the Charlie-Gibbs Fracture Zone

The first long-term (250 d) current measurements from the southern trough of the CharlieGibbs Fracture Zone indicate persistent westward flow along the north wall and a steady eastward drift along the lower south wall. Net volume transport varies from westerly to easterly with a 2-3 month periodicity, but no seasonal cycle is evident. Overall, the separate westward and eastward transports are in balance...

Outdoor Mosquito Control Using Odour-Baited Devices: Development and Evaluation of a Potential New Strategy to Complement Indoor Malaria Prevention Methods

A considerable effort is currently underway to develop a malaria vaccine based on live Plasmodium falciparum sporozoites. The first requisite of a sporozoite vaccine is the guarantee of parasite arrest prior to the onset of the pathogenic blood stage. Immunisation with genetically attenuated parasites (GAP) that arrest in the liver forms a promising approach. Work in this thesis describes the development and characterisation of a P. berghei Δb9Δslarp GAP that fully arrests in the liver. Immunisation of multiple mouse strains with low numbers of Δb9Δslarp GAP resulted in sterile protection. The Δb9Δslarp GAP is there- fore the leading GAP vaccine candidate. Work in this the- sis further describes the effect of varying the parameters of sporozoite inoculation on parasite liver load. These findings provide a rationale for the design of clinical trials aimed at the administration of live attenuated P. falciparum sporozoites

Detection of hydrogen peroxide with chemiluminescent micelles

The overproduction of hydrogen peroxide is implicated in the progress of numerous life-threatening diseases and there is a great need for the development of contrast agents that can detect hydrogen peroxide in vivo. In this communication, we present a new contrast agent for hydrogen peroxide, termed peroxalate micelles, which detect hydrogen peroxide through chemiluminescence, and have the physical/chemical properties needed for in vivo imaging applications. The peroxalate micelles are composed of amphiphilic peroxalate based copolymers and the fluorescent dye rubrene, they have a ‘stealth’ polyethylene glycol (PEG) corona to evade macrophage phagocytosis, and a diameter of 33 nm to enhance extravasation into permeable tissues. The peroxalate micelles can detect nanomolar concentrations of hydrogen peroxide (>50 nM) and thus have the sensitivity needed to detect physiological concentrations of hydrogen peroxide. We anticipate numerous applications of the peroxalate micelles for in vivo imaging of hydrogen peroxide, given their high sensitivity, small size, and biocompatible PEG corona

Triggered Star Formation in a Massive Galaxy at z=3.8: 4C41.17

Spectropolarimetric observations obtained with the W. M. Keck Telescope of the z=3.8 radio galaxy 4C41.17 show that the UV continuum emission from this galaxy, which is aligned with the radio axis, is unpolarized (P[2sigma] < 2.4%). This implies that scattered AGN light, which is generally the dominant contributor to the rest-frame UV emission in z~1 radio galaxies, is unlikely to be a major component of the UV flux from 4C41.17. The spectrum shows absorption lines that are similar to those detected in the spectra of the recently discovered population of star forming galaxies at z~2-3. A galaxian outflow may contribute partially to the low ionization absorption lines; however, the high velocity wings of the high ionization lines are unlikely to be dominated by a galaxian wind since the implied outflow mass is very large. The detection of stellar absorption lines, the shape of the SiIV profile, the unpolarized continuum, the inability of any AGN-related processes to account for the UV flux, and the similarity of the UV continuum spectra of 4C41.17 and the nearby starburst region NGC 1741B1 suggest that the UV light in 4C41.17 is dominated by young stars. If so, the implied star-formation rate is roughly 140-1100Msun/yr. We discuss the possibility that star formation in 4C41.17 was triggered by the radio source. Our data are consistent with the hypothesis that 4C41.17 is undergoing its major epoch of star formation at z~4, and that by z~1 it will have evolved to have spectral and morphological properties similar to those observed in known z~1 powerful radio galaxies.Comment: 28 pages (Latex text + figures); Accepted for publication in The Astrophysical Journal (Dec 1, 1997 issue

Consistent Quantum Counterfactuals

An analysis using classical stochastic processes is used to construct a consistent system of quantum counterfactual reasoning. When applied to a counterfactual version of Hardy's paradox, it shows that the probabilistic character of quantum reasoning together with the ``one framework'' rule prevents a logical contradiction, and there is no evidence for any mysterious nonlocal influences. Counterfactual reasoning can support a realistic interpretation of standard quantum theory (measurements reveal what is actually there) under appropriate circumstances.Comment: Minor modifications to make it agree with published version. Latex 8 pages, 2 figure

Purification and Characterization of meta-Cresol Purple for Spectrophotometric Seawater pH Measurements

Spectrophotometric procedures allow rapid and precise measurements of the pH of natural waters. However, impurities in the acid–base indicators used in these analyses can significantly affect measurement accuracy. This work describes HPLC procedures for purifying one such indicator, meta-cresol purple (mCP), and reports mCP physical–chemical characteristics (thermodynamic equilibrium constants and visible-light absorbances) over a range of temperature (T) and salinity (S). Using pure mCP, seawater pH on the total hydrogen ion concentration scale (pHT) can be expressed in terms of measured mCP absorbance ratios (R = λ2A/λ1A) as follows:where −log(K2Te2) = a + (b/T) + c ln T – dT; a = −246.64209 + 0.315971S + 2.8855 × 10–4S2; b = 7229.23864 – 7.098137S – 0.057034S2; c = 44.493382 – 0.052711S; d = 0.0781344; and mCP molar absorbance ratios (ei) are expressed as e1 = −0.007762 + 4.5174 × 10–5T and e3/e2 = −0.020813 + 2.60262 × 10–4T + 1.0436 × 10–4 (S – 35). The mCP absorbances, λ1A and λ2A, used to calculate R are measured at wavelengths (λ) of 434 and 578 nm. This characterization is appropriate for 278.15 ≤ T ≤ 308.15 and 20 ≤ S ≤ 40

Torsion pairs and rigid objects in tubes

We classify the torsion pairs in a tube category and show that they are in bijection with maximal rigid objects in the extension of the tube category containing the Pruefer and adic modules. We show that the annulus geometric model for the tube category can be extended to the larger category and interpret torsion pairs, maximal rigid objects and the bijection between them geometrically. We also give a similar geometric description in the case of the linear orientation of a Dynkin quiver of type A.Comment: 25 pages, 13 figures. Paper shortened. Minor errors correcte

Grain Sorghum Date-of-Planting and Spacing Experiments.

71 p