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CaltechTHESIS (10.133 recursos)
CALIFORNIA INST OF TECH (CIT) Thesis
Status = Unpublished
CALIFORNIA INST OF TECH (CIT) Thesis
Status = Unpublished
Ellis, Stephen Dean
A dual quark model is developed from the usual Veneziano model
by explicitly including the Dirac spin of the quarks. Resonances
appear without the parity doubling and new ghosts present in previous
models with spin. This is accomplished by eliminating the contributions
of the negative parity components (MacDowell-twins) of the
spin quarks 1/2 through the introduction of fixed J-plane cuts. The
resonances belong to an SU6 symmetric spectrum identical, on the
leading trajectory, with that of the usual static symmetrical quark
model. All resonances couple via SU6w x O2Lz symmetric vertices
and the model factorizes with essentially the same degeneracy as the
usual Veneziano model....
Pall, Martin Lawrence
A technique for inducing very high levels of tyrosinase activity
with various antimetabol ites is described. A modification of this technique
was used for studying tyrosinase induction in Neurospora over
periods of a few hours. An amount of the antimetabolite inducer
sufficient to induce the enzyme is rapidly taken up into the mycelium.
Following uptake, however, there is a lag period of about two hours
before tyrosi nase is synthesized. During the lag period, some active,
energy requiring process prepares the mycelium for tyrosinase synthesis.
Rapid synthesis of tyrosinase then ensues. High concentrations of
cycloheximide, an inhibitor of protein synthesis,...
Williams, Larry Gale
The metabolism of thymidine by Neurospora crassa was investigated
after radioactive labeling experiments showed that thymidine is not
specifically incorporated into the DNA of Neurospora; a finding in
contrast to the results of labeled thymidine experiments with many
other organisms. Labeling experiments in which 2-C14 deoxyuridine,
2-C14 thymidine and 2-C14 thymine were administered to Neurospora
revealed that in each case ninety per cent of the nucleic acid label
was in the RNA fraction. When thymidine methyl-H3 was administered
no label was found in either the RNA or DNA. This and other evidence
was taken as proof that Neurospora lacks phosphorylating enzymes for
Buhler, Vivian Huang
In her most celebrated and controversial poem, Goblin Market, Christina Rossetti presents an allegory of her own spiritual journey toward redemption as a woman, a sinner, and a reform worker. Through the stories of three young maidens’ misadventures among the goblin men’s “haunted glen,” Rossetti reveals the unjust Victorian binaries of male versus female, as well as virgin versus prostitute, and proposes an alternative definition of virtue attained through redemption that is accessible to all regardless of gender or social background. Using Jeanie, Lizzie, and Laura as figures for fallen woman, penitent, and sister, Rossetti further recasts the parallel feminine...
Niesen, Michiel Jacobus Maria
This thesis describes coarse-grained approaches for simulating the co-translational integration and translocation of proteins via the Sec translocon, which is a key step in the biogenesis of membrane and secretory proteins. We present a coarse-grained simulation approach that is capable of simulating minute-timescale dynamics while retaining sufficient chemical and structural detail to capture sequence-specific interactions. The model is validated through comparison to existing experimental data and applied to characterize the forces that act on nascent proteins and drive successful integration and translocation. We also apply coarse-grained simulations of the integration of multi-spanning membrane proteins to understand the effect of sequence...
Salzman, Paul Klenett
A shock model is developed that leads to an analytical expression
for the Hugoniot of condensed media. In the analysis the final
state is selected to coincide with the end of the shock transition so
that the total energy change across the shock front is evaluated from
changes in configurational energy only using an n-6 pair potential
(shown to be valid for all n > 0) and a given lattice structure.
Thermal energy changes are ignored because the dwell time of the molecules
in the shock transition region is less than the thermal relaxation
time. The total energy change is equated to...
Thiene, Paul George, Jr.
The topic of this research is the hitherto uninvestigated absorption of electromagnetic energy by polar symmetric-top molecules in a static electric field, which arises by virtue of direct transitions between sublevels of a single rotational state. A short theoretical treatment of the Stark effect of a rigid molecule is included. The factors governing the absorption of quanta from the surrounding radiation field are discussed in a rudimentary derivation of a formula for the maximum linear absorption coefficient of a gas.
A new microwave Stark-effect spectrometer constructed for
an exploratory investigation is described. The instrument
operates in an unusual manner whereby the spectral position of
the absorption line is varied, while the frequency...
Sedat, John W.
General methods for the chromatography of nucleic acids on benzoylated (naphthoylated) DEAE cellulose are described. This procedure results in well-resolved peaks with good recovery and seems to separate nucleic acids on the basis of their secondary structure almost independently of their molecular weight. These methods have proved to be useful in the analysis of the replicative intermediates of MS-2 RNA, ØX RFDNA, and ØX single stranded DNA, for example.
Specific methods for the purification of E. coli.
pulse-labeled RNA based on the chromatography on benzoylated
DEAE cellulose at pH 7.5 and pH 3.5 were developed. Greater
than 60% of the pulse label with...
Rogers, Alicia Kathryn
An important characteristic for life is the ability to persist – to reproduce and defend oneself against different stresses. The ability of a species to persist from one generation to the next heavily depends on the integrity of the genetic material being passed down, and thus organisms have developed strategies to ensure the integrity of their genomes remain in tact. In Metazoan germlines, piwi proteins and their associated piwi-interacting RNAs (piRNAs) provide a RNA-interference (RNAi) based defense system against the expression of transposable elements (TEs). TE expression is detrimental to an organism’s genome – resulting in disruption of genes, double-stranded...
Above ground liquid storage tanks have suffered serious damage during earthquakes. The damage of tanks can vary from local yielding or buckling of the tank wall, to loss of contents, or to collapse which leads to an unrepairable tank. Considerable work has been carried out on this problem with varying degree of success. However, the results are largely directed toward response rather than failure prediction. The information on failure mechanisms is very limited. The present work consists of scale model testing, correlation with existing analysis and failure prediction with laboratory verification. The scale model testing incorporates dynamic similarity of the fluid/structure...
Sharon, Thomas Edward
Amorphous alloys of composition FexPd80-xP20 (13 ≤ x ≤ 44) have been prepared by rapid quenching from the liquid state. The Mössbauer effect in Fe57 has been used to study the magnetic properties of these materials. The hyperfine field distributions have been determined from these experiments, as a function of composition and temperature. The results indicate that the electronic state of Fe in these alloys remains essentially constant throughout the composition range, and that the Pd d band is filled by electron transfer from phosphorus.
The variation of the magnetic transition temperature with
composition has been determined by combining the Mössbauer effect
results with complementary magnetic measurements. There is a
Ma, Charlotte K. Lowe
The crystal structures of three iodide-containing quasi-one-dimensional conductors, (tetrathiotetracene)2(iodide)3 (high disorder), tetrathiotetracene-iodide, and (hexamethylenetetraselenofulvalene)-(iodide)x were solved by single crystal X-ray diffraction methods. These three iodides are single charge-carrier conductors and allow a comparison of such competing effects as disorder, interchain coupling, and overlap.
The crystal structure of metallic (tetrathiotetracene)2(iodide)3 (high disorder), TTT2I3 (h.d.), was solved at room temperature (~294° K), 164° K, 74° K, and at 19° K. At all four temperatures the lattice symmetry remained orthorhombic and the structures were successfully refined in the space group Cmca. During slow cooling the diffuse layer lines were also carefully monitored. In contrast...
Stroyan, Keith Duncan
We use a nonstandard model of analysis to study two main topics in complex analysis.
UNIFORM CONTINUITY AND RATES OF GROWTH OF MEROMORPHIC FUNCTIONS is a unified nonstandard approach to several theories; the Julia-Milloux theorem and Julia exceptional functions, Yosida's class (A), normal meromorphic functions, and Gavrilov's Wp classes. All of these theories are reduced to the study of uniform continuity in an appropriate metric by means of S-continuity in the nonstandard model (which was introduced by A. Robinson).
The connection with the classical Picard theorem is made through a generalization of a result of A. Robinson on S-continuous *-holomorphic functions.
S-continuity offers considerable simplifications over the standard
sequential approach and permits a...
For centuries, planet formation theories were tuned to reproduce the remarkable coplanarity of our Solar System. Specifically, the eight planetary orbital planes exhibit mutual inclinations limited to ~1−2 degrees. Furthermore, the misalignment between the Sun's spin axis and the orbital planes of the planets – the 'spin-orbit misalignment'– is only about 6 degrees. However, observational characterization of close-in extrasolar planetary systems has revealed an abundance of spin-orbit misalignments ranging all the way from 0 to 180 degrees (Winn et al. 2010). Particularly among the hot Jupiters (giant planets with orbital periods shorter than ~1 week), spin-orbit misalignments are more prevalent...
Henyey, Thomas Louis
Seventeen heat flow measurements have been made near the
San Andreas, San Jacinto, and Garlock faults of California in regions representative of several levels of seismic activity. Data from these measurements in conjunction with results of other heat flow investigations in central and southern California show no maxima directly attributable to the fault zones. This negative result along with stress-drop
results from earthquakes suggests an upper bound of the order of 200 bars for the absolute stress in the vicinity of the San Andreas fault. In addition, the average heat flow in the four regions investigated (San Bernardino Mountains - Lake Hughes,...
O'Connell, Richard John
Part 1. Analytic approximate solutions have been found for the response of a phase change to pressure loading. These solutions allow the behavior of the system to be analyzed in terms of simple parameters of the system. Different characteristic types of behavior are shown to obtain for short times and long times, and criteria for defining these characteristic time scales are given in
terms of known parameters. The distribution of heat sources and convective heat transport are shown to generally have only minor influence on the solution, and may be neglected in many cases. The important parameters are the latent heat...
Dana, Stephen Winchester
The Zoeppritz equations are used to determine the energy
partition in seismic waves reflected and refracted at the earth's core. First, the assumption is made that the core is fluid and hence does not transmit any shear waves. Then the four possible cases are treated; an incident longitudinal wave in the mantle against the core, an incident longitudinal wave in the core against the mantle, and an incident shear wave both of the SV type (particles
vibrating in the plane of incidence) and of the SH type
(particles vibrating perpendicular to the plane of incidence) in the mantle against the core. The square...
Spetzler, Hartmut A. W.
A possible explanation of the low-velocity, low-Q zone in the upper mantle is partial melting, but laboratory data has not been available to test this conjecture. As a first step in obtaining an idea of the role that partial melting plays in affecting seismic variables, the longitudinal and shear velocities and attenuations were measured in a simple binary system that is completely solid at low temperatures and involves 17% melt at the highest experimental
temperature. The system investigated was NaCl•H2O. At temperatures below the eutectic the material is a solid mixture of H2O (ice)
and NaCl•H2O. At higher temperatures the system is...
Thatcher, Wayne Raymond
A number of aspects of seismic surface wave propagation and earthquake mechanism in the Gulf of California region are investigated in this thesis. In addition, several associated problems raised by this study are also explored in some detail.
Surface wave dispersion and P-wave travel time delays are
measured to delineate the crust and upper mantle structure in the Imperial Valley-Gulf of California region. Crustal thicknesses beneath Baja California and Sonora are comparable and near 25 km, while within the Gulf crustal structure varies laterally from nearly oceanic on the
western side to continental shelf thicknesses (~20 km) towards the north and east. Love...
This thesis presents theoretical and observational investigations in two areas of cosmology: the detection of inflationary gravitational waves using the circular polarization of the redshifted 21cm line from neutral hydrogen during the Dark Ages, and the study of galactic foregrounds at low-frequencies using the Owens Valley Radio Observatory Long Wavelength Array (OVRO LWA).
In the theoretical part of this thesis, we propose a new method to measure the tensorto-scalar ratio r using the circular polarization of the 21 cm radiation from the Dark Ages. In Chapter II we discuss the basic principles of inflationary physics, which is now accepted as a...