Studies on serum somatedin activity and cartilage responsiveness in the regulation of growth

A Thesis Submitted to the Faculty of Science University of the Witwatersrand, Johannesburg for the Degree of Doctor of Philosophy Johannesburg 1976This thesis describes the results of experimental investigation of aspects of the endocrine regulation of growth in the rabbit, rat and man. In particular the role of serum somatomedin and cartilage responsiveness to somatomedin have been examined. Throughout a relationship between the physiological control mechanisms, namely the stimulus and the degree of end- organ responsiveness, and the velocity of growth has been sought.IT201

Optimization and evaluation of the performance of thin-film molecularly imprinted polymers for the analysis of cotinine in fluids from human subjects

Molecularly imprinted polymers (MIPs) are cross-linked synthetic polymers that can selectively take up target analytes from a solution. They are often used in bulk format for solid phase extraction and HPLC. In this work, the main goal was to develop MIPs in a thin-film format for direct analysis of analyte species by desorption electrospray ionization-mass spectrometry (DESI-MS). A cotinine template was used with methacrylic acid (MAA) monomer and ethyleneglycol dimethacrylate (EDGMA) cross-linker to synthesize these MIPs. Cotinine is the primary metabolite of nicotine and was chosen as the template due to its high concentration in biological fluids from smokers and non-smokers. Optimization of the ratios of polymer components (template:monomer:cross-linker) and porogen was completed using a modified Box-Behnken experimental design. Each composition tested was assessed for polymer robustness, imprinting factor and sorption capacity. The optimal molar ratio was 1:2:22.5 (template:monomer:cross-linker), with 239 μL porogen added for each 0.02 mol of template. Template removal from the MIP was studied and reduced from 2 h to 100 min. For optimal analyte uptake, MIPs were placed for 90 min in samples buffered at pH 7.0. Cotinine was quantified in extracts using GC-MS. Myosmine, B-nicotyrine, 1-phenyl-3-pyrazolidinone and nicotine-N-oxide were used as pseudo-templates to overcome template bleed were studied but with little success due to the lack of uptake by these pseudo-templates. Scanning electron microscopy showed that the MIPs were porous and up to approximately 0.05 μm in diameter. Cotinine calibration curves for human urine spiked with cotinine gave results of R²=0.6 with n=2. Testing with saliva samples did not produce any promising results. Proof of principle was demonstrated for detection of cotinine using MIPs with DESI-MS

A numerical adaptation of SAW identities from the honeycomb to other 2D lattices

Recently, Duminil-Copin and Smirnov proved a long-standing conjecture by Nienhuis that the connective constant of self-avoiding walks on the honeycomb lattice is $\sqrt{2+\sqrt{2}}.$ A key identity used in that proof depends on the existence of a parafermionic observable for self-avoiding walks on the honeycomb lattice. Despite the absence of a corresponding observable for SAW on the square and triangular lattices, we show that in the limit of large lattices, some of the consequences observed on the honeycomb lattice persist on other lattices. This permits the accurate estimation, though not an exact evaluation, of certain critical amplitudes, as well as critical points, for these lattices. For the honeycomb lattice an exact amplitude for loops is proved.Comment: 21 pages, 7 figures. Changes in v2: Improved numerical analysis, giving greater precision. Explanation of why we observe what we do. Extra reference

Nova Scotia Barristers’ Society v Leahey

he Hearing Panel of the Hearing Subcommittee, empanelled by the Chair of the Hearing Subcommittee in accordance with Regulation 40 of the Nova Scotia Barristers’ Society Regulations (hereafter, the Regulations ) made under the authority in s. 59 of the Barristers and Solicitors Act, R.S.N.S 1989, as am.(hereafter, the Act ) to hear and decide this matter, consisted of: G. Wayne Beaton, QC David K. Macdonald Dr, Charles T. Schafer Philip J. Star, QC Innis Christie, QC, Chair The Panel met to hear evidence and submissions by counsel on July 9, 10, 11 and12, and on August 14, 15, 16. The Society was represented by Alan Stern, QC . Mr. Leahey was represented by Raymond Riddel, QC in the July days of hearing and thereafter by himself. The final written submission by Mr. Leahey was received on September 26, 2002

Translational Vestibulo-Ocular Reflex and Motion Perception During Interaural Linear Acceleration: Comparison of Different Motion Paradigms

The neural mechanisms to resolve ambiguous tilt-translation motion have been hypothesized to be different for motion perception and eye movements. Previous studies have demonstrated differences in ocular and perceptual responses using a variety of motion paradigms, including Off-Vertical Axis Rotation (OVAR), Variable Radius Centrifugation (VRC), translation along a linear track, and tilt about an Earth-horizontal axis. While the linear acceleration across these motion paradigms is presumably equivalent, there are important differences in semicircular canal cues. The purpose of this study was to compare translation motion perception and horizontal slow phase velocity to quantify consistencies, or lack thereof, across four different motion paradigms. Twelve healthy subjects were exposed to sinusoidal interaural linear acceleration between 0.01 and 0.6 Hz at 1.7 m/s/s (equivalent to 10 tilt) using OVAR, VRC, roll tilt, and lateral translation. During each trial, subjects verbally reported the amount of perceived peak-to-peak lateral translation and indicated the direction of motion with a joystick. Binocular eye movements were recorded using video-oculography. In general, the gain of translation perception (ratio of reported linear displacement to equivalent linear stimulus displacement) increased with stimulus frequency, while the phase did not significantly vary. However, translation perception was more pronounced during both VRC and lateral translation involving actual translation, whereas perceptions were less consistent and more variable during OVAR and roll tilt which did not involve actual translation. For each motion paradigm, horizontal eye movements were negligible at low frequencies and showed phase lead relative to the linear stimulus. At higher frequencies, the gain of the eye movements increased and became more inphase with the acceleration stimulus. While these results are consistent with the hypothesis that the neural computational strategies for motion perception and eye movements differ, they also indicate that the specific motion platform employed can have a significant effect on both the amplitude and phase of each

Comparative Analysis of TRGBs (CATs) from Unsupervised, Multi-Halo-Field Measurements: Contrast is Key

The Tip of the Red Giant Branch (TRGB) is an apparent discontinuity in the color-magnitude diagram (CMD) along the giant branch due to the end of the red giant evolutionary phase and is used to measure distances in the local universe. In practice, the tip is often fuzzy and its localization via edge detection response (EDR) relies on several methods applied on a case-by-case basis. It is hard to evaluate how individual choices affect a distance estimation using only a single host field while also avoiding confirmation bias. To devise a standardized approach, we compare unsupervised, algorithmic analyses of the TRGB in multiple halo fields per galaxy, up to 11 fields for a single host and 50 fields across 10 galaxies, using high signal-to-noise stellar photometry obtained by the GHOSTS survey with the Hubble Space Telescope. We first optimize methods for the lowest field-to-field dispersion including spatial filtering to remove star forming regions, smoothing and weighting of the luminosity function, selection of the RGB by color, and tip selection based on the number of likely RGB stars and the ratio of stars above versus below the tip ($R$). We find $R$, which we call the tip `contrast', to be the most important indicator of the quality of EDR measurements; we find that field-to-field EDR repeatability varies from 0.3 mag to $\leq$ 0.05 mag for $R=4$ to 7, respectively, though less than half the fields reach the higher quality. Further, we find that $R$, which varies with the age/metallicity of the stellar population based on models, correlates with the magnitude of the tip (and after accounting for low internal extinction), i.e., a tip-contrast relation with slope of $-0.023\pm0.0046$ mag/ratio, a $\sim 5\sigma$ result that improves standardization of the TRGB. We discuss the value of consistent TRGB standardization across rungs for robust distance ladder measurements.Comment: Submitted to ApJ. Comments welcome

Automobile emissions in Mexico City

In order to determine the exhaust characteristics of the Mexico City vehicle fleet, a Fuel Efficiency Automotive Test (FEAT) unit was placed at 5 different sites over a 10 day period from 11 February 1991 through 21 February 1991. Valid data for the percent of carbon Monoxide (CO), hydrocarbons (HC), and carbon dioxide (CO{sub 2}) were obtained on 31 838 vehicles. This represents approximately 1 % of the entire Mexico City fleet

An examination of the influence of prenatal sex hormones on handedness: Literature review and amniotic fluid data

Competing theories have posited roles for foetal androgen exposure in the development of human handedness. However, due to practical and ethical considerations, few studies have used hormonal measures to examine this possibility. The current paper reviews this literature and reveals a generally inconsistent pattern of results. We also present data from a longitudinal study of prenatal sex hormone exposure and subsequent handedness. More specifically, we examine correlations between testosterone and estradiol measured from second trimester amniotic fluid and hand preference (Dutch language version of the Edinburgh Handedness Inventory) and hand skill asymmetry (pegboard task) measured at 15 years of age. Prenatal sex hormone exposure was not associated with the direction of hand preference in either males or females. However, in females, high levels of prenatal testosterone were associated with weaker lateralisation of hand skill, and high levels of prenatal estradiol were associated with weaker hand preference. In addition, high levels of prenatal testosterone were associated with increased task duration (i.e., slow hand speed) for the right and left hands of males. The pattern of results observed here is not entirely consistent with any of the main theories linking sex hormones with handedness, suggesting that an association between these variables may be more complex than initially thought