Corneal asphericity in eye bank eyes implanted with the intrastromal corneal ring

The endogenous circadian rhythm of melatonin in humans provides information regarding the resetting response of the human circadian timing system to changes in the light-dark (LD) cycle. Alterations in the LD cycle have both acute and chronic effects on the observed melatonin rhythm. Investigations to date have firmly established that the melatonin rhythm can be reentrained following an inversion of the LD cycle. Exposure to bright light and darkness given over a series of days can rapidly induce large-magnitude phase shifts of the melatonin rhythm. Even single pulses of bright light can shift the timing of the melatonin rhythm. Recent data have demonstrated that lower light intensities than originally believed are capable of resetting the melatonin rhythm and that stimulation of photopically sensitive photoreceptors (i.e., cones) is sufficient to reset the endogenous circadian melatonin rhythm. In addition to phase resetting, exposure to light of critical timing, strength, and duration can attenuate the amplitude of the endogenous circadian rhythm of melatonin. Measurement of melatonin throughout resetting trials provides a dynamic view of the resetting response of the human circadian pacemaker to light. Future studies of the melatonin rhythm in humans may further characterize the resetting response of the human circadian timing system to light.     

An index of relationship quality based on attachment theory.

Two measures are reported of the nature or quality of a mother-offspring (MO) relationship during development using brown capuchin monkeys (Cebus apella) as models. One is a qualitative classification of MO relationships as secure, resistant, or avoidant attachments. The other is an empirical ratio of relative affiliation to agonism called the MO relationship quality, or MORQ, Index. The two methods tapped similar relationship features so relationships high or low of a median split of MORQ values were heuristically labeled secure (n = 22) or insecure (n = 16), respectively. A comparison revealed extensive behavioral differences between secure and insecure MO relationships and suggested MORQ provided an objective, continuous measure of attachment security. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Atomic Clocks and Oscillators for Deep-Space Navigation and Radio Science

This paper describes new oscillator and atomic clock technologies that, when combined, create a master oscillator for use in deep-space navigation and science measurements. This atomic clock promises to execute spacecraft navigation using a one-way downlink only method, saving many millions of dollars per year. We will describe the complementary technology developments by the Jet Propulsion Laboratory toward a space-ready mercury atomic-ion clock and by the Applied Physics Laboratory, Johns Hopkins University, in reducing the size, mass, and operating power of its quartz, ultrastable oscillator.     

Functional interactions of genes mediating convergent extension, knypek and trilobite, during the partitioning of the eye primordium in zebrafish

Vertebrate eye development in the anterior region of the neural plate involves a series of inductive interactions dependent on the underlying prechordal plate and signals from the midline of the neural plate, including Hedgehog. The mechanisms controlling the spatiotemporal expression pattern of hedgehog genes are currently not understood. Cyclopia is observed in trilobite (tri) and knypek (kny) mutants with affected convergent extension of the embryonic axis during gastrulation. Here, we demonstrate that tri mutants show a high frequency of partial or complete cyclopia, kny mutants exhibit cyclopia infrequently, while knym119 trim209 double-mutant embryos have dramatically reduced convergent extension and are completely cyclopic. We analyzed the relationships between the convergent extension defect, the expression of hedgehog and prechordal plate genes, and the formation of cyclopia in knym119 and trim209 mutants. Our results correlate the cyclopia phenotype with the abnormal location of hh-expressing cells with respect to the optic primordium. We show that cyclopia in these mutants is not due to an incompetence of tri and kny cells to respond to Hedgehog signaling. Rather, it is a consequence of exceeding a critical distance (>40-50 micrometer) between hedgehog-expressing cells and the prospective eye field. We hypothesize that at this distance, midline cells are not in an appropriate position to physically separate the eye field and that HH and other signals do not reach the appropriate target cells. Furthermore, tri and kny have overlapping functions in establishing proper alignment of the anterior neural plate and midline cells expressing shh and twhh genes when the partitioning of the eye primordium takes place.     

New aspects of unsaturated polyester resin synthesis. Part 2. Reactant sequence distribution and its effect on cure kinetics

The distribution of unsaturations in the prepolymer of a typical unsaturated polyester (UP) resin (maleic anhydride, phthalic anhydride and 1,2‐propylene glycol) has been shown to influence the kinetics of the cure process with styrene monomer. Segments containing double bonds in close proximity appear to lower the reactivity of the resin due to steric hindrance, as indicated by the fact that the rate of cure and the final degree of cure, measured by differential scanning calorimetry (DSC), increase as the average sequence length (SL) of maleic units decreases. This implies that the reactivity of UP resins may be improved by synthesis of prepolymers with certain reactant sequence‐length distributions. The copolymer formed by the melt condensation process of maleic anhydride, phthalic anhydride and 1,2‐propylene glycol in the absence of a transesterification catalyst has a non‐random structure with a tendency towards blockiness. This was established using ¹H NMR analysis in tandem with deterministic and Monte Carlo modelling techniques. Copyright © 2003 Society of Chemical Industry     

Effect of immunotherapy on sCD23 levels in patients allergic to Hymenoptera venom

BACKGROUND: sCD23 is the designation given to the low affinity IgE receptor. The soluble fragment of this receptor (sCD23) participates in the regulation of IgE synthesis. OBJECTIVE: The purpose of this study is to examine the effect of a venom immunotherapy regimen on sCD23 levels. METHODS: We measured sCD23 levels by ELISA in Hymenoptera venom-allergic patients (positive skin tests and a history of systemic reactions to Hymenoptera sting) in serial sera collected over a course of venom immunotherapy with a mean duration of 54 months. Mean pre-sCD23 and post-sCD23 levels were compared using a Student's two-tailed t test. RESULTS: sCD23 levels were found to be unchanged over the course of venom immunotherapy. CONCLUSIONS: This is the first longitudinal study that has been done. It suggests that while both immunotherapy and sCD23 are known to be involved in the regulations of IgE synthesis in the atopic patient, the immunomodulation seen in venom immunotherapy is not mediated through sCD23 in any simple regulatory manner.     

Enhancement of oxidative cell injury and antitumor effects of localized 44 degrees C hyperthermia upon combination with respiratory hyperoxia and xanthine oxidase

Polymerase chain reaction (PCR) assays were designed to amplify 56- and 99-base regions of the pmoA gene from Methylosinus trichosporium OB3b and Methylomicrobium albus BG8, two species of methanotrophic bacteria that are of interest for monitoring bioremediation activity. The PCR product sizes are in a mass range that is accessible to analysis by MALDI-TOF mass spectrometry. A rapid purification procedure using commercially available reversed-phase cartridges was applied prior to MALDI-TOF analysis. A small aliquot (1.5%, 1.5 microL) from a single 100-microL PCR reaction was sufficient for reliable detection. No cross-amplification products were observed when primers designed for one bacterial species were used with genomic DNA of the other species. The methodology described here has potential to allow less expensive and faster characterization of the ability of microbial populations to destroy pollutants in groundwater and soil at contaminated industrial sites.