Stabilization of gravity oriented satellites Patent

Stabilization system for gravity-oriented satellites using single damper ro

Manual abort guidance from the midcourse region of a lunar mission

Manual abort guidance from midcourse region of lunar missio

Estimation and prediction of the attitude of a passive gravity-stabilized satellite

Method for predicting attitude of passive gravity stabilized satellit

A technique for passive attitude control of solar oriented interplanetary spacecraft

Passive damping technique for attitude control of solar orientated interplanetary spacecraf

Study for fabrication, evaluation, and testing of monolayer woven type materials for space suit insulation

An alternative space suit insulation concept using a monolayer woven pile material is discussed. The material reduces cost and improves the durability of the overgarment, while providing protection similar to that provided by multilayer insulation (MLI). Twelve samples of different configurations were fabricated and tested for compressibility and thermal conductivity as a function of compression loading. Two samples which showed good results in the initial tests were further tested for thermal conductivity with respect to ambient pressure and temperature. Results of these tests were similar to results of the MLI tests, indicating the potential of the monolayer fabric to replace the present MLI. A seaming study illustrated that the fabric can be sewn in a structurally sound seam with minimal heat loss. It is recommended that a prototype thermal meteroid garment be fabricated

Robust Estimation of Integrated Volatility

We introduce a new method to estimate the integrated volatility (IV) based on noisy high-frequency data. Our method employs the ReMeDI approach introduced by Li and Linton (2021a) to estimate the moments of the microstructure noise and thereby eliminate their influence, and the pre-averaging method to target the volatility parameter. The method is robust: it can be applied when the efficient price exhibits stochastic volatility and jumps, the observation times are random and endogenous, and the noise process is nonstationary, autocorrelated and dependent on the efficient price. We derive the limit distribution for the proposed estimators under infill asymptotics in a general setting. Our simulation and empirical studies demonstrate the robustness, accuracy and computational efficiency of our estimators compared to several alternatives recently proposed in the literature

NGF-mediated transcriptional targets of p53 in PC12 neuronal differentiation

<p>Abstract</p> <p>Background</p> <p>p53 is recognized as a critical regulator of the cell cycle and apoptosis. Mounting evidence also suggests a role for p53 in differentiation of cells including neuronal precursors. We studied the transcriptional role of p53 during nerve growth factor-induced differentiation of the PC12 line into neuron-like cells. We hypothesized that p53 contributed to PC12 differentiation through the regulation of gene targets distinct from its known transcriptional targets for apoptosis or DNA repair.</p> <p>Results</p> <p>Using a genome-wide chromatin immunoprecipitation cloning technique, we identified and validated 14 novel p53-regulated genes following NGF treatment. The data show p53 protein was transcriptionally activated and contributed to NGF-mediated neurite outgrowth during differentiation of PC12 cells. Furthermore, we describe stimulus-specific regulation of a subset of these target genes by p53. The most salient differentiation-relevant target genes included <it>wnt7b </it>involved in dendritic extension and the <it>tfcp2l4/grhl3 </it>grainyhead homolog implicated in ectodermal development. Additional targets included <it>brk</it>, <it>sdk2</it>, <it>sesn3</it>, <it>txnl2</it>, <it>dusp5</it>, <it>pon3</it>, <it>lect1</it>, <it>pkcbpb15 </it>and other genes.</p> <p>Conclusion</p> <p>Within the PC12 neuronal context, putative p53-occupied genomic loci spanned the entire <it>Rattus norvegicus </it>genome upon NGF treatment. We conclude that receptor-mediated p53 transcriptional activity is involved in PC12 differentiation and may suggest a contributory role for p53 in neuronal development.</p