The effect of inertial coupling in the dynamics and control of flexible robotic manipulators

A general model of the dynamics of flexible robotic manipulators is presented, including the gross motion of the links, the vibrations of the links and joints, and the dynamic coupling between the gross motions and vibrations. The vibrations in the links may be modeled using lumped parameters, truncated modal summation, a component mode synthesis method, or a mixture of these methods. The local link inertia matrix is derived to obtain the coupling terms between the gross motion of the link and the vibrations of the link. Coupling between the motions of the links results from the kinematic model, which utilizes the method of kinematic influence. The model is used to simulate the dynamics of a flexible space-based robotic manipulator which is attached to a spacecraft, and is free to move with respect to the inertial reference frame. This model may be used to study the dynamic response of the manipulator to the motions of its joints, or to externally applied disturbances

Methods Of Measuring Visual Scanning Of Upright And Inverted Ecological Images

Facial recognition has been long held as a special perceptual process at which humans excel, and is primarily a function of perceptual experience. However, there are experimental manipulations that impede this perceptual process and make it more difficult for humans to recognize the face (i.e. only presenting half a face or inverting the face). In the case of inversion, it is though that the inverted face interrupts a person\u27s ability to process the face holistically and forces a change to featural processing. The purpose of this experiment was to examine if inversion of ecologically valid images would also impact recognition memory. In this study, individual differences in adult participant\u27s natural propensity to scan, recognition memory response latency, and recall memory for upright and inverted urban and office scenes was investigated. Overall, using a 2 (Group: Upright versus Inverted) x 3 (Trail Block) design, it was found that visual scanning rate tended to be faster for upright versus inverted images, recognition memory response latencies were significantly slower for inverted images, and rates of fixation tended to decrease across trial blocks. However, differences in fixation rates arose when assessing natural propensities to scan and during the item recall task

Explorations in Historical Method

In 1985 The Academy of Accounting Historians established a new committee named The Accounting History Research Methodology (AHRM) Committee. The Academy specified the objectives of the Committee as identifying the range of historical research methods and facilitating accounting historians\u27 access to literature on historical methodology in general. More broadly, its role was envisaged as one of encouraging a greater awareness and use of historical method in accounting history research

The effect of helium-enhanced stellar populations on the ultraviolet-upturn phenomenon of early-type galaxies

Recent observations and modeling of globular clusters with multiple populations strongly indicate the presence of super helium-rich subpopulations in old stellar systems. Motivated by this, we have constructed new population synthesis models with and without helium-enhanced subpopulations to investigate their impact on the UV-upturn phenomenon of quiescent early-type galaxies. We find that our models with helium- enhanced subpopulations can naturally reproduce the strong UV-upturns observed in giant elliptical galaxies assuming an age similar to that of old globular clusters in the Milky Way. The major source of far-UV (FUV) flux, in this model, is relatively metal- poor and helium-enhanced hot horizontal branch stars and their progeny. The Burstein et al. (1988) relation of the F U V - V color with metallicity is also explained either by the variation of the fraction of helium-enhanced subpopulations or by the spread in mean age of stellar populations in early-type galaxies.Comment: 12 pages, 4 figures, 1 table, Accepted for publication in ApJ

Emission Corrections for Hydrogen Features of the Graves et. al 2007 Sloan Digital Sky Survey Averages of Early Type, Non-liner Galaxies

For purposes of stellar population analysis, emission corrections for Balmer series indices on the Lick index system in Sloan Digital Sky Survey (SDSS) stacked quiescent galaxy spectra are derived, along with corrections for continuum shape and gross stellar content, as a function of the Mg $b$ Lick index strength. These corrections are obtained by comparing the observed Lick index measurements of the SDSS with new observed measurements of 13 Virgo Cluster galaxies, and checked with model grids. From the H$\alpha$ Mg $b$ diagram a linear correction for the observed measurement is constructed using best fit trend lines. Corrections for H$\beta$, H$\gamma$ and H$\delta$ are constructed using stellar population models to predict continuum shape changes as a function of Mg $b$ and Balmer series emission intensities typical of H{\sc II} regions. The corrections themselves are fairly secure, but the interpretation for H$\delta$ and H$\gamma$ indices is complicated by the fact that the H$\delta$ and H$\gamma$ indices are sensitive to elemental abundances other than hydrogen

Protein-tyrosine Kinase Pyk2 Mediates Endothelin-induced p38 MAPK Activation in Glomerular Mesangial Cells

Endothelin-1 (ET-1), a member of a family of 21 amino acid peptides possessing vasoconstrictor properties, is known to stimulate mesangial cell proliferation. In this study, ET-1 (100 nm) induced a rapid activation of p21(ras) in human glomerular mesangial cells (HMC). Inhibition of Src family tyrosine kinase activation with [4-Amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine] or chelation of intracellular free calcium with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester significantly decreased ET-1dependent p21(ras) activation and suggested the involvement of the cytoplasmic proline-rich tyrosine kinase Pyk2. We have observed that Pyk2 was expressed in HMC and was tyrosine-phosphorylated within 5 min of ET-1 treatment. ET-1-induced activation of Pyk2 was further confirmed using phospho-specific anti-Pyk2 antibodies. Surprisingly, Src kinase activity was required upstream of ET-1-induced autophosphorylation of Pyk2. To determine whether Pyk2 autophosphorylation mediated ET-1-dependent p21(ras) activation, adenovirus-mediated transfer was employed to express a dominant-negative form of Pyk2 (CRNK). CRNK expression inhibited ET-1-induced endogenous Pyk2 autophosphorylation, but did not abolish ET-1-mediated increases in GTP-bound p21(ras) levels. ET-1-induced activation of the p38 MAPK (but not ERK) pathway was inhibited in HMC and in rat glomerular mesangial cells expressing the dominant-negative form of Pyk2. These findings suggest that the engagement of Pyk2 is important for ET-1-mediated p38 MAPK activation and hence the biological effect of this peptide in mesangial cells

Examining influences on boys\u27 and girls\u27 physical activity patterns: the a-class project

Understanding children&rsquo;s physical activity (PA) patterns and the factors that may influence PA are important for developing interventions within this population. One hundred and ten children aged 9&ndash;0 years from 8 schools had their PA patterns assessed over 7 days. Physiological and self-report data were also collected. Multilevel analyses revealed that cardiorespiratory fitness was a consistent, significant and positive predictor of weekday and weekend PA, while the availability of home sedentary activities was a significant but negative predictor of PA. Since a range of variables were associated with PA levels, intervention developers should be cognizant of variables that may influence children&rsquo;s activity<br /

Comparing the physiological cost of step-powered video gaming, sedentary video gaming and self paced ambulatory activity in university students

Objectives: Methods for converting inactive video gaming to active video gaming have gained popularity in recent years. This study compared the physiological cost of a new peripheral device that used steps to power video gaming in an interactive manner against sedentary video gaming and self-paced ambulatory activity of university students (aged 19-29 years).Methods: Nineteen adults (9 male, 10 female) performed six 10-minute activities, namely self-paced leisurely walking, self-paced brisk walking, self-paced jogging, two forms of sedentary video gaming, and step-powered video gaming. Activities were performed in a random order. Physiological cost during the activities was measured using Actiheart.Results: Energy expenditure during step-powered video gaming (388.8 kcal.h-1) was comparable to the energy expended during brisk walking (373.8 kcal.h-1), and elicited a higher energy cost than sedentary video gaming (124.1 kcal.h-1) but a lower energy cost than jogging (694.5 kcal.h-1).Conclusion: Overall, step-powered video gaming could be used as an entertaining and appealing tool to increase physical activity, though it should not be used as a complete substitute for traditional exercise, such as jogging.<br /

DIMP53-1:A novel small-molecule dual inhibitor of p53-MDM2/X interactions with multifunctional p53-dependent anticancer properties

The transcription factor p53 plays a crucial role in cancer development and dissemination, and thus, p53-targeted therapies are among the most encouraging anticancer strategies. In human cancers with wild-type (wt) p53, its inactivation by interaction with murine double minute (MDM)2 and MDMX is a common event. Simultaneous inhibition of the p53 interaction with both MDMs is crucial to restore the tumor suppressor activity of p53. Here, we describe the synthesis of the new tryptophanol-derived oxazoloisoindolinone DIMP53-1 and identify its activity as a dual inhibitor of the p53-MDM2/X interactions using a yeast-based assay. DIMP53-1 caused growth inhibition, mediated by p53 stabilization and upregulation of p53 transcriptional targets involved in cell cycle arrest and apoptosis, in wt p53-expressing tumor cells, including MDM2- or MDMX-overexpressing cells. Importantly, DIMP53-1 inhibits the p53-MDM2/X interactions by potentially binding to p53, in human colon adenocarcinoma HCT116 cells. DIMP53-1 also inhibited the migration and invasion of HCT116 cells, and the migration and tube formation of HMVEC-D endothelial cells. Notably, in human tumor xenograft mice models, DIMP53-1 showed a p53-dependent antitumor activity through induction of apoptosis and inhibition of proliferation and angiogenesis. Finally, no genotoxicity or undesirable toxic effects were observed with DIMP53-1. In conclusion, DIMP53-1 is a novel p53 activator, which potentially binds to p53 inhibiting its interaction with MDM2 and MDMX. Although target-directed, DIMP53-1 has a multifunctional activity, targeting major hallmarks of cancer through its antiproliferative, proapoptotic, antiangiogenic, anti-invasive, and antimigratory properties. DIMP53-1 is a promising anticancer drug candidate and an encouraging starting point to develop improved derivatives for clinical application