Design of a Torque Current Generator for Strapdown Gyroscopes

The design, analysis, and experimental evaluation of an optimum performance torque current generator for use with strapdown gyroscopes, is presented. Among the criteria used to evaluate the design were the following: (1) steady-state accuracy; (2) margins of stability against self-oscillation; (3) temperature variations; (4) aging; (5) static errors drift errors, and transient errors, (6) classical frequency and time domain characteristics; and (7) the equivalent noise at the input of the comparater operational amplifier. The DC feedback loop of the torque current generator was approximated as a second-order system. Stability calculations for gain margins are discussed. Circuit diagrams are shown and block diagrams showing the implementation of the torque current generator are discussed

Spillovers from Foreign Direct Investment in Central and Eastern Europe. An index for measuring a country’s potential to benefit from technology spillovers

In the paper, we construct a composite indicator to estimate the potential of four Central and Eastern European countries (the Czech Republic, Hungary, Poland and Slovakia) to benefit from productivity spillovers from foreign direct investment (FDI) in the manufacturing sector. Such transfers of technology are one of the main benefits of FDI for the host country, and should also be one of the main determinants of FDI incentives offered to investing multinationals by governments, but they are difficult to assess ex ante. For our composite index, we use six components to proxy the main channels and determinants of these spillovers. We have tried several weighting and aggregation methods, and we consider our results robust. According to the analysis of our results, between 2003 and 2007 all four countries were able to increase their potential to benefit from such spillovers, although there are large differences between them. The Czech Republic clearly has the most potential to benefit from productivity spillovers, while Poland has the least. The relative positions of Hungary and Slovakia depend to some extent on the exact weighting and aggregation method of the individual components of the index, but the differences are not large. These conclusions have important implication both the investment strategies of multinationals and government FDI policies

Managing the Socially Marginalized: Attitudes Towards Welfare, Punishment and Race

Welfare and incarceration policies have converged to form a system of governance over socially marginalized groups, particularly racial minorities. In both of these policy areas, rehabilitative and social support objectives have been replaced with a more punitive and restrictive system. The authors examine the convergence in individual-level attitudes concerning welfare and criminal punishment, using national survey data. The authors\u27 analysis indicates a statistically significant relationship between punitive attitudes toward welfare and punishment. Furthermore, accounting for the respondents\u27 racial attitudes explains the bivariate relationship between welfare and punishment. Thus, racial attitudes seemingly link support for punitive approaches to opposition to welfare expenditures. The authors discuss the implications of this study for welfare and crime control policies by way of the conclusion

What’s Sex (Composition) Got to Do with It? The Importance of Sex Composition of Gangs for Female and Male Members’ Offending and Victimization

Sex composition of groups has been theorized in organizational sociology and found in prior work to structure female and male members’ behaviors and experiences. Peer group and gang literature similarly finds that the sex gap in offending varies across groups of differing sex ratios. Drawing on this and other research linking gang membership, offending, and victimization, we examine whether sex composition of gangs is linked to sex differences in offending in this sample, further assess whether sex composition similarly structures females’ and males’ victimization experiences, and if so, why. Self-report data from gang members in a multi-site, longitudinal study of 3,820 youths are employed. Results support previous findings about variations in member delinquency by both sex and sex composition of the gang and also indicate parallel variations in members’ victimization. These results are further considered within the context of facilitating effects such as gender dynamics, gang characteristics, and normative orientation

Laser Pulse Production for NASA's Global Ecosystem Dynamics Investigation (GEDI) Lidar

The Lasers and Electro-Optics Branch at Goddard Space Flight Center has been tasked with building the Lasers for the Global Ecosystems Dynamics Investigation (GEDI) Lidar Mission, to be installed on the Japanese Experiment Module (JEM) on the International Space Station (ISS). GEDI will use three NASA-developed lasers, each coupled with a Beam Dithering Unit (BDU) to produce three sets of staggered footprints on the Earth's surface to accurately measure global biomass. We will report on the design, assembly progress, test results, and delivery process of this laser system

Asymmetric intergroup bullying: the enactment and maintenance of societal inequality at work

What does inequality mean for dysfunctional organizational behaviours, such as workplace bullying? This article argues that workplace bullying can be understood as a manifestation of intergroup dynamics originating beyond the organization. We introduce the construct of asymmetric intergroup bullying: the disproportionate mistreatment of members of low status groups, with the intended effect of enhancing the subordination of that group in society at large. Analysis of data from 38 interviews with public and private sector workers in Turkey depicts a pattern of asymmetric intergroup bullying, undertaken to achieve organizational and broader sociopolitical goals. Respondents reported bullying acts used to get rid of unwanted personnel, with the goal of avoiding severance pay, or of removing supporters of the former government from positions of political and economic influence. Bullying was also described as working towards the dominance of the sociocultural worldview of one political group over another. We discuss asymmetric intergroup bullying as one mechanism through which acute intergroup hierarchy in the broader society corrupts management practice and employee interactions, in turn exacerbating economic inequality along group lines

The Effect Of Powerpoint On Student Performance In Principles Of Economics: An Exploratory Study

Due to technological advances and media-savvy college students, the use of multimedia presentations on college campuses has increased rapidly. Both faculty and students think that multimedia presentations enhance learning. Empirical evidence supporting these perceptions is inconsistent, however. The purpose of this study is to empirically test whether multimedia presentation formats improve student learning of economics over traditional lecture methods. The results indicate that multimedia presentations can improve test scores significantly. Additionally, students who are above-average academic performers receive more benefit from multimedia presentations than students of below-average academic performance.&nbsp

Retargeted adenoviruses for radiation-guided gene delivery

The combination of radiation with radiosensitizing gene delivery or oncolytic viruses promises to provide an advantage that could improve the therapeutic results for glioblastoma. X-rays can induce significant molecular changes in cancer cells. We isolated the GIRLRG peptide that binds to radiation-inducible 78 kDa glucose-regulated protein (GRP78), which is overexpressed on the plasma membranes of irradiated cancer cells and tumor-associated microvascular endothelial cells. The goal of our study was to improve tumor-specific adenovirus-mediated gene delivery by selectively targeting the adenovirus binding to this radiation-inducible protein. We employed an adenoviral fiber replacement approach to conduct a study of the targeting utility of GRP78-binding peptide. We have developed fiber-modified adenoviruses encoding the GRP78-binding peptide inserted into the fiber-fibritin. We have evaluated the reporter gene expression of fiber-modified adenoviruses in vitro using a panel of glioma cells and a human D54MG tumor xenograft model. The obtained results demonstrated that employment of the GRP78-binding peptide resulted in increased gene expression in irradiated tumors following infection with fiber-modified adenoviruses, compared with untreated tumor cells. These studies demonstrate the feasibility of adenoviral retargeting using the GRP78-binding peptide that selectively recognizes tumor cells responding to radiation treatment

Regulation of the Mitogen Activated Protein Kinase Kinase (MEK)-1 by NAD-Dependent Deacetylases

Sirtuins are class III deacetylases that regulate many essential processes, including cellular stress, genome stability, and metabolism. Although these NAD+-dependent deacetylases control adaptive cellular responses, identification of sirtuin-regulated signaling targets remain under-studied. Here, we demonstrate that acetylation of the mitogen-activated protein kinase kinase-1 (MEK1) stimulates its kinase activity, and that acetylated MEK1 is under the regulatory control of the sirtuin family members SIRT1 and SIRT2. Treatment of cells with sirtuin inhibitors, or siRNA knockdown of SIRT1 or SIRT2 proteins, increases MEK1 acetylation and subsequent phosphorylation of the extracellular signal-regulated kinase (ERK). Generation of an acetyl-specific MEK1 antibody demonstrates that endogenous acetylated MEK1 is extensively enriched in the nucleus following epidermal growth factor (EGF) stimulation. An acetyl-mimic of MEK1 increases inappropriate growth properties, suggesting that acetylation of MEK1 has oncogenic potential