Homosexuality: out of the educational closet

This article confronts the issue of homosexuality as it relates to the school. The treatment that educators have generally given to homosexuality reflects an unfortunate potpourri of prejudice and misinformation that is shared by a great portion of the public. This article provides basic information to educators who have not been in a position to objectively consider the issue of homosexuality and the school, and attempts to nudge educators toward further fact-finding and consideration of the problems so that they foster change in their schools and communities

Isoenergetic penta- and hexanucleotide microarray probing and chemical mapping provide a secondary structure model for an RNA element orchestrating R2 retrotransposon protein function

LNA (locked nucleic acids, i.e. oligonucleotides with a methyl bridge between the 2′ oxygen and 4′ carbon of ribose) and 2,6-diaminopurine were incorporated into 2′-O-methyl RNA pentamer and hexamer probes to make a microarray that binds unpaired RNA approximately isoenergetically. That is, binding is roughly independent of target sequence if target is unfolded. The isoenergetic binding and short probe length simplify interpretation of binding to a structured RNA to provide insight into target RNA secondary structure. Microarray binding and chemical mapping were used to probe the secondary structure of a 323 nt segment of the 5′ coding region of the R2 retrotransposon from Bombyx mori (R2Bm 5′ RNA). This R2Bm 5′ RNA orchestrates functioning of the R2 protein responsible for cleaving the second strand of DNA during insertion of the R2 sequence into the genome. The experimental results were used as constraints in a free energy minimization algorithm to provide an initial model for the secondary structure of the R2Bm 5′ RNA

Genetic control of mammalian T-cell proliferation with synthetic RNA regulatory systems

RNA molecules perform diverse regulatory functions in natural biological systems, and numerous synthetic RNA-based control devices that integrate sensing and gene-regulatory functions have been demonstrated, predominantly in bacteria and yeast. Despite potential advantages of RNA-based genetic control strategies in clinical applications, there has been limited success in extending engineered RNA devices to mammalian gene-expression control and no example of their application to functional response regulation in mammalian systems. Here we describe a synthetic RNA-based regulatory system and its application in advancing cellular therapies by linking rationally designed, drug-responsive, ribozyme-based regulatory devices to growth cytokine targets to control mouse and primary human T-cell proliferation. We further demonstrate the ability of our synthetic controllers to effectively modulate T-cell growth rate in response to drug input in vivo. Our RNA-based regulatory system exhibits unique properties critical for translation to therapeutic applications, including adaptability to diverse ligand inputs and regulatory targets, tunable regulatory stringency, and rapid response to input availability. By providing tight gene-expression control with customizable ligand inputs, RNA-based regulatory systems can greatly improve cellular therapies and advance broad applications in health and medicine

Galactic winds driven by cosmic-ray streaming

Galactic winds are observed in many spiral galaxies with sizes from dwarfs up to the Milky Way, and they sometimes carry a mass in excess of that of newly formed stars by up to a factor of ten. Multiple driving processes of such winds have been proposed, including thermal pressure due to supernova-heating, UV radiation pressure on dust grains, or cosmic ray (CR) pressure. We here study wind formation due to CR physics using a numerical model that accounts for CR acceleration by supernovae, CR thermalization, and advective CR transport. In addition, we introduce a novel implementation of CR streaming relative to the rest frame of the gas. We find that CR streaming drives powerful and sustained winds in galaxies with virial masses M_200 < 10^{11} Msun. In dwarf galaxies (M_200 ~ 10^9 Msun) the winds reach a mass loading factor of ~5, expel ~60 per cent of the initial baryonic mass contained inside the halo's virial radius and suppress the star formation rate by a factor of ~5. In dwarfs, the winds are spherically symmetric while in larger galaxies the outflows transition to bi-conical morphologies that are aligned with the disc's angular momentum axis. We show that damping of Alfven waves excited by streaming CRs provides a means of heating the outflows to temperatures that scale with the square of the escape speed. In larger haloes (M_200 > 10^{11} Msun), CR streaming is able to drive fountain flows that excite turbulence. For halo masses M_200 > 10^{10} Msun, we predict an observable level of H-alpha and X-ray emission from the heated halo gas. We conclude that CR-driven winds should be crucial in suppressing and regulating the first epoch of galaxy formation, expelling a large fraction of baryons, and - by extension - aid in shaping the faint end of the galaxy luminosity function. They should then also be responsible for much of the metal enrichment of the intergalactic medium.Comment: 25 pages, 14 figures, accepted by MNRA

Astrometry and geodesy with radio interferometry: experiments, models, results

Summarizes current status of radio interferometry at radio frequencies between Earth-based receivers, for astrometric and geodetic applications. Emphasizes theoretical models of VLBI observables that are required to extract results at the present accuracy levels of 1 cm and 1 nanoradian. Highlights the achievements of VLBI during the past two decades in reference frames, Earth orientation, atmospheric effects on microwave propagation, and relativity.Comment: 83 pages, 19 Postscript figures. To be published in Rev. Mod. Phys., Vol. 70, Oct. 199

What's in a copy?

ABSTRACTI will answer the question “What’s in a copy?” by considering three sets of related issues: the importance of copies in academia; in cultural life; and in the economic world. In academia the current capability of making copies is challenging pedagogical practices and the trust of its members, plagiarism being the most immediate problem. The notion of authorship is also undergoing changes provoked by a proliferation of authors and new possibilities opened up by cyberspace. In cultural life, imitation and mimesis have long been fundamental engines of socialization. Our enhanced capacity of copying problematizes, with new intensity, the relationships between homogeneity and heterogeneity, between the genuine and the spurious. In the economic world, the digital era is threatening some of the fundamental tenets of capitalism, especially of its variant called the “knowledge society”, regarding the control of intellectual property rights. The gap between normativity and social practices is widening. The many dilemmas and tensions identified in the text are understood as symptoms of two major characteristics of the current times: hyperfetishism and hyperanimism. ________________________________________________________________________________ RESUMOResponderei à pergunta “O que existe em uma cópia?” considerando três conjuntos de questões relacionadas: a importância das cópias na academia, na vida cultural, no mundo econômico. Na academia a presente capacidade de fazer cópias está desafiando práticas pedagógicas e a confiança dos seus membros, o plágio sendo o problema mais imediato. A noção de autoria também está sofrendo mudanças provocadas por uma proliferação de autores e novas possibilidades abertas pelo ciberespaço. Na vida cultural, a imitação e a mimese de há muito são importantes motores de socialização. A nossa capacidade ampliada de fazer cópias problematiza, com nova intensidade, as relações entre homogeneidade e heterogeneidade, entre o genuíno e o espúrio. No mundo econômico, a era digital ameaça algumas das premissas fundamentais do capitalismo, especialmente da sua variante “sociedade do conhecimento”, no tocante aos direitos de propriedade intelectual. Cresce a distância entre normatividade e práticas sociais. Os muitos dilemas e tensões identificados no texto são compreendidos como sintomas de duas grandes características do presente: o hiperfetichismo e o hiperanimismo

1963: Abilene Christian College Bible Lectures - Full Text

THE CHRISTIAN AND MORALITY” Being the Abilene Christian College Annual Bible Lectures 1963 Price: $3.95 Published by ABILENE CHRISTIAN COLLEGE STUDENTS EXCHANGE ACC Station Abilene, Texa