Surface composition and erosion yields for CVD TiB/sub 2/ films subjected to low energy deuterium ion bombardment

The surface composition and low energy sputter yield of deuterium bombarded CVD TiB/sub 2/ films have been measured. The sputter yield increases with energy up to 1 keV where it reaches a maximum of 0.024 atoms/ion. Above 1 keV the yield decreases due to ion penetration effects. Surface composition measurements using Auger, x-ray photoelectron and secondary ion mass spectroscopies show that a surface layer about 200 A thick is depleted in B during 2 keV deuterium bombardment. This effect is attributed to preferential sputtering. Oxides and deuterides of titanium are also observed on the deuterium bombardment TiB/sub 2/ surface

A structural role for arginine in proteins: Multiple hydrogen bonds to backbone carbonyl oxygens

We propose that arginine side chains often play a previously unappreciated general structural role in the maintenance of tertiary structure in proteins, wherein the positively charged guanidinium group forms multiple hydrogen bonds to backbone carbonyl oxygens. Using as a criterion for a “structural” arginine one that forms 4 or more hydrogen bonds to 3 or more backbone carbonyl oxygens, we have used molecular graphics to locate arginines of interest in 4 proteins: Arg 180 in Thermus thermophilus manganese superoxide dismutase, Arg 254 in human carbonic anhydrase II, Arg 31 in Streptomyces rubiginosus xylose isomerase, and Arg 313 in Rhodospirillum rubrum ribulose‐1,5‐bisphosphate carboxylase/oxygenase. Arg 180 helps to mold the active site channel of superoxide dismutase, whereas in each of the other enzymes the structural arginine is buried in the “mantle” (i.e., inside, but near the surface) of the protein interior well removed from the active site, where it makes 5 hydrogen bonds to 4 backbone carbonyl oxygens. Using a more relaxed criterion of 3 or more hydrogen bonds to 2 or more backbone carbonyl oxygens, arginines that play a potentially important structural role were found in yeast enolase, Bacillus stearothermophilus glyceraldehyde‐3‐phosphate dehydrogenase, bacteriophage T4 and human lysozymes, Enteromorpha prolifera plastocyanin, HIV‐1 protease, Trypanosoma brucei brucei and yeast triosephosphate isomerases, and Escherichia coli trp aporepressor (but not trp repressor or the trp repressor/operator complex). In addition to helping form the active site funnel in superoxide dismutase, the structural arginines found in this study play such diverse roles as stapling together 3 strands of backbone from different regions of the primary sequence, and tying α‐helix to α‐helix, βturn to β‐turn, and subunit to subunit. Copyright © 1994 The Protein Societ

Surrogate: A Body-Dexterous Mobile Manipulation Robot with a Tracked Base

Robotics platforms in accordance with various embodiments of the invention can be utilized to implement highly dexterous robots capable of whole body motion. Robotics platforms in accordance with one embodiment of the invention include: a memory containing a whole body motion application; a spine, where the spine has seven degrees of freedom and comprises a spine actuator and three spine elbow joints that each include two spine joint actuators; at least one limb, where the at least one limb comprises a limb actuator and three limb elbow joints that each include two limb joint actuators; a tracked base; a connecting structure that connects the at least one limb to the spine; a second connecting structure that connects the spine to the tracked base; wherein the processor is configured by the whole body motion application to move the at least one limb and the spine to perform whole body motion

Robotics Platforms Incorporating Manipulators Having Common Joint Designs

Manipulators in accordance with various embodiments of the invention can be utilized to implement statically stable robots capable of both dexterous manipulation and versatile mobility. Manipulators in accordance with one embodiment of the invention include: an azimuth actuator; three elbow joints that each include two actuators that are offset to allow greater than 360 degree rotation of each joint; a first connecting structure that connects the azimuth actuator and a first of the three elbow joints; a second connecting structure that connects the first elbow joint and a second of the three elbow joints; a third connecting structure that connects the second elbow joint to a third of the three elbow joints; and an end-effector interface connected to the third of the three elbow joints

Five Ws and an H: Digital Challenges in Newspaper Newsrooms and Boardrooms

It is no news to anyone involved with the media, from the newsroom to the boardroom to the classroom, that journalism is at a crossroads as an occupation, a business, a content form, and a public good. This is perhaps particularly true of journalism in the traditional news medium of record, the newspaper, where enormous uncertainty surrounds virtually every facet of the enterprise as it adjusts to being part of a digital network. This essay uses a framework familiar to journalists and journalism educators -- the traditional “five Ws and an H” of who, what, when, where, why, and how -- to address some of the significant issues facing corporate and newsroom managers, as well as journalists themselves

Counselor Education and Supervision

Abstract: Approaches to mentoring junior faculty in counselor education departments have received minimal attention in the counseling literature. In this article, the authors describe a successful program based on the 10 principles for good mentoring recommended b

Fatal flaws in the UK asylum decision-making system: an analysis of Home Office refusal letters

The process of deciding who is in need of international protection is well established most western liberal democracies, and has been subject to critical scrutiny for decades. And yet asylum seekers remain vulnerable to serious and ongoing flaws in that system. In this paper, based on research conducted in Afghanistan 2012–2018, Schuster explores a number of shortcomings in the asylum decision-making process, specifically with regard to the rejection of claims from Afghans. The analysis of Reasons for Refusal Letters, allows Schuster to examine the use of key tools in that process (previous cases and country of origin reports). Schuster argues that the current adversarial approach, which seeks to prove an applicant is not credible or does not need protection, undermines the legitimacy of the asylum and risks refusing protection to those in need and or condemning others to years of damaging appeals before they are granted asylum. She concludes by arguing for a shift to a more investigative approach, one that seeks to identify those in need of protection, rather than to keep numbers low

Measurement of the WW Boson Mass

A measurement of the mass of the $W$ boson is presented based on a sample of 5982 $W \rightarrow e \nu$ decays observed in $p\overline{p}$ collisions at $\sqrt{s}$ = 1.8~TeV with the D\O\ detector during the 1992--1993 run. From a fit to the transverse mass spectrum, combined with measurements of the $Z$ boson mass, the $W$ boson mass is measured to be $M_W = 80.350 \pm 0.140 (stat.) \pm 0.165 (syst.) \pm 0.160 (scale) GeV/c^2$.Comment: 12 pages, LaTex, style Revtex, including 3 postscript figures (submitted to PRL

Search for W~1Z~2\widetilde{W}_1\widetilde{Z}_2 Production via Trilepton Final States in ppˉp\bar{p} collisions at s=1.8\sqrt{s}=1.8 TeV

We have searched for associated production of the lightest chargino, $\widetilde{W}_1$, and next-to-lightest neutralino, $\widetilde{Z}_2$, of the Minimal Supersymmetric Standard Model in $p\bar{p}$ collisions at \mbox{$\sqrt{s}$ = 1.8 TeV} using the \D0 detector at the Fermilab Tevatron collider. Data corresponding to an integrated luminosity of 12.5$\pm 0.7$ \ipb were examined for events containing three isolated leptons. No evidence for $\widetilde{W}_1\widetilde{Z}_2$ pair production was found. Limits on $\sigma(\widetilde{W}_1\widetilde{Z}_2)$Br$(\widetilde{W}_1\to l\nu\widetilde{Z}_1)$Br$(\widetilde{Z}_2\to l\bar{l}\widetilde{Z}_1)$ are presented.Comment: 17 pages (13 + 1 page table + 3 pages figures). 3 PostScript figures will follow in a UUEncoded, gzip'd, tar file. Text in LaTex format. Submitted to Physical Review Letters. Replace comments - Had to resumbmit version with EPSF directive