277 research outputs found
Development of a ground robot for indoor SLAM using Low‐Cost LiDAR and remote LabVIEW HMI
The simultaneous localization and mapping problem (SLAM) is crucial to autonomous navigation and robot mapping. The main purpose of this thesis is to develop a ground robot that implements SLAM to test the performance of the low‐cost RPLiDAR A1M8 by DFRobot. The HectorSLAM package, available in ROS was used with a Raspberry Pi to implement SLAM and build maps. These maps are sent to a remote desktop via TCP/IP communication to be displayed on a LabVIEW HMI where the user can also control robot. The LabVIEW HMI and the project in its entirety is intended to be as easy to use as possible to the layman, with many processes being automated to make this possible.
The quality of the maps created by HectorSLAM and the RPLiDAR were evaluated both qualitatively and quanitatively to determine how useful the low‐cost LiDAR can be for this application. It is hoped that the apparatus developed in this project will be used with drones in the future for 3D mapping
Targeted infection of HIV-1 Env expressing cells by HIV(CD4/CXCR4) vectors reveals a potential new rationale for HIV-1 mediated down-modulation of CD4
BACKGROUND: Efficient targeted gene transfer and cell type specific transgene expression are important for the safe and effective expression of transgenes in vivo. Enveloped viral vectors allow insertion of exogenous membrane proteins into their envelopes, which could potentially aid in the targeted transduction of specific cell types. Our goal was to specifically target cells that express the T cell tropic HIV-1 envelope protein (Env) using the highly specific interaction of Env with its cellular receptor (CD4) inserted into the envelope of an HIV-1-based viral vector. RESULTS: To generate HIV-1-based vectors carrying the CD4 molecule in their envelope, the CD4 ectodomain was fused to diverse membrane anchors and inserted together with the HIV-1 coreceptor CXCR4 into the envelopes of HIV-1 vector particles. Independent of the type of CD4 anchor, all chimeric CD4 proteins inserted into HIV-1 vector envelopes and the resultant HIV(CD4/CXCR4) particles were able to selectively confer neomycin resistance to cells expressing the fusogenic T cell tropic HIV-1 Env protein. Unexpectedly, in the absence of Env on the target cells, all vector particles carrying the CD4 ectodomain anchored in their envelope adhered to various cell types without infecting these cells. This cell adhesion was very avid. It was independent of the presence of Env on the target cell, the type of CD4 anchor or the presence of CXCR4 on the particle. In mixed cell populations with defined ratios of Env(+)/Env(- )cells, the targeted transduction of Env(+ )cells by HIV(CD4/CXCR4) particles was diminished in proportion to the number of Env(- )cells. CONCLUSION: Vector diversion caused by a strong, non-selective cell binding of CD4(+)-vector particles effectively prevents the targeted transduction of HIV-1 Env expressing cells in mixed cell populations. This Env-independent cell adhesion severely limits the effective use of targeted HIV(CD4/CXCR4) vectors designed to interfere with HIV-1 replication in vivo. Importantly, the existence of this newly described and remarkably strong CD4-dependent cell adhesion suggests that the multiple viral efforts to reduce CD4 cell surface expression may, in part, be to prevent cell adhesion to non-target cells and thereby to increase the infectivity of viral progeny. Preventing CD4 down-modulation by HIV-1 might be an effective component of a multi-faceted antiviral strategy
1979: Abilene Christian College Bible Lectures - Full Text
THE HOME IN CRISIS
Being the Abilene Christian University Annual Bible Lectures 1979
Published by Abilene Christian University Book Store
ACU Station Abilene, Texas 7960
Automatized One-Loop Calculations in 4 and D dimensions
Two program packages are presented for evaluating one-loop amplitudes. They
can work either in dimensional regularization or in constrained differential
renormalization. The latter method is found at the one-loop level to be
equivalent to regularization by dimensional reduction.Comment: 16 pages, uses amstex and axodraw, 1 eps figur
Generalizing the GAGA Principle
This paper generalizes the fundamental GAGA results of Serre cite{MR0082175}
in three ways---to the non-separated setting, to stacks, and to families. As an
application of these results, we show that analytic compactifications of
possessing modular interpretations are algebraizable.Comment: 19 page
Atmospheric Reanalyses-Recent Progress and Prospects for the Future. A Report from a Technical Workshop, April 2010
In April 2010, developers representing each of the major reanalysis centers met at Goddard Space Flight Center to discuss technical issues - system advances and lessons learned - associated with recent and ongoing atmospheric reanalyses and plans for the future. The meeting included overviews of each center s development efforts, a discussion of the issues in observations, models and data assimilation, and, finally, identification of priorities for future directions and potential areas of collaboration. This report summarizes the deliberations and recommendations from the meeting as well as some advances since the workshop
Nickel(II) and iron(II) triple helicates assembled from expanded quaterpyridines incorporating flexible linkages
In the present study the interaction of Fe(II) and Ni(II) with the related expanded quaterpyridines, 1,2-, 1,3- and 1,4-bis-(5'-methyl-[2,2']bipyridinyl-5-ylmethoxy)benzene ligands (4–6 respectively), incorporating flexible, bis-aryl/methylene ether linkages in the bridges between the dipyridyl domains, was shown to predominantly result in the assembly of [M2L3]4+ complexes; although with 4 and 6 there was also evidence for the (minor) formation of the corresponding [M4L6]8+ species. Overall, this result contrasts with the behaviour of the essentially rigid 'parent' quaterpyridine 1 for which only tetrahedral [M4L6]8+ cage species were observed when reacted with various Fe(II) salts. It also contrasts with that observed for 2 and 3 incorporating essentially rigid substituted phenylene and biphenylene bridges between the dipyridyl domains where reaction with Fe(II) and Ni(II) yielded both [M2L3]4+ and [M4L6]8+ complex types, but in this case it was the latter species that was assigned as the thermodynamically favoured product type. The X-ray structures of the triple helicate complexes [H2O⊂Ni2(4)3](PF6)4·THF·.2H2O, [Ni2(6)3](PF6)4·195MeCN·1.THF·1.82O, and the very unusual triple helicate PF6− inclusion complex, [(PF6)⊂Ni2(5)3](PF6)3·1.75eCN·5.25TF·0.25H2O are reported
Report of the 1st Workshop on Generative AI and Law
This report presents the takeaways of the inaugural Workshop on Generative AI
and Law (GenLaw), held in July 2023. A cross-disciplinary group of
practitioners and scholars from computer science and law convened to discuss
the technical, doctrinal, and policy challenges presented by law for Generative
AI, and by Generative AI for law, with an emphasis on U.S. law in particular.
We begin the report with a high-level statement about why Generative AI is both
immensely significant and immensely challenging for law. To meet these
challenges, we conclude that there is an essential need for 1) a shared
knowledge base that provides a common conceptual language for experts across
disciplines; 2) clarification of the distinctive technical capabilities of
generative-AI systems, as compared and contrasted to other computer and AI
systems; 3) a logical taxonomy of the legal issues these systems raise; and, 4)
a concrete research agenda to promote collaboration and knowledge-sharing on
emerging issues at the intersection of Generative AI and law. In this report,
we synthesize the key takeaways from the GenLaw workshop that begin to address
these needs. All of the listed authors contributed to the workshop upon which
this report is based, but they and their organizations do not necessarily
endorse all of the specific claims in this report
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