Growth of Pseudotypes of Vesicular Stomatitis Virus with N-Tropic Murine Leukemia Virus Coats in Cells Resistant to N-Tropic Viruses

Formation of pseudotypes between murine RNA tumor viruses and vesicular stomatitis virus (VSV) has been confirmed. Pseudotypes of VSV genomes coated by the surface envelope from an N-tropic tumor virus grew equally well in cells homozygous for either the Fv-1n or Fv-1b alleles. Therefore, the product of the Fv-1 locus, which restricts growth of murine RNA tumor viruses, must act on an intracellular aspect of tumor virus replication, a step after attachment and penetration

Determinants of Mortality and Disease Progression of Kaposi Sarcoma in a Primary care ART Programme in Khayelitsha, South Africa

CROI 200

A Calculation of the plane wave string Hamiltonian from N=4 super-Yang-Mills theory

Berenstein, Maldacena, and Nastase have proposed, as a limit of the strong form of the AdS/CFT correspondence, that string theory in a particular plane wave background is dual to a certain subset of operators in the N=4 super-Yang-Mills theory. Even though this is a priori a strong/weak coupling duality, the matrix elements of the string theory Hamiltonian, when expressed in gauge theory variables, are analytic in the 't Hooft coupling constant. This allows one to conjecture that, like the masses of excited string states, these can be recovered using perturbation theory in Yang-Mills theory. In this paper we identify the difference between the generator of scale transformations and a particular U(1) R-symmetry generator as the operator dual to the string theory Hamiltonian for nonvanishing string coupling. We compute its matrix elements and find that they agree with the string theory prediction provided that the state-operator map is modified for nonvanishing string coupling. We construct this map explicitly and calculate the anomalous dimensions of the new operators. We identify the component arising from the modification of the state-operator map with the contribution of the string theory contact terms to the masses of string states.Comment: 38 pages, Latex; v2: Comparison with string theory changed in light of corrections to string theory results in hep-th/0206073 v3; state-operator map modified; Physical interpretation and conclusions unchange

Structure and stereochemistry of the base excision repair glycosylase MutY reveal a mechanism similar to retaining glycosidases.

MutY adenine glycosylases prevent DNA mutations by excising adenine from promutagenic 8-oxo-7,8-dihydroguanine (OG):A mismatches. Here, we describe structural features of the MutY active site bound to an azaribose transition state analog which indicate a catalytic role for Tyr126 and approach of the water nucleophile on the same side as the departing adenine base. The idea that Tyr126 participates in catalysis, recently predicted by modeling calculations, is strongly supported by mutagenesis and by seeing close contact between the hydroxyl group of this residue and the azaribose moiety of the transition state analog. NMR analysis of MutY methanolysis products corroborates a mechanism for adenine removal with retention of stereochemistry. Based on these results, we propose a revised mechanism for MutY that involves two nucleophilic displacement steps akin to the mechanisms accepted for 'retaining' O-glycosidases. This new-for-MutY yet familiar mechanism may also be operative in related base excision repair glycosylases and provides a critical framework for analysis of human MutY (MUTYH) variants associated with inherited colorectal cancer

It's Hard to Learn How Gravity and Electromagnetism Couple

We construct the most general effective Lagrangian coupling gravity and electromagnetism up to mass dimension 6 by enumerating all possible non-minimal coupling terms respecting both diffeomorphism and gauge invariance. In all, there are only two unique terms after field re-definitions; one is known to arise from loop effects in QED while the other is a parity violating term which may be generated by weak interactions within the standard model of particle physics. We show that neither the cosmological propagation of light nor, contrary to earlier claims, solar system tests of General Relativity are useful probes of these terms. These non-minimal couplings of gravity and electromagnetism may remain a mystery for the foreseeable future.Comment: 9 pages. Minor corrections made. To appear in Phys. Rev.

CAD/CAM/CNC of dies for car alloy wheels and golf clubs

This paper presents 3D solid feature based modelling of a new design of a car alloy wheel derived from the ball pattern of the World Cup 2006 and golf clubs using a CAD system. Finite Element Analysis was applied to improve the new designs. Their dies were extracted from the parts/assemblies. The dies were scaled down to 20% of their original size using the CAD system, and these models were transferred into a CAM system. The machining processes were simulated for a three axis CNC mill controller using the CAM system. The tool paths were produced and the CNC programmes were generated by the modified postprocessor for controlling the CNC machine. The models of the dies of the new car alloy wheel and the golf clubs were produced using the modified CNC programmes with accurate shapes and reasonable surface finish. There is good potential for die making markets and industrial developments

Assessment of ocean prediction model for Naval Operations using acoustic preset

OCEANS2005, MTS/IEEE Conference Proceedings, DVD-ROMThe outcome of a battlefield engagement is often determined by the advantages and disadvantages held by each adversary. On the modern battlefield, the possessor of the best technology often has the upper hand, but only if that advanced technology is used properly and efficiently. In order to exploit this advantage and optimize the effectiveness of high technology sensor and weapon systems, it is essential to understand the impact on them by the environment. In the arena of Anti-Submarine Warfare (ASW), the ocean environment determines the performance of the acoustic sensors employed and the success of any associated weapon systems. Since acoustic sensors detect underwater sound waves, understanding how those waves propagate is crucial to knowing how the sensors will perform and being able to optimize their performance in a given situation. To gain this understanding, an accurate depiction of the ocean environment is necessary. How acoustic waves propagate from one location to another under water is determined by many factors, some of which are described by the sound speed profile (SSP). If the environmental properties of temperature and salinity are known over the entire depth range, the SSP can be compiled by using them in an empirical formula to calculate the expected sound speed in a vertical column of water. One way to determine these environmental properties is to measure them in situ, such as by conductivity-temperature-depth or expendable bathythermograph (XBT) casts. This method is not always tactically feasible and only gives the vertical profile at one location producing a very limited picture of the regional ocean structure. Another method is to estimate the ocean conditions using numerical models. The valued-aided ocean prediction models to ASW is assessed in this study. Such quantitative analyses offer a means to optimize the ASW requirements and technical capabilities of new weapon systems. We use observed and modeled 3-D fields of temperature, salinity, and sound speed. Compare model profiles to observed profiles. Do ocean models predict the vertical features of the observational data? Run representative modeled and observed SSP profiles through Navy’s acoustic models to see if there is an acoustic difference in propagation and weapon preset

Genie: A Generator of Natural Language Semantic Parsers for Virtual Assistant Commands

To understand diverse natural language commands, virtual assistants today are trained with numerous labor-intensive, manually annotated sentences. This paper presents a methodology and the Genie toolkit that can handle new compound commands with significantly less manual effort. We advocate formalizing the capability of virtual assistants with a Virtual Assistant Programming Language (VAPL) and using a neural semantic parser to translate natural language into VAPL code. Genie needs only a small realistic set of input sentences for validating the neural model. Developers write templates to synthesize data; Genie uses crowdsourced paraphrases and data augmentation, along with the synthesized data, to train a semantic parser. We also propose design principles that make VAPL languages amenable to natural language translation. We apply these principles to revise ThingTalk, the language used by the Almond virtual assistant. We use Genie to build the first semantic parser that can support compound virtual assistants commands with unquoted free-form parameters. Genie achieves a 62% accuracy on realistic user inputs. We demonstrate Genie's generality by showing a 19% and 31% improvement over the previous state of the art on a music skill, aggregate functions, and access control.Comment: To appear in PLDI 201

Molecular characterization, biofilm analysis and experimental biofouling study of Fusarium isolates from recent cases of fungal keratitis in New York State

BACKGROUND: To characterize Fusarium isolates from recent cases of fungal keratitis in contact lens wearers, and to investigate fungal association with MoistureLoc solution. METHODS: We studied six fungal isolates from recent cases of keratitis in New York State. The isolates were characterized by nucleotide sequencing and phylogenetic analyses of multiple genes, and then typed using minisatellite and microsatellite probes. Experimental fungal biofilm formation was tested by standard methods. MoistureLoc solutions were tested in biofouling studies for their efficacy in elimination of Fusarium contamination. RESULTS: Fusarium solani – corneal ulcers (2 isolates), lens case (1 isolate), and F. oxysporum – corneal ulcer (1 isolate), eye (1 isolate), were recovered from five patients. An opened bottle of MoistureLoc solution provided by a patient also yielded F. solani. Two distinct genotypes of F. solani as well as of F. oxysporum were present in the isolated strains. Remarkably, F. solani strains from the lens case and lens solution in one instance were similar, based on phylogenetic analyses and molecular typing. The solution isolate of F. solani formed biofilm on contact lenses in control conditions, but not when co-incubated with MoistureLoc solution. Both freshly opened and 3-month old MoistureLoc solutions effectively killed F. solani and F. oxysporum, when fungal contamination was simulated under recommended lens treatment regimen (4-hr). However, simulation of inappropriate use (15 – 60 min) led to the recovery of less than 1% of original inoculum of F. solani or F. oxysporum. CONCLUSION: Temporary survival of F. solani and F. oxysporum in MoistureLoc suggested that improper lens cleaning regimen could be a possible contributing factor in recent infections