RELBET 4.0 user's guide

This manual describes the operation and use of RELBET 4.0 implemented on the Hewlett Packard model 9000. The RELBET System is an integrated collection of computer programs which support the analysis and post-flight reconstruction of vehicle to vehicle relative trajectories of two on-orbit free-flying vehicles: the Space Shuttle Orbiter and some other free-flyer. The manual serves both as a reference and as a training guide. Appendices provide experienced users with details and full explanations of program usage. The body of the manual introduces new users to the system by leading them through a step by step example of a typical production. This should equip the new user both to execute a typical production process and to understand the most significant variables in that process

RELBET 4.0 programmer's manual

The RELBET 4.0 System as implemented on the Hewlett Packard model 9000 computer system is described. The manual is directed toward programmers and system maintenance personnel. It is intended to serve both as a reference and as a introductory guide to the software. The body of the manual provides an overview of major features and indicates where to look for further information. Full details are left to Appendices

Chasing charge localization and chemical reactivity following photoionization in liquid water

The ultrafast dynamics of the cationic hole formed in bulk liquid water following ionization is investigated by ab initio molecular dynamics simulations and an experimentally accessible signature is suggested that might be tracked by femtosecond pump-probe spectroscopy. This is one of the fastest fundamental processes occurring in radiation-induced chemistry in aqueous systems and biological tissue. However, unlike the excess electron formed in the same process, the nature and time evolution of the cationic hole has been hitherto little studied. Simulations show that an initially partially delocalized cationic hole localizes within similar to 30 fs after which proton transfer to a neighboring water molecule proceeds practically immediately, leading to the formation of the OH radical and the hydronium cation in a reaction which can be formally written as H(2)O(+) + H(2)O -> OH + H(3)O(+). The exact amount of initial spin delocalization is, however, somewhat method dependent, being realistically described by approximate density functional theory methods corrected for the self-interaction error. Localization, and then the evolving separation of spin and charge, changes the electronic structure of the radical center. This is manifested in the spectrum of electronic excitations which is calculated for the ensemble of ab initio molecular dynamics trajectories using a quantum mechanics/molecular mechanics (QM/MM) formalism applying the equation of motion coupled-clusters method to the radical core. A clear spectroscopic signature is predicted by the theoretical model: as the hole transforms into a hydroxyl radical, a transient electronic absorption in the visible shifts to the blue, growing toward the near ultraviolet. Experimental evidence for this primary radiation-induced process is sought using femtosecond photoionization of liquid water excited with two photons at 11 eV. Transient absorption measurements carried out with similar to 40 fs time resolution and broadband spectral probing across the near-UV and visible are presented and direct comparisons with the theoretical simulations are made. Within the sensitivity and time resolution of the current measurement, a matching spectral signature is not detected. This result is used to place an upper limit on the absorption strength and/or lifetime of the localized H(2)O((aq))(+) species. (C) 2011 American Institute of Physics. doi:10.1063/1.3664746

EL virus del HIV-1 de pacientes de May Harbor de diferentes subtipos filogenéticos: las implicancias para la evolución de la pandemia HIV/SIDA

Las variantes virales aisladas de pacientes infectados con HIV a través del mundo comparten una diversidad notable, especialmente en la glicoproteína de envoltura gp120. Los estudios filogenéticos han agrupado a los aislamientos de HIV-1 en ocho subtipos (A-H). No obstante, aún dentro de una sola persona infectada, el HIV está presente como unas «cuasi-especies,» o un enjambre de variantes estrechamente conexas. Esta diversidad genética, que en el caso del HIV-1 se acumula a una tasa de aproximadamente una sustitución de nucleótido por genoma por ciclo de replicación, da al virus una flexibilidad enorme para responder a un amplio conjunto de presiones de selección in vivo. Como una consecuencia, la droga-resistencia y las mutantes inmunológica se generan rápidamente en personas infectadas mediante todas las etapas de infección. Sobre una escala global, la pandemia del HIV se reconoce como consistiendo de muchas epidemias separadas, cada una con una geografía característica, poblaciones afectadas, y tipo predominante de cepa viral. Con unos estimados 15 millones de personas infectadas, la distribución geográfica de los subtipos virales está llegando a ser más dispersa, y estas demarcaciones son además confundidas por la evidencia creciente de infecciones mixtas.Facultad de Ciencias Veterinaria

EL virus del HIV-1 de pacientes de May Harbor de diferentes subtipos filogenéticos: las implicancias para la evolución de la pandemia HIV/SIDA

Las variantes virales aisladas de pacientes infectados con HIV a través del mundo comparten una diversidad notable, especialmente en la glicoproteína de envoltura gp120. Los estudios filogenéticos han agrupado a los aislamientos de HIV-1 en ocho subtipos (A-H). No obstante, aún dentro de una sola persona infectada, el HIV está presente como unas «cuasi-especies,» o un enjambre de variantes estrechamente conexas. Esta diversidad genética, que en el caso del HIV-1 se acumula a una tasa de aproximadamente una sustitución de nucleótido por genoma por ciclo de replicación, da al virus una flexibilidad enorme para responder a un amplio conjunto de presiones de selección in vivo. Como una consecuencia, la droga-resistencia y las mutantes inmunológica se generan rápidamente en personas infectadas mediante todas las etapas de infección. Sobre una escala global, la pandemia del HIV se reconoce como consistiendo de muchas epidemias separadas, cada una con una geografía característica, poblaciones afectadas, y tipo predominante de cepa viral. Con unos estimados 15 millones de personas infectadas, la distribución geográfica de los subtipos virales está llegando a ser más dispersa, y estas demarcaciones son además confundidas por la evidencia creciente de infecciones mixtas.Facultad de Ciencias Veterinaria

EL virus del HIV-1 de pacientes de May Harbor de diferentes subtipos filogenéticos: las implicancias para la evolución de la pandemia HIV/SIDA

Las variantes virales aisladas de pacientes infectados con HIV a través del mundo comparten una diversidad notable, especialmente en la glicoproteína de envoltura gp120. Los estudios filogenéticos han agrupado a los aislamientos de HIV-1 en ocho subtipos (A-H). No obstante, aún dentro de una sola persona infectada, el HIV está presente como unas «cuasi-especies,» o un enjambre de variantes estrechamente conexas. Esta diversidad genética, que en el caso del HIV-1 se acumula a una tasa de aproximadamente una sustitución de nucleótido por genoma por ciclo de replicación, da al virus una flexibilidad enorme para responder a un amplio conjunto de presiones de selección in vivo. Como una consecuencia, la droga-resistencia y las mutantes inmunológica se generan rápidamente en personas infectadas mediante todas las etapas de infección. Sobre una escala global, la pandemia del HIV se reconoce como consistiendo de muchas epidemias separadas, cada una con una geografía característica, poblaciones afectadas, y tipo predominante de cepa viral. Con unos estimados 15 millones de personas infectadas, la distribución geográfica de los subtipos virales está llegando a ser más dispersa, y estas demarcaciones son además confundidas por la evidencia creciente de infecciones mixtas.Facultad de Ciencias Veterinaria

Genetic variation in Pneumocystis carinii isolates from different geographic regions: implications for transmission.

To study transmission patterns of Pneumocystis carinii pneumonia (PCP) in persons with AIDS, we evaluated P. carinii isolates from patients in five U.S. cities for variation at two independent genetic loci, the mitochondrial large subunit rRNA and dihydropteroate synthase. Fourteen unique multilocus genotypes were observed in 191 isolates that were examined at both loci. Mixed infections, accounting for 17.8% of cases, were associated with primary PCP. Genotype frequency distribution patterns varied by patients' place of diagnosis but not by place of birth. Genetic variation at the two loci suggests three probable characteristics of transmission: that most cases of PCP do not result from infections acquired early in life, that infections are actively acquired from a relatively common source (humans or the environment), and that humans, while not necessarily involved in direct infection of other humans, are nevertheless important in the transmission cycle of P. carinii f. sp. hominis

Babesia divergens–like Infection, Washington State

Most reported U.S. zoonotic cases of babesiosis have occurred in the Northeast and been caused by Babesia microti. In Washington State, three cases of babesiosis have been reported previously, which were caused by WA1 (for “Washington 1”)-type parasites. We investigated a case of babesiosis in Washington in an 82–year-old man whose spleen had been removed and whose parasitemia level was 41.4%. The complete 18S ribosomal RNA gene of the parasite was amplified from specimens of his whole blood by polymerase chain reaction. Phylogenetic analysis showed the parasite is most closely related, but not identical, to B. divergens (similarity score, 99.5%), a bovine parasite in Europe. By indirect fluorescent-antibody testing, his serum reacted to B. divergens but not to B. microti or WA1 antigens. This case demonstrates that babesiosis can be caused by novel parasites detectable by manual examination of blood smears but not by serologic or molecular testing for B. microti or WA1-type parasites

Polymorphism in Gag Gene Cleavage Sites of HIV-1 Non-B Subtype and Virological Outcome of a First-Line Lopinavir/Ritonavir Single Drug Regimen

Virological failure on a boosted-protease inhibitor (PI/r) first-line triple combination is usually not associated with the detection of resistance mutations in the protease gene. Thus, other resistance pathways are being investigated. First-line PI/r monotherapy is the best model to investigate in vivo if the presence of mutations in the cleavage sites (CS) of gag gene prior to any antiretroviral treatment might influence PI/r efficacy. 83 patients were assigned to initiate antiretroviral treatment with first-line lopinavir/r monotherapy in the randomised Monark trial. We compared baseline sequence of gag CS between patients harbouring B or non-B HIV-1 subtype, and between those who achieved viral suppression and those who experienced virological failure while on LPV/r monotherapy up to Week 96. Baseline sequence of gag CS was available for 82/83 isolates; 81/82 carried at least one substitution in gag CS compared to HXB2 sequence. At baseline, non-B subtype isolates were significantly more likely to harbour mutations in gag CS than B subtype isolates (p<0.0001). Twenty-three patients experienced virological failure while on lopinavir/r monotherapy. The presence of more than two substitutions in p2/NC site at baseline significantly predicted virological failure (p = 0.0479), non-B subtype isolates being more likely to harbour more than two substitutions in this specific site. In conclusion, gag cleavage site was highly polymorphic in antiretroviral-naive patients harbouring a non-B HIV-1 strain. We show that pre-therapy mutations in gag cleavage site sequence were significantly associated with the virological outcome of a first-line LPV/r single drug regimen in the Monark trial