The x-ray atomic form-factor determines the x-ray optical properties of materials and is a fundamental parameter for critical x-ray investigations. However, despite uncertainty estimates of order 1%, differences of 2-10% between x-ray mass attenuation measurements render comparison with the various theoretical tabulations meaningless. Moreover, such uncertainties impose limits on the accuracy of various quantitative investigations. We determine the imaginary component of the atomic form-factor from measurements of the x-ray mass attenuation coefficient. With the exception of the measurements of Tran et.al. [Phys. Rev. A 64, (062506); 67, (042716); J. Phys. B 38, (89)] with a 0.3% accuracy, previous work has been unable to achieve accuracies below 1%, and differences between results claiming this accuracy often exceed 6%.We have developed a full-foil mapping technique which has improved the measurement accuracy by an order of magnitude. This technique overcomes limitations arising from absorber thickness variations, using the average integrated column density and attenuation measurements across the entire surface of the absorber. We have examined measurements obtained over a wide range of parameter space for systematic deviations indicative of experimental error. Among others, this has led to the identification and correction of a 1% discrepancy arising from the x-ray bandwidth. Resulting measurement accuracies for molybdenum are 0.02-0.15%. Preliminary results for tin suggest a final accuracy of 0.1-1%. We compare these measurements with several commonly-used tabulations and identify a number of systematic discrepancies whose causes are discussed.

The quest to discover simple, sensitive and global bioindicators of nutrient enrichment and ecological health continues. The present study is the first to address this quest in Hervey Bay by investigating links between key physico-chemical water quality parameters and two diatom forms. Free floating in the water column as phytoplankton, and attached to seagrass leaves and artificial substrates as microalgal epiphytes, diatoms are assessed for their abundance and diversity along an environmental gradient. Relationships between Secchi depth (Zsd), light attenuation coefficient (Kz) and minimum seagrass compensation depth (Zc) are established for the recovery, growth and survival of aquatic plants following disturbance, with equations derived specifically for this region to allow conversions from Zsd to Kz. These relationships allow predictions to be made and provide a management tool to meet water quality targets and combat elevated nutrient and sediment loads that result from anthropogenic activity and affect all marine life, from microalgae to marine mammals. Environmental links, identified as drivers of change to biodiversity, focus research effort and provide predictive management tools. Consequently, catchment and coastal activities such as dredging, construction and canal development, with the potential to increase nutrient and sediment loads, can be managed and scheduled at times least likely to adversely impact near shore ecosystems and therefore improve the balance between growth and sustainability. Seasonal and zone differences were significant for many of the water quality parameters monitored in Hervey Bay during 1994. Water clarity measures consistently showed significant differences between near and offshore zones (Secchi depth; P<0.01, turbidity; P<0.05 and TSS; P<0.01) as well as oxygen (P<0.01), soluble reactive phosphate (SRP, P<0.05), oxides of nitrogen (NOx, P<0.01), chlorophyll a (Chl a, P<0.01) and pH (P<0.01). Some default trigger values for water quality targets listed by ANZECC/ARMCANZ (2000) for concentrations of key indicators, a threshold for risk of adverse biological effects, were exceeded in dry and flood periods during the 1993 to 1995 survey. The community structure of phytoplankton and seagrass epiphytes were examined by monitoring changes to and 35 seagrass epiphyte species coincident with changes in some key water quality parameters along a water quality gradient. Chl a, Secchi depth (Zsd), soluble reactive phosphate (SRP) and pH were found to be the best subset of water quality parameters to maximise the rank correlation with phytoplankton communities whereas NOx and temperature maximised the rank correlation with the Halophila ovalis seagrass epiphyte communities. These parameters statistically link key water quality parameters to changes in phytoplankton and seagrass epiphyte density and assemblage structure and are supported as significant drivers of change in biodiversity research. Evidence for nitrogen limitation was found in the post flood surveys for phytoplankton and the growth and assemblage structure for seagrass systems and their epiphytes. Seasonal and zone differences in phytoplankton assemblage structure were most apparent with some site influence detected. Cylindrotheca closterium dominated the phytoplankton assemblage structure at the near shore zone while Thalassionema nitzschioides and Chaetoceros sp. differentiated the river from the Waste Water Treatment Plant (WWTP) creek site. Rhizolsolenia and Guinardia sp. were found in significantly higher concentrations at offshore sites (P < 0.01) and Thalassionema nitzschioides (P < 0.01), Thalassiosira sp. (P < 0.01) and Pseudonitzschia sp. (P < 0.05) were found in significantly higher abundance in the near shore zone A Trichodesmium bloom was examined and post flood changes to the phytoplankton assemblage structure associated with increased nutrient loads, reduced water clarity (Secchi depth, TSS and turbidity) and changes to pH and salinity were assessed. The results of analyses of variance provided support to multivariate statistical analyses to identify phytoplankton as a useful and sensitive bioindicator of environmental change. Post flood phytoplankton cell density increased and species diversity rose from 10 to 38 species at the Mary River mouth however, the changes to cell density and assemblage structure were not reflected in Chl a concentrations. The Mary River mouth experienced growth of mainly small phytoplankton species (< 20 µm) while Pulgul Creek, a source of WWTP effluent, experienced a disproportional increase in the larger phytoplankton species (>20µm). The increase in phytoplankton cell density at offshore sites occurred for both large and small species. Phytoplankton species dominance changed at each site during the postflood period. C. closterium remained the dominant species but increased from 34 to 648 cells/mL at Pulgul Creek however, C. similis, the second most dominant species was replaced by Pseudonitszchia sp., whose cell density rose from 2.0 to 320 cells/mL. A recent study also found that Cylindrotheca closterium, Skeletonema costatum, and Cyclotella choctawhatcheeana had strong positive relationships with coastal nutrients and suggested these species be used as potential reliable indicators of eutrophication (Toming and Jaanus, 2007). Some Pseudonitszchia sp. and dinoflagellate species have previously been noted as toxic and Chaetoceros sp. are associated with gill damage and fish kills. Rhizosolenia sp. and the Guinardia species G. flaccida and G. striatula, were indicators for the offshore relatively pristine sites, which may conversely, determine these species as indicators of environmental health in this waterway. Specificity of epiphyte attachment to particular seagrass species were detected and microalgal epiphyte assemblages on Halophila ovalis were identified as useful bioindicators of environmental gradients as this seagrass species is located at intertidal, shallow and deep water sites for a substantial part of the year. H. ovalis also recorded the highest average annual epiphyte loads (3873 ± 1882 cells/mm2) with the diatoms Diatoma vulgare and Cocconeis scutellum representing 19.6% and 17.2% of the total epiphyte cover. Highest cell density was recorded in autumn, followed by summer and winter: spring recorded the lowest epiphyte cover. Micro-algal epiphyte load was assessed as dry weight (g/m2), Chl a (µg/L) and cell density (cells/mm2) on artificial seagrass deployed along a water quality gradient. Equations were derived to describe percentage light transmission as a function of each measure of epiphyte load which allows transformation of data from one unit of expression to another and hence, allow comparison of past, current and future studies. Water column light attenuation was evaluated along a water quality gradient and linked to Secchi depths (Zsd) to derive equations that describe this relationship where for Hervey Bay, when Zsd < 4.26m, Kz = -1.2 ln Zsd + 1.74 and when Zsd ≥ 4.26m, Kz=1.37/Zsd. Species succession, diversity and seagrass growth were monitored for the first time during a recovery phase and limits for the seagrass compensation depth (Zc), were established on a seasonal basis for five seagrass species at four locations within intertidal, shallow and deep water zones in Hervey Bay and the Great Sandy Straits. Conceptual models for each site were constructed to describe habitat characteristics and include nutrient concentrations for SRP, NOx and ammonia (NH4+), Chl a, phytoplankton density, epiphyte density and light requirements measured as light attenuation, total suspended sediment, turbidity and Secchi depth at each location. The study provides a descriptive model for light attenuation and establishes (1) an annual and seasonal baseline water quality data set that characterises the waterways of Hervey Bay and the Great Sandy Straits (2) identification of phytoplankton species in Hervey Bay and their response to post flood changes in water quality (3) phytoplankton density and diversity along an environmental gradient with links established to Chl a, Secchi depth, SRP and pH (4) seagrass epiphyte assemblage structure along an environmental gradient with links established to NOx and temperature (5) conversion factors for epiphyte load expressed as dry weight, Chl a and cell density (6) functions to convert Secchi depth to light attenuation coeffiecients (Kz) (7) seagrass species succession at intertidal, shallow and deep water sites during a recovery growth phase in Hervey Bay (8) seagrass compensation depths (Zc) for five seagrass species at four locations and (9) habitat characterisation for seagrass recovery in Hervey Bay. Identification catalogues for phytoplankton and seagrass epiphytes were prepared with light and electron micrographs to assist future identification studies of diatoms in this region and for other similar biogeographical areas. The management of water quality to reach specific targets requires the capacity to predict seagrass compensation depth (Zc) as a function of water quality. Seasonal and annual light attenuation measurements are derived as a function of water quality at intertidal, shallow and deep water habitats during the colonisation of Zostera Capricornii, Halodule uninervis, Halophila ovalis, Halophila spinulosa and Halophila decipiens.

Biot's theory when applied to homogeneous media (involving the macroscopic flow mechanism) cannot explain the high level of attenuation observed in natural porous media over the seismic frequency range. However, several successful mesocopic inhomogeneity models have been developed to account for P wave attenuation. In this thesis I further develop the approaches to tackle S wave velocity and attenuation, to simulate transient wave propagation in poroelastic media, and to construct new models for determining the effective parameters of porous media containing mesoscopic inhomogeneities. As an important application of the double-porosity dual-permeability (DPDP) model, I have reformulated the effective Biot model using the total-field variables. This gives rise to new and more general governing equations than the previous approach based on the host phase field variables (which become a special case of the more general treatment). The analytical transient solution and dispersion characteristics for the double-porosity model and also for a poro-viscoacoustic model are derived over the entire frequency range for a homogeneous medium. The comparison between the results of the two models shows that dissipation by local mesoscopic flow of the double porosity model is very hard to fit by a single Zener element over a broad band. I chose the relaxation function to approximate the dispersion behaviour of the double porosity model just around the source centre frequency. It is shown that for most water-filled sandstones having a double porosity structure, wave propagation can be well described by the poro-viscoaoustic model with a single Zener element in the seismic frequency range. The transient solution for heterogeneous double porosity media is obtained by a numerical pseudospectral time splitting technique. This method is extended to 2.5-D poro-viscoelastic media to capture both P and S wave behaviour. I also demonstrate that if the frequency is below several Hz, then a single Kelvin-Voigt element gives an even better result than a single Zener element. I propose a two-phase permeability spherical inclusion model and obtain the dispersion curves of phase velocity and dissipation factor for the composite. I then determine the effective dynamic permeability of porous media with mesoscopic heterogeneities over the whole frequency range. This result is used to check the validity of other measures of effective dynamic permeability, deduced from the effective hydraulic permeability by replacing the permeability of the components with their dynamic values as determined from the Johnson, Koplik and Dashen (JKD) model. I also investigate the scattering of plane transverse waves by a spherical porous inclusion embedded in an infinite poroelastic medium. The vector displacement wave equations of Biot’s theory are solved as an infinite series of vector spherical harmonics for the case of a plane S-wave incidence. Then, the non-self-consistent theory is used to derive the dispersion characteristics of shear wave velocity and attenuation for a porous rock having mesoscopic spherical inclusions which are designed to represent either the patchy saturation model or the double porosity model with dilute concentrations of identical inclusions. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1457632 / Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2009

Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph.D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Dr. Joseph B. Hughes; Committee Member: Dr. Jian Luo; Committee Member: Dr. Jim C. Spain; Committee Member: Dr. Patricia Sobecky; Committee Member: Dr. Spyros G. Pavlostathis

Orientador: Angelo Berchieri Junior / Banca: Nilce Maria Soares Queiroz Gama / Banca: Manoel Victor Franco Lemos / Resumo: Salmonella Gallinarum (SG) causa o Tifo Aviário, uma doença caracterizada por alta mortalidade e morbidade em aves. Salmonella Enteritidis (SE) é uma salmonela paratífica, capaz de acometer aves e mamíferos. Carne de aves e ovos são as principais fontes de transmissão de SE, causando doença transmitida por alimentos em humanos. O controle destas bactérias nas criações avícolas é feito através da combinação de medidas sanitárias e a vacinação das aves. As vacinas vivas mostram-se melhores do que as inativadas para combater esses sorotipos, no entanto, a proteção contra SE, é parcial. A cepa SG cobS cbiA é incapaz de sintetizar vitamina B12. A ausência dessa substância prejudicou a sobrevivência da bactéria no organismo parasitado, causando atenuação na virulência. Neste trabalho, foram avaliadas a mortalidade e a infecção sistêmica causadas por SG cobS cbiA em comparação com uma cepa selvagem de SG. Também foi avaliado seu potencial vacinal contra SG e SE em aves de postura e sua utilização para impedir a colonização cecal por SE em pintinhos de corte de um dia. As aves de postura foram vacinadas com uma dose aos cinco dias, ou com duas doses aos cinco e vinte e cinco dias de vida e foram desafiadas com as respectivas cepas de SG e SE aos 45 dias de vida. As aves que receberam tanto uma quanto duas doses da cepa vacinal foram parcialmente protegidas contra SG. A proteção contra SE foi significativa no grupo de aves que recebeu duas doses de SG cobS cbiA. Porém, a inoculação de SG cobS cbiA em pintinhos com um dia de vida não impediu a colonização do ceco por SE. A cepa SG cobS cbiA demonstrou ter potencial vacinal contra SG e SE. / Abstract: Salmonella Gallinarum (SG) causes Fowl Typhoid, a disease caracterized by high mortality and morbidity rates in poultry. Salmonella Enteritidis (SE) is a paratyphoid salmonelae that infects birds and mammals. Poultry meat and eggs are the main sources of transmission of SE, causing foodborne disease in humans. The control of these bacterias inside the avian breeding sites is done by the combination of sanitary measures and poultry vaccination. Live vaccines have demonstrated greater efficacy on the protection of poultry against these serovars than the killed vaccines, though, protection against SE is still partial. The strain SG cobS cbiA is uncapable to synthesize vitamin B12. The absence of this substance harmed the bacterial survival in the infected organism, causing attenuation of the virulence. On this work, the mortality and the sistemic infection by SG cobS cbiA were measured and compared with a wild strain of SG. It was also evaluated the potential use of the attenuated strain as a vaccine against SG and SE in laying hens and its utilization to prevent the colonization of the ceca by SE on 1-day-old chickens. The laying hens were vaccinated with one dose at 5- day-old, or with two doses at 5 and 25-day-old and were challenged at 45-day-old with the respective strain of SG or SE. The vaccination either with one or two doses was able to protect the birds against challenge with SG. The administration of two doses of SG cobS cbiA protected the laying hens against SE. Although, the inoculation of SG cobS cbiA by oral gavage on newly hatched chicks was unable to prevent the colonization of the ceca by SE. The protection confered by the strain SG cobS cbiA demonstrated its potential to be used as a vaccine. / Mestre

Orientador: Ricardo Tokio Higuti / Resumo: Este trabalho apresenta o desenvolvimento de um sistema de medição de propriedades de líquidos por ultrassom, tais como velocidade de propagação e coeficiente de atenuação, com as seguintes características: modo de operação pulsado em transmissão-recepção, faixa de frequências entre 20 e 80~MHz, controle de temperatura com variações menores do que 0,01ºC, além do uso de cubetas descartáveis e/ou esterilizáveis com volume menor ou igual a 3 ml. Células Peltier controladas eletronicamente foram utilizadas como atuadores térmicos para o controle de temperatura da célula de medição proposta, e também, para o controle da temperatura de uma caixa térmica utilizada para minimizar os efeitos das variações da temperatura ambiente na amostra. Testes de estabilidade com água destilada mostraram que a temperatura controlada apresenta uma variação menor que 0,01ºC, e que a incerteza para medidas de velocidade de propagação é da ordem de 5 cm/s, a uma temperatura de 25ºC e frequência de 50 MHz. Em relação as medidas de atenuação, o sistema apresentou incertezas na ordem de 0,3 dB/cm para água destilada a 25ºC. Foram realizados ensaios com misturas de água e NaCl, que apresentam valores de atenuação mais baixos que os da água destilada e com amostras de óleos de rícino e de silicone, que apresentam valores de atenuação elevados. Como exemplos de aplicação, a célula de medição foi utilizada para medir propriedades de biocombustíveis, tais como concentração de água em misturas de água e etano... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work describes the development of an ultrasonic spectrometer for liquids, which operates in the frequency range from 20 MHz to 80 MHz. Important characteristics are its high thermal stability (better than 0.01ºC) and practical sample handling by the use of commercial cuvettes, which have small volumes (<3 ml) and can be easily removed from the spectrometer, cleaned/sterilized or simply discarded. Electronically controlled Peltier cells were used as thermal actuators for the temperature control. Through-transmission operation is used to measure propagation velocity and attenuation coefficient with uncertainty in the order of 5 cm/s and 0.03 db/cm, respectively, at 25ºC and 50 MHz. The spectrometer was tested with mixtures of water and NaCl, which have attenuations smaller than that of distilled water, and higher attenuation samples of silicone and castor oil. As a practical application, the spectrometer was used to measure some properties of biofuels, like concentration of water and ethanol mixtures, thermal-degradation effects in soybean biodiesel and percentage of biodiesel in mixtures of diesel and biodiesel. / Doutor

Made available in DSpace on 2014-10-09T12:46:49Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:48Z (GMT). No. of bitstreams: 1 08357.pdf: 3145355 bytes, checksum: e97667e5f2c069c9a76dad1d729d7c6c (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Orientador: Douglas Domingues Bueno / Resumo: A redução de vibração estrutural tem sido um importante tópico para muitas aplicações de engenharia. Nos projetos tradicionais, diferentes técnicas de controle passivo envolvendo mate- riais visco-elásticos e absorvedores dinâmicos e, mais recentemente, metodologias de controle ativo incluindo atuadores e sensores têm sido empregado com sucesso. Diferentes pesquisas tem demostrado que redução de vibração pode ser obtida usando o conceito de periodicidade. As estruturas periódicas envolvem elementos idênticos ou partes conectadas repetidamente. O projeto de estruturas periódicas pode ser empregado para conseguir bandas de frequências em que não há propagação de ondas elásticas, denominadas de "stop bands", introduzindo um efeito similar ao de um filtro. Neste contexto, o presente trabalho apresenta uma abordagem alterna- tiva para o projeto de barras periódicas. Esta alternativa envolve a modelagem de uma barra periódica do tipo híbrida infinita na qual uma estrutura periódica finita é conectada entre duas barras semi-infinitas. Para isto, é utilizada uma metodologia que relaciona vetor de estados e amplitude de ondas. A principal proposta deste trabalho é desenvolver uma relação entre as amplitudes de ondas longitudinais transmitidas e incidentes em termos das propriedades físi- cas e geométricas de uma genérica estrutura periódica para simplificar o processo do projeto. Usando esta formulação mostra-se que uma barra periódica pode ser projetada para satisfazer os requisitos de um... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The reduction of structural vibration has been an important topic for many engineering applica- tions. In traditional projects different passive control techniques involving viscoelastic materials and dynamic absorbers and, more recently, active control methodologies including actuators and sensors have been successfully employed. Different researches have demonstrated that vibra- tion reduction can be obtained using the concept of periodicity. The periodic structures involve identical elements or parts connected repeatedly. The design of periodic structures can be em- ployed to get frequency band without elastic waves propagation, i.e., stop bands, introducing an effect similar to the filter. In this context, the present work introduces an alternative approach for designing periodic rods. This alternative involves the modeling of an infinite hybrid type periodic rod in which a finite periodic structure is connected between two semi-infinite rods. It is used a methodology that relates state vector and wave amplitudes. The main proposal of this work is to develop a relation between the transmitted and incident longitudinal waves amplitudes in terms of physical and geometrical properties of a generic candidate structure to simplify the process of designing. Based on this approach is shown that a periodic rod can be designed to satisfy requirements of a vibration suppression. A hypothetical problem is proposed and numerical and experimental results show the stop bands obtained to so... (Complete abstract click electronic access below) / Doutor

Le syndrome d'immunodéficience acquise (SIDA) est une maladie provoquée chez l'homme par le virus de l'immunodéficience humaine (VIH), un lentivirus à ARN monocaténaire qui infecte les cellules humaines qui expriment les CD4 à leur surface. Depuis son apparition en 1982 chez l’homme, il y a eu environ 80 millions d'individus infectés dans le monde et près de la moitié d'entre eux sont déjà décédés. Aucun vaccin n'existe actuellement mais l'espérance de vie d’un grand nombre de patients est maintenant prolongée grâce au développement et la disponibilité d'un traitement antirétroviral hautement actif (HAART en anglais). En raison de la complexité des interactions hôte/pathogène liées à l'infection par le VIH-1 chez l'homme et les modèles primates non-humains actuels, le développement d’un modèle plus simple est nécessaire pour étudier et mieux comprendre les mécanismes sous-jacents de l'augmentation de la pathogenèse du VIH-1 chez l’humain. Dans ce but, un virus chimérique CAL-HIV-R1 a été construit dans notre laboratoire en échangeant les longues séquences répétées terminales (LTR) du VIH par celles du CAEV, un lentivirus caprin. Parce que ces LTR de CAEV ont un promoteur constitutif qui est indépendant du trans-activateur de la transcription, ce virus chimérique ne devrait pas subir de latence dans les cellules T CD4+ mémoire. Pour rendre son efficacité réplicative plus performante, cette chimère a subi plusieurs passages successifs sur des cellules humaines en culture. En plus de la présence de son récepteur primaire, la protéine CD4, le VIH doit interagir avec une seconde molécule co-réceptrice pour entrer dans la cellule hôte. Des clones moléculaires infectieux contenant des génomes proviraux complets de plusieurs isolats de VIH-1 ont été reçus de la banque de produits "NIH AIDS Reagent Program Repository". Trois d'entre eux, à savoir pNL4-3, p89.6 et WARO, ont été utilisés pour produire des stocks de virus après transfection des cellules de la lignée humaine HEK-293T et utilisés pour infecter d’autres lignées cellulaires telles que : 1) des cellules GHOST, utilisées pour examiner le tropisme des virus en fonction de leur utilisation des co-récepteurs et qui sont respectivement X4, X4/R5 et R5; 2) la lignée cellulaire M8166, utilisée comme cellules indicatrices du fait de ses propriétés fusogéniques, et qui sert à examiner les capacités de réplication et enfin, 3) la lignée cellulaire TZM-bl utilisée pour évaluer le titre infectieux des virus. Par ailleurs, un vaccin basé sur un vecteur ADN lentiviral chimérique, le CAL-SHIV-IN-, a été développé au laboratoire et testé chez des macaques. Dans le cadre de cette étude, un test de séro-neutralisation a été réalisé sur des échantillons de sérum des macaques vaccinés avec ce vecteur, et des animaux témoins, pour examiner la présence d'anticorps pouvant neutraliser le virus. Bien que des anticorps furent présents aucune capacité neutralisante n'a pu être détectée. / Acquired Immuno-Deficiency Syndrome (AIDS) is a disease caused by immunodeficiency viruses in human (HIV-1) and some animal species. The virus is a small enveloped particle that has a single-strand RNA genome and belongs to the lentivirus genus that belongs to the Retroviridae family. In human the virus infects and replicates mainly in cells that express the CD4 on their surface. Since its apparition in human in 1982 the virus has infected around 80 million individuals worldwide and caused the death of nearly half of them. No vaccine exists but life expectancy of near half of HIV-1-infected individuals has been now prolonged due to extensive highly active antiretroviral therapy (HAART). Because of the complexity of the host/pathogen interactions that are associated with HIV-1 infection in human and non-human primate models, a simple model system is strongly needed to ease the studies aiming at better understanding the underlying mechanisms of increased pathogenesis of HIV-1 in human. A chimeric virus CAL-HIV-R1 was created in our laboratory by exchanging the long terminal repeats (LTRs) of HIV with those of CAEV, a caprine lentivirus. Because these CAEV LTRs have a constitutive promoter, which is independent of the trans-activator of transcription, we expect that this chimeric virus should not undergo latency in memory CD4+ T cells. To increase the potency of this chimera, serial passages on cultured human cells were performed. Besides its primary receptor, CD4, HIV needs to interact with another molecule as a co-receptor. Several infectious molecular clones of HIV-1 isolates pDNAs containing the complete proviral genomes were received from the NIH AIDS Reagent Program Repository. Three of these, namely pNL4-3, p89.6 and WARO, were used to produce virus stocks following transfection in the human HEK-293T cell line and used to infect a variety of cell lines such as: 1) GHOST cells that were used to examine the tropism for the co-receptor that were X4, X4/R5 and R5 respectively; 2) M8166 a fusogenic indicator cell line to evaluate the replication competency, 3) TZM-bl to determine the infectivity titers of the viruses by scoring the blue cells enabled by infections. A vaccine based on a chimeric DNA vector, CAL-SHIV-IN-, has been developed in our laboratory and tested in macaques. A sero-neutralization assay was performed on sera of macaques, which had been vaccinated with this vector and challenged in parallel with control animals with a pathogenic virus. This assay was used to verify the presence of neutralizing antibodies, but, unfortunately none could be detected.