Effect of a selenium-deficient diet on blood values of T3 and T4 in cows

Pastures in the south of Chile have been shown to be selenium deficient, and as selenium is a component of deiodinase type 1, which is necessary for the synthesis of triiodothyronine (T3) at peripheral levels, the effect of selenium deficiency on the blood concentration of theses hormones in cows was studied. Twelve pregnant Friesian cows were randomly allocated into two homogeneous groups of six animals each-selenium supplemented and selenium deficient. The selenium deficient diet consisted of 11.5 kg of hay, 500 g of soya bran, 150 g of mineral mix (without selenium), 500 g of fat for animal feeding, and was given from day 15 of lactation until the end of the study. A commercial concentrate (Cosetan) and urea was also given according to lactation requirements (up to 5 kg and up to 120 g, respectively). The selenium content was 0.05 ppm of dry matter (equivalent to 18% of the daily requirements). The supplemented group was injected subcutaneously with 1 mg Se/kg, using the commercial product Deposel (1 ml/50kg). Blood samples were obtained by coccygeous vein venepuncture before supplementation (prepartum basal values) and thereafter every 15 days. GSH-Px activity in plasma was measured using a HITACHI 4020 spectrophotometer. Serum T3 and thyroxine (T4) concentrations were measured by electrochemiluminiscence. ANOVA, Tuckey test and Student's t-test were used to establish the significance of the intra group differences, with p = < 0.05 being considered significant. There were no significant differences in blood values of T4 in either the supplemented or non-supplemented groups during pregnancy and lactation. However the blood values of T4 decreased significantly (p = < 0.05) during days 30-60 of lactation to values below the reference range. The T3 serum concentrations in the supplemented group of cows were significantly lower (p = < 0.05) at 60, 90 and 150 days of lactation than cows that had been supplemented with selenium

Relación entre exposición ambiental al plomo y biomarcadores de estrés oxidativo en niños atendidos en un hospital público de La Plata, Argentina

El plomo es un metal neurotóxico ampliamente distribuido en el ambiente. Uno de los mecanismos de acción propuesto es su capacidad de inducir estrés oxidativo. Estudios experimentales en animales y observacionales en adultos expuestos ocupacionalmente han establecido una relación entre la exposición al plomo y alteraciones en biomarcadores de estrés oxidativo. Sin embargo la evidencia no es concluyente en poblaciones pediátricas expuestas ambientalmente al plomo. Objetivo: Determinar las plombemias de niños expuestos ambientalmente al plomo y establecer su relación con la actividad de enzimas antioxidantes y con el grado de peroxidación lipídica.Trabajo presentado en la LVII Reunión Anual de la Sociedad Latinoamericana de Investigación Pediátrica - SLAIP (Brasil, noviembre de 2019

Comprehensive Characterization of Solar Eruptions with Remote and In-Situ Observations, and Modeling : The Major Solar Events on 4 November 2015

Solar energetic particles (SEPs) are an important product of solar activity. They are connected to solar active regions and flares, coronal mass ejections (CMEs), EUV waves, shocks, Type II and III radio emissions, and X-ray bursts. These phenomena are major probes of the partition of energy in solar eruptions, as well as for the organization, dynamics, and relaxation of coronal and interplanetary magnetic fields. Many of these phenomena cause terrestrial space weather, posing multiple hazards for humans and their technology from space to the ground. Since particular flares, shocks, CMEs, and EUV waves produce SEP events but others do not, since propagation effects from the low corona to 1 AU appear important for some events but not others, and since Type II and III radio emissions and X-ray bursts are sometimes produced by energetic particles leaving these acceleration sites, it is necessary to study the whole system with a multi-frequency and multi-instrument perspective that combines both in-situ and remote observations with detailed modeling of phenomena. This article demonstrates this comprehensive approach and shows its necessity by analyzing a trio of unusual and striking solar eruptions, radio and X-ray bursts, and SEP events that occurred on 4 November 2015. These events show both strong similarities and differences from standard events and each other, despite having very similar interplanetary conditions and only two flare sites and CME genesis regions. They are therefore major targets for further in-depth observational studies, and for testing both existing and new theories and models. We present the complete suite of relevant observations, complement them with initial modeling results for the SEPs and interplanetary magnetic connectivity, and develop a plausible scenario for the eruptions. Perhaps controversially, the SEPs appear to be reasonably modelled and evidence points to significant non-Parker magnetic fields. Based on the very limited modeling available, we identify the aspects that are and are not understood, and we discuss ideas that may lead to improved understanding of the SEP, radio, and space-weather events.Peer reviewe

A Comprehensive Phenotypic and Functional Immune Analysis Unravels Circulating Anti-Phospholipase A2 Receptor Antibody Secreting Cells in Membranous Nephropathy Patients

Introduction: Primary membranous nephropathy (MN) is characterized by the presence of antipodocyte antibodies, but studies describing phenotypic and functional abnormalities in circulating lymphocytes are limited. Methods: We analyzed 68 different B- and T-cell subsets using flow cytometry in 30 MN patients (before initiating immunosuppression) compared with 31 patients with non-immune-mediated chronic kidney disease (CKD) and 12 healthy individuals. We also measured 19 serum cytokines in MN patients and in healthy controls. Lastly, we quantified the ex vivo production of phospholipase A2 receptor (PLA2R)-specific IgG by plasmablasts (measuring antibodies in culture supernatants and by the newly developed FluoroSpot assay [AutoImmun Diagnostika, Strasberg, Germany]) and assessed the circulating antibody repertoire by phage immunoprecipitation sequencing (PhIP-Seq). Results: After adjusting for multiple testing, plasma cells and regulatory B cells (BREG) were significantly higher (P < 0.05) in MN patients compared with both control groups. The percentages of circulating plasma cells correlated with serum anti-PLA2R antibody levels (P = 0.042) and were associated with disease activity. Ex vivo-expanded PLA2R-specific IgG-producing plasmablasts generated from circulating PLA2R-specific memory B cells (mBCs) correlated with serum anti-PLA2R IgG antibodies (P < 0.001) in MN patients. Tumor necrosis factor-alpha (TNF-alpha) was the only significantly increased cytokine in MN patients (P < 0.05), whereas there was no significant difference across study groups in the autoantibody and antiviral antibody repertoire. Conclusion: This extensive phenotypic and functional immune characterization shows that autoreactive plasma cells are present in the circulation of MN patients, providing a new therapeutic target and a candidate biomarker of disease activity

The effect of air pollution on children's health: A comparative study between La Plata and Bahía Blanca, Buenos Aires province, Argentina

We present the results of a study of outdoor air quality in two comparable regions of Buenos Aires province (Argentina); La Plata and Bahía Blanca, developed jointly by researchers of the National University in both cities, and of the Hospital of Bahía Blanca, between 2009 and 2011. Both regions are characterized by a large petrochemical complex and a village with outstanding traffic. In this study, we measure levels of volatile organic compounds (VOCs), particulate matter suspended in air (PM) in air outdoor and affectation of respiratory system in children between 6 and 12 years. Also, analysis of the effect of the air pollution exposure was made through the calculation of potentially increased life time cancer risk (LCR) in children. In both regions, including three areas: urban, industrial and residential (reference area), 20 VOCs were sampled by passive monitoring (3M 3500), and determined by GC/FID, comprising n-alkanes, cycloalkanes, aromatics, chlorinated compounds, terpenoids and ketones; particulate matter (PM10) was token using a low flow sampler MiniVol TAS, and spirometry were performed, using a portable spirometer. The collected data show higher levels of PM10 in Bahía Blanca, both in the industrial zone and urban areas, the industrial area of Bahía Blanca with very bad air quality, associable with a 5% increase in mortality. The levels of total VOCs found in the residential area for both regions are comparable. Spirometry parameters of children living in an industrial area evidence respiratory disease with respect to urban and residential areas.Facultad de Ciencias ExactasFacultad de Ingenierí

Function of glutathione peroxidases in legume root nodules

© The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.[EN] Glutathione peroxidases (Gpxs) are antioxidant enzymes not studied so far in legume nodules, despite the fact that reactive oxygen species are produced at different steps of the symbiosis. The function of two Gpxs that are highly expressed in nodules of the model legume Lotus japonicus was examined. Gene expression analysis, enzymatic and nitrosylation assays, yeast cell complementation, in situ mRNA hybridization, immunoelectron microscopy, and LjGpx-green fluorescent protein (GFP) fusions were used to characterize the enzymes and to localize each transcript and isoform in nodules. The LjGpx1 and LjGpx3 genes encode thioredoxin-dependent phospholipid hydroperoxidases and are differentially regulated in response to nitric oxide (NO) and hormones. LjGpx1 and LjGpx3 are nitrosylated in vitro or in plants treated with S-nitrosoglutathione (GSNO). Consistent with the modification of the peroxidatic cysteine of LjGpx3, in vitro assays demonstrated that this modification results in enzyme inhibition. The enzymes are highly expressed in the infected zone, but the LjGpx3 mRNA is also detected in the cortex and vascular bundles. LjGpx1 is localized to the plastids and nuclei, and LjGpx3 to the cytosol and endoplasmic reticulum. Based on yeast complementation experiments, both enzymes protect against oxidative stress, salt stress, and membrane damage. It is concluded that both LjGpxs perform major antioxidative functions in nodules, preventing lipid peroxidation and other oxidative processes at different subcellular sites of vascular and infected cells. The enzymes are probably involved in hormone and NO signalling, and may be regulated through nitrosylation of the peroxidatic cysteine essential for catalytic function.AS and PBS were the recipients of predoctoral (Formacion de Personal Investigador) and postdoctoral (Marie Curie) contracts, respectively. We thank Martin Crespi for help with in situ RNA hybridization and Simon Avery for sharing the yeast mutant and for helpful advice. This work was supported by Ministerio de Economia y Competitividad-Fondo Europeo de Desarrollo Regional (AGL2011-24524 and AGL2014-53717-R). The UMR1136 is supported by a grant overseen by the French National Research Agency (ANR) as part of the 'Investissements d'Avenir' programme (ANR-11-LABX-0002-01, Lab of Excellence ARBRE). MM and KJD acknowledge support within SPP1710. The proteomic analysis was performed in the CSIC/UAB Proteomics Facility of IIBB-CSIC that belongs to ProteoRed, PRB2-ISCIII, supported by grant PT13/0001.Matamoros, MA.; Saiz Andres, A.; Peñuelas, M.; Bustos-Sanmamed, P.; Mulet Salort, JM.; Barja, MV.; Rouhier, N.... (2015). Function of glutathione peroxidases in legume root nodules. Journal of Experimental Botany. 66(10):2979-2990. https://doi.org/10.1093/jxb/erv066S297929906610Astier, J., Kulik, A., Koen, E., Besson-Bard, A., Bourque, S., Jeandroz, S., … Wendehenne, D. (2012). Protein S-nitrosylation: What’s going on in plants? Free Radical Biology and Medicine, 53(5), 1101-1110. doi:10.1016/j.freeradbiomed.2012.06.032Avery, A. M., & Avery, S. V. (2001). Saccharomyces cerevisiaeExpresses Three Phospholipid Hydroperoxide Glutathione Peroxidases. Journal of Biological Chemistry, 276(36), 33730-33735. doi:10.1074/jbc.m105672200Avsian-Kretchmer, O., Gueta-Dahan, Y., Lev-Yadun, S., Gollop, R., & Ben-Hayyim, G. (2004). The Salt-Stress Signal Transduction Pathway That Activates the gpx1 Promoter Is Mediated by Intracellular H2O2, Different from the Pathway Induced by Extracellular H2O2. Plant Physiology, 135(3), 1685-1696. doi:10.1104/pp.104.041921Balmer, Y., Koller, A., del Val, G., Manieri, W., Schurmann, P., & Buchanan, B. B. (2002). Proteomics gives insight into the regulatory function of chloroplast thioredoxins. Proceedings of the National Academy of Sciences, 100(1), 370-375. doi:10.1073/pnas.232703799Becana, M., Matamoros, M. A., Udvardi, M., & Dalton, D. A. (2010). Recent insights into antioxidant defenses of legume root nodules. New Phytologist, 188(4), 960-976. doi:10.1111/j.1469-8137.2010.03512.xBrigelius-Flohé, R., & Maiorino, M. (2013). Glutathione peroxidases. Biochimica et Biophysica Acta (BBA) - General Subjects, 1830(5), 3289-3303. doi:10.1016/j.bbagen.2012.11.020Bright, J., Desikan, R., Hancock, J. T., Weir, I. S., & Neill, S. J. (2005). ABA-induced NO generation and stomatal closure in Arabidopsis are dependent on H2 O2 synthesis. The Plant Journal, 45(1), 113-122. doi:10.1111/j.1365-313x.2005.02615.xBroughton, W. J., & Dilworth, M. J. (1971). Control of leghaemoglobin synthesis in snake beans. Biochemical Journal, 125(4), 1075-1080. doi:10.1042/bj1251075Camerini, S., Polci, M. L., Restuccia, U., Usuelli, V., Malgaroli, A., & Bachi, A. (2007). A Novel Approach to Identify Proteins Modified by Nitric Oxide:  the HIS-TAG Switch Method. Journal of Proteome Research, 6(8), 3224-3231. doi:10.1021/pr0701456Chang, C. C. C., Ślesak, I., Jordá, L., Sotnikov, A., Melzer, M., Miszalski, Z., … Karpiński, S. (2009). Arabidopsis Chloroplastic Glutathione Peroxidases Play a Role in Cross Talk between Photooxidative Stress and Immune Responses. Plant Physiology, 150(2), 670-683. doi:10.1104/pp.109.135566Colebatch, G., Kloska, S., Trevaskis, B., Freund, S., Altmann, T., & Udvardi, M. K. (2002). Novel Aspects of Symbiotic Nitrogen Fixation Uncovered by Transcript Profiling with cDNA Arrays. Molecular Plant-Microbe Interactions, 15(5), 411-420. doi:10.1094/mpmi.2002.15.5.411Dalton, D. A. (1995). Antioxidant Defenses of Plants and Fungi. Oxidative Stress and Antioxidant Defenses in Biology, 298-355. doi:10.1007/978-1-4615-9689-9_9FOYER, C. H., & NOCTOR, G. (2005). Oxidant and antioxidant signalling in plants: a re-evaluation of the concept of oxidative stress in a physiological context. Plant, Cell and Environment, 28(8), 1056-1071. doi:10.1111/j.1365-3040.2005.01327.xFu, L.-H., Wang, X.-F., Eyal, Y., She, Y.-M., Donald, L. J., Standing, K. G., & Ben-Hayyim, G. (2002). A Selenoprotein in the Plant Kingdom. Journal of Biological Chemistry, 277(29), 25983-25991. doi:10.1074/jbc.m202912200Gaber, A., Ogata, T., Maruta, T., Yoshimura, K., Tamoi, M., & Shigeoka, S. (2012). The Involvement of Arabidopsis Glutathione Peroxidase 8 in the Suppression of Oxidative Damage in the Nucleus and Cytosol. Plant and Cell Physiology, 53(9), 1596-1606. doi:10.1093/pcp/pcs100Daniel Gietz, R., & Woods, R. A. (2002). Transformation of yeast by lithium acetate/single-stranded carrier DNA/polyethylene glycol method. Methods in Enzymology, 87-96. doi:10.1016/s0076-6879(02)50957-5Gueta-Dahan, Y., Yaniv, Z., Zilinskas, B. A., & Ben-Hayyim, G. (1997). Salt and oxidative stress: similar and specific responses and their relation to salt tolerance in Citrus. Planta, 203(4), 460-469. doi:10.1007/s004250050215Herbette, S., Lenne, C., Leblanc, N., Julien, J.-L., Drevet, J. R., & Roeckel-Drevet, P. (2002). Two GPX-like proteins fromLycopersicon esculentumandHelianthus annuusare antioxidant enzymes with phospholipid hydroperoxide glutathione peroxidase and thioredoxin peroxidase activities. European Journal of Biochemistry, 269(9), 2414-2420. doi:10.1046/j.1432-1033.2002.02905.xHerbette, S., Roeckel-Drevet, P., & Drevet, J. R. (2007). Seleno-independent glutathione peroxidases. FEBS Journal, 274(9), 2163-2180. doi:10.1111/j.1742-4658.2007.05774.xJaffrey, S. R., Erdjument-Bromage, H., Ferris, C. D., Tempst, P., & Snyder, S. H. (2001). Protein S-nitrosylation: a physiological signal for neuronal nitric oxide. Nature Cell Biology, 3(2), 193-197. doi:10.1038/35055104Jung, B. G., Lee, K. O., Lee, S. S., Chi, Y. H., Jang, H. H., Kang, S. S., … Lee, S. Y. (2002). A Chinese Cabbage cDNA with High Sequence Identity to Phospholipid Hydroperoxide Glutathione Peroxidases Encodes a Novel Isoform of Thioredoxin-dependent Peroxidase. Journal of Biological Chemistry, 277(15), 12572-12578. doi:10.1074/jbc.m110791200Koh, C. S., Didierjean, C., Navrot, N., Panjikar, S., Mulliert, G., Rouhier, N., … Corbier, C. (2007). Crystal Structures of a Poplar Thioredoxin Peroxidase that Exhibits the Structure of Glutathione Peroxidases: Insights into Redox-driven Conformational Changes. Journal of Molecular Biology, 370(3), 512-529. doi:10.1016/j.jmb.2007.04.031Kuranda, K., Leberre, V., Sokol, S., Palamarczyk, G., & Francois, J. (2006). Investigating the caffeine effects in the yeast Saccharomyces cerevisiae brings new insights into the connection between TOR, PKC and Ras/cAMP signalling pathways. Molecular Microbiology, 61(5), 1147-1166. doi:10.1111/j.1365-2958.2006.05300.xLivak, K. J., & Schmittgen, T. D. (2001). Analysis of Relative Gene Expression Data Using Real-Time Quantitative PCR and the 2−ΔΔCT Method. Methods, 25(4), 402-408. doi:10.1006/meth.2001.1262Maiorino, M., Gregolin, C., & Ursini, F. (1990). [47] Phospholipid hydroperoxide glutathione peroxidase. Methods in Enzymology, 448-457. doi:10.1016/0076-6879(90)86139-mMargis, R., Dunand, C., Teixeira, F. K., & Margis-Pinheiro, M. (2008). Glutathione peroxidase family - an evolutionary overview. FEBS Journal, 275(15), 3959-3970. doi:10.1111/j.1742-4658.2008.06542.xMiao, Y., Lv, D., Wang, P., Wang, X.-C., Chen, J., Miao, C., & Song, C.-P. (2006). An Arabidopsis Glutathione Peroxidase Functions as Both a Redox Transducer and a Scavenger in Abscisic Acid and Drought Stress Responses. The Plant Cell, 18(10), 2749-2766. doi:10.1105/tpc.106.044230Mullineaux, P. M., Karpinski, S., Jimenez, A., Cleary, S. P., Robinson, C., & Creissen, G. P. (1998). Identification of cDNAS encoding plastid-targeted glutathione peroxidase. The Plant Journal, 13(3), 375-379. doi:10.1046/j.1365-313x.1998.00052.xNakagawa, T., Kurose, T., Hino, T., Tanaka, K., Kawamukai, M., Niwa, Y., … Kimura, T. (2007). Development of series of gateway binary vectors, pGWBs, for realizing efficient construction of fusion genes for plant transformation. Journal of Bioscience and Bioengineering, 104(1), 34-41. doi:10.1263/jbb.104.34Navrot, N., Collin, V., Gualberto, J., Gelhaye, E., Hirasawa, M., Rey, P., … Rouhier, N. (2006). Plant Glutathione Peroxidases Are Functional Peroxiredoxins Distributed in Several Subcellular Compartments and Regulated during Biotic and Abiotic Stresses. Plant Physiology, 142(4), 1364-1379. doi:10.1104/pp.106.089458Passaia, G., Queval, G., Bai, J., Margis-Pinheiro, M., & Foyer, C. H. (2014). The effects of redox controls mediated by glutathione peroxidases on root architecture in Arabidopsis thaliana. Journal of Experimental Botany, 65(5), 1403-1413. doi:10.1093/jxb/ert486Perazzolli, M., Dominici, P., Romero-Puertas, M. C., Zago, E., Zeier, J., Sonoda, M., … Delledonne, M. (2004). Arabidopsis Nonsymbiotic Hemoglobin AHb1 Modulates Nitric Oxide Bioactivity. The Plant Cell, 16(10), 2785-2794. doi:10.1105/tpc.104.025379Puppo, A., Herrada, G., & Rigaud, J. (1991). Lipid Peroxidation in Peribacteroid Membranes from French-Bean Nodules. Plant Physiology, 96(3), 826-830. doi:10.1104/pp.96.3.826Puppo, A., Pauly, N., Boscari, A., Mandon, K., & Brouquisse, R. (2013). Hydrogen Peroxide and Nitric Oxide: Key Regulators of the Legume—Rhizobium and Mycorrhizal Symbioses. Antioxidants & Redox Signaling, 18(16), 2202-2219. doi:10.1089/ars.2012.5136Ramos, J., Matamoros, M. A., Naya, L., James, E. K., Rouhier, N., Sato, S., … Becana, M. (2008). The glutathione peroxidase gene family of Lotus japonicus : characterization of genomic clones, expression analyses and immunolocalization in legumes. New Phytologist, 181(1), 103-114. doi:10.1111/j.1469-8137.2008.02629.xMilla, M. A. R., Maurer, A., Huete, A. R., & Gustafson, J. P. (2003). Glutathione peroxidase genes in Arabidopsis are ubiquitous and regulated by abiotic stresses through diverse signaling pathways. The Plant Journal, 36(5), 602-615. doi:10.1046/j.1365-313x.2003.01901.xROMERO-PUERTAS, M. C., RODRIGUEZ-SERRANO, M., CORPAS, F. J., GOMEZ, M., DEL RIO, L. A., & SANDALIO, L. M. (2004). Cadmium-induced subcellular accumulation of O2.- and H2O2 in pea leaves. Plant, Cell and Environment, 27(9), 1122-1134. doi:10.1111/j.1365-3040.2004.01217.xRubio, M. C., Becana, M., Kanematsu, S., Ushimaru, T., & James, E. K. (2009). Immunolocalization of antioxidant enzymes in high-pressure frozen root and stem nodules of Sesbania rostrata. New Phytologist, 183(2), 395-407. doi:10.1111/j.1469-8137.2009.02866.xSainz, M., Pérez-Rontomé, C., Ramos, J., Mulet, J. M., James, E. K., Bhattacharjee, U., … Becana, M. (2013). Plant hemoglobins may be maintained in functional form by reduced flavins in the nuclei, and confer differential tolerance to nitro-oxidative stress. The Plant Journal, 76(5), 875-887. doi:10.1111/tpj.12340Seidel, T., Kluge, C., Hanitzsch, M., Roß, J., Sauer, M., Dietz, K.-J., & Golldack, D. (2004). Colocalization and FRET-analysis of subunits c and a of the vacuolar H+-ATPase in living plant cells. Journal of Biotechnology, 112(1-2), 165-175. doi:10.1016/j.jbiotec.2004.04.027Serrano, R., Mulet, J. M., Rios, G., Marquez, J. A., Larrinoa, I. igo F. de, Leube, M. P., … Montesinos, C. (1999). A glimpse of the mechanisms of ion homeostasis during salt stress. Journal of Experimental Botany, 50(Special_Issue), 1023-1036. doi:10.1093/jxb/50.special_issue.1023Tovar-Méndez, A., Matamoros, M. A., Bustos-Sanmamed, P., Dietz, K.-J., Cejudo, F. J., Rouhier, N., … Becana, M. (2011). Peroxiredoxins and NADPH-Dependent Thioredoxin Systems in the Model Legume Lotus japonicus. Plant Physiology, 156(3), 1535-1547. doi:10.1104/pp.111.177196Wolff, S. P. (1994). [18] Ferrous ion oxidation in presence of ferric ion indicator xylenol orange for measurement of hydroperoxides. Oxygen Radicals in Biological Systems Part C, 182-189. doi:10.1016/s0076-6879(94)33021-

RT-SHIV subpopulation dynamics in infected macaques during anti-HIV therapy

<p>Abstract</p> <p>Background</p> <p>To study the dynamics of wild-type and drug-resistant HIV-1 RT variants, we developed a methodology that follows the fates of individual genomes over time within the viral quasispecies. Single genome sequences were obtained from 3 pigtail macaques infected with a recombinant simian immunodeficiency virus containing the RT coding region from HIV-1 (RT-SHIV) and treated with short-course efavirenz monotherapy 13 weeks post-infection followed by daily combination antiretroviral therapy (ART) beginning at week 17. Bioinformatics tools were constructed to trace individual genomes from the beginning of infection to the end of the treatment.</p> <p>Results</p> <p>A well characterized challenge RT-SHIV inoculum was used to infect three monkeys. The RT-SHIV inoculum had 9 variant subpopulations and the dominant subpopulation accounted for 80% of the total genomes. In two of the three monkeys, the inoculated wild-type virus was rapidly replaced by new wild type variants. By week 13, the original dominant subpopulation in the inoculum was replaced by new dominant subpopulations, followed by emergence of variants carrying known NNRTI resistance mutations. However, during ART, virus subpopulations containing resistance mutations did not outgrow the wide-type subpopulations until a minor subpopulation carrying linked drug resistance mutations (K103N/M184I) emerged. We observed that persistent viremia during ART is primarily made up of wild type subpopulations. We also found that subpopulations carrying the V75L mutation, not known to be associated with NNRTI resistance, emerged initially in week 13 in two macaques. Eventually, all subpopulations from these two macaques carried the V75L mutation.</p> <p>Conclusion</p> <p>This study quantitatively describes virus evolution and population dynamics patterns in an animal model. The fact that wild type subpopulations remained as dominant subpopulations during ART treatment suggests that the presence or absence of at least some known drug resistant mutations may not greatly affect virus replication capacity <it>in vivo</it>. Additionally, the emergence and prevalence of V75L indicates that this mutation may provide the virus a selective advantage, perhaps escaping the host immure system surveillance. Our new method to quantitatively analyze viral population dynamics enabled us to observe the relative competitiveness and adaption of different viral variants and provided a valuable tool for studying HIV subpopulation emergence, persistence, and decline during ART.</p

Beam Charge Asymmetries for Deeply Virtual Compton Scattering on the Proton at CLAS12

The parameterization of the nucleon structure through Generalized Parton Distributions (GPDs) shed a new light on the nucleon internal dynamics. For its direct interpretation, Deeply Virtual Compton Scattering (DVCS) is the golden channel for GPDs investigation. The DVCS process interferes with the Bethe-Heitler (BH) mechanism to constitute the leading order amplitude of the $eN \to eN\gamma$ process. The study of the $ep\gamma$ reaction with polarized positron and electron beams gives a complete set of unique observables to unravel the different contributions to the $ep \gamma$ cross section. This separates the different reaction amplitudes, providing a direct access to their real and imaginary parts which procures crucial constraints on the model dependences and associated systematic uncertainties on GPDs extraction. The real part of the BH-DVCS interference amplitude is particularly sensitive to the $D$-term which parameterizes the Gravitational Form Factors of the nucleon. The separation of the imaginary parts of the interference and DVCS amplitudes provides insights on possible higher-twist effects. We propose to measure the unpolarized and polarized Beam Charge Asymmetries (BCAs) of the $\vec{e}^{\pm}p \to e^{\pm}p \gamma$ process on an unpolarized hydrogen target with {\tt CLAS12}, using polarized positron and electron beams at 10.6~GeV. The azimuthal and $t$-dependences of the unpolarized and polarized BCAs will be measured over a large $(x_B,Q^2)$ phase space using a 100 day run with a luminosity of 0.66$\times 10^{35}$cm$^{-2}\cdot$s$^{-1}$.Comment: Proposal to the Jefferson Lab Program Advisory Committee (PAC51