Regulation of the Respiration Quotient Across Ocean Basins

A key uncertainty for predicting future ocean oxygen levels is the response and feedback of organic matter respiration demand. One poorly constrained component of the respiration demand is the oxygen-to-carbon remineralization ratio—the respiration quotient. Currently, multiple biological hypotheses can explain variation in the respiration quotient of organic matter produced in the surface ocean. To test these hypotheses, we directly quantified the particulate respiration quotient in 715 samples along a meridional section of the Atlantic Ocean and compared to previous Pacific Ocean observations. We demonstrate significant regional shifts in the respiration quotient and a two-basin average of 1.16. Possible diel oscillations were also observed in the respiration quotient. Basin and regional variation in the respiration quotient were positively linked to temperature, N versus P stress, and plankton size structure. These observations suggest a complex regulation of the respiration quotient with important implications for the regional coupling of carbon and oxygen cycling

Recombination in Streptococcus pneumoniae Lineages Increase with Carriage Duration and Size of the Polysaccharide Capsule.

Streptococcus pneumoniae causes a high burden of invasive pneumococcal disease (IPD) globally, especially in children from resource-poor settings. Like many bacteria, the pneumococcus can import DNA from other strains or even species by transformation and homologous recombination, which has allowed the pneumococcus to evade clinical interventions such as antibiotics and pneumococcal conjugate vaccines (PCVs). Pneumococci are enclosed in a complex polysaccharide capsule that determines the serotype; the capsule varies in size and is associated with properties including carriage prevalence and virulence. We determined and quantified the association between capsule and recombination events using genomic data from a diverse collection of serotypes sampled in Malawi. We determined both the amount of variation introduced by recombination relative to mutation (the relative rate) and how many individual recombination events occur per isolate (the frequency). Using univariate analyses, we found an association between both recombination measures and multiple factors associated with the capsule, including duration and prevalence of carriage. Because many capsular factors are correlated, we used multivariate analysis to correct for collinearity. Capsule size and carriage duration remained positively associated with recombination, although with a reduced P value, and this effect may be mediated through some unassayed additional property associated with larger capsules. This work describes an important impact of serotype on recombination that has been previously overlooked. While the details of how this effect is achieved remain to be determined, it may have important consequences for the serotype-specific response to vaccines and other interventions. IMPORTANCE: The capsule determines >90 different pneumococcal serotypes, which vary in capsule size, virulence, duration, and prevalence of carriage. Current serotype-specific vaccines elicit anticapsule antibodies. Pneumococcus can take up exogenous DNA by transformation and insert it into its chromosome by homologous recombination. This mechanism has disseminated drug resistance and generated vaccine escape variants. It is hence crucial to pneumococcal evolutionary response to interventions, but there has been no systematic study quantifying whether serotypes vary in recombination and whether this is associated with serotype-specific properties such as capsule size or carriage duration. Larger capsules could physically inhibit DNA uptake, or given the longer carriage duration for larger capsules, this may promote recombination. We find that recombination varies among capsules and is associated with capsule size, carriage duration, and carriage prevalence and negatively associated with invasiveness. The consequence of this work is that serotypes with different capsules may respond differently to selective pressures like vaccines

Slx8 removes Pli1-dependent protein-SUMO conjugates including SUMOylated Topoisomerase I to promote genome stability

Peer reviewedPublisher PD

Inhibiting ERK Activation with CI-1040 Leads to Compensatory Upregulation of Alternate MAPKs and Plasminogen Activator Inhibitor-1 following Subtotal Nephrectomy with No Impact on Kidney Fibrosis

Extracellular-signal regulated kinase (ERK) activation by MEK plays a key role in many of the cellular processes that underlie progressive kidney fibrosis including cell proliferation, apoptosis and transforming growth factor β1-mediated epithelial to mesenchymal transition. We therefore assessed the therapeutic impact of ERK1/2 inhibition using a MEK inhibitor in the rat 5/6 subtotal nephrectomy (SNx) model of kidney fibrosis. There was a twentyfold upregulation in phospho-ERK1/2 expression in the kidney after SNx in Male Wistar rats. Rats undergoing SNx became hypertensive, proteinuric and developed progressive kidney failure with reduced creatinine clearance. Treatment with the MEK inhibitor, CI-1040 abolished phospho- ERK1/2 expression in kidney tissue and prevented phospho-ERK1/2 expression in peripheral lymphocytes during the entire course of therapy. CI-1040 had no impact on creatinine clearance, proteinuria, glomerular and tubular fibrosis, and α-smooth muscle actin expression. However, inhibition of ERK1/2 activation led to significant compensatory upregulation of the MAP kinases, p38 and JNK in kidney tissue. CI-1040 also increased the expression of plasminogen activator inhibitor-1 (PAI-1), a key inhibitor of plasmin-dependent matrix metalloproteinases. Thus inhibition of ERK1/2 activation has no therapeutic effect on kidney fibrosis in SNx possibly due to increased compensatory activation of the p38 and JNK signalling pathways with subsequent upregulation of PAI-1

Online Social Networking Technologies, HIV Knowledge, and Sexual Risk and Testing Behaviors Among Homeless Youth

This study evaluates associations between online social networking and sexual health behaviors among homeless youth in Los Angeles. We analyzed survey data from 201 homeless youth accessing services at a Los Angeles agency. Multivariate (regression and logistic) models assessed whether use of (and topics discussed on) online social networking technologies affect HIV knowledge, sexual risk behaviors, and testing for sexually transmitted infections (STIs). One set of results suggests that using online social networks for partner seeking (compared to not using the networks for seeking partners) is associated with increased sexual risk behaviors. Supporting data suggest that (1) using online social networks to talk about safe sex is associated with an increased likelihood of having met a recent sex partner online, and (2) having online sex partners and talking to friends on online social networks about drugs and partying is associated with increased exchange sex. However, results also suggest that online social network usage is associated with increased knowledge and HIV/STI prevention among homeless youth: (1) using online social networks to talk about love and safe sex is associated with increased knowledge about HIV, (2) using the networks to talk about love is associated with decreased exchange sex, and (3) merely being a member of an online social network is associated with increased likelihood of having previously tested for STIs. Taken together, this study suggests that online social networking and the topics discussed on these networks can potentially increase and decrease sexual risk behaviors depending on how the networks are used. Developing sexual health services and interventions on online social networks could reduce sexual risk behaviors

Atomically dispersed Pt-N-4 sites as efficient and selective electrocatalysts for the chlorine evolution reaction

Chlorine evolution reaction (CER) is a critical anode reaction in chlor-alkali electrolysis. Although precious metal-based mixed metal oxides (MMOs) have been widely used as CER catalysts, they suffer from the concomitant generation of oxygen during the CER. Herein, we demonstrate that atomically dispersed Pt-N-4 sites doped on a carbon nanotube (Pt-1/CNT) can catalyse the CER with excellent activity and selectivity. The Pt-1/CNT catalyst shows superior CER activity to a Pt nanoparticle-based catalyst and a commercial Ru/Ir-based MMO catalyst. Notably, Pt-1/CNT exhibits near 100% CER selectivity even in acidic media, with low Cl- concentrations (0.1M), as well as in neutral media, whereas the MMO catalyst shows substantially lower CER selectivity. In situ electrochemical X-ray absorption spectroscopy reveals the direct adsorption of Cl- on Pt-N-4 sites during the CER. Density functional theory calculations suggest the PtN4C12 site as the most plausible active site structure for the CER

Comparative Study of Monoclonal and Recombinant Antibody-Based Immunoassays for Fungicide Analysis in Fruit juices

[EN] A comparative study of the analytical performance of enzyme-linked immunosorbent assays (ELISAs), based on monoclonal and recombinant antibodies, for the determination of fungicide residues in fruit juices has been carried out. To this aim, three murine hybridoma cell lines secreting specific monoclonal antibodies against (RS)-2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propyl-1,1,2,2-tetrafluoroethyl ether (tetraconazole), 2-(4-triazolyl)benzimidazole (thiabendazole), and (RS)-1-(beta-allyloxy-2,4-dichlorophenylethyl)imidazole (imazalil) were used as a source of immunoglobulin gene fragments for the production of single-chain variable fragment (scFv) and fusion scFv-pIII recombinant antibodies in Escherichia coli. Selected recombinant antibodies displayed cross-reactivity profiles very similar to those of the parent monoclonal antibodies. Imazalil and tetraconazole recombinant antibodies showed one order of magnitude lower affinity than their respective monoclonal antibodies, whereas the thiabendazole recombinant antibodies showed an affinity similar to that of their parent monoclonal antibody. On the other hand, scFv-pIII fusion fragments showed similar analytical properties as, and occasionally better than, scFv recombinant antibodies. Finally, ELISAs developed from each antibody type showed similar analytical performance when applied to the analysis of the target fungicides in fruit juices.This work was funded by Ministerio de Educacion y Ciencia (MEC, Spain, Project AGL2002-03266). E. P. was the recipient of a doctoral fellowship from Conselleria d'Educacio (Generalitat Valenciana, Spain).Moreno Tamarit, MJ.; Plana Andani, E.; Manclus Ciscar, JJ.; Montoya Baides, Á. (2014). Comparative Study of Monoclonal and Recombinant Antibody-Based Immunoassays for Fungicide Analysis in Fruit juices. Food Analytical Methods. 7(2):481-489. https://doi.org/10.1007/s12161-013-9655-zS48148972Abad A, Manclús JJ, Moreno M, Montoya A (2001) J AOAC Int 84:1–6Alcocer MJC, Doyen C, Lee HA, Morgan MRA (2000) J Agric Food Chem 48:4053–4059Brichta J, Vesela H, Franek M (2003) Vet Med 48:237–247Brichta J, Hnilova M, Viskovic T (2005) Vet Med 50:231–252Charlton K, Harris WJ, Potter AJ (2001) Biosens Bioelec 16:639–646EU Pesticide Database (2013) Pesticide EU-MRLs. http://ec.europa.eu/sanco_pesticides/public/index.cfm . Accessed Jan 2013Ferrer C, Martínez-Bueno MJ, Lozano A, Fernández-Alba AR (2011) Talanta 83:1552–1561Garret SD, Appleford DJA, Wyatt GM, Lee HA, Morgan MRA (1997) J Agric Food Chem 45:4183–4189Graham BM, Porter AJ, Harris WJ (1995) J Chem Technol Biotech 63:279–289Hiemstra M, de Kok A (2007) J Chromatog A 1154:3–25Kipriyanov SM, Moldenhauer G, Little M (1997) J Immunol Meth 200:69–77Kramer K, Hock B (2007) Recombinant antibodies for agrochemicals: Evolutionary optimization. In: Kennedy IR, Solomon KR, Gee SJ, Crossan AN, Wang S, Sánchez-Bayo F (eds) Rational environmental management of agrochemicals: Risk assessment, monitoring, and remedial action. ACS Symposium Series, vol. 966, pp 155−170Krebber A, Bornhauser S, Burmester J, Honegger A, Willuda J, Bosshard HR, Plückthun A (1997) J Immunol Meth 201:35–55Leong SSJ, Chen WN (2008) Chem Engin Sci 63:1401–1414Li T, Zhang Q, Liu Y, Chen D, Hu B, Blake DA, Liu F (2006) J Agric Food Chem 54:9085–9091Manclús JJ, Moreno M, Plana E, Montoya A (2008) J Agric Food Chem 56:8790–8800Markus V, Janne L, Urpo L (2011) Trends Anal Chem 30:219–226Mersmann M, Schmidt A, Tesar M, Schöneberg A, Welschof M, Kipriyanov S, Terness P, Little M, Pfizenmaier K, Moosmayer D (1998) J Immunol Meth 220:51–58Moreno M, Plana E, Montoya A, Caputo P, Manclús JJ (2007) Food Addit Contam 24:704–712Morozova VS, Levashova AI, Eremin SA (2005) J Anal Chem 60:202–217Nishi K, Imajuku Y, Nakata M, Ohde K, Miyake S, Morimune K, Kawata M, Ohkawa H (2003) J Pest Sci 28:301–309Nishi K, Ishiuchi M, Morimune K, Ohkawa H (2005) J Agric Food Chem 53:5096–5104Scholthof KB, Whang G, Karu AE (1997) J Agric Food Chem 45:1509–1517Sheedy C, MacKenzie CR, Hall JC (2007) Biotech Adv 25:25333–25352Tout NL, Yau KYF, Trevors JT, Lee H, Hall JC (2001) J Agric Food Chem 49:3628–3637Webb SR, Lee H, Hall JC (1997) J Agric Food Chem 45:535–541Yau KYF, Tout NL, Trevors JT, Lee H, Hall JC (1998) J Agric Food Chem 46:4457–4463Yoshioka N, Akiyama Y, Matsuoka T, Mitsuhashi T (2010) Food Control 21:212–21

Validation of the SCID-hu Thy/Liv mouse model with four classes of licensed antiretrovirals.

BackgroundThe SCID-hu Thy/Liv mouse model of HIV-1 infection is a useful platform for the preclinical evaluation of antiviral efficacy in vivo. We performed this study to validate the model with representatives of all four classes of licensed antiretrovirals.Methodology/principal findingsEndpoint analyses for quantification of Thy/Liv implant viral load included ELISA for cell-associated p24, branched DNA assay for HIV-1 RNA, and detection of infected thymocytes by intracellular staining for Gag-p24. Antiviral protection from HIV-1-mediated thymocyte depletion was assessed by multicolor flow cytometric analysis of thymocyte subpopulations based on surface expression of CD3, CD4, and CD8. These mice can be productively infected with molecular clones of HIV-1 (e.g., the X4 clone NL4-3) as well as with primary R5 and R5X4 isolates. To determine whether results in this model are concordant with those found in humans, we performed direct comparisons of two drugs in the same class, each of which has known potency and dosing levels in humans. Here we show that second-generation antiretrovirals were, as expected, more potent than their first-generation predecessors: emtricitabine was more potent than lamivudine, efavirenz was more potent than nevirapine, and atazanavir was more potent than indinavir. After interspecies pharmacodynamic scaling, the dose ranges found to inhibit viral replication in the SCID-hu Thy/Liv mouse were similar to those used in humans. Moreover, HIV-1 replication in these mice was genetically stable; treatment of the mice with lamivudine did not result in the M184V substitution in reverse transcriptase, and the multidrug-resistant NY index case HIV-1 retained its drug-resistance substitutions.ConclusionGiven the fidelity of such comparisons, we conclude that this highly reproducible mouse model is likely to predict clinical antiviral efficacy in humans

Sofosbuvir and Velpatasvir for HCV Genotype 1, 2, 4, 5, and 6 Infection

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