5,880 research outputs found

    P02-07. High Concentrations of Interleukin-15 and Low Concentrations of CCL5 in Breast Milk are Associated with Protection against Postnatal HIV Transmission

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    Background: Natural variations in IL-15 concentration have not been investigated for an association with an immune-protection against HIV. Given IL-15's central role in anti-HIV immunity, we hypothesized that higher concentrations of IL-15 in breast milk may protect against postnatal mother-to-child HIV transmission. Methods: In a case-control study nested within a clinical trial in Zambia, we compared IL-15 concentrations in breast milk of 22 HIV-infected women who transmitted HIV to their infants through breastfeeding with those of 72 who did not, as well as 18 HIV-uninfected women. Breast milk HIV RNA quantity, sodium, CXCL12, CCL5, and IL-8 concentrations were measured as well as maternal plasma HIV RNA concentrations and CD4 cell count. We used logistic regression modeling to adjust for potential confounders. Results: Higher concentrations of IL-15 in breast milk (adjusted odds ratio [AOR]: 0.01 per log10 pg/ml increase, 95% confidence interval [CI]: <0.001 to 0.3) were associated with protection against postnatal HIV transmission in univariate analysis and after adjusting for maternal CD4 cell counts, breast milk HIV RNA, CCL5, CXCL12, and IL-8 concentrations. Breast milk IL-15 concentration correlated with breast milk sodium, the other cytokines and HIV RNA concentration. It was inversely correlated with infant birth weight and tended to be higher in 1 week than in 1 month post-partum samples. Breast milk CCL5 concentrations were associated with increased risk of HIV transmission (AOR: 12.7 95% CI: 1.6 to 102.0) in adjusted analysis. Breast milk CXCL12 and IL-8 concentrations were not independently associated with transmission. Conclusion: High concentration of IL-15 were associated with a protection against breastfeeding HIV transmission after adjusting for other pro-inflammatory cytokines, HIV RNA in breast milk, and maternal CD4 cell count. These results corroborate a protective role of IL-15-mediated cellular immunity against HIV transmission during breastfeeding. They are informative for vaccination studies using IL-15 as an adjuvant

    THE INTRODUCED SABELLID POLYCHAETE TEREBRASABELLA HETEROUNCINATA IN CALIFORNIA: TRANSMISSION, METHODS OF CONTROL AND SURVEY FOR PRESENCE IN NATIVE GASTROPOD POPULATIONS

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    The sabellid polychaete Terebrasabella heterouncinata (Fitzhugh &amp; Rouse 1999) has a unique life history in which larvae settle on the edge of gastropod shells and rely on shell deposition to create a tube with an opening to the exterior. This worm was accidentally imported to California, USA on abalone from South Africa in the 1980s and spread with abalone shipments to most culture facilities and some public aquaria throughout the state. Its ability to infest California's native gastropods has sparked concern regarding potential establishment in intertidal habitats adjacent to facilities that held sabellid-positive abalone. We examined the ability of T. heterouncinata to transmit between individual turban snails, Tegula funebralis. We found that transmission between T.funebralis did occur, but at a significantly slower rate than that between red abalone Haliotis rufescens. During 2002 to 2006 native gastropods (turban snails and limpets) were collected at most sabellid-exposed sites and no T. heterouncinata were detected; it thus appears that this species has not become established in California. Freshwater exposure was examined as a method to kill T. heterouncinala in shell fragments that may remain after abalone are removed from production or display units. Freshwater immersion for up to 8 hours but not 16 or 32 h resulted in survival of adults and/or larvae resident in brood chambers. In a similar study, motile T. heterouncinata larvae were found to survive up to 32 see of freshwater exposure, whereas none survived a 64-sec exposure. These data can be used by abalone culture and display facilities to establish reliable sanitization procedures to prevent T. heterouncinata transmission or reinfestation

    Caenorhabditis elegans chromosome arms are anchored to the nuclear membrane via discontinuous association with LEM-2

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    Abstract Background Although Caenorhabditis elegans was the first multicellular organism with a completely sequenced genome, how this genome is arranged within the nucleus is not known. Results We determined the genomic regions associated with the nuclear transmembrane protein LEM-2 in mixed-stage C. elegans embryos via chromatin immunoprecipitation. Large regions of several megabases on the arms of each autosome were associated with LEM-2. The center of each autosome was mostly free of such interactions, suggesting that they are largely looped out from the nuclear membrane. Only the left end of the X chromosome was associated with the nuclear membrane. At a finer scale, the large membrane-associated domains consisted of smaller subdomains of LEM-2 associations. These subdomains were characterized by high repeat density, low gene density, high levels of H3K27 trimethylation, and silent genes. The subdomains were punctuated by gaps harboring highly active genes. A chromosome arm translocated to a chromosome center retained its association with LEM-2, although there was a slight decrease in association near the fusion point. Conclusions Local DNA or chromatin properties are the main determinant of interaction with the nuclear membrane, with position along the chromosome making a minor contribution. Genes in small gaps between LEM-2 associated regions tend to be highly expressed, suggesting that these small gaps are especially amenable to highly efficient transcription. Although our data are derived from an amalgamation of cell types in mixed-stage embryos, the results suggest a model for the spatial arrangement of C. elegans chromosomes within the nucleus

    First Records of Stelis permaculata Cockerell (Hymenoptera: Megachilidae) in Minnesota, United States of America and Manitoba, Canada

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    Abstract New records are reported for the cleptoparasitic bee Stelis permaculata Cockerell (Hymenoptera: Megachilidae) from Minnesota, United States of America and Manitoba, Canada. Minnesota records come from trap-nests, which also collected the host, Heriades carinata Cresson

    The ebb and flow of adaptive co-management: a longitudinal evaluation of a conservation conflict

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    Adaptive co-management (ACM) is an emerging approach to the governance of social-ecological systems, but there are few long-term assessments of its efficacy. This is especially true in conservation conflicts, where ACM can mitigate disputes between polarised stakeholders. We evaluated ACM that emerged in 2005 to address conflict between seal conservation and fisheries interests in the Moray Firth, Scotland. We interviewed 20 stakeholders in 2015, repeating a survey carried out in 2011 which applied an indicator framework to measure outcomes and pre-conditions for ACM to continue. In 2015, all but one of the 12 outcome indicators were positive, the exception being the conservation status of salmon. However, pre-conditions for ACM’s continuation had weakened, with declines between 2005, 2011 and 2015. These were most marked for three indicators: leaders prepared to champion the process, presence of a bridging organisation or individual, and participation of all impacted stakeholders. The results show that ACM in this conservation conflict is dynamic. Perceived declines in salmon abundance and increases in seal numbers have renewed tensions amongst stakeholders, triggering a ‘revival’ phase of ACM initiated by fishery interests. Our study provides empirical evidence of ACM’s fluid nature, and how resource crises can reignite ACM. We suggest that participatory evaluation is a potentially important early-warning mechanism that can identify remedial action and galvanise stakeholders to respond to the re-emergence of conflict

    The role of aerodynamic drag in propagation of interplanetary coronal mass ejections

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    Context. The propagation of interplanetary coronal mass ejections (ICMEs) and the forecast of their arrival on Earth is one of the central issues of space weather studies. Aims. We investigate to which degree various ICME parameters (mass, size, take-off speed) and the ambient solar-wind parameters (density and velocity) affect the ICME Sun-Earth transit time. Methods. We study solutions of a drag-based equation of motion by systematically varying the input parameters. The analysis is focused on ICME transit times and 1 AU velocities. Results. The model results reveal that wide ICMEs of low masses adjust to the solar-wind speed already close to the sun, so the transit time is determined primarily by the solar-wind speed. The shortest transit times and accordingly the highest 1 AU velocities are related to narrow and massive ICMEs (i.e. high-density eruptions) propagating in high-speed solar wind streams. We apply the model to the Sun-Earth event associated with the CME of 25 July 2004 and compare the results with the outcome of the numerical MHD modeling

    Minnesota State Records for Osmia georgica, Megachile inimica, and Megachile frugalis (Hymenoptera, Megachilidae), Including a New Nest Description for Megachile frugalis Compared with Other Species in the Subgenus Sayapis

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    In this note, we report the first Minnesota state records of Osmia (Helicosmia) georgica Cresson 1878,Megachile (Sayapis) inimica Cresson 1872, and Megachile (Sayapis) frugalis Cresson 1872, which were collected in 2018. We also provide the first description of the nest structure of M. frugalis. All three species typically have more southern distributions. The nest of M. frugalis shows similar structure to other species in the subgenus Sayapis Titus, such as M. inimica and M. pugnata, particularly in that the longitudinal nest cell walls lack a lining of leaf pieces, and the cell partitions are made from a layer of leaf pieces followed by a layer of masticated vegetation and soil particles
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