47 research outputs found
Macroalgal-Associated Dinoflagellates Belonging to the Genus Symbiodinium in Caribbean Reefs
Coral-algal symbiosis has been a subject of great attention during the last two decades in response to global coral reef decline. However, the occurrence and dispersion of free-living dinoflagellates belonging to the genus Symbiodinium are less documented. Here ecological and molecular evidence is presented demonstrating the existence of demersal free-living Symbiodinium populations in Caribbean reefs and the possible role of the stoplight parrotfish (Sparisoma viride) as Symbiodinium spp. dispersers. Communities of free-living Symbiodinium were found within macroalgal beds consisting of Halimeda spp., Lobophora variegata, Amphiroa spp., Caulerpa spp. and Dictyota spp. Viable Symbiodinium spp. cells were isolated and cultured from macroalgal beds and S. viride feces. Further identification of Symbiodinium spp. type was determined by length variation in the Internal Transcribed Spacer 2 (ITS2, nuclear rDNA) and length variation in domain V of the chloroplast large subunit ribosomal DNA (cp23S-rDNA). Determination of free-living Symbiodinium and mechanisms of dispersal is important in understanding the life cycle of Symbiodinium spp
Flow-flame interaction in a closed chamber
Numerous studies of flame interaction with a single vortex and recent simulations of burning in vortex arrays in open tubes demonstrated the same tendency for the turbulent burning rate Urms2/3, where Urms is the root-mean-square velocity and is the vortex size. Here, it is demonstrated that this tendency is not universal for turbulent burning. Flame interaction with vortex arrays is investigated for the geometry of a closed burning chamber by using direct numerical simulations of the complete set of gas-dynamic combustion equations. Various initial conditions in the chamber are considered, including gas at rest and several systems of vortices of different intensities and sizes. It is found that the burning rate in a closed chamber (inverse burning time) depends strongly on the vortex intensity; at sufficiently high intensities it increases with Urms approximately linearly in agreement with the above tendency. On the contrary, dependence of the burning rate on the vortex size is nonmonotonic and qualitatively different from the law 2/3. It is shown that there is an optimal vortex size in a closed chamber, which provides the fastest total burning rate. In the present work, the optimal size is six times smaller than the chamber height
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Metabolic Changes Associated With the Use of Integrase Strand Transfer Inhibitors Among Virally Controlled Women.
BackgroundIntegrase strand transfer inhibitors (INSTIs) have been associated with weight gain among women living with HIV. We aimed to investigate the association between INSTIs and change in cardiometabolic risk indicators.SettingRetrospective cohort.MethodsData from 2006 to 2017 were analyzed from women living with HIV enrolled in the longitudinal Women's Interagency HIV Study who were virally controlled on antiretroviral therapy (ART) for ≥5 consecutive semiannual visits. Women who switched/added an INSTI to ART (INSTI group) were compared with women who remained on non-INSTI ART (non-INSTI group). Outcomes included changes in fasting lipids and glucose, hemoglobin A1c (HbA1c), blood pressure (BP), and incident diabetes, hypertension, and insulin resistance. Outcomes were measured 6-12 months before and 6-18 months after INSTI switch/add in the INSTI group with comparable visits in the non-INSTI group. Longitudinal linear regression models compared change over time in each outcome by the study group.ResultsOne thousand one hundred eighteen participants (234 INSTI, 884 non-INSTI) were followed for a median 2.0 (Q1 1.9, Q3 2.0) years. Participants were median age 49 years, 61% Black, and 73% overweight or obese (body mass index ≥25 kg/m). Compared with non-INSTI, the INSTI group experienced greater increases in HbA1c (+0.05 vs. -0.06 mg/dL, P = 0.0318), systolic BP (+3.84 vs. +0.84 mm Hg, P = 0.0191), and diastolic BP (+1.62 vs. -0.14 mm Hg, P = 0.0121), with greatest change in HbA1c among women on INSTIs with ≥5% weight gain.ConclusionsINSTI use was associated with unfavorable changes in HbA1c and systolic and diastolic BP during short-term follow-up. Further research is needed to understand long-term cardiometabolic effects of INSTI use
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980. Effects of Integrase Strand-Transfer Inhibitor Use on Lipids, Glycemic Control, and Insulin Resistance in the Women’s Interagency HIV Study (WIHS)
Abstract Background Integrase strand transfer inhibitor (INSTI)-based antiretroviral therapy (ART) is recommended first-line HIV treatment. We recently demonstrated increased weight gain associated with INSTI use among women living with HIV (WLH) enrolled in the Women’s Interagency HIV Study (WIHS), raising concern for cardiometabolic consequences. We, therefore, evaluated the effects of INSTI use on lipids, insulin resistance, and glycemic control in WLH. Methods Data from 2008 to 2017 were analyzed from WLH enrolled in WIHS. Women who switched to or added an INSTI to ART (SWAD group) were compared with women who remained on non-INSTI ART (STAY group). Outcomes included changes in fasting total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), and glucose; hemoglobin A1c; and incident insulin resistance (defined as homeostatic model assessment of insulin resistance [HOMA] score ≥2). Outcomes were measured 6–12 months before and 6–18 months after INSTI switch/add in the SWAD group with comparable time points in the STAY group. Linear regression models compared change over time in each outcome by SWAD/STAY group, adjusted for age, race, WIHS site, income, smoking status, statin use, and ART regimen at baseline. Results In total, 881 WIHS participants (182 SWAD and 699 STAY) were followed for a mean 1.8 (±1.1) years. Mean age was 49 (±8.8) years, BMI was 31 (±8.2) kg/m2, and 49% were Black. At baseline, SWAD vs. STAY was more likely to report NNRTI (vs. PI)-based ART and statin use (both P < 0.0001), but all baseline lipid and glucose variables were similar. Compared with STAY, the SWAD group experienced significantly greater decreases in HDL (−2.4 vs. +0.09 mg/dL, P = 0.03) and trended toward greater decreases in TC (−2.6 vs. −2.4 mg/dL, P = 0.07) at follow-up, without significant differences in TG or LDL. The SWAD group had significantly greater increases in A1c (+0.08% vs. −0.05%, P = 0.01) but trended toward lower incidence of insulin resistance (19% vs. 32%, P = 0.05). Conclusion Despite reported increases in weight, INSTI use was associated with only modest changes in lipid measurements and glycemic control during short-term follow-up of WLH compared with non-INSTI ART. Research is needed to elucidate long-term cardiometabolic effects. Disclosures Anandi N. Sheth, MD, MS, Gilead Sciences, Inc.: Research Grant