1,813 research outputs found

    Relationships between Larval and Juvenile Abundance of Winter-Spawned Fishes in North Carolina, USA

    Get PDF
    We analyzed the relationships between the larval and juvenile abundances of selected estuarine-dependent fishes that spawn during the winter in continental shelf waters of the U.S. Atlantic coast. Six species were included in the analysis based on their ecological and economic importance and relative abundance in available surveys: spot Leiostomus xanthurus, pinfish Lagodon rhomboides, southern flounder Paralichthys lethostigma, summer flounder Paralichthys dentatus, Atlantic croaker Micropogonias undulatus, and Atlantic menhaden Brevoortia tyrannus. Cross-correlation analysis was used to examine the relationships between the larval and juvenile abundances within species. Tests of synchrony across species were used to find similarities in recruitment dynamics for species with similar winter shelf-spawning life-history strategies. Positive correlations were found between the larval and juvenile abundances for three of the six selected species (spot, pinfish, and southern flounder). These three species have similar geographic ranges that primarily lie south of Cape Hatteras. There were no significant correlations between the larval and juvenile abundances for the other three species (summer flounder, Atlantic croaker, and Atlantic menhaden); we suggest several factors that could account for the lack of a relationship. Synchrony was found among the three southern species within both the larval and juvenile abundance time series. These results provide support for using larval ingress measures as indices of abundance for these and other species with similar geographic ranges and winter shelf-spawning life-history strategies

    High-Density Lipoprotein Antioxidant Responses to High-Intensity Interval and Steady-State Moderate-Intensity Exercise

    Get PDF
    High-intensity interval exercise (HIIE) may impart health benefits beyond what is acquired through moderate-intensity steady state exercise (SSE). Paraoxonase 1 (PON1), an antioxidant associated with high-density lipoprotein (HDL), may be altered with exercise; however, it is unclear whether HIIE provides a greater stimulus for increasing PON1 antioxidant activity than a comparable or greater amount of SSE. PURPOSE: Determine the influence of HIIE on PON1 concentration and activity relative to a comparable amount of moderate-intensity SSE and a dose that is half that of SSE. METHODS: Seventeen male participants (age 27.8 + 6.4 yr; weight 80.6 + 9.0 kg; BMI 25.1 + 2.4 kg/m2; %fat = 19 + 5; VO2max 52.1 + 7.5 ml/kg/min) underwent HIIE by treadmill running (90% and 40% of VO2reserve in 3:2 min ratio) to expend 500 kcals (H500); HIIE to expend 250 kcals (H250), and; SSE at 70% VO2reserve to expend 500 kcals (M500) in a randomized crossover design. Intensities of all exercise conditions averaged 70% VO2reserve. Blood measures of total antioxidant capacity (TAC) in copper reducing equivalents, HDL (g/mL), apolipoprotein A-1 (ApoA1: g/L), PON1 concentration (PON1c: g/mL) and arylesterase activity (PON1a: kU/L) were obtained just before, immediately after, 2 hr and 24 hr after exercise. Significant differences were determined using 3 by 4 repeated measures ANOVAs. Effect sizes were calculated to determine the magnitude of dependent variable responses to exercise. RESULTS: Pre-exercise HDL concentration was lower in H250 and increased most in H250 versus other exercise conditions (p \u3c 0.001, ES = 0.83). Other antioxidant responses were similar across exercise conditions. ApoA1 (+ 8.0%) and PON1a (+ 9.3%) increased immediately after exercise and remained elevated 24 hr after exercise (p \u3c 0.0001 for each; ApoA1 ES = 0.85, PON1a ES = 0.57). PON1c was increased 2.4% above baseline at 2 hr post-exercise (p = 0.0296, ES = 0.18) and TAC was elevated 8.6% above baseline at 24 hr post-exercise (p = 0.0227, ES = 0.48). SUMMARY: HDL and HDL antioxidant properties are transiently potentiated by HIIE with as little as 250 kcals of energy expenditure. HDL antioxidant activity and total antioxidant capacity are elevated with HIIE and SSE of moderate intensity in a similar manner and are observed for up to 24 hr after exercise

    3-Nitrotyrosine and Soluble Vascular and Intracellular Adhesion Molecule Responses to High-Intensity Interval and Steady-State Moderate-Intensity Exercise

    Get PDF
    Vascular endothelium may respond differently to high-intensity interval exercise (HIIE) when compared to moderate-intensity steady state exercise (SSE). We hypothesized that greater sympathetic stimulation of soluble vascular adhesion molecule-1 (sVCAM-1) and intracellular adhesion molecule-1 (sICAM-1) and greater oxidative and nitrative stress on the vascular endothelium may transiently result from HIIE. PURPOSE: Determine the influence of HIIE on sVCAM-1, sICAM-1 and 3-nitrotyrosine (NT), a marker of nitric oxide-dependent reactive nitrogen species and nitrative stress, relative to a comparable amount of moderate-intensity SSE and a dose that is half that of SSE. METHODS: Seventeen male participants (age 27.8 + 6.4 yr; weight 80.6 + 9.0 kg; BMI 25.1 + 2.4 kg/m2; %fat = 19 + 5; VO2max 52.1 + 7.5 ml/kg/min) underwent HIIE by treadmill running (90% and 40% of VO2reserve in 3:2 min ratio) to expend 500 kcals (H500); HIIE to expend 250 kcals (H250), and; SSE at 70% VO2reserve to expend 500 kcals (M500) in a randomized crossover design. Intensities of all exercise conditions averaged 70% VO2reserve. Blood measures of sVCAM-1 (ng/mL), sICAM-1 (ng/mL), NT (nM), epinephrine (EPI) and norepinephrine (NE) in pg/mL, were obtained just before, immediately after, 2 hr and 24 hr after exercise. Significant differences were determined using 3 by 4 repeated measures ANOVAs. Effect sizes were calculated to determine the magnitude of dependent variable responses to exercise. RESULTS: HIIE resulted in 2 to 2.5 fold greater EPI responses immediately after exercise versus SSE (p = 0.0059, H250 ES = 1.89; H500 ES = 3.04). NE increased an average of 5.4 times above pre-exercise values across all exercise conditions (p \u3c 0.0001). NT decreased immediately after HIIE (H250 ES = - 0.39; H500 ES = -0.97) and returned to baseline by 2 hr post-exercise; whereas, NT was elevated 111% 2 hr (ES = 2.46) and remained 24 hr after SSE (p = 0.0001). sVCAM-1 was unchanged with HIIE but increased 6% immediately following moderate-intensity SSE and remained elevated 24 hr post-exercise (p \u3c 0.0005, ES = 1.01). SUMMARY: Our results are in direct opposition to our hypothesis. Transient elevations in NT and sVCAM-1 after moderate-intensity SSE but not HIIE of similar average intensity and duration may indicate unique effects of interval exercise. NT and sVCAM-1 were not elevated after HIIE in spite of a greater sympathetic response than what was observed after moderate-intensity SSE

    Confirming TDP2 mutation in spinocerebellar ataxia autosomal recessive 23 (SCAR23)

    Get PDF
    Objective To address the relationship between mutations in the DNA strand break repair protein tyrosyl DNA phosphodiesterase 2 (TDP2) and spinocerebellar ataxia autosomal recessive 23 (SCAR23) and to characterize the cellular phenotype of primary fibroblasts from this disease. Methods We have used exome sequencing, Sanger sequencing, gene editing and cell biology, biochemistry,and subcellular mitochondrial analyses for this study. Results We have identified a patient in the United States with SCAR23 harboring the same homozygous TDP2 mutation as previously reported in 3 Irish siblings (c.425+1G>A). The current and Irish patients share the same disease haplotype, but the current patient lacks a homozygous variant present in the Irish siblings in the closely linked gene ZNF193, eliminating this as a contributor to the disease. The current patient also displays symptoms consistent with mitochondrial dysfunction, although levels of mitochondrial function in patient primary skin fibroblasts are normal. However, we demonstrate an inability in patient primary fibroblasts to rapidly repair topoisomerase-induced DNA double-strand breaks (DSBs) in the nucleus and profound hypersensitivity to this type of DNA damage. Conclusions These data confirm the TDP2 mutation as causative for SCAR23 and highlight the link between defects in nuclear DNA DSB repair, developmental delay, epilepsy, and ataxia

    Introduction to COFFE: The Next-Generation HPCMP CREATE-AV CFD Solver

    Get PDF
    HPCMP CREATE-AV Conservative Field Finite Element (COFFE) is a modular, extensible, robust numerical solver for the Navier-Stokes equations that invokes modularity and extensibility from its first principles. COFFE implores a flexible, class-based hierarchy that provides a modular approach consisting of discretization, physics, parallelization, and linear algebra components. These components are developed with modern software engineering principles to ensure ease of uptake from a user's or developer's perspective. The Streamwise Upwind/Petrov-Galerkin (SU/PG) method is utilized to discretize the compressible Reynolds-Averaged Navier-Stokes (RANS) equations tightly coupled with a variety of turbulence models. The mathematics and the philosophy of the methodology that makes up COFFE are presented

    Spitzer mid-infrared spectroscopy of compact symmetric objects: What powers radio-loud active galactic nuclei?

    Full text link
    We present low- and high-resolution mid-infrared (mid-IR) spectra and photometry for eight compact symmetric objects (CSOs) taken with the Infrared Spectrograph on the Spitzer Space Telescope. The hosts of these young, powerful radio galaxies show significant diversity in their mid-IR spectra. This includes multiple atomic fine-structure lines, H2 gas, polycyclic aromatic hydrocarbon (PAH) emission, warm dust from T = 50 to 150 K, and silicate features in both emission and absorption. There is no evidence in the mid-IR of a single template for CSO hosts, but 5/8 galaxies show similar moderate levels of star formation (<10 M_sun/yr from PAH emission) and silicate dust in a clumpy torus. The total amount of extinction ranges from A_V ~ 10 to 30, and the high-ionization [Ne V] 14.3 and 24.3 um transitions are not detected for any galaxy in the sample. Almost all CSOs show contributions both from star formation and active galactic nuclei (AGNs), suggesting that they occupy a continuum between pure starbursts and AGNs. This is consistent with the hypothesis that radio galaxies are created following a galactic merger; the timing of the radio activity onset means that contributions to the IR luminosity from both merger-induced star formation and the central AGN are likely. Bondi accretion is capable of powering the radio jets for almost all CSOs in the sample; the lack of [Ne V] emission suggests an advection-dominated accretion flow mode as a possible candidate. Merging black holes (BHs) with M_BH > 10^8 M_sun likely exist in all of the CSOs in the sample; however, there is no direct evidence from these data that BH spin energy is being tapped as an alternative mode for powering the radio jets.Comment: 22 pages, 14 figures; published in Ap
    • …
    corecore