636 research outputs found
Scalar mixing and entrainment in an axisymmetric jet subjected to external turbulence
The effect of zero-mean-flow external turbulence on the topology of the
scalar turbulent/turbulent interface (TTI) has been recently studied in
axisymmetric jets (Kohan & Gaskin, J. Fluid Mech., vol. 950, 2022, A32). The
present study aims to understand the process of turbulent entrainment into a
jet, as affected by background turbulence, using scalar statistics.
Planar-laser-induced fluorescence was employed to capture the orthogonal cross
sections of the jet at a fixed downstream station with varying background
turbulence intensities and length scales. The conditional scalar profiles
revealed that the thickness of the scalar TTI is greater than that of the
traditional turbulent/non-turbulent interface (TNTI), and the interfacial
thickness is an increasing function of the background turbulence intensity.
Although nibbling remains the primary entrainment mechanism in the far field,
increased occurrence of concentration 'holes' within the interfacial layer in
the presence of ambient turbulence suggests a more significant role of
large-scale engulfment in the turbulent/turbulent entrainment process. Enhanced
contribution of the area of detached jet patches (i.e. 'islands') to that of
the main jet is hypothesized to be evidence of intense detrainment events in
the background turbulence. This can potentially explain the reduced net
entrainment into the jet, which manifests as less negative values of scalar
skewness within the jet core
Astrophysical Observations with the HEROES Balloon-borne Payload
The High Energy Replicated Optics to Explore the Sun (HEROES) payload flew on a balloon from Ft. Sumner, NM, September 21-22, 2013. HEROES is sensitive from about 20-75 keV and comprises 8 optics modules, each consisting of 13-14 nickel replicated optics shells and 8 Xenon-filled positionsensitive proportional counter detectors. HEROES is unique in that it is the first hard X-ray telescope that will observe the Sun and astrophysical targets in the same balloon flight. Our astrophysics targets include the Crab nebula and pulsar and the black hole binary GRS 1915+105. In this presentation, I will describe the HEROES mission, the data analysis pipeline and calibrations, and preliminary astrophysics results
Tamarix minoa (Tamaricaceae), a new species from the island of Crete (Greece) based on morphological and plastid molecular sequence data
Tamarix minoa is described from material collected on the S Aegean island of Crete (Kriti), Greece. A morphological comparison with the species considered to be closest, T. africana and T. hampeana, is provided. An original illustration showing the main morphological characters of the new species is also given, as are photographs of the new species in its habitat. The isolated phylogenetic position of T. minoa is shown to be strongly supported by plastid molecular sequence data (trnS-trnG, trnQ-rps16 and ndhF-rpl32), thus warranting its recognition at specific rank.National Geographic Society, research project “Human recreation versus plant diversity on maritime sands in Crete” (NGS grant no. 8573-08). The FPU programme (Mº de Educación, Spain), the I+D+I project CGL2008-05056 (Mº de Educación y Ciencia, Spanish Government), the project OAPN 354-2011 (Mº de Agricultura, Alimentación y Medio Ambiente, Spanish Government) and complementary supporting funds ACIE10-01, ACIE11-05 and ACIE13-08 (University of Alicante, Spain)
The HEROES Balloon-Borne Hard X-Ray Telescope
The High Energy Replicated Optics to Explore the Sun (HEROES) payload flew on a balloon from Ft. Sumner, NM, September 21-22, 2013. HEROES is sensitive from about 20-75 keV and comprises 8 optics modules (HPD approximately 33" as flown), each consisting of 13-14 nickel replicated optics shells and 8 matching Xenon-filled position-sensitive proportional counter detectors (dE/E=0.05 @ 60 keV). Our targets included the Sun, the Crab Nebula and pulsar and the black hole binary GRS 1915+105. HEROES was pointed using a day/night star camera system for astrophysical observations and a newly developed Solar Aspect System for solar observations (with a shutter protecting the star camera.) We have successfully detected the Crab Nebula. Analyses for GRS 1915+105 and the Sun are ongoing. In this presentation, I will describe the HEROES mission, the data analysis pipeline and calibrations, preliminary results, and plans for follow-on missions
Interferon alpha on NZM2328.Lc1R27: Enhancing autoimmunity and immune complex-mediated glomerulonephritis without end stage renal failure
Interferon alpha (IFN alpha) may play a significant role in systemic lupus erythematosus (SLE) pathogenesis. Recent literature suggests that IFN alpha does not correlate with disease activities and blockade of IFN alpha is not effective in treating SLE. This study aims to delineate further the role of IFN alpha in SLE. 12-week old NZM2328 and its congenic NZM2328.Lc1R27 (R27) female mice were challenged with adenovirus-IFN alpha (adeno-IFN alpha) or adenovirus-LacZ (adeno-LacZ). Only adeno-IFN alpha treated NZM2328 developed severe proteinuria and died of chronic glomerulonephritis (GN) and end stage renal disease. Adeno-IFN alpha treated R27 did develop immune complex-mediated GN but had normal renal function. Adeno-LacZ treated NZM2328 showed enlarged glomeruli and increased cellularity without immune complex deposition. Adeno-LacZ treated R27 did not show serological and histological abnormalities. Adeno-IFN alpha induced anti-dsDNA and anti-kidney autoantibodies in NZM2328 and R27. These results suggest that end organ damage is host-dependent and less related to autoimmunity and may have significant implications in SLE pathogenesis. (C) 2014 Published by Elsevier Inc
Full-Shell X-Ray Optics Development at NASA Marshall Space Flight Center
NASAs Marshall Space Flight Center (MSFC) maintains an active research program toward the development of high-resolution, lightweight, grazing-incidence x-ray optics to serve the needs of future x-ray astronomy missions such as Lynx. MSFC development efforts include both direct fabrication (diamond turning and deterministic computer-controlled polishing) of mirror shells and replication of mirror shells (from figured, polished mandrels). Both techniques produce full-circumference monolithic (primary + secondary) shells that share the advantages of inherent stability, ease of assembly, and low production cost. However, to achieve high-angular resolution, MSFC is exploring significant technology advances needed to control sources of figure error including fabrication- and coating-induced stresses and mounting-induced distortions
Effects of a clinician referral and exercise program for men who have completed active treatment for prostate cancer: A multicenter cluster randomized controlled trial (ENGAGE)
BACKGROUNDThe purpose of this study was to determine the efficacy of a clinician referral and exercise program in improving exercise levels and quality of life for men with prostate cancer.METHODSThis was a multicenter cluster randomized controlled trial in Melbourne, Australia comprising 15 clinicians: 8 clinicians were randomized to refer eligible participants (n = 54) to a 12-week exercise program comprising 2 supervised gym sessions and 1 home-based session per week, and 7 clinicians were randomized to follow usual care (n = 93). The primary outcome was self-reported physical activity; the secondary outcomes were quality of life, anxiety, and symptoms of depression.RESULTSA significant intervention effect was observed for vigorous-intensity exercise (effect size: Cohen\u27s d, 0.46; 95% confidence interval [CI], 0.09-0.82; P = .010) but not for combined moderate and vigorous exercise levels (effect size: d, 0.08; 95% CI, −0.28 to 0.45; P = .48). Significant intervention effects were also observed for meeting exercise guidelines (≥150 min/wk; odds ratio, 3.9; 95% CI, 1.9-7.8; P = .002); positive intervention effects were observed in the intervention group for cognitive functioning (effect size: d, 0.34; 95% CI, −0.02 to 0.70; P = .06) and depression symptoms (effect size: d, −0.35; 95% CI, −0.71 to 0.02; P = .06). Eighty percent of participants reported that the clinician\u27s referral influenced their decision to participate in the exercise program.CONCLUSIONSThe clinician referral and 12-week exercise program significantly improved vigorous exercise levels and had a positive impact on mental health outcomes for men living with prostate cancer. Further research is needed to determine the sustainability of the exercise program and its generalizability to other cancer populations
Pollination ecology of the rare desert species Eremosparton songoricum (Fabaceae)
The pollination ecology of Eremosparton songoricum (Litv.) Vass., a rare desert species endemic to central Asia, was examined by a series of observational studies and manipulative experiments in two natural populations during 2007-2008. Results showed that the duration of flowering lasted 21 and 23 days, respectively, in Populations A and B from late May to late June in 2008. Anthesis of a single flower often lasted for 3 days. However, if pollinators were excluded, both the anthesis and stigma receptivity lasted 2 days longer. Mating-system experiment showed that E. songoricum was self-compatible and pollination success relied on pollinators. Fruit set after bagging without emasculation was 0.02 +/- 0.01%. This suggested that spontaneous autogamy rarely happened. E. songoricum primarily relies on a combination of large floral display, secretion of nectar and a yellow 'nectar guide' on the standard to further attract pollinators, which may be the result of adaptation to a habitat with unreliable access to pollinators. A single flower produced similar to 0.18 mu L and 0.50 mu L of nectar during 2 days in Populations A and B, respectively. The peak secretion occurred at 1300-1500 hours, which overlapped with the climax of visitation of the effective pollinators at 1300-1400 hours. There were four effective pollinators in both populations, namely Colletes popovi Nosk., Megachile terminate Morawitz, Coelioxys sp. and Bembix planifrons F. Mor. The most frequent one, Colletes popovi Nosk., was observed pollinating many flowers of the same individual plant (65.8 +/- 1.1%) in Population A, suggesting that geitonogamous self-pollination is unavoidable. Inbreeding depression played a role during the period from fertilisation to fruit maturation
Establishment and Spread of a Single Parthenogenic Genotype of the Mediterranean arundo wasp, Tetramesa romana1, In the Variable Climate of Texas
As part of a biological control program for the invasive weed, Arundo donax L., several genotypically unique populations of the parthenogenetic stemgalling wasp, Tetramesa romana Walker (Hymenoptera: Eurytomidae), from Spain and France were released in an infested riparian zone along the Rio Grande from Brownsville to Del Rio, TX. An adventive population of the wasp of unknown origin with limited distribution in Texas was also discovered, evaluated, and released as part of the program. More than 1.2 million wasps representing the mixture of genotypes were aerially released from 2009 to 2011. Wasps dispersed from their original release locations and now have a continuous distribution along the Rio Grande from Brownsville to Del Rio, and have dispersed throughout most of Central Texas with satellite populations as far west as San Angelo (Tom Green County), north as far as Kaufman (Kaufman County), and east to Navasota (Grimes County). The most successful genotype (#4) represented 390 of the 409 wasps recovered and matched both an imported population from the Mediterranean coast of Spain and an adventive population established in Texas before the start of the biological control program. Several other European genotypes of the wasp released in the program apparently failed to establish. This result demonstrated the benefits of evaluating and releasing the maximum genetic diversity of the biological control agent in the introduced range. Abundance of T. romana on the Rio Grande from Laredo to Del Rio averaged 190% more in 2013-2014 compared to a similar study in 2008-2009 before release of the European wasps. A favorability index was developed that showed that conditions from 1969 to 1977 would have been adverse to the wasp; conditions after 2009 were more favorable. Climate matching predicts the wasp will disperse throughout the southern U.S. and Mexico
Population structure of anisakis simplex (nematoda) in harbor porpoises phocoena phocoena off Denmark
The population structure and habitat selection of Anisakis simplex in 35 harbor porpoises off Denmark are described. The nematodes were collected from the stomach and duodenal ampulla and were categorized as third-stage larvae, fourth-stage larvae, subadults, and adults. The porpoises harbored 8,043 specimens of A. simplex. The proportion of adults and subadults increased with infrapopulation size. The number of development stages across infrapopulations covaried significantly (Kendall's test of concordance). Concordance was higher in hosts with the highest intensities than in those with low and medium intensities. All stages occurred mainly in the forestomach, but this trend was stronger for the adults. Adult and subadult sex ratios did not depart significantly from 1:1. Our data suggested that recruitment and duration of each stage were the main factors accounting for infrapopulation structure. The preference of A. simplex for the forestomach conformed with previous studies, but the narrower distribution of adults relative to other stages might indicate a strategy to enhance mating opportunities. Information on sex ratios of A. simplex is scarce and contradictory. We suggest that the discrepancies might partly reflect differences in categorization criteria and statistical methods.Herreras Belled, Maria Victoria, [email protected] ; Balbuena Diaz-Pines, Juan Antonio, [email protected] ; Aznar Avendaño, Francisco Javier, [email protected] ; Raga Esteve, Juan Antonio, [email protected]
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