Beyond the Brim of the Hat: Kinematics of Globular Clusters out to Large Radius in the Sombrero Galaxy

We have obtained radial velocity measurements for 51 new globular clusters around the Sombrero galaxy. These measurements were obtained using spectroscopic observations from the AAOmega spectrograph on the Anglo-Australian Telescope and the Hydra spectrograph at WIYN. Combined with our own past measurements and velocity measurements obtained from the literature we have constructed a large database of radial velocities that contains a total of 360 confirmed globular clusters. Previous studies' analyses of the kinematics and mass profile of the Sombrero globular cluster system have been constrained to the inner ~9' (~24 kpc or ~5 effective radii), but our new measurements have increased the radial coverage of the data, allowing us to determine the kinematic properties of M104 out to ~15' (~41 kpc or ~9 effective radii). We use our set of radial velocities to study the GC system kinematics and to determine the mass profile and V-band mass-to-light profile of the galaxy. We find that the V-band mass-to-light ratio increases from 4.5 at the center to a value of 20.9 at 41 kpc (~9 effective radii or 15'), which implies that the dark matter halo extends to the edge of our available data set. We compare our mass profile at 20 kpc (~4 effective radii or ~7.4') to the mass computed from x-ray data and find good agreement. We also use our data to look for rotation in the globular cluster system as a whole, as well as in the red and blue subpopulations. We find no evidence for significant rotation in any of these samples.Comment: Accepted for publication in the Astronomical Journal; 23 pages, 14 figures, and 2 table

Inorganic nitrate supplementation improves muscle oxygenation, O2 uptake kinetics and exercise tolerance at high but not low pedal rates

Copyright © 2014, Journal of Applied PhysiologyWe tested the hypothesis that inorganic nitrate (NO3-) supplementation would improve muscle oxygenation, pulmonary O2 uptake (VO2) kinetics and exercise tolerance (Tlim) to a greater extent when cycling at high compared low pedal rates. In a randomized, placebo-controlled, cross-over study, seven subjects (mean ± SD, age 21 ± 2 yr, body mass 86 ± 10 kg) completed severe-intensity step cycle tests at pedal cadences of 35 rpm and 115 rpm during separate 9 day supplementation periods with NO3--rich beetroot juice (BR; providing 8.4 mmol NO3-∙day-1) and placebo (PLA). Compared to PLA, plasma nitrite concentration increased 178% with BR (P0.05). However, when cycling at 115 rpm, muscle [O2Hb] was higher at baseline and throughout exercise, phase II VO2 kinetics was faster (47 ± 16 s vs. 61 ± 25 s; P<0.05) and Tlim was greater (362 ± 137 s vs. 297 ± 79 s; P<0.05) with BR compared to PLA. These results suggest that short-term BR supplementation can increase muscle oxygenation, expedite the adjustment of oxidative metabolism and enhance exercise tolerance when cycling at a high, but not a low, pedal cadence in healthy recreationally-active subjects. These findings support recent observations that NO3- supplementation may be particularly effective at improving physiological and functional responses in type II muscle fibers

Leak detection using cepstrum of cross-correlation of transient pressure wave signals

A new leak detection method is proposed here which is based on the cepstrum of the cross-correlation of the pressure signals from two transducers. Computational simulations of leaks with different properties, size, position and shape, in a straight pipe and a T-Junction network were studied. The proposed method was successful in estimating leakages and the pipeline features with a high precision. For the results with a straight pipe, this method is considerably more accurate than using the cross-correlation leak detection method or the cepstrum method alone. However, the results obtained by cepstrum and cepstrum of cross-correlation for the T-Junction case were quite accurate, while cepstrum alone showed a slightly better precision

3-Amino-1-methyl­pyrazin-1-ium iodide

In the cation of the title compound, C5H8N3 +·I−, the C—N(H2) bond distance [1.338 (8) Å] is at the lower end of the range for aryl amines. In the crystal structure, cations and anions are linked via N—H⋯I hydrogen bonds, forming centrosymmetric four-component clusters

Detection of the gas–liquid two-phase flow regimes using non-intrusive microwave cylindrical cavity sensor

Gas–liquid two-phase flow phenomenon occurs in various engineering applications and the measurement of it is important. A microwave sensor in the form of a cylindrical cavity has been designed to operate between 5 and 5.7 GHz. The aim is to analyse a two phase gas–liquid flow regime in a pipeline. LabVIEW software is utilised to capture the data, process them and display the results in real time. The results have shown that the microwave sensor has successfully detected the two-phase flow regimes in both the static and dynamic flow environments with reasonable accuracy. The study has also shown the independence of the technique and its accuracy to the temperature change (28–83 °C). Several flow regimes of the gas–liquid two-phase flow have been discussed. The system is also able to detect the stratified, wavy, elongated bubbles and homogeneous flow regimes

Dietary nitrate supplementation attenuates the reduction in exercise tolerance following blood donation

Dietary nitrate supplementation attenuates the reduction in exercise tolerance following blood donatio

Improvement in blood pressure after short-term inorganic nitrate supplementation is attenuated in cigarette smokers compared to non-smoking controls

Dietary supplementation with inorganic nitrate (NO3-) has been reported to improve cardiovascular health indices in healthy adults. Cigarette smoking increases circulating thiocyanate (SCN-), which has been suggested to competitively inhibit salivary nitrate (NO3-) uptake, a rate-limiting step in dietary NO3 - metabolism. Therefore, this study tested the hypothesis that dietary NO3 - supplementation would be less effective at increasing the circulating plasma nitrite concnetration ([NO2-]) and lowering blood pressure in smokers (S)compared to non-smokers (NS). Nine healthy smokers and eight healthy non-smoking controls reported to the laboratory at baseline (CON) and following six day supplementation periods with 140 ml∙day-1 NO3--rich (8.4 mmol NO3 -∙day-1; NIT) and NO3--depleted (0.08mmol NO3 -∙day-1; PLA) beetroot juice in a cross-over experiment. Plasma and salivary [SCN-] were elevated in smokers compared to non-smokers in all experimental conditions (P<0.05). Plasma and salivary [NO3 -] and nitrite ([NO2-]) were elevated in the NIT condition compared to CON and PLA conditions in smokers and non-smokers (P<0.05). However, the change in salivary [NO3-] (S: 3.5 ± 2.1 vs. NS: 7.5 ± 4.4 mM), plasma [NO3-] (S: 484 ± 198 vs. NS: 802 ± 199 μM) and plasma [NO2-] (S: 218 ± 128 vs. NS: 559 ± 419 nM) between the CON and NIT conditions was lower in the smokers compared to the non-smokers (P<0.05). Salivary [NO2 -] increased above CON to a similar extent with NIT in smokers and nonsmokers (P>0.05). Systolic blood pressure was lowered compared to PLA with NIT in nonsmokers (P0.05). These findings suggest that dietary NO3- metabolism is compromised in smokers leading to an attenuated blood pressure reduction compared to non-smokers after NO3- supplementation. These observations may provide novel insights into the cardiovascular risks associated with cigarette smoking and suggest that this population may be less likely to benefit from improved cardiovascular health if they increase dietary NO3 - intake

Dose-dependent effects of dietary nitrate on the oxygen cost of moderate-intensity exercise: acute vs. chronic supplementation

Purpose To investigate whether chronic supplementation with a low or moderate dose of dietary nitrate (NO3−) reduces submaximal exercise oxygen uptake (View the MathML sourceO2) and to assess whether or not this is dependent on acute NO3− administration prior to exercise. Methods Following baseline tests, 34 healthy subjects were allocated to receive 3 mmol NO3−, 6 mmol NO3− or placebo. Two hours following the first ingestion, and after 7, 28 and 30 days of supplementation, subjects completed two moderate-intensity step exercise tests. On days 28 and 30, subjects in the NO3− groups completed the test 2 h post consumption of a NO3− dose (CHR + ACU) and a placebo dose (CHR). Results Plasma nitrite concentration ([NO2−]) was elevated in a dose-dependent manner at 2 h, 7 days and 28–30 days on the CHR + ACU visit. Compared to pre-treatment baseline, 6 mmol NO3− reduced the steady-state View the MathML sourceO2 during moderate-intensity exercise by 3% at 2 h (P = 0.06), 7 days and at 28–30 days (both P < 0.05) on the CHR + ACU visit, but was unaffected by 3 mmol NO3− at all measurement points. On the CHR visit in the 6 mmol group, plasma [NO2−] had returned to pre-treatment baseline, but the steady-state View the MathML sourceO2 remained reduced. Conclusion Up to ∼4 weeks supplementation with 6 but not 3 mmol NO3− can reduce submaximal exercise View the MathML sourceO2. A comparable reduction in submaximal exercise View the MathML sourceO2 following chronic supplementation with 6 mmol NO3− can be achieved both with and without the acute ingestion of NO3− and associated elevation of plasma [NO2−]

ICTV Virus Taxonomy Profile : Potyviridae 2022

The family Potyviridae includes plant viruses with single-stranded, positive-sense RNA genomes of 8-11 kb and flexuous filamentous particles 650-950 nm long and 11-20 nm wide. Genera in the family are distinguished by the host range, genomic features and phylogeny of the member viruses. Most genomes are monopartite, but those of members of the genus Bymovirus are bipartite. Some members cause serious disease epidemics in cultivated plants. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Potyviridae, which is available at ictv.global/report/potyviridae.Peer reviewe

Two weeks of watermelon juice supplementation improves nitric oxide bioavailability but not endurance exercise performance in humans

This study tested the hypothesis that watermelon juice supplementation would improve nitric oxide bioavailability and exercise performance. Eight healthy recreationally-active adult males reported to the laboratory on two occasions for initial testing without dietary supplementation (control condition). Thereafter, participants were randomly assigned, in a cross-over experimental design, to receive 16 days of supplementation with 300 mL·day-1 of a watermelon juice concentrate, which provided ~3.4g L-citrulline·day-1 and an apple juice concentrate as a placebo. Participants reported to the laboratory on days 14 and 16 of supplementation to assess the effects of the interventions on blood pressure, plasma [Lcitrulline], plasma [L-arginine], plasma [nitrite], muscle oxygenation and time-to-exhaustion during severe-intensity exercise. Compared to control and placebo, plasma [L-citrulline] (29 ± 4, 22 ± 6 and 101 ± 23 μM), [L-arginine] (74 ± 9, 67 ± 13 and 116 ± 9 μM) and [nitrite] (102 ± 29, 106 ± 21 and 201 ± 106 nM) were higher after watermelon juice supplementation (P<0.01). However, systolic blood pressure was higher in the watermelon juice (130 ± 11) and placebo (131 ± 9) conditions compared to the control condition (124 ± 8 mmHg; P<0.05). The skeletal muscle oxygenation index during moderate-intensity exercise was greater in the watermelon juice condition than the placebo and control conditions (P<0.05), but time-to-exhaustion during the severe-intensity exercise test (control: 478 ± 80, placebo: 539 ± 108, watermelon juice: 550 ± 143 s) was not significantly different between conditions (P<0.05). In conclusion, while watermelon juice supplementation increased baseline plasma [nitrite] and improved muscle oxygenation during moderate-intensity exercise, it increased resting blood pressure and did not improve time-to-exhaustion during severe-intensity exercise. These findings do not support the use of watermelon juice supplementation as a nutritional intervention to lower blood pressure or improve endurance exercise performance in healthy adults