scholarly journals Radio, Millimeter and Infrared Observations of the Local Hot Bubble and Its Environment

1997 ◽  
Vol 166 ◽  
pp. 199-210
Author(s):  
Ulrich Mebold ◽  
Jürgen Kerp ◽  
Peter M.W. Kalberla
Keyword(s):  
High Latitude ◽  
Molecular Clouds ◽  
Rapid Expansion ◽  
The Sun ◽  
Local Bubble ◽  
Infrared Observations ◽  
Neutral Gas ◽  
The Mean ◽  
Frequency Window ◽  
Definition Of

AbstractWe present a definition of the local void of neutral gas from observations in the radio frequency window. We question the concept of the Local Bubble in sense of a more or less spherical volume which is surrounded by a shell of denser gas. The concept of the Local Bubble is challenged by the discovery of numerous neutral, dense clouds inside the local void. The search for a “shell” around the suspected Bubble has resulted only in inconclusive findings so far. The sample of high latitude molecular clouds illustrates the situation particularly well. The statistical properties of their spatial distribution, e.g. the mean distance, seem to fit very nicely to the spatial extent of the Local Bubble. But a more detailed investigation shows that the concept of a bubble – in particular an expanding bubble – is not supported. We suggest that the local void is nothing more than a typical place in an interarm region of our Galaxy.Finally, a discussion of the high latitude boundary of the local void does not give strong evidence for the concept of a bubble, that has once been in rapid expansion and is still showing signs of interaction with its environment. However, indications for interactions of IVCs or HVCs with their surroundings are found. These hint at the presence of a gaseous disk which is much more vertically extended than previously believed, or at a Galactic wind which may be blowing from the Galactic neighbourhood of the Sun.

scholarly journals Radio and UV Observations of High Latitude HI

1984 ◽  
Vol 81 ◽  
pp. 280-280
Author(s):  
Felix J. Lockman ◽  
L.M. Hobbs ◽  
J. Michael Shull
Keyword(s):  
High Latitude ◽  
Column Density ◽  
Solar Neighborhood ◽  
The Sun ◽  
Radio Observations ◽  
Ob Stars ◽  
Neutral Gas

Interstellar Lyman-α observations toward high latitude stars, which give the column density of HI between us and the star, and 21 cm radio observations, which give the total HI column density to and beyond the star, can be combined to map out the amount of neutral gas as a function of distance from the sun. We present recent observations of the 21 cm and Lyman-α lines made toward ~50 high latitude OB stars, and use these data to discuss the distribution of HI in the solar neighborhood.

The Sun’s distance from the Galactic Centre and mid-plane, and the Galactic old bulge’s morphology: 715 VVV Type II Cepheids

2021 ◽  
Vol 502 (3) ◽  
pp. 4194-4198
Author(s):  
Evgeny Griv ◽  
Michael Gedalin ◽  
Pawel Pietrukowicz ◽  
Daniel Majaess ◽  
Ing-Guey Jiang
Keyword(s):  
Statistical Method ◽  
High Latitude ◽  
Gravitational Lensing ◽  
Near Infrared ◽  
Major Axis ◽  
Galactic Centre ◽  
The Sun ◽  
Type Ii ◽  
Infrared Observations ◽  
Centrally Symmetric

ABSTRACT A statistical method is employed in tandem with new VISTA Variables in the Via Lactea (VVV) near-infrared observations to determine the Sun’s distance from the Galactic Centre (r0, GC), the Sun’s height from the local mid-plane (z0), and to likewise infer the shape of the Galactic ∼10 Gyr old bulge. Specifically, the conclusions stem from an investigation of 715 high-latitude (|b| > 1°) and centrally symmetric concentrated Type II Cepheids (T2Cs) recently identified in the VVV survey by Braga et al. The analysis yields r0 = 8.35 ± 0.10 kpc and z0 = 10 ± 2 pc. The T2Cs distribution within the effective bulge radius rbulge = 2–3 kpc is an ellipsoid exhibiting axial ratios of ≈1:0.7:0.6, with the major axis inclined at an angle θ ≈ −3° to the Sun–GC sightline. T2Cs do not trace a prominent barred structure at distances >1 kpc from the GC. A key conclusion is that analyses of independent optical and infrared Optical Gravitational Lensing Experiment (OGLE) and VVV observations yield consistent results (e.g. r0 > 8.0 kpc and both observations display a comparable shape of an ellipsoid), thus providing a constrained and reduced systematic uncertainty.

Comparison of Fluorine(18)-fluorodeoxyglucose and Gallium(68)-citrate PET/CT in patients with tuberculosis

2019 ◽  
Vol 58 (05) ◽  
pp. 371-378
Author(s):  
Alfred O. Ankrah ◽  
Ismaheel O. Lawal ◽  
Tebatso M.G. Boshomane ◽  
Hans C. Klein ◽  
Thomas Ebenhan ◽  
...  
Keyword(s):  
Tracer Uptake ◽  
Pet Ct ◽  
The Mean ◽  
18F Fdg ◽  
Definition Of ◽  
Gallium 68 ◽  
Attending Physician ◽  
Pet Scans ◽  
The Brain

Abstract 18F-FDG and 68Ga-citrate PET/CT have both been shown to be useful in the management of tuberculosis (TB). We compared the abnormal PET findings of 18F-FDG- and 68Ga-citrate-PET/CT in patients with TB. Methods Patients with TB on anti-TB therapy were included. Patients had a set of PET scans consisting of both 18F-FDG and 68Ga-citrate. Abnormal lesions were identified, and the two sets of scans were compared. The scan findings were correlated to the clinical data as provided by the attending physician. Results 46 PET/CT scans were performed in 18 patients, 11 (61 %) were female, and the mean age was 35.7 ± 13.5 years. Five patients also had both studies for follow-up reasons during the use of anti-TB therapy. Thirteen patients were co-infected with HIV. 18F-FDG detected more lesions than 68Ga-citrate (261 vs. 166, p < 0.0001). 68Ga-citrate showed a better definition of intracerebral lesions due to the absence of tracer uptake in the brain. The mean SUVmax was higher for 18F-FDG compared to 68Ga-citrate (5.73 vs. 3.01, p < 0.0001). We found a significant correlation between the SUVmax of lesions that were determined by both tracers (r = 0.4968, p < 0.0001). Conclusion Preliminary data shows 18F-FDG-PET detects more abnormal lesions in TB compared to 68Ga-citrate. However, 68Ga-citrate has better lesion definition in the brain and is therefore especially useful when intracranial TB is suspected.

scholarly journals The Sankara Nethralaya Tamil Nadu Essilor Myopia (STEM) Study—Defining a Threshold for Non-Cycloplegic Myopia Prevalence in Children

2021 ◽  
Vol 10 (6) ◽  
pp. 1215
Author(s):  
Aparna Gopalakrishnan ◽  
Jameel Rizwana Hussaindeen ◽  
Viswanathan Sivaraman ◽  
Meenakshi Swaminathan ◽  
Yee Ling Wong ◽  
...  
Keyword(s):  
Open Field ◽  
Tamil Nadu ◽  
Mean Difference ◽  
School Vision ◽  
Elite School ◽  
Prevalence Estimates ◽  
The Mean ◽  
Clinically Significant ◽  
Set Up ◽  
Definition Of

The aim of this study was to investigate the agreement between cycloplegic and non-cycloplegic autorefraction with an open-field auto refractor in a school vision screening set up, and to define a threshold for myopia that agrees with the standard cycloplegic refraction threshold. The study was conducted as part of the Sankara Nethralaya Tamil Nadu Essilor Myopia (STEM) study, which investigated the prevalence, incidence, and risk factors for myopia among children in South India. Children from two schools aged 5 to 15 years, with no ocular abnormalities and whose parents gave informed consent for cycloplegic refraction were included in the study. All the children underwent visual acuity assessment (Pocket Vision Screener, Elite school of Optometry, India), followed by non-cycloplegic and cycloplegic (1% tropicamide) open-field autorefraction (Grand Seiko, WAM-5500). A total of 387 children were included in the study, of whom 201 were boys. The mean (SD) age of the children was 12.2 (±2.1) years. Overall, the mean difference between cycloplegic and non-cycloplegic spherical equivalent (SE) open-field autorefraction measures was 0.34 D (limits of agreement (LOA), 1.06 D to −0.38 D). For myopes, the mean difference between cycloplegic and non-cycloplegic SE was 0.13 D (LOA, 0.63D to −0.36D). The prevalence of myopia was 12% (95% CI, 8% to 15%) using the threshold of cycloplegic SE ≤ −0.50 D, and was 14% (95% CI, 11% to 17%) with SE ≤ −0.50 D using non-cycloplegic refraction. When myopia was defined as SE of ≤−0.75 D under non-cycloplegic conditions, there was no difference between cycloplegic and non-cycloplegic open-field autorefraction prevalence estimates (12%; 95% CI, 8% to 15%; p = 1.00). Overall, non-cycloplegic refraction underestimates hyperopia and overestimates myopia; but for subjects with myopia, this difference is minimal and not clinically significant. A threshold of SE ≤ −0.75 D agrees well for the estimation of myopia prevalence among children when using non-cycloplegic refraction and is comparable with the standard definition of cycloplegic myopic refraction of SE ≤ −0.50 D.

scholarly journals The Ballistic Particle Model

1983 ◽  
Vol 100 ◽  
pp. 133-134
Author(s):  
Frank N. Bash
Keyword(s):  
Radial Velocity ◽  
Gravitational Potential ◽  
Molecular Clouds ◽  
Milky Way ◽  
Terminal Velocity ◽  
Particle Model ◽  
The Sun ◽  
Giant Molecular Clouds ◽  
Spiral Pattern ◽  
Armed Spiral

Bash and Peters (1976) suggested that giant molecular clouds (GMC's) can be viewed as ballistic particles launched from the two-armed spiral-shock (TASS) wave with orbits influenced only by the overall galactic gravitational potential perturbed by the spiral gravitational potential in the arms. For GMC's in the Milky Way, the model predicts that the radial velocity observed from the Sun increases with age (time since launch). We showed that the terminal velocity of CO observed from l ≃ 30° to l ≃ 60° can be understood if all GMC's are born in the spiral pattern given by Yuan (1969) and live 30 × 106 yrs. Older GMC's were predicted to have radial velocities which exceed observed terminal velocities.

Detection and Analysis of Rats’ Bioelectromagnetic Signal

2014 ◽  
Vol 536-537 ◽  
pp. 13-17
Author(s):  
Hong Long Cao ◽  
Fen Ju Qin ◽  
Xue Guan Liu ◽  
He Ming Zhao
Keyword(s):  
Standard Deviation ◽  
Automatic System ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Biological Activities ◽  
Measurement Data ◽  
Measured Data ◽  
The Mean ◽  
Frequency Window ◽  
Window Effects

In this paper, we designed an automatic system and automatic test software, and they can carry out Kunming rats bioelectromagnetic measurement in standard status and anesthesia automatically in anechoic chamber where the electromagnetic field outside is shielded, the reflection wave is absorbed, and the measurement accuracy will be improved. We get a great number of measurement data with frequency-sweep measurement method. The mean and standard deviation of amplitudes vs. frequencies is calculated and analyzed. The results show the measurement method is feasible. We have plotted the means of measured data as multiple sets of Y values in a series of bars with standard deviations bars included and distributed in the frequency axis of X. It is found that the fluctuation of the mean and standard deviation in some frequencies is not evident which may explain frequency window effects, while in other frequencies, such a fluctuation can be obviously observed, which may suggest that bioelectromagnetic signal is influenced by biological activities (standard and anaesthesia status) in these frequency points.

Changes in the legal environment and enforcement of firearm transfer laws in Pennsylvania and Maryland

2018 ◽  
Vol 25 (Suppl 1) ◽  
pp. i2-i4 ◽  
Author(s):  
Cassandra K Crifasi ◽  
Molly Merrill-Francis ◽  
Daniel W Webster ◽  
Garen J Wintemute ◽  
Jon S Vernick
Keyword(s):  
Court Decision ◽  
Annual Number ◽  
Legal Environment ◽  
Background Check ◽  
The Mean ◽  
Definition Of

The effectiveness of laws depends on circumstances affecting their enforcement. To assess such circumstances for comprehensive background check (CBC) and straw purchase laws for firearm sales, we examined prosecutions for CBC and straw purchase violations in Pennsylvania and CBC violations in Maryland. We generated pre-post variables and conducted t-tests to assess differences in the mean number of prosecutions filed following changes to the legal environments. The annual number of prosecutions for straw purchase violations increased significantly in Pennsylvania following the passage of a law that strengthened penalties for these violations (difference in means = +1310.86, P=0.003). The annual number of prosecutions for CBC violations decreased significantly in Maryland following a court decision that narrowed the definition of a firearm transfer making enforcement more difficult (difference in means = −20.52, P=0.026). Our findings suggest enforcement is likely influenced by the penalties associated with violating these laws and the interpretation of the language of the laws.

scholarly journals Solar barycentric dynamics from a new solar-planetary ephemeris

2018 ◽  
Vol 615 ◽  
pp. A153 ◽  
Author(s):  
Rodolfo G. Cionco ◽  
Dmitry A. Pavlov
Keyword(s):  
High Precision ◽  
Orbital Motion ◽  
Giant Planets ◽  
Reference Plane ◽  
The Sun ◽  
The Future ◽  
Dynamical Parameters ◽  
Definition Of ◽  
Invariable Plane ◽  
Planetary Theories

Aims. The barycentric dynamics of the Sun has increasingly been attracting the attention of researchers from several fields, due to the idea that interactions between the Sun’s orbital motion and solar internal functioning could be possible. Existing high-precision ephemerides that have been used for that purpose do not include the effects of trans-Neptunian bodies, which cause a significant offset in the definition of the solar system’s barycentre. In addition, the majority of the dynamical parameters of the solar barycentric orbit are not routinely calculated according to these ephemerides or are not publicly available. Methods. We developed a special version of the IAA RAS lunar–solar–planetary ephemerides, EPM2017H, to cover the whole Holocene and 1 kyr into the future. We studied the basic and derived (e.g., orbital torque) barycentric dynamical quantities of the Sun for that time span. A harmonic analysis (which involves an application of VSOP2013 and TOP2013 planetary theories) was performed on these parameters to obtain a physics-based interpretation of the main periodicities present in the solar barycentric movement. Results. We present a high-precision solar barycentric orbit and derived dynamical parameters (using the solar system’s invariable plane as the reference plane), widely accessible for the whole Holocene and 1 kyr in the future. Several particularities and barycentric phenomena are presented and explained on dynamical bases. A comparison with the Jet Propulsion Laboratory DE431 ephemeris, whose main differences arise from the modelling of trans-Neptunian bodies, shows significant discrepancies in several parameters (i.e., not only limited to angular elements) related to the solar barycentric dynamics. In addition, we identify the main periodicities of the Sun’s barycentric movement and the main giant planets perturbations related to them.

Mean Diameters in Parallel-Flow and Counter-Flow Aerosol Systems

1976 ◽  
Vol 98 (2) ◽  
pp. 297-302 ◽  
Author(s):  
K. G. T. Hollands ◽  
K. C. Goel
Keyword(s):  
Mass Transfer ◽  
Continuous Phase ◽  
General Concept ◽  
Parallel Flow ◽  
General Definition ◽  
Single Pair ◽  
Counter Flow ◽  
Mean Diameter ◽  
The Mean ◽  
Definition Of

The general concept of the mean diameter of the disperse phase of an aerosol system, first introduced by Mugele and Evans in 1951, has proven to be a very useful one. In this concept, the proper mean diameter, xp,q, is characterized by a single pair of indices, p and q, which are dependent on the actual type of aerosol system under consideration. This paper re-examines the validity of this concept of mean diameter in heat and mass transfer aerosol systems. The concept is found to be applicable only under a very narrow range of conditions. Attention is then given to a more general definition of a mean diameter, applicable to aerosol heat or mass exchangers. Analyses of these devices shows that the more general mean diameter is a function of the capacity rate ratio, R, and effectiveness of the heat exchanger, ε. Solutions to the governing equations have permitted the mean diameter to be presented graphically as a function of these variables. These solutions are given for two types of particle size distributions, the Rosin-Rammler and the log-probability, and for both parallel-flow and counter-flow heat exchangers. The solutions are, however, restricted to cases where the resistance to heat or mass transfer lies exclusively in the continuous phase.

scholarly journals The mean magnetic field of the Sun: Observations at Stanford

Solar Physics ◽  
1977 ◽  
Vol 54 (2) ◽  
pp. 353-361 ◽  
Author(s):  
Philip H. Scherrer ◽  
John M. Wilcox ◽  
Leif Svalgaard ◽  
Thomas L. Duvall ◽  
Phil H. Dittmer ◽  
...  
Keyword(s):  
Magnetic Field ◽  
The Sun ◽  
The Mean
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