82 research outputs found
Comparison of Range of Motion After Aquatic vs Land Exercises on Young Adult Men
Range of motion is the degree to which joints in the body can extend or flex. This is essential to performing actions such as bending over, reaching, and other daily activities. This study investigated the effects of aquatic versus land exercises on range of motion. It was hypothesized that the participant completing the aquatic exercises would have a greater increase of range of motion. Three male participants were recruited to participate in the study. Each participant was placed into a different group- control, aquatic, or land. The control participant measured their range of motion at the beginning and end of the experiment without modifying anything in their daily life. The aquatic and land-based participants measured their range of motion at the beginning and end of the experiment, while doing exercises in either land or water, whichever group they were in, and stretches over a course of two weeks. The experiment was conducted over a two-week span with participants completing 10 total days of exercises, 5 each week. No face-to-face research was completed due to COVID-19, eliminating personal contact. The data was compiled and examined proving that although the aquatic group increased range of motion, there was no significant difference. This did not support the hypothesis previously stated. Therefore, it cannot be assumed that aquatic exercises will increase range of motion greater than land exercises to a significant amount. Possible modifications to this experiment that could have changed the outcome are increasing sample size and lengthening the duration of the study
Locating Planetesimal Belts in the Multiple-planet Systems HD 128311, HD 202206, HD 82943, and HR 8799
In addition to the Sun, six other stars are known to harbor multiple planets and debris disks: HD 69830, HD 38529, HD 128311, HD 202206, HD 82943, and HR 8799. In this paper, we set constraints on the location of the dust-producing planetesimals around the latter four systems. We use a radiative transfer model to analyze the spectral energy distributions of the dust disks (including two new Spitzer IRS spectra presented in this paper), and a dynamical model to assess the long-term stability of the planetesimals' orbits. As members of a small group of stars that show evidence of harboring a multiple planets and planetesimals, their study can help us learn about the diversity of planetary systems
OSSOS: XXVII. Population Estimates for Theoretically Stable Centaurs Between Uranus and Neptune
We calculate the upper bounds of the population of theoretically stable
Centaur orbits between Uranus and Neptune. These small bodies are on
low-eccentricity, low-inclination orbits in two specific bands of semi-major
axis, centred at 24.6 au and 25.6 au. They exhibit unusually long
Gyr-stable lifetimes in previously published numerical integrations, orders of
magnitude longer than that of a typical Centaur. Despite the increased breadth
and depth of recent solar system surveys, no such objects have been found.
Using the Outer Solar System Origins Survey (OSSOS) survey simulator to
calculate the detection efficiency for these objects in an ensemble of fully
characterised surveys, we determine that a population of 72 stable Centaurs
with absolute magnitude ( confidence upper limit) could
remain undetected. The upcoming Legacy Survey of Space and Time (LSST) will be
able to detect this entire intrinsic population due to its complete coverage of
the ecliptic plane. If detected, these objects will be interesting
dynamically-accessible mission targets -- especially as comparison of the
stable Centaur orbital phase space to the outcomes of several modern planetary
migration simulations suggests that these objects could be close to primordial
in nature.Comment: Accepted to PSJ. 8 pages, 3 figures. Comments welcom
OSSOS VI. Striking Biases in the detection of large semimajor axis Trans-Neptunian Objects
The accumulating, but small, set of large semi-major axis trans-Neptunian
objects (TNOs) shows an apparent clustering in the orientations of their
orbits. This clustering must either be representative of the intrinsic
distribution of these TNOs, or else arise as a result of observation biases
and/or statistically expected variations for such a small set of detected
objects. The clustered TNOs were detected across different and independent
surveys, which has led to claims that the detections are therefore free of
observational bias. This apparent clustering has led to the so-called "Planet
9" hypothesis that a super-Earth currently resides in the distant solar system
and causes this clustering. The Outer Solar System Origins Survey (OSSOS) is a
large program that ran on the Canada-France-Hawaii Telescope from 2013--2017,
discovering more than 800 new TNOs. One of the primary design goals of OSSOS
was the careful determination of observational biases that would manifest
within the detected sample. We demonstrate the striking and non-intuitive
biases that exist for the detection of TNOs with large semi-major axes. The
eight large semi-major axis OSSOS detections are an independent dataset, of
comparable size to the conglomerate samples used in previous studies. We
conclude that the orbital distribution of the OSSOS sample is consistent with
being detected from a uniform underlying angular distribution.Comment: Accepted for publicatio
OSSOS III - Resonant Trans-Neptunian Populations: Constraints from the first quarter of the Outer Solar System Origins Survey
The first two observational sky "blocks" of the Outer Solar System Origins
Survey (OSSOS) have significantly increased the number of well-characterized
observed trans-Neptunian objects (TNOs) in Neptune's mean motion resonances. We
describe the 31 securely resonant TNOs detected by OSSOS so far, and we use
them to independently verify the resonant population models from the
Canada-France Ecliptic Plane Survey (CFEPS; Gladman et al. 2012), with which we
find broad agreement. We confirm that the 5:2 resonance is more populated than
models of the outer Solar System's dynamical history predict; our minimum
population estimate shows that the high eccentricity (e>0.35) portion of the
resonance is at least as populous as the 2:1 and possibly as populated as the
3:2 resonance. One OSSOS block was well-suited to detecting objects trapped at
low libration amplitudes in Neptune's 3:2 resonance, a population of interest
in testing the origins of resonant TNOs. We detected three 3:2 objects with
libration amplitudes below the cutoff modeled by CFEPS; OSSOS thus offers new
constraints on this distribution. The OSSOS detections confirm that the 2:1
resonance has a dynamically colder inclination distribution than either the 3:2
or 5:2 resonances. Using the combined OSSOS and CFEPS 2:1 detections, we
constrain the fraction of 2:1 objects in the symmetric mode of libration to be
0.2-0.85; we also constrain the fraction of leading vs. trailing asymmetric
librators, which has been theoretically predicted to vary depending on
Neptune's migration history, to be 0.05-0.8. Future OSSOS blocks will improve
these constraints.Comment: Accepted for publication in A
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