Motion Analysis and Electromyographic Analysis of Ambulation with Assistive Devices

Purpose: The purpose of this study is to analyze the amount of muscle activity of the rectus abdominis and external obliques during the gait cycle with the use of forearm crutches and three different weight bearing statuses. Subjects: Seven female adults were recruited from the University of North Dakota Physical Therapy program. Inclusion criteria: between the ages of 19 and 40 years of age, current physical therapy students, and healthy with no current upper or lower extremity injuries. Instrumentation: The EMG data was collected by the Noraxon Telemyo 900 telemetry unit and analyzed using the MyoResearch XP software. Six Vicon MX40 infrared cameras were used to capture the marker motion. The Vicon Polygon 3.1 software was used to qualitatively analyze all of the motion and EMG data. Procedure: Prior to beginning the trials, surface electrodes were placed over the right and left rectus abdominis and right and left external oblique muscles to record the EMG activity. A MVC was performed using an isometric sit-up to establish a normalization baseline. Reflective markers were placed on bony prominences according to the Plug-in-Gait Marker Placement. Participants were fitted for forearm crutches and were allowed to practice a swing-to three point gait prior to the trials. Each participant performed two trials of each weight bearing status. Data Analysis: The EMG data from the crutch walking trials was compared with the EMG data from the MVC trials. The results were represented as a percent of the MVC. The EMG data was synchronized with the motion analysis data and displayed in graph form which shows the stickman figure along with the muscle activity during each point in time during the walking trial. This was used to qualitatively describe when each muscle was active during the gait cycle. Results: The quantitative assessment of EMG showed that both the rectus abdominis and the external oblique muscle groups were the most active during the non-weight bearing gait pattern. Activity between the right and left muscle groups was similar in amplitude. The qualitative assessment showed that both the rectus abdominis and the external obliques were the most active during the swing phase of a gait pattern. Conclusion: The abdominal musculature is active during crutch walking throughout the gait cycle. Physical therapists can benefit from the results of this study by evaluating the abdominal musculature strength during the examination prior to assigning an assistive device and by implementing core strengthening into the rehabilitation phase for those individuals who demonstrate weakness

DFT calculation of the intermolecular exchange interaction in the magnetic Mn4_4 dimer

The dimeric form of the single-molecule magnet [Mn$_4$O$_3$Cl$_4$(O$_2$CEt)$_3$(py)$_3$]$_2$ recently revealed interesting phenomena: no quantum tunneling at zero field and tunneling before magnetic field reversal. This is attributed to substantial antiferromagnetic exchange interaction between different monomers. The intermolecular exchange interaction, electronic structure and magnetic properties of this molecular magnet are calculated using density-functional theory within generalized-gradient approximation. Calculations are in good agreement with experiment.Comment: 4 page

Multipole Approach to Orientational Interactions in Solid C\u3csub\u3e60\u3c/sub\u3e

We calculate electrostatic multipole moments of C60 up to l=18 using the quantum-mechanical charge distribution with icosahedral symmetry obtained from ab initio calculations. It is found that the second nonzero moment (l=10) is comparable to the first nonzero moment (l=6). The values of several low-order multipole moments are almost 10 times smaller than those found from the charge distribution of recently proposed potential models and thus the actual Coulomb interaction between C60 molecules is much smaller than previously predicted. Much better agreement with calculated multipoles is obtained from a model which introduces point charges at the center of hexagonal and pentagonal plaquettes, following the physical arguments of David et al. [Nature 353, 147 (1991)]. We show that a multipole expansion including only l=6 and 10 moments can predict the potential due to a C60 molecule at distances R≥2R0 within an error of about 5%, where R0 is the radius of the C60 molecule. At distances less than R\u3c3/2R0 the multipole expansion is qualitatively incorrect even if one includes the terms up to l=18, indicating the importance of short-range quantum effects at these distances. The Coulomb interaction we obtain predicts two nearly degenerate, locally stable configurations for solid C60: (1) a metastable structure with Pa3 symmetry and setting angle φ=23.3°, close to experimentally observed value, and (2) a global minimum with the Pa3 structure but a setting angle φ=93.6°. We give physical arguments for expecting two such configurations and give a qualitative explanation for their near degeneracy. We conclude that a satisfactory intermolecular potential requires a first-principles calculation of the quantum-mechanical short-range repulsive interactions

Swine Manure Rate, Timing, and Application Method Effects on Post-Harvest Soil Nutrients, Crop Yield, and Water Quality Implications in a Corn-Soybean Rotation

This report documents results from a six-year study (1996-2001) that evaluated effects of liquid swine manure application management practices on soil nutrients, organic matter, pH, crop yield; and also discussed water quality implications. Swine manure management practices included single-rate (SR) and double-rate (DR) nitrogen (N)-based application rates (168 and 336 kg N ha-1, respectively), three timings (fall injection [FI], winter broadcast [WB], and spring injection [SI]), and two methods (broadcast and injection) of liquid swine manure. Analysis of these practices involved comparing levels of residual soil total phosphorus (P) as Bray-1 available P (RSP), residual soil nitrate-N (RSN), percent organic matter (OM%), pH, carbon:nitrogen (C:N) ratio, and crop yields (kg ha-1) in a corn-soybean rotation. Results of this study indicated that long-term application of higher liquid swine manure rates during winter and spring application times resulted in significantly higher post-harvest accumulation of RSN and RSP in the soil profile, with no significant changes in soil OM%, pH, and C:N ratio. These results also showed that incorporation of swine manure during the spring application time produced significantly higher corn yields compared with fall and winter application times. Overall results suggest that while RSN and RSP content may be significantly higher from spring versus fall manure application times, N and P runoff losses and the potential threat to surface water quality may be substantially lower during spring and summer compared with fall and winter due to effects from crop nutrient uptake, microbial activity, leaching, and evapotranspiration during the growing season

Electronic Structure of Superconducting Ba6c60

We report the results of first-principles electronic-structure calculations for superconducting Ba6C60. Unlike the A3C60 superconductors, this new compound shows strong Ba-C hybridization in the valence and conduction regions, mixed covalent/ionic bonding character, partial charge transfer, and insulating zero-gap band structure.Comment: 11 pages + 4 figures (1 appended, others on request), LaTeX with REVTE

Incommensurate Transverse Anisotropy Induced by Disorder and Spin-Orbit-Vibron Coupling in Mn12-acetate

It has been shown within density-functional theory that in Mn$_{12}$-acetate there are effects due to disorder by solvent molecules and a coupling between vibrational and electronic degrees of freedom. We calculate the in-plane principal axes of the second-order anisotropy caused by the second effect and compare them with those of the fourth-order anisotropy due to the first effect. We find that the two types of the principal axes are not commensurate with each other, which results in a complete quenching of the tunnel-splitting oscillation as a function of an applied transverse field.Comment: Will be presented at MMM conference 200

Hopewell Newsletter- June 2010

1. Small Scale Geoarchaeological Investigations of Earthen Wall Construction at the Hopeton Earthworks (33RO 26) Several geoarchaeological and geophysical investigations have been conducted at the Hopeton Earthworks (33RO26) and met with good success (Figure 1). As such, soil cores excavated in the summer of 2007 were studied using a two-pronged methodology of soil profile characterization and magnetic susceptibility testing. These techniques were employed to closely examine three sections of earthen wall at different locations at Hopeton as a means of understanding the soil composition of the walls and assessing possible uniformity in wall construction across the site. The following focuses solely on the geoarchaeological study of the selected locations. 2. The Role of Geophysics at Hopewell Culture National Historical Park Hopewell Culture National Historical Park is best known for its earthwork complexes built by the Hopewell during the Middle Woodland period. The park was originally established in 1923 to preserve the Mound City site after its use as a World War I training camp. In the past two decades, the park has added four additional earthworks—Hopeton Earthworks, Hopewell Mound Group, Seip Earthworks, and High Bank Works—and recently had its boundaries increased to include Spruce Hill. The recent growth in land located within the park has provided opportunities for archaeological research, most of which used some sort of geophysical technique. 3. Recent Investigations at the Mound City Group Ohio Hopewell earthworks have been studied extensively, both in historic and in modern times. Mound excavations during historic and modern times have revealed much about the construction and use of mound space. More recent research at Hopewell sites in Ohio has focused on non-mound areas both within and adjacent to the earthworks. This article focuses on current research conducted outside of the enclosure at the Mound City Group. 4. Clues to the Relationship of the Riverbank Site (33RO1059) to other Ohio Hopewell Sites Through Instrumental Neutron Activation Analysis on Pottery Excavations were conducted at the Riverbank Site (33RO1059), located by the Hopewell Site (33RO27), in 2004 and 2006 to gather data from the site before it is eroded away by the Paint Creek and to improve understanding of the role of small sites located near large Hopewell earthworks. Instrumental Neutron Activation Analysis (INAA) was conducted on pottery from the Riverbank Site to help clarify its relationship with other nearby sites. Fifteen sherds from the site were sent to the University of Missouri Research Reactor (MURR) for INAA, and the results were compared to the larger database of Hopewell ceramics. Based on the results, which show that the fifteen sherds formed a unique trace element compositional group, the site likely represents a shortterm occupation, possibly for a pilgrimage to the Hopewell Site, and the ceramics were likely either locally constructed for use at the site or constructed elsewhere to carry items on the way to Hopewell. 5. Feature Finds from the Riverbank Site, 33RO1059 Located just south and east of the Hopewell site’s Square Enclosure by about 225 meters is the Riverbank site, 33RO1059, which represents multiple occupations spanning the Archaic through historic periods, and includes a significant Middle Woodland component. Particularly noteworthy are two impressive pit features that were encountered in 2006 during a data recovery project undertaken by the Midwest Archeological Center. These pits, Features 7 and 8, would have been contemporaneous with Hopewell activities at the nearby earthwork complex, and the material culture recovered from them provides an intriguing glimpse of activities outside of the earthwork walls. 6. The Initial Phase of the Magnetic Investigations of the Mound City Group (32RO 32) at the Hopewell Culture National Historical Park, Ross County, Ohio The Mound City Group (Site 32RO32) covers approximately 13 acres. It contained at least 23 mounds when Squier and Davis made the first study of the mound complex in 1846. In the summer of 2009, the Midwest Archeological Center conducted the initial phase of a magnetic survey of the entire site. The magnetic survey in the southern portion of the site covered 11,200 m2 or 2.77 acres. The magnetic data indicated the presence of numerous magnetic anomalies associated with the Hopewell occupation and with the World War I training facility of Camp Sherman

Reply to Simon and Reed: Independent and Converging Results Rule Out Historic Disturbance and Confirm Age Constraints for Barrier Canyon Rock Art

We welcome this further discussion of our results on the age of the Great Gallery rock art in the Canyonlands of Utah. The comment by Simon and Reed (1) focuses on just one of the three components of our study (2), which is presented in greater technical detail in ref. 3 and is surely our best-constrained and least-surprising result: the dating of a rock-fall that removed some of the art and thus provides a minimum age. Simon and Reed (1) point out that the Great Gallery panel is not pristine and relate the sordid human history of visitation and possible disturbance to the site. Indeed, being aware of this during our research, one of our initial hypotheses was that the rock fall may be historic. Despite the possibility of recent disturbance to some of the talus boulders, our results document that the rock fall occurred ∼900 y ago, and for the boulder we sampled a scenario of historic disturbance and exposure such as postulated by Simon and Reed (1) can be ruled out