Lower Extremity Kinetics in High and Low-Arched Athletes during Landing

Abnormal foot function has been associated with an increased rate of injury in the athletic population. It has been shown that high-arched (HA) and low-arched (LA) athletes experience different injury patterns. These may be the manifestation of different loading and joint torque patterns in HA and LA athletes. It has been shown that HA and LA athletes have unique kinematic and kinetic patterns during running. However, little research has examined ground reaction forces (GRF) and lower extremity joint kinetics in HA and LA athletes during landing tasks. PURPOSE: To examine GRF and knee and ankle joint torques in HA and LA athletes during a landing task. METHODS: Ten HA (age: 20.8±2.5 years; height: 1.62±0.07 m; mass: 58.3±5.4 kg; arch index: 0.386±0.010) and 10 LA (age: 21.1±2.3; height: 1.63±0.07m; mass: 58.9±10.9kg; arch index: 0.259±0.043) female recreational athletes participated in this study. Each subject performed five barefooted drop landing trials from a height of 30 cm. GRFs and three-dimensional (3D) kinematics were recorded simultaneously using a force plate (1200 Hz, AMTI) and 7-camera motion analysis system (240 Hz, Vicon). GRFs and joint torques were calculated using Visual 3D (C-Motion, Inc.) and critical events were determined using custom software. A one-way ANOVA was used to compare group differences with an alpha level of p\u3c0.05. RESULTS: The GRF profiles were similar between the HA and LA athletes. However, HA athletes exhibited a mean eversion moment compared to an inversion moment in LA athletes (HA: -0.05±0.08 Nm/kg; LA: 0.04±0.07 Nm/kg). Additionally, the HA athletes generated greater peak knee external rotation torques (HA: 0.18±0.06 Nm/kg; LA: 0.26±0.08 Nm/kg) compared to LA athletes during the landing task. Knee extension and abduction torques were similar between the two groups in contrast to previous findings. CONCLUSIONS: The greater mean eversion torques exhibited by the HA athletes may be a response to being more inverted throughout the landing task. Increased eccentric contraction of the ankle everters would control eversion during landing. Similarly, the increased knee external rotation torques would act to limit knee internal rotation during landing. These altered kinetic patterns may increase the risk of injury within these groups of athletes

KSFNM: Faculty Chamber Players, Soldier\u27s and Devil\u27s Tales

This special performance of the 2017 Kennesaw State Festival of New Music (KSFNM) features KSU faculty performing Igor Stravinsky\u27s L\u27Histoire du soldat (The Soldier\u27s Tale) followed by The Devil\u27s Tale, James M. Stephenson\u27s sequel to Stravinsky\u27s esteemed work.https://digitalcommons.kennesaw.edu/musicprograms/1878/thumbnail.jp

XO-5b: A Transiting Jupiter-sized Planet With A Four Day Period

The star XO-5 (GSC 02959-00729, V=12.1, G8V) hosts a Jupiter-sized, Rp=1.15+/-0.12 Rjup, transiting extrasolar planet, XO-5b, with an orbital period of P=4.187732+/-0.00002 days. The planet mass (Mp=1.15+/-0.08 Mjup) and surface gravity (gp=22+/-5 m/s^2) are significantly larger than expected by empirical Mp-P and Mp-P-[Fe/H] relationships. However, the deviation from the Mp-P relationship for XO-5b is not large enough to suggest a distinct type of planet as is suggested for GJ 436b, HAT-P-2b, and XO-3b. By coincidence XO-5 overlies the extreme H I plume that emanates from the interacting galaxy pair NGC 2444/NGC 2445 (Arp 143).Comment: 10 pages, 9 Figures, Submitted to Ap

Bicarbonate-based Purge Solution As A Bleeding Reduction Strategy in Patients on Impella Support

Study: The Impella Catheters require a heparin-containing purge solution to maintain proper pump function by reducing the risk of biomaterial deposition in the purge gaps. A bicarbonate-based purge solution (BBPS) has been proposed as an alternative to a heparin-based purge solution. We review performance in patients supported to date with a BBPS (heparin-induced thrombocytopenia patients were excluded from this analysis). Methods: This review includes patients (n=26) supported using sodium bicarbonate (25 mEq/1L of D5W) in the purge from September 2020 to February 2021. These patients were supported with BBPS post-operatively where heparin in the purge was not desired or were transitioned to BBPS because of bleeding issues. Case data were collected from an internal database to develop the clinical narrative and cross-referenced against Impella Controller data logs to assess purge trends and pump function. Results: All pumps were switched to BBPS in the purge if not started with BBPS (Figure 1A). The average time to initiating BBPS was 1.6 days (excluding n=3 outliers where time to switching was \u3e15 days). The average duration of support with BBPS was 5 days and a maximum duration of 22 days (Figure 1B). Figure 1C shows clinical indications for use. Purge pressure and purge flow remained stable while on BBPS (Figure 1D). In conclusion, this preliminary experience suggests the feasibility of using BBPS to maintain purge patency, ensure pump motor reliability, reduce bleeding risk, and simplify anticoagulation management. Use of a BBPS may be a safe and effective alternative to heparin in the purge for patients in which heparin is contraindicated or not feasible. More patient experience and analysis are needed to evaluate how bicarbonate compares to heparin in the purge for all patients

Bicarbonate Purge Solution to Support Impella Devices for Patients with Clinically Suspected or Confirmed Heparin-induced Thrombocytopenia

Study: The Impella catheter is a transvalvular, micro-axial left ventricular assist device that provides temporary mechanical circulatory support and requires a heparin-containing purge solution to reduce the risk of biomaterial deposition in the purge gaps and also maintain proper pump function. For patients with suspected or confirmed heparin-induced thrombocytopenia (HIT), direct thrombin inhibitors (DTI) have been proposed as an alternative to heparin in the purge, but have been associated with pump failure requiring temporary tPA in the purge solution to normalize pump function. In this report, we review HIT patients supported with a sodium bicarbonate-based purge solution (BBPS). Methods: Patients with suspected or confirmed HIT on Impella support using sodium bicarbonate (25 mEq in 1L D5W solution) in the purge from September 2020 to January 2021 were reviewed. Case data were obtained from Impella Quality (IQ) database for those supported with a BBPS and clinically suspected or confirmed HIT. Purge pressures and purge flows were evaluated from the Automated Impella Controller (AIC). Results: Ten patients were supported with a BBPS during this period. Impella support was begun either with no anticoagulant (n=5), DTI (n=2), or heparin (n=3) and then switched to BBPS. Impella run time using a BBPS ranged from 1-14 days; five pumps had a run time with a BBPS \u3e 10 days (Figure 1). Systemic DTI use was used in five cases along with a BBPS. No purge pathway thrombosis or bleeding events were observed, along with no changes in purge flow or purge pressures observed. In conclusion, preliminary experience suggests the use of BBPS in the setting suspected or confirmed HIT patients supported with an Impella is safe and effective and may provide a useful therapeutic option for heparin intolerant patients. Future work should investigate mechanisms and purge reliability of BBPS in this setting

Dual-Wavelength ALMA Observations of Dust Rings in Protoplanetary Disks

We present new Atacama Large Millimeter/submillimeter Array (ALMA) observations for three protoplanetary disks in Taurus at 2.9\,mm and comparisons with previous 1.3\,mm data both at an angular resolution of $\sim0.''1$ (15\,au for the distance of Taurus). In the single-ring disk DS Tau, double-ring disk GO Tau, and multiple-ring disk DL Tau, the same rings are detected at both wavelengths, with radial locations spanning from 50 to 120\,au. To quantify the dust emission morphology, the observed visibilities are modeled with a parametric prescription for the radial intensity profile. The disk outer radii, taken as 95\% of the total flux encircled in the model intensity profiles, are consistent at both wavelengths for the three disks. Dust evolution models show that dust trapping in local pressure maxima in the outer disk could explain the observed patterns. Dust rings are mostly unresolved. The marginally resolved ring in DS Tau shows a tentatively narrower ring at the longer wavelength, an observational feature expected from efficient dust trapping. The spectral index ($\alpha_{\rm mm}$) increases outward and exhibits local minima that correspond to the peaks of dust rings, indicative of the changes in grain properties across the disks. The low optical depths ($\tau\sim$0.1--0.2 at 2.9\,mm and 0.2--0.4 at 1.3\,mm) in the dust rings suggest that grains in the rings may have grown to millimeter sizes. The ubiquitous dust rings in protoplanetary disks modify the overall dynamics and evolution of dust grains, likely paving the way towards the new generation of planet formation.Comment: accepted for publication in Ap

Gaps and Rings in an ALMA Survey of Disks in the Taurus Star-forming Region

Rings are the most frequently revealed substructure in ALMA dust observations of protoplanetary disks, but their origin is still hotly debated. In this paper, we identify dust substructures in 12 disks and measure their properties to investigate how they form. This subsample of disks is selected from a high-resolution ($\sim0.12''$) ALMA 1.33 mm survey of 32 disks in the Taurus star-forming region, which was designed to cover a wide range of sub-mm brightness and to be unbiased to previously known substructures. While axisymmetric rings and gaps are common within our sample, spiral patterns and high contrast azimuthal asymmetries are not detected. Fits of disk models to the visibilities lead to estimates of the location and shape of gaps and rings, the flux in each disk component, and the size of the disk. The dust substructures occur across a wide range of stellar mass and disk brightness. Disks with multiple rings tend to be more massive and more extended. The correlation between gap locations and widths, the intensity contrast between rings and gaps, and the separations of rings and gaps could all be explained if most gaps are opened by low-mass planets (super-Earths and Neptunes) in the condition of low disk turbulence ($\alpha=10^{-4}$). The gap locations are not well correlated with the expected locations of CO and N$_2$ ice lines, so condensation fronts are unlikely to be a universal mechanism to create gaps and rings, though they may play a role in some cases.Several ERC grants

Skunk River Review Autumn 1994, vol 6

https://openspace.dmacc.edu/skunkriver/1009/thumbnail.jp