Risk Factors Associated With Osteoarthritis Post-ACL Injury: A Literature Review

Background: Anterior cruciate ligament ruptures are a relatively common injury in both contact and non-contact sports and are known to have a long rehabilitation process. In addition to a long recovery to get back to competitive sport levels, ACL tears are also associated with a high risk of early onset osteoarthritis, resulting in pain, functional limitations, and a diminished quality of life. There are many variables that have been studied that have a correlation to the occurrence of this condition. Objectives: To examine peer reviewed literature to determine evidence based risk factors for developing osteoarthritis post-ACL injury. Data sources: Resources were pulled from PubMed, SPORTDiscus, and MEDLINE, between the years of 1999 and 2016 using the key words anterior cruciate ligament, ACL, osteoarthritis, and risk factors. Inclusion criteria consisted of the following: peer reviewed studies that were published after 1999, studies that were done on human subjects, ACL ruptures that were treated by either conservative management, patella graft, or hamstring graft, and radiographic follow-up five years or more post-surgery. Abstracts and unpublished data were excluded. Conclusion: There are seven important factors associated with the incidence of post-traumatic osteoarthritis following ACL injury. Treatment decisions, graft choice, meniscal status, age at the time of reconstruction, time between injury and reconstruction, sport activity post-injury, and body mass index all play a role in the development of OA. Some variables can be controlled, while others cannot, which makes it difficult to entirely diminish the occurrence of OA

Nondestructive ultrasonic measurement of bolt preload using the pulsed-phase locked-loop interferometer

Achieving accurate preload in threaded fasteners is an important and often critical problem which is encountered in nearly all sectors of government and industry. Conventional tensioning methods which rely on torque carry with them the disadvantage of requiring constant friction in the fastener in order to accurately correlate torque to preload. Since most of the applied torque typically overcomes friction rather than tensioning the fastener, small variations in friction can cause large variations in preload. An instrument called a pulsed phase locked loop interferometer, which was recently developed at NASA Langley, has found widespread use for measurement of stress as well as material properties. When used to measure bolt preload, this system detects changes in the fastener length and sound velocity which are independent of friction. The system is therefore capable of accurately establishing the correct change in bolt tension. This high resolution instrument has been used for precision measurement of preload in critical fasteners for numerous applications such as the space shuttle landing gear and helicopter main rotors

Functional Implications of Impaired Control of Submaximal Hip Flexion Following Stroke

Introduction: We quantified sub-maximal torque regulation during low to moderate intensity isometric hip flexion contractions in individuals with stroke and the associations with leg function. Methods: 10 participants with chronic stroke and 10 controls performed isometric hip flexion contractions at 5%, 10%, 15%, 20%, and 40% of maximal voluntary contraction (MVC) in paretic, non-paretic, and control legs. Results: Participants with stroke had larger torque fluctuations (coefficient of variation, CV), for both the paretic and non-paretic legs, than controls (Pr2 =0.45) and Berg Balance Score (r2=0.38). At 5% MVC, there were larger torque fluctuations in the contralateral leg during paretic contractions compared with the control leg. Conclusions: Impaired low-force regulation of paretic leg hip flexion can be functionally relevant and related to control versus strength deficits post stroke

NATO: the view from the East

Relations between Russia, Ukraine and Belarus and NATO have placed more emphasis on cooperation than confrontation since the Cold War, and Ukraine has begun to move towards membership. At the popular level, on the evidence of national surveys in 2004 and 2005, NATO continues to be perceived as a significant threat, but in Russia and Ukraine it comes behind the United States (in Belarus the numbers are similar). There are few socioeconomic predictors of support for NATO membership that are significant across all three countries, but there are wide differences by region, and by attitudinal variables such as support for a market economy and for EU membership. The relationship between popular attitudes and foreign policy is normally a distant one; but in Ukraine NATO membership will require public support in a referendum, and in all three cases public attitudes on foreign policy issues can influence foreign policy in other ways, including the composition of parliamentary committees. In newly independent states whose international allegiances are still evolving, the associations between public opinion and foreign and security policy may often be closer than in the established democracies

An XMM-Newton View of the Radio Galaxy 3C 411

We present the first high signal-to-noise XMM-Newton observations of the broad-line radio galaxy 3C 411. After fitting various spectral models, an absorbed double power-law continuum and a blurred relativistic disk reflection model (kdblur) are found to be equally plausible descriptions of the data. While the softer power-law component ($\Gamma$=2.11) of the double power-law model is entirely consistent with that found in Seyfert galaxies (and hence likely originates from a disk corona), the additional power law component is very hard ($\Gamma$=1.05); amongst the AGN zoo, only flat-spectrum radio quasars have such hard spectra. Together with the very flat radio-spectrum displayed by this source, we suggest that it should instead be classified as a FSRQ. This leads to potential discrepancies regarding the jet inclination angle, with the radio morphology suggesting a large jet inclination but the FSRQ classification suggesting small inclinations. The kdblur model predicts an inner disk radius of at most 20 r$_g$ and relativistic reflection

Investigation of critical burning of fuel droplets

Fuel droplets were simulated by porous spheres having diameters in the range 0.63 to 1.9 cm and combustion tests were conducted at pressures up to 78 atm in a quiescent cold air environment. Measurements were made of the burning rate and liquid surface temperature during steady combustion. A high pressure flat flame burner apparatus is under development in order to allow testing of high pressure droplet burning in a combustion gas environment. Work was continued on the high pressure strand combustion characteristics of liquid fuels, with the major emphasis on hydrazine. Data was obtained on the burning rate and liquid surface temperatures at pressures in the range 7 to 500 psia. The response of a burning liquid monopropellant to imposed pressure oscillations is being investigated

The effect of tetrathionate on the stability and immunological properties of muscle triosephosphate dehydrogenases

Tetrathionate effect on stability and immunological properties of muscle triosephosphate dehydrogenase

The issuance of series-1996 $100 Federal Reserve notes: goals, strategy, and likely results.

In March 1996, the Federal Reserve began issuing series-1996 $100 Federal Reserve notes. Culminating a cooperative effort by the U.S. Department of the Treasury and the Federal Reserve System that dated from the 1980s, the series-1996 note was the first major design change in U.S. currency in sixty-six years. The new note was developed to provide better protection for users of U.S. currency against the growing threat of counterfeiting, especially that posed by increasingly affordable and capable color scanning and printing systems. This article discusses the Federal Reserve's strategy for issuing newly designed$100 notes and says that it appears likely to achieve its objectives: a replacement of pre-series-1996 $100 notes that is timely in relation to the developing threat of counterfeiting, with a minimum impact on holders and users of those notes throughout the world.Money

Galaxy pairs as a probe for mergers at z ~ 2

In this work I investigate the redshift evolution of pair fraction of a sample of 196 massive galaxies from z = 0 to 3, selected from the COSMOS field. We find that on average a massive galaxy undergoes ~ 1.1 \pm 0.5 major merger since z = 3. I will review the current limitations of using the pair fraction as a probe for quantifying the impact of mergers on galaxy evolution. This work is based on the paper Man et al. (2011).Comment: 4 pages; to appear on the Conference Proceedings for "Galaxy Mergers in an Evolving Universe", held in Hualien, Taiwan (October 2011