Effects of Obesity on Knee Extensor Structure, Function, and Gait: A Systematic Review and Meta-Analysis

Obesity is a common, costly, and critical disease that increases the risk of disability and premature death. Most commonly, obesity is caused by an increased consumption of energy dense foods and decreased time spent being physically active. The greater weight with obesity interrupts normal musculoskeletal function which can lead to physical adaptations such as decreased lower-extremity muscle strength and abnormal walking patterns, both of which are among top risk factors for falls in older individuals. However, the effects of obesity on walking and lower-extremity muscle strength have not previously been examined by incorporating the results of all existing studies in a comprehensive systematic review and meta-analysis. Therefore, the purpose of this dissertation was to (1) determine the effect of obesity on measures of walking in adults, and to (2) determine the effect of obesity on knee extensor strength, muscle size, and muscle quality in children, adolescents, adults and older adults. In the first study, there were 47 studies included in the systematic review and 44 in the meta-analyses. Study two included 35 studies in the systematic review and 29 in the meta-analyses. The results suggest that (1) obesity reduces self-selected walking speed and step length, but increases step width and the amount of time spent with both feet in contact with the ground, and (2) obesity increases absolute maximal measures of knee extensor strength and muscle size, but decreases relative maximal measures of knee extensor strength and muscle quality. However, the effect of obesity on knee extensor size, quality, and strength appears to diminish with age. The results of this dissertation will improve our understanding of how obesity influences walking and knee extensor function, which will allow the design of better treatments for those suffering from obesity as well as a basis of knowledge to guide researchers going forward

The Missing Course: An Introduction to College Teaching for Graduate Instructors

A book review of David Gooblar’s book, The Missing Course: Everything they Never Taught You About College Teaching

Cranial Cruciate Ligament Desmotomies in Sheep Resulting in Peroneus Tertius Injury

Surgical destabilization of the stifle joint via cranial cruciate ligament desmotomy (CCLD) is a routine procedure for the study of osteoarthritis (OA). Traditionally performed in rats, rabbits, cats, and dogs, CCLD in sheep provides an opportunity to study the pathology and treatment of joint instability in a species whose stifle better represents the equivalent human femorotibial joint. The surgical approaches for CCLD in sheep are variable and can result in inconsistent outcomes. Eight sheep underwent CCLD for use in a gene therapy study. We report this case in which six of the eight sheep were clinically diagnosed by pathognomonic signs and later confirmed by postmortem dissection, with injury of the peroneus tertius (PT) muscle. The PT plays a crucial role in the normal gait of large animals, including sheep. Injury to the PT results in failure of the reciprocal apparatus of the hind limb in which the hock can be extended during stifle flexion creating a varied gait and an indiscriminate increase in instability of the stifle and hock joints. Restricted movement postoperatively may provide decreased variability in surgical outcomes. Alternatively, increased stifle instability via CCLD coupled with PT transection or PT transection alone could potentially provide a superior model of stifle instability and OA development in sheep

Luminescence evidence for bulk and surface excitons in free xenon clusters

Cathodoluminescence spectra of free xenon clusters produced by condensation of xenon-argon gas mixtures in supersonic jets expanding into vacuum were studied. By varying initial experimental parameters, including xenon concentration, we could obtain clusters with a xenon core (300-3500 atoms) covered by an argon outer shell as well as shell-free xenon clusters (about 1500 atoms). The cluster size and temperature (about 40 K for both cases) were measured electronographically. Luminescence bands evidencing the existence of bulk and surface excitons were detected for shell-free xenon clusters. The emission from bulk excitons in small clusters is supposed to be due to processes of their multiple elastic reflections from the xenon-vacuum interface. A presence of an argon shell causes extinction of the excitonic bands. In addition, some new bands were found which have no analogs for bulk xenon cryosamples.Comment: The final modified version will be published in Phys. Rev. A 76 (2007

A systematic review and meta-analysis comparing the effect of aquatic and land exercise on dynamic balance in older adults

Publisher's version (útgefin grein)Abstract Background: Balance impairments are the leading causes of falls in older adults. Aquatic-based exercises have been broadly practiced as an alternative to land-based exercises; however, the effects on dynamic balance have not been comprehensively reviewed and compared to land exercises. Thus, the purpose of this systematic review and meta-analysis was to compare the effectiveness of aquatic exercises (AE) to land exercises (LE) on dynamic balance in older adults. Methods: Electronic databases (PubMed, MEDLINE, CINAHL, SPORTDiscus, psycINFO), from inception to November 2019, were searched. Studies met the following eligibility criteria: Randomized controlled trials, English language, older adults aged 65 years or older, a minimum of one AE and LE group, at least one assessment for dynamic balance. For the meta-analysis, the effect sizes of dynamic balance outcomes were calculated using a standardized mean difference (SMD) and a 95% confidence interval (CI). Results: A total of 11 trials met the inclusion criteria, and 10 studies were eligible for the meta-analysis. The meta-analysis presented that older adults in AE groups demonstrated comparable enhancements in dynamic steady-state balance (SMD =−0.24; 95% CI,−.81 to .34), proactive balance (SMD =−0.21; 95% CI,−.59 to .17), and balance test batteries (SMD =−0.24; 95% CI,−.50 to .03) compared with those in LE groups. Conclusions: AE and LE have comparable impacts on dynamic balance in older adults aged 65 years or older. Thus, this review provides evidence that AE can be utilized as a reasonable alternative to LE to improve dynamic balance and possibly reduce the risk of falls.Peer reviewe

A Tool for GIXRF/XRR simulation and data analysis

Ponencia presentada en el Monte Carlo Simulation Tools for X-Ray Imaging and Fluorescence Workshop, 2014The IAEA has developed a beamline end-station facility that it is currently installed at the newly developed XRF beamline of Elettra Sincrotrone Trieste, ItalyThe end-station called Ultra High Vacuum Chamber (UHVC) is a multipurpose facility for applying simultaneously various complementary and advanced variants of X-Ray Spectrometry (XRS) techniques, including: Total Reflection X-ray Fluorescence Analysis (TXRF) Grazing Incidence/Exit XRF analysis (GIXRF- GEXRF) Near Edge X-ray Absorption Fine Structure (NEXAFS) X-ray Reflectometry (XRR) The current development of GIXRF/XRR simulations/analysis tool aims at assisting end-users in data processing and interpretation.Fil: Leani, Juan José. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Leani, Juan José. Nuclear Science and Instrumentation Laboratory, IAEA Laboratories; Austria.Física Atómica, Molecular y Química (física de átomos y moléculas incluyendo colisión, interacción con radiación, resonancia magnética, Moessbauer Efecto.