Isolation and Characterization of a High Energy Iron-Sulfur Protein From Mammalian Cells

A sulfur-containing protein (S-protein) was proposed to be an intermediate in the sulfation of cellular constituents containing ester sulfate after it was observed that S-protein isolated from the particulate fraction of the cell was unaffected by avitaminosis E, the stress of malathion intoxication or the level of inorganic sulfate in the diet. The present investigation was undertaken in an attempt to identify the cellular role of the S-protein in sulfate utilization. The role of the S-protein as a possible intermediate in the sulfation of ester sulfates was determined using both a natural sulfate acceptor, mucopolysaccharide, and an artificial sulfate acceptor, p-nitrophenol. The S-protein appeared to possess the energy required to raise inorganic sulfate to the level of ester sulfate when muco-polysaccharide was the acceptor, but not when the artificial acceptor, p-nitrophenol, was used. Since the S-protein appeared to possess a high energy configuration, and in view of its particulate origin, further experiments were designed to determine the relationship of the high energy configuration to the oxidative reactions of the cell. Since other investigators had previously suggested that an Fe-S protein is involved in sulfhydryl-disulfide oxidoreductions in the energy conservation at Site I, the modified sulfhydryl-disulfide exchange reaction between the S-protein and 2-mercaptoethanol led to the assumption that the S-protein might be involved in energy conservation at Site I. The evidence that the S-protein (Fe-S protein) was involved in energy conservation was strengthened by feeding rats 2,4 dinitrophenol, an uncoupler of oxidative phosphorylation, prior to isolation of Fe-S protein. Results of this experiment and an experiment determining the uptake of a test dose of 59Fe++ and 35SO=4 suggested that rats increased the synthesis of Fe-S protein to compensate for the decreased energy conservation that resulted from the injection of the uncoupler of oxidative phosphorylation. The-relationship between the Fe-S protein and the formation of ATP was then investigated. When the Fe-S protein was incubated with inorganic phosphate and ADP there was an increase in the disappearance of phosphate which paralleled the amount of Fe-S protein in the incubation mixture. The actual esterification of inorganic phosphate with ADP was demonstrated using 32PO≡4 in the incubation medium and isolating pure ATP containing 32P. Therefore, it is concluded that the Fe-S protein functioned to trap a portion of the energy of the respiratory chain by oxidatively binding inorganic sulfate, which it can then exchange for inorganic phosphate. The high energy phosphate could then be transferred to ADP to generate ATP

Assessment of Repeated Measurement Variance in Shear Wave Elastography of the Medial and Lateral Gastrocnemius and Soleus

The use of shear wave elastography (SWE) as a method to measure intrinsic muscle stiffness is gaining increasing interest in the scientific community. To date, a few studies exist that have evaluated reliability of SWE of the gastrocnemius muscle under various conditions. However, data on day-to-day variance, inter-rater variance and frame use in reporting stiffness is missing. PURPOSE: The purpose of this study was to calculate the variance of repeated measures for SWE in 2 different muscles using different raters and to analyze the number of elastogram frames needed for stiffness assessment. METHODS: 12 raters measured SWE of the gastrocnemius and soleus in 2 different ankle positions of 1 subject (12 different subjects total) on 5 separate days, and calculated stiffness using both velocity (m/s) and young’s modulus model (kPa) based on 10 separate elastogram frames. All subjects lay prone on the exam table with their bare foot and ankle hanging off. SWE of the visual center of the lateral head (LH) and medial head (MH) of the gastrocnemius, as well as the medial and lateral portion of the soleus were taken when the ankle was in a relaxed position (how the ankle naturally lay off the end of table) and a neutral position (requiring a strap to slightly dorsiflex the ankle joint to 90 degrees. RESULTS: Variance of young’s modulus model data (kPa) were analyzed using a Bayesian model. Muscles and muscle state (neutral or relaxed) were considered to be fixed effects, and the variance components (for subject, rater, day, frame, and error) were estimated using a hyperprior structure for those effects. Variance component results for day (0.186) and frame (0.063) were very low. Variance components for rater (6.170) and subject (6.126). Variance of random error was higher than expected at 62.620, indicating incidences of non-systematic abnormal kPa measurement values. CONCLUSION: SWE measurements are consistent day to day results with minimal variation indicating that controlled multiple day measurements are valid. Rater variance indicates an expected variability of 2.5 Kpa combined for all muscles and positions tested. Frame variance indicates that 10 frames are not necessary for calculation of kPa values which has not been established in current literature

Increasing Student Learning through Arts Integration

This action research study was designed to examine the effects of the arts integration on student learning. Student learning was broken down by focusing on student engagement, critical thinking, and creative response. Research was conducted with 72 participants from fourth grade, fifth grade, and ninth grade classrooms within the social studies curriculum. Data collection methods included a pre-assessment survey, student journal prompts, observation tally sheets, student self-assessments, and the post-assessment survey. The results of our study indicated that student learning in each classroom maintained or improved when the arts were integrated. Students showed enthusiasm and felt optimistic towards integrating the arts into their learning. According to our student survey many students noted an increase in their critical thinking skills and explained that the arts helped them display their knowledge and creativity. However, in the future we would guide students to be more specific in their journal responses to better communicate their ideas. As a result of our study, we have committed to improving student learning by continuing to integrate the arts into the curriculum. Keywords: arts integration, student learning, student engagement, critical thinking, creative respons

Variations in running technique between female sprinters, middle, and distance runners

International Journal of Exercise Science 6(1) : 43-51, 2013. In the sport of track and field, runners excel not only due to physiological characteristics but also aspects in running technique. Optimal technique allows runners the perfect the balance between running speed and economy. The ideal movement pattern may vary between events as the goal goes from economy of movement in the long-distance events to speed and power in the sprints. Understanding how each type of runner moves differently will help coaches more effectively train their athletes for each specific running event. This study was conducted to determine if sprinters, middle-distance, and long-distance runners would exhibit differences in form while running at the same speeds. Thirty female Division I collegiate runners participated in this study. Runners were separated into categories based on the events for which they were currently training in: 10 sprinters, 10 middle-distance, and 10 long-distance runners. Participants were asked to run twenty-two steps at five selected speeds. Knee angles, ground contact time, center of mass separation, and stride length were measured using a Vicon Nexus motion analysis system. Data was processed using analysis of variance and a Tukey post hoc analysis. Significant differences (p \u3c .05) occurred between long-distance runners and the other two groups (middle-distance and sprinters) for knee range, ground contact time, center of mass separation, and stride length at all five speeds. While running at the same speeds, there are specific characteristics of technique that distinguish long-distance runners from middle-distance and sprinters

Effects of Whole-Body Vibration on Flexibility and Stiffness: A Literature Review

International Journal of Exercise Science 12(3): 735-747, 2019. The effects of whole-body vibration (WBV) on flexibility and muscle stiffness are focused areas of research. Many studies have been performed over a large range of vibratory conditions and have reported varied results on effectiveness. When reviewing the published literature, it is difficult to track the vibration parameters that have positive effects and which have negative or no effects. In writing this paper,over 80 articles were evaluated, 24 of which met the inclusion requirements. The data gathered in the articles were used to develop charts that illustrate the vibration conditions that elicit helpful, harmful, and no effects on flexibility and muscle stiffness. A combination of published data shows that acceleration is the best metric to predict the effectiveness of WBV for improving flexibility and muscle stiffness. This review shows that acceleration in the range of 5g to 10g was most effective in increasing flexibility. Published data on muscle and tendon stiffness are limited, but shows that although WBV is generally significantly less effective in increasing stiffness than increasing flexibility, accelerations below 6.4g were the most effective

A Nitinol-Based Solar Array Deployment Mechanism

This document describes a simple, light weight, and scalable mechanism capable of deploying flexible or rigid substrate solar arrays that have been configured in an accordion-like folding scheme. This mechanism is unique in that it incorporates a Shape Memory Alloy (SMA) actuator made of Nitinol. This paper documents the design of the mechanism in full detail while offering to designers a foundation of knowledge by which they can develop future applications with SMA's

The ‘responsibility’ factor in imagining the future of education in China

Design and creativity have been a considerable force for improving life conditions. A lot of effort has been invested in explaining the design process and creativity mainly through the design thinking methodology, but design accountability and responsible actions in the design process are, yet, to be fully explored. The concept of design ethics is now increasingly scrutinized on both the level of business organization and of the individual designer. A 4-day design workshop that involved creativity techniques provided the base to explore responsibility in the fuzzy front end of the design process. The future of education in 2030 was defined as the workshop's theme and fifty-six students from China were asked to create detailed alternative scenarios. A number of imagination exercises, implementation of technological innovations and macro-environment evolutions employed in the workshop are discussed. The aim was to incite moral and responsible actions among students less familiar with creative educational contexts of student-led discovery and collaborative learning. This paper reflects on the use of creativity methods to stimulate anticipation in (non)design students

Acute Stretching Effect on Hamstring Muscle Stiffness using Elastography

Having first been introduced in the 1990s, shear wave elastography (SWE) has more recently been used to investigate intrinsic muscle stiffness. While studies have shown SWE to be an effective way of determining muscle stiffness, few have been conducted to measure the effects of stretching on the hamstring muscles. PURPOSE: to determine if there is a measurable difference of hamstring muscle stiffness with acute stretching using ultrasound elastography. METHODS: 16 subjects participated in this study (11 men and 5 women). Mean age 23.4 ± 2.6yrs for men and 21.2 ±1.5 for women. Mean height (cm) is 180.3± 4.7 for men and 172.7±2.5 for women. Mean weight (kg) is 76.8±9.7 for men and 70.0±14.9 for women. Participants lay supine and positioned to 90° hip and 90° knee flexion. Each participant came in for two sessions that consisted of (1) static stretching and (2) PNF stretching protocols. Maximum ROM of the knee joint, force, and muscle stiffness of the biceps femoris (BF), semimembranosus (SM) and semitendinosus (ST) were recorded both before and 1 minute after stretching. RESULTS: After accounting for age, weight and height, there was no significant difference between the use of static and PNF stretching techniques on either velocity (p= 0.4805) or kPa (p=0.5423) stiffness values. Both static and PNF stretching resulted in significant reductions in both velocity and kPa stiffness (pCONCLUSION: Stiffness as measured using SWE decreases following an acute stretching session for both static and PNF stretching techniques. This suggests alterations to intrinsic muscle characteristics beyond just “stretch tolerance” as suggested in previous literature. Changes in both ROM and force also support this claim. Further research on retention of decreased stiffness are needed as acute stretching has previously been shown to be temporary. Longer term stretching studies to determine if intrinsic muscle stiffness changes models plastic deformation are also needed and may help better elucidate duration and stretch technique differences

Comparison of Gastrocnemius Shear Wave Elastography Stiffness Over 5 Different Zones

A few studies report that shear wave elastography (SWE) is a reliable method of measuring gastrocnemius muscle stiffness. To date there are no studies assessing variance in stiffness measures at different locations on the muscle. This led us to ask whether the spot at which gastrocnemius stiffness is measured matters. PURPOSE: To determine if measurement site on the medial and lateral gastrocnemius affects SWE stiffness values. METHODS: Twelve subjects (3 men, 9 women) completed this study (Mean age is 23.0 (SD = 1.0) for men and 21.7 (SD = 2.0) for women (t p = 0.3035). Mean height (cm) is 179.5 (SD = 2.9) for men and 167.1 (SD = 7.8) for women (t p = 0.0256). Mean weight (kg) is 74.9 (SD =10.4) for men and 62.5 (SD = 9.7) for women (t p = 0.0892). Subjects wore shorts and lay prone on a treatment table with their bare feet hanging off the edge of the table. Ultrasound images to confirm borders of the medial and lateral gastrocnemius were confirmed and marked. SWE of both the Medial head (MG) and lateral head (LG) were taken with each head area divided into 4 zones (1=superior medial, 2=superior lateral, 3=inferior medial, 4= inferior lateral). A fifth zone was collected at the center of the muscle at 70% of the length of the lateral malleolus to lateral femoral epicondyle. All 5 points were assessed for SWE in both a relaxed and neutral (900) ankle joint position. Three separate elastogram frames were used to calculate muscle stiffness using both the velocity (m/s) and young’s modulus model (kPa) utilizing an overall area analysis for each. RESULTS: MG velocity and kPa values were significantly greater than LG in the relaxed and neutral positions (pCONCLUSION: MG stiffness is greater than LG regardless of position while intrinsic stiffness of MG increases more relative to LG when placed in neutral. Measurement of stiffness is best represented at the center of the muscle belly in the neutral position, but zones 2,3 and 5 produce similar stiffness values in the relaxed position

Preliminary Analysis of Male and Female Size Differences of the Achilles Tendon in Active Aging Adults

Achilles tendinopathy impacts athletes of all ages. The Achilles tendon plays a key role in most athletic movements and is vital in the gait cycle. The prevalence of Achilles tendinopathy is associated with increasing age, which causes problems with gait and decreases quality of life. PURPOSE: We investigated factors associated with differences in Achilles size — cross sectional area (CSA) and thickness — in active maturing adults. METHODS: Participants were chosen from volunteers competing in the Huntsman World Senior Games in St. George, UT, October 2021. Participants rested prone on a treatment table with the ankle in a neutral position. A strap connected to the end of the table was placed around each foot to create a 90-degree angle at the ankle. Ultrasound (US) transmission gel was applied to the head of the probe to collect transverse and longitudinal images using a ML 6-15 Probe. The midportion of the Achilles tendon CSA was measured at the intersection of a line between the medial and lateral malleoli. The probe was then rotated 90 at this point to capture thickness measurements. Random selection of 20 males (age=68.050, weight=181.780 lbs., height=67.925 in., body fat=13.875%) and 20 females (age=63.391, weight=147.409 lbs., height=65.543 in., body fat=33.500%) were chosen from a larger data set and analyzed by a single researcher in this preliminary study. RESULTS: There was a significant difference between the CSA of males and females (p=0.046), with an average of 0.747 cm2 and 0.565 cm2 respectively. Achilles thickness also had a significant difference when comparing males and females (p=0.029), with an average of 0.601 cm and 0.491 cm respectively. Weight, body fat, and age were significant independent variables for both CSA and thickness. There was not a significant relationship between left and right Achilles tendons (p0.23). Large effect sizes (1.07 and 0.97) were found for CSA and thickness between groups indicative of a meaningful clinical difference. CONCLUSION: Males and females have a quantifiable size difference of the midportion of the Achilles tendon in an active older adult population. These values are important for interpreting images within this population and may also be important in determining pathologic tendons