Muscle Cramping During a 161-km Ultramarathon: Comparison of Characteristics of Those With and Without Cramping

Background: This work sought to identify characteristics differing between those with and without muscle cramping during a 161-km ultramarathon. Methods: In this observational study, race participants underwent body weight measurements before, during, and after the race; completed a post-race questionnaire about muscle cramping and “near” cramping (controllable, not reaching full-blown cramping), drinking strategies, and use of sodium supplementation during four race segments; and underwent a post-race blood draw for determination of serum sodium and blood creatine kinase (CK) concentrations. Results: The post-race questionnaire was completed by 280 (74.5 %) of the 376 starters. A post-race blood sample was provided by 181 (61.1 %) of the 296 finishers, and 157 (53.0 %) of finishers completed the post-race survey and also provided a post-race blood sample. Among those who completed the survey, the prevalence of cramping and near cramping was 14.3 and 26.8 %, respectively, with greatest involvement being in the calf (54 %), quadriceps (44 %), and hamstring (33 %) muscles. Those with cramping or near cramping were more likely to have a prior history of muscle cramping during an ultramarathon (p \u3c 0.0001) and had higher blood CK concentrations (p = 0.001) than those without cramping. Weight change during the race, use of sodium supplements, intake rate of sodium in supplements, and post-race serum sodium concentration did not differ between those with and without cramping. Conclusions: Muscle cramping is most common in those with a prior history of cramping and greater muscle damage during an ultramarathon, suggesting an association with relative muscular demand. Impaired fluid and sodium balance did not appear to be an etiology of muscle cramping during an ultramarathon

Muscle Cramping During a 161-km Ultramarathon: Comparison of Characteristics of Those With and Without Cramping

Background: This work sought to identify characteristics differing between those with and without muscle cramping during a 161-km ultramarathon. Methods: In this observational study, race participants underwent body weight measurements before, during, and after the race; completed a post-race questionnaire about muscle cramping and “near” cramping (controllable, not reaching full-blown cramping), drinking strategies, and use of sodium supplementation during four race segments; and underwent a post-race blood draw for determination of serum sodium and blood creatine kinase (CK) concentrations. Results: The post-race questionnaire was completed by 280 (74.5 %) of the 376 starters. A post-race blood sample was provided by 181 (61.1 %) of the 296 finishers, and 157 (53.0 %) of finishers completed the post-race survey and also provided a post-race blood sample. Among those who completed the survey, the prevalence of cramping and near cramping was 14.3 and 26.8 %, respectively, with greatest involvement being in the calf (54 %), quadriceps (44 %), and hamstring (33 %) muscles. Those with cramping or near cramping were more likely to have a prior history of muscle cramping during an ultramarathon (p \u3c 0.0001) and had higher blood CK concentrations (p = 0.001) than those without cramping. Weight change during the race, use of sodium supplements, intake rate of sodium in supplements, and post-race serum sodium concentration did not differ between those with and without cramping. Conclusions: Muscle cramping is most common in those with a prior history of cramping and greater muscle damage during an ultramarathon, suggesting an association with relative muscular demand. Impaired fluid and sodium balance did not appear to be an etiology of muscle cramping during an ultramarathon

Obstacle avoidance for redundant robots using configuration control

A redundant robot control scheme is provided for avoiding obstacles in a workspace during the motion of an end effector along a preselected trajectory by stopping motion of the critical point on the robot closest to the obstacle when the distance between is reduced to a predetermined sphere of influence surrounding the obstacle. Algorithms are provided for conveniently determining the critical point and critical distance

Visual Communications on the Road in Arkansas: Analysis of Secondary Students Videos

In the summer of 2010, the Visual Communications on the Road in Arkansas: Creative Photo and Video Projects to Promote Agriculture program was initiated. The program consisted of a two-week agricultural communications curriculum that would be taught by agricultural science teachers in Arkansas. The curriculum was composed of lessons about photography, writing, and videography, and the program introduced students to digital photography and videography equipment and the proper uses of equipment. Once the curriculum was taught in secondary schools, a mobile classroom unit—consisting of a travel trailer, photography and videography equipment, and laptop computers equipped with editing software—would visit the school to assist students with the creation of short promotional videos about agriculture. The student-created videos were used as a hands-on extension of the curriculum learned in the classroom. Completed videos were posted to YouTube and then analyzed to assess student application of competencies taught in the curriculum. The researchers created a coding sheet to systematically assess all posted videos and inter- and intrarater reliability was maintained. An analysis of data gathered from the video assessment showed that secondary students were able to effectively apply many of the techniques taught in the curriculum through the agricultural videos created. Additional findings and recommendations for application and future research are presented

Opportunities and challenges of the U.S. dollar as an increasingly global currency: a Federal Reserve perspective

The rapid growth of demand for U.S. currency over the past two decades, especially the proportion estimated to be held abroad, has posed challenges for the Federal Reserve in meeting its congressionally mandated responsibilities for currency availability and distribution. Those challenges lie in making certain that the Bureau of Engraving and Printing (BEP) prints adequate amounts of currency; that overseas distribution channels have sufficient capacity to distribute U.S. currency when and where it is needed; and that the integrity of U.S. currency is maintained by monitoring counterfeiting activity. In the process of meeting these challenges, the Federal Reserve has improved its methods of forecasting demand for U.S. currency, expanded currency distribution channels, and worked with the BEP and the U.S. Secret Service to protect against counterfeiting threats. This article gives an overview of the evolution of the Federal Reserve's responsibilities for U.S. currency, particularly in relation to the increase in foreign demand over the past two decades, and also discusses work on counterfeit deterrence.International finance ; Money ; Dollar, American

Association of Gastrointestinal Distress in Ultramarathoners with Race Diet

Context: Gastrointestinal (GI) distress is common during ultrarunning. Purpose: To determine if race diet is related to GI distress in a 161-km ultramarathon. Methods: Fifteen (10 male, 5 female) consenting runners in the Javelina Jundred (6.5 loops on a desert trail) participated. Body mass was measured immediately pre-race and after each loop. Runners reported if they had nausea, vomiting, abdominal cramps, and/or diarrhea after each loop. Subjects were interviewed after each loop to record food, fluid, and electrolyte consumption. Race diets were analyzed using Nutritionist Pro. Results: Nine (8 male, 1 female) of 15 runners experienced GI distress including nausea (89%), abdominal cramps (44%), diarrhea (44%), and vomiting (22%). Fluid consumption rate was higher (p = .001) in runners without GI distress (10.9 ± 3.2 ml · kg–1 · hr–1) than in those with GI distress (5.9 ± 1.6 ml · kg–1 · hr–1). Runners without GI distress consumed a higher percentage fat (p = .03) than runners with GI distress (16.5 ± 2.6 vs. 11.1 ± 5.0). In addition, fat intake rate was higher (p = .01) in runners without GI distress (0.06 ± 0.03 g · kg–1 · hr–1) than in runners with GI distress (0.03 ± 0.01 g · kg–1 · hr–1). Lower fluid and fat intake rates were evident in those developing GI distress before the onset of symptoms. Conclusions: A race diet with higher percentage fat and higher intake rates of fat and fluid may protect ultramarathoners from GI distress. However, these associations do not indicate cause and effect, and factors other than race diet may have contributed to GI distress

Bone: An Acute Buffer of Plasma Sodium during Exhaustive Exercise?

Both hyponatremia and osteopenia separately have been well documented in endurance athletes. Although bone has been shown to act as a “sodium reservoir” to buffer severe plasma sodium derangements in animals, recent data have suggested a similar function in humans. We aimed to explore if acute changes in bone mineral content were associated with changes in plasma sodium concentration in runners participating in a 161 km mountain footrace. Eighteen runners were recruited. Runners were tested immediately pre- and post-race for the following main outcome measures: bone mineral content (BMC) and density (BMD) via dual-energy X-ray absorptiometry (DEXA); plasma sodium concentration ([Na+]p), plasma arginine vasopressin ([AVP]p), serum aldosterone concentration ([aldosterone]s), and total sodium intake. Six subjects finished the race in a mean time of 27.0±2.3 h. All subjects started and finished the race with [Na+]p within the normal range (137.7±2.3 and 136.7±1.6 mEq/l, pre- and post-race, respectively). Positive correlations were noted between change (Δ; post-race minus pre-race) in total BMC (grams) and [Na+]p (mEq/l) (r=0.99;

Multi-camera Realtime 3D Tracking of Multiple Flying Animals

Automated tracking of animal movement allows analyses that would not otherwise be possible by providing great quantities of data. The additional capability of tracking in realtime - with minimal latency - opens up the experimental possibility of manipulating sensory feedback, thus allowing detailed explorations of the neural basis for control of behavior. Here we describe a new system capable of tracking the position and body orientation of animals such as flies and birds. The system operates with less than 40 msec latency and can track multiple animals simultaneously. To achieve these results, a multi target tracking algorithm was developed based on the Extended Kalman Filter and the Nearest Neighbor Standard Filter data association algorithm. In one implementation, an eleven camera system is capable of tracking three flies simultaneously at 60 frames per second using a gigabit network of nine standard Intel Pentium 4 and Core 2 Duo computers. This manuscript presents the rationale and details of the algorithms employed and shows three implementations of the system. An experiment was performed using the tracking system to measure the effect of visual contrast on the flight speed of Drosophila melanogaster. At low contrasts, speed is more variable and faster on average than at high contrasts. Thus, the system is already a useful tool to study the neurobiology and behavior of freely flying animals. If combined with other techniques, such as `virtual reality'-type computer graphics or genetic manipulation, the tracking system would offer a powerful new way to investigate the biology of flying animals.Comment: pdfTeX using libpoppler 3.141592-1.40.3-2.2 (Web2C 7.5.6), 18 pages with 9 figure

Moving out of the Margins: Mattering and the International Student Experience

Deeply personal challenges confront all new students when they arrive at their college or university. Some of their core questions include: “Are we part of things; do we belong; are we central or marginal? Do we make a difference; do others care about us and make us feel we matter?” (Schlossberg, 1989, p. 6). For international students who may be marginalized by race, ethnicity, nationality, socioeconomic background or language, these questions can be particularly painful. This article recommends a new foundation for working with international students: mattering. It provides a theoretical background for the constructs of marginalization and mattering, examines their relevancy in the context of the experiences of international students, and begins to define strategies for colleges and universities to make international students feel that they do indeed matter

A Study of the Actuarial Profession

The aim of this thesis is to educate the reader about the career of an actuary and will put into practice some of the rigorous mathematical applications that are used. There will also be an emphasis on the financial and business applications of the previous information, which encompasses the well roundedness of the profession. The actuarial profession is ranked one of the best in the country and rightfully so because of the skill and time it takes to perform it well. This thesis will guide the reader in understanding more clearly the high rank of the actuarial profession and the details of the statistical mathematics that are used