TECHNIQUE VARIABILITY OF PERFORMANCE ON ROTATIONAL AERIAL SKILLS IN GYMNASTICS

Elite performance is typically associated with a low level of technique variability over repeated performances. The purpose of this study was to test the variability of technique performance of an elite level gymnast performing two fundamental skills on the balance beam, salto backward, tucked (SBT) and front aerial walkover (FAW). Results showed that the gymnast was capable of performing both skills with consistency and minimal variability. Before one extrapolates this observation to all skilled performers and performances, a larger sample of athletes and skills should be tested

Comparison of bungee-aided and free-bouncing accelerations on trampoline

Trampolines remain the single best apparatus for the training of aerial acrobatics skills. Trampoline use has led to catastrophic injuries from poor landings. Passive injury prevention countermeasures such as specialized matting have been largely ineffective. Active injury countermeasures such as hand spotting, “throw-in” mats, and overhead spotting rigs provide the most effective methods. The recent addition of several bungee cords between the ropes and the gymnast’s spotting harness has resulted in altered teaching and coaching of trampoline-related acrobatics. Bungee cords have eliminated the need for a coach/spotter to manage the ropes during skill learning. The purpose of this study was to assess the influence of the addition of bungee cords with a traditional rope-based overhead spotting rig. There is a paucity of any research involving trampoline injury countermeasures. Ten experienced trampoline acrobatic athletes (5 males, 5 females) from the U.S. Ski and Snowboard Association Aerials National Team performed 10 bounces as high as they could control. A triaxial accelerometer (200 Hz) characterized 10 bungee cord aided bounces and 10 freebounces on a trampoline from each athlete. Bed contact times, peak accelerations, and average accelerations were obtained. The results supported our hypotheses that the bungeeaided bounces achieved only 40% (average) to 70% (peak) of the free-bouncing accelerations (all ρ 0.092). The bed contact time was approximately 65% longer during the bungee-aided bounces (ρ < 0.001). Bungee cords may reduce the harshness of landings on trampoline

Study on normal and otosclerotic bone cell cultures: an advance in understanding the pathogenesis of otosclerosis

The authors first reviewed the main theories concerning the pathogenesis of otosclerosis and studied the morphologic and functional characteristics of cell cultures derived from normal and otosclerotic bones. Light transmission and scanning electron microscopy did not permit definite identification of the cultured cells as predominantly osteoblasts, nor did these techniques show significant differences between cultured cells derived from normal and pathologic bone. Functional tests of the cell cultures proved more interesting. First, the bony nature of the cultured cells was demonstrated by studying the intracellular 45Ca++ uptake after stimulation with calcitonin and dybutryl-cAMP. Second, cell cultures derived from otosclerotic bone behaved differently from those derived from normal bone. Their peak uptake of calcium appeared later, and post-stimulatory values were higher, suggesting that cells derived from otosclerotic bone store a greater quantity of 45Ca++. Furthermore, after stimulation with calcitonin and propranolol, we observed an inhibition of the calcium uptake and decreased intracellular cAMP levels in normal bone cell cultures. In contrast, the cell cultures derived from otosclerotic bone exhibited an initial inhibition of calcium absorption followed by massive calcium penetration. The response of adenylate cyclase to the action of Mg++, Ca++, and F− ions was evaluated in cultures derived from normal bone, otosclerotic bone, and normal skin fibroblasts. The resulting data show that activation due to Mg++ is much lower in cultured cells derived from otosclerotic bone than in those from either normal bone or skin fibroblasts. No significant differences were found after Ca++ inhibition in any of the cell cultures. Moreover, in cell cultures derived from normal bone, F− ions induced a strong activation that was lower than the levels observed in cultures of otosclerotic bone or in normal fibroblasts. We hypothesize that an alteration at the calcitonin receptor site is responsible for the difference in calcium uptake and cAMP levels observed in the cells derived from otosclerotic bone as compared to those cultured from normal cells

Chronicle of a death foretold. It is time for echocardiographic screening in young athletes

Abstract Background The novel "Chronicle of a death foretold" by Gabriel Garcia Marquez is a story of a sudden death which could have been prevented. In 1976, within the University of Maryland basketball program and only 8 weeks apart, two athletes died suddenly during physical exertion. They were affected by hypertrophic cardiomyopathy and Marfan syndrome and in both cases an echocardiogram would have prevented the tragic epilogue. This coincidence drew everyone's attention and experts' interest on sudden death in sports. Methods and results Even in recent Italian history, unexpected deaths continue to affect athletes but surprisingly any real knowledge regarding the numbers and the impact of those tragedies must take medical literature and non-medical press into consideration. Herein we report the clinical case of a 13-year-old patient with a bicuspid aortic valve, whose mother was alarmed by the news of a young boy who died because of an anomalous origin of coronary artery (AOCA) which had not been diagnosed at transthoracic echocardiography (TTE). Her obstinacy induced the physicians to repeat TTE and led to the same diagnosis in her son: actually, his right coronary artery originated from the opposite sinus of Valsalva. The suspicion was confirmed by coronary CT scan and, thanks to appropriate therapy, the boy now fares well. Conclusions AOCA is the second most common cause of sudden death in young athletes. Although AOCA is often undetectable at ECG, TTE increases sensitivity of preparticipation screening. It could therefore allow us to avoid such coincidences and prevent sudden juvenile death

Patent foramen ovale and ischemic stroke: more shadows than lights? What the internist should know

The foramen ovale (FO) is an anatomical structure normally present in the fetus, which can persist in up to 25%-30% of the general population after birth. Normally it does not cause any harm but it has been associated with different pathological conditions; the more frequently encountered in clinical practice is an ischemic stroke or transient ischemic attack without any recognizable cause. However, a causal link between the cerebrovascular event and a right to left shunt through the FO is hard to demonstrate in most cases and which is the best treatment for secondary prevention is still a matter of debate with antithrombotic therapy or transcatheter closure of the FO as possible options. No definitive evidence of which is the most effective treatment is actually available so that a careful evaluation of each single patient is mandatory in order to select who will probably benefit the most from the interventional treatment as opposed to who will reasonably do well with medical therapy alone

Data-Driven Energy Storage Scheduling to Minimise Peak Demand on Distribution Systems with PV Generation

The growing adoption of decentralised renewable energy generation (such as solar photovoltaic panels and wind turbines) and low-carbon technologies will increase the strain experienced by the distribution networks in the near future. In such a scenario, energy storage is becoming a key alternative to traditional expensive reinforcements to network infrastructure, due to its flexibility, decreasing costs and fast deployment capabilities. In this work, an end-to-end data-driven solution to optimally design the control of a battery unit with the aim of reducing the peak electricity demand is presented. The proposed solution uses state-of-the-art machine learning methods for forecasting electricity demand and PV generation, combined with an optimisation strategy to maximise the use of photovoltaic energy to charge the energy storage unit. To this end, historical demand, weather, and solar energy generation data collected at the Stentaway Primary substation near Plymouth, UK, and at other six locations were employed

Hot water epilepsy and Mccune–Albright syndrome: A case report

AbstractWe observed a 15-year-old Caucasian boy with a rare form of reflex epilepsy, known as hot water epilepsy (HWE), associated to McCune–Albright syndrome (MAS). This is a rare disease due to post-zygotic and somatic mutations of the Gs-alpha gene, that results in cellular mosaicism. Predominant features of MAS occur in the bony skeleton, the skin, the endocrine system, and, in atypical presentations, in other non-endocrine tissues. It is unknown whether or not an expression of the GNAS1 product in the brain does exist. Although the association of MAS with HWE in our patient may be merely casual, it brings up the possibility that the striking phenotypic variability of MAS might also include epilepsy

A Feasibility Study of Energy Production

This report presents the opportunity for the Ithaca Area Wastewater Treatment Facility (IAWWTF) to maximize its revenue by utilizing the potential of existing Combined Heat and Power (CHP) turbines and exploring other energy sources and their possible implementations. The report also analyzes four different scenarios to maximize revenues for the plant by increasing the capacity of CHP turbines and adding other alternative sources of energy, such as biodiesel, solar photovoltaic and hydro-turbines. This feasibility study is intended for the use of the IAWWTF and professionals interested in producing electricity and heat in a more environmentally friendly way. We hope that our study will help the IAWWTF and the Ithaca communities to reduce their CO2 footprints