WorldWideScience

Sample records for ski nights join

  1. The Effect of 12 Weeks of Ski Training on Some Biometric Features of Girls

    Science.gov (United States)

    Tas, Murat; Kiyici, Elif; Kiyci, Fatih

    2018-01-01

    The aim of this study was to investigate the effect of skiing on the biomotoric characteristics of children with evaluating tests of girls between the ages of eight and 14 before and after the season. The experimental group of this study was 15 girls who had just started skiing and the control group of 30 girls. In total, 45 volunteers joined the…

  2. Ski jumping takeoff in a wind tunnel with skis.

    Science.gov (United States)

    Virmavirta, Mikko; Kivekäs, Juha; Komi, Paavo

    2011-11-01

    The effect of skis on the force-time characteristics of the simulated ski jumping takeoff was examined in a wind tunnel. Takeoff forces were recorded with a force plate installed under the tunnel floor. Signals from the front and rear parts of the force plate were collected separately to examine the anteroposterior balance of the jumpers during the takeoff. Two ski jumpers performed simulated takeoffs, first without skis in nonwind conditions and in various wind conditions. Thereafter, the same experiments were repeated with skis. The jumpers were able to perform very natural takeoff actions (similar to the actual takeoff) with skis in wind tunnel. According to the subjective feeling of the jumpers, the simulated ski jumping takeoff with skis was even easier to perform than the earlier trials without skis. Skis did not much influence the force levels produced during the takeoff but they still changed the force distribution under the feet. Contribution of the forces produced under the rear part of the feet was emphasized probably because the strong dorsiflexion is needed for lifting the skis to the proper flight position. The results presented in this experiment emphasize that research on ski jumping takeoff can be advanced by using wind tunnels.

  3. SKI's research strategy

    International Nuclear Information System (INIS)

    2002-01-01

    SKI's research is a prerequisite for SKI's ability to fulfil its assignment. Research to support supervision is focused today on a number of strategically important areas such as reactor technology, material and fuel questions, human factors, waste and non-proliferation (safeguards). SKI's intelligence analysis shows that this focus should be maintained over the next few years. Some reallocation of priorities between research areas may be necessary due to changes in the nuclear area. For this research, SKI contracts universities as well as consulting companies. The resources that are of importance for nuclear research are concentrated to a few organisations in Sweden. But the national research resources alone do not cover the existing needs. One reason is that the previously highly competent and well funded Swedish expert organisations within the nuclear power utilities have gradually been phased out or transformed into consulting firms. Changes have also taken place at the Swedish vendor of boiling-water plants, now Westinghouse Atom, and the activities have been down sized considerably in Sweden. There has been a similar trend in other countries. Moreover, countries which previously conducted expensive experiments have themselves increasingly sought international support as their research resources have dwindled. As a result, numerous international projects have or are planned to be started. SKI notes that Swedish nuclear activities are also becoming increasingly dependent on international collaboration. SKI further notes that in order to fulfil its assignment, the Inspectorate needs not only financial resources but also competent personnel. This enables targeted support to be maintained to strategic national infrastructure and to international cooperation including internationally financed projects. With this is meant above all experimental research where small countries such as Sweden can join forces with other countries on to important research information at

  4. Skiing trends

    Science.gov (United States)

    Charles R. Goeldner; Stacy Standley

    1980-01-01

    A brief historical overview of skiing is presented, followed by a review of factors such as energy, population trends, income, sex, occupation and attitudes which affect the future of skiing. A. C. Neilson's Sports Participation Surveys show that skiing is the second fastest growing sport in the country. Skiing Magazine's study indicates there are...

  5. Ski Club

    CERN Multimedia

    Ski Club

    2012-01-01

    René Oberli, un très bon ami et un des membres importants des débuts du Ski Club CERN est décédé à Noël 2011. Membre co-fondateur du Ski Club CERN en 1963, René Oberli a été 13 ans au comité dont 11 ans en tant que président. Grace à son action, le Ski Club a pris de l’ampleur, et était devenu un club actif et familial, proposant des cours de ski pour enfants et adultes, des week-ends de ski, des randonnées pédestres en été. René était aussi un moniteur de ski très apprécié et a enseigné le ski pendant de longues années. Nous nous souviendrons de sa grande compétence, de sa gentillesse, de sa bonne humeur et de son enthousiasme.  

  6. Biomechanical aspects of new techniques in alpine skiing and ski-jumping.

    Science.gov (United States)

    Müller, Erich; Schwameder, Hermann

    2003-09-01

    There have been considerable changes in equipment design and movement patterns in the past few years both in alpine skiing and ski-jumping. These developments have been matched by methods of analysing movements in field conditions. They have yielded new insights into the skills of these specific winter sports. Analytical techniques have included electromyography, kinetic and kinematic methods and computer simulations. Our aim here is to review biomechanical research in alpine skiing and ski-jumping. We present in detail the techniques currently used in alpine skiing (carving technique) and ski-jumping (V-technique), primarily using data from the authors' own research. Finally, we present a summary of the most important results in biomechanical research both in alpine skiing and ski-jumping. This includes an analysis of specific conditions in alpine skiing (type of turn, terrain, snow, speed, etc.) and the effects of equipment, materials and individual-specific abilities on performance, safety and joint loading in ski-jumping.

  7. Materials, Designs and Standards Used in Ski-Boots for Alpine Skiing

    Directory of Open Access Journals (Sweden)

    Matteo Moncalero

    2013-10-01

    Full Text Available This review article reports the recent advances in the study, design and production of ski-boots for alpine skiing. An overview of the different designs and the materials used in ski-boot construction is provided giving particular emphasis to the effect of these parameters on the final performances and on the prevention of injuries. The use of specific materials for ski-boots dedicated to different disciplines (race skiing, mogul skiing, ski-mountaineering etc. has been correlated with the chemical and physical properties of the polymeric materials employed. A review of the scientific literature and the most interesting patents is also presented, correlating the results reported with the performances and industrial production of ski-boots. Suggestions for new studies and the use of advanced materials are also provided. A final section dedicated to the standards involved in ski-boot design completes this review article.

  8. Skiing research in Japan.

    Science.gov (United States)

    Watanabe, K

    1981-01-01

    Skiing and skiing techniques were introduced by the Austrians to Japanese soldiers in 1911. After that, skiing spread beyond the original purpose and recently produced the ski sciences. From a sports biomechanical aspect, the development of the study of ski jumping, alpine skiing, and the basic movement in skiing is introduced in this paper. One of the characteristic points of these studies in Japan was that the ski sciences were supported not only by biomechanists and physiologists, but also basically by physicists and engineers. The fundamental research and studies from divergent fields are supporting each other and being integrated into ski science.

  9. SKI's research strategy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    SKI's research is a prerequisite for SKI's ability to fulfil its assignment. Research to support supervision is focused today on a number of strategically important areas such as reactor technology, material and fuel questions, human factors, waste and non-proliferation (safeguards). SKI's intelligence analysis shows that this focus should be maintained over the next few years. Some reallocation of priorities between research areas may be necessary due to changes in the nuclear area. For this research, SKI contracts universities as well as consulting companies. The resources that are of importance for nuclear research are concentrated to a few organisations in Sweden. But the national research resources alone do not cover the existing needs. One reason is that the previously highly competent and well funded Swedish expert organisations within the nuclear power utilities have gradually been phased out or transformed into consulting firms. Changes have also taken place at the Swedish vendor of boiling-water plants, now Westinghouse Atom, and the activities have been down sized considerably in Sweden. There has been a similar trend in other countries. Moreover, countries which previously conducted expensive experiments have themselves increasingly sought international support as their research resources have dwindled. As a result, numerous international projects have or are planned to be started. SKI notes that Swedish nuclear activities are also becoming increasingly dependent on international collaboration. SKI further notes that in order to fulfil its assignment, the Inspectorate needs not only financial resources but also competent personnel. This enables targeted support to be maintained to strategic national infrastructure and to international cooperation including internationally financed projects. With this is meant above all experimental research where small countries such as Sweden can join forces with other countries on to important research

  10. Ski club

    CERN Multimedia

    Ski club

    2013-01-01

    Gym Comme chaque année, la première activité à reprendre du service au SKI Club du CERN est la gymnastique ; les cours reprendront le mardi 17 septembre prochain. Si vous voulez améliorer votre condition physique en vue de la prochaine saison de ski (alpin ou de fond, ou snowboard), venez participer à nos cours au CO La Golette à Meyrin. Vous pouvez déjà vous inscrire en vous rendant sur le site du Ski club : http://cern.ch/club-ski/.

  11. Physics and Skiing.

    Science.gov (United States)

    Swinson, Derek B.

    1992-01-01

    Presents examples of physics as applied to the sport of skiing. Examples examine the physics of sliding, unweighting, ski turning, wind resistance, the parabolic and circular motion of aerial skiers, and the aerial maneuvers of ski jumpers. (MDH)

  12. Ski club

    CERN Multimedia

    Ski club

    2013-01-01

    For it 50 anniversary the ski club CERN organise a conference the Wednesday 23th of January from 7:00 pm to  8:30 pm in the council room at CERN. The subject of the conference will be : « Approche scientifique du ski : de la perception à l’action… », by Nicolas Coulmy, responsible of the technical and scientific department of the French Federation of Ski.

  13. Ski club

    CERN Multimedia

    Ski club

    2015-01-01

    The ski season 2015-2016 is approaching! An information evening will take place: Thursday, November 5th, at 6.30 pm in the Salle de Pas Perdus (next to the Council Chamber) Online registration to the Ski Club activities will open the same evening at http://cern.ch/club-ski. Regular permanences will take place every Thursday starting with November 12th, at 6 pm in the 1st floor of Bld. 504 (Restaurant 2). All members can collect their Carte Neige from the 26th of November. New members and members who did not have a Carte Neige before must provide when signing up a medical certificate certifying that there are no medical restrictions for practicing ski activities (French legally correct formulation: certificat médical de "non-contre indication à la pratique du ski"). You can obtain one from your family doctor: certificates in English, French, Italian, German, Spanish are accepted. Please note that you are the only responsible for the validity of your medical certificate ...

  14. Telemark skiing injuries.

    Science.gov (United States)

    Tuggy, M L

    1996-09-01

    Telemark skiing has become increasingly popular over the past 5 years. Telemark skiing poses unique risks when compared to alpine skiing, because of different equipment, technique, and varied skiing environments. A retrospective survey of telemark skiers was conducted in Western Washington in 1994 to obtain skier information on ski habits, demographics, frequency and types of injury, and equipment used at time of injury. During the 5 month survey period, 118 (63%) of 187 surveys distributed at 7 sites were returned. The overall injury rate was comparable to alpine skiing injury rates at 10.7/1000 skier days. Less experienced skiers and women had higher injury rates, 20/1000 and 13.1/1000 skier days, respectively. The predominant injury sites were knee (41%), hip (13%), and thumb (8%). The knee injuries sustained by telemark skiers appear to be less severe than alpine skiers, with less duration of disability and lower surgical rates. An association was found between the use of plastic reinforced boots and significant ligamentous knee injuries when compared to skiers with leather boots (p < 0.01, chi 2 = 5.43).

  15. Ski Club

    CERN Document Server

    Ski Club

    2012-01-01

    The Ski Club CERN invites you to a Public Information Meeting Thursday, 8th November at 6:30 pm Filtration Plant (222/R–001) for the presentation of its activities during the season 2012/2013. After the presentation, the people responsible for the different sections will be available to answer your questions and to provide you with detailed information about our activities. Come and learn more about our club over a drink! For more information on our activities please have look at our web site: http://club-ski.web.cern.ch/club-ski/

  16. Ski Club

    CERN Multimedia

    Ski Club

    2011-01-01

    The Ski Club CERN invites you to a Public Information Meeting Thursday, 3rd November at 6:30 pm Council Chamber (503/1–001) for the presentation of its activities during the season 2011/2012. After the presentation, the people responsible for the different sections will be available to answer your questions and to provide you with detailed information about our activities. Come and learn more about our club over a drink! For more information on our activities please have look at our web site: http://club-ski.web.cern.ch/club-ski/

  17. [Fractures of the lower extremity in skiing - the influence of ski boots and injury pattern].

    Science.gov (United States)

    Bürkner, A; Simmen, H P

    2008-12-01

    Though the injury patterns of the lower extremities in skiing have changed since 1970, tibial fractures remain daily work of hospitals near ski slopes. A lot of medical studies have analysed the relevance of well adjusted bindings of the common lesions of the knee joint ligaments. However the influence of the flexibility of the ski boot and the injury pattern has been neglected. 49 tibial fractures have been analysed in a hospital near a large ski resort in the alpes. All fractures occurred during alpine skiing. The type of the fracture, according to the AO-classification and the injury pattern have been documented. Also demographic data, ski experience and specification concerning the ski boot have been questioned. The type of the ski boot and the grade of flexibility, have been documented if possible. It has also been recorded whether the binding opened. In contrast to other studies our patients are represented in widely spread age-groups with a large share of elderly and experienced persons. Young or unexperienced sportsmen suffer primarily from fractures of the tibial diaphysis. With increasing skiing experience the injury pattern is widening on the whole leg. 62 % of all fractures are caused by rotation traumas. Compression, dorsal forces and direct collisions are the other causes. In 59 % of all accidents the binding failed to open. There is an increased risk of complex fractures in the proximal or distal epiphysis if the binding has not opened. 23 % of all fractures occurred with rented ski boots. Only 16 % of all ski boots are labelled with a flexibility index. There is no standardized value for the flexibility of ski boots. The trend can be derived that rigid ski boots with a high flexibility index cause above all fractures of the diaphysis. 10 % of all fractures happened to patients wearing "snowblades". These short skis without safety bindings contributed a considerable share to tibial fractures, even though there is no big leverage. Tibial fractures are

  18. SKI`s Evaluation of SKB`s RD and D Programme 95. Review Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    SKI (the Swedish Nuclear Power Inspectorate) has sent SKB`s (the Swedish Nuclear Fuel and Waste Management Co.) RD and D Programme 95 to sixty authorities and organizations for review. 35 reviewing bodies have replied. In various ways, most of the comments are related to the decision-making process, both with regard to site selection and choice of method and only a small number of reviewing bodies have dealt with the more purely technical issues such as the function of the barriers and the safety assessment methodology. SKI`s review of the programme is based on the premises of establishing whether and how the programme can fulfill its actual purpose to identify and implement solutions for the final disposal of the spent nuclear fuel from the Swedish nuclear power plants. SKI`s statement to the Government includes a `Summary and Conclusions` of the `Review Report`. In (the present) `Review Report` SKI reviews the programme and deals with comments from the other reviewing bodies. Furthermore, SKI has commissioned a separate report with the `Comments of the Reviewing Bodies`. 32 refs.

  19. Characterisation of alpine skis

    OpenAIRE

    Wikerman, Fredrik

    2016-01-01

    Skiing is a fast and competitive sport where skiers must push their performance limit to win medals, the di↵erence can be within hundreds of a second. Therefore, technical improvements are essential for assisting in the skier’s improvement. This thesis project is a joint project between KTH and the Swedish Ski Association and Swedish Ski Team with the purpose of obtaining a better understanding of the structural properties of alpine skis, aiming to improve the individual selection process of ...

  20. Ski Club

    CERN Document Server

    Ski Club

    2013-01-01

    The registration for the ski season 2013-2014 is open. The standard permanences for the inscriptions will start: Thursday, November 14th at 6 pm CERN, Restaurant 2 (Bldg 504) (1st floor) Old members can collect their Carte neige from the 28th of november. New members and members who did not have a carte neige before must produce a medical certificate certifying that there are no medical reasons for which they should not be allowed to ski (french (legally correct) formulation : certificat médical de "non-contre indication à la pratique du ski"). You can obtain one from your family doctor.

  1. An Epidemiological Investigation of Skiing Injuries in Erciyes Ski Centre

    Directory of Open Access Journals (Sweden)

    Gökmen Özen

    2017-06-01

    Material and Methods: This research was conducted using data that were recorded in the Erciyes Ski Centre Injury Surveillance System from 2012 to 2016 by ski patrols. We calculated the number of skiers from sold lift cards and tickets. A total of 616 cases of skiing injuries were recorded over the four seasons. Results: The calculated injury rate was 2.6 per 1000 skiers in the period of 2012-2016. A total of 372 (60.4% patients were males and 244 were (39.6% females and their mean ages were 27.2 ± 9.8 (range 7-65 years. The most common mechanisms of injuries were falling (82.3 followed by collision (11.5%. Skiing injuries occurred mostly at the lower extremities (52.6%, followed by upper extremities (20.4%.The most frequently seen cases were contusions (59.7% and sprains (12.5%. Conclusion: The rate of injury was compatible with reference ranges (2-4‰ for Erciyes Ski Centre during all seasons. Injuries were seen mostly in adults. The most frequent injuries were at the lower extremities, which were falling-related and contusions. There were no substantial proportional changes in terms of the variables between the seasons.

  2. Myths concerning alpine skiing injuries.

    Science.gov (United States)

    Johnson, Robert J; Ettlinger, Carl F; Shealy, Jasper E

    2009-11-01

    There are many commonly discussed myths about ski safety that are propagated by industry, physicians, and skiers. Through a review of the literature concerning 12 such topics, this article demonstrates that the following are untrue: (1) Broken legs have been traded for blown-out knees. (2) If you know your DIN (a slang term for release indicator value), you can adjust your own bindings. (3) Toe and heel piece settings must be the same to function properly. (4) Formal ski instruction will make you safer. (5) Very short skis do not need release bindings. (6) Spending a lot of money on children's equipment is not worth the cost. (7) Children need plenty of room in ski boots for their growing feet. (8) If you think you are going to fall, just relax. (9) Exercise can prevent skiing injuries. (10) Lower release settings can reduce the risk of anterior cruciate ligament injury. (11) Buying new ski equipment is safer than renting. (12) Skiing is among the most dangerous of activities. It is important for the skiing public, physicians, and all those interested in improving skiing safety to verify the measures they advocate. The statements analyzed here are simply untrue and have the potential to cause harm if taken as fact by those exposed to these unsupported opinions.

  3. [Influence of ski boots on balance performance].

    Science.gov (United States)

    Mildner, E; Lembert, S; Raschner, C

    2010-03-01

    Modern ski carving technique demands that skiers have a strong sense of balance and edge their skis with precision and feeling. Stiff ski boots facilitate the transfer of power to the ski but increase the difficulty of balancing. The aim of this study was to analyse the influence of ski boots on balance performance of alpine skiers. 76 experienced skiers (female 33/male 43) and 76 ski racers of the Skigymnasium Stams (female 31/male 45) were tested on the MFT S 3 Check with and without ski boots. Ski boots significantly influenced balance. There were also significant differences between experienced skiers and ski racers, but gender differences were minimal. In addition to general conditioning, skiers should utilise general and ski-specific balance and sensomotor training which could help in ski injury prevention, especially knee injuries. Georg Thieme Verlag KG Stuttgart, New York.

  4. Do Maximal Roller Skiing Speed and Double Poling Performance Predict Youth Cross-Country Skiing Performance?

    Directory of Open Access Journals (Sweden)

    Roland Stöggl, Erich Müller, Thomas Stöggl

    2017-09-01

    Full Text Available The aims of the current study were to analyze whether specific roller skiing tests and cycle length are determinants of youth cross-country (XC skiing performance, and to evaluate sex specific differences by applying non-invasive diagnostics. Forty-nine young XC skiers (33 boys; 13.8 ± 0.6 yrs and 16 girls; 13.4 ± 0.9 yrs performed roller skiing tests consisting of both shorter (50 m and longer durations (575 m. Test results were correlated with on snow XC skiing performance (PXC based on 3 skating and 3 classical distance competitions (3 to 6 km. The main findings of the current study were: 1 Anthropometrics and maturity status were related to boys’, but not to girls’ PXC; 2 Significant moderate to acceptable correlations between girls’ and boys’ short duration maximal roller skiing speed (double poling, V2 skating, leg skating and PXC were found; 3 Boys’ PXC was best predicted by double poling test performance on flat and uphill, while girls’ performance was mainly predicted by uphill double poling test performance; 4 When controlling for maturity offset, boys’ PXC was still highly associated with the roller skiing tests. The use of simple non-invasive roller skiing tests for determination of PXC represents practicable support for ski clubs, schools or skiing federations in the guidance and evaluation of young talent.

  5. Effect of ski boot settings on tibio-femoral abduction and rotation during standing and simulated skiing.

    Science.gov (United States)

    Böhm, Harald; Senner, Veit

    2008-01-01

    Ski boots are designed to transfer high forces from the skier to the ski. For this purpose they are made of stiff materials and constrain the leg of the skier to an unnatural position. To overcome the problem of unnatural knee posture, the ski boots can be adjusted in the frontal plane as well as in the horizontal plane by the canting mechanism and the "v-position", respectively. Canting enables lateral and medial orientation of the shaft with respect to the base of the boot. The "v-position" is a pronounced outward rotation of the boot's base with respect to the ski's long axis. The purpose of this study is to investigate the effect of different foot rotations and ski boot canting settings on knee kinematics during standing and simulated skiing. Knee kinematics was measured by means of motion analysis and with the help of skin-mounted markers on 20 subjects. The ski boots in their standard settings significantly constrained the skier to an unnatural valgus position. Ski boot base rotation had a significant effect on internal external knee rotation, whereas canting had an effect on varus-valgus angles during standing. However, for the simulated skiing position no effects were observed. The study suggests that the constraints of the ski boots result in a clinically relevant valgus misalignment. Canting settings reduced the misalignment but only by about 10%. Increased ski boot canting settings would therefore be desirable. Knee kinematics showed that rotational misalignment could not be linked to any significant increase in injury risk.

  6. Semenic Mountains’ alpine skiing area

    Directory of Open Access Journals (Sweden)

    Petru BANIAȘ

    2017-03-01

    Full Text Available The present paper presents, after a short history of alpine skiing which describes apparition, necessity, utility and universality of skiing during time, a comparative study referring to the alpine skiing domain in the Semenic Mountains area. In the paper are also presented general notions about alpine skiing methodology together with an ample description of the plateau area form Semenic Mountains, describing localization and touristic potential. Based on the SWOT analysis made for each slope, was realized a complex analysis of the entire skiing domain, an analysis which includes technical, financial, climatic and environmental aspects, along with an analysis of the marketing policy applied for the specific zone.

  7. How Hinge Positioning in Cross-Country Ski Bindings Affect Exercise Efficiency, Cycle Characteristics and Muscle Coordination during Submaximal Roller Skiing

    Science.gov (United States)

    Bolger, Conor M.; Sandbakk, Øyvind; Ettema, Gertjan; Federolf, Peter

    2016-01-01

    The purposes of the current study were to 1) test if the hinge position in the binding of skating skis has an effect on gross efficiency or cycle characteristics and 2) investigate whether hinge positioning affects synergistic components of the muscle activation in six lower leg muscles. Eleven male skiers performed three 4-min sessions at moderate intensity while cross-country ski-skating and using a klapskate binding. Three different positions were tested for the binding’s hinge, ranging from the front of the first distal phalange to the metatarsal-phalangeal joint. Gross efficiency and cycle characteristics were determined, and the electromyographic (EMG) signals of six lower limb muscles were collected. EMG signals were wavelet transformed, normalized, joined into a multi-dimensional vector, and submitted to a principle component analysis (PCA). Our results did not reveal any changes to gross efficiency or cycle characteristics when altering the hinge position. However, our EMG analysis found small but significant effects of hinge positioning on muscle coordinative patterns (P skating klapskates. Finally, the within-subject results of the EMG analysis suggested that in addition to the between-subject effects, further forms of muscle coordination patterns appear to be employed by some, but not all participants. PMID:27203597

  8. [Sport today: ski acrobatics (author's transl)].

    Science.gov (United States)

    Steinbrück, K

    1978-03-17

    Stunt skiing is popular. It includes three disciplines: ski ballet, "hot dog" or "rough track" skiing and jumping. An extensive series of investigations showed that for well-trained professionals with suitable equipment and good outdoor conditions, the danger of injury is only slightly higher compared with normal skiing. Practising ballet figures considerably improves the stability of the good all-round skier.

  9. Dynamics of human flight on skis: improvements in safety and fairness in ski jumping.

    Science.gov (United States)

    Müller, W; Platzer, D; Schmölzer, B

    1996-08-01

    This study of ski jumping includes three areas of research: Wind tunnel measurements with world class athletes in various flight positions, field measurements during the World Championships in Ski Flying 1994 in Planica (Slovenia) and a highly reliable mapping of ski jumping to a computable simulation model. The results explain the effects of equipment, flight style changes, the reason for the enhanced tumbling risk and high gust sensitivity observed. Consequences can be drawn for changes to the FIS regulations, the design of jumping hills and training methods. The internationally induced anorexia of the athletes could be prohibited by a new ski length regulation. Women jumpers could become a real competitive threat.

  10. Biomechanical comparison of the double-push technique and the conventional skate skiing technique in cross-country sprint skiing.

    Science.gov (United States)

    Stöggl, Thomas; Müller, Erich; Lindinger, Stefan

    2008-09-01

    The aims of the study were to: (1) adapt the "double-push" technique from inline skating to cross-country skiing; (2) compare this new skiing technique with the conventional skate skiing cross-country technique; and (3) test the hypothesis that the double-push technique improves skiing speed in a short sprint. 13 elite skiers performed maximum-speed sprints over 100 m using the double-push skate skiing technique and using the conventional "V2" skate skiing technique. Pole and plantar forces, knee angle, cycle characteristics, and electromyography of nine lower body muscles were analysed. We found that the double-push technique could be successfully transferred to cross-country skiing, and that this new technique is faster than the conventional skate skiing technique. The double-push technique was 2.9 +/- 2.2% faster (P push technique had a longer cycle length and a lower cycle rate, and it was characterized by higher muscle activity, higher knee extension amplitudes and velocities, and higher peak foot forces, especially in the first phase of the push-off. Also, the foot was more loaded laterally in the double-push technique than in the conventional skate skiing technique.

  11. Downhill Skiing Injuries.

    Science.gov (United States)

    McKay, D H

    1981-01-01

    In brief: Lower extremity injuries are common in downhill skiing. Fifty-three percent of the skiing injuries in one study, and 81% in another, were below the knee. Twelve case reports are presented and their treatment is discussed. The author suggests that skiers undertake a physical fitness program to increase stamina and elasticity of muscles and ligaments.

  12. ANALYSIS OF DESIGN ELEMENTS IN SKI SUITS

    Directory of Open Access Journals (Sweden)

    Birsen Çileroğlu

    2014-06-01

    Full Text Available Popularity of Ski Sport in 19th century necessitated a new perspective on protective skiing clothing ag ainst the mountain climates and excessive cold. Winter clothing were the basis of ski attire during this period. By the beginning of 20th century lining cloth were used to minimize the wind effect. The difference between the men and women’s ski attire of the time consisted of a knee - length skirts worn over the golf trousers. Subsequent to the First World War, skiing suit models were influenced by the period uniforms and the producers reflected the fashion trends to the ski clothing. In conformance with th e prevailing trends, ski trousers were designed and produced for the women thus leading to reduction in gender differences. Increases in the ski tourism and holding of the first winter olympics in 1924 resulted in variations in ski attires, development of design characteristics, growth in user numbers, and enlargement of production capacities. Designers emphasized in their collections combined presence of elegance and practicality in the skiing attire. In 1930s, the ski suits influenced by pilots’ uniforms included characteristics permitting freedom of motion, and the design elements exhibited changes in terms of style, material and aerodynamics. In time, the ski attires showed varying design features distinguishing professionals from the amateurs. While protective functionality was primary consideration for the amateurs, for professionals the aerodynamic design was also a leading factor. Eventually, the increased differences in design characteristics were exhibited in ski suit collections, World reknown brands were formed, production and sales volumes showed significant rise. During 20th century the ski suits influenced by fashion trends to acquire unique styles reached a position of dominance to impact current fashion trends, and apart from sports attir es they became a style determinant in the clothing of cold climates. Ski suits

  13. Particle-based model for skiing traffic.

    Science.gov (United States)

    Holleczek, Thomas; Tröster, Gerhard

    2012-05-01

    We develop and investigate a particle-based model for ski slope traffic. Skiers are modeled as particles with a mass that are exposed to social and physical forces, which define the riding behavior of skiers during their descents on ski slopes. We also report position and speed data of 21 skiers recorded with GPS-equipped cell phones on two ski slopes. A comparison of these data with the trajectories resulting from computer simulations of our model shows a good correspondence. A study of the relationship among the density, speed, and flow of skiers reveals that congestion does not occur even with arrival rates of skiers exceeding the maximum ski lift capacity. In a sensitivity analysis, we identify the kinetic friction coefficient of skis on snow, the skier mass, the range of repelling social forces, and the arrival rate of skiers as the crucial parameters influencing the simulation results. Our model allows for the prediction of speed zones and skier densities on ski slopes, which is important in the prevention of skiing accidents.

  14. [Development of Achilles tendon rupture in skiing].

    Science.gov (United States)

    Suckert, K; Benedetto, K P; Vogel, A

    1983-06-01

    This is an analysis of decline of rupture of the Achilles tendon in skiing while there is a steady increase of skiing injuries. Three groups, equipped with three different types of ski boots were observed once on a plane slope on the other hand on a bump track. The simultaneous size of angle of knee and ankle was measured by telemetry. The high plastic ski boot, which obstructs the ankle forward and lateral is apart from the rise of heel in the boot, the safety binding and the new skiing style the main reason for decline of rupture of the Achilles tendon in skiing.

  15. How Hinge Positioning in Cross-Country Ski Bindings Affect Exercise Efficiency, Cycle Characteristics and Muscle Coordination during Submaximal Roller Skiing.

    Directory of Open Access Journals (Sweden)

    Conor M Bolger

    Full Text Available The purposes of the current study were to 1 test if the hinge position in the binding of skating skis has an effect on gross efficiency or cycle characteristics and 2 investigate whether hinge positioning affects synergistic components of the muscle activation in six lower leg muscles. Eleven male skiers performed three 4-min sessions at moderate intensity while cross-country ski-skating and using a klapskate binding. Three different positions were tested for the binding's hinge, ranging from the front of the first distal phalange to the metatarsal-phalangeal joint. Gross efficiency and cycle characteristics were determined, and the electromyographic (EMG signals of six lower limb muscles were collected. EMG signals were wavelet transformed, normalized, joined into a multi-dimensional vector, and submitted to a principle component analysis (PCA. Our results did not reveal any changes to gross efficiency or cycle characteristics when altering the hinge position. However, our EMG analysis found small but significant effects of hinge positioning on muscle coordinative patterns (P < 0.05. The changed patterns in muscle activation are in alignment with previously described mechanisms that explain the effects of hinge positioning in speed-skating klapskates. Finally, the within-subject results of the EMG analysis suggested that in addition to the between-subject effects, further forms of muscle coordination patterns appear to be employed by some, but not all participants.

  16. METHODICAL MODEL FOR TEACHING BASIC SKI TURN

    Directory of Open Access Journals (Sweden)

    Danijela Kuna

    2013-07-01

    Full Text Available With the aim of forming an expert model of the most important operators for basic ski turn teaching in ski schools, an experiment was conducted on a sample of 20 ski experts from different countries (Croatia, Bosnia and Herzegovina and Slovenia. From the group of the most commonly used operators for teaching basic ski turn the experts picked the 6 most important: uphill turn and jumping into snowplough, basic turn with hand sideways, basic turn with clapping, ski poles in front, ski poles on neck, uphill turn with active ski guiding. Afterwards, ranking and selection of the most efficient operators was carried out. Due to the set aim of research, a Chi square test was used, as well as the differences between frequencies of chosen operators, differences between values of the most important operators and differences between experts due to their nationality. Statistically significant differences were noticed between frequencies of chosen operators (c2= 24.61; p=0.01, while differences between values of the most important operators were not obvious (c2= 1.94; p=0.91. Meanwhile, the differences between experts concerning thier nationality were only noticeable in the expert evaluation of ski poles on neck operator (c2=7.83; p=0.02. Results of current research are reflected in obtaining useful information about methodological priciples of learning basic ski turn organization in ski schools.

  17. Nordic (cross-country) skiing injuries in Australia.

    Science.gov (United States)

    Sherry, E; Asquith, J

    1987-03-02

    A retrospective study of 88 nordic skiing injuries from the 1984 and 1985 skiing seasons in Australia is presented. To our knowledge, this is the largest study to date of such injuries. These injuries are compared with alpine skiing injuries from the same medical clinic for the 1985 skiing season. There was a much lower incidence of injury from nordic skiing; however, when injuries did occur, they tended to be more serious than those of alpine skiing and frequently required immediate evacuation to hospital for treatment. As the nordic skier is relatively isolated from medical services, these findings need to be considered in the future planning of rescue services for such skiers.

  18. ANALYSIS OF DESIGN ELEMENTS IN SKI SUITS

    OpenAIRE

    Çileroğlu, Birsen; Kelleci Özeren, Figen; Kıvılcımlar, İnci Seda

    2015-01-01

    Popularity of Ski Sport in 19th century necessitated a new perspective on protective skiing clothing against the mountain climates and excessive cold. Winter clothing were the basis of ski attire during this period.  By the beginning of 20th century lining cloth were used to minimize the wind effect. The difference between the men and women’s ski attire of the time consisted of a knee-length skirts worn over the golf trousers.  Subsequent to the First World War, skiing suit models were influe...

  19. Psychological factors of performance in ski jumping : a quantitative study of World Cup ski jumpers

    OpenAIRE

    Sklett, Vegard Haukø

    2017-01-01

    Purpose – The present study investigated the relationship between psychological factors (self-efficacy, flow, positive- and negative affect, worry) and ski jumping performance, as well as the influential functions these psychological factors have on ski jumping performance. Method – World Cup ski jumpers (N = 40) responded to four questionnaires in the middle of the World Cup season, reporting their subjective experience during a competitive setting. Social Cognitive Theory (SCT) (Bandura...

  20. Epistolary testimony of filial love (Zygmunt Krasiński – Wincenty Krasiński [Epistolarne świadectwa miłości synowskiej (Zygmunt Krasiński – Wincenty Krasiński

    Directory of Open Access Journals (Sweden)

    Henryk GRADKOWSKI

    2017-11-01

    Full Text Available The article discusses the motif of filial love of distinctive romantic poet, the author of Nie-Boska Komedia, Zygmunt Krasiński. The unusual fascination by the paternal will mainly shown in letters written by the son to his father, as Zygmunt Krasiński spent most of his life abroad and from there he maintained a continuous correspondence with his father, general Wincenty Krasiński, the deputy and then the chief warden of the Polish Kingdom. The poet’s father, the former Napoleonic general, chose the service for the new leader – the Russian tsar. That was something irreconcilable for the feeble son who kept using the services of bathing sanatoria and maintained epistolary discussion with the beloved father. The ideological conflict usually concluded in admitting the righteousness to the “beloved daddy” in particular matters. That, however, caused real ethical dilemmas for the sensitive condescending youth. The unusually rich correspondence of Zygmunt Krasiński is undoubtedly a precious contribution to nineteenth century thought, and also into family and existential aspects of the two uncommon men – Zygmunt and Wincenty Krasiński.

  1. 50 CFR 27.33 - Water skiing.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Water skiing. 27.33 Section 27.33 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM PROHIBITED ACTS Disturbing Violations: With Vehicles § 27.33 Water skiing. When water skiing is permitted upon national wildlife refuge waters, the public will be notified under...

  2. Morphologic analysis of the SKI preparedness

    International Nuclear Information System (INIS)

    Stenstroem, Maria

    2003-08-01

    The Swedish Nuclear Power Inspectorate (SKI) is an independent government agency responsible for technical assessments and information concerning accidents involving nuclear facilities at home and abroad. With the events of September 11 in New York and Washington D.C., circumstances have also changed for Swedish government agencies. Increased focus had been placed on a broadened threat spectrum, especially as concerns terrorism and the use of non-conventional weapons and methods. This means that SKI must develop adequate preparedness for new types of threats and events. What types of threats, and how SKI's preparedness planning should be developed, are questions which were addressed in a study by a working group from SKI and FOI -the Swedish National Defence Research Agency. The purpose of the study was to identify serious threats and events, which would require SKI's involvement, and to analyze what resources and competencies would by needed in order for SKI to fulfill it responsibilities. Investigating a broadened threat spectrum involves defining and analyzing a multi-dimensional problem complex, which is both difficult to quantify and involves very complicated internal relationships. Morphological analysis is a method for structuring and analyzing such problem complexes, and for developing models based on natural language concepts. The working group developed and studied ten different scenarios, which defined the parameter space for a broadened threat spectrum for SKI. On the basis of these scenarios, a morphological model was developed which describes the demands that these scenarios place on SKI as an organization. On the basis of this, a further morphological model was developed, in order to systematically dimension the resources that would be needed in the face of these demands. Through this analysis, a clearer picture of the demands and required resources for future threats has emerged. The information and insights generated will serve to better develop

  3. [Changes in stress to the knee joint in skiing from a medical viewpoint with special reference to the modern ski shoe and the skiing technic].

    Science.gov (United States)

    Hörterer, H

    1982-01-21

    The changed skiing-technique with more knee flexion (so called jet-position) has lead to rising pressures in the femoro-patellar joint. The danger of traumatic and arthritic diseases has increased as well. We suggest to avoid extreme anteflexed crural position in the ski-boots (more than 5 degrees). It should be possible to walk and stand in ski-boots without pressure on the knee-joint. This problem is most important in the growing locomotor system.

  4. The Russians Are the Fastest in Marathon Cross-Country Skiing: The “Engadin Ski Marathon”

    Directory of Open Access Journals (Sweden)

    Pantelis Theodoros Nikolaidis

    2017-01-01

    Full Text Available It is well known that athletes from a specific region or country are dominating certain sports disciplines such as marathon running or Ironman triathlon; however, little relevant information exists on cross-country skiing. Therefore, the aim of the present study was to investigate the aspect of region and nationality in one of the largest cross-country skiing marathons in Europe, the “Engadin Ski Marathon.” All athletes (n=197,125 who finished the “Engadin Ski Marathon” between 1998 and 2016 were considered. More than two-thirds of the finishers (72.5% in women and 69.6% in men were Swiss skiers, followed by German, Italian, and French athletes in both sexes. Most of the Swiss finishers were from Canton of Zurich (20.5%, Grisons (19.2%, and Berne (10.3%. Regarding performance, the Russians were the fastest and the British the slowest. Considering local athletes, finishers from Canton of Uri and Glarus were the fastest and those from Canton of Geneva and Basel the slowest. Based on the findings of the present study, it was concluded that local athletes were not the fastest in the “Engadin Ski Marathon.” Future studies need to investigate other cross-country skiing races in order to find the nationalities and regions of the fastest cross-country skiers.

  5. Snowboarding and ski boarding injuries in Niigata, Japan.

    Science.gov (United States)

    Sakamoto, Yuko; Sakuraba, Keishoku

    2008-05-01

    The purpose of this study was to compare the injury patterns and incidence of snowboarding and ski boarding injuries with that of alpine skiing in 2000 to 2005, as there are few previous studies comparing these 3 sports, especially in Asia. The injury patterns are different among the 3 snow sports. Descriptive epidemiology study. The subjects were alpine skiers (1240 cases), snowboarders (2220 cases), and ski boarders (132 cases) who were injured in 2 ski resorts located in Niigata prefecture in Japan and visited the authors' clinics in these ski resorts between 2000 and 2005. On visiting the clinics, patients completed a questionnaire reviewing the circumstances surrounding the injury event, and physicians documented the diagnosis. The injury rate, which was based on all purchased lift tickets, in snowboarding decreased gradually, although it was still 2 times higher than that of alpine skiing. Snowboarding and ski boarding had a higher fracture and dislocation rate. Both sports also had a 4 times higher rate of injuries because of jumping. The characteristics of ski boarding were a lower head and neck injury rate and collision injury rate than those of the other 2 snow sports, as well as a 2 times higher rate of fractures compared with alpine skiing injuries and a 1.4 times higher incidence than that of snowboarding injuries. Of the fractures caused by ski boarding accidents, 39.6% affected the lower leg bones. Injury prevention strategies should focus on jumps for snowboarders and ski boarders.

  6. Snow management practices in French ski resorts

    Science.gov (United States)

    Spandre, Pierre; Francois, Hugues; George-Marcelpoil, Emmanuelle; Morin, Samuel

    2016-04-01

    Winter tourism plays a fundamental role in the economy of French mountain regions but also in other countries such as Austria, USA or Canada. Ski operators originally developed grooming methods to provide comfortable and safe skiing conditions. The interannual variability of snow conditions and the competition with international destinations and alternative tourism activities encouraged ski resorts to mitigate their dependency to weather conditions through snowmaking facilities. However some regions may not be able to produce machine made snow due to inadequate conditions and low altitude resorts are still negatively impacted by low snow seasons. In the meantime, even though the operations of high altitude resorts do not show any dependency to the snow conditions they invest in snowmaking facilities. Such developments of snowmaking facilities may be related to a confused and contradictory perception of climate change resulting in individualistic evolutions of snowmaking facilities, also depending on ski resorts main features such as their altitude and size. Concurrently with the expansion of snowmaking facilities, a large range of indicators have been used to discuss the vulnerability of ski resorts such as the so-called "100 days rule" which was widely used with specific thresholds (i.e. minimum snow depth, dates) and constraints (i.e. snowmaking capacity). The present study aims to provide a detailed description of snow management practices and major priorities in French ski resorts with respect to their characteristics. We set up a survey in autumn 2014, collecting data from 56 French ski operators. We identify the priorities of ski operators and describe their snowmaking and grooming practices and facilities. The operators also provided their perception of the ski resort vulnerability to snow and economic challenges which we could compare with the actual snow conditions and ski lift tickets sales during the period from 2001 to 2012.

  7. Determinants of a simulated cross-country skiing sprint competition using V2 skating technique on roller skis.

    Science.gov (United States)

    Mikkola, Jussi; Laaksonen, Marko; Holmberg, Hans-Christer; Vesterinen, Ville; Nummela, Ari

    2010-04-01

    The present study investigated the performance-predicting factors of a simulated cross-country (XC) skiing sprint competition on roller skis, on a slow surface. Sixteen elite male XC skiers performed a simulated sprint competition (4 x 850 m heat with a 20-minute recovery) using V2 skating technique on an indoor tartan track. Heat velocities, oxygen consumption, and peak lactate were measured during or after the heats. Maximal skiing velocity was measured by performing a 30-m speed test. Explosive and maximal force production in the upper body was determined by bench press (BP). Subjects also performed maximal anaerobic skiing test (MAST) and the 2 x 2-km double poling (DP) test. The maximal velocity of MAST (VMAST) and velocities at 3 (V3), 5 (V5), 7 (V7) mmol.L lactate levels in MAST were determined. In the 2 x 2-km test, DP economy (VO2SUBDP) and maximal 2-km DP velocity (VDP2KM) were determined. The best single performance-predicting factors for the sprint performance were VDP2KM (r = 0.73, p < 0.01), V7 (r = 0.70, p < 0.01), and VO2SUBDP (r = -0.70, p < 0.01). Faster skiers in sprint simulation had a higher absolute VO2 (L.min) (p < 0.05-0.01) during sprint heats, and higher anaerobic skiing power (VMAST, p < 0.05) and better anaerobic skiing economy (V3, V5, V7, p < 0.05-0.001) than slower skiers. Faster skiers were also stronger in BP, with regard to both absolute (p < 0.01) and relative (p < 0.05) values. In addition, anaerobic characteristics seem to be of importance at the beginning of the XC skiing sprint competition, whereas the aerobic characteristics become more important as the XC skiing sprint competition progressed. This study indicates that sprint skiers should emphasize sport-specific upper body training, and training skiing economy at high speeds.

  8. Crossing physical simulations of snow conditions and a geographic model of ski area to assess ski resorts vulnerability

    Science.gov (United States)

    François, Hugues; Spandre, Pierre; Morin, Samuel; George-Marcelpoil, Emmanuelle; Lafaysse, Matthieu; Lejeune, Yves

    2016-04-01

    In order to face climate change, meteorological variability and the recurrent lack of natural snow on the ground, ski resorts adaptation often rely on technical responses. Indeed, since the occurrence of episodes with insufficient snowfalls in the early 1990's, snowmaking has become an ordinary practice of snow management, comparable to grooming, and contributes to optimise the operation of ski resorts. It also participates to the growth of investments and is associated with significant operating costs, and thus represents a new source of vulnerability. The assessment of the actual effects of snowmaking and of snow management practices in general is a real concern for the future of the ski industry. The principal model use to simulate snow conditions in resorts, Ski Sim, has also been moving this way. Its developers introduced an artificial input of snow on ski area to complete natural snowfalls and considered different organisations of ski lifts (lower and upper zones). However the use of a degree-day model prevents them to consider the specific properties of artificial snow and the impact of grooming on the snowpack. A first proof of concept in the French Alps has shown the feasibility and the interest to cross the geographic model of ski areas and the output of the physically-based reanalysis of snow conditions SAFRAN - Crocus (François et al., CRST 2014). Since these initial developments, several ways have been explored to refine our model. A new model of ski areas has been developed. Our representation is now based on gravity derived from a DEM and ski lift localisation. A survey about snow management practices also allowed us to define criteria in order to model snowmaking areas given ski areas properties and tourism infrastructures localisation. We also suggest to revisit the assessment of ski resort viability based on the "one hundred days rule" based on natural snow depth only. Indeed, the impact of snow management must be considered so as to propose

  9. Climate Change Risk Appraisal in the Austrian Ski Industry

    Science.gov (United States)

    Wolfsegger, C.

    2009-04-01

    Ski tourism is an economically and culturally important industry in many parts of Europe. A growing number of studies in Europe, North America, Japan, and Australia have concluded that climate change has potentially serious implications for the sustainability of ski operations by reducing the average length of ski seasons and, where applicable, increasing snowmaking costs. To date, however, the climate change risk awareness and adaptive responses of stakeholders in the ski industry have not been examined. A survey of managers at low elevation ski areas in Austria was undertaken to explore their perceptions of climate change (past and future), how climate change had/will affect their operations, and their adaptive responses (past and planned). The results indicate that climate change is not perceived to be a serious threat to ski operations and that with technological adaptation, principally snowmaking, ski area managers believe they will be able to effectively cope with climate change in the 21st century. The consequences of these perceptions for the future operation of these ski areas are discussed and conclusions drawn for the future of ski tourism in Austria.

  10. Historical Development of Skiing: Case Study in Durmitor Area

    Directory of Open Access Journals (Sweden)

    Rajko Milašinović

    2017-02-01

    Full Text Available The objective of this study is the history of skiing, while the main goal will be the historical development of skiing in the mountain Durmitor area in Montenegro. The study consists two goals. The first goal is the emergence of the first ski in the Montenegro and benefits that are brought. The second and the main goal is the occurrence and development of skiing and ski sports in the territory of mountain Durmitor. During the making of this study, the authors used descriptive method with consulting of competent literature. The previous authors’ experience in this field was also so useful. Moreover, the author used the analytic method and parallel method that is the most productive if you make some inferences about some appearance. The main outcome of this study was showing of historical progress of ski sports in the territory of mountain Durmitor from early beginnings to the modern Olympic skiing. Skis and ski sport were early appeared in the region of Mount Durmitor. The mountain and the region around it, are very rich with slopes with Olympic diameter, with plenty of snowfall and long winters. However, lack of financial investment, channeling money to other centers, led to the fact that the skiing in this area is at a low level.

  11. Historical Development of Skiing with Special Retrospection in Montenegro

    Directory of Open Access Journals (Sweden)

    Rajko Milašinović

    2016-02-01

    Full Text Available The objective of this study is the history of skiing, while the main goal will be the historical development of skiing in Montenegro. The study consists three goals. The first goal is the emergence of the first ski in the world and benefits that are brought. Another goal is focused on the development of skiing in the former Yugoslavia. The third and the main goal is the occurrence and development of skiing and ski sports in the territory of Montenegro. During the making of this study, the author used descriptive method with consulting of competent literature. The previous author experience in this field was also so useful. Moreover, the author used the analytic method and parallel method that is the most productive if you make some inferences about some appearance. Consequently, the main outcome of this study was showing of historical progress of ski sports in Montenegro from early beginnings to the modern Olympic skiing.

  12. Injuries among World Cup ski and snowboard athletes.

    Science.gov (United States)

    Flørenes, T W; Nordsletten, L; Heir, S; Bahr, R

    2012-02-01

    There is little information available on injuries to World Cup skiers and snowboarders. The aim of this study was to describe and compare the injury risk to World Cup athletes in alpine skiing, freestyle skiing, snowboarding, ski jumping, Nordic combined and cross country skiing. We performed retrospective interviews with the International Ski Federation (FIS) World Cup athletes from selected nations during the 2006-2007 and 2007-2008 winter seasons and recorded all acute injuries occurring during the seasons. We interviewed 2121 athletes and recorded 705 injuries. There were 520 (72%) time-loss injuries and 196 (28%) severe injuries (absence >28 days). In freestyle skiing, alpine skiing and snowboarding, there were 27.6, 29.8 and 37.8 time-loss and 14.4, 11.3 and 13.8 severe injuries per 100 athletes per season, respectively. In Nordic combined, ski jumping and cross country skiing, there were 15.8, 13.6 and 6.3 time-loss and 3.3, 5.6 and 0.7 severe injuries per 100 athletes per season, respectively. In conclusion about 1/3 of the World Cup alpine, freestyle and snowboard athletes sustain a time-loss injury each season, while the risk is low in the Nordic disciplines. A particular concern was the high proportion of severe injuries observed among alpine, freestyle and snowboard athletes, which is in contrast to most other sports. © 2010 John Wiley & Sons A/S.

  13. PROSNOW - Provision of a prediction system allowing for management and optimization of snow in Alpine ski resorts

    Science.gov (United States)

    Morin, Samuel; Ghislain, Dubois

    2017-04-01

    Snow on the ground is a critical resource for mountain regions to sustain river flow, to provide freshwater input to ecosystems and to support winter tourism, in particular in ski resorts. The level of activity, employment, turnover and profit of hundreds of ski resorts in the European Alps primarily depends on meteorological conditions, in particular natural snowfall but also increasingly conditions favourable for snowmaking (production of machine made snow, also referred to as technical snow). Ski resorts highly depend on appropriate conditions for snowmaking (mainly the availability of cold water, as well as sub-freezing temperature with sufficiently low humidity conditions). However, beyond the time scale of weather forecasts (a few days), managers of ski resorts have to rely on various and scattered sources of information, hampering their ability to cope with highly variable meteorological conditions. Improved anticipation capabilities at all time scales, spanning from "weather forecast" (up to 5 days typically) to "climate prediction" at the seasonal scale (up to several months) holds significant potential to increase the resilience of socio-economic stakeholders and supports their real-time adaptation potential. To address this issue, the recently funded (2017-2020) H2020 PROSNOW project will build a demonstrator of a meteorological and climate prediction and snow management system from one week to several months ahead, specifically tailored to the needs of the ski industry. PROSNOW will apply state-of-the-art knowledge relevant to the predictability of atmospheric and snow conditions, and investigate and document the added value of such services. The project proposes an Alpine-wide system (including ski resorts located in France, Switzerland, Germany, Austria and Italy). It will join and link providers of weather forecasts and climate predictions at the seasonal scale, research institutions specializing in snowpack modelling, a relevant ensemble of at least

  14. The SKI communication programme

    International Nuclear Information System (INIS)

    Carlberg, Susanne

    2000-01-01

    Sweden has, since many years, an ongoing debate on nuclear power in general and nuclear safety and nuclear waste in particular. SKI is not the only part who wants to communicate about these subjects. The nuclear power plants, other authorities, the anti-nuclear groups and the politicians are other parts on the communication scene. The role of SKI is to provide the Swedish public with objective and prompt information based on facts. (author)

  15. Investigations on socio economic indicators of French Alps ski industry from an explicit spatial modelling of managed snow on ski slopes

    Science.gov (United States)

    Spandre, Pierre; François, Hugues; Morin, Samuel; George-Marcelpoil, Emmanuelle; Lafaysse, Matthieu

    2017-04-01

    Investigations of the capacity of ski resorts to anticipate, cope with and recover from the impact of natural snow scarcity through snow management (grooming, snowmaking) have been realized in most of the major regions in terms of international ski offer although not in the French Alps hitherto. The present work therefore introduces an innovative approach for the investigation of socio economic implications of changes in snow conditions for the French Alps ski resorts based on a panel of 129 resorts representing 96% of the total French Alps ski lifts infrastructures. We integrated detailed spatial representations of ski resorts (including priority areas for snowmaking equipment) along with physically based snowpack modelling (including the physical impact of grooming and snowmaking). The viability of ski resorts was further adressed thanks to a commonly used rule based on the snow season duration at the village and ski lifts average elevations along with the development of original viability indicators of snow conditions in the French Alps ski resorts based on the specific periods for the economic success of winter sports: Christmas and February school holidays. Such indicators were correlated to the number of ski lifts tickets sales over the 2001 - 2014 period and proved to be relevant to investigate and predict the evolutions of ski lifts tickets sales under the current ski market conditions in the French Alps. Our results outlined the contrast of snow conditions between French Alps ski resorts, even when accounting for snow management, particularly regarding the geographical location of resorts (Southern versus Northern Alps), the size and related elevation range of ski resorts. Our physically based approach also allowed to compute the water and energy requirements for the production of Machine Made snow since the start of the development of snowguns in the French Alps. Our computations proved to be strongly correlated to the observed amounts of water from the

  16. The relationship between performance in core exercises and performance ability in ski jumping : a cross-sectional study of competitive ski jumpers

    OpenAIRE

    Norwich, Andreas Tørum

    2017-01-01

    Background: The concept of core stability and balance are emphasized during athletic training for Norwegian ski jumpers. The impression of how important it can be for sport performance has long been a matter of interest within research. The purpose of this study was to examine the association between core stability, balance and ski-jumping performance ability in competitive ski jumpers. Methods: Eleven male ski jumpers were tested for steadiness in two commonly used core exercises (plank a...

  17. 14 medals for the CERN Ski Club

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    From 22 to 29 January, the ski resort of La Clusaz in Haute Savoie hosted the 11th Winter Atomiades. With nine gold medals and four silver medals in cross-country skiing, and a bronze medal in downhill skiing, the team from the CERN Ski Club finished third in the medals table.   Group photo at the 2011 Atomiades Organised by the Association of Sports Communities of European Research Institutes, nearly 260 participants from 15 research centres throughout Europe competed against each other in this skiing event. Each in their own discipline and age category, the fourteen members of the CERN team defended the colours of the Organization in the spirit of fun and fair play: “I had a really good week,” explained Simone Campana from the IT Department. “There was a great atmosphere. I’m only sorry that there was no general ranking this year. Let’s hope they’ll think about having one next time!” Despite the competition, the event is ...

  18. [Skiing injuries in school sport and possibilioties to prevent them].

    Science.gov (United States)

    Greier, K

    2011-12-01

    Tyrol (Austria) is one of the regions which pioneered skiing. Skiing is considered as a national sport and is deeply rooted within the school system. Thus most pupils partake in skiing courses in this period. It is clear that such a large group of pupils also leads to a significant number of skiing injuries. Preventive issues may be derived from an analysis of the pattern and circumstances of skiing injuries. During a period of ten years (2000 - 2009) 1522 school sports injuries have been reported to the health insurance agency (Allgemeine Unfallversicherungsanstalt) from all secondary schools in Tyrol. The major disciplines were ski (48 %, n = 734) ice skateing (23 %, n = 349) and snowboard injuries (21 %, n = 315), followed by tobogganing (6 %, n = 91), cross-country skiing (1 %, n = 17) and other wintersports (1 %, n = 16). Fractures (31 %) dominated in skiing, followed by contusions (23 %), and sprains (22 %). In the analysis of the distribution of injuries during alpine skiing accidents, lower extremity injuries (39 %) dominated followed by upper extremity injuries (34 %). Head and spine injuries (13 %) were rare. Analysing the circumstances of the injuries, most injuries during skiing occurred without person to person collision (82 %), 81 % either shortly before lunch-break or in the afternoon. Skiing injuries account for a significant proportion of all school sport-related injuries in Tyrol. Lower extremity injuries account for the vast majority of all injuries. Overestimation and overtiredness may be responsible for skiing sport injuries. Preventive measures such as a fitness training (e. g., skiing exercises) prior to skiing courses, appropriate breaks and proper protective gear (i. e., helmet and spine protector) may reduce the injury rate in skiing school sport. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Attitude Estimation of Skis in Ski Jumping Using Low-Cost Inertial Measurement Units

    Directory of Open Access Journals (Sweden)

    Xiang Fang

    2018-02-01

    Full Text Available This paper presents an approach to estimate the attitude of skis for an entire ski jump using wearable, MEMS-based, low-cost Inertial Measurement Units (IMUs. First of all, a kinematic attitude model based on rigid-body dynamics and a sensor error model considering bias and scale factor error are established. Then, an extended Rauch-Tung-Striebel (RTS smoother is used to combine measurement data provided by both gyroscope and magnetometer to achieve an attitude estimation. Moreover, parameters for the bias and scale factor error in the sensor error model and the initial attitude are determined via a maximum-likelihood principle based parameter estimation algorithm. By implementing this approach, an attitude estimation of skis is achieved without further sensor calibration. Finally, results based on both the simulated reference data and the real experimental measurement data are presented, which proves the practicability and the validity of the proposed approach.

  20. Biomechanics research in ski jumping, 1991-2006.

    Science.gov (United States)

    Schwameder, Hermann

    2008-01-01

    In this paper, I review biomechanics research in ski jumping with a specific focus on publications presented between 1991 and 2006 on performance enhancement, limiting factors of the take-off, specific training and conditioning, aerodynamics, and safety. The first section presents a brief description of ski jumping phases (in-run, take-off, early flight, stable flight, and landing) regarding the biomechanical and functional fundamentals. The most important and frequently used biomechanical methods in ski jumping (kinematics, ground reaction force analyses, muscle activation patterns, aerodynamics) are summarized in the second section. The third section focuses on ski jumping articles and research findings published after the establishment of the V-technique in 1991, as the introduction of this technique has had a major influence on performance enhancement, ski jumping regulations, and the construction of hill profiles. The final section proposes topics for future research in the biomechanics of ski jumping, including: take-off and early flight and the relative roles of vertical velocity and forward somersaulting angular momentum; optimal jumping patterns utilizing the capabilities of individual athletes; development of kinematic and kinetic feedback systems for hill jumps; comparisons of simulated and hill jumps; effect of equipment modifications on performance and safety enhancement.

  1. Kinematic Chains in Ski Jumping In-run Posture.

    Science.gov (United States)

    Janurová, Eva; Janura, Miroslav; Cabell, Lee; Svoboda, Zdeněk; Vařeka, Ivan; Elfmark, Milan

    2013-12-18

    The concept of kinematic chains has been systematically applied to biological systems since the 1950s. The course of a ski jump can be characterized as a change between closed and open kinematic chains. The purpose of this study was to determine a relationship between adjacent segments within the ski jumper's body's kinematic chain during the in-run phase of the ski jump. The in-run positions of 267 elite male ski jumpers who participated in the FIS World Cup events in Innsbruck, Austria, between 1992 and 2001 were analyzed (656 jumps). Two-dimensional (2-D) kinematic data were collected from the bodies of the subjects. Relationships between adjacent segments of the kinematic chain in the ski jumper's body at the in-run position are greater nearer the chain's ground contact. The coefficient of determination between the ankle and knee joint angles is 0.67. Changes in the segments' positions in the kinematic chain of the ski jumper's body are stable during longitudinal assessment. Changes in shank and thigh positions, in the sense of increase or decrease, are the same.

  2. Motor abilities and anthropometrics in youth cross-country skiing.

    Science.gov (United States)

    Stöggl, R; Müller, E; Stöggl, T

    2015-02-01

    The purposes were to validate whether general motor abilities and anthropometrics are determinants of youth cross-country (XC) skiing performance; evaluate gender-specific differences; and to establish noninvasive diagnostics. Fifty-one youth XC skiers (34 boys; 13.8 ± 0.6 years and 17 girls; 13.4 ± 0.9 years) performed motor skill and laboratory tests, and anthropometric data were collected and correlated with XC skiing performance. Anthropometrics and maturity status were related to boys but not to girls XC skiing performance. Push-ups and 20-m sprint were correlated to XC skiing performance in both boys and girls. XC skiing performance of boys was predominantly influenced by upper body and trunk strength capacities (medicine ball throw, push-ups, and pull-ups) and jumping power (standing long and triple jump), whereas XC skiing of girls was mainly influenced by aerobic capacities (3000-m run). Laboratory measures did not reveal greater correlations to XC skiing performance compared with simple test concepts of speed, strength, and endurance. Maturity was a major confounding variable in boys but not girls. Use of noninvasive simple test concepts for determination of upper body strength, speed, and endurance represent practicable support for ski clubs, schools, or skiing federations in the guidance and evaluation of young talent, being aware of the effect of maturity especially in boys. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. 78 FR 38842 - Definition of a Ski Area

    Science.gov (United States)

    2013-06-28

    ..., local, or tribal government or anyone in the private sector. Therefore, a statement under section 202 of... DEPARTMENT OF AGRICULTURE Forest Service 36 CFR Part 251 RIN 0596-AD12 Definition of a Ski Area... definition of a ski area in its regulations to make it consistent with the authority in section 3 of the Ski...

  4. Induction of Ski Protein Expression upon Luteinization in Rat Granulosa Cells

    Directory of Open Access Journals (Sweden)

    Hyun Kim

    2012-05-01

    Full Text Available Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinizationto predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rats, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of the corpus luteum (CL. Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-Ski was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggests that its expression is regulated post-transcriptionally.

  5. Alpine ski sport injuries in Swedish Lapland

    OpenAIRE

    Made, Curt

    2009-01-01

    Downhill skiing is associated with recreation, youth, speed, aerials and crowded courses which carry increased risk of injuries. The aim of this study was to evaluate downhill sport injuries in a Swedish ski resort. Material and methodsIn a case-control study ongoing 1989/90–2006/07, 3,696 injured skiers were registered. After informed consent the injured were assessed by a physician and asked to answer a questionnaire concerning skier, skiing and injury. ResultsAfter three years 481 injured ...

  6. Numerical investigation of the early flight phase in ski-jumping.

    Science.gov (United States)

    Gardan, N; Schneider, A; Polidori, G; Trenchard, H; Seigneur, J M; Beaumont, F; Fourchet, F; Taiar, R

    2017-07-05

    The purpose of this study is to develop a numerical methodology based on real data from wind tunnel experiments to investigate the effect of the ski jumper's posture and speed on aerodynamic forces in a wide range of angles of attack. To improve our knowledge of the aerodynamic behavior of the ski jumper and his equipment during the early flight phase of the ski jump, we applied CFD methodology to evaluate the influence of angle of attack (α=14°, 21.5°, 29°, 36.5° and 44°) and speed (u=23, 26 and 29m/s) on aerodynamic forces in the situation of stable attitude of the ski jumper's body and skis. The standard k-ω turbulence model was used to investigate both the influence of the ski jumper's posture and speed on aerodynamic performance during the early flight phase. Numerical results show that the ski jumper's speed has very little impact on the lift and drag coefficients. Conversely, the lift and drag forces acting on the ski jumper's body during the early flight phase of the jump are strongly influenced by the variations of the angle of attack. The present results suggest that the greater the ski jumper's angle of inclination, with respect to the relative flow, the greater the pressure difference between the lower and upper parts of the skier. Further studies will focus on the dependency of the parameters with both the angle of attack α and the body-ski angle β as control variables. It will be possible to test and optimize different ski jumping styles in different ski jumping hills and investigate different environmental conditions such as temperature, altitude or crosswinds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Muscle glycogen depletion and lactate concentration during downhill skiing.

    Science.gov (United States)

    Tesch, P; Larsson, L; Eriksson, A; Karlsson, J

    1978-01-01

    Skilled and unskilled skiers were studied during downhill skiing. Muscle glycogen and muscle lactate concentrations in the vastus lateralis muscle were determined following different skiing conditions. Heavy glycogen utilization was found in the groups studied during a day of skiing. The skilled and unskilled skiers differed with respect to selective glycogen depletion pattern and the skilled subjects demonstrated greater depletion of slow twitch fibers than the unskilled subjects. Lactate concentrations ranged from approximately 5-26 mmoles x kg-1 wet muscle after approximately one minute of maximal skiing. This wide range was not found to be related to the level of skiing proficiency. However, skiing with varyingly angled boots, resulting in different knee angles, did affect lactate concentration. Lactate concentration was positively correlated to individual muscle fiber composition expressed as a percent of fast twitch fibers. The results suggest more pronounced involvement of aerobic energy metabolism in skilled skiers than in unskilled skiers.

  8. Knee injuries in skiing. A prospective study from northern Sweden.

    Science.gov (United States)

    Edlund, G; Gedda, S; Hemborg, A

    1980-01-01

    This paper evaluates 420 ski injuries occurring in Northern Sweden in 1977. Our main aim was to correlate knee injuries with types of skiing and to note a change in incidence with evolution of equipment. Fifty-eight lesions (13.8%) affected the knee joint which is about the same frequency as 10 years earlier nor has introduction of high stiff boots in downhill skiing increased incidence of knee injuries. Cross-country and long-distance skiing produced more knee injuries (24.7%) than downhill skiing (11.4%). Cross-country skiers were older and more women in this group sustained knee injuries. The use of non-release type bindings is probably the main reason for this higher incidence but age and different skiing techniques seem to contribute.

  9. The influence of ski helmets on sound perception and sound localisation on the ski slope

    Directory of Open Access Journals (Sweden)

    Lana Ružić

    2015-04-01

    Full Text Available Objectives: The aim of the study was to investigate whether a ski helmet interferes with the sound localization and the time of sound perception in the frontal plane. Material and Methods: Twenty-three participants (age 30.7±10.2 were tested on the slope in 2 conditions, with and without wearing the ski helmet, by 6 different spatially distributed sound stimuli per each condition. Each of the subjects had to react when hearing the sound as soon as possible and to signalize the correct side of the sound arrival. Results: The results showed a significant difference in the ability to localize the specific ski sounds; 72.5±15.6% of correct answers without a helmet vs. 61.3±16.2% with a helmet (p < 0.01. However, the performance on this test did not depend on whether they were used to wearing a helmet (p = 0.89. In identifying the timing, at which the sound was firstly perceived, the results were also in favor of the subjects not wearing a helmet. The subjects reported hearing the ski sound clues at 73.4±5.56 m without a helmet vs. 60.29±6.34 m with a helmet (p < 0.001. In that case the results did depend on previously used helmets (p < 0.05, meaning that that regular usage of helmets might help to diminish the attenuation of the sound identification that occurs because of the helmets. Conclusions: Ski helmets might limit the ability of a skier to localize the direction of the sounds of danger and might interfere with the moment, in which the sound is firstly heard.

  10. Aerodynamics of ski jumping flight and its control: I. Experiments

    Science.gov (United States)

    Jung, Daehan; Bang, Kyeongtae; Kim, Heesu; Ahn, Eunhye; Choi, Haecheon

    2015-11-01

    In a ski jumping competition, it is essential to analyze the effect of various posture parameters of a ski jumper to achieve a longer flight distance. For this purpose, we construct a model of a ski jumper by using three-dimensional surface data obtained by scanning a ski jumper's body (Mr. Chil-Ku Kang, member of the Korean national team). An experiment on this model is conducted in a wind tunnel. We consider four posture parameters (forward leaning angle, ski opening angle, ski rolling angle, and ski spacing) and measure the drag and lift forces for various flight postures at various angles of attack (α = 0° - 40°) and Reynolds numbers (Re = 5.4 × 105 - 1.6 × 106) based on the length of the jump ski. Then, we derive optimum values of posture parameters for maximum lift-to-drag ratio using a response surface method. We also conduct a full-scale wind tunnel experiment with members of the Korean national team and confirm the results obtained from the experiment on the model. Supported by the NRF program (2014M3C1B1033848).

  11. Searching for ski-lift injury: an uphill struggle?

    Science.gov (United States)

    Smartt, Pam; Chalmers, David

    2010-03-01

    Injuries arising from ski-lift malfunction are rare. Most arise from skier error when embarking or disembarking, or from improper lift operation. A search of the literature failed to uncover any studies focusing specifically on ski-lift injuries. The purpose of this study was to identify and characterise ski-lift injury resulting in hospitalisation and comment on barriers to reporting and reporting omissions. New Zealand hospitalised injury discharges 2000-2005 formed the primary dataset. To aid case identification these data were linked to ACC compensated claims for the same period and the data searched for all hospitalised cases of injury arising from ski-lifts. 44 cases were identified representing 2% of snow-skiing/snowboarding cases. 28 cases (64%) were male and 16 (36%) female, the average age was 32 yrs (range 5-73 yrs). The majority of cases were snow-skiers (35 cases, 80%). Most of the injuries were serious, or potentially so, with 1 case of traumatic pneumothorax, one of pulmonary embolism (after jumping from a ski-lift) and 28 cases sustaining fractures (six to the neck-of-femur, one to the lumbar spine and one to the pubis). ICISS scores for all cases ranged from 1.00 to 0.8182 (probability of dying in hospital 0-18.18%). Only 14 (32%) cases could be easily identified from ICD-10-AM e-codes and activity codes in the discharge summary. The ICD-10-AM external cause code for ski-lift injury V98 ("other specified transport accidents") was only assigned to 39% of cases. The type of ski-lift could only be determined in 24 cases (55%). Copyright 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  12. Wetlands and ski resorts in the French Alps: main issues and innovative ideas for the preservation of wetlands in ski areas

    Science.gov (United States)

    Gaucherand, S.; Evette, A.; François, H.; Paccard, P.; Perretier, C.; Wlerick, L.

    2009-04-01

    This presentation is a synthesis of a symposium held last October in Cemagref, Grenoble with contributions from scientists as well as lift operators, NGO's, and administrations. In the context of global change, ski resorts must rethink their development models. The diversification of the touristic offer is encouraged and the specificity of the mountain territory is at the heart of a sustainable development. In this context, the preservation of interesting and fragile habitats such as wetlands is topical. Wetlands have many recognized functions: flooding reduction, water remediation, fertilization, biodiversity conservation… In mountain areas, wetlands are small and scattered. They are of special interest in particular for their role in biodiversity conservation and for their cultural and recreational benefits. However, in ski areas, wetlands can interact with the ski activity. Indeed, wetlands can speed up snow melting in spring and they often occupy ledges, which are strategic positions for the establishment of ski resort's facilities. The development of ski resorts can lead to the destruction or the deterioration of wetlands because of hydrologic interferences, fill in, pollution, etc. However, a few judicious steps can be taken to reduce or suppress these negative effects. In the Alps, geographical and administrative tools have been developed to help the decisions of ski-resort's administrators. Meetings between lift-operators, administrators of protected areas scientists and NGO's have also proved efficient when done at an early stage of a project, as shown by the example of the ski-resort "Les Saisies".

  13. Sir Galahad, skiing and a woman's quest for freedom

    DEFF Research Database (Denmark)

    Pfister, Gertrud Ursula

    2013-01-01

    in winter. She also learned ski jumping. The little information that is available about her skiing activities clearly demonstrates that this sport played a key role in her life. Besides perfectly keeping up with her self-image as a competent woman, skiing provided her with the opportunity of escaping normal...

  14. Chemical exposure among professional ski waxers--characterization of individual work operations.

    Science.gov (United States)

    Freberg, Baard Ingegerdsson; Olsen, Raymond; Thorud, Syvert; Ellingsen, Dag G; Daae, Hanne Line; Hersson, Merete; Molander, Paal

    2013-04-01

    Preparation of skis prior to skiing competitions involves several individual work operations and the use of a wide variety of chemically based ski waxing products to improve the performance of the skis, including products used after skiing for wax removal and ski sole cleaning. Modern ski waxes consist mainly of petroleum-derived straight-chain aliphatic hydrocarbons, perfluoro-n-alkanes or polyfluorinated n-alkanes. The wax cleaning products contain solvents such as neat aliphatic hydrocarbons (aliphates) or a mixture with limonene. Different ski waxing work operations can result in contaminated workroom atmospheres. The aim of this study was to assess the chemical exposures related to the individual ski waxing work operations by investigating the specific work operations in controlled model experiments. Four main work operations with potential exposures were identified: (i) application of glider waxes, (ii) scraping and brushing of applied glider waxes, (iii) application of base/grip waxes, and (iv) ski sole cleaning. Aerosol particle masses were sampled using conical samplers equipped with 37-mm PVC, 5-µm pore size filters and cyclones equipped with 37-mm PVC, 0.8-µm pore size filters for the inhalable and the respirable aerosol mass fractions, respectively. For measurements of particle number concentrations, a Scanning Mobility Particle Sizer was used. Mean aerosol particle mass concentrations of 18.6 mg m(-3) and 32.2 mg m(-3) were measured during application of glider wax powders in the respirable and in the inhalable aerosol mass fractions, respectively. Particle number concentration of ~900 000 particles cm(-3) was measured during application of glider wax powder products. Ski sole cleaning with products containing aliphates displayed solvent air concentrations up to 62.5 p.p.m. This study shows that the potential exposure to generated particles during ski waxing and ski preparation is considerable, especially during work using glide wax powders.

  15. Nordic ski jumping injuries. A survey of active American jumpers.

    Science.gov (United States)

    Wright, J R; McIntyre, L; Rand, J J; Hixson, E G

    1991-01-01

    Little data are available in the medical literature on nordic ski jumping injuries. Injury questionnaires were sent to all active American ski jumpers registered either with the United States Ski Association or with a jumping club registered with the United States Ski Association. One hundred thirty-three of 286 (46.5%) injury questionnaires were returned. Eighty-one of the 133 respondents (60.9%) had been injured sufficiently to require examination by a physician at least once during their jumping careers. This report describes the types and frequencies of injuries sustained by this group of nordic ski jumpers as well as provides demographic data about American ski jumpers. The risk of injury per 100 participant years was 9.4, a rate less than that reported for most high school or college intermural sports.

  16. "no snow - no skiing excursion - consequences of climatic change?"

    Science.gov (United States)

    Neunzig, Thilo

    2014-05-01

    Climatology and climate change have become central topics in Geography at our school. Because of that we set up a climatological station at our school. The data are an important basis to observe sudden changes in the weather. The present winter (2013/2014) shows the importance of climate change in Alzey / Germany. In winter many students think of the yearly skiing trip to Schwaz / Austria which is part of our school programme. Due to that the following questions arise: Will skiing still be possible if climate change accelerates? How are the skiing regions in the Alpes going to change? What will happen in about 20 years? How does artificial snow change the landscape and the skiing sport? Students have to be aware of the ecological damage of skiing trips. Each class has to come up with a concept how these trips can be as environmentally friendly as possible. - the trip is for a restricted number of students only (year 8 only) - a small skiing region is chosen which is not overcrowded - snow has to be guaranteed in the ski area to avoid the production of artificial snow (avoidance of high water consumption) - the bus arrives with a class and returns with the one that had been there before These are but a few ideas of students in order to make their trip as environmentally friendly as possible. What is missing is only what is going to happen in the future. What will be the effect of climate change for skiing regions in the secondary mountains? How is the average temperature for winter going to develop? Are there possibilities for summer tourism (e.g. hiking) instead of skiing in winter? The students are going to try to find answers to these questions which are going to be presented on a poster on the GIFT-Workshop in Vienna.

  17. Ski jumping boots limit effective take-off in ski jumping.

    Science.gov (United States)

    Virmavirta, M; Komi, P V

    2001-12-01

    In this study, we measured the vertical and horizontal take-off forces, plantar pressures and activation patterns of four muscles (vastus lateralis, gluteus maximus, tibialis anterior, gastrocnemius) in 10 ski jumpers in simulated laboratory conditions when wearing either training shoes or ski jumping boots. We found significant differences in vertical (P boots condition resulted in a smaller displacement in the final position of the following joint angles: ankle angle (P knee angle (P boots condition, significantly more pressure was recorded under the heel (P knee and hip extensors when wearing jumping boots. We conclude that the stiffness of the structure of the jumping boots may result in a forward shift of pressure, thus limiting the effective vertical force. To avoid this pressure shift, the pattern of movement of simulated take-offs should be carefully controlled, particularly when wearing training shoes.

  18. Aerodynamics of ski jumping flight and its control: II. Simulations

    Science.gov (United States)

    Lee, Jungil; Lee, Hansol; Kim, Woojin; Choi, Haecheon

    2015-11-01

    In a ski jumping competition, it is essential to analyze the effect of various posture parameters of a ski jumper to achieve a longer flight distance. For this purpose, we conduct a large eddy simulation (LES) of turbulent flow past a model ski jumper which is obtained by 3D scanning a ski jumper's body (Mr. Chil-Ku Kang, member of the Korean national team). The angle of attack of the jump ski is 30° and the Reynolds number based on the length of the jump ski is 540,000. The flow statistics including the drag and lift coefficients in flight are in good agreements with our own experimental data. We investigate the flow characteristics such as the flow separation and three-dimensional vortical structures and their effects on the drag and lift. In addition to LES, we construct a simple geometric model of a ski jumper where each part of the ski jumper is modeled as a canonical bluff body such as the sphere, cylinder and flat plate, to find its optimal posture. The results from this approach will be compared with those by LES and discussed. Supported by NRF program (2014M3C1B1033848, 2014R1A1A1002671).

  19. Flight style optimization in ski jumping on normal, large, and ski flying hills.

    Science.gov (United States)

    Jung, Alexander; Staat, Manfred; Müller, Wolfram

    2014-02-07

    In V-style ski jumping, aerodynamic forces are predominant performance factors and athletes have to solve difficult optimization problems in parts of a second in order to obtain their jump length maximum and to keep the flight stable. Here, a comprehensive set of wind tunnel data was used for optimization studies based on Pontryagin's minimum principle with both the angle of attack α and the body-ski angle β as controls. Various combinations of the constraints αmax and βmin(t) were analyzed in order to compare different optimization strategies. For the computer simulation studies, the Olympic hill profiles in Esto-Sadok, Russia (HS 106m, HS 140m), and in Harrachov, Czech Republic, host of the Ski Flying World Championships 2014 (HS 205m) were used. It is of high importance for ski jumping practice that various aerodynamic strategies, i.e. combinations of α- and β-time courses, can lead to similar jump lengths which enables athletes to win competitions using individual aerodynamic strategies. Optimization results also show that aerodynamic behavior has to be different at different hill sizes (HS). Optimized time courses of α and β using reduced drag and lift areas in order to mimic recent equipment regulations differed only in a negligible way. This indicates that optimization results presented here are not very sensitive to minor changes of the aerodynamic equipment features when similar jump length are obtained by using adequately higher in-run velocities. However, wind tunnel measurements with athletes including take-off and transition to stabilized flight, flight, and landing behavior would enable a more detailed understanding of individual flight style optimization. © 2013 Published by Elsevier Ltd.

  20. Fundamental considerations in ski binding analysis.

    Science.gov (United States)

    Mote, C D; Hull, M L

    1976-01-01

    1. The static adjustment of a ski binding by hand or by available machines is only an adjustment and is neither a static nor a dynamic evaluation of the binding design. Bindings of different design with identical static adjustments will perform differently in environments in which the forces are static or dynamic. 2. The concept of binding release force is a useful measure of binding adjustment, but it is inappropriate as a criterion for binding evaluation. First, it does not direct attention toward the injury causing mechanism, strain, or displacement in the leg. Second, it is only part of the evaluation in dynamic problems. 3. The binding release decision in present bindings is displacement controlled. The relative displacement of the boot and ski is the system variable. For any specified relative displacement the binding force can be any of an infinite number of possibilities determined by the loading path. 4. The response of the leg-ski system to external impulses applied to the ski is independent of the boot-ski relative motion as long as the boot recenters quickly in the binding. Response is dependent upon the external impulse plus system inertia, damping and stiffness. 5. When tested under half sinusoidal forces applied to a test ski, all bindings will demonstrate static and impulse loading regions. In the static region the force drives the binding to a relative release displacement. In the impulse region the initial velocity of the ski drives the binding to a release displacement. 6. The transition between the static and impulse loading regions is determined by the binding's capacity to store and dissipate energy along the principal loading path. Increased energy capacity necessitates larger external impulses to produce release. 7. In all bindings examined to date, the transmitted leg displacement or strain at release under static loading exceeds leg strain under dynamic or impact loading. Because static loading is responsible for many injuries, a skier

  1. Restoration of eroded surfaces in Serbian ski-areas

    Directory of Open Access Journals (Sweden)

    Ristić Ratko

    2009-01-01

    Full Text Available The environmental impacts in Serbian ski areas are very strong, leading to landscape degradation and functionality losses. Construction or improvement works cause serious destruction of topsoil and native vegetation. Some activities enhance erosion production and sediment yield: clear cuttings; trunk transport down the slope; road construction and large excavations. Also, lack of erosion control works in ski areas, especially between April and October, result in various forms of land degradation such as furrows, gullies, landslides, or debris from rock weathering. The consequences of mismanagement in ski areas are noticeable in downstream sections of river beds, causing floods and bed-load deposition. Planning and designing activities, with the application of technical and biotechnical erosion control structures, through the concept of restoration, are necessary measures in the protection of ski areas.

  2. [Ski boots versus the knee joint. 2: What produces the forward leaning position of the ski boot?].

    Science.gov (United States)

    Schaff, P; Hauser, W

    1990-03-01

    In contrast to the drop in the incidence of fracture of the lower leg that has been observed in recent years, the incidence of knee injuries has not decreased in skiing. There has even been a relative increase of severe knee lesions and isolated ACL ruptures, prompting us to conduct a comprehensive study of the causes of this phenomena. The goal of part 2 of the study was to comprehensively examine the forward movement in skiboots in the lab and on the slope. Studying nine beginners and eight experts, we found a 20% (sign. 0.05) lower forward-lean capability for the beginner group in the same boot. A randomized study with crossover design conducted on the slope, where we equipped 16 skiers with either soft or stiff boots for the duration of five ski days, revealed the learning behaviour and forward position on the slope depending on the boot. The pupils became definitely less adept at learning if they were required to wear stiff skiboots and showed a sign, lower forward flex angle. A skiiing style in backward lean position was adopted and supported by the fixed backward spoiler. Therefore another study was necessary and will follow (part 3) to examine the effect of a stiff backward spoiler and skiing in a backward lean position. In consideration of the facts known up to now, it is concluded that to improve safety in skiing recommendations must be given as to which boot to choose, according to the skiing level. In addition, the setting of safety bindings must consider the type of skiboot used.

  3. The Effects of a Ski Training Program Employing“ Buddy Systems” on the Skiing Techniques of Women’s University Students from the Cooperative Learning’s Viewpoint

    OpenAIRE

    松本, 裕史; 中西, 匠; Hiroshi, Matsumoto; Takumi, Nakanishi

    2017-01-01

    The purpose of this study was to examine the effects of a ski training program, grounded in the“ buddy system,” on the skiing techniques of students at a women’s university. A group of twelve students, serving as the intervention group, participated in the ski training program using the buddy system, while another group of twelve students participated in program lacking the buddy system, as a control group. The measurement of skiing techniques( parallel turn, stem turn and wedeln) was conduct...

  4. Land degradation at the Stara Planina ski resort.

    Science.gov (United States)

    Ristić, Ratko; Kašanin-Grubin, Milica; Radić, Boris; Nikić, Zoran; Vasiljević, Nevena

    2012-03-01

    The environmental impacts of ski resorts in the Balkan region are great and can lead to landscape degradation and loss of land functionality. In this study, we present an example of the negative effects of human activities at the Stara Planina ski resort in southeastern Serbia. The objective of this study is detailed analysis of the characteristics of environmental impacts at the Stara Planina. The management of the ski area and ski slope development caused severe degradation of topsoil and native vegetation. The morphological characteristics of the area, lithological properties of the exposed material and climate conditions resulted in various geomorphic impacts, including rills, deep gullies, solifluctions and debris from rock weathering. Significant changes in land usage altered hydrological conditions, resulting in more frequent torrential floods in the downstream sections of the Zubska River and increased the sediment yield. Environmental impacts were analyzed in the immediate and wider zones of the ski resort in accordance with the specific topography and visual exposure. The restoration and erosion control measures have stopped degradation processes and helped to rehabilitate the appearance and functions of the landscape. The results show the importance of considering lithological (the type and characteristics of minerals present) and hydrological (precipitation, water storage capacity of soil, runoff) factors under the conditions of significant changes in land usage. The results of this investigation can contribute to the improvement of planning processes and the implementation of development projects in ski areas.

  5. A Coupled Snow Operations-Skier Demand Model for the Ontario (Canada) Ski Region

    Science.gov (United States)

    Pons, Marc; Scott, Daniel; Steiger, Robert; Rutty, Michelle; Johnson, Peter; Vilella, Marc

    2016-04-01

    The multi-billion dollar global ski industry is one of the tourism subsectors most directly impacted by climate variability and change. In the decades ahead, the scholarly literature consistently projects decreased reliability of natural snow cover, shortened and more variable ski seasons, as well as increased reliance on snowmaking with associated increases in operational costs. In order to develop the coupled snow, ski operations and demand model for the Ontario ski region (which represents approximately 18% of Canada's ski market), the research utilized multiple methods, including: a in situ survey of over 2400 skiers, daily operations data from ski resorts over the last 10 years, climate station data (1981-2013), climate change scenario ensemble (AR5 - RCP 8.5), an updated SkiSim model (building on Scott et al. 2003; Steiger 2010), and an agent-based model (building on Pons et al. 2014). Daily snow and ski operations for all ski areas in southern Ontario were modeled with the updated SkiSim model, which utilized current differential snowmaking capacity of individual resorts, as determined from daily ski area operations data. Snowmaking capacities and decision rules were informed by interviews with ski area managers and daily operations data. Model outputs were validated with local climate station and ski operations data. The coupled SkiSim-ABM model was run with historical weather data for seasons representative of an average winter for the 1981-2010 period, as well as an anomalously cold winter (2012-13) and the record warm winter in the region (2011-12). The impact on total skier visits and revenues, and the geographic and temporal distribution of skier visits were compared. The implications of further climate adaptation (i.e., improving the snowmaking capacity of all ski areas to the level of leading resorts in the region) were also explored. This research advances system modelling, especially improving the integration of snow and ski operations models with

  6. Lift mechanics of downhill skiing and snowboarding.

    Science.gov (United States)

    Wu, Qianhong; Igci, Yesim; Andreopoulos, Yiannis; Weinbaum, Sheldon

    2006-06-01

    This study is conducted to develop a simplified mathematical model to describe the lift mechanics of downhill skiing and snowboarding, where the lift contributions due to both the transiently trapped air and the compressed solid phase (snow crystals) are determined. To our knowledge, this is the first time that anyone has attempted to realistically estimate the relative contribution of the transiently trapped air to the total lift in skiing and snowboarding. The model uses Shimizu's empirical relation to predict the local variation in Darcy permeability due to the compression of the solid phase. The forces and moments on the skier or snowboarder are used to predict the angle of attack of the planing surface, the penetration depth at the leading edge, and the shift in the center of pressure for two typical snow types, fresh and wind-packed snow. We present numerical solutions for snowboarding and asymptotic analytic solutions for skiing for the case where there are no edging or turning maneuvers. The force and moment balance are then used to develop a theory for control and stability in response to changes in the center of mass as the individual shifts his/her weight. Our model predicts that for fine-grained, windpacked snow that when the velocity (U) of the snowboarder or skier is 20 m.s, approximately 50% of the total lift force is generated by the trapped air for snowboarding and 40% for skiing. For highly permeable fresh powder snow, the lift contribution from the pore air pressure drops substantially. This paper develops a new theoretical framework for analyzing the lift mechanics and stability of skis and snowboards that could have important applications in future ski and snowboard design.

  7. The effect of skiing on soil, hydrology and erosion hazard in the ski area of Sölden, Tyrol, Austria

    NARCIS (Netherlands)

    Thonon, I.

    2006-01-01

    In July and August 1999, we investigated the influence of skiing on the catchment hydrology and soil (erosion) in the surroundings of Sölden, Tyrol, Austria. Sölden is a ski village located in the Ötztal valley in between the Ötztaler and Stubaier Alps. During this research, we conducted 122

  8. Spinal column damage from water ski jumping.

    Science.gov (United States)

    Horne, J; Cockshott, W P; Shannon, H S

    1987-01-01

    We conducted a radiographic survey of 117 competitive water ski jumpers to determine whether this sport can cause spinal column damage and, if so, whether damage is more likely to occur in those who participate during the period of spinal growth and development (age 15 years or younger). We found a high prevalence of two types of abnormality: Scheuermann (adolescent) spondylodystrophy (present in 26% of the skiers) and vertebral body wedging (present in 34%). The prevalence of adolescent spondylodystrophy increased with the number of years of participation in the sport before age 15 years or less. Of those in this age group who had skied for 5 years or more, 57 showed adolescent spondylodystrophy; of those in the same age group who had skied for 9 years or more, 100% were affected. Wedged vertebrae increased as time of participation increased, regardless of the age at which exposure began. We conclude that competitive water ski jumping may damage the spinal column and that consideration should be given to regulating this sport, particularly for children.

  9. Spinal column damage from water ski jumping

    International Nuclear Information System (INIS)

    Horne, J.; Cockshott, W.P.; Shannon, H.S.

    1987-01-01

    We conducted a radiographic survey of 117 competitive water ski jumpers to determine whether this sport can cause spinal column damage and, if so, whether damage is more likely to occur in those who participate during the period of spinal growth and development (age 15 years or younger). We found a high prevalence of two types of abnormality: Scheuermann (adolescent) spondylodystrophy (present in 26% of the skiers) and vertebral body wedging (present in 34%). The prevalence of adolescent spondylodystrophy increased with the number of years of participation in the sport before age 15 years or less. Of those in this age group who had skied for 5 years or more, 57 showed adolescent spondylodystrophy; of those in the same age group who had skied for 9 years or more, 100% were affected. Wedged vertebrae increased as time of participation increased, regardless of the age at which exposure began. We conclude that competitive water ski jumping may damage the spinal column and that consideration should be given to regulating this sport, particularly for children. (orig.)

  10. Spinal column damage from water ski jumping

    Energy Technology Data Exchange (ETDEWEB)

    Horne, J.; Cockshott, W.P.; Shannon, H.S.

    1987-11-01

    We conducted a radiographic survey of 117 competitive water ski jumpers to determine whether this sport can cause spinal column damage and, if so, whether damage is more likely to occur in those who participate during the period of spinal growth and development (age 15 years or younger). We found a high prevalence of two types of abnormality: Scheuermann (adolescent) spondylodystrophy (present in 26% of the skiers) and vertebral body wedging (present in 34%). The prevalence of adolescent spondylodystrophy increased with the number of years of participation in the sport before age 15 years or less. Of those in this age group who had skied for 5 years or more, 57 showed adolescent spondylodystrophy; of those in the same age group who had skied for 9 years or more, 100% were affected. Wedged vertebrae increased as time of participation increased, regardless of the age at which exposure began. We conclude that competitive water ski jumping may damage the spinal column and that consideration should be given to regulating this sport, particularly for children. (orig.)

  11. Skiing in the Great Lakes States: the industry and the skier.

    Science.gov (United States)

    William A. Leuschner

    1970-01-01

    Describes the skiers and ski areas in the Midwest. Analyzes market structure for the industry, the factors associated with financial success, the impact of spending on local economies, and the potential of ski area investment. Includes ski area financial statements.

  12. Cross-country skiing movement factorization to explore relationships between skiing economy and athletes' skills.

    Science.gov (United States)

    Pellegrini, B; Zoppirolli, C; Boccia, G; Bortolan, L; Schena, F

    2018-02-01

    We investigated the relationships between the biomechanics of the double poling (DP) technique in cross-country skiing, its economy, and athletes' skill. To this aim, skiers' motion has been factorized into components through principal component analysis (PCA). Eight high-level (HL) and eight regional level (RL) male cross-country skiers performed a 5-minute submaximal DP trial while roller skiing on a treadmill at 14 km h -1 and 2° incline. Whole-body kinematics was recorded with a motion capture system. PCA was applied to markers coordinates to extract principal movements (PM k ), which were ranked by their variance. Energy cost (EC) of locomotion was calculated from ergospirometric measurements. Results showed that 96.7%±0.6% of total skiing pattern variance can be described with the first three PM k. (Shoulder and trunk flexion-extension are described PM 1 and PM 2 and elbow flexion-extension are mainly represented in PM 2 and PM 3. The variance of further components, consisting of residual movements (eg, slow postural changes or high-frequency vibrations), was greater for the RL than the HL skiers (4.0%±0.5% vs 2.6%±0.3%; P<.001) and was positively correlated with EC (R 2 =.646; P<.001). PCA permitted to describe the biomechanics of the DP technique through a limited set of principal movements. Skiing skills and economy appeared to be related to a skier's ability to simplify movement complexity, suggesting that an efficient skier is better able to reduce superfluous movement components during DP. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Injury patterns in nordic ski jumpers. A retrospective analysis of injuries occurring at the Intervale Ski Jump Complex from 1980 to 1985.

    Science.gov (United States)

    Wright, J R; Hixson, E G; Rand, J J

    1986-01-01

    No studies describing the types and frequencies of nordic ski jumping injuries have been reported in the medical literature. We examined records of injuries sustained at the Intervale Ski Jump Complex (15, 40, 70, and 90 meter jumps) in Lake Placid from 1980 to 1985. Forty-seven injured jumpers sustained 72 total injuries. The most frequent injuries were contusions. Fractures occurred in 11 jumpers; most were nondisplaced. Upper extremity fractures outnumbered lower extremity fractures. Injuries requiring hospitalization were uncommon; none of these resulted in permanent disability. Injury rates for non-World Cup and for World Cup competitions were 4.3 and 1.2 injuries per 1,000 skier-days, respectively. This is roughly equivalent to injury rates in alpine skiing. Our study suggests that the dangers of nordic ski jumping have been overestimated.

  14. A sit-ski design aimed at controlling centre of mass and inertia.

    Science.gov (United States)

    Langelier, Eve; Martel, Stéphane; Millot, Anne; Lessard, Jean-Luc; Smeesters, Cécile; Rancourt, Denis

    2013-01-01

    This article introduces a sit-ski developed for the Canadian Alpine Ski Team in view of the Vancouver 2010 Paralympic games. The design is predominantly based on controlling the mass distribution of the sit-ski, a critical factor in skiing performance and control. Both the antero-posterior location of the centre of mass and the sit-ski moment of inertia were addressed in our design. Our design provides means to adjust the antero-posterior centre of mass location of a sit-ski to compensate for masses that would tend to move the antero-posterior centre of mass location away from the midline of the binding area along the ski axis. The adjustment range provided is as large as 140 mm, thereby providing sufficient adaptability for most situations. The suspension mechanism selected is a four-bar linkage optimised to limit antero-posterior seat movement, due to suspension compression, to 7 mm maximum. This is about 5% of the maximum antero-posterior centre of mass control capacity (151 mm) of a human participant. Foot rest inclination was included in the design to modify the sit-ski inertia by as much as 11%. Together, these mass adjustment features were shown to drastically help athletes' skiing performance.

  15. SkiROS

    DEFF Research Database (Denmark)

    Rovida, Francesco; Schou, Casper; Andersen, Rasmus Skovgaard

    During the last decades, the methods for intuitive task level programming of robots have become a fundamental point of interest for industrial application. The paper in hand presents SkiROS (Skill-based Robot Operating System) a novel software architecture based on the skills paradigm. The skill ...... of a flexible, highly modular system for the development of cognitive robot tasks....

  16. Salzburg Skiing for the Elderly Study

    DEFF Research Database (Denmark)

    Niederseer, David; Ledl-Kurkowski, E; Kvita, K

    2011-01-01

    the effects of alpine skiing on CVRF in elderly skiers. Subjects (n=42) were randomized into an intervention group (IG; n=22; 12 males/10 females; age: 66.6 ± 2.1 years) completing 12 weeks of guided skiing or a control group (CG; n=20; 10 males/10 females; age: 67.3 ± 4.4 years). CVRF were assessed before......: -2.3%, Pelderly is safe with respect to cardiovascular events, and improves some, but not all CVRF....

  17. Perspectives for comprehensive biomechanical analyses in Mogul skiing.

    Science.gov (United States)

    Kurpiers, Nicolas; McAlpine, Paul R; Kersting, Uwe G

    2009-01-01

    The purpose of this study was to examine the effects of using a force measurement device on riding technique in mogul skiing. A mock-up version of such a device was positioned between ski boot and binding. Data on three-dimensional kinematics and perception were collected for eight subjects skiing down a mogul course. Parameters analysed were knee angle, side and forward lean of the trunk and hip, and the path of the body's centre of mass. A perception questionnaire was used on selective aspects to assess the skiers' perception of the performances. Perception ratings showed no significant detrimental effects. All assessed components showed a trend of improvement from the first to last run, thus suggesting familiarisation was achieved. Kinematic analysis revealed that no significant alterations occurred. In conclusion, it is intended to utilise a functional force plate similar to the one presented by Kiefmann et al. (2006) for future studies in freestyle skiing.

  18. A Comparison between Alpine Skiing, Cross-Country Skiing and Indoor Cycling on Cardiorespiratory and Metabolic Response

    Directory of Open Access Journals (Sweden)

    Thomas Stöggl, Christoph Schwarzl, Edith E. Müller, Masaru Nagasaki, Julia Stöggl, Peter Scheiber, Martin Schönfelder, Josef Niebauer

    2016-03-01

    Full Text Available Since physical inactivity especially prevails during winter months, we set out to identify outdoor alternatives to indoor cycling (IC by comparing the metabolic and cardiorespiratory responses during alpine skiing (AS, cross-country skiing (XCS and IC and analyse the effects of sex, age and fitness level in this comparison. Twenty one healthy subjects performed alpine skiing (AS, cross-country skiing (XCS, and IC. Oxygen uptake (VO2, total energy expenditure (EE, heart rate (HR, lactate, blood glucose and rate of perceived exertion (RPE were determined during three 4-min stages of low, moderate and high intensity. During XCS and IC VO2max and EE were higher than during AS. At least 2½ hours of AS are necessary to reach the same EE as during one hour of XCS or IC. HR, VO2, lactate, and RPEarms were highest during XCS, whereas RPEwhole-body was similar and RPElegs lower than during AS and IC, respectively. Weight adjusted VO2 and EE were higher in men than in women while fitness level had no effect. Male, fit and young participants were able to increase their EE and VO2 values more pronounced. Both AS and XCS can be individually tailored to serve as alternatives to IC and may thus help to overcome the winter activity deficit. XCS was found to be the most effective activity for generating a high EE and VO2 while AS was the most demanding activity for the legs.

  19. Additional Smooth and Rough Water Trials of SKI-CAT.

    Science.gov (United States)

    1981-08-01

    REPORT & PERIOD COVERED ADDITIONAL SMOOTH AND ROUGH WATER TRIALS OF FINAL SKI- CAT S. PERFORMING ORO. REPORT NUMSER 7. AUTHOR() I. CONTRACT OR GRANT NUMUr...Identif by bloc membe) ’ " -Further tests of SKI- CAT were made in smooth and rough water. Smooth water results confirmed the performance results of...reductions in the accelerations and motions of SKI- CAT over against the head seasreut DD , +A ,3 1473 EDITION OF I NOVS IS OBSOLETE UNCIbSJFIED SIME 0102-014

  20. The effectiveness of ski bindings and their professional adjustment for preventing alpine skiing injuries.

    Science.gov (United States)

    Finch, C F; Kelsall, H L

    1998-06-01

    This article presents a critical review of the extent to which alpine ski bindings and their adjustment have been formally demonstrated to prevent injuries. It considers a range of evidence, from anecdotal evidence and informed opinion to biomechanical studies, testing of equipment, epidemiological studies and controlled field evaluations. A total of 15 published studies examining the effectiveness of bindings and their adjustment were identified. All of these included anecdotal or informed opinion, and all but one focused on equipment design. Seven studies involved the testing of bindings or binding prototypes, 2 studies presented biomechanical models of the forces involved in binding operation, 6 reported an epidemiological evaluation of ski bindings and 2 considered skiers' behaviours towards binding adjustment. Some of the reviewed articles relate to the study of the biomechanics of ski bindings and their release in response to various loads and loading patterns. Other studies examined the contribution of bindings and binding-release to lower extremity, equipment-related injuries, the effect of various methods of binding adjustment on injury risk and the determinants of skiers' behaviour relating to professional binding adjustment. Most of the evidence suggests that currently used bindings are insufficient for the multidirectional release required to reduce the risk of injury to the lower limb, especially at the knee. This evidence suggests that further technical developments and innovations are required. The standard of the manufacture of bindings and boots also needs to be considered. The optimal adjustment of bindings using a testing device has been shown to be associated with a reduced risk of lower extremity injury. Generally, however, the adjustment of bindings has been shown to be inadequate, especially for children's bindings. Recommendations for further research, development and implementation with respect to ski binding and their adjustment are given

  1. Biomechanical factors influencing the performance of elite Alpine ski racers.

    Science.gov (United States)

    Hébert-Losier, Kim; Supej, Matej; Holmberg, Hans-Christer

    2014-04-01

    Alpine ski racing is a popular international winter sport that is complex and challenging from physical, technical, and tactical perspectives. Despite the vast amount of scientific literature focusing on this sport, including topical reviews on physiology, ski-snow friction, and injuries, no review has yet addressed the biomechanics of elite alpine ski racers and which factors influence performance. In World Cup events, winning margins are often mere fractions of a second and biomechanics may well be a determining factor in podium place finishes. The aim of this paper was to systematically review the scientific literature to identify the biomechanical factors that influence the performance of elite alpine ski racers, with an emphasis on slalom, giant slalom, super-G, and downhill events. Four electronic databases were searched using relevant medical subject headings and key words, with an additional manual search of reference lists, relevant journals, and key authors in the field. Articles were included if they addressed human biomechanics, elite alpine skiing, and performance. Only original research articles published in peer-reviewed journals and in the English language were reviewed. Articles that focused on skiing disciplines other than the four of primary interest were excluded (e.g., mogul, ski-cross and freestyle skiing). The articles subsequently included for review were quality assessed using a modified version of a validated quality assessment checklist. Data on the study population, design, location, and findings relating biomechanics to performance in alpine ski racers were extracted from each article using a standard data extraction form. A total of 12 articles met the inclusion criteria, were reviewed, and scored an average of 69 ± 13% (range 40-89%) upon quality assessment. Five of the studies focused on giant slalom, four on slalom, and three on downhill disciplines, although these latter three articles were also relevant to super-G events

  2. Anterior cruciate ligament injury/reinjury in alpine ski racing

    DEFF Research Database (Denmark)

    Jordan, Matthew J; Aagaard, Per; Herzog, Walter

    2017-01-01

    and return to sport after ACL injury in alpine ski racing. Given that most of the scientific studies on ACL injuries in alpine ski racing have been descriptive, and that very few studies contributed higher level scientific evidence, a nonsystematic narrative review was employed. Three scholarly databases...... were searched for articles on ACL injury or knee injury in alpine ski racing. Studies were classified according to their relevance in relation to epidemiology, etiology, risk factors, and return to sport/reinjury prevention. Alpine ski racers (skiers) were found to be at high risk for knee injuries...... injuries in development-level skiers, there was limited scientific data on ACL injury risk factors among elite skiers. Based on expert opinion, research on injury risk factors should focus on equipment design, course settings/speed, and athlete factors (eg, fitness). While skiers seem to make a successful...

  3. Effect of ski geometry and standing height on kinetic energy: equipment designed to reduce risk of severe traumatic injuries in alpine downhill ski racing.

    Science.gov (United States)

    Gilgien, Matthias; Spörri, Jörg; Kröll, Josef; Müller, Erich

    2016-01-01

    Injuries in downhill (DH) are often related to high speed and, therefore, to high energy and forces which are involved in injury situations. Yet to date, no study has investigated the effect of ski geometry and standing height on kinetic energy (EKIN) in DH. This knowledge would be essential to define appropriate equipment rules that have the potential to protect the athletes' health. During a field experiment on an official World Cup DH course, 2 recently retired world class skiers skied on 5 different pairs of skis varying in width, length and standing height. Course characteristics, terrain and the skiers' centre of mass position were captured by a differential Global Navigational Satellite System-based methodology. EKIN, speed, ski-snow friction force (FF), ground reaction force (FGRF) and ski-snow friction coefficient (CoeffF) were calculated and analysed in dependency of the used skis. In the steep terrain, longer skis with reduced width and standing height significantly decreased average EKIN by ∼ 3%. Locally, even larger reductions of EKIN were observed (up to 7%). These local decreases in EKIN were mainly explainable by higher FF. Moreover, CoeffF differences seem of greater importance for explaining local FF differences than the differences in FGRF. Knowing that increased speed and EKIN likely lead to increased forces in fall/crash situations, the observed equipment-induced reduction in EKIN can be considered a reasonable measure to improve athlete safety, even though the achieved preventative gains are rather small and limited to steep terrain. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  4. Long-Term Athletic Development in Youth Alpine Ski Racing: The Effect of Physical Fitness, Ski Racing Technique, Anthropometrics and Biological Maturity Status on Injuries

    Science.gov (United States)

    Müller, Lisa; Hildebrandt, Carolin; Müller, Erich; Fink, Christian; Raschner, Christian

    2017-01-01

    Alpine ski racing is known to be a sport with a high risk of injuries. Because most studies have focused mainly on top-level athletes and on traumatic injuries, limited research exists about injury risk factors among youth ski racers. The aim of this study was to determine the intrinsic risk factors (anthropometrics, biological maturity, physical fitness, racing technique) for injury among youth alpine ski racers. Study participants were 81 youth ski racers attending a ski boarding school (50 males, 31 females; 9–14 years). A prospective longitudinal cohort design was used to monitor sports-related risk factors over two seasons and traumatic (TI) and overuse injuries (OI). At the beginning of the study, anthropometric characteristics (body height, body weight, sitting height, body mass index); biological maturity [status age at peak height velocity (APHV)]; physical performance parameters related to jump coordination, maximal leg and core strength, explosive and reactive strength, balance and endurance; and ski racing technique were assessed. Z score transformations normalized the age groups. Multivariate binary logistic regression (dependent variable: injury yes/no) and multivariate linear regression analyses (dependent variable: injury severity in total days of absence from training) were calculated. T-tests and multivariate analyses of variance were used to reveal differences between injured and non-injured athletes and between injury severity groups. The level of significance was set to p jump contact time; and higher drop jump reactive strength index were at a lower injury risk or more vulnerable for fewer days of absence from training. However, significant differences between injured and non-injured athletes were only observed with respect to the drop jump reactive strength index. Regular documentation of anthropometric characteristics, biological maturity and physical fitness parameters is crucial to help to prevent injury in youth ski racing. The present

  5. Long-Term Athletic Development in Youth Alpine Ski Racing: The Effect of Physical Fitness, Ski Racing Technique, Anthropometrics and Biological Maturity Status on Injuries.

    Science.gov (United States)

    Müller, Lisa; Hildebrandt, Carolin; Müller, Erich; Fink, Christian; Raschner, Christian

    2017-01-01

    Alpine ski racing is known to be a sport with a high risk of injuries. Because most studies have focused mainly on top-level athletes and on traumatic injuries, limited research exists about injury risk factors among youth ski racers. The aim of this study was to determine the intrinsic risk factors (anthropometrics, biological maturity, physical fitness, racing technique) for injury among youth alpine ski racers. Study participants were 81 youth ski racers attending a ski boarding school (50 males, 31 females; 9-14 years). A prospective longitudinal cohort design was used to monitor sports-related risk factors over two seasons and traumatic (TI) and overuse injuries (OI). At the beginning of the study, anthropometric characteristics (body height, body weight, sitting height, body mass index); biological maturity [status age at peak height velocity (APHV)]; physical performance parameters related to jump coordination, maximal leg and core strength, explosive and reactive strength, balance and endurance; and ski racing technique were assessed. Z score transformations normalized the age groups. Multivariate binary logistic regression (dependent variable: injury yes/no) and multivariate linear regression analyses (dependent variable: injury severity in total days of absence from training) were calculated. T -tests and multivariate analyses of variance were used to reveal differences between injured and non-injured athletes and between injury severity groups. The level of significance was set to p core flexion strength; smaller core flexion:extension strength ratio; shorter drop jump contact time; and higher drop jump reactive strength index were at a lower injury risk or more vulnerable for fewer days of absence from training. However, significant differences between injured and non-injured athletes were only observed with respect to the drop jump reactive strength index. Regular documentation of anthropometric characteristics, biological maturity and physical fitness

  6. Changes in the Balance Performance of Polish Recreational Skiers after Seven Days of Alpine Skiing

    Directory of Open Access Journals (Sweden)

    Wojtyczek Beata

    2014-12-01

    Full Text Available Alpine skiing is one of the most popular leisure time winter sporting activities. Skiing imposes high requirements concerning physical fitness, particularly regarding balance abilities. The main objective of this study was to evaluate the changes in balance performance of recreational skiers after a seven-day ski camp. A total of 78 students - 24 women and 54 men - participated in the study. The ski course was held in accordance with the official program of the Polish Ski Federation. The study sample was comprised of 43 beginners and 35 intermediate skiers. All students were tested with the MFT S3-Check, the day before and the day after the ski camp. The test system consisted of an unstable uniaxial platform, with an integrated sensor and corresponding software. Changes in balance performance (sensory and stability index were evaluated using paired t-tests. Additionally, changes in sensory and stability categories, which were based on the norm data, were analyzed. Female and male participants showed significantly better sensory and stability indices after skiing. Considerable changes from weak or very weak to average or good balance categories could be seen after skiing for both sexes. Regarding skiing experience, both beginners and intermediate skiers improved their sensory and stability indices significantly after skiing. Hence, recreational alpine skiing resulted in better balance performance regardless of sex or skiing experience. Skiing as an outdoor activity offers the opportunity to improve balance performance with a positive impact on everyday life activities.

  7. Impact of lowering ski binding settings on the outcome of the self-release test of ski bindings among female recreational skiers

    Directory of Open Access Journals (Sweden)

    Posch M

    2017-12-01

    Full Text Available Markus Posch,1 Martin Burtscher,1 Alois Schranz,2 Katja Tecklenburg,2 Kenneth Helle,2 Gerhard Ruedl1 1Department of Sport Science, University of Innsbruck, Innsbruck, Austria; 2Medalp Sportclinic, Imst, Austria Background and purpose: The ability to successfully self-release the ski binding can prevent skiing-related injuries of the lower extremities. Failure of binding release associated with a knee injury is significantly higher among females compared to males. The International Standards Organization ISO 11088 standard for binding setting values allows a lowering by 15% upon request of the skier. Thus, the aim of this study was to evaluate the impact of lowered ski binding settings by 15% on the outcome of the self-release test among female recreational skiers. Materials and methods: In this randomized single-blinded study, a cohort of 20 females (24.5±2.7 years performed the self-release test in the laboratory thrice with each leg under two conditions: 1 with an actual ISO 11088 setting and 2 with a setting lowered by 15%. For each attempt, torques calculated via the force plate were normalized to torques measured by a binding adjustment system (relative release torque, RRT. Results: Among 240 trials in total, more females were significantly able to self-release their ski bindings with lowered binding settings when compared to their actual ISO settings (53% vs 9%, p<0.001. Thirteen females (65% were able to release their bindings at least once with both legs with lowered binding settings compared to only three females (15% with their actual binding settings (p<0.001. Mean RRT of all failure of binding release trials significantly differed between lowered and actual binding settings (58.6%±22.2% vs 50.5%±20.4%, p=0.003. Conclusion: Four times more females were able to self-release their ski bindings at least once with both legs with a 15% lowered binding setting compared to their normal ISO 11088 setting. The fact that the ISO standard

  8. Georneys joins AGU's blog network

    Science.gov (United States)

    Viñas, Maria-José

    2011-07-01

    A blog on geological musings, wanderings, and adventures, called Georneys, has joined AGU's network of Earth and space science blogs. With the addition of Georneys, on 11 July, the AGU Blogosphere (http://blogs.agu.org), as the network is known, has grown to showcase eight independent blogs since its launch last fall. “One reason I write this blog is to maintain my sanity as I finish up my Ph.D. In the midst of much stress, long days in lab, and long nights writing thesis chapters, I write to remind myself of why I love geology,” says Georneys blogger Evelyn Mervine. “I also write to document some of my geological adventures and to share my love of geology with others.”

  9. Changes in Quadriceps Muscle Activity During Sustained Recreational Alpine Skiing

    Science.gov (United States)

    Kröll, Josef; Müller, Erich; Seifert, John G.; Wakeling, James M.

    2011-01-01

    During a day of skiing thousands of repeated contractions take place. Previous research on prolonged recreational alpine skiing show that physiological changes occur and hence some level of fatigue is inevitable. In the present paper the effect of prolonged skiing on the recruitment and coordination of the muscle activity was investigated. Six subjects performed 24 standardized runs. Muscle activity during the first two (PREskiing) and the last two (POSTskiing) runs was measured from the vastus lateralis (VL) and rectus femoris (RF) using EMG and quantified using wavelet and principal component analysis. The frequency content of the EMG signal shifted in seven out of eight cases significantly towards lower frequencies with highest effects observed for RF on outside leg. A significant pronounced outside leg loading occurred during POSTskiing and the timing of muscle activity peaks occurred more towards turn completion. Specific EMG frequency changes were observed at certain time points throughout the time windows and not over the whole double turn. It is suggested that general muscular fatigue, where additional specific muscle fibers have to be recruited due to the reduced power output of other fibers did not occur. The EMG frequency decrease and intensity changes for RF and VL are caused by altered timing (coordination) within the turn towards a most likely more uncontrolled skiing technique. Hence, these data provide evidence to suggest recreational skiers alter their skiing technique before a potential change in muscle fiber recruitment occurs. Key points The frequency content of the EMG signal shifted in seven out of eight cases significantly towards lower frequencies with highest effects observed for RF. General muscular fatigue, where additional specific fibers have to be recruited due to the reduced power output of other fibers, did not occur. A modified skiing style towards a less functional and hence more uncontrolled skiing technique seems to be a key

  10. Alpine ski bindings and injuries. Current findings.

    Science.gov (United States)

    Natri, A; Beynnon, B D; Ettlinger, C F; Johnson, R J; Shealy, J E

    1999-07-01

    In spite of the fact that the overall incidence of alpine ski injuries has decreased during the last 25 years, the incidence of serious knee sprains usually involving the anterior cruciate ligament (ACL) has risen dramatically since the late 1970s. This trend runs counter to a dramatic reduction in lower leg injuries that began in the early 1970s and to date has lowered the risk of injury below the knee by almost 90%. One of the primary design objectives of modern ski boots and bindings has been to protect the skier from tibia and ankle fractures. So, in that sense, they have done an excellent job. However, despite advances in equipment design, modern ski bindings have not protected the knee from serious ligament trauma. At the present time, we are unaware of any binding design, settings or function that can protect both the knee and lower extremities from serious ligament sprains. No innovative change in binding design appears to be on the horizon that has the potential to reduce the risk of these severe knee injuries. Indeed, only 1 study has demonstrated a means to help reduce this risk of serious knee sprains, and this study involved education of skiers, not ski equipment. Despite the inability of bindings to reduce the risk of severe knee injuries there can be no doubt that improvement in ski bindings has been the most important factor in the marked reduction in incidence of lower leg and ankle injuries during the last 25 years. The authors strongly endorse the application of present International Standards Organisation (ISO) and American Society for Testing and Materials (ASTM) standards concerning mounting, setting and maintaining modern 'state of the art' bindings.

  11. Online community marketing of ski resorts : an in-depth best practice study of aspen/snowmass and breckenridge ski resort

    OpenAIRE

    Kráľ, Branislav

    2013-01-01

    Online brand community is a novel phenomenon that carries a number of benefits, but lack of clarity in antecedents of its effectiveness as a marketing alternative. Aspen/Snowmass and Breckenridge Ski Resort are two leading players in the ski industry, and this paper analyzes their activity in-depth in order to bring clarity by extracting implications on best practice. For the purpose, a tailor-made methodology is constructed. It consists of combining two analytical frameworks, interviews with...

  12. Long-Term Athletic Development in Youth Alpine Ski Racing: The Effect of Physical Fitness, Ski Racing Technique, Anthropometrics and Biological Maturity Status on Injuries

    Directory of Open Access Journals (Sweden)

    Lisa Müller

    2017-08-01

    Full Text Available Alpine ski racing is known to be a sport with a high risk of injuries. Because most studies have focused mainly on top-level athletes and on traumatic injuries, limited research exists about injury risk factors among youth ski racers. The aim of this study was to determine the intrinsic risk factors (anthropometrics, biological maturity, physical fitness, racing technique for injury among youth alpine ski racers. Study participants were 81 youth ski racers attending a ski boarding school (50 males, 31 females; 9–14 years. A prospective longitudinal cohort design was used to monitor sports-related risk factors over two seasons and traumatic (TI and overuse injuries (OI. At the beginning of the study, anthropometric characteristics (body height, body weight, sitting height, body mass index; biological maturity [status age at peak height velocity (APHV]; physical performance parameters related to jump coordination, maximal leg and core strength, explosive and reactive strength, balance and endurance; and ski racing technique were assessed. Z score transformations normalized the age groups. Multivariate binary logistic regression (dependent variable: injury yes/no and multivariate linear regression analyses (dependent variable: injury severity in total days of absence from training were calculated. T-tests and multivariate analyses of variance were used to reveal differences between injured and non-injured athletes and between injury severity groups. The level of significance was set to p < 0.05. Relatively low rates of injuries were reported for both traumatic (0.63 TI/athlete and overuse injuries (0.21 OI/athlete. Athletes with higher body weight, body height, and sitting height; lower APHV values; better core flexion strength; smaller core flexion:extension strength ratio; shorter drop jump contact time; and higher drop jump reactive strength index were at a lower injury risk or more vulnerable for fewer days of absence from training. However

  13. A reappraisal of success factors for Olympic cross-country skiing.

    Science.gov (United States)

    Sandbakk, Øyvind; Holmberg, Hans-Christer

    2014-01-01

    Cross-country (XC) skiing has been an Olympic event since the first Winter Games in Chamonix, France, in 1924. Due to more effective training and tremendous improvements in equipment and track preparation, the speed of Olympic XC-ski races has increased more than that of any other Olympic endurance sport. Moreover, pursuit, mass-start, and sprint races have been introduced. Indeed, 10 of the 12 current Olympic competitions in XC skiing involve mass starts, in which tactics play a major role and the outcome is often decided in the final sprint. Accordingly, reappraisal of the success factors for performance in this context is required. The very high aerobic capacity (VO2max) of many of today's world-class skiers is similar that of their predecessors. At the same time, the new events provide more opportunities to profit from anaerobic capacity, upper-body power, high-speed techniques, and "tactical flexibility." The wide range of speeds and slopes involved in XC skiing requires skiers to continuously alternate between and adapt different subtechniques during a race. This technical complexity places a premium on efficiency. The relative amounts of endurance training performed at different levels of intensity have remained essentially constant during the past 4 decades. However, in preparation for the Sochi Olympics in 2014, XC skiers are performing more endurance training on roller skis on competition-specific terrain, placing greater focus on upper-body power and more systematically performing strength training and skiing at high speeds than previously.

  14. Impact of climate change on the operation of ski slopes in South Korea

    Science.gov (United States)

    Kim, S.; Park, J. H.; Lee, D. K.

    2017-12-01

    The purpose of this study is to predict changes in the operation of ski slopes due to climate change and offer meaningful implications that the ski industry can refer to when preparing to address climate change. All 17 ski resorts in South Korea were selected as study sites. To determine the weather and managerial conditions for the operation of ski slopes, interviews with operators and a review of past weather and operational conditions were conducted. To project future changes in the season of operation for ski slopes, future weather data for the 2030s, 2060s, and 2090s from RCP scenarios were adapted to the conditions for the operation of ski slopes.The study found that the artificial snowmaking begins when the temperature reaches -2 °C, the slope is opened 9 days after artificial snowmaking starts, and the slope is closed when the temperature reaches 0 °C. By applying future weather data to these conditions, it is estimated that the ski season will decrease in the future as follows: from around 130 days at present to around 120 days based on RCP 2.0 and RCP 6.0, around 130 days based on RCP 4.5, and 90 days based on RCP 8.5 in the areas where the average temperature of the ski season is below -2 °C; from around 120 days at present to around 120 days based on RCP 2.0 and 4.5, around 100-days based on RCP 6.0, and 60 days based on RCP 8.5 in the areas where the average temperature of the ski season is below 0 °C; from around 90 days at present to around 80 days based on RCP 2.0, around 90 days based on RCP 4.5, around 50 days based on RCP 6.0, and 10 days based on RCP 8.5 in the areas where the average temperature of the ski season is above 0 °C. In addition, it is also estimated that in the 2090s, 16 of 17 ski resorts can survive based on RCP 2.6 and RCP 4.5, 13 ski resorts can survive based on RCP 6.0, and none of the resorts can survive based on RCP 8.5, according to the 100-days rule, which is the minimum required duration of the operation of ski resorts

  15. Cross-Country Skiing Injuries and Training Methods.

    Science.gov (United States)

    Nagle, Kyle B

    2015-01-01

    Cross-country skiing is a low injury-risk sport that has many health benefits and few long-term health risks. Some concern exists that cross-country skiing may be associated with a higher incidence of atrial fibrillation; however, mortality rates among skiers are lower than those among the general population. While continuing to emphasize aerobic and anaerobic training, training methods also should promote ski-specific strength training to increase maximum force and its rate of delivery and to build muscular endurance to maintain that power through a race. Multiple tests are available to monitor training progress. Which tests are most appropriate depends on the specific events targeted. In addition to laboratory-based tests, there also are many simpler, more cost-effective tests, such as short time trials, that can be used to monitor training progress and predict performance particularly at the junior skier level where access and cost may be more prohibitive.

  16. Radioprotective effect of c-ski on rat skin fibroblast in vitro

    International Nuclear Information System (INIS)

    Liu Xia; Li Ping; Zhang En; Liu Ping; Zhou Ping; Zhou Yuanguo

    2006-01-01

    Objective: To examine radioprotective effect of c-ski on rat skin fibroblast in vitro and explore its possible mechanism. Methods: The effect of soft X-ray irradiation at dose varied from 2 to 8 Gy on cell apoptosis in rat skin fibroblast were determined by flow cytometry with Annexin-V-FITC-PI labelling. The effect of c-ski gene transfection on cell apoptosis was evaluated after soft X-ray irradiation of 4 Gy. The protein expressions of Bax and Bcl-2 after c-ski gene transfection were measured with the Western blot method. Results: Soft X-ray irradiation increases cell apoptosis, and the increase is proportional to the irradiation dose. Apoptosis ratio increases with time since the irradiation, and reaches its peak at 36h after the irradiation, c-ski gene was observed to markedly decrease apoptosis index at 24 h after soft X-ray irradiation of 4 Gy compared to the control group, significant increase of the protein expression of Bcl-2 was observed. C-ski gene was found no significant effect on the protein expression of Bax. Conclusion: c-ski gene can decrease radiation sensitivity of skin fibroblast, promoting Bcl-2 protein expression is one of its possible mechanism for this radioprotective effects. (authors)

  17. Ski jump takeoff performance predictions for a mixed-flow, remote-lift STOVL aircraft

    Science.gov (United States)

    Birckelbaw, Lourdes G.

    1992-01-01

    A ski jump model was developed to predict ski jump takeoff performance for a short takeoff and vertical landing (STOVL) aircraft. The objective was to verify the model with results from a piloted simulation of a mixed flow, remote lift STOVL aircraft. The prediction model is discussed. The predicted results are compared with the piloted simulation results. The ski jump model can be utilized for basic research of other thrust vectoring STOVL aircraft performing a ski jump takeoff.

  18. Ecological impacts of revegetation and management practices of ski slopes in northern Finland.

    Science.gov (United States)

    Kangas, Katja; Tolvanen, Anne; Kälkäjä, Tarja; Siikamäki, Pirkko

    2009-09-01

    Outdoor recreation and nature-based tourism represent an increasingly intensive form of land use that has considerable impacts on native ecosystems. The aim of this paper is to investigate how revegetation and management of ski runs influence soil nutrients, vegetation characteristics, and the possible invasion of nonnative plant species used in revegetation into native ecosystems. A soil and vegetation survey at ski runs and nearby forests, and a factorial experiment simulating ski run construction and management (factors: soil removal, fertilization, and seed sowing) were conducted at Ruka ski resort, in northern Finland, during 2003-2008. According to the survey, management practices had caused considerable changes in the vegetation structure and increased soil nutrient concentrations, pH, and conductivity on the ski runs relative to nearby forests. Seed mixture species sown during the revegetation of ski runs had not spread to adjacent forests. The experimental study showed that the germination of seed mixture species was favored by treatments simulating the management of ski runs, but none of them could eventually establish in the study forest. As nutrient leaching causes both environmental deterioration and changes in vegetation structure, it may eventually pose a greater environmental risk than the spread of seed mixture species alone. Machine grading and fertilization, which have the most drastic effects on soils and vegetation, should, therefore, be minimized when constructing and managing ski runs.

  19. Ecological Impacts of Revegetation and Management Practices of Ski Slopes in Northern Finland

    Science.gov (United States)

    Kangas, Katja; Tolvanen, Anne; Kälkäjä, Tarja; Siikamäki, Pirkko

    2009-09-01

    Outdoor recreation and nature-based tourism represent an increasingly intensive form of land use that has considerable impacts on native ecosystems. The aim of this paper is to investigate how revegetation and management of ski runs influence soil nutrients, vegetation characteristics, and the possible invasion of nonnative plant species used in revegetation into native ecosystems. A soil and vegetation survey at ski runs and nearby forests, and a factorial experiment simulating ski run construction and management (factors: soil removal, fertilization, and seed sowing) were conducted at Ruka ski resort, in northern Finland, during 2003-2008. According to the survey, management practices had caused considerable changes in the vegetation structure and increased soil nutrient concentrations, pH, and conductivity on the ski runs relative to nearby forests. Seed mixture species sown during the revegetation of ski runs had not spread to adjacent forests. The experimental study showed that the germination of seed mixture species was favored by treatments simulating the management of ski runs, but none of them could eventually establish in the study forest. As nutrient leaching causes both environmental deterioration and changes in vegetation structure, it may eventually pose a greater environmental risk than the spread of seed mixture species alone. Machine grading and fertilization, which have the most drastic effects on soils and vegetation, should, therefore, be minimized when constructing and managing ski runs.

  20. Ski protein levels increase during in vitro progression of HPV16-immortalized human keratinocytes and in cervical cancer

    International Nuclear Information System (INIS)

    Chen, Yi; Pirisi, Lucia; Creek, Kim E.

    2013-01-01

    We compared the levels of the Ski oncoprotein, an inhibitor of transforming growth factor-beta (TGF-β) signaling, in normal human keratinocytes (HKc), HPV16 immortalized HKc (HKc/HPV16), and differentiation resistant HKc/HPV16 (HKc/DR) in the absence and presence of TGF-β. Steady-state Ski protein levels increased in HKc/HPV16 and even further in HKc/DR, compared to HKc. TGF-β treatment of HKc, HKc/HPV16, and HKc/DR dramatically decreased Ski. TGF-β-induced Ski degradation was delayed in HKc/DR. Ski and phospho-Ski protein levels are cell cycle dependent with maximal Ski expression and localization to centrosomes and mitotic spindles during G2/M. ShRNA knock down of Ski in HKc/DR inhibited cell proliferation. More intense nuclear and cytoplasmic Ski staining and altered Ski localization were found in cervical cancer samples compared to adjacent normal tissue in a cervical cancer tissue array. Overall, these studies demonstrate altered Ski protein levels, degradation and localization in HPV16-transformed human keratinocytes and in cervical cancer. - Highlights: • Ski oncoprotein levels increase during progression of HPV16-transformed cells. • Ski and phospho-Ski protein levels are cell cycle dependent. • Ski knock-down in HPV16-transformed keratinocytes inhibited cell proliferation. • Cervical cancer samples overexpress Ski

  1. The Effect of a Vibration Absorber on the Damping Properties of Alpine Skis

    Directory of Open Access Journals (Sweden)

    Stefan Schwanitz

    2018-02-01

    Full Text Available Coupled bending-torsion vibrations at the shovel are a severe problem when running an alpine ski at high velocities on hard or icy slopes. Thus, a major goal for ski manufacturers is to dampen vibrations through a proper multi-material design and/or additional absorbers. The aim of this study was to examine the effectiveness of a particular vibration absorber on a commercial slalom ski through a series of laboratory tests as well as a subjective field evaluation. Therefore, two identical pairs of ski were used and the absorber was deactivated on one pair. Laboratory tests revealed reductions of 5% to 49% of bending vibrations on skis with activated absorber. Subjective evaluation by 6 subjects suggested minor differences in the mean of the evaluated criteria turnablity, edge grip, steering behavior and stability towards a better performance of the skis with activated absorber. Subjects were able to identify the absorber mode with a success rate of 61.1%.

  2. Full-field Strain Analysis of a Ski Boot

    Science.gov (United States)

    Reiter, M.; Singer, G.; Major, Z.

    2010-06-01

    The quality of the ski boots plays an extraordinary important role in the performance and in the safety of the skiers. The deformation behavior of a racing class ski boot was characterized by using the digital image correlation technique in this study. The boot was gripped in the ski binding and 3 types of motions of the skiers and the deformations of the boot were simulated by a professional skier in the laboratory. First, the buckles were closed in 4 stages and the resulting strains were measured. Furthermore, the skier positioned his balance continuously forward, resulting in a high overall bending deformation of the boot. The leg of the skier acted as a bending arm and pushed the upper part of the boot forward. This loading situation was assumed as quasistatic and was repeated several times. Finally, the skier jumped and this dynamic movement was recorded by using two high speed cameras for 3D analysis. Special focus was devoted to the measurement of the deformation of the boot during the contact of the ski with the ground of the laboratory. Both the displacement of the upper part and the local strain in selected areas of the boot was determined for both quasi-static and dynamic test conditions and are discussed in the paper.

  3. Kick, Glide, Pole! Cross-Country Skiing Fun (Part II)

    Science.gov (United States)

    Duoos, Bridget A.

    2012-01-01

    Part I of Kick, Glide, Pole! Cross-Country Skiing Fun, which was published in last issue, discussed how to select cross-country ski equipment, dress for the activity and the biomechanics of the diagonal stride. Part II focuses on teaching the diagonal stride technique and begins with a progression of indoor activities. Incorporating this fun,…

  4. SKI's Evaluation of SKB's RD and D Programme 95. Review Report

    International Nuclear Information System (INIS)

    1996-10-01

    SKI (the Swedish Nuclear Power Inspectorate) has sent SKB's (the Swedish Nuclear Fuel and Waste Management Co.) RD and D Programme 95 to sixty authorities and organizations for review. 35 reviewing bodies have replied. In various ways, most of the comments are related to the decision-making process, both with regard to site selection and choice of method and only a small number of reviewing bodies have dealt with the more purely technical issues such as the function of the barriers and the safety assessment methodology. SKI's review of the programme is based on the premises of establishing whether and how the programme can fulfill its actual purpose to identify and implement solutions for the final disposal of the spent nuclear fuel from the Swedish nuclear power plants. SKI's statement to the Government includes a 'Summary and Conclusions' of the 'Review Report'. In (the present) 'Review Report' SKI reviews the programme and deals with comments from the other reviewing bodies. Furthermore, SKI has commissioned a separate report with the 'Comments of the Reviewing Bodies'. 32 refs

  5. Modelling of Aerodynamic Drag in Alpine Skiing

    OpenAIRE

    Elfmark, Ola

    2017-01-01

    Most of the breaking force in the speed disciplines in alpine skiing is caused by the aerodynamic drag, and a better knowledge of the drag force is therefore desirable to gain time in races. In this study a complete database of how the drag area (CDA) changes, with respect to the different body segments, was made and used to explain a complete body motion in alpine skiing. Three experiments were performed in the wind tunnel at NTNU, Trondheim. The database from a full body measurement on an a...

  6. Characteristics of the early flight phase in the Olympic ski jumping competition.

    Science.gov (United States)

    Virmavirta, Mikko; Isolehto, Juha; Komi, Paavo; Brüggemann, Gert-Peter; Müller, Erich; Schwameder, Hermann

    2005-11-01

    Early flight phase (approximately 40 m) of the athletes participating in the final round of the individual large hill ski jumping competition in Salt Lake City Olympics was filmed with two high-speed pan & tilt video cameras. The results showed that jumpers' steady flight position was almost completed within 0.5s. The most significant correlation with the length of the jump was found in the angle between the skis and body (r=.714, p.001 at 1.1s after the take-off). This particular phase seemed to be important because the ski angle of attack was also related to the jumping distance at the same phase. Although the more upright ski position relative to flight path resulted in longer jumping distance, the winner of the competition had significantly lower ski position as compared to the other good jumpers. This may be due to the high altitude (>2000 m) of the ski jumping stadium in this competition. Because of the low air density, the aerodynamic forces were also low and this probably caused less skillful jumpers to lean too much forward at this phase. Maintenance of speed seemed to be emphasized in this particular competition.

  7. [The ski camp doctor's role in the the prevention of winter sport accidents].

    Science.gov (United States)

    Felkai, Péter

    2007-08-26

    Skiing is a risky sport for many, even for children and beginners. When the ski-group is escorted by doctors who are able to provide advanced life support on the scene and are trained either in the field of emergency medicine or in travel medicine, a good possibility is given for the prevention of ski-accidents and for decreasing the number of travel related illnesses. This fact has led to the basic idea of training ski-camp doctors in Hungary. There is no similar initiative in the Hungarian literature. Therefore the article tries to summarise the medical knowledge and requirements of a ski-camp doctor, and analyses the prevention tasks of the doctor as well. The camp doctor must be well informed and highly trained in the field of emergency and travel medicine. The main tasks are: pre-travel advice, treatment of the common (travel-related) diseases, providing basic and advanced life-support on the scene, and to organise the hospitalisation and repatriation of patient, in cooperation with the hospital and insurance doctor. Moreover, the prevention should start before departure: the estimation of the physical and health condition of the skiers, a continuous care of the chronic people, and supervision of the place (hygienic circumstances, rescue forces available, the condition of the ski slopes, etc.) are vital--as for the primary prevention. The secondary level of the prevention is the treatment of the injured/sick persons, and assistance in the medical evacuation. During the training, not only postgraduate medical, mountain and alpine medicine lessons have been provided, but basic legal and insurance information as well. Moreover, the doctors received ski-course from professional ski-trainers in order to improve their ski-technique and skills on different slopes and off-piste places. In the future the local mountain rescue and air-rescue forces have to be involved in postgraduate training. Hopefully different travel-insurance companies and travel offices will use

  8. Nordic ski jumping fatalities in the United States: a 50-year summary.

    Science.gov (United States)

    Wright, J R

    1988-06-01

    Nordic ski-jumping fatalities are rare events. Six jumping fatalities have occurred in the United States during the past 50 years. The fatality rate for nordic ski jumping, estimated to be roughly 12 fatalities/100,000 participants annually, appears to be within the range of fatality rates for other "risky" outdoor sports. Cervical fractures appear to be the most frequent fatal ski-jumping injury.

  9. Downhill ski injuries in children and adolescents.

    Science.gov (United States)

    Meyers, Michael C; Laurent, C Matthew; Higgins, Robert W; Skelly, William A

    2007-01-01

    Downhill skiing is considered to be an enjoyable activity for children and adolescents, but it is not without its risks and injuries. Injury rates now range between 3.9 and 9.1 injuries per 1000 skier days, and there has been a well documented increase in the number of trauma cases and fatalities associated with this sport. Head and neck injuries are considered the primary cause of fatal injuries and constitute 11-20% of total injuries among children and adolescents. Cranial trauma is responsible for up to 54% of total hospital injuries and 67% of all fatalities, whereas thoracoabdominal and spine injuries comprise 4-10% of fatalities. Furthermore, there has been an increase in the proportion of upper extremity trauma with acromioclavicular dislocations, and clavicle and humeral fractures accounting for the majority (22-79%) of the injuries. However, the most common and potentially serious injuries in children and adolescents are those to the lower extremity, with knee sprains and anterior cruciate ligament tears accounting for up to 47.7% of total injuries. Knee sprains and grade III ligament trauma associated with lower leg fractures account for 39-77% of ski injuries in this young population. Approximately 15% of downhill skiing injuries among children and adolescents are caused by musculoskeletal immaturity. Other factors include excessive fatigue, age, level of experience, and inappropriate or improperly adjusted equipment. Collisions and falls constitute a significant portion (up to 76%) of trauma, and are commonly associated with excessive speed, adverse slope conditions, overconfidence leading to carelessness, and behavioural patterns within and among gender. The type and severity of injuries are typically functions of biomechanical efficiency, skiing velocity or slope conditions; however, a multiplicative array of intrinsic and extrinsic factors may simultaneously be involved. Despite extensive efforts to provide a comprehensive picture of the aetiology of

  10. Unique aspects of downhill ski injuries part 1: epidemiology and equipment.

    Science.gov (United States)

    Buck, P G; Sophocles, A M; Beckenbauch, R D

    1982-03-01

    Skiing is an exciting sport with a significant potential /or serious injury. This potential for injury can be minimized but never entirely eliminated by modern safety equipment.Upper extremity injuries have become relatively more common as the incidence of lower extremity injuries has decreased. Ankle and foot injuries have become infrequent since the advent of the rigid plastic boot, while the incidence of knee injuries has remained essentially constant.Three major mechanisms of injury to the lower extremity include external rotation and abduction, forward fall, and internal rotation. Each mechanism can produce a distinctive set of injured structures.The "skier at risk" is characterized by a lower level of ability, lighter weight, and extremes of age. Injuries can be minimized by purchasing good quality equipment and maintaining it properly; discarding obsolete equipment; using ski brakes, antifriction devices and pistol grip poles; using multirelease bindings for beginners or intermediates; good physical conditioning; taking ski lessons and coupling this with skiing experience; and skiing in control and using common sense on the slopes.Areas which need the most improvement in equipment design include multi-release bindings suitable for all skiers and children's boots. Copyright 2013, SLACK Incorporated.

  11. High Performance Skiing. How to Become a Better Alpine Skier.

    Science.gov (United States)

    Yacenda, John

    This book is intended for people who desire to improve their skiing by exploring high performance techniques leading to: (1) more consistent performance; (2) less fatigue and more endurance; (3) greater strength and flexibility; (4) greater versatility; (5) greater confidence in all skiing conditions; and (6) the knowledge to participate in…

  12. Kinematic structure at the early flight position in ski jumping.

    Science.gov (United States)

    Vodičar, Janez; Coh, Milan; Jošt, Bojan

    2012-12-01

    The purpose of our research was to establish the variability of correlation between the length of the jumps and selected multi-item kinematic variables (n=9) in the early flight phase technique of ski jumping. This study was conducted on a sample of elite Slovenian ski jumpers (N=29) who participated in the experiment on a jumping hill in Hinterzarten, Germany (HS95m) on the 20(th) of August, 2008. The highest and most significant correlations (p=0.01) with the length of the ski jump were found in the multi-item variable height of flying, which was also expressed with the highest level of stability of the explained total variance (TV) on the first factor (TV=69.13%). The most important characteristic of the aerodynamic aspect of early flight was the variable angle between the body chord and the horizontal axis with significantly high correlations (pjump. Only two more variables, the angle between the upper body and the horizontal plane (TV=53.69%), and the angle between left ski and left leg (TV=50.13%), had an explained common variance on the first factor greater than 50% of total variance. The results indicated that some kinematic parameters of ski jumping early flight technique were more important for success considering the length of the jump.

  13. SKIs evaluation of SKBs RD and D programme 92

    International Nuclear Information System (INIS)

    1993-07-01

    Section 11 of the Act (1984:3) on Nuclear Activities stipulates that the holder of a licence to own or operate a nuclear power reactor shall ensure that the necessary comprehensive research and development work is conducted in order to safely handle and finally dispose of the nuclear waste produced and to safely decommission and dismantle installation where the nuclear activity is no longer carried out. According to section 12 of the Act on nuclear activities, the reactor owners shall, in consultation with each other, prepare or have prepared a programme for the necessary comprehensive research and development work and the other measures. The programme shall contain an overview of all measures that may be necessary and also specify, in detail, the measures that are intended to be taken within a period of at least six years. The programme shall be submitted to the Government or to the authority designated by the Government for examination and evaluation. According to section 22 of the ordinance on nuclear activities, the Swedish Nuclear Power Inspectorate (SKI) shall ensure that the research and development work which the reactor owners are responsible for undertaking according to sections 11 and 12 of the act of nuclear activities, is actually carried out. SKIs premise for evaluating the programme has been to examine it as an integrated R and D programme, which essentially focusses on structure, strategy and planning in order to effectively realize the defined goals of the programme, i.e. finding a safe, final solution to the disposal of spent nuclear fuel. Keeping to the time-schedule should not be the controlling factor in carrying out the research and development programme. The essential objective is to attain the goal without jeopardizing quality. SKIs examination has been documented in the form of the following: summary and conclusions, evaluation report, report of comments by reviewing bodies, and consultants reports. SKIs statement to the Government has been

  14. The prevalence of ski jumping among pupils in the first triad of primary school

    OpenAIRE

    Vtič, Maja

    2016-01-01

    As one of the most widespread sports discipline in Slovenia, ski jumping has a long tradition. Ski jumping is a competitive sport at which recreational engagement is not possible because of its special features and specifics. It is one of the basic sports activities for the development of children's motor skills, since ski jumping requires an integrated training of the trainee. Ski jumping is basically a winter sport, whereas in the summer season, it has also become increasingly present with ...

  15. Analysis of Landing in Ski Jumping by Means of Inertial Sensors and Force Insoles

    Directory of Open Access Journals (Sweden)

    Veronica Bessone

    2018-02-01

    Full Text Available Landing and its preparation are important phases for performance and safety of ski jumpers. A correct ski positioning could influence the jump length as also the cushioning effect of the aerodynamic forces that permits the reduction of landing impacts. Consequently, the detection of ski angles during landing preparation could allow for analyzing landing techniques that result in reduced impact forces for the athletes. In this study, two athletes performed with force insoles and inertial sensors positioned on the ski during training conditions on the ski jumping hill. The results confirmed previous studies, showing that impact forces can reach more than four times body weight. In the analyzed cases, the force distribution resulted to be more concentrated on the forefoot and the main movement influencing the impact was the pitch. The combination of inertial sensors, in particular gyroscopes, plus force insoles demonstrated to be an interesting set up for ski jumping movement analysis.

  16. Engineering movement of qualified skiers-racers skating style in the current development of ski races

    Directory of Open Access Journals (Sweden)

    Sergey Kotliar

    2015-08-01

    Full Text Available Purpose: analysis of technique of skiing skating style of leading sportsmen of the world. Material and Methods: research was conducted by means of analysis of video data and кинограмм of of skilled racing cross-country ski and biathlon of leading countries of the world. Results: the analysis of dynamic descriptions of technique of the same name ski motions educed the row of factors, from that sportsmen, what applied «Double Push» in the technique of skiing, increase speed of passing of short segments on 4-6%. Conclusions: implementation of «Double Push» can useful for racing cross-country ski and biathlon on competitions on a sprint, on rollers-ski and at implementation of short accelerations on distance, and also on a finish

  17. The importance of being light: aerodynamic forces and weight in ski jumping.

    Science.gov (United States)

    Schmölzer, B; Müller, W

    2002-08-01

    Many contemporary world class ski jumpers are alarmingly underweight and several cases of anorexia nervosa have come to light. Athletes strive for low body weight because it gives them a major competitive advantage. In order to stop this hazardous development, changes to the regulations are being discussed, and the International Ski Federation and the International Olympic Committee wish to be proactive in safe guarding the interest of the athletes and their health. This study of ski jumping uses field studies conducted during World Cup competitions, large-scale wind tunnel measurements with 1:1 models of ski jumpers in current equipment and highly accurate computer simulations of the flight phase that include the effects due to the athlete's position changes. Particular attention has been directed to the design of a reference jump that mirrors current flight style and equipment regulations (2001), and to the investigation of effects associated with variation in body mass, air density, and wind gusts during the simulated flight. The detailed analysis of the physics of ski jumping described here can be used for the investigation of all initial value and parameter variations that determine the flight path of a ski jumper and will form a reliable basis for setting regulations that will make it less attractive or even disadvantageous for the athlete to be extremely light.

  18. Take-off aerodynamics in ski jumping.

    Science.gov (United States)

    Virmavirta, M; Kivekäs, J; Komi, P V

    2001-04-01

    The effect of aerodynamic forces on the force-time characteristics of the simulated ski jumping take-off was examined in a wind tunnel. Vertical and horizontal ground reaction forces were recorded with a force plate installed under the wind tunnel floor. The jumpers performed take-offs in non-wind conditions and in various wind conditions (21-33 m s(-1)). EMGs of the important take-off muscles were recorded from one jumper. The dramatic decrease in take-off time found in all jumpers can be considered as the result of the influence of aerodynamic lift. The loss in impulse due to the shorter force production time with the same take-off force is compensated with the increase in lift force, resulting in a higher vertical velocity (V(v)) than is expected from the conventional calculation of V(v) from the force impulse. The wind conditions emphasized the explosiveness of the ski jumping take-off. The aerodynamic lift and drag forces which characterize the aerodynamic quality of the initial take-off position (static in-run position) varied widely even between the examined elite ski jumpers. According to the computer simulation these differences can decisively affect jumping distance. The proper utilization of the prevailing aerodynamic forces before and during take-off is a very important prerequisite for achieving a good flight position.

  19. CHANGES IN QUADRICEPS MUSCLE ACTIVITY DURING SUSTAINED RECREATIONAL ALPINE SKIING

    Directory of Open Access Journals (Sweden)

    Josef Kröll

    2011-03-01

    Full Text Available During a day of skiing thousands of repeated contractions take place. Previous research on prolonged recreational alpine skiing show that physiological changes occur and hence some level of fatigue is inevitable. In the present paper the effect of prolonged skiing on the recruitment and coordination of the muscle activity was investigated. Six subjects performed 24 standardized runs. Muscle activity during the first two (PREskiing and the last two (POSTskiing runs was measured from the vastus lateralis (VL and rectus femoris (RF using EMG and quantified using wavelet and principal component analysis. The frequency content of the EMG signal shifted in seven out of eight cases significantly towards lower frequencies with highest effects observed for RF on outside leg. A significant pronounced outside leg loading occurred during POSTskiing and the timing of muscle activity peaks occurred more towards turn completion. Specific EMG frequency changes were observed at certain time points throughout the time windows and not over the whole double turn. It is suggested that general muscular fatigue, where additional specific muscle fibers have to be recruited due to the reduced power output of other fibers did not occur. The EMG frequency decrease and intensity changes for RF and VL are caused by altered timing (coordination within the turn towards a most likely more uncontrolled skiing technique. Hence, these data provide evidence to suggest recreational skiers alter their skiing technique before a potential change in muscle fiber recruitment occurs

  20. [Ski shoe versus knee joint--3: Risk for falling backward].

    Science.gov (United States)

    Schaff, P; Hauser, W

    1990-12-01

    In contrast to the drop in the incidence of fractures of the lower leg that has been observed in recent years, the incidence of knee injuries has not decreased in skiing. There has even been a relative increase of severe knee lesions and isolated ACL ruptures, prompting us to conduct a comprehensive study of the causes of this phenomena. The goal of the study was to develop a new measuring device for alpine skiing research by combining motion analysis, pressure and force measurement, comprehensive examine the forward/backward movement in skiboots in the lab and by means of telemetry on the slope (Skiboot versus knee joint part 1/Sportverlerletzung. Sportschaden 3, 1989, pp. 149-161) and to come up with a proposal for a new safety concept to reduce the high number of knee injuries in alpine skiing in the future. The first study was devoted to the forward movement in skiboots (Skiboot versus knee joint part 2/Sportverletzung. Sportschaden 4, 1990, pp. 1-13). The results showed that a skiing style in backward lean position was adopted by skiers wearing boots with a stiff forward flexion and was supported by the fixed backward spoiler. In order to quantify the influence of the backward spoiler a special skiboot was constructed allowing the rear spoiler to give way at a variable, defined stiffness and register the angular displacement and horizontal force Fh. The results showed most clearly that even a medium rear spoiler resistance will sign, reduce the peak force values by a factor of 5.5. The acceleration at the knee joint level is significantly higher (factor 1.6, p less than 0.05) in case of a rigid spoiler. The lab tests could be confirmed on the slope (sign. reduction of max. force by factor 8). It also proved that normal skiing can be performed in such a boot without limitations. In consideration of our facts it is concluded that the principle of safety bindings must definitely apply in future in equal measure also to the ski boot. As a proposal for future

  1. Alpine Skiing With total knee ArthroPlasty (ASWAP)

    DEFF Research Database (Denmark)

    Koesters, A.; Poetzelsberger, B.; Dela, F.

    2015-01-01

    The aim of this study was to monitor the long-term effects of skiing on health-related parameters and implant related factors like loosening and wear in patients with total knee arthroplasty. This paper describes the overall study design, general demographics, and physiological demand of the inte......The aim of this study was to monitor the long-term effects of skiing on health-related parameters and implant related factors like loosening and wear in patients with total knee arthroplasty. This paper describes the overall study design, general demographics, and physiological demand...

  2. Effect of ski geometry and standing height on kinetic energy: equipment designed to reduce risk of severe traumatic injuries in alpine downhill ski racing

    Science.gov (United States)

    Gilgien, Matthias; Spörri, Jörg; Kröll, Josef; Müller, Erich

    2016-01-01

    Background Injuries in downhill (DH) are often related to high speed and, therefore, to high energy and forces which are involved in injury situations. Yet to date, no study has investigated the effect of ski geometry and standing height on kinetic energy (EKIN) in DH. This knowledge would be essential to define appropriate equipment rules that have the potential to protect the athletes’ health. Methods During a field experiment on an official World Cup DH course, 2 recently retired world class skiers skied on 5 different pairs of skis varying in width, length and standing height. Course characteristics, terrain and the skiers’ centre of mass position were captured by a differential Global Navigational Satellite System-based methodology. EKIN, speed, ski–snow friction force (FF), ground reaction force (FGRF) and ski–snow friction coefficient (CoeffF) were calculated and analysed in dependency of the used skis. Results In the steep terrain, longer skis with reduced width and standing height significantly decreased average EKIN by ∼3%. Locally, even larger reductions of EKIN were observed (up to 7%). These local decreases in EKIN were mainly explainable by higher FF. Moreover, CoeffF differences seem of greater importance for explaining local FF differences than the differences in FGRF. Conclusions Knowing that increased speed and EKIN likely lead to increased forces in fall/crash situations, the observed equipment-induced reduction in EKIN can be considered a reasonable measure to improve athlete safety, even though the achieved preventative gains are rather small and limited to steep terrain. PMID:26702013

  3. THE ROLE OF MARKETING IN MODERN SPORT PROCEDURE AT EXAMPLE OF SKIING

    OpenAIRE

    Stevo Popović; Blažo Jabučanin

    2008-01-01

    The object of this project is marketing in modern sport procedure. The main focus will be directional to skiing and specific marketing in the area where it participated. The questions of sport marketing will be tested at Ski club “Mogren” from Budva. The main goal refers the requirement that sport in modern world should be presented as less simpler, cheaper and more attractive way. During last 30 years, sports, including the skiing, alike one of the Olympic sports, became much more active in ...

  4. Underweight in ski jumping: The solution of the problem.

    Science.gov (United States)

    Müller, W; Gröschl, W; Müller, R; Sudi, K

    2006-11-01

    Underweight is becoming increasingly prevalent in many sports. Among world class ski jumpers, the body mass index BMI has decreased by 4 units since 1970. The BMI ignores different body properties of individuals. Particular care should be taken in groups with unusual leg length to avoid classifying them inappropriately as thin or overweight (WHO). The improved measure MI (mass index) for relative body weight overcomes this shortcoming. Anthropometric data of ski jumpers was collected during the Olympic Games in Salt Lake City (2002; participation 81 %, n = 57), during the Summer Grand Prix in Hinterzarten (2000; participation 100 %, n = 92), and during the World Cup in Planica (2000; n = 56). The BMI and the MI were determined. The MI considers the individual leg length: A person with longer legs than average has an MI > BMI, and vice versa: MI = 0.28 m/s2 (m: mass in kg, s: sitting height in meters). BMI classes of ski jumpers in the season 2004/2005 were calculated from their official individual ski length limitation which is a function of their BMI. BMI means were 19.84 in Planica, 19.58 in Hinterzarten, and 19.43 kg m(-2) in SLC. Lowest BMI was 16.4 kg m(-2). The percentage of underweight ski jumpers (BMI ski jumping regulations. The ratio s/h = C (s = sitting height, h = height, C = cormic index) ranged from 0.49 to 0.57. Accordingly, the MI values (which are leg length corrected BMI values according to MI = BMI (C /C) (k) with k = 2 and C = 0.53) deviated remarkably from BMI values. For the 49 cases with BMI or MI or both below 18.5 kg m(-2), the classification to be underweight or not changed in 69 % when the MI was used instead of the BMI. Underweight or overweight is not only a question of cut-off points; the measure used determines the classification accuracy. A substantial improvement of weight analyses in sports medicine, public health, and general medicine as well can be obtained by using the MI instead of the BMI.

  5. Anterior cruciate ligament injury/reinjury in alpine ski racing: a narrative review

    Science.gov (United States)

    Jordan, Matthew J; Aagaard, Per; Herzog, Walter

    2017-01-01

    The purpose of the present review was to: 1) provide an overview of the current understanding on the epidemiology, etiology, risk factors, and prevention methods for anterior cruciate ligament (ACL) injury in alpine ski racing; and 2) provide an overview of what is known pertaining to ACL reinjury and return to sport after ACL injury in alpine ski racing. Given that most of the scientific studies on ACL injuries in alpine ski racing have been descriptive, and that very few studies contributed higher level scientific evidence, a nonsystematic narrative review was employed. Three scholarly databases were searched for articles on ACL injury or knee injury in alpine ski racing. Studies were classified according to their relevance in relation to epidemiology, etiology, risk factors, and return to sport/reinjury prevention. Alpine ski racers (skiers) were found to be at high risk for knee injuries, and ACL tears were the most frequent diagnosis. Three primary ACL injury mechanism were identified that involved tibial internal rotation and anteriorly directed shear forces from ski equipment and the environment. While trunk muscle strength imbalance and genetics were found to be predictive of ACL injuries in development-level skiers, there was limited scientific data on ACL injury risk factors among elite skiers. Based on expert opinion, research on injury risk factors should focus on equipment design, course settings/speed, and athlete factors (eg, fitness). While skiers seem to make a successful recovery following ACL injury, there may be persistent neuromuscular deficits. Future research efforts should be directed toward prospective studies on ACL injury/reinjury prevention in both male and female skiers and toward the effects of knee injury on long-term health outcomes, such as the early development of osteoarthritis. International collaborations may be necessary to generate sufficient statistical power for ACL injury/reinjury prevention research in alpine ski racing

  6. Developing a business plan for Ski School Jasna

    OpenAIRE

    Dubovská, Jana

    2014-01-01

    The Master's Thesis analyses and evaluates the conditions for the Ski & Snowboard School Lúčky development in the Jasná Nízke Tatry ski resort as well as it illustrates specific steps and actions in the realistic business plan. Firstly, it introduces theoretical background of feasibility analysis, business model, and the business plan focusing on the importance and structure of each topic. Secondly, the thesis portrays the results of an empirical research conducted on the target audience that...

  7. Biomechanical pole and leg characteristics during uphill diagonal roller skiing.

    Science.gov (United States)

    Lindinger, Stefan Josef; Göpfert, Caroline; Stöggl, Thomas; Müller, Erich; Holmberg, Hans-Christer

    2009-11-01

    Diagonal skiing as a major classical technique has hardly been investigated over the last two decades, although technique and racing velocities have developed substantially. The aims of the present study were to 1) analyse pole and leg kinetics and kinematics during submaximal uphill diagonal roller skiing and 2) identify biomechanical factors related to performance. Twelve elite skiers performed a time to exhaustion (performance) test on a treadmill. Joint kinematics and pole/plantar forces were recorded separately during diagonal roller skiing (9 degrees; 11 km/h). Performance was correlated to cycle length (r = 0.77; P Push-off demonstrated performance correlations for impulse of leg force (r = 0.84), relative duration (r= -0.76) and knee flexion (r = 0.73) and extension ROM (r = 0.74). Relative time to peak pole force was associated with performance (r = 0.73). In summary, diagonal roller skiing performance was linked to 1) longer cycle length, 2) greater impulse of force during a shorter push-off with larger flexion/extension ROMs in leg joints, 3) longer leg swing, and 4) later peak pole force, demonstrating the major key characteristics to be emphasised in training.

  8. Kinematic analysis of the flight phase of the Nordic combined and ski jump on a large hill (HS-134 m) during the 2009 Nordic World Ski Championships.

    Science.gov (United States)

    Svoboda, Zdenek; Janura, Miroslav; Cabell, Lee; Janurová, Eva

    2011-01-01

    The purpose of this study was to assess the execution of the flight phase in the Nordic combined (NC) among three groups of competitors, representing different skill levels, and to compare them with three groups of ski jumpers (SJs). Thirty NC and thirty SJ competitors, who performed ski jumps on an HS-134 m jumping hill, were divided into three subgroups based on jump length execution. Two-dimensional (2-D) kinematic data were collected from the lower extremities, trunks, and skis of the competitors. The SJ group had a smaller lower extremity angle ( p jump lengths comparable to those of the SJ competitors by having significantly higher in-run velocities.

  9. Vulnerability assessment of skiing-dependent businesses to the effects of climate change in Banff and Jasper National Parks, Canada

    Science.gov (United States)

    Reynolds, David Michael

    This qualitative study examines the potential positive and negative socio-economic impacts that may emerge from the long-term effects of climate change on skiing-dependent businesses in Banff and Jasper National Parks, Canada. My goal was to determine whether or not skiing-related tourism in the parks in the 2020s and 2050s is more or less socio-economically vulnerable to the effects of climate change on snow cover, temperatures and ski season length at ski resorts in the parks. My study explored the level of awareness and personal perceptions of 60 skiing-dependent business managers about how the impact of climate change on ski resorts may influence future socio-economics of ski tourism businesses. I employed a vulnerability assessment approach and adopted some elements of grounded theory. My primary data sources are interviews with managers and the outcome of the geographical factors index (GFI). Supporting methods include: an analysis and interpretation of climate model data and an interpretation of the economic analysis of skiing in the parks. The interview data were sorted and coded to establish concepts and findings by interview questions, while the GFI model rated and ranked 24 regional ski resorts in the Canadian Cordillera. The findings answered the research questions and helped me conclude what the future socio-economic vulnerability may be of skiing-dependent businesses in the parks. The interviews revealed that managers are not informed about climate change and they have not seen any urgency to consider the effects on business. The GFI revealed that the ski resorts in the parks ranked in the top ten of 24 ski resorts in the Cordillera based on 14 common geographical factors. The economic reports suggest skiing is the foundation of the winter economy in the parks and any impact on skiing would directly impact other skiing-dependent businesses. Research indicates that the effects of climate change may have less economic impact on skiing

  10. In-frame mutations in exon 1 of SKI cause dominant Shprintzen-Goldberg syndrome.

    Science.gov (United States)

    Carmignac, Virginie; Thevenon, Julien; Adès, Lesley; Callewaert, Bert; Julia, Sophie; Thauvin-Robinet, Christel; Gueneau, Lucie; Courcet, Jean-Benoit; Lopez, Estelle; Holman, Katherine; Renard, Marjolijn; Plauchu, Henri; Plessis, Ghislaine; De Backer, Julie; Child, Anne; Arno, Gavin; Duplomb, Laurence; Callier, Patrick; Aral, Bernard; Vabres, Pierre; Gigot, Nadège; Arbustini, Eloisa; Grasso, Maurizia; Robinson, Peter N; Goizet, Cyril; Baumann, Clarisse; Di Rocco, Maja; Sanchez Del Pozo, Jaime; Huet, Frédéric; Jondeau, Guillaume; Collod-Beroud, Gwenaëlle; Beroud, Christophe; Amiel, Jeanne; Cormier-Daire, Valérie; Rivière, Jean-Baptiste; Boileau, Catherine; De Paepe, Anne; Faivre, Laurence

    2012-11-02

    Shprintzen-Goldberg syndrome (SGS) is characterized by severe marfanoid habitus, intellectual disability, camptodactyly, typical facial dysmorphism, and craniosynostosis. Using family-based exome sequencing, we identified a dominantly inherited heterozygous in-frame deletion in exon 1 of SKI. Direct sequencing of SKI further identified one overlapping heterozygous in-frame deletion and ten heterozygous missense mutations affecting recurrent residues in 18 of the 19 individuals screened for SGS; these individuals included one family affected by somatic mosaicism. All mutations were located in a restricted area of exon 1, within the R-SMAD binding domain of SKI. No mutation was found in a cohort of 11 individuals with other marfanoid-craniosynostosis phenotypes. The interaction between SKI and Smad2/3 and Smad 4 regulates TGF-β signaling, and the pattern of anomalies in Ski-deficient mice corresponds to the clinical manifestations of SGS. These findings define SGS as a member of the family of diseases associated with the TGF-β-signaling pathway. Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  11. SKI - ASAR - O3. As operated Safety Analysis Report. Recurring safety review 1996 Oskarshamn 3

    International Nuclear Information System (INIS)

    1997-12-01

    According to Swedish law, the reactor owner is responsible for performing a safety review and writing a ''ASAR''-report. The Nuclear Power Inspectorate (SKI) examines this report, and reports the findings to the government (the ''SKI-ASAR'' report). Each Swedish reactor should pass through three full ASAR reviews during its life-time, similar to the licensing inspection before start-up of the reactor. The first series ASAR was delivered by OKG to SKI in December 1996, and forms the basis for the SKI analysis in the present report

  12. SKI - ASAR - F3. As operated Safety Analysis Report. Recurring safety review 1996 Forsmark 3

    International Nuclear Information System (INIS)

    1997-12-01

    According to Swedish law, the reactor owner is responsible for performing a safety review and writing a ''ASAR''-report. The Nuclear Power Inspectorate (SKI) examines this report, and reports the findings to the government (the ''SKI-ASAR'' report). Each Swedish reactor should pass through three full ASAR reviews during its life-time, similar to the licensing inspection before start-up of the reactor. The first series ASAR was delivered by FKA to SKI in December 1996, and forms the basis for the SKI analysis in the present report

  13. SKI - ASAR - R1. As operated Safety Analysis Report. Recurring safety review 1995 Ringhals 1

    International Nuclear Information System (INIS)

    2000-01-01

    According to Swedish law, the reactor owner is responsible for performing a safety review and writing a so called ASAR-report. The Nuclear Power Inspectorate (SKI) examines this report, and reports the findings to the government (the so called SKI-ASAR-report). Each Swedish reactor should pass through three full ASAR reviews during its lifetime, similar to the licensing inspection before start-up of the reactor. The second series ASAR was delivered by the Ringhals utility to SKI in September 1995, and forms the basis for the SKI analysis in the present report

  14. Enhanced UV exposure on a ski-field compared with exposures at sea level.

    Science.gov (United States)

    Allen, Martin; McKenzie, Richard

    2005-05-01

    Personal erythemal UV monitoring badges, which were developed to monitor the UV exposure of school children, were used to measure UV exposures received by one of the authors (MA) at the Mt Hutt ski-field, in New Zealand. These were then compared with measurements taken at the same times from a nearby sea level site in Christchurch city. The badges were designed to give instantaneous readings of erythemally-weighted (i.e., "sun burning") UV radiation and were cross-calibrated against meteorological grade UV instruments maintained by the National Institute of Water & Atmospheric Research (NIWA). All skiing and calibration days were clear and almost exclusively cloud free. It was found that the UV maxima for horizontal surfaces at the ski-field (altitude approximately 2 km) were 20-30% greater than at the low altitude site. Larger differences between the sites were observed when the sensor was oriented perpendicular to the sun. The personal doses of UV received by a sensor on the skier's lapel during two days of skiing activity were less than those received by a stationary detector on a horizontal surface near sea level. The exposures depended strongly on the time of year, and in mid-October the maximum UV intensity on the ski-field was 60% greater than in mid-September. The UV exposure levels experienced during skiing were smaller than the summer maxima at low altitudes.

  15. The relative age effect and the influence on performance in youth alpine ski racing.

    Science.gov (United States)

    Müller, Lisa; Hildebrandt, Carolin; Raschner, Christian

    2015-03-01

    The relative age effect (RAE), which refers to an over representation of athletes born early in a selection year, recently was proven to be present in alpine skiing. However, it was not made apparent whether the RAE exists as early as at the youngest level of youth ski racing at national level, nor whether the relative age influences racing performance. As a consequence, the purpose of the present study was twofold: first, to examine the extent of the RAE and second, to assess the influence the relative age has on the overall performance at the youngest levels of youth ski racing. The study included the investigation of 1,438 participants of the Austrian Kids Cup and 1,004 participants of the Teenager Cup at the provincial level, as well as 250 finalists of the Kids Cup and 150 finalists of the Teenager Cup at the national level. Chi²-tests revealed a highly significant RAE already at the youngest level of youth ski racing (Kids Cup) at both the provincial and national levels. There are not again favorably selected the relatively older athletes from the first into the second level of youth ski racing (Teenager Cup). Among the athletes of the Kids Cup, the relative age quarter distribution differed highly significantly from the distribution of the total sample with an over representation of relatively older athletes by comparison taking the top three positions. The data revealed that relative age had a highly significant influence on performance. This study demonstrated that the RAE poses a problem as early as the youngest level of youth ski racing, thereby indicating that many young talented kids are discriminated against, diminishing any chance they might have of becoming elite athletes despite their talents and efforts. The RAE influences not only the participation rate in alpine skiing, but also the performances. As a result, changes in the talent development system are imperative. Key pointsThe relative age influences not only the participation in youth ski

  16. Impact assessment of proposed ski areas: A GIS approach integrating biological, physical and landscape indicators

    International Nuclear Information System (INIS)

    Geneletti, Davide

    2008-01-01

    Ski centres are characterized by significant environmental impacts that occur during both the construction and the operation phase. In Trentino, a well-known ski destination located in northern Italy, new ski areas were identified by planning tools without conducting a formal assessment of their effects on the environment. This paper presents a study to assess and compare the impacts of the proposed ski areas within two valleys strongly linked to winter tourism: the Fiemme and Fassa Valleys. The method is based on the computation of spatial indicators using a Geographical Information System (GIS) to predict and quantify critical impacts, such as ecosystem loss and fragmentation, soil erosion, geomorphologic hazards, interference with flora and fauna, and visibility. Subsequently, multicriteria analysis was applied to generate composite indices, and to rank ski areas according to their overall suitability. Finally, sensitivity analyses allowed to test the stability of the results. The study concluded that two of the proposed ski areas are located in highly unsuitable environment, and the relevant plan provisions should be revised

  17. A characterisation of the paddle-ski fishery in KwaZulu-Natal, South ...

    African Journals Online (AJOL)

    ... many were confused by the safety requirements for paddle-skis. The future management of this fishery is discussed in light of its comparatively low impact on coastal resources. Keywords: catch and effort, fisher demographics, fisheries management, paddle-ski, recreational fishing. African Journal of Marine Science 2012, ...

  18. Multi-Axis Prosthetic Knee Resembles Alpine Skiing Movements of an Intact Leg

    Directory of Open Access Journals (Sweden)

    Ivan Demšar, Jože Duhovnik, Blaž Lešnik, Matej Supej

    2015-12-01

    Full Text Available The purpose of the study was to analyse the flexion angles of the ski boot, ankle and knee joints of an above-knee prosthesis and to compare them with an intact leg and a control group of skiers. One subject with an above-knee amputation of the right leg and eight healthy subjects simulated the movement of a skiing turn by performing two-leg squats in laboratory conditions. By adding additional loads in proportion to body weight (BW; +1/3 BW, +2/3 BW, +3/3 BW, various skiing regimes were simulated. Change of Flexion Angle (CoFA and Range of Motion (RoM in the ski boot, ankle and knee joints were calculated and compared. An average RoM in the skiing boot on the side of prosthesis (4.4 ± 1.1° was significantly lower compared to an intact leg (5.9 ± 1.8° and the control group (6.5 ± 2.3°. In the ankle joint, the average RoM was determined to be 13.2±2.9° in the prosthesis, 12.7 ± 2.8° in an intact leg and 14.8±3.6 in the control group. However, the RoM of the knee joint in the prosthesis (42.2 ± 4.2° was significantly larger than that of the intact leg (34.7 ± 4.4°. The average RoM of the knee joint in the control group was 47.8 ± 5.4°. The influences of additional loads on the kinematics of the lower extremities were different on the side of the prosthesis and on the intact leg. In contrast, additional loads did not produce any significant differences in the control group. Although different CoFAs in the ski boot, ankle and knee joints were used, an above-knee prosthesis with a built-in multi-axis prosthetic knee enables comparable leg kinematics in simulated alpine skiing.

  19. Measurement of the dynamics in ski jumping using a wearable inertial sensor-based system.

    Science.gov (United States)

    Chardonnens, Julien; Favre, Julien; Cuendet, Florian; Gremion, Gérald; Aminian, Kamiar

    2014-01-01

    Dynamics is a central aspect of ski jumping, particularly during take-off and stable flight. Currently, measurement systems able to measure ski jumping dynamics (e.g. 3D cameras, force plates) are complex and only available in few research centres worldwide. This study proposes a method to determine dynamics using a wearable inertial sensor-based system which can be used routinely on any ski jumping hill. The system automatically calculates characteristic dynamic parameters during take-off (position and velocity of the centre of mass perpendicular to the table, force acting on the centre of mass perpendicular to the table and somersault angular velocity) and stable flight (total aerodynamic force). Furthermore, the acceleration of the ski perpendicular to the table was quantified to characterise the skis lift at take-off. The system was tested with two groups of 11 athletes with different jump distances. The force acting on the centre of mass, acceleration of the ski perpendicular to the table, somersault angular velocity and total aerodynamic force were different between groups and correlated with the jump distances. Furthermore, all dynamic parameters were within the range of prior studies based on stationary measurement systems, except for the centre of mass mean force which was slightly lower.

  20. Multi-Axis Prosthetic Knee Resembles Alpine Skiing Movements of an Intact Leg

    Science.gov (United States)

    Demšar, Ivan; Duhovnik, Jože; Lešnik, Blaž; Supej, Matej

    2015-01-01

    The purpose of the study was to analyse the flexion angles of the ski boot, ankle and knee joints of an above-knee prosthesis and to compare them with an intact leg and a control group of skiers. One subject with an above-knee amputation of the right leg and eight healthy subjects simulated the movement of a skiing turn by performing two-leg squats in laboratory conditions. By adding additional loads in proportion to body weight (BW; +1/3 BW, +2/3 BW, +3/3 BW), various skiing regimes were simulated. Change of Flexion Angle (CoFA) and Range of Motion (RoM) in the ski boot, ankle and knee joints were calculated and compared. An average RoM in the skiing boot on the side of prosthesis (4.4 ± 1.1°) was significantly lower compared to an intact leg (5.9 ± 1.8°) and the control group (6.5 ± 2.3°). In the ankle joint, the average RoM was determined to be 13.2±2.9° in the prosthesis, 12.7 ± 2.8° in an intact leg and 14.8±3.6 in the control group. However, the RoM of the knee joint in the prosthesis (42.2 ± 4.2°) was significantly larger than that of the intact leg (34.7 ± 4.4°). The average RoM of the knee joint in the control group was 47.8 ± 5.4°. The influences of additional loads on the kinematics of the lower extremities were different on the side of the prosthesis and on the intact leg. In contrast, additional loads did not produce any significant differences in the control group. Although different CoFAs in the ski boot, ankle and knee joints were used, an above-knee prosthesis with a built-in multi-axis prosthetic knee enables comparable leg kinematics in simulated alpine skiing. Key points The RoM in the ski boot on the side of the prosthetic leg was smaller than the RoM of the intact leg and the control group of healthy subjects. The RoM in the ankle joint of prosthetic leg was comparable to that of the intact leg and the control group of healthy subjects. The RoM in the prosthetic knee joint was greater than the RoM in the knee joint of the

  1. SphK1 inhibitor II (SKI-II) inhibits acute myelogenous leukemia cell growth in vitro and in vivo

    International Nuclear Information System (INIS)

    Yang, Li; Weng, Wei; Sun, Zhi-Xin; Fu, Xian-Jie; Ma, Jun; Zhuang, Wen-Fang

    2015-01-01

    Previous studies have identified sphingosine kinase 1 (SphK1) as a potential drug target for treatment of acute myeloid leukemia (AML). In the current study, we investigated the potential anti-leukemic activity of a novel and specific SphK1 inhibitor, SKI-II. We demonstrated that SKI-II inhibited growth and survival of human AML cell lines (HL-60 and U937 cells). SKI-II was more efficient than two known SphK1 inhibitors SK1-I and FTY720 in inhibiting AML cells. Meanwhile, it induced dramatic apoptosis in above AML cells, and the cytotoxicity by SKI-II was almost reversed by the general caspase inhibitor z-VAD-fmk. SKI-II treatment inhibited SphK1 activation, and concomitantly increased level of sphingosine-1-phosphate (S1P) precursor ceramide in AML cells. Conversely, exogenously-added S1P protected against SKI-II-induced cytotoxicity, while cell permeable short-chain ceramide (C6) aggravated SKI-II's lethality against AML cells. Notably, SKI-II induced potent apoptotic death in primary human AML cells, but was generally safe to the human peripheral blood mononuclear cells (PBMCs) isolated from healthy donors. In vivo, SKI-II administration suppressed growth of U937 leukemic xenograft tumors in severe combined immunodeficient (SCID) mice. These results suggest that SKI-II might be further investigated as a promising anti-AML agent. - Highlights: • SKI-II inhibits proliferation and survival of primary and transformed AML cells. • SKI-II induces apoptotic death of AML cells, but is safe to normal PBMCs. • SKI-II is more efficient than two known SphK1 inhibitors in inhibiting AML cells. • SKI-II inhibits SphK1 activity, while increasing ceramide production in AML cells. • SKI-II dose-dependently inhibits U937 xenograft growth in SCID mice

  2. SphK1 inhibitor II (SKI-II) inhibits acute myelogenous leukemia cell growth in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li; Weng, Wei; Sun, Zhi-Xin; Fu, Xian-Jie; Ma, Jun, E-mail: majuntongrensh1@126.com; Zhuang, Wen-Fang, E-mail: wenfangzhuangmd@163.com

    2015-05-15

    Previous studies have identified sphingosine kinase 1 (SphK1) as a potential drug target for treatment of acute myeloid leukemia (AML). In the current study, we investigated the potential anti-leukemic activity of a novel and specific SphK1 inhibitor, SKI-II. We demonstrated that SKI-II inhibited growth and survival of human AML cell lines (HL-60 and U937 cells). SKI-II was more efficient than two known SphK1 inhibitors SK1-I and FTY720 in inhibiting AML cells. Meanwhile, it induced dramatic apoptosis in above AML cells, and the cytotoxicity by SKI-II was almost reversed by the general caspase inhibitor z-VAD-fmk. SKI-II treatment inhibited SphK1 activation, and concomitantly increased level of sphingosine-1-phosphate (S1P) precursor ceramide in AML cells. Conversely, exogenously-added S1P protected against SKI-II-induced cytotoxicity, while cell permeable short-chain ceramide (C6) aggravated SKI-II's lethality against AML cells. Notably, SKI-II induced potent apoptotic death in primary human AML cells, but was generally safe to the human peripheral blood mononuclear cells (PBMCs) isolated from healthy donors. In vivo, SKI-II administration suppressed growth of U937 leukemic xenograft tumors in severe combined immunodeficient (SCID) mice. These results suggest that SKI-II might be further investigated as a promising anti-AML agent. - Highlights: • SKI-II inhibits proliferation and survival of primary and transformed AML cells. • SKI-II induces apoptotic death of AML cells, but is safe to normal PBMCs. • SKI-II is more efficient than two known SphK1 inhibitors in inhibiting AML cells. • SKI-II inhibits SphK1 activity, while increasing ceramide production in AML cells. • SKI-II dose-dependently inhibits U937 xenograft growth in SCID mice.

  3. Profesor Kazimierz Bartoszyński (1921–2015

    Directory of Open Access Journals (Sweden)

    Ewa Kosowska

    2015-11-01

    Full Text Available Prof. Kazimierz Bartoszyński was one of the most respected theoreticians of literature in Poland. He worked closely with the Institute of Literary Research of the Polish Academy of Sciences. The period of Professor Bartoszyński’s greatest activity as a researcher coincided with the time when he was fascinated with structuralism, but his interests went far beyond these methodological issues. The author of this memoir, who was the Professor’s doctoral student, portrays him through the prism of their conversations on scholarly topics and her private relationship with Mr. and Mrs. Bartoszyński, which lasted for many years.

  4. The influence of increased distal loading on metabolic cost, efficiency, and kinematics of roller ski skating.

    Science.gov (United States)

    Bolger, Conor M; Bessone, Veronica; Federolf, Peter; Ettema, Gertjan; Sandbakk, Øyvind

    2018-01-01

    The purpose of the present study was to examine the influence of increased loading of the roller ski on metabolic cost, gross efficiency, and kinematics of roller ski skating in steep and moderate terrain, while employing two incline-specific techniques. Ten nationally ranked male cross-country skiers were subjected to four 7-minute submaximal intervals, with 0, 0.5, 1.0, and 1.5 kg added beneath the roller-ski in a randomized order. This was done on two separate days, with the G2 skating at 12% incline and 7 km/h speed and G3 skating at 5% incline and 14 km/h speed, respectively. At 12% incline, there was a significant increase in metabolic rate and a decrease in gross efficiency with added weight (P0.05). No changes in cycle characteristics were observed between the different ski loadings at either incline, although the lateral and vertical displacements of the foot/skis were slightly altered at 12% incline with added weight. In conclusion, the present study demonstrates that increased loading of the ski increases the metabolic cost and reduces gross efficiency during steep uphill roller skiing in G2 skating, whereas no significant effect was revealed when skating on relatively flat terrain in G3. Cycle characteristics remained unchanged across conditions at both inclines, whereas small adjustments in the displacement of the foot coincided with the efficiency changes in uphill terrain. The increased RPE values with added ski-weight at both inclines indicates that other factors than those measured here could have influenced effort and/or fatigue when lifting a heavier ski.

  5. Skis to demonstrate new atomic techniques

    International Nuclear Information System (INIS)

    1969-01-01

    Skis in which part of the material consists of birch wood impregnated with the basic chemicals of plastic and then irradiated are now undergoing tests. They are a demonstration of the new material created when this technique is applied to wood and fibres. (author)

  6. Consumption Skill Acquisition in Ski Schools

    DEFF Research Database (Denmark)

    Woermann, Niklas; Wieser, Verena

    2016-01-01

    Remedying the absence of a cultural theory of consumption skill acquisition, we use video data to explore how consumers learn in ski schools. We identify six modes of skill acquisition and theorize the interplay between the sensori-motor system, the conscious state of skillful coping...

  7. Precision Joining Center

    Science.gov (United States)

    Powell, J. W.; Westphal, D. A.

    1991-08-01

    A workshop to obtain input from industry on the establishment of the Precision Joining Center (PJC) was held on July 10-12, 1991. The PJC is a center for training Joining Technologists in advanced joining techniques and concepts in order to promote the competitiveness of U.S. industry. The center will be established as part of the DOE Defense Programs Technology Commercialization Initiative, and operated by EG&G Rocky Flats in cooperation with the American Welding Society and the Colorado School of Mines Center for Welding and Joining Research. The overall objectives of the workshop were to validate the need for a Joining Technologists to fill the gap between the welding operator and the welding engineer, and to assure that the PJC will train individuals to satisfy that need. The consensus of the workshop participants was that the Joining Technologist is a necessary position in industry, and is currently used, with some variation, by many companies. It was agreed that the PJC core curriculum, as presented, would produce a Joining Technologist of value to industries that use precision joining techniques. The advantage of the PJC would be to train the Joining Technologist much more quickly and more completely. The proposed emphasis of the PJC curriculum on equipment intensive and hands-on training was judged to be essential.

  8. Thermal comfort of dual-chamber ski gloves

    Science.gov (United States)

    Dotti, F.; Colonna, M.; Ferri, A.

    2017-10-01

    In this work, the special design of a pair of ski gloves has been assessed in terms of thermal comfort. The glove 2in1 Gore-Tex has a dual-chamber construction, with two possible wearing configurations: one called “grip” to maximize finger flexibility and one called “warm” to maximize thermal insulation in extremely cold conditions. The dual-chamber gloves has been compared with two regular ski gloves produced by the same company. An intermittent test on a treadmill was carried out in a climatic chamber: it was made of four intense activity phases, during which the volunteer ran at 9 km/h on a 5% slope for 4 minutes, spaced out by 5-min resting phases. Finger temperature measurements were compared with the thermal sensations expressed by two volunteers during the test.

  9. A kinematic and kinetic study of alpine skiing technique in slalom

    OpenAIRE

    Reid, Robert C.

    2010-01-01

    Avhandling (doktorgrad) - Norges idrettshøgskole, 2010. Despite a large body of lay and professional literature covering numerous aspects of alpine skiing technique, only a limited number of published scientific investigations have examined the relationship between skier technical and tactical characteristics and racing performance. As a consequence, our scientific understanding of how the underlying mechanics of alpine ski racing technique relate to performance is surprisin...

  10. A simulation of cross-country skiing on varying terrain by using a mathematical power balance model.

    Science.gov (United States)

    Moxnes, John F; Sandbakk, Oyvind; Hausken, Kjell

    2013-01-01

    The current study simulated cross-country skiing on varying terrain by using a power balance model. By applying the hypothetical inductive deductive method, we compared the simulated position along the track with actual skiing on snow, and calculated the theoretical effect of friction and air drag on skiing performance. As input values in the model, air drag and friction were estimated from the literature, whereas the model included relationships between heart rate, metabolic rate, and work rate based on the treadmill roller-ski testing of an elite cross-country skier. We verified this procedure by testing four models of metabolic rate against experimental data on the treadmill. The experimental data corresponded well with the simulations, with the best fit when work rate was increased on uphill and decreased on downhill terrain. The simulations predicted that skiing time increases by 3%-4% when either friction or air drag increases by 10%. In conclusion, the power balance model was found to be a useful tool for predicting how various factors influence racing performance in cross-country skiing.

  11. Kinematics and Kinetics of Squats, Drop Jumps and Imitation Jumps of Ski Jumpers

    Science.gov (United States)

    Pauli, Carole A.; Keller, Melanie; Ammann, Fabian; Hübner, Klaus; Lindorfer, Julia; Taylor, William R.

    2016-01-01

    Abstract Pauli, CA, Keller, M, Ammann, F, Hübner, K, Lindorfer, J, Taylor, WR, and Lorenzetti, S. Kinematics and kinetics of squats, drop jumps and imitation jumps of ski jumpers. J Strength Cond Res 30(3): 643–652, 2016—Squats, drop jumps, and imitation jumps are commonly used training exercises in ski jumping to enhance maximum force, explosive force, and sport-specific skills. The purpose of this study was to evaluate the kinetics and kinematics of training exercises in ski jumping and to find objective parameters in training exercises that most correlate with the competition performance of ski jumpers. To this end, barbell squats, drop jumps, and imitation jumps were measured in a laboratory environment for 10 elite ski jumpers. Force and motion data were captured, and the influence of maximum vertical force, force difference, vertical take-off velocity, knee moments, knee joint power, and a knee valgus/varus index was evaluated and correlated with their season jump performance. The results indicate that, especially for the imitation jumps, a good correlation exists between the vertical take-off velocity and the personal jump performance on the hill (R = 0.718). Importantly, however, the more the athletes tended toward a valgus knee alignment during the measured movements, the worse their performance (R = 0.729 imitation jumps; R = 0.685 squats). Although an evaluation of the athletes' lower limb alignment during competitive jumping on the hill is still required, these preliminary data suggest that performance training should additionally concentrate on improving knee alignment to increase ski jumping performance. PMID:26418370

  12. Whole-Body Vibrations Associated With Alpine Skiing: A Risk Factor for Low Back Pain?

    Directory of Open Access Journals (Sweden)

    Matej Supej

    2018-03-01

    Full Text Available Alpine skiing, both recreational and competitive, is associated with high rates of injury. Numerous studies have shown that occupational exposure to whole-body vibrations is strongly related to lower back pain and some suggest that, in particular, vibrations of lower frequencies could lead to overuse injuries of the back in connection with alpine ski racing. However, it is not yet known which forms of skiing involve stronger vibrations and whether these exceed safety thresholds set by existing standards and directives. Therefore, this study was designed to examine whole-body vibrations connected with different types of skiing and the associated potential risk of developing low back pain. Eight highly skilled ski instructors, all former competitive ski racers and equipped with five accelerometers and a Global Satellite Navigation System to measure vibrations and speed, respectively, performed six different forms of skiing: straight running, plowing, snow-plow swinging, basic swinging, short swinging, and carved turns. To estimate exposure to periodic, random and transient vibrations the power spectrum density (PSD and standard ISO 2631-1:1997 parameters [i.e., the weighted root-mean-square acceleration (RMS, crest factor, maximum transient vibration value and the fourth-power vibration dose value (VDV] were calculated. Ground reaction forces were estimated from data provided by accelerometers attached to the pelvis. The major novel findings were that all of the forms of skiing tested produced whole-body vibrations, with highest PSD values of 1.5–8 Hz. Intensified PSD between 8.5 and 35 Hz was observed only when skidding was involved. The RMS values for 10 min of short swinging or carved turns, as well as all 10-min equivalent VDV values exceeded the limits set by European Directive 2002/44/EC for health and safety. Thus, whole-body vibrations, particularly in connection with high ground reaction forces, contribute to a high risk for low back

  13. MARKETING POLICIES THROUGH THE INTERNET: THE CASE OF SKIING CENTERS IN GREECE

    Directory of Open Access Journals (Sweden)

    Panagiotis LEFAKIS

    2012-09-01

    Full Text Available Lately, Internet constitutes a major tool for transactions in every aspect and supports innovative marketing policies. Broadband Internet has become “the key to success” for businesses, as it offers various advantages and benefits through Internet marketing (e-marketing policies. In Greece, mountainous areas are usually covered with snow during winter months; so, skiing centers have become an important asset for winter tourism. The Internet evolution and the development of network infrastructure enhance marketing policies for winter tourism activities. This paper studies the use of marketing policies in Greek skiing centers through the Internet, such as promotional activities, website interactivity, accommodation & entertainment information, online weather forecast, guest book, etc Therefore, the paper aims to optimize and evaluate skiing centers in Greece, qualitatively and quantitatively according to e-marketing policies used as criteria, based on the multicriteria method of PROMETHEE II and further to classify them in groups. Finally we identify and describe the optimum group of skiing centers to be used as a model with enhanced customer communication services.

  14. THE ROLE OF MARKETING IN MODERN SPORT PROCEDURE AT EXAMPLE OF SKIING

    Directory of Open Access Journals (Sweden)

    Stevo Popović

    2008-08-01

    Full Text Available The object of this project is marketing in modern sport procedure. The main focus will be directional to skiing and specific marketing in the area where it participated. The questions of sport marketing will be tested at Ski club “Mogren” from Budva. The main goal refers the requirement that sport in modern world should be presented as less simpler, cheaper and more attractive way. During last 30 years, sports, including the skiing, alike one of the Olympic sports, became much more active in the filed of selling the irproducts. The main tasks of this project are presenting and arranging the concept of marketing, strategic marketing, specific marketing in sport, marketing and sponsorship and importance of marketing in the modern sport at example of skiing. During the making of this project the authors used descriptive method with consulting of competent literature. The previous author’s experience in this field was so useful. More over, the authors used the analytic method and parallel method which is the most productive if you make some inferences about some appearance.

  15. Energy system contributions and determinants of performance in sprint cross-country skiing

    DEFF Research Database (Denmark)

    Andersson, E; Björklund, G; Holmberg, H-C

    2017-01-01

    To improve current understanding of energy contributions and determinants of sprint-skiing performance, 11 well-trained male cross-country skiers were tested in the laboratory for VO2max , submaximal gross efficiency (GE), maximal roller skiing velocity, and sprint time-trial (STT) performance...... during the STT was predicted from the submaximal relationships for GE against velocity and incline, allowing computation of metabolic rate and O2 deficit. The skiers completed the STT in 232 ± 10 s (distributed as 55 ± 3% DP and 45 ± 3% DS) with a mean power output of 324 ± 26 W. The anaerobic energy......-skiing has demonstrated an anaerobic energy contribution of 18%, with GE being the strongest predictor of performance....

  16. Frostbite in ski boots for marines

    NARCIS (Netherlands)

    Heus, R.; Schols, E.; Kistemaker, L.

    2005-01-01

    Previous research have showed that cold injuries of feet occur more often than cold injuries of hands. Recently, an unexpectedly large number of cold injuries were observed during military training in Norway and a relationship between cold injuries and the use of the Alico ski boot was suspected.

  17. Anterior cruciate ligament injury/reinjury in alpine ski racing: a narrative review

    Directory of Open Access Journals (Sweden)

    Jordan MJ

    2017-03-01

    Full Text Available Matthew J Jordan,1 Per Aagaard,2 Walter Herzog1 1Human Performance Laboratory, The University of Calgary, Calgary, AB, Canada; 2Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC, University of Southern Denmark, Odense M, Denmark Abstract: The purpose of the present review was to: 1 provide an overview of the current understanding on the epidemiology, etiology, risk factors, and prevention methods for anterior cruciate ligament (ACL injury in alpine ski racing; and 2 provide an overview of what is known pertaining to ACL reinjury and return to sport after ACL injury in alpine ski racing. Given that most of the scientific studies on ACL injuries in alpine ski racing have been descriptive, and that very few studies contributed higher level scientific evidence, a nonsystematic narrative review was employed. Three scholarly databases were searched for articles on ACL injury or knee injury in alpine ski racing. Studies were classified according to their relevance in relation to epidemiology, etiology, risk factors, and return to sport/reinjury prevention. Alpine ski racers (skiers were found to be at high risk for knee injuries, and ACL tears were the most frequent diagnosis. Three primary ACL injury mechanism were identified that involved tibial internal rotation and anteriorly directed shear forces from ski equipment and the environment. While trunk muscle strength imbalance and genetics were found to be predictive of ACL injuries in development-level skiers, there was limited scientific data on ACL injury risk factors among elite skiers. Based on expert opinion, research on injury risk factors should focus on equipment design, course settings/speed, and athlete factors (eg, fitness. While skiers seem to make a successful recovery following ACL injury, there may be persistent neuromuscular deficits. Future research efforts should be directed toward prospective studies on ACL injury/reinjury prevention in both

  18. The SKI proto-oncogene enhances the in vivo repopulation of hematopoietic stem cells and causes myeloproliferative disease.

    Science.gov (United States)

    Singbrant, Sofie; Wall, Meaghan; Moody, Jennifer; Karlsson, Göran; Chalk, Alistair M; Liddicoat, Brian; Russell, Megan R; Walkley, Carl R; Karlsson, Stefan

    2014-04-01

    The proto-oncogene SKI is highly expressed in human myeloid leukemia and also in murine hematopoietic stem cells. However, its operative relevance in these cells remains elusive. We have over-expressed SKI to define its intrinsic role in hematopoiesis and myeloid neoplasms, which resulted in a robust competitive advantage upon transplantation, a complete dominance of the stem and progenitor compartments, and a marked enhancement of myeloid differentiation at the expense of other lineages. Accordingly, enforced expression of SKI induced a gene signature associated with hematopoietic stem cells and myeloid differentiation, as well as hepatocyte growth factor signaling. Here we demonstrate that, in contrast to what has generally been assumed, the significant impact of SKI on hematopoiesis is independent of its ability to inhibit TGF-beta signaling. Instead, myeloid progenitors expressing SKI are partially dependent on functional hepatocyte growth factor signaling. Collectively our results demonstrate that SKI is an important regulator of hematopoietic stem cell activity and its overexpression leads to myeloproliferative disease.

  19. Injuries in skiing and snowboarding: Epidemiology and risk factors as a basis for prevention measures

    Directory of Open Access Journals (Sweden)

    Ropret Robert

    2014-01-01

    Full Text Available This paper deals with the subject of injury in alpine skiing and snowboarding and the aim was to define the characteristics of injuries and the risk factors as the basis for establishing preventive measures. The types of injuries and risk factors were analyzed by examining previous papers. During the last thirty years, the number of injuries has generally decreased by 50-70%. The changes were recorded in the types of injuries, and the number of certain injuries increased. It was found that there was a mutual difference in the number and structure of the injuries of skiers and snowboarders. Injuries can be classified topologically and according to risk factors. The risk factors may be manifold: the characteristics of the equipment, the characteristics of the trail and snow surface, protective equipment, age, gender, physical fitness, risky behaviours, time of day, skiing discipline, climate factors, the presence of other skiers and others. By the analysis of these factors it was concluded that there were three entities in the implementation of security measures: the state that stipulates laws (relevant ministries, owners or organizers who provide services in skiing (ski centres, ski services, ski schools, clubs and skiers and snowboarders themselves.

  20. THE COMPARISON OF PHYSICAL ABILITIES BETWEEN ALPINE SKIING SKIERS' AND TENNIS PLAYERS

    Directory of Open Access Journals (Sweden)

    Giovanis Vassilis.

    2012-11-01

    Full Text Available The aim of the present research was the physical abilities diagnosis of Alpine skiing skiers and tennis players, as well the comparison of these before and after the ski period. The sample of 54 individuals emanated from two teams of different sports: skiing (N = 28 and tennis (N = 26, while the level was advancing for both. For the diagnosis and the comparison of physical abilities used four tests of Alpine skiing on dry ground the same day of December 2008 and April 2009 respectively: 30m flight start, eight continuous jumping, slalom on "folder", jumping up and down on a step with height 40cm x 40sec. The statistical analysis done with SPSS 18 program, included controls t - test, p=bilateral, for dependent samples and correlation analysis at significance level a= 0.05 with freedom degrees df = N - 1. In conclusion, in the present research the ski team (men and women presented the improvement afterwards the season in 2 of 4 tests and in the corresponding physical abilities (explosive force, t = 2,970, p < .01 and agility t = 3.533, p < .00, while also the tennis team (men and women presented improvement in 2 of 4 tests (explosive force, t = 2,397, p < .02 and anaerobic ability, t = 3.192, p < .00. Finally the common characteristic of the two teams was the performance improvement in the explosive force and their decreased attribution in speed.

  1. The physiological and biomechanical contributions of poling to roller ski skating.

    Science.gov (United States)

    Sandbakk, Øyvind; Ettema, Gertjan; Holmberg, Hans-Christer

    2013-08-01

    Poling is considered to make a significant contribution to cross-country skiing with the skating technique. To better understand this contribution, the current investigation compared roller ski skating on a treadmill with the so-called G3 skating technique with (G3-P) and without poling (G3-NP). Seven male elite skiers performed 5-min submaximal tests at 8, 12, and 15 km h(-1), as well as an incremental test to exhaustion with both techniques on a 5 % incline. Ventilatory variables were assessed by open-circuit indirect calorimetry and three-dimensional kinematics analyzed using the Qualisys Pro Reflex system. G3-P was associated with approximately 15 % higher peak velocity and 10 % higher peak oxygen uptake than G3-NP in the incremental test (both P skating, specifically by enhancing peak oxygen uptake, skiing efficiency and associated biomechanical variables.

  2. The effects of skiing velocity on mechanical aspects of diagonal cross-country skiing.

    Science.gov (United States)

    Andersson, Erik; Pellegrini, Barbara; Sandbakk, Oyvind; Stüggl, Thomas; Holmberg, Hans-Christer

    2014-09-01

    Cycle and force characteristics were examined in 11 elite male cross-country skiers using the diagonal stride technique while skiing uphill (7.5°) on snow at moderate (3.5 ± 0.3 m/s), high (4.5 ± 0.4 m/s), and maximal (5.6 ± 0.6 m/s) velocities. Video analysis (50 Hz) was combined with plantar (leg) force (100 Hz), pole force (1,500 Hz), and photocell measurements. Both cycle rate and cycle length increased from moderate to high velocity, while cycle rate increased and cycle length decreased at maximal compared to high velocity. The kick time decreased 26% from moderate to maximal velocity, reaching 0.14 s at maximal. The relative kick and gliding times were only altered at maximal velocity, where these were longer and shorter, respectively. The rate of force development increased with higher velocity. At maximal velocity, sprint-specialists were 14% faster than distance-specialists due to greater cycle rate, peak leg force, and rate of leg force development. In conclusion, large peak leg forces were applied rapidly across all velocities and the shorter relative gliding and longer relative kick phases at maximal velocity allow maintenance of kick duration for force generation. These results emphasise the importance of rapid leg force generation in diagonal skiing.

  3. In-Field Validation of an Inertial Sensor-Based System for Movement Analysis and Classification in Ski Mountaineering

    Directory of Open Access Journals (Sweden)

    Jules Gellaerts

    2018-03-01

    Full Text Available Ski Mountaineering (SkiMo is a fast growing sport requiring both endurance and technical skills. It involves different types of locomotion with and without the skis. The aim of this study is to develop and validate in the snowfield a novel inertial-based system for analysing cycle parameters and classifying movement in SkiMo in real-time. The study was divided into two parts, one focused on real-time parameters estimation (cadence, distance from strides, stride duration, stride length, number of strides, slope gradient, and power and, second, on transition detection (kickturns, skin on, skin off, ski on and off backpack in order to classify between the different types of locomotion. Experimental protocol involved 16 experienced subjects who performed different SkiMo trials with their own equipment instrumented with a ski-mounted inertial sensor. The results obtained by the algorithm showed precise results with a relative error near 5% on all parameters. The developed system can, therefore, be used by skiers to obtain quantitative training data analysis and real-time feedback in the field. Nevertheless, a deeper validation of this algorithm might be necessary in order to confirm the accuracy on a wider population of subjects with various skill levels.

  4. Effect of ski mountaineering track on foot sole loading pattern.

    Science.gov (United States)

    Haselbacher, Matthias; Mader, Katharina; Werner, Maximiliane; Nogler, Michael

    2014-09-01

    Ski mountaineering is becoming a popular sport. The ascending techniques (tracks) can be divided into 3 different groups: flat field, direct ascent, and traversing. This study examines the relationship between different mechanical loads on the foot and the 4 different mountaineering ascending techniques. All subjects used the same pair of ski boots and the same skis while performing the 4 different ascending techniques. An in-shoe dynamic pressure measuring system was used to measure the mechanical load on the foot soles of each ski mountaineer. The foot sole was divided into 6 anatomic sections to measure the different loads in each section. Thirteen men with an average age of 29 years were enrolled in the study. The results showed small, not significant differences in the mechanical foot load in the flat field or in the direct ascent. The average mechanical foot load was highest on the valley side foot while traversing (179 kPa to 117 kPa). The higher load forces were in the medial ball of the foot and the longitudinal aspect of the foot side closer to the hill. The higher impact placed on the valley side foot and the concentration of force placed on the medial ball of the valley side foot suggested the influence of the track on the load pattern of the foot sole. This higher impact may result in upward forces that affect the force distribution in the ankle and knee joints. Copyright © 2014. Published by Elsevier Inc.

  5. A COMPARISON OF GROUND REACTION FORCES DETERMINED BY PORTABLE FORCE-PLATE AND PRESSURE-INSOLE SYSTEMS IN ALPINE SKIING

    Directory of Open Access Journals (Sweden)

    Kosuke Nakazato

    2011-12-01

    Full Text Available For the determination of ground reaction forces in alpine skiing, pressure insole (PI systems and portable force plate (FP systems are well known and widely used in previous studies. The purposes of this study were 1 to provide reference data for the vertical component of the ground reaction forces (vGRF during alpine skiing measured by the PI and FP systems, and 2 to analyze whether the differences in the vGRF measured by the PI and the FP depend on a skier's level, skiing mode and pitch. Ten expert and ten intermediate level skiers performed 10 double turns with the skiing technique "Carving in Short Radii" as High Dynamic Skiing mode and "Parallel Ski Steering in Long Radii" as Low Dynamic Skiing mode on both the steep (23 ° and the flat (15 ° slope twice. All subjects skied with both the PI and the FP system simultaneously. During the outside phase, the mean vGRF and the maximum vGRF determined by the FP are greater than the PI (p < 0.01. Additionally during the inside phase, the mean vGRF determined by the FP were greater than the PI (p < 0.01. During the edge changing phases, the mean vGRF determined by the FP were greater than the PI (p < 0.01. However, the minimum vGRF during the edge changing phases determined by the FP were smaller than the PI (p < 0.01 in the High-Steep skiing modes of Experts and Intermediates (p < 0.001. We have found that generally, the PI system underestimates the total vGRF compared to the FP system. However, this difference depends not only the phase in the turn (inside, outside, edge changing, but also is affected by the skier's level, the skiing mode performed and pitch.

  6. Frequency of injuries, in particular dental injuries, in ski jumping and Nordic combined.

    Science.gov (United States)

    Stillhard, Angela; Buschor, Cornel; Krastl, Gabriel; Kühl, Sebastian; Filippi, Andreas

    This study investigates the frequency of injuries, in particular dental injuries, among ski jumpers and Nordic combined athletes. It also examines the level of knowledge regarding tooth protection and tooth rescue boxes in this population. Of the 465 sportswomen and sportsmen who took part in the study, 230 (62.5%) of the 368 ski jumpers and 56 (56.5%) of the 97 Nordic combined athletes had sustained an injury. In both disciplines injury was most likely among professionals. The survey participants reported injuries to the limbs (n = 216), head and lips (n = 273 and n = 253, respectively), torso or spine (n = 249), teeth (n = 246), nose (n = 229) and jaw (n = 26). Dental injuries were more common among professionals than either amateur or junior ski jumpers, whereas, among the Nordic combined athletes, juniors were most likely to sustain a dental injury. Overall, the frequency of dental injury was significantly (p = 0.019) higher among adults 12.7% (n = 234) than junior athletes 6.1% (n = 212). The level of awareness of mouthguards and tooth rescue boxes varied between countries. The high injury rate recorded in this study demonstrates that ski jumping contains a considerable risk of injury, including tooth damage. Consequently, it seems reasonable to inform skiing organisations, trainers and athletes about the potential benefits of mouthguards and tooth rescue boxes in order to reduce the risk of dental injury.

  7. Kinematics and Kinetics of Squats, Drop Jumps and Imitation Jumps of Ski Jumpers.

    Science.gov (United States)

    Pauli, Carole A; Keller, Melanie; Ammann, Fabian; Hübner, Klaus; Lindorfer, Julia; Taylor, William R; Lorenzetti, Silvio

    2016-03-01

    Squats, drop jumps, and imitation jumps are commonly used training exercises in ski jumping to enhance maximum force, explosive force, and sport-specific skills. The purpose of this study was to evaluate the kinetics and kinematics of training exercises in ski jumping and to find objective parameters in training exercises that most correlate with the competition performance of ski jumpers. To this end, barbell squats, drop jumps, and imitation jumps were measured in a laboratory environment for 10 elite ski jumpers. Force and motion data were captured, and the influence of maximum vertical force, force difference, vertical take-off velocity, knee moments, knee joint power, and a knee valgus/varus index was evaluated and correlated with their season jump performance. The results indicate that, especially for the imitation jumps, a good correlation exists between the vertical take-off velocity and the personal jump performance on the hill (R = 0.718). Importantly, however, the more the athletes tended toward a valgus knee alignment during the measured movements, the worse their performance (R = 0.729 imitation jumps; R = 0.685 squats). Although an evaluation of the athletes' lower limb alignment during competitive jumping on the hill is still required, these preliminary data suggest that performance training should additionally concentrate on improving knee alignment to increase ski jumping performance.

  8. Chromosomal instability in mouse embryonic fibroblasts null for the transcriptional co-repressor Ski.

    Science.gov (United States)

    Marcelain, Katherine; Armisen, Ricardo; Aguirre, Adam; Ueki, Nobuhide; Toro, Jessica; Colmenares, Clemencia; Hayman, Michael J

    2012-01-01

    Ski is a transcriptional regulator that has been considered an oncoprotein given its ability to induce oncogenic transformation in avian model systems. However, studies in mouse and in some human tumor cells have also indicated a tumor suppressor activity for this protein. We found that Ski-/- mouse embryo fibroblasts exhibit high levels of genome instability, namely aneuploidy, consistent with a tumor suppressor function for Ski. Time-lapse microscopy revealed lagging chromosomes and chromatin/chromosome bridges as the major cause of micronuclei (MN) formation and the subsequent aneuploidy. Although these cells arrested in mitosis after treatment with spindle disrupting drugs and exhibited a delayed metaphase/anaphase transition, spindle assembly checkpoint (SAC) was not sufficient to prevent chromosome missegregation, consistent with a weakened SAC. Our in vivo analysis also showed dynamic metaphase plate rearrangements with switches in polarity in cells arrested in metaphase. Importantly, after ectopic expression of Ski the cells that displayed this metaphase arrest died directly during metaphase or after aberrant cell division, relating SAC activation and mitotic cell death. This increased susceptibility to undergo mitosis-associated cell death reduced the number of MN-containing cells. The presented data support a new role for Ski in the mitotic process and in maintenance of genetic stability, providing insights into the mechanism of tumor suppression mediated by this protein. Copyright © 2011 Wiley Periodicals, Inc.

  9. Does listening to music with an audio ski helmet impair reaction time to peripheral stimuli?

    Science.gov (United States)

    Ruedl, G; Pocecco, E; Wolf, M; Schöpf, S; Burtscher, M; Kopp, M

    2012-12-01

    With the recent worldwide increase in ski helmet use, new market trends are developing, including audio helmets for listening to music while skiing or snowboarding. The aim of this study was to evaluate whether listening to music with an audio ski helmet impairs reaction time to peripheral stimuli. A within-subjects design study using the Compensatory-Tracking-Test was performed on 65 subjects (36 males and 29 females) who had a mean age of 23.3 ± 3.9 years. Using repeated measures analysis of variance, we found significant differences in reaction times between the 4 test conditions (p=0.039). The lowest mean reaction time (± SE) was measured for helmet use while listening to music (507.9 ± 13.2 ms), which was not different from helmet use alone (514.6 ± 12.5 ms) (p=0.528). However, compared to helmet use while listening to music, reaction time was significantly longer for helmet and ski goggles used together (535.8 ± 14.2 ms, p=0.005), with a similar trend for helmet and ski goggles used together while listening to music (526.9 ± 13.8 ms) (p=0.094). In conclusion, listening to music with an audio ski helmet did not increase mean reaction time to peripheral stimuli in a laboratory setting. © Georg Thieme Verlag KG Stuttgart · New York.

  10. a Study on Mental Representations for Realistic Visualization the Particular Case of Ski Trail Mapping

    Science.gov (United States)

    Balzarini, R.; Dalmasso, A.; Murat, M.

    2015-08-01

    This article presents preliminary results from a research project in progress that brings together geographers, cognitive scientists, historians and computer scientists. The project investigates the evolution of a particular territorial model: ski trails maps. Ski resorts, tourist and sporting innovations for mountain economies since the 1930s, have needed cartographic representations corresponding to new practices of the space.Painter artists have been involved in producing ski maps with painting techniques and panoramic views, which are by far the most common type of map, because they allow the resorts to look impressive to potential visitors. These techniques have evolved throughout the mutations of the ski resorts. Paper ski maps no longer meet the needs of a large part of the customers; the question now arises of their adaptation to digital media. In a computerized process perspective, the early stage of the project aims to identify the artist-representations, based on conceptual and technical rules, which are handled by users-skiers to perform a task (location, wayfinding, decision-making) and can be transferred to a computer system. This article presents the experimental phase that analyzes artist and user mental representations that are at stake during the making and the reading of a paper ski map. It particularly focuses on how the invention of the artist influences map reading.

  11. A STUDY ON MENTAL REPRESENTATIONS FOR REALISTIC VISUALIZATION THE PARTICULAR CASE OF SKI TRAIL MAPPING

    Directory of Open Access Journals (Sweden)

    R. Balzarini

    2015-08-01

    Full Text Available This article presents preliminary results from a research project in progress that brings together geographers, cognitive scientists, historians and computer scientists. The project investigates the evolution of a particular territorial model: ski trails maps. Ski resorts, tourist and sporting innovations for mountain economies since the 1930s, have needed cartographic representations corresponding to new practices of the space.Painter artists have been involved in producing ski maps with painting techniques and panoramic views, which are by far the most common type of map, because they allow the resorts to look impressive to potential visitors. These techniques have evolved throughout the mutations of the ski resorts. Paper ski maps no longer meet the needs of a large part of the customers; the question now arises of their adaptation to digital media. In a computerized process perspective, the early stage of the project aims to identify the artist-representations, based on conceptual and technical rules, which are handled by users-skiers to perform a task (location, wayfinding, decision-making and can be transferred to a computer system. This article presents the experimental phase that analyzes artist and user mental representations that are at stake during the making and the reading of a paper ski map. It particularly focuses on how the invention of the artist influences map reading.

  12. Economic Impacts of Climate Change on Winter Tourism: Challenges for Ski Area Operators

    Science.gov (United States)

    Damm, A.; Köberl, J.; Prettenthaler, F.; Töglhofer, C.

    2012-04-01

    Increasing temperatures and snow scarce winter seasons pose a big challenge for the winter tourism industry. Changing natural snow reliability influences tourism demand and ski area operators are faced with an enhanced need of technical snow production. The goal of the present research work is to analyze the economic effects of technical snow production under future climate conditions. Snowmaking as an adaptation strategy to climate change impacts on the ski tourism industry is already taken into consideration in several studies from a scientific perspective concerning snowmaking potentials under future climate conditions and the impacts on ski season length (e.g. Scott et al. 2003; Scott & McBoyle 2007; Hennessy et al. 2008; Steiger 2010). A few studies considered economic aspects of technical snowmaking (e.g. Teich et al. 2007; Gonseth 2008). However, a detailed analysis of the costs and benefits of snowmaking under future climate and snow conditions based on sophisticated climate and snow models has not been carried out yet. The present study addresses the gap of knowledge concerning the economic profitability of prospective snowmaking requirements under future climate scenarios. We carry out a detailed cost-revenue analysis of snowmaking under current and future climate conditions for a case study site in Styria (Austria) using dynamic investment models. The starting point of all economic calculations is the daily demand for artificial snow that determines the requirements for additional snowmaking investments and additional operating costs. The demand for artificial snow is delivered by the snow cover model AMUNDSEN (see Strasser et al. 2011) and is driven by four climate scenarios. Apart from future climate conditions the profitability of snowmaking depends on changes in costs and visitor numbers. The results of a ski tourism demand model analyzing daily visitor numbers and their dependencies of prevailing weather conditions enter the cost-revenue analysis of

  13. [Ski boots from an orthopedic point of view].

    Science.gov (United States)

    Hipp, E

    1976-01-22

    1. A ski-boot should have an adequate arch support and a variable, as well as an exact fitting of the dorsal part. This can be achieved with flow, foam, air or wax. 2. Isolated pressure of compression systems of different kinds should be avoided (e.g. pressure of buckles above the ankle). New results are demonstrated by the possibility of putting on the boot from behind and having the buckles at the back of the boot. 3. The strap from ankle to foot has to be continuous to avoid pressure points. 4. It should be possible to walk and stand in a ski-boot without either muscular strain or pressure on the knee-joint. In addition, the sole has to give an optimal grip also on icy ground to prevent slipping.

  14. The Relative Age Effect and the Influence on Performance in Youth Alpine Ski Racing

    Directory of Open Access Journals (Sweden)

    Lisa Müller

    2015-03-01

    Full Text Available The relative age effect (RAE, which refers to an over representation of athletes born early in a selection year, recently was proven to be present in alpine skiing. However, it was not made apparent whether the RAE exists as early as at the youngest level of youth ski racing at national level, nor whether the relative age influences racing performance. As a consequence, the purpose of the present study was twofold: first, to examine the extent of the RAE and second, to assess the influence the relative age has on the overall performance at the youngest levels of youth ski racing. The study included the investigation of 1,438 participants of the Austrian Kids Cup and 1,004 participants of the Teenager Cup at the provincial level, as well as 250 finalists of the Kids Cup and 150 finalists of the Teenager Cup at the national level. Chi²-tests revealed a highly significant RAE already at the youngest level of youth ski racing (Kids Cup at both the provincial and national levels. There are not again favorably selected the relatively older athletes from the first into the second level of youth ski racing (Teenager Cup. Among the athletes of the Kids Cup, the relative age quarter distribution differed highly significantly from the distribution of the total sample with an over representation of relatively older athletes by comparison taking the top three positions. The data revealed that relative age had a highly significant influence on performance. This study demonstrated that the RAE poses a problem as early as the youngest level of youth ski racing, thereby indicating that many young talented kids are discriminated against, diminishing any chance they might have of becoming elite athletes despite their talents and efforts. The RAE influences not only the participation rate in alpine skiing, but also the performances. As a result, changes in the talent development system are imperative.

  15. Skiing injuries in children.

    Science.gov (United States)

    Moreland, M S

    1982-07-01

    Skiing injuries in children continue to represent a significant health problem. The incidence of injuries in young teenagers remains significantly above the rate for all ages, and tibial fractures are particularly common. Continued efforts are needed to design adequate binding systems for the child that will account for the demands of a broad range of varying sizes and skill levels. As organized competition becomes more popular, there must be an increasing awareness and supervision of the unique musculoskeletal requirements of young competitors in both Alpine and Nordic events.

  16. Fast and scalable inequality joins

    KAUST Repository

    Khayyat, Zuhair

    2016-09-07

    Inequality joins, which is to join relations with inequality conditions, are used in various applications. Optimizing joins has been the subject of intensive research ranging from efficient join algorithms such as sort-merge join, to the use of efficient indices such as (Formula presented.)-tree, (Formula presented.)-tree and Bitmap. However, inequality joins have received little attention and queries containing such joins are notably very slow. In this paper, we introduce fast inequality join algorithms based on sorted arrays and space-efficient bit-arrays. We further introduce a simple method to estimate the selectivity of inequality joins which is then used to optimize multiple predicate queries and multi-way joins. Moreover, we study an incremental inequality join algorithm to handle scenarios where data keeps changing. We have implemented a centralized version of these algorithms on top of PostgreSQL, a distributed version on top of Spark SQL, and an existing data cleaning system, Nadeef. By comparing our algorithms against well-known optimization techniques for inequality joins, we show our solution is more scalable and several orders of magnitude faster. © 2016 Springer-Verlag Berlin Heidelberg

  17. Rapid Hamstrings/Quadriceps strength in ACL-reconstructed elite alpine ski racers

    DEFF Research Database (Denmark)

    Jordan, Matthew J; Aagaard, Per; Herzog, Walter

    2015-01-01

    PURPOSE: Due to the importance of hamstrings (HAM) and quadriceps (QUAD) strength for anterior cruciate ligament (ACL) injury prevention, and the high incidence of ACL injury in ski racing, HAM and QUAD maximal and explosive strength was assessed in ski racers with and without ACL reconstruction...... (ACL-R). METHODS: Uninjured (n=13 males; n=8 females) and ACL-R (n=3 males; n=5 females; 25.0±11.3 months post-op) elite ski racers performed maximal voluntary isometric HAM and QUAD contractions to obtain maximal torque (MVC) and rate of torque development (RTD) at 0-50, 0-100, 0-150 and 0-200 ms. MVC...... and RTD (per kg body mass) were calculated for the uninjured group to compare between sexes, and to compare the control group with the ACL-R limb and unaffected limb of the ACL-R skiers. H/Q MVC and RTD strength ratios were also compared RESULTS: The ACL-R limb demonstrated significant HAM and QUAD...

  18. SKI's evaluation of SKB's Supplement to RD and D Programme 92

    International Nuclear Information System (INIS)

    1995-05-01

    On December 16, 1993, the Government decided (M93/2525/6), with regard to the 1992 Programme for Research, Development, Demonstration and Other Measures (RD and D Programme 92), compiled by the Swedish Nuclear Fuel and Waste Management Co (SKB) in accordance with Section 12 of the Act on Nuclear Activities, that RD and D Programme 92 should be supplemented by SKB in the manner specified in the decision. On August 19, 1992, SKB submitted the requested supplement to the Swedish Nuclear Power Inspectorate (SKI). SKI has examined the supplement and has requested and obtained comments from a large number of reviewing bodies. SKI hereby submits the documents on the matter along with its own review report. The review report contains an evaluation of SKB's supplement in relation to the government decision and certain recommendations for the structuring of the licensing procedure for planned facilities. These recommendations have taken into account the statements of the reviewing bodies

  19. Modelling technical snow production for skiing areas in the Austrian Alps with the physically based snow model AMUNDSEN

    Science.gov (United States)

    Hanzer, F.; Marke, T.; Steiger, R.; Strasser, U.

    2012-04-01

    Tourism and particularly winter tourism is a key factor for the Austrian economy. Judging from currently available climate simulations, the Austrian Alps show a particularly high vulnerability to climatic changes. To reduce the exposure of ski areas towards changes in natural snow conditions as well as to generally enhance snow conditions at skiing sites, technical snowmaking is widely utilized across Austrian ski areas. While such measures result in better snow conditions at the skiing sites and are important for the local skiing industry, its economic efficiency has also to be taken into account. The current work emerges from the project CC-Snow II, where improved future climate scenario simulations are used to determine future natural and artificial snow conditions and their effects on tourism and economy in the Austrian Alps. In a first step, a simple technical snowmaking approach is incorporated into the process based snow model AMUNDSEN, which operates at a spatial resolution of 10-50 m and a temporal resolution of 1-3 hours. Locations of skiing slopes within a ski area in Styria, Austria, were digitized and imported into the model environment. During a predefined time frame in the beginning of the ski season, the model produces a maximum possible amount of technical snow and distributes the associated snow on the slopes, whereas afterwards, until to the end of the ski season, the model tries to maintain a certain snow depth threshold value on the slopes. Due to only few required input parameters, this approach is easily transferable to other ski areas. In our poster contribution, we present first results of this snowmaking approach and give an overview of the data and methodology applied. In a further step in CC-Snow, this simple bulk approach will be extended to consider actual snow cannon locations and technical specifications, which will allow a more detailed description of technical snow production as well as cannon-based recordings of water and energy

  20. Influence of facilities of ski preparation on the bodily condition of teenagers 11-12 years.

    Directory of Open Access Journals (Sweden)

    Vorona V.V.

    2011-04-01

    Full Text Available The indexes of bodily condition of teenagers were determined. A dynamics and increase of the explored indexes were analyzed in the process of ski preparation in the system of lessons of the physical culture of schoolchildren. The 156 teenagers at the age 11-12 years old took part in the experiment. The positive effect of ski training in the bodily condition of the investigated teenagers is proved. Reliable intercommunication was determined between the ski movements and indexes of bodily condition, which characterize work of the cardiovascular system.

  1. Comprehensive outreach, prevention education, and skin cancer screening for Utah ski resorts.

    Science.gov (United States)

    Varedi, Amir; Secrest, Aaron M; Harding, Garrett; Maness, Lori; Branson, Donna; Smith, Kristi; Hull, Christopher M

    2018-02-15

    Outdoor recreation can lead to substantial sun exposure. Employees of outdoor recreation establishments with extended time outdoors have amplified cumulative exposure to ultraviolet (UV) radiation and an increased risk of skin cancer. The "Sun Safe on the Slopes" program was created by Huntsman Cancer Institute at the University of Utah and the Utah Cancer Action Network to address increased UV exposure and skin cancer risk with free skin cancer screenings, outreach, and prevention education to local ski resorts. Herein, we describe the processes and barriers to implementation of a ski resort skin screening and education program and our 5-year report of the experience and screening data. Nine free skin cancer screenings were held at Utah ski resorts between 2011 and 2016, resulting in the presumptive diagnosis of 38 skin cancers (9.6%) in 394 participants. Behavioral data collected from participants indicates suboptimal sun safety practices, including underuse of sunscreen and protective clothing. Ski resort employees who experience sun exposure during peak hours at high altitudes and UV reflection from the snow are at an increased risk of skin cancer. These data indicate a need for emphasis on sun safety education and screening and can serve as a model for future endeavors.

  2. The effect of wind on jumping distance in ski jumping--fairness assessed.

    Science.gov (United States)

    Virmavirta, Mikko; Kivekäs, Juha

    2012-09-01

    The special wind compensation system recently adopted by Fédération Internationale de Ski (FIS; International Ski Federation) to consider the effects of changing wind conditions has caused some controversy. Here, the effect of wind on jumping distance in ski jumping was studied by means of computer simulation and compared with the wind compensation factors used by FIS during the World Cup season 2009/2010. The results showed clearly that the effect of increasing head/tail wind on jumping distance is not linear: +17.4 m/-29.1 m, respectively, for a wind speed of 3 m/s. The linear formula used in the trial period of the wind compensation system was found to be appropriate only for a limited range of jumping distances as the gradient of the landing slope slows down the rate of distance change in long jumps.

  3. The role of eccentric regime of leg muscle work in alpine skiing

    Directory of Open Access Journals (Sweden)

    Ropret Robert

    2017-01-01

    Full Text Available Alpine skiing is characterized by a great number of leg movements with muscle contractions in eccentric regime. The role of these movements is to absorb gravitation and inertial forces, manage skis more precisely and maintain balance. Recent studies have determined the volume, duration and intenisty of eccentric contractions as well as the basic characteristics of movement amplitudes and velocities. Based on the previous findings the experiments involving eccentric training using a bicycle ergometer confirmed a positive impact that this kind of training has on increasing maximum power, strength, endurance, coordination, injury prevention, metabolic work efficiency, more efficient work with longer muscle length and its role in miming skiers' movements. This paper is an review of the studies so far in the field of kinematics, skiing dynamics and the effect of eccentric training on the development of athletes' performances.

  4. Environmental Management and Sustainable Labels in the Ski Industry: A Critical Review

    Directory of Open Access Journals (Sweden)

    Stefano Duglio

    2016-08-01

    Full Text Available Sustainability is increasing in importance in relation to the competitiveness of winter tourism, particularly when considering mountain destinations. Exploring in more detail winter tourism related to ski resorts, operators are especially concerned about environmental issues caused by climate change. Therefore, they have gradually become aware of the importance of finding adequate solutions to cope with such issues as well as being able to sensitize tourists. The main goal of this paper is to analyze the different sustainable tools that can be adopted by the ski industry. In this field there appear to be two main approaches. The first line is that of sustainable labels being applied to local ski resorts; whereas the second consists in operators—such as the managers of cable cars—making use of specific labels or management systems that are environmentally oriented.

  5. Projected climate change impacts on skiing and snowmobiling: A case study of the United States

    Science.gov (United States)

    A physically-based water and energy balance model is used to simulate natural snow accumulation at 247 winter recreation locations across the continental United States. We combine this model with projections of snowmaking conditions to determine downhill skiing, cross-country ski...

  6. Opinions on SKB's Safety Assessments SR 97 and SFL 3-5. A Review by SKI Consultants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    The Swedish Nuclear Fuel and Waste Management Co. (SKB) has presented their safety assessment 'Deep repository for spent nuclear fuel, SR 97 - Post-closure safety'. SKB's report is part of the documentation that has been required by the Government before the start of site investigations. The Swedish Nuclear Power Inspectorate (SKI) is reviewing SR 97 according to earlier Government decisions. In its review work SKI has asked several consultants, that recently have been performing research work for SKI, to give their opinions on SR 97. SKI and the Swedish Radiation Protection Institute (SSI) have used these reports from the consultants as one complementary basis for the formulation of the SKI/SSI review report. This is a compilation of the reports from the different consultants, and therefore the different contributions vary in length, style and language. Included are also two consultant reports, giving comments on SKB's preliminary safety assessment for SFL 3-5 (deep repository for long-lived low- and intermediate-level waste). The 17 contributions have all been separately indexed.

  7. Opinions on SKB's Safety Assessments SR 97 and SFL 3-5. A Review by SKI Consultants

    International Nuclear Information System (INIS)

    2000-12-01

    The Swedish Nuclear Fuel and Waste Management Co. (SKB) has presented their safety assessment 'Deep repository for spent nuclear fuel, SR 97 - Post-closure safety'. SKB's report is part of the documentation that has been required by the Government before the start of site investigations. The Swedish Nuclear Power Inspectorate (SKI) is reviewing SR 97 according to earlier Government decisions. In its review work SKI has asked several consultants, that recently have been performing research work for SKI, to give their opinions on SR 97. SKI and the Swedish Radiation Protection Institute (SSI) have used these reports from the consultants as one complementary basis for the formulation of the SKI/SSI review report. This is a compilation of the reports from the different consultants, and therefore the different contributions vary in length, style and language. Included are also two consultant reports, giving comments on SKB's preliminary safety assessment for SFL 3-5 (deep repository for long-lived low- and intermediate-level waste). The 17 contributions have all been separately indexed

  8. ENERGY MANAGEMENT INNOVATION IN THE US SKI INDUSTRY

    Science.gov (United States)

    Ski areas represent a unique opportunity to develop innovative energy management practices in an industrial setting. Through a unique synergy of onsite generation, preferably by renewable sources and innovative technologies, and the energy storage potential of exis...

  9. A COMPARISON OF WAKEBOARD-, WATER SKIING-, AND TUBING-RELATED INJURIES IN THE UNITED STATES, 2000-2007

    Directory of Open Access Journals (Sweden)

    John I. Baker

    2010-03-01

    Full Text Available The purpose of the study was to compare tubing-related injuries to wakeboarding- and water skiing-related injuries. Data was collected from the 2000-2007 National Electronic Injury Surveillance Survey for 1,761 individuals seeking care at an emergency department due to a tubing-, wakeboarding, or water skiing-related injury. Data included patient age and sex, as well as injury characteristics including body region injured (i.e., head and neck, trunk, shoulder and upper extremity, and hip and lower extremity and diagnosis of injury (e.g., contusion, laceration, or fracture. Case narratives were reviewed to ensure that a tubing-, wakeboarding-, or water skiing-related injury occurred while the individual was being towed behind a boat. Severe injury (defined as an injury resulting in the individual being hospitalized, transferred, held for observation was compared among the groups using logistic regression. Wakeboard- and tubing-related injuries more commonly involved the head and neck, while water skiing- related injuries were likely to involve the hip and lower extremity. Tubing-related injuries, compared to water skiing-related injuries, were more likely to be severe (OR 2.31, 95% CI 1.23-4. 33. Like wakeboarding and water skiing, tubing has inherent risks that must be understood by the participant. While tubing is generally considered a safer alternative to wakeboarding and water skiing, the results of the current study suggest otherwise. Both the number and severity of tubing- related injuries could be prevented through means such as advocating the use of protective wear such as helmets while riding a tube or having recommended safe towing speeds prominently placed on inner tubes

  10. Evolution of revegetated ski slopes in different environments

    Directory of Open Access Journals (Sweden)

    Argenti G

    2011-12-01

    Full Text Available Revegetation of ski slopes is a useful technique to limit soil erosion, reduce the visual impact of the tracks and lengthen the duration of snow cover. Restoration is often performed with commercial forage mixtures with the aim of creating a fast soil cover, then allowing the natural recolonization of artificial swards in the mid-long term. To investigate on the recolonization dynamics, data were collected from 21 different plots from the Alps and the Apennines (Valtellina, Plan de Corones, Sappada, Cimone. Knowledge of both the original mixtures used for restoration and the timespan since intervention (ranging from 1 to 21 years allowed to throw light on the naturalization process for the studied plots. Ground cover, floristic richness and relative presence of sown and native species were measured along linear transects established on the analyzed ski tracks. Results showed the effectiveness of plant restoration, in terms of soil coverage and (in some cases persistence of species of the original mixtures. Recovery of autochthonous species was strongly affected by site elevation and time elapsed since restoration. Moreover, the distance of ski lanes from forest edges seems to influence the dynamics of recolo­nisation process. Renaturalization was remarkably faster in the lower-altitude Apennine study plot. Application of a regression analysis revealed that elevation and timespan since restoration may be considered useful predictors of the level of naturalization of the restored canopies.

  11. Soil nitrogen dynamics in high-altitude ski runs during the winter season (Monterosaski - Vallée d

    Science.gov (United States)

    Freppaz, M.; Icardi, M.; Filippa, G.; Zanini, E.

    2009-04-01

    In many Alpine catchments, the development of winter tourism determined a widespread change in land use, shifting from forested and cultivated lands to ski slopes. The construction of a ski slope implies a strong impact on the landscape, with potential consequences on the soil quality. In most cases, the construction procedures include the total or partial removal of the soil body, the reallocation of the fine hearth fraction, the subsequent seeding of plants and the use of organic fertilizers. This work aims to evaluate soil physical and chemical properties and nitrogen (N) dynamics in anthropogenic soils from ski slopes of different age. Study sites were located in Champoluc (AO)- NW Italy between 2400 and 2700 m ASL. Topsoils (0-10 cm depth) were sampled in 4 ski slopes hydroseeded with commercial mixtures 4, 6, 10 and 12 years earlier, and in 4 control plots at the same exposure and altitude as the ski slopes. Soil samples were characterized, N dynamics in winter was evaluated with the buried bag technique and snowpack was analyzed for chemical and physical properties. Total nitrogen (TN) content in topsoil ranged 0.75-1.06 g kg-1 and was not correlated with the ski slope age. In all but one site, the TN content was significantly lower in the ski slope than in the control plot. A positive net ammonification and nitrification throughout the winter were found in all but one ski runs. These results suggest a high variability in the evolution degree of these anthropogenic soils. The net overwinter N mineralization that we report demonstrates that these soils are biologically active during the winter season. Such activity results in a pool of labile inorganic nitrogen potentially available for plant demand at the spring snowmelt.

  12. Variations in relative age effects in individual sports: skiing, figure skating and gymnastics.

    Science.gov (United States)

    Baker, Joseph; Janning, Christina; Wong, Harmonie; Cobley, Stephen; Schorer, Jörg

    2014-01-01

    In many sports, policy-makers and administrators employ annual cohorts to reduce differences between athletes during childhood and youth. Although well-intended, unintended relative age effects (RAEs) usually occur. RAEs refer to the specific selection, participation and attainment disadvantages associated with participants' birthdates relative to an arbitrary 'cutoff' date used to group participants within annual age groups. To date, we have little understanding of RAEs in individual sports. In this article, Study 1 considered the presence of RAEs in 1474 ski jumping, 7501 cross-country skiing, 15,565 alpine skiing, 4179 snowboarders and 713 Nordic combined athletes. Chi-square analyses revealed significant RAEs for most of these contexts across sexes. In Study 2, RAEs in the aesthetic sports of figure skating (n=502) and female gymnastics (n=612) were considered. There was no effect for the figure skaters and an atypical effect for the gymnasts. The significant effects across most ski sports coupled with the null effects in figure skating and atypical effect in gymnastics suggest that sport-specific contextual factors are important elements in understanding the mechanisms of RAEs, although further work is necessary to validate these findings.

  13. The use of multimedia tools for improving movement notion and increasing the efficiency of motor learning in skiing

    Directory of Open Access Journals (Sweden)

    Ruzicka Ivan

    2016-01-01

    Full Text Available The aim of this paper is focused on the problem of improving movement notion and increasing the efficiency of motor learning in skiing using multimedia tools. The text approaches the system providing a targeted feedback in the process of the acquisition of skiing skills. The platform influencing the movement notion introduces innovative means of the acquisition of essential skiing skills in ski courses organized by the Department of PE and Sport of the Faculty of Education, University of Hradec Králové. The paper presents the selected results of the survey realized by an enquiring method, which was aimed to find out opinions on a monitored platform among students specializing in physical education and sport, who took part in this form of education. The research results indicate that the use of multimedia tools in providing visual feedback can effectively influence the process and the final effect of the acquisition of skiing skills. Positive opinions of the overwhelming majority of respondents illustrate that the use of video analysis in combination with verbal mistake correction is an effective support in skiing practice and it is an efficient platform that accelerates results in learning skiing technique, especially in the context of educational courses. Conclusions also point to some of the negative aspects related to the use of multimedia tools within the platform.

  14. Biological Maturity Status Strongly Intensifies the Relative Age Effect in Alpine Ski Racing.

    Directory of Open Access Journals (Sweden)

    Lisa Müller

    Full Text Available The relative age effect (RAE is a well-documented phenomenon in youth sports. This effect exists when the relative age quarter distribution of selected athletes shows a biased distribution with an over-representation of relatively older athletes. In alpine ski racing, it exists in all age categories (national youth levels up to World Cup. Studies so far could demonstrate that selected ski racers are relatively older, taller and heavier. It could be hypothesized that relatively younger athletes nearly only have a chance for selection if they are early maturing. However, surprisingly this influence of the biological maturity status on the RAE could not be proven, yet. Therefore, the aim of the present study was to investigate the influence of the biological maturity status on the RAE in dependence of the level of competition. The study investigated 372 elite youth ski racers: 234 provincial ski racers (P-SR; high level of competition and 137 national ski racers (N-SR; very high level of competition. Anthropometric characteristics were measured to calculate the age at peak height velocity (APHV as an indicator of the biological maturity status. A significant RAE was present among both P-SR and N-SR, with a larger effect size among the latter group. The N-SR significantly differed in APHV from the P-SR. The distribution of normal, early and late maturing athletes significantly differed from the expected normal distribution among the N-SR, not among the P-SR. Hardly any late maturing N-SR were present; 41.7% of the male and 34% of the female N-SR of the last relative age quarter were early maturing. These findings clearly demonstrate the significant influence of the biological maturity status on the selection process of youth alpine ski racing in dependence of the level of competition. Relatively younger athletes seem to have a chance of selection only if they are early maturing.

  15. DEVELOPMENT OF SOME OF STUDENTS` MOTORIC ABILITIES AFTER TEN-DAY-SKIING COURSE

    Directory of Open Access Journals (Sweden)

    Ljubiša Lilić

    2007-05-01

    Full Text Available Considering the fact that one of the most fundamental tasks of training is developing motoric dimensions of sportsmen, the common goal of this work was to achieve relevant knowledge on the infl uence of ten-day-skiing course on students`* development and to establish their level. The special aim of this work was diagnosing the amount of some of the students` motoric abilities. According to the subjects, problems and goal of the research, there was a hypothesis put: motoric and morphological dimensions of students are coherent with their chrono logical growth and development ten-day-skiing course has signifi cant infl uence on developing some of the students` motoric abilities Besides remaining, the choice of examined samples was put under limits of organizational capacities for realizing researching procedure.It was necessary to insure required devices and standardized conditions under which planned research was supposed to be realized. The sample is taken from students` population implied in regular skiing course. Examined sample consists of thirty male students, each of which is twenty years old. Because of technical and organizational reasons it was not possible to diagnose the whole motoric range of tested students. Due to that a specifi c selection of tests was done and only six variables (that reliably predict levels of motoric abilities on which the training affects were taken: foot tapping, medicine ball throwing, pull-ups with undertaking, trunk lifting in 60 seconds and deep forward band. The level of students` motoric abilities after ten-day-skiing course is on a higher level then initial measuring, and we can certainly claim that it is the result of programmed training process during skiing course. According to the data gained from control and fi nal measuring you can fi nd out the effects of applied resources towards initial measuring.

  16. Degradation of landscape in Serbian ski resorts-aspects of scale and transfer of impacts

    Directory of Open Access Journals (Sweden)

    Ristić Ratko

    2009-01-01

    Full Text Available The environmental impacts in Serbian ski resorts (Kopaonik, Zlatibor, Stara planina, Divčibare are very strong, leading to degradation of unique mountain landscape, and functionality losses. Processes of urbanization, construction or improvement works, cause hard degradation of topsoil and native vegetation. The logging, large excavation activities, erosion, noise and water pollution constantly impact the habitats of all animal and plant species residing in small areas. The process leads to severe fragmentation of the remaining old-growth forests, endangering future subsistence. Consequences of mismanagement in ski areas are noticeable in downstream sections of river beds, causing floods and bed-load deposition, with high concentration of pollutants, in reservoirs for water supply. Legal nature-protection standards are weakly implemented in regional ski areas. Effective protection of landscape in Serbian ski-areas is based on careful considerations of impact assessment at all levels of planning (spatial and urban planning and designing activities, which enables application of restoration concept, in accordance with general goals of environmental protection (preserving biodiversity, CO2 sequestration, attenuation of effects of global climate changes.

  17. SKI - ASAR - B1/B2 As operated Safety Analysis Report. Recurring safety review 1995 Barsebaeck 1 and 2

    International Nuclear Information System (INIS)

    1996-12-01

    According to Swedish law, the reactor owner is responsible for performing a safety review and writing a so called ASAR-report. The Nuclear Power Inspectorate (SKI) examines this report, and reports the findings to the government (the so called SKI-ASAR-report). Each Swedish reactor should pass through three full ASAR reviews during its lifetime, similar to the licensing inspection before start-up of the reactor. The second series ASAR was delivered by the Barsebaeck utility to SKI in September 1995, and forms the basis for the SKI analysis in the present report

  18. Impact of the initial classic section during a simulated cross-country skiing skiathlon on the cardiopulmonary responses during the subsequent period of skate skiing.

    Science.gov (United States)

    Mourot, Laurent; Fabre, Nicolas; Andersson, Erik; Willis, Sarah J; Hébert-Losier, Kim; Holmberg, Hans-Christer

    2014-08-01

    The aim of this study was to assess potential changes in the performance and cardiorespiratory responses of elite cross-country skiers following transition from the classic (CL) to the skating (SK) technique during a simulated skiathlon. Eight elite male skiers performed two 6 km (2 × 3 km) roller-skiing time trials on a treadmill at racing speed: one starting with the classic and switching to the skating technique (CL1-SK2) and another employing the skating technique throughout (SK1-SK2), with continuous monitoring of gas exchanges, heart rates, and kinematics (video). The overall performance times in the CL1-SK2 (21:12 ± 1:24) and SK1-SK2 (20:48 ± 2:00) trials were similar, and during the second section of each performance times and overall cardiopulmonary responses were also comparable. However, in comparison with SK1-SK2, the CL1-SK2 trial involved significantly higher increases in minute ventilation (V̇E, 89.8 ± 26.8 vs. 106.8 ± 17.6 L·min(-1)) and oxygen uptake (V̇O2; 3.1 ± 0.8 vs 3.5 ± 0.5 L·min(-1)) 2 min after the transition as well as longer time constants for V̇E, V̇O2, and heart rate during the first 3 min after the transition. This higher cardiopulmonary exertion was associated with ∼3% faster cycle rates. In conclusion, overall performance during the 2 time trials did not differ. The similar performance times during the second sections were achieved with comparable mean cardiopulmonary responses. However, the observation that during the initial 3-min post-transition following classic skiing cardiopulmonary responses and cycle rates were slightly higher supports the conclusion that an initial section of classic skiing exerts an impact on performance during a subsequent section of skate skiing.

  19. [Effect of equipment on current ski injuries, their development in the last 20 years and their prevention].

    Science.gov (United States)

    Zucco, P

    1994-01-01

    Ski injuries depend from many factors which involve the skier and his behavior, the environment, especially the weather and slopes conditions, but first of all, the typical equipment, skis, boots and bindings. These materials have undergone a great technical improvement in recent years which allowed a significant decrease of ski injuries, first of all of the typical lower leg fracture, the so called "boot fracture". Nevertheless alpine skiers are exposed to conditions not encountered in other sports. The ski and the stiff plastic ski boot combine to form an extension to the human anatomy, which subjects the lower extremities to loads not normally encountered in other activities. The velocity of the skier combine with the equipment used to expose to a risk of injury that by type, severity and incidence is unusual. The more frequent ski injury in the last 15 years involve the knee and his ligaments. These lesions often involve the medial and lateral compartment and the anterior cruciate ligament (ACL, more than 65% of all knee lesions) and the etiology is related to both the boot and bindings characteristics. Many studies have shown the direct relationship between injuries of the lower extremity and equipment (the so called LEER-injuries, near 46% of all lesions in US studies) and also the importance of a proper binding setting for a lower risk. Ski boots are indicated as the primary cause of the ACL tears but, at this moment, for this lesion 4 mechanisms are described.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Supervision of School and Youth Groups on Lift-Served Ski Slopes: A Research Perspective

    Science.gov (United States)

    Brookes, Andrew; Holmes, Peter

    2014-01-01

    Supervised practice is a common feature of many snow sports excursions to downhill ski resorts by school or youth groups, often in combination with lessons from a ski school. What is the role of supervision in preventing mishaps, injury, or fatalities? This article presents results of a search of published snow sports safety research for evidence…

  1. Alpine ski and snowboarding traumatic injuries: incidence, injury patterns, and risk factors for 10 years.

    Science.gov (United States)

    McBeth, Paul B; Ball, Chad G; Mulloy, Robert H; Kirkpatrick, Andrew W

    2009-05-01

    Alpine skiing and snowboarding are popular winter sports in Canada. Every year participation in these activities results in traumatic injury. The purpose of this study was to identify the incidence and injury patterns, as well as risk factors associated with ski and snowboarding injuries. A comprehensive 10-year retrospective review of Alpine ski and snowboarding injuries from 1996 to 2006 was conducted. The Alberta Trauma Registry was used as the primary source of data. A total of 196 patients (56.6% skiers, 43.4% snowboarders) were identified as having major traumatic injuries (Injury Severity Score, >or=12). Forty-three patients required intensive care unit support. The majority of injuries were related to falls and collisions with natural objects. Head injuries were most common, followed by chest, spinal, and extremity trauma. Seventy-nine patients required emergency surgery. Skiing and snowboarding represent activities with high potential for traumatic injury. Safety initiatives should be developed to target this population.

  2. Take-off analysis of the Olympic ski jumping competition (HS-106m).

    Science.gov (United States)

    Virmavirta, Mikko; Isolehto, Juha; Komi, Paavo; Schwameder, Hermann; Pigozzi, Fabio; Massazza, Giuseppe

    2009-05-29

    The take-off phase (approximately 6m) of the jumps of all athletes participating in the individual HS-106m hill ski jumping competition at the Torino Olympics was filmed with two high-speed cameras. The high altitude of the Pragelato ski jumping venue (1600m) and slight tail wind in the final jumping round were expected to affect the results of this competition. The most significant correlation with the length of the jump was found in the in-run velocity (r=0.628, pski jumping, and suggests that good jumpers simply had smaller friction between their skis and the in-run tracks and/or the aerodynamic quality of their in-run position was better. Angular velocity of the hip joint of the best jumpers was also correlated with jumping distance (r=0.651, pjumped approximately the same distance. This certainly improves the interests in ski jumping among athletes and spectators. The comparison between the take-off techniques of the best jumpers showed that even though the more marked upper body movement creates higher air resistance, it does not necessarily result in shorter jumping distance if the exposure time to high air resistance is not too long. A comparison between the first and second round jumps of the same jumpers showed that the final results in this competition were at least partly affected by the wind conditions.

  3. Joining of advanced materials

    CERN Document Server

    Messler, Robert W

    1993-01-01

    Provides an unusually complete and readable compilation of the primary and secondary options for joining conventional materials in non-conventional ways. Provides unique coverage of adhesive bonding using both organic and inorganic adhesives, cements and mortars. Focuses on materials issues without ignoring issues related to joint design, production processing, quality assurance, process economics, and joining performance in service.Joining of advanced materials is a unique treatment of joining of both conventional and advanced metals andalloys, intermetallics, ceramics, glasses, polymers, a

  4. A local scale assessment of the climate change sensitivity of snow in Pyrenean ski resorts

    Science.gov (United States)

    Pesado, Cristina; Pons, Marc; Vilella, Marc; López-Moreno, Juan Ignacio

    2016-04-01

    The Pyrenees host one of the largest ski area in Europe after the Alps that encompasses the mountain area of the south of France, the north of Spain and the small country of Andorra. In this region, winter tourism is one of the main source of income and driving force of local development on these mountain communities. However, this activity was identified as one of the most vulnerable to a future climate change due to the projected decrease of natural snow and snowmaking capacity. However, within the same ski resorts different areas showed to have a very different vulnerability within the same resort based on the geographic features of the area and the technical management of the slopes. Different areas inside a same ski resort could have very different vulnerability to future climate change based on aspect, steepness or elevation. Furthermore, the technical management of ski resorts, such as snowmaking and grooming were identified to have a significant impact on the response of the snowpack in a warmer climate. In this line, two different ski resorts were deeply analyzed taken into account both local geographical features as well as the effect of the technical management of the runs. Principal Component Analysis was used to classify the main areas of the resort based on the geographic features (elevation, aspect and steepness) and identify the main representative areas with different local features. Snow energy and mass balance was simulated in the different representative areas using the Cold Regions Hydrological Model (CRHM) assuming different magnitudes of climate warming (increases of 2°C and 4°C in the mean winter temperature) both in natural conditions and assuming technical management of the slopes. Theses first results showed the different sensitivity and vulnerability to climate changes based on the local geography of the resort and the management of the ski runs, showing the importance to include these variables when analyzing the local vulnerability

  5. Evaluation of Explosive Power Performance in Ski Jumpers and Nordic Combined Competitive Athletes: A 19-Year Study.

    Science.gov (United States)

    Janura, Miroslav; Cabell, Lee; Svoboda, Zdenek; Elfmark, Milan

    2016-01-01

    Between 1992 and 2010, a total of 334 males participated in this study that assessed the differences and relationships between anthropometric variables and lower limb muscle strength in young and adult ski jumpers (n = 207) and Nordic combined (NC, n = 127) athletes. All athletes completed a maximal vertical jump from an in-run position and a maximal relative isometric force (MRIF) of the knee extensor measurement in a laboratory setting. The body mass index (BMI) in young competitors was lower than in adult groups (NC: p ski jumping [SJ]: p jump height (VJH) was lower for young competitors than for adults (NC: p ≤ 0.05; SJ: p ski jumpers even at lower-body weights. These changes are in accordance with the change in ski jump techniques.

  6. Joining by plastic deformation

    DEFF Research Database (Denmark)

    Mori, Ken-ichiro; Bay, Niels; Fratini, Livan

    2013-01-01

    As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating opportuni......As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating...

  7. A system to measure the kinematics during the entire ski jump sequence using inertial sensors.

    Science.gov (United States)

    Chardonnens, Julien; Favre, Julien; Cuendet, Florian; Gremion, Gérald; Aminian, Kamiar

    2013-01-04

    Three-dimensional analysis of the entire sequence in ski jumping is recommended when studying the kinematics or evaluating performance. Camera-based systems which allow three-dimensional kinematics measurement are complex to set-up and require extensive post-processing, usually limiting ski jumping analyses to small numbers of jumps. In this study, a simple method using a wearable inertial sensors-based system is described to measure the orientation of the lower-body segments (sacrum, thighs, shanks) and skis during the entire jump sequence. This new method combines the fusion of inertial signals and biomechanical constraints of ski jumping. Its performance was evaluated in terms of validity and sensitivity to different performances based on 22 athletes monitored during daily training. The validity of the method was assessed by comparing the inclination of the ski and the slope at landing point and reported an error of -0.2±4.8°. The validity was also assessed by comparison of characteristic angles obtained with the proposed system and reference values in the literature; the differences were smaller than 6° for 75% of the angles and smaller than 15° for 90% of the angles. The sensitivity to different performances was evaluated by comparing the angles between two groups of athletes with different jump lengths and by assessing the association between angles and jump lengths. The differences of technique observed between athletes and the associations with jumps length agreed with the literature. In conclusion, these results suggest that this system is a promising tool for a generalization of three-dimensional kinematics analysis in ski jumping. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Ceramic joining

    Energy Technology Data Exchange (ETDEWEB)

    Loehman, R.E. [Sandia National Lab., Albuquerque, NM (United States)

    1996-04-01

    This paper describes the relation between reactions at ceramic-metal interfaces and the development of strong interfacial bonds in ceramic joining. Studies on a number of systems are described, including silicon nitrides, aluminium nitrides, mullite, and aluminium oxides. Joints can be weakened by stresses such as thermal expansion mismatch. Ceramic joining is used in a variety of applications such as solid oxide fuel cells.

  9. A Retrospective Analysis of Concurrent Pathology in ACL-Reconstructed Knees of Elite Alpine Ski Racers

    DEFF Research Database (Denmark)

    Jordan, Matthew J; Doyle-Baker, Patricia; Heard, Mark

    2017-01-01

    /chondral surgery, 60% of meniscal tears and 80% of chondral lesions had worsened since the time of primary ACLR. CONCLUSION: Concurrent injury was common in this group of elite ski racers. Primary ACL tears were typically accompanied by lateral compartment chondral lesions and complex meniscal tears that worsened...... over time. ACL/MCL tears were the most common multiligament injury pattern.......BACKGROUND: Anterior cruciate ligament (ACL) tear is the most frequent injury in alpine ski racing, and there is a high prevalence of ACL reinjury. Limited data exist on the concurrent pathology with primary ACL tears in elite alpine ski racers and the magnitude of injury progression after primary...

  10. Chromosomal instability in mouse embryonic fibroblasts null for the transcriptional co-repressor Ski

    OpenAIRE

    Marcelain, Katherine; Armisen, Ricardo; Aguirre, Adam; Ueki, Nobuhide; Toro, Jessica; Colmenares, Clemencia; Hayman, Michael J

    2012-01-01

    Ski is a transcriptional regulator that has been considered an oncoprotein, given its ability to induce oncogenic transformation in avian model systems. However, studies in mouse and in some human tumor cells have also indicated a tumor suppressor activity for this protein. We found that Ski−/− mouse embryo fibroblasts exhibit high levels of genome instability, namely aneuploidy, consistent with a tumor suppressor function for Ski. Time-lapse microscopy revealed lagging chromosomes and chroma...

  11. HEART RATE, MOOD STATES, AND RATING OF PERCEIVED EXERTION AMONG ELDERLY SUBJECTS DURING 3.5 HOURS OF RECREATIONAL ALPINE SKIING

    Directory of Open Access Journals (Sweden)

    Sabine Krautgasser

    2012-12-01

    Full Text Available A decline in physiological functioning and mental wellbeing is common with advancing age. However, these changes may vary among elderly individuals. Physical activity and the response of the elderly to exercise during recreational activities, i.e., recreational alpine skiing, may serve as a catalyst for the improvement of wellbeing and general health. Purpose: The aim of the study was to assess the heart rate (HR response modulations in a group of elderly recreational alpine skiers during 3.5h of skiing. In addition, each group's perceived responses of mood state (MS and rating of perceived exertion (RPE were collected to determine possible contributions to changes in wellbeing as a result of recreational skiing. Methods: Forty-nine healthy elderly participants (mean age: 63±6 yrs, weight: 75.4+13.1 kg, height: 170.5+9.1 cm, BMI: 26+3.2 with at least basic alpine skiing ability participated in a 3.5h ski test. GPS data (GPS Garmin Forerunner 301 were used to monitor altitude and HR and were recorded continuously during the 3.5h of skiing. During skiing, participants were asked at three different times to report RPE and MS. Results: The time spent on the lift during the 3.5h skiing ranged from 21-58% followed by recovery breaks of 17-53% and time spent in downhill skiing ranged from 12-40%. Participants completed 9-23 downhill runs in 3.5h. Average intensities during 3.5 h downhill runs for over 80% of the group were between 50-80% of maximal heart rate (HRmax (220-age. Peak heart rate (HRpeak values during downhill runs for 35% of the group were between 60-70% of HRmax. Statistical analysis revealed numerous significant differences between RPE and MS values for the three different sampling times. The MS in general remained positive and even increased in the categories of happiness and sociability despite an increase in fatigue. Conclusion: The results of this study suggest that the duration and intensity of skiing was appropriate and yielded

  12. TRAVEL PLANNING PROPOSALS SKI AREA IN NORTH OLTENIA TO INCREASE VISIBILITY AT NATIONAL LEVEL

    Directory of Open Access Journals (Sweden)

    CONSTANŢA ENEA

    2015-06-01

    Full Text Available Mountain tourism potential is complex and varied in structure, size and spatial distribution, which is related to massive expansion, differentiation altitude, geological composition, configuration and specific geological landforms, fragmentation, vegetation cover and peculiarities of the river system, etc. Therefore under the mountain in northern Oltenia highlights some differences in the regions in terms of structure, volume, value, capitalizing on opportunities in tourism mountain tourism potential. Mountain tourism is one of the traditional forms of tourism in affirming Romanian tourism internationally, both through natural potential available by the low level of degradation of landscapes and through investment efforts that were made in the specific offer. European alpine countries (France, Switzerland, Austria, Italy, etc. attaches great importance to the potential of mountain tourism available and submitted in this regard, special efforts for the development of mountain resorts attract millions of tourists annually amateur ski of sports winter mountain in general. Romania has a great value ski area that can compete successfully with the ski areas of central and Western Europe. What are the strengths and weaknesses of Romanian mountain tourism potential in comparability with famous country ski area for winter sports will see throughout this paper.

  13. Physical training of 30–40 years old tourists skiers to ski sports hiking

    Directory of Open Access Journals (Sweden)

    Alexander Toporkov

    2015-02-01

    Full Text Available Purpose: compare the test results obtained at different stages of physical training of tourists skiers, immediately after passing of the ski sports hiking of the third category of complexity and 14 days after hiking. Determine the effectiveness of the designed program to improve the physical readiness of 30–40 years old tourists skiers. Material and Methods: 14 people aged 30 to 40 years old who have a different experience in water, hiking and mountain as well as ski-sport hiking took part in research. Analysis of scientific and methodical literature, pedagogical observations, pedagogical experiment, methods of mathematical statistics is used. Results: the test results of 30–40 years old tourists skiers which are the participants in the experimental group received at different stages of preparation and preparatory period and the results after passing ski sports hiking of the third category of complexity are processed. Their comparative analysis is held. Conclusions: it was found that the developed training program can effectively influence the physical readiness of tourists skiers, as well as all functions and systems that contribute to the successful passage of ski sports categorized hike.

  14. Automatic Identification of Subtechniques in Skating-Style Roller Skiing Using Inertial Sensors

    Science.gov (United States)

    Sakurai, Yoshihisa; Fujita, Zenya; Ishige, Yusuke

    2016-01-01

    This study aims to develop and validate an automated system for identifying skating-style cross-country subtechniques using inertial sensors. In the first experiment, the performance of a male cross-country skier was used to develop an automated identification system. In the second, eight male and seven female college cross-country skiers participated to validate the developed identification system. Each subject wore inertial sensors on both wrists and both roller skis, and a small video camera on a backpack. All subjects skied through a 3450 m roller ski course using a skating style at their maximum speed. The adopted subtechniques were identified by the automated method based on the data obtained from the sensors, as well as by visual observations from a video recording of the same ski run. The system correctly identified 6418 subtechniques from a total of 6768 cycles, which indicates an accuracy of 94.8%. The precisions of the automatic system for identifying the V1R, V1L, V2R, V2L, V2AR, and V2AL subtechniques were 87.6%, 87.0%, 97.5%, 97.8%, 92.1%, and 92.0%, respectively. Most incorrect identification cases occurred during a subtechnique identification that included a transition and turn event. Identification accuracy can be improved by separately identifying transition and turn events. This system could be used to evaluate each skier’s subtechniques in course conditions. PMID:27049388

  15. Automatic Identification of Subtechniques in Skating-Style Roller Skiing Using Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Yoshihisa Sakurai

    2016-04-01

    Full Text Available This study aims to develop and validate an automated system for identifying skating-style cross-country subtechniques using inertial sensors. In the first experiment, the performance of a male cross-country skier was used to develop an automated identification system. In the second, eight male and seven female college cross-country skiers participated to validate the developed identification system. Each subject wore inertial sensors on both wrists and both roller skis, and a small video camera on a backpack. All subjects skied through a 3450 m roller ski course using a skating style at their maximum speed. The adopted subtechniques were identified by the automated method based on the data obtained from the sensors, as well as by visual observations from a video recording of the same ski run. The system correctly identified 6418 subtechniques from a total of 6768 cycles, which indicates an accuracy of 94.8%. The precisions of the automatic system for identifying the V1R, V1L, V2R, V2L, V2AR, and V2AL subtechniques were 87.6%, 87.0%, 97.5%, 97.8%, 92.1%, and 92.0%, respectively. Most incorrect identification cases occurred during a subtechnique identification that included a transition and turn event. Identification accuracy can be improved by separately identifying transition and turn events. This system could be used to evaluate each skier’s subtechniques in course conditions.

  16. Development of SKI's Regulatory Approach to the Siting of a Spent Nuclear Fuel Repository

    International Nuclear Information System (INIS)

    Westerlind, Magnus

    2003-01-01

    Since the beginning of the 1990s the Swedish Nuclear Fuel and Waste Management Co., SKB, is actively working with the siting of a spent nuclear fuel repository. Feasibility studies have been completed in a total of eight municipalities, and in December 2000 three municipalities (Oskarshamn, Tierp and Oesthammar) were proposed for further investigations. These site investigations include surface based site characterisation from deep bore holes but also further studies of infrastructure, land use, transportation etc. SKB's proposal was reviewed by SKI and about 60 other organisations, including municipalities, NGOs, government agencies etc. during the winter/spring 2000/2001. In June 2001 SKI reported the review findings to the Government. In parallel with SKI also the Swedish Council for Nuclear Waste (KASAM) reviewed SKB's proposal and reported to the Government. In its decision in November 2001 the Government supported SKB's proposal to continue with site investigations. Based on SKB's material, the reviews and the Government's decision the municipalities of Oesthammar and Oskarshamn have agreed to site investigations while Tierp have decided no to continue. The site investigations in Oesthammar and Oskarshamn started during 2002. The siting process has meant that several new actors have been engaged in nuclear waste management in general and disposal of spent nuclear fuel in particular. This has meant that 'old' actors, particularly SKB, the regulators (the Swedish Nuclear Power Inspectorate, SKI, and the Swedish Radiation Protection Authority, SSI) have had to evaluate, develop and clarify their roles and strategies for dialogue. This paper presents reflections on the impacts on some of SKI's regulatory activities

  17. Progressivity of Basic Elements of the Slovenian National Alpine Ski School

    Directory of Open Access Journals (Sweden)

    Blaž Lešnik

    2014-05-01

    Full Text Available Progressivity of Basic Elements of the Slovenian National Alpine Ski School Ski school programmes in different countries are adapted to the local conditions and skiing trends. The aim of the study was to establish the progressivity of the three basic elements of the Slovenian ski school in terms of the duration of individual turns and their phases. Eight participants were recorded as they performed three basic elements of the Slovenian national ski school: wedge curves – E1, turns with a wedge push-off – E2 and basic swinging – E3. According to the ski school, the elements were divided into phases. The results of the computer-aided video analysis showed that in the beginning types of skiing in the same conditions on the same length of terrain, the average durations of turns and the times of comparable initiation and steering phases of the elements shortened on the methodical upward scale (from E1 to E3. The number of turns executed on the same length of terrain from E1 to E3 increased. A larger step in motor task complexity was indicated when a pole plant was included in skiing elements. Further, relatively large differences were observed in time durations among subjects executing the same elements. In conclusion, it can be assessed that the basic elements of the ski school are placed gradually in terms of progressivity in time durations. Progresivita základních elementů slovinské národní školy alpského lyžování Programy lyžařských škol v různých zemích jsou přizpůsobeny místním podmínkám a lyžařským trendům. Cílem této studie bylo stanovit progresivitu tří základních prvků slovinské lyžařské školy, pokud jde o dobu trvání jednotlivých zatočení a jejich fází. U osmi účastníků bylo zaznamenáno, jak provádějí tři základní prvky ze slovinské národní lyžařské školy: E1 – oblouk z pluhu; E2 – oblouk z přívratu vyšší lyží E3 – paralelní oblouk. Podle lyžařské

  18. Adjustments of muscle capillarity but not mitochondrial protein with skiing in the elderly

    DEFF Research Database (Denmark)

    van Ginkel, S; Amami, M; Dela, F

    2015-01-01

    Downhill skiing in the elderly increases maximal oxygen uptake (VO2max) and carbohydrate handling, and produces muscle hypertrophy. We hypothesized that adjustments of the cellular components of aerobic glucose combustion in knee extensor muscle, and cardiovascular adjustments, would increase...... lateralis muscle were analyzed for capillary density and expression of respiratory chain markers (NDUFA9, SDHA, UQCRC1, ATP5A1) and the glucose transporter GLUT4. Statistical significance was assessed with a repeated analysis of variance and Fisher's post-hoc test at a P value of 5%. VO2max increased...... selectively with ski training (+7 ± 2%). Capillary density (+11 ± 5%) and capillary-to-fiber ratio (12 ± 5%), but not the concentration of metabolic proteins, in vastus lateralis were increased after skiing. Cardiovascular parameters did not change. Fold changes in VO2max and capillary-to-fiber ratio were...

  19. A comparison of wakeboard-, water skiing-, and tubing-related injuries in the United States, 2000-2007.

    Science.gov (United States)

    Baker, John I; Griffin, Russell; Brauneis, Paul F; Rue, Loring W; McGwin, Gerald

    2010-01-01

    The purpose of the study was to compare tubing-related injuries to wakeboarding- and water skiing-related injuries. Data was collected from the 2000-2007 National Electronic Injury Surveillance Survey for 1,761 individuals seeking care at an emergency department due to a tubing-, wakeboarding, or water skiing-related injury. Data included patient age and sex, as well as injury characteristics including body region injured (i.e., head and neck, trunk, shoulder and upper extremity, and hip and lower extremity) and diagnosis of injury (e.g., contusion, laceration, or fracture). Case narratives were reviewed to ensure that a tubing-, wakeboarding-, or water skiing-related injury occurred while the individual was being towed behind a boat. Severe injury (defined as an injury resulting in the individual being hospitalized, transferred, held for observation) was compared among the groups using logistic regression. Wakeboard- and tubing-related injuries more commonly involved the head and neck, while water skiing- related injuries were likely to involve the hip and lower extremity. Tubing-related injuries, compared to water skiing-related injuries, were more likely to be severe (OR 2.31, 95% CI 1.23-4. 33). Like wakeboarding and water skiing, tubing has inherent risks that must be understood by the participant. While tubing is generally considered a safer alternative to wakeboarding and water skiing, the results of the current study suggest otherwise. Both the number and severity of tubing- related injuries could be prevented through means such as advocating the use of protective wear such as helmets while riding a tube or having recommended safe towing speeds prominently placed on inner tubes. Key pointsIncrease annual injury rate trend in wakeboard injuries.Wakeboard- and tubing-related injuries more often to head and neck, waterskiing-related injuries more often to hip and lower extremity.Tubing-related injuries over 2-times as likely to be severe compared to

  20. Professor Adam Stalony-Dobrzański - the Master and the Teacher of Jerzy Nowosielski

    Directory of Open Access Journals (Sweden)

    Jarosław Szmajda

    2014-11-01

    Full Text Available When analyzing the history of Polish religious art of the XX century, we can affirm that the entire creative work of Adam Stalony-Dobrzański, professor at Kraków Academy of Fine Arts, remains in the shadow of the artistic output of Prof. Jerzy Nowosielski, his student and follower. Jerzy Nowosielski had a noticeable impact on the interest in the problems of the sacred in modern painting. The follower of Prof. Adam Stalony-Dobrzański was inspired by the art and the spirituality of Eastern Christianity. Prof. Jerzy Nowosielski filled some kind of a void in Polish religious art in the period of its evident crisis. Prof. Jerzy Nowosielski together with Prof. Adam Stalony-Dobrzański created polychrome frescoes of numerous religious buildings. The styling and the artistic accomplishments of Prof. Adam Stalony-Dobrzański are unknown for the wide audience which makes an evident gap in the history of Polish art. Polychrome frescoes and stainedglass windows can be seen in interiors of Catholic, Orthodox, and Protestant temples. The creative work of the Kraków artist is an example of the great and highly authentic vision of the sacred, which was stronger than communist censorship. The concept of Adam Stalony-Dobrzański’s art is not based on his theoretical conclusions but only on the analysis of correspondence of the artist with the then Metropolitan Archbishop of Kraków Karol Wojtyła - now St. Pope JohnPaul II. The topic of their letters was the issues of modern art and religious art, in particular the attempt to define a way in which art should be developed to meet the current needs of the Church. In contrast to the master, Prof. Adam Stalony-Dobrzański, his follower Prof. Jerzy Nowosielski has left ample commentary on his artwork. Prof. Adam Stalony-Dobrzański was rather a practitioner than a theoretician. Thus the fact of how great an impact he had on the character and the artwork of Jerzy Nowosielski is puzzling. In the first half of the

  1. Researchers' Night: science at the shops

    CERN Multimedia

    Corinne Pralavorio

    2015-01-01

    On 25 September, as part of European Researchers’ Night, CERN and POPScience joined forces to welcome the public at the Balexert shopping centre in Geneva. The Bulletin presents its gallery of photographs from the exciting and educational event.   Science through comic strips, games, cinema and television: POPScience approaches scientific questions through popular culture, with great success! Around 500 children attended the sessions for schools at Balexert's multiplex cinema, and 600 spectators flocked to the public screenings.  Using the big screen, scientists, directors and authors were on hand to disentangle truth from untruths and science from science fiction. The guests, some of whom appeared in person and others via video link, included Jorge Cham, author of PhD Comics and the spin-off film; David Saltzberg, physicist at CMS and scientific consultant for the television series The Big Bang Theory; Kip Thorne, scientific consultant for the film Interstellar; Lawrence ...

  2. SKI SITE-94. Deep Repository Performance Assessment Project. Summary

    International Nuclear Information System (INIS)

    1997-02-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry's R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is neither a safety assessment nor a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The main report (SKI-R--96-36) gives a detailed description of the many inter-related studies undertaken as part of the research project, while the present report presents a condensed summary of the main report. 46 refs

  3. Opinions on SKB's Safety Assessments SR 97 and SFL 3-5. A Review by SKI Consultants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    The Swedish Nuclear Fuel and Waste Management Co. (SKB) has presented their safety assessment 'Deep repository for spent nuclear fuel, SR 97 - Post-closure safety'. SKB's report is part of the documentation that has been required by the Government before the start of site investigations. The Swedish Nuclear Power Inspectorate (SKI) is reviewing SR 97 according to earlier Government decisions. In its review work SKI has asked several consultants, that recently have been performing research work for SKI, to give their opinions on SR 97. SKI and the Swedish Radiation Protection Institute (SSI) have used these reports from the consultants as one complementary basis for the formulation of the SKI/SSI review report. This is a compilation of the reports from the different consultants, and therefore the different contributions vary in length, style and language. Included are also two consultant reports, giving comments on SKB's preliminary safety assessment for SFL 3-5 (deep repository for long-lived low- and intermediate-level waste). The 17 contributions have all been separately indexed.

  4. 78 FR 33047 - Humboldt-Toiyabe National Forest, Carson Ranger District Mt. Rose Ski Tahoe-Atoma Area...

    Science.gov (United States)

    2013-06-03

    ... Mt. Rose Ski Tahoe--Atoma Area Environmental Impact Statement AGENCY: Forest Service, USDA. ACTION... the effects of a proposal from Mt. Rose Ski Tahoe (Mt. Rose) to expand its lift and terrain network. The project is located approximately 12 miles west of the intersection of Mt. Rose Highway (Nevada...

  5. Chrysler Upset Protrusion Joining Techniques for Joining Dissimilar Metals

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Stephen [FCA US LLC, Auburn Hills, MI (United States)

    2017-09-28

    The project goal was to develop and demonstrate a robust, cost effective, and versatile joining technique, known as Upset Protrusion Joining (UPJ), for joining challenging dissimilar metal com-binations, especially those where one of the metals is a die cast magnesium (Mg) component. Since two of the key obstacles preventing more widespread use of light metals (especially in high volume automotive applications) are 1) a lack of robust joining techniques and 2) susceptibility to galvanic corrosion, and since the majority of the joint combinations evaluated in this project include die cast Mg (the lightest structural metal) as one of the two materials being joined, and since die casting is the most common and cost effective process for producing Mg components, then successful project completion provides a key enabler to high volume application of lightweight materials, thus potentially leading to reduced costs, and encouraging implementation of lightweight multi-material vehicles for significant reductions in energy consumption and reduced greenhouse gas emissions. Eco-nomic benefits to end-use consumers are achieved primarily via the reduction in fuel consumption. Unlike currently available commercial processes, the UPJ process relies on a very robust mechanical joint rather than intermetallic bonding, so the more cathodic material can be coated prior to joining, thus creating a robust isolation against galvanic attack on the more anodic material. Additionally, since the UPJ protrusion is going through a hole that can be pre-drilled or pre-punched prior to coating, the UPJ process is less likely to damage the coating when the joint is being made. Further-more, since there is no additional cathodic material (such as a steel fastener) used to create the joint, there is no joining induced galvanic activity beyond that of the two parent materials. In accordance with its originally proposed plan, this project has successfully developed process variants of UPJ to enable

  6. Extended probabilistic system assessment calculations within the SKI project-90

    International Nuclear Information System (INIS)

    Pereira, A.

    1993-03-01

    The probabilistic system assessment calculation reported in the SKI Project-90 final documents were restricted to the following nuclides: 14 C, 129 I, 135 Cs, 237 Np and 240 Pu. In this report we have extended those calculations to another five nuclides: 79 Se, 243 Am, 240 Pu, 93 Zr and 99 Tc. The execution of probabilistic assessment calculations integrated in the context of SKIs first safety analysis exercise of an hypothetic final repository for high-level nuclear waste in Sweden, was a learning experience of relevance for the conduction of probabilistic safety assessment in future exercises. Some major conclusions and viewpoints of future need related with probabilistic assessment were withdrawn from this work and are presented in our report

  7. Anatol Stern e Bruno Jasieński [Anatol Stern and Bruno Jasieński

    Directory of Open Access Journals (Sweden)

    Giovanna Tomassucci

    2016-12-01

    Full Text Available The Author presents her first Italian translation of Anatol Stern’s article (excerpted from his monograph on Polish Avantgarde Rebelled Poetry. Sketches on Interwar Period Poetry [1964, 2nd issue 1970] about another prominent initiator and ideologist of Polish futurism, Bruno Jasieński. After the Thaw, Stern first contributed to Jasieński’s rehabilitation, publishing his poetry and the novel I burn Paris and writing several essays about his work. The article presented also offers a choice of translated fragments of Jasieński’s poetry, just a few known in Italy, and an artistic profile of Stern.

  8. Join Operations in Temporal Databases

    DEFF Research Database (Denmark)

    Gao, D.; Jensen, Christian Søndergaard; Snodgrass, R.T.

    2005-01-01

    Joins are arguably the most important relational operators. Poor implementations are tantamount to computing the Cartesian product of the input relations. In a temporal database, the problem is more acute for two reasons. First, conventional techniques are designed for the evaluation of joins...... with equality predicates rather than the inequality predicates prevalent in valid-time queries. Second, the presence of temporally varying data dramatically increases the size of a database. These factors indicate that specialized techniques are needed to efficiently evaluate temporal joins. We address...... this need for efficient join evaluation in temporal databases. Our purpose is twofold. We first survey all previously proposed temporal join operators. While many temporal join operators have been defined in previous work, this work has been done largely in isolation from competing proposals, with little...

  9. [Doctor's degree thesis of Tomasz Adolf Wołkowiński "Carditidis rheumaticae historia"].

    Science.gov (United States)

    Stembrowicz, W

    2001-01-01

    In 1817 on the University of Vilnius Faculty of Medicine, T. A. Wołkowiński, a student of the eminent clinician Józef Frank, defended his doctor's degree thesis about a direct relation between rheumatic disease and cardiomegaly. It was probably the first paper in Poland describing with details the rheumatic heart disease. Unfortunately we don't know much about T. A. Wołkowiński's life.

  10. Alpine Skiing With total knee ArthroPlasty (ASWAP)

    DEFF Research Database (Denmark)

    Kristensen, M.; Pötzelsberger, B.; Scheiber, P.

    2015-01-01

    We investigated the effect of alpine skiing for 12 weeks on skeletal muscle characteristics and biomarkers of glucose homeostasis and cardiovascular risk factors. Twenty-three patients with a total knee arthroplasty (TKA) were studied 2.9 ± 0.9 years (mean ± SD) after the operation. Fourteen...

  11. SKI's Evaluation of SKB's RD and D Programme 95. Summary and Conclusions

    International Nuclear Information System (INIS)

    1996-07-01

    In SKI's opinion, the Swedish Nuclear Fuel and Waste Management Co (SKB) has presented a research and development program which fulfills the basic requirements stipulated in the Act on Nuclear Activities. On the whole, the program is appropriate with regard to the development and evaluation of a method for the final disposal of spent nuclear fuel and nuclear waste in the Swedish bedrock. The quality of the supporting research program is high. However, in SKI's view, the General Siting Study should be supplemented with regard to certain points and the siting factors should be further specified

  12. Forming technique of ski sport of students of the first course of sporting institute of higher education

    Directory of Open Access Journals (Sweden)

    Sidorova T.V.

    2010-06-01

    Full Text Available Is certain the most rational method of the speed-up teaching of students of the first course of discipline «Ski sport». Positions are taken into account to credit-module departmental teaching. The individual differentiated technology of the accelerated training to ways of movement on a ski is proved. Technology includes three methods of teaching. Application of methods is varied depending on sporting specialization of students and development of their physical qualities. The rational parity of employment on training to technics of classical and skating styles of movement on a ski is determined.

  13. How Do World-Class Nordic Combined Athletes Differ From Specialized Cross-Country Skiers and Ski Jumpers in Sport-Specific Capacity and Training Characteristics?

    Science.gov (United States)

    Sandbakk, Øyvind; Rasdal, Vegard; Bråten, Steinar; Moen, Frode; Ettema, Gertjan

    2016-10-01

    To compare sport-specific laboratory capacities and the annual training of world-class Nordic combined (NC) athletes with specialized ski jumpers (SJ) and cross-country (XC) skiers. Five world-class athletes from each sports discipline were compared. Ski jump imitations were performed on a 3-dimensional force plate in NC athletes and SJ, whereas XC skiing characteristics were obtained from submaximal and maximal roller ski skating on a treadmill in NC athletes and XC skiers. In addition, anthropometrics and annual training characteristics were determined. NC athletes demonstrated 9% higher body mass and showed 17% lower vertical speed in the ski jump imitation than SJ (all P ski-jumping-specific sessions and outdoor ski jumps compared with SJ. NC athletes performed 31% less endurance training, mainly caused by lower amounts of low- and moderate-intensity training in the classical technique, whereas high-intensity strength and speed training and endurance training in the skating technique did not differ substantially from XC skiers. To simultaneously optimize endurance, explosive, and technical capacities in 2 different disciplines, world-class NC athletes train approximately two-thirds of the XC skier's endurance training volume and perform one-half of the ski-jump-specific training compared with SJ. Still, the various laboratory capacities differed only 10-17% compared with SJ and XC skiers.

  14. EMG activities and plantar pressures during ski jumping take-off on three different sized hills.

    Science.gov (United States)

    Virmavirta, M; Perttunen, J; Komi, P V

    2001-04-01

    Different profiles of ski jumping hills have been assumed to make the initiation of take-off difficult especially when moving from one hill to another. Neuromuscular adaptation of ski jumpers to the different jumping hills was examined by measuring muscle activation and plantar pressure of the primary take-off muscles on three different sized hills. Two young ski jumpers volunteered as subjects and they performed several trials from each hill (K-35 m, K-65 m and K-90 m) with the same electromyographic (EMG) electrode and insole pressure transducer set-up. The results showed that the differences in plantar pressure and EMGs between the jumping hills were smaller than expected for both jumpers. The small changes in EMG amplitudes between the hills support the assumption that the take-off was performed with the same intensity on different jumping hills and the timing of the gluteus EMG demonstrates well the similarity of the muscle activation on different hills. On the basis of the results obtained it seems that ski jumping training on small hills does not disturb the movement patterns for bigger hills and can also be helpful for special take-off training with low speed.

  15. Localization and roles of Ski8p protein in Sordaria meiosis and delineation of three mechanistically distinct steps of meiotic homolog juxtaposition.

    Science.gov (United States)

    Tessé, Sophie; Storlazzi, Aurora; Kleckner, Nancy; Gargano, Silvana; Zickler, Denise

    2003-10-28

    Ski8p is implicated in degradation of non-poly(A) and double-stranded RNA, and in meiotic DNA recombination. We have identified the Sordaria macrospora SKI8 gene. Ski8p is cytoplasmically localized in all vegetative and sexual cycle cells, and is nuclear localized, specifically in early-mid-meiotic prophase, in temporal correlation with Spo11p, the meiotic double-strand break (DSB) transesterase. Localizations of Ski8p and Spo11p are mutually interdependent. ski8 mutants exhibit defects in vegetative growth, entry into the sexual program, and sporulation. Diverse meiotic defects, also seen in spo11 mutants, are diagnostic of DSB absence, and they are restored by exogenous DSBs. These results suggest that Ski8p promotes meiotic DSB formation by acting directly within meiotic prophase chromosomes. Mutant phenotypes also divide meiotic homolog juxtaposition into three successive, mechanistically distinct steps; recognition, presynaptic alignment, and synapsis, which are distinguished by their differential dependence on DSBs.

  16. Blind-date Conversation Joining

    Directory of Open Access Journals (Sweden)

    Luca Cesari

    2013-07-01

    Full Text Available We focus on a form of joining conversations among multiple parties in service-oriented applications where a client may asynchronously join an existing conversation without need to know in advance any information about it. More specifically, we show how the correlation mechanism provided by orchestration languages enables a form of conversation joining that is completely transparent to clients and that we call 'blind-date joining'. We provide an implementation of this strategy by using the standard orchestration language WS-BPEL. We then present its formal semantics by resorting to COWS, a process calculus specifically designed for modelling service-oriented applications. We illustrate our approach by means of a simple, but realistic, case study from the online games domain.

  17. Assessment of the economic risk for the ski resorts of changes in snow cover duration

    Directory of Open Access Journals (Sweden)

    S. A. Sokratov

    2014-01-01

    Full Text Available Winter tourism that is intensively developed in the Russian Federation in recent years strongly depends on the snow availability and properties in the region. Climate changes exert significant influence on the functioning of mountain ski resorts, especially if they are located in areas with relatively high air temperatures in winter season. At the present time, a snowy cluster of mountain ski resorts is intensively progressing in vicinity of Krasnaya Polyana. This region in the West Caucasus (Russia is characterized by relatively warm climate conditions. The snow cover thickness (of 1% insurance in area of the Aibga mountain range may reach 8.1 m. But the snow cover thickness is not the only characteristic of the mountain skiing attractiveness. According to the Swiss standards a mountain ski resort can be considered reliable if during seven seasons of ten ones the snow cover with minimal thickness of 30–50 cm exists for a time not shorter than 100 days during a period from 1st December till 15th April.According to the forecast, during future decades the calculated amount of solid precipitation should reduce by 25–30% in mountain regions on the south macro-slope of the Great Caucasus. As the calculations show, by 2041–2050 the maximal decade thickness of snow cover will decrease by 29–35% while a number of days with snow – by 35–40%. If this is the case, artificial snow will be needed in addition to the natural one. But, under warm climate conditions using of plants for artificial snow production will require a certain perfecting of the nowadays technologies, and very likely, with use of chemicals. That is why a shadowing of existing mountain ski routes by means of the tree planting along them could be ecologically more promising. As for the mountain ski resorts of the West Caucasus, we should mention a possible weakening of the avalanche activity as a potential positive effect of the climate warming predicted by models.

  18. Improved safety in ski jumping.

    Science.gov (United States)

    Wester, K

    1988-01-01

    Among approximately 2,600 licensed Norwegian ski jumpers, only three injuries that caused a permanent medical disability of at least 10% were incurred during the 5 year period from 1982 through 1986. When compared to the previous 5 year period (1977 to 1981), a dramatic improvement in safety is seen, as both number and severity of such injuries were markedly reduced. There are several probable reasons for this improved safety record: better preparation of the jumps, the return to using only one standard heel block, and the fact that coaches are being more responsible, especially with younger jumpers.

  19. Dynamics of the in-run in ski jumping: a simulation study.

    Science.gov (United States)

    Ettema, Gertjan J C; Bråten, Steinar; Bobbert, Maarten F

    2005-08-01

    A ski jumper tries to maintain an aerodynamic position in the in-run during changing environmental forces. The purpose of this study was to analyze the mechanical demands on a ski jumper taking the in-run in a static position. We simulated the in-run in ski jumping with a 4-segment forward dynamic model (foot, leg, thigh, and upper body). The curved path of the in-run was used as kinematic constraint, and drag, lift, and snow friction were incorporated. Drag and snow friction created a forward rotating moment that had to be counteracted by a plantar flexion moment and caused the line of action of the normal force to pass anteriorly to the center of mass continuously. The normal force increased from 0.88 G on the first straight to 1.65 G in the curve. The required knee joint moment increased more because of an altered center of pressure. During the transition from the straight to the curve there was a rapid forward shift of the center of pressure under the foot, reflecting a short but high angular acceleration. Because unrealistically high rates of change of moment are required, an athlete cannot do this without changing body configuration which reduces the required rate of moment changes.

  20. The Effects of Short-Term Ski Trainings on Dynamic Balance Performance and Vertical Jump in Adolescents

    Science.gov (United States)

    Camliguney, Asiye Filiz

    2013-01-01

    Skiing is a sport where balance and strength are critical and which can be practiced actively especially from early years to old age. The purpose of this study is to examine the effect of a 5-day training of skiing skills on dynamic balance performance and development of vertical jump strength in adolescents. Sixteen adolescent volunteers who do…

  1. The use of computer graphics in the visual analysis of the proposed Sunshine Ski Area expansion

    Science.gov (United States)

    Mark Angelo

    1979-01-01

    This paper describes the use of computer graphics in designing part of the Sunshine Ski Area in Banff National Park. The program used was capable of generating perspective landscape drawings from a number of different viewpoints. This allowed managers to predict, and subsequently reduce, the adverse visual impacts of ski-run development. Computer graphics have proven,...

  2. The effects of the arm swing on biomechanical and physiological aspects of roller ski skating.

    Science.gov (United States)

    Hegge, Ann Magdalen; Ettema, Gertjan; de Koning, Jos J; Rognstad, Asgeir Bakken; Hoset, Martin; Sandbakk, Øyvind

    2014-08-01

    This study analyzed the biomechanical and physiological effects of the arm swing in roller ski skating, and compared leg-skating (i.e. ski skating without poles) using a pronounced arm swing (SWING) with leg-skating using locked arms (LOCKED). Sixteen elite male cross-country skiers performed submaximal stages at 10, 15 and 20kmh(-1) on a 2% inclined treadmill in the two techniques. SWING demonstrated higher peak push-off forces and a higher force impulse at all speeds, but a longer cycle length only at the highest speed (all Pskating increases the ski forces and aerobic energy cost at low and moderate speeds, whereas the greater forces at high speed lead to a longer cycle length and smaller anaerobic contribution. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Tibial Fractures in Alpine Skiing and Snowboarding in Finland: A Retrospective Study on Fracture Types and Injury Mechanisms in 363 Patients.

    Science.gov (United States)

    Stenroos, A; Pakarinen, H; Jalkanen, J; Mälkiä, T; Handolin, L

    2016-09-01

    Alpine skiing and snowboarding share the hazards of accidents accounting for tibial fractures. The aim of this study was to evaluate the fracture patterns and mechanisms of injury of tibial fractures taking place in downhill skiing and snowboarding. All patients with tibial fracture due to alpine skiing or snowboarding accident treated in four trauma centers next to the largest ski resorts in Finland were analyzed between 2006 and 2012. The hospital records were retrospectively reviewed for data collection: equipment used (skis or snowboard), age, gender, and mechanism of injury. Fractures were classified according to AO-classification. There were 342 skiing and 30 snowboarding related tibial fractures in 363 patients. Tibial shaft fracture was the most common fracture among skiers (n = 215, 63%), followed by proximal tibial fractures (n = 92, 27%). Snowboarders were most likely to suffer from proximal tibial fracture (13, 43%) or tibial shaft fracture (11, 37%). Snowboarders were also more likely than skiers to suffer complex AO type C fractures (23% vs 9%, p jumping (46%). The most important finding was the relatively high number of the tibial plateau fractures among adult skiers. The fracture patterns between snowboarding and skiing were different; the most common fracture type in skiers was spiral tibial shaft fracture compared to proximal tibial fractures in snowboarders. Children had more simple fractures than adults. © The Finnish Surgical Society 2016.

  4. VALIDITY OF THE DIMENSIONAL CONFIGURATION OF THE REDUCED POTENTIAL PERFORMANCE MODEL IN SKI JUMPING

    OpenAIRE

    Ulaga, Maja; Čoh, Milan; Jošt, Bojan

    2007-01-01

    The aim of the study was to establish the validity of the dimensional configuration of the reduced po-tential performance model in ski jumping. Two performance models were prepared (models A and B), dif-fering only in terms of their method of determining the weights (dimensional configuration). Model A in-volves the dependent determination of weights while model B includes the independent determination of weights. The sample consisted of 104 Slovenian ski jumpers from the senior-men’s categor...

  5. Automatic measurement of key ski jumping phases and temporal events with a wearable system.

    Science.gov (United States)

    Chardonnens, Julien; Favre, Julien; Le Callennec, Benoit; Cuendet, Florian; Gremion, Gérald; Aminian, Kamiar

    2012-01-01

    We propose a new method, based on inertial sensors, to automatically measure at high frequency the durations of the main phases of ski jumping (i.e. take-off release, take-off, and early flight). The kinematics of the ski jumping movement were recorded by four inertial sensors, attached to the thigh and shank of junior athletes, for 40 jumps performed during indoor conditions and 36 jumps in field conditions. An algorithm was designed to detect temporal events from the recorded signals and to estimate the duration of each phase. These durations were evaluated against a reference camera-based motion capture system and by trainers conducting video observations. The precision for the take-off release and take-off durations (indoor jumping technique did not influence the error of take-off release and take-off. Therefore, the proposed system can provide valuable information for performance evaluation of ski jumpers during training sessions.

  6. The effects of poling on physiological, kinematic and kinetic responses in roller ski skating.

    Science.gov (United States)

    Grasaas, Erik; Hegge, Ann Magdalen; Ettema, Gertjan; Sandbakk, Øyvind

    2014-09-01

    We investigated the effects of poling on physiological, kinematic and kinetic responses in the G4 skating technique where the poling movement is synchronized with the leg push-off on one side (strong side) followed by a forward arm swing during the leg push-off on the other side (weak side). G4 skating with (G4-P) and without (G4-NP) poling was compared in 17 elite male cross-country skiers during 4-min submaximal tests on a 2% inclined roller ski treadmill at 10, 15 and 20 km h(-1). G4-P demonstrated less ventilatory stress and higher gross efficiency compared to G4-NP at all velocities, and the blood lactate concentration was lower at the high velocity (all P skating technique. Thus, poling provides possibilities to increase total propulsion, to reduce ski forces and to enhance skiing efficiency.

  7. Lightning Fast and Space Efficient Inequality Joins

    KAUST Repository

    Khayyat, Zuhair

    2015-09-01

    Inequality joins, which join relational tables on inequality conditions, are used in various applications. While there have been a wide range of optimization methods for joins in database systems, from algorithms such as sort-merge join and band join, to various indices such as B+-tree,R*-tree and Bitmap, inequality joins have received little attention and queries containing such joins are usually very slow. In this paper, we introduce fast inequality join algorithms. We put columns to be joined in sorted arrays and we use permutation arrays to encode positions of tuples in one sorted array w.r.t. the other sorted array. In contrast to sort-merge join, we use space effcient bit-arrays that enable optimizations, such as Bloom filter indices, for fast computation of the join results. We have implemented a centralized version of these algorithms on top of PostgreSQL, and a distributed version on top of Spark SQL. We have compared against well known optimization techniques for inequality joins and show that our solution is more scalable and several orders of magnitude faster.

  8. Lightning fast and space efficient inequality joins

    KAUST Repository

    Khayyat, Zuhair

    2015-09-01

    Inequality joins, which join relational tables on inequality conditions, are used in various applications. While there have been a wide range of optimization methods for joins in database systems, from algorithms such as sort-merge join and band join, to various indices such as B+-tree, R*-tree and Bitmap, inequality joins have received little attention and queries containing such joins are usually very slow. In this paper, we introduce fast inequality join algorithms. We put columns to be joined in sorted arrays and we use permutation arrays to encode positions of tuples in one sorted array w.r.t. the other sorted array. In contrast to sort-merge join, we use space efficient bit-arrays that enable optimizations, such as Bloom filter indices, for fast computation of the join results. We have implemented a centralized version of these algorithms on top of PostgreSQL, and a distributed version on top of Spark SQL. We have compared against well known optimization techniques for inequality joins and show that our solution is more scalable and several orders of magnitude faster.

  9. Lightning fast and space efficient inequality joins

    KAUST Repository

    Khayyat, Zuhair; Lucia, William; Singh, Meghna; Ouzzani, Mourad; Papotti, Paolo; Quiané -Ruiz, Jorge-Arnulfo; Tang, Nan; Kalnis, Panos

    2015-01-01

    Inequality joins, which join relational tables on inequality conditions, are used in various applications. While there have been a wide range of optimization methods for joins in database systems, from algorithms such as sort-merge join and band join, to various indices such as B+-tree, R*-tree and Bitmap, inequality joins have received little attention and queries containing such joins are usually very slow. In this paper, we introduce fast inequality join algorithms. We put columns to be joined in sorted arrays and we use permutation arrays to encode positions of tuples in one sorted array w.r.t. the other sorted array. In contrast to sort-merge join, we use space efficient bit-arrays that enable optimizations, such as Bloom filter indices, for fast computation of the join results. We have implemented a centralized version of these algorithms on top of PostgreSQL, and a distributed version on top of Spark SQL. We have compared against well known optimization techniques for inequality joins and show that our solution is more scalable and several orders of magnitude faster.

  10. Effects of changes in skiing posture on the kinetics of the knee joint.

    Science.gov (United States)

    Koyanagi, Maki; Shino, Konsei; Yoshimoto, Yoji; Inoue, Satoru; Sato, Mutsumi; Nakata, Ken

    2006-01-01

    This study was performed to investigate the effects of changes in the skiing posture on mechanical stress across the knee joint. The aim of the present study was to establish a safer form of skiing for the prevention of injury to the anterior cruciate ligament of the knee (ACL). Ten healthy volunteers were placed on a force plate on an artificial slope, and assumed forward and backward bending postures with a single leg by changing their centre of gravity. The knee flexion angles were limited to approximately 30 degrees by orthotics in each posture. Joint moments of the lower extremity were analyzed using a motion analysis system, and the muscle activities of the lower extremity were recorded by EMG and digitised to integrated EMG in each posture. In addition, extrusion of the lower leg by the boot was measured using a force sensor sheet inserted behind the calf. We found that the extension moment of the hip and ankle joints, and muscular activity of the hamstrings were increased in forward bending, whereas the extension moment of the knee and muscular activity of the quadriceps were decreased. Conversely, the muscular activity of the quadriceps, the flexion moment of the hip, extension moment of the knee joint, and pressure of the boot were increased in backward bending, whereas muscular activity of the hamstrings was decreased. The dependency on the hamstrings increased in forward bending in a skiing posture on a slope with slight knee flexion. Therefore, forward bending seemed to be an advantageous posture for the prevention of ACL injury. Conversely, in a backward bending skiing posture, the extension moment of the knee joint produced by muscle contraction of the quadriceps also increased imbalance in the hamstrings. The results of this study suggest that the internal force exerted by the quadriceps, in addition to the passive factor of extrusion of the lower leg by the boot, may contribute to non-contact ACL injury in a backward bending posture while skiing.

  11. Vaginal laceration following a jet-ski accident.

    Science.gov (United States)

    Haefner, H K; Andersen, H F; Johnson, M P

    1991-11-01

    A 17-year-old woman riding as a passenger on a jet-ski fell behind the jet nozzle while jumping waves. A vaginal laceration with intra-abdominal extension occurred as a result of the accident. Hypogastric artery ligation controlled the hemorrhage and avoided more extensive surgery. The case represents an unusual injury from this type of watercraft and illustrates important points in the management of genital tract trauma.

  12. SKI's and SSI's comments on SKB's RandD/RDandD Programme 1986-2007; SKI:s och SSI:s synpunkter paa SKB:s FoU/Fud-program 1986-2007

    Energy Technology Data Exchange (ETDEWEB)

    Toverud, Oeivind (Bromma Geokonsult (Sweden))

    2010-10-15

    SKB has since 1986 submitted RDandD program every three years to former Nuclear Power Inspectorate (SKI) for review and evaluation. SKI and former Radiation Protection Inst. (SSI) have commented on a large number of issues in connection with the audits. The authorities' goal has been to influence the SKB's design of the RDandD programs, inter alia with a view to future repository applications to fulfill the requirements they are tested against. SKB plans to submit applications for the final repository for spent Fuel first quarter of 2011 and it is therefore important for Radiation Safety Authority (SSM) to follow up on SKB's handling of critical comments on RDandD programs. A starting point for this monitoring is to establish how SKB has dealt with major issues raised by authorities in the audits of the RDandD programs and in consultation process which has been linked to the programs. The follow-up is expected to be an important contribution to the planning and implementation of the examination of applications for nuclear fuel repository

  13. [Anorectal injury after a fall from a jet ski

    NARCIS (Netherlands)

    Nieboer, T.E.; Assmann, R.F.; Withagen, M.I.J.; Geeraedts, L.M.G.

    2007-01-01

    A 28-year-old female sustained an anorectal rupture after a fall from a jet ski. The rupture was sutured and a double-loop colostomy was created. Three months later, following a test of functional continence, the colostomy was removed. The patient recovered without complications and with

  14. How do elite ski jumpers handle the dynamic conditions in imitation jumps?

    Science.gov (United States)

    Ettema, Gertjan; Hooiveld, Jo; Braaten, Steinar; Bobbert, Maarten

    2016-01-01

    We examined the effect of boundary conditions in imitation ski jumping on movement dynamics and coordination. We compared imitation ski jumps with--and without--the possibility to generate shear propulsion forces. Six elite ski jumpers performed imitation jumps by jumping from a fixed surface and from a rolling platform. The ground reaction force vector, kinematics of body segments, and EMG of eight lower limb muscles were recorded. Net joint dynamics were calculated using inverse dynamics. The two imitation jumps differed considerably from each other with regard to the dynamics (moments, forces), whereas the kinematics were very similar. Knee power was higher and hip power was lower on the rolling platform than on the fixed surface. Mean EMG levels were very similar for both conditions, but differences in the development of muscle activity were indicated for seven of eight muscles. These differences are reflected in a subtle difference of the alignment of ground reaction force with centre of mass: the ground reaction force runs continuously close to but behind the centre of mass on the rolling platform and fluctuates around it on the fixed surface. This likely reflects a different strategy for controlling angular momentum.

  15. Effects of frequency on gross efficiency and performance in roller ski skating.

    Science.gov (United States)

    Leirdal, S; Sandbakk, O; Ettema, G

    2013-06-01

    The purpose of the present study was to examine the effect of frequency on efficiency and performance during G3 roller ski skating. Eight well-trained male cross-country skiers performed three submaximal 5-min speeds (10, 13, and 16 km/h) and a time-to-exhaustion (TTE) performance (at 20 km/h) using the G3 skating technique using freely chosen, high, and low frequency at all four speeds. All tests were done using roller skis on a large treadmill at 5% incline. Gross efficiency (GE) was calculated as power divided by metabolic rate. Power was calculated as the sum of power against frictional forces and power against gravity. Metabolic rate was calculated from oxygen consumption and blood lactate concentration. Freely chosen frequency increased from 60 to 70 strokes/min as speed increased from 10 to 20 km/h. GE increased with power. At high power (20 km/h performance test), both efficiency and performance were significantly reduced by high frequency. In regard to choice of frequency during G3 roller ski skating, cross-country skiers seems to be self-optimized both in relation to energy saving (efficiency) and performance (TTE). © 2011 John Wiley & Sons A/S.

  16. Snowboarding injuries, a four-year study with comparison with alpine ski injuries.

    Science.gov (United States)

    Davidson, T M; Laliotis, A T

    1996-03-01

    Snowboarding is a rapidly growing winter sport. Its unorthodox maneuvers and young participants raise many safety concerns. We examined injury patterns in recreational snowboarders, comparing these patterns with those found in alpine skiers. Snowboarding and skiing injury patterns differed significantly (P knee (17% versus 39%) or thumb (2% versus 4%) injuries than skiers. For snowboarders, wrist injuries were most common in beginners (30%), knee injuries in low intermediates (28%), ankle injuries in intermediates (17%), and shoulder or clavicle injuries in advanced snowboarders (14%). Most snowboarders (90%) wore soft-shelled boots, 73% of lower extremity injuries occurred to the lead-foot side, and 73% of wrist injuries occurred during backward falls; 67% of knee injuries occurred during forward falls. Of all injuries, 8% occurred while loading onto or unloading from a ski lift. The sport of snowboarding brings with it a different set of injuries from those seen in alpine skiing. The data focus attention on improvements such as wrist guards or splints, releasable front-foot bindings, and better instruction for beginner snowboarders to improve the safety of this sport. Finally, the data confirm that snowboarders and skiers may be safely combined on the same slopes.

  17. Joining uranium to steel

    International Nuclear Information System (INIS)

    Perkins, M.A.

    1976-05-01

    A method has been devised which will allow the joining of uranium to steel by fusion welding through the use of an intermediate material. Uranium-0.5 titanium was joined to AISI 304L stainless steel by using a vanadium insert. Also, a method is now available for selecting possible filler metals when two entirely dissimilar metals need to be joined. This method allows a quantitative ranking to be made of the possible filler metals and thus the most likely candidate can be selected

  18. Influence of a nine-day alpine ski training programme on the postural stability of people with different levels of skills

    Directory of Open Access Journals (Sweden)

    Staniszewski Michał

    2016-03-01

    Full Text Available Study aim: In alpine skiing, balance is one of the key elements that determine the effectiveness of the ride. Because of ski boots, the foot and ankle joint complex is excluded from the process of maintaining the stability of the body. The aim of the study was to determine to what extent a few days of skiing activities and the level of technical skills affect the skiers’ level of postural stability.

  19. Authenticated join processing in outsourced databases

    KAUST Repository

    Yang, Yin

    2009-01-01

    Database outsourcing requires that a query server constructs a proof of result correctness, which can be verified by the client using the data owner\\'s signature. Previous authentication techniques deal with range queries on a single relation using an authenticated data structure (ADS). On the other hand, authenticated join processing is inherently more complex than ranges since only the base relations (but not their combination) are signed by the owner. In this paper, we present three novel join algorithms depending on the ADS availability: (i) Authenticated Indexed Sort Merge Join (AISM), which utilizes a single ADS on the join attribute, (ii) Authenticated Index Merge Join (AIM) that requires an ADS (on the join attribute) for both relations, and (iii) Authenticated Sort Merge Join (ASM), which does not rely on any ADS. We experimentally demonstrate that the proposed methods outperform two benchmark algorithms, often by several orders of magnitude, on all performance metrics, and effectively shift the workload to the outsourcing service. Finally, we extend our techniques to complex queries that combine multi-way joins with selections and projections. ©2009 ACM.

  20. Authenticated join processing in outsourced databases

    KAUST Repository

    Yang, Yin; Papadias, Dimitris; Papadopoulos, Stavros; Kalnis, Panos

    2009-01-01

    Database outsourcing requires that a query server constructs a proof of result correctness, which can be verified by the client using the data owner's signature. Previous authentication techniques deal with range queries on a single relation using an authenticated data structure (ADS). On the other hand, authenticated join processing is inherently more complex than ranges since only the base relations (but not their combination) are signed by the owner. In this paper, we present three novel join algorithms depending on the ADS availability: (i) Authenticated Indexed Sort Merge Join (AISM), which utilizes a single ADS on the join attribute, (ii) Authenticated Index Merge Join (AIM) that requires an ADS (on the join attribute) for both relations, and (iii) Authenticated Sort Merge Join (ASM), which does not rely on any ADS. We experimentally demonstrate that the proposed methods outperform two benchmark algorithms, often by several orders of magnitude, on all performance metrics, and effectively shift the workload to the outsourcing service. Finally, we extend our techniques to complex queries that combine multi-way joins with selections and projections. ©2009 ACM.

  1. Mechanism of Folding and Activation of Subtilisin Kexin Isozyme-1 (SKI-1)/Site-1 Protease (S1P)*

    Science.gov (United States)

    da Palma, Joel Ramos; Cendron, Laura; Seidah, Nabil Georges; Pasquato, Antonella; Kunz, Stefan

    2016-01-01

    The proprotein convertase subtilisin kexin isozyme-1 (SKI-1)/site-1 protease (S1P) is implicated in lipid homeostasis, the unfolded protein response, and lysosome biogenesis. The protease is further hijacked by highly pathogenic emerging viruses for the processing of their envelope glycoproteins. Zymogen activation of SKI-1/S1P requires removal of an N-terminal prodomain, by a multistep process, generating the mature enzyme. Here, we uncover a modular structure of the human SKI-1/S1P prodomain and define its function in folding and activation. We provide evidence that the N-terminal AB fragment of the prodomain represents an autonomous structural and functional unit that is necessary and sufficient for folding and partial activation. In contrast, the C-terminal BC fragment lacks a defined structure but is crucial for autoprocessing and full catalytic activity. Phylogenetic analysis revealed that the sequence of the AB domain is highly conserved, whereas the BC fragment shows considerable variation and seems even absent in some species. Notably, SKI-1/S1P of arthropods, like the fruit fly Drosophila melanogaster, contains a shorter prodomain comprised of full-length AB and truncated BC regions. Swapping the prodomain fragments between fly and human resulted in a fully mature and active SKI-1/S1P chimera. Our study suggests that primordial SKI-1/S1P likely contained a simpler prodomain consisting of the highly conserved AB fragment that represents an independent folding unit. The BC region appears as a later evolutionary acquisition, possibly allowing more subtle fine-tuning of the maturation process. PMID:26645686

  2. SKI review of SKB research programs 1992. Compilation of scientific reports

    International Nuclear Information System (INIS)

    1993-03-01

    Swedish Nuclear Power Inspectorate (SKI) has reviewed the research programs 1992 of the Swedish Nuclear Fuel and Waste Management Co (SKB). This report presents the examination of the individual programs

  3. Using the power balance model to simulate cross-country skiing on varying terrain.

    Science.gov (United States)

    Moxnes, John F; Sandbakk, Oyvind; Hausken, Kjell

    2014-01-01

    The current study adapts the power balance model to simulate cross-country skiing on varying terrain. We assumed that the skier's locomotive power at a self-chosen pace is a function of speed, which is impacted by friction, incline, air drag, and mass. An elite male skier's position along the track during ski skating was simulated and compared with his experimental data. As input values in the model, air drag and friction were estimated from the literature based on the skier's mass, snow conditions, and speed. We regard the fit as good, since the difference in racing time between simulations and measurements was 2 seconds of the 815 seconds racing time, with acceptable fit both in uphill and downhill terrain. Using this model, we estimated the influence of changes in various factors such as air drag, friction, and body mass on performance. In conclusion, the power balance model with locomotive power as a function of speed was found to be a valid tool for analyzing performance in cross-country skiing.

  4. Multi-Body Ski Jumper Model with Nonlinear Dynamic Inversion Muscle Control for Trajectory Optimization

    Directory of Open Access Journals (Sweden)

    Patrick Piprek

    2018-02-01

    Full Text Available This paper presents an approach to model a ski jumper as a multi-body system for an optimal control application. The modeling is based on the constrained Newton-Euler-Equations. Within this paper the complete multi-body modeling methodology as well as the musculoskeletal modeling is considered. For the musculoskeletal modeling and its incorporation in the optimization model, we choose a nonlinear dynamic inversion control approach. This approach uses the muscle models as nonlinear reference models and links them to the ski jumper movement by a control law. This strategy yields a linearized input-output behavior, which makes the optimal control problem easier to solve. The resulting model of the ski jumper can then be used for trajectory optimization whose results are compared to literature jumps. Ultimately, this enables the jumper to get a very detailed feedback of the flight. To achieve the maximal jump length, exact positioning of his body with respect to the air can be displayed.

  5. Application software GeoniCS when designing the olympic ski runs

    Directory of Open Access Journals (Sweden)

    Konstantin N. Makarov

    2010-10-01

    Full Text Available GeoniCS implementation for Olympic mountain skiing routes designing is considered an international standard. This program allows optimizing plan and profiling development. Besides, the author adapted the program for lines engineering protection with special metal mesh.

  6. 15th June 2009-His Excellency Mr Lech Kaczyński,President of the Republic of Poland,visiting CMS Experiment

    CERN Multimedia

    Maximilien Brice

    2009-01-01

    Tirage 1;16-17:First Lady,H.E. M. KACZYŃSKA,President of the Republic of Poland,H.E. L. KACZYŃSKI with Technology Department,Machine Protection & Electrical Integrity Group Leader,A.Siemko Tirage 2;10:CMS Collaboration Spokesperson,T. Virdee with H.E. M. KACZYŃSKA,H.E. L. KACZYŃSKI and Coordinator for External Relations,F. Pauss visiting CMS experimental area Tirage 3:Representative of the French Republic,Sous-Préfet de Gex,Mr O. Laurens-Bernard and H.E. L. KACZYŃSKI Tirage 6 to 9:Signature of the Guest book with the Director-General,R. Heuer Tirage 11-12:the delegation visiting CMS experimental area Tirage 18-26:H.E. L. KACZYŃSKI with Polish scientists at CERN

  7. Evaluation of a specific test in cross-country skiing

    DEFF Research Database (Denmark)

    Mygind, Erik; Larsson, Benny; Klausen, Tom

    1991-01-01

    -poling was correlated with performance, expressed as a ranking score during 10 ski races. The tests were undertaken in September, December and April. Upper body maximal oxygen uptake increased 5.8% from September to December, decreasing to 2.3% above the September level in April. Upper body work output (2 min...

  8. Application of dGNSS in Alpine Ski Racing: Basis for Evaluating Physical Demands and Safety.

    Science.gov (United States)

    Gilgien, Matthias; Kröll, Josef; Spörri, Jörg; Crivelli, Philip; Müller, Erich

    2018-01-01

    External forces, such as ground reaction force or air drag acting on athletes' bodies in sports, determine the sport-specific demands on athletes' physical fitness. In order to establish appropriate physical conditioning regimes, which adequately prepare athletes for the loads and physical demands occurring in their sports and help reduce the risk of injury, sport-and/or discipline-specific knowledge of the external forces is needed. However, due to methodological shortcomings in biomechanical research, data comprehensively describing the external forces that occur in alpine super-G (SG) and downhill (DH) are so far lacking. Therefore, this study applied new and accurate wearable sensor-based technology to determine the external forces acting on skiers during World Cup (WC) alpine skiing competitions in the disciplines of SG and DH and to compare these with those occurring in giant slalom (GS), for which previous research knowledge exists. External forces were determined using WC forerunners carrying a differential global navigation satellite system (dGNSS). Combining the dGNSS data with a digital terrain model of the snow surface and an air drag model, the magnitudes of ground reaction forces were computed. It was found that the applied methodology may not only be used to track physical demands and loads on athletes, but also to simultaneously investigate safety aspects, such as the effectiveness of speed control through increased air drag and ski-snow friction forces in the respective disciplines. Therefore, the component of the ground reaction force in the direction of travel (ski-snow friction) and air drag force were computed. This study showed that (1) the validity of high-end dGNSS systems allows meaningful investigations such as characterization of physical demands and effectiveness of safety measures in highly dynamic sports; (2) physical demands were substantially different between GS, SG, and DH; and (3) safety-related reduction of skiing speed might be

  9. Mechanism of Folding and Activation of Subtilisin Kexin Isozyme-1 (SKI-1)/Site-1 Protease (S1P).

    Science.gov (United States)

    da Palma, Joel Ramos; Cendron, Laura; Seidah, Nabil Georges; Pasquato, Antonella; Kunz, Stefan

    2016-01-29

    The proprotein convertase subtilisin kexin isozyme-1 (SKI-1)/site-1 protease (S1P) is implicated in lipid homeostasis, the unfolded protein response, and lysosome biogenesis. The protease is further hijacked by highly pathogenic emerging viruses for the processing of their envelope glycoproteins. Zymogen activation of SKI-1/S1P requires removal of an N-terminal prodomain, by a multistep process, generating the mature enzyme. Here, we uncover a modular structure of the human SKI-1/S1P prodomain and define its function in folding and activation. We provide evidence that the N-terminal AB fragment of the prodomain represents an autonomous structural and functional unit that is necessary and sufficient for folding and partial activation. In contrast, the C-terminal BC fragment lacks a defined structure but is crucial for autoprocessing and full catalytic activity. Phylogenetic analysis revealed that the sequence of the AB domain is highly conserved, whereas the BC fragment shows considerable variation and seems even absent in some species. Notably, SKI-1/S1P of arthropods, like the fruit fly Drosophila melanogaster, contains a shorter prodomain comprised of full-length AB and truncated BC regions. Swapping the prodomain fragments between fly and human resulted in a fully mature and active SKI-1/S1P chimera. Our study suggests that primordial SKI-1/S1P likely contained a simpler prodomain consisting of the highly conserved AB fragment that represents an independent folding unit. The BC region appears as a later evolutionary acquisition, possibly allowing more subtle fine-tuning of the maturation process. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Technical snow production in skiing areas: conditions, practice, monitoring and modelling. A case study in Mayrhofen/Austria

    Science.gov (United States)

    Strasser, Ulrich; Hanzer, Florian; Marke, Thomas; Rothleitner, Michael

    2017-04-01

    The production of technical snow today is a self-evident feature of modern alpine skiing resort management. Millions of Euros are invested every year for the technical infrastructure and its operation to produce a homogeneous and continuing snow cover on the skiing slopes for the winter season in almost every larger destination in the Alps. In Austria, skiing tourism is a significant factor of the national economic structure. We present the framing conditions of technical snow production in the mid-size skiing resort of Mayrhofen (Zillertal Alps/Austria, 136 km slopes, elevation range 630 - 2.500 m a.s.l.). Production conditions are defined by the availability of water, the planned date for the season opening, and the climatic conditions in the weeks before. By means of an adapted snow production strategy an attempt is made to ecologically and economically optimize the use of water and energy resources. Monitoring of the snow cover is supported by a network of low-cost sensors and mobile snow depth recordings. Finally, technical snow production is simulated with the spatially distributed, physically based hydroclimatological model AMUNDSEN. The model explicitly considers individual snow guns and distributes the produced snow along the slopes. The amount of simulated snow produced by each device is a function of its type, of actual wet-bulb temperature at the location, of ski area infrastructure (in terms of water supply and pumping capacity), and of snow demand.

  11. Night-to-night arousal variability and interscorer reliability of arousal measurements.

    Science.gov (United States)

    Loredo, J S; Clausen, J L; Ancoli-Israel, S; Dimsdale, J E

    1999-11-01

    Measurement of arousals from sleep is clinically important, however, their definition is not well standardized, and little data exist on reliability. The purpose of this study is to determine factors that affect arousal scoring reliability and night-to-night arousal variability. The night-to-night arousal variability and interscorer reliability was assessed in 20 subjects with and without obstructive sleep apnea undergoing attended polysomnography during two consecutive nights. Five definitions of arousal were studied, assessing duration of electroencephalographic (EEG) frequency changes, increases in electromyographic (EMG) activity and leg movement, association with respiratory events, as well as the American Sleep Disorders Association (ASDA) definition of arousals. NA. NA. NA. Interscorer reliability varied with the definition of arousal and ranged from an Intraclass correlation (ICC) of 0.19 to 0.92. Arousals that included increases in EMG activity or leg movement had the greatest reliability, especially when associated with respiratory events (ICC 0.76 to 0.92). The ASDA arousal definition had high interscorer reliability (ICC 0.84). Reliability was lowest for arousals consisting of EEG changes lasting <3 seconds (ICC 0.19 to 0.37). The within subjects night-to-night arousal variability was low for all arousal definitions In a heterogeneous population, interscorer arousal reliability is enhanced by increases in EMG activity, leg movements, and respiratory events and decreased by short duration EEG arousals. The arousal index night-to-night variability was low for all definitions.

  12. Parallel trajectory similarity joins in spatial networks

    KAUST Repository

    Shang, Shuo

    2018-04-04

    The matching of similar pairs of objects, called similarity join, is fundamental functionality in data management. We consider two cases of trajectory similarity joins (TS-Joins), including a threshold-based join (Tb-TS-Join) and a top-k TS-Join (k-TS-Join), where the objects are trajectories of vehicles moving in road networks. Given two sets of trajectories and a threshold θ, the Tb-TS-Join returns all pairs of trajectories from the two sets with similarity above θ. In contrast, the k-TS-Join does not take a threshold as a parameter, and it returns the top-k most similar trajectory pairs from the two sets. The TS-Joins target diverse applications such as trajectory near-duplicate detection, data cleaning, ridesharing recommendation, and traffic congestion prediction. With these applications in mind, we provide purposeful definitions of similarity. To enable efficient processing of the TS-Joins on large sets of trajectories, we develop search space pruning techniques and enable use of the parallel processing capabilities of modern processors. Specifically, we present a two-phase divide-and-conquer search framework that lays the foundation for the algorithms for the Tb-TS-Join and the k-TS-Join that rely on different pruning techniques to achieve efficiency. For each trajectory, the algorithms first find similar trajectories. Then they merge the results to obtain the final result. The algorithms for the two joins exploit different upper and lower bounds on the spatiotemporal trajectory similarity and different heuristic scheduling strategies for search space pruning. Their per-trajectory searches are independent of each other and can be performed in parallel, and the mergings have constant cost. An empirical study with real data offers insight in the performance of the algorithms and demonstrates that they are capable of outperforming well-designed baseline algorithms by an order of magnitude.

  13. Parallel trajectory similarity joins in spatial networks

    KAUST Repository

    Shang, Shuo; Chen, Lisi; Wei, Zhewei; Jensen, Christian S.; Zheng, Kai; Kalnis, Panos

    2018-01-01

    The matching of similar pairs of objects, called similarity join, is fundamental functionality in data management. We consider two cases of trajectory similarity joins (TS-Joins), including a threshold-based join (Tb-TS-Join) and a top-k TS-Join (k-TS-Join), where the objects are trajectories of vehicles moving in road networks. Given two sets of trajectories and a threshold θ, the Tb-TS-Join returns all pairs of trajectories from the two sets with similarity above θ. In contrast, the k-TS-Join does not take a threshold as a parameter, and it returns the top-k most similar trajectory pairs from the two sets. The TS-Joins target diverse applications such as trajectory near-duplicate detection, data cleaning, ridesharing recommendation, and traffic congestion prediction. With these applications in mind, we provide purposeful definitions of similarity. To enable efficient processing of the TS-Joins on large sets of trajectories, we develop search space pruning techniques and enable use of the parallel processing capabilities of modern processors. Specifically, we present a two-phase divide-and-conquer search framework that lays the foundation for the algorithms for the Tb-TS-Join and the k-TS-Join that rely on different pruning techniques to achieve efficiency. For each trajectory, the algorithms first find similar trajectories. Then they merge the results to obtain the final result. The algorithms for the two joins exploit different upper and lower bounds on the spatiotemporal trajectory similarity and different heuristic scheduling strategies for search space pruning. Their per-trajectory searches are independent of each other and can be performed in parallel, and the mergings have constant cost. An empirical study with real data offers insight in the performance of the algorithms and demonstrates that they are capable of outperforming well-designed baseline algorithms by an order of magnitude.

  14. On the Expressiveness of Joining

    Directory of Open Access Journals (Sweden)

    Thomas Given-Wilson

    2015-08-01

    Full Text Available The expressiveness of communication primitives has been explored in a common framework based on the pi-calculus by considering four features: synchronism (asynchronous vs synchronous, arity (monadic vs polyadic data, communication medium (shared dataspaces vs channel-based, and pattern-matching (binding to a name vs testing name equality vs intensionality. Here another dimension coordination is considered that accounts for the number of processes required for an interaction to occur. Coordination generalises binary languages such as pi-calculus to joining languages that combine inputs such as the Join Calculus and general rendezvous calculus. By means of possibility/impossibility of encodings, this paper shows coordination is unrelated to the other features. That is, joining languages are more expressive than binary languages, and no combination of the other features can encode a joining language into a binary language. Further, joining is not able to encode any of the other features unless they could be encoded otherwise.

  15. Diagnosing night sweats.

    Science.gov (United States)

    Viera, Anthon J; Bond, Michael M; Yates, Scott W

    2003-03-01

    Night sweats are a common outpatient complaint, yet literature on the subject is scarce. Tuberculosis and lymphoma are diseases in which night sweats are a dominant symptom, but these are infrequently found to be the cause of night sweats in modern practice. While these diseases remain important diagnostic considerations in patients with night sweats, other diagnoses to consider include human immunodeficiency virus, gastroesophageal reflux disease, obstructive sleep apnea, hyperthyroidism, hypoglycemia, and several less common diseases. Antihypertensives, antipyretics, other medications, and drugs of abuse such as alcohol and heroin may cause night sweats. Serious causes of night sweats can be excluded with a thorough history, physical examination, and directed laboratory and radiographic studies. If a history and physical do not reveal a possible diagnosis, physicians should consider a purified protein derivative, complete blood count, human immunodeficiency virus test, thyroid-stimulating hormone test, erythrocyte sedimentation rate evaluation, chest radiograph, and possibly chest and abdominal computed tomographic scans and bone marrow biopsy.

  16. 78 FR 39608 - Safety Zone; Summer in the City Water Ski Show; Fox River, Green Bay, WI

    Science.gov (United States)

    2013-07-02

    ...-AA00 Safety Zone; Summer in the City Water Ski Show; Fox River, Green Bay, WI AGENCY: Coast Guard, DHS... River in Green Bay, WI. This safety zone is intended to restrict vessels from a portion of the Fox River... Waterboard Warrior Ski Team will perform two 30-minute shows on the Fox River between the Hwy 141 Bridge and...

  17. Kinematics of cross-country sit skiing during a Paralympic race

    NARCIS (Netherlands)

    Bernardi, Marco; Janssen, Thomas; Bortolan, Lorenzo; Pellegrini, Barbara; Fischer, Gabriela; Schena, Federico

    The study had three purposes: to verify a hypothesized speed decrease during the 15km cross-country sit skiing (CCSS) race; documenting this possible fatigue effect (speed decrease), to evaluate changes among the four laps in kinematics parameters (cycle speed, cycle duration, cycle length, duty

  18. Snow reliability in ski resorts considering artificial snowmaking

    Science.gov (United States)

    Hofstätter, M.; Formayer, H.; Haas, P.

    2009-04-01

    Snow reliability is the key factor to make skiing on slopes possible and to ensure added value in winter tourism. In this context snow reliability is defined by the duration of a snowpack on the ski runs of at least 50 mm snow water equivalent (SWE), within the main season (Dec-Mar). Furthermore the snowpack should form every winter and be existent early enough in season. In our work we investigate the snow reliability of six Austrian ski resorts. Because nearly all Austrian resorts rely on artificial snowmaking it is of big importance to consider man made snow in the snowpack accumulation and ablation in addition to natural snow. For each study region observed weather data including temperature, precipitation and snow height are used. In addition we differentiate up to three elevations on each site (valley, intermediate, mountain top), being aware of the typical local winter inversion height. Time periods suitable for artificial snow production, for several temperature threshold (-6,-4 or -1 degree Celsius) are calculated on an hourly base. Depending on the actual snowpack height, man made snow can be added in the model with different defined capacities, considering different technologies or the usage of additives. To simulate natural snowpack accumulation and ablation we a simple snow model, based on daily precipitation and temperature. This snow model is optimized at each site separately through certain parameterization factors. Based on the local observations and the monthly climate change signals from the climate model REMO-UBA, we generate long term time series of temperature and precipitation, using the weather generator LARS. Thereby we are not only able to simulate the snow reliability under current, but also under future climate conditions. Our results show significant changes in snow reliability, like an increase of days with insufficient snow heights, especially at mid and low altitudes under natural snow conditions. Artificial snowmaking can partly

  19. Injury situations in Freestyle Ski Cross (SX): a video analysis of 33 cases.

    Science.gov (United States)

    Randjelovic, Stefan; Heir, Stig; Nordsletten, Lars; Bere, Tone; Bahr, Roald

    2014-01-01

    Although injury risk in Freestyle Ski Cross (SX) is high, little is known about the situations leading up to time-loss injuries. To describe the situations leading up to time-loss injuries in elite Freestyle SX. Descriptive video analysis. Thirty-three video recordings of SX injuries reported through the International Ski Federation Injury Surveillance System for four World Cup seasons (2006/2007 through 2010) were obtained. Five experts in the fields of sport medicine and SX analysed each case to describe in detail the situation leading up to the injury (skiing situation and skier behaviour). Injuries occurred in four different skiing situations: jumping (n=16), turning (n=8), jumping and turning (n=7) and rollers (n=2). All injured skiers lost control before time of injury (n=33), due to skier-opponent contact (n=13), technical errors (n=8) or inappropriate strategy (n=8), which led to a fall (n=29). Contact occurred in 21 of 33 cases, usually unintentional at landing or take-off, caused by the opponent (n=11) or injured skier (n=8). The technical error cases (n=8) were dominated by bad jumping technique (n=6) and too much inside lean in turning situations (n=2), while inappropriate course line and bad timing at take off (n=7) dominated the inappropriate strategy cases (n=8). We identified four main injury situations in elite SX, dominated by jumping situations. The primary cause of injury was unintentional skier-opponent contact in jumping, bank turning and roller situations. Another common cause of injury was personal errors (inappropriate technique and strategy) at take-off and in turning situations.

  20. The starlight night the sky in the writings of Shakespeare, Tennyson, and Hopkins

    CERN Document Server

    Levy, David H

    2016-01-01

    In this updated second edition renowned amateur comet-searcher David H. Levy expands on his work about the intricate relationship between the night sky and the works of English Literature. This revised and expanded text includes new sections on Alfred Lord Tennyson and Gerald Manley Hopkins (both amateur astronomers), extending the time period analyzed in the first edition from early modern literature to encompass the Victorian age. Although the sky enters into much of literature through the ages, British authors offer an especially fertile connection to the heavens, and Levy links the works of seminal authors from Shakespeare on to specific celestial events and scientific advances.  From the impact of comets and supernovae to eclipses, Levy’s ultimate goal in this book is to inspire his readers to do the same thing as their ancestors did so long ago—look up and appreciate the stars. His insights in this revised book spread farther and wider than ever before in this learned and enchanting tour of the ski...

  1. Skier and Snowboarder Motivations and Knowledge Related to Voluntary Environmental Programs at an Alpine Ski Area

    Science.gov (United States)

    Little, Christopher M.; Needham, Mark D.

    2011-11-01

    Many alpine ski areas have recently adopted voluntary environmental programs (VEPs) such as using recycling, renewable energy, and biofuels to help reduce their environmental impacts. Studies have addressed the performance of these VEPs in mitigating environmental impacts of this industry, but little is known about visitor awareness and perceptions of these programs. This article addresses this knowledge gap by exploring skier and snowboarder knowledge of VEPs at a ski area and the influence of these programs on their motivations to visit this area currently and behavioral intentions to visit again in the future. Data were obtained from an onsite survey at the Mt. Bachelor ski area in Oregon, USA ( n = 429, 89.7% response rate). Few skiers and snowboarders were knowledgeable of VEPs at this area and fewer than 20% were motivated to visit on their current trip because of these programs. Other attributes such as scenery, snow conditions, and access were more important for influencing visitation. Up to 38% of skiers and snowboarders, however, intend to visit this ski area more often if it adopts and promotes more VEPs. Managers can use these results to inform communication and marketing of their environmental programs and performance to visitors. Additional implications for management and future research are discussed.

  2. The preparation of tourists to the ski sports tours in a limited time in order to prevent injuries and accidents

    Directory of Open Access Journals (Sweden)

    A.N. Toporkov

    2014-08-01

    Full Text Available Purpose: compare indicators of testing tourist skiers at different stages of the preparatory period to ski sports hike of third grade. Determine the effectiveness of training programs created to the tourists Categorical ski sports to prevent injuries and accidents in a limited time. Material: The study involved 13 people aged from 21 to 65 (4 women and 9 men with different experiences of hiking trails and various levels of total tourist preparedness. Results: The test results obtained before beginning the process of preparation are treated upon its completion, and immediately after passing categorical hike. In practice, the effectiveness of the proposed training programs of tourists to ski sports tours is proved. Conclusions : The created program can be recommended to tourist clubs, associations and organizations as the base in preparation for ski sports campaigns for the prevention of accidents and injuries.

  3. Little Brother Joins the Large Family

    Science.gov (United States)

    2006-12-01

    On the night of 15 December 2006, the fourth and last-to-be-installed VLTI Auxiliary Telescope (AT4) obtained its 'First Light'. The first images demonstrate that AT4 will be able to deliver the excellent image quality already delivered by the first three ATs. It will soon join its siblings to perform routinely interferometric measurements. ESO PR Photo 51a/06 ESO PR Photo 51a/06 VLT Auxiliary Telescope The VLT is composed of four 8.2-m Unit Telescope (Antu, Kueyen, Melipal and Yepun). They have been progressively put into service together with a vast suite of the most advanced astronomical instruments and are operated every night in the year. Contrary to other large astronomical telescopes, the VLT was designed from the beginning with the use of interferometry as a major goal. The VLT Interferometer (VLTI) combines starlight captured by two or three 8.2- VLT Unit Telescopes, dramatically increasing the spatial resolution and showing fine details of a large variety of celestial objects. ESO PR Photo 51b/06 ESO PR Photo 51b/06 One AT Under the Sky However, most of the time the large telescopes are used for other research purposes. They are therefore only available for interferometric observations during a limited number of nights every year. Thus, in order to exploit the VLTI each night and to achieve the full potential of this unique setup, some other (smaller), dedicated telescopes were included into the overall VLT concept. These telescopes, known as the VLTI Auxiliary Telescopes (ATs), are mounted on tracks and can be placed at precisely defined "parking" observing positions on the observatory platform. From these positions, their light beams are fed into the same common focal point via a complex system of reflecting mirrors mounted in an underground system of tunnels. The Auxiliary Telescopes are real technological jewels. They are placed in ultra-compact enclosures, complete with all necessary electronics, an air conditioning system and cooling liquid for

  4. Common Influence Join

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Mamoulis, Nikos; Karras, Panagiotis

    2008-01-01

    We identify and formalize a novel join operator for two spatial pointsets P and Q. The common influence join (CIJ) returns the pairs of points (p,q),p isin P,q isin Q, such that there exists a location in space, being closer to p than to any other point in P and at the same time closer to q than ......-demand, is very efficient in practice, incurring only slightly higher I/O cost than the theoretical lower bound cost for the problem....

  5. The SKI SITE-94 Project: An International Peer Review Carried out by an OECD/NEA Team of Experts

    International Nuclear Information System (INIS)

    Sagar, Budhi; Devillers, C.; Smith, Paul; Laliuex, P.; Pescatore, C.

    1997-10-01

    The recently completed SITE-94 project is an SKI effort directed at building competence and capacity in the assessment of safety of a spent-fuel geologic repository. Emphasis is given to the assimilation of site-specific data, with its associated uncertainties, into the performance assessment. Specific attention is also given to improving the understanding of mechanisms that might compromise canister integrity. This report represents the common views of an International Review Team (IRT) established by the NEA Secretariat, at the request of SKI, to perform a peer review of SITE-94. The basis for the report is the understanding of SITE-94 and its background obtained by IRT in the course of several months of study of SITE-94 documentation, internal discussions and a meeting with SKI in Stockholm. The report is limited to the main findings of IRT. The intended audience of the report is the staff of SKI and, accordingly, the style of the report is suited to a technical audience familiar with the contents of the SITE-94 project

  6. The Year Without a Ski Season: An Analysis of the Winter of 2015 for Three Ski Resorts in Western Canada Using Historical and Simulation Model Forecasted Climate Data

    Science.gov (United States)

    Pidwirny, M. J.; Goode, J. D.; Pedersen, S.

    2015-12-01

    The winter of 2015 will go down as "the year without a ski season" for many ski resorts located close to the west coast of Canada and the USA. During this winter season, a large area of the eastern North Pacific Ocean had extremely high sea surface temperatures. These high sea surface temperatures influenced weather patterns on the west coast of North America producing very mild temperatures inland. Further, in alpine environments precipitation that normally arrives in the form of snow instead fell as rain. This research examines the climate characteristics of the winter of 2015 in greater detail for three ski resorts in British Columbia, Canada: Mount Washington, Cypress Mountain and Hemlock Valley. For these resorts, historical (1901 to 2013) and IPCC AR5 climate model forecasted climate data (RCP8.5 for 2025, 2055, and 2085) was generated for the variable winter degree days climate database ClimateBC. A value for winter degree days climate data at nearby meteorological stations for comparative analysis. For all three resorts, the winter of 2015 proved to be warmer than any individual year in the period 1901 to 2013. Interpolations involving the multi-model ensemble forecast means suggest that the climate associated with winter of 2015 will become the average normal for these resorts in only 35 to 45 years under the RCP8.5 emission scenario.

  7. 76 FR 40322 - Mt. Hood Meadows Ski Resort Parking Improvements

    Science.gov (United States)

    2011-07-08

    ... fleet. Also, the location of the current maintenance shop impedes traffic flow and removes potential... new Sunrise Vehicle Maintenance Shop on the north side of the Sunrise parking lot. DATES: Comments... increasing parking capacity and improving traffic flow in at Mt. Hood Meadows Ski Resort. Parking capacity...

  8. Speeding Up Neighbour-Joining Tree Construction

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Mailund, Thomas

    A widely used method for constructing phylogenetic trees is the neighbour-joining method of Saitou and Nei. We develope heuristics for speeding up the neighbour-joining method which generate the same phylogenetic trees as the original method. All heuristics are based on using a quad-tree to guide...... the search for the next pair of nodes to join, but di#er in the information stored in quad-tree nodes, the way the search is performed, and in the way the quad-tree is updated after a join. We empirically evaluate the performance of the heuristics on distance matrices obtained from the Pfam collection...... of alignments, and compare the running time with that of the QuickTree tool, a well-known and widely used implementation of the standard neighbour-joining method. The results show that the presented heuristics can give a significant speed-up over the standard neighbour-joining method, already for medium sized...

  9. a geometric property of the sierpiński carpet

    African Journals Online (AJOL)

    The main aim of this paper is to find formulae for the computation of the geodesic metric on the Sierpiński carpet. This is accomplished by introducing carpet coordinates. Subsequently we show the equivalence of the Euclidean and the geodesic metric on this fractal. Mathematics Subject Classification (2000): 28A80, 54E35 ...

  10. From après-ski to après-tourism: the Alps in transition?

    Directory of Open Access Journals (Sweden)

    Philippe Bourdeau

    2009-12-01

    Full Text Available Winter sports occupy a prominent place in European tourism, not only because of their economic importance in mountainous areas but also due to their major symbolic significance in the "leisure civilisation". Yet the world of winter tourism is full of uncertainties connected with climate change and also with evolutions and structural breaks that call into question the development model on which it is based. This context of profound change gives us the opportunity to question the limits of the industrial model that has governed the development of the Alps for the practice of skiing and to examine alternative future scenarios to "all-out skiing" and even "all-out tourism".Les sports d’hiver occupent une place de premier plan dans le tourisme européen, non seulement du fait de leur poids économique dans les régions de montagne, mais aussi par leur forte dimension symbolique dans la « civilisation des loisirs ». Pourtant l’univers du tourisme hivernal est parcouru par de nombreuses incertitudes liées au changement climatique, mais aussi à des évolutions et des ruptures structurelles qui remettent en question le modèle de développement sur lequel il repose. Ce contexte de mutation permet d’interroger les limites du modèle industriel qui a présidé à l’aménagement des Alpes pour la pratique du ski et d’examiner des figures d’avenir alternatives au « tout ski » et même au « tout tourisme ».

  11. Minor Characters in William Shakespeare's Twelfth Night and A Midsummer Night's Dream

    Directory of Open Access Journals (Sweden)

    Zahraa Adnan Baqer

    2018-01-01

    Full Text Available This paper aims at discussing the role of the minor characters in William Shakespeare's Twelfth Night and A Midsummer Night's Dream. The study assumes that without the first group of minor characters, associated with Olivia, the play Twelfth Night would lose much of its humor, and without the second group, associated with Sebastian, the play would fall apart. On the other hand, in Shakespeare's A Midsummer Night's Dream minor characters play important roles, without them, the action dose not ran smoothly, or does not ran at all. The paper falls into three sections. Section one deals with the role of each minor character in Twelfth Night.  Section two focuses on the minor characters in A Midsummer Night's Dream. Section three is a conclusion which sums up the findings of the study.

  12. PARTICLE-larly Enriching Night at CERN!

    CERN Multimedia

    Yves-Marie Ducimetière

    2010-01-01

    After the 2010 European Researchers' Night, a contest was organised for its participants, asking them to write about their experience. We are now pleased to announce the winner: Yves-Marie Ducimetière, a 14-year-old student at the Lycée International de Ferney-Voltaire.    Yves-Marie Ducimetière. The visit began for me around 20.30, as we all joined our respective groups to board a CERN shuttle to our final destination, which was LHCb in my case. I was heading into the unknown! On leaving, I knew nothing about this place, and the discovery made it all the more interesting. Upon arriving, a woman explained that their research looked at antimatter, or rather, the reason why it disappeared from our Universe – she then accompanied us inside. Amazingly, I found the place to be both friendly and serious. One physicist spoke passionately about the purpose of LHCb, in short: colliding particles in order to understand the Big Bang, the origin of t...

  13. Simulation of realization of ski-racers’ functional potentials in passing ski trails of different complexity

    Directory of Open Access Journals (Sweden)

    J.K. Khmelnytska

    2016-08-01

    Full Text Available Purpose: to substantiate model characteristics of functional fitness components of elite ski-racers, depending on competitions’ conditions. Material: We tested 20 sportsmen of combined team of Ukraine. Results: it was found that climbing hills of different length and steepness is accompanied by certain functional tension of organism and changes in cardio-respiratory system. It influences on effectiveness of further descent and moving on plain. It was also determined that correlation of aerobic and anaerobic efficiency changes according to trail relief. Conclusions: we worked out model characteristics of skiers’ fitness most important parameters, usage of which can facilitate maintaining high special workability on all segments of competition distance. In particular it concerns climbing hills of different steepness.

  14. Efficient Joins with Compressed Bitmap Indexes

    Energy Technology Data Exchange (ETDEWEB)

    Computational Research Division; Madduri, Kamesh; Wu, Kesheng

    2009-08-19

    We present a new class of adaptive algorithms that use compressed bitmap indexes to speed up evaluation of the range join query in relational databases. We determine the best strategy to process a join query based on a fast sub-linear time computation of the join selectivity (the ratio of the number of tuples in the result to the total number of possible tuples). In addition, we use compressed bitmaps to represent the join output compactly: the space requirement for storing the tuples representing the join of two relations is asymptotically bounded by min(h; n . cb), where h is the number of tuple pairs in the result relation, n is the number of tuples in the smaller of the two relations, and cb is the cardinality of the larger column being joined. We present a theoretical analysis of our algorithms, as well as experimental results on large-scale synthetic and real data sets. Our implementations are efficient, and consistently outperform well-known approaches for a range of join selectivity factors. For instance, our count-only algorithm is up to three orders of magnitude faster than the sort-merge approach, and our best bitmap index-based algorithm is 1.2x-80x faster than the sort-merge algorithm, for various query instances. We achieve these speedups by exploiting several inherent performance advantages of compressed bitmap indexes for join processing: an implicit partitioning of the attributes, space-efficiency, and tolerance of high-cardinality relations.

  15. SKI SITE-94. Deep Repository Performance Assessment Project Volume I and II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry`s R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is not a safety assessment or a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The report gives a detailed description of the many inter-related studies undertaken as part of the research project. As a general conclusion it is noted that the SITE-94 project has significantly advanced SKI`s capability of reviewing performance assessments and has led to the development of a tool-kit for carrying out assessment calculations, both in terms of numerical and scoping analyses. The study has highlighted a number of key issues for safety assessment (and consequently for disposal system design): Canister performance; Derived parameters of geosphere retention properties; Spatial variability of groundwater flow and geochemistry of migration paths; Time dependency (more emphasis on transient, time-dependent processes); Buffer evolution over long time. 488 refs.

  16. Welding and Joining of Titanium Aluminides

    Science.gov (United States)

    Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai

    2014-01-01

    Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials. PMID:28788113

  17. Adnyamathanha Night Skies

    Science.gov (United States)

    Curnow, Paul

    2009-06-01

    Aboriginal Australians have been viewing the night skies of Australia for some 45,000 years and possibly much longer. During this time they have been able to develop a complex knowledge of the night sky, the terrestrial environment in addition to seasonal changes. However, few of us in contemporary society have an in-depth knowledge of the nightly waltz of stars above.

  18. Snowmaking in ski resorts: spatial decision support for management of snowpack

    Science.gov (United States)

    Loubier, Jean-Christophe; Kanevski, Mikhail; Doctor, Marut; Schumacher, Michael; Timonin, Vadim

    2010-05-01

    Since the early 2000s, the question of snowmaking that ensures activity in ski areas is controversial, because solutions to face climate change and sustainable development seem to be opposed to the economical needs of winter tourism. Actually, according to the Advisory Body on Climate Change (OCCC), we can expect an average rise of the limit of 0 degrees to 360 m in 2050. The application of the rule of 100 days (30 cm of snow for 100 days) shows that 1 ° increase in temperature reduced by 20% the number of viable skiing areas. Snowmaking seems thus to be a solution for continuing an optimal economical usage of the ski resorts. The usage of machine-made snow raises environmental issues which can no longer be denied. [Badre et al.2009] However, these issues should not be disconnected from local economic specificities of the high mountain valleys, where the ski economy is critical. This paper presents a study at the economic-environmental interface. The aim is to develop a tool for managing the production of artificial snow, with the goal to: • Reduce production costs and improve profit margins of companies operating ski areas; • Reduce environmental impacts by an optimized snow production "just in time". In this way, water and energy needs will be reduced. The problem of managing the snow is a highly complex problem: it cannot be solved analytically. Indeed, changes in height of snow are subject to intakes of snow (natural or manufactured) associated with changing weather conditions and the impact of skiers. Therefore, the work presented in this paper has chosen a probabilistic approach in a simulation using neural networks to predict and to manage snow height. We do this in two points: • We measure snowpack heights with radars mounted on grooming machines; • We produce a snow cover prediction in relation with weather prediction using a neuron network. This neural approach thus deals with the spatial prediction of snow cover [Kanevski et al., 2009] The

  19. Alpine skiing habitual practices as free time entertainment for the students of West University of Timişoara – case study

    Directory of Open Access Journals (Sweden)

    Felix Sinitean-Singer

    2011-12-01

    Full Text Available The students of the West University of Timişoara represent a numerous social category, thus quite significant, continuously in search of new ways to practice sports in their free time. The winter season brings to our attention a number of specific activities, most appealing, amongst which alpine skiing, too. The present paper aims at defining the students’ habits regarding the way they spend their spare time, mainly as practicing alpine skiing. This sports branch enhances its attractiveness by the very special environment it can be practiced – into the mountains, in the open air, which actually raises the students’ interest for this free time activity, mainly during the winter vacation or the vacation between semesters, when the number of students largely exceeds the number of those practicing ski during the week or in weekends. We must take into account the fact that they prefer mountain resorts in Romania, not being picky at all when it comes to meals and accommodation facilities, but very demanding about the quality of the ski slopes and the correspondent facilities. The window of time allocated for skiing activities, an average between 1-3 hours/day, illustrates the students’ interest in spending their spare time in an active way. The relatively high costs of this sports branch, mainly because of the expensive equipments but also because of the high costs of the activity itself- courses, utilities, etc.- haven’t kept the students away; they have been manifesting their availability to invest the necessary amounts of money in order to be able to practice this sport. An excellent promotion factor of the alpine skiing amongst students has been the Timisoara West University by organizing theme camps – like ski teaching, but also a number of activities related to such a camp.

  20. Realizing User-Relevant Conceptual Model for the Ski Jump Venue of the Vancouver 2010 Winter Olympics

    Science.gov (United States)

    Teakles, Andrew; Mo, Ruping; Dierking, Carl F.; Emond, Chris; Smith, Trevor; McLennan, Neil; Joe, Paul I.

    2014-01-01

    As was the case for most other Olympic competitions, providing weather guidance for the ski jump and Nordic combined events involved its own set of unique challenges. The extent of these challenges was brought to light before the Vancouver 2010 Winter Olympics during a series of outflow wind events in the 2008/2009 winter season. The interactions with the race officials during the difficult race conditions brought on by the outflows provided a new perspective on the service delivery requirements for the upcoming Olympic Games. In particular, the turbulent nature of the winds and its impact on the ski jump practice events that season highlighted the need of race officials for nowcasting advice at very short time scales (from 2 min to 1 h) and forecast products tailored to their decision-making process. These realizations resulted in last minute modifications to the monitoring strategy leading up to the Olympic Games and required forecasters' conceptual models for flow within the Callaghan Valley to be downscaled further to reflect the evolution of turbulence at the ski jump site. The SNOW-V10 (Science of Nowcasting Olympic Weather for Vancouver 2010) team provided support for these efforts by supplying diagnostic case analyses of important events using numerical weather data and by enhancing the real-time monitoring capabilities at the ski jump venue.

  1. Welding and Joining of Titanium Aluminides

    Directory of Open Access Journals (Sweden)

    Jian Cao

    2014-06-01

    Full Text Available Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials.

  2. SKI's engagement in the process for siting a spent nuclear fuel repository

    Energy Technology Data Exchange (ETDEWEB)

    Paeivioe Jonsson, Josefin; Westerlind, Magnus [Swedish Nuclear Power Inspectorate, Stockholm (Sweden)

    2006-09-15

    In Sweden, issues concerning the disposal of nuclear waste historically required co-operation among primarily two main actors: The nuclear industry and the state. Municipalities involved in SKB's feasibility studies objected to the fact that they lacked resources to keep the people in the municipality informed about the ongoing work. As a result the Parliament decided that municipalities involved in SKB's siting process should receive money from the nuclear waste fund for their engagement. Since 2005 resources also have been made available for NGO's participating in SKB's ongoing EIA-process. In total they can yearly receive up to 2.5 million Swedish kronor. The fact that new actors continuously have been engaged in disposal of spent nuclear fuel has meant that 'old' actors, particularly SKB, the regulators (the Swedish Nuclear Power Inspectorate, SKI, and the Swedish Radiation Protection Authority, SSI) have had to evaluate, develop and clarify their roles and strategies for dialogue and regulatory oversight. This paper presents the effects the increased engagement has had on SKI's regulatory activities. Looking back it is possible to identify two well-defined break points in SKI's views on communication and active participation in the siting process. The first was the so-called DIALOGUE-project, which was initiated by SKI in the early 1990s. In this research project there were participants from e.g. SKI and SSI, municipalities and environmental organisations. The two most important conclusions for SKI were firstly that regulators can and should participate already in the early stages of a siting process, and that this can be done without loosing credibility as an independent reviewer of a licence application and secondly that actors (in the siting process) with conflicting interests and views can reach agreement on the basis for decisions. The second break point occurred in the mid 1990s when SKB announced that the

  3. Metabolic Responses and Pacing Strategies during Successive Sprint Skiing Time Trials

    DEFF Research Database (Denmark)

    Andersson, Erik; Holmberg, Hans-Christer; Ørtenblad, Niels

    2016-01-01

    PURPOSE: To examine the metabolic responses and pacing strategies during the performance of successive sprint time trials (STTs) in cross-country skiing. METHODS: Ten well-trained male cross-country skiers performed four self-paced 1300-m STTs on a treadmill, each separated by 45 min of recovery...... to estimate the anaerobic energy supply. RESULTS: The individual trial-to-trial variability in STT performance time was 1.3%, where variations in O2 deficit and V˙O2 explained 69% (P 0.05) of the variation in performance. The first and last STTs were equally fast (228 ± 10 s), and ~ 1...... on the first than second course half. In addition, metabolic rates were substantially higher (~_30%) for uphill than for flat skiing, indicating that pacing was regulated to the terrain. CONCLUSIONS: The fastest STTs were characterized primarily by a greater anaerobic energy production, which also explained 69...

  4. Determinants of ski-jump performance and implications for health, safety and fairness.

    Science.gov (United States)

    Müller, Wolfram

    2009-01-01

    Ski jumping puts high demands on the athlete's ability to control posture and movement. The athlete has to solve extremely difficult optimization problems. These implicit decisions and the resulting control manoeuvres can be understood by means of computer simulations. Computer simulations based on wind tunnel input data can identify the determinants for high performance and answer many questions of training methods, safety and health, role of weight, fairness, optimized hill design, sport development, and changes to the regulations. Each of the performance determinants has to be seen in the context of all others in order to understand its importance; the predominant factors are: high in-run velocity, high momentum perpendicular to the ramp at take-off due to the jump and the lift force, accurate timing of the take-off with respect to the ramp edge, appropriate angular momentum at take-off in order to obtain an aerodynamically advantageous and stable flight position as soon as possible, choice of advantageous body and equipment configurations during the entire flight in order to obtain optimum lift and drag values, and the ability to control the flight stability. Wind blowing up the hill increases the jump length dramatically and decreases the landing velocity, which eases the landing, and vice versa for wind from behind. Improvements to reduce unfairness due to changing wind are urgently needed. The current practice of the judges to reduce the score when the athlete has to perform body movements in order to counteract dangerous gusts is irrational. The athletes should rather be rewarded and not punished for their ability to handle such dangerous situations. For the quantification of underweight it is suggested to use the mass index: MI=0.28 m/s2 (where m is the jumper mass and s is the sitting height), which indirectly considers the individual leg length. The MI formula is similar to the body mass index (BMI) formula: the height is replaced by the sitting height s

  5. Expert - Non-expert differences in visual behaviour during alpine slalom skiing.

    Science.gov (United States)

    Decroix, Marjolein; Wazir, Mohd Rozilee Wazir Norjali; Zeuwts, Linus; Deconinck, Frederik F J A; Lenoir, Matthieu; Vansteenkiste, Pieter

    2017-10-01

    The aim of this study was to investigate visual behaviour of expert and non-expert ski athletes during an alpine slalom. Fourteen non-experts and five expert slalom skiers completed an alpine slalom course in an indoor ski slope while wearing a head-mounted eye tracking device. Experts completed the slalom clearly faster than non-experts, but no significant difference was found in timing and position of the turn initiation. Although both groups already looked at future obstacles approximately 0,5s before passing the upcoming pole, the higher speed of experts implied that they shifted gaze spatially earlier in the bend than non-experts. Furthermore, experts focussed more on the second next pole while non-expert slalom skiers looked more to the snow surface immediately in front of their body. No difference was found in the fixation frequency, average fixation duration, and quiet eye duration between both groups. These results suggest that experts focus on the timing of their actions while non-experts still need to pay attention to the execution of these actions. These results also might suggest that ski trainers should instruct non-experts and experts to focus on the next pole and, shift their gaze to the second next pole shortly before reaching it. Based on the current study it seems unadvisable to instruct slalom skiers to look several poles ahead during the actual slalom. However, future research should test if these results still hold on a real outdoor slope, including multiple vertical gates. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Ring-constrained Join

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Karras, Panagiotis; Mamoulis, Nikos

    2008-01-01

    . This new operation has important applications in decision support, e.g., placing recycling stations at fair locations between restaurants and residential complexes. Clearly, RCJ is defined based on a geometric constraint but not on distances between points. Thus, our operation is fundamentally different......We introduce a novel spatial join operator, the ring-constrained join (RCJ). Given two sets P and Q of spatial points, the result of RCJ consists of pairs (p, q) (where p ε P, q ε Q) satisfying an intuitive geometric constraint: the smallest circle enclosing p and q contains no other points in P, Q...

  7. [S100A7 promotes the metastasis and epithelial-mesenchymal transition on HeLa and CaSki cells].

    Science.gov (United States)

    Tian, T; Hua, Z; Wang, L Z; Wang, X Y; Chen, H Y; Liu, Z H; Cui, Z M

    2018-02-25

    Objective: To elucidate the impact of over-expression of S100A7 on migration, invasion, proliferation, cell cycle, and epithelial-mesenchymal transition (EMT) in human cervical cancer HeLa and CaSki cells. Methods: (1) Immunohistochemistry of SP was used to examine the expression of S100A7 in 40 cases of squamous cervical cancer tissues and 20 cases of normal cervical tissues. (2) The vectors of pLVX-IRES-Neo-S100A7 and pLVX-IRES-Neo were used to transfect human cervical cancer HeLa and CaSki cells, and the positive clones were screened and identified. Next, transwell migration assay, cell counting kit-8 (CCK-8) assay and fluorescence activating cell sorter (FACS) were used to detect the effect of S100A7-overexpression on the migration, invasion, proliferation and cell cycle of cervical cancer cells. Furthermore, western blot was performed to observe the expression of epithelial marker (E-cadherin) and mesenchymal markers (N-cadherin, vimentin, and fibronectin) of EMT. Results: (1) S100A7 expression was significantly higher in cervical squamous cancer tissues (median 91.6) than that in normal cervical tissues (median 52.1; Z=- 2.948, P= 0.003) . (2) Stable S100A7-overexpressed cells were established using lentiviral-mediated gene delivery in HeLa and CaSki cells. S100A7 was detected by real-time quantitative reverse transcription PCR, S100A7 mRNA of S100A7-overexpressed cells were 119±3 and 177±16, increased significantly compared with control groups of median ( Pcells, the number of S100A7-overexpressed HeLa and CaSki cells that passed the transwell membrane assay were increased significanatly (572±51 vs 337±25, PHeLa and CaSki cells that passed the transwell membrane were respectively 441±15 and 110±14, elevated significantly compared with control cells (156±21 and 59±7; Pcell cycle progression of HeLa and CaSki cells ( P> 0.05) . Expression of E-cadherin was dramatically decreased, while N-cadherin, vimentin, and fibronectin increased in S100A7

  8. No Snow? No Problem! Ski Statutes Still Provide Legal Protection

    Science.gov (United States)

    Buckmaster, Melanie E.; Young, Sarah J.

    2018-01-01

    In August 2012, Barbara Fakhouri visited Ober Gatlinburg, a ski resort located in eastern Tennessee to vacation with her family. Ms. Fakhouri used a wheelchair to ambulate. Despite the absence of snow on the ground, the resort operated year-round with many amenities such as an amusement park, restaurant, lounge, and shopping center to captivate…

  9. SNOW AVALANCHE ACTIVITY IN PARÂNG SKI AREA REVEALED BY TREE-RINGS

    Directory of Open Access Journals (Sweden)

    F. MESEȘAN

    2014-11-01

    Full Text Available Snow Avalanche Activity in Parâng Ski Area Revealed by Tree-Rings. Snow avalanches hold favorable conditions to manifest in Parâng Mountains but only one event is historically known, without destructive impact upon infrastructure or fatalities and this region wasn’t yet the object of avalanche research. The existing ski infrastructure of Parâng resort located in the west of Parâng Mountains is proposed to be extended in the steep slopes of subalpine area. Field evidence pinpoints that these steep slopes were affected by snow avalanches in the past. In this study we analyzed 11 stem discs and 31 increment cores extracted from 22 spruces (Picea abies (L. Karst impacted by avalanches, in order to obtain more information about past avalanches activity. Using the dendrogeomorphological approach we found 13 avalanche events that occurred along Scărița avalanche path, since 1935 until 2012, nine of them produced in the last 20 years. The tree-rings data inferred an intense snow avalanche activity along this avalanche path. This study not only calls for more research in the study area but also proves that snow avalanches could constitute an important restrictive factor for the tourism infrastructure and related activities in the area. It must be taken into consideration by the future extension of tourism infrastructure. Keywords: snow avalanche, Parâng Mountains, dendrogeomorphology, ski area.

  10. Straight into the Eyes - Jacek Łumiński and the Silesian Dance Theatre (1991-2011)

    OpenAIRE

    Alicja Iwańska

    2012-01-01

    The final decade of the 20th century was the turning-point for the development of Polish contemporary dance. In 1991 Jacek Łumiński established the Silesian Dance Theatre in Bytom. The theatre is said to be in the avant-garde of all activities related to contemporary dance development in Poland. It was J. Łumiński and his theatre who pioneered new trends in contemporary dance at the beginning of the nineties of the 20th century, at the same time they have conducted educational activity over t...

  11. The role of incline, performance level, and gender on the gross mechanical efficiency of roller ski skating.

    Science.gov (United States)

    Sandbakk, Oyvind; Hegge, Ann Magdalen; Ettema, Gertjan

    2013-01-01

    The ability to efficiently utilize metabolic energy to produce work is a key factor for endurance performance. The present study investigated the effects of incline, performance level, and gender on the gross mechanical efficiency during roller ski skating. Thirty-one male and nineteen female elite cross-country skiers performed a 5-min submaximal session at approximately 75% of VO2peak on a 5% inclined treadmill using the G3 skating technique. Thereafter, a 5-min session on a 12% incline using the G2 skating technique was performed at a similar work rate. Gross efficiency was calculated as the external work rate against rolling friction and gravity divided by the metabolic rate using gas exchange. Performance level was determined by the amount of skating FIS points [the Federation of International Skiing (FIS) approved scoring system for ski racing] where fewer points indicate a higher performance level. Strong significant correlations between work rate and metabolic rate within both inclines and gender were revealed (r = -0.89 to 0.98 and P gender differences being apparent. Significant correlations between gross efficiency and performance level were found for both inclines and genders (r = -0.65 to 0.81 and P genders used less metabolic energy to perform the same amount of work at steeper inclines, and that the better ranked elite male and female skiers skied more efficiently.

  12. History of the Night

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The definition of the night, as the period between sunset and sunrise, is consistent and unalterable, regardless of culture and time. However the perception of the night and its economic, social, and cultural roles are subject to change. Which parameters determine these changes? What can we learn by studying them about the specific character of a culture? Why do people experience the night in different ways in different historical periods and how did this affect their lives? How do references to nocturnal activities in historical sources (works of art, narratives) reveal what the artists/authors wish to communicate to their audiences? Can the night be a meaningful subject of historical and archaeological enquiry? A study of the source material in the Greek world (ca. 400 BC-ca. AD 400) shows a continuous effort to colonize the night with activities of the day, to make the night safer, more productive, more rational, more efficient. The main motors for this change were social developments and religion, no...

  13. Spatial Analysis of the Effects of the Anomalous Winter of 2014/15 on 157 Ski Resorts Located in Western North America

    Science.gov (United States)

    Bahbahani, K. M.; Pidwirny, M. J.

    2017-12-01

    The winter of 2014/2015 was one of the warmest in recent history for many locations in western North America. The cause of this climate irregularity was the development of extremely warm ocean surface waters (The Blob) over much of the eastern North Pacific Ocean. During this winter season, many ski resorts in western Canada and the United States either did not open or were forced to close their ski season early. Here, we examine climate data from 157 ski resorts to develop a picture of where the effected locations were in western North America. Using the climate database software ClimateBC and ClimateNA, high quality downscaled historical data was generated for the winter season (December, January, and February) for the variables mean temperature, snowfall, and rainfall. Values for winter of 2014/15 were statistically compared to the 30-year normal period from 1981-2010. Z-scores were calculated for 2014/15 relative to the selected 30-year normal period. These Z-score values were then mapped using ArcGIS. From the mean winter temperature map, it is apparent that abnormally warm temperatures influenced many ski resorts in California, Nevada, western Oregon, Washington, Arizona, Utah, southern Idaho, and parts of southern British Columbia. The winter snowfall map shows anomalous below normal conditions only at two resorts in south-central British Columbia and a single above normal situation at one site in central Colorado. The winter rainfall map displays that many ski resorts in New Mexico, Arizona, southern Utah, Colorado, Wyoming, Montana, Idaho, western Washington, and southwestern British Columbia experienced exceptional above normal winter season rainfalls. It is highly likely that the next Blob will be forecasted many months in advance of its occurrence. The results of this study have identified which ski resorts could be climatically influenced by such an event. This information may help reduce potential financial losses to ski resorts and their associated

  14. Ski Resort Real Estate: Does Supply prevent Appreciation?

    OpenAIRE

    William C. Wheaton

    2005-01-01

    This paper examines the behavior of ski resort property in a major New England market over the last 25 years. A constructed property price series reveals that nominal prices are quite volatile and only slightly higher today than in 1980. These ?uctuations and trends are investigated with a time series VAR model. The ?ndings indicate that (1) natural snowfall is crucial to business;(2) regional annual business is central to individual resort demand and hence price appreciation; and (3) resort ...

  15. Telemark skiing injuries: characteristics and risk factors.

    Science.gov (United States)

    Federiuk, C S; Mann, N C

    1999-01-01

    To determine the types of injuries associated with telemark skiing and the effects of ability level, equipment, and terrain. A survey was mailed to a sample of North American telemark skiers. Completed surveys were returned by 548 telemarkers (response rate = 74.5%). The mean age was 42.7 (+/- 9.3) years, and 69% were male. A total of 439 injury events resulted in 494 body injuries, reported by 285 skiers (52%). Lower-extremity injuries (n = 231) were more frequent than upper-extremity injuries (n = 187). Knee injuries were most common with 128 cases, followed by 80 thumb, 66 shoulder, and 44 ankle injuries. Surgery was required in 39 cases. Skiers suffering thumb injuries with sequela lasting greater than 3 months were 10.1 times less likely to have sought medical attention than skiers with other long-term injuries (p boot type and overall knee or ankle injury, but risk of severe ankle injury was increased in leather boots compared to plastic (OR = 8.0, CI = 1.05, 60.59). Release bindings were used by 27.9% of all skiers but were in use in only 18.7% of injury events, suggesting that release plates have a protective effect against injury (OR = 0.59, p knee, thumb, shoulder, and ankle are most frequently injured telemark skiing. Injuries are more likely to occur at lift-served areas than in the backcountry. Thumb injuries are often ignored and may result in long-term sequela. Ankle injuries appear more severe in leather boots. Release bindings appear protective against injury, but they often do not release.

  16. Biomechanics of optimal flight in ski-jumping.

    Science.gov (United States)

    Remizov, L P

    1984-01-01

    The flight in a vertical plane of a ski-jumper after take-off was studied with the purpose of maximising flight distance. To solve the problem of optimal flight (how a jumper must change his angle of attack to obtain the longest jump) the basic theorem of the optimal control theory--Pontriagin's maximum principle--was applied. The calculations were based on data from wind tunnel experiments. It was shown that the maximum flight distance is achieved when the angle of attack is gradually increased according to a convex function the form of which depends on the individual aerodynamic parameters.

  17. CAN A SMALL WINTER RESORT BE MANAGED AND MARKETED LIKE A LARGE ONE: A CASE OF BULGARIAN SKI RESORT BANSKO

    Directory of Open Access Journals (Sweden)

    Filip Shabanski

    2013-12-01

    Full Text Available Throughout the world today there are about 80 countries which practice various winter sports. Regardless of the wide geographical range demand in terms of existing infrastructure is highly concentrated in a few regions of the world. To be competitive ski resorts have to deliver good experiences and excellent value to tourists. Current community officials and destination managers of the Bulgarian ski resort of Bansko believe that the main weakness of this ski centre is the extensive waiting at the bottom gondola station and advocates expansion of the ski runs and lift capacity. The aim of the article is to research the strengths and weaknesses of the resort in regional and world context and to prove that further expansion will not forge a strong emotional connection with visitors and thus will not bring success in destination markets. The methodology used in this article follows three steps: 1 Literature review on the nature of the ski market in the world, as well as factors contributing to effective destination management; 2 International, national and regional data analysis of existing secondary data on winter sports market and 3 Qualitative study carried out with a purposive sample of key informants. The SWOT analysis based on the results of the qualitative study show that touristic shareholders in Bansko should apply an appropriate strategy for small winter resorts by offering a unique product that speaks to the world instead of trying to promote universal broad product for the mass market.

  18. Trajectory similarity join in spatial networks

    KAUST Repository

    Shang, Shuo

    2017-09-07

    The matching of similar pairs of objects, called similarity join, is fundamental functionality in data management. We consider the case of trajectory similarity join (TS-Join), where the objects are trajectories of vehicles moving in road networks. Thus, given two sets of trajectories and a threshold θ, the TS-Join returns all pairs of trajectories from the two sets with similarity above θ. This join targets applications such as trajectory near-duplicate detection, data cleaning, ridesharing recommendation, and traffic congestion prediction. With these applications in mind, we provide a purposeful definition of similarity. To enable efficient TS-Join processing on large sets of trajectories, we develop search space pruning techniques and take into account the parallel processing capabilities of modern processors. Specifically, we present a two-phase divide-and-conquer algorithm. For each trajectory, the algorithm first finds similar trajectories. Then it merges the results to achieve a final result. The algorithm exploits an upper bound on the spatiotemporal similarity and a heuristic scheduling strategy for search space pruning. The algorithm\\'s per-trajectory searches are independent of each other and can be performed in parallel, and the merging has constant cost. An empirical study with real data offers insight in the performance of the algorithm and demonstrates that is capable of outperforming a well-designed baseline algorithm by an order of magnitude.

  19. Recrafting the neighbor-joining method

    Directory of Open Access Journals (Sweden)

    Pedersen Christian NS

    2006-01-01

    Full Text Available Abstract Background The neighbor-joining method by Saitou and Nei is a widely used method for constructing phylogenetic trees. The formulation of the method gives rise to a canonical Θ(n3 algorithm upon which all existing implementations are based. Results In this paper we present techniques for speeding up the canonical neighbor-joining method. Our algorithms construct the same phylogenetic trees as the canonical neighbor-joining method. The best-case running time of our algorithms are O(n2 but the worst-case remains O(n3. We empirically evaluate the performance of our algoritms on distance matrices obtained from the Pfam collection of alignments. The experiments indicate that the running time of our algorithms evolve as Θ(n2 on the examined instance collection. We also compare the running time with that of the QuickTree tool, a widely used efficient implementation of the canonical neighbor-joining method. Conclusion The experiments show that our algorithms also yield a significant speed-up, already for medium sized instances.

  20. Willmore energy for joining of carbon nanostructures

    Science.gov (United States)

    Sripaturad, P.; Alshammari, N. A.; Thamwattana, N.; McCoy, J. A.; Baowan, D.

    2018-06-01

    Numerous types of carbon nanostructure have been found experimentally, including nanotubes, fullerenes and nanocones. These structures have applications in various nanoscale devices and the joining of these structures may lead to further new configurations with more remarkable properties and applications. The join profile between different carbon nanostructures in a symmetric configuration may be modelled using the calculus of variations. In previous studies, carbon nanostructures were assumed to deform according to perfect elasticity, thus the elastic energy, depending only on the axial curvature, was used to determine the join profile consisting of a finite number of discrete bonds. However, one could argue that the relevant energy should also involve the rotational curvature, especially when its size is comparable to the axial curvature. In this paper, we use the Willmore energy, a natural generalisation of the elastic energy that depends on both the axial and rotational curvatures. Catenoids are absolute minimisers of this energy and pieces of these may be used to join various nanostructures. We focus on the cases of joining a fullerene to a nanotube and joining two fullerenes along a common axis. By comparing our results with the earlier work, we find that both energies give similar joining profiles. Further work on other configurations may reveal which energy provides a better model.

  1. SKI2 mediates degradation of RISC 5'-cleavage fragments and prevents secondary siRNA production from miRNA targets in Arabidopsis.

    Science.gov (United States)

    Branscheid, Anja; Marchais, Antonin; Schott, Gregory; Lange, Heike; Gagliardi, Dominique; Andersen, Stig Uggerhøj; Voinnet, Olivier; Brodersen, Peter

    2015-12-15

    Small regulatory RNAs are fundamental in eukaryotic and prokaryotic gene regulation. In plants, an important element of post-transcriptional control is effected by 20-24 nt microRNAs (miRNAs) and short interfering RNAs (siRNAs) bound to the ARGONAUTE1 (AGO1) protein in an RNA induced silencing complex (RISC). AGO1 may cleave target mRNAs with small RNA complementarity, but the fate of the resulting cleavage fragments remains incompletely understood. Here, we show that SKI2, SKI3 and SKI8, subunits of a cytoplasmic cofactor of the RNA exosome, are required for degradation of RISC 5', but not 3'-cleavage fragments in Arabidopsis. In the absence of SKI2 activity, many miRNA targets produce siRNAs via the RNA-dependent RNA polymerase 6 (RDR6) pathway. These siRNAs are low-abundant, and map close to the cleavage site. In most cases, siRNAs were produced 5' to the cleavage site, but several examples of 3'-spreading were also identified. These observations suggest that siRNAs do not simply derive from RDR6 action on stable 5'-cleavage fragments and hence that SKI2 has a direct role in limiting secondary siRNA production in addition to its function in mediating degradation of 5'-cleavage fragments. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  2. EUROPEAN VOLCANOES' NIGHT: building a link between general public and volcanologists in a relaxed and welcoming setting

    Science.gov (United States)

    Calvo, David; González-Cárdenas, María E.; Baldrich, Laura; Solana, Carmen; Nave, Rosella; Calvari, Sonia; Harangi, Szabolcs; Chouraqui, Floriane; Dionis, Samara; Silva, Sonia V.; Forjaz, Victor H.; D'Auria, Luca; Pérez, Nemesio M.

    2017-04-01

    and their communities. Now we are planning the 2017 European Volcanoes' Night and looking for additional institutions and municipalities to join this volcano adventure.

  3. Intra-articular temperatures of the knee in sports – An in-vivo study of jogging and alpine skiing

    Directory of Open Access Journals (Sweden)

    Cerulli Guiliano

    2008-04-01

    Full Text Available Abstract Background Up to date, no information exists about the intra-articular temperature changes of the knee related to activity and ambient temperature. Methods In 6 healthy males, a probe for intra-articular measurement was inserted into the notch of the right knee. Each subject was jogging on a treadmill in a closed room at 19°C room temperature and skiing in a ski resort at -3°C outside temperature for 60 minutes. In both conditions, temperatures were measured every fifteen minutes intra-articulary and at the skin surface of the knee. A possible influence on joint function and laxity was evaluated before and after activity. Statistical analysis of intra-articular and skin temperatures was done using nonparametric Wilcoxon's sign rank sum test and Mann-Whitney's-U-Test. Results Median intra-articular temperatures increased from 31.4°C before activity by 2.1°C, 4°C, 5.8°C and 6.1°C after 15, 30, 45 and 60 min of jogging (all p ≤ 0.05. Median intra-articular temperatures dropped from 32.2°C before activity by 0.5°C, 1.9°C, 3.6°C and 1.1°C after 15, 30, 45 and 60 min of skiing (all n.s.. After 60 minutes of skiing (jogging, the median intra-articular temperature was 19.6% (8.7% higher than the skin surface temperature at the knee. Joint function and laxity appeared not to be different before and after activity within both groups. Conclusion This study demonstrates different changes of intra-articular and skin temperatures during sports in jogging and alpine skiing and suggests that changes are related to activity and ambient temperature.

  4. MICROWAVE JOINING OF ALUMINA CERAMIC AND HYDROXYLAPATITE BIOCERAMIC

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Microwave joining is a rapid developmental new techniqu e in recent years.This paper introduces a new microwave joining equipment which was made by our lab,succeeds in alumina ceramic-hydroxylapatite bioceramic j o in in the equipment, and analyzes the join situation of join boundary by using s canni ng electron microscope(SEM),this paper analyzes the mechanism of microwave joini ng also.

  5. Comparison of tibial shaft ski fractures in children and adults.

    Science.gov (United States)

    Hamada, Tomo; Matsumoto, Kazu; Ishimaru, Daichi; Sumi, Hiroshi; Shimizu, Katsuji

    2014-09-01

    To examine whether child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures. Descriptive epidemiological study. Prospectively analyzed the epidemiologic factors, injury types, and injury mechanisms at Sumi Memorial Hospital. This study analyzed information obtained from 276 patients with tibial fractures sustained during skiing between 2004 and 2012. We focused on 174 ski-related tibial shaft fractures with respect to the following factors: age, gender, laterality of fracture, skill level, mechanism of fracture (fall vs collision), scene of injury (steepness of slope), snow condition, and weather. Fracture pattern was graded according to Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification and mechanical direction [external (ER) or internal rotation (IR)]. Tibial shaft fractures were the most common in both children (89.3%) and adults (47.4%). There were no significant differences in gender, side of fracture, mechanism of fracture, snow condition, or weather between children and adults. Skill levels were significantly lower in children than in adults (P differences in some of these parameters, suggesting that child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures.

  6. Prospects of joining multi-material structures

    Science.gov (United States)

    Sankaranarayanan, R.; Hynes, N. Rajesh Jesudoss

    2018-05-01

    Spring up trends and necessities make the pipelines for the brand new Technologies. The same way, Multimaterial structures emerging as fruitful alternatives for the conventional structures in the manufacturing sector. Especially manufacturing of transport vehicles is placing a perfect platform for these new structures. Bonding or joining technology plays a crucial role in the field of manufacturing for sustainability. These latest structures are purely depending on such joining technologies so that multi-material structuring can be possible practically. The real challenge lies on joining dissimilar materials of different properties and nature. Escalation of thermoplastic usage in large structural components also faces similar ambiguity for joining multi-material structures. Adhesive bonding, mechanical fastening and are the answering technologies for multi-material structures. This current paper analysis the prospects of these bonding technologies to meet the challenges of tomorrow.

  7. Using the power balance model to simulate cross-country skiing on varying terrain

    Directory of Open Access Journals (Sweden)

    Moxnes JF

    2014-05-01

    Full Text Available John F Moxnes,1 Øyvind Sandbakk,2 Kjell Hausken31Department for Protection, Norwegian Defence Research Establishment, Kjeller, Norway; 2Center for Elite Sports Research, Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway; 3Faculty of Social Sciences, University of Stavanger, Stavanger, NorwayAbstract: The current study adapts the power balance model to simulate cross-country skiing on varying terrain. We assumed that the skier’s locomotive power at a self-chosen pace is a function of speed, which is impacted by friction, incline, air drag, and mass. An elite male skier’s position along the track during ski skating was simulated and compared with his experimental data. As input values in the model, air drag and friction were estimated from the literature based on the skier's mass, snow conditions, and speed. We regard the fit as good, since the difference in racing time between simulations and measurements was 2 seconds of the 815 seconds racing time, with acceptable fit both in uphill and downhill terrain. Using this model, we estimated the influence of changes in various factors such as air drag, friction, and body mass on performance. In conclusion, the power balance model with locomotive power as a function of speed was found to be a valid tool for analyzing performance in cross-country skiing.Keywords: air drag, efficiency, friction coefficient, speed, locomotive power

  8. A power function profile of a ski jumping in-run hill.

    Science.gov (United States)

    Zanevskyy, Ihor

    2011-01-01

    The aim of the research was to find a function of the curvilinear segment profile which could make possible to avoid an instantaneous increasing of a curvature and to replace a circle arc segment on the in-run of a ski jump without any correction of the angles of inclination and the length of the straight-line segments. The methods of analytical geometry and trigonometry were used to calculate an optimal in-run hill profile. There were two fundamental conditions of the model: smooth borders between a curvilinear segment and straight-line segments of an in-run hill and concave of the curvilinear segment. Within the framework of this model, the problem has been solved with a reasonable precision. Four functions of a curvilinear segment profile of the in-run hill were investigated: circle arc, inclined quadratic parabola, inclined cubic parabola, and power function. The application of a power function to the in-run profile satisfies equal conditions for replacing a circle arc segment. Geometrical parameters of 38 modern ski jumps were investigated using the methods proposed.

  9. Effective long term adaptation and metabolic state regulation of ski-racers

    Directory of Open Access Journals (Sweden)

    A.S. Bakhareva

    2016-06-01

    Full Text Available Purpose: to scientifically substantiate effective mechanisms of organism’s bio-chemical adaptation of ski-racers in competition period with the help of lipid peroxidation indicators, oxidative modification of proteins and activity of hypothalamus pituitary adrenocortical system. Material: in the research 14 sportsmen of 18-25 years’ age (combined team of university with different level of sportsmanship participated. Assessment of free radical oxidation, anti-oxidant system, cortisol level was fulfilled with the help of indicators’ quantitative analysis by bio-chemical methods applied to blood serum samples. Results: it was found that in the basis of bio-chemical changes under intensive physical loads is increase of catabolic processes’ speed. Change of organism’s metabolic orientation of ski racers at optimal level results in working muscles’ energy supply improvement, increase of energy systems’ power and sports efficiency. Conclusions: Application of interval trainings at stages of preparation to special significant competitions results in expected adaptation and increase of sports efficiency. We also showed their effective role in ensuring long term reactions, conditioning high sports efficiency.

  10. Demand-supply dynamics in tourism systems: A spatio-temporal GIS analysis. The Alberta ski industry case study

    Science.gov (United States)

    Bertazzon, Stefania

    The present research focuses on the interaction of supply and demand of down-hill ski tourism in the province of Alberta. The main hypothesis is that the demand for skiing depends on the socio-economic and demographic characteristics of the population living in the province and outside it. A second, consequent hypothesis is that the development of ski resorts (supply) is a response to the demand for skiing. From the latter derives the hypothesis of a dynamic interaction between supply (ski resorts) and demand (skiers). Such interaction occurs in space, within a range determined by physical distance and the means available to overcome it. The above hypotheses implicitly define interactions that take place in space and evolve over time. The hypotheses are tested by temporal, spatial, and spatio-temporal regression models, using the best available data and the latest commercially available software. The main purpose of this research is to explore analytical techniques to model spatial, temporal, and spatio-temporal dynamics in the context of regional science. The completion of the present research has produced more significant contributions than was originally expected. Many of the unexpected contributions resulted from theoretical and applied needs arising from the application of spatial regression models. Spatial regression models are a new and largely under-applied technique. The models are fairly complex and a considerable amount of preparatory work is needed, prior to their specification and estimation. Most of this work is specific to the field of application. The originality of the solutions devised is increased by the lack of applications in the field of tourism. The scarcity of applications in other fields adds to their value for other applications. The estimation of spatio-temporal models has been only partially attained in the present research. This apparent limitation is due to the novelty and complexity of the analytical methods applied. This opens new

  11. Kinematic characteristics of the ski jump inrun: a 10-year longitudinal study.

    Science.gov (United States)

    Janura, Miroslav; Cabell, Lee; Elfmark, Milan; Vaverka, Frantisek

    2010-05-01

    The athlete's inrun position affects the outcome for take-off in ski jumping. The purpose of this study was to examine the kinematic parameters between skiers' adjacent body segments during their first straight path of the inrun. Elite ski jumpers participated in the study at the World Cup events in Innsbruck, Austria, during the years 1992 through 2001. A video image was taken at a right angle to the tracks of the K-110 (meter) jumping hill. Kinematic data were collected from the lower extremities and trunk of the athletes. Findings indicated that jumpers had diminished ankle and knee joint angles and increased trunk and hip angles over the 10 years. In recent years, the best athletes achieved a further length of their jumps, while they experienced slower inrun average velocity. These results are perhaps explained by several possible contributing factors, such as new technique of the jumper's body kinematics, advancements in equipment technology, and somatotype of the jumpers.

  12. Conjoint Forming - Technologies for Simultaneous Forming and Joining

    International Nuclear Information System (INIS)

    Groche, P; Wohletz, S; Mann, A; Krech, M; Monnerjahn, V

    2016-01-01

    The market demand for new products optimized for e. g. lightweight applications or smart components leads to new challenges in production engineering. Hybrid structures represent one promising approach. They aim at higher product performance by using a suitable combination of different materials. The developments of hybrid structures stimulate the research on joining of dissimilar materials. Since they allow for joining dissimilar materials without external heating technologies based on joining by plastic deformation seem to be of special attractiveness. The paper at hand discusses the conjoint forming approach. This approach combines forming and joining in one process. Two or more workpieces are joined while at least one workpiece is plastically deformed. After presenting the fundamental joining mechanisms, the conjoint forming approach is discussed comprehensively. Examples of conjoint processes demonstrate the effectiveness and reveal the underlying phenomena. (paper)

  13. SKI2 mediates degradation of RISC 5′-cleavage fragments and prevents secondary siRNA production from miRNA targets in Arabidopsis

    Science.gov (United States)

    Branscheid, Anja; Marchais, Antonin; Schott, Gregory; Lange, Heike; Gagliardi, Dominique; Andersen, Stig Uggerhøj; Voinnet, Olivier; Brodersen, Peter

    2015-01-01

    Small regulatory RNAs are fundamental in eukaryotic and prokaryotic gene regulation. In plants, an important element of post-transcriptional control is effected by 20–24 nt microRNAs (miRNAs) and short interfering RNAs (siRNAs) bound to the ARGONAUTE1 (AGO1) protein in an RNA induced silencing complex (RISC). AGO1 may cleave target mRNAs with small RNA complementarity, but the fate of the resulting cleavage fragments remains incompletely understood. Here, we show that SKI2, SKI3 and SKI8, subunits of a cytoplasmic cofactor of the RNA exosome, are required for degradation of RISC 5′, but not 3′-cleavage fragments in Arabidopsis. In the absence of SKI2 activity, many miRNA targets produce siRNAs via the RNA-dependent RNA polymerase 6 (RDR6) pathway. These siRNAs are low-abundant, and map close to the cleavage site. In most cases, siRNAs were produced 5′ to the cleavage site, but several examples of 3′-spreading were also identified. These observations suggest that siRNAs do not simply derive from RDR6 action on stable 5′-cleavage fragments and hence that SKI2 has a direct role in limiting secondary siRNA production in addition to its function in mediating degradation of 5′-cleavage fragments. PMID:26464441

  14. The Relationship among Leg Strength, Leg Power and Alpine Skiing Success.

    Science.gov (United States)

    Gettman, Larry R.; Huckel, Jack R.

    The purpose of this study was to relate leg strength and power to alpine skiing success as measured by FIS points. Isometric leg strength was represented by the knee extension test described by Clarke. Leg power was measured by the vertical jump test and the Margaria-Kalamen stair run. Results in the strength and power tests were correlated with…

  15. "Chrono-functional milk": The difference between melatonin concentrations in night-milk versus day-milk under different night illumination conditions.

    Science.gov (United States)

    Asher, A; Shabtay, A; Brosh, A; Eitam, H; Agmon, R; Cohen-Zinder, M; Zubidat, A E; Haim, A

    2015-01-01

    Pineal melatonin (MLT) is produced at highest levels during the night, under dark conditions. We evaluated differences in MLT-concentration by comparing daytime versus night time milk samples, from two dairy farms with different night illumination conditions: (1) natural dark (Dark-Night); (2) short wavelength Artificial Light at Night (ALAN, Night-Illuminated). Samples were collected from 14 Israeli Holstein cows from each commercial dairy farm at 04:30 h ("Night-milk") 12:30 h ("Day-milk") and analyzed for MLT-concentration. In order to study the effects of night illumination conditions on cows circadian rhythms, Heart Rate (HR) daily rhythms were recorded. MLT-concentrations of Night-milk samples from the dark-night group were significantly (p Night-illuminated conditions (30.70 ± 1.79 and 17.81 ± 0.33 pg/ml, respectively). Interestingly, night illumination conditions also affected melatonin concentrations at daytime where under Dark-Night conditions values are significantly (p Night-Illuminated conditions, (5.36 ± 0.33 and 3.30 ± 0.18 pg/ml, respectively). There were no significant differences between the two treatments in the milk yield and milk composition except somatic cell count (SCC), which was significantly lower (p = 0.02) in the Dark-Night group compared with the Night-Illuminated group. Cows in both groups presented a significant (p night illuminated cows feeding and milking time are the "time keeper", while in the Dark-night cows, HR rhythms were entrained by the light/dark cycle. The higher MLT-concentration in Dark-night cows with the lower SCC values calls upon farmers to avoid exposure of cows to ALAN. Therefore, under Dark-night conditions milk quality will improve by lowering SCC values where separation between night and day of such milk can produce chrono-functional milk, naturally rich with MLT.

  16. Night Terrors in Children

    OpenAIRE

    Feferman, Irv

    1988-01-01

    Night terrors are a bizarre sleep disorder that affects young children. The child partially awakes during the night agitated, afraid and terrified, and cannot be consoled. These events, which may be related to emotional turmoil, are self-limiting. Psychiatric evaluation is indicated in certain cases, and drug therapy is almost never necessary. Parents should be reassured that night terrors are not dangerous and do not reflect any serious pathology.

  17. The role of incline, performance level and gender on the gross mechanical efficiency of roller ski skating

    Directory of Open Access Journals (Sweden)

    Øyvind eSandbakk

    2013-10-01

    Full Text Available The ability to efficiently utilize metabolic energy to produce work is a key factor for endurance performance. The present study investigated the effects of incline, performance level and gender on the gross mechanical efficiency during roller ski skating. Thirty-one male and nineteen female elite cross-country skiers performed a 5-min submaximal session at approximately 75% of VO2peak on a 5% inclined treadmill using the G3 skating technique. Thereafter, a 5-min session on a 12% incline using the G2 skating technique was performed at a similar work rate. Gross efficiency was calculated as the external work rate against rolling friction and gravity divided by the metabolic rate using gas exchange. Performance level was determined by the amount of skating FIS points (the Federation of International Skiing approved scoring system for ski racing where fewer points indicate a higher performance level. Strong significant correlations between work rate and metabolic rate within both inclines and gender were revealed (r=-0.89-0.98 and P

  18. How do different definitions of night shift affect the exposure assessment of night work?

    DEFF Research Database (Denmark)

    Garde, Anne Helene; Hansen, Johnni; Kolstad, Henrik A

    2016-01-01

    the reference definition (at least 3 h of work between 24:00 and 05:00) and definitions using a period during the night. The overlap with definitions based on starting and ending time was less pronounced (64-71 %). The proportion of classified night shifts differs little when night shifts are based...

  19. Night-vision goggles for night-blind subjects : subjective evaluation after 2 years of use

    NARCIS (Netherlands)

    Hartong, D. T.; Kooijman, A. C.

    Purpose: To evaluate the usefulness of night-vision goggles (NVG) for night-blind subjects after 1 and 2 years of use. Methods: Eleven night-blind subjects with retinitis pigmentosa used NVG for a 2-year period. At the end of each year, they were requested to fill-in two questionnaires regarding

  20. MiR-34a/miR-93 target c-Ski to modulate the proliferaton of rat cardiac fibroblasts and extracellular matrix deposition in vivo and in vitro.

    Science.gov (United States)

    Zhang, Chengliang; Zhang, Yanfeng; Zhu, Hong; Hu, Jiajia; Xie, Zhongshang

    2018-06-01

    Cardiac fibrosis is associated with diverse heart diseases. In response to different pathological irritants, cardiac fibroblasts may be induced to proliferate and differentiate into cardiac myofibroblasts, thus contributing to cardiac fibrosis. TGF-β signaling is implicated in the development of heart failure through the induction of cardiac fibrosis. C-Ski, an inhibitory regulator of TGF-β signaling, has been reported to suppress TGF-β1-induced human cardiac fibroblasts' proliferation and ECM protein increase; however, the underlying molecular mechanism needs further investigation. In the present study, we demonstrated that c-Ski could ameliorate isoproterenol (ISO)-induced rat myocardial fibrosis model and TGF-β1-induced primary rat cardiac fibroblasts' proliferation, as well as extracellular matrix (ECM) deposition. The protein level of c-Ski was dramatically decreased in cardiac fibrosis and TGF-β1-stimulated primary rat cardiac fibroblasts. In recent decades, a family of small non-coding RNA, namely miRNAs, has been reported to regulate gene expression by interacting with diverse mRNAs and inducing either translational suppression or mRNA degradation. Herein, we selected miR-34a and miR-93 as candidate miRNAs that might target to regulate c-Ski expression. After confirming that miR-34a/miR-93 targeted c-Ski to inhibit its expression, we also revealed that miR-34a/miR-93 affected TGF-β1-induced fibroblasts' proliferation and ECM deposition through c-Ski. Taken together, we demonstrated a miR-34a/miR-93-c-Ski axis which modulates TGF-β1- and ISO-induced cardiac fibrosis in vitro and in vivo; targeting the inhibitory factors of c-Ski to rescue its expression may be a promising strategy for the treatment of cardiac fibrosis. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Night shift work exposure profile and obesity: Baseline results from a Chinese night shift worker cohort.

    Science.gov (United States)

    Sun, Miaomiao; Feng, Wenting; Wang, Feng; Zhang, Liuzhuo; Wu, Zijun; Li, Zhimin; Zhang, Bo; He, Yonghua; Xie, Shaohua; Li, Mengjie; Fok, Joan P C; Tse, Gary; Wong, Martin C S; Tang, Jin-Ling; Wong, Samuel Y S; Vlaanderen, Jelle; Evans, Greg; Vermeulen, Roel; Tse, Lap Ah

    2018-01-01

    This study aimed to evaluate the associations between types of night shift work and different indices of obesity using the baseline information from a prospective cohort study of night shift workers in China. A total of 3,871 workers from five companies were recruited from the baseline survey. A structured self-administered questionnaire was employed to collect the participants' demographic information, lifetime working history, and lifestyle habits. Participants were grouped into rotating, permanent and irregular night shift work groups. Anthropometric parameters were assessed by healthcare professionals. Multiple logistic regression models were used to evaluate the associations between night shift work and different indices of obesity. Night shift workers had increased risk of overweight and obesity, and odds ratios (ORs) were 1.17 (95% CI, 0.97-1.41) and 1.27 (95% CI, 0.74-2.18), respectively. Abdominal obesity had a significant but marginal association with night shift work (OR = 1.20, 95% CI, 1.01-1.43). A positive gradient between the number of years of night shift work and overweight or abdominal obesity was observed. Permanent night shift work showed the highest odds of being overweight (OR = 3.94, 95% CI, 1.40-11.03) and having increased abdominal obesity (OR = 3.34, 95% CI, 1.19-9.37). Irregular night shift work was also significantly associated with overweight (OR = 1.56, 95% CI, 1.13-2.14), but its association with abdominal obesity was borderline (OR = 1.26, 95% CI, 0.94-1.69). By contrast, the association between rotating night shift work and these parameters was not significant. Permanent and irregular night shift work were more likely to be associated with overweight or abdominal obesity than rotating night shift work. These associations need to be verified in prospective cohort studies.

  2. Night shift work exposure profile and obesity: Baseline results from a Chinese night shift worker cohort

    Science.gov (United States)

    Feng, Wenting; Wang, Feng; Zhang, Liuzhuo; Wu, Zijun; Li, Zhimin; Zhang, Bo; He, Yonghua; Xie, Shaohua; Li, Mengjie; Fok, Joan P. C.; Tse, Gary; Wong, Martin C. S.; Tang, Jin-ling; Wong, Samuel Y. S.; Vlaanderen, Jelle; Evans, Greg; Vermeulen, Roel; Tse, Lap Ah

    2018-01-01

    Aims This study aimed to evaluate the associations between types of night shift work and different indices of obesity using the baseline information from a prospective cohort study of night shift workers in China. Methods A total of 3,871 workers from five companies were recruited from the baseline survey. A structured self-administered questionnaire was employed to collect the participants’ demographic information, lifetime working history, and lifestyle habits. Participants were grouped into rotating, permanent and irregular night shift work groups. Anthropometric parameters were assessed by healthcare professionals. Multiple logistic regression models were used to evaluate the associations between night shift work and different indices of obesity. Results Night shift workers had increased risk of overweight and obesity, and odds ratios (ORs) were 1.17 (95% CI, 0.97–1.41) and 1.27 (95% CI, 0.74–2.18), respectively. Abdominal obesity had a significant but marginal association with night shift work (OR = 1.20, 95% CI, 1.01–1.43). A positive gradient between the number of years of night shift work and overweight or abdominal obesity was observed. Permanent night shift work showed the highest odds of being overweight (OR = 3.94, 95% CI, 1.40–11.03) and having increased abdominal obesity (OR = 3.34, 95% CI, 1.19–9.37). Irregular night shift work was also significantly associated with overweight (OR = 1.56, 95% CI, 1.13–2.14), but its association with abdominal obesity was borderline (OR = 1.26, 95% CI, 0.94–1.69). By contrast, the association between rotating night shift work and these parameters was not significant. Conclusion Permanent and irregular night shift work were more likely to be associated with overweight or abdominal obesity than rotating night shift work. These associations need to be verified in prospective cohort studies. PMID:29763461

  3. Effects of an Arctic Ocean Ski Traverse on the Protective Capabilities of Expedition Footwear

    National Research Council Canada - National Science Library

    Endrusick, Thomas; Frykman, Peter; O'Brien, Catherine; Giblo, Joseph

    2005-01-01

    A traverse of the Arctic Ocean during a 2000-km unsupported ski expedition provided an opportunity to assess the impact of an extreme cold environment on the protective capabilities of a specialized footwear system (FS...

  4. Differential Recognition of Old World and New World Arenavirus Envelope Glycoproteins by Subtilisin Kexin Isozyme 1 (SKI-1)/Site 1 Protease (S1P)

    Science.gov (United States)

    Burri, Dominique J.; Ramos da Palma, Joel; Seidah, Nabil G.; Zanotti, Giuseppe; Cendron, Laura

    2013-01-01

    The arenaviruses are an important family of emerging viruses that includes several causative agents of severe hemorrhagic fevers in humans that represent serious public health problems. A crucial step of the arenavirus life cycle is maturation of the envelope glycoprotein precursor (GPC) by the cellular subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P). Comparison of the currently known sequences of arenavirus GPCs revealed the presence of a highly conserved aromatic residue at position P7 relative to the SKI-1/S1P cleavage side in Old World and clade C New World arenaviruses but not in New World viruses of clades A and B or cellular substrates of SKI-1/S1P. Using a combination of molecular modeling and structure-function analysis, we found that residueY285 of SKI-1/S1P, distal from the catalytic triad, is implicated in the molecular recognition of the aromatic “signature residue” at P7 in the GPC of Old World Lassa virus. Using a quantitative biochemical approach, we show that Y285 of SKI-1/S1P is crucial for the efficient processing of peptides derived from Old World and clade C New World arenavirus GPCs but not of those from clade A and B New World arenavirus GPCs. The data suggest that during coevolution with their mammalian hosts, GPCs of Old World and clade C New World viruses expanded the molecular contacts with SKI-1/S1P beyond the classical four-amino-acid recognition sequences and currently occupy an extended binding pocket. PMID:23536681

  5. Night Eating Disorders

    Directory of Open Access Journals (Sweden)

    Deniz Tuncel

    2009-08-01

    Full Text Available Hunger is an awakening related biological impulse. The relationship between hunger and sleep is moderated by the control of homeostatic and circadian rhytms of the body. Abnormal eating behavior during sleep period could result from different causes. Abnormal eating during the main sleep period has been categorized as either night eating syndrome or sleep related eating disorder. Night eating syndrome (NES is an eating disorder characterised by the clinical features of morning anorexia, evening hyperphagia, and insomnia with awakenings followed by nocturnal food ingestion. Recently night eating syndrome, conceptualized as a delayed circadian intake of food. Sleep-related eating disorder, thought to represent a parasomnia and as such included within the revised International Classification of Sleep Disorders (ICSD-2, and characterized by nocturnal partial arousals associated with recurrent episodes of involuntary food consumption and altered levels of consciousness. Whether, however, sleep-related eating disorder and night eating syndrome represent different diseases or are part of a continuum is still debated. This review summarizes their characteristics, treatment outcomes and differences between them.

  6. Cardiorespiratory endurance evaluation using heart rate analysis during ski simulator exercise and the Harvard step test in elementary school students.

    Science.gov (United States)

    Lee, Hyo Taek; Roh, Hyo Lyun; Kim, Yoon Sang

    2016-01-01

    [Purpose] Efficient management using exercise programs with various benefits should be provided by educational institutions for children in their growth phase. We analyzed the heart rates of children during ski simulator exercise and the Harvard step test to evaluate the cardiopulmonary endurance by calculating their post-exercise recovery rate. [Subjects and Methods] The subjects (n = 77) were categorized into a normal weight and an overweight/obesity group by body mass index. They performed each exercise for 3 minutes. The cardiorespiratory endurance was calculated using the Physical Efficiency Index formula. [Results] The ski simulator and Harvard step test showed that there was a significant difference in the heart rates of the 2 body mass index-based groups at each minute. The normal weight and the ski-simulator group had higher Physical Efficiency Index levels. [Conclusion] This study showed that a simulator exercise can produce a cumulative load even when performed at low intensity, and can be effectively utilized as exercise equipment since it resulted in higher Physical Efficiency Index levels than the Harvard step test. If schools can increase sport durability by stimulating students' interests, the ski simulator exercise can be used in programs designed to improve and strengthen students' physical fitness.

  7. A Midsummer Night's Science

    CERN Multimedia

    2001-01-01

    Last year, the first Science Night attracted nearly 1500 people. Dipping into history for the space of one night? This is the idea of Geneva's Museum of the History of Science, which is organizing its second Science Night, on 7 and 8 July, on the history of science. The first such event, held last year, was a considerable success with almost 15 000 visitors. The second Science Night, to be held in the magnificent setting of the Perle du Lac Park in Geneva, promises to be a winner too. By making science retell its own history, this major event is intended to show how every scientific and technical breakthrough is the culmination of a long period of growth that began hundreds of years in the past. Dozens of activities and events are included in this programme of time travel: visitors can study the night sky through telescopes and see what Galileo first observed, and then go to see a play on the life of the Italian scientist. Another play, commissioned specially for the occasion, will honour Geneva botanist De ...

  8. Thin layer joining by gas adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Taga, Yasunori, E-mail: y-taga@isc.chubu.ac.jp; Fukumura, Toshio

    2014-10-01

    Highlights: • We report thin layer molecular joining between glass and COP by gas adsorption. Thickness of joining layer is 1–2 nm and joining process was carried out at low temperature at about 100 °C. • Adhesion strength measured by 180 degree peel test revealed to be 1–10 N/25 mm and the joined stack showed high durability for practical use. - Abstract: Attempt has been made to join borosilicate glass and cycloolefin (COP) polymer film by using gas adsorption method. After corona plasma treat, COP was exposed to (3-glycidoxypropyl) trimethoxysilane (GPS) and glass to (3-aminopropyl) triethoxysilane (APS) both in air atmosphere, resulting in co-adsorption of water vapor in the atmosphere and organosilane gases. Surface characterization of plasma treated and gas adsorbed surfaces was carried out by X-ray photoelectron spectroscopy (XPS) using Mg Kα X-ray source. Joining was carried out by a roll laminator after contact of both surfaces at room temperature, followed by annealing at 130 °C for 10 min. Adhesion strength was evaluated by 180 degree peel test based on ASTM D-903 and durability was examined under the conditions of 60 °C and 95% RH. It was found that after plasma treatment, complex functional groups such as C-H, C-O, C=O, O-C=O and CO{sub 3} were found on COP and O-H on glass. Thickness of GPS gas adsorption layer on COP was evaluated by the XPS to be at least 1.1 nm by taking inelastic mean free path of Si{sub 2p} photoelectron into consideration. Joining force was found to be more than 5 N/25 mm corresponding to almost equal to COP bulk tensile strength. In addition, durability of this adhesion strength remained unchanged over 2000 h even after exposure to the durability test conditions of 60 °C and 95% RH. The results can be explained in terms of formation of H-H hydrogen bonding and Si-O covalent bonding via silanols will be made at the interface as a result of lamination and annealing processes. In conclusion, ultrathin joining method

  9. Spatio-temporal joins on symbolic indoor tracking data

    DEFF Research Database (Denmark)

    Lu, Hua; Yang, Bin; Jensen, Christian S.

    2011-01-01

    and studies probabilistic, spatio-temporal joins on historical indoor tracking data. Two meaningful types of join are defined. They return object pairs that satisfy spatial join predicates either at a time point or during a time interval. The predicates considered include “same X,” where X is a semantic...

  10. SKI Project-90. Geosphere calculations using CRYSTAL: Stand-alone and CALIBRE-CRYSTAL-biosphere integrated results

    International Nuclear Information System (INIS)

    Worgan, K.; Shaw, W.

    1992-02-01

    In Project-90, the far-field transport of nuclides is assumed to take place in a 200 m long section of rock mass, which starts at the outer boundary of the near-field and ends in a fracture zone. The nuclides are eventually discharged to the biosphere. This document provides an overview of the results obtained with the far-field model CRYSTAL developed by Intera Environmental Division for the Swedish Nuclear Power Inspectorate (SKI). It reports on the results of a series of calculation that have been performed within the SKIs Project-90, and provides some indication of the key parameters for the far field. A more thorough discussion of the implications for performance assessment is given in the Project-90 reports. (au)

  11. Impact of Climate Change on Natural Snow Reliability, Snowmaking Capacities, and Wind Conditions of Ski Resorts in Northeast Turkey: A Dynamical Downscaling Approach

    Directory of Open Access Journals (Sweden)

    Osman Cenk Demiroglu

    2016-04-01

    Full Text Available Many ski resorts worldwide are going through deteriorating snow cover conditions due to anthropogenic warming trends. As the natural and the artificially supported, i.e., technical, snow reliability of ski resorts diminish, the industry approaches a deadlock. For this reason, impact assessment studies have become vital for understanding vulnerability of ski tourism. This study considers three resorts at one of the rapidly emerging ski destinations, Northeast Turkey, for snow reliability analyses. Initially one global circulation model is dynamically downscaled by using the regional climate model RegCM4.4 for 1971–2000 and 2021–2050 periods along the RCP4.5 greenhouse gas concentration pathway. Next, the projected climate outputs are converted into indicators of natural snow reliability, snowmaking capacity, and wind conditions. The results show an overall decline in the frequencies of naturally snow reliable days and snowmaking capacities between the two periods. Despite the decrease, only the lower altitudes of one ski resort would face the risk of losing natural snow reliability and snowmaking could still compensate for forming the base layer before the critical New Year’s week. On the other hand, adverse high wind conditions improve as to reduce the number of lift closure days at all resorts. Overall, this particular region seems to be relatively resilient against climate change.

  12. Boolean Operations, Joins, and the Extended Low Hierarchy

    OpenAIRE

    Hemaspaandra, Lane A.; Jiang, Zhigen; Rothe, Joerg; Watanabe, Osamu

    1999-01-01

    We prove that the join of two sets may actually fall into a lower level of the extended low hierarchy than either of the sets. In particular, there exist sets that are not in the second level of the extended low hierarchy, EL_2, yet their join is in EL_2. That is, in terms of extended lowness, the join operator can lower complexity. Since in a strong intuitive sense the join does not lower complexity, our result suggests that the extended low hierarchy is unnatural as a complexity measure. We...

  13. [Artur Wołyński--A forgotten Polish historian in Italy in the second half of the 19th century].

    Science.gov (United States)

    Piskurewicz, Jan

    2011-01-01

    Artur Wołyński (1844-1893) was, undoubtedly, one of the most interesting personages of Polish émigrés after January Uprising. He belonged to these circles of Polish émigrés, who were able to reconcile their patriotic aspirations with realities and interest of the countries that entertained them. As far as Wołyński is concerned, it found its expression in the efforts that were made in order to assimilate two nations--Polish and Italian people--appealing to the common history and familiar cultural traditions. An important element of integrating all the above-discussed actions was his scientific activity. The mentioned activity included, first of all, his studies on Nicolaus Copernicus and Galileo Galilei. In the article were analyzed more comprehensive scientific descriptions dedicated to Copernicus and Galileo prepared by Wołyński, and their significance and opinions on them of the learned, whose works treated on Copernicus and Galileo as well. Secondly, in the field of scientific activity of Wołyńiski, one can also observe his researches and the process of elaborating sources for Polish and Italian his tory, particularly concerning the 17th century. However, most of his attention Wołyński paid to collecting and working out the materials concerning January Uprising. Speaking a modern language, one can say that Wołyński in a way polled the insurgents of January Uprising sending to them an appropriate list of questions, additionally allowing for their biographies. In the paper was also included a detailed description of this broad initiative together with its results. Up till now, not much attention has been paid to this significant scientific activity and its contexts. So, the present article is to remind of meritorious personage of Wołyński, and particularly of his output within the realm of history of science, history of Polish and Italian relationships, and of the role he played in bequeathing memory of January Uprising.

  14. Comparisons of Two Commercial and Two Low-cost Interfaces for Virtual Skiing

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Serafin, Stefania; Nordahl, Rolf

    2015-01-01

    In this paper we present two comparisons of two novel physical interface for interacting with a virtual environment in the form of a skiing game. The interfaces were compared through two separate within-subjects studies. In the first study we compared a wobble board augmented with a low-cost 3D a...

  15. Performance changes during a weeklong high-altitude alpine ski-racing training camp in lowlander young athletes.

    Science.gov (United States)

    Hydren, Jay R; Kraemer, William J; Volek, Jeff S; Dunn-Lewis, Courtenay; Comstock, Brett A; Szivak, Tunde K; Hooper, David R; Denegar, Craig R; Maresh, Carl M

    2013-04-01

    Thousands of youth athletes travel to high altitude to participate in lift-access alpine sports. The purpose of this study was to examine the impact of acute high-altitude exposure on balance, choice reaction time, power, quickness, flexibility, strength endurance, and V[Combining Dot Above]O2max in youth lowlander athletes during a weeklong preseason training camp in Summit County, CO, USA. Eleven youth ski racers (4 boys and 7 girls; age, 13.7 ± 0.5 years; height, 157.2 ± 12.6 cm; weight, 52.4 ± 6.8 kg) with 7.7 ± 2.2 skiing years of experience participated in baseline testing at 160 m one week before the camp and a set of daily tests in the morning and afternoon at 2,828 m and skied between 3,328 and 3,802 m during a 6-day camp. Balance and choice reaction time tests were stagnant or improved slightly during the first 3 days and then improved on days 4 and 6. Vertical jump, flexibility, T-agility test, and push-ups in 1 minute improved on day 6. The number of sit-ups in 1 minute did not improve, and scores on the multistage fitness test decreased 20.34%. There was no effect of Lake Louise acute mountain sickness (AMS) questionnaire scores on performance variables measured. Athletes sojourning to high altitude for ski camps can train on immediate ascent but should slowly increase training volume over the first 3 days. Athletes should expect improvements in balance and reaction time 3-6 days into acclimatization. Coaches and athletes should expect about 20% of youth lowlander athletes to have signs and symptoms of AMS during the first 3 days of altitude exposure for alpine lift access sports at altitudes of up to 3,800 m.

  16. Ski and snowboard school programs: Injury surveillance and risk factors for grade-specific injury.

    Science.gov (United States)

    Sran, R; Djerboua, M; Romanow, N; Mitra, T; Russell, K; White, K; Goulet, C; Emery, C; Hagel, B

    2018-05-01

    The objective of our study was to evaluate incidence rates and profile of school program ski and snowboard-related injuries by school grade group using a historical cohort design. Injuries were identified via Accident Report Forms completed by ski patrollers. Severe injury was defined as those with ambulance evacuation or recommending patient transport to hospital. Poisson regression analysis was used to examine the school grade group-specific injury rates adjusting for risk factors (sex, activity, ability, and socioeconomic status) and accounting for the effect of clustering by school. Forty of 107 (37%) injuries reported were severe. Adolescents (grades 7-12) had higher crude injury rates (91 of 10 000 student-days) than children (grades 1-3: 25 of 10 000 student-days; grades 4-6: 65 of 10 000 student-days). Those in grades 1-3 had no severe injuries. Although the rate of injury was lower in grades 1-3, there were no statistically significant grade group differences in adjusted analyses. Snowboarders had a higher rate of injury compared with skiers, while higher ability level was protective. Participants in grades 1-3 had the lowest crude and adjusted injury rates. Students in grades 7-12 had the highest rate of overall and severe injuries. These results will inform evidence-based guidelines for school ski/snowboard program participation by school-aged children. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Joining elements of silicon carbide

    International Nuclear Information System (INIS)

    Olson, B.A.

    1979-01-01

    A method of joining together at least two silicon carbide elements (e.g.in forming a heat exchanger) is described, comprising subjecting to sufficiently non-oxidizing atmosphere and sufficiently high temperature, material placed in space between the elements. The material consists of silicon carbide particles, carbon and/or a precursor of carbon, and silicon, such that it forms a joint joining together at least two silicon carbide elements. At least one of the elements may contain silicon. (author)

  18. Recrafting the Neighbor-Joining Method

    DEFF Research Database (Denmark)

    Mailund; Brodal, Gerth Stølting; Fagerberg, Rolf

    2006-01-01

    Background: The neighbor-joining method by Saitou and Nei is a widely used method for constructing phylogenetic trees. The formulation of the method gives rise to a canonical Θ(n3) algorithm upon which all existing implementations are based. Methods: In this paper we present techniques for speeding...... up the canonical neighbor-joining method. Our algorithms construct the same phylogenetic trees as the canonical neighbor-joining method. The best-case running time of our algorithms are O(n2) but the worst-case remains O(n3). We empirically evaluate the performance of our algoritms on distance...... matrices obtained from the Pfam collection of alignments. Results: The experiments indicate that the running time of our algorithms evolve as Θ(n2) on the examined instance collection. We also compare the running time with that of the QuickTree tool, a widely used efficient implementation of the canonical...

  19. Alpine Skiing With total knee ArthroPlasty (ASWAP): physical self-concept, pain, and life satisfaction.

    Science.gov (United States)

    Amesberger, G; Müller, E; Würth, S

    2015-08-01

    Physical self-concept in the elderly is assumed to be structured in terms of different domains and to contribute substantially to life satisfaction. However, little is known about the role of the physical self-concept in older persons that are engaged in physical activity while suffering from typical age-related impairments or chronic diseases. The present study aimed to investigate the structure of physical self-concept in a group of older persons with total knee arthroplasty (TKA), its development throughout a 12-week skiing intervention, and its importance to life satisfaction. Factor analyses of the present data reveal that the physical self-concept consists of four dimensions addressing strength, flexibility/coordination, endurance, and sportiness. One higher order factor extracted by hierarchical factor analyses reflects a global physical self-concept. The 12-week skiing intervention had no substantial impact in terms of an improvement of self-concept. Life satisfaction is best predicted by positive changes in the subjective ratings between pre- and post-test (i.e., global physical self-concept, flexibility and coordination, and perceived sportiness) and not by objective physical performance (isokinetic strength, endurance, or coordination). Results support the assumption that physical self-concept of older people with TKA is only marginally sensitive to a 12-week skiing intervention. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Join or be excluded from biomedicine? JOINS and Post-colonial Korea.

    Science.gov (United States)

    Ma, Eunjeong

    2015-04-01

    This paper discusses re-emergence of Korean medicine(s) in the global context with a focus on a natural drug JOINS, a highly contentious drug regarding its legal status. By following through its life world, the paper contends that the drug is the embodiment of the postcolonial anxiety that crosses the intersections between the aspiring nation and globalizing strategies of the bio-pharmaceutical industry. JOINS is a natural drug prescribed to alleviate the symptoms of degenerative arthritis. SK Chemicals, Ltd., a giant domestic pharmaceutical company developed the drug by utilizing the knowledge of traditional pharmacopeia and put it on the market in 2001. In the domestic market, the drug is treated as a prescription drug, implying that Western medicine-trained doctors (as opposed to Korean medicine doctors) are entitled to prescribe drugs. It also indicates that the drug has undergone a series of lab tests such as toxicity, efficacy, and clinical trials in compliance with regulatory guidelines. However, the domestic standards are not rigorous enough to satisfy international standards, so that it is exported as a nutritional supplement abroad. The government, the pharmaceutical industry, and the Western medicine profession are happy with how the drug stands domestically and internationally. Rather, it is Korean doctors who try to disrupt the status quo and reclaim their rights to traditional knowledge, who have been alienated from the pharmaceuticalization of traditional knowledge. Thus, the JOINS tablet embodies the complex web of modern Korean society, professional interests, the pharmaceutical industry, and globalization.

  1. Decline of Low-Frequency Hearing in People With Ski-Slope Hearing Loss; Implications for Electrode Array Insertion.

    Science.gov (United States)

    Schuurbiers, Jasper; Dingemanse, Gertjan; Metselaar, Mick

    2017-12-01

    The decline of low-frequency hearing in people with ski-slope hearing loss varies and might depend on etiology. People with ski-sloping hearing loss might benefit from cochlear implantation with preservation of residual hearing. To reduce the risk of losing low-frequency hearing after implantation, the electrode-array can be inserted partially up to the desired frequency. That, however, obstructs electrical stimulation of lower frequencies. To decide between complete or partial insertion, knowledge regarding the natural decline of low-frequency hearing is helpful. Patients with at least two ski-slope audiograms over time were selected. We calculated progression at lower frequencies for 320 patients. Etiologies for hearing loss were retrieved from medical records. Progression of hearing loss was analyzed separately for patients with uni- and bilateral hearing losses. Relative progression of hearing loss was obtained by comparing progression to a reference group. Average progression of PTA was 1.73 dB/yr and was not significantly different in the bilateral and unilateral group. Etiologies that did not show significantly more progression compared with the reference group could be identified as single or short-lasting pathologic events, whereas long-lasting conditions had significant more progression of PTA. Patients with a ski-slope hearing loss that was caused by a single or short-lasting event have low progression rate and are viable for partial insertion to minimize the risk of damaging residual low-frequency hearing. In the absence of such an event, complete insertion should be considered because faster than normal deterioration of low-frequency hearing over time will probably limit the advantage of preservation of residual hearing.

  2. Nightmares and Night Terrors

    Science.gov (United States)

    ... able to tell you what happened in the dream and why it was scary. Your child may have trouble going back to sleep. Your child might have the same dream again on other nights. What are night terrors? ...

  3. Trends in skiing injury type and rates in Australia. A review of 22,261 injuries over 27 years in the Snowy Mountains.

    Science.gov (United States)

    Sherry, E; Fenelon, L

    1991-10-21

    To show the trends in the rate and type of skiing injuries in Australia. A retrospective analysis of skiing injuries in the Snowy Mountains from 1962 to 1988. All injuries were seen and treated at the Ski Injury Clinic in Perisher Valley. A total of 22,261 injuries were seen over this 27 year period (data for 1963, 1964, 1966, 1977, 1978, 1981 and 1982 were missing). Injured skiers were treated at the Clinic with a small number sent to main centres for tertiary care. The overall injury rate (1962-1988) and the specific injury rate for six subgroups of injuries (1974-1988) were calculated. The overall injury rate declined dramatically over this period. The incidence of tibial fractures, ankle injuries and lacerations also declined. Upper body injuries continue to rise although this trend was not statistically significant. There was a statistically significant increase in knee injuries. The trends reported here are similar to those overseas except that the incidence of thumb injuries has not changed in Australia. The changes in the rates of lacerations, and tibial and ankle injuries can be related to improvements in ski bindings and boots.

  4. JOINING DISSIMILAR MATERIALS USING FRICTION STIR SCRIBE TECHNIQUE

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep; Fifield, Leonard S.

    2016-09-01

    Development of robust and cost effective method of joining dissimilar materials can provide a critical pathway to enable widespread use of multi-material design and components in mainstream industrial applications. The use of multi-material components such as Steel-Aluminum, Aluminum-Polymer allows design engineers to optimize material utilization based on service requirements and often lead weight and cost reductions. However producing an effective joint between materials with vastly different thermal, microstructural and deformation response is highly problematic using conventional joining and /or fastening methods. This is especially challenging in cost sensitive high volume markets that largely rely on low–cost joining solutions. Friction Stir Scribe technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like Magnesium and Aluminum to high temperature materials like Steels and Titanium. Additionally viable joints between polymer composites and metal can also be made using this method. This paper will present state of the art, progress made and challenges associated with this innovative derivative of Friction Stir welding in reference to joining dissimilar metals and polymer/metal combinations.

  5. Joining Dissimilar Materials Using Friction Stir Scribe Technique

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Piyush [Pacific Northwest National Laboratory, Richland 99352, WA e-mail: piyush.upadhyay@pnnl.gov; Hovanski, Yuri [Pacific Northwest National Laboratory, Richland 99352, WA; Jana, Saumyadeep [Pacific Northwest National Laboratory, Richland 99352, WA; Fifield, Leonard S. [Pacific Northwest National Laboratory, Richland 99352, WA

    2016-10-03

    Development of a robust and cost-effective method of joining dissimilar materials could provide a critical pathway to enable widespread use of multi-material designs and components in mainstream industrial applications. The use of multi-material components such as steel-aluminum and aluminum-polymer would allow design engineers to optimize material utilization based on service requirements and could often lead to weight and cost reductions. However, producing an effective joint between materials with vastly different thermal, microstructural, and deformation responses is highly problematic using conventional joining and/or fastening methods. This is especially challenging in cost sensitive, high volume markets that largely rely on low cost joining solutions. Friction stir scribe technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like magnesium and aluminum to high temperature materials like steel and titanium. Viable joints between polymer composites and metal can also be made using this method. This paper will present the state of the art, progress made, and challenges associated with this innovative derivative of friction stir welding in reference to joining dissimilar metals and polymer/metal combinations.

  6. Effect of posture on the aerodynamic characteristics during take-off in ski jumping.

    Science.gov (United States)

    Yamamoto, Keizo; Tsubokura, Makoto; Ikeda, Jun; Onishi, Keiji; Baleriola, Sophie

    2016-11-07

    The purpose of this study was to investigate the effects of posture of a ski jumper on aerodynamic characteristics during the take-off using computational fluid dynamics (CFD). The CFD method adopted for this study was based on Large-Eddy Simulation. Body surface data were obtained by 3-D laser scanning of an active ski jumper. Based on video analysis of the actual take-off movement, two sets of motion data were generated (world-class jumper A and less-experienced jumper B). The inlet flow velocity that corresponds to the in-run velocity in actual ski jumping was set to 23.23m/s in the CFD. The aerodynamic force, flow velocity, and vortexes for each model were compared between models. The total drag force acting upon jumper A was lower than that acting upon jumper B through the whole movement. Regarding the total lift force, although jumper A׳s total lift force was less in the in-run posture, it became greater than that of jumper B at the end of the movement. In the latter half of the movement, low air-speed domain expansion was observed at the model׳s back. This domain of jumper B was larger. There were two symmetric vortexes in the wake of jumper A, but the disordered vortexes were observed behind the jumper B. In the case of jumper A, these two distinct vortexes generated by the arms produced a downwash flow in the wake. It is considered that the positioning of the arms in a very low position strongly influences the flow structure. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Determinants of day-night difference in blood pressure, a comparison with determinants of daytime and night-time blood pressure.

    Science.gov (United States)

    Musameh, M D; Nelson, C P; Gracey, J; Tobin, M; Tomaszewski, M; Samani, N J

    2017-01-01

    Blunted day-night difference in blood pressure (BP) is an independent cardiovascular risk factor, although there is limited information on determinants of diurnal variation in BP. We investigated determinants of day-night difference in systolic (SBP) and diastolic (DBP) BP and how these compared with determinants of daytime and night-time SBP and DBP. We analysed the association of mean daytime, mean night-time and mean day-night difference (defined as (mean daytime-mean night-time)/mean daytime) in SBP and DBP with clinical, lifestyle and biochemical parameters from 1562 adult individuals (mean age 38.6) from 509 nuclear families recruited in the GRAPHIC Study. We estimated the heritability of the various BP phenotypes. In multivariate analysis, there were significant associations of age, sex, markers of adiposity (body mass index and waist-hip ratio), plasma lipids (total and low-density lipoprotein cholesterol and triglycerides), serum uric acid, alcohol intake and current smoking status on daytime or night-time SBP and/or DBP. Of these, only age (P=4.7 × 10 -5 ), total cholesterol (P=0.002), plasma triglycerides (P=0.006) and current smoking (P=3.8 × 10 -9 ) associated with day-night difference in SBP, and age (P=0.001), plasma triglyceride (P=2.2 × 10 -5 ) and current smoking (3.8 × 10 -4 ) associated with day-night difference in DBP. 24-h, daytime and night-time SBP and DBP showed substantial heritability (ranging from 18-43%). In contrast day-night difference in SBP showed a lower heritability (13%) while heritability of day-night difference in DBP was not significant. These data suggest that specific clinical, lifestyle and biochemical factors contribute to inter-individual variation in daytime, night-time and day-night differences in SBP and DBP. Variation in day-night differences in BP is largely non-genetic.

  8. Determinants of day–night difference in blood pressure, a comparison with determinants of daytime and night-time blood pressure

    Science.gov (United States)

    Musameh, M D; Nelson, C P; Gracey, J; Tobin, M; Tomaszewski, M; Samani, N J

    2017-01-01

    Blunted day–night difference in blood pressure (BP) is an independent cardiovascular risk factor, although there is limited information on determinants of diurnal variation in BP. We investigated determinants of day–night difference in systolic (SBP) and diastolic (DBP) BP and how these compared with determinants of daytime and night-time SBP and DBP. We analysed the association of mean daytime, mean night-time and mean day–night difference (defined as (mean daytime−mean night-time)/mean daytime) in SBP and DBP with clinical, lifestyle and biochemical parameters from 1562 adult individuals (mean age 38.6) from 509 nuclear families recruited in the GRAPHIC Study. We estimated the heritability of the various BP phenotypes. In multivariate analysis, there were significant associations of age, sex, markers of adiposity (body mass index and waist–hip ratio), plasma lipids (total and low-density lipoprotein cholesterol and triglycerides), serum uric acid, alcohol intake and current smoking status on daytime or night-time SBP and/or DBP. Of these, only age (P=4.7 × 10−5), total cholesterol (P=0.002), plasma triglycerides (P=0.006) and current smoking (P=3.8 × 10−9) associated with day–night difference in SBP, and age (P=0.001), plasma triglyceride (P=2.2 × 10−5) and current smoking (3.8 × 10−4) associated with day–night difference in DBP. 24-h, daytime and night-time SBP and DBP showed substantial heritability (ranging from 18–43%). In contrast day–night difference in SBP showed a lower heritability (13%) while heritability of day–night difference in DBP was not significant. These data suggest that specific clinical, lifestyle and biochemical factors contribute to inter-individual variation in daytime, night-time and day–night differences in SBP and DBP. Variation in day–night differences in BP is largely non-genetic. PMID:26984683

  9. Joining of porous silicon carbide bodies

    Science.gov (United States)

    Bates, Carl H.; Couhig, John T.; Pelletier, Paul J.

    1990-05-01

    A method of joining two porous bodies of silicon carbide is disclosed. It entails utilizing an aqueous slip of a similar silicon carbide as was used to form the porous bodies, including the sintering aids, and a binder to initially join the porous bodies together. Then the composite structure is subjected to cold isostatic pressing to form a joint having good handling strength. Then the composite structure is subjected to pressureless sintering to form the final strong bond. Optionally, after the sintering the structure is subjected to hot isostatic pressing to further improve the joint and densify the structure. The result is a composite structure in which the joint is almost indistinguishable from the silicon carbide pieces which it joins.

  10. Efficient string similarity join in multi-core and distributed systems.

    Directory of Open Access Journals (Sweden)

    Cairong Yan

    Full Text Available In big data area a significant challenge about string similarity join is to find all similar pairs more efficiently. In this paper, we propose a parallel processing framework for efficient string similarity join. First, the input is split into some disjoint small subsets according to the joint frequency distribution and the interval distribution of strings. Then the filter-verification strategy is adopted in the computation of string similarity for each subset so that the number of candidate pairs is reduced before an effective pruning strategy is used to improve the performance. Finally, the operation of string join is executed in parallel. Para-Join algorithm based on the multi-threading technique is proposed to implement the framework in a multi-core system while Pada-Join algorithm based on Spark platform is proposed to implement the framework in a cluster system. We prove that Para-Join and Pada-Join cannot only avoid reduplicate computation but also ensure the completeness of the result. Experimental results show that Para-Join can achieve high efficiency and significantly outperform than state-of-the-art approaches, meanwhile, Pada-Join can work on large datasets.

  11. A Modeling Approach for Plastic-Metal Laser Direct Joining

    Science.gov (United States)

    Lutey, Adrian H. A.; Fortunato, Alessandro; Ascari, Alessandro; Romoli, Luca

    2017-09-01

    Laser processing has been identified as a feasible approach to direct joining of metal and plastic components without the need for adhesives or mechanical fasteners. The present work sees development of a modeling approach for conduction and transmission laser direct joining of these materials based on multi-layer optical propagation theory and numerical heat flow simulation. The scope of this methodology is to predict process outcomes based on the calculated joint interface and upper surface temperatures. Three representative cases are considered for model verification, including conduction joining of PBT and aluminum alloy, transmission joining of optically transparent PET and stainless steel, and transmission joining of semi-transparent PA 66 and stainless steel. Conduction direct laser joining experiments are performed on black PBT and 6082 anticorodal aluminum alloy, achieving shear loads of over 2000 N with specimens of 2 mm thickness and 25 mm width. Comparison with simulation results shows that consistently high strength is achieved where the peak interface temperature is above the plastic degradation temperature. Comparison of transmission joining simulations and published experimental results confirms these findings and highlights the influence of plastic layer optical absorption on process feasibility.

  12. The role of incline, performance level, and gender on the gross mechanical efficiency of roller ski skating

    Science.gov (United States)

    Sandbakk, Øyvind; Hegge, Ann Magdalen; Ettema, Gertjan

    2013-01-01

    The ability to efficiently utilize metabolic energy to produce work is a key factor for endurance performance. The present study investigated the effects of incline, performance level, and gender on the gross mechanical efficiency during roller ski skating. Thirty-one male and nineteen female elite cross-country skiers performed a 5-min submaximal session at approximately 75% of VO2peak on a 5% inclined treadmill using the G3 skating technique. Thereafter, a 5-min session on a 12% incline using the G2 skating technique was performed at a similar work rate. Gross efficiency was calculated as the external work rate against rolling friction and gravity divided by the metabolic rate using gas exchange. Performance level was determined by the amount of skating FIS points [the Federation of International Skiing (FIS) approved scoring system for ski racing] where fewer points indicate a higher performance level. Strong significant correlations between work rate and metabolic rate within both inclines and gender were revealed (r = −0.89 to 0.98 and P < 0.05 in all cases). Gross efficiency was higher at the steeper incline, both for men (17.1 ± 0.4 vs. 15.8 ± 0.5%, P < 0.05) and women (16.9 ± 0.5 vs. 15.7 ± 0.4%, P < 0.05), but without any gender differences being apparent. Significant correlations between gross efficiency and performance level were found for both inclines and genders (r = −0.65 to 0.81 and P < 0.05 in all cases). The current study demonstrated that cross-country skiers of both genders used less metabolic energy to perform the same amount of work at steeper inclines, and that the better ranked elite male and female skiers skied more efficiently. PMID:24155722

  13. Night Eating Disorders

    OpenAIRE

    Deniz Tuncel; Fatma Özlem Orhan

    2009-01-01

    Hunger is an awakening related biological impulse. The relationship between hunger and sleep is moderated by the control of homeostatic and circadian rhytms of the body. Abnormal eating behavior during sleep period could result from different causes. Abnormal eating during the main sleep period has been categorized as either night eating syndrome or sleep related eating disorder. Night eating syndrome (NES) is an eating disorder characterised by the clinical features of morning anorexia, even...

  14. Night shift work and modifiable lifestyle factors.

    Science.gov (United States)

    Pepłońska, Beata; Burdelak, Weronika; Krysicka, Jolanta; Bukowska, Agnieszka; Marcinkiewicz, Andrzej; Sobala, Wojciech; Klimecka-Muszyńska, Dorota; Rybacki, Marcin

    2014-10-01

    Night shift work has been linked to some chronic diseases. Modification of lifestyle by night work may partially contribute to the development of these diseases, nevertheless, so far epidemiological evidence is limited. The aim of the study was to explore association between night shift work and lifestyle factors using data from a cross-sectional study among blue-collar workers employed in industrial plants in Łódź, Poland. The anonymous questionnaire was self-administered among 605 employees (236 women and 369 men, aged 35 or more) - 434 individuals currently working night shifts. Distribution of the selected lifestyle related factors such as smoking, alcohol drinking, physical activity, body mass index (BMI), number of main meals and the hour of the last meal was compared between current, former, and never night shift workers. Adjusted ORs or predicted means were calculated, as a measure of the associations between night shift work and lifestyle factors, with age, marital status and education included in the models as covariates. Recreational inactivity (defined here as less than one hour per week of recreational physical activity) was associated with current night shift work when compared to never night shift workers (OR = 2.43, 95% CI: 1.13-5.22) among men. Alcohol abstinence and later time of the last meal was associated with night shift work among women. Statistically significant positive relationship between night shift work duration and BMI was observed among men (p = 0.029). This study confirms previous studies reporting lower exercising among night shift workers and tendency to increase body weight. This finding provides important public health implication for the prevention of chronic diseases among night shift workers. Initiatives promoting physical activity addressed in particular to the night shift workers are recommended.

  15. Night shift work and modifiable lifestyle factors

    Directory of Open Access Journals (Sweden)

    Beata Pepłońska

    2014-10-01

    Full Text Available Objectives: Night shift work has been linked to some chronic diseases. Modification of lifestyle by night work may partially contribute to the development of these diseases, nevertheless, so far epidemiological evidence is limited. The aim of the study was to explore association between night shift work and lifestyle factors using data from a cross-sectional study among blue-collar workers employed in industrial plants in Łódź, Poland. Material and Methods: The anonymous questionnaire was self-administered among 605 employees (236 women and 369 men, aged 35 or more - 434 individuals currently wor­king night shifts. Distribution of the selected lifestyle related factors such as smoking, alcohol drinking, physical activity, body mass index (BMI, number of main meals and the hour of the last meal was compared between current, former, and never night shift workers. Adjusted ORs or predicted means were calculated, as a measure of the associations between night shift work and lifestyle factors, with age, marital status and education included in the models as covariates. Results: Recreational inactivity (defined here as less than one hour per week of recreational physical activity was associated with current night shift work when compared to never night shift workers (OR = 2.43, 95% CI: 1.13-5.22 among men. Alcohol abstinence and later time of the last meal was associated with night shift work among women. Statistically significant positive relationship between night shift work duration and BMI was observed among men (p = 0.029. Conclusions: This study confirms previous studies reporting lower exercising among night shift workers and tendency to increase body weight. This finding provides important public health implication for the prevention of chronic diseases among night shift workers. Initiatives promoting physical activity addressed in particular to the night shift workers are recommended.

  16. QuickJoin—Fast Neighbour-Joining Tree Reconstruction

    DEFF Research Database (Denmark)

    Mailund; Pedersen, Christian N. Storm

    2004-01-01

    We have built a tool for fast construction of very large phylogenetic trees. The tool uses heuristics for speeding up the neighbour-joining algorithm—while still constructing the same tree as the original neighbour-joining algorithm—making it possible to construct trees for ~8000 species in less...

  17. Fermilab Friends for Science Education | Join Us

    Science.gov (United States)

    Fermilab Friends for Science Education FFSE Home About Us Join Us Support Us Contact Us Join Us improving science (science, technology, engineering and mathematics) education. Your donation allows us to membership dues allow us to create new, innovative science education programs, making the best use of unique

  18. Potentials of Industrie 4.0 and Machine Learning for Mechanical Joining

    OpenAIRE

    Jäckel, Mathias

    2017-01-01

    -Sensitivity analysis of the influence of component properties and joining parameters on the joining result for self-pierce riveting -Possibilities to link mechanical joining technologies with the automotive process chain for quality and flexibility improvements -Potential of using machine learning to reduce automotive product development cycles in relation to mechanical joining -Datamining for machine learning at mechanical joining

  19. Determination of the centre of mass kinematics in alpine skiing using differential global navigation satellite systems.

    Science.gov (United States)

    Gilgien, Matthias; Spörri, Jörg; Chardonnens, Julien; Kröll, Josef; Limpach, Philippe; Müller, Erich

    2015-01-01

    In the sport of alpine skiing, knowledge about the centre of mass (CoM) kinematics (i.e. position, velocity and acceleration) is essential to better understand both performance and injury. This study proposes a global navigation satellite system (GNSS)-based method to measure CoM kinematics without restriction of capture volume and with reasonable set-up and processing requirements. It combines the GNSS antenna position, terrain data and the accelerations acting on the skier in order to approximate the CoM location, velocity and acceleration. The validity of the method was assessed against a reference system (video-based 3D kinematics) over 12 turn cycles on a giant slalom skiing course. The mean (± s) position, velocity and acceleration differences between the CoM obtained from the GNSS and the reference system were 9 ± 12 cm, 0.08 ± 0.19 m · s(-1) and 0.22 ± 1.28 m · s(-2), respectively. The velocity and acceleration differences obtained were smaller than typical differences between the measures of several skiers on the same course observed in the literature, while the position differences were slightly larger than its discriminative meaningful change. The proposed method can therefore be interpreted to be technically valid and adequate for a variety of biomechanical research questions in the field of alpine skiing with certain limitations regarding position.

  20. Straight into the Eyes - Jacek Łumiński and the Silesian Dance Theatre (1991-2011

    Directory of Open Access Journals (Sweden)

    Alicja Iwańska

    2012-06-01

    Full Text Available The final decade of the 20th century was the turning-point for the development of Polish contemporary dance. In 1991 Jacek Łumiński established the Silesian Dance Theatre in Bytom. The theatre is said to be in the avant-garde of all activities related to contemporary dance development in Poland. It was J. Łumiński and his theatre who pioneered new trends in contemporary dance at the beginning of the nineties of the 20th century, at the same time they have conducted educational activity over the intervening twenty years. The aim of this article is to present the artistic and educational activity of the Silesian Dance Theatre of the recent twenty years. In the beginning the author presents a choreographic portrait of J. Łumiński, the founder and choreographer of the Silesian Dance Theatre, and creator of the Polish contemporary dance technique. Then an analysis of J. Łumiński’s dance style is carried out, and the review of the Silesian Dance Theatre’s choreographic attainments is presented. The final part of the article discusses the wide spectrum of educational activities undertaken in the field of contemporary professional dance by the Silesian Dance Theatre, and the phenomenon of the theatre on the Polish stage.

  1. Night and day in the VA: associations between night shift staffing, nurse workforce characteristics, and length of stay.

    Science.gov (United States)

    de Cordova, Pamela B; Phibbs, Ciaran S; Schmitt, Susan K; Stone, Patricia W

    2014-04-01

    In hospitals, nurses provide patient care around the clock, but the impact of night staff characteristics on patient outcomes is not well understood. The aim of this study was to examine the association between night nurse staffing and workforce characteristics and the length of stay (LOS) in 138 veterans affairs (VA) hospitals using panel data from 2002 through 2006. Staffing in hours per patient day was higher during the day than at night. The day nurse workforce had more educational preparation than the night workforce. Nurses' years of experience at the unit, facility, and VA level were greater at night. In multivariable analyses controlling for confounding variables, higher night staffing and a higher skill mix were associated with reduced LOS. © 2014 Wiley Periodicals, Inc.

  2. Human subtilase SKI-1/S1P is a master regulator of the HCV Lifecycle and a potential host cell target for developing indirect-acting antiviral agents.

    Directory of Open Access Journals (Sweden)

    Andrea D Olmstead

    2012-01-01

    Full Text Available HCV infection is a major risk factor for liver cancer and liver transplantation worldwide. Overstimulation of host lipid metabolism in the liver by HCV-encoded proteins during viral infection creates a favorable environment for virus propagation and pathogenesis. In this study, we hypothesize that targeting cellular enzymes acting as master regulators of lipid homeostasis could represent a powerful approach to developing a novel class of broad-spectrum antivirals against infection associated with human Flaviviridae viruses such as hepatitis C virus (HCV, whose assembly and pathogenesis depend on interaction with lipid droplets (LDs. One such master regulator of cholesterol metabolic pathways is the host subtilisin/kexin-isozyme-1 (SKI-1--or site-1 protease (S1P. SKI-1/S1P plays a critical role in the proteolytic activation of sterol regulatory element binding proteins (SREBPs, which control expression of the key enzymes of cholesterol and fatty-acid biosynthesis. Here we report the development of a SKI-1/S1P-specific protein-based inhibitor and its application to blocking the SREBP signaling cascade. We demonstrate that SKI-1/S1P inhibition effectively blocks HCV from establishing infection in hepatoma cells. The inhibitory mechanism is associated with a dramatic reduction in the abundance of neutral lipids, LDs, and the LD marker: adipose differentiation-related protein (ADRP/perilipin 2. Reduction of LD formation inhibits virus assembly from infected cells. Importantly, we confirm that SKI-1/S1P is a key host factor for HCV infection by using a specific active, site-directed, small-molecule inhibitor of SKI-1/S1P: PF-429242. Our studies identify SKI-1/S1P as both a novel regulator of the HCV lifecycle and as a potential host-directed therapeutic target against HCV infection and liver steatosis. With identification of an increasing number of human viruses that use host LDs for infection, our results suggest that SKI-1/S1P inhibitors may allow

  3. Serious ski jumping injuries in Norway.

    Science.gov (United States)

    Wester, K

    1985-01-01

    Injuries caused by ski jumping have been poorly investigated. Among approximately 2,200 licensed jumpers in Norway, there occurred at least 12 injuries with a permanent medical disability of greater than or equal to 10%. The risk of being seriously injured is approximately 5% in a 5 year period (1977 to 1981); it is higher in the age group 15 to 17 years. Seven injuries were very serious [four central nervous system (CNS) lesions, two leg amputations, and one blindness of one eye], and five were less serious (sequelae to fractures of the lower extremities). The first jump of the day is particularly dangerous, and so is the beginning and end of the season. It seems dangerous to use more than one standard heel block. Poor preparation of the jump may have contributed to the accidents. Based on the findings, several prophylactic measures are suggested.

  4. Evaluation of the anaerobic ability of alpine skiing skiers through the slalom simulator

    Directory of Open Access Journals (Sweden)

    Vasilios Giovanis

    2017-10-01

    Full Text Available Purpose: The purpose of the research was the evaluation of efficiency of anaerobic ability (power, anaerobic endurance, anaerobic fatigue and the restitution of the pulse rate of alpine skiing students through the slalom simulator. In addition, the aim of the research was the correlation of the special tests of alpine skiing on dry ground (octagon test and in snow (triangle test and slalom test with the target of determining ability levels. Methods: The 20 people sample was composed by two teams of male and female who took the course for advanced (n = 7 aged 23±1.40 years and for beginners course (n = 13 aged 20±1.49 years. For the evaluation process two special tests were used, on the ground and in snow. The ground test was completed in the slalom simulator for 40 seconds. The second ground test was the octagon bouncing (40cm each side x 3. The snow test was the Haczkiewicz test (triangle test and the slalom (7 gates, where the time of a try was measured. Results: The best efficiency in anaerobic power was made by the advanced males and females, while in the anaerobic endurance by the beginners males and females. The best performance in the dexterity tests in snow on the triangle and slalom test was made by the advanced males and beginners females respectively. Conclusions: The significant correlation between the results of anaerobic performance in the slalom simulator and the triangle test in snow confirms the means of diagnosing skill and fitness on dry ground and snow respectively. There is a significant correlation between snow test results and there is no correlation with the octagon test. The aforementioned results can be used in the talent selection process of alpine skiing.

  5. SKI Project-90: Chemical data

    International Nuclear Information System (INIS)

    Andersson, Karin

    1988-11-01

    In this report a set of parameter values for transport calculations is given for the safety assessment of a deep geological repository in crystalline rock. The selected data are intended for use in the performance assessment exercise of SKI, Project 90. Thus, they are primarily to be used for testing of transport models and evaluation of model performance, and the listed data must not be regarded as a set recommended for licensing purposes. 'Best estimates' are given for solubilities and sorption (distribution) data. Ranges of data are also provided that should be used to evaluate, e.g. by means of variational analysis, the need for more efforts in areas such as site characterization, geochemical modelling or review of thermodynamical data bases. Since the Project 90 performance assessment calculations are based on a synthetic site, without the possibility of correlation of hydraulic and geochemical parameters, the data given are generic for a typical Swedish crystalline rock. This also means that the ranges given are much broader than would be the case for a data set founded on site specific information (40 refs.) (au)

  6. New Joining Technology for Optimized Metal/Composite Assemblies

    Directory of Open Access Journals (Sweden)

    Holger Seidlitz

    2014-01-01

    Full Text Available The development of a new joining technology, which is used to manufacture high strength hybrid constructions with thermoplastic composites (FRP and metals, is introduced. Similar to natural regulation effects at trees, fibers around the FRP joint become aligned along the lines of force and will not be destroyed by the joining process. This is achieved by the local utilization of the specific plastic flow properties of the FRT and metal component. Compared with usual joining methods—such as flow drill screws, blind and self-piercing rivets—noticeably higher tensile properties can be realized through the novel process management. The load-bearing capability increasing effect could be proved on hybrid joints with hot-dip galvanized steel HX420LAD and orthotropic glass—as well as carbon—fiber reinforced plastics. The results, which were determined in tensile-shear and cross-shear tests according to DIN EN ISO 14273 and DIN EN ISO 14272, are compared with holding loads of established joining techniques with similar joining point diameter and material combinations.

  7. Oxidative DNA damage during night shift work.

    Science.gov (United States)

    Bhatti, Parveen; Mirick, Dana K; Randolph, Timothy W; Gong, Jicheng; Buchanan, Diana Taibi; Zhang, Junfeng Jim; Davis, Scott

    2017-09-01

    We previously reported that compared with night sleep, day sleep among shift workers was associated with reduced urinary excretion of 8-hydroxydeoxyguanosine (8-OH-dG), potentially reflecting a reduced ability to repair 8-OH-dG lesions in DNA. We identified the absence of melatonin during day sleep as the likely causative factor. We now investigate whether night work is also associated with reduced urinary excretion of 8-OH-dG. For this cross-sectional study, 50 shift workers with the largest negative differences in night work versus night sleep circulating melatonin levels (measured as 6-sulfatoxymelatonin in urine) were selected from among the 223 shift workers included in our previous study. 8-OH-dG concentrations were measured in stored urine samples using high performance liquid chromatography with electrochemical detection. Mixed effects models were used to compare night work versus night sleep 8-OH-dG levels. Circulating melatonin levels during night work (mean=17.1 ng/mg creatinine/mg creatinine) were much lower than during night sleep (mean=51.7 ng/mg creatinine). In adjusted analyses, average urinary 8-OH-dG levels during the night work period were only 20% of those observed during the night sleep period (95% CI 10% to 30%; psleep, is associated with reduced repair of 8-OH-dG lesions in DNA and that the effect is likely driven by melatonin suppression occurring during night work relative to night sleep. If confirmed, future studies should evaluate melatonin supplementation as a means to restore oxidative DNA damage repair capacity among shift workers. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Simulating the potential effects of climate change in two Colorado basins and at two Colorado ski areas

    Science.gov (United States)

    Battaglin, William; Hay, Lauren E.; Markstrom, Steve

    2011-01-01

    The mountainous areas of Colorado are used for tourism and recreation, and they provide water storage and supply for municipalities, industries, and agriculture. Recent studies suggest that water supply and tourist industries such as skiing are at risk from climate change. In this study, a distributed-parameter watershed model, the Precipitation-Runoff Modeling System (PRMS), is used to identify the potential effects of future climate on hydrologic conditions for two Colorado basins, the East River at Almont and the Yampa River at Steamboat Springs, and at the subbasin scale for two ski areas within those basins.Climate-change input files for PRMS were generated by modifying daily PRMS precipitation and temperature inputs with mean monthly climate-change fields of precipitation and temperature derived from five general circulation model (GCM) simulations using one current and three future carbon emission scenarios. All GCM simulations of mean daily minimum and maximum air temperature for the East and Yampa River basins indicate a relatively steady increase of up to several degrees Celsius from baseline conditions by 2094. GCM simulations of precipitation in the two basins indicate little change or trend in precipitation, but there is a large range associated with these projections. PRMS projections of basin mean daily streamflow vary by scenario but indicate a central tendency toward slight decreases, with a large range associated with these projections.Decreases in water content or changes in the spatial extent of snowpack in the East and Yampa River basins are important because of potential adverse effects on water supply and recreational activities. PRMS projections of each future scenario indicate a central tendency for decreases in basin mean snow-covered area and snowpack water equivalent, with the range in the projected decreases increasing with time. However, when examined on a monthly basis, the projected decreases are most dramatic during fall and spring

  9. Microwave joining of SiC ceramics and composites

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Silberglitt, R.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States); Katz, J.D. [Los Alamos National Lab., NM (United States)

    1997-04-01

    Potential applications of SiC include components for advanced turbine engines, tube assemblies for radiant burners and petrochemical processing and heat exchangers for high efficiency electric power generation systems. Reliable methods for joining SiC are required in order to cost-effectively fabricate components for these applications from commercially available shapes and sizes. This manuscript reports the results of microwave joining experiments performed using two different types of SiC materials. The first were on reaction bonded SiC, and produced joints with fracture toughness equal to or greater than that of the base material over an extended range of joining temperatures. The second were on continuous fiber-reinforced SiC/SiC composite materials, which were successfully joined with a commercial active brazing alloy, as well as by using a polymer precursor.

  10. Enabling Dissimilar Material Joining Using Friction Stir Scribe Technology

    Energy Technology Data Exchange (ETDEWEB)

    Hovanski, Yuri; Upadyay, Piyush; Kleinbaum, Sarah; Carlson, Blair; Boettcher, Eric; Ruokolainen, Robert

    2017-04-05

    One challenge in adapting welding processes to dissimilar material joining is the diversity of melting temperatures of the different materials. Although the use of mechanical fasteners and adhesives have mostly paved the way for near-term implementation of dissimilar material systems, these processes only accentuate the need for low-cost welding processes capable of joining dissimilar material components regardless of alloy, properties, or melting temperature. Friction stir scribe technology was developed to overcome the challenges of joining dissimilar material components where melting temperatures vary greatly, and properties and/or chemistry are not compatible with more traditional welding processes. Although the friction stir scribe process is capable of joining dissimilar metals and metal/polymer systems, a more detailed evaluation of several aluminum/steel joints is presented herein to demonstrate the ability to both chemically and mechanically join dissimilar materials.

  11. Aerodynamics of ski jumping: experiments and CFD simulations

    Energy Technology Data Exchange (ETDEWEB)

    Meile, W.; Reisenberger, E.; Brenn, G. [Graz University of Technology, Institute of Fluid Mechanics and Heat Transfer, Graz (Austria); Mayer, M. [VRVis GmbH, Vienna (Austria); Schmoelzer, B.; Mueller, W. [Medical University of Graz, Department for Biophysics, Graz (Austria)

    2006-12-15

    The aerodynamic behaviour of a model ski jumper is investigated experimentally at full-scale Reynolds numbers and computationally applying a standard RANS code. In particular we focus on the influence of different postures on aerodynamic forces in a wide range of angles of attack. The experimental results proved to be in good agreement with full-scale measurements with athletes in much larger wind tunnels, and form a reliable basis for further predictions of the effects of position changes on the performance. The comparison of CFD results with the experiments shows poor agreement, but enables a clear outline of simulation potentials and limits when accurate predictions of effects from small variations are required. (orig.)

  12. Aerodynamics of ski jumping: experiments and CFD simulations

    Science.gov (United States)

    Meile, W.; Reisenberger, E.; Mayer, M.; Schmölzer, B.; Müller, W.; Brenn, G.

    2006-12-01

    The aerodynamic behaviour of a model ski jumper is investigated experimentally at full-scale Reynolds numbers and computationally applying a standard RANS code. In particular we focus on the influence of different postures on aerodynamic forces in a wide range of angles of attack. The experimental results proved to be in good agreement with full-scale measurements with athletes in much larger wind tunnels, and form a reliable basis for further predictions of the effects of position changes on the performance. The comparison of CFD results with the experiments shows poor agreement, but enables a clear outline of simulation potentials and limits when accurate predictions of effects from small variations are required.

  13. Pedagogical aspects of effective use of simulator "Straps with ring" during the formation motor skills of pupils of 10 classes during the skiing training in the lessons of physical culture

    Directory of Open Access Journals (Sweden)

    M.G. Lazarenko

    2014-12-01

    Full Text Available Purpose : to develop a system of ski training exercises using a functional simulator at physical training lessons. Material : The study took 90 young men attended 10 class. To determine the level of formation of motor skills of pupils were tested on 7 indicators: skiing skating style 5 km; skiing classic style 3 km; pulling up on the bar; long jump with space, running 60 meters, running 3 miles, 4x9 meters shuttle run. A year after the first experiment was conducted a second experiment. Results : The developed and adapted to the physical education class simulator exercises which compounded the gravity load and moving straps with rings. The test results confirmed that the proposed method makes it possible to more effectively shape the motor skills of pupils in the process of ski training at physical training lessons. Conclusions : It is recommended to the lessons of physical training on use of ski training complex of 22 exercises that will most effectively influence the formation of motor skills of pupils.

  14. Water demand for ski resort development in the Austrian Alps: an Overview

    Science.gov (United States)

    Breiling, M.; Sokratov, S.

    2012-04-01

    Austria has the highest national added value from winter tourism in Europe, as well as worldwide. 15.7 million arrivals were counted in Austrian accommodation establishments in the 2010/11 winter season. There were more than 62 million overnight stays and 51.2 million skier-days were consumed. 588 million transports were carried out by more than 3000 lifts (cable cars, chair lifts and T-bars). Including indirect and induced effects, this resulted in more than 10 billion euros in added value being generated. The lack of snow in many Austrian skiing areas during the 2006/2007 winter season demonstrated the extent to which meteorological conditions influence operations. Declines in the number of skiers transported and total skier days were the result. The cable-car operators also had to struggle with little snow in the 2010/2011 winter. The Austrian Cable Car Operators' Association stated that the opening of 70-80% of all skiing areas outside of the peak season could only be assured through the use of snowmaking equipment. The central criterion for winter sports enthusiasts to make a trip is the guarantee that they will find snow at their destination and Austria's cable-car operators invest more than 100 million euros in the erection and improvement of snowmaking complexes every year to satisfy this deand. In the 2010/2011 season, this provided for 17,800 jobs. Cable car operators set up snowmaking equipment to become independent from meteorological conditions and improve the capacity utilisation of their expensive investments in transport systems in the early winter. Austria has a skiing area of around 25,400 hectares - around 17,000 hectares at altitudes between 600m and 3200m are currently suitable for snowmaking. As much as 70% of the snow is produced immediately before the start of the season. This recent trend is responsible that the irrigation pattern of Austrian land use changed significantly in the last decade. Previously maize fields and low lands in summer

  15. Organization and management of ATLAS nightly builds

    International Nuclear Information System (INIS)

    Luehring, F; Obreshkov, E; Quarrie, D; Rybkine, G; Undrus, A

    2010-01-01

    The automated multi-platform software nightly build system is a major component in the ATLAS collaborative software organization, validation and code approval schemes. Code developers from ATLAS participating Institutes spread all around the world use about 30 branches of nightly releases for testing new packages, verification of patches to existing software, and migration to new platforms and compilers. The nightly releases lead up to, and are the basis of, stable software releases used for data processing worldwide. The ATLAS nightly builds are managed by the fully automated NICOS framework on the computing farm with 44 powerful multiprocessor nodes. The ATN test tool is embedded within the nightly system and provides results shortly after full compilations complete. Other test frameworks are synchronized with NICOS jobs and run larger scale validation jobs using the nightly releases. NICOS web pages dynamically provide information about the progress and results of the builds. For faster feedback, E-mail notifications about nightly releases problems are automatically distributed to the developers responsible.

  16. Network brand management : study of competencies of place branding ski destinations

    OpenAIRE

    Moilanen, Teemu

    2008-01-01

    Several industries have turned to a network form of organization to coordinate complex products or services in uncertain and competitive environments, and the network form of organization also appears to be becoming more common in the field of branding. Examples of brands formed by a network of independent firms include One-World and Star Alliance brands in the airline industry, Verbier and Chamonix ski destination brands in tourism industry and the Santa Foods brand in food production. Many ...

  17. On the Complexity of Inner Product Similarity Join

    DEFF Research Database (Denmark)

    Ahle, Thomas Dybdahl; Pagh, Rasmus; Razenshteyn, Ilya

    2016-01-01

    A number of tasks in classification, information retrieval, recommendation systems, and record linkage reduce to the core problem of inner product similarity join (IPS join): identifying pairs of vectors in a collection that have a sufficiently large inner product. IPS join is well understood when...... bounds for (A)LSH-based algorithms. In particular, we show that asymmetry can be avoided by relaxing the LSH definition to only consider the collision probability of distinct elements. A new indexing method for IPS based on linear sketches, implying that our hardness results are not far from being tight...

  18. Assignment of the porcine SKI and GABRD genes to chromosome 6q22-q23

    Czech Academy of Sciences Publication Activity Database

    Stratil, Antonín; Knorr, C.; Knoll, Aleš; Kubíčková, S.; Musilová, P.; Van Poucke, M.; Rubeš, J.; Brenig, B.; Peelman, L. J.

    2005-01-01

    Roč. 36, - (2005), s. 272-273 ISSN 0268-9146 R&D Projects: GA ČR GA523/03/0858 Institutional research plan: CEZ:AV0Z50450515 Keywords : SKI gene * GABRD gene Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.437, year: 2005

  19. Associations between number of consecutive night shifts and impairment of neurobehavioral performance during a subsequent simulated night shift.

    Science.gov (United States)

    Magee, Michelle; Sletten, Tracey L; Ferguson, Sally A; Grunstein, Ronald R; Anderson, Clare; Kennaway, David J; Lockley, Steven W; Rajaratnam, Shantha Mw

    2016-05-01

    This study aimed to investigate sleep and circadian phase in the relationships between neurobehavioral performance and the number of consecutive shifts worked. Thirty-four shift workers [20 men, mean age 31.8 (SD 10.9) years] worked 2-7 consecutive night shifts immediately prior to a laboratory-based, simulated night shift. For 7 days prior, participants worked their usual shift sequence, and sleep was assessed with logs and actigraphy. Participants completed a 10-minute auditory psychomotor vigilance task (PVT) at the start (~21:00 hours) and end (~07:00 hours) of the simulated night shift. Mean reaction times (RT), number of lapses and RT distribution was compared between those who worked 2-3 consecutive night shifts versus those who worked 4-7 shifts. Following 4-7 shifts, night shift workers had significantly longer mean RT at the start and end of shift, compared to those who worked 2-3 shifts. The slowest and fastest 10% RT were significantly slower at the start, but not end, of shift among participants who worked 4-7 nights. Those working 4-7 nights also demonstrated a broader RT distribution at the start and end of shift and had significantly slower RT based on cumulative distribution analysis (5 (th), 25 (th), 50 (th), 75 (th)percentiles at the start of shift; 75th percentile at the end of shift). No group differences in sleep parameters were found for 7 days and 24 hours prior to the simulated night shift. A greater number of consecutive night shifts has a negative impact on neurobehavioral performance, likely due to cognitive slowing.

  20. Effects of processing parameters on Be/CuCrZr joining

    International Nuclear Information System (INIS)

    Park, Jeong-Yong; Lee, Jung-Suk; Choi, Byung-Kwon; Park, Sang-Yun; Hong, Bong Guen; Jeong, Yong Hwan; Jung, Ki-Jung

    2007-01-01

    A joining of Be/CuCrZr has been considered as the key technology for the fabrication of the ITER first wall. Among the joining methods, Hot isostatic pressing (HIP), which is one of the diffusion bonding methods, is the most feasible method to join the Be and CuCrZr alloy. In the HIP joining of Be and CuCrZr, the interlayer was used to prevent the formation of brittle intermetallic compounds in the interface. Therefore, it is crucial to select a suitable interlayer for a joining of Be and CuCrZr. On the other hand, the diffusion between Be and CuCrZr would be enhanced with an increase of the HIP joining temperature, thereby increasing the joint strength. However, the HIP joining temperature is limited by the mechanical properties of CuCrZr. During the fabrication process of the ITER first wall, CuCrZr is subjected to several thermal cycles including a solution annealing, a cooling and an aging. The HIP joining of Be and CuCrZr corresponds to the aging of CuCrZr. The HIP joining at a higher temperature would cause a degradation of the mechanical properties of CuCrZr by an overaging effect although it is preferable for an improvement of the joint strength. In this study, the effect of the cooling rate on the mechanical properties of aged CuCrZr was investigated to find the maximum HIP temperature without a degradation of the mechanical properties of CuCrZr

  1. AHP 47: A NIGHT DATE

    Directory of Open Access Journals (Sweden)

    Phun tshogs dbang rgyal ཕུན་ཚོགས་དབང་རྒྱལ།

    2017-04-01

    Full Text Available The author was born in 1993 in Ska chung (Gaqun Village, Nyin mtha' (Ningmute Township, Rma lho (Henan Mongolian Autonomous County, Rma lho (Huangnan Tibetan Autonomous Prefecture, Mtsho sngon (Qinghai Province, PR China. Night dating was popular for teenage boys some years ago. They rode horses and yaks when they went night dating. They generally rode yaks, because horses were important for their families and used for such important tasks as pursuing bandits and going to the county town for grain and supplies. An early experience with night dating is described.

  2. Effects of a 12-week alpine skiing intervention on endothelial progenitor cells, peripheral arterial tone and endothelial biomarkers in the elderly

    DEFF Research Database (Denmark)

    Niederseer, David; Steidle-Kloc, Eva; Mayr, Matthias

    2016-01-01

    : +0.18±0.76) and CG (-0.39±0.85; p=0.045), as did homocysteine (IG: -1.3±1.3μmol/l; CG: -0.4±1.4μmol/l; p=0.037) while other endothelial biomarkers remained essentially unchanged. CONCLUSIONS: This study shows that skiing induces several beneficial effects on markers of atherogenesis including EPCs......, peripheral arterial tone and homocysteine. Our findings suggest that recreational alpine skiing may serve as a further mode of preventive exercise training, which might result in improved compliance with current recommendations....

  3. Concept of Operating Indoor Skiing Halls with

    DEFF Research Database (Denmark)

    Paul, Joachim

    2003-01-01

    Indoor skiing halls are conventionally operated at low temperatures and with either crushed ice as snow substitute or snow made from freezing water in cold air. Both systems have a high energy demand for air cooling, floor freezing and consequently snow harvest. At the same time the snow at the top...... floor cooling/freezing and insulation become obsolete, significant savings in piping and building costs can be achieved. Due to the much higher evaporating temperature for the refrigeration system, the energy demand is kept low. Since the same equipment is used for both snowmaking and air cooling......, the running time of the equipment is high, resulting in a better economy. Using Binary Snow, with its unique qualities such as fluffy, crisp, white and ¿ since made daily ¿ "fresh and hygienic", offers great advantages in operating costs, investment costs and quality....

  4. Discover POPSCIENCE on Researchers' Night

    CERN Multimedia

    The POPSCIENCE Team

    2014-01-01

    On Friday 26 September 2014, CERN will be celebrating European Researchers' Night at three venues in Geneva and St. Genis-Pouilly. Inspired by Andy Warhol, this year's theme is “Pop science is for everyone”.     Every year, on the last Friday of September, the European Researchers’ Night takes place in about 300 cities all over Europe, with funding from the EU, to promote research and highlight researchers in engaging and fun ways for the general public. Andy Warhol said, “Pop art is for everyone”. This year, “Pop science is for everyone” is the motto of the Researchers’ Night event organised by CERN and its partners*. The night will offer everyone the opportunity to learn about the latest discoveries in physics and cosmology through poetry, theatre and music. This will be in addition to the event's traditional activities for the general public. To attract new audiences,...

  5. Joining of Gamma Titanium Aluminides

    National Research Council Canada - National Science Library

    Baeslack, William

    2002-01-01

    .... Although organized and presented by joining process, many of the observations made and relationships developed, particularly those regarding the weldability and welding metallurgy of gamma titanium...

  6. Jumping for recognition: Women's ski jumping viewed as a struggle for rights.

    Science.gov (United States)

    Andersen, W; Loland, S

    2017-03-01

    With the campaign for women's participation in international and Olympic ski jumping as a practical case, sport's potential for recognition of individual rights is explored. In line with Honneth's influential ethical theory, recognition of rights refers to a mutual recognition between persons of each other as rational and responsible agents with an equal right to take part in the public formation and development of their community or practice. The argument is that women ski jumpers were entitled to compete as they had actual and/or potential capabilities and skills to contribute in the public formation and development of their sport. Their exclusion was a violation of individual rights. At a more general level, sport is discussed as a sphere for recognition of rights. It is argued that the basic principles of equal opportunity to take part and to perform make sport a particularly clear and potent sphere for such recognition, and also for the identification of rights violations. In sport, rights, or the violation of rights, are demonstrated in concrete and embodied ways. It is concluded that struggles for recognition and individual rights are a continuous process in sport as in most other human institutions and practices. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. [Early prenatal diagnosis of diprosopic syncephalic joined twins].

    Science.gov (United States)

    Picaud, A; Nlome-Nze, A R; Engongha-Beka, T; Ogowet-Igumu, N

    1990-06-01

    The authors summarize the case of diprosopic syncephalic joined twins diagnosed at 22 weeks of pregnancy by ultrasonography performed because of hydramnios. The rate of separation anomalies of monozygotic twins is assessed by a review of the literature: from 1 to twenty to fifty thousands for joined twins to 1 per cent fifty thousand to fifteen millions for diprosopus. The etiology is the result of a late division of the egg between D12 and D16. Often an encephalic diprosopic joined twins cause elevated levels of maternal serum alpha protein. Early ultrasonography permits to consider a vaginal therapeutic abortion.

  8. A contribution to the knowledge of the species Rafalskia olympica (Kulczyński, 1903

    Directory of Open Access Journals (Sweden)

    Karaman, Ivo M.

    2002-10-01

    Full Text Available Balkan populations of Rafalskia olympica (Kulczyński, 1903 are distinguished as separate subspecies Rafalskia olympica bulgarica Staręga, 1963 nov. stat.. Certain novel details of the R. olympica female body structure are presented. It is stated that Metaplatybunus drenskii Šilhavý, 1965 in not a synonym of R. olympica.

  9. Alpine Skiing With total knee ArthroPlasty (ASWAP)

    DEFF Research Database (Denmark)

    Narici, Marco; Conte, M; Salvioli, Stefano

    2015-01-01

    This study investigated features of skeletal muscle ageing in elderly individuals having previously undergone unilateral total knee arthroplasty (TKA) and whether markers of sarcopenia could be mitigated by a 12-week alpine skiing intervention. Novel biomarkers agrin, indicative of neuromuscular...... junction (NMJ) degeneration, tumor suppressor protein p53, associated with muscle atrophy, and a new ultrasound-based muscle architecture biomarker were used to characterize sarcopenia. Participant details and study design are presented by Kösters et al. (2015). The results of this study show that NMJ...... degeneration is widespread among active septuagenarians previously subjected to TKA: all participants showed elevated agrin levels upon recruitment. At least 50% of individuals were identified as sarcopenic based on their muscle architecture, supporting the hypothesis that NMJ alterations precede sarcopenia...

  10. Traffic Light Detection at Night

    DEFF Research Database (Denmark)

    Jensen, Morten Bornø; Philipsen, Mark Philip; Bahnsen, Chris

    2015-01-01

    Traffic light recognition (TLR) is an integral part of any in- telligent vehicle, it must function both at day and at night. However, the majority of TLR research is focused on day-time scenarios. In this paper we will focus on detection of traffic lights at night and evalu- ate the performance...... of three detectors based on heuristic models and one learning-based detector. Evaluation is done on night-time data from the public LISA Traffic Light Dataset. The learning-based detector out- performs the model-based detectors in both precision and recall. The learning-based detector achieves an average...

  11. Joining NbTi superconductors by ultrasonic welding

    International Nuclear Information System (INIS)

    Hafstrom, J.W.; Killpatrick, D.H.; Niemann, R.C.; Purcell, J.R.; Thresh, H.R.

    1976-01-01

    An important consideration in the design and construction of large, high-field, superconducting magnets is the capability to fabricate reliable, high-strength, low-resistance joints. A process for joining NbTi, copper stabilized, superconducting composites by ultrasonic welding is described. This process yields a joint strength comparable to that of the superconducting composite and a resistivity significantly lower than achieved by conventional soft soldering. The superconducting properties of the composite are not affected by the joining process. Scarfing the joint to maintain a constant conductor cross section does not degrade its electrical or mechanical properties. The application of the ultrasonic joining process, including process control, scarfing, and NDT procedures, in the construction of the superconducting magnet (U.S. SCMS) for the joint U. S. -- Soviet MHD program is described

  12. The systemic roles of SKI and SSI in the Swedish nuclear waste management system. Syncho's report for project RISCOM

    International Nuclear Information System (INIS)

    Espejo, R.; Gill, A.

    1998-01-01

    The purpose of this report is to share and summarize our findings about the regulatory roles of SKI/SSI in the context of the Swedish Nuclear System (SNS), with an emphasis on nuclear waste management. The driving force in this review is to make decision processes more transparent. What is reported is based on interviews conducted with employees at SKI/SSI/SKB during early December 1996, the presentation to SKI/SSI in January 1997, discussions during the Shap Wells meeting in Cumbria during March 1997 and RISCOM internal discussions. We offer two hypotheses about the way the Nuclear Waste Management System (NWMS) appears to work. We choose one and derive from it a view about structural issues in SNS and NWMS. The conclusion is a set of systemic roles for the regulators. It is the comparison between these systemic roles and the actual situation that may trigger some adjustments in the system. Our hope is that these findings will make apparent feasible and desirable changes in the system in order to increase the chances for transparent decisions in the Nuclear Waste Management System. In summary, Section 2 includes a general background of the NWMS based on interviews and general information. Section 3 makes a more focused attempt to work out the issues expressed by people in the interviews. Section 4 discusses at a more conceptual level systemic ideas such as the unfolding of complexity. Section 5 is an attempt to organize viewpoints about the NWMS and offers hypotheses to support a preliminary diagnosis of the system in Section 6. We call this section 'A problem of identity'. It is only in Section 7 that basic systemic arguments are unfolded with the intention of supporting an appreciation of SKI/SSI's regulatory roles in the nuclear industry as a whole and nuclear waste management in particular. Section 8 offers a summary of conclusions

  13. Volunteers for Researchers’ Night wanted

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    Every year, on the last Friday of September, the European Researchers’ Night (see here) takes place in about 300 cities all over Europe - promoting research in engaging and fun ways for the general public. This year, CERN will be participating once again, hosting dozens of events across the Balexert shopping centre – and we’ll need YOUR help to make the celebration a success.   From film screenings and celebrity Q&A sessions to “Ask a Researcher” and build-your-own LEGO LHC events, this year’s Researchers’ Night is going to be jam-packed! The fun will kick off prior to the night itself with a mock-up of the LHC tunnel installed in the central court of the Balexert shopping centre, 8-12 September*. CERN people will be on hand to speak to shoppers about the LHC, and to encourage them to participate in Researchers’ Night! The CERN organisers are recruiting volunteers and support staff for Researchers’ ...

  14. Estimation of Joint Forces and Moments for the In-Run and Take-Off in Ski Jumping Based on Measurements with Wearable Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Grega Logar

    2015-05-01

    Full Text Available This study uses inertial sensors to measure ski jumper kinematics and joint dynamics, which was until now only a part of simulation studies. For subsequent calculation of dynamics in the joints, a link-segment model was developed. The model relies on the recursive Newton–Euler inverse dynamics. This approach allowed the calculation of the ground reaction force at take-off. For the model validation, four ski jumpers from the National Nordic center performed a simulated jump in a laboratory environment on a force platform; in total, 20 jumps were recorded. The results fit well to the reference system, presenting small errors in the mean and standard deviation and small root-mean-square errors. The error is under 12% of the reference value. For field tests, six jumpers participated in the study; in total, 28 jumps were recorded. All of the measured forces and moments were within the range of prior simulated studies. The proposed system was able to indirectly provide the values of forces and moments in the joints of the ski-jumpers’ body segments, as well as the ground reaction force during the in-run and take-off phases in comparison to the force platform installed on the table. Kinematics assessment and estimation of dynamics parameters can be applied to jumps from any ski jumping hill.

  15. Estimation of joint forces and moments for the in-run and take-off in ski jumping based on measurements with wearable inertial sensors.

    Science.gov (United States)

    Logar, Grega; Munih, Marko

    2015-05-13

    This study uses inertial sensors to measure ski jumper kinematics and joint dynamics, which was until now only a part of simulation studies. For subsequent calculation of dynamics in the joints, a link-segment model was developed. The model relies on the recursive Newton-Euler inverse dynamics. This approach allowed the calculation of the ground reaction force at take-off. For the model validation, four ski jumpers from the National Nordic center performed a simulated jump in a laboratory environment on a force platform; in total, 20 jumps were recorded. The results fit well to the reference system, presenting small errors in the mean and standard deviation and small root-mean-square errors. The error is under 12% of the reference value. For field tests, six jumpers participated in the study; in total, 28 jumps were recorded. All of the measured forces and moments were within the range of prior simulated studies. The proposed system was able to indirectly provide the values of forces and moments in the joints of the ski-jumpers' body segments, as well as the ground reaction force during the in-run and take-off phases in comparison to the force platform installed on the table. Kinematics assessment and estimation of dynamics parameters can be applied to jumps from any ski jumping hill.

  16. Investigating potential effects of heli-skiing on golden eagles in the Wasatch Mountains, Utah

    Science.gov (United States)

    Teryl G. Grubb; David K. Delaney; William W. Bowerman

    2007-01-01

    Implementing further research was beyond the scope of the U.S. Forest Service's 2004 Final Environmental Impact Statement (FEIS) and 2005 Wasatch Powderbird Guides (WPG) Special Use Permit Renewal process for heli-skiing in the Tri-Canyon Area in the Wasatch Mountains, just east of Salt Lake City, Utah. However, in their Record of Decision the Wasaatch-Cache (WCNF...

  17. Motivational Factors Affecting Athletes in Selecting the Sport Branches of Athletics, Ski and Tennis

    Science.gov (United States)

    Akyüz, Murat; Agar, Muharrem; Akyüz, Öznur; Dogru, Yeliz

    2016-01-01

    The aim of this study is to research the motivational factors affecting athletes to select the branches of athletics, ski and tennis. Within the scope of the research, the survey developed by H. Sunay in 1996 was implemented and solution for the problem of the research was searched through the findings that were obtained from the survey. SPSS…

  18. 5 CFR 532.505 - Night shift differentials.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Night shift differentials. 532.505... PREVAILING RATE SYSTEMS Premium Pay and Differentials § 532.505 Night shift differentials. (a) Employees shall be entitled to receive night shift differentials in accordance with section 5343 of title 5...

  19. Motivi biblici nell’opera teatrale di Stanisław Wyspiański e Jerzy Grotowski

    Directory of Open Access Journals (Sweden)

    Luca Bernardini

    2011-06-01

    The second play partly centered on a biblical theme is Akropolis (1904, a monumental drama set in Cracow’s Pantheon, the Wawel cathedral. In the second act of the play, the characters of the tapestries hanging on the walls of the cathedral come to life. One of the tapestries portraits the story of Jacob (Genesis: 25-33. Wyspiański was very likely inspired by  Raffaello’s fresco paintings in Eliodor’s room at the Vatican, and by Gerhard Hauptmann’s fragment Das Hirtenlied. The playwright closely follows the text of the Bible but for a few „apocryphical” insertions, the more relevant of which refer to Jacob’s struggle with the Angel. The Angel defies Jacob, founder of tribes”, claiming that he’ll thread „on the weak ones, in this graveyard of tribes”. Much has been debated on where the action of the drama should take place. Wyspiański himself thought about staging Akropolis in the cathedral on the Wawel hill, but the best known production of the play, performed by Jerzy Grotowski (1962, dispensed from the original setting. For Wyspiański, the cathedral on the Wawel hill, with her tombs, was the most significant achievement in Polish national history  and culture, but for Grotowski the most meaningful event in the history of the whole humankind had taken place in Auschwitz extermination camp. Grotowski sees the setting of the play – using Wyspianski’s words - „in a graveyard of tribes”. This graveyard is not longer the peaceful and magnificent cathedral where the playwright used to stroll in search of inspiration, but a dramatically real one, the graveyard in which millions of human beings belonging to all nations have been buried after having completed the crematorium in which they and their companions will be burned. Grotowski has not altered Wyspiański’s lines, just changed the order of the scenes, so that Jacob’s struggle with the Angel could be at the centre of  a play which could be reintepreted by the light shed on

  20. Automatic Classification of Sub-Techniques in Classical Cross-Country Skiing Using a Machine Learning Algorithm on Micro-Sensor Data

    Directory of Open Access Journals (Sweden)

    Ole Marius Hoel Rindal

    2017-12-01

    Full Text Available The automatic classification of sub-techniques in classical cross-country skiing provides unique possibilities for analyzing the biomechanical aspects of outdoor skiing. This is currently possible due to the miniaturization and flexibility of wearable inertial measurement units (IMUs that allow researchers to bring the laboratory to the field. In this study, we aimed to optimize the accuracy of the automatic classification of classical cross-country skiing sub-techniques by using two IMUs attached to the skier’s arm and chest together with a machine learning algorithm. The novelty of our approach is the reliable detection of individual cycles using a gyroscope on the skier’s arm, while a neural network machine learning algorithm robustly classifies each cycle to a sub-technique using sensor data from an accelerometer on the chest. In this study, 24 datasets from 10 different participants were separated into the categories training-, validation- and test-data. Overall, we achieved a classification accuracy of 93.9% on the test-data. Furthermore, we illustrate how an accurate classification of sub-techniques can be combined with data from standard sports equipment including position, altitude, speed and heart rate measuring systems. Combining this information has the potential to provide novel insight into physiological and biomechanical aspects valuable to coaches, athletes and researchers.

  1. Transition piece for joining together tubular pieces

    International Nuclear Information System (INIS)

    Holko, K.H.

    1981-01-01

    A transition piece for joining together tubular pieces formed respectively from a low alloy or carbon steel and a high temperature alloy containing at least 16% chromium includes a plurality of tubular parts welded together and formed from materials of selected composition with a maximum chromium content difference of 5% between adjacent parts when the chromium content of each part is below 10% and a maximum chromium difference of 7% between adjacent parts when the chromium content of either part is above 10%. The transition parts are also graded as to such characteristics as thermal expansion coefficient. The transition parts at opposite ends of the transition joint have chromium percentages similar to the tubular pieces to which they are to be joined. The parts may be joined by fusion and/or friction welding and parts may be formed by fusion weld deposition. (author)

  2. Night airglow in RGB mode

    Directory of Open Access Journals (Sweden)

    Mikhalev А.V.

    2016-09-01

    Full Text Available To study dynamics of the upper atmosphere, we consider results of the night sky photometry, using a color CCD camera and taking into account the night airglow and features of its spectral composition. We use night airglow observations for 2010–2015, which have been obtained at the ISTP SB RAS Geophysical Observatory (52° N, 103° E by the camera with KODAK KAI-11002 CCD sensor. We estimate average brightness of the night sky in R, G, B channels of the color camera for eastern Siberia with typical values ranging from ~0.008 to 0.01 erg·cm–2·s–1. Besides, we determine seasonal variations in the night sky luminosities in R, G, B channels of the color camera. In these channels, luminosities decrease in spring, increase in autumn, and have a pronounced summer maximum, which can be explained by scattered light and is associated with the location of the Geophysical Observatory. We consider geophysical phenomena with their optical effects in R, G, B channels of the color camera. For some geophysical phenomena (geomagnetic storms, sudden stratospheric warmings, we demonstrate the possibility of quantitative relationship between enhanced signals in R and G channels and increases in intensities of discrete 557.7 and 630 nm emissions, which are predominant in the airglow spectrum

  3. Injuries and illnesses in a cohort of elite youth alpine ski racers and the influence of biological maturity and relative age: a two-season prospective study

    Science.gov (United States)

    Müller, Lisa; Hildebrandt, Carolin; Müller, Erich; Oberhoffer, Renate; Raschner, Christian

    2017-01-01

    Background Studies on injuries and illnesses involving youth ski racers younger than 15 years are lacking in the literature. The aim of this study was prospectively to assess the incidence, prevalence, and severity of traumatic and overuse injuries, as well as illnesses of elite youth ski racers with regard to sex, biological maturity status, and relative age. Subjects and methods A prospective, longitudinal cohort design was used to monitor the anthropometrics, training characteristics, traumatic and overuse injuries, and illnesses of 82 elite youth ski racers (51 males, 31 females, age 9–14 years) over 2 consecutive years. The exact training exposure (skiing and athletic) was recorded. Relative age and estimated biological maturity status were assessed. Results Relatively low injury incidence or prevalence (traumatic, 0.86/1,000 hours of training; overuse, 0.28/1,000 hours) and comparably high illness prevalence (2.4/athlete) were reported. The knee was the most commonly affected body part (traumatic injuries 36.5%, overuse injuries 82%). A high number of bone fractures were revealed (46%), while no stress fractures occurred; 66% of the illnesses were respiratory tract infections. No differences were found between males and females, the differing maturity groups, or relative age quartiles. Early-maturing athletes had comparably low traumatic and overuse-injury rates. Relatively younger athletes had low traumatic injury rates. Conclusion The injury-prevention measures implemented in the training process of youth ski racers seem to contribute to a low incidence of injury. Biological maturity status should be considered in the training process to prevent injuries in late-maturing athletes. PMID:28546774

  4. Summary of Dissimilar Metal Joining Trials Conducted by Edison Welding Institute

    Energy Technology Data Exchange (ETDEWEB)

    MJ Lambert

    2005-11-18

    Under the direction of the NASA-Glenn Research Center, the Edison Welding Institute (EWI) in Columbus, OH performed a series of non-fusion joining experiments to determine the feasibility of joining refractory metals or refractory metal alloys to Ni-based superalloys. Results, as reported by EWI, can be found in the project report for EWI Project 48819GTH (Attachment A, at the end of this document), dated October 10, 2005. The three joining methods used in this investigation were inertia welding, magnetic pulse welding, and electro-spark deposition joining. Five materials were used in these experiments: Mo-47Re, T-111, Hastelloy X, Mar M-247 (coarse-grained, 0.5 mm to several millimeter average grain size), and Mar M-247 (fine-grained, approximately 50 {micro}m average grain size). Several iterative trials of each material combination with each joining method were performed to determine the best practice joining method. Mo-47Re was found to be joined easily to Hastelloy X via inertia welding, but inertia welding of the Mo-alloy to both Mar M-247 alloys resulted in inconsistent joint strength and large reaction layers between the two metals. T-111 was found to join well to Hastelloy X and coarse-grained Mar M-247 via inertia welding, but joining to fine-grained Mar M-247 resulted in low joint strength. Magnetic pulse welding (MPW) was only successful in joining T-111 tubing to Hastelloy X bar stock. The joint integrity and reaction layer between the metals were found to be acceptable. This single joining trial, however, caused damage to the electromagnetic concentrators used in this process. Subsequent design efforts to eliminate the problem resulted in a loss of power imparted to the accelerating work piece, and results could not be reproduced. Welding trials of Mar M-247 to T-111 resulted in catastrophic failure of the bar stock, even at lower power. Electro-spark deposition joining of Mo-47Re, in which the deposited material was Hastelloy X, did not have a

  5. Summary of Dissimilar Metal Joining Trials Conducted by Edison Welding Institute

    International Nuclear Information System (INIS)

    MJ Lambert

    2005-01-01

    Under the direction of the NASA-Glenn Research Center, the Edison Welding Institute (EWI) in Columbus, OH performed a series of non-fusion joining experiments to determine the feasibility of joining refractory metals or refractory metal alloys to Ni-based superalloys. Results, as reported by EWI, can be found in the project report for EWI Project 48819GTH (Attachment A, at the end of this document), dated October 10, 2005. The three joining methods used in this investigation were inertia welding, magnetic pulse welding, and electro-spark deposition joining. Five materials were used in these experiments: Mo-47Re, T-111, Hastelloy X, Mar M-247 (coarse-grained, 0.5 mm to several millimeter average grain size), and Mar M-247 (fine-grained, approximately 50 (micro)m average grain size). Several iterative trials of each material combination with each joining method were performed to determine the best practice joining method. Mo-47Re was found to be joined easily to Hastelloy X via inertia welding, but inertia welding of the Mo-alloy to both Mar M-247 alloys resulted in inconsistent joint strength and large reaction layers between the two metals. T-111 was found to join well to Hastelloy X and coarse-grained Mar M-247 via inertia welding, but joining to fine-grained Mar M-247 resulted in low joint strength. Magnetic pulse welding (MPW) was only successful in joining T-111 tubing to Hastelloy X bar stock. The joint integrity and reaction layer between the metals were found to be acceptable. This single joining trial, however, caused damage to the electromagnetic concentrators used in this process. Subsequent design efforts to eliminate the problem resulted in a loss of power imparted to the accelerating work piece, and results could not be reproduced. Welding trials of Mar M-247 to T-111 resulted in catastrophic failure of the bar stock, even at lower power. Electro-spark deposition joining of Mo-47Re, in which the deposited material was Hastelloy X, did not have a

  6. Validation of functional calibration and strap-down joint drift correction for computing 3D joint angles of knee, hip, and trunk in alpine skiing.

    Science.gov (United States)

    Fasel, Benedikt; Spörri, Jörg; Schütz, Pascal; Lorenzetti, Silvio; Aminian, Kamiar

    2017-01-01

    To obtain valid 3D joint angles with inertial sensors careful sensor-to-segment calibration (i.e. functional or anatomical calibration) is required and measured angular velocity at each sensor needs to be integrated to obtain segment and joint orientation (i.e. joint angles). Existing functional and anatomical calibration procedures were optimized for gait analysis and calibration movements were impractical to perform in outdoor settings. Thus, the aims of this study were 1) to propose and validate a set of calibration movements that were optimized for alpine skiing and could be performed outdoors and 2) to validate the 3D joint angles of the knee, hip, and trunk during alpine skiing. The proposed functional calibration movements consisted of squats, trunk rotations, hip ad/abductions, and upright standing. The joint drift correction previously proposed for alpine ski racing was improved by adding a second step to reduce separately azimuth drift. The system was validated indoors on a skiing carpet at the maximum belt speed of 21 km/h and for measurement durations of 120 seconds. Calibration repeatability was on average boots. Joint angle precision was <4.9° for all angles and accuracy ranged from -10.7° to 4.2° where the presence of an athlete-specific bias was observed especially for the flexion angle. The improved joint drift correction reduced azimuth drift from over 25° to less than 5°. In conclusion, the system was valid for measuring 3D joint angles during alpine skiing and could be used outdoors. Errors were similar to the values reported in other studies for gait. The system may be well suited for within-athlete analysis but care should be taken for between-athlete analysis because of a possible athlete-specific joint angle bias.

  7. Optimizing Half Squat Postactivation Potential Load in Squat Jump Training for Eliciting Relative Maximal Power in Ski Jumpers.

    Science.gov (United States)

    Gołaś, Artur; Wilk, Michal; Stastny, Petr; Maszczyk, Adam; Pajerska, Katarzyna; Zając, Adam

    2017-11-01

    Gołaś, A, Wilk, M, Stastny, P, Maszczyk, A, Pajerska, K, and Zając, A. Optimizing half squat postactivation potential load in squat jump training for eliciting relative maximal power in ski jumpers. J Strength Cond Res 31(11): 3010-3017, 2017-Training load manipulation in a single workout session can increase or decrease training effectiveness in terms of athletes' strength or power gains. In ski jumping, the complex training that elicits maximal power gains may take advantage of the postactivation potentiation (PAP) mechanism. The aim of this research was to evaluate the changes in rate of force development (RFD), rate of power development (RPD), and jump height during a complex training session consisted of the barbell half squat (Sq) as a conditioning exercise with loads ranged between 60 and 100% of 1 repetition maximum (1RM), followed by a body weight squat jump (SqJ) as a performance task. The study was conducted with 16 elite athletes from the Polish National Ski Jumping Team, age 23 ± 8 years, body mass 56 ± 9 kg, and height 172 ± 12 cm. Complex training session started with the Sq at 60% of 1RM as the conditioning exercise, followed by 3 minutes of rest and the SqJ. The conditioning barbell half Sq was performed with 70, 80, 90, and 100% of 1RM with 5 minutes of rest. The differences in RFD occurred between an SqJ following the application of 80% of 1RM and all other SqJs (p = 0.01), and in RPD between SqJ without conditioning, SqJ after 60% of 1RM and 80% of 1RM (p = 0.02). On average, the most effective load in inducing PAP during ski jumpers' SqJ training is 80% of 1RM. The intensity of the conditioning exercise that elicits the greatest PAP effect should be individualized (60-100% 1RM), as it is dependent on the level of maximal strength.

  8. Injuries and illnesses in a cohort of elite youth alpine ski racers and the influence of biological maturity and relative age: a two-season prospective study

    Directory of Open Access Journals (Sweden)

    Müller L

    2017-05-01

    Full Text Available Lisa Müller,1 Carolin Hildebrandt,1,2 Erich Müller,3 Renate Oberhoffer,2 Christian Raschner1 1Department of Sport Science, University of Innsbruck, Innsbruck, Austria; 2Department of Sport and Health Science, Preventative Pediatrics, Technical University of Munich, Munich, Germany; 3Department of Sport Science and Kinesiology, University of Salzburg, Salzburg, Austria Background: Studies on injuries and illnesses involving youth ski racers younger than 15 years are lacking in the literature. The aim of this study was prospectively to assess the incidence, prevalence, and severity of traumatic and overuse injuries, as well as illnesses of elite youth ski racers with regard to sex, biological maturity status, and relative age.Subjects and methods: A prospective, longitudinal cohort design was used to monitor the anthropometrics, training characteristics, traumatic and overuse injuries, and illnesses of 82 elite youth ski racers (51 males, 31 females, age 9–14 years over 2 consecutive years. The exact training exposure (skiing and athletic was recorded. Relative age and estimated biological maturity status were assessed.Results: Relatively low injury incidence or prevalence (traumatic, 0.86/1,000 hours of training; overuse, 0.28/1,000 hours and comparably high illness prevalence (2.4/athlete were reported. The knee was the most commonly affected body part (traumatic injuries 36.5%, overuse injuries 82%. A high number of bone fractures were revealed (46%, while no stress fractures occurred; 66% of the illnesses were respiratory tract infections. No differences were found between males and females, the differing maturity groups, or relative age quartiles. Early-maturing athletes had comparably low traumatic and overuse-injury rates. Relatively younger athletes had low traumatic injury rates.Conclusion: The injury-prevention measures implemented in the training process of youth ski racers seem to contribute to a low incidence of injury. Biological

  9. Menstrual characteristics and night work among nurses.

    Science.gov (United States)

    Moen, Bente E; Baste, Valborg; Morken, Tone; Alsaker, Kjersti; Pallesen, Ståle; Bjorvatn, Bjørn

    2015-01-01

    Night work has been associated with adverse effects in terms of reproductive health. Specifically, menstruation has been suggested to be negatively impacted by night work, which again may influence fertility. This study investigated whether working nights is related to menstrual characteristics and if there is a relationship between shift work disorder (SWD) and menstruation. The study was cross-sectional, response rate 38%. The sample comprised female nurses who were members of the Norwegian Nurses Association; below 50 yr of age, who were not pregnant, did not use hormonal pills or intrauterine devices and who had not reached menopause (n=766). The nurses answered a postal survey including questions about night work and menstrual characteristics. Fifteen per cent reported to have irregular menstruations. Thirty-nine per cent of the nurses were classified as having SWD. Logistic regression analyses concerning the relationship between irregular menstruations and night work did not show any associations. Furthermore, no associations were found between cycle length or bleeding period and night work parameters. No associations were found between menstrual characteristics and SWD.

  10. SKI's and SSI's experiences from their participation in the siting of a final repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Westerlind, M.; Hedberg, B.

    2000-01-01

    This paper summarises some experiences gained by the SKI and SSI during the ongoing process for siting a final repository for spent nuclear fuel. The focus is on activities in the municipalities involved in the siting process. In order to give the proper context some basic elements in the legislation, which are important for public participation and confidence in the siting process, are outlined. The importance of clearly defined responsibilities and early participation of the regulators in the siting process are emphasised. It should be pointed out that this paper is not a comprehensive review of the Swedish situation but only contains a few selected issues and personal remarks from the authors. Thus, the views and opinions do not necessarily coincide with those of SKI and SSI. (authors)

  11. 78 FR 60816 - Proposed Directive for Additional Seasonal or Year-Round Recreation Activities at Ski Areas

    Science.gov (United States)

    2013-10-02

    ... land management plan. Since SAROEA provides that snow sports must remain paramount at ski areas on NFS... Winter Sports Program Manager, 707-562-8842. Individuals who use telecommunication devices for the deaf...., Eastern Daylight Time, Monday through Friday. SUPPLEMENTARY INFORMATION: 1. Background and Need for the...

  12. Hot Flashes amd Night Sweats (PDQ)

    Science.gov (United States)

    ... Professionals Questions to Ask about Your Treatment Research Hot Flashes and Night Sweats (PDQ®)–Patient Version Overview ... quality of life in many patients with cancer. Hot flashes and night sweats may be side effects ...

  13. Development of Joining Technologies for the ITER Blanket First Wall

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byoung Kwon; Jung, Yang Il; Park, Dong Jun; Kim, Hyun Gil; Park, Sang Yoon; Park, Jeong Yong; Jeong, Yong Hwan; Lee, Dong Won; Kim, Suk Kwon [KAERI, Daejeon (Korea, Republic of)

    2011-01-15

    The design of the ITER blanket first wall includes the Beryllium amour tiles joined to CuCrZr heat sink with stainless steel cooling tubes. For the ITER application, the Be/CuCrZr/SS joint was proposed as a first wall material. The joining of Be/CuCrZr as well as CuCrZr/SS was generally carried out by using a hot isostatic pressing (CuC) in many countries. The joining strength for Be/CuCrZr is relatively lower than that for CuCrZr/SS, since we usually forms surface oxides (BeO) and brittle a metallics with Cu. Therefore, the joining technology for the Be/CuCrZr joint has been investigated. Be is apt to adsorb oxygen in an air atmosphere, so we should be etched to eliminate the surface pre-oxide using a chemical solution and Ar ions in a vacuum chamber. Then we is coated with a first was to prevent further oxidation. The kinds of a first we are chosen to be able to enhance the joining strength as inhibiting excessive be diffusion. The performance of the Be/CuCrZr/SS joint used for the ITER first wall is primarily dependent on the joining strength of the Be/CuCrZr interface. The Cr/Cu and Ti/Cr/Cu interlayers enabled the successful joining of be tile to CuCrZr plate. Moreover, ion-beam assisted deposition (IBAD) increased joining strength of the Be/CuCrZr joint mock-ups. IBAD induced the increased packing of depositing atoms, which resulted in denser and more adhesive interlayers. The interlayers formed by IBAD process revealed about 40% improved resistance to the scratch test. It is suggested that the improved adhesion of coating interlayers enabled tight joining of Be and CuCrZr blocks. As compared to without IBAD coating, the shear strength as well as the 4-point bend strength were increased more than 20% depending on interlayer types and coating conditions

  14. Development of Joining Technologies for the ITER Blanket First Wall

    International Nuclear Information System (INIS)

    Choi, Byoung Kwon; Jung, Yang Il; Park, Dong Jun; Kim, Hyun Gil; Park, Sang Yoon; Park, Jeong Yong; Jeong, Yong Hwan; Lee, Dong Won; Kim, Suk Kwon

    2011-01-01

    The design of the ITER blanket first wall includes the Beryllium amour tiles joined to CuCrZr heat sink with stainless steel cooling tubes. For the ITER application, the Be/CuCrZr/SS joint was proposed as a first wall material. The joining of Be/CuCrZr as well as CuCrZr/SS was generally carried out by using a hot isostatic pressing (CuC) in many countries. The joining strength for Be/CuCrZr is relatively lower than that for CuCrZr/SS, since we usually forms surface oxides (BeO) and brittle a metallics with Cu. Therefore, the joining technology for the Be/CuCrZr joint has been investigated. Be is apt to adsorb oxygen in an air atmosphere, so we should be etched to eliminate the surface pre-oxide using a chemical solution and Ar ions in a vacuum chamber. Then we is coated with a first was to prevent further oxidation. The kinds of a first we are chosen to be able to enhance the joining strength as inhibiting excessive be diffusion. The performance of the Be/CuCrZr/SS joint used for the ITER first wall is primarily dependent on the joining strength of the Be/CuCrZr interface. The Cr/Cu and Ti/Cr/Cu interlayers enabled the successful joining of be tile to CuCrZr plate. Moreover, ion-beam assisted deposition (IBAD) increased joining strength of the Be/CuCrZr joint mock-ups. IBAD induced the increased packing of depositing atoms, which resulted in denser and more adhesive interlayers. The interlayers formed by IBAD process revealed about 40% improved resistance to the scratch test. It is suggested that the improved adhesion of coating interlayers enabled tight joining of Be and CuCrZr blocks. As compared to without IBAD coating, the shear strength as well as the 4-point bend strength were increased more than 20% depending on interlayer types and coating conditions

  15. Inference of Large Phylogenies Using Neighbour-Joining

    DEFF Research Database (Denmark)

    Simonsen, Martin; Mailund, Thomas; Pedersen, Christian Nørgaard Storm

    2011-01-01

    The neighbour-joining method is a widely used method for phylogenetic reconstruction which scales to thousands of taxa. However, advances in sequencing technology have made data sets with more than 10,000 related taxa widely available. Inference of such large phylogenies takes hours or days using...... the Neighbour-Joining method on a normal desktop computer because of the O(n^3) running time. RapidNJ is a search heuristic which reduce the running time of the Neighbour-Joining method significantly but at the cost of an increased memory consumption making inference of large phylogenies infeasible. We present...... two extensions for RapidNJ which reduce the memory requirements and \\makebox{allows} phylogenies with more than 50,000 taxa to be inferred efficiently on a desktop computer. Furthermore, an improved version of the search heuristic is presented which reduces the running time of RapidNJ on many data...

  16. The night sky brightness at McDonald Observatory

    Science.gov (United States)

    Kalinowski, J. K.; Roosen, R. G.; Brandt, J. C.

    1975-01-01

    Baseline observations of the night sky brightness in B and V are presented for McDonald Observatory. In agreement with earlier work by Elvey and Rudnick (1937) and Elvey (1943), significant night-to-night and same-night variations in sky brightness are found. Possible causes for these variations are discussed. The largest variation in sky brightness found during a single night is approximately a factor of two, a value which corresponds to a factor-of-four variation in airglow brightness. The data are used to comment on the accuracy of previously published surface photometry of M 81.

  17. SKI SITE-94. Deep Repository Performance Assessment Project Volume I and II

    International Nuclear Information System (INIS)

    1996-12-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry's R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is not a safety assessment or a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The report gives a detailed description of the many inter-related studies undertaken as part of the research project. As a general conclusion it is noted that the SITE-94 project has significantly advanced SKI's capability of reviewing performance assessments and has led to the development of a tool-kit for carrying out assessment calculations, both in terms of numerical and scoping analyses. The study has highlighted a number of key issues for safety assessment (and consequently for disposal system design): Canister performance; Derived parameters of geosphere retention properties; Spatial variability of groundwater flow and geochemistry of migration paths; Time dependency (more emphasis on transient, time-dependent processes); Buffer evolution over long time. 488 refs

  18. Toonart Rääski ja Aivar Riisalu firma ostab Rocca al Mare Suurhalli / Kristina Traks

    Index Scriptorium Estoniae

    Traks, Kristina, 1976-

    2003-01-01

    Ilmunud ka: Delovõje Vedomosti 22. okt. lk. 7. Rocca al Mare Suurhalli aktsionärid otsustasid müüa suurhalli hotelliärimehe Toonart Rääski ja meelelahutusettevõtja Aivar Riisaluga seotud firmale Neckman Group. Diagramm: Lemminkäinen Eesti, Neckman Groupi, Eesti riigi ja Tallinna linna osalused Rocca al Mare Suurhallis

  19. Swedish skiers knowledge, experience and attitudes towards off-piste skiing and avalanches

    OpenAIRE

    Mårtensson, Stefan; Wikberg, Per-Olov; Palmgren, Petter

    2013-01-01

    The winter of 2012/2013 was the most accident-prone season in the Swedish avalanche history with a total of seven dead Swedes. In April 2013 the Swedish Mountain Safety Council initiated a web-based survey aimed towards Swedish skiers. The aim was to identify the target group's knowledge, experience and attitudes towards off-piste skiing and avalanches. Respondents were asked to answer a total of 28 questions. 1047 Swedish off-piste skiers answered, and we analysed them in more detail. The Sw...

  20. Biomechanical characteristics and speed adaptation during kick double poling on roller skis in elite cross-country skiers.

    Science.gov (United States)

    Göpfert, Caroline; Holmberg, Hans-Christer; Stöggl, Thomas; Müller, Erich; Lindinger, Stefan Josef

    2013-06-01

    Recent developments in cross-country ski racing should promote the use of kick double poling. This technique, however, has not been the focus in athletes' training and has barely been investigated. The aims of the present study were to develop a function-based phase definition and to analyse speed adaptation mechanisms for kick double poling in elite cross-country skiers. Joint kinematics and pole/plantar forces were recorded in 10 athletes while performing kick double poling at three submaximal roller skiing speeds. A speed increase was associated with increases in cycle length and rate, while absolute poling and leg push-off durations shortened. Despite maintained impulses of force, the peak and average pole/leg forces increased. During double poling and leg push-off, ranges of motion of elbow flexion and extension increased (p push-off showed high variability among elite skiers, thus illustrating important aspects for technique training.

  1. Prediction of performance in Vasaloppet through long lasting ski- ergometer and rollerski tests in cross-country skiers

    DEFF Research Database (Denmark)

    Mygind, Erik; Wulff, Kristian; Jensen, Mads Rosenkilde

    2015-01-01

    -ergometer and Rollerski field tests correlate strongly with performance in Vasaloppet and therefore might be useful test tools for recreational skiers who wish to participate in long lasting c-c competitions. Keywords: Cross-country ski training, Upper body, Exercise intensity, Field test, Body composition blood lactate......The main purpose was to investigate if long lasting cross-country (c-c) test procedures could predict performance time in ‘Vasaloppet’ and secondly the effect of a 16 weeks training period on a 90 min double poling performance test. 24 moderate trained c-c skiers participated in the study...... and completed Vasaloppet. All skiers carried out pre and post training tests in a 90 minutes ski-ergometer double poling test and a 120 minutes rollerski field test on a closed paved circuit. 19 skiers provided detailed training logs that could sufficiently establish their training preparation for Vasaloppet...

  2. Dark nights reverse metabolic disruption caused by dim light at night.

    Science.gov (United States)

    Fonken, L K; Weil, Z M; Nelson, R J

    2013-06-01

    The increasing prevalence of obesity and related metabolic disorders coincides with increasing exposure to light at night. Previous studies report that mice exposed to dim light at night (dLAN) develop symptoms of metabolic syndrome. This study investigated whether mice returned to dark nights after dLAN exposure recover metabolic function. Male Swiss-Webster mice were assigned to either: standard light-dark (LD) conditions for 8 weeks (LD/LD), dLAN for 8 weeks (dLAN/dLAN), LD for 4 weeks followed by 4 weeks of dLAN (LD/dLAN), and dLAN for 4 weeks followed by 4 weeks of LD (dLAN/LD). After 4 weeks in their respective lighting conditions both groups initially placed in dLAN increased body mass gain compared to LD mice. Half of the dLAN mice (dLAN/LD) were then transferred to LD and vice versa (LD/dLAN). Following the transfer dLAN/dLAN and LD/dLAN mice gained more weight than LD/LD and dLAN/LD mice. At the conclusion of the study dLAN/LD mice did not differ from LD/LD mice with respect to weight gain and had lower fat pad mass compared to dLAN/dLAN mice. Compared to all other groups dLAN/dLAN mice decreased glucose tolerance as indicated by an intraperitoneal glucose tolerance test at week 7, indicating that dLAN/LD mice recovered glucose metabolism. dLAN/dLAN mice also increased MAC1 mRNA expression in peripheral fat as compared to both LD/LD and dLAN/LD mice, suggesting peripheral inflammation is induced by dLAN, but not sustained after return to LD. These results suggest that re-exposure to dark nights ameliorates metabolic disruption caused by dLAN exposure. Copyright © 2013 The Obesity Society.

  3. The impact of short night-time naps on performance, sleepiness and mood during a simulated night shift.

    Science.gov (United States)

    Centofanti, Stephanie A; Hilditch, Cassie J; Dorrian, Jillian; Banks, Siobhan

    2016-01-01

    Short naps on night shift are recommended in some industries. There is a paucity of evidence to verify the sustained recovery benefits of short naps in the last few hours of the night shift. Therefore, the current study aimed to investigate the sustained recovery benefits of 30 and 10-min nap opportunities during a simulated night shift. Thirty-one healthy participants (18F, 21-35 y) completed a 3-day, between-groups laboratory study with one baseline night (22:00-07:00 h time in bed), followed by one night awake (time awake from 07:00 h on day two through 10:00 h day three) with random allocation to: a 10-min nap opportunity ending at 04:00 h, a 30-min nap opportunity ending at 04:00 h or no nap (control). A neurobehavioral test bout was administered approximately every 2 h during wake periods. There were no significant differences between nap conditions for post-nap psychomotor vigilance performance after controlling for pre-nap scores (p > 0.05). The 30-min nap significantly improved subjective sleepiness compared to the 10-min nap and no-nap control (p effect.

  4. Professional ski waxers' exposure to PFAS and aerosol concentrations in gas phase and different particle size fractions.

    Science.gov (United States)

    Nilsson, Helena; Kärrman, Anna; Rotander, Anna; van Bavel, Bert; Lindström, Gunilla; Westberg, Håkan

    2013-04-01

    Previous reports show that professional ski waxers have elevated blood levels of perfluorinated substances (PFAS) such as perfluorooctanoate (PFOA) and are exposed to very high concentrations of PFAS in air during ski waxing. Aerosol exposure increases the risk of cardiovascular disease, and PFOA is a potential hormonal disruptor and carcinogen, and can affect the fatty acid metabolism. Animal studies have shown that 8:2 FTOH can undergo biotransformation to PFOA. For the first time, this study presents an occupational scenario of professional ski waxers who are exposed to extremely high dust levels as well as per- and polyfluorinated compounds. Personal and fixed measurements of total aerosol, inhalable and respirable fractions were performed during World Cup events 2007-2010. The occupational exposure limit (OEL) is exceeded in 37% of the personal measurements with concentrations up to 15 mg m(-3) in air. There are differences between personal and area total aerosol concentrations with levels from personal measurements twice as high as those from the area measurements. The personal levels for FTOH ranged up to 996 μg m(-3) (mean = 114 μg m(-3)) and for PFOA up to 4.89 μg m(-3) (mean = 0.53 μg m(-3)) in ENV+ sorbent samples as compared to the general exposure levels from air reaching only low ng m(-3) (PFAS is not in compliance with the occupational exposure standards and by far exceed the general populations' exposure. Preventive measures must be taken to minimize the exposure in this occupational group.

  5. Joining of thin thickness SiCf/SiC composites: research of a joining composition and of an associated elaboration process

    International Nuclear Information System (INIS)

    Jacques, E.

    2012-01-01

    The present work is part of the Fourth Generation Fast Reactors program. One of the key issues is the joining of the SiC f /SiC ceramic matrix composites (CMC) to seal the combustible cladding. At the present time, no chemical composition as a joint is refractive enough to face the expected operating temperatures. The aims of this study are the following: (1) the identification of a joining composition and its associated elaboration process answering the specifications, (2) the validation of a local and fast heating process and (3) the definition of mechanical tests to characterise these joinings. We describe the methodology and the results for joining SiC and SiC f /SiC substrates at solid and liquid state using metallic silicides. Joint integrity and joint strength can be improved by adding small SiC particles to the silicides powders. Chemical reactivity, wettability tests and thermomechanical properties analysis have been carried out on the joints. Cross sections of the assembly were prepared to study the joint/substrate chemical bonding, the cracking and the crack deflection in the vicinity of the interface. Also, one of the challenge consists in using a local heating at a high temperature (around 1800 C) for a short time to avoid the degradation of the composite structure. The assemblies have been then performed in an inductive furnace but in order to prepare the joining technology, trials of local heating have also been investigated with a CO 2 laser beam and a microwave generator. Finally, descriptions of the 4-points bending mechanical test used and the associated results are presented. (author) [fr

  6. Microstructure and properties of ceramics and composites joined by plastic deformation.

    Energy Technology Data Exchange (ETDEWEB)

    Goretta, K. C.; Singh, D.; Chen, N.; Gutierrez-Mora, F.; Lorenzo-Martin, M. de la, Cinta; Dominguez-Rodriguez, A.; Routbort, J. L.; Energy Systems; Univ. of Seville

    2008-12-01

    A review is presented of the design of suitable materials systems for joining by high-temperature plastic deformation, details of the joining techniques, microstructures and properties of the resulting composite bodies, and prospects and limitation for this type of joining technology. Joining parameters and resulting forms are discussed for Al{sub 2}O{sub 3}/mullite particulate composites, Y{sub 2}O{sub 3}-stabilized ZrO{sub 2} particulate/Al{sub 2}O{sub 3} particulate and whisker-reinforced composites, hydroxyapatite bioceramics, La{sub 0.85}Sr{sub 0.15}MnO{sub 3} electronic ceramics, MgF{sub 2} optical ceramics, and Ni{sub 3}Al intermetallics. Results are contrasted with those obtained by other methods of joining brittle, high-temperature materials, with special focus on durability and mechanical properties.

  7. Microstructure and properties of ceramics and composites joined by plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Goretta, K.C. [Argonne National Laboratory, Argonne, IL 60439-4838 (United States)], E-mail: ken.goretta@aoard.af.mil; Singh, D.; Chen Nan [Argonne National Laboratory, Argonne, IL 60439-4838 (United States); Gutierrez-Mora, F.; Cinta Lorenzo-Martin, M. de la [Argonne National Laboratory, Argonne, IL 60439-4838 (United States); University of Seville, Seville 41080 (Spain); Dominguez-Rodriguez, A. [University of Seville, Seville 41080 (Spain); Routbort, J.L. [Argonne National Laboratory, Argonne, IL 60439-4838 (United States)

    2008-12-20

    A review is presented of the design of suitable materials systems for joining by high-temperature plastic deformation, details of the joining techniques, microstructures and properties of the resulting composite bodies, and prospects and limitation for this type of joining technology. Joining parameters and resulting forms are discussed for Al{sub 2}O{sub 3}/mullite particulate composites, Y{sub 2}O{sub 3}-stabilized ZrO{sub 2} particulate/Al{sub 2}O{sub 3} particulate and whisker-reinforced composites, hydroxyapatite bioceramics, La{sub 0.85}Sr{sub 0.15}MnO{sub 3} electronic ceramics, MgF{sub 2} optical ceramics, and Ni{sub 3}Al intermetallics. Results are contrasted with those obtained by other methods of joining brittle, high-temperature materials, with special focus on durability and mechanical properties.

  8. What is the preferred number of consecutive night shifts?

    DEFF Research Database (Denmark)

    Nabe-Nielsen, Kirsten; Jensen, Marie Aarrebo; Hansen, Åse Marie

    2016-01-01

    % preferred '2 + 2' and 26% preferred '7 + 7'. Participants, who preferred longer spells of night work experienced that night work was less demanding, found it easier to sleep at different times of the day, and were more frequently evening types compared with participants who preferred shorter spells of night...... the longer spells of night work found night work less demanding, found it easier to sleep at different times of the day, and were more frequently evening types....

  9. The Use of Body Worn Sensors for Detecting the Vibrations Acting on the Lower Back in Alpine Ski Racing

    Directory of Open Access Journals (Sweden)

    Jörg Spörri

    2017-07-01

    Full Text Available This study explored the use of body worn sensors to evaluate the vibrations that act on the human body in alpine ski racing from a general and a back overuse injury prevention perspective. In the course of a biomechanical field experiment, six male European Cup-level athletes each performed two runs on a typical giant slalom (GS and slalom (SL course, resulting in a total of 192 analyzed turns. Three-dimensional accelerations were measured by six inertial measurement units placed on the right and left shanks, right and left thighs, sacrum, and sternum. Based on these data, power spectral density (PSD; i.e., the signal's power distribution over frequency was determined for all segments analyzed. Additionally, as a measure expressing the severity of vibration exposure, root-mean-square (RMS acceleration acting on the lower back was calculated based on the inertial acceleration along the sacrum's longitudinal axis. In both GS and SL skiing, the PSD values of the vibrations acting at the shank were found to be largest for frequencies below 30 Hz. While being transmitted through the body, these vibrations were successively attenuated by the knee and hip joint. At the lower back (i.e., sacrum sensor, PSD values were especially pronounced for frequencies between 4 and 10 Hz, whereas a corresponding comparison between GS and SL revealed higher PSD values and larger RMS values for GS. Because vibrations in this particular range (i.e., 4 to 10 Hz include the spine's resonant frequency and are known to increase the risk of structural deteriorations/abnormalities of the spine, they may be considered potential components of mechanisms leading to overuse injuries of the back in alpine ski racing. Accordingly, any measure to control and/or reduce such skiing-related vibrations to a minimum should be recognized and applied. In this connection, wearable sensor technologies might help to better monitor and manage the overall back overuse-relevant vibration

  10. Joining of Aluminium Alloy Sheets by Rectangular Mechanical Clinching

    International Nuclear Information System (INIS)

    Abe, Y.; Mori, K.; Kato, T.

    2011-01-01

    A mechanical clinching has the advantage of low running costs. However, the joint strength is not high. To improve the maximum load of the joined sheets by a mechanical clinching, square and rectangular mechanical clinching were introduced. In the mechanical clinching, the two sheets are mechanically joined by forming an interlock between the lower and upper sheets by the punch and die. The joined length with the interlock was increased by the rectangular punch and die. The deforming behaviours of the sheets in the mechanical clinching were investigated, and then the interlock in the sheets had distribution in the circumference of the projection. Although the interlocks were formed in both projection side and diagonal, the interlock in the diagonal was smaller because of the long contact length between the lower sheet and the die cavity surface. The maximum load of the joined sheets by the rectangular mechanical clinching was two times larger than the load by the round mechanical clinching.

  11. Night Rover Challenge

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Night Rover Challenge was to foster innovations in energy storage technology. Specifically, this challenge asked competitors to create an energy...

  12. Impacts of and adaptation to GHG climate change on the ski and golf recreational activities and the tourism industry : a case study in Quebec

    Energy Technology Data Exchange (ETDEWEB)

    Singh, B.; Bryant, C.; Andre, P.; Thouez, J.P.; Savoie, M.; Tapes, V.; Granjon, D.; Pecheux, I.; Davey, N. [Montreal Univ., PQ (Canada). Dept. of Geography

    2006-03-31

    The ski and golf industries in southern Quebec are 2 major sectors of the province's tourism industry and both are sensitive to climate change. The impacts that are attributable to future climate change can significantly affect the profitability and viability of these recreational activities in southern Quebec. This paper presented the results of detailed studies conducted in regions around Montreal, Quebec City and the Eastern Townships in which the diagnostic outputs of 2 coupled atmosphere-ocean general circulation models (GCM) were used to analyze the impact of climate change on the ski and golf industries. The models were used for 3 time periods: a control period from 1961 to 1990; a short term future period from 2010 to 2039; and a long-term future period from 2040-2069. The climate variables chosen for the impacts and adaptation studies included maximum and minimum air temperature, precipitation, atmospheric humidity and wind speeds. Environment Canada provided the data for the control period, and the gaps for missing data were filled by regression analyses between neighbouring stations. The outputs of the 2 GCMs were used to determine the changes in the selected climate variables for the 2 future time periods. Irrigation requirements for the golfing season were calculated for each of the stations within the study area for the 3 time periods. The study showed that future climate change and variability will have significant impacts on these 2 key sectors in southern Quebec. The important changes in variety of key climate variables and parameters, mainly temperature and precipitation, will cause negative impacts, more so for the ski industry as opposed to the golf sector. There will be a significant reduction in the length of the ski season in the future, and snow-making may be the only possibility for some of the 84 ski centers in southern Quebec to continue to operate. However, less intense cold may favour the number of skiable days for certain centres

  13. Fast and scalable inequality joins

    KAUST Repository

    Khayyat, Zuhair; Lucia, William; Singh, Meghna; Ouzzani, Mourad; Papotti, Paolo; Quiané -Ruiz, Jorge Arnulfo; Tang, Nan; Kalnis, Panos

    2016-01-01

    an incremental inequality join algorithm to handle scenarios where data keeps changing. We have implemented a centralized version of these algorithms on top of PostgreSQL, a distributed version on top of Spark SQL, and an existing data cleaning system, Nadeef

  14. Night sky a falcon field guide

    CERN Document Server

    Nigro, Nicholas

    2012-01-01

    Night Sky: A Falcon Field Guide covers both summer and winter constellations, planets, and stars found in the northern hemisphere. Conveniently sized to fit in a pocket and featuring detailed photographs, this informative guide makes it easy to identify objects in the night sky even from one's own backyard. From information on optimal weather conditions, preferred viewing locations, and how to use key tools of the trade, this handbook will help you adeptly navigate to and fro the vast and dynamic nighttime skies, and you'll fast recognize that the night sky's the limit.

  15. Relationship between thyroid stimulating hormone and night shift work.

    Science.gov (United States)

    Moon, So-Hyun; Lee, Bum-Joon; Kim, Seong-Jin; Kim, Hwan-Cheol

    2016-01-01

    Night shift work has well-known adverse effects on health. However, few studies have investigated the relationship between thyroid diseases and night shift work. This study aimed to examine night shift workers and their changes in thyroid stimulating hormones (TSH) levels over time. Medical check-up data (2011-2015) were obtained from 967 female workers at a university hospital in Incheon, Korea. Data regarding TSH levels were extracted from the records, and 2015 was used as a reference point to determine night shift work status. The relationships between TSH levels and night shift work in each year were analyzed using the general linear model (GLM). The generalized estimating equation (GEE) was used to evaluate the repeated measurements over the 5-year period. The GEE analysis revealed that from 2011 to 2015, night shift workers had TSH levels that were 0.303 mIU/L higher than the levels of non-night shift workers (95 % CI: 0.087-0.519 mIU/L, p  = 0.006) after adjusting for age and department. When we used TSH levels of 4.5 ≥ mIU/L to identify subclinical hypothyroidism, night shift workers exhibited a 1.399 fold higher risk of subclinical hypothyroidism (95 % CI: 1.050-1.863, p  = 0.022), compared to their non-night shift counterparts. This result of this study suggests that night shift workers may have an increased risk of thyroid diseases, compared to non-night shift workers.

  16. Customer Journey and Experience in The FIS Nordic World Ski Championships 2017

    OpenAIRE

    Pelttari, Johanna

    2017-01-01

    This report covers a research of a Customer Journey and Customer Experience in the FIS Nordic World Ski Championships 2017. The key aim of this research is to do a research for the event and analyse their customer journey and customer experience. In that way aim is also to help event organizers with de-veloping events in the future. Specific service points and service touch points along the customer journey are analysed in this research. Commissioner of this research is the FIS Nordic Wo...

  17. Features of construction of the training process skiers aged 17-18 years to compete in different styles of skiing

    Directory of Open Access Journals (Sweden)

    T.V. Sidorova

    2013-05-01

    Full Text Available The work is devoted to the improvement of precompetitive preparation of skiers, taking into account the need to participate in competitions of different styles of skiing. The experiment included 20 athletes aged 17-18 years. Isolated model characteristics of athletes who successfully perform classic and skating style of movement. The range of indicators of physical fitness of athletes, which is the norm for this level of qualification. The technique of constructing precompetitive preparation of athletes on the basis of a combination of style of movement. It was established experimentally that the combination of training sessions during the day improves athletic performance in racing classic and skating style. In this case, primary and secondary occupation to carry out a different style of skiing with a change of their rotation on the next day.

  18. 49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe: Qualifying joining procedures. 192... Materials Other Than by Welding § 192.283 Plastic pipe: Qualifying joining procedures. (a) Heat fusion... for making plastic pipe joints by a heat fusion, solvent cement, or adhesive method, the procedure...

  19. Superplasticity and joining of zirconia-based ceramics

    International Nuclear Information System (INIS)

    Dominguez-Rodriguez, A.; Gutierrez-Mora, F.; Jimenez-Melendo, M.; Chaim, R.; Routbort, J. L.

    1999-01-01

    Steady-state creep and joining of alumina/zirconia composites containing alumina volume fractions of 20, 60, and 85% have been investigated between 1,250 and 1,350 C. Superplasticity of these compounds is controlled by grain-boundary sliding and the creep rate is a function of alumina volume fraction, not grain size. Using the principles of superplasticity, pieces of the composite have been joined by applying the stress required to achieve 5 to 10% strain to form a strong interface at temperatures as low as 1,200 C

  20. Superplasticity and joining of zirconia-based ceramics

    International Nuclear Information System (INIS)

    Gutierrez-Mora, F.; Dominguez-Rodriguez, A.; Jimenez-Melendo, M.; Chaim, R.; Ravi, G.B.; Routbort, J.L.

    2000-01-01

    Steady-state creep and joining of alumina/zirconia composites containing alumina volume fractions of 20, 60 and 85% have been investigated between 1,250 and 1,350 C. Superplasticity of these compounds is controlled by grain-boundary sliding and the creep rate is a function of alumina volume fraction, not grain size. Using the principles of superplasticity, pieces of the composite have been joined by applying the stress required to achieve 5 to 10% strain to form a strong interface at temperatures as low as 1,200 C

  1. Development of a procedure for forming assisted thermal joining of tubes

    Science.gov (United States)

    Chen, Hui; Löbbe, Christian; Staupendahl, Daniel; Tekkaya, A. Erman

    2018-05-01

    With the demand of lightweight design in the automotive industry, not only the wall-thicknesses of tubular components of the chassis or spaceframe are continuously decreased. Also the thicknesses of exhaust system parts are reduced to save material and mass. However, thinner tubular parts bring about additional challenges in joining. Welding or brazing methods, which are utilized in joining tubes with specific requirements concerning leak tightness, are sensitive to the gap between the joining partners. Furthermore, a large joining area is required to ensure the durability of the joint. The introduction of a forming step in the assembled state prior to thermal joining can define and control the gap for subsequent brazing or welding. The mechanical pre-joint resulting from the previously described calibration step also results in easier handling of the tubes prior to thermal joining. In the presented investigation, a spinning process is utilized to produce force-fit joints of varying lengths and diameter reduction and form-fit joints with varying geometrical attributes. The spinning process facilitates a high formability and geometrical flexibility, while at the achievable precision is high and the process forces are low. The strength of the joints is used to evaluate the joint quality. Finally, a comparison between joints produced by forming with subsequent brazing and original tube is conducted, which presents the high performance of the developed procedure for forming assisted thermal joining.

  2. Model Checking Processes Specified In Join-Calculus Algebra

    Directory of Open Access Journals (Sweden)

    Sławomir Piotr Maludziński

    2014-01-01

    Full Text Available This article presents a model checking tool used to verify concurrent systems specified in join-calculus algebra. The temporal properties of systems under verification are expressed in CTL logic. Join-calculus algebra with its operational semantics defined by the chemical abstract machine serves as the basic method for the specification of concurrent systems and their synchronization mechanisms, and allows the examination of more complex systems.

  3. Night time cooling by ventilation or night sky radiation combined with in-room radiant cooling panels including phase change materials

    DEFF Research Database (Denmark)

    Bourdakis, Eleftherios; Olesen, Bjarne W.; Grossule, Fabio

    Night sky radiative cooling technology using PhotoVoltaic/Thermal panels (PVT) and night time ventilation have been studied both by means of simulations and experiments to evaluate their potential and to validate the created simulation model used to describe it. An experimental setup has been...... depending on the sky clearness. This cooling power was enough to remove the stored heat and regenerate the ceiling panels. The validation simulation model results related to PCM were close to the corresponding results extracted from the experiment, while the results related to the production of cold water...... through the night sky radiative cooling differed significantly. The possibility of night time ventilation was studied through simulations for three different latitudes. It was concluded that for Danish climatic conditions night time ventilation would also be able to regenerate the panels while its...

  4. Glass-Metal Joining in Nuclear Environment: the State of the Art

    International Nuclear Information System (INIS)

    Jacobs, M.

    2007-01-01

    Full text of publication follows: In the ITER fusion machine and in material testing fission reactors, it is not possible to avoid the use of non-metallic materials like glass for example. There is therefore a need to apply metal to glass joints. This problem arose already at the beginning of the 19. century when the electric light bulb was invented. Nowadays this type of glass-metal joint is very successful and widely used in the electronic industry. In the case of ITER and material testing reactors, glass-metal joints are necessary for the fixation of the optical windows and optical fibres to a metal structure to perform diagnostics. These types of joints are still difficult to make and their behaviour is not fully understood. A joint between glass and metal for a nuclear or fusion application has indeed to resist high temperatures and high neutron fluences, while keeping a good mechanical strength and remaining leak tight. These characteristics are difficult to obtain under these severe conditions. This paper presents an overview of the different joining technologies that can be used to join glass to metal in a severe nuclear environment. The working mechanism of the technologies are explained, together with their respective advantages and drawbacks. Three different types of joining are discussed: fastening, liquid phase joining and solid phase joining. Fastening is a mechanical attachment technique, not achieving easily hermetic seals. Liquid and solid phase joining on the other hand form a real bond, what makes the joint much stronger. The most important technologies using liquid phase joining are adhesive bonding, fusion welding and brazing. In the case of the solid phase joining the choices are ultrasonic torsion welding, diffusion bonding and electrostatic bonding. If it is usually not possible to join the glass directly to the metal, an interlayer must be used. One speaks then of indirect joining. The paper will conclude with a discussion on the best

  5. ACTIVITY BUDGETS OF MALE MACCOA DUCKS FitzPatrick ...

    African Journals Online (AJOL)

    study first of time budgets and then the allocation of energetic costs to the various ..... tions made during two full-moon nights suggested that non-breeding birds did nothing ... activities (Running Flight, Souse, Ski and Fight) were rated 8 x BMR.

  6. Taiwan university joins search for antimatter

    CERN Multimedia

    Chiu, Y

    2002-01-01

    National Cheng Kung University announced yesterday that it will be joining the Alpha Magnetic Spectrometer, an international scientific research project aimed at looking for antimatter in space (1 page).

  7. High-energy electron beams for ceramic joining

    Science.gov (United States)

    Turman, Bob N.; Glass, S. J.; Halbleib, J. A.; Helmich, D. R.; Loehman, Ron E.; Clifford, Jerome R.

    1995-03-01

    Joining of structural ceramics is possible using high melting point metals such as Mo and Pt that are heated with a high energy electron beam, with the potential for high temperature joining. A 10 MeV electron beam can penetrate through 1 cm of ceramic, offering the possibility of buried interface joining. Because of transient heating and the lower heat capacity of the metal relative to the ceramic, a pulsed high power beam has the potential for melting the metal without decomposing or melting the ceramic. We have demonstrated the feasibility of the process with a series of 10 MeV, 1 kW electron beam experiments. Shear strengths up to 28 MPa have been measured. This strength is comparable to that reported in the literature for bonding silicon nitride (Si3N4) to molybdenum with copper-silver-titanium braze, but weaker than that reported for Si3N4 - Si3N4 with gold-nickel braze. The bonding mechanism appears to be formation of a thin silicide layer. Beam damage to the Si3N4 was also assessed.

  8. [Shift and night work and mental health].

    Science.gov (United States)

    Sancini, Angela; Ciarrocca, Manuela; Capozzella, Assunta; Corbosiero, Paola; Fiaschetti, Maria; Caciari, Tiziana; Cetica, Carlotta; Scimitto, Lara; Ponticiello, Barnaba Giuseppina; Tasciotti, Zaira; Schifano, Maria Pia; Andreozzit, Giorgia; Tomei, Francesco; Tomei, Gianfranco

    2012-01-01

    Aim of our study was to evaluate the influence that shift work and night work could have on mental health. A review of literary articles from 1990 to 2011 on shift work and night work was carried out. The results of this review confirmed that the shift work and night work affect mental health with the onset of neuropsychological disorders such as mood disorders, anxiety, nervousness, depressive anxiety syndromes, chronic fatigue and chronic insomnia irritability, sleep disturbances, reduction in levels of attention, cognitive impairments, alteration of circadian rhythm. Night work and shift work cause severe desynchronization of the cronobiological rhythms and a disruption of social life with negative effects on performance at work, on health and on social relationships. In the light of these results and recognizing shift work and night work as risk factors for the health of workers is necessary to implement preventive and periodic health checks by the occupational doctor to ensure the health and safety of workers taking account of the different environmental and individual factors.

  9. Top scientists join Stephen Hawking at Perimeter Institute

    Science.gov (United States)

    Banks, Michael

    2009-03-01

    Nine leading researchers are to join Stephen Hawking as visiting fellows at the Perimeter Institute for Theoretical Physics in Ontario, Canada. The researchers, who include string theorists Leonard Susskind from Stanford University and Asoka Sen from the Harisch-Chandra Research Institute in India, will each spend a few months of the year at the institute as "distinguished research chairs". They will be joined by another 30 scientists to be announced at a later date.

  10. On-line measurement of ski-jumper trajectory: combining stereo vision and shape description

    Science.gov (United States)

    Nunner, T.; Sidla, O.; Paar, G.; Nauschnegg, B.

    2010-01-01

    Ski jumping has continuously raised major public interest since the early 70s of the last century, mainly in Europe and Japan. The sport undergoes high-level analysis and development, among others, based on biodynamic measurements during the take-off and flight phase of the jumper. We report on a vision-based solution for such measurements that provides a full 3D trajectory of unique points on the jumper's shape. During the jump synchronized stereo images are taken by a calibrated camera system in video rate. Using methods stemming from video surveillance, the jumper is detected and localized in the individual stereo images, and learning-based deformable shape analysis identifies the jumper's silhouette. The 3D reconstruction of the trajectory takes place on standard stereo forward intersection of distinct shape points, such as helmet top or heel. In the reported study, the measurements are being verified by an independent GPS measurement mounted on top of the Jumper's helmet, synchronized to the timing of camera exposures. Preliminary estimations report an accuracy of +/-20 cm in 30 Hz imaging frequency within 40m trajectory. The system is ready for fully-automatic on-line application on ski-jumping sites that allow stereo camera views with an approximate base-distance ratio of 1:3 within the entire area of investigation.

  11. Heart rate profiles and energy cost of locomotion during cross-country skiing races.

    Science.gov (United States)

    Mognoni, P; Rossi, G; Gastaldelli, F; Canclini, A; Cotelli, F

    2001-07-01

    The purpose of this study was to compare heart rate responses and speed in two cross-country skiing races, which were run by seven male and seven female subjects by using classic and free style. Heart rates and skiing velocities were analyzed over flat, uphill and downhill sections, which were run from one to three times. Heart rates were higher in uphill sections than in flat sections; a steady-state heart rate was never reached in the downhill section. When the same uphill section was repeated, the heart rate tended to increase but the speed to decrease. Oxygen uptake (VO2) was calculated from heart rate:VO2 ratio, measured during uphill walking with the aid of poles. The mean (SD) energy cost of locomotion (i.e., the ratio between net VO2 and speed) was 162.1 (9.4) ml.km(-1).kg(-1) and 147.7 (7.1) ml.km(-1).kg(-1) when male subjects ran the flat section after first downhill by using classic and free style, respectively. Females had lower values for VO2 and speed, but similar energy costs. In general, the variability of the energy cost of locomotion in skiers of a similar competitive level is of the same order as that found in uphill walking on a treadmill.

  12. ROMANIA'S MACROECONOMIC ACHIEVEMENTS FOR JOINING THE UNIQUE EUROPEAN CURENCY

    Directory of Open Access Journals (Sweden)

    SILVIA POPESCU

    2011-04-01

    Full Text Available The Romanian government has announced plans to join the eurozone by 2015. Currently, the leu is not yet part of ERM II but plans to join in 2010-2012. The economic advantages of the monetary union grow with expansion of the Euro zone. There is also a high level of skepticism; the main fear about the Euro is the inflation –that is considerable promoted by the Euro currency’s exchange rate in comparison with 2002; another restraint is due to member states inability to establish their own interest rates. The IMF arose the option of joining the Euro zone criteria relaxing. A one-sided Euro’s joining was suggested by International Monetary Fund on March-April 2009, in a confidential report mentioned by The Financial Times as the emergent states in Central and Eastern Europe to be able to pass to the unique currency, but not being represented in the Central European Bank Board. By its side, CEB considers that emergent states of the European Union must not pass to the unique currency unilaterally, because such a fact could under-mine the trust in Euro currency worldwide. This option would hardly deepen the macroeconomic controversies inside the Euro zone and would contradict the previous conditions already imposed. An acceptable solution could be the fastening of emergent countries joining the Exchange Rate Mechanism 2, after they are aware of risks arisen by such a step. The European Commission endorses in the Convergence Report on 2010 that Romania doesn’t meet any criteria needed by passing to the unique European currency, respectively: prices stability; budget position of the government; stability of exchange rate; interest convergence on long run and there are also law impediments. Our paper discusses arguments for a faster passing to the Euro currency versus arguments for a late joining the Euro currency in Romania.

  13. NIGHT SKY BRIGHTNESS ABOVE ZAGREB 2012.-2017.

    Directory of Open Access Journals (Sweden)

    Željko Andreić

    2018-01-01

    Full Text Available The night sky brightness at the RGN site (near the centre of Zagreb, Croatia was monitored form January 2012. to December 2017. The gathered data show that the average night sky brightness in this period did not change significantly, apart from differences caused by yearly variations in meteorological parameters. The nightly minima, maxima and mean values of the sky brightness do change considerably due to changes in meteorological conditions, often being between 2 and 3 magnitudes. The seasonal probability curves and histograms are constructed and are used to obtain additional information on the light pollution at the RGN site. They reveal that the night sky brightness clutters around two peaks, at about 15.0 mag/arcsec2 and at about 18.2 mag/arcsec2. The tendency to slightly lower brightness values in spring and summer can also be seen in the data. Two peaks correspond to cloudy and clear nights respectively, the difference in brightness between them being about 3 magnitudes. A crude clear/cloudy criterion can be defined too: the minimum between two peaks is around 16.7 mag/arcsec2. The brightness values smaller than thisare attributed to clear nights and vice-versa. Comparison with Vienna and Hong-Kong indicates that the light pollution of Zagreb is a few times larger.

  14. Night shift decreases cognitive performance of ICU physicians.

    Science.gov (United States)

    Maltese, François; Adda, Mélanie; Bablon, Amandine; Hraeich, Sami; Guervilly, Christophe; Lehingue, Samuel; Wiramus, Sandrine; Leone, Marc; Martin, Claude; Vialet, Renaud; Thirion, Xavier; Roch, Antoine; Forel, Jean-Marie; Papazian, Laurent

    2016-03-01

    The relationship between tiredness and the risk of medical errors is now commonly accepted. The main objective of this study was to assess the impact of an intensive care unit (ICU) night shift on the cognitive performance of a group of intensivists. The influence of professional experience and the amount of sleep on cognitive performance was also investigated. A total of 51 intensivists from three ICUs (24 seniors and 27 residents) were included. The study participants were evaluated after a night of rest and after a night shift according to a randomized order. Four cognitive skills were tested according to the Wechsler Adult Intelligence Scale and the Wisconsin Card Sorting Test. All cognitive abilities worsened after a night shift: working memory capacity (11.3 ± 0.3 vs. 9.4 ± 0.3; p night shift. The cognitive abilities of intensivists were significantly altered following a night shift in the ICU, regardless of either the amount of professional experience or the duration of sleep during the shift. The consequences for patients' safety and physicians' health should be further evaluated.

  15. Night-Time Light Dynamics during the Iraqi Civil War

    Directory of Open Access Journals (Sweden)

    Xi Li

    2018-06-01

    Full Text Available In this study, we analyzed the night-time light dynamics in Iraq over the period 2012–2017 by using Visible Infrared Imaging Radiometer Suite (VIIRS monthly composites. The data quality of VIIRS images was improved by repairing the missing data, and the Night-time Light Ratio Indices (NLRIs, derived from urban extent map and night-time light images, were calculated for different provinces and cities. We found that when the Islamic State of Iraq and Syria (ISIS attacked or occupied a region, the region lost its light rapidly, with the provinces of Al-Anbar, At-Ta’min, Ninawa, and Sala Ad-din losing 63%, 73%, 88%, and 56%, of their night-time light, respectively, between December 2013 and December 2014. Moreover, the light returned after the Iraqi Security Forces (ISF recaptured the region. In addition, we also found that the night-time light in the Kurdish Autonomous Region showed a steady decline after 2014, with the Arbil, Dihok, and As-Sulaymaniyah provinces losing 47%, 18%, and 31% of their night-time light between December 2013 and December 2016 as a result of the economic crisis in the region. The night-time light in Southern Iraq, the region controlled by Iraqi central government, has grown continuously; for example, the night-time light in Al Basrah increased by 75% between December 2013 and December 2017. Regions formerly controlled by ISIS experienced a return of night-time light during 2017 as the ISF retook almost all this territory in 2017. This indicates that as reconstruction began, electricity was re-supplied in these regions. Our analysis shows the night-time light in Iraq is directly linked to the socioeconomic dynamics of Iraq, and demonstrates that the VIIRS monthly night-time light images are an effective data source for tracking humanitarian disasters in that country.

  16. The city at night (the case of Maribor, Slovenia

    Directory of Open Access Journals (Sweden)

    Vladimir Drozg

    2016-12-01

    Full Text Available This paper focuses on the city at night. The distinctive aspect of the discussed topic is the time dimension of spaces and areas – places that “live” at night. The night has economic, cultural, social and formal elements; and it is these elements that underpin how we see and come to know the city at night. A range of topics have been explored: places of retailing and consumption, workplaces, places of entertainment, places that embody the night image of the city and places of socially unacceptable, delinquent behaviour. In the empirical part, we examined the city of Maribor, Slovenia.

  17. Night vision: changing the way we drive

    Science.gov (United States)

    Klapper, Stuart H.; Kyle, Robert J. S.; Nicklin, Robert L.; Kormos, Alexander L.

    2001-03-01

    A revolutionary new Night Vision System has been designed to help drivers see well beyond their headlights. From luxury automobiles to heavy trucks, Night Vision is helping drivers see better, see further, and react sooner. This paper describes how Night Vision Systems are being used in transportation and their viability for the future. It describes recent improvements to the system currently in the second year of production. It also addresses consumer education and awareness, cost reduction, product reliability, market expansion and future improvements.

  18. Microwave joining of SiC

    Energy Technology Data Exchange (ETDEWEB)

    Silberglitt, R.; Ahmad, I. [FM Technologies, Inc., Fairfax, VA (United States); Black, W.M. [George Mason Univ., Fairfax, VA (United States)] [and others

    1995-05-01

    The purpose of this work is to optimize the properties of SiC-SiC joints made using microwave energy. The current focus is on optimization of time-temperature profiles, production of SiC from chemical precursors, and design of new applicators for joining of long tubes.

  19. SKI SITE-94, deep repository performance assessment project, summary

    International Nuclear Information System (INIS)

    1999-01-01

    SITE-94 is a comprehensive performance assessment exercise for a hypothetical repository for spent nuclear fuel at a real site in Sweden. SITE-94 was carried out to develop the capability and tools to enable Swedish Nuclear Power Inspectorate (SKI) to review fully the proposals for a deep repository which are expected to be made by the Swedish Nuclear Fuel and Waste Management Company, SKB (the implementor). Sweden is one of the leading countries in the research and development of geological disposal of radioactive waste. The developed methodology for performance assessment has attracted interests from other countries. The Summary of the main report of the SITE-94 project is translated here into Japanese to allow to make the information on the methodology and the related issues available among Japanese concerned. (author)

  20. Joining of SiCf/SiC composites for thermonuclear fusion reactors

    International Nuclear Information System (INIS)

    Ferraris, M.; Badini, C.; Montorsi, M.; Appendino, P.; Scholz, H.W.

    1994-01-01

    Due to their favourable radiological behaviour, SiC f /SiC composites are promising structural materials for future use in fusion reactors. A problem to cope with is the joining of the ceramic composite material (CMC) to itself for more complex structures. Maintenance concepts for a reactor made of SiC f /SiC will demand a method of joining. The joining agents should comply with the low-activation approach of the base material. With the acceptable elements Si and Mg, sandwich structures of composite/metal/composite were prepared in Ar atmosphere at temperatures just above the melting points of the metals. Another promising route is the use of joining agents of boro-silicate glasses: their composition can be tailored to obtain softening temperatures of interest for fusion applications. The glassy joint can be easily ceramised to improve thermomechanical properties. The joining interfaces were investigated by SEM-EDS, XRD and mechanical tests. ((orig.))