Reducing injury risk from body checking in boys' youth ice hockey.

Science.gov (United States)

Brooks, Alison; Loud, Keith J; Brenner, Joel S; Demorest, Rebecca A; Halstead, Mark E; Kelly, Amanda K Weiss; Koutures, Chris G; LaBella, Cynthia R; LaBotz, Michele; Martin, Stephanie S; Moffatt, Kody

2014-06-01

Ice hockey is an increasingly popular sport that allows intentional collision in the form of body checking for males but not for females. There is a two- to threefold increased risk of all injury, severe injury, and concussion related to body checking at all levels of boys' youth ice hockey. The American Academy of Pediatrics reinforces the importance of stringent enforcement of rules to protect player safety as well as educational interventions to decrease unsafe tactics. To promote ice hockey as a lifelong recreational pursuit for boys, the American Academy of Pediatrics recommends the expansion of nonchecking programs and the restriction of body checking to elite levels of boys' youth ice hockey, starting no earlier than 15 years of age.

Hypothenar hammer syndrome from ice hockey stick-handling.

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Zayed, Mohamed A; McDonald, Joey; Tittley, Jacques G

2013-11-01

Ulnar artery thrombosis and hypothenar hammer syndrome are rare vascular complications that could potentially occur with repeated blows or trauma to the hand. Although initially reported as an occupational hazard among laborers and craftsmen, it has been observed more recently among recreationalists and athletes. Until now, it has never been reported as a complication in ice hockey players. In this case report, a 26-year-old Canadian professional ice hockey player presented with acute dominant right hand paleness, coolness, and pain with hand use. The patient used a wooden hockey stick with a large knob of tape at the end of the handle, which he regularly gripped in the palm of his right hand to help with face-offs and general stick-handling. Sonographic evaluation demonstrated no arterial flow in the distal right ulnar artery distribution, and ulnar artery occlusion with no aneurysmal degeneration was confirmed by magnetic resonance angiogram. Intraarterial thrombolytic therapy was initiated, and subsequent serial angiograms demonstrated significant improvement in distal ulnar artery flow as well as recanalization of right hand deep palmar arch and digital arteries. The patient's symptoms resolved, and he was maintained on therapeutic anticoagulation for 3 months prior to returning to playing ice hockey professionally, but with a padded glove and no tape knob at the handle tip. This case highlights a unique presentation of hockey stick-handling causing ulnar artery thrombosis that was likely from repeated palmar hypothenar trauma. Appropriate diagnostic imaging, early intraarterial thrombolysis, and postoperative surveillance and follow-up were crucial for the successful outcome in this patient. Copyright © 2013 Elsevier Inc. All rights reserved.

Gender in ice hockey: women in a male territory.

Science.gov (United States)

Gilenstam, K; Karp, S; Henriksson-Larsén, K

2008-04-01

This study investigates how female ice hockey players describe and explain their situation within as well as outside their sport. Information was obtained by semi-structured interviews with female ice hockey players. The results were analyzed in a gender perspective where the main starting point was the concepts of different levels of power relations in society developed by Harding and applied to sports by Kolnes (the symbolic, structural, and individual level). The study shows that the players appeared to share the traditional views of men and women. They also described gender differences in terms of financial and structural conditions as well as differences in ice hockey history. Even though the players described structural inequalities, they were quite content with their situation and the differences in conditions were not considered when they explained the gender differences in ice hockey performance. At the individual level, the players considered themselves different from other women and appeared to share the traditional views of femininity and masculinity. It has been suggested that performance of a sport traditionally associated with the other sex might alter the traditional view of men and women; however, our results lend little support to this suggestion.

Reversible photoluminescence in spiropyran-modified porous silicon

International Nuclear Information System (INIS)

Lee, Chen-Yu; Hu, Chih-Hsuan; Cheng, Sheng-Lin; Chu, Chih-Chien; Hsiao, Vincent K.S.

2015-01-01

Spiropyran-modified porous silicon (spiro-PS) was used for the first time as an organic–inorganic hybrid material by using reversible photoluminescence (PL). Before spiropyran modification, the peak wavelength from PS was approximately 600 nm. Subsequent spiropyran modification strongly quenched the PL intensity, from 15,000 to 2000 counts. However, under UV light irradiation, the PL intensity from spiro-PS was increased gradually to 20,000 counts because of the photoinduced ring opening from a colorless spiropyran (SP-form) to a colored merocyanine (MC-form). Furthermore, the resulting peak wavelength of the PL of an MC–PS sample red-shifted from 600 to 650 nm, and the PL intensity was higher than that of unmodified PS. Because the fluorescence emission band (500–700 nm) of PS substantially overlapped the absorption band (500–700 nm) of the MC-form of spiropyran, the energy transfer from the PS (donor) to the open-ring-state MC-form (acceptor) occurs efficiently. The intensity of the PL from spiro-PS can be reversibly modulated using a heat stimulus. The current demonstrations have potential in reversible solid-state lighting or data storage applications. - Highlights: • Spiropyran-modified porous silicon (spiro-PS) was used for the first time as an organic–inorganic hybrid material with reversible photoluminescence (PL). • UV light irradiation make PL intensity from spiro-PS increased due to the photo-induced ring opening process. • The energy transfer from the PS (donor) to the open-ring state of spiropyran (acceptor) was to be efficient due to the fluorescence emission band of PS substantially overlapped with the absorption band of the ring-opened spiro. • The intensity of the PL from spiro-PS can be reversibly modulated using a heat stimulus

Physical profiles of elite male field hockey and soccer players ...

African Journals Online (AJOL)

Background. The physical demands of field hockey and soccer, based on match analysis, are comparable. As a consequence many exercise scientists and coaches have started to use the same type of field tests for hockey and soccer for the purposes of talent identification and training prescription. The validity of this ...

Morphological, Physiological and Skating Performance Profiles of Male Age-Group Elite Ice Hockey Players.

Science.gov (United States)

Allisse, Maxime; Sercia, Pierre; Comtois, Alain-Steve; Leone, Mario

2017-09-01

The purpose of this study was to describe the evolution of morphological, physiological and skating performance profiles of elite age-group ice hockey players based on repeated measures spread over one season. In addition, the results of fitness tests and training programs performed in off-ice conditions and their relationship with skating performance were analyzed. Eighteen high level age-group ice hockey players (13.1 ± 0.6 years) were assessed off and on-ice at the beginning and at the end of the hockey season. A third evaluation was also conducted at the beginning of the following hockey season. The players were taller, heavier, and showed bone breadths and muscle girths above the reference population of the same age. Muscular variables improved significantly during and between the two hockey seasons (p skating performance tests exhibited significant enhancements during the hockey season, but not during the off-season where some degradation was observed. Finally, weak observed variances (generally skating performance tests indicated important gaps, both in the choice of the off-ice assessment tools as well as in training methods conventionally used. The reflection on the best way to assess and train hockey players certainly deserves to be continued.

Head-impact mechanisms in men's and women's collegiate ice hockey.

Science.gov (United States)

Wilcox, Bethany J; Machan, Jason T; Beckwith, Jonathan G; Greenwald, Richard M; Burmeister, Emily; Crisco, Joseph J

2014-01-01

Concussion injury rates in men's and women's ice hockey are reported to be among the highest of all collegiate sports. Quantification of the frequency of head impacts and the magnitude of head acceleration as a function of the different impact mechanisms (eg, head contact with the ice) that occur in ice hockey could provide a better understanding of this high injury rate. To quantify and compare the per-game frequency and magnitude of head impacts associated with various impact mechanisms in men's and women's collegiate ice hockey players. Cohort study. Collegiate ice hockey rink. Twenty-three men and 31 women from 2 National Collegiate Athletic Association Division I ice hockey teams. We analyzed magnitude and frequency (per game) of head impacts per player among impact mechanisms and between sexes using generalized mixed linear models and generalized estimating equations to account for repeated measures within players. Participants wore helmets instrumented with accelerometers to allow us to collect biomechanical measures of head impacts sustained during play. Video footage from 53 games was synchronized with the biomechanical data. Head impacts were classified into 8 categories: contact with another player; the ice, boards or glass, stick, puck, or goal; indirect contact; and contact from celebrating. For men and women, contact with another player was the most frequent impact mechanism, and contact with the ice generated the greatest-magnitude head accelerations. The men had higher per-game frequencies of head impacts from contact with another player and contact with the boards than did the women (P < .001), and these impacts were greater in peak rotational acceleration (P = .027). Identifying the impact mechanisms in collegiate ice hockey that result in frequent and high-magnitude head impacts will provide us with data that may improve our understanding of the high rate of concussion in the sport and inform injury-prevention strategies.

Moral disengagement in the legitimation and realization of aggressive behavior in soccer and ice hockey.

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Traclet, Alan; Moret, Orlan; Ohl, Fabien; Clémence, Alain

2015-03-01

The aim of the present study was to verify that the level of tolerance for aggression is higher in a collective context than in an individual context (polarization effect), and to test the association between moral disengagement, team and self-attitudes toward aggression, and tolerance and realization of aggressive acts in Swiss male soccer and ice hockey. In individual or collective answering conditions, 104 soccer and 98 ice hockey players viewed videotaped aggressive acts and completed a questionnaire, including measures of the perceived legitimacy of videotaped aggression, of the teammates, coach, and self attitudes toward transgressions (modified TNQ), of the moral disengagement in sport (modified MDSS-S), and of self-reported aggressive behavior. A multilevel analysis confirmed a strong polarization effect on the perception of instrumental aggression, the videotaped aggressive acts appearing more tolerated in the collective than in the individual answering condition. Using a structural equation modeling, we found that the moral disengagement, which mediates the effects of perceived coach and ego attitudes toward transgressions, correlates positively with the tolerance of hostile aggression within teams, and with the level of aggressive acts reported by the participants. Aggr. Behav. Aggr. Behav. 42:123-133, 2015. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

Body composition of italian female hockey players

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P Pavan

2009-07-01

Full Text Available Objective: In this work the anthropometric features and the body composition of Italian hockey players, members of the Female National team, were analysed. The purpose of the research was to verify if morphological features could influence the performance of different positional groups. Materials and Methods: Each player was measured for her total and sitting height, weight, 9 skinfolds thickness and bioelectrical impedance analysis. Different equations were used to calculate the Fat% from skinfolds thickness. Results: Average height is not a crucial advantage for this sport. On the contrary the proportion trunk-limb seems to play an important role for the performance of the midfield players. Percentage of body fat of the hockey players was lower than the Fat% of the non-athletes women of the same age. Significant differences were found between Fat% determined by skinfolds thickness and Fat% obtained by bioelectrical impedance analysis. Conclusions: The results of this study indicate that there are significant differences in anthropometric features and in body composition between positional groups, stressing the importance of a specific training program. Keywords: field hockey, bioelectrical impedance, skinfolds thickness, anthropometry.

Player and Game Characteristics and Head Impacts in Female Youth Ice Hockey Players.

Science.gov (United States)

Reed, Nick; Taha, Tim; Greenwald, Richard; Keightley, Michelle

2017-08-01

  Despite the growing popularity of ice hockey among female youth and interest in the biomechanics of head impacts in sport, the head impacts sustained by this population have yet to be characterized.   To describe the number of, biomechanical characteristics of, and exposure to head impacts of female youth ice hockey players during competition and to investigate the influences of player and game characteristics on head impacts.   Cohort study.   Twenty-seven female youth ice hockey players (mean age = 12.5 ± 0.52 years) wore instrumented ice hockey helmets during 66 ice hockey games over a 3-year period. Data specific to player, game, and biomechanical head impact characteristics were recorded. A multiple regression analysis identified factors most associated with head impacts of greater frequency and severity.   A total of 436 total head impacts were sustained during 6924 minutes of active ice hockey participation (0.9 ± 0.6 impacts per player per game; range, 0-2.1). A higher body mass index (BMI) significantly predicted a higher number of head impacts sustained per game (P = .008). Linear acceleration of head impacts was greater in older players and those who played the forward position, had a greater BMI, and spent more time on the ice (P = .008), whereas greater rotational acceleration was present in older players who had a greater BMI and played the forward position (P = .008). During tournament games, increased ice time predicted increased severity of head impacts (P = .03).   This study reveals for the first time that head impacts are occurring in female youth ice hockey players, albeit at a lower rate and severity than in male youth ice hockey players, despite the lack of intentional body checking.

Morphological, Physiological and Skating Performance Profiles of Male Age-Group Elite Ice Hockey Players

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Allisse Maxime

2017-08-01

Full Text Available The purpose of this study was to describe the evolution of morphological, physiological and skating performance profiles of elite age-group ice hockey players based on repeated measures spread over one season. In addition, the results of fitness tests and training programs performed in off-ice conditions and their relationship with skating performance were analyzed. Eighteen high level age-group ice hockey players (13.1 ± 0.6 years were assessed off and on-ice at the beginning and at the end of the hockey season. A third evaluation was also conducted at the beginning of the following hockey season. The players were taller, heavier, and showed bone breadths and muscle girths above the reference population of the same age. Muscular variables improved significantly during and between the two hockey seasons (p < 0.05. However, maximal aerobic power improved only during the off-season. All skating performance tests exhibited significant enhancements during the hockey season, but not during the off-season where some degradation was observed. Finally, weak observed variances (generally <20% of the explained variance between physiological variables measured off-ice and on-ice skating performance tests indicated important gaps, both in the choice of the off-ice assessment tools as well as in training methods conventionally used. The reflection on the best way to assess and train hockey players certainly deserves to be continued.

Incidence of hockey ankle injuries in Kwa-Zulu Natal, South Africa ...

African Journals Online (AJOL)

ankle injuries amongst hockey players was 26.41%. The most frequent ankle injury sustained by male adolescent hockey players was an inversion ankle sprain (84.62% of the 26.41% injured subjects of the sample cohort). The mechanisms of ankle injuries were attributed to rapid rotational movements of the ankle joint ...

Spinal mobility and trunk muscle strength in elite hockey players.

Science.gov (United States)

Lindgren, S; Twomey, L

1988-01-01

Elite hockey players of both sexes from the Australian Institute of Sport were assessed for lumbar spine mobility, trunk flexion and back extensor muscle strength, hamstring flexibility and postural characteristics over a two year period. All the athletes were more mobile in rotation than the 'normal' West Australian population, and demonstrated flexible hamstrings and powerful back extensor muscles; trunk flexion was less strong initially, but improved after intervention in the form of a specific exercise programme, over the measurement period. A questionnaire disclosed that low back pain is a common complaint of hockey players, but rarely required intensive physical and medical treatment. The term 'hockey player's back' has been coined in recognition of the long flat thoracolumbar spine frequently noted in these subjects. Copyright © 1988 Australian Physiotherapy Association. Published by . All rights reserved.

Hockey lines for simulation-based learning.

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Topps, David; Ellaway, Rachel; Kupsh, Christine

2015-06-01

Simulation-based health professional education is often limited in accommodating large numbers of students. Most organisations do not have enough simulation suites or staff to support growing demands. We needed to find ways to make simulation sessions more accommodating for larger groups of learners, so that more than a few individuals could be active in a simulation scenario at any one time. Moreover, we needed to make the experience meaningful for all participating learners. We used the metaphor of (ice) hockey lines and substitution 'on the fly' to effectively double the numbers of learners that can be actively engaged at once. Team players must communicate clearly, and observe keenly, so that currently playing members understand what is happening from moment to moment and incoming substitutes can take over their roles seamlessly. Most organisations do not have enough simulation suites or staff to support growing demands We found that this hockey lines approach to simulation-based team scenarios will raise learners' levels of engagement, reinforce good crew resource management (CRM) practices, enhance closed-loop communication, and help learners to understand their cognitive biases and limitations when working in high-pressure situations. During our continuing refinement of the hockey-lines approach, we developed a number of variations on the basic activity model, with various benefits and applications. Both students and teachers have been enthusiastically positive about this approach when it was introduced at our various courses and participating institutions. © 2015 John Wiley & Sons Ltd.

Creating a goaltending development manual for Belgium Ice Hockey

OpenAIRE

Guay, Eddy

2014-01-01

The objective of the thesis and was to create a goalie development manual for the Royal Belgian Ice Hockey Federation (RBIHF). The manual will provide goalies and coaches a guide for developing players in the position. The manual aims to provide a technical resources for goalies and coaches on the skills that goalies need to focus on to allow them to improve their play. ! “The backbone of a hockey team”or “The most important position in sports” are two of many phrases that i...

Do physical maturity and birth date predict talent in male youth ice hockey players?

Science.gov (United States)

Sherar, Lauren B; Baxter-Jones, Adam D G; Faulkner, Robert A; Russell, Keith W

2007-06-01

The aim of this study was to examine the relationships among biological maturity, physical size, relative age (i.e. birth date), and selection into a male Canadian provincial age-banded ice hockey team. In 2003, 619 male ice hockey players aged 14-15 years attended Saskatchewan provincial team selection camps, 281 of whom participated in the present study. Data from 93 age-matched controls were obtained from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-1997). During the initial selection camps, birth dates, heights, sitting heights, and body masses were recorded. Age at peak height velocity, an indicator of biological maturity, was determined in the controls and predicted in the ice hockey players. Data were analysed using one-way analysis of variance, logistic regression, and a Kolmogorov-Smirnov test. The ice hockey players selected for the final team were taller, heavier, and more mature (P born in the months January to June. In conclusion, team selectors appear to preferentially select early maturing male ice hockey players who have birth dates early in the selection year.

Knee joint position sense of roller hockey players: a comparative study.

Science.gov (United States)

Venâncio, João; Lopes, Diogo; Lourenço, Joaquim; Ribeiro, Fernando

2016-06-01

This study aimed to compare knee joint position sense of roller hockey players with an age-matched group of non-athletes. Forty-three male participants voluntarily participated in this cross-sectional study: 21 roller hockey players (mean age: 23.2 ± 4.2 years old, mean weight: 81.8 ± 9.8 kg, mean height: 180.5 ± 4.1 cm) and 22 age-matched non-athletes (mean age: 23.7 ± 3.9 years old, mean weight: 85.0 ± 6.2 kg, mean height: 181.5 ± 5.0 cm). Knee joint position sense of the dominant limb was evaluated using a technique of open-kinetic chain and active knee positioning. Joint position sense was reported using absolute, relative and variable angular errors. The main results indicated that the group of roller hockey players showed significantly lower absolute (2.4 ± 1.2º vs. 6.5 ± 3.2º, p ≤ 0.001) and relative (1.7 ± 2.1º vs. 5.8 ± 4.4º, p ≤ 0.001) angular errors in comparison with the non-athletes group. In conclusion, the results from this present study suggest that proprioceptive acuity, assessed by measuring joint position sense, is increased in roller hockey players. The enhanced proprioception of the roller hockey players could contribute to injury prevention and improved performance during sporting activities.

Physiological correlates of skating performance in women's and men's ice hockey.

Science.gov (United States)

Gilenstam, Kajsa M; Thorsen, Kim; Henriksson-Larsén, Karin B

2011-08-01

The purpose of the current investigation was to identify relationships between physiological off-ice tests and on-ice performance in female and male ice hockey players on a comparable competitive level. Eleven women, 24 ± 3.0 years, and 10 male ice hockey players, 23 ± 2.4 years, were tested for background variables: height, body weight (BW), ice hockey history, and lean body mass (LBM) and peak torque (PT) of the thigh muscles, VO2peak and aerobic performance (Onset of Blood Lactate Accumulation [OBLA], respiratory exchange ratio [RER1]) during an incremental bicycle ergometer test. Four different on-ice tests were used to measure ice skating performance. For women, skating time was positively correlated (p skating time was positively correlated to VO2peak (L O2·min(-1)) in the Acceleration test. The male group had significantly higher physiological test values in all variables (absolute and relative to BW) but not in relation to LBM. Selected off-ice tests predict skating performance for women but not for men. The group of women was significantly smaller and had a lower physiological performance than the group of men and were slower in the on-ice performance tests. However, gender differences in off-ice variables were reduced or disappeared when values were related to LBM, indicating a similar capacity of producing strength and aerobic power in female and male hockey players. Skating performance in female hockey players may be improved by increasing thigh muscle strength, oxygen uptake, and relative muscle mass.

The effect of a complex training program on skating abilities in ice hockey players.

Science.gov (United States)

Lee, Changyoung; Lee, Sookyung; Yoo, Jaehyun

2014-04-01

[Purpose] Little data exist on systemic training programs to improve skating abilities in ice hockey players. The purpose of this study was to evaluate the effectiveness of a complex training program on skating abilities in ice hockey players. [Methods] Ten male ice hockey players (training group) that engaged in 12 weeks of complex training and skating training and ten male players (control group) that only participated in 12 weeks of skating training completed on-ice skating tests including a 5 time 18 meters shuttle, t-test, Rink dash 5 times, and line drill before, during, and the training. [Results] Significant group-by-time interactions were found in all skating ability tests. [Conclusion] The complex training program intervention for 12 weeks improved their skating abilities of the ice hockey players.

Integration of the functional movement screen into the National Hockey League Combine.

Science.gov (United States)

Rowan, Chip P; Kuropkat, Christiane; Gumieniak, Robert J; Gledhill, Norman; Jamnik, Veronica K

2015-05-01

The sport of ice hockey requires coordination of complex skills involving musculoskeletal and physiological abilities while simultaneously exposing players to a high risk for injury. The Functional Movement Screen (FMS) was developed to assess fundamental movement patterns that underlie both sport performance and injury risk. The top 111 elite junior hockey players from around the world took part in the 2013 National Hockey League Entry Draft Combine (NHL Combine). The FMS was integrated into the comprehensive medical and physiological fitness evaluations at the request of strength and conditioning coaches with affiliations to NHL teams. The inclusion of the FMS aimed to help develop strategies that could maximize its utility among elite hockey players and to encourage or inform further research in this field. This study evaluated the outcomes of integrating the FMS into the NHL Combine and identified any links to other medical plus physical and physiological fitness assessment outcomes. These potential associations may provide valuable information to identify elements of future training programs that are individualized to athletes' specific needs. The results of the FMS (total score and number of asymmetries identified) were significantly correlated to various body composition measures, aerobic and anaerobic fitness, leg power, timing of recent workouts, and the presence of lingering injury at the time of the NHL Combine. Although statistically significant correlations were observed, the implications of the FMS assessment outcomes remain difficult to quantify until ongoing assessment of FMS patterns, tracking of injuries, and hockey performance are available.

Mechanisms of injury for concussions in university football, ice hockey, and soccer.

Science.gov (United States)

Delaney, J Scott; Al-Kashmiri, Ammar; Correa, José A

2014-05-01

To examine the mechanisms of injury for concussions in university football, ice hockey, and soccer. Prospective cohort design. McGill University Sport Medicine Clinic. Male and female athletes participating in varsity football, ice hockey, and soccer. Athletes were followed prospectively over a 10-year period to determine the mechanisms of injury for concussions and whether contact with certain areas of the body or individual variables predisposed to longer recovery from concussions. For soccer, data were collected on whether concussions occurred while attempting to head the ball. There were 226 concussions in 170 athletes over the study period. The side/temporal area of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. Contact from another player's head or helmet was the most probable mechanism in football and soccer. In hockey, concussion impacts were more likely to occur from contact with another body part or object rather than another head/helmet. Differences in mechanisms of injuries were found between males and females in soccer and ice hockey. Athletes with multiple concussions took longer to return to play with each subsequent concussion. Half of the concussions in soccer were related to attempting to head the soccer ball. The side of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. In ice hockey and soccer, there are differences in the mechanisms of injury for males and females within the same sport.

Physiological, physical and on-ice performance criteria for selection of elite ice hockey teams

Directory of Open Access Journals (Sweden)

R Roczniok

2016-01-01

Full Text Available The purpose of this study was to examine physiological and physical determinants of ice-hockey performance in order to assess their impact on the result during a selection for ice hockey. A total of 42 ice hockey players took part in the selection camp. At the end of the camp 20 best players were selected by team of expert coaches to the ice hockey team and created group G1, while the second group (G2 consisted of not selected players (non-successful group Evaluation of goodness of fit of the model to the data was based on the Hosmer Lemeshow test Ice hockey players selected to the team were taller 181.95±4.02 cm, had lower % body fat 13.17±3.17%, a shorter time to peak power 2.47±0.35 s , higher relative peak power 21.34±2.41 W • kg-1 and higher relative total work 305.18±28.41 J • kg-1. The results of the aerobic capacity test showed significant differences only in case of two variables. Ice hockey players in the G1 had higher VO2max 4.07±0.31 l • min-1 values than players in the G2 as well as ice hockey players in G1 showed a higher level of relative VO2max 51.75±2.99 ml • min-1 • kg-1 than athletes in G2. Ice hockey players selected to the team (G1 performed better in the 30 m Forwards Sprint 4.28±0.31 s; 6x9 Turns 12.19±0.75 s; 6x9 stops 12.79±0.49 s and Endurance test (6x30 m stops 32.01±0.80 s than players in G2. The logistic regression model showed that the best predictors of success in the recruitment process of top level ice hockey players were time to peak power, relative peak power, VO2max and 30 m sprint forwards on ice. On the basis of the constructed predictive logistic regression model it will be possible to determine the probability of success of the athletes during following the selection processes to the team.

Analisys and energy saving measures of kastvallen ice hockey rink arena

OpenAIRE

Igual Bueno, Mario; Bielsa Azcona, José Enrique

2011-01-01

Nowadays efficiency measures are more and more important because the price of the energy is increasing every year. Moreover, saving energy it is also important for decrease the environmental impact. Kastvallen is a hockey arena built in 1997 that cools the hockey rink with electric compressors. The changing rooms are heating by using district heating. Actually the total invoice of electricity is above the 800000 SEK. Meanwhile the district heating invoice reaches the 60000SE...

Conservative management of an elite ice hockey goaltender with femoroacetabular impingement (FAI): a case report

Science.gov (United States)

MacIntyre, Kyle; Gomes, Brendan; MacKenzie, Steven; D’Angelo, Kevin

2015-01-01

Objective: To detail the presentation of an elite male ice hockey goaltender with cam-type femoroacetabular impingement (FAI) and acetabular labral tears. This case will outline the prevalence, clinical presentation, imaging criteria, pathomechanics, and management of FAI, with specific emphasis on the ice hockey goaltender. Clinical Features: A 22-year old retired ice hockey goaltender presented to a chiropractor after being diagnosed by an orthopaedic surgeon with MRI confirmed left longitudinal and chondral flap acetabular labral tears and cam-type femoroacetabular impingement (FAI). As the patient was not a candidate for surgical intervention, a multimodal conservative treatment approach including manual therapy, electroacupuncture and rehabilitation exercises were implemented. Summary: FAI is prevalent in ice hockey players, particularly with goaltenders. Both skating and position-dependent hip joint mechanics involved in ice hockey may exacerbate or contribute to acquired and congenital forms of symptomatic FAI. As such, practitioners managing this population must address sport-specific demands in manual therapy, rehabilitation and physical training, to improve functional outcomes and prevent future injury. PMID:26816416

A test of motor skill-specific action embodiment in ice-hockey players.

Science.gov (United States)

Ong, Nicole T; Lohse, Keith R; Chua, Romeo; Sinnett, Scott; Hodges, Nicola J

2014-07-01

To further our understanding of the role of the motor system in comprehending action-related sentences, we compared action experts (athletes) to visual experts (fans) and novices when responding with an action-specific effector (either hand or foot). These conditions allowed inferences about the degree and specificity of embodiment in language comprehension. Ice hockey players, fans and novices made speeded judgments regarding the congruence between an auditorily presented sentence and a subsequently presented picture. Picture stimuli consisted of either hockey or everyday items. Half of these pictures 'matched' the action implied in the preceding sentence. Further, the action in these images involved either primarily the hand or the foot. For everyday items, action-matched items were responded to faster than action-mismatched items. However, only the players and fans showed the action-match effect for hockey items. There were no consistent effector-stimuli compatibility effects, nor skill-based interactions with compatibility, suggesting that the action-match effect was not based on motor ability per se, but rather a construction of the action based on knowledge or visual experience with the hockey related sentences. Copyright © 2014 Elsevier B.V. All rights reserved.

Adolescent perspectives of the recreational ice hockey food environment and influences on eating behaviour revealed through photovoice.

Science.gov (United States)

Caswell, M Susan; Hanning, Rhona M

2018-05-01

Unhealthy dietary behaviours are prevalent among adolescents. This might relate, in part, to obesogenic environments, including recreation food facilities. The REFRESH Study (Recreation Environment and Food Research: Experiences from Hockey) aimed to explore, from the perspectives of adolescent ice hockey players and parents, broad social and physical environmental influences on adolescent food behaviours associated with hockey participation. Players used photovoice to describe their food experiences in relation to ice hockey. The approach included photos, individual interviews and focus groups. Exemplar photographs were exhibited for stakeholders, including five parents who were interviewed. Interview and focus group transcripts were thematically analysed. Recreational ice hockey environment, Ontario, Canada, 2015-16. Ice hockey players (n 24) aged 11-15 years recruited from five leagues. Dominant influences among players included: their perceived importance of nutrients (e.g. protein) or foods (e.g. chocolate milk) for performance and recovery; marketing and branding (e.g. the pro-hockey aura of Tim Horton's®, Canada's largest quick-service restaurant); social aspects of tournaments and team meals; and moral values around 'right' and 'wrong' food choices. Both players and parents perceived recreational facility food options as unhealthy and identified that travel and time constraints contributed to less healthy choices. Results indicate recreation facilities are only one of a range of environments that influence eating behaviours of adolescent ice hockey players. Players' susceptibility to advertising/brand promotion and the value of healthy food choices for performance are findings that can inform policy and interventions to support healthy environments and behaviours.

Social Problems in Canadian Ice Hockey: An Exploration Through Film

Directory of Open Access Journals (Sweden)

Fogel Curtis A.

2014-12-01

Full Text Available While celebrated as a highly popular sport in Canada, there are many social problems existing within and around Canadian ice hockey. These problems are often overlooked and rarely depicted in academic and journalistic research on sport. These social problems include, but are not limited to: extreme violence resulting in injuries and death, hazing rituals, multiple types of sexual violence, drug abuse, financial corruption, as well as various forms of prejudice and discrimination. Prompted by pop-cultural depictions in films, this paper further identifies and explores social problems in Canadian ice hockey revealing the realism embedded within various seemingly fictional films.

Incidence of concussions in youth ice hockey players

OpenAIRE

Linzmeier, Kathleen A.; LaBella, Cynthia R.

2016-01-01

Investigators from the University of Pittsburg, University of Arkansas, Lake Erie College of Osteopathic Medicine, and Boston Children’s Hospital/Harvard Medical College researched the incidence of concussions in youth hockey in relation to age and activity setting.

Exploring Gaps in Concussion Knowledge and Knowledge Translation Among Coaches of Youth Female Hockey.

Science.gov (United States)

Guo, David; Verweel, Lee; Reed, Nick

2017-10-27

To better understand the level of concussion knowledge of youth female hockey coaches and to identify preferred methods of knowledge translation for this population. Cross-sectional survey. Participants independently completed written surveys before in-person concussion information sessions or online surveys through link provided in emails. Convenience sampling yielded 130 coaches of youth female hockey from Canada. Knowledge level on concussion, resources from which coaches obtained information on concussion, opinions on the current level of concussion knowledge, and knowledge translation. Coaches demonstrated adequate knowledge on concussion, achieving 84% correct on true-false questions and 92% correct on symptom identification accuracy. However, coaches showed limited awareness of concussion specific to mechanisms for injury (identification) and postconcussion symptoms. Internet resources were rated as the most used resources for concussion yet were not rated very helpful. Nonetheless, coaches indicated online courses and web sites as the most preferred method for concussion knowledge translation. Youth female hockey coaches have overall adequate knowledge of concussion; however, gaps in knowledge do exist. Future efforts to raise the concussion knowledge among coaches of female youth hockey should include information specific to the mechanism of injury, along with sign and symptom identification, with particular attention paid to emotional symptoms. Given the reported preferences and the widespread availability of the Internet, further exploration and research validation of online courses and web sites tailored to the youth female hockey community is encouraged.

Analysis of High-Intensity Skating in Top-Class Ice Hockey Match-Play in Relation to Training Status and Muscle Damage

DEFF Research Database (Denmark)

Lignell, Erik; Fransson, Dan; Krustrup, Peter

2018-01-01

of training status. Male ice-hockey players (n = 36) from the National Hockey League participated. Match analysis was performed during a game and physical capacity was assessed by a submaximal Yo-Yo Intermittent Recovery Ice-hockey test, level 1 (YYIR1-IHSUB). Venous blood samples were collected 24-hour post...

Prevalence of Os Styloideum in National Hockey League Players

Science.gov (United States)

Greditzer, Harry G.; Hutchinson, Ian D.; Geannette, Christian S.; Hotchkiss, Robert N.; Kelly, Bryan T.; Potter, Hollis G.

2017-01-01

Background: Os styloideum describes an accessory carpal ossicle between the trapezoid, the capitate, and the second and third metacarpals. Injuries to this tissue have been described as part of the carpal boss syndrome. While the etiology of os styloideum remains uncertain, it may represent a physiologic response to altered loading forces in the wrist, similar to the development of cam-type deformity in the hips of ice hockey players or the Bennett lesion in the shoulders of baseball pitchers. Hypothesis: Professional hockey players will have a higher prevalence of os styloideum compared with the general population. Study Design: Case series. Level of Evidence: Level 4. Methods: A retrospective review of 16 professional hockey players from 4 different National Hockey League (NHL) teams who underwent unilateral imaging of the wrist was performed. Seventeen wrists were reviewed for the presence of os styloideum. Results: Thirteen of 16 players (81%) had an os styloideum, representing an increased prevalence compared with the general population. Previous clinical and cadaveric studies estimated a general prevalence of up to 19% (P < 0.001). For the 10 players who had their leading wrist scanned, 9 had an os styloideum (90%). Ten of 11 (91%) players demonstrated a bone marrow edema pattern within the metacarpal and the os styloideum on magnetic resonance imaging. There was no significant association between the presence of an os styloideum and the player’s position, leading wrist, or years in the league. Conclusion: There appears to be an increased prevalence of os styloideum among NHL players, and team physicians should consider this finding while formulating a differential diagnosis for dorsal wrist pain. Clinical Relevance: This study identified NHL players as having an increased prevalence of os styloideum compared with the general population. By doing so, these findings represent an opportunity to enhance our understanding of the etiology, clinical significance

Cardiovascular Response to Recreational Hockey in Middle-Aged Men.

Science.gov (United States)

Goodman, Zack A; Thomas, Scott G; Wald, Robert C; Goodman, Jack M

2017-06-15

The present study examined the hemodynamic response to recreational pick-up hockey relative to maximal exercise testing in middle-aged men. A total of 23 men with a mean age of 53 ± 7 years were studied. Graded exercise testing on a cycle ergometer determined maximal oxygen consumption, blood pressure (BP), and heart rate (HR). Ambulatory BP and Holter electrocardiographic monitoring was performed during one of their weekly hockey games (mean duration = 45 ± 7.2 minutes): for "On-Ice" responses (PLAY; data recorded while standing immediately after a shift; 8.0 ± 1.4 shifts per game) and during seated recovery (BENCH), 15 minutes after the game. On-Ice HRs and BPs were significantly higher than values obtained during maximal cycle exercise, respectively (HR 174 ± 8.9 vs 163 ± 11.0 beats/min) (systolic blood pressure 202 ± 20 vs 173 ± 31 mm Hg; p game, whereas HR increased from 139 ± 20 to 155 ± 16 beats/min during the game. The myocardial oxygen demand (myocardial time tension index) increased significantly during PLAY concurrent with a decrease in estimated myocardial oxygen supply (diastolic pressure time index), with the endocardial viability ratio during PLAY demonstrating a significant decrease during the third quarter of the game (1.25 ± 0.24) versus the first quarter (1.56 ± 0.30), which remained depressed 15 minutes post-game (p men is an extremely vigorous interval exercise with increasing relative intensity as the game progresses. Hockey elicits peak BPs and HRs that can exceed values observed during maximal exercise testing and is characterized by progressive increases in myocardial oxygen demand and lowered supply during PLAY and BENCH time. Given the progressive and high cardiovascular demands, caution is warranted when estimating the cardiovascular demands of hockey from clinical stress testing, particularly in those whom coronary reserve may be compromised. Copyright © 2017 Elsevier Inc. All rights reserved.

Bodychecking rules and concussion in elite hockey.

Directory of Open Access Journals (Sweden)

Laura Donaldson

Full Text Available Athletes participating in contact sports such as ice hockey are exposed to a high risk of suffering a concussion. We determined whether recent rule changes regulating contact to the head introduced in 2010-11 and 2011-12 have been effective in reducing the incidence of concussion in the National Hockey League (NHL. A league with a longstanding ban on hits contacting the head, the Ontario Hockey League (OHL, was also studied. A retrospective study of NHL and OHL games for the 2009-10 to 2011-12 seasons was performed using official game records and team injury reports in addition to other media sources. Concussion incidence over the 3 seasons analyzed was 5.23 per 100 NHL regular season games and 5.05 per 100 OHL regular season games (IRR 1.04; 95% CI 1.01, 1.50. When injuries described as concussion-like or suspicious of concussion were included, incidences rose to 8.8 and 7.1 per 100 games respectively (IRR 1.23; 95% CI 0.81, 1.32. The number of NHL concussions or suspected concussions was lower in 2009-10 than in 2010-11 (IRR 0.61; 95% CI 0.45, 0.83, but did not increase from 2010-11 to 2011-12 (IRR 1.05; 95% CI 0.80, 1.38. 64.2% of NHL concussions were caused by bodychecking, and only 28.4% of concussions and 36.8% of suspected concussions were caused by illegal incidents. We conclude that rules regulating bodychecking to the head did not reduce the number of players suffering concussions during NHL regular season play and that further changes or stricter enforcement of existing rules may be required to minimize the risk of players suffering these injuries.

Development of offensive individual game skills and offensive game combinations in ice hockey

OpenAIRE

Janek, Michael

2015-01-01

Title: Development of offensive individual game skills and offensive game combinations in ice hockey Goals: The main aim of this thesis is to gather theoretical information about development and improvement of offensive individual game skills and offensive game combinations in ice hockey and suggest essential and key exercises of this issue. Methods: The thesis was primarily written with the use of searching method based on information from available expert literature, electronic sources and ...

Ice hockey arena: national pride or normal business?

Czech Academy of Sciences Publication Activity Database

Münich, Daniel; Humphreys, B. R.

2002-01-01

Roč. 7, č. 6 (2002), s. 11 ISSN 1211-3514 Institutional research plan: CEZ:AV0Z7085904 Keywords : ice hockey arena * costs and benefits Subject RIV: AH - Economics http://search.ebscohost.com/login.aspx?direct=true&db=bth&AN=6129219&site=ehost-live

Identification of total reversible cysteine oxidation in an atherosclerosis model using a modified biotin switch assay.

Science.gov (United States)

Li, Ru; Huang, Jiqing; Kast, Juergen

2015-05-01

Oxidative stress due to the imbalance of reactive oxygen species (ROS) and the resulting reversible cysteine oxidation (CysOX) are involved in the early proatherogenic aspect of atherosclerosis. Given that the corresponding redox signaling pathways are still unclear, a modified biotin switch assay was developed to quantify the reversible CysOX in an atherosclerosis model established by using a monocytic cell line treated with platelet releasate. The accumulation of ROS was observed in the model system and validated in human primary monocytes. Through the application of the modified biotin switch assay, we obtained the first reversible CysOX proteome for this model. A total of 75 peptides, corresponding to 53 proteins, were quantified with oxidative modification. The bioinformatics analysis of these CysOX-containing proteins highlighted biological processes including glycolysis, cytoskeleton arrangement, and redox regulation. Moreover, the reversible oxidation of three glycolysis enzymes was observed using this method, and the regulation influence was verified by an enzyme activity assay. NADPH oxidase (NOX) inhibition treatment, in conjunction with the modified biotin switch method, was used to evaluate the global CysOX status. In conclusion, this versatile modified biotin switch assay provides an approach for the quantification of all reversible CysOX and for the study of redox signaling in atherosclerosis as well as in diseases in other biological systems.

Estudio etnográfico del portero de hockey sobre patines: una vida entre paradojas

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Guillem Trabal Tañá

2016-12-01

Full Text Available Este estudio es la primera investigación en las ciencias de la actividad física y el deporte que ha analizado desde una perspectiva etnográfica el portero de hockey sobre patines. El objetivo principal es conocer cuáles son las valoraciones y los juicios que la comunidad del hockey sobre patines ha otorgado a esta figura y poder comprender cuál es la lógica externa existente a su alrededor. La metodología utilizada en este estudio ha sido la observación, la observación participante y 8 entrevistas en profundidad a porteros, jugadores y entrenadores de la máxima categoría del hockey sobre patines nacional. Los principales resultados muestran que: a el portero es considerado el jugador más determinante del equipo; b los juicios que se hacen de las actuaciones del portero tienen en cuenta variables cuantitativas: los goles encajados y el resultado final de un partido y/o competición; c dentro de la comunidad del hockey sobre patines se ha enquistado una definición de la identidad del portero que lo asocia a la locura, la soledad, la extravagancia y la rareza; d los porteros comparten una forma particular de comprender este deporte que fundamenta su asociación y su cooperación, y e la existencia del portero dentro del hockey sobre patines está llena de paradojas que se contraponen a la alta importancia atribuida a esta figura.

Lesbian erotics at women's hockey: fans, flashing, and the Booby Orrs.

Science.gov (United States)

Davidson, Judy

2009-01-01

This article analyzes a public breast flashing event that occurred during the women's ice hockey tournament at the OutGames/Western Cup Lesbigay athletic event in 2007. Employing a postfoundational perspective, I first contextualize the ice hockey subculture of the team called the Booby Orrs, outlining some of our history, norms, and context. I then tell the particular story that leads to our fans flashing their breasts as we finally scored some goals. I end with my analysis of this event: how a public nude display of sexualized women's breasts in a lesbian-coded public space prompted a resistant sporting moment, at least contingently.

Aggression, Violence and Injury in Minor League Ice Hockey: Avenues for Prevention of Injury.

Directory of Open Access Journals (Sweden)

Michael D Cusimano

Full Text Available In North America, more than 800,000 youth are registered in organized ice hockey leagues. Despite the many benefits of involvement, young players are at significant risk for injury. Body-checking and aggressive play are associated with high frequency of game-related injury including concussion. We conducted a qualitative study to understand why youth ice hockey players engage in aggressive, injury-prone behaviours on the ice.Semi-structured interviews were conducted with 61 minor ice hockey participants, including male and female players, parents, coaches, trainers, managers and a game official. Players were aged 13-15 playing on competitive body checking teams or on non-body checking teams. Interviews were manually transcribed, coded and analyzed for themes relating to aggressive play in minor ice hockey.Parents, coaches, teammates and the media exert a large influence on player behavior. Aggressive behavior is often reinforced by the player's social environment and justified by players to demonstrate loyalty to teammates and especially injured teammates by seeking revenge particularly in competitive, body-checking leagues. Among female and male players in non-body checking organizations, aggressive play is not reinforced by the social environment. These findings are discussed within the framework of social identity theory and social learning theory, in order to understand players' need to seek revenge and how the social environment reinforces aggressive behaviors.This study provides a better understanding of the players' motivations and environmental influences around aggressive and violent play which may be conducive to injury. The findings can be used to help design interventions aimed at reducing aggression and related injuries sustained during ice hockey and sports with similar cultures and rules.

Aggression, Violence and Injury in Minor League Ice Hockey: Avenues for Prevention of Injury.

Science.gov (United States)

Cusimano, Michael D; Ilie, Gabriela; Mullen, Sarah J; Pauley, Christopher R; Stulberg, Jennifer R; Topolovec-Vranic, Jane; Zhang, Stanley

2016-01-01

In North America, more than 800,000 youth are registered in organized ice hockey leagues. Despite the many benefits of involvement, young players are at significant risk for injury. Body-checking and aggressive play are associated with high frequency of game-related injury including concussion. We conducted a qualitative study to understand why youth ice hockey players engage in aggressive, injury-prone behaviours on the ice. Semi-structured interviews were conducted with 61 minor ice hockey participants, including male and female players, parents, coaches, trainers, managers and a game official. Players were aged 13-15 playing on competitive body checking teams or on non-body checking teams. Interviews were manually transcribed, coded and analyzed for themes relating to aggressive play in minor ice hockey. Parents, coaches, teammates and the media exert a large influence on player behavior. Aggressive behavior is often reinforced by the player's social environment and justified by players to demonstrate loyalty to teammates and especially injured teammates by seeking revenge particularly in competitive, body-checking leagues. Among female and male players in non-body checking organizations, aggressive play is not reinforced by the social environment. These findings are discussed within the framework of social identity theory and social learning theory, in order to understand players' need to seek revenge and how the social environment reinforces aggressive behaviors. This study provides a better understanding of the players' motivations and environmental influences around aggressive and violent play which may be conducive to injury. The findings can be used to help design interventions aimed at reducing aggression and related injuries sustained during ice hockey and sports with similar cultures and rules.

Skating start propulsion: three-dimensional kinematic analysis of elite male and female ice hockey players.

Science.gov (United States)

Shell, Jaymee R; Robbins, Shawn M K; Dixon, Philippe C; Renaud, Philippe J; Turcotte, René A; Wu, Tom; Pearsall, David J

2017-09-01

The forward skating start is a fundamental skill for male and female ice hockey players. However, performance differences by athlete's sex cannot be fully explained by physiological variables; hence, other factors such as skating technique warrant examination. Therefore, the purpose of this study was to evaluate the body movement kinematics of ice hockey skating starts between elite male and female ice hockey participants. Male (n = 9) and female (n = 10) elite ice hockey players performed five forward skating start accelerations. An 18-camera motion capture system placed on the arena ice surface captured full-body kinematics during the first seven skating start steps within 15 meters. Males' maximum skating speeds were greater than females. Skating technique sex differences were noted: in particular, females presented ~10° lower hip abduction throughout skating stance as well as ~10° greater knee extension at initial ice stance contact, conspicuously followed by a brief cessation in knee extension at the moment of ice contact, not evident in male skaters. Further study is warranted to explain why these skating technique differences exist in relation to factors such as differences in training, equipment, performance level, and anthropometrics.

The Size and Strength Development in Elite Youth Ice Hockey Players

Directory of Open Access Journals (Sweden)

Jeff R. Leiter

2016-07-01

Full Text Available Background: Ice hockey is a fast, physical sport that requires high levels of muscular strength, muscular endurance and agility. Objectives: This study was conducted to create a profile including: anthropometric measurement, muscular strength, muscular endurance, lower body jump height and distance, and agility characteristics for elite youth hockey players.  Methods: Pre-season off-ice testing results were retrospectively reviewed from a human performance database.  Variables included height, weight, body fat percentage, grip strength, push-ups/bench press, supine rows, the plank test, vertical jump, standing long jump, hip adductor and abductor strength, and the 5-10-5 shuttle, and. One-way ANOVAs (1group x 4 time and Tukeys post-hoc tests were performed to determine changes in the immediately successive age group (p<0.05. Results: Participants included male Bantam-(age: 13-14 and Midget-(age: 15-17 AAA ice-hockey players (n=260.  Age categories were grouped as 13 years old (yo(n=75, 14 yo (n=70, 15 yo (n=58, and 16-17 yo (n=57.  Increases between successive age groups were observed in the following variables: weight (13, 14, 15 and 16-17 yo, height (13 and 14 yo, left and right grip strength (13, 14, 15, and 16-17 yo, bench press (15 and 16-17 yo, left and right hip abduction (14, 15, and 16-17 yo, and vertical and standing long jump (13, 14, and 15 yo. Total time for the 5-10-5 shuttle run test decreased from 13 to 14yo, and 14 to 15 yo. Conclusion: Changes with age in off-ice performance variables of elite amateur hockey players should be recognized, followed, and addressed during player development to maximize the potential for elite performance and reduce the risk of injury.   Keywords: Athletic Performance, Training, Physical Fitness

A biomechanical comparison in the lower limb and lumbar spine between a hit and drag flick in field hockey.

Science.gov (United States)

Ng, Leo; Rosalie, Simon M; Sherry, Dorianne; Loh, Wei Bing; Sjurseth, Andreas M; Iyengar, Shrikant; Wild, Catherine Y

2018-03-01

Research has revealed that field hockey drag flickers have greater odds of hip and lumbar injuries compared to non-drag flickers (DF). This study aimed to compare the biomechanics of a field hockey hit and a specialised field hockey drag flick. Eighteen male and seven female specialised hockey DF performed a hit and a drag flick in a motion analysis laboratory with an 18-camera three-dimensional motion analysis system and a calibrated multichannel force platform to examine differences in lower limb and lumbar kinematics and kinetics. Results revealed that drag flicks were performed with more of a forward lunge on the left lower limb resulting in significantly greater left ankle dorsiflexion, knee, hip and lumbar flexion (Pshit. Drag flicks were also performed with significantly greater lateral flexion (P hit. Differences in kinematics lead to greater shear, compression and tensile forces in multiple left lower limb and lumbar joints in the drag flick compared to the hit (P hit may have ramifications with respect to injury in field hockey drag flickers.

Neck injuries presenting to emergency departments in the United States from 1990 to 1999 for ice hockey, soccer, and American football.

Science.gov (United States)

Delaney, J S; Al-Kashmiri, A

2005-04-01

To examine the number and rate of neck injuries in the community as a whole for ice hockey, soccer, and American football by analysing data from patients presenting to emergency departments in the United States from 1990 to 1999. Data compiled for the US Consumer Product Safety Commission were used to generate estimates for the total number of neck injuries and the more specific diagnoses of neck fractures, dislocations, contusions, sprains, strains, and lacerations occurring nationally from 1990 to 1999. These data were combined with yearly participation figures to generate rates of injury presenting to emergency departments for each sport. There were an estimated 5038 neck injuries from ice hockey, 19,341 from soccer, and 114 706 from American football. These could be broken down as follows: 4964 contusions, sprains, or strains from ice hockey, 17,927 from soccer, and 104 483 from football; 105 neck fractures or dislocations from ice hockey, 214 from soccer, and 1588 from football; 199 neck lacerations for ice hockey, 0 for soccer, and 621 for football. The rates for total neck injuries and combined neck contusions, sprains, or strains were higher for football than for ice hockey or soccer in all years for which data were available. The rate of neck injury in the United States was higher in football than in ice hockey or soccer in the time period studied.

Differences in Lower Body Kinematics during Forward Treadmill Skating Between Two Different Hockey Skate Designs

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Mike R. Hellyer

2016-01-01

Full Text Available Purpose: The purpose of this study was to investigate the differences in ankle flexibility and skating technique between a traditional hockey skate boot and a hockey skate boot with a flexible rear tendon guard. Skating technique was further investigated at different speeds to give insight on how skating technique alters as skating speed is increased. Methods: Eight elite hockey players were selected for the present study, which was conducted while skating on an Endless Ice Skating Treadmill.  Variables were recorded using a three-camera setup and measured from video records at five selected treadmill speeds using the Dartfish Team Pro v6 software.  Kinematic variables were then compared between the two skate designs with a doubly multivariate repeated measures design.  Statistical significance was set at p<0.05.  Results: Post hoc univariate tests comparing skate designs displayed significant increases in plantar flexion, plantar flexion angular velocity, hip extension, hip extension angular velocity, stride length, and stride velocity while participants were wearing the skates that had a flexible rear tendon guard.  Significant increases were also displayed in plantar flexion, plantar flexion angular velocity, knee extension, knee extension angular velocity, hip extension, hip extension angular velocity, hip abduction range of motion, hip abduction angular velocity, stride width, stride length, and stride velocity as the treadmill speed increased. There was also a significant decrease in the time the skate was in contact with the treadmill as treadmill speed increased. Conclusion: The results suggested that while skating forward, hockey players could improve their hockey skating technique by using hockey skates that have a flexible rear tendon guard.  This flexible tendon guard improved skating technique by increasing the time of force application to the ice by increasing the range of ankle plantar flexion during propulsion of the

Laboratory- and field-based testing as predictors of skating performance in competitive-level female ice hockey.

Science.gov (United States)

Henriksson, Tommy; Vescovi, Jason D; Fjellman-Wiklund, Anncristine; Gilenstam, Kajsa

2016-01-01

The purpose of this study was to examine whether field-based and/or laboratory-based assessments are valid tools for predicting key performance characteristics of skating in competitive-level female hockey players. Cross-sectional study. Twenty-three female ice hockey players aged 15-25 years (body mass: 66.1±6.3 kg; height: 169.5±5.5 cm), with 10.6±3.2 years playing experience volunteered to participate in the study. The field-based assessments included 20 m sprint, squat jump, countermovement jump, 30-second repeated jump test, standing long jump, single-leg standing long jump, 20 m shuttle run test, isometric leg pull, one-repetition maximum bench press, and one-repetition maximum squats. The laboratory-based assessments included body composition (dual energy X-ray absorptiometry), maximal aerobic power, and isokinetic strength (Biodex). The on-ice tests included agility cornering s-turn, cone agility skate, transition agility skate, and modified repeat skate sprint. Data were analyzed using stepwise multivariate linear regression analysis. Linear regression analysis was used to establish the relationship between key performance characteristics of skating and the predictor variables. Regression models (adj R (2)) for the on-ice variables ranged from 0.244 to 0.663 for the field-based assessments and from 0.136 to 0.420 for the laboratory-based assessments. Single-leg tests were the strongest predictors for key performance characteristics of skating. Single leg standing long jump alone explained 57.1%, 38.1%, and 29.1% of the variance in skating time during transition agility skate, agility cornering s-turn, and modified repeat skate sprint, respectively. Isokinetic peak torque in the quadriceps at 90° explained 42.0% and 32.2% of the variance in skating time during agility cornering s-turn and modified repeat skate sprint, respectively. Field-based assessments, particularly single-leg tests, are an adequate substitute to more expensive and time

Establishment of modified reversible regional cerebral ischemic models

International Nuclear Information System (INIS)

Ji Xunming; Ling Feng; Zhao Xiqing; Xuan Yun; Wang Yueqin; Ling Xiaolan; Chang Hongjun; Zhang Zhiping

2005-01-01

Objective: Modifying the method of establishing reversible middle cerebral ischemic models in rats for improvement of the stability and rate of success, so as to raise the reliability of cerebral ischemic study. Methods: Sixty male Wistar rats were randomly divided into two groups, modified and control groups, 30 rats in each group. The method of silicone- tipping on one end of the nylon suture was used to modify the establishment of embolus, and tip-heating method was used to establish the traditional embolus with all the other steps of the procedure just the same. The Zea Longa 5 scoring scale was used to estimate the neurological deficiency while TTC staining method was used to measure and calculate the volume of cerebral infarction. The percentage of successful models with 3-4 grade scorings and the coefficient of the variations of cerebral infarct volume were used to estimate the stability of the models. Results: The rate of success of establishment models in the modification group was significantly higher in comparing with the traditional group (93% vs 60%, χ 2 =9.32, P=0.002). The percentage of model establishment with 3-4 grade neurological scores in modification group was higher than that in the traditional group 96.4% vs 61.2%, χ 2 =9.51, P=0.002). The cerebral infarct volume in modification group and traditional group were (4.1450±0.5019) cm 3 and (3.8435 ± 0.8164) cm 3 , and the coefficients of variation were 12.01% and 21.24% respectively, which indicated that the stability of models was significantly higher in modification group than in the traditional one. Conclusions: The rates of success and stability of the models for reversible focal cerebral ischemia made by the modification method were significantly improved, with decreasing the cost of model creation and increasing the accuracy of study of ischemic cerebral vascular disease. (authors)

The hockey-stick method to estimate evening dim light melatonin onset (DLMO) in humans.

Science.gov (United States)

Danilenko, Konstantin V; Verevkin, Evgeniy G; Antyufeev, Viktor S; Wirz-Justice, Anna; Cajochen, Christian

2014-04-01

The onset of melatonin secretion in the evening is the most reliable and most widely used index of circadian timing in humans. Saliva (or plasma) is usually sampled every 0.5-1 hours under dim-light conditions in the evening 5-6 hours before usual bedtime to assess the dim-light melatonin onset (DLMO). For many years, attempts have been made to find a reliable objective determination of melatonin onset time either by fixed or dynamic threshold approaches. The here-developed hockey-stick algorithm, used as an interactive computer-based approach, fits the evening melatonin profile by a piecewise linear-parabolic function represented as a straight line switching to the branch of a parabola. The switch point is considered to reliably estimate melatonin rise time. We applied the hockey-stick method to 109 half-hourly melatonin profiles to assess the DLMOs and compared these estimates to visual ratings from three experts in the field. The DLMOs of 103 profiles were considered to be clearly quantifiable. The hockey-stick DLMO estimates were on average 4 minutes earlier than the experts' estimates, with a range of -27 to +13 minutes; in 47% of the cases the difference fell within ±5 minutes, in 98% within -20 to +13 minutes. The raters' and hockey-stick estimates showed poor accordance with DLMOs defined by threshold methods. Thus, the hockey-stick algorithm is a reliable objective method to estimate melatonin rise time, which does not depend on a threshold value and is free from errors arising from differences in subjective circadian phase estimates. The method is available as a computerized program that can be easily used in research settings and clinical practice either for salivary or plasma melatonin values.

THE COMPETITIVE DEMANDS OF ELITE MALE RINK HOCKEY

Directory of Open Access Journals (Sweden)

Aladino Fernández

2013-06-01

Full Text Available The aim of this study was to simulate the activity pattern of rink hockey by designing a specific skate test (ST to study the energy expenditure and metabolic responses to this intermittent high-intensity exercise and extrapolate the results from the test to competition. Six rink hockey players performed, in three phases, the 20-metre multi-stage shuttle roller skate test, a tournament match and the ST. Heart rate was monitored in all three phases. Blood lactate, oxygen consumption, ventilation and respiratory exchange ratio were also recorded during the ST. Peak HR was 190.7±7.2 beats · min-1. There were no differences in peak HR between the three tests. Mean HR was similar between the ST and the match (86% and 87% of HRmax, respectively. Peak and mean ventilation averaged 111.0±8.8 L · min-1 and 70.3±14.0 L · min-1 (60% of VEmax, respectively. VO2max was 56.3±8.4 mL · kg-1 · min-1, and mean oxygen consumption was 40.9±7.9 mL · kg-1 · min-1 (70% of VO2max. Maximum blood lactate concentration was 7.2±1.3 mmol · L-1. ST yielded an energy expenditure of 899.1±232.9 kJ, and energy power was 59.9±15.5 kJ · min-1. These findings suggest that the ST is suitable for estimating the physiological demands of competitive rink hockey, which places a heavy demand on the aerobic and anaerobic systems, and requires high energy consumption.

Movement Characteristics and Heart Rate Profiles Displayed by Female University Ice Hockey Players

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Joel Jackson

2016-01-01

Full Text Available Background: Women’s ice hockey is widely popular but the various movement patterns, heart rate responses and work to rest ratios during competitive games has not been adequately investigated.  Objectives: This study determined the frequency and duration of movements that female players perform in ice hockey games using time-motion analysis. The intensity of the game activities were also assessed by heart rate (HR responses and work to rest ratios (W:R. Methods: Twenty-two university female ice hockey players were filmed performing a number of movements during three regular season league games. Results: The following movement patterns were categorized in percent of time performed during the games: forward gliding on ice (36.3 ± 6.2%, forward skating at a moderate intensity (31.2 ± 6.2%, backward glide (9.5 ± 4.1%, standing (7.1 ± 5.9%, struggling (6.3 ± 2.6%, forward skating at maximal intensity (5.3 ± 3.3%, backwards skating at moderate intensity (3.1 ± 3.3%. Defense stood and glided backward more than forwards but skated less at a high or maximal intensity. Positional differences were also observed during different game play situations. The highest HR (±SD achieved during shifts was 182 ± 10 and HR averaged 174 ± 9 bpm for the whole duration of the shifts. The shift and game W:R ratios for all players were 1:1.6 and 1: 3.7, respectively. Conclusions: The findings of this study indicate that female ice hockey games are played at a low to moderate intensity most of the time (~84% of the time spent and are interspersed with brief, intermittent high intensity activities that vary according to player position and game play situation. It was also apparent that female players display markedly high HR responses during game-play indicative of a substantial cardiovascular demand in ice hockey. Keywords: game analysis, work to rest ratios, exercise intensity

Analysis of High-Intensity Skating in Top-Class Ice Hockey Match-Play in Relation to Training Status and Muscle Damage.

Science.gov (United States)

Lignell, Erik; Fransson, Dan; Krustrup, Peter; Mohr, Magni

2018-05-01

Lignell, E, Fransson, D, Krustrup, P, and Mohr, M. Analysis of high-intensity skating in top-class ice hockey match-play in relation to training status and muscle damage. J Strength Cond Res 32(5): 1303-1310, 2018-We examined high-intensity activities in a top-class ice-hockey game and the effect of training status. Male ice-hockey players (n = 36) from the National Hockey League participated. Match analysis was performed during a game and physical capacity was assessed by a submaximal Yo-Yo Intermittent Recovery Ice-hockey test, level 1 (YYIR1-IHSUB). Venous blood samples were collected 24-hour post-game to determine markers of muscle damage. Players performed 119 ± 8 and 31 ± 3 m·min of high intensity and sprint skating, respectively, during a game. Total distance covered was 4,606 ± 219 m (2,260-6,749 m), of which high-intensity distance was 2042 ± 97 m (757-3,026 m). Sprint-skating speed was 5-8% higher (p ≤ 0.05) in periods 1 and 2 vs. period 3 and overtime. Defensemen (D) covered 29% more (p ≤ 0.05) skating in total than forwards (F) and were on the ice 47% longer. However, F performed 54% more (p ≤ 0.05) high-intensity skating per minute than defensemen. Plasma creatine kinase (CK) was 338 ± 45 (78-757) U·L 24-hour post-game. Heart rate loading during YYIR1-IHSUB correlated inversely (p ≤ 0.05) to the frequency of high-intensity skating bouts (r = -0.55) and V[Combining Dot Above]O2max (r = -0.85) and positively to post-game CK (r = 0.49; p ≤ 0.05). In conclusion, ice hockey is a multiple-sprint sport that provokes fatigue in the latter half of a game. Forwards perform more intense skating than defensemen. Moreover, high-intensity game activities during top-class ice hockey are correlated with cardiovascular loading during a submaximal skating test. Taken together, training of elite ice-hockey players should improve the ability for repeated high-intensity skating, and testing should include the YYIR1-IHSUB test as an indicator for ice-hockey

Effectiveness of interventions to reduce aggression and injuries among ice hockey players: a systematic review

Science.gov (United States)

Cusimano, Michael D.; Nastis, Sofia; Zuccaro, Laura

2013-01-01

Background: The increasing incidence of injuries related to playing ice hockey is an important public health issue. We conducted a systematic review to evaluate the effectiveness of interventions designed to reduce injuries related to aggressive acts in ice hockey. Methods: We identified relevant articles by searching electronic databases from their inception through July 2012, by using Internet search engines, and by manually searching sports medicine journals, the book series Safety in Ice Hockey and reference lists of included articles. We included studies that evaluated interventions to reduce aggression-related injuries and reported ratings of aggressive behaviour or rates of penalties or injuries. Results: We identified 18 eligible studies. Most involved players in minor hockey leagues. Of 13 studies that evaluated changes in mandatory rules intended to lessen aggression (most commonly the restriction of body-checking), 11 observed a reduction in penalty or injury rates associated with rule changes, and 9 of these showed a statistically significant decrease. The mean number of penalties decreased by 1.2–5.9 per game, and injury rates decreased 3- to 12-fold. All 3 studies of educational interventions showed a reduction in penalty rates, but they were not powered or designed to show a change in injury rates. In 2 studies of cognitive behavioural interventions, reductions in aggressive behaviours were observed. Interpretation: Changes to mandatory rules were associated with reductions in penalties for aggressive acts and in injuries related to aggression among ice hockey players. Effects of educational and cognitive behavioural interventions on injury rates are less clear. Well-designed studies of multifaceted strategies that combine such approaches are required. PMID:23209118

Factors Influencing the Underreporting of Concussion in Sports: A Qualitative Study of Minor Hockey Participants.

Science.gov (United States)

Cusimano, Michael D; Topolovec-Vranic, Jane; Zhang, Stanley; Mullen, Sarah J; Wong, Mattew; Ilie, Gabriela

2017-07-01

The present study is to identify factors contributing to underreporting of concussion in adolescent athletes. Qualitative interviews. Participants were interviewed in an office environment. Interviews were conducted with 31 minor hockey players, 10 parents, 6 coaches, 4 trainers, 2 managers, and one game official. Players were 13 to 15 year old. With selective sampling, an inductive approach of analyzing the interviews was undertaken and themes were identified and analyzed. Underreporting is a complex phenomenon. A number of risk factors related to hockey culture, players, reference others, and rules of play were assessed. Reasons not reporting concussion is accepted in minor hockey. Aspects of hockey culture such as an overemphasis on winning games and upheld misperceptions about the risks associated with concussion were identified as relevant to the underreporting of concussions. Various factors relevant to the underreporting of concussions include player's motivation to win, group membership dynamics such as a player's role as the team's "enforcer," coaches' own motivation to win to further their own opportunities in the sport, and parents' personal financial interest or alternative agenda in terms of time commitments and their child's future career prospects. Our findings indicate that underreporting of concussion among those players interviewed appears to be prevalent and associated with misconceptions about injury risk, and a culture that both reinforces and encourages underreporting with tacit or overt complicity of parents and coaches. Our findings support the need to alter the culture of violence and tough play in hockey by education, rule changes, economic measures, and changes in governance of the sport. Interviewing more stakeholders and policy makers would shed light on such potential interventions.

The Protective Effect of Kevlar ® Socks Against Hockey Skate Blade Injuries: A Biomechanical Study

Science.gov (United States)

Nauth, Aaron; Aziz, Mina; Tsuji, Matthew; Whelan, Daniel B.; Theodoropoulos, John S.; Zdero, Rad

2014-01-01

Objectives: Several recent high profile injuries to elite players in the National Hockey League (NHL) secondary to skate blade lacerations have generated significant interest in these injuries and possible methods to protect against them. These injuries are typically due to direct contact of the skate blade of another player with posterior aspect of the calf resulting in a range of potential injuries to tendons or neurovascular structures. The Achilles tendon is most commonly involved. Kevlar® reinforced socks have recently become available for hockey players to wear and are cited as providing possible protection against such injuries. However, there has been no investigation of the possible protective effects of Kevlar® reinforced socks against skate blade injuries, and it is currently unknown what protective effects, if any, that these socks provide against these injuries. The proposed study sought to address this by conducting a biomechanical investigation of the protective effects of Kevlar® reinforced socks against Achilles tendon injuries in a simulated model of skate blade injury using human cadaver limbs. This novel investigation is the first to address the possible benefits to hockey players of wearing Kevlar® reinforced socks. Methods: Seven matched pairs of human cadaver lower limbs were fitted with a Kevlar ® reinforced sock comprised of 60% Kevlar®/20% Coolmax® polyester/18 % Nylon/12% Spandex (Bauer Elite Performance Skate Sock) on one limb and a standard synthetic sock comprised of 51% polyester/47% nylon/2% spandex (Bauer Premium Performance Skate Sock) on the contralateral limb as a control. Each limb was then mounted on a Materials Testing System (MTS) with the ankle dorsiflexed to 90° and the knee held in full extension using a custom designed jig. Specimens were then impacted with a hockey skate blade directed at the posterior calf, 12 cm above the heel, at an angle of 45° and a speed of 31m/s, to a penetration depth of 4.3 cm, to

La eficacia del efecto látigo en el drag flick en el hockey hierba The effectiveness of the bullwhip effect in the Drag-flick in field hockey

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C. López de Subijana

2010-09-01

Full Text Available

El penalty córner es una de las jugadas más importantes en el hockey hierba. El drag-flick es la técnica de golpeo más eficaz en las jugadas de penalty córner (McLaughin, 1997. Los objetivos del presente estudio fueron el describir los parámetros cinemáticos del drag-flick en jugadores de nivel internacional y analizar las diferencias intergénero. La muestra fueron trece sujetos, un modelo, seis hombres y seis mujeres. El sistema de captura automático VICON registró 20 lanzamientos de cada jugador con una frecuencia de muestreo de 250 Hz. Las velocidades máximas angulares de las caderas, hombros y stick  fueron superiores  (p<0.01 en el modelo que en ambos grupos de género. Mediante la comparación estadística del modelo con ambos grupos de género se han podido determinar las claves de este gesto técnico, siendo necesario un movimiento hacia atrás del stick (efecto látigo antes de la aceleración de caderas y hombros, para terminar el gesto con la máxima aceleración del stick.
Palabras Clave: Biomecánica, drag-flick, hockey hierba, cinemática

The penalty corner is one of the most important goal plays in field hockey. The drag-flick is more efficient than other techniques when playing a penalty corner. The aims of this study were to describe the kinematics of international field hockey players during the drag-flick and to analyse gender differences. Thirteen participants, one male drag-flicker, six males and six females participated in the study. VICON optoelectronic system measured the kinematic parameters from the drag-flick with six cameras sampling at 250 Hz. Twenty trials were captured from each subject. Ball velocity at release, hips maximum angular velocity, stick minimum and maximum angular velocities were higher (p<0.01 in the drag-flicker than in both gender groups. Comparing with the drag-flicker we have found the cues of the skill, being necessary a

Reversible end-to-end assembly of gold nanorods using a disulfide-modified polypeptide

International Nuclear Information System (INIS)

Walker, David A; Gupta, Vinay K

2008-01-01

Directing the self-assembly of colloidal particles into nanostructures is of great interest in nanotechnology. Here, reversible end-to-end assembly of gold nanorods (GNR) is induced by pH-dependent changes in the secondary conformation of a disulfide-modified poly(L-glutamic acid) (SSPLGA). The disulfide anchoring group drives chemisorption of the polyacid onto the end of the gold nanorods in an ethanolic solution. A layer of poly(vinyl pyrrolidone) is adsorbed on the positively charged, surfactant-stabilized GNR to screen the surfactant bilayer charge and provide stability for dispersion of the GNR in ethanol. For comparison, irreversible end-to-end assembly using a bidentate ligand, namely 1,6-hexanedithiol, is also performed. Characterization of the modified GNR and its end-to-end linking behavior using SSPLGA and hexanedithiol is performed using dynamic light scattering (DLS), UV-vis absorption spectroscopy and transmission electron microscopy (TEM). Experimental results show that, in a colloidal solution of GNR-SSPLGA at a pH∼3.5, where the PLGA is in an α-helical conformation, the modified GNR self-assemble into one-dimensional nanostructures. The linking behavior can be reversed by increasing the pH (>8.5) to drive the conformation of the polypeptide to a random coil and this reversal with pH occurs rapidly within minutes. Cycling the pH multiple times between low and high pH values can be used to drive the formation of the nanostructures of the GNR and disperse them in solution.

A survey of mental skills training among South African field hockey ...

African Journals Online (AJOL)

African Journal for Physical Activity and Health Sciences ... observed for concentration, achievement motivation and activation control. ... The participants in the study perceived MST as an important tool to enhance performance in field hockey.

Robust and Reversible Audio Watermarking by Modifying Statistical Features in Time Domain

Directory of Open Access Journals (Sweden)

Shijun Xiang

2017-01-01

Full Text Available Robust and reversible watermarking is a potential technique in many sensitive applications, such as lossless audio or medical image systems. This paper presents a novel robust reversible audio watermarking method by modifying the statistic features in time domain in the way that the histogram of these statistical values is shifted for data hiding. Firstly, the original audio is divided into nonoverlapped equal-sized frames. In each frame, the use of three samples as a group generates a prediction error and a statistical feature value is calculated as the sum of all the prediction errors in the frame. The watermark bits are embedded into the frames by shifting the histogram of the statistical features. The watermark is reversible and robust to common signal processing operations. Experimental results have shown that the proposed method not only is reversible but also achieves satisfactory robustness to MP3 compression of 64 kbps and additive Gaussian noise of 35 dB.

Common Ice Hockey Injuries and Treatment: A Current Concepts Review.

Science.gov (United States)

Mosenthal, William; Kim, Michael; Holzshu, Robert; Hanypsiak, Bryan; Athiviraham, Aravind

Injuries are common in ice hockey, a contact sport where players skate at high speeds on a sheet of ice and shoot a vulcanized rubber puck in excess of one hundred miles per hour. This article reviews the diagnoses and treatment of concussions, injuries to the cervical spine, and lower and upper extremities as they pertain to hockey players. Soft tissue injury of the shoulder, acromioclavicular joint separation, glenohumeral joint dislocation, clavicle fractures, metacarpal fractures, and olecranon bursitis are discussed in the upper-extremity section of the article. Lower-extremity injuries reviewed in this article include adductor strain, athletic pubalgia, femoroacetabular impingement, sports hernia, medial collateral and anterior cruciate ligament tears, skate bite, and ankle sprains. This review is intended to aid the sports medicine physician in providing optimal sports-specific care to allow their athlete to return to their preinjury level of performance.

MODEL PENGEMBANGAN PERMAINAN FUN HOCKEY PADA SISWA KELAS XI SMA NEGERI 1 BAWANG KECAMATAN BAWANG KABUPATEN BATANG TAHUN 2014.

Directory of Open Access Journals (Sweden)

Wahyu Putri Vembriana Dewi

2015-07-01

Full Text Available The purpose of this study was to produce a model of the development of the game Fun Hockey in the XI student class of SMAN 1 Bawang, Bawang Subdistrict, Batang. The method used is the development of Borg & Gall, namely: (1 to analyze the products that will be developed that are obtained from the information collection, including field observations and study of literature, (2 develop a form of initial product model game Fun Hockey, (3 expert validation test which uses a physical education expert (hockey skills and learning experts physical education in high school, as well as small scale test, using questionnaires and consultations later in the analysis, (4 the first product revision, revision of the product based on the results of expert evaluation and testing of small-scale (12 students, (5 field trials (28 students, (6 the revision of the final product is done based on the results of field trials, (7 the outcome Fun Hockey game for students of XI class generated through the revision of field trials. From the data on the differences can concluded that the Fun Hockey Game model development can be implemented as an alternative model for students learning physical education XI class SMAN 1 Bawang, Bawang Subdistrict, Batang.

Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players

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effrey M. Janot, Nicholas M. Beltz, Lance D. Dalleck

2015-09-01

Full Text Available The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15 and women (n = 11 hockey players (age = 20.5 ± 1.4 years participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ, 40-yd dash (36.58m, 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop, and 1.5 mile (2.4km run. Results indicated that 40-yd dash (36.58m, VJ, 1.5 mile (2.4km run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1 slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time + (0.005 x 1.5 mile run, 2 fastest repeat skate time = 9.762 - (0.089 x VJ - (0.998 x 40-yd dash time, 3 average repeat skate time = 7.770 + (1.041 x 40-yd dash time - (0.63 x VJ + (0.003 x 1.5 mile time, and 4 47.85 m speed test = 7.707 - (0.050 x VJ - (0.01 x % drop. It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players.

Mental skill levels of South African male student field hockey players ...

African Journals Online (AJOL)

Mental skill levels of South African male student field hockey players in different playing positions. ... African Journal for Physical Activity and Health Sciences ... The positional results were compared by means of effect sizes (expressed as ...

MASCULINITY AND SPORT REVISTED: A REVIEW OF LITERATURE ON HEGEMONIC MASCULINITY AND MEN'S ICE HOCKEY IN CANADA

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Cheryl A. MacDonald

2014-04-01

Full Text Available Ice hockey is particularly significant in Canada as it acts as a primary site of socialization for boys and men. This form of socialization raises questions about masculinity on the public agenda in terms of the problematic nature of hypermasculinity in sport, stereotypical images of athletes, and questions of social responsibility as both men and athletes. These issues are presently relevant as Canada (and perhaps all of North America finds itself in an era characterized by accounts in mainstream media of competitive athletes’ cavalier lifestyles, hazing, violence, homophobia, drug addictions, and suicides. This review of literature uses secondary research to problematize masculinity in the ice hockey context by presenting the overarching claim that male hockey players are hegemonically masculine individuals. The piece begins by defining Australian sociologist R.W. Connell’s (1987 concept of hegemonic masculinity and situating it in the contemporary academic context. Next, it offers an overview of relevant literature on masculinity and sport along with a concise examination of scholarly work on the relationship between hegemonic masculinity and ice hockey in Canada. It concludes by summarising calls for further research in the literature and by suggesting approaches to future studies in the field.

A 26 year physiological description of a National Hockey League team.

Science.gov (United States)

Quinney, H A; Dewart, Randy; Game, Alex; Snydmiller, Gary; Warburton, Darren; Bell, Gordon

2008-08-01

The primary purpose of this investigation was to examine the physiological profile of a National Hockey League (NHL) team over a period of 26 years. All measurements were made at a similar time of year (pre-season) in 703 male (mean age +/- SD = 24 +/- 4 y) hockey players. The data were analyzed across years, between positions (defensemen, forwards, and goaltenders), and between what were deemed successful and non-successful years using a combination of points acquired during the season and play-off success. Most anthropometric (height, mass, and BMI) and physiological parameters (absolute and relative VO2 peak, relative peak 5 s power output, abdominal endurance, and combined grip strength) showed a gradual increase over the 26 year period. Defensemen were taller and heavier, had higher absolute VO2 peak, and had greater combined grip strength than forwards and goaltenders. Forwards were younger and had higher values for relative VO2 peak. Goaltenders were shorter, had less body mass, a higher sum of skinfolds, lower VO2 peak, and better flexibility. The overall pre-season fitness profile was not related to team success. In conclusion, this study revealed that the fitness profile for a professional NHL ice-hockey team exhibited increases in player size and anaerobic and aerobic fitness parameters over a 26 year period that differed by position. However, this evolution of physiological profile did not necessarily translate into team success in this particular NHL franchise.

Campo de hockey Mariñamansa. Orense (España

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García Tolosana, Carlos

2000-06-01

Full Text Available This article concerns the construction of a Hockey Court made of artificial green and the building where is located the changing room. The arrangement of the surrounding land and the forecast of the necessary room lo allow the construction of a complementary building where the gymnasium will be located, as well as the Federation headquarters, classrooms, a center lo control drugs and some warehouses, are also foreseen.La actuación de que se trata se concreta en la construcción de un Campo de Hockey de Hierba Artificial y del edificio de vestuarios que lo apoya y complementa. También se contempla la ordenación del entorno próximo y la previsión de espacio para permitir la construcción de un edificio complementario en el que ubicar un gimnasio, los locales de la federación, aulas, un centro de control de dopaje y una dotación de almacenes.

A Hockey Night in Canada: An Imagined Conversation between Theorists

Science.gov (United States)

Fogel, Curtis

2010-01-01

In this paper, various methodological issues surrounding the sociological study of sport are explored. Through an imagined dialogue between two graduate students at a hockey game, this work brings together three divergent approaches to social enquiry: Positivist Grounded Theory, Constructivist Grounded Theory, and Actor-Network Theory. This paper…

Comparison of dynamic balance in collegiate field hockey and football players using star excursion balance test.

Science.gov (United States)

Bhat, Rashi; Moiz, Jamal Ali

2013-09-01

The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45° increments. The subjects were instructed to maintain a stable single leg stance with the test leg with shoes off and to reach for maximal distance with the other leg in each of the 8 directions. A pencil was used to point and read the distance to which each subject's foot reached. The normalized leg reach distances in each direction were summed for both limbs and the total sum of the mean of summed normalized distances of both limbs were calculated. There was no significant difference in all the directions of star excursion balance test scores in both the groups. Additionally, composite reach distances of both groups also found non-significant (P=0.5). However, the posterior (P=0.05) and lateral (P=0.03) normalized reach distances were significantly more in field hockey players. Field hockey players and football players did not differ in terms of dynamic balance.

Modified interferometric imaging condition for reverse-time migration

Science.gov (United States)

Guo, Xue-Bao; Liu, Hong; Shi, Ying

2018-01-01

For reverse-time migration, high-resolution imaging mainly depends on the accuracy of the velocity model and the imaging condition. In practice, however, the small-scale components of the velocity model cannot be estimated by tomographical methods; therefore, the wavefields are not accurately reconstructed from the background velocity, and the imaging process will generate artefacts. Some of the noise is due to cross-correlation of unrelated seismic events. Interferometric imaging condition suppresses imaging noise very effectively, especially the unknown random disturbance of the small-scale part. The conventional interferometric imaging condition is extended in this study to obtain a new imaging condition based on the pseudo-Wigner distribution function (WDF). Numerical examples show that the modified interferometric imaging condition improves imaging precision.

An intelligent talent recognition of male youth field hockey players ...

African Journals Online (AJOL)

The aim of this study was to determine the most significant of physical fitness, anthro-energy intake and psychological variables in identifying the talented male youth field hockey players. 40 male players (age, 14.6 ± 1.2 years) from Terengganu sport academy were evaluated in different tests and measurements.

Heart Rate and Energy Expenditure in Division I Field Hockey Players During Competitive Play.

Science.gov (United States)

Sell, Katie M; Ledesma, Allison B

2016-08-01

Sell, KM and Ledesma, AB. Heart rate and energy expenditure in Division I field hockey players during competitive play. J Strength Cond Res 30(8): 2122-2128, 2016-The purpose of this study was to quantify energy expenditure and heart rate data for Division I female field hockey players during competitive play. Ten female Division I collegiate field hockey athletes (19.8 ± 1.6 years; 166.4 ± 6.1 cm; 58.2 ± 5.3 kg) completed the Yo-Yo intermittent endurance test to determine maximal heart rate. One week later, all subjects wore a heart rate monitor during a series of 3 matches in an off-season competition. Average heart rate (AvHR), average percentage of maximal heart rate (AvHR%), peak exercise heart rate (PExHR), and percentage of maximal heart rate (PExHR%), time spent in each of the predetermined heart rate zones, and caloric expenditure per minute of exercise (kcalM) were determined for all players. Differences between positions (backs, midfielders, and forwards) were assessed. No significant differences in AvHR, AvHR%, PExHR, PExHR%, and %TM were observed between playing positions. The AvHR% and PExHR% for each position fell into zones 4 (77-93% HRmax) and 5 (>93% HRmax), respectively, and significantly more time was spent in zone 4 compared with zones 1, 2, 3, and 5 across all players (p ≤ 0.05). The kcalM reflected very heavy intensity exercise. The results of this study will contribute toward understanding the sport-specific physiological demands of women's field hockey and has specific implications for the duration and schedule of training regimens.

Improvement of Ice Hockey Players' On-Ice Sprint With Combined Plyometric and Strength Training.

Science.gov (United States)

Dæhlin, Torstein E; Haugen, Ole C; Haugerud, Simen; Hollan, Ivana; Raastad, Truls; Rønnestad, Bent R

2017-08-01

Combined plyometric and strength training has previously been suggested as a strategy to improve skating performance in ice hockey players. However, the effects of combined plyometric and strength training have not previously been compared with the effects of strength training only. To compare the effects of combined plyometric and strength training on ice hockey players' skating sprint performance with those of strength training only. Eighteen participants were randomly assigned to 2 groups that completed 5 strength-training sessions/wk for 8 wk. One group included plyometric exercises at the start of 3 sessions/wk (PLY+ST), and the other group included core exercises in the same sessions (ST). Tests of 10- and 35-m skating sprints, horizontal jumping, 1-repetition-maximum (1 RM) squat, skating multistage aerobic test (SMAT), maximal oxygen consumption, repeated cycle sprints, and body composition were performed before and after the intervention. The participants increased their 1RM squat, lean mass, and body mass (P plyometric and strength training for 8 wk was superior to strength training alone at improving 10-m on-ice sprint performance in high-level ice hockey players.

Hockey, iPads, and Projectile Motion in a Physics Classroom

Science.gov (United States)

Hechter, Richard P.

2013-01-01

With the increased availability of modern technology and handheld probeware for classrooms, the iPad and the Video Physics application developed by Vernier are used to capture and analyze the motion of an ice hockey puck within secondary-level physics education. Students collect, analyze, and generate digital modes of representation of physics…

Reversed phase column extraction studies to recovery of uranium using a modified perlite

International Nuclear Information System (INIS)

Akcay, H.

2006-01-01

Reversed phase column (RPC) extraction chromatography is an useful technique and has been carried out successfully to the separation of various metals and organic compounds. Its application has received considerable attention because it combines the selectivity of LLE with the advantage of chromatography. The efficiency of the separation by RPC depends on both the chemical and physical properties of the solid support and the stationary phase. This work describes the preparation of an improved adsorbent from natural perlite and its properties to uptake of uranyl ion. Perlite is a volcanic glassy rock produced in commercially workable quantities from mines of Aegean region of Turkey and contains 70-75% CO 2 .The CO 2 was converted to soluble silicates with NaOH modification then its acidification to form hydrogen which turned into xerogels upon drying. Fundamental parameters (particle size, specific surface area, pore size and volume, surface hydroxyl group density) were determined for modified perlite and it was silanized then loaded with 20% (w/w) TBP before being used as reversed phase column chromatography solid support. Finally the sorption of UO 2 + 2 from aqueous solutions by the modified perlite was investigated using Batch techniques. The use of TBP-loaded perlite as a reversed phase column (RPC) extraction chromatography support seems to be useful to uptake of UO 2 + 2 from aqueous solutions and to separate from various cations

Fuerza lumbar en jugadores de hockey hierba

OpenAIRE

Til Pérez, Lluís; Barceló Peiró, Oriol; Pomés Díes, Teresa; Martínez Navas, Roberto; Galilea Ballarini, Pedro; Bellver Vives, Montserrat

2007-01-01

Introducción: El dolor lumbar tiene una alta prevalencia entre los deportistas, se ha relacionado con déficits en la fuerza extensora lumbar, y el hecho de padecerlo representa un obstáculo importante para la práctica de deportes de alta intensidad. Método: Se ha medido la fuerza lumbar en 2 grupos de practicantes de hockey hierba mediante máquina MedX® y un test de resistencia isométrico lumbar. Resultados: Entre ambos grupos los resultados han sido muy homogéneos....

Examining the relationship between relative age, competition level, and dropout rates in male youth ice-hockey players.

Science.gov (United States)

Lemez, S; Baker, J; Horton, S; Wattie, N; Weir, P

2014-12-01

The relative age effect suggests that athletes born in the first two quartiles of a given selection year experience a selection advantage and therefore a greater opportunity for success. We describe two studies examining the relationship between relative age, competition level, and dropout rates of Ontario Minor Hockey Association male ice-hockey players from ages 10 to 15 years (n = 14 325). In Study 1, dropout was highest among players born in quartiles three and four [χ(2) (3) = 16.32, P < 0.05; w = 0.06], while Study 2 found dropped out players to have less movement between competition levels compared to retained players. This study confirms a relationship between relative age and dropout from ice-hockey and adds further depth to our understanding of this persistent phenomenon. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Update and Overview of Spinal Injuries in Canadian Ice Hockey, 1943 to 2011: The Continuing Need for Injury Prevention and Education.

Science.gov (United States)

Tator, Charles H; Provvidenza, Christine; Cassidy, J David

2016-05-01

To identify spinal injuries in Canadian ice hockey from 2006 to 2011 and to discuss data from 1943 to 2011 and impact of injury prevention programs. Data about spinal injuries with and without spinal cord injury in ice hockey have been collected by ThinkFirst's (now Parachute Canada) Canadian Ice Hockey Spinal Injuries Registry since 1981 through questionnaires from practitioners, ice hockey organizations, and media. All Canadian provinces and territories. All registered Canadian ice hockey players. Age, gender, level of play, location, mechanism of injury. Incidence, incidence rate, prevalence, and nature (morbidity) of the injuries. Between 2006 and 2011, 44 cases occurred, 4 (9.1%) of which were severe. The incidence in the recent years continues to be lower than the peak years. From 1943 to 2011, 355 cases have been documented, primarily males (97.7%) and cervical spine injuries (78.9%), resulting from impact with the boards (64.2%). Check or push from behind (36.0%) was still the most common cause of injury, although slightly lower during 2006 to 2011. From 1943 to 2011, Prince Edward Island, New Brunswick, and British Columbia/Yukon had the highest injury rates. Ontario and Quebec continued to show markedly different injury rates, with Ontario more than twice that of Quebec. Current data for 2006 to 2011 indicate that spinal injuries in ice hockey continue to occur, although still at lower rates than the peak years 1982 to 1995. It is imperative to continue educating players and team officials about spinal injury prevention and to reinforce the rules against checking or pushing from behind to reduce the incidence of these serious injuries.

An on-ice measurement approach to analyse the biomechanics of ice hockey skating.

Science.gov (United States)

Buckeridge, Erica; LeVangie, Marc C; Stetter, Bernd; Nigg, Sandro R; Nigg, Benno M

2015-01-01

Skating is a fundamental movement in ice hockey; however little research has been conducted within the field of hockey skating biomechanics due to the difficulties of on-ice data collection. In this study a novel on-ice measurement approach was tested for reliability, and subsequently implemented to investigate the forward skating technique, as well as technique differences across skill levels. Nine high caliber (High) and nine low caliber (Low) hockey players performed 30 m forward skating trials. A 3D accelerometer was mounted to the right skate for the purpose of stride detection, with the 2nd and 6th strides defined as acceleration and steady-state, respectively. The activity of five lower extremity muscles was recorded using surface electromyography. Biaxial electro-goniometers were used to quantify hip and knee angles, and in-skate plantar force was measured using instrumented insoles. Reliability was assessed with the coefficient of multiple correlation, which demonstrated moderate (r>0.65) to excellent (r>0.95) scores across selected measured variables. Greater plantar-flexor muscle activity and hip extension were evident during acceleration strides, while steady state strides exhibited greater knee extensor activity and hip abduction range of motion (p<0.05). High caliber exhibited greater hip range of motion and forefoot force application (p<0.05). The successful implementation of this on-ice mobile measurement approach offers potential for athlete monitoring, biofeedback and training advice.

Evaluation of cardiovascular demands of game play and practice in women's ice hockey.

Science.gov (United States)

Spiering, Barry A; Wilson, Meredith H; Judelson, Daniel A; Rundell, Kenneth W

2003-05-01

Preparation for the physical demands of competition often involves game simulation during practice. This paradigm is thought to promote physiological adaptations that enhance maximal performance. However, a mismatch between practice intensity and actual competition intensity may not provide adequate training to achieve optimal game-play fitness. The purpose of this study was to evaluate the effectiveness of practice in meeting the cardiovascular demands of a women's ice hockey game. Heart rate (HR) data from 11 U.S. National Women's Ice Hockey team members were collected (5-second intervals) during a game and a typical practice session. Data was normalized to individual HRmax determined during Vo(2)max testing. Working time was defined as a game shift or practice-working interval. Mean working HR was greater during the game than the practice, 90 +/- 2% and 76 +/- 3% of HRmax, respectively (p game or practice) >90% HRmax was also longer during the game than the practice, 10.5 +/- 4.1% and 5.6 +/- 3.5% (p 80% HRmax, and mean resting HR were not different between game and practice (68 +/- 7% vs. 69 +/- 5%, 23.2 +/- 5.3% vs. 26.1 +/- 9.2%, and 59 +/- 8% vs. 56 +/- 5%, respectively). Elite women hockey players experience significantly greater cardiovascular load during game play than during practice. This mismatch in cardiovascular demand may prevent players from achieving "game shape," thus affecting competition play.

Developmental contexts and sporting success: birth date and birthplace effects in national hockey league draftees 2000-2005.

Science.gov (United States)

Baker, Joseph; Logan, A Jane

2007-08-01

To examine relative age and birth place effects in hockey players drafted to play in the National Hockey League (NHL) between 2000 and 2005 and determine whether these factors influenced when players were chosen in the draft. 1013 North American draftees were evaluated from the official NHL website, which provided birthplace, date of birth and selection order in the draft. Population size was collected from Canadian and American census information. Athletes were divided into four quartiles on the basis of selection date to define age cohorts in hockey. Data between the Canadian and American players were also compared to see if the optimal city sizes differed between the two nations. Relative age and birthplace effects were found, although the optimal city size found was dissimilar to that found in previous studies. Further, there were inconsistencies between the Canadian and American data. Contextual factors such as relative age and size of birthplace have a significant effect on likelihood of being selected in the NHL draft.

Impact of visors on eye and orbital injuries in the National Hockey League.

Science.gov (United States)

Micieli, Jonathan A; Zurakowski, David; Ahmed, Iqbal Ike K

2014-06-01

Eye and orbital injuries are a significant risk to professional hockey league players and have resulted in career-ending injuries. The goal of this study was to determine the incidence, value lost, mechanism, and effect of visors on eye and orbital injuries over the last 10 National Hockey League (NHL) seasons: 2002-2003 to 2012-2013. Retrospective case-control study. Participants were 8741 NHL players who had played at least 1 game during the last 10 seasons. Using The Sports Network (TSN), ProSportsTransactions, and the Sporting News Hockey Register, NHL players were searched to identify eye and orbital injuries. The mechanism of injury was obtained from media reports and direct observation from online videos. The number of players wearing visors each year was obtained from The Hockey News annual visor survey. A total of 149 eye or orbital injuries over the last 10 seasons resulted in an overall incidence of 2.48 per 10 000 athlete exposures. A total of 1120 missed games led to a lost financial value of more than $33 million. Visor use among players grew from 32% in 2002-2003 to 73% in 2012-2013, and there was a significantly increased risk for having an eye or orbital injury when a visor was not worn (OR 4.23, 95% CI 2.84-6.30). Most injuries were a result of being hit by a deflected or direct puck (37%) followed by being struck by a high stick (28%). Players who did not wear a visor were found to be involved in more fights, hits, and penalty minutes (p < 0.001). Eye and orbital injuries are mostly accidental in nature and represent a significant risk and cost to the NHL and its players. Eye and orbital injuries are significantly more likely in players who do not wear visors. Copyright © 2014 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Muscle Power and Velocity During Trunk Rotations after 6 Weeks of Training in Ice-Hockey Players

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Poór Oliver

2017-05-01

Full Text Available The study evaluates changes of muscle power and velocity during trunk rotations in ice-hockey players after six weeks of training in competition period. A group of 15 ice-hockey players performed 2 trunk rotations to each direction in a standing position with barbell of 6, 10, 12, 16, 20, 22, 26 kg placed on the shoulders. Basic biomechanical parameters during the movement were monitored using the FiTRO Torso Dyne system. Results showed that mean velocity in acceleration phase of trunk rotation significantly increased after 6 weeks of training at 6 kg (from 259 to 282.6 deg/s, p = 0.003 and 12 kg (from 218.8 to 244.1 deg/s p = 0.004. However, its values did not changed significantly during rotations with 10, 16, 20, 22 and 26 kg. Mean power of trunk rotation did not changed significantly with any of used weight. These findings indicate that there are only small changes in muscle power in competition period of ice hockey-players.

Sports hernia in National Hockey League players: does surgery affect performance?

Science.gov (United States)

Jakoi, Andre; O'Neill, Craig; Damsgaard, Christopher; Fehring, Keith; Tom, James

2013-01-01

Athletic pubalgia is a complex injury that results in loss of play in competitive athletes, especially hockey players. The number of reported sports hernias has been increasing, and the importance of their management is vital. There are no studies reporting whether athletes can return to play at preinjury levels. The focus of this study was to evaluate the productivity of professional hockey players before an established athletic pubalgia diagnosis contrasted with the productivity after sports hernia repair. Cohort study; Level of evidence, 3. Professional National Hockey League (NHL) players who were reported to have a sports hernia and who underwent surgery from 2001 to 2008 were identified. Statistics were gathered on the players' previous 2 full seasons and compared with the statistics 2 full seasons after surgery. Data concerning games played, goals, average time on ice, time of productivity, and assists were gathered. Players were divided into 3 groups: group A incorporated all players, group B were players with 6 or fewer seasons of play, and group C consisted of players with 7 or more seasons of play. A control group was chosen to compare player deterioration or improvement over a career; each player selected for the study had a corresponding control player with the same tenure in his career and position during the same years. Forty-three hockey players were identified to have had sports hernia repairs from 2001 to 2008; ultimately, 80% would return to play 2 or more full seasons. Group A had statistically significant decreases in games played, goals scored, and assists. Versus the control group, the decreases in games played and assists were supported. Statistical analysis showed significant decreases in games played, goals scored, assists, and average time on ice the following 2 seasons in group C, which was also seen in comparison with the control group. Group B (16 players) showed only statistical significance in games played versus the control group

Describing Strategies Used by Elite, Intermediate, and Novice Ice Hockey Referees

Science.gov (United States)

Hancock, David J.; Ste-Marie, Diane M.

2014-01-01

Much is known about sport officials' decisions (e.g., anticipation, visual search, and prior experience). Comprehension of the entire decision process, however, requires an ecologically valid examination. To address this, we implemented a 2-part study using an expertise paradigm with ice hockey referees. Purpose: Study 1 explored the…

Today's talented youth field hockey players, the stars of tomorrow? : a study

NARCIS (Netherlands)

Elferink-Gemser, Marije Titia

2005-01-01

The aim of the thesis was addressed by conducting research within a group of all talented field hockey players, measuring multidimensional performance characteristics in a sports-specific way, and following talented players across time by adopting a longitudinal study design. With caution because

Ground reaction forces produced by two different hockey skating arm swing techniques.

Science.gov (United States)

Hayward-Ellis, Julie; Alexander, Marion J L; Glazebrook, Cheryl M; Leiter, Jeff

2017-10-01

The arm swing in hockey skating can have a positive effect on the forces produced by each skate, and the resulting velocity from each push off. The main purpose of this study was to measure the differences in ground reaction forces (GRFs) produced from an anteroposterior versus a mediolateral style hockey skating arm swing. Twenty-four elite-level female hockey players performed each technique while standing on a ground-mounted force platform, and all trials were filmed using two video cameras. Force data was assessed for peak scaled GRFs in the frontal and sagittal planes, and resultant GRF magnitude and direction. Upper limb kinematics were assessed from the video using Dartfish video analysis software, confirming that the subjects successfully performed two distinct arm swing techniques. The mediolateral arm swing used a mean of 18.38° of glenohumeral flexion/extension and 183.68° of glenohumeral abduction/adduction while the anteroposterior technique used 214.17° and 28.97° respectively. The results of this study confirmed that the mediolateral arm swing produced 37% greater frontal plane and 33% less sagittal plane GRFs than the anteroposterior arm swing. The magnitudes of the resultant GRFs were not significantly different between the two techniques; however, the mediolateral technique produced a resultant GRF with a significantly larger angle from the direction of travel (44.44°) as compared to the anteroposterior technique (31.60°). The results of this study suggest that the direction of GRFs produced by the mediolateral arm swing more closely mimic the direction of lower limb propulsion during the skating stride.

An on-ice measurement approach to analyse the biomechanics of ice hockey skating.

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Erica Buckeridge

Full Text Available Skating is a fundamental movement in ice hockey; however little research has been conducted within the field of hockey skating biomechanics due to the difficulties of on-ice data collection. In this study a novel on-ice measurement approach was tested for reliability, and subsequently implemented to investigate the forward skating technique, as well as technique differences across skill levels. Nine high caliber (High and nine low caliber (Low hockey players performed 30 m forward skating trials. A 3D accelerometer was mounted to the right skate for the purpose of stride detection, with the 2nd and 6th strides defined as acceleration and steady-state, respectively. The activity of five lower extremity muscles was recorded using surface electromyography. Biaxial electro-goniometers were used to quantify hip and knee angles, and in-skate plantar force was measured using instrumented insoles. Reliability was assessed with the coefficient of multiple correlation, which demonstrated moderate (r>0.65 to excellent (r>0.95 scores across selected measured variables. Greater plantar-flexor muscle activity and hip extension were evident during acceleration strides, while steady state strides exhibited greater knee extensor activity and hip abduction range of motion (p<0.05. High caliber exhibited greater hip range of motion and forefoot force application (p<0.05. The successful implementation of this on-ice mobile measurement approach offers potential for athlete monitoring, biofeedback and training advice.

Skating mechanics of change-of-direction manoeuvres in ice hockey players.

Science.gov (United States)

Fortier, Antoine; Turcotte, René A; Pearsall, David J

2014-11-01

Ice hockey requires rapid transitions between skating trajectories to effectively navigate about the ice surface. Player performance relates in large part to effective change-of-direction manoeuvres, but little is known about how those skills are performed mechanically and the effect of equipment design on them. The purpose of this study was to observe the kinetics involved in those manoeuvres as well as to compare whether kinetic differences may result between two skate models of varying ankle mobility. Eight subjects with competitive ice hockey playing experience performed rapid lateral (90°) left and right change-of-direction manoeuvres. Kinetic data were collected using force strain gauge transducers on the blade holders of the skates. Significantly greater forces were applied by the outside skate (50-70% body weight, %BW) in comparison to the inside skate (12-24%BW, p Skate model and turn direction had no main effect, though significant mixed interactions between leg side (inside/outside) with skate model or turn direction (p skating change-of-direction tasks.

Sports chiropractic management at the World Ice Hockey Championships

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Vitiello Andrew L

2010-12-01

Full Text Available Abstract Background Ice hockey is an international sport. Injuries occur in a full body fashion, to a number of tissues, commonly through body contact. There is a lack of literature documenting the scope of sports chiropractic practice. Thus, it was the aim to document the type, scope and severity of conditions presenting to, and the treatment provided by, the New Zealand team chiropractor acting as a primary health provider for the duration of the 2007 World Ice Hockey Championships. Methods All conditions presenting were recorded. Diagnosis was recorded along with clinical parameters of injury: injury type, severity, mechanism and whether referral or advanced imaging was required. All treatment provided was continuously recorded, including information on the number of treatments required and the reason, duration, type and location of treatment. Results Players presented for diagnosis of injury 50 times. Muscle (34%, joint (24% and tendon injuries (18% were most common. Players presented with a new injury 76% of the time. Most injuries had been present for less than one week (84%, with 53% occurring through a contact mechanism. Injuries were common at training and match locations. Only two injuries required the player to stop playing or training, both of which were referred for advanced imaging. During the study, 134 treatment consultations were rendered to 45 player injuries. Eighty per-cent of injuries were managed with four or less treatments. Three quarters of treatment was provided at training locations with treatment duration predominantly being between 11-15 minutes (71% and 16-20 minutes (27%. Most treatment delivered was passive in nature (71% although combination active and passive care was provided (27%. Treatment typically involved joint (81% and soft tissue based therapies (81% and was delivered in a full body manner. Conclusions This study documented the injury profile of ice hockey at an international level of competition. It

Relationship between Physiological Off-Ice Testing, On-Ice Skating, and Game Performance in Division I Women's Ice Hockey Players.

Science.gov (United States)

Boland, Michelle; Miele, Emily M; Delude, Katie

2017-10-07

The purpose was to identify off-ice testing variables that correlate to skating and game performance in Division I collegiate women ice hockey players. Twenty female, forward and defensive players (19.95 ± 1.35 yr) were assessed for weight, height, percent fat mass (%FAT), bone mineral density, predicted one repetition maximum (RM) absolute and relative (REL%) bench press (BP) and hex bar deadlift (HDL), lower body explosive power, anaerobic power, countermovement vertical jump (CMJ), maximum inspiratory pressure (MIP), and on-ice repeated skate sprint (RSS) performance. The on-ice RSS test included 6 timed 85.6 m sprints with participants wearing full hockey equipment; fastest time (FT), average time (AT) and fatigue index (FI) for the first length skate (FLS; 10 m) and total length skate (TLS; 85.6 m) were used for analysis. Game performance was evaluated with game statistics: goals, assists, points, plus-minus, and shots on goal (SOG). Correlation coefficients were used to determine relationships. Percent fat mass was positively correlated (p Game performance in women ice hockey players may be enhanced by greater MIP, repeat acceleration ability, and mode-specific training. Faster skating times were associated with lower %FAT. Skating performance in women ice hockey players may be enhanced by improving body composition, anaerobic power, and both lower and upper body strength in off-ice training.

Characterization of lipase in reversed micelles formulated by Cibacron Blue F-3GA modified Span 85

DEFF Research Database (Denmark)

Zhang, Dong Hao; Guo, Zheng; Sun, Yan

2007-01-01

Sorbitan trioleate (Span 85) modified by Cibacron Blue F-3GA (CB) was prepared and used as an affinity surfactant to formulate a reversed micellar system for Candida rugosa lipase (CRL) solubilization. The system was characterized and evaluated by employing CRL-catalyzed hydrolysis of olive oil...... of the encapsulated lipase remained unchanged, but the apparent activity was significantly higher than that of the native enzyme in bulk solution. Kinetic studies indicated that the encapsulated lipase in the reversed micelles of CB-formulated Span 85 followed the Michaelis-Menten equation. The Michaelis constant...... was found to decrease with increasing surfactant concentration, suggesting an increase of the enzyme affinity for the substrate. Stability of the lipase in the reversed micelles was negatively correlated to W0. Introduction Reversed micelles are nanometer-scale transparent aggregates of water and surfactant...

Are Canadian-born Major League Baseball players more likely to bat left-handed? A partial test of the hockey-influence on batting hypothesis.

Science.gov (United States)

Cairney, John; Chirico, Daniele; Li, Yao-Chuen; Bremer, Emily; Graham, Jeffrey D

2018-01-01

It has been suggested that Canadian-born Major League Baseball (MLB) players are more likely to bat left-handed, possibly owing to the fact that they learn to play ice hockey before baseball, and that there is no clear hand-preference when shooting with a hockey stick; approximately half of all ice hockey players shoot left. We constructed a database on active (i.e., October, 2016) MLB players from four countries/regions based on place of birth (Canada, United States of America [USA], Dominican Republic and South Asia [i.e., Japan, Taiwan and South Korea]), including information on which hand they use to bat and throw. We also extracted information on all Canadian-born MLB players, dating back to 1917. Our results confirm that the proportion of left-handed batters born in Canada is higher when compared to the other countries selected; also, since 1917, the proportion of Canadian MLB players who bat left has been consistently higher than the league average. We also compared the proportion of left-handed batters in Canada with players born in states in the USA grouped into high, average and low based on hockey participation. The proportion of MLB players born in states with a high level of hockey participation were more likely to bat left, although the differences were significant at trend level only (p bat left-handed, this did not correspond with a greater left-hand dominance, as determined by throwing hand. In conclusion, the present study confirms that Canadian-born MLB players are more likely to bat left-handed when compared to American, Dominican Republic and South Asian-born MLB players, providing partial support for the hockey influence on batting hypothesis.

Back Squat Potentiates Both Vertical and Horizontal Jump Performance in Collegiate Ice Hockey Players

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Cale Bechtel

2018-01-01

Full Text Available Background: Back squats (BSQ have been shown to transiently improve performance in explosive vertical movements such as the vertical jump (VJ. Still, understanding of this phenomenon, termed post-activation potentiation (PAP, remains nebulous as it relates to explosive horizontal movements. Objective: Therefore, the purpose of the present investigation was to assess whether heavy BSQ can potentiate both VJ and horizontal jump (HJ performance. Method: Nine male ice hockey players from the Long Beach State ice hockey team performed five testing sessions separated by 96-hours. The first testing session consisted of a one repetition maximum (1-RM BSQ to determine subsequent testing loads. The four subsequent testing sessions, which were randomized for order, consisted of five repetitions of BSQ at 87% 1-RM followed by horizontal jump (BSQ-HJ, five repetitions of BSQ at 87% 1-RM followed by vertical jump (BSQ-VJ, horizontal jump only (CT-HJ and vertical jump only (CT-VJ. During the potentiated conditions, rest intervals were set at five minutes between the BSQ and either VJ or HJ. Alpha-level was set a priori at 0.05. Results: The results indicate that both vertical (p=0.017 and horizontal (p=0.003 jump were significantly increased (VJ= +5.51cm, HJ= +11.55cm following a BSQ.  Conclusion: These findings suggest that BSQ may improve both vertical and horizontal jump performance in athletes who participate in sports emphasizing horizontal power, such as ice hockey.

Comparison of Concussion Rates Between NCAA Division I and Division III Men's and Women's Ice Hockey Players.

Science.gov (United States)

Rosene, John M; Raksnis, Bryan; Silva, Brie; Woefel, Tyler; Visich, Paul S; Dompier, Thomas P; Kerr, Zachary Y

2017-09-01

Examinations related to divisional differences in the incidence of sports-related concussions (SRC) in collegiate ice hockey are limited. To compare the epidemiologic patterns of concussion in National Collegiate Athletic Association (NCAA) ice hockey by sex and division. Descriptive epidemiology study. A convenience sample of men's and women's ice hockey teams in Divisions I and III provided SRC data via the NCAA Injury Surveillance Program during the 2009-2010 to 2014-2015 academic years. Concussion counts, rates, and distributions were examined by factors including injury activity and position. Injury rate ratios (IRRs) and injury proportion ratios (IPRs) with 95% confidence intervals (CIs) were used to compare concussion rates and distributions, respectively. Overall, 415 concussions were reported for men's and women's ice hockey combined. The highest concussion rate was found in Division I men (0.83 per 1000 athlete-exposures [AEs]), followed by Division III women (0.78/1000 AEs), Division I women (0.65/1000 AEs), and Division III men (0.64/1000 AEs). However, the only significant IRR was that the concussion rate was higher in Division I men than Division III men (IRR = 1.29; 95% CI, 1.02-1.65). The proportion of concussions from checking was higher in men than women (28.5% vs 9.4%; IPR = 3.02; 95% CI, 1.63-5.59); however, this proportion was higher in Division I women than Division III women (18.4% vs 1.8%; IPR = 10.47; 95% CI, 1.37-79.75). The proportion of concussions sustained by goalkeepers was higher in women than men (14.2% vs 2.9%; IPR = 4.86; 95% CI, 2.19-10.77), with findings consistent within each division. Concussion rates did not vary by sex but differed by division among men. Checking-related concussions were less common in women than men overall but more common in Division I women than Division III women. Findings highlight the need to better understand the reasons underlying divisional differences within men's and women's ice hockey and the

Effects of badminton and ice hockey on bone mass in young males: a 12-year follow-up.

Science.gov (United States)

Tervo, Taru; Nordström, Peter; Nordström, Anna

2010-09-01

The purpose of the present study was to investigate the influence of different types of weight bearing physical activity on bone mineral density (BMD, g/cm(2)) and evaluate any residual benefits after the active sports career. Beginning at 17 years of age, BMD was measured 5 times, during 12 years, in 19 badminton players, 48 ice hockey players, and 25 controls. During the active career, badminton players gained significantly more BMD compared to ice hockey players at all sites: in their femoral neck (mean difference (Delta) 0.06 g/cm(2), p=0.04), humerus (Delta 0.06 g/cm(2), p=0.01), lumbar spine (Delta 0.08 g/cm(2), p=0.01), and their legs (Delta 0.05 g/cm(2), p=0.003), after adjusting for age at baseline, changes in weight, height, and active years. BMD gains in badminton players were higher also compared to in controls at all sites (Delta 0.06-0.17 g/cm(2), pbadminton players and 37 ice hockey players stopped their active career a mean of 6 years before the final follow-up. Both these groups lost significantly more BMD at the femoral neck and lumbar spine compared to the control group (Delta 0.05-0.12 g/cm(2), pbadminton players had significantly higher BMD of the femoral neck, humerus, lumbar spine, and legs (Delta 0.08-0.20 g/cm(2), pbadminton is a more osteogenic sport compared to ice hockey. The BMD benefits from previous training were partially sustained with reduced activity. Copyright 2010 Elsevier Inc. All rights reserved.

Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.

Science.gov (United States)

Kujala, U M; Taimela, S; Antti-Poika, I; Orava, S; Tuominen, R; Myllynen, P

1995-12-02

To determine the acute injury profile in each of six sports and compare the injury rates between the sports. Analysis of national sports injury insurance registry data. Finland during 1987-91. 621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and their doctors. 54,186 sports injuries were recorded. Injury rates were low in athletes aged under 15, while 20-24 year olds had the highest rates. Differences in injury rates between the sports were minor in this adult age group. Overall injury rates were higher in sports entailing more frequent and powerful body contact. Each sport had a specific injury profile. Fractures and dental injuries were most common in ice hockey and karate and least frequent in volleyball. Knee injuries were the most common cause of permanent disability. Based on the defined injury profiles in the different sports it is recommended that sports specific preventive measures should be employed to decrease the number of violent contacts between athletes, including improved game rules supported by careful refereeing. To prevent dental injuries the wearing of mouth guards should be encouraged, especially in ice hockey, karate, and basketball.

Characterization and Evaluation of the Improved Performance of Modified Reverse Osmosis Membranes by Incorporation of Various Organic Modifiers and SnO2 Nanoparticles

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Kh. M. AL-Sheetan

2015-01-01

Full Text Available Reverse osmosis (RO membranes modified with SnO2 nanoparticles of varied concentrations (0.001–0.1 wt.% were developed via in situ interfacial polymerization (IP of trimesoyl chloride (TMC and m-phenylenediamine (MPD on nanoporous polysulfone supports. The nanoparticles dispersed in the dense nodular polyamide on the polysulfone side. The effects of IP reaction time and SnO2 loading on membrane separation performance were studied. The modified reverse osmosis membranes were characterized by scanning electron microscopy (SEM, X-ray diffractometer (XRD, energy dispersive X-ray spectroscopy (EDX, transmission electron microscopy (TEM, contact angle measurement, and atomic force microscopy (AFM. The synthesized SnO2 nanoparticles size varies between 10 and 30 nm. The results exhibited a smooth membrane surface and average surface roughness from 31 to 68 nm. Moreover, hydrophilicity was enhanced and contact angle decreased. The outcomes showed that an IP reaction time was essential to form a denser SnO2-polyamide layer for higher salt rejection, the developed reverse osmosis membranes with the incorporation of the SnO2 nanoparticles were examined by measuring permeate fluxes and salt rejection, and the permeate flux increased from 26 to 43.4 L/m2·h, while salt rejection was high at 98% (2000 ppm NaCl solution at 225 psi (1.55 MPa, 25°C.

Nutrition review for hockey players : enhancing performance through nutrition

OpenAIRE

Bursich, Chris

2011-01-01

With the advancement of sports medicine in the past decade, hockey players all over the world are always trying to find a competitive edge through nutritional education and proper eating. It is very common to find young junior players looking to make the jump into the professional game always trying to find ways to get bigger and add lean muscle mass, likewise, there are always players looking to drop a few pounds while keeping their muscle mass. Research has proven that through proper educat...

The effect of laryngoscope handle size on possible endotracheal intubation success in university football, ice hockey, and soccer players.

Science.gov (United States)

Delaney, J Scott; Al-Kashmiri, Ammar; Baylis, Penny-Jane; Aljufaili, Mahmood; Correa, José A

2012-07-01

To assess the effectiveness of a standard long-handle laryngoscope and a short-handle laryngoscope on ease of possible intubation in football, ice hockey, and soccer players. Prospective crossover study. University Sport Medicine Clinic. Sixty-two university varsity football (62 males), 45 ice hockey (26 males and 19 females), and 39 soccer players (20 males, 19 females). Athletes were assessed for different airway and physical characteristics. Three different physicians then assessed the use of laryngoscopes of different handle sizes in supine athletes who were wearing protective equipment while in-line cervical spine immobilization was maintained. The ease of passage of a laryngoscope blade into the posterior oropharynx of a supine athlete was assessed using both a standard long-handle and a short-handle laryngoscope. Use of a short-handle laryngoscope was easier for all physicians in all sports as compared with a standard-sized laryngoscope. Passage of a laryngoscope blade into the posterior oropharynx of a supine athlete was easiest in soccer players and most difficult in football and ice hockey players for both sizes of laryngoscope. Interference from chest or shoulder pads was a common cause for difficulty in passing the laryngoscope blade into the posterior oropharynx for football and ice hockey players. In the rare instances that an endotracheal intubation is to be attempted on an unconscious athlete, a short-handle laryngoscope may provide the best chance for successful intubation.

Laboratory- and field-based testing as predictors of skating performance in competitive-level female ice hockey

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Henriksson T

2016-08-01

Full Text Available Tommy Henriksson,1,2 Jason D Vescovi,3 Anncristine Fjellman-Wiklund,4 Kajsa Gilenstam1 1Sport Medicine Unit, Department of Community Medicine and Rehabilitation, 2The National Graduate School of Gender Studies, Umeå University, Umeå, Sweden; 3Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada; 4Physiotherapy Unit, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden Objectives: The purpose of this study was to examine whether field-based and/or laboratory-based assessments are valid tools for predicting key performance characteristics of skating in competitive-level female hockey players.Design: Cross-sectional study.Methods: Twenty-three female ice hockey players aged 15–25 years (body mass: 66.1±6.3 kg; height: 169.5±5.5 cm, with 10.6±3.2 years playing experience volunteered to participate in the study. The field-based assessments included 20 m sprint, squat jump, countermovement jump, 30-second repeated jump test, standing long jump, single-leg standing long jump, 20 m shuttle run test, isometric leg pull, one-repetition maximum bench press, and one-repetition maximum squats. The laboratory-based assessments included body composition (dual energy X-ray absorptiometry, maximal aerobic power, and isokinetic strength (Biodex. The on-ice tests included agility cornering s-turn, cone agility skate, transition agility skate, and modified repeat skate sprint. Data were analyzed using stepwise multivariate linear regression analysis. Linear regression analysis was used to establish the relationship between key performance characteristics of skating and the predictor variables.Results: Regression models (adj R2 for the on-ice variables ranged from 0.244 to 0.663 for the field-based assessments and from 0.136 to 0.420 for the laboratory-based assessments. Single-leg tests were the strongest predictors for key performance characteristics of skating. Single leg standing

Human Immunodeficiency Virus type-1 reverse transcriptase exists as post-translationally modified forms in virions and cells

Directory of Open Access Journals (Sweden)

Warrilow David

2008-12-01

Full Text Available Abstract Background HIV-1 reverse transcriptase (RT is a heterodimer composed of p66 and p51 subunits and is responsible for reverse transcription of the viral RNA genome into DNA. RT can be post-translationally modified in vitro which may be an important mechanism for regulating RT activity. Here we report detection of different p66 and p51 RT isoforms by 2D gel electrophoresis in virions and infected cells. Results Major isoforms of the p66 and p51 RT subunits were observed, with pI's of 8.44 and 8.31 respectively (p668.44 and p518.31. The same major isoforms were present in virions, virus-infected cell lysates and intracellular reverse transcription complexes (RTCs, and their presence in RTCs suggested that these are likely to be the forms that function in reverse transcription. Several minor RT isoforms were also observed. The observed pIs of the RT isoforms differed from the pI of theoretical unmodified RT (p668.53 and p518.60, suggesting that most of the RT protein in virions and cells is post-translationally modified. The modifications of p668.44 and p518.31 differed from each other indicating selective modification of the different RT subunits. The susceptibility of RT isoforms to phosphatase treatment suggested that some of these modifications were due to phosphorylation. Dephosphorylation, however, had no effect on in vitro RT activity associated with virions, infected cells or RTCs suggesting that the phospho-isoforms do not make a major contribution to RT activity in an in vitro assay. Conclusion The same major isoform of p66 and p51 RT is found in virions, infected cells and RTC's and both of these subunits are post-translationally modified. This post-translational modification of RT may be important for the function of RT inside the cell.

Structural study of the AOT reverse micellar system. Influence of attractive interactions induced by the solubilisation of native and modified proteins

International Nuclear Information System (INIS)

Cassin, Guillaume

1994-01-01

This research thesis reports the study of the influence of intra-micellar attractions on the thermodynamic behaviour of reverse micellar systems, as well as of the effects induced by the solubilisation of natives or modified proteins. The author proposes a model to explain the decrease of attractions between droplets when the volume fraction occupied by reverse micelles increases. This model which highlights the importance of depletion forces between reverse micelles, allows the building up of a theoretical relationship between the bonding parameter and the volume fraction of reverse micelles. In order to understand the appearance of an attractive term related to the solubilisation of native cytochrome-c in these systems, this protein has been chemically modified. The author highlights the role of the charge born by a micellar probe on the thermodynamic behaviour of micro-emulsions. Then, the author applies the model of dimerizing adhesive spheres to reverse micellar systems containing native cytochrome-c. He shows that theoretical predictions of this model are in agreement with obtained experimental results [fr

Self-esteem and injury in competitive field hockey players.

Science.gov (United States)

Kolt, G S; Roberts, P D

1998-08-01

A volunteer sample of 50 competitive field hockey players completed the Coopersmith Self-esteem Inventory at pre- and postseason and prospectively collected injury data over a 20-wk. season. Multiple regression analysis showed no relationship between scores on Self-esteem and the number of injuries, the participation time affected due to injury, and sex of players. Further multiple regression analysis showed that frequency of the more severe injuries significantly predicted scores on Self-esteem. This finding can be interpreted as evidence of the relationship between low self-esteem and injury in sport.

A Comparison of Somatic Variables of Elite Ice Hockey Players from the Czech ELH and Russian KHL

Directory of Open Access Journals (Sweden)

Kutáč Petr

2015-03-01

Full Text Available The goals of this study were to evaluate the basic morphological variables of contemporary elite ice hockey players, compare the parameters of players in the top Russian ice hockey league (KHL with those of the top Czech ice hockey league (ELH, and to evaluate the parameters of players according to their position in the game. The research participants included 30 KHL players (mean age: 27.1 ± 5.1 years and 25 ELH players (mean age: 26.4 ± 5.8 years. We determined body height, body mass, and body composition (body fat, fat-free mass, segmental fat analysis. All measurements were performed at the end of preseason training. The KHL players had the following anthropometric characteristics: body height 182.97 ± 5.61 cm (forward and 185.72 ± 3.57 cm (defenseman, body mass 89.70 ± 5.28 kg (forward and 92.52 ± 4.01 kg (defenseman, body fat 10.76 ± 0.63 kg (forward and 11.10 ± 0.48 kg (defenseman, fatfree mass 78.94 ± 4.65 kg (forward and 81.42 ± 3.52 kg (defenseman. The values for ELH players were as follows: body height 182.06 ± 5.93 cm (forward and 185.88 ± 7.13 cm (defenseman, body mass 88.47 ± 7.06 kg (forward and 89.36 ± 10.91 kg (defenseman, body fat 12.57 ± 2.89 kg (forward and 11.91 ± 3.10 kg (defenseman, fat-free mass 75.93 ± 6.54 kg (forward and 77.46 ± 7.89 kg (defenseman. The results indicate that it is beneficial to ice hockey players to have increased body mass and lower body fat, which leads to higher muscle mass, thus enabling a player to perform at the highest level and meet the specific challenges of the game.

Less efficient oculomotor performance is associated with increased incidence of head impacts in high school ice hockey.

Science.gov (United States)

Kiefer, Adam W; DiCesare, Christopher; Nalepka, Patrick; Foss, Kim Barber; Thomas, Staci; Myer, Gregory D

2018-01-01

To evaluate associations between pre-season oculomotor performance on visual tracking tasks and in-season head impact incidence during high school boys ice hockey. Prospective observational study design. Fifteen healthy high school aged male hockey athletes (M=16.50±1.17years) performed two 30s blocks each of a prosaccade and self-paced saccade task, and two trials each of a slow, medium, and fast smooth pursuit task (90°s -1 ; 180°s -1 ; 360°s -1 ) during the pre-season. Regular season in-game collision data were collected via helmet-mounted accelerometers. Simple linear regressions were used to examine relations between oculomotor performance measures and collision incidence at various impact thresholds. The variability of prosaccade latency was positively related to total collisions for the 20g force cutoff (p=0.046, adjusted R 2 =0.28). The average self-paced saccade velocity (p=0.020, adjusted R 2 =0.37) and variability of smooth pursuit gaze velocity (p=0.012, adjusted R 2 =0.47) were also positively associated with total collisions for the 50g force cutoff. These results provide preliminary evidence that less efficient oculomotor performance on three different oculomotor tasks is associated with increased incidence of head impacts during a competitive ice hockey season. The variability of prosaccade latency, the average self-paced saccade velocity and the variability of gaze velocity during predictable smooth pursuit all related to increased head impacts. Future work is needed to further understand player initiated collisions, but this is an important first step toward understanding strategies to reduce incidence of injury risk in ice hockey, and potentially contact sports more generally. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.

Science.gov (United States)

Kujala, U. M.; Taimela, S.; Antti-Poika, I.; Orava, S.; Tuominen, R.; Myllynen, P.

1995-01-01

OBJECTIVE--To determine the acute injury profile in each of six sports and compare the injury rates between the sports. DESIGN--Analysis of national sports injury insurance registry data. SETTING--Finland during 1987-91. SUBJECTS--621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. MAIN OUTCOME MEASURES--Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and their doctors. RESULTS--54,186 sports injuries were recorded. Injury rates were low in athletes aged under 15, while 20-24 year olds had the highest rates. Differences in injury rates between the sports were minor in this adult age group. Overall injury rates were higher in sports entailing more frequent and powerful body contact. Each sport had a specific injury profile. Fractures and dental injuries were most common in ice hockey and karate and least frequent in volleyball. Knee injuries were the most common cause of permanent disability. CONCLUSIONS--Based on the defined injury profiles in the different sports it is recommended that sports specific preventive measures should be employed to decrease the number of violent contacts between athletes, including improved game rules supported by careful refereeing. To prevent dental injuries the wearing of mouth guards should be encouraged, especially in ice hockey, karate, and basketball. PMID:8520333

Modified lignin: Preparation and use in reversible gel via Diels-Alder reaction.

Science.gov (United States)

Zhou, Wanpeng; Zhang, Hui; Chen, Fangeng

2018-02-01

In this study, popular soda lignin was modified with either furan or maleimide ring, and the modified lignins were subjected to reversible Diels-Alder reaction. A new process was proposed to prepare the functionalized lignin. A long chain was introduced to the hydroxyl groups of lignin, and then either the furan or maleimide ring was added to the other end of the chain. The test results confirmed that either the furan ring or the maleimide ring was bound to lignin. Furan- and maleimide-functionalized lignins were also combined to generate crosslinking via Diels-Alder [4+2] cycloaddition reaction. Under appropriate conditions, the formation of a gel was identified, which reverted to liquid state after retro Diels-Alder reaction upon heating at 120°C. This study reveals the significant versatility and potential of the developed strategy for the utilization of lignin-based recyclable networks. Copyright © 2017 Elsevier B.V. All rights reserved.

THE ROLE OF AEROBIC CAPACITY IN HIGH-INTENSITY INTERMITTENT EFFORTS IN ICE-HOCKEY

Directory of Open Access Journals (Sweden)

A. Stanula

2014-08-01

Full Text Available The primary objective of this study was to determine a relationship between aerobic capacity ( ·VO2max and fatigue from high-intensity skating in elite male hockey players. The subjects were twenty-four male members of the senior national ice hockey team of Poland who played the position of forward or defence. Each subject completed an on-ice Repeated-Skate Sprint test (RSS consisting of 6 timed 89-m sprints, with 30 s of rest between subsequent efforts, and an incremental test on a cycle ergometer in the laboratory, the aim of which was to establish their maximal oxygen uptake ( ·VO2max. The analysis of variance showed that each next repetition in the 6x89 m test was significantly longer than the previous one (F5,138=53.33, p<0.001. An analysis of the fatigue index (FI calculated from the times recorded for subsequent repetitions showed that the value of the FI increased with subsequent repetitions, reaching its maximum between repetitions 5 and 6 (3.10±1.16%. The total FI was 13.77±1.74%. The coefficient of correlation between ·VO2max and the total FI for 6 sprints on the distance of 89 m (r =–0.584 was significant (p=0.003. The variance in the index of players’ fatigue in the 6x89 m test accounted for 34% of the variance in ·VO2max. The 6x89 m test proposed in this study offers a high test-retest correlation coefficient (r=0.78. Even though the test is criticized for being too exhaustive and thereby for producing highly variable results it still seems that it was well selected for repeated sprint ability testing in hockey players.

Reversibility of hepatocyte nuclear modifications in mice fed on genetically modified soybean

Directory of Open Access Journals (Sweden)

M Malatesta

2009-06-01

Full Text Available In the literature, the reports on the effects of a genetically modified (GM diet are scanty and heterogeneous; in particular, no direct evidence has so far been reported that GM food may affect human or animal health. Hepatocytes represent a suitable model for monitoring the effects of a GM diet, the liver potentially being a primary target. In a previous study, we demonstrated that some modifications occur in hepatocyte nuclei of mice fed on GM soybean. In order to elucidate whether such modifications can be reversed, in the present study, 3 months old mice fed on GM soybean since their weaning were submitted to a diet containing wild type soybean only, for one month. In parallel, to investigate the influence of GM soybean on adult individuals, mice fed on wild type soybean were changed to a GM diet, for the same time. Using immunoelectron microscopy, we demonstrated that a one-month diet reversion can influence some nuclear features in adult mice, restoring typical characteristics of controls in GM-fed animals, and inducing in control mice modifications similar to those observed in animals fed on GM soybean from weaning. This suggests that the modifications related to GM soybean are potentially reversible, but also that some modifications are inducible in adult organisms in a short time.

Role of energy systems in two intermittent field tests in women field hockey players

NARCIS (Netherlands)

Lemmink, Koen A. P. M.; Visscher, Susan H.

The energetics of 2 field tests that reflect physical performance in intermittent sports (i.e., the Interval Shuttle Sprint Test [ISST] and the Interval Shuttle Run Test [ISRT]) were examined in 21 women field hockey players. The ISST required the players to perform 10 shuttle sprints starting every

An Examination of the Relative Age Effect in Developmental Girls' Hockey in Ontario

Science.gov (United States)

Smith, Kristy L.; Weir, Patricia L.

2013-01-01

The relative age effect (RAE) suggests that athletes may be provided with greater opportunities for success depending on the position of their birthdate in a sport's selection year. While the effect has been well established in men's sports, less is known about women's sports. This study examined the RAE in developmental girls' hockey in Ontario.…

Proprioception of foot and ankle complex in young regular practitioners of ice hockey, ballet dancing and running.

Science.gov (United States)

Li, Jing Xian; Xu, Dong Qing; Hoshizaki, Blaine

2009-01-01

This study examined the proprioception of the foot and ankle complex in regular ice hockey practitioners, runners, and ballet dancers. A total of 45 young people with different exercise habits formed four groups: the ice hockey, ballet dancing, running, and sedentary groups. Kinesthesia of the foot and ankle complex was measured in plantarflexion (PF), dorsiflexion (DF), inversion (IV), and eversion (EV) at 0.4 degrees /s using a custom-made device. The results showed the following: (1) significantly better perceived passive motion sense in PF/DF was found as compared with the measurements in IV/EV within each group (P ballet groups perceived significantly better passive motion sense in IV/EV than the running (P ballet dancing on proprioception may be associated with their movement characteristics.

Relationship Between Skating Economy and Performance During a Repeated-Shift Test in Elite and Subelite Ice Hockey Players.

Science.gov (United States)

Lamoureux, Nicholas R; Tomkinson, Grant R; Peterson, Benjamin J; Fitzgerald, John S

2018-04-01

Lamoureux, NR, Tomkinson, GR, Peterson, BJ, and Fitzgerald, JS. Relationship between skating economy and performance during a repeated-shift test in elite and subelite ice hockey players. J Strength Cond Res 32(4): 1109-1113, 2018-The purpose of this study was to determine the importance of skating economy to fatigue during repeated high-intensity efforts of a simulated ice hockey shift. Forty-five collegiate and Junior A male ice hockey players (aged 18-24 years) performed a continuous graded exercise test using a skate treadmill. Breath-by-breath data for oxygen consumption (V[Combining Dot Above]O2) and respiratory exchange ratio were collected and used to derive energy expenditure (EE) averaged over the final 10 seconds of each stage. Economy was determined as the slope of the regression line relating V[Combining Dot Above]O2 and EE against skating speed separately. Participants also completed 8 bouts of maximal ice skating through a course designed to simulate typical shift, with timing gates determining first half, second half, and total fatigue decrement, calculated by a percent decrement score. Partial correlation was used to determine the association between economy measures and decrement during the repeated-shift test. Twenty-six participants met inclusion criteria and were included in data analysis. Skating economy measures (both relative V[Combining Dot Above]O2 and EE) were very likely moderate positive correlates of total fatigue decrement (r [95% confidence interval]: V[Combining Dot Above]O2, 0.46 [0.09, 0.72] and EE, 0.44, [0.06, 0.71]) but not with first or second gate decrement. Our results indicate that skating economy plays an important role in fatigue resistance over repeated on-ice sprints designed to simulate a typical shift. This supports the use of technical skating coaching and training techniques to enhance skating economy as a means of improving ice hockey performance.

Upper respiratory tract infection and mucosal immunity in young ice hockey players during the pre-tournament training period.

Science.gov (United States)

Orysiak, Joanna; Witek, Konrad; Malczewska-Lenczowska, Jadwiga; Zembron-Lacny, Agnieszka; Pokrywka, Andrzej; Sitkowski, Dariusz

2018-02-27

The aim of this study was to determine the effects of 17 days of training during preparation for the Ice Hockey Under 18 World Championship of the Polish ice hockey national team on the mucosal immune function and monitor upper respiratory tract infection (URTI) incidence before, during and after the competition. Twelve male ice hockey players (age 17.7±0.5 years) were recruited for this study. The first saliva/blood collection took place at the beginning of the training camp (without training at the training camp), the second one was conducted on the 9th day of the training camp immediately after the intensification of training, and the third collection was carried out on the 13th day of training (4 days before leaving for the World Championship) in the tapering phase. To assess the mucosal immune function, concentrations of secretory immunoglobulin A (sIgA), sIgA1, and sIgA2 were analyzed in saliva. Cortisol concentration and creatine kinase activity were determined in blood, as indicators of stress and muscle damage, respectively. The Wisconsin Upper Respiratory Symptom Survey-21 questionnaire was used to assess URTI symptoms. A significant increase in the sIgA1 and sIgA2 concentrations was observed in the third collection compared with the second time point (114.45±33.00 vs 77.49±27.29 and 88.97±25.33 vs 71.65±32.44 U, respectively). There were no statistically significant correlations between the URTI incidence and saliva variables. In conclusion, the tapering period positively affects the mucosal immune function, especially sIgA1 and sIgA2 concentrations, with no significant change in frequency of URTI in young ice hockey players.

Three-dimensional kinematics of the knee and ankle joints for three consecutive push-offs during ice hockey skating starts.

Science.gov (United States)

Lafontaine, Dany

2007-09-01

Little biomechanical research has been conducted recently on hockey skating despite the sport's worldwide appeal. One reason for this lack of biomechanical knowledge stems from the difficulty of collecting data. The lack of accuracy, the disputable realism of treadmills, and the large field of view required are some of the technical challenges that have to be overcome. The main objective of the current study was to improve our knowledge of the joint kinematics during the skating stroke. A second objective was to improve the data collection system we developed and the third was to establish if a kinematic progression exists in the hockey skating stroke similar to that in speed skating. Relative motions at the knee and ankle joints were computed using a joint coordinate system approach. The differences at the knee joints in push-offs indicated that the skating skill was progressively changing with each push-off. The relative stability of the ankle angles can be attributed to the design of the skate boots, which have recently become very rigid. Further research on ice hockey skating is warranted and should include more skaters and investigate the effect various starting strategies and variations in equipment have on skaters' performance.

Head injuries presenting to emergency departments in the United States from 1990 to 1999 for ice hockey, soccer, and football.

Science.gov (United States)

Delaney, J Scott

2004-03-01

To examine the number and rates of head injuries occurring in the community as a whole for the team sports of ice hockey, soccer, and football by analyzing data from patients presenting to US emergency departments (EDs) from 1990 to 1999. Retrospective analysis. Data compiled for the US Consumer Product Safety Commission using the National Electronic Injury Surveillance System were used to generate estimates for the total number of head injuries, concussions, internal head injuries, and skull fractures occurring on a national level from the years 1990 to 1999. These data were combined with yearly participation figures to generate rates of injuries presenting to the ED for each sport. There were an estimated 17,008 head injuries from ice hockey, 86,697 from soccer, and 204,802 from football that presented to US EDs from 1990 to 1999. The total number of concussions presenting to EDs in the United States over the same period was estimated to be 4820 from ice hockey, 21,715 from soccer, and 68,861 from football. While the rates of head injuries, concussions, and combined concussions/internal head injuries/skull fractures presenting to EDs per 10,000 players were not always statistically similar for all 3 sports in each year data were available, they were usually comparable. While the total numbers of head injuries, concussions, and combined concussions/skull fractures/internal head injuries presenting to EDs in the United States are different for ice hockey, soccer, and football for the years studied, the yearly rates for these injuries are comparable among all 3 sports.

Novel hockey-stick mesogens with the nematic, synclinic and anticlinic smectic C phase sequence

Czech Academy of Sciences Publication Activity Database

Novotná, Vladimíra; Žurek, J.; Kozmik, V.; Svoboda, J.; Glogarová, Milada; Kroupa, Jan; Pociecha, D.

2008-01-01

Roč. 35, č. 8 (2008), 1023-1036 ISSN 0267-8292 R&D Projects: GA AV ČR IAA100100710 Institutional research plan: CEZ:AV0Z10100520 Keywords : liquid crystals * synclinic and anticlinic ordering * hockey-stick mezogens Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.132, year: 2008

Checking in: An Analysis of the (Lack of) Body Checking in Women's Ice Hockey

Science.gov (United States)

Weaving, Charlene; Roberts, Samuel

2012-01-01

Despite the growing popularity of women's ice hockey in North America, players continue to face limitations because of the prohibition of body checking. In this paper, we argue from a liberal feminist philosophical perspective that this prohibition reinforces existing traditional stereotypes of female athletes. Because the women's game does not…

A School-Based Application of Modified Habit Reversal for Tourette Syndrome via a Translator: A Case Study

Science.gov (United States)

Gilman, Rich; Connor, Nancy; Haney, Michelle

2005-01-01

A school-based modified habit reversal intervention was utilized with an adolescent diagnosed with Tourette syndrome who recently immigrated from Mexico. Because the student possessed little proficiency of the English language, an interpreter was needed to help implement the procedure. The frequency of motor tics markedly decreased from baseline…

Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players.

Science.gov (United States)

Janot, Jeffrey M; Beltz, Nicholas M; Dalleck, Lance D

2015-09-01

The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15) and women (n = 11) hockey players (age = 20.5 ± 1.4 years) participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ), 40-yd dash (36.58m), 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop), and 1.5 mile (2.4km) run. Results indicated that 40-yd dash (36.58m), VJ, 1.5 mile (2.4km) run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time) and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1) slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time) + (0.005 x 1.5 mile run), 2) fastest repeat skate time = 9.762 - (0.089 x VJ) - (0.998 x 40-yd dash time), 3) average repeat skate time = 7.770 + (1.041 x 40-yd dash time) - (0.63 x VJ) + (0.003 x 1.5 mile time), and 4) 47.85 m speed test = 7.707 - (0.050 x VJ) - (0.01 x % drop). It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players. Key pointsThe 40-yd dash (36.58m) and vertical jump tests are significant predictors of on-ice skating performance specific to speed.In addition to 40-yd dash and vertical jump, the 1.5 mile (2.4km) run for time and percent power drop from the Wingate anaerobic power test were also significant predictors of skating performance that incorporates the aspect of recovery from skating activity.Due to the specificity of selected off-ice variables as predictors of on-ice performance, coaches can

Coste energético del dribling en hockey sobre patines

OpenAIRE

Blanco, Dr. Alfonso; Balagué, Dra. Natàlia

1997-01-01

El objetivo del presente estudio ha sido analizar y comparar el coste energético del dribling en hockey sobre patines con respecto a la acción de patinar. Doce jugadores amateurs bien entrenados han realizado, durante cinco minutos a 11, 13 y 15 km/h, patinaje solamente y patinaje mientras driblaban la bola con el stick. En ambos casos se evaluaron directamente y compararon consumo de oxígeno, ventilación, frecuencia cardíaca y nivel de percepción subjetiva del esfuerzo. Las variables fisioló...

Does self-confidence link to motivation? A study in field hockey athletes

OpenAIRE

Sari, İhsan; Ekici, Sümmani; Soyer, Fikret; Eskiler, Ersin

2015-01-01

Previous research indicated some evidence of a positive relationship between motivation and self-efficacy beliefs/perceived competence/self-perceptions. Therefore, the relationship between self-confidence and motivation was investigated in sport context in this study. Participants of this study were 111 field hockey athletes. Sport Motivation Scale (Pelletier et al., 1995) and Self-confidence Scales (Tokinan, 2008) were used for data collection. SPSS.17 package program was used to analyse the...

Bebop on the Hockey pitch: Cross-disciplinary creativity and skills transfer

Directory of Open Access Journals (Sweden)

Clive Maxwell Harrison

2016-02-01

Full Text Available This paper generalises task-specific (but dissimilar skills, from the jazz concert stage and from the hockey field, into the domain of creativity research. What is sought are clues to what skills or creativities are transferable across dissimilar domains. It is argued that certain domain-general skills are transferable across domains, but a domain-general or ‘c’ creative capacity, is not. Rather than transferring some over-arching capacity to be universally creative, this research highlights factors likely to facilitate successful cross-disciplinary creative expression and posits a correlation between the capacities for discriminant pattern-recognition, task-specific expertise, and sensory data-collection, and the transferability of creativity. Of particular significance is the capacity for informed, selective pattern-breaking based on the ‘depth’ or ‘insider’ perspective of the domain expert; such ‘expert variation and selective retention’ (EVSR provides creative choices and responses that are likely to be perceived by the field as creative: valuable, novel and surprising. The author is a renowned Australian studio bassist, jazz musician, and music educator who also plays field hockey for Australia at Masters level. His recently completed PhD thesis, based on a performance and composition career spanning 46 years, takes the form of an analytical autoethnography drawn from personal field notes, diaries and interviews as well as published record albums.

Development of the interval endurance capacity in elite and sub-elite youth field hockey players

NARCIS (Netherlands)

Elferink-Gemser, MT; Visscher, C; van Duijn, MAJ; Lemmink, KAPM

Objectives: To gain more insight into the mechanisms that underlie the development of interval endurance capacity in talented youth field hockey players in the 12-19 age band. Methods: A total of 377 measurements were taken over three years. A longitudinal model for interval endurance capacity was

A prospective study of concussions among National Hockey League players during regular season games: the NHL-NHLPA Concussion Program.

Science.gov (United States)

Benson, Brian W; Meeuwisse, Willem H; Rizos, John; Kang, Jian; Burke, Charles J

2011-05-17

In 1997, the National Hockey League (NHL) and NHL Players' Association (NHLPA) launched a concussion program to improve the understanding of this injury. We explored initial postconcussion signs, symptoms, physical examination findings and time loss (i.e., time between the injury and medical clearance by the physician to return to competitive play), experienced by male professional ice-hockey players, and assessed the utility of initial postconcussion clinical manifestations in predicting time loss among hockey players. We conducted a prospective case series of concussions over seven NHL regular seasons (1997-2004) using an inclusive cohort of players. The primary outcome was concussion and the secondary outcome was time loss. NHL team physicians documented post-concussion clinical manifestations and recorded the date when a player was medically cleared to return to play. Team physicians reported 559 concussions during regular season games. The estimated incidence was 1.8 concussions per 1000 player-hours. The most common postconcussion symptom was headache (71%). On average, time loss (in days) increased 2.25 times (95% confidence interval [CI] 1.41-3.62) for every subsequent (i.e., recurrent) concussion sustained during the study period. Controlling for age and position, significant predictors of time loss were postconcussion headache (p < 0.001), low energy or fatigue (p = 0.01), amnesia (p = 0.02) and abnormal neurologic examination (p = 0.01). Using a previously suggested time loss cut-point of 10 days, headache (odds ratio [OR] 2.17, 95% CI 1.33-3.54) and low energy or fatigue (OR 1.72, 95% CI 1.04-2.85) were significant predictors of time loss of more than 10 days. Postconcussion headache, low energy or fatigue, amnesia and abnormal neurologic examination were significant predictors of time loss among professional hockey players.

Multidimensional performance characteristics and standard of performance in talented youth field hockey players : A longitudinal study

NARCIS (Netherlands)

Elferink-Gemser, Marije T.; Visscher, Chris; Lemmink, Koen A. P. M.; Mulder, Theo

2007-01-01

To identify performance characteristics that could help predict future elite field hockey players, we measured the anthropometric, physiological, technical, tactical, and psychological characteristics of 30 elite and 35 sub-elite youth players at the end of three consecutive seasons. The mean age of

Comparison of effectiveness of advertising expenses during broadcasts of main hockey events

OpenAIRE

Kozlová, Natálie

2017-01-01

Title: Comparison of effectiveness of advertising expenses during broadcasts of main hockey events Objectives: The main goal of this dissertation is to compare the amount of money invested into the commercial advertisement during sport broadcasts at the ČT sport channel with viewer ratings. The used metric is a coefficient computed as a ratio between the viewer rating of the particular broadcast and the corresponding advertisement cost, normalized using Cost per Thousand method. Another goal ...

Modified Borohydrides for Reversible Hydrogen Storage (2)

International Nuclear Information System (INIS)

Ming Au

2006-01-01

This paper reports the results in the effort to destabilize lithium borohydride for reversible hydrogen storage. A number of metals, metal hydrides, metal chlorides and complex hydrides were selected and evaluated as the destabilization agents for reducing de-hydriding temperature and generating de-hydriding-re-hydriding reversibility. It is found that some additives are effective. The Raman spectroscopic analysis shows the change of B-H binding nature. (authors)

A systematic video analysis of National Hockey League (NHL) concussions, part I: who, when, where and what?

Science.gov (United States)

Hutchison, Michael G; Comper, Paul; Meeuwisse, Willem H; Echemendia, Ruben J

2015-04-01

Although there is a growing understanding of the consequences of concussions in hockey, very little is known about the precipitating factors associated with this type of injury. To describe player characteristics and situational factors associated with concussions in the National Hockey League (NHL). Case series of medically diagnosed concussions for regular season games over a 3.5-year period during the 2006-2010 seasons using an inclusive cohort of professional hockey players. Digital video records were coded and analysed using the Heads Up Checklist. Of 197 medically diagnosed concussions, 88% involved contact with an opponent. Forwards accounted for more concussions than expected compared with on-ice proportional representation (95% CI 60 to 73; p=0.04). Significantly more concussions occurred in the first period (47%) compared with the second and third periods (p=0.047), with the majority of concussions occurring in the defensive zone (45%). Approximately 47% of the concussions occurred in open ice, 53% occurred in the perimeter. Finally, 37% of the concussions involved injured players' heads contacting the boards or glass. This study describes several specific factors associated with concussions in the NHL, including period of the game, player position, body size, and specific locations on the ice and particular situations based on a player's position. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

ANÁLISIS DE LA ACCIÓN DE GOL EN EL PORTERO DE HOCKEY HIERBA

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J. Sampedro

2010-09-01

Full Text Available

RESUMEN

El objetivo fundamental del estudio es analizar el rendimiento del portero de hockey hierba, desde la perspectiva del número de goles encajados en función de la zona de tiro y del lugar por donde entra el lanzamiento. Se analizó una muestra de 278 lanzamientos a portería que acabaron en gol, marcados a 30 porteros/as de nivel internacional de selecciones nacionales absolutas. La técnica de recogida de datos empleada fue la observación sistemática utilizando para ello la base de datos OBANGOHH (Piñeiro, 2006. Los resultados obtenidos determinan que la zona de la tabla, la zona izquierda de la portería, la zona GIT, y el poste largo, son “puntos débiles” del portero/a. Los porteros/as tienen mayores o menores probabilidades de encajar gol dependiendo de la zona del área desde la que tira el delantero y la zona de portería por la que entra el lanzamiento. Además existen diferencias significativas en relación al género del portero. El nivel de significación establecido fue del 95% (p<0,05.
Palabras Clave: hockey hierba, rendimiento, portero, gol.

ABSTRACT

The main aim of the study is to analyze the performance of field hockey goalkeeper, from the perspective of the number of goals achieved depending on the zone of shot and of the place where the throwing was goal. 278 shots on goal scored to different goalkeepers of international level of senior national teams were analyzed. According to Piñeiro (2006, the technique of collection of the data used was the systematic observation; using for it the notational data base OBANGOFH. The obtained results determine that the side-boards and back-boards zone, the left zone of the goal, the zone

Professional-applied physical training students by means of field hockey

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Pylypey L.P.

2010-01-01

Full Text Available Description of the modern crisis state of health and physical preparedness of graduating students of higher institutes is resulted. Most graduating students can not high-quality work on a production. Not efficiency of the existent system of physical education is rotined in the institutes of higher. The terms of intensification of educational process are considered. Efficiency and forming actuality is investigational for the students of motivation to the select kind of sport (field hockey. The stages of introduction of innovative approaches, new credit-module technologies in the river-bed of the Bologna system are presented.

Scheduling for the National Hockey League Using a Multi-objective Evolutionary Algorithm

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Craig, Sam; While, Lyndon; Barone, Luigi

We describe a multi-objective evolutionary algorithm that derives schedules for the National Hockey League according to three objectives: minimising the teams' total travel, promoting equity in rest time between games, and minimising long streaks of home or away games. Experiments show that the system is able to derive schedules that beat the 2008-9 NHL schedule in all objectives simultaneously, and that it returns a set of schedules that offer a range of trade-offs across the objectives.

Game Intensity Analysis of Elite Adolescent Ice Hockey Players

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Stanula Arkadiusz

2014-12-01

Full Text Available The purpose of this study was to determine ice-hockey players’ playing intensity based on their heart rates (HRs recorded during a game and on the outcomes of an incremental maximum oxygen uptake test. Twenty ice-hockey players, members of the Polish junior national team (U18, performed an incremental test to assess their maximal oxygen uptake (V̇ O2max in the two week’s period preceding 5 games they played at the World Championships. Players’ HRs at the first and second ventilatory thresholds obtained during the test were utilized to determine intensity zones (low, moderate, and high that were subsequently used to classify HR values recorded during each of the games. For individual intensity zones, the following HRs expressed as mean values and as percentages of the maximal heart rate (HRmax were obtained: forwards 148-158 b⋅min-1 (79.5-84.8% HRmax, 159-178 b⋅min-1 (85.4-95.6% HRmax, 179-186 b⋅min-1 (96.1-100.0% HRmax; defensemen 149-153 b⋅min-1 (80.0-82.1% HRmax, 154-175 b⋅min-1 (82.6- 94.0% HRmax, 176-186 b⋅min-1 (94.5-100.0% HRmax. The amount of time the forwards and defensemen spent in the three intensity zones expressed as percentages of the total time of the game were: 54.91 vs. 55.62% (low, 26.40 vs. 22.38% (moderate and 18.68 vs. 22.00% (high. The forwards spent more time in the low intensity zone than the defensemen, however, the difference was not statistically significant. The results of the study indicate that using aerobic and anaerobic metabolism variables to determine intensity zones can significantly improve the reliability of evaluation of the physiological demands of the game, and can be a useful tool for coaches in managing the training process.

The positioning of federate sports in Portugal: handball, basketball, roller hockey and volleyball

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Gonçalves, Celina; Correia, Abel

2005-01-01

Sport is constituted by a multiplicity of activities with different purposes, concepts and cultural representations. Before the increase of supply, Sports Federations need to understand the practitioners in relation to the several possibilities of practice and to position their sports according to their competitors. In this context, the purpose of this study is the positioning of team federate sports (handball, basketball, roller hockey and volleyball). According to Lindon et al.,...

Practicing field hockey skills along the contextual interference continuum: a comparison of five practice schedules.

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Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J Robert; Medic, Nikola; Razman, Rizal

2012-01-01

To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners.

High-intensity interval training has positive effects on performance in ice hockey players.

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Naimo, M A; de Souza, E O; Wilson, J M; Carpenter, A L; Gilchrist, P; Lowery, R P; Averbuch, B; White, T M; Joy, J

2015-01-01

In spite of the well-known benefits that have been shown, few studies have looked at the practical applications of high-intensity interval training (HIIT) on athletic performance. This study investigated the effects of a HIIT program compared to traditional continuous endurance exercise training. 24 hockey players were randomly assigned to either a continuous or high-intensity interval group during a 4-week training program. The interval group (IG) was involved in a periodized HIIT program. The continuous group (CG) performed moderate intensity cycling for 45-60 min at an intensity that was 65% of their calculated heart rate reserve. Body composition, muscle thickness, anaerobic power, and on-ice measures were assessed pre- and post-training. Muscle thickness was significantly greater in IG (p=0.01) when compared to CG. The IG had greater values for both ∆ peak power (p<0.003) and ∆ mean power (p<0.02). Additionally, IG demonstrated a faster ∆ sprint (p<0.02) and a trend (p=0.08) for faster ∆ endurance test time to completion for IG. These results indicate that hockey players may utilize short-term HIIT to elicit positive effects in muscle thickness, power and on-ice performance. © Georg Thieme Verlag KG Stuttgart · New York.

The Assessment of Airway Maneuvers and Interventions in University Canadian Football, Ice Hockey, and Soccer Players

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Delaney, J. Scott; Al-Kashmiri, Ammar; Baylis, Penny-Jane; Troutman, Tracy; Aljufaili, Mahmood; Correa, José A.

2011-01-01

Abstract Context: Managing an airway in an unconscious athlete is a lifesaving skill that may be made more difficult by the recent changes in protective equipment. Different airway maneuvers and techniques may be required to help ventilate an unconscious athlete who is wearing full protective equipment. Objective: To assess the effectiveness of different airway maneuvers with football, ice hockey, and soccer players wearing full protective equipment. Design: Crossover study. Setting: University sports medicine clinic. Patients or Other Participants: A total of 146 university varsity athletes, consisting of 62 football, 45 ice hockey, and 39 soccer players. Intervention(s): Athletes were assessed for different airway and physical characteristics. Three investigators then evaluated the effectiveness of different bag-valve-mask (BVM) ventilation techniques in supine athletes who were wearing protective equipment while inline cervical spine immobilization was maintained. Main Outcome Measure(s): The effectiveness of 1-person BVM ventilation (1-BVM), 2-person BVM ventilation (2-BVM), and inline immobilization and ventilation (IIV) was judged by each investigator for each athlete using a 4-point rating scale. Results: All forms of ventilation were least difficult in soccer players and most difficult in football players. When compared with 1-BVM, both 2-BVM and IIV were deemed more effective by all investigators for all athletes. Interference from the helmet and stabilizer were common reasons for difficult ventilation in football and ice hockey players. Conclusions: Sports medicine professionals should practice and be comfortable with different ventilation techniques for athletes wearing full equipment. The use of a new ventilation technique, termed inline immobilization and ventilation, may be beneficial, especially when the number of responders is limited. PMID:21391796

Upper body strength and power are associated with shot speed in men's ice hockey

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Juraj Bežák

2017-06-01

Full Text Available Background: Recent studies that addressed shot speed in ice hockey have focused on the relationship between shot speed and variables such as a player's skills or hockey stick construction and its properties. There has been a lack of evidence that considers the relationship between shot speed and player strength, particularly in players at the same skill level. Objective: The aim of this study was to identify the relationship between maximal puck velocity of two shot types (the wrist shot and the slap shot and players' upper body strength and power. Methods: Twenty male professional and semi-professional ice hockey players (mean age 23.3 ± 2.4 years participated in this study. The puck velocity was measured in five trials of the wrist shot and five trials of the slap shot performed by every subject. All of the shots were performed on ice in a stationary position 11.6 meters in front of an electronic device that measures the speed of the puck. The selected strength and power variables were: muscle power in concentric contraction in the countermovement bench press with 40 kg and 50 kg measured with the FiTRODyne Premium device; bench press one-repetition maximum; and grip strength measured by digital hand dynamometer. Results: The correlations between strength/power variables and the puck velocity in the wrist shot and the slap shot ranged between .29-.72 and .16-.62, respectively. Puck velocities produced by wrist shots showed significant correlations with bench press muscle power with 40 kg (p = .004 and 50 kg (p < .001; and one-repetition maximum in bench press (p = .004. The slap shot puck velocity was significantly associated with bench press muscle power with 40 kg (p = .014 and 50 kg (p = .004. Conclusions: This study provides evidence that there are significant associations between shot speed and upper body strength and power.

From Fact to Fiction – An Introduction to the Mythology of Ice Hockey in Canadian Life and Literature

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Jason Blake

2004-12-01

Full Text Available The title of Alice Munro’s Who do you think you are? could just as easily be asked of Canada, without eliciting an easy answer. In ethnic, linguistic, even geographical terms, Canada is hardly homogeneous. Because of this, we can only dream of a unified identity; we are, as Leonard Cohen writes in Beautiful Losers, condemned to “nightmares of identity.” If Canada is too complex for a uniform national identity, one derived from a convenient mythology and distilled into simple symbols, it often seems we have yet to realize it. We long for a mythology, even a modern, and blatantly constructed one. In contemporary Canadian society, ice hockey has filled that symbolic role, serving as a mythology that binds a fragmented people. This paper examines the role of ice hockey as a mythologized symbol of Canadian unity in literature, and questions the appropriateness of that usage.

Variables determinantes del drag-flick en jugadoras de hockey hierba

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Cristina López de Subijana Hernández

2012-12-01

Full Text Available El penalti córner es una de las situaciones de juego más importantes en el hockey hierba. Las mujeres utilizan menos el drag-flick que los hombres. Los objetivos de este estudio fueron describir los parámetros cinemáticos del drag-flick en jugadoras especialistas y hallar las variables determinantes en el rendimiento en este gesto técnico en jugadoras de hockey. Se analizaron quince lanzamientos de cinco lanzadoras con 6 cámaras del sistema de captura automática VICON registrando a 250 Hz. Para la comparación de medias se utilizó un análisis no paramétrico Kruskall Wallis de un factor (sujeto. Aquellos parámetros en los que se hallaron diferencias significativas, se compararon por pares por medio de una U de Mann Whitney. Las jugadoras 1 (22,5 ± 0,9 m/s y 3 (22,6 ± 0,7 m/s registraron velocidades de salida de la bola superiores (p < 0,001 a todas las demás jugadoras (19,1 ± 0,7 m/s jugadora 2; 20,5 ± 0,4 m/s jugadora 4 y 19,9 ± 0,4 m/s jugadora 5. La jugadora 1 basa su aceleración final en un doble apoyo largo, con una secuencia de velocidades y una distancia recorrida lo más amplia posible. Sin embargo, jugadora 3 basa su velocidad en la carrera previa, y en una secuencia de movimientos explosiva. Las características individuales de cada jugadora juegan un papel importante en la elección de una estrategia técnica u otra de lanzamiento.

Multidisciplinary approach to non-surgical management of inguinal disruption in a professional hockey player treated with platelet-rich plasma, manual therapy and exercise: a case report.

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St-Onge, Eric; MacIntyre, Ian G; Galea, Anthony M

2015-12-01

To present the clinical management of inguinal disruption in a professional hockey player and highlight the importance of a multidisciplinary approach to diagnosis and management. A professional hockey player with recurrent groin pain presented to the clinic after an acute exacerbation of pain while playing hockey. The patient received a clinical diagnosis of inguinal disruption. Imaging revealed a tear in the rectus abdominis. Management included two platelet-rich plasma (PRP) injections to the injured tissue, and subsequent manual therapy and exercise. The patient returned to his prior level of performance in 3.5 weeks. This case demonstrated the importance of a multidisciplinary team and the need for advanced imaging in athletes with groin pain. Research quality concerning the non-surgical management of inguinal disruption remains low. This case adds evidence that PRP, with the addition of manual therapy and exercise may serve as a relatively quick and effective non-surgical management strategy.

The role of visual perception measures used in sports vision programmes in predicting actual game performance in Division I collegiate hockey players.

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Poltavski, Dmitri; Biberdorf, David

2015-01-01

Abstract In the growing field of sports vision little is still known about unique attributes of visual processing in ice hockey and what role visual processing plays in the overall athlete's performance. In the present study we evaluated whether visual, perceptual and cognitive/motor variables collected using the Nike SPARQ Sensory Training Station have significant relevance to the real game statistics of 38 Division I collegiate male and female hockey players. The results demonstrated that 69% of variance in the goals made by forwards in 2011-2013 could be predicted by their faster reaction time to a visual stimulus, better visual memory, better visual discrimination and a faster ability to shift focus between near and far objects. Approximately 33% of variance in game points was significantly related to better discrimination among competing visual stimuli. In addition, reaction time to a visual stimulus as well as stereoptic quickness significantly accounted for 24% of variance in the mean duration of the player's penalty time. This is one of the first studies to show that some of the visual skills that state-of-the-art generalised sports vision programmes are purported to target may indeed be important for hockey players' actual performance on the ice.

Multiparametric MRI changes persist beyond recovery in concussed adolescent hockey players

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Manning, Kathryn Y.; Schranz, Amy; Bartha, Robert; Dekaban, Gregory A.; Barreira, Christy; Brown, Arthur; Fischer, Lisa; Asem, Kevin; Doherty, Timothy J.; Fraser, Douglas D.; Holmes, Jeff

2017-01-01

Objective: To determine whether multiparametric MRI data can provide insight into the acute and long-lasting neuronal sequelae after a concussion in adolescent athletes. Methods: Players were recruited from Bantam hockey leagues in which body checking is first introduced (male, age 11–14 years). Clinical measures, diffusion metrics, resting-state network and region-to-region functional connectivity patterns, and magnetic resonance spectroscopy absolute metabolite concentrations were analyzed from an independent, age-matched control group of hockey players (n = 26) and longitudinally in concussed athletes within 24 to 72 hours (n = 17) and 3 months (n = 14) after a diagnosed concussion. Results: There were diffusion abnormalities within multiple white matter tracts, functional hyperconnectivity, and decreases in choline 3 months after concussion. Tract-specific spatial statistics revealed a large region along the superior longitudinal fasciculus with the largest decreases in diffusivity measures, which significantly correlated with clinical deficits. This region also spatially intersected with probabilistic tracts connecting cortical regions where we found acute functional connectivity changes. Hyperconnectivity patterns at 3 months after concussion were present only in players with relatively less severe clinical outcomes, higher choline concentrations, and diffusivity indicative of relatively less axonal disruption. Conclusions: Changes persisted well after players' clinical scores had returned to normal and they had been cleared to return to play. Ongoing white matter maturation may make adolescent athletes particularly vulnerable to brain injury, and they may require extended recovery periods. The consequences of early brain injury for ongoing brain development and risk of more serious conditions such as second impact syndrome or neural degenerative processes need to be elucidated. PMID:29070666

Investigation of Positional Differences in Fitness of Male University Ice Hockey Players and the Frequency, Time Spent and Heart Rate of Movement Patterns during Competition

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Joel Jackson

2017-07-01

Full Text Available Background:  Men’s university ice hockey has received little scientific attention over the past 30 years, a time in which the traits of the players and the demands of the game have evolved.  Objectives: This study compared the physiological characteristics of university ice hockey players and examined the frequency and duration of the different movement patterns and heart rate (HR responses during competition. Methods: Twenty male ice hockey players from the same team ( age ± SD = 22±2 years underwent a fitness evaluation and were filmed and HR monitored during regular season games. Results: Forwards and defense had similar fitness and only differed on % fatigue index and peak heart during on-ice sprinting (P<0.05. Defense stood, glided and skated backwards more than forwards and forwards skated at a moderate intensity and glided forward more than defense (P<0.05. All players spent the majority of game time gliding forward (60% of the time followed by skating forward at a moderate intensity (17% and standing with little movement (9%. Average HR during the game reached 96 and 92 % and peak HR was 100 and 96 % of maximum in forwards and defense, respectively. Conclusions: Male university hockey players present with a high level of physical fitness in a variety of categories with few differences between forwards and defense. Movement patterns during games suggest that players are performing low to moderate intensity on-ice activities the majority of the time. Paradoxically, HR continues to climb to near maximum during on ice shifts.

Development and Validation of a Method for Determining Tridimensional Angular Displacements with Special Applications to Ice Hockey Motions.

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Gagnon, Micheline; And Others

1983-01-01

A method for determining the tridimensional angular displacement of skates during the two-legged stop in ice hockey was developed and validated. The angles were measured by geometry, using a cinecamera and specially equipped skates. The method provides a new tool for kinetic analyses of skating movements. (Authors/PP)

The Geomagnetic Field During a Reversal

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Heirtzler, James R.

2003-01-01

By modifying the IGRF it is possible to learn what may happen to the geomagnetic field during a geomagnetic reversal. If the entire IGRF reverses then the declination and inclination only reverse when the field strength is zero. If only the dipole component of the IGRF reverses a large geomagnetic field remains when the dipole component is zero and he direction of the field at the end of the reversal is not exactly reversed from the directions at the beginning of the reversal.

Cold power creates artificial ice for the ice hockey championship. Football arena is used as an ice stadium; Kaeltepower schafft Kunsteis fuer Eishockey-WM. Fussballarena wird zum Eisstadion

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Hoffmann, Franz

2010-11-15

On 7th May 2010, the Veltins arena in Gelsenkirchen (Federal Republic of Germany) became the greatest ice hockey stadium of the world. There, the opening play of the world championship between the host Germany and the USA took place. Germany as a clear outsider won 2:1 against the US-Boys. However, before this historical victory extensive building operations had to be realized 'Auf Schalke' in order to convert the lawn into a complete ice hockey court.

Motivational climate, goal orientation, perceived sport ability, and enjoyment within Finnish junior ice hockey players.

Science.gov (United States)

Jaakkola, T; Ntoumanis, N; Liukkonen, J

2016-01-01

The aim of this study was to investigate the relations among situational motivational climate, dispositional approach and avoidance achievement goals, perceived sport ability, and enjoyment in Finnish male junior ice hockey players. The sample comprised 265 junior B-level male players with a mean age of 17.03 years (SD = 0.63). Players filled questionnaires tapping their perceptions of coach motivational climate, achievement goals, perceived sport ability, and enjoyment. For the statistical analysis, players were divided into high and low perceived sport ability groups. Multigroup structural equation modeling (SEM) revealed an indirect path from task-involving motivational climate via task-approach goal to enjoyment. Additionally, SEM demonstrated four other direct associations, which existed in both perceived ability groups: from ego-involving motivational climate to ego-approach and ego-avoidance goals; from ego-approach goal to ego-avoidance goal; and from task-avoidance goal to ego-avoidance goal. Additionally, in the high perceived sport ability group, there was an association from task-involving motivational climate to enjoyment. The results of this study reveal that motivational climate emphasizing effort, personal development and improvement, and achievement goal mastering tasks are significant elements of enjoyment in junior ice hockey. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Juego, Cultura y Desarrollo en la Infancia: El caso del Palín Mapuche y el Hockey. Play, Culture and Development in Childhood: Analysis of Mapuche’s Palin and Hockey.

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Garoz , Ignacio

2006-01-01

Full Text Available ResumenEl propósito del presente trabajo consiste en analizar los juegos de reglas, partiendo de su papel como transmisores de conocimiento sobre el mundo social (valores, creencias, normas, roles, etc., a partir del planteamiento piagetiano de la comprensión de las reglas de los juegos por los niños. Se aborda cómo se produce la evolución del conocimiento práctico y teórico de las reglas y se incorpora el estudio sobre el desarrollo del conocimiento del significado de los juegos, de sus reglas y acciones. Se utiliza un enfoque transcultural que nos permita comprender las diferencias entre el desarrollo de la regla a través de un juego deportivo como el hockey hierba en España y un juego tradicional del pueblo indígena mapuche de Chile, el palín o chueca.AbstractThe aim of this work is to analyse rule games and their importance in conveying understanding of the social world (values, beliefs, norms, roles, etc., following the Piagetian explanation of how children understand the rules of the games. Starting with the development of practical and theoretical grasp of rules the study includes children's understanding of meaning of games, their rules and play actions. A crosscultural comparison is used to explore the differences between how an understanding of rule is developed in a sporting game such as grass hockey in Spain and in a traditional game of the Mapuche indigenous tribe of Chile, such as palin (or chueca.

Neck injuries presenting to emergency departments in the United States from 1990 to 1999 for ice hockey, soccer, and American football

OpenAIRE

Delaney, J; Al-Kashmiri, A

2005-01-01

Objective: To examine the number and rate of neck injuries in the community as a whole for ice hockey, soccer, and American football by analysing data from patients presenting to emergency departments in the United States from 1990 to 1999.

Mild Dehydration Does Not Influence Performance Or Skeletal Muscle Metabolism During Simulated Ice Hockey Exercise In Men.

Science.gov (United States)

Palmer, Matthew S; Heigenhauser, George J F; Duong, MyLinh; Spriet, Lawrence L

2017-04-01

This study determined whether mild dehydration influenced skeletal muscle glycogen use, core temperature or performance during high-intensity, intermittent cycle-based exercise in ice hockey players vs. staying hydrated with water. Eight males (21.6 ± 0.4 yr, 183.5 ± 1.6 cm, 83.9 ± 3.7 kg, 50.2 ± 1.9 ml·kg -1 ·min -1 ) performed two trials separated by 7 days. The protocol consisted of 3 periods (P) containing 10 × 45-s cycling bouts at ~133% VO 2max , followed by 135 s of passive rest. Subjects drank no fluid and dehydrated during the protocol (NF), or maintained body mass by drinking WATER. Muscle biopsies were taken at rest, immediately before and after P3. Subjects were mildly dehydrated (-1.8% BM) at the end of P3 in the NF trial. There were no differences between the NF and WATER trials for glycogen use (P1+P2; 350.1 ± 31.9 vs. 413.2 ± 33.2, P3; 103.5 ± 16.2 vs. 131.5 ± 18.9 mmol·kg dm -1 ), core temperature (P1; 37.8 ± 0.1 vs. 37.7 ± 0.1, P2; 38.2 ± 0.1 vs. 38.1 ± 0.1, P3; 38.3 ± 0.1 vs. 38.2 ± 0.1 °C) or performance (P1; 156.3 ± 7.8 vs. 154.4 ± 8.2, P2; 150.5 ± 7.8 vs. 152.4 ± 8.3, P3; 144.1 ± 8.7 vs. 148.4 ± 8.7 kJ). This study demonstrated that typical dehydration experienced by ice hockey players (~1.8% BM loss), did not affect glycogen use, core temperature, or voluntary performance vs. staying hydrated by ingesting water during a cycle-based simulation of ice hockey exercise in a laboratory environment.

Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.

OpenAIRE

Kujala, U. M.; Taimela, S.; Antti-Poika, I.; Orava, S.; Tuominen, R.; Myllynen, P.

1995-01-01

OBJECTIVE--To determine the acute injury profile in each of six sports and compare the injury rates between the sports. DESIGN--Analysis of national sports injury insurance registry data. SETTING--Finland during 1987-91. SUBJECTS--621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. MAIN OUTCOME MEASURES--Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and...

Four Weeks of Off-Season Training Improves Peak Oxygen Consumption in Female Field Hockey Players

OpenAIRE

Lindsey T. Funch; Erik Lind; Larissa True; Deborah Van Langen; John T. Foley; James F. Hokanson

2017-01-01

The purpose of the study was to examine the changes in peak oxygen consumption ( V ˙O2peak) and running economy (RE) following four-weeks of high intensity training and concurrent strength and conditioning during the off-season in collegiate female field hockey players. Fourteen female student-athletes (age 19.29 ± 0.91 years) were divided into two training groups, matched from baseline V ˙O2peak: High Intensity Training (HITrun; n = 8) and High Intensity Interval Training (HIIT; ...

Effect of ice surface size on collision rates and head impacts at the World Junior Hockey Championships, 2002 to 2004.

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Wennberg, Richard

2005-03-01

To determine if collision rates and head impacts in elite junior hockey differed between games played on the small North American ice surface (85 ft wide), an intermediate-size Finnish ice surface (94 ft wide), and the large standard international ice surface (100 ft wide). Videotape analysis of all games involving Team Canada from the 2002 (large ice, Czech Republic), 2003 (small ice, Canada), and 2004 (intermediate ice, Finland) World Junior Championships. All collisions were counted and separated into various categories (volitional player/player bodychecks, into boards or open ice, plus accidental/incidental player/boards, player/ice, head/stick, head/puck). Further subdivisions included collisions involving the head directly or indirectly and notably severe head impacts. Small, intermediate, and large ice surface mean collisions/game, respectively, were 295, 258, 222, total collisions; 251, 220, 181, volitional bodychecks; 126, 115, 88, into boards; 125, 106, 93, open ice; 71, 52, 44, total head; 44, 36, 30, indirect head; 26, 16, 13, direct head; and 1.3, 0.5, 0.3, severe head (P < 0.05 for small-intermediate ice and intermediate-large ice differences in total collisions; P < 0.005 for small-large ice difference; P < 0.05 for small-intermediate ice differences in head impacts; P < 0.01 for small-large ice differences in total and severe head impacts). There is a significant inverse correlation between ice size and collision rates in elite hockey, including direct, indirect, and severe head impacts. These findings suggest that uniform usage of the larger international rinks could reduce the risk of injury, and specifically, concussions in elite hockey by decreasing the occurrence of collisions and head impacts.

Relationship between body composition, leg strength, anaerobic power, and on-ice skating performance in division I men's hockey athletes.

Science.gov (United States)

Potteiger, Jeffrey A; Smith, Dean L; Maier, Mark L; Foster, Timothy S

2010-07-01

The purpose of this study was to examine relationships between laboratory tests and on-ice skating performance in division I men's hockey athletes. Twenty-one men (age 20.7 +/- 1.6 years) were assessed for body composition, isokinetic force production in the quadriceps and hamstring muscles, and anaerobic muscle power via the Wingate 30-second cycle ergometer test. Air displacement plethysmography was used to determine % body fat (%FAT), fat-free mass (FFM), and fat mass. Peak torque and total work during 10 maximal effort repetitions at 120 degrees .s were measured during concentric muscle actions using an isokinetic dynamometer. Muscle power was measured using a Monark cycle ergometer with resistance set at 7.5% of body mass. On-ice skating performance was measured during 6 timed 89-m sprints with subjects wearing full hockey equipment. First length skate (FLS) was 54 m, and total length skate (TLS) was 89 m with fastest and average skating times used in the analysis. Correlation coefficients were used to determine relationships between laboratory testing and on-ice performance. Subjects had a body mass of 88.8 +/- 7.8 kg and %FAT of 11.9 +/- 4.6. First length skate-Average and TLS-Average skating times were moderately correlated to %FAT ([r = 0.53; p = 0.013] and [r = 0.57; p = 0.007]) such that a greater %FAT was related to slower skating speeds. First length skate-Fastest was correlated to Wingate percent fatigue index (r = -0.48; p = 0.027) and FLS-Average was correlated to Wingate peak power per kilogram body mass (r = -0.43; p = 0.05). Laboratory testing of select variables can predict skating performance in ice hockey athletes. This information can be used to develop targeted and effective strength and conditioning programs that will improve on-ice skating speed.

Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

Science.gov (United States)

Vescovi, Jason D.

2016-01-01

Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,…

Improving Pullulanase Catalysis via Reversible Immobilization on Modified Fe3O4@Polydopamine Nanoparticles.

Science.gov (United States)

Wang, Jianfeng; Liu, Zhongmei; Zhou, Zhemin

2017-08-01

To improve the catalysis of pullulanase from Anoxybacillus sp.WB42, Fe 3 O 4 @polydopamine nanoparticles (Fe 3 O 4 @PDA) were prepared and modified with functional groups for immobilization of pullulanases via covalent binding or ionic adsorption. Immobilized pullulanases had lower thermal stability than that of free pullulanase, whereas their catalysis depended on the surface characteristics of nanoparticles. As for covalent immobilization of pullulanases onto Fe 3 O 4 @PDA derivatives, the spacer grafted onto Fe 3 O 4 @PDA made the catalytic efficiency of pullulanase increase up to the equivalence of free enzyme but dramatically reduced the pullulanase thermostability. In contrast, pullulanases bounded ionically to Fe 3 O 4 @PDA derivatives had higher activity recovery and catalytic efficiency, and their catalytic behaviors varied with the modifier grafted onto Fe 3 O 4 @PDA. Among these immobilized pullulanases, ionic adsorption of pullulanase on Fe 3 O 4 @PDA-polyethyleneimine-glycidyltrimethylammonium gave a high-performance and durable catalyst, which displayed not only 1.5-fold increase in catalytic efficiency compared to free enzyme but also a significant improvement in operation stability with a half of initial activity after 27 consecutive cycles with a total reaction time of 13.5 h, and was reversible, making this nanoparticle reusable for immobilization.

A molecular theory of chemically modified electrodes with self-assembled redox polyelectrolye thin films: Reversible cyclic voltammetry

Energy Technology Data Exchange (ETDEWEB)

Tagliazucchi, Mario; Calvo, Ernesto J. [INQUIMAE, DQIAyQF Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Szleifer, Igal [Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)

2008-10-01

A molecular theory of chemically modified electrodes is applied to study redox polyelectroyte modified electrodes. The molecular approach explicitly includes the size, shape, charge distribution, and conformations of all of the molecular species in the system as well as the chemical equilibria (redox and acid-base) and intermolecular interactions. An osmium pyridine-bipyridine complex covalently bound to poly(allyl-amine) backbone (PAH-Os) adsorbed onto mercapto-propane sulfonate (MPS) thiolated gold electrode is described. The potential and electrolyte composition dependent redox and nonredox capacitance can be calculated with the molecular theory in very good agreement with voltammetric experiments under reversible conditions without the use of freely adjustable parameter. Unlike existing phenomenological models the theory links the electrochemical behavior with the structure of the polymer layer. The theory predicts a highly inhomogeneous distribution of acid-base and redox states that strongly couples with the spatial arrangement of the molecular species in the nanometric redox film. (author)

The strains recommended for use in the bacterial reverse mutation test (OECD guideline 471) can be certified as non-genetically modified organisms.

Science.gov (United States)

Sugiyama, Kei-Ichi; Yamada, Masami; Awogi, Takumi; Hakura, Atsushi

2016-01-01

The bacterial reverse mutation test, commonly called Ames test, is used worldwide. In Japan, the genetically modified organisms (GMOs) are regulated under the Cartagena Domestic Law, and organisms obtained by self-cloning and/or natural occurrence would be exempted from the law case by case. The strains of Salmonella typhimurium and Escherichia coli recommended for use in the bacterial reverse mutation test (OECD guideline 471), have been considered as non-GMOs because they can be constructed by self-cloning or naturally occurring bacterial strains, or do not disturb the biological diversity. The present article explains the reasons why these tester strains should be classified as non-GMOs.

Rationale set of indicators and prioritize relevant to assess competitive activity of hockey players of high qualification of different roles

Directory of Open Access Journals (Sweden)

A.P. Mikhnov

2015-02-01

Full Text Available Purpose: organize technical and tactical actions and determine their priority importance for high-end players of different roles. Establish their priority importance for the success of competitive activity hockey with the game roles. Material : the study involved 54 experts on hockey coaches and players of high class. The significance of technical and tactical actions evaluated for players of different roles. Results : systematic account of technical and tactical actions of athletes and prioritize them to assess the significance of competitive activity. Three groups of technical and tactical actions: 1 active attacks; 2 - active safety; 3 - organizational and maneuvering. Set priorities for technical and tactical actions for players of different roles. Conclusions : the proposed technical and tactical actions can be recommended for the evaluation of the effectiveness of competitive activity players. In the process of estimating the action game players need to consider their role playing. Identification of priority in the implementation of technical and tactical actions in the game can be used in integrated assessment of actions players different roles.

Quasi-invariant modified Sobolev norms for semi linear reversible PDEs

International Nuclear Information System (INIS)

Faou, Erwan; Grébert, Benoît

2010-01-01

We consider a general class of infinite dimensional reversible differential systems. Assuming a nonresonance condition on linear frequencies, we construct for such systems almost invariant pseudo-norms that are close to Sobolev-like norms. This allows us to prove that if the Sobolev norm of index s of the initial data z 0 is sufficiently small (of order ε) then the Sobolev norm of the solution is bounded by 2ε over a very long time interval (of order ε −r with r arbitrary). It turns out that this theorem applies to a large class of reversible semi-linear partial differential equations (PDEs) including the nonlinear Schrödinger (NLS) equation on the d-dimensional torus. We also apply our method to a system of coupled NLS equations which is reversible but not Hamiltonian. We also note that for the same class of reversible systems we can prove a Birkhoff normal form theorem, which in turn implies the same bounds on the Sobolev norms. Nevertheless the techniques that we use to prove the existence of quasi-invariant pseudo-norms are much more simple and direct

MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

Energy Technology Data Exchange (ETDEWEB)

T.M. Whitworth; Liangxiong Li

2002-09-15

This report describes work performed during the second year of the project ''Modified reverse osmosis system for treatment of produced waters.'' We performed two series of reverse osmosis experiments using very thin bentonite clay membranes compacted to differing degrees. The first series of 10 experiments used NaCl solutions with membranes that ranged between 0.041 and 0.064mm in thickness. Our results showed compaction of such ultra-thin clay membranes to be problematic. The thickness of the membranes was exceeded by the dimensional variation in the machined experimental cell and this is believed to have resulted in local bypassing of the membrane with a resultant decrease in solute rejection efficiency. In two of the experiments, permeate flow was varied as a percentage of the total flow to investigate results of changing permeate flow on solute rejection. In one experiment, the permeate flow was varied between 2.4 and 10.3% of the total flow with no change in solute rejection. In another experiment, the permeate flow was varied between 24.6 and 52.5% of the total flow. In this experiment, the solute rejection rate decreased as the permeate occupied greater fractions of the total flow. This suggests a maximum solute rejection efficiency for these clay membranes for a permeate flow of between 10.3 and 24.6% of the total; flow. Solute rejection was found to decrease with increasing salt concentration and ranged between 62.9% and 19.7% for chloride and between 61.5 and 16.8% for sodium. Due to problems with the compaction procedure and potential membrane bypassing, these rejection rates are probably not the upper limit for NaCl rejection by bentonite membranes. The second series of four reverse osmosis experiments was conducted with a 0.057mm-thick bentonite membrane and dilutions of a produced water sample with an original TDS of 196,250 mg/l obtained from a facility near Loco Hill, New Mexico, operated by an independent. These experiments

MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

Energy Technology Data Exchange (ETDEWEB)

T.M. Whitworth; Liangxiong Li

2002-09-15

This report describes work performed during the first year of the project ''Modified Reverse Osmosis System for Treatment of Produced Waters.'' This research project has two objectives. The first objective is to test the use of clay membranes in the treatment of produced waters by reverse osmosis. The second objective is to test the ability of a system patented by the New Mexico Tech Research Foundation to remove salts from reverse osmosis waste streams as a solid. We performed 12 experiments using clay membranes in cross-flow experimental cells. We found that, due to dispersion in the porous frit used adjacent to the membrane, the concentration polarization layer seems to be completely (or nearly completely) destroyed at low flow rates. This observation suggests that clay membranes used with porous frit material many reach optimum rejection rates at lower pumping rates than required for use with synthetic membranes. The solute rejection efficiency decreases with increasing solution concentration. For the membranes and experiments reported here, the rejection efficiency ranged from 71% with 0.01 M NaCl solution down to 12% with 2.3 M NaCl solution. More compacted clay membranes will have higher rejection capabilities. The clay membranes used in our experiments were relatively thick (approximately 0.5 mm). The active layer of most synthetic membranes is only 0.04 {micro}m (0.00004 mm), approximately 1250 times thinner than the clay membranes used in these experiments. Yet clay membranes as thin as 12 {micro}m have been constructed (Fritz and Eady, 1985). Since Darcy's law states that the flow through a material of constant permeability is inversely proportional to it's the material's thickness, then, based on these experimental observations, a very thin clay membrane would be expected to have much higher flow rates than the ones used in these experiments. Future experiments will focus on testing very thin clay membranes. The

Reversibility of Al/Ti Modified LiBH4

DEFF Research Database (Denmark)

Blanchard, Didier; Shi, Qing; Boothroyd, Chris

2009-01-01

Lithium borohydride has a high reversible hydrogen storage capacity. For its practical use as an on-board hydrogen storage medium in mobile applications, the temperature and pressure conditions along with the kinetics of the hydrogenation/dehydrogenation cycles have to be improved. Lithium borohy...

Reverse osmosis water purification system

Science.gov (United States)

Ahlstrom, H. G.; Hames, P. S.; Menninger, F. J.

1986-01-01

A reverse osmosis water purification system, which uses a programmable controller (PC) as the control system, was designed and built to maintain the cleanliness and level of water for various systems of a 64-m antenna. The installation operates with other equipment of the antenna at the Goldstone Deep Space Communication Complex. The reverse osmosis system was designed to be fully automatic; with the PC, many complex sequential and timed logic networks were easily implemented and are modified. The PC monitors water levels, pressures, flows, control panel requests, and set points on analog meters; with this information various processes are initiated, monitored, modified, halted, or eliminated as required by the equipment being supplied pure water.

Anterior Cruciate Ligament Injuries in the National Hockey League: Epidemiology and Performance Impact.

Science.gov (United States)

Longstaffe, Robert; Leiter, Jeff; MacDonald, Peter

2018-03-27

To determine the incidence of anterior cruciate ligament (ACL) injuries in the National Hockey League (NHL) and to examine the effects of this injury on return-to-play status and performance. Case series; level of evidence, 4. This was a 2-phase study. Phase I used the NHL electronic injury surveillance system and Athlete Health Management System to collect data on ACL injuries and man games lost over 10 seasons (2006/2007-2015/2016). Data collected in phase I were received in deidentified form. Phase II examined the performance impact of an ACL injury. Players were identified through publically available sources, and performance-related statistics were analyzed. Data collected in phase II were not linked to data collected in phase I. A paired t test was used to determine any difference in the matching variables between controls and cases in the preinjury time period. A General linear model (mixed) was used to determine the performance impact. Phase I: 67 ACL injuries occurred over 10 seasons. The incidence for all players was 0.42/1000 player game hours (forward, 0.61; defenseman, 0.32, goalie, 0.08) and by game exposure was 0.2/1000 player game exposures (forward, 0.33; defenseman, 0.11; goalie, 0.07). Forwards had a greater incidence rate of ACL tears with both game hours and game exposures when compared with defensemen and goalies (P game (P game (0.001). Number of games and seasons played after an ACL injury did not differ compared with controls (P = 0.068, 0.122, respectively). Anterior cruciate ligament injuries occur infrequently, as it relates to other hockey injuries. Despite a high return to play, the performance after an ACL injury demonstrated a decrease in points and goals per game and per season.

MASCULINITY AND SPORT REVISTED: A REVIEW OF LITERATURE ON HEGEMONIC MASCULINITY AND MEN'S ICE HOCKEY IN CANADA

OpenAIRE

Cheryl A. MacDonald

2014-01-01

Ice hockey is particularly significant in Canada as it acts as a primary site of socialization for boys and men. This form of socialization raises questions about masculinity on the public agenda in terms of the problematic nature of hypermasculinity in sport, stereotypical images of athletes, and questions of social responsibility as both men and athletes. These issues are presently relevant as Canada (and perhaps all of North America) finds itself in an era characterized by accounts in main...

The Control of Externalities in Sports Leagues: An Analysis of Restrictions in the National Hockey League

OpenAIRE

Dennis W. Carlton; Alan S. Frankel; Elisabeth M. Landes

2004-01-01

This paper provides one of the few successful demonstrations of the efficiency of certain types of restrictions in the context of a joint venture. The joint venture we examine is the National Hockey League (NHL) in the 1980s, which was then composed of 21 separately owned teams. (It now has 30 teams.) The restriction we analyze is the NHL rule on franchise relocation. Before one can fully understand the effect of the restriction, one must understand the theory of how sports leagues operate an...

Carbon Monoxide Exposure in Youth Ice Hockey.

Science.gov (United States)

Macnow, Theodore; Mannix, Rebekah; Meehan, William P

2017-11-01

To examine the effect of ice resurfacer type on carboxyhemoglobin levels in youth hockey players. We hypothesized that players in arenas with electric resurfacers would have normal, stable carboxyhemoglobin levels during games, whereas those in arenas with internal combustion engine (IC) resurfacers would have an increase in carboxyhemoglobin levels. Prospective cohort study. Enclosed ice arenas in the northeastern United States. Convenience sample of players aged 8 to 18 years old in 16 games at different arenas. Eight arenas (37 players) used an IC ice resurfacer and 8 arenas (36 players) an electric resurfacer. Carboxyhemoglobin levels (SpCO) were measured using a pulse CO-oximeter before and after the game. Arena air was tested for carbon monoxide (CO) using a metered gas detector. Players completed symptom questionnaires. The change in SpCO from pregame to postgame was compared between players at arenas with electric versus IC resurfacers. Carbon monoxide was present at 6 of 8 arenas using IC resurfacers, levels ranged from 4 to 42 parts per million. Carbon monoxide was not found at arenas with electric resurfacers. Players at arenas with IC resurfacers had higher median pregame SpCO levels compared with those at electric arenas (4.3% vs 1%, P carboxyhemoglobin during games and have elevated baseline carboxyhemoglobin levels compared with players at arenas with electric resurfacers. Electric resurfacers decrease the risk of CO exposure.

Knowing what to do and doing it : Differences in self-assessed tactical skills of regional, sub-elite, and elite youth field hockey players

NARCIS (Netherlands)

Elferink-Gemser, Marije T.; Kannekens, Rianne; Lyons, Jim; Tromp, Yvonne; Visscher, Chris

2010-01-01

To determine whether youth athletes with an oaverageo (regional), ohigho (sub-elite), and overy higho (elite) level of performance differ with respect to their self-assessed tactical skills, 191 youth field hockey players (mean age 15.5 years, s=1.6) completed the Tactical Skills Inventory for

Vitamin D status and V[combining dot above]O2peak during a skate treadmill graded exercise test in competitive ice hockey players.

Science.gov (United States)

Fitzgerald, John S; Peterson, Ben J; Warpeha, Joseph M; Wilson, Patrick B; Rhodes, Greg S; Ingraham, Stacy J

2014-11-01

Vitamin D status has been associated with cardiorespiratory fitness (CRF) in cross-sectional investigations in the general population. Data characterizing the association between 25-hydroxyvitamin D (25(OH)D) concentration and CRF in athletes are lacking. Junior and collegiate ice hockey players were recruited from the Minneapolis, MN (44.9° N), area during the off-season period (May 16-June 28). The purpose of this study was to examine the cross-sectional association between 25(OH)D concentration and CRF in a sample population of competitive ice hockey players. Circulating 25(OH)D level was assessed from a capillary blood sample analyzed using liquid chromatography-tandem mass spectrometry. V[Combining Dot Above]O2peak during a skate treadmill graded exercise test (GXT) was used to assess CRF. Data on both 25(OH)D concentration and V[Combining Dot Above]O2peak were available for 52 athletes. Insufficient 25(OH)D concentrations were found in 37.7% of the athletes (skate treadmill GXT.

An examination of the cohesion-performance relationship in university hockey teams.

Science.gov (United States)

Slater, M R; Sewell, D F

1994-10-01

The objective of this study was to assess, using the Group Environment Questionnaire, whether team cohesion in university-level field hockey was a cause for, or an effect of, successful performance. A quasi-experimental longitudinal design with cross-lagged correlational analysis was adopted and measures of cohesion and performance were taken midway and later in the season. The results of the synchronous correlations showed a positive relationship (with good stationarity) between team cohesion and performance outcome. Although non-significant cross-lagged differentials indicated a circular relationship, the magnitudes of both the cross-lagged correlations and the partial correlations, together with multiple-regression analyses, revealed that the stronger flow was from cohesion to performance. The socially oriented aspects of cohesion, in particular, had significant associations with performance. The results imply that cohesion-performance relationships should be examined within a circular model, in which cohesion and performance are interdependent.

CATECHOLAMINES AND β2-ADRENOCEPTOR GENE EXPRESSION BEFORE AND AFTER MAXIMAL INCREMENTAL CYCLE TEST IN YOUNG ICE HOCKEY PLAYERS: RELATION TO WORK PERFORMED

Directory of Open Access Journals (Sweden)

Urszula Mazurek

2013-04-01

Full Text Available The aim of this study was to assess the plasma adrenaline and noradrenaline concentrations as well as whole blood β2-adrenoceptor gene (ADRB2 expression in young ice hockey players before and immediately after exercise in relation to performed work. Nineteen Youth National Team ice hockey players were subjected to the maximal incremental cycloergometer exercise. The test was done in the pre-competitive phase of training. Among many parameters the plasma adrenaline and noradrenaline concentrations and ADRB2 gene expression in peripheral blood mononuclear cells (PBMC were determined before and after exercise. The average performed work was 3261.3 ± 558.3 J · kg-1 and maximal oxygen consumption (VO2max for all players was 53.85 ± 3.91 mL · kg-1 min-1. The geometric mean of the ADRB2 gene expression was statistically significantly different before and after exercise (P ≤ 0.05, while adrenaline and noradrenaline levels in plasma significantly increased after exercise. In the analysed group of athletes we found that initial level of plasma noradrenaline correlated with the performed work (r = - 0.55, P < 0.014 and normalized ADRB2 expression before the exercise correlated with the work done by them (r = 0.48, P<0.039. However, no statistically significant correlations were found between the plasma adrenaline or noradrenaline concentrations and ADRB2 gene expression in peripheral blood of the players. The performed work in the maximal incremental exercise test of regularly training young ice hockey players depends on the initial levels of noradrenaline in plasma and ADRB2 mRNA in PBMC.

Probabilities of Pulmonary and Cardiac Complications and Radiographic Parameters in Breast Cancer Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Noh, O Kyu; Paek, Sung Ho; Ahn, Seung Do; Choi, Eun Kyung; Lee, Sang Wook; Song, Si Yeol; Yoon, Sang Min; Kim, Jong Hoon [Dept. of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2010-11-15

To evaluate the relationship between the normal tissue complication probability (NTCP) of 3- dimensional (3-D) radiotherapy and the radiographic parameters of 2-dimensional (2-D) radiotherapy such as central lung distance (CLD) and maximal heart distance (MHD). We analyzed 110 patients who were treated with postoperative radiotherapy for breast cancer. A two-field tangential technique, a three-field technique, and the reverse hockey stick method were used. The radiation dose administered to whole breast or the chest wall was 50.4 Gy, whereas a 45 Gy was administered to the supraclavicular field. The NTCPs of the heart and lung were calculated by the modified Lyman model and the relative seriality model. For all patients, the NTCPs of radiation-induced pneumonitis and cardiac mortality were 0.5% and 0.7%, respectively. The NTCP of radiation-induced pneumonitis was higher in patients treated with the reverse hockey stick method than in those treated by other two techniques (0.0%, 0.0%, 3.1%, p<0.001). The NTCP of radiation-induced pneumonitis increased with CLD. The NTCP of cardiac mortality increased with MHD (R2=0.808). We found a close correlation between the NTCP of 3-D radiotherapy and 2-D radiographic parameters. Our results are useful to reanalyze the previous 2-D based clinical reports about breast radiation therapy complications as a viewpoint of NTCP.

Probabilities of Pulmonary and Cardiac Complications and Radiographic Parameters in Breast Cancer Radiotherapy

International Nuclear Information System (INIS)

Noh, O Kyu; Paek, Sung Ho; Ahn, Seung Do; Choi, Eun Kyung; Lee, Sang Wook; Song, Si Yeol; Yoon, Sang Min; Kim, Jong Hoon

2010-01-01

To evaluate the relationship between the normal tissue complication probability (NTCP) of 3- dimensional (3-D) radiotherapy and the radiographic parameters of 2-dimensional (2-D) radiotherapy such as central lung distance (CLD) and maximal heart distance (MHD). We analyzed 110 patients who were treated with postoperative radiotherapy for breast cancer. A two-field tangential technique, a three-field technique, and the reverse hockey stick method were used. The radiation dose administered to whole breast or the chest wall was 50.4 Gy, whereas a 45 Gy was administered to the supraclavicular field. The NTCPs of the heart and lung were calculated by the modified Lyman model and the relative seriality model. For all patients, the NTCPs of radiation-induced pneumonitis and cardiac mortality were 0.5% and 0.7%, respectively. The NTCP of radiation-induced pneumonitis was higher in patients treated with the reverse hockey stick method than in those treated by other two techniques (0.0%, 0.0%, 3.1%, p<0.001). The NTCP of radiation-induced pneumonitis increased with CLD. The NTCP of cardiac mortality increased with MHD (R2=0.808). We found a close correlation between the NTCP of 3-D radiotherapy and 2-D radiographic parameters. Our results are useful to reanalyze the previous 2-D based clinical reports about breast radiation therapy complications as a viewpoint of NTCP.

Examining social identity and intrateam moral behaviours in competitive youth ice hockey using stimulated recall.

Science.gov (United States)

Bruner, Mark W; Boardley, Ian D; Allan, Veronica; Root, Zach; Buckham, Sara; Forrest, Chris; Côté, Jean

2017-10-01

Social identity - identity formed through membership in groups - may play an important role in regulating intrateam moral behaviour in youth sport (Bruner, M. W., Boardley, I., & Côté, J. (2014). Social identity and prosocial and antisocial behavior in youth sport. Psychology of Sport and Exercise, 15(1), 56-64. doi:10.1016/j.psychsport.2013.09.003). The aim of this study was to qualitatively examine this potential role through stimulated recall interviews with competitive youth-ice-hockey players. Twenty-three players (M age  = 13.27 years, SD = 1.79) who reported engaging in high, median or low frequency of antisocial teammate behaviour (determined through pre-screening with the Prosocial and Antisocial Behaviour in Sport Scale [Kavussanu, M., & Boardley, I. D. (2009). The prosocial and antisocial behavior in sport scale. Journal of Sport and Exercise Psychology, 31(1), 97-117. doi:10.1123/jsep.31.1.97]) were recruited from eight youth-ice-hockey teams in Canada. Interviews involved participants recalling their thoughts during prosocial/antisocial interactions with teammates, prompted by previously recorded video sequences of such incidents. Thematic analysis of interview data revealed all athletes - regardless of reported frequency of intrateam antisocial behaviour - felt prosocial interactions with teammates enhanced social identity. In contrast, the perceived influence of antisocial teammate behaviour on social identity differed depending on athletes' reported frequency of intrateam antisocial behaviour; those reporting low and median frequencies described how such behaviour undermines social identity, whereas athletes reporting high frequency did not perceive this effect. The study findings highlight the potential importance of intrateam moral behaviour and social identity for youth-sport team functioning.

The relationship between ventilatory threshold and repeated-sprint ability in competitive male ice hockey players

Directory of Open Access Journals (Sweden)

Matthew R. Lowery

2018-04-01

Full Text Available Background/objective: The relationship between ventilatory threshold (VT1, VT2 and repeated-sprint ability (RSA in competitive male ice hockey players was investigated. Methods: Forty-three male ice hockey players aged 18–23 years competing in NCAA Division I, NCAA Division III, and Junior A level participated. Participants performed an incremental graded exercise test on a skate treadmill to determine V˙O2peak, VT1, and VT2 using MedGraphics Breezesuit™ software (v-slope. Participants performed an on-ice repeated shift (RSA test consisting of 8-maximal skating bouts, lasting approximately 25 s and interspersed with 90 s of passive recovery, to determine first gate, second gate, and total sprint decrement (%dec. Pearson product-moment correlations and multiple regressions were used to assess relationships between ventilatory threshold variables (VT1, VT2, Stage at VT1, and Stage at VT2 and RSA (first gate, second gate, and total course decrement. Results: Stage at VT2 was the only variable substantially correlated with first gate (r = −0.35; P < 0.05, second gate (r = −0.58; P < 0.001 and total course decrement (r = −0.42; P < 0.05. Conclusion: The results of this study demonstrated that VT is substantially associated with RSA, and VT2 is more strongly correlated with RSA than V˙O2peak. This study suggests that longer duration high-intensity interval training at intensities that increase workrate at VT2 may lead to possible improvements in RSA. Keywords: Athletes, Aerobic capacity, Fatigue, Sprint decrement

The Role of Visual Feedback on Power Output During Intermittent Wingate Testing in Ice Hockey Players

Directory of Open Access Journals (Sweden)

Petr Stastny

2018-04-01

Full Text Available Background: Visual feedback may help elicit peak performance during different types of strength and power testing, but its effect during the anaerobic Wingate test is unexplored. Therefore, the purpose of this study was to determine the effect of visual feedback on power output during a hockey-specific intermittent Wingate test (AnWT6x6 consisting of 6 stages of 6 s intervals with a 1:1 work-to-rest ratio. Methods: Thirty elite college-aged hockey players performed the AnWT6x6 with either constant (n = 15 visual feedback during all 6 stages (CVF or restricted (n = 15 visual feedback (RVF where feedback was shown only during the 2nd through 5th stages. Results: In the first stage, there were moderate-to-large effect sizes for absolute peak power (PP output and PP relative to body mass and PP relative to fat-free mass. However, the remaining stages (2–6 displayed small or negligible effects. Conclusions: These data indicate that visual feedback may play a role in optimizing power output in a non-fatigued state (1st stage, but likely does not play a role in the presence of extreme neuromuscular fatigue (6th stage during Wingate testing. To achieve the highest peak power, coaches and researchers could provide visual feedback during Wingate testing, as it may positively influence performance in the early stages of testing, but does not result in residual fatigue or negatively affect performance during subsequent stages.

Greater circadian disadvantage during evening games for the National Basketball Association (NBA), National Hockey League (NHL) and National Football League (NFL) teams travelling westward.

Science.gov (United States)

Roy, Jonathan; Forest, Geneviève

2018-02-01

We investigated the effects of a circadian disadvantage (i.e. playing in a different time zone) on the winning percentages in three major sport leagues in North America: the National Basketball Association, the National Hockey League and the National Football League. We reviewed 5 years of regular season games in the National Basketball Association, National Hockey League and National Football League, and noted the winning percentage of the visiting team depending on the direction of travel (west, east, and same time zone) and game time (day and evening games). T-tests and analysis of variance were performed to evaluate the effects of the circadian disadvantage, its direction, the number of time zones travelled, and the game time on winning percentages in each major league. The results showed an association between the winning percentages and the number of time zones traveled for the away evening games, with a clear disadvantage for the teams travelling westward. There was a significant difference in the teams' winning percentages depending on the travelling direction in the National Basketball Association (F 2,5908  = 16.12, P < 0.0001) and the National Hockey League (F 2,5639  = 4.48, P = 0.011), and a trend was found in the National Football League (F 2,1279  = 2.86, P = 0.058). The effect of the circadian disadvantage transcends the type of sport and needs to be addressed for greater equity among the western and eastern teams in professional sports. These results also highlight the importance of circadian rhythms in sport performance and athletic competitions. © 2017 European Sleep Research Society.

Inicios del Hockey patines en Sevilla. El Patín Claret en la década de los 70 del siglo XX = Beginnings of Roller Hockey in Seville. Claret Skate in the Decade of the Twenthieh Century 70

Directory of Open Access Journals (Sweden)

Jaime Segundo Cuesta Pérez

2013-10-01

Full Text Available En el siguiente artículo, se trata de presentar una de las páginas más importantes de la historia del Hockey Patines en Andalucía y más concretamente en la ciudad de Sevilla. Un deporte prácticamente copado desde sus inicios por equipos catalanes y cuya implantación en el resto del país ha sido muy complicada, siendo aún hoy en día muy escasa por toda España, salvo en regiones muy localizadas como Cataluña, Madrid, o Galicia. Estos que ahora presentamos son parte de los orígenes de este deporte en la capital andaluza, de los cuales nacería, para sorpresa de muchos, un equipo que alcanzaría importantes hitos en la División de Honor Nacional de este deporte.---------------------------------------------------------------------In the next article, we try to present one of the most important papers of the roller hockey history in Andalucía, concretely in Seville. This sport has been surrounded from its beginning by teams from Cataluña, while the establishment in the rest of the country has been very difficult, being still today quite scarce all over Spain, except in some regions such as Cataluña, Madrid or Galicia. We will try to show you the origin of this sport in the capital of Andalucía, from where was born, surprising everybody, a team wich achieved great landmark in the Pride National Division of this sport.

MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

Energy Technology Data Exchange (ETDEWEB)

Robert L. Lee; Junghan Dong

2004-06-03

This final report of ''Modified Reverse Osmosis System for Treatment of Produced Water,'' DOE project No. DE-FC26-00BC15326 describes work performed in the third year of the project. Several good results were obtained, which are documented in this report. The compacted bentonite membranes were replaced by supported bentonite membranes, which exhibited the same salt rejection capability. Unfortunately, it also inherited the clay expansion problem due to water invasion into the interlayer spaces of the compacted bentonite membranes. We noted that the supported bentonite membrane developed in the project was the first of its kind reported in the literature. An {alpha}-alumina-supported MFI-type zeolite membrane synthesized by in-situ crystallization was fabricated and tested. Unlike the bentonite clay membranes, the zeolite membranes maintained stability and high salt rejection rate even for a highly saline solution. Actual produced brines from gas and oil fields were then tested. For gas fields producing brine, the 18,300 ppm TDS (total dissolved solids) in the produced brine was reduced to 3060 ppm, an 83.3% rejection rate of 15,240 ppm salt rejection. For oilfield brine, while the TDS was reduced from 181,600 ppm to 148,900 ppm, an 18% rejection rate of 32,700 ppm reduction, the zeolite membrane was stable. Preliminary results show the dissolved organics, mainly hydrocarbons, did not affect the salt rejection. However, the rejection of organics was inconclusive at this point. Finally, the by-product of this project, the {alpha}-alumina-supported Pt-Co/Na Y catalytic zeolite membrane was developed and demonstrated for overcoming the two-step limitation of nonoxidation methane (CH{sub 4}) conversion to higher hydrocarbons (C{sub 2+}) and hydrogen (H{sub 2}). Detailed experiments to obtain quantitative results of H{sub 2} generation for various conditions are now being conducted. Technology transfer efforts included five manuscripts submitted to

Using Elite Athletes to Promote Drug Abstinence: Evaluation of a Single-Session School-Based Drug Use Prevention Program Delivered by Junior Hockey Players

Science.gov (United States)

Wong, Jennifer

2016-01-01

School-based substance use prevention programs are a common method to approaching drug use in youths. Project SOS is a single-session drug prevention program developed by police officers and delivered by elite junior hockey players to students in grades 6 and 7. The current study evaluates the effects of Project SOS at achieving its objectives of…

Building a Better Microreactor: Enzyme Catalysis in AOT/Bile Salt Reversed Micelles

National Research Council Canada - National Science Library

McGown, Linda

2001-01-01

.... We have shown that trihydroxy bile salts modify the interfacial properties of AOT reversed micelles, thereby affecting the reversed micellar structure, the biological activity of entrapped enzymes...

Individual Alpha Peak Frequency in Ice Hockey Shooting Performance

Directory of Open Access Journals (Sweden)

Sommer Christie

2017-05-01

Full Text Available There are several important inter- and intra-individual variations in individual alpha peak frequency (IAPF in the cognitive domain. The rationale for the present study was to extend the research on IAPF in the cognitive domain to IAPF in the sport domain. Specifically, the purpose of the present study was twofold: (a to explore whether baseline IAPF is related to performance in an ice hockey shooting task and (b to explore whether a shooting task has an effect on IAPF variability. The present investigation is one of the first studies to examine links between IAPF and sport performance. Study results did not show significant changes in IAPF when comparing baseline IAPF and pre- to post-task IAPF across three performance levels. The findings support previous literature in the cognitive domain suggesting that IAPF is a stable neurophysiological marker. Future research should consider the following methodological suggestions: (a measuring IAPF during sport performance instead of at a resting state, (b changing the pre-performance resting baseline instructions to take into account sport-specific mental preparation, (c exploring an expert-novice paradigm to accentuate performance ability differences between groups (d comparing tasks with different levels of complexity, and (e analyzing the possible correlation between IAPF and performance on different days.

High-performance liquid chromatography using reversed-phase stationary phases dynamically modified with organophosphorus compound for the separation and determination of lanthanoid elements

International Nuclear Information System (INIS)

Tsuyoshi, Akira; Akiba, Kenichi

2000-01-01

An acidic organophosphorus compound, 2-ethylhexylphosphonic acid mono-2-ethlhexyl ester (EHPA), has been applied to reversed-phase high-performance liquid chromatography (RP-HPLC). The reversed-phase stationary phase was dynamically modified with EHPA by flowing the mobile phase of an acetone-water mixture containing the extracting regent. The retention of lanthanoid elements was widely varied by changing the conditions of the mobile phase, i.e., the pH, the EHPA concentration and the acetone content. The selectivity of EHPA is well reflected to the chromatographic systems, and a precise separation of lanthanoid elements was achieved with sufficient resolution. The determination of Sm was examined in the presence of a large amount of Nd. A linear calibration graph was obtained for Sm at the level of 10 -7 mol dm -3 , in the presence of 1x10 -4 mol dm -3 of Nd. (author)

Habituation of 10-year-old hockey players to treadmill skating.

Science.gov (United States)

Lockwood, Kelly L; Frost, Gail

2007-05-01

This study assessed changes in selected physiological and kinematic variables over 6 weeks of treadmill skating in an effort to understand the process of habituation to this novel training modality. Seven male, Atom-A hockey players who were injury-free and had no previous treadmill skating experience participated in the study. Players performed four 1-min skating bouts at progressively increasing speeds, each week, for 6 weeks. One speed (10.5 km/h) was repeated weekly to allow for assessment of the habituation process. Our criteria for habituation were: a decrease in stride rate, heart rate and rating of perceived exertion, and an increase in stride length, trunk angle and vertical movement of the centre of mass, leading to a plateau, over the course of the 6-week study. Significant decreases were seen in stride rate, heart rate and ratings of perceived exertion, and significant increases were found in stride length. Some of these changes were evident after only one week of training and all were present by week 4. After 6 weeks (24 min) of exposure to treadmill skating, all participants displayed a visibly more efficient skating style.

Control of biofouling on reverse osmosis polyamide membranes modified with biocidal nanoparticles and antifouling polymer brushes

KAUST Repository

Rahaman, Md. Saifur

2014-01-01

Thin-film composite (TFC) polyamide reverse osmosis (RO) membranes are prone to biofouling due to their inherent physicochemical surface properties. In order to address the biofouling problem, we have developed novel surface coatings functionalized with biocidal silver nanoparticles (AgNPs) and antifouling polymer brushes via polyelectrolyte layer-by-layer (LBL) self-assembly. The novel surface coating was prepared with polyelectrolyte LBL films containing poly(acrylic acid) (PAA) and poly(ethylene imine) (PEI), with the latter being either pure PEI or silver nanoparticles coated with PEI (Ag-PEI). The coatings were further functionalized by grafting of polymer brushes, using either hydrophilic poly(sulfobetaine) or low surface energy poly(dimethylsiloxane) (PDMS). The presence of both LBL films and sulfobetaine polymer brushes at the interface significantly increased the hydrophilicity of the membrane surface, while PDMS brushes lowered the membrane surface energy. Overall, all surface modifications resulted in significant reduction of irreversible bacterial cell adhesion. In microbial adhesion tests with E. coli bacteria, a normalized cell adhesion in the range of only 4 to 16% on the modified membrane surfaces was observed. Modified surfaces containing silver nanoparticles also exhibited strong antimicrobial activity. Membranes coated with LBL films of PAA/Ag-PEI achieved over 95% inactivation of bacteria attached to the surface within 1 hour of contact time. Both the antifouling and antimicrobial results suggest the potential of using these novel surface coatings in controlling the fouling of RO membranes. © The Royal Society of Chemistry 2014.

Reversal modes in asymmetric Ni nanowires

Energy Technology Data Exchange (ETDEWEB)

Leighton, B.; Pereira, A. [Departamento de Fisica, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Escrig, J., E-mail: jescrigm@gmail.com [Departamento de Fisica, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avda. Ecuador 3493, 917-0124 Santiago (Chile)

2012-11-15

We have investigated the evolution of the magnetization reversal mechanism in asymmetric Ni nanowires as a function of their geometry. Circular nanowires are found to reverse their magnetization by the propagation of a vortex domain wall, while in very asymmetric nanowires the reversal is driven by the propagation of a transverse domain wall. The effect of shape asymmetry of the wire on coercivity and remanence is also studied. Angular dependence of the remanence and coercivity is also addressed. Tailoring the magnetization reversal mechanism in asymmetric nanowires can be useful for magnetic logic and race-track memory, both of which are based on the displacement of magnetic domain walls. Finally, an alternative method to detect the presence of magnetic drops is proposed. - Highlights: Black-Right-Pointing-Pointer Asymmetry strongly modifies the magnetic behavior of a wire. Black-Right-Pointing-Pointer Very asymmetric nanowires reverse their magnetization by a transverse domain wall. Black-Right-Pointing-Pointer An alternative method to detect the presence of magnetic drops is proposed. Black-Right-Pointing-Pointer Tailoring the reversal mode in asymmetric nanowires can be useful for potential applications.

Ice Hockey Lung – A Case of Mass Nitrogen Dioxide Poisoning in The Czech Republic

Directory of Open Access Journals (Sweden)

Kristian Brat

2013-01-01

Full Text Available Nitrogen dioxide (NO2 is a toxic gas, a product of combustion in malfunctioning ice-resurfacing machines. NO2 poisoning is rare but potentially lethal. The authors report a case of mass NO2 poisoning involving 15 amateur ice hockey players in the Czech Republic. All players were treated in the Department of Respiratory Diseases at Brno University Hospital in November 2010 – three as inpatients because they developed pneumonitis. All patients were followed-up until November 2011. Complete recovery in all but one patient was achieved by December 2010. None of the 15 patients developed asthma-like disease or chronic cough. Corticosteroids appeared to be useful in treatment. Electric-powered ice-resurfacing machines are preferable in indoor ice skating arenas.

PRACTICING FIELD HOCKEY SKILLS ALONG THE CONTEXTUAL INTERFERENCE CONTINUUM: A COMPARISON OF FIVE PRACTICE SCHEDULES

Directory of Open Access Journals (Sweden)

Jadeera Phaik Geok Cheong

2012-06-01

Full Text Available To overcome the weakness of the contextual interference (CI effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners

Solid-phase synthesis of protein-polymers on reversible immobilization supports.

Science.gov (United States)

Murata, Hironobu; Carmali, Sheiliza; Baker, Stefanie L; Matyjaszewski, Krzysztof; Russell, Alan J

2018-02-27

Facile automated biomacromolecule synthesis is at the heart of blending synthetic and biologic worlds. Full access to abiotic/biotic synthetic diversity first occurred when chemistry was developed to grow nucleic acids and peptides from reversibly immobilized precursors. Protein-polymer conjugates, however, have always been synthesized in solution in multi-step, multi-day processes that couple innovative chemistry with challenging purification. Here we report the generation of protein-polymer hybrids synthesized by protein-ATRP on reversible immobilization supports (PARIS). We utilized modified agarose beads to covalently and reversibly couple to proteins in amino-specific reactions. We then modified reversibly immobilized proteins with protein-reactive ATRP initiators and, after ATRP, we released and analyzed the protein polymers. The activity and stability of PARIS-synthesized and solution-synthesized conjugates demonstrated that PARIS was an effective, rapid, and simple method to generate protein-polymer conjugates. Automation of PARIS significantly reduced synthesis/purification timelines, thereby opening a path to changing how to generate protein-polymer conjugates.

The Effect of the "Zero Tolerance for Head Contact" Rule Change on the Risk of Concussions in Youth Ice Hockey Players.

Science.gov (United States)

Krolikowski, Maciej P; Black, Amanda M; Palacios-Derflingher, Luz; Blake, Tracy A; Schneider, Kathryn J; Emery, Carolyn A

2017-02-01

Ice hockey is a popular winter sport in Canada. Concussions account for the greatest proportion of all injuries in youth ice hockey. In 2011, a policy change enforcing "zero tolerance for head contact" was implemented in all leagues in Canada. To determine if the risk of game-related concussions and more severe concussions (ie, resulting in >10 days of time loss) and the mechanisms of a concussion differed for Pee Wee class (ages 11-12 years) and Bantam class (ages 13-14 years) players after the 2011 "zero tolerance for head contact" policy change compared with players in similar divisions before the policy change. Cohort study; Level of evidence, 3. The retrospective cohort included Pee Wee (most elite 70%, 2007-2008; n = 891) and Bantam (most elite 30%, 2008-2009; n = 378) players before the rule change and Pee Wee (2011-2012; n = 588) and Bantam (2011-2012; n = 242) players in the same levels of play after the policy change. Suspected concussions were identified by a team designate and referred to a sport medicine physician for diagnosis. Incidence rate ratios (IRRs) were estimated based on multiple Poisson regression analysis, controlling for clustering by team and other important covariates and offset by game-exposure hours. Incidence rates based on the mechanisms of a concussion were estimated based on univariate Poisson regression analysis. The risk of game-related concussions increased after the head contact rule in Pee Wee (IRR, 1.85; 95% CI, 1.20-2.86) and Bantam (IRR, 2.48; 95% CI, 1.17-5.24) players. The risk of more severe concussions increased after the head contact rule in Pee Wee (IRR, 4.12; 95% CI, 2.00-8.50) and Bantam (IRR, 7.91; 95% CI, 3.13-19.94) players. The rates of concussions due to body checking and direct head contact increased after the rule change. The "zero tolerance for head contact" policy change did not reduce the risk of game-related concussions in Pee Wee or Bantam class ice hockey players. Increased concussion awareness and

Spectroscopic and impedance studies of reverse biased degraded dye solar cells

CSIR Research Space (South Africa)

Le Roux, Lukas J

2011-03-01

Full Text Available The work that is presented here is focused on the results that were obtained during studies of the performance of Dye Solar Cells under certain reverse bias conditions. This reverse voltage could permanently modify or damage a cell...

Cardiovascular prevention in a high risk sport, ice hockey: applications in wider sports physical therapy practice.

Science.gov (United States)

Hopkins-Rosseel, Diana H

2006-11-01

Although acute myocardial infarction and sudden cardiac death are relatively rare occurrences in athletics, cardiovascular accidents do occur. This manuscript presents information on the cardiovascular risks in athletics. In addition, information is provided on screening for cardiovascular risk - including history taking, chart review, physical examination - and the appropriate guidelines on the treatment of athletes found to be at risk. For the purpose of this article, the sport of ice hockey is used to illustrate the subject matter and highlight the behaviors in sport that carry cardiovascular risk. Physical therapists have ethical and legal responsibility to undertake the necessary screening procedures to recognize and respond to any signs of cardiovascular risk in their clients.

Updating the Skating Multistage Aerobic Test and Correction for V[Combining Dot Above]O2max Prediction Using a New Skating Economy Index in Elite Youth Ice Hockey Players.

Science.gov (United States)

Allisse, Maxime; Bui, Hung Tien; Léger, Luc; Comtois, Alain-Steve; Leone, Mario

2018-05-07

Allisse, M, Bui, HT, Léger, L, Comtois, A-S, and Leone, M. Updating the skating multistage aerobic test and correction for V[Combining Dot Above]O2max prediction using a new skating economy index in elite youth ice hockey players. J Strength Cond Res XX(X): 000-000, 2018-A number of field tests, including the skating multistage aerobic test (SMAT), have been developed to predict V[Combining Dot Above]O2max in ice hockey players. The SMAT, like most field tests, assumes that participants who reach a given stage have the same oxygen uptake, which is not usually true. Thus, the objectives of this research are to update the V[Combining Dot Above]O2 values during the SMAT using a portable breath-by-breath metabolic analyzer and to propose a simple index of skating economy to improve the prediction of oxygen uptake. Twenty-six elite hockey players (age 15.8 ± 1.3 years) participated in this study. The oxygen uptake was assessed using a portable metabolic analyzer (K4b) during an on-ice maximal shuttle skate test. To develop an index of skating economy called the skating stride index (SSI), the number of skating strides was compiled for each stage of the test. The SMAT enabled the prediction of the V[Combining Dot Above]O2max (ml·kg·min) from the maximal velocity (m·s) and the SSI (skating strides·kg) using the following regression equation: V[Combining Dot Above]O2max = (14.94 × maximal velocity) + (3.68 × SSI) - 24.98 (r = 0.95, SEE = 1.92). This research allowed for the update of the oxygen uptake values of the SMAT and proposed a simple measure of skating efficiency for a more accurate evaluation of V[Combining Dot Above]O2max in elite youth hockey players. By comparing the highest and lowest observed SSI scores in our sample, it was noted that the V[Combining Dot Above]O2 values can vary by up to 5 ml·kg·min. Our results suggest that skating economy should be included in the prediction of V[Combining Dot Above]O2max to improve prediction accuracy.

Hidden Randomness between Fitness Landscapes Limits Reverse Evolution

Science.gov (United States)

Tan, Longzhi; Serene, Stephen; Xiao Chao, Hui; Gore, Jeff

2012-02-01

Natural populations must constantly adapt to the ever-changing environment. A fundamental question in evolutionary biology is whether adaptations can be reversed by returning the population to its ancestral environment. Traditionally, reverse evolution is defined as restoring an ancestral phenotype (physical characteristics such as body size), and the classic Dollo's Law has hypothesized the impossibility of reversing complex adaptations. However, this ``law'' remains ambiguous unless reverse evolution can be studied at the level of genotypes (the underlying genome sequence). We measured the fitness landscapes of a bacterial antibiotic-resistance gene and analyzed the reversibility of evolution as a global, statistical feature of the landscapes. In both experiments and simulations, we find that an adaptation's reversibility declines as the number of mutations it involves increases, suggesting a probabilistic form of Dollo's Law at the molecular level. We also show computationally that slowly switching between environments facilitates reverse evolution in small populations, where clonal interference is negligible or moderate. This is an analogy to thermodynamics, where the reversibility of a physical process is maximized when conditions are modified infinitely slowly.

Three-dimensional kinematics of the lower limbs during forward ice hockey skating.

Science.gov (United States)

Upjohn, Tegan; Turcotte, René; Pearsall, David J; Loh, Jonathan

2008-05-01

The objectives of the study were to describe lower limb kinematics in three dimensions during the forward skating stride in hockey players and to contrast skating techniques between low- and high-calibre skaters. Participant motions were recorded with four synchronized digital video cameras while wearing reflective marker triads on the thighs, shanks, and skates. Participants skated on a specialized treadmill with a polyethylene slat bed at a self-selected speed for 1 min. Each participant completed three 1-min skating trials separated by 5 min of rest. Joint and limb segment angles were calculated within the local (anatomical) and global reference planes. Similar gross movement patterns and stride rates were observed; however, high-calibre participants showed a greater range and rate of joint motion in both the sagittal and frontal planes, contributing to greater stride length for high-calibre players. Furthermore, consequent postural differences led to greater lateral excursion during the power stroke in high-calibre skaters. In conclusion, specific kinematic differences in both joint and limb segment angle movement patterns were observed between low- and high-calibre skaters.

Physical fitness and performance of polish ice-hockey players competing at different sports levels

Directory of Open Access Journals (Sweden)

Roczniok Robert

2016-06-01

Full Text Available The study aimed to determine the values of selected aerobic and anaerobic capacity variables, physical profiles, and to analyze the results of on-ice tests performed by ice-hockey players relegated to a lower league. Performance of 24 ice-hockey players competing in the top league in the 2012/2013 season was analysed to this end. In the 2013/2014 season, 14 of them still played in the top league (the control group, while 10 played in the first league (the experimental group. The study was conducted one week after the end of the playoffs in the seasons under consideration. The results revealed that only in the experimental group the analysed variables changed significantly between the seasons. In the Wingate test, significant changes were only noted in mean relative power (a decrease from 9.91 to 9.14 W/kg; p=0.045 and relative total work (a decrease from 299.17 to 277.22 J/kg; p=0.048. The ramp test indicated significantly lower power output in its final stages (364 compared with 384 W; p=0.034, as well as a significant decrease in relative VO2max (from 52.70 to 48.30 ml/min/kg. Blood lactate concentrations were recorded at the 3rd, 6th, 9th and 12th min of recovery after the ramp test. The rate of post-exercise recovery, ∆LA, recorded after the ramp test turned out to be significantly lower. The times recorded in the on-ice “6x30 m stop” test increased from 32.18 to 33.10 s (p=0.047. The study showed that playing in a lower league where games were less intensive, training sessions shorter and less frequent, had an adverse effect on the performance level of the investigated players. Lower VO2max recorded in the study participants slowed down their rates of post-exercise recovery and led to a significantly worse performance in the 6x30 m stop test, as well as lower relative power and relative total work in the Wingate test.

A Change in Team Culture Towards an Autonomy Supportive Working Environment - A Case Study of the Finnish Women’s National Ice Hockey Team

OpenAIRE

Andler, Martin

2017-01-01

This study presents how the change in team culture has impacted the Finnish Women’s National Ice Hockey Team. The structure of the study is based on the self-determination theory, autonomy supportive coaching and change in team culture. The sub chapters’ focus on motivation, the coaches' and athletes' role within the autonomy supportive team working environment, autonomous goal setting and transformational leadership. The subchapter for cultural change is focused on the complex on-going proce...

Effectiveness of competitive activity of high class hockey players accounting a level of their self-esteem

Directory of Open Access Journals (Sweden)

Mikhnov A.P.

2015-02-01

Full Text Available Purpose : study the effect of increasing the level of self-esteem on the efficiency of competitive activity of high class players. Material : the study involved sixteen athletes (Atlanta, Moscow region. - Continental Hockey League. Results : it was found that the application of special training self-esteem increases the level of implementation of technical and tactical action games. Number of goals increased by 8.92%, assists - 21.5%, the total number of shots on goal - to 20.02%. Conclusions : it is recommended specialized program correction level of self-esteem from 10 separate studies. Classes have different target setting: habit forming positive attitudes towards themselves, develop skills of active life position, securing high self-esteem. The program is used for two weeks in the preparatory period of training.

Why do sleeping nematodes adopt a hockey-stick-like posture?

Directory of Open Access Journals (Sweden)

Nora Tramm

Full Text Available A characteristic posture is considered one of the behavioral hallmarks of sleep, and typically includes functional features such as support for the limbs and shielding of sensory organs. The nematode C. elegans exhibits a sleep-like state during a stage termed lethargus, which precedes ecdysis at the transition between larval stages. A hockey-stick-like posture is commonly observed during lethargus. What might its function be? It was previously noted that during lethargus, C. elegans nematodes abruptly rotate about their longitudinal axis. Plausibly, these "flips" facilitate ecdysis by assisting the disassociation of the old cuticle from the new one. We found that body-posture during lethargus was established using a stereotypical motor program and that body bends during lethargus quiescence were actively maintained. Moreover, flips occurred almost exclusively when the animals exhibited a single body bend, preferentially in the anterior or mid section of the body. We describe a simple biomechanical model that imposes the observed lengths of the longitudinally directed body-wall muscles on an otherwise passive elastic rod. We show that this minimal model is sufficient for generating a rotation about the anterior-posterior body axis. Our analysis suggests that posture during lethargus quiescence may serve a developmental role in facilitating flips and that the control of body wall muscles in anterior and posterior body regions are distinct.

Predicting flux decline of reverse osmosis membranes

NARCIS (Netherlands)

Schippers, J.C.; Hanemaayer, J.H.; Smolders, C.A.; Kostense, A.

1981-01-01

A mathematical model predicting flux decline of reverse osmosis membranes due to colloidal fouling has been verified. This mathema- tical model is based on the theory of cake or gel filtration and the Modified Fouling Index (MFI). Research was conducted using artificial colloidal solutions and a

Evaluation of a genetically modified foot-and-mouth disease virus vaccine candidate generated by reverse genetics

Science.gov (United States)

2012-01-01

Background Foot-and-mouth disease (FMD) is the most economically important and highly contagious disease of cloven-hoofed animals worldwide. Control of the disease has been mainly based on large-scale vaccinations with whole-virus inactivated vaccines. In recent years, a series of outbreaks of type O FMD occurred in China (including Chinese Taipei, Chinese Hong Kong) posed a tremendous threat to Chinese animal husbandry. Its causative agent, type O FMDV, has evolved into three topotypes (East–South Asia (ME-SA), Southeast Asia (SEA), Cathay (CHY)) in these regions, which represents an important obstacle to disease control. The available FMD vaccine in China shows generally good protection against ME-SA and SEA topotype viruses infection, but affords insufficient protection against some variants of the CHY topotype. Therefore, the choice of a new vaccine strain is of fundamental importance. Results The present study describes the generation of a full-length infectious cDNA clone of FMDV vaccine strain and a genetically modified virus with some amino acid substitutions in antigenic sites 1, 3, and 4, based on the established infectious clone. The recombinant viruses had similar growth properties to the wild O/HN/CHA/93 virus. All swine immunized with inactivated vaccine prepared from the O/HN/CHA/93 were fully protected from challenge with the viruses of ME-SA and SEA topotypes and partially protected against challenge with the virus of CHY topotype at 28 days post-immunization. In contrast, the swine inoculated with the genetically modified vaccine were completely protected from the infection of viruses of the three topotypes. Conclusions Some amino acid substitutions in the FMDV vaccine strain genome did not have an effect on the ability of viral replication in vitro. The vaccine prepared from genetically modified FMDV by reverse genetics significantly improved the protective efficacy to the variant of the CHY topotype, compared with the wild O/HN/CHA/93 virus

Evaluation of a genetically modified foot-and-mouth disease virus vaccine candidate generated by reverse genetics

Directory of Open Access Journals (Sweden)

Li Pinghua

2012-05-01

Full Text Available Abstract Background Foot-and-mouth disease (FMD is the most economically important and highly contagious disease of cloven-hoofed animals worldwide. Control of the disease has been mainly based on large-scale vaccinations with whole-virus inactivated vaccines. In recent years, a series of outbreaks of type O FMD occurred in China (including Chinese Taipei, Chinese Hong Kong posed a tremendous threat to Chinese animal husbandry. Its causative agent, type O FMDV, has evolved into three topotypes (East–South Asia (ME-SA, Southeast Asia (SEA, Cathay (CHY in these regions, which represents an important obstacle to disease control. The available FMD vaccine in China shows generally good protection against ME-SA and SEA topotype viruses infection, but affords insufficient protection against some variants of the CHY topotype. Therefore, the choice of a new vaccine strain is of fundamental importance. Results The present study describes the generation of a full-length infectious cDNA clone of FMDV vaccine strain and a genetically modified virus with some amino acid substitutions in antigenic sites 1, 3, and 4, based on the established infectious clone. The recombinant viruses had similar growth properties to the wild O/HN/CHA/93 virus. All swine immunized with inactivated vaccine prepared from the O/HN/CHA/93 were fully protected from challenge with the viruses of ME-SA and SEA topotypes and partially protected against challenge with the virus of CHY topotype at 28 days post-immunization. In contrast, the swine inoculated with the genetically modified vaccine were completely protected from the infection of viruses of the three topotypes. Conclusions Some amino acid substitutions in the FMDV vaccine strain genome did not have an effect on the ability of viral replication in vitro. The vaccine prepared from genetically modified FMDV by reverse genetics significantly improved the protective efficacy to the variant of the CHY topotype, compared with the

Magnetization reversal in ferromagnetic film through solitons by electromagnetic field

International Nuclear Information System (INIS)

Veerakumar, V.; Daniel, M.

2001-07-01

We study the reversal of magnetization in an isotopic ferromagnetic film free from charges by exposing it to a circularly polarized electromagnetic (EM) field. The magnetization excitations are obtained in the form of line and lump solitons of the completely integrable modified KP-II equation which is derived using a reductive perturbation method from the set of coupled Landau-Lifschitz and Maxwell equations. It is observed that when the polarization of the EM-field is reversed followed by a rotation, for every (π)/2-degrees, the magnetization is reversed. (author)

Survey of methods for rapid spin reversal

International Nuclear Information System (INIS)

McKibben, J.L.

1980-01-01

The need for rapid spin reversal technique in polarization experiments is discussed. The ground-state atomic-beam source equipped with two rf transitions for hydrogen can be reversed rapidly, and is now in use on several accelerators. It is the optimum choice provided the accelerator can accept H + ions. At present all rapid reversal experiments using H - ions are done with Lamb-shift sources; however, this is not a unique choice. Three methods for the reversal of the spin of the atomic beam within the Lamb-shift source are discussed in order of development. Coherent intensity and perhaps focus modulation seem to be the biggest problems in both types of sources. Methods for reducing these modulations in the Lamb-shift source are discussed. The same Lamb-shift apparatus is easily modified to provide information on the atomic physics of quenching of the 2S/sub 1/2/ states versus spin orientation, and this is also discussed. 2 figures

Using a modified time-reverse imaging technique to locate low-frequency earthquakes on the San Andreas Fault near Cholame, California

Science.gov (United States)

Horstmann, Tobias; Harrington, Rebecca M.; Cochran, Elizabeth S.

2015-01-01

We present a new method to locate low-frequency earthquakes (LFEs) within tectonic tremor episodes based on time-reverse imaging techniques. The modified time-reverse imaging technique presented here is the first method that locates individual LFEs within tremor episodes within 5 km uncertainty without relying on high-amplitude P-wave arrivals and that produces similar hypocentral locations to methods that locate events by stacking hundreds of LFEs without having to assume event co-location. In contrast to classic time-reverse imaging algorithms, we implement a modification to the method that searches for phase coherence over a short time period rather than identifying the maximum amplitude of a superpositioned wavefield. The method is independent of amplitude and can help constrain event origin time. The method uses individual LFE origin times, but does not rely on a priori information on LFE templates and families.We apply the method to locate 34 individual LFEs within tremor episodes that occur between 2010 and 2011 on the San Andreas Fault, near Cholame, California. Individual LFE location accuracies range from 2.6 to 5 km horizontally and 4.8 km vertically. Other methods that have been able to locate individual LFEs with accuracy of less than 5 km have mainly used large-amplitude events where a P-phase arrival can be identified. The method described here has the potential to locate a larger number of individual low-amplitude events with only the S-phase arrival. Location accuracy is controlled by the velocity model resolution and the wavelength of the dominant energy of the signal. Location results are also dependent on the number of stations used and are negligibly correlated with other factors such as the maximum gap in azimuthal coverage, source–station distance and signal-to-noise ratio.

Reversible infantile mitochondrial diseases.

Science.gov (United States)

Boczonadi, Veronika; Bansagi, Boglarka; Horvath, Rita

2015-05-01

Mitochondrial diseases are usually severe and progressive conditions; however, there are rare forms that show remarkable spontaneous recoveries. Two homoplasmic mitochondrial tRNA mutations (m.14674T>C/G in mt-tRNA(Glu)) have been reported to cause severe infantile mitochondrial myopathy in the first months of life. If these patients survive the first year of life by extensive life-sustaining measures they usually recover and develop normally. Another mitochondrial disease due to deficiency of the 5-methylaminomethyl-2-thiouridylate methyltransferase (TRMU) causes severe liver failure in infancy, but similar to the reversible mitochondrial myopathy, within the first year of life these infants may also recover completely. Partial recovery has been noted in some other rare forms of mitochondrial disease due to deficiency of mitochondrial tRNA synthetases and mitochondrial tRNA modifying enzymes. Here we summarize the clinical presentation of these unique reversible mitochondrial diseases and discuss potential molecular mechanisms behind the reversibility. Understanding these mechanisms may provide the key to treatments of potential broader relevance in mitochondrial disease, where for the majority of the patients no effective treatment is currently available.

Experimental hydrophobicity parameters of perfluorinated alkylated substances from reversed-phase high performance liquid chromatography

NARCIS (Netherlands)

de Voogt, P.; Zurano, L.; Serné, P.; Haftka, J.J.H.

2012-01-01

Capacity factors of perfluorinated alkylated substances were obtained from isocratic reversed-phase high-performance liquid chromatography-mass spectrometry experiments at different organic modifier strengths of the mobile phase. The resulting capacity factor v. modifier strengths plots were

[The relevance of core muscles in ice hockey players: a feasibility study].

Science.gov (United States)

Rogan, S; Blasimann, A; Nyffenegger, D; Zimmerli, N; Radlinger, L

2013-12-01

Good core strength is seen as a condition for high performance in sports. In general, especially maximum voluntary contraction (MVC) and strength endurance (SE) measurements of the core muscles are used. In addition, a few studies can be found that examine the core muscles in terms of MVC, rate of force development (RFD) and SE. Primary aims of this feasibility study were to investigate the feasibility regarding recruiting process, compliance and safety of the testing conditions and raise the force capabilities MVC, RFD and SE of the core muscles in amateur ice hockey players. Secondarily, tendencies of correlations between muscle activity and either shot speed and sprint time shall be examined. In this feasibility study the recruitment process has been approved by 29 ice hockey players, their adherence to the study measurements of trunk muscles, and safety of the measurements was evaluated. To determine the MVC, RFD and SE for the ventral, lateral and dorsal core muscles a dynamic force measurement was performed. To determine the correlation between core muscles and shot speed and 40-m sprint, respectively, the rank correlation coefficient (rho) from Spearman was used. The recruited number of eight field players and one goal-keeper was not very high. The compliance with 100 % was excellent. The players reported no adverse symptoms or injuries after the measurements. The results show median values for the ventral core muscles for MVC with 46.5 kg for RFD with 2.23 m/s2 and 96 s for the SE. For lateral core muscle median values of the lateral core muscles for MVC with 71.10 kg, RFD with 2.59 m/s2 and for SE over 66 s were determined. The dorsal core muscles shows values for MVC 69.7 kg, for RFD 3.39 m/s2 and for SE of 75 s. High correlations between MVC of the ventral core muscles (rho = -0.721, p = 0.021), and between the SE of the ventral core muscles (rho = 0.787, p = 0.012), and the shot velocity rate were determined. Another

The Preparation and Properties of Thermo-reversibly Cross-linked Rubber Via Diels-Alder Chemistry

NARCIS (Netherlands)

Polgar, Lorenzo Massimo; van Duin, Martin; Picchioni, Francesco

2016-01-01

A method for using Diels Alder thermo-reversible chemistry as cross-linking tool for rubber products is demonstrated. In this work, a commercial ethylene-propylene rubber, grafted with maleic anhydride, is thermo-reversibly cross-linked in two steps. The pending anhydride moieties are first modified

Reversal Strategies for NOACs

DEFF Research Database (Denmark)

Husted, Steen; Verheugt, Freek; Comuth, Willemijn

2015-01-01

, coagulation factor concentrates or NOAC-specific antidotes could be used. Coagulation factor concentrates can be used in patients with haemophilia and to reverse the effect of VKAs but, in NOAC-treated patients, results are inconsistent and these agents could potentially have pro-thrombotic effects. Specific...... antidotes for NOACs are expected to be on the market soon. Phase III clinical trials with a humanized antibody fragment directed against dabigatran (idarucizumab) and recombinant, modified factor Xa (andexanet alfa) are ongoing. A molecule (aripazine) with broad activity against various anticoagulants...

Acid-degradable and bioerodible modified polyhydroxylated materials

Energy Technology Data Exchange (ETDEWEB)

Frechet, Jean M. J.; Bachelder, Eric M.; Beaudette, Tristan T.; Broaders, Kyle E.

2017-05-09

Compositions and methods of making a modified polyhydroxylated polymer comprising a polyhydroxylated polymer having reversibly modified hydroxyl groups, whereby the hydroxyl groups are modified by an acid-catalyzed reaction between a polydroxylated polymer and a reagent such as acetals, aldehydes, vinyl ethers and ketones such that the modified polyhydroxylated polymers become insoluble in water but freely soluble in common organic solvents allowing for the facile preparation of acid-sensitive materials. Materials made from these polymers can be made to degrade in a pH-dependent manner. Both hydrophobic and hydrophilic cargoes were successfully loaded into particles made from the present polymers using single and double emulsion techniques, respectively. Due to its ease of preparation, processability, pH-sensitivity, and biocompatibility, of the present modified polyhydroxylated polymers should find use in numerous drug delivery applications.

Characterizing the selectivity of stationary phases and organic modifiers in reversed-phase high-performance liquid chromatographic systems by a general solvation equation using gradient elution.

Science.gov (United States)

Du, C M; Valko, K; Bevan, C; Reynolds, D; Abraham, M H

2000-11-01

Retention data for a set of 69 compounds using rapid gradient elution are obtained on a wide range of reversed-phase stationary phases and organic modifiers. The chromatographic stationary phases studied are Inertsil (IN)-ODS, pentafluorophenyl, fluoro-octyl, n-propylcyano, Polymer (PLRP-S 100), and hexylphenyl. The organic solvent modifiers are 2,2,2-trifluoroethanol (TFE); 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP); isopropanol; methanol (MeOH); acetonitrile (AcN); tetrahydrofuran; 1,4-dioxane; N,N-dimethylformamide; and mixed solvents of dimethylsulfoxide (DMSO) with AcN and DMSO with MeOH (1:1). A total of 25 chromatographic systems are analyzed using a solvation equation. In general, most of the systems give reasonable statistics. The selectivity of the reversed phase-high-performance liquid chromatographic (HPLC) systems with respect to the solute's dipolarity-polarity, hydrogen-bond acidity, and basicity are reflected in correspondingly large coefficients in the solvation equation. We wanted to find the most orthogonal HPLC systems, showing the highest possible selectivity difference in order to derive molecular descriptors using the gradient retention times of a compound. We selected eight chromatographic systems that have a large range of coefficients of interest (s, a, and b) similar to those found in water-solvent partitions used previously to derive molecular descriptors. The systems selected are IN-ODS phases with AcN, MeOH, TFE, and HFIP as mobile phase, PLRP-S 100 phase with AcN, propylcyano phase with AcN and MeOH, and fluorooctyl phase with TFE. Using the retention data obtained for a compound in the selected chromatographic systems, we can estimate the molecular descriptors with the faster and simpler gradient elution method.

Modificación en la composición corporal de jugadores de Hockey luego del período de preparación

OpenAIRE

Perrice, Constanza

2009-01-01

El presente estudio tiene como objetivo determinar la relación entre el tipo de alimentación y el cambio en la composición corporal en jugadores de hockey sobre césped masculino que integran el Seleccionado Bonaerense de primera división, luego del período de preparación del año 2009 y si se ve influenciado por el grado de información en el campo de la nutrición deportiva. A través del mismo se establece la variación en el porcentaje de masa magra y masa grasa, mediante medi...

Exact analysis of Packet Reversed Packet Combining Scheme and Modified Packet Combining Scheme; and a combined scheme

International Nuclear Information System (INIS)

Bhunia, C.T.

2007-07-01

Packet combining scheme is a well defined simple error correction scheme for the detection and correction of errors at the receiver. Although it permits a higher throughput when compared to other basic ARQ protocols, packet combining (PC) scheme fails to correct errors when errors occur in the same bit locations of copies. In a previous work, a scheme known as Packet Reversed Packet Combining (PRPC) Scheme that will correct errors which occur at the same bit location of erroneous copies, was studied however PRPC does not handle a situation where a packet has more than 1 error bit. The Modified Packet Combining (MPC) Scheme that can correct double or higher bit errors was studied elsewhere. Both PRPC and MPC schemes are believed to offer higher throughput in previous studies, however neither adequate investigation nor exact analysis was done to substantiate this claim of higher throughput. In this work, an exact analysis of both PRPC and MPC is carried out and the results reported. A combined protocol (PRPC and MPC) is proposed and the analysis shows that it is capable of offering even higher throughput and better error correction capability at high bit error rate (BER) and larger packet size. (author)

Reversal of Hartmann's procedure following acute diverticulitis: is timing everything?

LENUS (Irish Health Repository)

Fleming, Fergal J

2012-02-01

BACKGROUND: Patients who undergo a Hartmann\\'s procedure may not be offered a reversal due to concerns over the morbidity of the second procedure. The aims of this study were to examine the morbidity post reversal of Hartmann\\'s procedure. METHODS: Patients who underwent a Hartmann\\'s procedure for acute diverticulitis (Hinchey 3 or 4) between 1995 and 2006 were studied. Clinical factors including patient comorbidities were analysed to elucidate what preoperative factors were associated with complications following reversal of Hartmann\\'s procedure. RESULTS: One hundred and ten patients were included. Median age was 70 years and 56% of the cohort were male (n = 61). The mortality and morbidity rate for the acute presentation was 7.3% (n = 8) and 34% (n = 37) respectively. Seventy six patients (69%) underwent a reversal at a median of 7 months (range 3-22 months) post-Hartmann\\'s procedure. The complication rate in the reversal group was 25% (n = 18). A history of current smoking (p = 0.004), increasing time to reversal (p = 0.04) and low preoperative albumin (p = 0.003) were all associated with complications following reversal. CONCLUSIONS: Reversal of Hartmann\\'s procedure can be offered to appropriately selected patients though with a significant (25%) morbidity rate. The identification of potential modifiable factors such as current smoking, prolonged time to reversal and low preoperative albumin may allow optimisation of such patients preoperatively.

Recycling tires? Reversible crosslinking of poly(butadiene).

Science.gov (United States)

Trovatti, Eliane; Lacerda, Talita M; Carvalho, Antonio J F; Gandini, Alessandro

2015-04-01

Furan-modified poly(butadiene) prepared by the thiol-ene click reaction is crosslinked with bismaleimides through the Diels-Alder reaction, giving rise to a novel recyclable elastomer. This is possible because of the thermal reversibility of the adducts responsible for the formation of the network. The use of this strategy provides the possibility to produce recyclable tires. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Doping reversed-phase media for improved peptide purification.

Science.gov (United States)

Khalaf, Rushd; Forrer, Nicola; Buffolino, Gianluca; Gétaz, David; Bernardi, Susanna; Butté, Alessandro; Morbidelli, Massimo

2015-06-05

The purification of therapeutic peptides is most often performed using one or more reversed phase chromatography steps. This ensures high purities while keeping the costs of purification under control. In this paper, a doped reversed phase chromatographic material is tested and compared to traditional reversed phase materials. The doping consists of adding limited amounts of ion exchange ligands to the surface of the material to achieve orthogonal separation and increase the non-hydrophobic interactions with the surface. These ionic groups can either be attractive (opposite charge), or repulsive (same charge) to the peptide. The benefit of this new doped reversed phase material is shown through increases in selectivity in diluted conditions and yield and productivity in overloaded (i.e. industrial) conditions. It is the conjectured that all performance characteristics should increase using repulsive doping groups, whereas these characteristics should decrease when using attractive doping groups. This conjecture is shown to be true through several examples, including purifications of industrially relevant peptide crudes, in industrially relevant conditions. Moreover, the effect of ionic strength and organic modifier concentration was explored and shown to be in line with the expected behavior. Copyright © 2015 Elsevier B.V. All rights reserved.

Reversal of rocuronium-induced (1.2 mg/kg) profound neuromuscular block by sugammadex: a multicenter, dose-finding and safety study.

NARCIS (Netherlands)

Boer, H.D. de; Driessen, J.J.; Marcus, M.A.; Kerkkamp, H.E.M.; Heeringa, M.; Klimek, M.

2007-01-01

BACKGROUND: Reversal of rocuronium-induced neuromuscular blockade can be accomplished by chemical encapsulation of rocuronium by sugammadex, a modified gamma-cyclodextrin derivative. This study investigated the efficacy and safety of sugammadex in reversing rocuronium-induced profound neuromuscular

Development of modified rational buyer auction for procurement of ancillary services utilizing participation matrix

International Nuclear Information System (INIS)

Jamalzadeh, R.; Ardehali, M.M.; Rashidinejad, M.

2008-01-01

The rational buyer auction is based on a simultaneous auction that is the redesigned auction mechanism for ancillary services by the California independent system operator (CAISO). The incentive for the rational buyer auction is CAISO's intent to adopt a common sense rule of substituting higher-quality lower-cost services for lower-quality higher-cost services, when it results in reduced total procurement cost. For the purposes of designing a desirable auction where the minimum cost for the objective function as well as prevention of price reversal are achieved, either the payment cost in marginal pricing auction must be lowered or price reversal in rational buyer auction must be avoided. The objectives of this study are (a) to develop a newly proposed 'modified rational buyer' auction that does not allow price reversal and (b) to propose and validate a solution procedure that is based on participation matrix and discrete programming. The validation of the proposed solution procedure is accomplished through examination of two case studies available in the literature. Based on the first case study data, it is shown that the newly developed modified rational buyer auction avoids price reversal occurrence, while the total payment of ISO is increased by 5.8%, as compared with rational buyer auction. Also in comparison with marginal pricing auction, the ISO payment is lowered by 38.8%, when the newly developed modified rational buyer auction is utilized. For future work, it is recommended that the application of the modified rational buyer auction to joint dispatch of energy and ancillary services is investigated

Splitting of the rate matrix as a definition of time reversal in master equation systems

International Nuclear Information System (INIS)

Liu Fei; Le, Hong

2012-01-01

Motivated by recent progress in nonequilibrium fluctuation relations, we present a generalized time reversal for stochastic master equation systems with discrete states, which is defined as a splitting of the rate matrix into irreversible and reversible parts. An immediate advantage of this definition is that a variety of fluctuation relations can be attributed to different matrix splittings. Additionally, we find that the accustomed total entropy production formula and conditions of the detailed balance must be modified appropriately to account for the reversible rate part, which was previously ignored. (paper)

Hip abduction-adduction strength and one-leg hop tests: test-retest reliability and relationship to function in elite ice hockey players.

Science.gov (United States)

Kea, J; Kramer, J; Forwell, L; Birmingham, T

2001-08-01

Single group, test-retest. To determine: (1) hip abduction and adduction torques during concentric and eccentric muscle actions, (2) medial and lateral one-leg hop distances, (3) the test-retest reliability of these measurements, and (4) the relationship between isokinetic measures of hip muscle strength and hop distances in elite ice hockey players. The skating motion used in ice hockey requires strong contractions of the hip and knee musculature. However, baseline scores for hip strength and hop distances, their test-retest reliability, and measures of the extent to which these tests are related for this population are not available. The dominant leg of 27 men (mean age 20 +/- 3 yrs) was tested on 2 occasions. Hip abduction and adduction movements were completed at 60 degrees.s(-1) angular velocity, with the subject lying on the non-test side and the test leg moving vertically in the subject's coronal plane. One-leg hops requiring jumping from and landing on the same leg without losing balance were completed in the medial and lateral directions. Hip adduction torques were significantly greater than abduction torques during both concentric and eccentric muscle actions, while no significant difference was observed between medial and lateral hop distances. Although hop test scores produced excellent ICCs (> 0.75) when determined using scores on 1 occasion, torques needed to be averaged over 2 test occasions to reach this level. Correlations between the strength and hop tests ranged from slight to low (r = -0.26 to 0.27) and were characterized by wide 95% confidence intervals (-0.54 to 0.61). Isokinetic tests of hip abduction and adduction did not provide a strong indication of performance during sideways hop tests. Although isokinetic tests can provide a measure of muscular strength under specific test conditions, they should not be relied upon as a primary indicator of functional abilities or readiness to return to activity.

Reverse Engineering of Modified Genes by Bayesian Network Analysis Defines Molecular Determinants Critical to the Development of Glioblastoma

Science.gov (United States)

Kunkle, Brian W.; Yoo, Changwon; Roy, Deodutta

2013-01-01

In this study we have identified key genes that are critical in development of astrocytic tumors. Meta-analysis of microarray studies which compared normal tissue to astrocytoma revealed a set of 646 differentially expressed genes in the majority of astrocytoma. Reverse engineering of these 646 genes using Bayesian network analysis produced a gene network for each grade of astrocytoma (Grade I–IV), and ‘key genes’ within each grade were identified. Genes found to be most influential to development of the highest grade of astrocytoma, Glioblastoma multiforme were: COL4A1, EGFR, BTF3, MPP2, RAB31, CDK4, CD99, ANXA2, TOP2A, and SERBP1. All of these genes were up-regulated, except MPP2 (down regulated). These 10 genes were able to predict tumor status with 96–100% confidence when using logistic regression, cross validation, and the support vector machine analysis. Markov genes interact with NFkβ, ERK, MAPK, VEGF, growth hormone and collagen to produce a network whose top biological functions are cancer, neurological disease, and cellular movement. Three of the 10 genes - EGFR, COL4A1, and CDK4, in particular, seemed to be potential ‘hubs of activity’. Modified expression of these 10 Markov Blanket genes increases lifetime risk of developing glioblastoma compared to the normal population. The glioblastoma risk estimates were dramatically increased with joint effects of 4 or more than 4 Markov Blanket genes. Joint interaction effects of 4, 5, 6, 7, 8, 9 or 10 Markov Blanket genes produced 9, 13, 20.9, 26.7, 52.8, 53.2, 78.1 or 85.9%, respectively, increase in lifetime risk of developing glioblastoma compared to normal population. In summary, it appears that modified expression of several ‘key genes’ may be required for the development of glioblastoma. Further studies are needed to validate these ‘key genes’ as useful tools for early detection and novel therapeutic options for these tumors. PMID:23737970

Reverse engineering of modified genes by Bayesian network analysis defines molecular determinants critical to the development of glioblastoma.

Directory of Open Access Journals (Sweden)

Brian W Kunkle

Full Text Available In this study we have identified key genes that are critical in development of astrocytic tumors. Meta-analysis of microarray studies which compared normal tissue to astrocytoma revealed a set of 646 differentially expressed genes in the majority of astrocytoma. Reverse engineering of these 646 genes using Bayesian network analysis produced a gene network for each grade of astrocytoma (Grade I-IV, and 'key genes' within each grade were identified. Genes found to be most influential to development of the highest grade of astrocytoma, Glioblastoma multiforme were: COL4A1, EGFR, BTF3, MPP2, RAB31, CDK4, CD99, ANXA2, TOP2A, and SERBP1. All of these genes were up-regulated, except MPP2 (down regulated. These 10 genes were able to predict tumor status with 96-100% confidence when using logistic regression, cross validation, and the support vector machine analysis. Markov genes interact with NFkβ, ERK, MAPK, VEGF, growth hormone and collagen to produce a network whose top biological functions are cancer, neurological disease, and cellular movement. Three of the 10 genes - EGFR, COL4A1, and CDK4, in particular, seemed to be potential 'hubs of activity'. Modified expression of these 10 Markov Blanket genes increases lifetime risk of developing glioblastoma compared to the normal population. The glioblastoma risk estimates were dramatically increased with joint effects of 4 or more than 4 Markov Blanket genes. Joint interaction effects of 4, 5, 6, 7, 8, 9 or 10 Markov Blanket genes produced 9, 13, 20.9, 26.7, 52.8, 53.2, 78.1 or 85.9%, respectively, increase in lifetime risk of developing glioblastoma compared to normal population. In summary, it appears that modified expression of several 'key genes' may be required for the development of glioblastoma. Further studies are needed to validate these 'key genes' as useful tools for early detection and novel therapeutic options for these tumors.

Neutrino helicity reversal and fundamental symmetries

International Nuclear Information System (INIS)

Jentschura, U D; Wundt, B J

2014-01-01

A rather elusive helicity reversal occurs in a gedanken experiment in which a massive left-handed Dirac neutrino, traveling at a velocity u < c, is overtaken on a highway by a speeding vehicle (traveling at velocity v with u < v < c). Namely, after passing the neutrino, looking back, one would see a right-handed neutrino (which has never been observed in nature). The Lorentz-invariant mass of the right-handed neutrino is still the same as before the passing. The gedanken experiment thus implies the existence of right-handed, light neutrinos, which are not completely sterile. Furthermore, overtaking a bunch of massive right-handed Dirac neutrinos leads to gradual de-sterilization. We discuss the helicity reversal and the concomitant sterilization and de-sterilization mechanisms by way of an illustrative example calculation, with a special emphasis on massive Dirac and Majorana neutrinos. We contrast the formalism with a modified Dirac neutrino described by a Dirac equation with a pseudoscalar mass term proportional to the fifth current. (paper)

Reversible flowchart languages and the structured reversible program theorem

DEFF Research Database (Denmark)

Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

2008-01-01

Many irreversible computation models have reversible counterparts, but these are poorly understood at present. We introduce reversible flowcharts with an assertion operator and show that any reversible flowchart can be simulated by a structured reversible flowchart using only three control flow...... operators. Reversible flowcharts are r- Turing-complete, meaning that they can simuluate reversible Turing machines without garbage data. We also demonstrate the injectivization of classical flowcharts into reversible flowcharts. The reversible flowchart computation model provides a theoretical...

Evaluation of Dimethylformamide (DMF) as an Organic Modifier in ...

African Journals Online (AJOL)

... (DMF) as an organic modifier in hydrophobicity index (Rm) determination. Method: We quantitatively evaluated the problem of partial miscibility of phases associated with the reversed phase thin layer chromatographic (RPTLC) system, using liquid paraffin as stationary phase and acetone/water mixtures as mobile phase.

Educational strategies used in increasing fluid intake and enhancing hydration status in field hockey players preparing for competition in a hot and humid environment: a case study.

Science.gov (United States)

Dabinett, J A; Reid, K; James, N

2001-09-01

The purpose of the present study was to develop a hydration strategy for use by female English field hockey players at the 1998 Commonwealth Games in Malaysia. An additional aim was to initiate the process of acclimation. Fifteen elite players, mean age (+/-SEM) 24.1 +/- 1.19 years, height 1.67 +/- 0.01 m, and body mass 62.8 +/- 1.76 kg, took part in a 5-day training camp immediately prior to departure for the Games. In order to develop the hydration strategy, training took place under similar environmental conditions to those to be experienced in Malaysia (i.e., 32 degrees C, 80% humidity). Acclimation training consisted of 30-50 min of either continuous, low intensity cycling or high intensity intermittent cycling, which more closely replicated the pattern of activity in field hockey. Body mass measures taken each morning, and pre and post training, together with urine color measures, were used to assess hydration status. Pre-loading with up to 1 L of a 3% carbohydrate-electrolyte solution or water immediately prior to acclimation training, as well as regular drinks throughout, ensured that players avoided significant dehydration, with percent body mass changes ranging from -0.34% to +4.24% post training. Furthermore, the protocol used was sufficient to initiate the process of acclimation as demonstrated by a significant reduction in exercising heart rate and core temperature at all time points by days 4 and 5. In conclusion, although labor intensive and time consuming, the camp was successful in developing a hydration strategy that players were able to utilize once at the Games.

Reverse Algols

Science.gov (United States)

Leung, K. C.

1989-01-01

Reverse Algols, binary systems with a semidetached configuration in which the more massive component is in contact with the critical equipotential surface, are examined. Observational evidence for reverse Algols is presented and the parameters of seven reverse Algols are listed. The evolution of Algols and reverse Algols is discussed. It is suggested that, because reverse Algols represent the premass-reversal semidetached phase of close binary evolution, the evolutionary time scale between regular and reverse Algols is the ratio of the number of confirmed systems of these two Algol types.

Why just exercise if you can play? Interest in a modified sports program to enhance physical activity among primary care patients

Directory of Open Access Journals (Sweden)

Christopher N. Sciamanna

2017-12-01

Full Text Available Fewer adults meet guidelines for aerobic physical activity, and many report a lack of enjoyment as a barrier. This survey was designed to determine the interest of primary care patients in participating in program designed to maximize enjoyment. Primary care patients (n=540 in Central Pennsylvania reported their interest in participating in a “a regular fitness program where people your own age played games, such as softball, floor hockey and soccer, that were made to be easier to play and less competitive.” Mean age was 58.4years (SD=16.5, range=18–98. More than one-third (37.0%, including 59.6% of those under age 50, were interested in the modified sports fitness program. After adjusting for confounders, patients under age 40 were 5.9 (95% CI: 2.6–13.9 times as interested (v. age>70 and non-white patients were 3.4 (95% CI: 1.3–8.5 times interested. Female patients and those with hypertension, high cholesterol or obesity were equally interested. A fitness program that consists of modified sports may be of interest to most primary care patients under age 50. Patients' initial interest appears high enough to warrant further development and testing. Keywords: Physical activity, Exercise, Primary care

A modified two-level three-phase quasi-soft-switching inverter

DEFF Research Database (Denmark)

Liu, Yusheng; Wu, Weimin; Blaabjerg, Frede

2014-01-01

A traditional Voltage Source Inverter (VSI) has higher efficiency than a Current Voltage Source (CSI) due to the less conduction power loss. However, the reverse recovery of the free-wheeling diode limits the efficiency improvement for the silicon devices based hard-switching VSI. The traditional...... quasi-soft-switching inverter can alternate between VSI and CSI by using a proper control scheme and thereby reduce the power losses caused by the reverse recovery of the free-wheeling diode. Nevertheless, slightly extra conduction power loss of the auxiliary switch is also introduced. In order...... to reduce the extra conduction power loss and the voltage stress across the DC-link capacitor, a modified two-level three-phase quasi-soft-switching inverter is proposed by using a SiC MOSFET instead of an IGBT. The principle of the modified two-level three-phase quasi-soft-switching inverter is analyzed...

The error analysis of the reverse saturation current of the diode in the modeling of photovoltaic modules

International Nuclear Information System (INIS)

Wang, Gang; Zhao, Ke; Qiu, Tian; Yang, Xinsheng; Zhang, Yong; Zhao, Yong

2016-01-01

In the modeling and simulation of photovoltaic modules, especially in calculating the reverse saturation current of the diode, the series and parallel resistances are often neglected, causing certain errors. We analyzed the errors at the open circuit point, and proposed an iterative algorithm to calculate the modified values of the reverse saturation current, series resistance and parallel resistance of the diode, in order to reduce the errors. Assuming independent irradiation and temperature effects, the irradiation-dependence and the temperature-dependence of the open circuit voltage were introduced to obtain the modified formula of the open circuit voltage under any condition. Experimental results show that this modified formula has high accuracy, even at irradiance as low as 40 W/m"2. The errors of open circuit voltage were significantly reduced, indicating that this modified model is suitable for simulations of photovoltaic modules. - Highlights: • We propose a new method for modeling PV modules with higher accuracy. • The errors of open circuit voltage are significantly reduced. • I_o under any condition is calculated.

A novel reverse osmosis membrane modified by polyvinyl alcohol with maleic anhydride crosslinking

Science.gov (United States)

Samnani, Mohit; Rathod, Harshad; Raval, Hiren

2018-03-01

In the era of increasing energy crisis, it is inevitable to decrease process energy consumption to increase process viability and curtail green-house gas emission. The Reverse Osmosis plant requires significant energy to transfer water overcoming the osmotic pressure. This paper focuses on increasing the water flux for Thin Film Composite Reverse Osmosis (TFC RO) membrane without compromising salt rejection performance leading to the environmentally friendly and economically attractive process. The virgin TFC RO membrane was exposed to solution of sodium hypochlorite of concentration 2000 mg l-1 for 1 h to activate the surface of the membrane, followed by the treatment with the mixture of polyvinyl alcohol and maleic anhydride with varying concentrations for 1 h and curing in the oven at 80 °C temperature for 10 min. Out of all the treated membranes, the membrane treated with 2000 mg l-1 polyvinyl alcohol and 1000 mg l-1 maleic anhydride demonstrated the highest salt rejection of 96.83 % with 2% increase as compared to the virgin TFC RO membrane. The water flux of the membrane was around 44% higher than the virgin TFC RO membrane. The membrane samples were characterized by atomic force micrographs, ATR-FTIR, Nuclear magnetic resonance and Dynamic mechanical analysis.

Does fair play reduce concussions? A prospective, comparative analysis of competitive youth hockey tournaments.

Science.gov (United States)

Smith, Aynsley M; Gaz, Daniel V; Larson, Dirk; Jorgensen, Janelle K; Eickhoff, Chad; Krause, David A; Fenske, Brooke M; Aney, Katie; Hansen, Ashley A; Nanos, Stephanie M; Stuart, Michael J

2016-01-01

To determine if Boys Bantam and Peewee and Girls U14 sustain fewer concussions, head hits, 'other injuries' and penalties in hockey tournaments governed by intensified fair play (IFP) than non-intensified fair play (NIFP). A prospective comparison of IFP, a behaviour modification programme that promotes sportsmanship, versus control (non-intensified, NIFP) effects on numbers of diagnosed concussions, head hits without diagnosed concussion (HHWDC), 'other injuries', number of penalties and fair play points (FPPs). 1514 players, ages 11-14 years, in 6 IFP (N=950) and 5 NIFP (N=564) tournaments were studied. Two diagnosed concussions, four HHWDC, and six 'other injuries' occurred in IFP tournaments compared to one concussion, eight HHWDC and five 'other injuries' in NIFP. There were significantly fewer HHWDC in IFP than NIFP (p=0.018). However, diagnosed concussions, 'other injuries', penalties and FPPs did not differ significantly between conditions. In IFP, a minority of teams forfeited the majority of FPPs. Most diagnosed concussions, HHWDC, and other injuries occurred to Bantam B players and usually in penalised teams that forfeited their FPPs. In response to significant differences in HHWDC between IFP and NIFP tournaments, the following considerations are encouraged: mandatory implementation of fair play in regular season and tournaments, empowering tournament directors to not accept heavily penalised teams, and introducing 'no body checking' in Bantam.

Reversibility: An Engineer's Point of View

Energy Technology Data Exchange (ETDEWEB)

Berest, Pierre [LMS, ecole Polytechnique (France)

2012-07-01

Reversibility is the most consistent option in a democratic country. However reversibility may also have several drawbacks which must be identified and mitigated. Reversibility of a geological repository is a relatively new idea in France. The 1991 law dedicated to nuclear waste management considered reversibility as a possible option. Fifteen years later, the 2006 law mandated that a deep repository must be reversible and that the exact content of this notion should be defined by a new law to be discussed by the Parliament in 2015. Reversibility was not a concern put forward by engineers. It clearly originated from a societal demand sponsored and formulated by the Parliament. Since 1991, the exact meaning of this mandate progressively became more precise. In the early days, reversibility meant the technical and financial capability to retrieve the wastes from the repository, at least for some period of time after being emplaced. Progressively, a broader definition, suggested by Andra, was accepted: reversibility also means that a disposal facility should be operated in such a way that a stepwise decision-making process is possible. At each step, society must be able to decide to proceed to the next step, to pause or to reverse a step. Several benefits can be expected from a reversible repository. Some technical safety concerns may be only recognised after waste emplacement. Radioactive wastes may become a resource whose recoverability is desirable. Regulations may change, alternative waste treatment or better disposal techniques may be developed, or the need to modify a component of the facility may arise. Looking back at how chemical or domestic wastes were managed some 50 years ago easily underscores that it is not unreasonable to hope for significant advances in the future. For scientists and engineers, reversibility proves to have several other merits. To design and build a good repository, time is needed. The operator of a mine or of an oil field knows that

Managing Reverse Logistics or Reversing Logistics Management?

OpenAIRE

Brito, Marisa

2004-01-01

textabstractIn the past, supply chains were busy fine-tuning the logistics from raw material to the end customer. Today an increasing flow of products is going back in the chain. Thus, companies have to manage reverse logistics as well.This thesis contributes to a better understanding of reverse logistics. The thesis brings insights on reverse logistics decision-making and it lays down theoretical principles for reverse logistics as a research field.In particular it puts together a framework ...

Effects of orbitofrontal cortex lesions on autoshaped lever pressing and reversal learning.

Science.gov (United States)

Chang, Stephen E

2014-10-15

A cue associated with a rewarding event can trigger behavior towards the cue itself due to the cue acquiring incentive value through its pairing with the rewarding outcome (i.e., sign-tracking). For example, rats will approach, press, and attempt to "consume" a retractable lever conditioned stimulus (CS) that signals delivery of a food unconditioned stimulus (US). Attending to food-predictive CSs is important when seeking out food, and it is just as important to be able to modify one's behavior when the relationships between CSs and USs are changed. Using a discriminative autoshaping procedure with lever CSs, the present study investigated the effects of orbitofrontal cortex (OFC) lesions on sign-tracking and reversal learning. Insertion of one lever was followed by sucrose delivery upon retraction, and insertion of another lever was followed by nothing. After the acquisition phase, the contingencies between the levers and outcomes were reversed. Bilateral OFC lesions had no effect on the acquisition of sign-tracking. However, OFC-lesioned rats showed substantial deficits in acquiring sign-tracking compared to sham-lesioned rats once the stimulus-outcome contingencies were reversed. Over the course of reversal learning, OFC-lesioned rats were able to reach comparable levels of sign-tracking as sham-lesioned rats. These findings suggest that OFC is not necessary for the ability of a CS to acquire incentive value and provide more evidence that OFC is critical for modifying behavior appropriately following a change in stimulus-outcome contingencies. Copyright © 2014 Elsevier B.V. All rights reserved.

Reverse-phase HPLC analysis of human alpha crystallin.

Science.gov (United States)

Swamy, M S; Abraham, E C

1991-03-01

A rapid and highly sensitive reverse-phase HPLC (RP-HPLC) method was used to separate crystallin subunits from human alpha crystallin. Three distinct peaks were separated; by electrophoretic and immunological analyses the first and second peaks were identified as alpha B and alpha A respectively. On the other hand, peak 3 appeared to be a modified form of alpha crystallin. The ratio of alpha A and alpha B proteins was 3:1 in 1 day old lenses which gradually changed to 2:1 in 17 year old lenses and to 1:1 in the 50 and 82 year old whole lenses and 82 year old lens cortex, with a concomitant increase in the modified alpha, suggesting that alpha A subunits are relatively more involved in aggregation. Analysis of the 82 year old lens nucleus also supported this conclusion. The RP-HPLC analysis of the HMW aggregate fraction showed substantial enrichment of the modified alpha. The alpha A and alpha B subunits independently reassociated to form polymeric alpha crystallin whereas the modified alpha reassociated to form HMW aggregates as shown by molecular sieve HPLC. Hence it appears that the HMW aggregate peak was constituted by modified alpha crystallin. Only in the peak 3 material the 280 nm absorbance was about 2-fold higher than what was expected from the actual protein content. The data suggest that the changes induced by post-translational modifications may have some role in the formation of modified alpha. The present RP-HPLC method is useful in separating these modified alpha from the unmodified alpha A and alpha B subunits.

Sugammadex: A Review of Neuromuscular Blockade Reversal.

Science.gov (United States)

Keating, Gillian M

2016-07-01

Sugammadex (Bridion(®)) is a modified γ-cyclodextrin that reverses the effect of the steroidal nondepolarizing neuromuscular blocking agents rocuronium and vecuronium. Intravenous sugammadex resulted in rapid, predictable recovery from moderate and deep neuromuscular blockade in patients undergoing surgery who received rocuronium or vecuronium. Recovery from moderate neuromuscular blockade was significantly faster with sugammadex 2 mg/kg than with neostigmine, and recovery from deep neuromuscular blockade was significantly faster with sugammadex 4 mg/kg than with neostigmine or spontaneous recovery. In addition, recovery from neuromuscular blockade was significantly faster when sugammadex 16 mg/kg was administered 3 min after rocuronium than when patients spontaneously recovered from succinylcholine. Sugammadex also demonstrated efficacy in various special patient populations, including patients with pulmonary disease, cardiac disease, hepatic dysfunction or myasthenia gravis and morbidly obese patients. Intravenous sugammadex was generally well tolerated. In conclusion, sugammadex is an important option for the rapid reversal of rocuronium- or vecuronium-induced neuromuscular blockade.

Charge reversal and surface charge amplification in asymmetric valence restricted primitive model planar electric double layers in the modified Poisson-Boltzmann theory

Directory of Open Access Journals (Sweden)

L.B. Bhuiyan

2017-12-01

Full Text Available The modified Poisson-Boltzmann theory of the restricted primitive model double layer is revisited and recast in a fresh, slightly broader perspective. Derivation of relevant equations follow the techniques utilized in the earlier MPB4 and MPB5 formulations and clarifies the relationship between these. The MPB4, MPB5, and a new formulation of the theory are employed in an analysis of the structure and charge reversal phenomenon in asymmetric 2:1/1:2 valence electrolytes. Furthermore, polarization induced surface charge amplification is studied in 3:1/1:3 systems. The results are compared to the corresponding Monte Carlo simulations. The theories are seen to predict the "exact" simulation data to varying degrees of accuracy ranging from qualitative to almost quantitative. The results from a new version of the theory are found to be of comparable accuracy as the MPB5 results in many situations. However, in some cases involving low electrolyte concentrations, theoretical artifacts in the form of un-physical "shoulders" in the singlet ionic distribution functions are observed.

Reverse Logistics

OpenAIRE

Kulikova, Olga

2016-01-01

This thesis was focused on the analysis of the concept of reverse logistics and actual reverse processes which are implemented in mining industry and finding solutions for the optimization of reverse logistics in this sphere. The objective of this paper was the assessment of the development of reverse logistics in mining industry on the example of potash production. The theoretical part was based on reverse logistics and mining waste related literature and provided foundations for further...

Barriers and Prospects for Reverse Logistics as Regards oil Lube and its Packaging

Directory of Open Access Journals (Sweden)

Luis Alfredo Sencovici

2015-08-01

Full Text Available This article aims to discuss the main challenges and prospects for the implementation of reverse logistics to lube oil and its packaging. The methodology focuses on conducting in-depth interviews with representatives of these products’ chains, and the results show that technological advances now allow for the generation of re-refined oil with better economic and environmental features than crude oil, and there have been noticeable advances as to packaging too. However, issues such as conflicts in the reverse chain as to the distribution costs of collection, lack of regional solutions to recycling activities, poor supervision, lack of tax incentives and manufacturers’ low interest in modify their products and processes emphasis on prevention challenge the expansion of large-scale reverse logistics activity in the country.

Haiku: New paradigm for the reverse genetics of emerging RNA viruses.

Directory of Open Access Journals (Sweden)

Thérèse Atieh

Full Text Available Reverse genetics is key technology for producing wild-type and genetically modified viruses. The ISA (Infectious Subgenomic Amplicons method is a recent versatile and user-friendly reverse genetics method to rescue RNA viruses. The main constraint of its canonic protocol was the requirement to produce (e.g., by DNA synthesis or fusion PCR 5' and 3' modified genomic fragments encompassing the human cytomegalovirus promoter (pCMV and the hepatitis delta virus ribozyme/simian virus 40 polyadenylation signal (HDR/SV40pA, respectively. Here, we propose the ultimately simplified "Haiku" designs in which terminal pCMV and HDR/SV40pA sequences are provided as additional separate DNA amplicons. This improved procedure was successfully applied to the rescue of a wide range of viruses belonging to genera Flavivirus, Alphavirus and Enterovirus in mosquito or mammalian cells using only standard PCR amplification techniques and starting from a variety of original materials including viral RNAs extracted from cell supernatant media or animal samples. We also demonstrate that, in specific experimental conditions, the presence of the HDR/SV40pA is not necessary to rescue the targeted viruses. These ultimately simplified "Haiku" designs provide an even more simple, rapid, versatile and cost-effective tool to rescue RNA viruses since only generation of overlapping amplicons encompassing the entire viral genome is now required to generate infectious virus. This new approach may completely modify our capacity to obtain infectious RNA viruses.

End-shorting and electric field in edge plasmas with application to field-reversed configurations

International Nuclear Information System (INIS)

Steinhauer, Loren C.

2002-01-01

The shorting of open field lines where they intersect external boundaries strongly modifies the transverse electric field all along the field lines. The modified electric field is found by an extension of the familiar Boltzmann relation for the electric potential. This leads to a prediction of the electric drift. Flow generation by electrical shorting is applied here to three aspects of elongated field-reversed configurations: plasma rotation rate; the particle-loss spin-up mechanism; and the sustainability of the rotating magnetic field current drive method

Efficient reversible data hiding in encrypted H.264/AVC videos

Science.gov (United States)

Xu, Dawen; Wang, Rangding

2014-09-01

Due to the security and privacy-preserving requirements for cloud data management, it is sometimes desired that video content is accessible in an encrypted form. Reversible data hiding in the encrypted domain is an emerging technology, as it can perform data hiding in encrypted videos without decryption, which preserves the confidentiality of the content. Furthermore, the original cover can be losslessly restored after decryption and data extraction. An efficient reversible data hiding scheme for encrypted H.264/AVC videos is proposed. During H.264/AVC encoding, the intraprediction mode, motion vector difference, and the sign bits of the residue coefficients are encrypted using a standard stream cipher. Then, the data-hider who does not know the original video content, may reversibly embed secret data into the encrypted H.264/AVC video by using a modified version of the histogram shifting technique. A scale factor is utilized for selecting the embedding zone, which is scalable for different capacity requirements. With an encrypted video containing hidden data, data extraction can be carried out either in the encrypted or decrypted domain. In addition, real reversibility is realized so that data extraction and video recovery are free of any error. Experimental results demonstrate the feasibility and efficiency of the proposed scheme.

Modification of Polyamide-Urethane (PAUt Thin Film Composite Membrane for Improving the Reverse Osmosis Performance

Directory of Open Access Journals (Sweden)

Li-Fen Liu

2018-03-01

Full Text Available In the current study, the poly (amide-urethane (PAUt membranes were successfully fabricated by interfacial polymerization of m-phenylenediamine (MPD and 5-choroformyloxyisophaloyl chloride (CFIC on the polysulfone substrates. Two modification methods based on layer-by-layer assembly were applied to modify the PAUt membrane surface to achieve antifouling property: 1. Chitosan (CS was directly self-assembled on the PAUt membrane (i.e., PAUt-CS; and 2. polydimethyl diallyl ammonium chloride (PDDA, polystyrene sulfonate (PSS, and CS were successively self-assembled on the membrane surface (i.e., PAUt-PDDA/PSS/CS. The resultant membranes were symmetrically characterized by Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR, X-ray Photoelectron Spectroscopy (XPS, Scanning Electron Microscopy (SEM, Atomic Force Microscopy (AFM and Contact Angle Meter (CAM, respectively. The results indicated that the modified membranes had much smoother and more hydrophilic surfaces as compared to the nascent PAUt membrane. Meanwhile, the modified membranes exhibited better reverse osmosis performance in terms of water permeability and salt rejection. After the modified membranes were fouled by lake water, the PAUt-PDDA/PSS/CS membrane presented the best antifouling performance among the three types of membranes. Combining the reverse osmosis performance with the anti-fouling property obviously, the PAUt-PDDA/PSS/CS membrane behaved as a promising candidate to be used in real applications.

Exercise reverses metabolic syndrome in high-fat diet-induced obese rats.

Science.gov (United States)

Touati, Sabeur; Meziri, Fayçal; Devaux, Sylvie; Berthelot, Alain; Touyz, Rhian M; Laurant, Pascal

2011-03-01

Chronic consumption of a high-fat diet induces obesity. We investigated whether exercise would reverse the cardiometabolic disorders associated with obesity without it being necessary to change from a high- to normal-fat diet. Sprague-Dawley rats were placed on a high-fat (HFD) or control diet (CD) for 12 wk. HFD rats were then divided into four groups: sedentary HFD (HFD-S), exercise trained (motor treadmill for 12 wk) HFD (HFD-Ex), modified diet (HFD to CD; HF/CD-S), and exercise trained with modified diet (HF/CD-Ex). Cardiovascular risk parameters associated with metabolic syndrome were measured, and contents of aortic Akt, phospho-Akt at Ser (473), total endothelial nitric oxide synthase (eNOS), and phospho-eNOS at Ser (1177) were determined by Western blotting. Chronic consumption of HFD induced a metabolic syndrome. Exercise and dietary modifications reduced adiposity, improved glucose and insulin levels and plasma lipid profile, and exerted an antihypertensive effect. Exercise was more effective than dietary modification in improving plasma levels of thiobarbituric acid-reacting substance and in correcting the endothelium-dependent relaxation to acetylcholine and insulin. Furthermore, independent of the diet used, exercise increased Akt and eNOS phosphorylation. Metabolic syndrome induced by HFD is reversed by exercise and diet modification. It is demonstrated that exercise training induces these beneficial effects without the requirement for dietary modification, and these beneficial effects may be mediated by shear stress-induced Akt/eNOS pathway activation. Thus, exercise may be an effective strategy to reverse almost all the atherosclerotic risk factors linked to obesity, particularly in the vasculature.

Thoracic Outlet Syndrome and Volkmann's Contracture in a Field Hockey Player

Directory of Open Access Journals (Sweden)

Morgan Sawyer

2016-05-01

Full Text Available Background: A 19-year-old female field hockey player presents with bilateral upper trapezius and rhomboid tightness and spasm beginning in January of 2016. She has no previous history of upper back pain or injury. The student first reported the injury immediately after running sprints. She stated that she could not move or feel her fingers or hands. She presents with a visible hump on her left upper trapezius. She also has forward-rounded shoulders. She has regular and equal radial pulses. She has decreased sensation upon palpation of her fingers, hands and forearms. After extraneous exercise, the athlete’s hands, wrists and forearms go into contracture and flexion and she is unable to move from this position until manual extension is applied, or 10 or more minutes of rest occurs. She is TTP over her upper trapezius musculature. She had a positive Military Brace test. Differential Diagnosis: Based on evaluation, the athlete could simply just have upper trapezius musculature spasms. The diagnosis could also be shoulder impingement syndrome, due to the neurological signs and symptoms. Compartment syndrome could produce similar s/s that the athlete experiences, as well. Treatment: X-rays show no bony abnormalities and no extra ribs. The athlete’s injury has been treated with ice post-practice, heat pre-practice and upper body stretching exercises. Three days a week the athlete works on postural exercises that strengthen her back musculature. The athlete also receives combination therapy over her upper trapezius trigger points, along with massage and Hawkgrip technique over the same areas. Uniqueness: The uniqueness in this case is that the athlete has both TOS and Volkmann’s contracture. Volkmann’s contractures typically occur in pediatrics, which is another reason why this particular case is unique. Conclusion: This case allows other clinicians to understand the causes of TOS and the secondary s/s that TOS can potentially cause.

Tissue-Engineered Skeletal Muscle Organoids for Reversible Gene Therapy

Science.gov (United States)

Vandenburgh, Herman; DelTatto, Michael; Shansky, Janet; Lemaire, Julie; Chang, Albert; Payumo, Francis; Lee, Peter; Goodyear, Amy; Raven, Latasha

1996-01-01

Genetically modified murine skeletal myoblasts were tissue engineered in vitro into organ-like structures (organoids) containing only postmitotic myofibers secreting pharmacological levels of recombinant human growth hormone (rhGH). Subcutaneous organoid Implantation under tension led to the rapid and stable appearance of physiological sera levels of rhGH for up to 12 weeks, whereas surgical removal led to its rapid disappearance. Reversible delivery of bioactive compounds from postimtotic cells in tissue engineered organs has several advantages over other forms of muscle gene therapy.

Reversible logic gates based on enzyme-biocatalyzed reactions and realized in flow cells: a modular approach.

Science.gov (United States)

Fratto, Brian E; Katz, Evgeny

2015-05-18

Reversible logic gates, such as the double Feynman gate, Toffoli gate and Peres gate, with 3-input/3-output channels are realized using reactions biocatalyzed with enzymes and performed in flow systems. The flow devices are constructed using a modular approach, where each flow cell is modified with one enzyme that biocatalyzes one chemical reaction. The multi-step processes mimicking the reversible logic gates are organized by combining the biocatalytic cells in different networks. This work emphasizes logical but not physical reversibility of the constructed systems. Their advantages and disadvantages are discussed and potential use in biosensing systems, rather than in computing devices, is suggested. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reversible Thermoset Adhesives

Science.gov (United States)

Mac Murray, Benjamin C. (Inventor); Tong, Tat H. (Inventor); Hreha, Richard D. (Inventor)

2016-01-01

Embodiments of a reversible thermoset adhesive formed by incorporating thermally-reversible cross-linking units and a method for making the reversible thermoset adhesive are provided. One approach to formulating reversible thermoset adhesives includes incorporating dienes, such as furans, and dienophiles, such as maleimides, into a polymer network as reversible covalent cross-links using Diels Alder cross-link formation between the diene and dienophile. The chemical components may be selected based on their compatibility with adhesive chemistry as well as their ability to undergo controlled, reversible cross-linking chemistry.

Photo- and electro-chromism of diarylethene modified ITO electrodes - towards molecular based read-write-erase information storage

NARCIS (Netherlands)

Areephong, J.; Browne, W.R.; Katsonis, N.; Feringa, B.L.

2006-01-01

Molecular memory devices based on dithienylethene switch modified ITO electrodes undergo reversible ring opening/closing both photo- and electro-chemically with non-destructive electrochemical readout.

Zero field reversal probability in thermally assisted magnetization reversal

Science.gov (United States)

Prasetya, E. B.; Utari; Purnama, B.

2017-11-01

This paper discussed about zero field reversal probability in thermally assisted magnetization reversal (TAMR). Appearance of reversal probability in zero field investigated through micromagnetic simulation by solving stochastic Landau-Lifshitz-Gibert (LLG). The perpendicularly anisotropy magnetic dot of 50×50×20 nm3 is considered as single cell magnetic storage of magnetic random acces memory (MRAM). Thermally assisted magnetization reversal was performed by cooling writing process from near/almost Curie point to room temperature on 20 times runs for different randomly magnetized state. The results show that the probability reversal under zero magnetic field decreased with the increase of the energy barrier. The zero-field probability switching of 55% attained for energy barrier of 60 k B T and the reversal probability become zero noted at energy barrier of 2348 k B T. The higest zero-field switching probability of 55% attained for energy barrier of 60 k B T which corespond to magnetif field of 150 Oe for switching.

Charge reversible gold nanoparticles for high efficient absorption and desorption of DNA

Energy Technology Data Exchange (ETDEWEB)

Wang Can; Zhuang Jiaqi; Jiang Shan; Li Jun; Yang Wensheng, E-mail: wsyang@jlu.edu.cn [Jilin University, State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry (China)

2012-10-15

Mercaptoundecylamine and mercaptoundecanoic acid co-modified Au nanoparticles were prepared by two-step ligand exchange of 6-mercaptohexanoic acid modified gold nanoparticles. Such particles terminated by appropriate ratios of the amine and carboxyl groups (R{sub N/C}) were identified to show reversible charge on their surface, which were switchable by pH of the solution. The isoelectric point (IEP) of the particles is tunable by changing the ratios of the amine and carboxyl groups on the particle surfaces. The particles can absorb DNA effectively at pH lower than the IEP driven by the direct electrostatic interactions between DNA and the particle surface. When pH of the solutions was elevated to be higher than the IEP, the absorbed DNA can be released almost completely due to the electrostatic repulsion between the particle surface and DNA. With appropriate R{sub N/C} ratios of 0.8, the absorption and desorption efficiencies of DNA were 97 and 98%, respectively, corresponding an extraction efficiency of 95 %. Such particles with reversible surface charges allow the high efficient extraction of DNA by simply changing pH instead of by changing salt concentration in the conventional salt bridge method.Graphical Abstract.

Reverse Osmosis

Indian Academy of Sciences (India)

many applications, one of which is desalination of seawater. The inaugural Nobel Prize in Chemistry was awarded in 1901 to van 't Hoff for his seminal work in this area. The present article explains the principle of osmosis and reverse osmosis. Osmosis and Reverse Osmosis. As the name suggests, reverse osmosis is the ...

Time course and dimensions of postural control changes following neuromuscular training in youth field hockey athletes.

Science.gov (United States)

Zech, Astrid; Klahn, Philipp; Hoeft, Jon; zu Eulenburg, Christine; Steib, Simon

2014-02-01

Injury prevention effects of neuromuscular training have been partly attributed to postural control adaptations. Uncertainty exists regarding the magnitude of these adaptations and on how they can be adequately monitored. The objective was to determine the time course of neuromuscular training effects on functional, dynamic and static balance measures. Thirty youth (14.9 ± 3 years) field hockey athletes were randomised to an intervention or control group. The intervention included a 20-min neuromuscular warm-up program performed twice weekly for 10 weeks. Balance assessments were performed at baseline, week three, week six and post-intervention. They included the star excursion balance test (SEBT), balance error scoring system (BESS), jump-landing time to stabilization (TTS) and center of pressure (COP) sway velocity during single-leg standing. No baseline differences were found between groups in demographic data and balance measures. Adherence was at 86%. All balance measures except the medial-lateral TTS improved significantly over time (p controls (31.8 ± 22.1%). There were no significant group by time interactions in the SEBT, TTS and COP sway velocity. Neuromuscular training was effective in improving postural control in youth team athletes. However, this effect was not reflected in all balance measures suggesting that the neuromuscular training did not influence all dimensions of postural control. Further studies are needed to confirm the potential of specific warm-up programs to improve postural control.

Reactive chemically modified piezoelectric crystal detectors: A new class of high-selectivity sensors

International Nuclear Information System (INIS)

Fadeev, A.Yu.; Filatov, A.L.; Lisichkin, G.V.

1994-01-01

A great number of works have focused on the study of properties of modified piezoelectric quartz crystal detectors (PQCDs) coated with sorbing substrates and on applying sensors based on them for the analysis of diluted gas mixtures and solutions. This work offers a new class of gravemetric sensors characterized by a reversible chemical reaction that occurs on their surface. Silica films are proposed as a sorbing coating of quartz detectors, and a chemical modification of a surface is suggested for covalent fixation of the necessary compounds. PQCDs were chemically modified with reactive diene derivatives that can also act as dienophiles. Hexachlorocyclopentadiene (HCCPD, resonater I) and cyclopentadiene (CPD, resonator II) were fixed on a PQCD surface in several stages. After treatment with the resonaters, the PQCD in a CPD gas phase exhibited time dependent frequency shifts from 20-100 Hz. The results suggest that there is a reversible chemical reaction on the electrode surface of resonators I and II when they interact with CPD vapors. Therefore, PQCDs modified with reactive dienes were prepared for the first time and may be employed as selective sensors for CPD

A major locus on mouse chromosome 18 controls XX sex reversal in Odd Sex (Ods) mice.

Science.gov (United States)

Qin, Yangjun; Poirier, Christophe; Truong, Cavatina; Schumacher, Armin; Agoulnik, Alexander I; Bishop, Colin E

2003-03-01

We have previously reported a dominant mouse mutant, Odd sex (Ods), in which XX Ods/+ mice on the FVB/N background show complete sex reversal, associated with expression of Sox9 in the fetal gonads. Remarkably, when crossed to the A/J strain approximately 95% of the (AXFVB) F(1) XX Ods/+ mice developed as fully fertile, phenotypic females, the remainder developing as males or hermaphrodites. Using a (AXFVB) F(2) population, we conducted a genome-wide linkage scan to identify the number and chromosomal location of potential Ods modifier genes. A single major locus termed Odsm1 was mapped to chromosome 18, tightly linked to D18Mit189 and D18Mit210. Segregation at this locus could account for the presence of sex reversal in 100% of XX Ods/+ mice which develop as males, for the absence of sex reversal in approximately 92% of XX Ods/+ mice which develop as females, and for the mixed sexual phenotype in approximately 72% of XX Ods/+ mice that develop with ambiguous genitalia. We propose that homozygosity for the FVB-derived allele strongly favors Ods sex reversal, whereas homozygosity for the A/J-derived allele inhibits it. In mice heterozygous at Odsm1, the phenotypic outcome, male, female or hermaphrodite, is determined by a complex interaction of several minor modifying loci. The close proximity of Smad2, Smad7 and Smad4 to D18Mit189/210 provides a potential mechanism through which Odsm1 might act.

The use of Fourier reverse transforms in crystallographic phase refinement

Energy Technology Data Exchange (ETDEWEB)

Ringrose, Sharon [Iowa State Univ., Ames, IA (United States)

1997-10-08

Often a crystallographer obtains an electron density map which shows only part of the structure. In such cases, the phasing of the trial model is poor enough that the electron density map may show peaks in some of the atomic positions, but other atomic positions are not visible. There may also be extraneous peaks present which are not due to atomic positions. A method for determination of crystal structures that have resisted solution through normal crystallographic methods has been developed. PHASER is a series of FORTRAN programs which aids in the structure solution of poorly phased electron density maps by refining the crystallographic phases. It facilitates the refinement of such poorly phased electron density maps for difficult structures which might otherwise not be solvable. The trial model, which serves as the starting point for the phase refinement, may be acquired by several routes such as direct methods or Patterson methods. Modifications are made to the reverse transform process based on several assumptions. First, the starting electron density map is modified based on the fact that physically the electron density map must be non-negative at all points. In practice a small positive cutoff is used. A reverse Fourier transform is computed based on the modified electron density map. Secondly, the authors assume that a better electron density map will result by using the observed magnitudes of the structure factors combined with the phases calculated in the reverse transform. After convergence has been reached, more atomic positions and less extraneous peaks are observed in the refined electron density map. The starting model need not be very large to achieve success with PHASER; successful phase refinement has been achieved with a starting model that consists of only 5% of the total scattering power of the full molecule. The second part of the thesis discusses three crystal structure determinations.

Cross flow filtration for radwaste applications reverse osmosis demonstration case studies

International Nuclear Information System (INIS)

Malkmus, D.

1995-01-01

Today's radwaste economic and regulatory scenarios signify the importance in the improvement of operational practices to reduce generator liabilities. This action is largely due to the rising cost dealing with burial sites and the imposed waste volume restriction. To control the economical burdens associated with waste burial and to comply with stricter environmental regulations, NPP's are attempting to modify their radwaste system(s) design and operating philosophy by placing a major emphasis on waste volume reduction and processing techniques. The utilization of reverse osmosis technology as a means for treatment of process and wastewater streams in the nuclear power industry has been investigated for many years. This paper will outline reverse osmosis theory and highlight performance data for process and waste stream purification applications. Case studies performed at 5 nuclear plants have been outlined. The demonstrations were performed on a widely variety of process stream for both a PWR and BWR application. The data provided by the pilot systems, the equipment design, and the economical impact a reverse osmosis unit will have on producing treated (high purity) are as follows

A Reverse Stroop Task with Mouse Tracking

Science.gov (United States)

Yamamoto, Naohide; Incera, Sara; McLennan, Conor T.

2016-01-01

In a reverse Stroop task, observers respond to the meaning of a color word irrespective of the color in which the word is printed—for example, the word red may be printed in the congruent color (red), an incongruent color (e.g., blue), or a neutral color (e.g., white). Although reading of color words in this task is often thought to be neither facilitated by congruent print colors nor interfered with incongruent print colors, this interference has been detected by using a response method that does not give any bias in favor of processing of word meanings or processing of print colors. On the other hand, evidence for the presence of facilitation in this task has been scarce, even though this facilitation is theoretically possible. By modifying the task such that participants respond to a stimulus color word by pointing to a corresponding response word on a computer screen with a mouse, the present study investigated the possibility that not only interference but also facilitation would take place in a reverse Stroop task. Importantly, in this study, participants’ responses were dynamically tracked by recording the entire trajectories of the mouse. Arguably, this method provided richer information about participants’ performance than traditional measures such as reaction time and accuracy, allowing for more detailed (and thus potentially more sensitive) investigation of facilitation and interference in the reverse Stroop task. These trajectories showed that the mouse’s approach toward correct response words was significantly delayed by incongruent print colors but not affected by congruent print colors, demonstrating that only interference, not facilitation, was present in the current task. Implications of these findings are discussed within a theoretical framework in which the strength of association between a task and its response method plays a critical role in determining how word meanings and print colors interact in reverse Stroop tasks. PMID:27199881

Managing Reverse Logistics or Reversing Logistics Management?

NARCIS (Netherlands)

M.P. de Brito (Marisa)

2004-01-01

textabstractIn the past, supply chains were busy fine-tuning the logistics from raw material to the end customer. Today an increasing flow of products is going back in the chain. Thus, companies have to manage reverse logistics as well.This thesis contributes to a better understanding of reverse

The effect of quadrupole fields on particle confinement in a field-reversed mirror

International Nuclear Information System (INIS)

McColl, D.B.; Berk, H.L.; Hammer, J.; Morse, E.C.

1982-01-01

A particle simulation code has been modified to simulate particle loss caused by quadrupole magnetic fields on a field-reversed mirror plasma device. Since analytic fields are chosen for the equilibrium, the numerical algorithm is highly accurate for long-time integrations of particle orbits. The resultant particle loss due to the quadrupole fields can be competitive with collisional loss in the device

Muscle oxygen changes following Sprint Interval Cycling training in elite field hockey players.

Directory of Open Access Journals (Sweden)

Ben Jones

Full Text Available This study examined the effects of Sprint Interval Cycling (SIT on muscle oxygenation kinetics and performance during the 30-15 intermittent fitness test (IFT. Twenty-five women hockey players of Olympic standard were randomly selected into an experimental group (EXP and a control group (CON. The EXP group performed six additional SIT sessions over six weeks in addition to their normal training program. To explore the potential training-induced change, EXP subjects additionally completed 5 x 30s maximal intensity cycle testing before and after training. During these tests near-infrared spectroscopy (NIRS measured parameters; oxyhaemoglobin + oxymyoglobin (HbO2+ MbO2, tissue deoxyhaemoglobin + deoxymyoglobin (HHb+HMb, total tissue haemoglobin (tHb and tissue oxygenation (TSI % were taken. In the EXP group (5.34 ± 0.14 to 5.50 ± 0.14 m.s(-1 but not the CON group (pre = 5.37 ± 0.27 to 5.39 ± 0.30 m.s(-1 significant changes were seen in the 30-15 IFT performance. EXP group also displayed significant post-training increases during the sprint cycling: ΔTSI (-7.59 ± 0.91 to -12.16 ± 2.70%; ΔHHb+HMb (35.68 ± 6.67 to 69.44 ± 26.48 μM.cm; and ΔHbO2+ MbO2 (-74.29 ± 13.82 to -109.36 ± 22.61 μM.cm. No significant differences were seen in ΔtHb (-45.81 ± 15.23 to -42.93 ± 16.24. NIRS is able to detect positive peripheral muscle oxygenation changes when used during a SIT protocol which has been shown to be an effective training modality within elite athletes.

Formation of field reversed configurations in a slow, multi-turn coil system: Appendix B

International Nuclear Information System (INIS)

Slough, J.T.; Hoffman, A.L.

1987-01-01

A previous field-reversed theta pinch, TRX-1, has been modified by replacing the single turn main compression coil with an array of three-turn coils. Field reversed configurations (FRCs) have been formed at relatively low values of azimuthal electric field, where ohmic dissipation and axial compressive heating are substituted for the radial shock heating which is dominant in high voltage theta pinches. The longer magnetic field risetime has allowed various controls to be applied to the formation timing, so that the axial implosion can be made to coincide with the peak of the applied magnetic field. This 'programmed formation' control results in maximum plasma heating, and minimizes the formation dynamics

pH-Sensitive Reversible Programmed Targeting Strategy by the Self-Assembly/Disassembly of Gold Nanoparticles.

Science.gov (United States)

Ma, Jinlong; Hu, Zhenpeng; Wang, Wei; Wang, Xinyu; Wu, Qiang; Yuan, Zhi

2017-05-24

A reversible programmed targeting strategy could achieve high tumor accumulation due to its long blood circulation time and high cellular internalization. Here, targeting ligand-modified poly(ethylene glycol) (PEG-ligand), dibutylamines (Bu), and pyrrolidinamines (Py) were introduced on the surface of gold nanoparticles (Au NPs) for reversible shielding/deshielding of the targeting ligands by pH-responsive self-assembly. Hydrophobic interaction and steric repulsion are the main driving forces for the self-assembly/disassembly of Au NPs. The precise self-assembly (pH ≥ 7.2) and disassembly (pH ≤ 6.8) of Au NPs with different ligands could be achieved by fine-tuning the modifying molar ratio of Bu and Py (R m ), which followed the formula R m = 1/(-0.0013X 2 + 0.0323X + 1), in which X is the logarithm of the partition coefficient of the targeting ligand. The assembled/disassembled behavior of Au NPs at pH 7.2 and 6.8 was confirmed by transmission electron microscopy and dynamic light scattering. Enzyme-linked immunosorbent assays and cellular uptake studies showed that the ligands could be buried inside the assembly and exposed when disassembled. More importantly, this process was reversible, which provides the possibility of prolonging blood circulation by shielding ligands associated with the NPs that were effused from tumor tissue.

“La deportista moderna”: género, clase y consumo en el fútbol, running y hockey argentinos

Directory of Open Access Journals (Sweden)

Gabriela Garton

2018-04-01

Full Text Available The advances achieved by the feminist movement since the 1970s have also been reflected in athletics, evidenced by the exponential growth in the participation of women. This change has produced new ideals of the female body –one that is strong, athletic, independent, and at the same time sexually attractive– which have been constructed by Western society and fostered by its mercantilist logic through advertising, social networks and certain messages about caring for your body and leading a “healthy lifestyle” chosen by brands which exploit these ideals. We analyze the image of women in three sports where women have reached unprecedented levels of participation and visibility: field hockey, soccer and running. Our study is based on ethnographic field work, along with the analysis of a series of advertisements, videos and pictures on social networks, where such women are portrayed, or self-represented, as models/examples of the new ideal of the female body. In this way, we hope to throw light on the ideals found in the sports women choose to practice and ask whether individual freedom and agency still exist in these activities. We also wonder if the hegemonic ideals of femininity continue to operate there or if the truth lies somewhere between the two alternatives.

NONLINEAR-REGRESSION METHODS FOR MODELING OF HETEROSCEDASTIC RETENTION DATA IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

NARCIS (Netherlands)

HENDRIKS, MMWB; COENEGRACHT, PMJ; DOORNBOS, DA

1994-01-01

New models have been developed that accurately describe the response surfaces of capacity factors that are a function of changes in the pH and the fraction of organic modifier in reversed-phase high-performance liquid chromatography (RP-HPLC). The purpose of this article is to illustrate one of the

Reverse genetics with animal viruses. NSV reverse genetics

International Nuclear Information System (INIS)

Mebatsion, T.

2005-01-01

New strategies to genetically manipulate the genomes of several important animal pathogens have been established in recent years. This article focuses on the reverse genetics techniques, which enables genetic manipulation of the genomes of non-segmented negative-sense RNA viruses. Recovery of a negative-sense RNA virus entirely from cDNA was first achieved for rabies virus in 1994. Since then, reverse genetic systems have been established for several pathogens of medical and veterinary importance. Based on the reverse genetics technique, it is now possible to design safe and more effective live attenuated vaccines against important viral agents. In addition, genetically tagged recombinant viruses can be designed to facilitate serological differentiation of vaccinated animals from infected animals. The approach of delivering protective immunogens of different pathogens using a single vector was made possible with the introduction of the reverse genetics system, and these novel broad-spectrum vaccine vectors have potential applications in improving animal health in developing countries. (author)

A kinematic analysis of the modified flight telerobotic servicer manipulator system

Science.gov (United States)

Crane, Carl; Carnahan, Tim; Duffy, Joseph

1992-01-01

A reverse kinematic analysis is presented of a six-DOF subchain of a modified seven-DOF flight telerobotic servicer manipulator system. The six-DOF subchain is designated as a TR-RT chain, which describes the sequence of manipulator joints beginning with the first grounded hook joint (universal joint) T, where the sequence R-R designates a pair of revolute joints with parallel axes. At the outset, it had been thought that the reverse kinematic analysis would be similar to a TTT manipulator previously analyzed, in which the third and fourth joints intersected at a finite point. However, this is shown not the case, and a 16th-degree tan-half-angle polynomial is derived for the TR-RT manipulator.

Production of field-reversed plasma with a magnetized coaxial plasma gun

International Nuclear Information System (INIS)

Turner, W.C.; Granneman, E.H.A.; Hartman, C.W.; Prono, D.S.; Taska, J.; Smith, A.C. Jr.

1981-01-01

Experimental data are presented on the production of field-reversed deuterium plasma by a modified coaxial plasma gun. The coaxial gun is constructed with solenoid coils along the inner and outer electrodes that, together with an external guide field solenoid, form a magnetic cusp at the gun muzzle. The net flux inside the inner electrode is arranged to be opposite the external guide field and is the source of field-reversed flux trapped by the plasma. The electrode length is 145 cm, the diameter of the inner (outer) electrode is 15 cm (32 cm). The gun discharge is driven with a 232-μF 40-kV capacitor bank. Acceleration of plasma through the magnetic cusp at the gun muzzle results in entrainment of field-reversed flux that is detected by magnetic probes 75 cm from the gun muzzle. Field-reversed plasma has been produced for a variety of experimental conditions. In one typical case, the guide magnetic field was B 0 =4.8 kG and the change in axial magnetic field ΔB/sub z/ normalized to B 0 was ΔB/sub z/ /B 0 =-3.1. Total field-reversed flux (poloidal flux) obtained by integrating ΔB/sub z/ profiles is in the range 2 x 10 3 kG cm 2 . Measurement of the orthogonal field component indicates a sizable toroidal field peaked off axis at rapprox. =10 cm with a magnitude of roughly one-half the poloidal field component that is measured on magnetic axis. Reconnection of the poloidal field lines has not been established for the data reported in the paper and will be addressed in future experiments which attempt to trap and confine the field-reversed plasma in a magnetic mirror

Application of Ionic Liquids in High Performance Reversed-Phase Chromatography

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Wentao Bi

2009-06-01

Full Text Available Ionic liquids, considered “green” chemicals, are widely used in many areas of analytical chemistry due to their unique properties. Recently, ionic liquids have been used as a kind of novel additive in separation and combined with silica to synthesize new stationary phase as separation media. This review will focus on the properties and mechanisms of ionic liquids and their potential applications as mobile phase modifier and surface-bonded stationary phase in reversed-phase high performance liquid chromatography (RP-HPLC. Ionic liquids demonstrate advantages and potential in chromatographic field.

Frequency behaviour of the modified Jiles-Atherton model

International Nuclear Information System (INIS)

Chwastek, Krzysztof

2008-01-01

In the paper the behaviour of the recently modified Jiles-Atherton model of hysteresis under a distorted magnetization pattern is examined. The modification is aimed at improving the modelling of reversible processes. The equation for anhysteretic model is replaced from Langevin function to the more general Brillouin function. The structure of model equation is similar to that of the product Preisach model. The dynamic effects are taken into account in the description by the introduction of the lagged response with respect to the input

Development of a reverse genetics system to generate a recombinant Ebola virus Makona expressing a green fluorescent protein

Energy Technology Data Exchange (ETDEWEB)

Albariño, César G., E-mail: calbarino@cdc.gov; Wiggleton Guerrero, Lisa; Lo, Michael K.; Nichol, Stuart T.; Towner, Jonathan S.

2015-10-15

Previous studies have demonstrated the potential application of reverse genetics technology in studying a broad range of aspects of viral biology, including gene regulation, protein function, cell entry, and pathogenesis. Here, we describe a highly efficient reverse genetics system used to generate recombinant Ebola virus (EBOV) based on a recent isolate from a human patient infected during the 2014–2015 outbreak in Western Africa. We also rescued a recombinant EBOV expressing a fluorescent reporter protein from a cleaved VP40 protein fusion. Using this virus and an inexpensive method to quantitate the expression of the foreign gene, we demonstrate its potential usefulness as a tool for screening antiviral compounds and measuring neutralizing antibodies. - Highlights: • Recombinant Ebola virus (EBOV) derived from Makona variant was rescued. • New protocol for viral rescue allows 100% efficiency. • Modified EBOV expresses a green fluorescent protein from a VP40-fused protein. • Modified EBOV was tested as tool to screen antiviral compounds and measure neutralizing antibodies.

Development of a reverse genetics system to generate a recombinant Ebola virus Makona expressing a green fluorescent protein

International Nuclear Information System (INIS)

Albariño, César G.; Wiggleton Guerrero, Lisa; Lo, Michael K.; Nichol, Stuart T.; Towner, Jonathan S.

2015-01-01

Previous studies have demonstrated the potential application of reverse genetics technology in studying a broad range of aspects of viral biology, including gene regulation, protein function, cell entry, and pathogenesis. Here, we describe a highly efficient reverse genetics system used to generate recombinant Ebola virus (EBOV) based on a recent isolate from a human patient infected during the 2014–2015 outbreak in Western Africa. We also rescued a recombinant EBOV expressing a fluorescent reporter protein from a cleaved VP40 protein fusion. Using this virus and an inexpensive method to quantitate the expression of the foreign gene, we demonstrate its potential usefulness as a tool for screening antiviral compounds and measuring neutralizing antibodies. - Highlights: • Recombinant Ebola virus (EBOV) derived from Makona variant was rescued. • New protocol for viral rescue allows 100% efficiency. • Modified EBOV expresses a green fluorescent protein from a VP40-fused protein. • Modified EBOV was tested as tool to screen antiviral compounds and measure neutralizing antibodies

Functional interface of polymer modified graphite anode

Science.gov (United States)

Komaba, S.; Ozeki, T.; Okushi, K.

Graphite electrodes were modified by polyacrylic acid (PAA), polymethacrylic acid (PMA), and polyvinyl alcohol (PVA). Their electrochemical properties were examined in 1 mol dm -3 LiClO 4 ethylene carbonate:dimethyl carbonate (EC:DMC) and propylene carbonate (PC) solutions as an anode of lithium ion batteries. Generally, lithium ions hardly intercalate into graphite in the PC electrolyte due to a decomposition of the PC electrolyte at ca. 0.8 V vs. Li/Li +, and it results in the exfoliation of the graphene layers. However, the modified graphite electrodes with PAA, PMA, and PVA demonstrated the stable charge-discharge performance due to the reversible lithium intercalation not only in the EC:DMC but also in the PC electrolytes since the electrolyte decomposition and co-intercalation of solvent were successfully suppressed by the polymer modification. It is thought that these improvements were attributed to the interfacial function of the polymer layer on the graphite which interacted with the solvated lithium ions at the electrode interface.

Experimental evolution and the dynamics of genomic mutation rate modifiers.

Science.gov (United States)

Raynes, Y; Sniegowski, P D

2014-11-01

Because genes that affect mutation rates are themselves subject to mutation, mutation rates can be influenced by natural selection and other evolutionary forces. The population genetics of mutation rate modifier alleles has been a subject of theoretical interest for many decades. Here, we review experimental contributions to our understanding of mutation rate modifier dynamics. Numerous evolution experiments have shown that mutator alleles (modifiers that elevate the genomic mutation rate) can readily rise to high frequencies via genetic hitchhiking in non-recombining microbial populations. Whereas these results certainly provide an explanatory framework for observations of sporadically high mutation rates in pathogenic microbes and in cancer lineages, it is nonetheless true that most natural populations have very low mutation rates. This raises the interesting question of how mutator hitchhiking is suppressed or its phenotypic effect reversed in natural populations. Very little experimental work has addressed this question; with this in mind, we identify some promising areas for future experimental investigation.

Artificial Specific Binders Directly Recovered from Chemically Modified Nucleic Acid Libraries

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Yuuya Kasahara

2012-01-01

Full Text Available Specific binders comprised of nucleic acids, that is, RNA/DNA aptamers, are attractive functional biopolymers owing to their potential broad application in medicine, food hygiene, environmental analysis, and biological research. Despite the large number of reports on selection of natural DNA/RNA aptamers, there are not many examples of direct screening of chemically modified nucleic acid aptamers. This is because of (i the inferior efficiency and accuracy of polymerase reactions involving transcription/reverse-transcription of modified nucleotides compared with those of natural nucleotides, (ii technical difficulties and additional time and effort required when using modified nucleic acid libraries, and (iii ambiguous efficacies of chemical modifications in binding properties until recently; in contrast, the effects of chemical modifications on biostability are well studied using various nucleotide analogs. Although reports on the direct screening of a modified nucleic acid library remain in the minority, chemical modifications would be essential when further functional expansion of nucleic acid aptamers, in particular for medical and biological uses, is considered. This paper focuses on enzymatic production of chemically modified nucleic acids and their application to random screenings. In addition, recent advances and possible future research are also described.

Artificial specific binders directly recovered from chemically modified nucleic acid libraries.

Science.gov (United States)

Kasahara, Yuuya; Kuwahara, Masayasu

2012-01-01

Specific binders comprised of nucleic acids, that is, RNA/DNA aptamers, are attractive functional biopolymers owing to their potential broad application in medicine, food hygiene, environmental analysis, and biological research. Despite the large number of reports on selection of natural DNA/RNA aptamers, there are not many examples of direct screening of chemically modified nucleic acid aptamers. This is because of (i) the inferior efficiency and accuracy of polymerase reactions involving transcription/reverse-transcription of modified nucleotides compared with those of natural nucleotides, (ii) technical difficulties and additional time and effort required when using modified nucleic acid libraries, and (iii) ambiguous efficacies of chemical modifications in binding properties until recently; in contrast, the effects of chemical modifications on biostability are well studied using various nucleotide analogs. Although reports on the direct screening of a modified nucleic acid library remain in the minority, chemical modifications would be essential when further functional expansion of nucleic acid aptamers, in particular for medical and biological uses, is considered. This paper focuses on enzymatic production of chemically modified nucleic acids and their application to random screenings. In addition, recent advances and possible future research are also described.

Vývoj protokolu o pozorování dovedností pro sledge hokej - pilotní studie Development of a skills observation protocol for sledge ice hockey - pilot study

Directory of Open Access Journals (Sweden)

Yves Vanlandewijck

2007-02-01

Full Text Available V průběhu několika posledních let vzrostly možnosti jedinců s tělesným postiženým zapojit se do fyzických činností. Z tohoto důvodu je uznáván význam zvládnutí sportovních dovedností ještě před samotnou účastí v soutěžích. O stále oblíbenějším sledge hokeji bylo dosud provedeno málo výzkumů. Hlavní složkou výkonu je analýza dovedností. Vzhledem k její uznávané důležitosti a současnému nedostatku příslušných výzkumů na tomto poli jsme při této studii využili videozáznamů z paralympijského sledge hokejového turnaje z Turína v roce 2006, které nám poskytly možnost vytvořit protokol o pozorování s podrobnými kritérii toho, co utváří vyspělé profesionální sledge hokejové dovednosti. Proběhly konzultace s odborníky z tohoto odvětví a jejich zpětná vazba nám umožnila vytvořit tento nástroj. Po dokončení protokolu jsme provedli pilotní vyhodnocení, pro které byli hráči vybíráni na základě statistik z paralympijských her. Tito hráči byli poté pomocí našeho protokolu hodnoceni. Bylo prokázáno, že protokol dokáže úspěšně rozlišovat hráče vyšší a nižší úrovně. Over the past few years opportunities have been increasing for individuals with physical disabilities to become involved in physical activities; hence there is a recognition of the importance of mastering sport skills before participation. Currently there is little research that has been performed on the increasingly popular sport of sledge hockey. A major component of performance is skill analysis. Having recognised its importance and the current unavailability of relevant research in the area, this study used video recordings of the Torino 2006 Paralympic sledge ice hockey tournament to provide a setting in which to produce a skill observation protocol with detailed criteria of what constitutes a mature professional sledge ice hockey skill. Experts in the field were

A simple video-based timing system for on-ice team testing in ice hockey: a technical report.

Science.gov (United States)

Larson, David P; Noonan, Benjamin C

2014-09-01

The purpose of this study was to describe and evaluate a newly developed on-ice timing system for team evaluation in the sport of ice hockey. We hypothesized that this new, simple, inexpensive, timing system would prove to be highly accurate and reliable. Six adult subjects (age 30.4 ± 6.2 years) performed on ice tests of acceleration and conditioning. The performance times of the subjects were recorded using a handheld stopwatch, photocell, and high-speed (240 frames per second) video. These results were then compared to allow for accuracy calculations of the stopwatch and video as compared with filtered photocell timing that was used as the "gold standard." Accuracy was evaluated using maximal differences, typical error/coefficient of variation (CV), and intraclass correlation coefficients (ICCs) between the timing methods. The reliability of the video method was evaluated using the same variables in a test-retest analysis both within and between evaluators. The video timing method proved to be both highly accurate (ICC: 0.96-0.99 and CV: 0.1-0.6% as compared with the photocell method) and reliable (ICC and CV within and between evaluators: 0.99 and 0.08%, respectively). This video-based timing method provides a very rapid means of collecting a high volume of very accurate and reliable on-ice measures of skating speed and conditioning, and can easily be adapted to other testing surfaces and parameters.

Roux en Y gastric bypass hypoglycemia resolves with gastric feeding or reversal: Confirming a non-pancreatic etiology

Directory of Open Access Journals (Sweden)

Dawn Belt Davis

2018-03-01

Full Text Available Objective: Postprandial hypoglycemia is an infrequent but disabling complication of Roux-en-Y gastric bypass (RYGB surgery. Controversy still exists as to whether the postprandial hyperinsulinemia observed is due to inherent changes in pancreatic β-cell mass or function or to reversible alterations caused by RYGB anatomy. We aimed to determine if gastric feeding or reversal of RYGB would normalize postprandial glucose and hormone excursions in patients with symptomatic hypoglycemia. Methods: We completed a prospective study of six patients with severe symptomatic RYGB hypoglycemia who underwent RYGB reversal. An additional subject without hypoglycemia who underwent RYGB reversal was also studied prospectively. Mixed meal tolerance testing (MTT was done orally (RYGB anatomy, via gastrostomy tube in the excluded stomach in the setting of RYGB, and several months after RYGB reversal. Results: All subjects reported symptomatic improvement of hypoglycemia after reversal of RYGB. Weight gain after reversal was moderate and variable. Postprandial glucose, insulin, and GLP-1 excursions were significantly diminished with gastric feeding and after reversal. Insulin secretion changed proportional to glucose levels and insulin clearance increased after reversal. Glucagon/insulin ratios were similar throughout study. We further compared the impact of modified sleeve gastrectomy reversal surgery to those with restoration of complete stomach and found no significant differences in weight regain or in postprandial glucose or hormone levels. Conclusions: Reversal of RYGB is an effective treatment option for severe postprandial hypoglycemia. The pathophysiology of this disorder is primarily due to RYGB anatomy resulting in altered glucose, gut, and pancreatic hormone levels and decreased insulin clearance, rather than inherent β-cell hyperplasia or hyperfunction. Keywords: Hypoglycemia, Insulin, Glucagon-like peptide 1, Roux en Y gastric bypass, Gastric bypass

An algebra of reversible computation.

Science.gov (United States)

Wang, Yong

2016-01-01

We design an axiomatization for reversible computation called reversible ACP (RACP). It has four extendible modules: basic reversible processes algebra, algebra of reversible communicating processes, recursion and abstraction. Just like process algebra ACP in classical computing, RACP can be treated as an axiomatization foundation for reversible computation.

On thermodynamic and microscopic reversibility

International Nuclear Information System (INIS)

Crooks, Gavin E

2011-01-01

The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa

Reversibility of female sterilization.

Science.gov (United States)

Siegler, A M; Hulka, J; Peretz, A

1985-04-01

The discussion considers the current status of reversibility of sterilization in the US and describes clinical and experimental efforts for developing techniques designed for reversibility. It focuses on regret following sterilization, reversal potential of current sterilization techniques, patient selection, current reversal techniques, results of sterilization procedures, experimental approaches to reversal of current techniques of sterilization, and sterilization procedures devised for reversibility, in humans and in animals. Request is the 1st stage of reversal, but a request for sterilization reversal (SR) does not always mean regret for a decision made at the time. Frequently it is a wish to restore fertility because life circumstances have changed after a sterilization that was ppropriate at the time it was performed. Schwyhart and Kutner reviewed 22 studies published between 1949-69 in which they found that the percentage of patients regretting the procedure ranged from 1.3-15%. Requests for reversal remain low in most countries, but if sterilization becomes a more popular method of contraception, requests will also increase. The ideal operation considered as a reversaible method of sterilization should include an easy, reliable outpatient method of tubal occlusion with miniml risk or patient discomfort that subsequently could be reversed without the need for a major surgical intervention. Endoscopic methods have progressed toward the 1st objective. A recent search of the literature uncovered few series of SR of more than 50 cases. The 767 operations found were analyzed with regard to pregnancy outcome. The precent of live births varied from 74-78.8%, and the occurance of tubal pregnancies ranged from 1.7-6.5%. All of the confounding variables in patient selection and small numbers of reported procedures preclude any conclusion about the different techniques or the number of operations that give a surgeon a level of expertise. Few authors classify their

Linguistic history of posterior reversible encephalopathy syndrome: mirror of developing knowledge.

Science.gov (United States)

Maizlin, Zeev V; Ghandehari, Hournaz; Maizels, Leonid; Shewchuk, Jason R; Kirby, John M; Vora, Parag; Clement, Jason J

2011-01-01

the term posterior reversible encephalopathy syndrome (PRES) was first proposed in 2000. Since then, the acronym PRES has become very popular in imaging and clinical literature as it is short, easy to say and remember, and neatly couples the frequent localization of neuroimaging findings along with the typical outcome of this syndrome. Another possible reason for the popularity of this acronym in clinical circles is the connotation of PRES with (elevated blood) PRESsure, as a majority of cases are believed to be associated with hypertension. However, problems exist with the interpretation and common understanding of PRES, questioning the appropriateness of "P" and "R" in the acronym. The linguistic issues related to the acronym of PRES are interesting. the aim of this work is to analyze the controversies related to the acronym of PRES. in 2006, modifying the meaning of the acronym was suggested, renaming it Potentially Reversible Encephalopathy Syndrome in order to adjust to the cases when posterior involvement is not prominent and emphasize that the reversibility is not spontaneous. This meant the creation of a backronym, where the new phrase is constructed by starting with an existing acronym. this new backronym indicates that the original acronym of PRES has become a misnomer.

High solute rejecting membranes for reverse osmosis: Polyetheramide hydrazide

International Nuclear Information System (INIS)

Bindal, R.C.; Ramachandhran, V.; Misra, B.M.; Ramani, M.P.S.

1991-01-01

Synthesis of benzhydrazide polymers and determination of reverse osmosis properties of their membranes were reported earlier. Their performance was not adequate for seawater desalination or for high radioactive decontamination factors (DF). The same hydrazide polymers modified by incorporation of additional monomers with ether linkages were synthesized by low temperature polycondensation of freshly prepared m-amino benzhydrazide, p-amino benzhydrazide, and 4,4'-diamino diphenyl ether, with isophthaloyl chloride and terephthaloyl chloride in dimethyl acetamide solvent. A series of film-forming polymers prepared by altering the molar ratios of the reacting monomers were characterized in terms of percent moisture regain, inherent viscosity, solubility parameters, and interfacial sorption characteristics. Asymmetric membranes prepared from these polymer samples were characterized in terms of the pure water permeability constant and the solute transport parameter, and were tested for their reverse osmosis performance. An optimum mole ratio of reaching monomers has been identified for the synthesis of polymer and the resulting membrane offered the best performance for reverse osmosis (salt rejection as high as 99.4% for 3.5% sodium chloride solution). The incorporation of aromatic ether linkages in the polyamide benzhydrazide polymeric chains appears to alter the polar and nonpolar character of the bulk polymer, and also the membrane solution interface characteristics, resulting in enhanced solute separation. These membranes appear to be potential candidates for single-stage seawater desalination and also for a variety of industrial effluent treatment applications for significantly high DF radioactive effluent treatment

Constraining the reversing and non-reversing modes of the geodynamo. New insights from magnetostratigraphy.

Science.gov (United States)

Gallet, Y.; Pavlov, V.; Shatsillo, A.; Hulot, G.

2015-12-01

Constraining the evolution in the geomagnetic reversal frequency over hundreds of million years is not a trivial matter. Beyond the fact that there are long periods without reversals, known as superchrons, and periods with many reversals, the way the reversal frequency changes through time during reversing periods is still debated. A smooth evolution or a succession of stationary segments have both been suggested to account for the geomagnetic polarity time scale since the Middle-Late Jurassic. Sudden changes from a reversing mode to a non-reversing mode of the geodynamo may also well have happened, the switch between the two modes having then possibly been controlled by the thermal conditions at the core-mantle boundary. There is, nevertheless, a growing set of magnetostratigraphic data, which could help decipher a proper interpretation of the reversal history, in particular in the early Paleozoic and even during the Precambrian. Although yielding a fragmentary record, these data reveal the occurrence of both additional superchrons and periods characterized by extremely high, not to say extraordinary, magnetic reversal frequencies. In this talk, we will present a synthesis of these data, mainly obtained from Siberia, and discuss their implication for the magnetic reversal behavior over the past billion years.

Generation of TALE-Based Designer Epigenome Modifiers.

Science.gov (United States)

Nitsch, Sandra; Mussolino, Claudio

2018-01-01

Manipulation of gene expression can be facilitated by editing the genome or the epigenome. Precise genome editing is traditionally achieved by using designer nucleases which are generally exploited to eliminate a specific gene product. Upon the introduction of a site-specific DNA double-strand break (DSB) by the nuclease, endogenous DSB repair mechanisms are in turn harnessed to induce DNA sequence changes that can result in target gene inactivation. Minimal off-target effects can be obtained by endowing designer nucleases with the highly specific DNA-binding domain (DBD) derived from transcription activator-like effectors (TALEs). In contrast, epigenome editing allows gene expression control without inducing changes in the DNA sequence by specifically altering epigenetic marks, as histone tails modifications or DNA methylation patterns within promoter or enhancer regions. Importantly, this approach allows both up- and downregulation of the target gene expression, and the effect is generally reversible. TALE-based designer epigenome modifiers combine the high specificity of TALE-derived DBDs with the power of epigenetic modifier domains to induce fast and long-lasting changes in the epigenetic landscape of a target gene and control its expression. Here we provide a detailed description for the generation of TALE-based designer epigenome modifiers and of a suitable reporter cell line to easily monitor their activity.

Particle-in-cell simulations of Earth-like magnetosphere during a magnetic field reversal

Science.gov (United States)

Barbosa, M. V. G.; Alves, M. V.; Vieira, L. E. A.; Schmitz, R. G.

2017-12-01

The geologic record shows that hundreds of pole reversals have occurred throughout Earth's history. The mean interval between the poles reversals is roughly 200 to 300 thousand years and the last reversal occurred around 780 thousand years ago. Pole reversal is a slow process, during which the strength of the magnetic field decreases, become more complex, with the appearance of more than two poles for some time and then the field strength increases, changing polarity. Along the process, the magnetic field configuration changes, leaving the Earth-like planet vulnerable to the harmful effects of the Sun. Understanding what happens with the magnetosphere during these pole reversals is an open topic of investigation. Only recently PIC codes are used to modeling magnetospheres. Here we use the particle code iPIC3D [Markidis et al, Mathematics and Computers in Simulation, 2010] to simulate an Earth-like magnetosphere at three different times along the pole reversal process. The code was modified, so the Earth-like magnetic field is generated using an expansion in spherical harmonics with the Gauss coefficients given by a MHD simulation of the Earth's core [Glatzmaier et al, Nature, 1995; 1999; private communication to L.E.A.V.]. Simulations show the qualitative behavior of the magnetosphere, such as the current structures. Only the planet magnetic field was changed in the runs. The solar wind is the same for all runs. Preliminary results show the formation of the Chapman-Ferraro current in the front of the magnetosphere in all the cases. Run for the middle of the reversal process, the low intensity magnetic field and its asymmetrical configuration the current structure changes and the presence of multiple poles can be observed. In all simulations, a structure similar to the radiation belts was found. Simulations of more severe solar wind conditions are necessary to determine the real impact of the reversal in the magnetosphere.

Redox control of capillary filling speed in poly(ferrocenylsilane)-modified microfluidic channels for switchable delay valves

NARCIS (Netherlands)

Dos Ramos, Lionel; Lajoinie, Guillaume Pierre Rene; Kieviet, B.D.; de Beer, Sissi; Versluis, Michel; Hempenius, Mark A.; Vancso, Gyula J.

2016-01-01

We present a method to reversibly change the wetting of gold-coated microchannel walls, and, as a result, alter the capillary filling speed of water inside such modified microchannels. To this end, we employ the redox-response of surface-anchored poly(ferrocenylsilane) (PFS) films, which allows for

Transport in reversibly laser-modified YBa2Cu3O/sub 7-//sub x/ superconducting thin films

International Nuclear Information System (INIS)

Krchnavek, R.R.; Chan, S.; Rogers, C.T.; De Rosa, F.; Kelly, M.K.; Miceli, P.F.; Allen, S.J.

1989-01-01

A focused argon ion laser beam in a controlled ambient is used to modify the transport properties of superconducting YBa 2 Cu 3 O/sub 7-//sub x/ thin films. The laser-modified region shows a sharp transition temperature (T/sub c/≅76 K) that is reduced from the unmodified regions of the film (T/sub c/≅87 K). In situ monitoring of the room-temperature electrical resistance is used to control the laser processing and prevent formation of the semiconducting phase. The original properties of the superconducting film can be recovered by plasma oxidation indicating that the laser-induced phase is oxygen deficient

Effect of sequence and stereochemistry reversal on p53 peptide mimicry.

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Alessio Atzori

Full Text Available Peptidomimetics effective in modulating protein-protein interactions and resistant to proteolysis have potential in therapeutic applications. An appealing yet underperforming peptidomimetic strategy is to employ D-amino acids and reversed sequences to mimic a lead peptide conformation, either separately or as the combined retro-inverso peptide. In this work, we examine the conformations of inverse, reverse and retro-inverso peptides of p53(15-29 using implicit solvent molecular dynamics simulation and circular dichroism spectroscopy. In order to obtain converged ensembles for the peptides, we find enhanced sampling is required via the replica exchange molecular dynamics method. From these replica exchange simulations, the D-peptide analogues of p53(15-29 result in a predominantly left-handed helical conformation. When the parent sequence is reversed sequence as either the L-peptide and D-peptide, these peptides display a greater helical propensity, feature reflected by NMR and CD studies in TFE/water solvent. The simulations also indicate that, while approximately similar orientations of the side-chains are possible by the peptide analogues, their ability to mimic the parent peptide is severely compromised by backbone orientation (for D-amino acids and side-chain orientation (for reversed sequences. A retro-inverso peptide is disadvantaged as a mimic in both aspects, and further chemical modification is required to enable this concept to be used fruitfully in peptidomimetic design. The replica exchange molecular simulation approach adopted here, with its ability to provide detailed conformational insights into modified peptides, has potential as a tool to guide structure-based design of new improved peptidomimetics.

Reverse logistics - a framework

NARCIS (Netherlands)

M.P. de Brito (Marisa); R. Dekker (Rommert)

2002-01-01

textabstractIn this paper we define and compare Reverse Logistics definitions. We start by giving an understanding framework of Reverse Logistics: the why-what-how. By this means, we put in context the driving forces for Reverse Logistics, a typology of return reasons, a classification of

Tubal Ligation Reversal

Science.gov (United States)

... seal off the fallopian tubes, such as the Essure or Adiana systems, generally aren't reversible. Why ... electrocautery). Some types of sterilization, such as the Essure or Adiana systems, aren't considered reversible. Risks ...

A BPF-FBP tandem algorithm for image reconstruction in reverse helical cone-beam CT

International Nuclear Information System (INIS)

Cho, Seungryong; Xia, Dan; Pellizzari, Charles A.; Pan Xiaochuan

2010-01-01

Purpose: Reverse helical cone-beam computed tomography (CBCT) is a scanning configuration for potential applications in image-guided radiation therapy in which an accurate anatomic image of the patient is needed for image-guidance procedures. The authors previously developed an algorithm for image reconstruction from nontruncated data of an object that is completely within the reverse helix. The purpose of this work is to develop an image reconstruction approach for reverse helical CBCT of a long object that extends out of the reverse helix and therefore constitutes data truncation. Methods: The proposed approach comprises of two reconstruction steps. In the first step, a chord-based backprojection-filtration (BPF) algorithm reconstructs a volumetric image of an object from the original cone-beam data. Because there exists a chordless region in the middle of the reverse helix, the image obtained in the first step contains an unreconstructed central-gap region. In the second step, the gap region is reconstructed by use of a Pack-Noo-formula-based filteredbackprojection (FBP) algorithm from the modified cone-beam data obtained by subtracting from the original cone-beam data the reprojection of the image reconstructed in the first step. Results: The authors have performed numerical studies to validate the proposed approach in image reconstruction from reverse helical cone-beam data. The results confirm that the proposed approach can reconstruct accurate images of a long object without suffering from data-truncation artifacts or cone-angle artifacts. Conclusions: They developed and validated a BPF-FBP tandem algorithm to reconstruct images of a long object from reverse helical cone-beam data. The chord-based BPF algorithm was utilized for converting the long-object problem into a short-object problem. The proposed approach is applicable to other scanning configurations such as reduced circular sinusoidal trajectories.

Four Weeks of Off-Season Training Improves Peak Oxygen Consumption in Female Field Hockey Players

Directory of Open Access Journals (Sweden)

Lindsey T. Funch

2017-11-01

Full Text Available The purpose of the study was to examine the changes in peak oxygen consumption ( V ˙O2peak and running economy (RE following four-weeks of high intensity training and concurrent strength and conditioning during the off-season in collegiate female field hockey players. Fourteen female student-athletes (age 19.29 ± 0.91 years were divided into two training groups, matched from baseline V ˙O2peak: High Intensity Training (HITrun; n = 8 and High Intensity Interval Training (HIIT; n = 6. Participants completed 12 training sessions. HITrun consisted of 30 min of high-intensity running, while HIIT consisted of a series of whole-body high intensity Tabata-style intervals (75–85% of age predicted maximum heart rate for a total of four minutes. In addition to the interval training, the off-season training included six resistance training sessions, three team practices, and concluded with a team scrimmage. V ˙O2peak was measured pre- and post-training to determine the effectiveness of the training program. A two-way mixed (group × time ANOVA showed a main effect of time with a statistically significant difference in V ˙O2peak from pre- to post-testing, F(1, 12 = 12.657, p = 0.004, partial η2 = 0.041. Average (±SD V ˙O2peak increased from 44.64 ± 3.74 to 47.35 ± 3.16 mL·kg−1·min−1 for HIIT group and increased from 45.39 ± 2.80 to 48.22 ± 2.42 mL·kg−1·min−1 for HITrun group. Given the similar improvement in aerobic power, coaches and training staff may find the time saving element of HIIT-type conditioning programs attractive.

Alkyne- and 1,6-elimination- succinimidyl carbonate - terminated heterobifunctional poly(ethylene glycol) for reversible "Click" PEGylation.

Science.gov (United States)

Xie, Yumei; Duan, Shaofeng; Forrest, M Laird

2010-01-01

A new heterobifunctional (succinimidyl carbonate, SC)-activated poly(ethylene glycol) (PEG) with a reversible 1,6-elimination linker and a terminal alkyne for "click" chemistry was synthesized with high efficiency and low polydispersity. The α-alkyne-ω-hydroxyl PEG was first prepared using trimethylsilyl-2-propargyl alcohol as an initiator for ring-opening polymerization of ethylene oxide followed by mild deprotection with tetrabutylammonium fluoride. The hydroxy end was then modified with diglycolic anhydride to generate α-alkyne-ω-carboxylic acid PEG. The reversible 1, 6-elimination linker was introduced by conjugation of a hydroxymethyl phenol followed by activation with N,N'-disuccinimidyl carbonate to generate the heterobifunctional α-alkyne-ω-SC PEG. The terminal alkyne is available for "click" conjugation to azido ligands via 1,3-dipolar cycloaddition, and the succinimidyl carbonate will form a reversible conjugate to amines (e.g. in proteins) that can release the unaltered amine after base or enzyme catalyzed cleavage of the 1,6-linker.

Photolithography and Fluorescence Correlation Spectroscopy used to examine the rates of exchange in reverse micelle systems

Science.gov (United States)

Norris, Zach; Mawson, Cara; Johnson, Kyron; Kessler, Sarah; Rebecca, Anne; Wolf, Nathan; Lim, Michael; Nucci, Nathaniel

Reverse micelles are molecular complexes that encapsulate a nanoscale pool of water in a surfactant shell dissolved in non-polar solvent. These complexes have a wide range of applications, and in all cases, the degree to which reverse micelles (RM) exchange their contents is relevant for their use. Despite its importance, this aspect of RM behavior is poorly understood. Photolithography is employed here to create micro and nano scale fluidic systems in which mixing rates can be precisely measured using fluorescence correlation spectroscopy (FCS). Micro-channel patterns are etched using reactive ion etching process into a layer of silicon dioxide on crystalline silicon substrates. Solutions containing mixtures of reverse micelles, proteins, and fluorophores are placed into reservoirs in the patterns, while diffusion and exchange between RMs is monitored using a FCS system built from a modified confocal Raman spectrometer. Using this approach, the diffusion and exchange rates for RM systems are measured as a function of the components of the RM mixture. Funding provided by Rowan University.

Temperature Scanning Stress Relaxation of an Autonomous Self-Healing Elastomer Containing Non-Covalent Reversible Network Junctions

Directory of Open Access Journals (Sweden)

Amit Das

2018-01-01

Full Text Available In this work, we report about the mechanical relaxation characteristics of an intrinsically self-healable imidazole modified commercial rubber. This kind of self-healing rubber was prepared by melt mixing of 1-butyl imidazole with bromo-butyl rubber (bromine modified isoprene-isobutylene copolymer, BIIR. By this melt mixing process, the reactive allylic bromine of bromo-butyl rubber was converted into imidazole bromide salt. The resulting development of an ionic character to the polymer backbone leads to an ionic association of the groups which ultimately results to the formation of a network structure of the rubber chains. The modified BIIR thus behaves like a robust crosslinked rubber and shows unusual self-healing properties. The non-covalent reversible network has been studied in detail with respect to stress relaxation experiments, scanning electron microscopic and X-ray scattering.

49 CFR 230.89 - Reverse gear.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse gear...

The Effect of Teaching Games of Understanding as a Coaching Instruction had on Adjust, Cover and Heart Rate among Malaysian and Indian Junior Hockey Players.

Science.gov (United States)

Nathan, Sanmuga

2017-06-20

The field hockey coaching process across both Malaysia and India favours a traditional, coach-centred approach of mastering technical skills in terms of game play parameters, fitness, intensity, and load training, whereas a tactical- and player-centred pedagogical approach still takes a backseat. On the other hand, the Teaching Games for Understanding (TGfU) model offers tactical-cognitive instruction and is gaining international recognition for its ability to produce intelligent players via a problem-solving approach in game play. Therefore, the purpose of this quasi-experimental study was to investigate the effect of TGfU compared to skill mastery instruction, termed as Skill Drill Technical (SDT), among Malaysian and Indian elite junior hockey players in term of the game play attributes of adjust and cover in 5 vs. 5 small-sided game play and game play intensity via heart rate (HR) at different points of game play. A total of n = 60 players with an average age of 15 ± 1.03 was selected via simple random sampling from both countries involved in this study and assigned equally to groups, with 15 per group for TGfU and for SDT across Malaysia and India. Gathered data were analysed using the ANOVA and ANCOVA techniques. Findings indicated that there were no significant differences for adjust in 5 vs. 5 game play between TGfU and SDT across Malaysia and India after the intervention. For cover, there was significant improvement for Malaysian players using the TGfU model compared to SDT. In contrast, there was no significant difference between these two models among the Indian players after the intervention. There was significant difference between these two models in terms of warm-up HR across the two countries, and HR was higher via TGfU. For HR immediately after the 5 vs. 5 game play intervention and HR after three minutes' recovery, Indian players with TGfU recorded a higher and significant difference compared to SDT. However, findings indicated no significant

Mass carbon monoxide poisoning at an ice-hockey game: initial approach and long-term follow-up.

Science.gov (United States)

Mortelmans, Luc J M; Populaire, Jacques; Desruelles, Didier; Sabbe, Marc B

2013-12-01

A mass carbon monoxide (CO) intoxication during an ice-hockey game is described. Two hundred and thirty-five patients were seen in different hospitals, 88 of them the same night at the nearby emergency department. To evaluate long-term implications and to identify relevant indicators, a follow-up study was organized 1 year after the incident. Apart from the file data from the emergency departments, a 1-year follow-up mailing was sent to all patients. One hundred and ninety-one patients returned their questionnaire (86%). The mean age of the patients was 28 years, with 61% men. The mean carboxyhaemoglobin (COHb) was 9.9%. COHb levels were significantly higher for individuals on the ice (referee, players and maintenance personnel). There was a significant relationship with the initial presence of dizziness, fatigue and the COHb level. Headache, abdominal pain, nausea and vomiting were not significantly related to the COHb levels. The relationship between symptoms and CO level, however, should be interpreted with caution as there was a wide range between exposure and blood tests. 5.2% of patients had residual complaints, all including headache, with a significant higher incidence with high COHb levels. Only two patients had an abnormal neurological control (one slightly disturbed electroencephalography and one persistent encephalopathic complaint). Work incapacity was also significantly related to COHb levels. CO mass poisonings remain a risk in indoor sporting events. Although it causes an acute mass casualty incident, it is limited in time and delayed problems are scarce. Symptomatology is a poor tool for triage. The best prevention is the use of nonmineral energy sources such as for example electricity.

Reversible Communicating Processes

Directory of Open Access Journals (Sweden)

Geoffrey Brown

2016-02-01

Full Text Available Reversible distributed programs have the ability to abort unproductive computation paths and backtrack, while unwinding communication that occurred in the aborted paths. While it is natural to assume that reversibility implies full state recovery (as with traditional roll-back recovery protocols, an interesting alternative is to separate backtracking from local state recovery. For example, such a model could be used to create complex transactions out of nested compensable transactions where a programmer-supplied compensation defines the work required to "unwind" a transaction. Reversible distributed computing has received considerable theoretical attention, but little reduction to practice; the few published implementations of languages supporting reversibility depend upon a high degree of central control. The objective of this paper is to demonstrate that a practical reversible distributed language can be efficiently implemented in a fully distributed manner. We discuss such a language, supporting CSP-style synchronous communication, embedded in Scala. While this language provided the motivation for the work described in this paper, our focus is upon the distributed implementation. In particular, we demonstrate that a "high-level" semantic model can be implemented using a simple point-to-point protocol.

Return to play after an initial or recurrent concussion in a prospective study of physician-observed junior ice hockey concussions: implications for return to play after a concussion.

Science.gov (United States)

Echlin, Paul Sean; Tator, Charles H; Cusimano, Michael D; Cantu, Robert C; Taunton, Jack E; Upshur, Ross E G; Czarnota, Michael; Hall, Craig R; Johnson, Andrew M; Forwell, Lorie A; Driediger, Molly; Skopelja, Elaine N

2010-11-01

The authors investigated return-to-play duration for initial and recurrent concussion in the same season in 2 teams of junior (16-21-year-old) ice hockey players during a regular season. The authors conducted a prospective cohort study during 1 junior regular season (2009-2010) of 67 male fourth-tier ice hockey players (mean age 18.2 ± 1.2 years [SD], range 16-21 years) from 2 teams. Prior to the start of the season, every player underwent baseline assessments that were determined using the Sideline Concussion Assessment Tool 2 (SCAT2) and the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT). The study protocol also required players who entered the study during the season to complete a baseline SCAT2 and ImPACT. If the protocol was not followed, the postinjury test results of a player without true baseline test results were compared with previously established age- and sex-matched group normative levels. Each game was directly observed by a physician and at least 1 neutral nonphysician observer. Players suspected of suffering a concussion were evaluated by the physician during the game. If a concussion was diagnosed, the player underwent clinical evaluation at the physician's office within 24 hours. The return-to-play decision was based on clinical evaluation guided by the Zurich return-to-play protocol (contained in the consensus statement of international expert opinion at the 3rd International Conference on Concussion in Sport held in Zurich, November 2008). This clinical evaluation and return-to-play protocol was augmented by the 2 tests (SCAT2 and ImPACT) also recommended by the Zurich consensus statement, for which baseline values had been obtained. Seventeen players sustained a physician-observed or self-reported, physician-diagnosed concussion during a physician-observed ice hockey game. The mean clinical return-to-play duration (in 15 cases) was 12.8 ± 7.02 days (median 10 days, range 7-29 days); the mean number of physician office visits

Electrochemical investigations of Pu(IV)/Pu(III) redox reaction using graphene modified glassy carbon electrodes and a comparison to the performance of SWCNTs modified glassy carbon electrodes

International Nuclear Information System (INIS)

Gupta, Ruma; Gamare, Jayashree; Sharma, Manoj K.; Kamat, J.V.

2016-01-01

Highlights: • First report of aqueous electrochemistry of Plutonium on graphene modified electrode. • Graphene is best electrocatalytic material for Pu(IV)/Pu(III) redox couple among the reported modifiers viz. reduced graphene oxide (rGO) and SWCNT’s. • The electrochemical reversibility of Pu(IV)/Pu(III) redox couple improves significantly on graphene modified electrode compared to previously reported rGO & SWCNTs modified electrodes • Donnan interaction between plutonium species and graphene surface offers a possibility for designing a highly sensitive sensor for plutonium • Graphene modified electrode shows higher sensitivity for the determination of plutonium compared to glassy carbon and single walled carbon nanotube modified electrode - Abstract: The work reported in this paper demonstrates for the first time that graphene modified glassy carbon electrode (Gr/GC) show remarkable electrocatalysis towards Pu(IV)/Pu(III) redox reaction and the results were compared with that of single-walled carbon nanotubes modified GC (SWCNTs/GC) and glassy carbon (GC) electrodes. Graphene catalyzes the exchange of current of the Pu(IV)/Pu(III) couple by reducing both the anodic and cathodic overpotentials. The Gr/GC electrode shows higher peak currents (i p ) and smaller peak potential separation (ΔE p ) values than the SWCNTs/GC and GC electrodes. The heterogeneous electron transfer rate constants (k s ), charge transfer coefficients (α) and the diffusion coefficients (D) involved in the electrocatalytic redox reaction were determined. Our observations show that graphene is best electrocatalytic material among both the SWCNTs and GC to study Pu(IV)/Pu(III) redox reaction.

Proliferation of Genetically Modified Human Cells on Electrospun Nanofiber Scaffolds

Directory of Open Access Journals (Sweden)

Mandula Borjigin

2012-01-01

Full Text Available Gene editing is a process by which single base mutations can be corrected, in the context of the chromosome, using single-stranded oligodeoxynucleotides (ssODNs. The survival and proliferation of the corrected cells bearing modified genes, however, are impeded by a phenomenon known as reduced proliferation phenotype (RPP; this is a barrier to practical implementation. To overcome the RPP problem, we utilized nanofiber scaffolds as templates on which modified cells were allowed to recover, grow, and expand after gene editing. Here, we present evidence that some HCT116-19, bearing an integrated, mutated enhanced green fluorescent protein (eGFP gene and corrected by gene editing, proliferate on polylysine or fibronectin-coated polycaprolactone (PCL nanofiber scaffolds. In contrast, no cells from the same reaction protocol plated on both regular dish surfaces and polylysine (or fibronectin-coated dish surfaces proliferate. Therefore, growing genetically modified (edited cells on electrospun nanofiber scaffolds promotes the reversal of the RPP and increases the potential of gene editing as an ex vivo gene therapy application.

Functional interface of polymer modified graphite anode

Energy Technology Data Exchange (ETDEWEB)

Komaba, S.; Ozeki, T.; Okushi, K. [Department of Applied Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601 (Japan)

2009-04-01

Graphite electrodes were modified by polyacrylic acid (PAA), polymethacrylic acid (PMA), and polyvinyl alcohol (PVA). Their electrochemical properties were examined in 1 mol dm{sup -3} LiClO{sub 4} ethylene carbonate:dimethyl carbonate (EC:DMC) and propylene carbonate (PC) solutions as an anode of lithium ion batteries. Generally, lithium ions hardly intercalate into graphite in the PC electrolyte due to a decomposition of the PC electrolyte at ca. 0.8 V vs. Li/Li{sup +}, and it results in the exfoliation of the graphene layers. However, the modified graphite electrodes with PAA, PMA, and PVA demonstrated the stable charge-discharge performance due to the reversible lithium intercalation not only in the EC:DMC but also in the PC electrolytes since the electrolyte decomposition and co-intercalation of solvent were successfully suppressed by the polymer modification. It is thought that these improvements were attributed to the interfacial function of the polymer layer on the graphite which interacted with the solvated lithium ions at the electrode interface. (author)

Novel Fouling-Reducing Coatings for Ultrafiltration, Nanofiltration, and Reverse Osmosis Membranes

Energy Technology Data Exchange (ETDEWEB)

Benny Freeman

2008-08-31

Polymeric membranes could potentially be the most flexible and viable long-term strategy for treatment of produced water from oil and gas production. However, widespread use of membranes, including reverse osmosis (RO) membranes, for produced water purification is hindered due to fouling caused by the impurities present in the water. Fouling of RO membranes is likely caused by surface properties including roughness, hydrophilicity, and charge, so surface modification is the most widely considered approach to improve the fouling properties of current RO membranes. This project focuses on two main approaches to surface modification: coating and grafting. Hydrophilic coating and grafting materials based on poly(ethylene glycol) (PEG) are applied to commercial RO membranes manufactured by Dow FilmTec and GE. Crossflow filtration experiments are used to determine the fouling resistance of modified membranes, and compare their performance to that of unmodified commercial RO membranes. Grafting and coating are shown to be two alternative methods of producing modified membranes with improved fouling resistance.

Modeling of uranium alloy response in plane impact and reverse ballistic experiments

International Nuclear Information System (INIS)

Herrmann, B.; Landau, A.; Shvarts, D.; Favorsky, V.; Zaretsky, E.

2002-01-01

The dynamic behavior of a solution heat-treated, water-quenched and aged U-0.75wt%Ti alloy was studied in planar (disk-on-disk) and reverse ballistic (disk-on-rod) impact experiments performed with a 25 mm light-gas gun. The impact velocity ranged from 100 to 500 m/sec. The impacted samples were softly recovered for further metallographic examination. The VISAR records of the sample free surface velocity, obtained in planar impact experiments, were simulated with 1-D hydrocode for calibrating the parameters of modified Steinberg-Cochran-Guinan (SCG) constitutive equation of the alloy. The same SCG equation was employed in 2-D AUTODYN simulation of the alloy response in the reverse ballistic experiments, with VISAR monitoring of the lateral sample surface velocity. Varying the parameters of the strain-dependent failure model allows relating the features of the recorded velocity profiles with the results of the examination of the damaged samples

The double-layer of penetrable ions: an alternative route to charge reversal.

Science.gov (United States)

Frydel, Derek; Levin, Yan

2013-05-07

We investigate a double-layer of penetrable ions near a charged wall. We find a new mechanism for charge reversal that occurs in the weak-coupling regime and, accordingly, the system is suitable for the mean-field analysis. The penetrability is achieved by smearing-out the ionic charge inside a sphere, so there is no need to introduce non-electrostatic forces and the system in the low coupling limit can be described by a modified version of the Poisson-Boltzmann equation. The predictions of the theory are compared with the Monte Carlo simulations.

Asymmetric polivinylidenfluoride (PVDF) radiation grafted membranes: Preparation and performance in reverse osmosis application

International Nuclear Information System (INIS)

Vigo, F.; Capannelli, G.; Uliana, C.; Munari, S.

1981-01-01

A new type of reverse osmosis membrane has been synthesized. Membranes were prepared starting from asymmetric PVDF films, obtained by the casting and gelation technique and modified by radiochemical grafting and sulphonation. These membranes were tested in an RO laboratory plant and their performances were determined as a function of preparative parameters. The influences of evaporation time and temperature grafting and solvents were investigated. These membranes exhibit permeabilities as high as 2000 1/m 2 d and sodium chloride rejections up to 70%. (orig.)

Effect of dimethyl sulfoxide (DMSO) on radiation-induced heteroallelic reversion in diploid yeast

International Nuclear Information System (INIS)

Singh, D.R.; Mahajan, J.M.; Krishnan, D.

1976-01-01

Dimethyl sulfoxide has cryoprotective and radioprotective properties. It is also an efficient scavenger of radicals produced by radiolysis of water. Gamma-induced reversion of diploid yeast in the presence of this chemical during irradiation have been studied. The dose-modifying factor was in the same range as for survival. When the yeast was irradiated in the frozen state, the observed protection by DMSO disappeared. The results are discussed in terms of direct and indirect actions of radiations and the radical-scavenging ability of this chemical

Muscular activation during reverse and non-reverse chewing cycles in unilateral posterior crossbite.

Science.gov (United States)

Piancino, Maria Grazia; Farina, Dario; Talpone, Francesca; Merlo, Andrea; Bracco, Pietro

2009-04-01

The aim of this study was to characterize the kinematics and masseter muscle activation in unilateral posterior crossbite. Eighty-two children (8.6 +/- 1.3 yr of age) with unilateral posterior crossbite and 12 children (8.9 +/- 0.6 yr of age) with normal occlusion were selected for the study. Electromyography (EMG) and kinematics were concurrently recorded during mastication of a soft bolus and a hard bolus. The percentage of reverse cycles in the group of patients was 59.0 +/- 33.1% (soft bolus) and 69.7 +/- 29.7% (hard bolus) when chewing on the crossbite side. When chewing on the non-affected side, the number of reverse cycles was 16.7 +/- 24.5% (soft bolus) and 16.7 +/- 22.3% (hard bolus). The reverse cycles on the crossbite side were narrower with respect to the cycles on the non-affected side. Although both types of cycles in patients resulted in lower EMG activity of the masseter of the crossbite side than of the contralateral masseter, the activity of the non-affected side was larger for reverse than for non-reverse cycles. It was concluded that when chewing on the crossbite side, the masseter activity is reduced on the mastication side (crossbite) and is unaltered (non-reverse cycles) or increased (reverse) on the non-affected side.

Gaze characteristics of elite and near-elite athletes in ice hockey defensive tactics.

Science.gov (United States)

Martell, Stephen G; Vickers, Joan N

2004-04-01

Traditional visual search experiments, where the researcher pre-selects video-based scenes for the participant to respond to, shows that elite players make more efficient decisions than non-elites, but disagree on how they temporally regulate their gaze. Using the vision-in-action [J.N. Vickers, J. Exp. Psychol.: Human Percept. Perform. 22 (1996) 342] approach, we tested whether the significant gaze that differentiates elite and non-elite athletes occurred either: early in the task and was of more rapid duration [A.M. Williams et al., Res. Quart. Exer. Sport 65 (1994) 127; A.M. Williams and K. Davids, Res. Quart. Exer. Sport 69 (1998) 111], or late in the task and was of longer duration [W. Helsen, J.M. Pauwels, A cognitive approach to visual search in sport, in: D. Brogan, K. Carr (Eds.), Visual Search, vol. II, Taylor and Francis, London, 1992], or whether a more complex gaze control strategy was used that consisted of both early and rapid fixations followed by a late fixation of long duration prior to the final execution. We tested this using a live defensive zone task in ice hockey. Results indicated that athletes temporally regulated their gaze using two different gaze control strategies. First, fixation/tracking (F/T) gaze early in the trial were significantly shorter than the final F/T and confirmed that the elite group fixated the tactical locations more rapidly than the non-elite on successful plays. And secondly, the final F/T prior to critical movement initiation (i.e. F/T-1) was significantly longer for both groups, averaging 30% of the final part of the phase and occurred as the athletes isolated a single object or location to end the play. The results imply that expertise in defensive tactics is defined by a cascade of F/T, which began with the athletes fixating or tracking specific locations for short durations at the beginning of the play, and concluded with a final gaze of long duration to a relatively stable target at the end. The results are

The Causes of Preference Reversal.

OpenAIRE

Tversky, Amos; Slovic, Paul; Kahneman, Daniel

1990-01-01

Observed preference reversal cannot be adequately explained by violations of independence, the reduction axiom, or transitivity. The primary cause of preference reversal is the failure of procedure invariance, especially the overpricing of low-probability, high-payoff bets. This result violates regret theory and generalized (nonindependent) utility models. Preference reversal and a new reversal involving time preferences are explained by scale compatibility, which implies that payoffs are wei...

Evaluation of the robustness of the preprocessing technique improving reversible compressibility of CT images: Tested on various CT examinations

Energy Technology Data Exchange (ETDEWEB)

Jeon, Chang Ho; Kim, Bohyoung; Gu, Bon Seung; Lee, Jong Min [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707 (Korea, Republic of); Kim, Kil Joong [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea and Department of Radiation Applied Life Science, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 110-799 (Korea, Republic of); Lee, Kyoung Ho [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea and Institute of Radiation Medicine, Seoul National University Medical Research Center, and Clinical Research Institute, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744 (Korea, Republic of); Kim, Tae Ki [Medical Information Center, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707 (Korea, Republic of)

2013-10-15

Purpose: To modify the preprocessing technique, which was previously proposed, improving compressibility of computed tomography (CT) images to cover the diversity of three dimensional configurations of different body parts and to evaluate the robustness of the technique in terms of segmentation correctness and increase in reversible compression ratio (CR) for various CT examinations.Methods: This study had institutional review board approval with waiver of informed patient consent. A preprocessing technique was previously proposed to improve the compressibility of CT images by replacing pixel values outside the body region with a constant value resulting in maximizing data redundancy. Since the technique was developed aiming at only chest CT images, the authors modified the segmentation method to cover the diversity of three dimensional configurations of different body parts. The modified version was evaluated as follows. In randomly selected 368 CT examinations (352 787 images), each image was preprocessed by using the modified preprocessing technique. Radiologists visually confirmed whether the segmented region covers the body region or not. The images with and without the preprocessing were reversibly compressed using Joint Photographic Experts Group (JPEG), JPEG2000 two-dimensional (2D), and JPEG2000 three-dimensional (3D) compressions. The percentage increase in CR per examination (CR{sub I}) was measured.Results: The rate of correct segmentation was 100.0% (95% CI: 99.9%, 100.0%) for all the examinations. The median of CR{sub I} were 26.1% (95% CI: 24.9%, 27.1%), 40.2% (38.5%, 41.1%), and 34.5% (32.7%, 36.2%) in JPEG, JPEG2000 2D, and JPEG2000 3D, respectively.Conclusions: In various CT examinations, the modified preprocessing technique can increase in the CR by 25% or more without concerning about degradation of diagnostic information.

Design and Performance of a Pinned Photodiode CMOS Image Sensor Using Reverse Substrate Bias.

Science.gov (United States)

Stefanov, Konstantin D; Clarke, Andrew S; Ivory, James; Holland, Andrew D

2018-01-03

A new pinned photodiode (PPD) CMOS image sensor with reverse biased p-type substrate has been developed and characterized. The sensor uses traditional PPDs with one additional deep implantation step to suppress the parasitic reverse currents, and can be fully depleted. The first prototypes have been manufactured on an 18 µm thick, 1000 Ω·cm epitaxial silicon wafers using 180 nm PPD image sensor process. Both front-side illuminated (FSI) and back-side illuminated (BSI) devices were manufactured in collaboration with Teledyne e2v. The characterization results from a number of arrays of 10 µm and 5.4 µm PPD pixels, with different shape, the size and the depth of the new implant are in good agreement with device simulations. The new pixels could be reverse-biased without parasitic leakage currents well beyond full depletion, and demonstrate nearly identical optical response to the reference non-modified pixels. The observed excessive charge sharing in some pixel variants is shown to not be a limiting factor in operation. This development promises to realize monolithic PPD CIS with large depleted thickness and correspondingly high quantum efficiency at near-infrared and soft X-ray wavelengths.

Electrochemical behavior of cysteine at a CuGeO3 nanowires modified glassy carbon electrode

International Nuclear Information System (INIS)

Dong Yongping; Pei Lizhai; Chu Xiangfeng; Zhang Wangbing; Zhang Qianfeng

2010-01-01

A CuGeO 3 nanowire modified glassy carbon electrode was fabricated and characterized by scanning electron microscopy. The results of electrochemical impedance spectroscopy reveal that electron transfer through nanowire film is facile compared with that of bare glassy carbon electrode. The modified electrode exhibited a novel electrocatalytic behavior to the electrochemical reactions of L-cysteine in neutral solution, which was not reported previously. Two pairs of semi-reversible electrochemical peaks were observed and assigned to the processes of oxidation/reduction and adsorption/desorption of cysteine at the modified electrode, respectively. The electrochemical response of cysteine is poor in alkaline condition and is enhanced greatly in acidic solution, suggesting that hydrogen ions participate in the electrochemical oxidation process of cysteine. The intensities of two anodic peaks varied linearly with the concentration of cysteine in the range of 1 x 10 -6 to 1 x 10 -3 mol L -1 , which make it possible to sensitive detection of cysteine with the CuGeO 3 nanowire modified electrode. Furthermore, the modified electrode exhibited good reproducibility and stability.

Multilayer Choline Phosphate Molecule Modified Surface with Enhanced Cell Adhesion but Resistance to Protein Adsorption.

Science.gov (United States)

Chen, Xingyu; Yang, Ming; Liu, Botao; Li, Zhiqiang; Tan, Hong; Li, Jianshu

2017-08-22

Choline phosphate (CP), which is a new zwitterionic molecule, and has the reverse order of phosphate choline (PC) and could bind to the cell membrane though the unique CP-PC interaction. Here we modified a glass surface with multilayer CP molecules using surface-initiated atom-transfer radical polymerization (SI-ATRP) and the ring-opening method. Polymeric brushes of (dimethylamino)ethyl methacrylate (DMAEMA) were synthesized by SI-ATRP from the glass surface. Then the grafted PDMAEMA brushes were used to introduce CP groups to fabricate the multilayer CP molecule modified surface. The protein adsorption experiment and cell culture test were used to evaluate the biocompatibility of the modified surfaces by using human umbilical veinendothelial cells (HUVECs). The protein adsorption results demonstrated that the multilayer CP molecule decorated surface could prevent the adsorption of fibrinogen and serum protein. The adhesion and proliferation of cells were improved significantly on the multilayer CP molecule modified surface. Therefore, the biocompatibility of the material surface could be improved by the modified multilayer CP molecule, which exhibits great potential for biomedical applications, e.g., scaffolds in tissue engineering.

Rešerše diplomových a závěrečných prací z ledního hokeje za rok 2000 až 2008

OpenAIRE

Sirotek, Jaroslav

2008-01-01

Thesis name: research ofthesis and final thesis concerning ice hockey in a year 2000 unti12008 Thesis aims: to research accesible thesis and final thesis with focus on ice hockey from the univerzity library of FTVS UK in Prague. Method: Data will be expressed in percentages and arranged based on frequency ofice hockey topics. Results: will be maped and divided according to themes ofthesis and final thesis accessible at the FTVS UK library. Keywords: thesis, research, ice hockey. 4

Nitrile group as infrared probe for the characterization of the conformation of bovine serum albumin solubilized in reverse micelles.

Science.gov (United States)

Xue, Luyan; Zou, Feixue; Zhao, Yin; Huang, Xirong; Qu, Yinbo

2012-11-01

Infrared spectroscopy is a powerful technique for structure characterization. For a protein hosted in a reversed micellar medium, the spectral features of the protein are always interfered by the IR absorption bands of the medium in addition to the congestion in their IR spectra. Fortunately, there is a transparent window in the 2500-2200 cm(-1) region. Incorporation of a vibrational probe with IR absorption frequencies in this region into proteins represents a promising strategy for the study of the conformation of a protein in a reverse micelle. In the present work, we incorporated 4-cyanobenzyl group (CN) into bovine serum albumin (BSA) via cysteine alkylation reactions under mild conditions. Circular dichroism spectroscopy showed that the CN modified BSA (CNBSA) could retain its conformation. When CNBSA was hosted in AOT reverse micelle, it was found that the nitrile group on BSA was sensitive to the conformational change of BSA induced by urea as an additive in the reverse micelle. The peak splitting of nitrile group was also observed when the size of AOT reverse micelle and the concentration of an electrolyte were varied. Obviously, the shift of the IR absorption peak and/or peak splitting of nitrile group on BSA are correlated with the change of BSA conformation in AOT reverse micelle. So we conclude that the nitrile infrared probe can be used to study protein conformation in a reverse micelle. Copyright © 2012 Elsevier B.V. All rights reserved.

Clofibrate prevents and reverses the hemodynamic manifestations of hyperthyroidism in rats.

Science.gov (United States)

Rodríguez-Gómez, Isabel; Cruz, Antonio; Moreno, Juan Manuel; Soler, Agatángelo; Osuna, Antonio; Vargas, Félix

2008-03-01

This study analyzed the effects of the chronic administration of clofibrate, a peroxisome proliferator-activated receptor-alpha (PPARalpha) agonist, on the development and established hemodynamic, morphologic, metabolic, and renal manifestations of hyperthyroidism in rats. The prevention study used four groups of male Wistar rats: control, clofibrate (240 mg/kg/day by gavage), T(4)(75 microg thyroxine/rat/day s.c.), and T(4)+clofibrate. All treatments were maintained for 3 weeks. Body weight (BW), tail systolic blood pressure (SBP), and heart rate (HR) were recorded weekly. Finally, temperature, SBP, pulse pressure (PP) and HR were recorded in conscious rats, and morphologic, metabolic, plasma, and renal variables were measured. The reversion study used two groups of rats, T(4)(treated for 6 weeks) and T(4)+clofibrate, measuring their hemodynamic variables and temperature for 3 weeks. T(4) increased BP, HR, PP, and temperature when compared with control rats. Clofibrate prevented and reversed the increase in SBP, HR, PP, and temperature produced by T(4) administration, reduced plasma thyroid hormone levels, and increased plasma thyroid-stimulating hormone values and phenol-uridine diphosphate-glucuronosyl-transferase (UGT) activity. However, clofibrate did not modify the cardiac or renal hypertrophy, polyphagia, polydipsia, or proteinuria of hyperthyroid rats. In normal rats, clofibrate treatment did not significantly change thyroid hormone levels, phenol-UGT activity, or any hemodynamic, morphologic, or renal variables. Chronic clofibrate treatment suppressed the hemodynamic manifestations and increased temperature of hyperthyroidism, an effect that can be produced by direct antithyroid effects. However, clofibrate administration did not modify the morphologic, metabolic, or renal alterations of hyperthyroid rats, indicating specificity in the antithyroid actions of clofibrate.

Reverse logistics policy – differences between conservative and innovative reverse logistics management

Directory of Open Access Journals (Sweden)

Alena Klapalová

2013-01-01

Full Text Available One of the of the key barriers that hampers effective and efficient management of reverse flows detected within a number of empirical surveys and case studies focused on reverse logistics and/or return management is business (organisational policy, specifically lack of policy, deficiency in existing policy or inferior policy. Despite this fact, there is a gap in literature which would show some evidence from practice that innovative reverse logistics policy both can pay off and is associated with certain aspects of reverse logistics management. Such proof can have several implications. It can support the call for better understanding and more research of the linkages of reverse logistics with other corporate functions, promote the acceptation of strategic character of reverse logistics and stress the role of RL policy within the rest of overall corporate management.The aim of this paper is to contribute and to enrich the existing body of knowledge concerning the above-mentioned gap through presentation of survey results that was realized in 2012 among managers of 244 Czech firms. The results demonstrate the statistically significant association between the innovativeness of RL policy and profitability of firms, quality of RL planning, perception of RL importance, level of RL knowledge and perception of product innovation importance for firms’ competitiveness and frequency of product innovation. They also reveal statistically significant differences between firms with conservative and innovative RL policy and the perceived existence of some barriers to manage RL.

Geomagnetic Field During a Reversal

Science.gov (United States)

Heirtzler, J. R.

2003-01-01

It has frequently been suggested that only the geomagnetic dipole, rather than higher order poles, reverse during a geomagnetic field reversal. Under this assumption the geomagnetic field strength has been calculated for the surface of the Earth for various steps of the reversal process. Even without an eminent a reversal of the field, extrapolation of the present secular change (although problematic) shows that the field strength may become zero in some geographic areas within a few hundred years.

Impact of drag reducing polymers on the onset of instability in a pipe with reverse flow

Science.gov (United States)

Shashank, H. J.; Sreenivas, K. R.

2014-11-01

The objective of this study is to understand the mechanism by which drag reducing polymer (DRP) additives modify turbulent flow, so as to reduce turbulent drag. Reverse flow in a pipe occurs when the fluid close to the wall moves in an opposite direction to that of the core fluid. Reverse flow is established by using a piston-cylinder mechanism, the programmed motion of which imparts a known impulse to the fluid. When the piston is stopped at the end of the stroke, fluid inertia makes the core of the flow to continue in the same direction. In order to conserve mass, reverse flow is established close to the wall. An inflection point is thus formed, leading to flow instability above a critical Reynolds number. Dye and streak flow visualization experiments are performed to highlight the impact of DRP additives (polyethylene oxide, PEO, dissolved in water). The time of onset of the instability and the wavelength of the observed instability are studied in systems with and without DRP additives. This study will provide further insight into the phenomenon of turbulent polymer drag reduction.

Expanding the Lotus japonicus reverse genetics toolbox – Development of LORE1 retrotransposon mutagenesis and artificial miRNA-mediated silencing

DEFF Research Database (Denmark)

Urbanski, Dorian Fabian

2011-01-01

. The protocols developed in the current project are now the cornerstone of a new LORE1 reverse genetics resource characterized by efficient mutant line generation and accurate mutation annotation. In parallel, artificial microRNAs (amiRNAs) were designed based on both Arabidopsis and Lotus backbones......Currently, the most common approach to studying Lotus japonicus (Lotus) genes is forward genetics in which a gene responsible for the studied phenotype is identified through map-based cloning. In reverse genetics, the activity of a gene of interest is modified to discover its mutant phenotype....... Prior to this project, the only reverse genetics resource available in Lotus was the TILLING resource. In an attempt to advance Lotus genetic studies, present study is focused on the development of two additional resources. The first is based on insertional mutagenesis and the second on harnessing post...

Supercritical fluid reverse micelle separation

Science.gov (United States)

Fulton, J.L.; Smith, R.D.

1993-11-30

A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W[sub o] that determines the maximum size of the reverse micelles. The maximum ratio W[sub o] of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions. 27 figures.

Quercetin-glutamic acid conjugate with a non-hydrolysable linker; a novel scaffold for multidrug resistance reversal agents through inhibition of P-glycoprotein.

Science.gov (United States)

Kim, Mi Kyoung; Kim, Yunyoung; Choo, Hyunah; Chong, Youhoon

2017-02-01

Previously, we have reported remarkable effect of a quercetin-glutamic acid conjugate to reverse multidrug resistance (MDR) of cancer cells to a broad spectrum of anticancer agents through inhibition of P-glycoprotein (Pgp)-mediated drug efflux. Due to the hydrolysable nature, MDR-reversal activity of the quercetin conjugate was attributed to its hydrolysis product, quercetin. However, several lines of evidence demonstrated that the intact quercetin-glutamic acid conjugate has stronger MDR-reversal activity than quercetin. In order to evaluate this hypothesis and to identify a novel scaffold for MDR-reversal agents, we prepared quercetin conjugates with a glutamic acid attached at the 7-O position via a non-hydrolysable linker. Pgp inhibition assay, Pgp ATPase assay, and MDR-reversal activity assay were performed, and the non-hydrolysable quercetin conjugates showed significantly higher activities compared with those of quercetin. Unfortunately, the quercetin conjugates were not as effective as verapamil in Pgp-inhibition and thereby reversing MDR, but it is worth to note that the structurally modified quercetin conjugates with a non-cleavable linker showed significantly improved MDR-reversal activity compared with quercetin. Taken together, the quercetin conjugates with appropriate structural modifications were shown to have a potential to serve as a scaffold for the design of novel MDR-reversal agents. Copyright © 2016 Elsevier Ltd. All rights reserved.

r-Universal reversible logic gates

International Nuclear Information System (INIS)

Vos, A de; Storme, L

2004-01-01

Reversible logic plays a fundamental role both in ultra-low power electronics and in quantum computing. It is therefore important to know which reversible logic gates can be used as building block for the reversible implementation of an arbitrary boolean function and which cannot

Quantum reverse hypercontractivity

Energy Technology Data Exchange (ETDEWEB)

Cubitt, Toby [Department of Computer Science, University College London, London, United Kingdom and Centre for Quantum Information and Foundations, DAMTP, University of Cambridge, Cambridge (United Kingdom); Kastoryano, Michael [NBIA, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Montanaro, Ashley [School of Mathematics, University of Bristol, Bristol (United Kingdom); Temme, Kristan [Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125 (United States)

2015-10-15

We develop reverse versions of hypercontractive inequalities for quantum channels. By generalizing classical techniques, we prove a reverse hypercontractive inequality for tensor products of qubit depolarizing channels. We apply this to obtain a rapid mixing result for depolarizing noise applied to large subspaces and to prove bounds on a quantum generalization of non-interactive correlation distillation.

Introduction to reversible computing

CERN Document Server

Perumalla, Kalyan S

2013-01-01

Few books comprehensively cover the software and programming aspects of reversible computing. Filling this gap, Introduction to Reversible Computing offers an expanded view of the field that includes the traditional energy-motivated hardware viewpoint as well as the emerging application-motivated software approach. Collecting scattered knowledge into one coherent account, the book provides a compendium of both classical and recently developed results on reversible computing. It explores up-and-coming theories, techniques, and tools for the application of rever

A Study on Reverse Logistics

OpenAIRE

Reddy, Dhananjaya

2011-01-01

In the competitive world of manufacturing, companies are often searching for new ways to improve their process, customer satisfaction and stay ahead in the game with their competitors. Reverse logistics has been considered a strategy to bring these things to life for the past decade or so. This thesis work tries to shed some light on the basics of reverse logistics and how reverse logistics can be used as a management strategy. This paper points out the fundamentals of reverse logistics and l...

Price Reversal Pattern of ARV Drugs: A Transaction-Cost Approach Digression

Directory of Open Access Journals (Sweden)

Frank LORNE

2015-05-01

Full Text Available A price reversal pattern of ARV drugs was noted across lower and middle income countries in that the lower-income countries have higher prices relative to higher-income countries based on a 2008-2009 Summary Report by World Health Organization. The transaction costs affecting AVR drug pricing can be broadly classified into two kinds: One between the final users and the opinion/knowledge experts, and the other between the opinion/knowledge experts and the manufacturers. Economist’s version of price discrimination needs to be modified by including transaction costs. Transaction costs also point to institution creditability factors that will affect NGO procurement.

Andexanet alfa effectively reverses edoxaban anticoagulation effects and associated bleeding in a rabbit acute hemorrhage model

Science.gov (United States)

Lu, Genmin; Pine, Polly; Leeds, Janet M.; DeGuzman, Francis; Pratikhya, Pratikhya; Lin, Joyce; Malinowski, John; Hollenbach, Stanley J.; Curnutte, John T.

2018-01-01

Introduction Increasing use of factor Xa (FXa) inhibitors necessitates effective reversal agents to manage bleeding. Andexanet alfa, a novel modified recombinant human FXa, rapidly reverses the anticoagulation effects of direct and indirect FXa inhibitors. Objective To evaluate the ability of andexanet to reverse anticoagulation in vitro and reduce bleeding in rabbits administered edoxaban. Materials and methods In vitro studies characterized the interaction of andexanet with edoxaban and its ability to reverse edoxaban-mediated anti-FXa activity. In a rabbit model of surgically induced, acute hemorrhage, animals received edoxaban vehicle+andexanet vehicle (control), edoxaban (1 mg/kg)+andexanet vehicle, edoxaban+andexanet (75 mg, 5-minute infusion, 20 minutes after edoxaban), or edoxaban vehicle+andexanet prior to injury. Results Andexanet bound edoxaban with high affinity similar to FXa. Andexanet rapidly and dose-dependently reversed the effects of edoxaban on FXa activity and coagulation pharmacodynamic parameters in vitro. In edoxaban-anticoagulated rabbits, andexanet reduced anti-FXa activity by 82% (from 548±87 to 100±41 ng/ml; P<0.0001), mean unbound edoxaban plasma concentration by ~80% (from 100±10 to 21±6 ng/ml; P<0.0001), and blood loss by 80% vs. vehicle (adjusted for control, 2.6 vs. 12.9 g; P = 0.003). The reduction in blood loss correlated with the decrease in anti-FXa activity (r = 0.6993, P<0.0001) and unbound edoxaban (r = 0.5951, P = 0.0035). Conclusion These data demonstrate that andexanet rapidly reversed the anticoagulant effects of edoxaban, suggesting it could be clinically valuable for the management of acute and surgery-related bleeding. Correlation of blood loss with anti-FXa activity supports the use of anti-FXa activity as a biomarker for assessing anticoagulation reversal in clinical trials. PMID:29590221

Optimized reversible binary-coded decimal adders

DEFF Research Database (Denmark)

Thomsen, Michael Kirkedal; Glück, Robert

2008-01-01

Abstract Babu and Chowdhury [H.M.H. Babu, A.R. Chowdhury, Design of a compact reversible binary coded decimal adder circuit, Journal of Systems Architecture 52 (5) (2006) 272-282] recently proposed, in this journal, a reversible adder for binary-coded decimals. This paper corrects and optimizes...... their design. The optimized 1-decimal BCD full-adder, a 13 × 13 reversible logic circuit, is faster, and has lower circuit cost and less garbage bits. It can be used to build a fast reversible m-decimal BCD full-adder that has a delay of only m + 17 low-power reversible CMOS gates. For a 32-decimal (128-bit....... Keywords: Reversible logic circuit; Full-adder; Half-adder; Parallel adder; Binary-coded decimal; Application of reversible logic synthesis...

Flux dependency of particulate/colloidal fouling in seawater reverse osmosis systems

KAUST Repository

Salinas Rodríguez, S. G.

2012-01-01

Fouling is the main operational problem in seawater reverse osmosis systems (SWRO). Particulate fouling is traditionally measured through the silt density index (SDI) and through the modified fouling index (MFI). In recent years, ultrafiltration membranes were used successfully at constant flux-MFI-UF-to measure particulate/colloidal fouling potential and tested in sea water applications. Furthermore, constant flux operation allows predicting the rate of fouling in RO systems. The objectives of this study are: (1) to measure the flux effect in MFI-UF with different membranes (100, 30 and 10 kDa) for raw seawater and pre-treated water before reverse osmosis in three different locations; (2) to study the particulate and colloidal fouling potential of seawater in reverse osmosis systems; (3) to project the increase in pressure due to cake resistance in reverse osmosis systems. In this research, flat ultrafiltration membranes (100, 50, 30 and 10 kDa) are used in a con- stant flux filtration mode to test and compare real seawaters from various locations (North and Mediterranean Sea) and from various full scale facilities including different pre-treatments (i.e., ultrafiltration and coagulation + dual media filtration). The operated fluxes range from 350 down to values close to real RO operation, 15l(m2h)-1. After each filtration test, the MFI-UF is calculated to assess the particulate fouling potential. The obtained results showed that: (1) the particulate and colloidal fouling potential is directly proportional to the applied flux during filtration. This proportionality is related to the compression of the cake deposit occurring at high flux values; (2) the higher the flux, the higher the required pressure, the less porous the cake and therefore the higher the specific cake resistance; (3) particulate and colloidal fouling potential of seawater is site specific and is influenced by pre-treatment. © 2012 Desalination Publications. All rights reserved.

Altitude training considerations for the winter sport athlete.

Science.gov (United States)

Chapman, Robert F; Stickford, Jonathon L; Levine, Benjamin D

2010-03-01

Winter sports events routinely take place at low to moderate altitudes, and nearly all Winter Olympic Games have had at least one venue at an altitude >1000 m. The acute and chronic effects of altitude can have a substantial effect on performance outcomes. Acutely, the decline in oxygen delivery to working muscle decreases maximal oxygen uptake, negatively affecting performance in endurance events, such as cross-country skiing and biathlon. The reduction in air resistance at altitude can dramatically affect sports involving high velocities and technical skill components, such as ski jumping, speed skating, figure skating and ice hockey. Dissociation between velocity and sensations usually associated with work intensity (ventilation, metabolic signals in skeletal muscle and heart rate) may impair pacing strategy and make it difficult to determine optimal race pace. For competitions taking place at altitude, a number of strategies may be useful, depending on the altitude of residence of the athlete and ultimate competition altitude, as follows. First, allow extra time and practice (how much is yet undetermined) for athletes to adjust to the changes in projectile motion; hockey, shooting, figure skating and ski jumping may be particularly affected. These considerations apply equally in the reverse direction; that is, for athletes practising at altitude but competing at sea level. Second, allow time for acclimatization for endurance sports: 3-5 days if possible, especially for low altitude (500-2000 m); 1-2 weeks for moderate altitude (2000-3000 m); and at least 2 weeks if possible for high altitude (>3000 m). Third, increase exercise-recovery ratios as much as possible, with 1:3 ratio probably optimal, and consider more frequent substitutions for sports where this is allowed, such as ice hockey. Fourth, consider the use of supplemental O(2) on the sideline (ice hockey) or in between heats (skating and Alpine skiing) to facilitate recovery. For competitions at sea

Modified Linnik microscopic interferometry for quantitative depth evaluation of diffraction-limited microgroove

Science.gov (United States)

Ye, Shiwei; Takahashi, Satoru; Michihata, Masaki; Takamasu, Kiyoshi

2018-05-01

The quality control of microgrooves is extremely crucial to ensure the performance and stability of microstructures and improve their fabrication efficiency. This paper introduces a novel optical inspection method and a modified Linnik microscopic interferometer measurement system to detect the depth of microgrooves with a width less than the diffraction limit. Using this optical method, the depth of diffraction-limited microgrooves can be related to the near-field optical phase difference, which cannot be practically observed but can be computed from practical far-field observations. Thus, a modified Linnik microscopic interferometer system based on three identical objective lenses and an optical path reversibility principle were developed. In addition, experiments for standard grating microgrooves on the silicon surface were carried out to demonstrate the feasibility and repeatability of the proposed method and developed measurement system.

The Effect of Teaching Games of Understanding as a Coaching Instruction had on Adjust, Cover and Heart Rate among Malaysian and Indian Junior Hockey Players

Directory of Open Access Journals (Sweden)

Sanmuga Nathan

2017-06-01

Full Text Available The field hockey coaching process across both Malaysia and India favours a traditional, coach-centred approach of mastering technical skills in terms of game play parameters, fitness, intensity, and load training, whereas a tactical- and player-centred pedagogical approach still takes a backseat. On the other hand, the Teaching Games for Understanding (TGfU model offers tactical-cognitive instruction and is gaining international recognition for its ability to produce intelligent players via a problem-solving approach in game play. Therefore, the purpose of this quasi-experimental study was to investigate the effect of TGfU compared to skill mastery instruction, termed as Skill Drill Technical (SDT, among Malaysian and Indian elite junior hockey players in term of the game play attributes of adjust and cover in 5 vs. 5 small-sided game play and game play intensity via heart rate (HR at different points of game play. A total of n = 60 players with an average age of 15 ± 1.03 was selected via simple random sampling from both countries involved in this study and assigned equally to groups, with 15 per group for TGfU and for SDT across Malaysia and India. Gathered data were analysed using the ANOVA and ANCOVA techniques. Findings indicated that there were no significant differences for adjust in 5 vs. 5 game play between TGfU and SDT across Malaysia and India after the intervention. For cover, there was significant improvement for Malaysian players using the TGfU model compared to SDT. In contrast, there was no significant difference between these two models among the Indian players after the intervention. There was significant difference between these two models in terms of warm-up HR across the two countries, and HR was higher via TGfU. For HR immediately after the 5 vs. 5 game play intervention and HR after three minutes’ recovery, Indian players with TGfU recorded a higher and significant difference compared to SDT. However, findings indicated

Quantitative analysis of planar technetium-99m-sestamibi myocardial perfusion images using modified background subtraction

International Nuclear Information System (INIS)

Koster, K.; Wackers, F.J.; Mattera, J.A.; Fetterman, R.C.

1990-01-01

Standard interpolative background subtraction, as used for thallium-201 ( 201 Tl), may create artifacts when applied to planar technetium-99m-Sestamibi ( 99m Tc-Sestamibi) images, apparently because of the oversubtraction of relatively high extra-cardiac activity. A modified background subtraction algorithm was developed and compared to standard background subtraction in 16 patients who had both exercise-delayed 201 Tl and exercise-rest 99m Tc-Sestamibi imaging. Furthermore, a new normal data base was generated. Normal 99m Tc-Sestamibi distribution was slightly different compared to 201 Tl. Using standard background subtraction, mean defect reversibility was significantly underestimated by 99m Tc-Sestamibi compared to 201 Tl (2.8 +/- 4.9 versus -1.8 +/- 8.4, p less than 0.05). Using the modified background subtraction, mean defect reversibility on 201 Tl and 99m Tc-Sestamibi images was comparable (2.8 +/- 4.9 versus 1.7 +/- 5.2, p = NS). We conclude, that for quantification of 99m Tc-Sestamibi images a new normal data base, as well as a modification of the interpolative background subtraction method should be employed to obtain quantitative results comparable to those with 201 Tl

Redes vir jeugdeelname aan onderwaterhokkie in Suid-Afrika ...

African Journals Online (AJOL)

This may suggest that coaches need not be overly concerned about the motive differences between the sexes if they happen to be coaching co-ed underwater hockey teams. Coaches and organizers of youth underwater hockey should place emphasis on the fun and skill development aspects of underwater hockey.

Image Compression using Haar and Modified Haar Wavelet Transform

Directory of Open Access Journals (Sweden)

Mohannad Abid Shehab Ahmed

2013-04-01

Full Text Available Efficient image compression approaches can provide the best solutions to the recent growth of the data intensive and multimedia based applications. As presented in many papers the Haar matrix–based methods and wavelet analysis can be used in various areas of image processing such as edge detection, preserving, smoothing or filtering. In this paper, color image compression analysis and synthesis based on Haar and modified Haar is presented. The standard Haar wavelet transformation with N=2 is composed of a sequence of low-pass and high-pass filters, known as a filter bank, the vertical and horizontal Haar filters are composed to construct four 2-dimensional filters, such filters applied directly to the image to speed up the implementation of the Haar wavelet transform. Modified Haar technique is studied and implemented for odd based numbers i.e. (N=3 & N=5 to generate many solution sets, these sets are tested using the energy function or numerical method to get the optimum one.The Haar transform is simple, efficient in memory usage due to high zero value spread (it can use sparse principle, and exactly reversible without the edge effects as compared to DCT (Discrete Cosine Transform. The implemented Matlab simulation results prove the effectiveness of DWT (Discrete Wave Transform algorithms based on Haar and Modified Haar techniques in attaining an efficient compression ratio (C.R, achieving higher peak signal to noise ratio (PSNR, and the resulting images are of much smoother as compared to standard JPEG especially for high C.R. A comparison between standard JPEG, Haar, and Modified Haar techniques is done finally which approves the highest capability of Modified Haar between others.

Modified Aggressive Packet Combining Scheme

International Nuclear Information System (INIS)

Bhunia, C.T.

2010-06-01

In this letter, a few schemes are presented to improve the performance of aggressive packet combining scheme (APC). To combat error in computer/data communication networks, ARQ (Automatic Repeat Request) techniques are used. Several modifications to improve the performance of ARQ are suggested by recent research and are found in literature. The important modifications are majority packet combining scheme (MjPC proposed by Wicker), packet combining scheme (PC proposed by Chakraborty), modified packet combining scheme (MPC proposed by Bhunia), and packet reversed packet combining (PRPC proposed by Bhunia) scheme. These modifications are appropriate for improving throughput of conventional ARQ protocols. Leung proposed an idea of APC for error control in wireless networks with the basic objective of error control in uplink wireless data network. We suggest a few modifications of APC to improve its performance in terms of higher throughput, lower delay and higher error correction capability. (author)

Heparin/heparan sulfate analysis by covalently modified reverse polarity capillary zone electrophoresis-mass spectrometry.

Science.gov (United States)

Sanderson, Patience; Stickney, Morgan; Leach, Franklin E; Xia, Qiangwei; Yu, Yanlei; Zhang, Fuming; Linhardt, Robert J; Amster, I Jonathan

2018-04-13

Reverse polarity capillary zone electrophoresis coupled to negative ion mode mass spectrometry (CZE-MS) is shown to be an effective and sensitive tool for the analysis of glycosaminoglycan mixtures. Covalent modification of the inner wall of the separation capillary with neutral or cationic reagents produces a stable and durable surface that provides reproducible separations. By combining CZE-MS with a cation-coated capillary and a sheath flow interface, a rapid and reliable method has been developed for the analysis of sulfated oligosaccharides from dp4 to dp12. Several different mixtures have been separated and detected by mass spectrometry. The mixtures were selected to test the capability of this approach to resolve subtle differences in structure, such as sulfation position and epimeric variation of the uronic acid. The system was applied to a complex mixture of heparin/heparan sulfate oligosaccharides varying in chain length from dp3 to dp12 and more than 80 molecular compositions were identified by accurate mass measurement. Copyright © 2018 Elsevier B.V. All rights reserved.

What do reversible programs compute?

DEFF Research Database (Denmark)

Axelsen, Holger Bock; Glück, Robert

2011-01-01

Reversible computing is the study of computation models that exhibit both forward and backward determinism. Understanding the fundamental properties of such models is not only relevant for reversible programming, but has also been found important in other fields, e.g., bidirectional model...... transformation, program transformations such as inversion, and general static prediction of program properties. Historically, work on reversible computing has focussed on reversible simulations of irreversible computations. Here, we take the viewpoint that the property of reversibility itself should...... are not strictly classically universal, but that they support another notion of universality; we call this RTM-universality. Thus, even though the RTMs are sub-universal in the classical sense, they are powerful enough as to include a self-interpreter. Lifting this to other computation models, we propose r...

Fundamentals of reversible flowchart languages

DEFF Research Database (Denmark)

Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

2016-01-01

Abstract This paper presents the fundamentals of reversible flowcharts. They are intended to naturally represent the structure and control flow of reversible (imperative) programming languages in a simple computation model, in the same way classical flowcharts do for conventional languages......, structured reversible flowcharts are as expressive as unstructured ones, as shown by a reversible version of the classic Structured Program Theorem. We illustrate how reversible flowcharts can be concretized with two example programming languages, complete with syntax and semantics: a low-level unstructured...... language and a high-level structured language. We introduce concrete tools such as program inverters and translators for both languages, which follow the structure suggested by the flowchart model. To further illustrate the different concepts and tools brought together in this paper, we present two major...

Magnetic reversals from planetary dynamo waves

DEFF Research Database (Denmark)

Sheyko, Andrey; Finlay, Chris; Jackson, Andrew

2016-01-01

A striking feature of many natural dynamos is their ability to undergo polarity reversals. The best documented example is Earth's magnetic field, which has reversed hundreds of times during its history. The origin of geomagnetic polarity reversals lies in a magnetohydrodynamic process that takes ...... to kinematic dynamo waves. Because our results are relevant in a regime of low viscosity and high magnetic diffusivity, and with geophysically appropriate boundary conditions, this form of dynamo wave may also be involved in geomagnetic reversals.......A striking feature of many natural dynamos is their ability to undergo polarity reversals. The best documented example is Earth's magnetic field, which has reversed hundreds of times during its history. The origin of geomagnetic polarity reversals lies in a magnetohydrodynamic process that takes...... place in Earth's core, but the precise mechanism is debated. The majority of numerical geodynamo simulations that exhibit reversals operate in a regime in which the viscosity of the fluid remains important, and in which the dynamo mechanism primarily involves stretching and twisting of field lines...

A functional language for describing reversible logic

DEFF Research Database (Denmark)

Thomsen, Michael Kirkedal

2012-01-01

Reversible logic is a computational model where all gates are logically reversible and combined in circuits such that no values are lost or duplicated. This paper presents a novel functional language that is designed to describe only reversible logic circuits. The language includes high....... Reversibility of descriptions is guaranteed with a type system based on linear types. The language is applied to three examples of reversible computations (ALU, linear cosine transformation, and binary adder). The paper also outlines a design flow that ensures garbage- free translation to reversible logic...... circuits. The flow relies on a reversible combinator language as an intermediate language....

Geomagnetic Reversals during the Phanerozoic.

Science.gov (United States)

McElhinny, M W

1971-04-09

An antalysis of worldwide paleomagnetic measurements suggests a periodicity of 350 x 10(6) years in the polarity of the geomagnetic field. During the Mesozoic it is predominantly normal, whereas during the Upper Paleozoic it is predominantly reversed. Although geomagnetic reversals occur at different rates throughout the Phanerozoic, there appeaars to be no clear correlation between biological evolutionary rates and reversal frequency.

Alkyne- and 1,6-elimination- succinimidyl carbonate – terminated heterobifunctional poly(ethylene glycol) for reversible "Click" PEGylation

OpenAIRE

Xie, Yumei; Duan, Shaofeng; Forrest, M. Laird

2010-01-01

A new heterobifunctional (succinimidyl carbonate, SC)-activated poly(ethylene glycol) (PEG) with a reversible 1,6-elimination linker and a terminal alkyne for "click" chemistry was synthesized with high efficiency and low polydispersity. The α-alkyne-ω-hydroxyl PEG was first prepared using trimethylsilyl-2-propargyl alcohol as an initiator for ring-opening polymerization of ethylene oxide followed by mild deprotection with tetrabutylammonium fluoride. The hydroxy end was then modified with di...

Resveratrol reverses morphine-induced neuroinflammation in morphine-tolerant rats by reversal HDAC1 expression

Directory of Open Access Journals (Sweden)

Ru-Yin Tsai

2016-06-01

Conclusion: Resveratrol restores the antinociceptive effect of morphine by reversing morphine infusion-induced spinal cord neuroinflammation and increase in TNFR1 expression. The reversal of the morphine-induced increase in TNFR1 expression by resveratrol is partially due to reversal of the morphine infusion-induced increase in HDAC1 expression. Resveratrol pretreatment can be used as an adjuvant in clinical pain management for patients who need long-term morphine treatment or with neuropathic pain.

Principles of a reversible programming language

DEFF Research Database (Denmark)

Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

2008-01-01

The principles of reversible programming languages are explicated and illustrated with reference to the design of a high-level imperative language, Janus. The fundamental properties for such languages include backward as well as forward determinism and reversible updates of data. The unique design...... languages, and demonstrate this for Janus. We show the practicality of the language by implementation of a reversible fast Fourier transform. Our results indicate that the reversible programming paradigm has fundamental properties that are relevant to many different areas of computer science....... features of the language include explicit post-condition assertions, direct access to an inverse semantics and the possibility of clean (i.e., garbage-free) computation of injective functions. We suggest the clean simulation of reversible Turing machines as a criterion for computing strength of reversible...

Reversed-phase thin-layer chromatography of homologs of Antimycin-A and related derivatives

Science.gov (United States)

Abidi, Sharon L.

1989-01-01

Using a reversed-phase high-performance liquid chromatographic (HPLC) technique, a mixture of antimycins A was separated into eight hitherto unreported subcomponents, Ala, Alb, A2a, A2b, A3a, A3b, A4a, and A4b. Although a base-line resolution of the known four major antimycins Al, A2, A3, and A4 was readily achieved with mobile phases containing acetate buffers, the separation of the new antibiotic subcomponents was highly sensitive to variation in mobile phase conditions. The type and composition of organic modifiers, the nature of buffer salts, and the concentration of added electrolytes had profound effects on capacity factors, separation factors, and peak resolution values. Of the numerous chromatographic systems examined, a mobile phase consisting of methanol-water (70:30) and 0.005 M tetrabutylammonium phosphate at pH 3.0 yielded the most satisfactory results for the separation of the subcomponents. Reversed-phase gradient HPLC separation of the dansylated or methylated antibiotic compounds produced superior chromatographic characteristics and the presence of added electrolytes was not a critical factor for achieving separation. Differences in the chromatographic outcome between homologous and structural isomers were interpretated based on a differential solvophobic interaction rationale. Preparative reversed-phase HPLC under optimal conditions enabled isolation of pure samples of the methylated antimycin subcomponents for use in structural studies.

Electromagnetic treatment to old Alzheimer's mice reverses β-amyloid deposition, modifies cerebral blood flow, and provides selected cognitive benefit.

Directory of Open Access Journals (Sweden)

Gary W Arendash

Full Text Available Few studies have investigated physiologic and cognitive effects of "long-term" electromagnetic field (EMF exposure in humans or animals. Our recent studies have provided initial insight into the long-term impact of adulthood EMF exposure (GSM, pulsed/modulated, 918 MHz, 0.25-1.05 W/kg by showing 6+ months of daily EMF treatment protects against or reverses cognitive impairment in Alzheimer's transgenic (Tg mice, while even having cognitive benefit to normal mice. Mechanistically, EMF-induced cognitive benefits involve suppression of brain β-amyloid (Aβ aggregation/deposition in Tg mice and brain mitochondrial enhancement in both Tg and normal mice. The present study extends this work by showing that daily EMF treatment given to very old (21-27 month Tg mice over a 2-month period reverses their very advanced brain Aβ aggregation/deposition. These very old Tg mice and their normal littermates together showed an increase in general memory function in the Y-maze task, although not in more complex tasks. Measurement of both body and brain temperature at intervals during the 2-month EMF treatment, as well as in a separate group of Tg mice during a 12-day treatment period, revealed no appreciable increases in brain temperature (and no/slight increases in body temperature during EMF "ON" periods. Thus, the neuropathologic/cognitive benefits of EMF treatment occur without brain hyperthermia. Finally, regional cerebral blood flow in cerebral cortex was determined to be reduced in both Tg and normal mice after 2 months of EMF treatment, most probably through cerebrovascular constriction induced by freed/disaggregated Aβ (Tg mice and slight body hyperthermia during "ON" periods. These results demonstrate that long-term EMF treatment can provide general cognitive benefit to very old Alzheimer's Tg mice and normal mice, as well as reversal of advanced Aβ neuropathology in Tg mice without brain heating. Results further underscore the potential for EMF

A systematic video analysis of National Hockey League (NHL) concussions, part II: how concussions occur in the NHL.

Science.gov (United States)

Hutchison, Michael G; Comper, Paul; Meeuwisse, Willem H; Echemendia, Ruben J

2015-04-01

Concussions in sports are a growing cause of concern, as these injuries can have debilitating short-term effects and little is known about the potential long-term consequences. This work aims to describe how concussions occur in the National Hockey League. Case series of medically diagnosed concussions for regular season games over a 3.5-year period during the 2006-2010 seasons. Digital video records were coded and analysed using a standardised protocol. 88% (n=174/197) of concussions involved player-to-opponent contact. 16 diagnosed concussions were a result of fighting. Of the 158 concussions that involved player-to-opponent body contact, the most common mechanisms were direct contact to the head initiated by the shoulder 42% of the time (n=66/158), by the elbow 15% (n=24/158) and by gloves in 5% of cases (n=8/158). When the results of anatomical location are combined with initial contact, almost half of these events (n=74/158) were classified as direct contact to the lateral aspect of the head. The predominant mechanism of concussion was consistently characterised by player-to-opponent contact, typically directed to the head by the shoulder, elbow or gloves. Also, several important characteristics were apparent: (1) contact was often to the lateral aspect of the head; (2) the player who suffered a concussion was often not in possession of the puck and (3) no penalty was called on the play. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

‘Picking People to Hate’: Reversible reversals in stand-up comedy

DEFF Research Database (Denmark)

Keisalo, Marianna Päivikki

2017-01-01

Generally speaking, ritual reversals mean switching to the opposite of what is considered ‘the normal order’. Such reversals can occur, for example, in terms of social hierarchies in rites of passage, in action in carnival, or in the framing of action as ritual or performance. For comedic figures...... cultural grounds and show how the study of comedic performance can offer insights into the semiotics of performance more broadly....

Periodicity and Immortality in Reversible Computing

OpenAIRE

Kari , Jarkko; Ollinger , Nicolas

2008-01-01

Additional material available on the web at http://www.lif.univ-mrs.fr/~nollinge/rec/gnirut/; We investigate the decidability of the periodicity and the immortality problems in three models of reversible computation: reversible counter machines, reversible Turing machines and reversible one-dimensional cellular automata. Immortality and periodicity are properties that describe the behavior of the model starting from arbitrary initial configurations: immortality is the property of having at le...

How decision reversibility affects motivation.

Science.gov (United States)

Bullens, Lottie; van Harreveld, Frenk; Förster, Jens; Higgins, Tory E

2014-04-01

The present research examined how decision reversibility can affect motivation. On the basis of extant findings, it was suggested that 1 way it could affect motivation would be to strengthen different regulatory foci, with reversible decision making, compared to irreversible decision making, strengthening prevention-related motivation relatively more than promotion-related motivation. If so, then decision reversibility should have effects associated with the relative differences between prevention and promotion motivation. In 5 studies, we manipulated the reversibility of a decision and used different indicators of regulatory focus motivation to test these predictions. Specifically, Study 1 tested for differences in participants' preference for approach versus avoidance strategies toward a desired end state. In Study 2, we used speed and accuracy performance as indicators of participants' regulatory motivation, and in Study 3, we measured global versus local reaction time performance. In Study 4, we approached the research question in a different way, making use of the value-from-fit hypothesis (Higgins, 2000, 2002). We tested whether a fit between chronic regulatory focus and focus induced by the reversibility of the decision increased participants' subjective positive feelings about the decision outcome. Finally, in Study 5, we tested whether regulatory motivation, induced by decision reversibility, also influenced participants' preference in specific product features. The results generally support our hypothesis showing that, compared to irreversible decisions, reversible decisions strengthen a prevention focus more than a promotion focus. Implications for research on decision making are discussed.

A functionalizable reverse thermal gel based on a polyurethane/PEG block copolymer

Science.gov (United States)

Park, Daewon; Wu, Wei; Wang, Yadong

2010-01-01

Injectable reverse thermal gels have great potentials as biomaterials for tissue engineering and drug delivery. However, most existing gels lack functional groups that can be modified with biomolecules that can guide cell/material interactions. We created an amine-functionalized ABA block copolymer, poly(ethylene glycol)-poly(serinol hexamethylene urethane), or ESHU. This reverse thermal gel consists of a hydrophobic block (B): poly(serinol hexamethylene urethane) and a hydrophilic block (A): poly(ethylene glycol). The polymer was characterized by GPC, FTIR and 1H FTNMR. Rheological study demonstrated that ESHU solution in phosphate-buffered saline initiated phase transition at 32°C and reached maximum elastic modulus at 37°C. The in vitro degradation tests performed in PBS and cholesterol esterase solutions revealed that the polymer was hydrolyzable and the presence of cholesterol esterase greatly accelerated the hydrolysis. The in vitro cytotoxicity tests carried out using baboon smooth muscle cells demonstrated that ESHU had good cytocompatibility with cell viability indistinguishable from tissue culture treated polystyrene. Subcutaneous implantation in rats revealed well tolerated accurate inflammatory response with moderate ED-1 positive macrophages in the early stages, which largely resolved 4 weeks post-implantation. We functionalized ESHU with a hexapeptide, Ile-Lys-Val-Ala-Val-Ser (IKVAVS), which gelled rapidly at body temperature. We expect this new platform of functionalizable reverse thermal gels to provide versatile biomaterials in tissue engineering and regenerative medicine. PMID:20937526

Profiling of modified nucleosides from ribonucleic acid digestion by supercritical fluid chromatography coupled to high resolution mass spectrometry.

Science.gov (United States)

Laboureur, Laurent; Guérineau, Vincent; Auxilien, Sylvie; Yoshizawa, Satoko; Touboul, David

2018-02-16

A method based on supercritical fluid chromatography coupled to high resolution mass spectrometry for the profiling of canonical and modified nucleosides was optimized, and compared to classical reverse-phase liquid chromatography in terms of separation, number of detected modified nucleosides and sensitivity. Limits of detection and quantification were measured using statistical method and quantifications of twelve nucleosides of a tRNA digest from E. coli are in good agreement with previously reported data. Results highlight the complementarity of both separation techniques to cover the largest view of nucleoside modifications for forthcoming epigenetic studies. Copyright © 2017 Elsevier B.V. All rights reserved.

MODELS OF PROJECT REVERSE ENGINEERING

Directory of Open Access Journals (Sweden)

Віктор Володимирович ІВАНОВ

2017-03-01

Full Text Available Reverse engineering decided important scientific and technical problems of increasing the cost of the existing technical product by transforming it into a product with other features or design. Search ideas of the new application of existing products on the base of heuristic analysis were created. The concept of reverse engineering and its division into three types: conceptual, aggregate and complete was expanded. The use of heuristic methods for reverse engineering concept was showed. The modification model of Reverse engineering based on the model of РМВОК was developed. Our model includes two new phases: identification and transformation. At the identification phase, technical control is made. At the transformation phase, search heuristic idea of the new applied existing technical product was made. The model of execution phase that included heuristic methods, metrological equipment, and CAD/CAM/CAE program complex was created. The model that connected economic indicators of reverse engineering project was developed.

Tips of the dual-lumen microcatheter-facilitated reverse wire technique in percutaneous coronary interventions for markedly angulated bifurcated lesions.

Science.gov (United States)

Nomura, Tetsuya; Kikai, Masakazu; Hori, Yusuke; Yoshioka, Kenichi; Kubota, Hiroshi; Miyawaki, Daisuke; Urata, Ryota; Sugimoto, Takeshi; Keira, Natsuya; Tatsumi, Tetsuya

2018-04-01

In practical settings of percutaneous coronary intervention (PCI), we sometimes encounter difficulty in introducing a guidewire (GW) to the markedly angulated side branch (SB), and the reverse wire technique is considered as a last resort to overcome such a situation. We analyzed 12 cases that underwent PCI with dual-lumen microcatheter-facilitated reverse wire technique between January 2013 and July 2016. We retrospectively investigated the lesion's characteristics and the details of the PCI procedures, and discussed tips about the use of this technique. The SB that exhibits both a smaller take-off angle and a larger carina angle is considered to be the most suitable candidate for this technique. The first step of this technique involves the delivery of the reverse wire system to the target bifurcation. However, most cases exhibit significant stenosis proximal to the bifurcation, which often hampers the delivery of the reverse wire system. Because the sharply curved reverse wire system is easier to pass the stenosis as compared to the roundly curved system, we recommend a sharp curve should be adopted for this technique. On the other hand, it is sure that device delivery is much easier on the GW with a round curve as compared to that with a sharp curve. Therefore, it is important to modify the details of this procedure on a case-by-case basis according to the lesion's characteristics.

Cardiac resynchronization induces major structural and functional reverse remodeling in patients with New York Heart Association class I/II heart failure

DEFF Research Database (Denmark)

St John Sutton, Martin; Ghio, Stefano; Plappert, Ted

2009-01-01

BACKGROUND: Cardiac resynchronization therapy (CRT) improves LV structure, function, and clinical outcomes in New York Heart Association class III/IV heart failure with prolonged QRS. It is not known whether patients with New York Heart Association class I/II systolic heart failure exhibit left...... ventricular (LV) reverse remodeling with CRT or whether reverse remodeling is modified by the cause of heart failure. METHODS AND RESULTS: Six hundred ten patients with New York Heart Association class I/II heart failure, QRS duration > or =120 ms, LV end-diastolic dimension > or =55 mm, and LV ejection...... reduction in LV end-diastolic and end-systolic volume indexes and a 3-fold greater increase in LV ejection fraction in patients with nonischemic causes of heart failure. CONCLUSIONS: CRT in patients with New York Heart Association I/II resulted in major structural and functional reverse remodeling at 1 year...

Garbage collection for reversible functional languages

DEFF Research Database (Denmark)

Mogensen, Torben Ægidius

2015-01-01

Reversible languages are programming languages where all programs can run both forwards and backwards. Reversible functional languages have been proposed that use symmetric pattern matching and data construction. To be reversible, these languages require linearity: Every variable must be used...

Test of feasibility of a novel high precision test of time reversal invariance

International Nuclear Information System (INIS)

Samuel, Deepak

2007-01-01

The first results of a feasibility test of a novel high precision test of time reversal invariance are reported. The Time Reversal Invariance test at COSY (TRIC) was planned to measure the time reversal violating observable A y,xz with an accuracy of 10 -6 in proton-deuteron (p-d) scattering. A novel technique for measuring total cross sections is introduced and the achievable precision of this measuring technique is tested. The correlation coefficient A y,y in p-d scattering fakes a time-reversal violating effect. This work reports the feasibility test of the novel method in the measurement of A y,y in p-p scattering. The first step in the experimental design was the development of a hard real-time data acquisition system. To meet stringent latency requirements, the capabilities of Windows XP had to be augmented with a real-time subsystem. The remote control feature of the data acquisition enables users to operate it from any place via an internet connection. The data acquisition proved its reliability in several beam times without any failures. The analysis of the data showed the presence of 1/f noise which substantially limits the quality of our measurements. The origin of 1/f noise was traced and found to be the Barkhausen noise from the ferrite core of the beam current transformer (BCT). A global weighted fitting technique based on a modified Wiener-Khinchin method was developed and used to suppress the influence of 1/f noise, which increased the error bar of the results by a factor 3. This is the only deviation from our expectations. The results are presented and discussed. (orig.)

Test of feasibility of a novel high precision test of time reversal invariance

Energy Technology Data Exchange (ETDEWEB)

Samuel, Deepak

2007-07-01

The first results of a feasibility test of a novel high precision test of time reversal invariance are reported. The Time Reversal Invariance test at COSY (TRIC) was planned to measure the time reversal violating observable A{sub y,xz} with an accuracy of 10{sup -6} in proton-deuteron (p-d) scattering. A novel technique for measuring total cross sections is introduced and the achievable precision of this measuring technique is tested. The correlation coefficient A{sub y,y} in p-d scattering fakes a time-reversal violating effect. This work reports the feasibility test of the novel method in the measurement of A{sub y,y} in p-p scattering. The first step in the experimental design was the development of a hard real-time data acquisition system. To meet stringent latency requirements, the capabilities of Windows XP had to be augmented with a real-time subsystem. The remote control feature of the data acquisition enables users to operate it from any place via an internet connection. The data acquisition proved its reliability in several beam times without any failures. The analysis of the data showed the presence of 1/f noise which substantially limits the quality of our measurements. The origin of 1/f noise was traced and found to be the Barkhausen noise from the ferrite core of the beam current transformer (BCT). A global weighted fitting technique based on a modified Wiener-Khinchin method was developed and used to suppress the influence of 1/f noise, which increased the error bar of the results by a factor 3. This is the only deviation from our expectations. The results are presented and discussed. (orig.)

Innovative modified hair follicle harvesting technique with reverse rake scalp elevator for lower occipital donor area in follicular unit extraction hair transplantation.

Science.gov (United States)

Gharwade, Chandrakant Rambhau

2016-01-01

Follicular unit extraction (FUE) is one of the widely practiced minimally invasive follicular harvesting techniques employed during hair transplantation. FUE technique has an advantage of utilising lower occipital area and supra-auricular region as a safe donor area described by Unger, in addition to the standard occipital donor area used in strip method (follicular unit transplant). Despite its potential advantages such as rapid recovery, minimal scarring and reduced post-operative pain; its widespread acceptance is limited due to various factors in variable contribution like steeper learning curve and potentially higher follicular transection rates (FTRs). The main practical drawbacks in harvesting FUE from lower occipital donor region that lie inferior to the standard donor area, is its acute angle (10°-15°) of emergent hair from scalp skin, higher variance angle (15°-35°) between hairs below the skin and hair exit angle above the skin and comparatively loose scalp, preventing to provide stable platform for punching. Hair transplant surgeon faces difficulty in aligning and engaging the FUE punch leading to very high hair follicle transection rate, and therefore, it is not a preferred site for harvesting follicles in FUE. Authors description of modified technique using reverse rake scalp elevator helps in negating the acute angle of the hair follicles exit from scalp skin and reducing the variance angle between emergent hair and hair below the skin in lower occipital region thereby reducing FTR. Furthermore, an added advantage of reducing the overall operative time and surgeon fatigue, improve donor area healing, availability of a comparatively larger donor area which increases the confidence of the beginners. This method will be of help as it is easy to duplicate and follow by novice hair transplant surgeons and also for those who are routinely doing mega hair transplants sessions.

Innovative modified hair follicle harvesting technique with reverse rake scalp elevator for lower occipital donor area in follicular unit extraction hair transplantation

Directory of Open Access Journals (Sweden)

Chandrakant Rambhau Gharwade

2016-01-01

Full Text Available Follicular unit extraction (FUE is one of the widely practiced minimally invasive follicular harvesting techniques employed during hair transplantation. FUE technique has an advantage of utilising lower occipital area and supra-auricular region as a safe donor area described by Unger, in addition to the standard occipital donor area used in strip method (follicular unit transplant. Despite its potential advantages such as rapid recovery, minimal scarring and reduced post-operative pain; its widespread acceptance is limited due to various factors in variable contribution like steeper learning curve and potentially higher follicular transection rates (FTRs. The main practical drawbacks in harvesting FUE from lower occipital donor region that lie inferior to the standard donor area, is its acute angle (10°–15° of emergent hair from scalp skin, higher variance angle (15°–35° between hairs below the skin and hair exit angle above the skin and comparatively loose scalp, preventing to provide stable platform for punching. Hair transplant surgeon faces difficulty in aligning and engaging the FUE punch leading to very high hair follicle transection rate, and therefore, it is not a preferred site for harvesting follicles in FUE. Authors description of modified technique using reverse rake scalp elevator helps in negating the acute angle of the hair follicles exit from scalp skin and reducing the variance angle between emergent hair and hair below the skin in lower occipital region thereby reducing FTR. Furthermore, an added advantage of reducing the overall operative time and surgeon fatigue, improve donor area healing, availability of a comparatively larger donor area which increases the confidence of the beginners. This method will be of help as it is easy to duplicate and follow by novice hair transplant surgeons and also for those who are routinely doing mega hair transplants sessions.

END-OF-USE PRODUCTS IN REVERSE LOGISTICS

OpenAIRE

Marta Starostka-Patyk

2007-01-01

Reverse logistics is a very useful tool for enterprises which have to deal with end-of-use products. Forward logistics is not able to manage them, because they show up on the beginning of reverse supply chain. That is the reason for growing importance of reverse flows. Reverse logistics is quite new logistics system. This paper presents the idea of reverse logistics and end-of-use products problems.

Reversal of subtidal dune asymmetries caused by seasonally reversing wind-driven currents in Torres Strait, northeastern Australia

Science.gov (United States)

Harris, Peter T.

1991-07-01

Large subtidal sand dunes (sandwaves) located in Adolphus Channel, Torres Strait, have been observed to reverse their asymmetric orientation between September-February. This has been attributed to a reversal in wind-driven currents, which flow westward during the SE trade season (April-November) and eastwards during the NW monsoon season [December-March: HARRIS (1989) Continental Shelf Research, 9, 981-1002]. Observations in September 1988 and February 1989 from another area of dunes in Torres Strait corroborate this asymmetry reversal pattern. The results indicate that such reversals may be common in Torres Strait and in other areas where subtidal bedforms are subject to modification by superimposed, seasonally reversing, wind-driven currents.

Magnetic reversals from planetary dynamo waves.

Science.gov (United States)

Sheyko, Andrey; Finlay, Christopher C; Jackson, Andrew

2016-11-24

A striking feature of many natural dynamos is their ability to undergo polarity reversals. The best documented example is Earth's magnetic field, which has reversed hundreds of times during its history. The origin of geomagnetic polarity reversals lies in a magnetohydrodynamic process that takes place in Earth's core, but the precise mechanism is debated. The majority of numerical geodynamo simulations that exhibit reversals operate in a regime in which the viscosity of the fluid remains important, and in which the dynamo mechanism primarily involves stretching and twisting of field lines by columnar convection. Here we present an example of another class of reversing-geodynamo model, which operates in a regime of comparatively low viscosity and high magnetic diffusivity. This class does not fit into the paradigm of reversal regimes that are dictated by the value of the local Rossby number (the ratio of advection to Coriolis force). Instead, stretching of the magnetic field by a strong shear in the east-west flow near the imaginary cylinder just touching the inner core and parallel to the axis of rotation is crucial to the reversal mechanism in our models, which involves a process akin to kinematic dynamo waves. Because our results are relevant in a regime of low viscosity and high magnetic diffusivity, and with geophysically appropriate boundary conditions, this form of dynamo wave may also be involved in geomagnetic reversals.

Multiple reversal olfactory learning in honeybees

Directory of Open Access Journals (Sweden)

Theo Mota

2010-07-01

Full Text Available In multiple reversal learning, animals trained to discriminate a reinforced from a non-reinforced stimulus are subjected to various, successive reversals of stimulus contingencies (e.g. A+ vs. B-, A- vs. B+, A+ vs. B-. This protocol is useful to determine whether or not animals learn to learn and solve successive discriminations faster (or with fewer errors with increasing reversal experience. Here we used the olfactory conditioning of proboscis extension reflex to study how honeybees Apis mellifera perform in a multiple reversal task. Our experiment contemplated four consecutive differential conditioning phases involving the same odors (A+ vs. B- to A- vs. B+ to A+ vs. B- to A- vs. B+. We show that bees in which the weight of reinforced or non-reinforced stimuli was similar mastered the multiple olfactory reversals. Bees which failed the task exhibited asymmetric responses to reinforced and non-reinforced stimuli, thus being unable to rapidly reverse stimulus contingencies. Efficient reversers did not improve their successive discriminations but rather tended to generalize their choice to both odors at the end of conditioning. As a consequence, both discrimination and reversal efficiency decreasedalong experimental phases. This result invalidates a learning-to-learn effect and indicates that bees do not only respond to the actual stimulus contingencies but rather combine these with an average of past experiences with the same stimuli.  

Synthesis and application of a triazene-ferrocene modifier for immobilization and characterization of oligonucleotides at electrodes.

Science.gov (United States)

Hansen, Majken N; Farjami, Elaheh; Kristiansen, Martin; Clima, Lilia; Pedersen, Steen Uttrup; Daasbjerg, Kim; Ferapontova, Elena E; Gothelf, Kurt V

2010-04-16

A new DNA modifier containing triazene, ferrocene, and activated ester functionalities was synthesized and applied for electrochemical grafting and characterization of DNA at glassy carbon (GC) and gold electrodes. The modifier was synthesized from ferrocenecarboxylic acid by attaching a phenyltriazene derivative to one of the ferrocene Cp rings, while the other Cp ring containing the carboxylic acid was converted to an activated ester. The modifier was conjugated to an amine-modified DNA sequence. For immobilization of the conjugate at Au or GC electrodes, the triazene was activated by dimethyl sulfate for release of the diazonium salt. The salt was reductively converted to the aryl radical which was readily immobilized at the surface. DNA grafted onto electrodes exhibited remarkable hybridization properties, as detected through a reversible shift in the redox potential of the Fc redox label upon repeated hybridization/denaturation procedures with a complementary target DNA sequence. By using a methylene blue (MB) labeled target DNA sequence the hybridization could also be followed through the MB redox potential. Electrochemical studies demonstrated that grafting through the triazene modifier can successfully compete with existing protocols for DNA immobilization through the commonly used alkanethiol linkers and diazonium salts. Furthermore, the triazene modifier provides a practical one-step immobilization procedure.

Reversible and non-reversible enlargement of cerebral spinal fluid spaces in anorexia nervosa

International Nuclear Information System (INIS)

Artmann, H.; Grau, H.; Adelmann, M.; Schleiffer, R.

1985-01-01

Brain CT studies of 35 patients with anoxia nervosa confirmed the observations of other authors: cerebral dystrophic changes correlate with weight loss and the reversibility of these changes also correlates with the normalization of body weight. Other corroborated facts are: the most numerous and most pronounced enlargements are of the cortical sulci and the interhemispheric fissure, moderate widening affects the ventricles and the rarest and most insignificant changes are those of the cerebellum. The reversibility of the changes showed a parallel to the extent of the changes themselves and to the duration of improvement of the body weight. The reversibility of the enlargement of the cortical sulci and of the distances between the frontal horns of the lateral ventricles was more often significant than that of the abnormal measurements of the cella media. This difference is based on minimal early acquired brain damage which occurs in 60% of our patients. This high incidence of early acquired minimal brain disease in patients with anorexia nervosa is here discussed as a nonspecific predisposing factor. Although there is no exact explanation of the etiology of the reversible enlargement of cerenral spinal fluid (CSF) spaces in anorexia nervosa, the changes resemble those in alcoholics. The mechanisms of brain changes in alcoholism, as shown experimentally, seem to us to throw light on the probable mechanism of reversible dystrophic brain changes in anorexia nervosa. (orig.)

Reversible and non-reversible enlargement of cerebral spinal fluid spaces in anorexia nervosa

Energy Technology Data Exchange (ETDEWEB)

Artmann, H.; Grau, H.; Adelmann, M.; Schleiffer, R.

1985-07-01

Brain CT studies of 35 patients with anoxia nervosa confirmed the observations of other authors: cerebral dystrophic changes correlate with weight loss and the reversibility of these changes also correlates with the normalization of body weight. Other corroborated facts are: the most numerous and most pronounced enlargements are of the cortical sulci and the interhemispheric fissure, moderate widening affects the ventricles and the rarest and most insignificant changes are those of the cerebellum. The reversibility of the changes showed a parallel to the extent of the changes themselves and to the duration of improvement of the body weight. The reversibility of the enlargement of the cortical sulci and of the distances between the frontal horns of the lateral ventricles was more often significant than that of the abnormal measurements of the cella media. This difference is based on minimal early acquired brain damage which occurs in 60% of our patients. This high incidence of early acquired minimal brain disease in patients with anorexia nervosa is here discussed as a nonspecific predisposing factor. Although there is no exact explanation of the etiology of the reversible enlargement of cerenral spinal fluid (CSF) spaces in anorexia nervosa, the changes resemble those in alcoholics. The mechanisms of brain changes in alcoholism, as shown experimentally, seem to us to throw light on the probable mechanism of reversible dystrophic brain changes in anorexia nervosa.

Reversal agents in anaesthesia and critical care

Directory of Open Access Journals (Sweden)

Nibedita Pani

2015-01-01

Full Text Available Despite the advent of short and ultra-short acting drugs, an in-depth knowledge of the reversal agents used is a necessity for any anaesthesiologist. Reversal agents are defined as any drug used to reverse the effects of anaesthetics, narcotics or potentially toxic agents. The controversy on the routine reversal of neuromuscular blockade still exists. The advent of newer reversal agents like sugammadex have made the use of steroidal neuromuscular blockers like rocuronium feasible in rapid sequence induction situations. We made a review of the older reversal agents and those still under investigation for drugs that are regularly used in our anaesthesia practice.

An Independent, Prospective, Head to Head Study of the Reliability and Validity of Neurocognitive Test Batteries for the Assessment of Mild Traumatic Brain Injury

Science.gov (United States)

2013-03-01

women), ice hockey, and wrestling. Baseline testing for football, lacrosse, rugby and soccer is scheduled for spring 2013. The postinjury protocol for...hockey, field hockey, rugby , wrestling), football will provide the large quantity of both baseline testing participants and concussed athletes. 6...test results to be rendered invalid for a variety of reasons (e.g., unsatisfactory test conditions, motivational factors, psychometric properties of

The misconception of mean-reversion

International Nuclear Information System (INIS)

Eliazar, Iddo I; Cohen, Morrel H

2012-01-01

The notion of random motion in a potential well is elemental in the physical sciences and beyond. Quantitatively, this notion is described by reverting diffusions—asymptotically stationary diffusion processes which are simultaneously (i) driven toward a reversion level by a deterministic force, and (ii) perturbed off the reversion level by a random white noise. The archetypal example of reverting diffusions is the Ornstein–Uhlenbeck process, which is mean-reverting. In this paper we analyze reverting diffusions and establish that: (i) if the magnitude of the perturbing noise is constant then the diffusion's stationary density is unimodal and the diffusion is mode-reverting; (ii) if the magnitude of the perturbing noise is non-constant then, in general, neither is the diffusion's stationary density unimodal, nor is the diffusion mode-reverting. In the latter case we further establish a result asserting when unimodality and mode-reversion do hold. In particular, we demonstrate that the notion of mean-reversion, which is fundamental in economics and finance, is a misconception—as mean-reversion is an exception rather than the norm. (fast track communication)

Parkinson’s disease managing reversible neurodegeneration

Science.gov (United States)

Hinz, Marty; Stein, Alvin; Cole, Ted; McDougall, Beth; Westaway, Mark

2016-01-01

Traditionally, the Parkinson’s disease (PD) symptom course has been classified as an irreversible progressive neurodegenerative disease. This paper documents 29 PD and treatment-induced systemic depletion etiologies which cause and/or exacerbate the seven novel primary relative nutritional deficiencies associated with PD. These reversible relative nutritional deficiencies (RNDs) may facilitate and accelerate irreversible progressive neurodegeneration, while other reversible RNDs may induce previously undocumented reversible pseudo-neurodegeneration that is hiding in plain sight since the symptoms are identical to the symptoms being experienced by the PD patient. Documented herein is a novel nutritional approach for reversible processes management which may slow or halt irreversible progressive neurodegenerative disease and correct reversible RNDs whose symptoms are identical to the patient’s PD symptoms. PMID:27103805

Reversible machine code and its abstract processor architecture

DEFF Research Database (Denmark)

Axelsen, Holger Bock; Glück, Robert; Yokoyama, Tetsuo

2007-01-01

A reversible abstract machine architecture and its reversible machine code are presented and formalized. For machine code to be reversible, both the underlying control logic and each instruction must be reversible. A general class of machine instruction sets was proven to be reversible, building...

A Typology of Reverse Innovation

DEFF Research Database (Denmark)

von Zedtwitz, Max; Corsi, Simone; Søberg, Peder Veng

2015-01-01

secondary market introduction, this study expands the espoused definition of reverse innovation beyond its market-introduction focus with reversals in the flow of innovation in the ideation and product development phases. Recognizing that each phase can take place in different geographical locations...... taking place in an emerging country. This analytical framework allows recasting of current research at the intersection between innovation and international business. Of the 10 reverse innovation flows, six are new and have not been covered in the literature to date. The study addresses questions......’s portfolio of global innovation competence and capability. The implications for management are concerned with internal and external resistance to reverse innovation. Most significantly, while greater recognition and power of innovation in formerly subordinate organizational units is inconvenient to some...

A Newly Improved Modified Method Development and Validation of Bromofenac Sodium Sesquihydrate in Bulk Drug Manufacturing

OpenAIRE

Sunil Kumar Yelamanchi V; Useni Reddy Mallu; I. V Kasi Viswanath; D. Balasubramanyam; G. Narshima Murthy

2016-01-01

The main objective of this study was to develop a simple, efficient, specific, precise and accurate newly improved modified Reverse Phase High Performance Liquid Chromatographic Purity (or) Related substance method for bromofenac sodium sesquihydrate active pharmaceuticals ingredient dosage form. Validation of analytical method is the confirmation by examination and the provision of objective evidence that the particular requirements for a specific intended use are fulfilled as per ICH, USP...

Elements of a Reversible Object-Oriented Language

DEFF Research Database (Denmark)

Schultz, Ulrik Pagh; Axelsen, Holger Bock

2016-01-01

This paper presents initial ideas for the design and implementation of a reversible object-oriented language based on extending Janus with object-oriented concepts such as classes that encapsulate behavior and state, inheritance, virtual dispatching, as well as constructors. We show that virtual...... dispatching is a reversible decision mechanism easily translatable to a standard reversible programming model such as Janus, and we argue that reversible management of state can be accomplished using reversible constructors. The language is implemented in terms of translation to standard Janus programs....

Drift reversal capability in helical systems

International Nuclear Information System (INIS)

Yokoyama, M.; Itoh, K.; Okamura, S.

2002-10-01

The maximum-J (J is the second adiabatic invariant) capability, i.e., the drift reversal capability, is examined in quasi-axisymmetric (QAS) stellarators and quasi-poloidally symmetric (QPS) stellarators as a possible mechanism for turbulent transport suppression. Due to the existence of non-axisymmetry of the magnetic field strength in QAS configurations, a local maximum of J is created to cause the drift reversal. The increase of magnetic shear in finite beta equilibria also has favorable effect in realizing the drift reversal. The radial variation of the uniform magnetic field component plays a crucial role for the drift reversal in a QPS configuration. Thus, the drift reversal capability and its external controllability are demonstrated for QAS and QPS stellarators, by which the impact of magnetic configuration on turbulent transport can be studied in experiments. (author)

Drift reversal capability in helical systems

International Nuclear Information System (INIS)

Yokoyama, M.; Itoh, K.; Okamura, S.; Matsuoka, K.; Nakajima, N.; Itoh, S.-I.; Neilson, G.H.; Zarnstorff, M.C.; Rewoldt, G.

2003-01-01

The maximum-J (J is the second adiabatic invariant) capability, i.e., the drift reversal capability, is examined in quasi-axisymmetric (QAS) stellarators and quasi-poloidally symmetric (QPS) stellarators as a possible mechanism for turbulent transport suppression. Due to the existence of non-axisymmetry of the magnetic field strength in QAS configurations, a local maximum of J is created to cause the drift reversal. The increase of magnetic shear in finite beta equilibria also has favorable effect in realizing the drift reversal. The radial variation of the uniform magnetic field component plays a crucial role for the drift reversal in a QPS configuration. Thus, the drift reversal capability and its external controllability are demonstrated for QAS and QPS stellarators, by which the impact of magnetic configuration on turbulent transport can be studied in experiments. (author)

Reversal of Increasing Tropical Ocean Hypoxia Trends With Sustained Climate Warming

Science.gov (United States)

Fu, Weiwei; Primeau, Francois; Keith Moore, J.; Lindsay, Keith; Randerson, James T.

2018-04-01

Dissolved oxygen (O2) is essential for the survival of marine animals. Climate change impacts on future oxygen distributions could modify species biogeography, trophic interactions, biodiversity, and biogeochemistry. The Coupled Model Intercomparison Project Phase 5 models predict a decreasing trend in marine O2 over the 21st century. Here we show that this increasing hypoxia trend reverses in the tropics after 2100 in the Community Earth System Model forced by atmospheric CO2 from the Representative Concentration Pathway 8.5 and Extended Concentration Pathway 8.5. In tropical intermediate waters between 200 and 1,000 m, the model predicts a steady decline of O2 and an expansion of oxygen minimum zones (OMZs) during the 21st century. By 2150, however, the trend reverses with oxygen concentration increasing and OMZ volume shrinking through 2300. A novel five-box model approach in conjunction with output from the full Earth system model is used to separate the contributions of biological and physical processes to the trends in tropical oxygen. The tropical O2 recovery is caused mainly by reductions in tropical biological export, coupled with a modest increase in ventilation after 2200. The time-evolving oxygen distribution impacts marine nitrogen cycling, with potentially important climate feedbacks.

Kinetic Line Voronoi Operations and Their Reversibility

DEFF Research Database (Denmark)

Mioc, Darka; Anton, François; Gold, Christopher

2010-01-01

In Geographic Information Systems the reversibility of map update operations has not been explored yet. In this paper we are using the Voronoi based Quad-edge data structure to define reversible map update operations. The reversibility of the map operations has been formalised at the lowest level...... mechanisms and dynamic map visualisations. In order to use the reversibility within the kinetic Voronoi diagram of points and open oriented line segments, we need to assure that reversing the map commands will produce exactly the changes in the map equivalent to the previous map states. To prove...... that reversing the map update operations produces the exact reverse changes, we show an isomorphism between the set of complex operations on the kinetic Voronoi diagram of points and open oriented line segments and the sets of numbers of new / deleted Voronoi regions induced by these operations, and its...

Reversal of Blindness in Animal Models of Leber Congenital Amaurosis Using Optimized AAV2-mediated Gene Transfer

OpenAIRE

Bennicelli, Jeannette; Wright, John Fraser; Komaromy, Andras; Jacobs, Jonathan B; Hauck, Bernd; Zelenaia, Olga; Mingozzi, Federico; Hui, Daniel; Chung, Daniel; Rex, Tonia S; Wei, Zhangyong; Qu, Guang; Zhou, Shangzhen; Zeiss, Caroline; Arruda, Valder R

2008-01-01

We evaluated the safety and efficacy of an optimized adeno-associated virus (AAV; AAV2.RPE65) in animal models of the RPE65 form of Leber congenital amaurosis (LCA). Protein expression was optimized by addition of a modified Kozak sequence at the translational start site of hRPE65. Modifications in AAV production and delivery included use of a long stuffer sequence to prevent reverse packaging from the AAV inverted-terminal repeats, and co-injection with a surfactant. The latter allows consis...

Atrioventricular Pacemaker Lead Reversal

Directory of Open Access Journals (Sweden)

Mehmet K Aktas, MD

2007-01-01

Full Text Available During cardiac surgery temporary epicardial atrial and ventricular leads are placed in case cardiac pacing is required postoperatively. We present the first reported series of patients with reversal of atrioventricular electrodes in the temporary pacemaker without any consequent deleterious hemodynamic effect. We review the electrocardiographic findings and discuss the findings that lead to the discovery of atrioventricular lead reversal.

Reversal of Cocaine-Associated Synaptic Plasticity in Medial Prefrontal Cortex Parallels Elimination of Memory Retrieval.

Science.gov (United States)

Otis, James M; Mueller, Devin

2017-09-01

Addiction is characterized by abnormalities in prefrontal cortex that are thought to allow drug-associated cues to drive compulsive drug seeking and taking. Identification and reversal of these pathologic neuroadaptations are therefore critical for treatment of addiction. Previous studies using rodents reveal that drugs of abuse cause dendritic spine plasticity in prelimbic medial prefrontal cortex (PL-mPFC) pyramidal neurons, a phenomenon that correlates with the strength of drug-associated memories in vivo. Thus, we hypothesized that cocaine-evoked plasticity in PL-mPFC may underlie cocaine-associated memory retrieval, and therefore disruption of this plasticity would prevent retrieval. Indeed, using patch clamp electrophysiology we find that cocaine place conditioning increases excitatory presynaptic and postsynaptic transmission in rat PL-mPFC pyramidal neurons. This was accounted for by increases in excitatory presynaptic release, paired-pulse facilitation, and increased AMPA receptor transmission. Noradrenergic signaling is known to maintain glutamatergic plasticity upon reactivation of modified circuits, and we therefore next determined whether inhibition of noradrenergic signaling during memory reactivation would reverse the cocaine-evoked plasticity and/or disrupt the cocaine-associated memory. We find that administration of the β-adrenergic receptor antagonist propranolol before memory retrieval, but not after (during memory reconsolidation), reverses the cocaine-evoked presynaptic and postsynaptic modifications in PL-mPFC and causes long-lasting memory impairments. Taken together, these data reveal that cocaine-evoked synaptic plasticity in PL-mPFC is reversible in vivo, and suggest a novel strategy that would allow normalization of prefrontal circuitry in addiction.

Introduction to time reversal theory

International Nuclear Information System (INIS)

Henley, E.M.

1987-01-01

Theory and reaction mechanisms relevant to time reversal invariance are reviewed. Consequences of time reversal invariance are presented under the headings of CP tests, electromagnetic moments, weak emissions or absorptions, and scattering reactions. 8 refs., 4 figs

Characterisation of a novel reverse-biased PPD CMOS image sensor

Science.gov (United States)

Stefanov, K. D.; Clarke, A. S.; Ivory, J.; Holland, A. D.

2017-11-01

A new pinned photodiode (PPD) CMOS image sensor (CIS) has been developed and characterised. The sensor can be fully depleted by means of reverse bias applied to the substrate, and the principle of operation is applicable to very thick sensitive volumes. Additional n-type implants under the pixel p-wells, called Deep Depletion Extension (DDE), have been added in order to eliminate the large parasitic substrate current that would otherwise be present in a normal device. The first prototype has been manufactured on a 18 μm thick, 1000 Ω .cm epitaxial silicon wafers using 180 nm PPD image sensor process at TowerJazz Semiconductor. The chip contains arrays of 10 μm and 5.4 μm pixels, with variations of the shape, size and the depth of the DDE implant. Back-side illuminated (BSI) devices were manufactured in collaboration with Teledyne e2v, and characterised together with the front-side illuminated (FSI) variants. The presented results show that the devices could be reverse-biased without parasitic leakage currents, in good agreement with simulations. The new 10 μm pixels in both BSI and FSI variants exhibit nearly identical photo response to the reference non-modified pixels, as characterised with the photon transfer curve. Different techniques were used to measure the depletion depth in FSI and BSI chips, and the results are consistent with the expected full depletion.

Vasectomy reversal: a clinical update

Directory of Open Access Journals (Sweden)

Abhishek P Patel

2016-01-01

Full Text Available Vasectomy is a safe and effective method of contraception used by 42-60 million men worldwide. Approximately 3%-6% of men opt for a vasectomy reversal due to the death of a child or divorce and remarriage, change in financial situation, desire for more children within the same marriage, or to alleviate the dreaded postvasectomy pain syndrome. Unlike vasectomy, vasectomy reversal is a much more technically challenging procedure that is performed only by a minority of urologists and places a larger financial strain on the patient since it is usually not covered by insurance. Interest in this procedure has increased since the operating microscope became available in the 1970s, which consequently led to improved patency and pregnancy rates following the procedure. In this clinical update, we discuss patient evaluation, variables that may influence reversal success rates, factors to consider in choosing to perform vasovasostomy versus vasoepididymostomy, and the usefulness of vasectomy reversal to alleviate postvasectomy pain syndrome. We also review the use of robotics for vasectomy reversal and other novel techniques and instrumentation that have emerged in recent years to aid in the success of this surgery.

Reversible deep storage: reversibility options for storage in deep geological formations

International Nuclear Information System (INIS)

2009-01-01

This report describes the definition approach to reversibility conditions, presents the main characteristics of high-activity and intermediate-activity long-lived wastes, describes the storage in deep geological formations (safety functions, general description of the storage centre), discusses the design options for the different types of wastes (container, storage module, handling processes, phenomenological analysis, monitoring arrangements) and the decision process in support reversibility (steering of the storage process, progressive development and step-by-step closing), and reports and discusses the researches concerning the memory of the storage site

Chemical reactions in reverse micelle systems

Science.gov (United States)

Matson, Dean W.; Fulton, John L.; Smith, Richard D.; Consani, Keith A.

1993-08-24

This invention is directed to conducting chemical reactions in reverse micelle or microemulsion systems comprising a substantially discontinuous phase including a polar fluid, typically an aqueous fluid, and a microemulsion promoter, typically a surfactant, for facilitating the formation of reverse micelles in the system. The system further includes a substantially continuous phase including a non-polar or low-polarity fluid material which is a gas under standard temperature and pressure and has a critical density, and which is generally a water-insoluble fluid in a near critical or supercritical state. Thus, the microemulsion system is maintained at a pressure and temperature such that the density of the non-polar or low-polarity fluid exceeds the critical density thereof. The method of carrying out chemical reactions generally comprises forming a first reverse micelle system including an aqueous fluid including reverse micelles in a water-insoluble fluid in the supercritical state. Then, a first reactant is introduced into the first reverse micelle system, and a chemical reaction is carried out with the first reactant to form a reaction product. In general, the first reactant can be incorporated into, and the product formed in, the reverse micelles. A second reactant can also be incorporated in the first reverse micelle system which is capable of reacting with the first reactant to form a product.

Status of time reversal invariance

International Nuclear Information System (INIS)

Henley, E.M.

1989-01-01

Time Reversal Invariance is introduced, and theories for its violation are reviewed. The present experimental and theoretical status of Time Reversal Invariance and tests thereof will be presented. Possible future tests will be discussed. 30 refs., 2 figs., 1 tab

Comparison between reverse Brayton and Kapitza based LNG boil-off gas reliquefaction system using exergy analysis

Science.gov (United States)

Kochunni, Sarun Kumar; Chowdhury, Kanchan

2017-02-01

LNG boil-off gas (BOG) reliquefaction systems in LNG carrier ships uses refrigeration devices which are based on reverse Brayton, Claude, Kapitza (modified Claude) or Cascade cycles. Some of these refrigeration devices use nitrogen as the refrigerants and hence nitrogen storage vessels or nitrogen generators needs to be installed in LNG carrier ships which consume space and add weight to the carrier. In the present work, a new configuration based on Kapitza liquefaction cycle which uses BOG itself as working fluid is proposed and has been compared with Reverse Brayton Cycle (RBC) on sizes of heat exchangers and compressor operating parameters. Exergy analysis is done after simulating at steady state with Aspen Hysys 8.6® and the comparison between RBC and Kapitza may help designers to choose reliquefaction system with appropriate process parameters and sizes of equipment. With comparable exergetic efficiency as that of an RBC, a Kaptiza system needs only BOG compressor without any need of nitrogen gas.

Modified Bluegrass Appliance: A Nonpunitive Therapy for Thumb Sucking in Pediatric Patients—A Case Report with Review of the Literature

Directory of Open Access Journals (Sweden)

Amish Diwanji

2013-01-01

Full Text Available Oral habits in form of digit/thumb sucking are common phenomenon and part of childhood behavior. They are normally associated with oral pleasure, hunger, anxiety, and sometimes psychological disturbances. Chronic practice can cause major orthopedic alterations to the skeletal structures of the oral cavity and lower face. Aversive approaches in form of punitive therapy have been moderately effective. Modified bluegrass appliance is nonpunitive therapy to treat sucking habits. It acts as a habit reversal technique and installs positive reinforcement in children. Modified blue grass appliance proved to be very comfortable to patients and encourages neuromuscular stimulations.

Towards a reversible functional language

DEFF Research Database (Denmark)

Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

2012-01-01

/equality operator also simplifies inverse computation and program inversion. We discuss the advantages of a reversible functional language using example programs, including run-length encoding. Program inversion is seen to be as lightweight as for imperative reversible languages and realized by recursive descent...

How decision reversibility affects motivation

NARCIS (Netherlands)

Bullens, L.; van Harreveld, F.; Förster, J.; Higgins, T.E.

2014-01-01

The present research examined how decision reversibility can affect motivation. On the basis of extant findings, it was suggested that 1 way it could affect motivation would be to strengthen different regulatory foci, with reversible decision making, compared to irreversible decision making,

Reversible networks in supramolecular polymers

NARCIS (Netherlands)

Havermans - van Beek, D.J.M.

2007-01-01

Non–covalent interactions between low molecular weight polymers form the basis of supramolecular polymers. The material properties of such polymers are determined by the strength and lifetime of the non–covalent reversible interactions. Due to the reversibility of the interactions between the low

Sex reversal in vertebrates

OpenAIRE

2016-01-01

This special topic issue of Sexual Development gives an overview of sex reversal in vertebrates, from fishes naturally changing their sex, to rodents escaping the mammalian SRY-determining system. It offers eight up-to-date reviews on specific subjects in sex reversal, considering fishes, amphibians, reptiles, birds, marsupials, and placental mammals, including humans. The broad scope of represented animals makes this ideal for students and researchers, especially those interested in the...

Enzymatic reactions in reversed micelles

NARCIS (Netherlands)

Hilhorst, M.H.

1984-01-01

It has been recognised that enzymes in reversed micelles have potential for application in chemical synthesis. Before these expectations will be realised many problems must be overcome. This thesis deals with some of them.
In Chapter 1 the present knowledge about reversed micelles and

Reversible arithmetic logic unit for quantum arithmetic

DEFF Research Database (Denmark)

Thomsen, Michael Kirkedal; Glück, Robert; Axelsen, Holger Bock

2010-01-01

This communication presents the complete design of a reversible arithmetic logic unit (ALU) that can be part of a programmable reversible computing device such as a quantum computer. The presented ALU is garbage free and uses reversible updates to combine the standard reversible arithmetic...... and logical operations in one unit. Combined with a suitable control unit, the ALU permits the construction of an r-Turing complete computing device. The garbage-free ALU developed in this communication requires only 6n elementary reversible gates for five basic arithmetic-logical operations on two n......-bit operands and does not use ancillae. This remarkable low resource consumption was achieved by generalizing the V-shape design first introduced for quantum ripple-carry adders and nesting multiple V-shapes in a novel integrated design. This communication shows that the realization of an efficient reversible...

Reverse engineering for quality systems

International Nuclear Information System (INIS)

Nolan, A.J.

1995-01-01

When the age of software engineering began, many companies were faced with a problem of how to support the older, pre-software-engineering, programs. The techniques of reverse engineering and re-engineering were developed to bridge the gap between the past and the present. Although reverse engineering can be used for generating missing documentation, it can also be used as a means to demonstrate quality in these older programs. This paper presents, in the form of a case study, how Rolls-Royce and Associates Limited addressed the quality issues of reverse engineering and re-engineering. (author)

Field reversal in mirror machines

International Nuclear Information System (INIS)

Pearlstein, L.D.; Anderson, D.V.; Boozer, A.H.

1978-01-01

This report discusses some of the physics issues anticipated in field-reversed mirrors. The effect of current cancellation due to electrons is described. An estimate is made of the required impurity level to maintain a field-reversed configuration. The SUPERLAYER code is used to simulate the high-β 2XIIB results, and favorable comparisons require inclusion of quasilinear RF turbulence. Impact of a quadrupole field on field-line closure and resonant transport is discussed. A simple self-consistent model of ion currents is presented. Conditions for stability of field-reversed configurations to E x B driven rotations are determined

Comprendre l'expérience de lecteurs désengagés lors d'un projet de cercle de lecture au sein d'une équipe de hockey de jeunes garçons au Canada

Directory of Open Access Journals (Sweden)

Jolicoeur Manon

2015-01-01

Full Text Available Cette recherche collaborative réunissant un entraineur de hockey et une chercheuse vise à décrire l'impact de l'expérimentation d'un dispositif de cercle de lecture auprès d'une équipe de jeunes garçons francophones de 9 et 10 ans du Nouveau-Brunswick (Canada. L'étude se penche particulièrement sur le vécu de trois lecteurs désengagés participant au projet. L'analyse qualitative des données recueillies par entrevues, questionnaires et observations démontre que la motivation a été soutenue et généralisée durant toute la tenue du cercle de lecture et que les lecteurs désengagés ont évolué vers l'engagement.

Direct electron transfer of horseradish peroxidase on Nafion-cysteine modified gold electrode

International Nuclear Information System (INIS)

Hong, Jun; Moosavi-Movahedi, Ali Akbar; Ghourchian, Hedayatollah; Rad, Ahmad Molaei; Rezaei-Zarchi, Saeed

2007-01-01

Direct electron transfer of horseradish peroxidase, immobilized on a functional membrane-modified gold electrode, was studied. The electrode showed a quasi-reversible electrochemical redox behavior with a formal potential of 60mV (versus Ag/AgCl) in 20mM potassium phosphate buffer solution at pH 7.0 and temperature 25 o C. The cathodic transfer coefficient was 0.42 and electron transfer rate constant was evaluated to be 1.6s -1 . Furthermore, the modified electrode was used as a biosensor and exhibited a satisfactory stability and sensitivity to H 2 O 2 . The linear range of this biosensor for H 2 O 2 determination was from 5.0x10 -6 to 1.5x10 -4 M while its detection limit, based on a signal-to-noise ratio of 3, was 1.3x10 -6 M. The apparent Michaelis-Menten constant (K m app ) for immobilized HRP was calculated to be 1.6x10 -4 M

Nicotine Modifies Corticostriatal Plasticity and Amphetamine Rewarding Behaviors in Mice123

Science.gov (United States)

Storey, Granville P.; Heimbigner, Lauren; Walwyn, Wendy M.; Bamford, Nigel S.

2016-01-01

Abstract Corticostriatal signaling participates in sensitized responses to drugs of abuse, where short-term increases in dopamine availability provoke persistent, yet reversible, changes in glutamate release. Prior studies in mice show that amphetamine withdrawal promotes a chronic presynaptic depression in glutamate release, whereas an amphetamine challenge reverses this depression by potentiating corticostriatal activity in direct pathway medium spiny neurons. This synaptic plasticity promotes corticostriatal activity and locomotor sensitization through upstream changes in the activity of tonically active cholinergic interneurons (ChIs). We used a model of operant drug-taking behaviors, in which mice self-administered amphetamine through an in-dwelling catheter. Mice acquired amphetamine self-administration under fixed and increasing schedules of reinforcement. Following a period of abstinence, we determined whether nicotinic acetylcholine receptors modified drug-seeking behavior and associated alterations in ChI firing and corticostriatal activity. Mice responding to conditioned reinforcement showed reduced ChI and corticostriatal activity ex vivo, which paradoxically increased following an amphetamine challenge. Nicotine, in a concentration that increases Ca2+ influx and desensitizes α4β2*-type nicotinic receptors, reduced amphetamine-seeking behaviors following abstinence and amphetamine-induced locomotor sensitization. Nicotine blocked the depression of ChI firing and corticostriatal activity and the potentiating response to an amphetamine challenge. Together, these results demonstrate that nicotine reduces reward-associated behaviors following repeated amphetamine and modifies the changes in ChIs firing and corticostriatal activity. By returning glutamatergic activity in amphetamine self-administering mice to a more stable and normalized state, nicotine limits the depression of striatal activity in withdrawal and the increase in activity following

Effect of CO{sub 2}-laser irradiation on properties and performance of thin-film composite polyamide reverse osmosis membrane

Energy Technology Data Exchange (ETDEWEB)

Jahangiri, Foad; Mousavi, Seyyed Abbas; Farhadi, Fathollah; Sabzi, Behnam; Chenari, Zeinab [Sharif University of Technology, Tehran (Iran, Islamic Republic of); Vatanpour, Vahid [Kharazmi (Tarbiat Moallem) University, Tehran (Iran, Islamic Republic of)

2016-03-15

CO{sub 2}-laser irradiation was used to modify the surface properties of thin-film composite (TFC) polyamide reverse osmosis (RO) membranes. These membranes were first synthesized via interfacial polymerization of m-phenylenediamine (MPD) monomers and trimesoyl chloride (TMC) over porous polysulfone ultrafiltration support, followed by a CO{sub 2}-irradiation. AFM, ATR-FTIR, SEM and contact angle measurements were used to characterize the surface properties of these membranes. The ATR-FTIR results indicated that CO{sub 2}-laser irradiation did not induce any functional groups on the membrane surface. However, it was found that the laser irradiation enhanced the NaCl salt rejection and slightly reduced the permeate flux. Moreover, the maintenance of the flux in modified membranes was much higher than untreated ones. Specially, after 180 min of filtration, the reduction in initial flux for the unmodified membranes was 22%. However, the reduction in initial flux for the modified membranes was less than 5%. Bovine serum albumin (BSA) filtration revealed an improvement in the antifouling properties of the modified membranes. The changes in the membrane surface morphology showed that the roughness of membrane surface is reduced significantly.

Effect of manual therapy versus proprioceptive neuromuscular facilitation in dynamic balance, mobility and flexibility in field hockey players. A randomized controlled trial.

Science.gov (United States)

Espí-López, Gemma V; López-Martínez, Susana; Inglés, Marta; Serra-Añó, Pilar; Aguilar-Rodríguez, Marta

2018-04-22

To compare the effectiveness of a specific Manual Therapy (MT) protocol applied to field hockey players (FHP), versus a Proprioceptive Neuromuscular Facilitation (PNF) protocol, in the improvement of dynamic balance, active range of movement and lumbar flexibility one-week and four-weeks after the treatment. Randomized controlled trial. Participants were assigned to 2 groups: MT and PNF. 30 min' sessions were performed once a week for three weeks. Three evaluations were performed: basal, one-week and four-weeks post-treatment. University of Valencia (Spain). 22 in MT group and 20 in PNF group. Dynamic Balance, measured with Star Excursion Balance Test; Active Range of Motion (ROM), using a manual goniometer and Lumbar Flexibility, assessed with Fingertip-to-floor test. Both groups significantly improved in lateral and medial dynamic balance one-week post-treatment (p < 0.05); but the improvement in the MT group lasted until the fourth-week after treatment in both reaches (lateral and medial) (p < 0.05). MT group also obtained significant improvements in dorsal flexion of the ankle in the fourth-week post-treatment (p < 0.05) and in lumbar flexibility one-week post-treatment (p < 0.05). MT and PNF improve dynamic balance one-week post-treatment; however, the improvement obtained through MT is maintained four-weeks later. Only MT improves dorsal flexion of the ankle four-weeks post-treatment and lumbar flexibility one-week post-treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Changes of the morphological characteristics in a professional ice hockey player with regard to the eight week intensive fitness training: case study

Directory of Open Access Journals (Sweden)

Sigmund Martin

2013-01-01

Full Text Available The present study deals with monitoring the changes of the morphological characteristics in a professional hockey player (NHL aged 22.5 years with regard to the eight weeks intensive fitness training. Fitness training occurred off the ice surface. To determine the body composition, the method of BIA and anthropometric procedure is used (Matiegka, Pařízková. Measurements were carried out in accordance with the recommended national and international standards. An effect size of the differences in the selected individual values measured at different times was assessed using 95% of confidence interval. Significant changes occur primarily at the level of body composition. Overall, the increase in fat free mass was 4 kg to the weight 79.3 kg (BIA. Representation of muscle increased from 51.4% to 54.5% (Matiegka. In absolute terms it is the increase in muscle from 47.1 kg to 49.9 kg. Body fat percentage decreased from 12.9% to 9.7% (Matiegka. This represents a reduction of 2.9 kg. There is no change at the level of skeletal and residual fractions. With regard to the eight week fitness training the major morhpohogical changes (80-90% are experienced during the first half of the training (4 weeks. The survey results are of immediate use in the professional practice of the monitored player. It allows specific modifications to the training of the monitored player as well as other cooperating individuals in the chosen specialization.

Sex Reversal in Birds.

Science.gov (United States)

Major, Andrew T; Smith, Craig A

2016-01-01

Sexual differentiation in birds is controlled genetically as in mammals, although the sex chromosomes are different. Males have a ZZ sex chromosome constitution, while females are ZW. Gene(s) on the sex chromosomes must initiate gonadal sex differentiation during embryonic life, inducing paired testes in ZZ individuals and unilateral ovaries in ZW individuals. The traditional view of avian sexual differentiation aligns with that expounded for other vertebrates; upon sexual differentiation, the gonads secrete sex steroid hormones that masculinise or feminise the rest of the body. However, recent studies on naturally occurring or experimentally induced avian sex reversal suggest a significant role for direct genetic factors, in addition to sex hormones, in regulating sexual differentiation of the soma in birds. This review will provide an overview of sex determination in birds and both naturally and experimentally induced sex reversal, with emphasis on the key role of oestrogen. We then consider how recent studies on sex reversal and gynandromorphic birds (half male:half female) are shaping our understanding of sexual differentiation in avians and in vertebrates more broadly. Current evidence shows that sexual differentiation in birds is a mix of direct genetic and hormonal mechanisms. Perturbation of either of these components may lead to sex reversal. © 2016 S. Karger AG, Basel.

Reverse engineering of RFID devices

NARCIS (Netherlands)

Bokslag, W.

2015-01-01

This paper discusses the relevance and potential impact of both RFID and reverse engineering of RFID technology, followed by a discussion of common protocols and internals of RFID technology. The focus of the paper is on providing an overview of the different approaches to reverse engineering RFID

Extreme reversed sexual dichromatism in a bird without sex role reversal.

Science.gov (United States)

Heinsohn, Robert; Legge, Sarah; Endler, John A

2005-07-22

Brilliant plumage is typical of male birds, reflecting differential enhancement of male traits when females are the limiting sex. Brighter females are thought to evolve exclusively in response to sex role reversal. The striking reversed plumage dichromatism of Eclectus roratus parrots does not fit this pattern. We quantify plumage color in this species and show that very different selection pressures are acting on males and females. Male plumage reflects a compromise between the conflicting requirements for camouflage from predators while foraging and conspicuousness during display. Females are liberated from the need for camouflage but compete for rare nest hollows.

Economic impact of reversion

International Nuclear Information System (INIS)

2005-01-01

Estimations of the Norwegian hydropower production and various reversion models' market value have been made. The value of the Norwegian hydropower production until 01.01.2007 is estimated to about Nok 289 billion after taxes, or about 2,42 Nok/kWh medium production, given an expected future electricity price of around 0,25 Nok/kWh and a discount rate at 6,5 percent in nominal terms after taxes. The estimate is slightly above the level of prices for Norwegian hydropower plants in the last 8-10 years. The value of reversion in private plants which today have a limited licence time is estimated to Nok 5,5 billion. The value of reversion in public-owned Norwegian hydropower plants are about Nok 21 billion with a 60 year licence period from 01.01.2007, and about 12 billion for 75 years (ml)

Synthesis, spectroscopic analysis and electrochemical performance of modified β-nickel hydroxide electrode with CuO

Directory of Open Access Journals (Sweden)

B. Shruthi

2017-03-01

Full Text Available In the present work, a modified β-nickel hydroxide (β-Ni(OH2 electrode material with CuO has been prepared using a co-precipitation method. The structure and property of the modified β-Ni(OH2 with CuO were characterized by X-ray diffraction (XRD, Fourier Transform infra-red (FT-IR, Raman and thermal gravimetric-differential thermal analysis (TG-DTA techniques. The results of the FT-IR spectroscopy and TG-DTA indicate that the modified β-Ni(OH2 electrode materials contain intercalated water molecules and anions. A pasted–type electrode was prepared using nickel hydroxide powder as the main active material on a nickel sheet as a current collector. Cyclic voltammetry (CV and Electrochemical impedance spectroscopy (EIS studies were undertaken to assess the electrochemical behavior of pure β-Ni(OH2 and modified β-Ni(OH2 electrode with CuO in a 6 M KOH electrolyte. The addition of CuO into β-nickel hydroxide was found to enhance the reversibility of the electrode reaction and also increase the separation of the oxidation current peak of the active material from the oxygen evolution current. The modified nickel hydroxide with CuO was also found to exhibit a higher proton diffusion coefficient and a lower charge transfer resistance. These findings suggest that the modified β-Ni(OH2 with CuO possesses an enhanced electrochemical response and thus can be recognized as a promising candidate for battery electrode applications.

Preparation of catechol-linked chitosan/carbon nanocomposite-modified electrode and its applications

Energy Technology Data Exchange (ETDEWEB)

Jirimali, Harishchandra Digambar; Saravanakumar, Duraisamy; Shin, Woon Sup [Dept. of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul (Korea, Republic of)

2015-04-15

In this study, we report the synthesis of 2,3-dihydroxybenzaldehyde (catechol)-linked chitosan (cat-chitosan) and the preparation of its composite with carbon (cat-chitosan/carbon) to construct a catechol-modified electrode. The synthesis is similar to our previous work on hydroquinone–chitosan/carbon composite electrode. We synthesized catechol-linked chitosan polymer and prepared the its composite electrode with carbon. The catchitosan/carbon composite electrode shows a reversible confined redox behavior by the catechol functional group. The electrode catalyzes the oxidation of NADH. It has Cu{sup 2+} ion-binding capability and its binding constant 8.7 μM.

Preparation of catechol-linked chitosan/carbon nanocomposite-modified electrode and its applications

International Nuclear Information System (INIS)

Jirimali, Harishchandra Digambar; Saravanakumar, Duraisamy; Shin, Woon Sup

2015-01-01

In this study, we report the synthesis of 2,3-dihydroxybenzaldehyde (catechol)-linked chitosan (cat-chitosan) and the preparation of its composite with carbon (cat-chitosan/carbon) to construct a catechol-modified electrode. The synthesis is similar to our previous work on hydroquinone–chitosan/carbon composite electrode. We synthesized catechol-linked chitosan polymer and prepared the its composite electrode with carbon. The catchitosan/carbon composite electrode shows a reversible confined redox behavior by the catechol functional group. The electrode catalyzes the oxidation of NADH. It has Cu"2"+ ion-binding capability and its binding constant 8.7 μM.

Reverse-symmetry waveguides: Theory and fabrication

DEFF Research Database (Denmark)

Horvath, R.; Lindvold, Lars René; Larsen, N.B.

2002-01-01

We present an extensive theoretical analysis of reverse-symmetry waveguides with special focus on their potential application as sensor components in aqueous media and demonstrate a novel method for fabrication of such waveguides. The principle of reverse symmetry is based on making the refractive...... index of the waveguide substrate less than the refractive index of the medium covering the waveguiding film (n(water) = 1.33). This is opposed to the conventional waveguide geometry, where the substrate is usually glass or polymers with refractive indices of approximate to1.5. The reverse configuration...... are combined with air-grooved polymer supports to form freestanding single-material polymer waveguides of reverse symmetry capable of guiding light....

Design of a novel quantum reversible ternary up-counter

Science.gov (United States)

Houshmand, Pouran; Haghparast, Majid

2015-08-01

Reversible logic has been recently considered as an interesting and important issue in designing combinational and sequential circuits. The combination of reversible logic and multi-valued logic can improve power dissipation, time and space utilization rate of designed circuits. Only few works have been reported about sequential reversible circuits and almost there are no paper exhibited about quantum ternary reversible counter. In this paper, first we designed 2-qutrit and 3-qutrit quantum reversible ternary up-counters using quantum ternary reversible T-flip-flop and quantum reversible ternary gates. Then we proposed generalized quantum reversible ternary n-qutrit up-counter. We also introduced a new approach for designing any type of n-qutrit ternary and reversible counter. According to the results, we can conclude that applying second approach quantum reversible ternary up-counter is better than the others.

Fibrinogen Motif Discriminates Platelet and Cell Capture in Peptide-Modified Gold Micropore Arrays.

Science.gov (United States)

Adamson, Kellie; Spain, Elaine; Prendergast, Una; Moran, Niamh; Forster, Robert J; Keyes, Tia E

2018-01-16

Human blood platelets and SK-N-AS neuroblastoma cancer-cell capture at spontaneously adsorbed monolayers of fibrinogen-binding motifs, GRGDS (generic integrin adhesion), HHLGGAKQAGDV (exclusive to platelet integrin α IIb β 3 ), or octanethiol (adhesion inhibitor) at planar gold and ordered 1.6 μm diameter spherical cap gold cavity arrays were compared. In all cases, arginine/glycine/aspartic acid (RGD) promoted capture, whereas alkanethiol monolayers inhibited adhesion. Conversely only platelets adhered to alanine/glycine/aspartic acid (AGD)-modified surfaces, indicating that the AGD motif is recognized preferentially by the platelet-specific integrin, α IIb β 3 . Microstructuring of the surface effectively eliminated nonspecific platelet/cell adsorption and dramatically enhanced capture compared to RGD/AGD-modified planar surfaces. In all cases, adhesion was reversible. Platelets and cells underwent morphological change on capture, the extent of which depended on the topography of the underlying substrate. This work demonstrates that both the nature of the modified interface and its underlying topography influence the capture of cancer cells and platelets. These insights may be useful in developing cell-based cancer diagnostics as well as in identifying strategies for the disruption of platelet cloaks around circulating tumor cells.

Kinematic reversal schemes for the geomagnetic dipole.

Science.gov (United States)

Levy, E. H.

1972-01-01

Fluctuations in the distribution of cyclonic convective cells, in the earth's core, can reverse the sign of the geomagnetic field. Two kinematic reversal schemes are discussed. In the first scheme, a field maintained by cyclones concentrated at low latitude is reversed by a burst of cyclones at high latitude. Conversely, in the second scheme, a field maintained predominantly by cyclones in high latitudes is reversed by a fluctuation consisting of a burst of cyclonic convection at low latitude. The precise fluid motions which produce the geomagnetic field are not known. However, it appears that, whatever the details are, a fluctuation in the distribution of cyclonic cells over latitude can cause a geomagnetic reversal.

Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2

International Nuclear Information System (INIS)

Anderson, D.V.; Auerbach, S.P.; Berk, H.L.

1980-01-01

Experimental and theoretical studies of field reversal in a mirror machine are reported. Plasma-gun experiments demonstrate that reversed-field plasma layers are formed. Low energy plasma flowing behind the initially produced plasma front prevents tearing of the layer from the gun muzzle. MHD simulation shows that tearing can be obtained by impeding the slow plasma flow with a plasma divider. It is demonstrated theoretically that a field-reversed mirror imbedded in a multipole field can be sustained in steady state with neutral-beam injection even in the absence of impurities. MHD stability analysis shows that growth rates of elongated reversed-field theta-pinch configurations decrease with axial extension, which indicates the importance of including finite Larmor radius in the analysis. Tilting-mode criteria are improved by proper shaping, and a problimak shape is proposed. Tearing mode stability of reversed-field theta-pinches is greatly enhanced by flux exclusion. Self-consistent, 1-1/2-dimensional transport codes have been developed, and initial results are presented

Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2

International Nuclear Information System (INIS)

Anderson, D.V.; Auerbach, S.P.; Berk, H.L.

1980-01-01

Experimental and theoretical studies of field reversal in a mirror machine are reported. Plasma-gun experiments demonstrate that reversed-field plasma layers are formed. Low energy plasma flowing behind the initially produced plasma front prevents tearing of the layer from the gun muzzle. MHD simulation shows that tearing can be obtained by impeding the slow plasma flow with a plasma divider. It is demonstrated theoretically that a field-reversed mirror imbedded in a multipole field can be sustained in steady state with neutral-beam injection even in the absence of impurities. MHD stability analysis shows that growth rates of elongated reversed-field theta-pinch configurations decrease with axial extension, which indicates the importance of including finite Larmor radius in the analysis. Tilting-mode criteria are dramatically improved by proper shaping, and a problimak shape is proposed. Tearing mode stability of reversed-field theta-pinches is greatly enhanced by flux exclusion. Self-consistent, 1-1/2-dimensional transport codes have been developed, and initial results are presented

Hydrogen Storage Properties of Lithium Aluminohydride Modified by Dopants and Mechanochemistry

Energy Technology Data Exchange (ETDEWEB)

Hosokawa, Ketia [Iowa State Univ., Ames, IA (United States)

2002-01-01

Alkali metal aluminohydrides have high potential as solid hydrogen storage materials. They have been known for their irreversible dehydrogenation process below 100 atm until Bogdanovic et al succeeded in the re-hydrogenation of NaAlH₄ below 70 atm. They achieved 4 wt.% H₂ reversible capacity by doping NaAlH₄ with Ti and/or Fe organo-metallic compounds as catalysts. This suggests that other alkali and, possibly alkaline earth metal aluminohydrides can be used for reversible hydrogen storage when modified by proper dopants. In this research, Zr₂₇Ti₉Ni₃₈V₅Mn₁₆Cr₅, LaNi _4.85Sn_0.15, Al₃Ti, and PdCl₂ were combined with LiAlH₄ by ball-milling to study whether or not LiAlH₄ is capable to both absorb and desorb hydrogen near ambient conditions. X-ray powder diffraction, differential thermal analysis, and scanning electron microscopy were employed for sample characterizations. All four compounds worked as catalysts in the dehydrogenation reactions of both LiAlH₄ and Li₃AlH₆ by inducing the decomposition at lower temperature. However, none of them was applicable as catalyst in the reverse hydrogenation reaction at low to moderate hydrogen pressure.

Reversible deep disposal

International Nuclear Information System (INIS)

2009-10-01

This presentation, given by the national agency of radioactive waste management (ANDRA) at the meeting of October 8, 2009 of the high committee for the nuclear safety transparency and information (HCTISN), describes the concept of deep reversible disposal for high level/long living radioactive wastes, as considered by the ANDRA in the framework of the program law of June 28, 2006 about the sustainable management of radioactive materials and wastes. The document presents the social and political reasons of reversibility, the technical means considered (containers, disposal cavities, monitoring system, test facilities and industrial prototypes), the decisional process (progressive development and blocked off of the facility, public information and debate). (J.S.)

Securing Biometric Images using Reversible Watermarking

OpenAIRE

Thampi, Sabu M.; Jacob, Ann Jisma

2011-01-01

Biometric security is a fast growing area. Protecting biometric data is very important since it can be misused by attackers. In order to increase security of biometric data there are different methods in which watermarking is widely accepted. A more acceptable, new important development in this area is reversible watermarking in which the original image can be completely restored and the watermark can be retrieved. But reversible watermarking in biometrics is an understudied area. Reversible ...

Metodika pro rozvoj techniky bruslení na bruslařském trenažeru

OpenAIRE

Soukup, Jan

2016-01-01

Title: Methodology for development of skating technique on a skatemill Goals: The objective of the present study is to compile available methodology knowledge re-garding the improvement of skating technique using a skatemill, and to analyse the pro-gress of skating technique in selected ice-hockey players during a comprehensive train-ing programme, where a skating simulator is used. Keywords: Ice Hockey, skatemill, kinematic analysis, hockey skills, motoric skills, ska-ting, modern aids. Powe...

Reverse genetics of avian metapneumoviruses

Science.gov (United States)

An overview of avian metapneumovirus (aMPV) infection in turkeys and development of a reverse genetics system for aMPV subgroup C (aMPV-C) virus will be presented. By using reverse genetics technology, we generated recombinant aMPV-C viruses containing a different length of glycoprotein (G) gene or...

Electric field-induced phase transitions in Li-modified Na{sub 0.5}K{sub 0.5}NbO{sub 3} at the polymorphic phase boundary

Energy Technology Data Exchange (ETDEWEB)

Iamsasri, Thanakorn; Jones, Jacob L., E-mail: jacobjones@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Tutuncu, Goknur [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Uthaisar, Chunmanus; Pojprapai, Soodkhet [School of Ceramic Engineering, Institute of Engineering, Suranaree University of Technology, Nakorn Ratchasima 30000 (Thailand); Wongsaenmai, Supattra [Program in Materials Science, Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand)

2015-01-14

The electric field-induced phase transitions in Li-modified Na{sub 0.5}K{sub 0.5}NbO{sub 3} at the polymorphic phase boundary (PPB) were observed using in situ X-ray diffraction. The ratio of monoclinic to tetragonal phase fraction was used as an indicator of the extent and reversibility of the phase transitions. The reversibility of the phase transition was greater in compositions further from the PPB. These results demonstrate that the field-induced phase transition is one of the origins of high piezoelectric properties in lead-free ferroelectric materials.

Reversal permanent charge and reversal potential: case studies via classical Poisson–Nernst–Planck models

International Nuclear Information System (INIS)

Eisenberg, Bob; Liu, Weishi; Xu, Hongguo

2015-01-01

In this work, we are interested in effects of a simple profile of permanent charges on ionic flows. We determine when a permanent charge produces current reversal. We adopt the classical Poisson–Nernst–Planck (PNP) models of ionic flows for this study. The starting point of our analysis is the recently developed geometric singular perturbation approach for PNP models. Under the setting in the paper for case studies, we are able to identify a single governing equation for the existence and the value of the permanent charge for a current reversal. A number of interesting features are established. The related topic on reversal potential can be viewed as a dual problem and is briefly examined in this work too. (paper)

THEORETICAL FRAMES FOR DESIGNING REVERSE LOGISTICS PROCESSES

OpenAIRE

Janusz K. Grabara; Sebastian Kot

2009-01-01

Logistics processes of return flow became more and more important in present business practice. Because of better customer satisfaction, environmental and financial aspects many enterprises deal with reverse logistics performance. The paper is a literature review focused on the design principles of reverse logistics processes Keywords: reverse logistics, designing.

Reversal of target-specific oral anticoagulants

Science.gov (United States)

Siegal, D.M.; Cuker, Adam

2014-01-01

Target-specific oral anticoagulants (TSOACs) provide safe and effective anticoagulation for the prevention and treatment of thrombosis in a variety of clinical settings by interfering with the activity of thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban, edoxaban, betrixaban). Although TSOACs have practical advantages over vitamin K antagonists (VKAs), there are currently no antidotes to reverse their anticoagulant effect. Herein we summarize the available evidence for TSOAC reversal using nonspecific and specific reversal agents. We discuss important limitations of existing evidence, which is derived from studies in human volunteers, animal models and in vitro experiments. Studies evaluating the safety and efficacy of reversal agents on clinical outcomes such as bleeding and mortality in patients with TSOAC-associated bleeding are needed. PMID:24880102

Optical reversible programmable Boolean logic unit.

Science.gov (United States)

Chattopadhyay, Tanay

2012-07-20

Computing with reversibility is the only way to avoid dissipation of energy associated with bit erase. So, a reversible microprocessor is required for future computing. In this paper, a design of a simple all-optical reversible programmable processor is proposed using a polarizing beam splitter, liquid crystal-phase spatial light modulators, a half-wave plate, and plane mirrors. This circuit can perform 16 logical operations according to three programming inputs. Also, inputs can be easily recovered from the outputs. It is named the "reversible programmable Boolean logic unit (RPBLU)." The logic unit is the basic building block of many complex computational operations. Hence the design is important in sense. Two orthogonally polarized lights are defined here as two logical states, respectively.

Synthesis of Environmentally Responsive Polymers by Atom Transfer Radical Polymerization: Generation of Reversible Hydrophilic and Hydrophobic Surfaces

Directory of Open Access Journals (Sweden)

Vikas Mittal

2010-05-01

Full Text Available Environmentally responsive poly(N-isopropylacrylamide brushes were grafted from the surface of polymer particles or flat surfaces in order to generate reversible hydrophilic and hydrophobic surfaces. The use of atom transfer radical polymerization was demonstrated for the grafting of polymer brushes as it allows efficient control on the amount of grafted polymer. The polymer particles were generated with or without surfactant in the emulsion polymerization and their surface could be modified with the atom transfer radical polymerization (ATRP initiator. The uniform functionalization of the surface with ATRP initiator was responsible for the uniform grafting of polymer brushes. The grafted brushes responded reversibly with changes in temperature indicating that the reversible responsive behavior could be translated to the particle surfaces. The particles were observed to adsorb and desorb protein and virus molecules by changing the temperatures below or higher than 32 °C. The initiator functionalized particles could also be adsorbed on the flat surfaces. The adsorption process also required optimization of the heat treatment conditions to form a uniform layer of the particles on the substrate. The grafted polymer brushes also responded to the changes in temperatures similar to the spherical particles studied through water droplets placed on the flat substrates.

Reversed-phase thin-layer chromatography behavior of aldopentose derivatives

Directory of Open Access Journals (Sweden)

Malbaša Radomir V.

2012-01-01

Full Text Available Quantitative structure-retention relationships (QSRR have been used to study the chromatographic behavior of some aldopentose. The behavior of aldopentose derivatives was investigated by means of the reversed-phase thin-layer chromatography (RP TLC on the silica gel impregnated with paraffin oil stationary phases. Binary mixtures of methanol-water, acetone-water and dioxane-water were used as mobile phases. Retention factors, RM0, corresponding to zero percent organic modifier in the aqueous mobile phase was determined. Lipophilicity C0 was calculated as the ratio of the intercept and slope values. There was satisfactory correlation between them and log P values calculated using different theoretical procedures. Some of these correlations offer very good predicting models, which are important for a better understanding of the relationships between chemical structure and retention. The study showed that the hydrophobic parameters RM0 and C0 can be used as a measures of lipophilicity of investigated compounds.

Time-Reversal MUSIC Imaging with Time-Domain Gating Technique

Science.gov (United States)

Choi, Heedong; Ogawa, Yasutaka; Nishimura, Toshihiko; Ohgane, Takeo

A time-reversal (TR) approach with multiple signal classification (MUSIC) provides super-resolution for detection and localization using multistatic data collected from an array antenna system. The theory of TR-MUSIC assumes that the number of antenna elements is greater than that of scatterers (targets). Furthermore, it requires many sets of frequency-domain data (snapshots) in seriously noisy environments. Unfortunately, these conditions are not practical for real environments due to the restriction of a reasonable antenna structure as well as limited measurement time. We propose an approach that treats both noise reduction and relaxation of the transceiver restriction by using a time-domain gating technique accompanied with the Fourier transform before applying the TR-MUSIC imaging algorithm. Instead of utilizing the conventional multistatic data matrix (MDM), we employ a modified MDM obtained from the gating technique. The resulting imaging functions yield more reliable images with only a few snapshots regardless of the limitation of the antenna arrays.

Reverse logistics in the construction industry.

Science.gov (United States)

Hosseini, M Reza; Rameezdeen, Raufdeen; Chileshe, Nicholas; Lehmann, Steffen

2015-06-01

Reverse logistics in construction refers to the movement of products and materials from salvaged buildings to a new construction site. While there is a plethora of studies looking at various aspects of the reverse logistics chain, there is no systematic review of literature on this important subject as applied to the construction industry. Therefore, the objective of this study is to integrate the fragmented body of knowledge on reverse logistics in construction, with the aim of promoting the concept among industry stakeholders and the wider construction community. Through a qualitative meta-analysis, the study synthesises the findings of previous studies and presents some actions needed by industry stakeholders to promote this concept within the real-life context. First, the trend of research and terminology related with reverse logistics is introduced. Second, it unearths the main advantages and barriers of reverse logistics in construction while providing some suggestions to harness the advantages and mitigate these barriers. Finally, it provides a future research direction based on the review. © The Author(s) 2015.

Electrochemical performance of SnO{sub 2}/modified graphite composite material as anode of lithium ion battery

Energy Technology Data Exchange (ETDEWEB)

Wang, Hong-Qiang [Guangxi Key Laboratory of Low Carbon Energy Materials, School of Chemical and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004 (China); Hubei Key Laboratory for Processing and Application of Catalytic Materials, Huanggang Normal University, Huanggang 438000 (China); Yang, Guan-Hua; Huang, You-Guo; Zhang, Xiao-Hui; Yan, Zhi-Xiong [Guangxi Key Laboratory of Low Carbon Energy Materials, School of Chemical and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004 (China); Li, Qing-Yu, E-mail: liqingyu62@126.com [Guangxi Key Laboratory of Low Carbon Energy Materials, School of Chemical and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004 (China)

2015-11-01

In this report, we synthesized SnO{sub 2}/modified graphite anode composite material by a simple reflux method using SnCl{sub 4}·5H{sub 2}O as tin source and modified graphite as carbon source. The as-obtained composite was investigated with the help of X-ray diffraction (XRD), scanning electron microscopy (SEM) and galvanostatic cycling tests. The results show that the composite has a wave-shaped fold structure and the SnO{sub 2} nanoparticles on it have an average size of about 50 nm. Compared to pure modified graphite, the SnO{sub 2}/modified graphite exhibits a better electrochemical performance with a reversible specific capacity of 581.7 mAh g{sup −1} after 80 cycles, owing to high mechanical stress and elasticity of modified graphite could hinder the volume effect of SnO{sub 2} nanoparticles during the Li{sup +} insertion/extraction process. All these favourable characters reveal that the composite is a great potential anode material in high-performance lithium ion batteries. - Highlights: • A simple synthetic method of SnO{sub 2}/modified graphite composite as anode. • The as-prepared composite with layered structure alleviates the huge reunion of SnO{sub 2}. • The composite exhibits a good capacity retention rate of 85.8% after 25 cycles.

Prefix reversals on binary and ternary strings

NARCIS (Netherlands)

Hurkens, C.A.J.; Iersel, van L.J.J.; Keijsper, J.C.M.; Kelk, S.M.; Stougie, L.; Tromp, J.T.

2007-01-01

Given a permutation $\\pi$, the application of prefix reversal $f^{(i)}$ to $\\pi$ reverses the order of the first $i$ elements of $\\pi$. The problem of sorting by prefix reversals (also known as pancake flipping), made famous by Gates and Papadimitriou (Discrete Math., 27 (1979), pp. 47–57), asks for

Reversal of laryngotracheal separation in paediatric patients.

LENUS (Irish Health Repository)

Young, Orla

2012-02-01

OBJECTIVE: Laryngotracheal separation (LTS) is an effective and reliable definitive treatment for intractable aspiration. A major advantage of this treatment for intractable aspiration is its\\' potential reversibility. Should the underlying disorder improve, a reversal of the procedure may be attempted. This has been successfully achieved in the adult population. To our knowledge, no previous cases have been reported of successful reversal of LTS in children. METHODS: A retrospective review from 2003 to 2010 identified four cases of intractable aspiration treated with LTS in our department. Two of these patients displayed objective evidence of sufficient recovery of their underlying aspiration to consider reversal. Patient selection for reversal was dependent upon successful oral intake for 9 months along with videofluoroscopic evidence of normal or minimally impaired swallow. RESULTS: Two children who were successfully treated for intractable aspiration with LTS demonstrated objective evidence of recovery sufficient to attempt reversal. Both children underwent successful surgical reversal of LTS using a cricotracheal resection with end-to-end anastamosis, similar to that used in treatment of subglottic stenosis. Both children can now tolerate oral diet and their speech and language development is in line with their overall developmental level. CONCLUSIONS: Laryngotracheal separation is an effective and reliable definitive treatment for intractable aspiration facilitating protection of the airway and allowing safe swallowing with unimpeded respiration, but with the major drawback of loss of phonation. To our knowledge, we document the first two cases of successful LTS reversal in children.

Epigenetic reversion of breast carcinoma phenotype is accompaniedby DNA sequestration

Energy Technology Data Exchange (ETDEWEB)

Sandal, Tone; Valyi-Nagy, Klara; Spencer, Virginia A.; Folberg,Robert; Bissell, Mina J.; Maniotis, Andrew J.

2006-07-19

The importance of microenvironment and context in regulation of tissue-specific genes is finally well established. DNA exposure to, or sequestration from, nucleases can be used to detect differences in higher order chromatin structure in intact cells without disturbing cellular or tissue architecture. To investigate the relationship between chromatin organization and tumor phenotype, we utilized an established 3-D assay where normal and malignant human breast cells can be easily distinguished by the morphology of the structures they make (acinus-like vs tumor-like, respectively). We show that these phenotypes can be distinguished also by sensitivity to AluI digestion where the malignant cells are resistant to digestion relative to non-malignant cells. Reversion of the T4-2 breast cancer cells by either cAMP analogs, or a phospatidylinositol 3-kinase (P13K) inhibitor not only reverted the phenotype, but also the chromatin sensitivity to AluI. By using different cAMP-analogs, we show that the cAMP-induced phenotypic reversion, polarization, and shift in DNA organization act through a cAMP-dependent-protein-kinase A-coupled signaling pathway. Importantly, inhibitory antibody to fibronectin also reverted the malignant phenotype, polarized the acini, and changed chromatin sequestration. These experiments show not only that modifying the tumor microenvironment can alter the organization of tumor cells but also that architecture of the tissues and the global chromatin organization are coupled and yet highly plastic.

Rotating Reverse-Osmosis for Water Purification

Science.gov (United States)

Lueptow, RIchard M.

2004-01-01

A new design for a water-filtering device combines rotating filtration with reverse osmosis to create a rotating reverse- osmosis system. Rotating filtration has been used for separating plasma from whole blood, while reverse osmosis has been used in purification of water and in some chemical processes. Reverse- osmosis membranes are vulnerable to concentration polarization a type of fouling in which the chemicals meant not to pass through the reverse-osmosis membranes accumulate very near the surfaces of the membranes. The combination of rotating filtration and reverse osmosis is intended to prevent concentration polarization and thereby increase the desired flux of filtered water while decreasing the likelihood of passage of undesired chemical species through the filter. Devices based on this concept could be useful in a variety of commercial applications, including purification and desalination of drinking water, purification of pharmaceutical process water, treatment of household and industrial wastewater, and treatment of industrial process water. A rotating filter consists of a cylindrical porous microfilter rotating within a stationary concentric cylindrical outer shell (see figure). The aqueous suspension enters one end of the annulus between the inner and outer cylinders. Filtrate passes through the rotating cylindrical microfilter and is removed via a hollow shaft. The concentrated suspension is removed at the end of the annulus opposite the end where the suspension entered.

Combining or Separating Forward and Reverse Logistics

DEFF Research Database (Denmark)

Herbert-Hansen, Zaza Nadja Lee; Larsen, Samuel; Nielsen, Anders

2018-01-01

Purpose – While forward logistics handles and manages the flow of goods downstream in the supply chain from suppliers to customers, reverse logistics (RL) manages the flow of returned goods upstream. A firm can combine reverse logistics with forward logistics, keep the flows separated, or choose......-research addresses intra-RL issues while the relationship between forward and reverse logistics is under-researched. This paper contributes to RL-theory by identifying the contextual factors that determine the most advantageous relationship between forward and reverse logistics, and proposes a novel decision making...

Sports betting: can gamblers beat randomness?

Science.gov (United States)

Cantinotti, Michael; Ladouceur, Robert; Jacques, Christian

2004-06-01

Although skills are not considered relevant in chance-governed activities, only a few studies have assessed the extent to which sport expert skills in wagering are a manifestation of the illusion of control. This study examined (a) whether expert hockey bettors could make better predictions than chance, (b) whether expert hockey bettors could achieve greater monetary gains than chance, and (c) what kind of strategies hockey gamblers rely on when betting. Accordingly, 30 participants were asked to report their state lottery hockey bets on 6 occasions. We suggest that the information used by bettors, along with near-misses, reinforces their perception of expertise. The results of this experiment suggest that the so-called "skills" of the sports bettors are cognitive distortions. (c) 2004 APA, all rights reserved

Parameter dependence of resonant spin torque magnetization reversal

International Nuclear Information System (INIS)

Fricke, L.; Serrano-Guisan, S.; Schumacher, H.W.

2012-01-01

We numerically study ultra fast resonant spin torque (ST) magnetization reversal in magnetic tunneling junctions (MTJ) driven by current pulses having a direct current (DC) and a resonant alternating current (AC) component. The precessional ST dynamics of the single domain MTJ free layer cell are modeled in the macro spin approximation. The energy efficiency, reversal time, and reversal reliability are investigated under variation of pulse parameters like direct and AC current amplitude, AC frequency and AC phase. We find a range of AC and direct current amplitudes where robust resonant ST reversal is obtained with faster switching time and reduced energy consumption per pulse compared to purely direct current ST reversal. However, for a certain range of AC and direct current amplitudes a strong dependence of the reversal properties on AC frequency and phase is found. Such regions of unreliable reversal must be avoided for ST memory applications.

Parameter dependence of resonant spin torque magnetization reversal

Science.gov (United States)

Fricke, L.; Serrano-Guisan, S.; Schumacher, H. W.

2012-04-01

We numerically study ultra fast resonant spin torque (ST) magnetization reversal in magnetic tunneling junctions (MTJ) driven by current pulses having a direct current (DC) and a resonant alternating current (AC) component. The precessional ST dynamics of the single domain MTJ free layer cell are modeled in the macro spin approximation. The energy efficiency, reversal time, and reversal reliability are investigated under variation of pulse parameters like direct and AC current amplitude, AC frequency and AC phase. We find a range of AC and direct current amplitudes where robust resonant ST reversal is obtained with faster switching time and reduced energy consumption per pulse compared to purely direct current ST reversal. However, for a certain range of AC and direct current amplitudes a strong dependence of the reversal properties on AC frequency and phase is found. Such regions of unreliable reversal must be avoided for ST memory applications.

Graphite felt modified with bismuth nanoparticles as negative electrode in a vanadium redox flow battery.

Science.gov (United States)

Suárez, David J; González, Zoraida; Blanco, Clara; Granda, Marcos; Menéndez, Rosa; Santamaría, Ricardo

2014-03-01

A graphite felt decorated with bismuth nanoparticles was studied as negative electrode in a vanadium redox flow battery (VRFB). The results confirm the excellent electrochemical performance of the bismuth modified electrode in terms of the reversibility of the V(3+) /V(2+) redox reactions and its long-term cycling performance. Moreover a mechanism that explains the role that Bi nanoparticles play in the redox reactions in this negative half-cell is proposed. Bi nanoparticles favor the formation of BiHx , an intermediate that reduces V(3+) to V(2+) and, therefore, inhibits the competitive irreversible reaction of hydrogen formation (responsible for the commonly observed loss of Coulombic efficiency of VRFBs). Thus, the total charge consumed during the cathodic sweep in this electrode is used to reduce V(3+) to V(2+) , resulting in a highly reversible and efficient process. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

21 CFR 177.2550 - Reverse osmosis membranes.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Reverse osmosis membranes. 177.2550 Section 177... Components of Articles Intended for Repeated Use § 177.2550 Reverse osmosis membranes. Substances identified in paragraph (a) of this section may be safely used as reverse osmosis membranes intended for use in...

Prefix reversals on binary and ternary strings

NARCIS (Netherlands)

Hurkens, C.A.J.; van Iersel, L.J.J.; Keijsper, J.C.M.; Kelk, S.M.; Stougie, L.; Tromp, J.T.

2007-01-01

Given a permutation $\\pi$, the application of prefix reversal $f^{(i)}$ to $\\pi$ reverses the order of the first $i$ elements of $\\pi$. The problem of sorting by prefix reversals (also known as pancake flipping), made famous by Gates and Papadimitriou (Discrete Math., 27 (1979), pp. 47–57), asks

Reverse innovation in maternal health.

Science.gov (United States)

Firoz, Tabassum; Makanga, Prestige Tatenda; Nathan, Hannah L; Payne, Beth; Magee, Laura A

2017-09-01

Reverse innovation, defined as the flow of ideas from low- to high-income settings, is gaining traction in healthcare. With an increasing focus on value, investing in low-cost but effective and innovative solutions can be of mutual benefit to both high- and low-income countries. Reverse innovation has a role in addressing maternal health challenges in high-income countries by harnessing these innovative solutions for vulnerable populations especially in rural and remote regions. In this paper, we present three examples of 'reverse innovation' for maternal health: a low-cost, easy-to-use blood pressure device (CRADLE), a diagnostic algorithm (mini PIERS) and accompanying mobile app (PIERS on the Move), and a novel method for mapping maternal outcomes (MOM).

Cost-Effectiveness of Reverse Total Shoulder Arthroplasty Versus Arthroscopic Rotator Cuff Repair for Symptomatic Large and Massive Rotator Cuff Tears.

Science.gov (United States)

Makhni, Eric C; Swart, Eric; Steinhaus, Michael E; Mather, Richard C; Levine, William N; Bach, Bernard R; Romeo, Anthony A; Verma, Nikhil N

2016-09-01

To compare the cost-effectiveness within the United States health care system of arthroscopic rotator cuff repair versus reverse total shoulder arthroplasty in patients with symptomatic large and massive rotator cuff tears without cuff-tear arthropathy. An expected-value decision analysis was constructed comparing the costs and outcomes of patients undergoing arthroscopic rotator cuff repair and reverse total shoulder arthroplasty for large and massive rotator cuff tears (and excluding cases of cuff-tear arthropathy). Comprehensive literature search provided input data to extrapolate costs and health utility states for these outcomes. The primary outcome assessed was that of incremental cost-effectiveness ratio (ICER) of reverse total shoulder arthroplasty versus rotator cuff repair. For the base case, both arthroscopic rotator cuff repair and reverse total shoulder were superior to nonoperative care, with an ICER of $15,500/quality-adjusted life year (QALY) and $37,400/QALY, respectively. Arthroscopic rotator cuff repair was dominant over primary reverse total shoulder arthroplasty, with lower costs and slightly improved clinical outcomes. Arthroscopic rotator cuff repair was the preferred strategy as long as the lifetime progression rate from retear to end-stage cuff-tear arthropathy was less than 89%. However, when the model was modified to account for worse outcomes when reverse shoulder arthroplasty was performed after a failed attempted rotator cuff repair, primary reverse total shoulder had superior outcomes with an ICER of $90,000/QALY. Arthroscopic rotator cuff repair-despite high rates of tendon retearing-for patients with large and massive rotator cuff tears may be a more cost-effective initial treatment strategy when compared with primary reverse total shoulder arthroplasty and when assuming no detrimental impact of previous surgery on outcomes after arthroplasty. Clinical judgment should still be prioritized when formulating treatment plans for these

Stability of the field-reversed mirror

International Nuclear Information System (INIS)

Morse, E.C.

1979-01-01

The stability of a field reversed mirror plasma configuration is studied with an energy principle derived from the Vlasov equation. Because of finite orbit effects, the stability properties of a field-reversed mirror are different from the stability properties of similar magnetohydrodynamic equilibria. The Vlasov energy principle developed here is applied to a computer simulation of an axisymmetric field-reversed mirror state. It has been possible to prove that the l = 0 modes, called tearing modes, satisfy a sufficient condition for stability. Precessional modes, with l = 1, 2, are found to be unstable at low growth rate. This suggests possible turbulent behavior (Bohm confinement) in the experimental devices aiming at field reversal. Techniques for suppressing these instabilities are outlined, and the applicability of the Vlasov energy principle to more complicated equilibrium models is shown

Reversible Lithium Neurotoxicity: Review of the Literature

Science.gov (United States)

Netto, Ivan

2012-01-01

Objective: Lithium neurotoxicity may be reversible or irreversible. Reversible lithium neurotoxicity has been defined as cases of lithium neurotoxicity in which patients recovered without any permanent neurologic sequelae, even after 2 months of an episode of lithium toxicity. Cases of reversible lithium neurotoxicity differ in clinical presentation from those of irreversible lithium neurotoxicity and have important implications in clinical practice. This review aims to study the clinical presentation of cases of reversible lithium neurotoxicity. Data Sources: A comprehensive electronic search was conducted in the following databases: MEDLINE (PubMed), 1950 to November 2010; PsycINFO, 1967 to November 2010; and SCOPUS (EMBASE), 1950 to November 2010. MEDLINE and PsycINFO were searched by using the OvidSP interface. Study Selection: A combination of the following search terms was used: lithium AND adverse effects AND central nervous system OR neurologic manifestation. Publications cited include articles concerned with reversible lithium neurotoxicity. Data Extraction: The age, sex, clinical features, diagnostic categories, lithium doses, serum lithium levels, precipitating factors, and preventive measures of 52 cases of reversible lithium neurotoxicity were extracted. Data Synthesis: Among the 52 cases of reversible lithium neurotoxicity, patients ranged in age from 10 to 80 years and a greater number were female (P = .008). Most patients had affective disorders, schizoaffective disorders, and/or depression (P lithium levels were less than or equal to 1.5 mEq/L (P lithium, underlying brain pathology, abnormal tissue levels, specific diagnostic categories, and elderly populations were some of the precipitating factors reported for reversible lithium neurotoxicity. The preventive measures were also described. Conclusions: Reversible lithium neurotoxicity presents with a certain clinical profile and precipitating factors for which there are appropriate

Reversible lithium neurotoxicity: review of the literatur.

Science.gov (United States)

Netto, Ivan; Phutane, Vivek H

2012-01-01

Lithium neurotoxicity may be reversible or irreversible. Reversible lithium neurotoxicity has been defined as cases of lithium neurotoxicity in which patients recovered without any permanent neurologic sequelae, even after 2 months of an episode of lithium toxicity. Cases of reversible lithium neurotoxicity differ in clinical presentation from those of irreversible lithium neurotoxicity and have important implications in clinical practice. This review aims to study the clinical presentation of cases of reversible lithium neurotoxicity. A comprehensive electronic search was conducted in the following databases: MEDLINE (PubMed), 1950 to November 2010; PsycINFO, 1967 to November 2010; and SCOPUS (EMBASE), 1950 to November 2010. MEDLINE and PsycINFO were searched by using the OvidSP interface. A combination of the following search terms was used: lithium AND adverse effects AND central nervous system OR neurologic manifestation. Publications cited include articles concerned with reversible lithium neurotoxicity. The age, sex, clinical features, diagnostic categories, lithium doses, serum lithium levels, precipitating factors, and preventive measures of 52 cases of reversible lithium neurotoxicity were extracted. Among the 52 cases of reversible lithium neurotoxicity, patients ranged in age from 10 to 80 years and a greater number were female (P = .008). Most patients had affective disorders, schizoaffective disorders, and/or depression (P lithium levels were less than or equal to 1.5 mEq/L (P lithium, underlying brain pathology, abnormal tissue levels, specific diagnostic categories, and elderly populations were some of the precipitating factors reported for reversible lithium neurotoxicity. The preventive measures were also described. Reversible lithium neurotoxicity presents with a certain clinical profile and precipitating factors for which there are appropriate preventive measures. This recognition will help in early diagnosis and prompt treatment of

Topology reconstruction for B-Rep modeling from 3D mesh in reverse engineering applications

Science.gov (United States)

Bénière, Roseline; Subsol, Gérard; Gesquière, Gilles; Le Breton, François; Puech, William

2012-03-01

Nowadays, most of the manufactured objects are designed using CAD (Computer-Aided Design) software. Nevertheless, for visualization, data exchange or manufacturing applications, the geometric model has to be discretized into a 3D mesh composed of a finite number of vertices and edges. But, in some cases, the initial model may be lost or unavailable. In other cases, the 3D discrete representation may be modified, for example after a numerical simulation, and does not correspond anymore to the initial model. A reverse engineering method is then required to reconstruct a 3D continuous representation from the discrete one. In previous work, we have presented a new approach for 3D geometric primitive extraction. In this paper, to complete our automatic and comprehensive reverse engineering process, we propose a method to construct the topology of the retrieved object. To reconstruct a B-Rep model, a new formalism is now introduced to define the adjacency relations. Then a new process is used to construct the boundaries of the object. The whole process is tested on 3D industrial meshes and bring a solution to recover B-Rep models.

On the study of oil paint adhesion on optically transparent glass: Conservation of reverse paintings on glass

International Nuclear Information System (INIS)

Bayle, M.; Waugh, D.G.; Colston, B.J.; Lawrence, J.

2015-01-01

Highlights: • Adhesion characteristics analysed with respect to reverse paintings on glass. • Physical properties of surfaces and pigments found to affect cohesion and adhesion. • Environmental effects on pigment adhesion to glass have been documented. • Vermillion pigment hardest compared to other pigments, especially with adhesives. • Wettability used to assess adhesion properties relating to reverse paintings on glass. - Abstract: Reverse painting on glass is a technique which consists of applying a cold paint layer on the reverse-side of glass. The main challenge facing these artworks is the fragile adhesion of the pictorial layer – a simple movement can modify the appearance of the painting. This paper details a study into the adhesion parameters of pigments on glass and the comparison between different pigments. The relationships between the binder (linseed oil) with pigments and the glass with or without the use of an adhesive are studied. Physical analyses by surface characterisation have been carried out to better understand the influence of the pigment. The use of a sessile drop device, optical microscopy, scanning electron microscopy (SEM), a surface 3D profiler and a pencil hardness scratch tester were necessary to establish a comparison of the pictorial layer adhesion. A comparison of the effect of two adhesives, namely ox gall and gum arabic, has shown that the adhesion is not only linked to the physical parameters but that possible chemical reactions can influence the results. Finally, a treatment based on humidity-extreme storage has shown the weakness of some pictorial layers.

On the study of oil paint adhesion on optically transparent glass: Conservation of reverse paintings on glass

Energy Technology Data Exchange (ETDEWEB)

Bayle, M. [Historic and Ancient Materials Group, School of Chemistry, University of Lincoln, Brayford Pool, Lincoln LN6 7TS (United Kingdom); Waugh, D.G., E-mail: d.waugh@chester.ac.uk [Laser Engineering and Manufacturing Research Centre, Faculty of Science and Engineering, University of Chester, Thornton Science Park, Ince, Chester CH2 4NU (United Kingdom); Colston, B.J. [Historic and Ancient Materials Group, School of Chemistry, University of Lincoln, Brayford Pool, Lincoln LN6 7TS (United Kingdom); Lawrence, J. [Laser Engineering and Manufacturing Research Centre, Faculty of Science and Engineering, University of Chester, Thornton Science Park, Ince, Chester CH2 4NU (United Kingdom)

2015-12-01

Highlights: • Adhesion characteristics analysed with respect to reverse paintings on glass. • Physical properties of surfaces and pigments found to affect cohesion and adhesion. • Environmental effects on pigment adhesion to glass have been documented. • Vermillion pigment hardest compared to other pigments, especially with adhesives. • Wettability used to assess adhesion properties relating to reverse paintings on glass. - Abstract: Reverse painting on glass is a technique which consists of applying a cold paint layer on the reverse-side of glass. The main challenge facing these artworks is the fragile adhesion of the pictorial layer – a simple movement can modify the appearance of the painting. This paper details a study into the adhesion parameters of pigments on glass and the comparison between different pigments. The relationships between the binder (linseed oil) with pigments and the glass with or without the use of an adhesive are studied. Physical analyses by surface characterisation have been carried out to better understand the influence of the pigment. The use of a sessile drop device, optical microscopy, scanning electron microscopy (SEM), a surface 3D profiler and a pencil hardness scratch tester were necessary to establish a comparison of the pictorial layer adhesion. A comparison of the effect of two adhesives, namely ox gall and gum arabic, has shown that the adhesion is not only linked to the physical parameters but that possible chemical reactions can influence the results. Finally, a treatment based on humidity-extreme storage has shown the weakness of some pictorial layers.

Monoamines stimulate sex reversal in the saddleback wrasse.

Science.gov (United States)

Larson, Earl T; Norris, David O; Gordon Grau, E; Summers, Cliff H

2003-02-15

Monoamine neurotransmitters (norepinephrine, dopamine, and serotonin) play an important role in reproduction and sexual behavior throughout the vertebrates. They are the first endogenous chemical signals in the regulation of the hypothalamo-pituitary-gonadal (HPG) axis. In teleosts with behavioral sex determination, much is known about behavioral cues that induce sex reversal. The cues are social, processed via the visual system and depend on the ratio of females to males in the population. The mechanisms by which these external behavioral cues are converted to an internal chemical regulatory process are largely unknown. The protogynous Hawaiian saddleback wrasse, Thalassoma duperrey, was used to investigate the biological pathway mediating the conversion of a social cue into neuroendocrine events regulating sex reversal. Because monoamines play an important role in the regulation of the HPG axis, they were selected as likely candidates for such a conversion. To determine if monoamines could affect sex reversal, drugs affecting monoamines were used in an attempt to either induce sex reversal under non-permissive conditions, or prevent sex reversal under permissive conditions. Increasing norepinephrine or blocking dopamine or serotonin lead to sex reversal in experimental animals under non-permissive conditions. Increasing serotonin blocked sex reversal under permissive conditions, while blocking dopamine or norepinephrine retarded the process. The results presented here demonstrate that monoamines contribute significantly to the control sex reversal. Norepinephrine stimulates initiation and completion of gonadal sex of reversal as well as color change perhaps directly via its effects on the HPG axis. Dopamine exercises inhibitory action on the initiation of sex reversal while 5-HT inhibits both initiation and completion of sex reversal. The serotonergic system appears to be an integral part of the pathway mediating the conversion of a social cue into a

On flow reversals in Rayleigh-Bénard convection

International Nuclear Information System (INIS)

Chandra, Mani; Verma, Mahendra K

2011-01-01

The dynamics of flow reversals are studied numerically using Fourier mode analysis. Our analysis shows that the Fourier modes represent the large-scale flows accurately. We observe that during the reversals, the amplitude of one of the large-scale modes vanishes, while another mode rises sharply, very similar to the cessation-led reversals observed earlier in experiments and numerical simulations. The Fourier coefficients of the RBC equations obey certain symmetries properties, which dictates which modes change sign in flow reversals. Based on our simulation results and symmetry properties of the Fourier modes, we provide a qualitative explanation for the flow reversals.

Surface modification of commercial seawater reverse osmosis membranes by grafting of hydrophilic monomer blended with carboxylated multiwalled carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Vatanpour, Vahid, E-mail: vahidvatanpour@khu.ac.ir; Zoqi, Naser

2017-02-28

Highlights: • A commercial PA RO membrane was modified by grafting of hydrophilic acrylic acid. • COOH-MWCNTs were mixed in grafting layer to increase permeability and antifouling. • However, more increase of CNTs caused in reduction of flux of the membranes. • Effect of acrylic acid amount, contact time and curing time was optimized. - Abstract: In this study, modification of commercial seawater reverse osmosis membranes was carried out with simultaneous use of surface grafting and nanoparticle incorporation. Membrane grafting with a hydrophilic acrylic acid monomer and thermal initiator was used to increase membrane surface hydrophilicity. The used nanomaterial was carboxylated multiwalled carbon nanotubes (MWCNTs), which were dispersed in the grafting solution and deposited on membrane surface to reduce fouling by creating polymer brushes and hydrodynamic resistance. Effectiveness of the grafting process (formation of graft layer on membrane surface) was proved by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses. Increase of membrane surface hydrophilicity was approved with contact angle test. First, the grafting was performed on the membrane surfaces with different monomer concentrations, various contact times and several membrane curing times (three variables for optimization). The modified membranes were tested by a cross-flow setup using saline solution for permeability and rejection tests, and bovine serum albumin (BSA) solution for fouling test. The results showed that the modified membranes with 0.75 M of monomer, 3 min contact time and 80 min curing time in an oven at 50 °C presented the highest flux and lowest rejection decline related to the commercial reverse osmosis membrane. In the next step, the optimum grafting condition was selected and the nanotubes with different weight percentages were dispersed in the acrylic acid monomer solution. The membrane containing 0.25 wt% COOH-MWCNTs showed the

Surface modification of commercial seawater reverse osmosis membranes by grafting of hydrophilic monomer blended with carboxylated multiwalled carbon nanotubes

International Nuclear Information System (INIS)

Vatanpour, Vahid; Zoqi, Naser

2017-01-01

Highlights: • A commercial PA RO membrane was modified by grafting of hydrophilic acrylic acid. • COOH-MWCNTs were mixed in grafting layer to increase permeability and antifouling. • However, more increase of CNTs caused in reduction of flux of the membranes. • Effect of acrylic acid amount, contact time and curing time was optimized. - Abstract: In this study, modification of commercial seawater reverse osmosis membranes was carried out with simultaneous use of surface grafting and nanoparticle incorporation. Membrane grafting with a hydrophilic acrylic acid monomer and thermal initiator was used to increase membrane surface hydrophilicity. The used nanomaterial was carboxylated multiwalled carbon nanotubes (MWCNTs), which were dispersed in the grafting solution and deposited on membrane surface to reduce fouling by creating polymer brushes and hydrodynamic resistance. Effectiveness of the grafting process (formation of graft layer on membrane surface) was proved by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses. Increase of membrane surface hydrophilicity was approved with contact angle test. First, the grafting was performed on the membrane surfaces with different monomer concentrations, various contact times and several membrane curing times (three variables for optimization). The modified membranes were tested by a cross-flow setup using saline solution for permeability and rejection tests, and bovine serum albumin (BSA) solution for fouling test. The results showed that the modified membranes with 0.75 M of monomer, 3 min contact time and 80 min curing time in an oven at 50 °C presented the highest flux and lowest rejection decline related to the commercial reverse osmosis membrane. In the next step, the optimum grafting condition was selected and the nanotubes with different weight percentages were dispersed in the acrylic acid monomer solution. The membrane containing 0.25 wt% COOH-MWCNTs showed the

Clean translation of an imperative reversible programming language

DEFF Research Database (Denmark)

Axelsen, Holger Bock

2011-01-01

We describe the translation techniques used for the code generation in a compiler from the high-level reversible imperative programming language Janus to the low-level reversible assembly language PISA. Our translation is both semantics preserving (correct), in that target programs compute exactly...... the same functions as their source programs (cleanly, with no extraneous garbage output), and efficient, in that target programs conserve the complexities of source programs. In particular, target programs only require a constant amount of temporary garbage space. The given translation methods are generic......, and should be applicable to any (imperative) reversible source language described with reversible flowcharts and reversible updates. To our knowledge, this is the first compiler between reversible languages where the source and target languages were independently developed; the first exhibiting both...

Parkinson’s disease managing reversible neurodegeneration

Directory of Open Access Journals (Sweden)

Hinz M

2016-04-01

Full Text Available Marty Hinz,1 Alvin Stein,2 Ted Cole,3 Beth McDougall,4 Mark Westaway5 1Clinical Research, NeuroResearch Clinics, Inc., Cape Coral, FL, 2Stein Orthopedic Associates, Plantation, FL, 3Cole Center for Healing, Cincinnati, OH, 4CLEARCenter of Health, Mill Valley, CA, USA; 5Four Pillars Health, Brendale, QLD, Australia Abstract: Traditionally, the Parkinson’s disease (PD symptom course has been classified as an irreversible progressive neurodegenerative disease. This paper documents 29 PD and treatment-induced systemic depletion etiologies which cause and/or exacerbate the seven novel primary relative nutritional deficiencies associated with PD. These reversible relative nutritional deficiencies (RNDs may facilitate and accelerate irreversible progressive neurodegeneration, while other reversible RNDs may induce previously undocumented reversible pseudo-neurodegeneration that is hiding in plain sight since the symptoms are identical to the symptoms being experienced by the PD patient. Documented herein is a novel nutritional approach for reversible processes management which may slow or halt irreversible progressive neurodegenerative disease and correct reversible RNDs whose symptoms are identical to the patient’s PD symptoms. Keywords: Parkinson’s disease, L-dopa, carbidopa, B6, neurodegeneration

AN OVERVIEW ON RETAIL REVERSE LOGISTICS

Directory of Open Access Journals (Sweden)

Ioana Olariu

2014-07-01

Full Text Available This article is a theoretical approach on retail reverse logistics. Environmental concern and the current marketing strategy have spurred retailers to implement strategies to facilitate product returns from end customers. Reverse logistics, indicating the process of this return flow, encompasses such activities as the movement of returned products, facilities to accommodate returned items, and overall remedy process for returned items. The retail industry, under great competitive pressure, has used return policies as a competitive weapon. Grocery retailers were the first to begin to focus serious attention on the problem of returns and to develop reverse logistics innovations. Grocery retailers first developed innovations such as reclamation centers. Reclamation centers, in turn, led to the establishment of centralized return centers. Centralizing returns has led to significant benefits for most firms that have implemented them. Over the last several years, retailers have consolidated. Now, more than ever, reverse logistics is seen as being important. This reverse distribution activity can be crucial to the survival of companies, because the permanent goodwill of the company is at stake. Businesses succeed because they respond to both external and internal changes and adjust in an effective manner to remain competitive.

Parallelization of Reversible Ripple-carry Adders

DEFF Research Database (Denmark)

Thomsen, Michael Kirkedal; Axelsen, Holger Bock

2009-01-01

The design of fast arithmetic logic circuits is an important research topic for reversible and quantum computing. A special challenge in this setting is the computation of standard arithmetical functions without the generation of \\emph{garbage}. Here, we present a novel parallelization scheme...... wherein $m$ parallel $k$-bit reversible ripple-carry adders are combined to form a reversible $mk$-bit \\emph{ripple-block carry adder} with logic depth $\\mathcal{O}(m+k)$ for a \\emph{minimal} logic depth $\\mathcal{O}(\\sqrt{mk})$, thus improving on the $mk$-bit ripple-carry adder logic depth $\\mathcal...

Time reversibility in the quantum frame

Energy Technology Data Exchange (ETDEWEB)

Masot-Conde, Fátima [Escuela Superior Ingenieros, Dpt. Física Aplicada III, Universidad de Sevilla Isla Mágica, 41092- Sevilla (Spain)

2014-12-04

Classic Mechanics and Electromagnetism, conventionally taken as time-reversible, share the same concept of motion (either of mass or charge) as the basis of the time reversibility in their own fields. This paper focuses on the relationship between mobile geometry and motion reversibility. The goal is to extrapolate the conclusions to the quantum frame, where matter and radiation behave just as elementary mobiles. The possibility that the asymmetry of Time (Time’s arrow) is an effect of a fundamental quantum asymmetry of elementary particles, turns out to be a consequence of the discussion.

Bridging the mantle: A comparison of geomagnetic polarity reversal rate, global subduction flux, and true polar wander records

Science.gov (United States)

Biggin, A. J.; Hounslow, M.; Domeier, M.

2017-12-01

The long-term variability in average geomagnetic reversal frequency over the Phanerozoic, consisting of superchrons interspersed with periods of hyper-reversal activity, remains one of the most prominent and enigmatic features evident within palaeomagnetic records. This variability is widely expected to reflect mantle convection modifying the pattern and/or magnitude of core-mantle boundary heat flow, and thereby affecting the geodynamo's operation, but actual causal links to surface geological processes remain tenuous. Previous studies have argued that mantle plumes, superplume oscillation, true polar wander, and avalanching of cold slabs into the lower mantle could all be at least partly responsible. Here we will present a re-evaluated reversal frequency record for the Phanerozoic and use it, together with published findings from numerical geodynamo simulations, to push further towards an integrated explanation of how the geomagnetic field has responded to mantle processes over the last few hundreds of million years. Recent work on absolute plate motions back through the Phanerozoic have allowed estimations to be made as to both the global subduction flux and rates of true polar wander through time. When considered alongside the outputs of numerical simulations of the geodynamo process, these can potentially explain long-timescale palaeomagnetic variations over the last few hundreds of million years.

Infrared absorption, multiphonon processes and time reversal effect on Si and Ge band structure

International Nuclear Information System (INIS)

Kunert, H.W.; Machatine, A.G.J.; Malherbe, J.B.; Barnas, J.; Hoffmann, A.; Wagner, M.R.

2008-01-01

We have examined the effect of Time Reversal Symmetry (TRS) on vibrational modes and on the electronic band structure of Si and Ge. Most of the primary non-interacting modes are not affected by TRS. Only phonons originating from high symmetry lines S and A of the Brillouin Zone (BZ) indicate extra degeneracy. Selection rules for some two and three phonons originating from high symmetry lines are determined. The states of electrons and holes described by electronic band structure due to spin-inclusion are assigned by spinor representations of the double space group. Inclusion of the TRS into the band structure results in extra degeneracy of electrons and holes, and therefore optical selection rules suppose to be modified

Reversible and irreversible heat engine and refrigerator cycles

Science.gov (United States)

Leff, Harvey S.

2018-05-01

Although no reversible thermodynamic cycles exist in nature, nearly all cycles covered in textbooks are reversible. This is a review, clarification, and extension of results and concepts for quasistatic, reversible and irreversible processes and cycles, intended primarily for teachers and students. Distinctions between the latter process types are explained, with emphasis on clockwise (CW) and counterclockwise (CCW) cycles. Specific examples of each are examined, including Carnot, Kelvin and Stirling cycles. For the Stirling cycle, potentially useful task-specific efficiency measures are proposed and illustrated. Whether a cycle behaves as a traditional refrigerator or heat engine can depend on whether it is reversible or irreversible. Reversible and irreversible-quasistatic CW cycles both satisfy Carnot's inequality for thermal efficiency, η ≤ η C a r n o t . Irreversible CCW cycles with two reservoirs satisfy the coefficient of performance inequality K ≤ K C a r n o t . However, an arbitrary reversible cycle satisfies K ≥ K C a r n o t when compared with a reversible Carnot cycle operating between its maximum and minimum temperatures, a potentially counterintuitive result.

Designing Novel Quaternary Quantum Reversible Subtractor Circuits

Science.gov (United States)

Haghparast, Majid; Monfared, Asma Taheri

2018-01-01

Reversible logic synthesis is an important area of current research because of its ability to reduce energy dissipation. In recent years, multiple valued logic has received great attention due to its ability to reduce the width of the reversible circuit which is a main requirement in quantum technology. Subtractor circuits are between major components used in quantum computers. In this paper, we will discuss the design of a quaternary quantum reversible half subtractor circuit using quaternary 1-qudit, 2-qudit Muthukrishnan-Stroud and 3-qudit controlled gates and a 2-qudit Generalized quaternary gate. Then a design of a quaternary quantum reversible full subtractor circuit based on the quaternary half subtractor will be presenting. The designs shall then be evaluated in terms of quantum cost, constant input, garbage output, and hardware complexity. The proposed quaternary quantum reversible circuits are the first attempt in the designing of the aforementioned subtractor.

Hydrogen Storage Properties of Lithium Aluminohydride modified by dopants and mechanochemistry

Energy Technology Data Exchange (ETDEWEB)

Hosokawa, Keita [Iowa State Univ., Ames, IA (United States)

2002-01-01

Alkali metal aluminohydrides have high potential as solid hydrogen storage materials. They have been known for their irreversible dehydrogenation process below 100 atm until Bogdanovic et al [1, 2] succeeded in the re-hydrogenation of NaAlH₄ below 70 atm. They achieved 4 wt.% H₂ reversible capacity by doping NaAlH₄ with Ti and/or Fe organo-metalic compounds as catalysts. This suggests that other alkali and, possibly alkaline earth metal aluminohydrides can be used for reversible hydrogen storage when modified by proper dopants. In this research, Zr₂₇Ti₉Ni₃₈V₅Mn₁₆Cr₅, LaNi_4.85Sn_0.15, Al₃Ti, and PdCl₂ were combined with LiAlH₄ by ball-milling to study whether or not LiAlH₄ is capable to both absorb and desorb hydrogen near ambient conditions. X-ray powder diffraction, differential thermal analysis, and scanning electron microscopy were employed for sample characterizations. All four compounds worked as catalysts in the dehydrogenation reactions of both LiAlH₄ and Li₃AlH₆ by inducing the decomposition at lower temperature. However, none of them was applicable as catalyst in the reverse hydrogenation reaction at low to moderate hydrogen pressure.

Time reversibility, computer simulation, algorithms, chaos

CERN Document Server

Hoover, William Graham

2012-01-01

A small army of physicists, chemists, mathematicians, and engineers has joined forces to attack a classic problem, the "reversibility paradox", with modern tools. This book describes their work from the perspective of computer simulation, emphasizing the author's approach to the problem of understanding the compatibility, and even inevitability, of the irreversible second law of thermodynamics with an underlying time-reversible mechanics. Computer simulation has made it possible to probe reversibility from a variety of directions and "chaos theory" or "nonlinear dynamics" has supplied a useful vocabulary and a set of concepts, which allow a fuller explanation of irreversibility than that available to Boltzmann or to Green, Kubo and Onsager. Clear illustration of concepts is emphasized throughout, and reinforced with a glossary of technical terms from the specialized fields which have been combined here to focus on a common theme. The book begins with a discussion, contrasting the idealized reversibility of ba...

Preventing Children's Sports Injuries

Science.gov (United States)

... well. For example, they should wear helmets for baseball , softball, bicycle riding , and hockey . They also should wear ... padding. For racquet sports, field hockey, lacrosse, basketball , softball, and baseball, ask about any protective eyewear, like ...

Epidemiology, pathomechanics, and prevention of athletic injuries to the cervical spine.

Science.gov (United States)

Torg, J S

1985-06-01

Athletic injuries to the cervical spine associated with quadriplegia most commonly occur as a result of axial loading. Whether it be a football player striking an opponent with the top or crown of his helmet, a poorly executed dive into a shallow body of water where the subject strikes his head on the bottom, or a hockey player pushed into the boards head first, the fragile cervical spine is compressed between the rapidly decelerated head and the continued momentum of the body. Appropriate rule changes recognizing this mechanism have resulted in a reduction of football quadriplegia by two-thirds. Presumably, educational efforts designed to inform the public of the dangers of diving would have a similar effect. The predominance of the axial loading mechanism is not as clearly defined in trampoline and minitrampoline injuries. However, both of these devices are dangerous when used in the best of circumstances, and their use has no place in recreational, educational, or competitive gymnastics. The emergence of severe cervical spine injuries resulting from ice hockey is recognized. Methods, based on sound scientific evidence, to modify the games so as to prevent these injuries are lacking.

Ice ages and geomagnetic reversals

Science.gov (United States)

Wu, Patrick

1992-01-01

There have been speculations on the relationship between climatic cooling and polarity reversals of the earth's magnetic field during the Pleistocene. Two of the common criticisms on this relationship have been the reality of these short duration geomagnetic events and the accuracy of their dates. Champion et al. (1988) have reviewed recent progress in this area. They identified a total of 10 short-duration polarity events in the last 1 Ma and 6 of these events have been found in volcanic rocks, which also have K-Ar dates. Supposing that the speculated relationship between climatic cooling and geomagnetic reversals actually exist, two mechanisms that assume climatic cooling causes short period magnetic reversals will be investigated. These two methods are core-mantle boundary topography and transfer of the rotational energy to the core.

Reverse Knowledge Transfer in MNEs

DEFF Research Database (Denmark)

Mudambi, Ram; Piscitello, Lucia; Rabbiosi, Larissa

2014-01-01

a positive correlation with the extent of reverse knowledge transfers to the parent MNE. Relying on the headquarters-subsidiary view of the MNE, we argue that, beyond a point, increasing subsidiary innovativeness will be associated with lower reverse knowledge transfers. Further, we argue......It is now well recognized that multinational enterprises (MNEs) are differentiated networks wherein subsidiaries vary in terms of their ability to create new knowledge and competencies for their parent groups. In much of this theory, it is taken for granted that subsidiary innovativeness has...... that this relationship is sensitive to the subsidiary entry mode. Using data from a sample of 293 Italian subsidiaries, we find strong support for our hypotheses. In particular, our results confirm that the effect of subsidiary innovativeness on reverse knowledge transfers displays an inverted-U shape...

Positioning paper on reversibility

International Nuclear Information System (INIS)

2016-01-01

After having recalled the legal framework adopted in 2006 for the deep geological storage of radioactive wastes, and briefly introduced the concept of reversibility, this publication presents the principle of geological storage, presents high and medium level and long life wastes, highlights the ethical necessity to deal with these radioactive wastes, outlines that geological storage is the generally admitted and adopted solution at the international level, and presents additional means implemented for radioactive waste management. It presents the Cigeo project as the technical answer to the issue of radioactive waste storage, describes the Cigeo development process, its current status and its development planning, and justifies the choice of this technical solution, notably from an ethical point of view. It addresses the issue of reversibility and proposes an overview of the various tools and means which aim at guaranteeing this reversibility. Appendices propose figures illustrating the Cigeo project and its development process, and a rather detailed Power Point presentation of the project by the ANDRA (history, object, planning, installations, and so on)