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Sample records for recreational long-distance runners

  1. Cardiovascular Risks in Long Distance Runners.

    PubMed

    Witham, Bethany Rolfe; Babbitt, Keven

    Distance running has become increasingly popular since the 1970s. Despite the health benefits, long-distance running has been associated with an increased risk for cardiac events. Healthcare professionals should be familiar with distance running cardiac risk factors and preparticipation screening recommendations from the American Heart Association, and should screen and educate patients during healthcare encounters. Nurses are particularly well suited to educate runners on risks and symptoms of cardiac dysfunction.

  2. α-Synuclein: The Long Distance Runner

    PubMed Central

    George, Sonia; Rey, Nolwen L; Reichenbach, Nicole; Steiner, Jennifer A; Brundin, Patrik

    2013-01-01

    Parkinson's disease is characterized by α-synuclein pathology in the form of Lewy bodies and Lewy neurites. Braak et al described the spatial and temporal spread of α-synuclein pathology in Parkinson's disease. Recent experimental studies have demonstrated that α-synuclein can transfer from cell to cell. In this review, we highlight the involvement of α-synuclein in Parkinson's disease and in Braak's staging of Parkinson's disease pathology. We discuss whether a prion-like mechanism of α-synuclein spread might contribute to Parkinson's disease pathology. We describe recent studies investigating cell-to-cell transfer of α-synuclein and focus our review on the long-distance axonal transport of α-synuclein along neurons. PMID:23587141

  3. α-Synuclein: the long distance runner.

    PubMed

    George, Sonia; Rey, Nolwen L; Reichenbach, Nicole; Steiner, Jennifer A; Brundin, Patrik

    2013-05-01

    Parkinson's disease is characterized by α-synuclein pathology in the form of Lewy bodies and Lewy neurites. Braak et al described the spatial and temporal spread of α-synuclein pathology in Parkinson's disease. Recent experimental studies have demonstrated that α-synuclein can transfer from cell to cell. In this review, we highlight the involvement of α-synuclein in Parkinson's disease and in Braak's staging of Parkinson's disease pathology. We discuss whether a prion-like mechanism of α-synuclein spread might contribute to Parkinson's disease pathology. We describe recent studies investigating cell-to-cell transfer of α-synuclein and focus our review on the long-distance axonal transport of α-synuclein along neurons. © 2013 The Authors; Brain Pathology © 2013 International Society of Neuropathology.

  4. Sulfur status in long distance runners

    NASA Astrophysics Data System (ADS)

    Kovacs, L.; Zamboni, C.; Lourenço, T.; Macedo, D.

    2015-07-01

    In sports medicine, sulfur plays an important role and its deficiency can cause muscle injury affecting the performance of the athletes. However, its evaluation is unusual in conventional clinical practice. In this study the sulfur levels were determined in Brazilian amateur athlete's blood using Neutron Activation Analyses (NAA) technique. Twenty six male amateur runners, age 18 to 36 years, participated of this study. The athletes had a balanced diet, without multivitamin/mineral supplements. The blood collection was performed at LABEX (Laboratoriode Bioquimica do Exercicio, UNICAMP-SP) and the samples were irradiated for 300 seconds in a pneumatic station in the nuclear reactor (IEA-R1, 3-4.5MW, pool type) at IPEN/CNEN-SP. The results were compared with the control group (subjects of same age but not involved with physical activities) and showed that the sulfur concentration was 44% higher in amateurs athletes than control group. These data can be considered for preparation of balanced diet, as well as contributing for proposing new protocols of clinical evaluation.

  5. Psycho-Social Parameters in Young Female Long Distance Runners.

    ERIC Educational Resources Information Center

    Burke, Edmund J.; And Others

    This study was designed to determine selected psycho-social parameters associated with a group of teenage, female long distance runners. These young women, who train by running approximately 50-90 miles per week, had scores in certain physiological and anthropometric measurements which were among the most advantageous for running ever recorded in…

  6. High hamstring tendinopathy in 3 female long distance runners

    PubMed Central

    White, Kristin E.

    2011-01-01

    Objective The purpose of this case report is to describe and discuss the clinical presentation, diagnosis, and management of 3 female long distance runners with high hamstring tendinopathy. Clinical Features Three female runners presented to a chiropractic office with proximal hamstring pain that was aggravated by running. Increasing mileage, hills, and/or interval training preceded the onset of symptoms in each case. The subjects all displayed weakness of the hip abductors, pelvic joint dysfunction, hamstring tightness, and ischial tuberosity tenderness. Other clinical findings included overpronation, proprioceptive weakness, and lumbar dysfunction. Intervention and Outcome All 3 patients were treated with Graston Instrument Assisted Soft Tissue Mobilization, lumbopelvic manipulation, and electrical muscle stimulation with ultrasound. Active exercise focused on hamstring stretching and strengthening, gluteal strengthening, and proprioceptive training. The 3 runners seen in this clinic had resolution of hamstring pain in an average of 13 treatments and were able to continue competing without restriction. Conclusion Runners with high hamstring tendinopathy may respond favorably to conservative chiropractic treatment and active rehabilitation with minimal time off of training. PMID:22014863

  7. Common Leg Injuries of Long-Distance Runners

    PubMed Central

    Gallo, Robert A.; Plakke, Michael; Silvis, Matthew L.

    2012-01-01

    Context Long-distance running (greater than 3000 m) is often recommended to maintain a healthy lifestyle. Running injury rates increase significantly when weekly mileage extends beyond 40 miles cumulatively. With the development of running analysis and other diagnostic tests, injuries to the leg secondary to bone, musculotendinous, and vascular causes can be diagnosed and successfully managed. Evidence Acquisition Searches used the terms running, injuries, lower extremity, leg, medial tibial stress syndrome, compartment syndrome, stress fractures, popliteal artery entrapment, gastrocnemius soleus tears, and Achilles tendinopathy. Sources included Medline, Google Scholar, and Ovid from 1970 through January 2012. Results Tibial stress fractures and medial tibial stress syndrome can sometimes be prevented and/or treated by correcting biomechanical abnormalities. Exertional compartment syndrome and popliteal artery entrapment syndrome are caused by anatomic abnormalities and are difficult to treat without surgical correction. Conclusion Leg pain due to bone, musculotendinous, and vascular causes is common among long-distance runners. Knowledge of the underlying biomechanical and/or anatomic abnormality is necessary to successfully treat these conditions. PMID:24179587

  8. Dynamic trunk strength of Canadian football players, soccer players, and middle to long distance runners.

    PubMed

    Willíams, C A; Singh, M

    1997-04-01

    Muscle strength data for sports which have varying demands on the trunk musculature are needed. The purpose of this study was to measure the trunk strength of three different sports groups of male varsity athletes and a recreationally active but nontrained group. Forty-six athletes (soccer: N = 16, Canadian football: N = 15, and middle and long distance runners: N = 15) and 15 recreationally active subjects were studied. Three consecutive concentric and eccentric contractions through a range of 60 degrees at an angular velocity of 30 degrees per second (0.5236 rad/sec) were performed to measure the strength of the trunk flexors and extensors. Results showed peak concentric and eccentric flexor torque for football and soccer players to be significantly greater than the other two groups (p < or = 0.05). Peak concentric and eccentric extensor torque was significantly greater for football players than runners (p < or = 0.05). Soccer players' eccentric flexor peak torque relative to body mass was significantly greater than runners and the recreationally active subjects (p < or = 0.05). This study compares trunk flexor and extensor data for specific sports populations.

  9. Illness behaviour in elite middle and long distance runners

    PubMed Central

    Currie, A.; Potts, S. G.; Donovan, W.; Blackwood, D.

    1999-01-01

    OBJECTIVES: To examine the illness attitudes and beliefs known to be associated with abnormal illness behaviour (where symptoms are present in excess of objective signs and pathology) in elite middle and long distance runners, in comparison with non-athlete controls. METHODS: A total of 150 athletes were surveyed using the illness behaviour questionnaire as an instrument to explore the psychological attributes associated with abnormal illness behaviour. Subjects also completed the general health questionnaire as a measure of psychiatric morbidity. A control group of 150 subjects, matched for age, sex, and social class, were surveyed using the same instruments. RESULTS: A multivariate analysis of illness behaviour questionnaire responses showed that the athletes' group differed significantly from the control group (Hotelling's T: Exact F = 2.68; p = 0.01). In particular, athletes were more somatically focused (difference between means -0.27; 95% confidence interval -0.50 to -0.03) and more likely to deny the impact of stresses in their life (difference between means 0.78; 95% confidence interval 0.31 to 1.25). Athletes were also higher scorers on the Whiteley Index of Hypochondriasis (difference between means 0.76; 95% confidence interval 0.04 to 1.48). There were no differences in the levels of psychiatric morbidity between the two groups. CONCLUSIONS: The illness attitudes and beliefs of athletes differ from those of a well matched control population. The origin of these psychological attributes is not clear but those who treat athletes need to be aware of them. 




 PMID:10027052

  10. Young long distance runners. Physiological and psychological characteristics.

    PubMed

    Nudel, D B; Hassett, I; Gurian, A; Diamant, S; Weinhouse, E; Gootman, N

    1989-11-01

    This study presents the physiological and psychological characteristics and the running histories of 16 subjects who began long distance running at age 4-12 years. Running duration was 3-15 years (mean 8.4 +/- 3.6 yrs). Seven children completed 41 marathons, seven 30-mile races, and eight 60-mile races. The other nine competed at shorter distances. All trained at 30-105 miles/week. Two stress fractures, one back sprain and one knee injury occurred. Athletes who reported injuries from recollection may have underreported some injuries. At age 15.4 +/- 4.2 years bone age was 15.3 +/- 2.6 years and height was at 51 +/- 26.0 percentile. Athletes had larger left ventricular diastolic diameter, higher max O2 uptake, and delayed onset of anaerobic metabolism compared to controls. Psychological profile: IQ = 121 +/- 11, scholastic grade point average (GPA) (n = 13) was less than or equal to 3.0 in four, 3.6-3.9 in four, and 4.0 in five. Cattell 16 personality factor (PF): Seven scored above the 85th percentile on boldness, warmth, conformity, sensitivity, dominance, and high drive with tension. Eight scored above the 93rd percentile for self discipline and emotional stability. Human Figure Drawing showed a distorted body image in seven. Two developed anorexia nervosa, and another girl committed suicide. Thus, high physical fitness and no growth retardation were observed. These runners, however, shared distinct positive and negative personality characteristics. The relatively high incidence of severe psychological disorders possibly suggests a need for psychological screening for young children entering a strenuous training program and for close monitoring for development of psychological problems during the program.

  11. Scintigraphic determination of ventricular function and coronary perfusion in long-distance runners

    SciTech Connect

    Osbakken, M.; Locko, R.

    1984-08-01

    Left ventricular function and coronary perfusion were evaluated with rest-exercise gated blood pool and stress-redistribution thallium scans in a group of long-distance runners and compared to a group of catheterization-proved normal subjects. Exercise duration, work load, and oxygen consumption were significantly greater for long-distance runners. Rest end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volumes (SV) were significantly larger in long-distance runners than in control subjects, while ejection fraction (EF), cardiac index (CI), and ejection rate were similar in both groups. Exercise EDV increased and ESV decreased, producing an increase in SV and EF in long-distance runners. Exercise EDV did not change and ESV decreased less, producing lesser increase in SV and EF in the control group. Qualitative evaluation of thallium scans showed apparent perfusion defects with normal redistribution in six myocardial segments in five long-distance runners. Quantitative evaluation demonstrated initial defects, which persisted on delay scans, but were associated with normal relative redistribution in three ventricular walls in three long-distance runners. In conclusion, left ventricular reserve function was greater in long-distance runners than in control subjects. Endurance exercise can be associated with apparent myocardial perfusion defects, which may be due to uneven ventricular hypertrophy resulting from the pressure and volume loads imposed by exercise.

  12. Heel Pain in Recreational Runners.

    ERIC Educational Resources Information Center

    Bazzoli, Allan S.; Pollina, Frank S.

    1989-01-01

    Provides physicians with the signs, symptoms, and management of heel/sole pain in recreational runners (usually due to plantar fasciitis, Achilles tendinitis, and calcaneal stress fractures). Remedies involve palliative treatment of symptoms, correction of underlying biomechanical problems, and flexibility exercises. (SM)

  13. Heel Pain in Recreational Runners.

    ERIC Educational Resources Information Center

    Bazzoli, Allan S.; Pollina, Frank S.

    1989-01-01

    Provides physicians with the signs, symptoms, and management of heel/sole pain in recreational runners (usually due to plantar fasciitis, Achilles tendinitis, and calcaneal stress fractures). Remedies involve palliative treatment of symptoms, correction of underlying biomechanical problems, and flexibility exercises. (SM)

  14. The Effect of a 20 km Run on Appetite Regulation in Long Distance Runners.

    PubMed

    Kojima, Chihiro; Ishibashi, Aya; Ebi, Kumiko; Goto, Kazushige

    2016-10-26

    The purpose of the present study was to investigate appetite-related hormonal responses and energy intake after a 20 km run in trained long distance runners. Twenty-three male long-distance runners completed two trials: either an exercise trial consisting of a 20 km outdoor run (EX) or a control trial with an identical period of rest (CON). Blood samples were collected to determine plasma acylated ghrelin, peptide YY3-36 (PYY3-36) and other hormonal and metabolite concentrations. Energy intake during a buffet test meal was also measured 30 min after the exercise or rest periods. Although plasma acylated ghrelin concentrations were significantly decreased after the 20 km run (p < 0.05), plasma PYY3-36 did not change significantly following exercise. Absolute energy intake during the buffet test meal in EX (1325 ± 55 kcal) was significantly lower than that in CON (1529 ± 55 kcal), and there was a relatively large degree of individual variability for exercise-induced changes in energy intake (-40.2% to 12.8%). However, exercise-induced changes in energy intake were not associated with plasma acylated ghrelin or PYY3-36 responses. The results demonstrated that a 20 km run significantly decreased plasma acylated ghrelin concentrations and absolute energy intake among well-trained long distance runners.

  15. The Effect of a 20 km Run on Appetite Regulation in Long Distance Runners

    PubMed Central

    Kojima, Chihiro; Ishibashi, Aya; Ebi, Kumiko; Goto, Kazushige

    2016-01-01

    The purpose of the present study was to investigate appetite-related hormonal responses and energy intake after a 20 km run in trained long distance runners. Twenty-three male long-distance runners completed two trials: either an exercise trial consisting of a 20 km outdoor run (EX) or a control trial with an identical period of rest (CON). Blood samples were collected to determine plasma acylated ghrelin, peptide YY3-36 (PYY3-36) and other hormonal and metabolite concentrations. Energy intake during a buffet test meal was also measured 30 min after the exercise or rest periods. Although plasma acylated ghrelin concentrations were significantly decreased after the 20 km run (p < 0.05), plasma PYY3-36 did not change significantly following exercise. Absolute energy intake during the buffet test meal in EX (1325 ± 55 kcal) was significantly lower than that in CON (1529 ± 55 kcal), and there was a relatively large degree of individual variability for exercise-induced changes in energy intake (−40.2% to 12.8%). However, exercise-induced changes in energy intake were not associated with plasma acylated ghrelin or PYY3-36 responses. The results demonstrated that a 20 km run significantly decreased plasma acylated ghrelin concentrations and absolute energy intake among well-trained long distance runners. PMID:27792164

  16. [Diseases and overuse injuries of the lower extremities in long distance runners].

    PubMed

    Tschopp, M; Brunner, F

    2017-02-24

    Running is one of the most popular sports worldwide, with running events attracting hundreds of thousands of runners of all age groups. Running is an effective way to improve health but is also associated with a high risk of injuries. Up to 50% of regular runners report having more than one injury each year. Some injuries are caused by an accident but most are caused by overuse. The most frequent diagnoses are patellofemoral pain syndrome, tibial stress syndrome (shin splint), Achilles tendinopathy, iliotibial band friction syndrome (runner's knee), plantar fasciitis and stress fractures of the metatarsals and tibia. The knee is the most frequently injured joint in runners at all distances. Hamstring injuries are typically acute resulting in a sudden, sharp pain in the posterior thigh. Hip injuries are less common but it can be more difficult to make the correct diagnosis and treatment is more complex. Clinicians confronted by runners with shin pain must distinguish between stress fractures of the tibia, tibial stress syndrome (shin splints) and chronic exertional compartment syndrome. Foot and ankle injuries are the most common injuries reported by long distance and marathon runners. Excess body weight and the number of kilometers run per week are high risk factors for injuries. The roles of other factors, such as shoes, stretching and biomechanics are less clear. A detailed anamnesis and physical examination are important for the correct diagnosis or the necessity for further diagnostic imaging and subsequent therapy.

  17. Athletic identity, compulsive exercise and eating psychopathology in long-distance runners.

    PubMed

    Turton, Robert; Goodwin, Huw; Meyer, Caroline

    2017-08-01

    Having a high athletic identity is thought to increase vulnerability for compulsive exercise and Eating Disorder (ED) psychopathology. This study examined whether there is an association between athletic identity and levels of compulsive exercise and ED psychopathology in long-distance runners. A sample of 501 long-distance runners completed the Athletic Identity Measurement Scale (AIMS), Compulsive Exercise Test (CET) and Eating Disorders Examination Questionnaire (EDEQ). There was a significant positive association between participants' AIMS and total CET scores (moderate effect size; r=0.34 for males and 0.33 for females). BMI did not influence the relationship between AIMS and CET scores in males. However, for females, AIMS scores were positively associated with levels of Weight Control Exercise when covarying for BMI (small to moderate effect size, r=0.22). No significant associations with EDEQ scores were found (negligible to small effect sizes; r=0.06 for males and r=0.14 for females). Following replication, coaches might need to be vigilant to the welfare of endurance runners that have a strong athletic identity, since this could be linked to them exercising compulsively. Future work should examine whether having a strong athletic identity predicts ED psychopathology when this identity is challenged (e.g., due to injury). Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Plantar Pressures During Long Distance Running: An Investigation of 10 Marathon Runners.

    PubMed

    Hohmann, Erik; Reaburn, Peter; Tetsworth, Kevin; Imhoff, Andreas

    2016-06-01

    The objective of this study was to record plantar pressures using an in-shoe measuring system before, during, and after a marathon run in ten experienced long-distance runners with a mean age of 37.7 ± 11.5 years. Peak and mean plantar pressures were recorded before, after, and every three km during a marathon race. There were no significant changes over time in peak and mean plantar pressures for either the dominant or non-dominant foot. There were significant between foot peak and mean plantar pressure differences for the total foot (p = 0.0001), forefoot (p = 0.0001), midfoot (p = 0.02 resp. p = 0.006), hindfoot (p = 0.0001), first ray (p = 0.01 resp. p = 0.0001) and MTP (p = 0.05 resp. p = 0.0001). Long-distance runners do not demonstrate significant changes in mean or peak plantar foot pressures over the distance of a marathon race. However, athletes consistently favoured their dominant extremity, applying significantly higher plantar pressures through their dominant foot over the entire marathon distance. Key pointsFatigue does not increase foot pressuresEvery runner has a dominant foot where pressures are higher and that he/she favoursFoot pressures do not increase over the distance of a marathon run.

  19. Strength-training with whole-body vibration in long-distance runners: a randomized trial.

    PubMed

    Bertuzzi, R; Pasqua, L A; Bueno, S; Damasceno, M V; Lima-Silva, A E; Bishop, D; Tricoli, V

    2013-10-01

    A parallel group randomized trial was designed to analyze the impact of 6 weeks of strength training programs performed with or without whole-body vibration on muscular and endurance performance parameters in long-distance runners. 22 endurance runners were allocated into strength with whole-body vibration (n=8), without (n=8), and control (n=6) groups. Before and after the experimental period the subjects performed the following tests: a) maximum dynamic strength test, b) maximal incremental treadmill test, and c) time to exhaustion at velocity corresponding to maximal oxygen uptake. The fractions of the aerobic and anaerobic contribution in time to exhaustion test were also calculated. Both strength trained groups showed a similar increase in maximum dynamic strength (~18%). The aerobic contribution was enhanced for strength training group without whole-body vibration (~25%) after experimental period. No statistical differences were observed in any other variable. These results suggest that 6 weeks of strength training performed with or without whole-body vibration improve similarly the maximum dynamic strength in long-distance runners. In addition, both training modes studied had no deleterious effects on the traditional parameters of endurance performance, traditional strength training program results in increased aerobic contribution during high-intensity aerobic exercise. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Plantar Pressures During Long Distance Running: An Investigation of 10 Marathon Runners

    PubMed Central

    Hohmann, Erik; Reaburn, Peter; Tetsworth, Kevin; Imhoff, Andreas

    2016-01-01

    The objective of this study was to record plantar pressures using an in-shoe measuring system before, during, and after a marathon run in ten experienced long-distance runners with a mean age of 37.7 ± 11.5 years. Peak and mean plantar pressures were recorded before, after, and every three km during a marathon race. There were no significant changes over time in peak and mean plantar pressures for either the dominant or non-dominant foot. There were significant between foot peak and mean plantar pressure differences for the total foot (p = 0.0001), forefoot (p = 0.0001), midfoot (p = 0.02 resp. p = 0.006), hindfoot (p = 0.0001), first ray (p = 0.01 resp. p = 0.0001) and MTP (p = 0.05 resp. p = 0.0001). Long-distance runners do not demonstrate significant changes in mean or peak plantar foot pressures over the distance of a marathon race. However, athletes consistently favoured their dominant extremity, applying significantly higher plantar pressures through their dominant foot over the entire marathon distance. Key points Fatigue does not increase foot pressures Every runner has a dominant foot where pressures are higher and that he/she favours Foot pressures do not increase over the distance of a marathon run PMID:27274662

  1. Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review

    PubMed Central

    van Gent, R N; Siem, D; van Middelkoop, M; van Os, A G; Bierma‐Zeinstra, S M A; Koes, B W

    2007-01-01

    The purpose of this study was to present a systematic overview of published reports on the incidence and associated potential risk factors of lower extremity running injuries in long distance runners. An electronic database search was conducted using the PubMed–Medline database. Two observers independently assessed the quality of the studies and a best evidence synthesis was used to summarise the results. The incidence of lower extremity running injuries ranged from 19.4% to 79.3%. The predominant site of these injuries was the knee. There was strong evidence that a long training distance per week in male runners and a history of previous injuries were risk factors for injuries, and that an increase in training distance per week was a protective factor for knee injuries. PMID:17473005

  2. The association between plantar heel pain and running surfaces in competitive long-distance male runners.

    PubMed

    Hotta, Takayuki; Nishiguchi, Shu; Fukutani, Naoto; Tashiro, Yuto; Adachi, Daiki; Morino, Saori; Aoyama, Tomoki

    2016-09-01

    Plantar heel pain (PHP) is a common complaint, and is most often caused by plantar fasciitis. Plantar fasciitis is reported to be associated with running surfaces, however the association between PHP and running surfaces has not previously been revealed in an epidemiological investigation. Therefore, the purpose of the current study was to examine the association between PHP and running surfaces. This is a cross-sectional study. A total of 347 competitive long-distance male runners participated in this study. The participants completed an original questionnaire, which included items assessing demographic characteristics, training characteristics focusing on running surfaces (soft surface, hard surface and tartan), and the prevalence of PHP during the previous 12 months. A logistic regression analysis was used to identify the effect of running surfaces on PHP. We found that 21.9% of participants had experienced PHP during the previous 12 months. The multivariate logistic regression analysis, after adjusting for demographic and training characteristics, revealed that running on tartan was associated with PHP (odds ratio 2.82, 95% confidence interval 1.42 to 5.61; P<0.01). Our findings suggest that running more than 25% on tartan is associated with PHP in competitive long-distance male runners.

  3. Nonsteroidal Anti-Inflammatory Drug Use and Endurance During Running in Male Long-Distance Runners

    PubMed Central

    Da Silva, Eduardo; Pinto, Ronei S.; Cadore, Eduardo L.; Kruel, Luiz F.

    2015-01-01

    Context: The effect of ibuprofen on pain tolerance during exercise is controversial, and its effects on endurance performance have been poorly investigated. Objective: To investigate the effect of prophylactic administration of the nonsteroidal anti-inflammatory drug ibuprofen on the time until the self-report of fatigue (tlim) in runners with exercise-induced muscle damage. Design: Randomized controlled clinical trial. Setting: Laboratory. Patients or Other Participants: Twenty healthy male long-distance runners (age = 18.8 ± 0.4 years, maximal oxygen consumption = 55.5 ± 5.9 mL·kg−1·min−1). Intervention(s): Participants were assigned to 2 groups (ibuprofen group = 10, placebo group = 10) to perform tlim trials (speed corresponded to their previously determined secondventilatory thresholds) 48 hours before and 48 hours after the induction of a lower limb muscle-damage protocol (isokinetic dynamometry). One hour before the second tlim trial, the ibuprofen group received 1.2 g ibuprofen, and the placebo group received lactose orally. Main Outcome Measure(s): Time until self-reported fatigue, heart rate, respiratory quotient, oxygen consumption, and perceived exertion were recorded during each tlim test. Results: Both groups reported increases in muscle pain in the knee extensors and flexors 48 hours after the muscle-damage protocol. We observed a reduction in the endurance performance of both groups (P < .01) but no difference between groups (P = .55). Conclusions: Ibuprofen did not reduce the effect of muscle damage and pain on performance. Prophylactic use of nonsteroidal anti-inflammatory drugs did not have an ergogenic effect on running performance after exercise-induced muscle damage in male long-distance runners. PMID:25622243

  4. Iliac artery endofibrosis in a middle-aged female long-distance runner.

    PubMed

    van Rensburg, Dina Christina Janse; van Rensburg, Audrey Jansen; van Duuren, Elsa Margaretha; Grant, Catharina Cornelia

    2014-12-01

    Exercise-induced iliac artery endofibrosis is a recently described abnormality of the external iliac artery that typically affects younger, healthy endurance athletes. Characteristic of the initially termed cyclist's iliac syndrome is lower limb pain during exercise with rapid recovery after exercise. This clinically complicated case describes an older female long-distance runner in whom an incorrect diagnosis of fibromuscular dysplasia was originally made when she presented with claudication and thrombosis of the right external iliac artery. A thrombectomy and bilateral balloon angioplasty were performed; however, her symptoms persisted. Four months later, she unexpectedly complained of dual calf claudication, a diagnosis of exercise-induced iliac artery endofibrosis was made, and a bilateral prosthetic graft bypass procedure was performed, which resulted in a good outcome.

  5. THE EFFECT OF STEP RATE MANIPULATION ON FOOT STRIKE PATTERN OF LONG DISTANCE RUNNERS.

    PubMed

    Allen, Darrell J; Heisler, Hollie; Mooney, Jennifer; Kring, Richard

    2016-02-01

    Running gait retraining to change foot strike pattern in runners from a heel strike pattern to a non heel- strike pattern has been shown to reduce impact forces and may help to reduce running related injuries. Step rate manipulation above preferred is known to help decrease step length, foot inclination angle, and vertical mass excursion, but has not yet been evaluated as a method to change foot strike pattern. The purpose of this study was to investigate the effect of step rate manipulation on foot strike pattern in shod recreational runners who run with a heel strike pattern. A secondary purpose was to describe the effect of step rate manipulation at specific percentages above preferred on foot inclination angle at initial contact. Forty volunteer runners, who were self-reported heel strikers and had a weekly running mileage of at least 10 miles, were recruited. Runners were confirmed to be heel strikers during the warm up period on the treadmill. The subject's step rate was determined at their preferred running pace. A metronome was used to increase step rate above the preferred step rate by 5%, 10% and 15%. 2D video motion analysis was utilized to determine foot strike pattern and to measure foot inclination angle at initial contact for each step rate condition. There was a statistically significant change in foot strike pattern from a heel strike pattern to a mid-foot or forefoot strike pattern at both 10% and 15% step rates above preferred. Seven of the 40 subjects (17.5%) changed from a heel- strike pattern to a non- heel strike pattern at +10% and 12 of the 40 subjects (30%) changed to a non-heel strike pattern at +15%. Mean foot inclination angle at initial contact showed a statistically significant change (reduction) as step rate increased. Step rate manipulation of 10% or greater may be enough to change foot strike pattern from a heel strike to a mid-foot or forefoot strike pattern in a small percentage of recreational runners who run in traditional

  6. Changes in low back pain in a long distance runner after stretching the iliotibial band

    PubMed Central

    Kasunich, Norman J.

    2003-01-01

    Abstract Objective This case report describes a long distance runner with low-back pain and sacroiliac pain and proposes iliotibial band tightness as a possible causative factor. Clinical Features A 38-year-old female amateur runner experienced an exacerbation of right-sided lower back and sacroiliac pain, which she had experienced for several months. The problem became worse as she increased the miles she ran. She had a positive Noble compression test and tightness of the iliotibial band on the right. Gaenslen's, Kemp's, and Patrick's tests were negative on the right, but created her pain of chief complaint. Trigger points were found in the gluteus maximus, gluteus medius, and tensor fascia lata muscles. Intervention and Outcome The patient was treated using chiropractic manipulative therapy, trigger point therapy and stretching of the iliotibial band. Her running schedule was also changed; at the beginning of treatment, she stopped running. As she progressed, she ran on flat surfaces, and with further rehabilitation, she resumed her pre-injury schedule and route. She did not demonstrate much improvement until extensive stretching was included in the treatment plan. Conclusion A patient had low back and sacroiliac pain that seemed to originate from a dysfunctional iliotibial band. This case illustrates that it is important to consider iliotibial band tightness as a possible cause of low back and sacroiliac pain and that proper management may need to include stretching of the iliotibial band along with trigger point therapy and chiropractic manipulation. PMID:19674593

  7. Intravascular haemolysis in the recreational runner.

    PubMed Central

    Deitrick, R W

    1991-01-01

    Intravascular haemolysis has been found to result from prolonged endurance competition, rigorous military training and participation in impact sports. Haematological research involving the recreational runner is sparse. Recreational runners frequently vary their training to avoid monotony and improve endurance capacity. This study investigated the haematological effects of a typical day of increased distance training in 15 male recreational runners (62.4(3.1) ml kg-1 min-1 treadmill VO2max; 44.6(8.4) km per week training (means(s.d.)). Venous blood samples were collected before, immediately after, 1 day, 4 days, and 10 days after a 13-km training run (about twice the subjects' typical running distance) and analysed for changes in bilirubin, serum potassium, haematocrit, haemoglobin, red blood cell count, haptoglobin, poikilocytosis and reticulocytosis. Urine samples were collected at the same times as the blood samples and analysed for urobilinogen. Significant (P less than 0.05) 1-day and 4-day decreases in mean haemoglobin, red blood cell count, and haptoglobin values, compared to before training venous blood values and significant (P less than 0.05) post-training increases in bilirubin, serum potassium, urobilinogen and poikilocytosis provided evidence for increased intravascular haemolysis. After 10 days the values for haematocrit, bilirubin, serum potassium, red blood cell count, urobilinogen and poikilocytosis were not significantly (P less than 0.05) different from pre-training values while haemoglobin remained significantly (P less than 0.05) lower, exhibiting a constant but not significant increase over the period from 1 to 10 days. The results indicate that mild intravascular 'footstrike' haemolysis can occur in the recreational runner when typical training distance is increased. This condition appears to be transient and benign. PMID:1810610

  8. Iron excess in recreational marathon runners.

    PubMed

    Mettler, S; Zimmermann, M B

    2010-05-01

    Iron deficiency and anemia may impair athletic performance, and iron supplements are commonly consumed by athletes. However, iron overload should be avoided because of the possible long-term adverse health effects. We investigated the iron status of 170 male and female recreational runners participating in the Zürich marathon. Iron deficiency was defined either as a plasma ferritin (PF) concentration <15 microg/l (iron depletion) or as the ratio of the concentrations of transferrin receptor (sTfR) to PF (sTfR:log(PF) index) of > or =4.5 (functional iron deficiency). After excluding subjects with elevated C-reactive protein concentrations, iron overload was defined as PF >200 microg/l. Iron depletion was found in only 2 out of 127 men (1.6% of the male study population) and in 12 out of 43 (28.0%) women. Functional iron deficiency was found in 5 (3.9%) and 11 (25.5%) male and female athletes, respectively. Body iron stores, calculated from the sTfR/PF ratio, were significantly higher (P<0.001) among male compared with female marathon runners. Median PF among males was 104 microg/l, and the upper limit of the PF distribution in males was 628 microg/l. Iron overload was found in 19 out of 127 (15.0%) men but only 2 out of 43 in women (4.7%). Gender (male sex), but not age, was a predictor of higher PF (P<0.001). Iron depletion was present in 28% of female runners but in <2% of males, whereas one in six male runners had signs of iron overload. Although iron supplements are widely used by athletes in an effort to increase performance, our findings indicate excess body iron may be common in male recreational runners and suggest supplements should only be used if tests of iron status indicate deficiency.

  9. Perceived Muscle Soreness in Recreational Female Runners.

    PubMed

    Burnett, D; Smith, K; Smeltzer, C; Young, K; Burns, S

    The purpose of this study was to determine if rating of perceived exertion correlated with perceived muscle soreness during delayed onset muscle soreness (DOMS) in female runners. This study examined the pre and post running economy measures and perceived muscle soreness before and after a 30-min downhill run (DHR) at -15% grade and 70% of the subjects predetermined maximum oxygen uptake (VO2 peak). Six female recreational runners (mean age = 24.5) performed level running at 65%, 75%, and 85% of their VO2 peak prior to DHR (baseline economy runs), as well as, immediately following and 4 successive days after the DHR. Subjective response related to perceived muscle soreness increased significantly from a mean of 2 (pre DHR) to 62 (2 days post DHR) on a scale of 1-100. Creatine kinase levels and oxygen consumption increased post DHR compared to pre DHR. Rating of perceived exertion did not change between the economy runs performed prior to or at any point after the DHR. Perceived muscle soreness is a better tool than the RPE scale to monitor exercise intensity for recreational female runners during periods of DOMS and running economy is adversely affected by DOMS.

  10. Perceived Muscle Soreness in Recreational Female Runners

    PubMed Central

    Burnett, D.; Smith, K.; Smeltzer, C.; Young, K.; Burns, S.

    2010-01-01

    The purpose of this study was to determine if rating of perceived exertion correlated with perceived muscle soreness during delayed onset muscle soreness (DOMS) in female runners. This study examined the pre and post running economy measures and perceived muscle soreness before and after a 30-min downhill run (DHR) at −15% grade and 70% of the subjects predetermined maximum oxygen uptake (VO2 peak). Six female recreational runners (mean age = 24.5) performed level running at 65%, 75%, and 85% of their VO2 peak prior to DHR (baseline economy runs), as well as, immediately following and 4 successive days after the DHR. Results: Subjective response related to perceived muscle soreness increased significantly from a mean of 2 (pre DHR) to 62 (2 days post DHR) on a scale of 1–100. Creatine kinase levels and oxygen consumption increased post DHR compared to pre DHR. Rating of perceived exertion did not change between the economy runs performed prior to or at any point after the DHR. Conclusion: Perceived muscle soreness is a better tool than the RPE scale to monitor exercise intensity for recreational female runners during periods of DOMS and running economy is adversely affected by DOMS. PMID:27182336

  11. Elevated Serum Hepcidin Levels during an Intensified Training Period in Well-Trained Female Long-Distance Runners.

    PubMed

    Ishibashi, Aya; Maeda, Naho; Sumi, Daichi; Goto, Kazushige

    2017-03-14

    Iron is essential for providing oxygen to working muscles during exercise, and iron deficiency leads to decreased exercise capacity during endurance events. However, the mechanism of iron deficiency among endurance athletes remains unclear. In this study, we compared iron status between two periods involving different training regimens. Sixteen female long-distance runners participated. Over a seven-month period, fasting blood samples were collected during their regular training period (LOW; middle of February) and during an intensified training period (INT; late of August) to determine blood hematological, iron, and inflammatory parameters. Three-day food diaries were also assessed. Body weight and lean body mass did not differ significantly between LOW and INT, while body fat and body fat percentage were significantly lower in INT (p < 0.05). Blood hemoglobin, serum ferritin, total protein, and iron levels, total iron-binding capacity, and transferrin saturation did not differ significantly between the two periods. Serum hepcidin levels were significantly higher during INT than LOW (p < 0.05). Carbohydrate and iron intakes from the daily diet were significantly higher during INT than LOW (p < 0.05). In conclusion, an elevated hepcidin level was observed during an intensified training period in long-distance runners, despite an apparently adequate daily intake of iron.

  12. Elevated Serum Hepcidin Levels during an Intensified Training Period in Well-Trained Female Long-Distance Runners

    PubMed Central

    Ishibashi, Aya; Maeda, Naho; Sumi, Daichi; Goto, Kazushige

    2017-01-01

    Iron is essential for providing oxygen to working muscles during exercise, and iron deficiency leads to decreased exercise capacity during endurance events. However, the mechanism of iron deficiency among endurance athletes remains unclear. In this study, we compared iron status between two periods involving different training regimens. Sixteen female long-distance runners participated. Over a seven-month period, fasting blood samples were collected during their regular training period (LOW; middle of February) and during an intensified training period (INT; late of August) to determine blood hematological, iron, and inflammatory parameters. Three-day food diaries were also assessed. Body weight and lean body mass did not differ significantly between LOW and INT, while body fat and body fat percentage were significantly lower in INT (p < 0.05). Blood hemoglobin, serum ferritin, total protein, and iron levels, total iron-binding capacity, and transferrin saturation did not differ significantly between the two periods. Serum hepcidin levels were significantly higher during INT than LOW (p < 0.05). Carbohydrate and iron intakes from the daily diet were significantly higher during INT than LOW (p < 0.05). In conclusion, an elevated hepcidin level was observed during an intensified training period in long-distance runners, despite an apparently adequate daily intake of iron. PMID:28335426

  13. Effects of plyometric training on endurance and explosive strength performance in competitive middle- and long-distance runners.

    PubMed

    Ramírez-Campillo, Rodrigo; Alvarez, Cristian; Henríquez-Olguín, Carlos; Baez, Eduardo B; Martínez, Cristian; Andrade, David C; Izquierdo, Mikel

    2014-01-01

    The purpose of this study was to examine the effect of a short-term plyometric training program on explosive strength and endurance performance in highly competitive middle- and long-distance runners. Athletes were randomly assigned to a control group (CG, n = 18, 12 men) and an explosive strength training group (TG, n = 18, 10 men). Drop jump (DJ) from 20 (DJ20) and 40 cm (DJ40), countermovement jump with arms (CMJA), 20-m sprint time, and 2.4-km endurance run time test were carried out before and after 6 weeks of explosive strength training. Also, the combined standardized performance (CSP) in the endurance and explosive strength test was analyzed. After intervention, the CG did not show any significant change in performance, whereas the TG showed a significant reduction in 2.4-km endurance run time (-3.9%) and 20-m sprint time (-2.3%) and an increase in CMJA (+8.9%), DJ20 (+12.7%), and DJ40 (16.7%) explosive performance. Strength training group also exhibited a significant increase in CSP, although the CG showed significant reduction. We conclude that properly programmed concurrent explosive strength and endurance training could be advantageous for middle- and long-distance runners in their competitive performance, especially in events characterized by sprinting actions with small time differences at the end of the race.

  14. Acute effects of submaximal endurance training on arterial stiffness in healthy middle- and long-distance runners.

    PubMed

    Müller, Jan; Wilms, Michael; Oberhoffer, Renate

    2015-05-01

    Measures of arterial stiffness are indicators for cardiovascular health and predictors of cardiovascular events. Arterial stiffness is responsive to acute physiologic stressors such as exercise. However, the acute effects of intensive exercise and recovery on arterial stiffness are controversial. Thirty-seven healthy middle- and long-distance runners (33 men, mean age 26.5±6.6 years) underwent evaluation of their cardiovascular stiffness at rest, after a 15-minute warm-up, immediately after vigorous running 3 km at the pace of their 10-km personal best, and finally 30 minutes after terminating their workout. Peripheral and central systolic blood pressure, as well as augmentation index and pulse wave velocity (PWV), increased during exercise in comparison to baseline (P<.001, general linear model). Thirty minutes after terminating the workout, a drop in peripheral blood pressure (P<.001), central blood pressure (P<.001), and PWV (P=.001) below baseline was observed. Therefore, the authors found that exercise of either moderate or vigorous intensity causes a temporary increase in arterial stiffness in middle- and long-distance runners.

  15. Predictor variables of performance in recreational male long-distance inline skaters.

    PubMed

    Knechtle, Beat; Knechtle, Patrizia; Rüst, Christoph Alexander; Senn, Oliver; Rosemann, Thomas; Lepers, Romuald

    2011-06-01

    We investigated the associations between selected anthropometric and training characteristics with race time in 84 recreational male long-distance inline skaters at the longest inline marathon in Europe, the 'Inline One-eleven' over 111 km in Switzerland, using bi- and multivariate analysis. The mean (s) race time was 264 (41) min. The bivariate analysis showed that age (r = 0.30), body mass (r = 0.42), body mass index (r = 0.35), circumference of upper arm (r = 0.32), circumference of thigh (r = 0.29), circumference of calf (r = 0.38), skin-fold of thigh (r = 0.22), skin-fold of calf (r = 0.27), the sum of skin-folds (r = 0.43), percent body fat (r = 0.45), duration per training unit in inline skating (r = 0.33), and speed during training (r = -0.46) were significantly and positively correlated to race time. Stepwise multiple regression showed that duration per training unit (P = 0.003), age (P = 0.029) and percent body fat (P = 0.016) were the best correlated with race time. Race time in a long-distance inline race such as the 'Inline One-eleven' over 111 km with a mean race time of ∼260 min might be predicted by the following equation (r(2) = 0.41): Race time (min) = 114.91 + 0:51* (duration per training unit, min) + 0:85* (age, years) +3:78* (body fat, %) for recreational long-distance inline skaters.

  16. Muscular balance, core stability, and injury prevention for middle- and long-distance runners.

    PubMed

    Fredericson, Michael; Moore, Tammara

    2005-08-01

    This article is intended to provide an understanding of the importance of core musculature to runners and to offer exercises that will help them achieve desired mobility, stability, muscular balance, and neuromuscular control. Please see Table 1 for an example of how to incorporate these exercises into a periodized training program. It is highly recommended, however, that athletes consult a skilled practitioner to address individual needs and maximize results from a program of this nature.

  17. Treatment of distal iliotibial band syndrome in a long distance runner with gait re-training emphasizing step rate manipulation.

    PubMed

    Allen, Darrell J

    2014-04-01

    Iliotibial band syndrome (ITBS) is a common injury associated with long distance running. Researchers have previously described biomechanical factors associated with ITBS. The purpose of this case report is to present the treatment outcomes in a runner with distal ITBS utilizing running gait re-training to increase step rate above the runner's preferred or self-chosen step rate. The subject was a 36 year old female runner with a diagnosis of left knee ITBS, whose pain prevented her from running greater than three miles for three months. Treadmill video analysis of running form was utilized to determine that the subject had an excessive stride length, strong heel strike, decreased knee flexion angle at initial foot contact, and excessive vertical displacement. Cadence was 168 steps/minute at a preferred running pace of 6.5 mph. Treatment emphasized gait re-training to increase cadence above preferred. Treatment also included iliotibial band flexibility and multi-plane eccentric lower extremity strengthening. The subject reported running pain free within 6 weeks of the intervention with a maximum running distance of 7 miles and 10-15 miles/week progressing to half marathon distance and 20-25 miles/week at 4 month follow up. Step rate increased 5% to 176 steps/minute and was maintained at both the 6 week and 4 month follow up. 5K run pace improved from 8:45 to 8:20 minutes/Km. LEFS score improved from 71/80 to 80/80 at 4 month follow up. This case demonstrated that a 5% increased step rate above preferred along with a home exercise program for hip strengthening and iliotibial band stretching, improved running mechanics and reduced knee pain in a distance runner. 4-single case report.

  18. Relationships between training load, salivary cortisol responses and performance during season training in middle and long distance runners.

    PubMed

    Balsalobre-Fernández, Carlos; Tejero-González, Carlos Ma; del Campo-Vecino, Juan

    2014-01-01

    Monitoring training from a multifactorial point of view is of great importance in elite endurance athletes. This study aims to analyze the relationships between indicators of training load, hormonal status and neuromuscular performance, and to compare these values with competition performance, in elite middle and long-distance runners. Fifteen elite middle and long-distance runners (12 men, 3 women; age = 26.3±5.1 yrs) were measured for training volume, training zone and session rate of perceived exertion (RPE) (daily), countermovement jump (CMJ) and salivary free cortisol (weekly) for 39 weeks (i.e., the whole season). Competition performance was also observed throughout the study, registering the season best and worst competitions. Season average salivary free cortisol concentrations correlate significantly with CMJ (r = -0.777) and RPE (r = 0.551). Also, weekly averages of CMJ significantly correlates with RPE (r = -0.426), distance run (r = -0.593, p<0.001) and training zone (r = 0.437, p<0.05). Finally, it was found that the CMJ (+8.5%, g = 0.65) and the RPE (-17.6%, g = 0.94) measured the week before the best competition performance of the season were significantly different compared with the measurement conducted the week before the season's worst competition performance. Monitoring weekly measurements of CMJ and RPE could be recommended to control training process of such athletes in a non-invasive, field-based, systematic way.

  19. Running economy assessment within cardiopulmonary exercise testing for recreational runners.

    PubMed

    Engeroff, Tobias; Bernardi, Andreas; Vogt, Lutz; Banzer, Winfried

    2016-03-01

    The aim of this study was to evaluate the influence of running economy (RE) on running performance within recreational runners of different maximal aerobic capacity, and the feasibility of RE assessment within routine cardiopulmonary exercise testing (CPET). Sixty-eight recreational runners (m: 49, f: 19; age: 21-54) completed a graded exercise test (GXT) until exhaustion. Maximal oxygen uptake and respiratory compensation point were obtained via CPET. RE was calculated as relative oxygen uptake per covered distance (mL/kg/km) one step below respiratory compensation point (RCP). Subjects were grouped for RE via median split and categorized into one of six fitness levels (Very Poor, Poor, Fair, Good, Excellent, Superior) (ACSM 2010). Irrespective of fitness levels, recreational runners with a more energy efficient movement (RE<215.28 mL/kg/km) reached a significant (P<0.05) higher velocity at RCP (12.2 vs. 10.8 km/h). The measured VO2max values ranged between 35.2 and 66.0 ml/min/kg. Running velocity at RCP of runners within VO2max categories Good and Superior differed significantly (P<0.05) between RE groups. This study provides evidence that RE influences submaximal running performance in recreational distance runners within a broad range of maximal aerobic capacity. Complementing routine CPET with RE assessment at physiological threshold intensities and ACSM based categorization seems feasible to delineate the impact of movement efficiency and aerobic fitness on performance in recreational runners.

  20. Does Muscle Mass Affect Running Times in Male Long-distance Master Runners?

    PubMed

    Knechtle, Beat; Rüst, Christoph Alexander; Knechtle, Patrizia; Rosemann, Thomas

    2012-12-01

    The aim of the present study was to investigate associations between skeletal muscle mass, body fat and training characteristics with running times in master athletes (age > 35 years) in half-marathon, marathon and ultra-marathon. We compared skeletal muscle mass, body fat and training characteristics in master half-marathoners (n=103), master marathoners (n=91) and master ultra-marathoners (n=155) and investigated associations between body composition and training characteristics with race times using bi- and multi-variate analyses. After multi-variate analysis, body fat was related to half-marathon (β=0.9, P=0.0003), marathon (β=2.2, P<0.0001), and ultra-marathon (β=10.5, P<0.0001) race times. In master half-marathoners (β=-4.3, P<0.0001) and master marathoners (β=-11.9, P<0.0001), speed during training was related to race times. In master ultra-marathoners, however, weekly running kilometers (β=-1.6, P<0.0001) were related to running times. To summarize, body fat and training characteristics, not skeletal muscle mass, were associated with running times in master half-marathoners, master marathoners, and master ultra-marathoners. Master half-marathoners and master marathoners rather rely on a high running speed during training whereas master ultra-marathoners rely on a high running volume during training. The common opinion that skeletal muscle mass affects running performance in master runners needs to be questioned.

  1. Protocol for evaluating the effects of a therapeutic foot exercise program on injury incidence, foot functionality and biomechanics in long-distance runners: a randomized controlled trial.

    PubMed

    Matias, Alessandra B; Taddei, Ulisses T; Duarte, Marcos; Sacco, Isabel C N

    2016-04-14

    Overall performance, particularly in a very popular sports activity such as running, is typically influenced by the status of the musculoskeletal system and the level of training and conditioning of the biological structures. Any change in the musculoskeletal system's biomechanics, especially in the feet and ankles, will strongly influence the biomechanics of runners, possibly predisposing them to injuries. A thorough understanding of the effects of a therapeutic approach focused on feet biomechanics, on strength and functionality of lower limb muscles will contribute to the adoption of more effective therapeutic and preventive strategies for runners. A randomized, prospective controlled and parallel trial with blind assessment is designed to study the effects of a "ground-up" therapeutic approach focused on the foot-ankle complex as it relates to the incidence of running-related injuries in the lower limbs. One hundred and eleven (111) healthy long-distance runners will be randomly assigned to either a control (CG) or intervention (IG) group. IG runners will participate in a therapeutic exercise protocol for the foot-ankle for 8 weeks, with 1 directly supervised session and 3 remotely supervised sessions per week. After the 8-week period, IG runners will keep exercising for the remaining 10 months of the study, supervised only by web-enabled software three times a week. At baseline, 2 months, 4 months and 12 months, all runners will be assessed for running-related injuries (primary outcome), time for the occurrence of the first injury, foot health and functionality, muscle trophism, intrinsic foot muscle strength, dynamic foot arch strain and lower-limb biomechanics during walking and running (secondary outcomes). This is the first randomized clinical trial protocol to assess the effect of an exercise protocol that was designed specifically for the foot-and-ankle complex on running-related injuries to the lower limbs of long-distance runners. We intend to show

  2. Sex differences in knee loading in recreational runners.

    PubMed

    Sinclair, J; Selfe, J

    2015-07-16

    Patellofemoral pain is the most common chronic pathology in recreational runners. Female runners are at greater risk of developing patellofemoral pain, although the exact mechanism behind this is not fully understood. This study aimed to determine whether female recreational runners exhibit distinct knee loading compared to males. Fifteen males and 15 females recreational runners underwent 3D running analysis at 4.0 ms(-1)±5%. Sagittal/coronal joint moments, patellofemoral contact forces (PTF) and pressures (PCP) were compared between sexes. The results show that females exhibited significantly greater knee extension (p<0.008, pη(2)=0.27: males=3.04; females=3.47 N m kg(-1)) and abduction (p<0.008, pη(2)=0.28: males=0.54; females=0.82 N m kg(-1)) moments as well as PTF (p<0.008, pη(2)=0.29: males=3.25; females=3.84 B.W.) and PCP (p<0.008, pη(2)=0.26: males=7.96; females=9.27 MPa) compared to males. Given the proposed relationship between knee joint loading and patellofemoral pathology, the current investigation provides insight into the incidence of patellofemoral pain in females.

  3. Methodological innovations for measuring economic impacts of long-distance recreation trails

    Treesearch

    Noah Pollock; Lisa C. Chase; Jane Kolodinsky

    2008-01-01

    Rural communities are increasingly interested in understanding the economic impacts of visitors drawn to their region for recreational opportunities. Economic impact assessments often rely on input-output (I/O) modeling software, which requires estimates of visitation rates and visitor expenditures. Collecting sufficient data for I/O models is relatively...

  4. Predictor Variables for Marathon Race Time in Recreational Female Runners

    PubMed Central

    Schmid, Wiebke; Knechtle, Beat; Knechtle, Patrizia; Barandun, Ursula; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

    2012-01-01

    Purpose We intended to determine predictor variables of anthropometry and training for marathon race time in recreational female runners in order to predict marathon race time for future novice female runners. Methods Anthropometric characteristics such as body mass, body height, body mass index, circumferences of limbs, thicknesses of skin-folds and body fat as well as training variables such as volume and speed in running training were related to marathon race time using bi- and multi-variate analysis in 29 female runners. Results The marathoners completed the marathon distance within 251 (26) min, running at a speed of 10.2 (1.1) km/h. Body mass (r=0.37), body mass index (r=0.46), the circumferences of thigh (r=0.51) and calf (r=0.41), the skin-fold thicknesses of front thigh (r=0.38) and of medial calf (r=0.40), the sum of eight skin-folds (r=0.44) and body fat percentage (r=0.41) were related to marathon race time. For the variables of training, maximal distance ran per week (r=− 0.38), number of running training sessions per week (r=− 0.46) and the speed of the training sessions (r= − 0.60) were related to marathon race time. In the multi-variate analysis, the circumference of calf (P=0.02) and the speed of the training sessions (P=0.0014) were related to marathon race time. Marathon race time might be partially (r 2=0.50) predicted by the following equation: Race time (min)=184.4 + 5.0 x (circumference calf, cm) –11.9 x (speed in running during training, km/h) for recreational female marathoners. Conclusions Variables of both anthropometry and training were related to marathon race time in recreational female marathoners and cannot be reduced to one single predictor variable. For practical applications, a low circumference of calf and a high running speed in training are associated with a fast marathon race time in recreational female runners. PMID:22942994

  5. Type of sport is related to injury profile: a study on cross country skiers, swimmers, long-distance runners and soccer players. A retrospective 12-month study.

    PubMed

    Ristolainen, L; Heinonen, A; Turunen, H; Mannström, H; Waller, B; Kettunen, J A; Kujala, U M

    2010-06-01

    This 12-month retrospective questionnaire compared the occurrence of sports injuries in 149 cross country skiers, 154 swimmers, 143 long-distance runners and 128 soccer players aged 15-35 years. Soccer had significantly more injuries (5.1 injuries/1000 exposure hour) than other sports (2.1-2.8, P<0.001). More runners than soccer players reported overuse injuries (59% vs 42%, P=0.005), locating typically in the foot in runners, soccer players and skiers. Swimmers reported overuse injuries in the shoulder more commonly than skiers (40% vs 1%, P<0.001), who also intensively load shoulders. Acute injuries in skiers (80%) and in swimmers (58%), and overuse injuries in skiers (61%), occurred during exercise other than own event. In soccer and running the absence time from sport because of injuries was significantly longer than in skiing and swimming. No severe permanent disabilities occurred due to injury but seven women quit sports because of injury. In conclusion, type of loading is strictly associated with the anatomical location of an overuse injury as shown by the difference in shoulder injury incidence between swimmers and cross country skiers. In some sports, a significant proportion of acute injuries occur in other than the main event.

  6. Proximal tibia volumetric bone mineral density is correlated to the magnitude of local acceleration in male long-distance runners

    PubMed Central

    Najafi, Bijan; Ballabeni, Pierluigi; Crettenand, Antoinette; Gobelet, Charles; Aminian, Kamiar; Rizzoli, René; Gremion, Gerald

    2010-01-01

    The beneficial effect of physical exercise on bone mineral density (BMD) is at least partly explained by the forces exerted directly on the bones. Male runners present generally higher BMD than sedentary individuals. We postulated that the proximal tibia BMD is related to the running distance, as well as to the magnitude of the shocks (while running) in male runners. A prospective study (three yearly measurements) included 81 healthy male subjects: 16 sedentary lean subjects, and 3 groups of runners (5–30 km/wk, n = 19; 30–50 km/wk, n = 29; 50–100 km/wk, n = 17). Several measurements were performed at the proximal tibia level: volumetric BMD (vBMD) and cortical index (CI), i.e., an index of cortical bone thickness and peak accelerations (an index of shocks during heel strike) while running (measured by a three-dimensional accelerometer). A general linear model assessed the prediction of vBMD or CI by 1) simple effects (running distance, peak accelerations, time); and 2) interactions (for instance, if vBMD prediction by peak acceleration depends on running distance). CI and vBMD 1) increase with running distance to reach a plateau over 30 km/wk; and 2) are positively associated with peak accelerations over 30 km/wk. Running may be associated with high peak accelerations to have beneficial effects on BMD. More important strains are needed to be associated with the same increase in BMD during running sessions of short duration than those of long duration. CI and vBMD are associated with the magnitude of the shocks during heel strike in runners. PMID:20133440

  7. Recreational runners with patellofemoral pain exhibit elevated patella water content.

    PubMed

    Ho, Kai-Yu; Hu, Houchun H; Colletti, Patrick M; Powers, Christopher M

    2014-09-01

    Increased bone water content resulting from repetitive patellofemoral joint overloading has been suggested to be a possible mechanism underlying patellofemoral pain (PFP). To date, it remains unknown whether persons with PFP exhibit elevated bone water content. The purpose of this study was to determine whether recreational runners with PFP exhibit elevated patella water content when compared to pain-free controls. Ten female recreational runners with a diagnosis of PFP (22 to 39years of age) and 10 gender, age, weight, height, and activity matched controls underwent chemical-shift-encoded water-fat magnetic resonance imaging (MRI) to quantify patella water content (i.e., water-signal fraction). Differences in bone water content of the total patella, lateral aspect of the patella, and medial aspect of the patella were compared between groups using independent t tests. Compared with the control group, the PFP group demonstrated significantly greater total patella bone water content (15.4±3.5% vs. 10.3±2.1%; P=0.001), lateral patella water content (17.2±4.2% vs. 11.5±2.5%; P=0.002), and medial patella water content (13.2±2.7% vs. 8.4±2.3%; P<0.001). The higher patella water content observed in female runners with PFP is suggestive of venous engorgement and elevated extracellular fluid. In turn, this may lead to an increase in intraosseous pressure and pain. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Training-overtraining: performance, and hormone levels, after a defined increase in training volume versus intensity in experienced middle- and long-distance runners.

    PubMed

    Lehmann, M; Gastmann, U; Petersen, K G; Bachl, N; Seidel, A; Khalaf, A N; Fischer, S; Keul, J

    1992-12-01

    Performance and hormones were determined in eight middle- and nine long-distance runners after an increase in training volume (ITV, February 1989) or intensity (ITI, February 1990). Seven runners participated in both studies. The objective was to cause an overtraining syndrome. The mean training volume of 85.9 km week-1 increased within 3 weeks to 176.6 km week-1 during ITV and 96-98% of training volume was performed as long-distance runs at mean(s.d.) 67(8)% of maximum capacity. Speed endurance, high-speed and interval runs averaging 9 km week-1 increased within 3 weeks to 22.7 km during ITI, and the total volume increased from 61.6 to 84.7 km. A plateau in endurance performance and decrease in maximum performance occurred during ITV, probably due to overtraining, with performance incompetence over months. Nocturnal catecholamine excretion decreased markedly (47-53%), contrary to exercise-related plasma catecholamine responses, which increased. Resting and exercise-related cortisol and aldosterone levels decreased. Improvement in endurance and maximum performance occurred during ITI indicating a failure to cause an overtraining syndrome in ITI. Decrease in noctural catecholamine excretion was clearly lower (9-26%), exercise-related catecholamine responses showed a significant decrease, cortisol and aldosterone levels remained almost constant, exercise-related prolactin levels decreased slightly. There were no differences in insulin, C-peptide, free testosterone, somatotropic hormone (STH), follicle stimulating hormone (FSH), luteinizing hormone (LH), thyroid stimulating hormone (TSH), tri-iodothyronine (T3) and thyroxine (T4). The decrease in nocturnal catecholamine excretion during ITV might indicate a decrease in intrinsic sympathetic activity in exhausted sportsmen. But it remains open whether this reflected a central nervous system incompetence.

  9. Mixed maximal and explosive strength training in recreational endurance runners.

    PubMed

    Taipale, Ritva S; Mikkola, Jussi; Salo, Tiina; Hokka, Laura; Vesterinen, Ville; Kraemer, William J; Nummela, Ari; Häkkinen, Keijo

    2014-03-01

    Supervised periodized mixed maximal and explosive strength training added to endurance training in recreational endurance runners was examined during an 8-week intervention preceded by an 8-week preparatory strength training period. Thirty-four subjects (21-45 years) were divided into experimental groups: men (M, n = 9), women (W, n = 9), and control groups: men (MC, n = 7), women (WC, n = 9). The experimental groups performed mixed maximal and explosive exercises, whereas control subjects performed circuit training with body weight. Endurance training included running at an intensity below lactate threshold. Strength, power, endurance performance characteristics, and hormones were monitored throughout the study. Significance was set at p ≤ 0.05. Increases were observed in both experimental groups that were more systematic than in the control groups in explosive strength (12 and 13% in men and women, respectively), muscle activation, maximal strength (6 and 13%), and peak running speed (14.9 ± 1.2 to 15.6 ± 1.2 and 12.9 ± 0.9 to 13.5 ± 0.8 km Ł h). The control groups showed significant improvements in maximal and explosive strength, but Speak increased only in MC. Submaximal running characteristics (blood lactate and heart rate) improved in all groups. Serum hormones fluctuated significantly in men (testosterone) and in women (thyroid stimulating hormone) but returned to baseline by the end of the study. Mixed strength training combined with endurance training may be more effective than circuit training in recreational endurance runners to benefit overall fitness that may be important for other adaptive processes and larger training loads associated with, e.g., marathon training.

  10. Effect of Intermittent Hypoxic Training Followed by Intermittent Hypoxic Exposure on Aerobic Capacity of Long Distance Runners.

    PubMed

    Nakamoto, Fernanda P; Ivamoto, Rafael K; Andrade, Marilia Dos S; de Lira, Claudio A B; Silva, Bruno M; da Silva, Antonio C

    2016-06-01

    Effects of intermittent hypoxic training (IHT) are still controversial and detraining effects remain uninvestigated. Therefore, we investigated (a) whether IHT improves aerobic capacity; (b) whether aerobic detraining occurs post-IHT; and (c) whether intermittent hypoxic exposure (IHE) at rest reduces a possible aerobic detraining post-IHT. Twenty eight runners (21 men/7 women; 36 ± 2 years; maximal oxygen uptake [V[Combining Dot Above]O2max] 55.4 ± 1.3 ml·kg·min) participated in a single-blinded placebo-controlled trial. Twice a week, 1 group performed 6 weeks of IHT (n = 11), followed by 4 weeks of IHE (n = 11) at rest (IHT+IHE group). Another group performed 6 weeks of IHT (n = 10), followed by 4 weeks of normoxic exposure (NE, n = 9) at rest (IHT+NE group). A control group performed 6 weeks of normoxic training (NT, n = 7), followed by 4 weeks of NE (n = 6) at rest (NT+NE group). Hematological and submaximal/maximal aerobic measurements were conducted in normoxia at pretraining, posttraining, and postexposure. Hemoglobin concentration did not change, but lactate threshold and running economy improved in all groups at posttraining (p ≤ 0.05 vs. pretraining). Ventilatory threshold, respiratory compensation point, and V[Combining Dot Above]O2max increased after IHT (IHT+IHE group: 7.3, 5.4, and 9.2%, respectively; IHT+NE group: 10.7, 7.5, and 4.8%; p ≤ 0.05 vs. pretraining), but not after NT (-1.1, -1.0, and -3.8%; p > 0.05 vs. pretraining). Such IHT-induced adaptations were maintained at postexposure (p > 0.05 vs. postexposure). In conclusion, IHT induced further aerobic improvements than NT. These additional IHT adaptations were maintained for 4 weeks post-IHT, regardless of IHE.

  11. Running economy and body composition between competitive and recreational level distance runners.

    PubMed

    Mooses, Martin; Jürimäe, J; Mäestu, J; Mooses, K; Purge, P; Jürimäe, T

    2013-09-01

    The aim of the present study was to compare running economy between competitive and recreational level athletes at their individual ventilatory thresholds on track and to compare body composition parameters that are related to the individual running economy measured on track. We performed a cross-sectional analysis of a total 45 male runners classified as competitive runners (CR; n = 28) and recreational runners (RR; n = 17). All runners performed an incremental test on treadmill until voluntary exhaustion and at least 48 h later a 2 × 2000 m test at indoor track with intensities according to ventilatory threshold 1, ventilator threshold 2. During the running tests, athletes wore portable oxygen analyzer. Body composition was measured with Dual energy X-ray absorptiometry (DXA) method. Running economy at the first ventilatory threshold was not significantly related to any of the measured body composition values or leg mass ratios either in the competitive or in the recreational runners group. This study showed that there was no difference in the running economy between distance runners with different performance level when running on track, while there was a difference in the second ventilatory threshold speed in different groups of distance runners. Differences in running economy between competitive and recreational athletes cannot be explained by body composition and/or different leg mass ratios.

  12. Can we detect non-functional overreaching in young elite soccer players and middle-long distance runners using field performance tests?

    PubMed

    Schmikli, Sandor L; Brink, M S; de Vries, W R; Backx, F J G

    2011-06-01

    To study whether field performance tests can make a valid distinction between non-functionally overreaching (NFO) athletes and control athletes. Monthly field performance tests were used to determine a performance decrement (PD) throughout a season. Athletes with a minimum of 1 month PD were compared with control athletes without a PD on mood characteristics and resting levels of stress hormones. Sporting field and sports medical laboratory. 129 young elite athletes, 77 soccer players and 52 middle-long distance runners were followed prospectively during the 2006-2007 season. Fifteen of them were invited to the laboratory. Eight athletes showed a performance decrease lasting longer than 1 month, and seven athletes without a performance decrease acted as their controls. Performance changes over time were measured using field tests. Profile of Mood States and resting levels of adrenocorticotrophic hormone (ACTH) and cortisol in blood were measured in the laboratory. PD athletes showed several symptoms typical of the non-functional state of overreaching (OR). The PD group scored higher on depression and anger than controls. They also showed a specific pattern of correlations between negative mood subscales (tension, fatigue and depression), which was absent in controls. ACTH levels at rest were similar, but lower cortisol levels in PD athletes pointed at a blunted cortisol response. Cortisol levels were decoupled from ACTH levels only in PD athletes. Implementing performance-related criteria in field tests can help coaches and sports physicians to distinguish NFO athletes from athletes with balanced workload and recovery.

  13. Relationship between foot strike pattern, running speed, and footwear condition in recreational distance runners.

    PubMed

    Cheung, Roy T H; Wong, Rodney Y L; Chung, Tim K W; Choi, R T; Leung, Wendy W Y; Shek, Diana H Y

    2017-06-01

    Compared to competitive runners, recreational runners appear to be more prone to injuries, which have been associated with foot strike patterns. Surprisingly, only few studies had examined the foot strike patterns outside laboratories. Therefore, this study compared the foot strike patterns in recreational runners at outdoor tracks with previously reported data. We also investigated the relationship between foot strike pattern, speed, and footwear in this cohort. Among 434 recreational runners analysed, 89.6% of them landed with rearfoot strike (RFS). Only 6.9 and 3.5% landed with midfoot and forefoot, respectively. A significant shift towards non-RFS was observed in our cohort, when compared with previously reported data. When speed increased by 1 m/s, the odds of having forefoot strike and midfoot strike relative to RFS increased by 2.3 times and 2.6 times, respectively. Runners were 9.2 times more likely to run with a forefoot strike in minimalists compared to regular running shoes, although 70% of runners in minimalists continued to use a RFS. These findings suggest that foot strike pattern may differ across running conditions and runners should consider these factors in order to mitigate potential injury.

  14. The Influence of Plantar Short Foot Muscle Exercises on Foot Posture and Fundamental Movement Patterns in Long-Distance Runners, a Non-Randomized, Non-Blinded Clinical Trial.

    PubMed

    Sulowska, Iwona; Oleksy, Łukasz; Mika, Anna; Bylina, Dorota; Sołtan, Jarosław

    2016-01-01

    The objective of this study was to evaluate the influence of two kinds of plantar short foot muscles exercise on foot posture and fundamental movement patterns in long-distance runners. A parallel group non-blinded trial with 6-week follow-up. Twenty five long-distance runners aged 22-35 years. They were divided into two groups. In group 1 (n = 13) subjects performed the exercise "Vele's Forward Lean" and "Reverse Tandem Gait" and in Group 2 (n = 12) the "Short Foot Exercise." The runners performed the exercises daily for 6 weeks. The Foot Posture Index (FPI-6) and The Functional Movement Screen (FMS) tests were performed twice: at baseline and after 6 weeks of the exercise. A significant improvement was observed in FPI -6 (talar head palpation in Group 1, and inversion/eversion of the calcaneus in Group 2). Also in Group 1 a significant improvement was noted in FMS tests: deep squat, active straight leg raise and in total score. Short foot muscles strengthening exercises have beneficial effect on functional movement patterns and on foot posture, therefore they should be included as a part of daily training program of runners. Australian New Zealand Clinical Trials Registry ACTRN12615001200572.

  15. The Influence of Plantar Short Foot Muscle Exercises on Foot Posture and Fundamental Movement Patterns in Long-Distance Runners, a Non-Randomized, Non-Blinded Clinical Trial

    PubMed Central

    Sulowska, Iwona; Oleksy, Łukasz; Mika, Anna; Bylina, Dorota; Sołtan, Jarosław

    2016-01-01

    Background The objective of this study was to evaluate the influence of two kinds of plantar short foot muscles exercise on foot posture and fundamental movement patterns in long-distance runners. Design A parallel group non-blinded trial with 6-week follow-up. Methods Twenty five long-distance runners aged 22–35 years. They were divided into two groups. In group 1 (n = 13) subjects performed the exercise “Vele’s Forward Lean” and “Reverse Tandem Gait” and in Group 2 (n = 12) the “Short Foot Exercise.” The runners performed the exercises daily for 6 weeks. The Foot Posture Index (FPI-6) and The Functional Movement Screen (FMS) tests were performed twice: at baseline and after 6 weeks of the exercise. Results A significant improvement was observed in FPI -6 (talar head palpation in Group 1, and inversion/eversion of the calcaneus in Group 2). Also in Group 1 a significant improvement was noted in FMS tests: deep squat, active straight leg raise and in total score. Conclusions Short foot muscles strengthening exercises have beneficial effect on functional movement patterns and on foot posture, therefore they should be included as a part of daily training program of runners. Trial Registration Australian New Zealand Clinical Trials Registry ACTRN12615001200572 PMID:27336689

  16. Effect of a Marathon Run on Serum Lipoproteins, Creatine Kinase, and Lactate Dehydrogenase in Recreational Runners

    ERIC Educational Resources Information Center

    Kobayashi, Yoshio; Takeuchi, Toshiko; Hosoi, Teruo; Yoshizaki, Hidekiyo; Loeppky, Jack A.

    2005-01-01

    The objective of this study was to determine the effect of a marathon run on serum lipid and lipoprotein concentrations and serum muscle enzyme activities and follow their recovery after the run. These blood concentrations were measured before, immediately after, and serially after a marathon run in 15 male recreational runners. The triglyceride…

  17. Effect of a Marathon Run on Serum Lipoproteins, Creatine Kinase, and Lactate Dehydrogenase in Recreational Runners

    ERIC Educational Resources Information Center

    Kobayashi, Yoshio; Takeuchi, Toshiko; Hosoi, Teruo; Yoshizaki, Hidekiyo; Loeppky, Jack A.

    2005-01-01

    The objective of this study was to determine the effect of a marathon run on serum lipid and lipoprotein concentrations and serum muscle enzyme activities and follow their recovery after the run. These blood concentrations were measured before, immediately after, and serially after a marathon run in 15 male recreational runners. The triglyceride…

  18. ACCURACY OF SELF-REPORTED FOOT STRIKE PATTERN IN INTERCOLLEGIATE AND RECREATIONAL RUNNERS DURING SHOD RUNNING

    PubMed Central

    Bade, Michael B.; Aaron, Katie

    2016-01-01

    ABSTRACT Background Clinicians are interested in the foot strike pattern (FSP) in runners because of the suggested relationship between the strike pattern and lower extremity injury. Purpose The purpose of this study was to assess the ability of collegiate cross-country runners and recreational runners to self-report their foot strike pattern during running. Study Design Cross-sectional Study Methods Twenty-three collegiate cross-country and 23 recreational runners voluntarily consented to participate. Inclusion criteria included running at least 18 miles per week, experience running on a treadmill, no history of lower extremity congenital or traumatic deformity, or acute injury three months prior to the start of the study. All participants completed a pre-test survey to indicate their typical foot strike pattern during a training run (FSPSurvey). Prior to running, reflective markers were placed on the posterior midsole and the vamp of the running shoe. A high-speed camera was used to film each runner in standing and while running at his or her preferred speed on a treadmill. The angle between the vector formed by the two reflective markers and the superior surface of the treadmill was used to calculate the foot strike angle (FSA). To determine the foot strike pattern from the video data (FSPVideo), the static standing angle was subtracted from the FSA at initial contact of the shoe on the treadmill. In addition to descriptive statistics, percent agreement and Chi square analysis was used to determine distribution differences between the video analysis results and the survey. Results The results of the chi-square analysis on the distribution of the FSPSurvey in comparison to the FSPVideo were significantly different for both the XCRunners (p < .01; Chi-square = 8.77) and the REC Runners (p < .0002; Chi-square = 16.70). The cross-country and recreational runners could correctly self-identified their foot strike pattern 56.5% and 43.5% of the time

  19. Bone mass and geometry of the tibia and the radius of master sprinters, middle and long distance runners, race-walkers and sedentary control participants: a pQCT study.

    PubMed

    Wilks, D C; Winwood, K; Gilliver, S F; Kwiet, A; Chatfield, M; Michaelis, I; Sun, L W; Ferretti, J L; Sargeant, A J; Felsenberg, D; Rittweger, J

    2009-07-01

    Mechanical loading is thought to be a determinant of bone mass and geometry. Both ground reaction forces and tibial strains increase with running speed. This study investigates the hypothesis that surrogates of bone strength in male and female master sprinters, middle and long distance runners and race-walkers vary according to discipline-specific mechanical loading from sedentary controls. Bone scans were obtained by peripheral Quantitative Computed Tomography (pQCT) from the tibia and from the radius in 106 sprinters, 52 middle distance runners, 93 long distance runners and 49 race-walkers who were competing at master championships, and who were aged between 35 and 94 years. Seventy-five age-matched, sedentary people served as control group. Most athletes of this study had started to practice their athletic discipline after the age of 20, but the current training regime had typically been maintained for more than a decade. As hypothesised, tibia diaphyseal bone mineral content (vBMC), cortical area and polar moment of resistance were largest in sprinters, followed in descending order by middle and long distance runners, race-walkers and controls. When compared to control people, the differences in these measures were always >13% in male and >23% in female sprinters (p<0.001). Similarly, the periosteal circumference in the tibia shaft was larger in male and female sprinters by 4% and 8%, respectively, compared to controls (p<0.001). Epiphyseal group differences were predominantly found for trabecular vBMC in both male and female sprinters, who had 15% and 18% larger values, respectively, than controls (p<0.001). In contrast, a reverse pattern was found for cortical vBMD in the tibia, and only few group differences of lower magnitude were found between athletes and control people for the radius. In conclusion, tibial bone strength indicators seemed to be related to exercise-specific peak forces, whilst cortical density was inversely related to running distance

  20. Bone mass and geometry of the tibia and the radius of master sprinters, middle and long distance runners, race-walkers and sedentary control participants: A pQCT study

    PubMed Central

    Wilks, D.C.; Winwood, K.; Gilliver, S.F.; Kwiet, A.; Chatfield, M.; Michaelis, I.; Sun, L.W.; Ferretti, J.L.; Sargeant, A.J.; Felsenberg, D.; Rittweger, J.

    2009-01-01

    Mechanical loading is thought to be a determinant of bone mass and geometry. Both ground reaction forces and tibial strains increase with running speed. This study investigates the hypothesis that surrogates of bone strength in male and female master sprinters, middle and long distance runners and race-walkers vary according to discipline-specific mechanical loading from sedentary controls. Bone scans were obtained by peripheral Quantitative Computed Tomography (pQCT) from the tibia and from the radius in 106 sprinters, 52 middle distance runners, 93 long distance runners and 49 race-walkers who were competing at master championships, and who were aged between 35 and 94 years. Seventy-five age-matched, sedentary people served as control group. Most athletes of this study had started to practice their athletic discipline after the age of 20, but the current training regime had typically been maintained for more than a decade. As hypothesised, tibia diaphyseal bone mineral content (vBMC), cortical area and polar moment of resistance were largest in sprinters, followed in descending order by middle and long distance runners, race-walkers and controls. When compared to control people, the differences in these measures were always > 13% in male and > 23% in female sprinters (p < 0.001). Similarly, the periosteal circumference in the tibia shaft was larger in male and female sprinters by 4% and 8%, respectively, compared to controls (p < 0.001). Epiphyseal group differences were predominantly found for trabecular vBMC in both male and female sprinters, who had 15% and 18% larger values, respectively, than controls (p < 0.001). In contrast, a reverse pattern was found for cortical vBMD in the tibia, and only few group differences of lower magnitude were found between athletes and control people for the radius. In conclusion, tibial bone strength indicators seemed to be related to exercise-specific peak forces, whilst cortical density was inversely related to

  1. Effects of prolonged exercise on left ventricular mechanical synchrony in long-distance runners: importance of previous exposure to endurance races.

    PubMed

    Sahlén, Anders; Shahgaldi, Kambiz; Aminoff, Anna; Aagaard, Philip; Manouras, Aristomenis; Winter, Reidar; Ehrenborg, Ewa; Braunschweig, Frieder

    2010-09-01

    Prolonged exercise has been shown to lead to elevated levels of cardiac troponin and altered cardiac function on echocardiography. It is not known if cardiac synchrony is altered by prolonged exercise. The aims of this study were to assess changes in intra-left ventricular mechanical synchrony and circulating levels of cardiac troponin following prolonged exercise and to evaluate the importance of prior exposure to endurance racing. Forty-three male participants in a 30-km cross-country race (20 new participants at this event [median, 3 previous endurance races] age matched against 23 repeat participants [median, 31 previous endurance events]) were assessed prospectively 1 to 2 days before and 24 hours after the race using troponin T and Doppler tissue imaging analyzing the standard deviation of time to peak myocardial systolic velocity (T(s)-SD) in a six-basal, six-midventricular segment model measuring myocardial synchrony. The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene was also analyzed, as I allele carriers reportedly have superior endurance performance, while the D allele predisposes to renin-angiotensin system-induced cardiac remodeling. Prerace troponin T was undetectable in all runners, and postrace levels were higher in new runners (median, 0.03 microg/L; interquartile range [IQR], 0.01-0.04 microg/L) than in repeat runners (median, 0.01 microg/L; IQR, 0.01-0.02 microg/L) (P = .03). Although new and repeat runners had similar T(s)-SD at baseline (32 msec [IQR, 22-43 msec] vs 34 msec [IQR, 29-45 msec], P = .13), dyssynchrony increased only in new runners (40 msec [IQR, 31-47 msec], P < .001; in repeat runners, median, 38 msec [IQR, 29-43 msec], P = .30; median relative difference, +13% vs +5%, P = .02). ACE genotype distribution was similar in both groups. Multivariate analysis showed that (1) a lack of prior endurance exposure; (2) more copies of the ACE D allele; and (3) lower peak systolic velocity were

  2. Comparison between recreational male Ironman triathletes and marathon runners.

    PubMed

    Gianoli, Daniele; Knechtle, Beat; Knechtle, Patrizia; Barandun, Ursula; Rüst, Christoph Alexander; Rosemann, Thomas

    2012-08-01

    Recent investigations described a personal best marathon time as a predictor variable for an Ironman race time in recreational male Ironman triathletes. Similarities and differences in anthropometry and training were investigated between 83 recreational male Ironman triathletes and 81 recreational male marathoners. Ironman triathletes were significantly taller and had a higher body mass and a higher skin-fold thickness of the calf compared to the marathoners. Weekly training volume in hours was higher in Ironman triathletes. In the Ironman triathletes, percent body fat was related to overall race time and both the split time in cycling and running. The weekly swim kilometres were related to the split time in swimming, and the speed in cycling was related to the bike split time. For the marathoners, the calf skin-fold thickness and running speed during training were related to marathon race time. Although personal best marathon time was a predictor of Ironman race time in male triathletes, anthropometric and training characteristics of male marathoners were different from those of male Ironman triathletes, probably due to training of different muscle groups and metabolic endurance beyond marathon running, as the triathletes are also training for high-level performance in swimming and cycling. Future studies should compare Olympic distance triathletes and road cyclists with Ironman triathletes.

  3. Cardiac Output and Performance during a Marathon Race in Middle-Aged Recreational Runners

    PubMed Central

    Billat, Véronique L.; Petot, Hélène; Landrain, Morgan; Meilland, Renaud; Koralsztein, Jean Pierre; Mille-Hamard, Laurence

    2012-01-01

    Purpose. Despite the increasing popularity of marathon running, there are no data on the responses of stroke volume (SV) and cardiac output (CO) to exercise in this context. We sought to establish whether marathon performance is associated with the ability to sustain high fractional use of maximal SV and CO (i.e, cardiac endurance) and/or CO, per meter (i.e., cardiac cost). Methods. We measured the SV, heart rate (HR), CO, and running speed of 14 recreational runners in an incremental, maximal laboratory test and then during a real marathon race (mean performance: 3 hr 30 min ± 45 min). Results. Our data revealed that HR, SV and CO were all in a high but submaximal steady state during the marathon (87.0 ± 1.6%, 77.2 ± 2.6%, and 68.7 ± 2.8% of maximal values, respectively). Marathon performance was inversely correlated with an upward drift in the CO/speed ratio (mL of CO × m−1) (r = −0.65, P < 0.01) and positively correlated with the runner's ability to complete the race at a high percentage of the speed at maximal SV (r = 0.83, P < 0.0002). Conclusion. Our results showed that marathon performance is inversely correlated with cardiac cost and positively correlated with cardiac endurance. The CO response could be a benchmark for race performance in recreational marathon runners. PMID:22645458

  4. Running Performance While Wearing a Heat Dissipating Compression Garment in Male Recreational Runners.

    PubMed

    Leoz-Abaurrea, Iker; Santos-Concejero, Jordan; Grobler, Lara; Engelbrecht, Louise; Aguado-Jiménez, Roberto

    2016-12-01

    Leoz-Abaurrea, I, Santos-Concejero, J, Grobler, L, Engelbrecht, L, and Aguado-Jiménez, R. Running performance while wearing a heat dissipating compression garment in male recreational runners. J Strength Cond Res 30(12): 3367-3372, 2016-The aim of this study was to investigate the effects of a heat dissipating compression garment (CG) during a running performance test. Ten male recreational runners (mean ± SD: age 23 ± 3 years; V[Combining Dot Above]O2max 55.8 ± 4.8 ml·kg·min) completed 2 identical sessions wearing either CG or conventional t-shirt (CON). Each trial included a 45-minute run at 60% of the peak treadmill speed (PTS) followed by a time to exhaustion (TTE) run at 80% of the PTS and a 10-minute recovery period. During the tests, thermoregulatory and cardiovascular responses were monitored. Participants wearing the CG displayed an impaired running performance (508 ± 281 vs. 580 ± 314 seconds, p = 0.046; effect size [ES] = 0.24). In addition, a higher respiratory exchange ratio (1.06 ± 0.04 vs. 1.02 ± 0.07, p = 0.01; ES = 0.70) was observed at TTE when wearing the CG in comparison to CON. Changes in core temperature did not differ between garments after the 45-minute run (p = 0.96; ES = 0.03) or TTE (1.97 ± 0.32 vs. 1.98 ± 0.38° C; p = 0.93; ES = 0.02) for CG and CON, respectively. During recovery, significantly higher heart rate and blood lactate values were observed when wearing CG (p ≤ 0.05). These findings suggest that the use of a heat dissipating CG may not improve running performance in male recreational runners during a running performance test to exhaustion.

  5. Energy Drinks Improve Five-Kilometer Running Performance in Recreational Endurance Runners.

    PubMed

    Prins, Philip J; Goss, Fredric L; Nagle, Elizabeth F; Beals, Kim; Robertson, Robert J; Lovalekar, Mita T; Welton, Gary L

    2016-11-01

    Prins, PJ, Goss, FL, Nagle, EF, Beals, K, Robertson, RJ, Lovalekar, MT, and Welton, GL. Energy drinks improve five-kilometer running performance in recreational endurance runners. J Strength Cond Res 30(11): 2979-2990, 2016-The purpose of this study was to evaluate exercise performance time and related physiological and perceptual responses of recreational endurance runners after they had ingested a commercially available energy drink (Red Bull, Red Bull GmbH, Fuschl am See, Austria) containing caffeine, glucose, and taurine. Recreational endurance runners (n = 18; 13 men and 5 women; age: 20.39 ± 3.27 years; weight: 71.25 ± 17.17 kg; height: 178.00 ± 7.57 cm; V[Combining Dot Above]O2max: 55.94 ± 7.66 ml·kg·min) participated in a double-blind, crossover, repeated-measures study where they were randomized to supplement with 500 ml of the commercially available energy drink Red Bull and a noncaffeinated, sugar-free placebo (PLA) 60 minutes before completing a 5-km time trial on a treadmill, separated by 7 days. Heart rate, rating of perceived exertion (RPE) (RPE-Overall; RPE-Chest; RPE-Legs), and affect were recorded at rest, 1 hour before ingestion, at 5-minute intervals during the 5-km time trial, and immediately after exercise. Session RPE and session affect were obtained 5 minutes after completion of the 5-km time trial. The distance covered at each 5-minute interval during the 5-km time trial was recorded. Performance improved with the energy drink compared with placebo (Red Bull: 1,413.2 ± 169.7 vs. PLA: 1,443.6 ± 179.2 seconds; p = 0.016), but there were no differences in RPE, affect, session RPE, session affect, or the distance covered at 5-minute splits between the two 5-km time trials (p > 0.05). These results demonstrate that consuming a commercially available energy drink before exercise can improve 5-km performance. These results may have application for altering pre-exercise nutritional strategies in recreational runners.

  6. The Effect of Clinical Pilates on Functional Movement in Recreational Runners.

    PubMed

    Laws, Anna; Williams, Sean; Wilson, Cassie

    2017-09-01

    Biomechanical imbalances and inefficient functional movements are considered contributing factors to running-related injuries. Clinical Pilates uses a series of exercises focused on retraining normal movement patterns. This study investigated whether a 6-week course of Clinical Pilates improves functional movement and thereby, potentially, reduces the risk of running-related injuries associated with movement dysfunction. A modified functional movement screen was used to analyze the functional movement ability of forty runners. Forty participants completed a 6-week course of Clinical Pilates delivered by a Clinical Pilates instructor. The movement screen was carried out 3 times for each runner: 6 weeks pre-intervention (baseline), within one week pre-intervention (pre) and within one week post-intervention (post). Repeated-measures analysis of variance and post-hoc tests found significant increases in scores between baseline and post (mean±SD; 13.4±2.4 vs. 17.0±1.7, p<0.01) and pre and post (mean±SD; 13.5±2.5 vs. 17.0±1.7, p<0.01), but no significant difference between baseline and pre (p=0.3). A 6-week course of Clinical Pilates significantly improves functional movement in recreational runners, and this may lead to a reduction in the risk of running-related injuries. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Reduced hip strength is associated with increased hip motion during running in young adult and adolescent male long-distance runners.

    PubMed

    Taylor-Haas, Jeffery A; Hugentobler, Jason A; DiCesare, Christopher A; Hickey Lucas, Kathryn C; Bates, Nathaniel A; Myer, Gregory D; Ford, Kevin R

    2014-08-01

    Controlled laboratory study. Anterior knee pain is one of the most common running symptoms reported in the literature. While the exact etiology is unknown, a lack of hip strength is suggested to contribute to abnormal running mechanics. The purpose of this research study was to evaluate the association between isokinetic hip strength and 3-D running kinematics. 33 male high school and collegiate cross country runners participated in this study. Peak isokinetic hip abductor and hip extensor strength were assessed. Each subject also completed a treadmill running protocol at a self-selected speed (mean = 3.8 m/s). 3-D kinematic data were collected at 240 Hz using a 10-camera motion capture system. Pearson correlation coefficients were used to determine the relationship between hip strength and hip range of motion (ROM) during the stance phase of running (p<0.05). Peak isokinetic hip extensor torque was inversely correlated with transverse plane hip ROM (r = -.387, p = .026) but was not significantly related to sagittal plane hip ROM or frontal plane hip ROM. Peak isokinetic hip abductor torque was inversely correlated with frontal plane hip ROM (r=-.462, p=.008) but was not significantly related to either sagittal plane hip ROM or transverse plane hip ROM. Peak isokinetic hip extensor torque and peak isokinetic hip abductor torque were not significantly related to knee kinematics in any plane. Peak isokinetic hip extensor torque and peak isokinetic hip abductor torque are associated with transverse plane and frontal plane hip kinematics, but not knee kinematics. Level 3b.

  8. The prevalence of fluid associated with the iliotibial band in asymptomatic recreational runners: an ultrasonographic study.

    PubMed

    Jelsing, Elena J; Finnoff, Jonathan; Levy, Bruce; Smith, Jay

    2013-07-01

    To evaluate the prevalence and distribution of fluid associated with the iliotibial band (ITB) in asymptomatic recreational runners. Prospective cohort study. Sports medicine center at a tertiary medical center. Five male and 15 female asymptomatic recreational runners (10-30 miles per week) ages 18-40 years. Participants were examined with the use of ultrasonography to assess for the presence of fluid at the level of the lateral femoral epicondyle and determine its relationship to the ITB at 0 and 30° of knee flexion in both supine (non-weight-bearing) and standing (weight-bearing) positions. Fluid was associated with the ITB in 100% of asymptomatic recreational runners and was bilateral in 90%. When examined in full extension with the subject supine, fluid was seen in 67.5% of knees (n = 40) compared with 95% of the knees when standing. When examined in 30° of flexion, the presence of fluid decreased to 30% when supine and 22.5% when standing. With the knee in full extension in a supine/standing position, fluid was located anterior and deep 70%/74% of the time and was anterior only 11%/0% of the time. With the knee flexed to 30° in a supine/standing position, fluid was located anterior and deep 50%/33% of the time and anterior only 33%/67% of the time. The prevalence of fluid associated with the ITB varied with body and knee position, was most common in the standing position with the knee extended, and was generally located anterior or anterior and deep to the ITB. The clinical significance of our findings are 2-fold: (1) body position should be considered when searching for fluid in the vicinity of the ITB, and (2) clinicians and imagers should exercise caution when interpreting the clinical significance of fluid associated with the ITB during ultrasonographic evaluation of runners with lateral knee pain. Copyright © 2013 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  9. Relationship between functional hamstring: quadriceps ratios and running economy in highly trained and recreational female runners.

    PubMed

    Sundby, Oyvind H; Gorelick, Mark L S

    2014-08-01

    The purpose of this study was to investigate the relationship between running economy (RE), functional hamstring:quadriceps peak torque ratios (f-H:Q), and flexibility among female runners. Seven highly trained (HT) female runners (age: 25.7 ± 4.7 years, VO2peak of 62.0 ± 4.8 ml·kg-1·min-1) and 11 recreational female runners (age of 28.8 ± 5.6 years, VO2peak of 49.2 ± 4.6 ml·kg-1·min-1) were measured for maximal aerobic power (VO2peak), RE, heart rate, respiratory exchange ratio, f-H:Q (Hecc:Qcon and Hcon:Qecc), and sit-and-reach hamstring/trunk flexibility. On 2 separate days, RE was measured on a treadmill at 1% grade at 2 velocities (160.9 and 201.2 m·min-1) for 6 minutes each, and isokinetic knee strength was measured at 3 angular velocities (60, 120, and 180°·s-1) for both concentric and eccentric muscle actions. The unpaired t-tests showed a consistent trend toward higher f-H:Q ratios at all angular velocities among the HT runners. Highly trained runners had significantly higher Hecc:Qcon at 120°·s-1 (p ≤ 0.05) and 180°·s-1 (p ≤ 0.05). Whole group correlations demonstrated a significant correlation between Hcon:Qecc at 180°·s-1 and RE (ml·kg-1·km-1) at 201.2 m·min-1 (R = -0.48, p ≤ 0.05). No significant relationships were found between flexibility, or hamstring and quadriceps peak torque (N·m) and RE (p > 0.05). This cross-sectional analysis suggests that higher f-H:Q torque ratios, and not muscle strength per se, are associated with a lower metabolic cost of running. Therefore, runners should consider implementing hamstring exercises to improve their f-H:Q ratios.

  10. Intensity related changes of running economy in recreational level distance runners.

    PubMed

    Engeroff, Tobias; Bernardi, Andreas; Niederer, Daniel; Wilke, Jan; Vogt, Lutz; Banzer, Winfried

    2017-09-01

    Running economy (RE) is often described as a key demand of running performance. The variety of currently used assessment methods with different running intensities and outcomes restricts interindividual comparability of RE in recreational level runners. The purpose of this study was to compare the influence of RE, assessed as oxygen cost (OC) and caloric unit cost (CUC), on running speed at individual physiological thresholds. Eighteen recreational runners performed: 1) a graded exercise test to estimate first ventilatory threshold (VT1), respiratory compensation point (RCP) and maximal oxygen uptake (VO2max); 2) discontinuous RE assessment to determine relative OC in milliliters per kilogram per kilometer (mL/kg/km) and CUC in kilocalories per kilogram per kilometer (kcal/kg/km) at three different running intensities: VT1, RCP and at a third standardized reference point (TP) in between. OC (mL/kg/km; at VT1: 235.4±26.2; at TP: 227.8±23.4; at RCP: 224.9±21.9) and CUC (kcal/kg/km at VT1: 1.18±0.13; at TP: 1.14±0.12; at RCP: 1.13±0.11) decreased with increasing intensities (P≤0.01). Controlling for the influence of sex OC and CUC linearly correlated with running speed at RCP and VO2max (P≤0.01). RE, even assessed at low intensity, is strongly related to running performance in recreational athletes. Both calculation methods used (OC and CUC) are sensitive for monitoring intensity related changes of substrate utilization. RE values decreased with higher running intensity indicating an increase of anaerobic and subsequent decrease of aerobic substrate utilization.

  11. Predictor variables for a half marathon race time in recreational male runners

    PubMed Central

    Rüst, Christoph Alexander; Knechtle, Beat; Knechtle, Patrizia; Barandun, Ursula; Lepers, Romuald; Rosemann, Thomas

    2011-01-01

    The aim of this study was to investigate predictor variables of anthropometry, training, and previous experience in order to predict a half marathon race time for future novice recreational male half marathoners. Eighty-four male finishers in the ‘Half Marathon Basel’ completed the race distance within (mean and standard deviation, SD) 103.9 (16.5) min, running at a speed of 12.7 (1.9) km/h. After multivariate analysis of the anthropometric characteristics, body mass index (r = 0.56), suprailiacal (r = 0.36) and medial calf skin fold (r = 0.53) were related to race time. For the variables of training and previous experience, speed in running of the training sessions (r = −0.54) were associated with race time. After multivariate analysis of both the significant anthropometric and training variables, body mass index (P = 0.0150) and speed in running during training (P = 0.0045) were related to race time. Race time in a half marathon might be partially predicted by the following equation (r2 = 0.44): Race time (min) = 72.91 + 3.045 * (body mass index, kg/m2) −3.884 * (speed in running during training, km/h) for recreational male runners. To conclude, variables of both anthropometry and training were related to half marathon race time in recreational male half marathoners and cannot be reduced to one single predictor variable. PMID:24198577

  12. Anthropometric and training variables related to half-marathon running performance in recreational female runners.

    PubMed

    Knechtle, Beat; Knechtle, Patrizia; Barandun, Ursula; Rosemann, Thomas

    2011-05-01

    The relationship between skin-fold thickness and running has been investigated in distances ranging from 100 m to the marathon distance (42.195 km), with the exclusion of the half-marathon distance (21.0975 km). We investigated the association between anthropometric variables, prerace experience, and training variables with race time in 42 recreational, nonprofessional, female half-marathon runners using bi- and multivariate analysis. Body weight (r, 0.60); body mass index (r, 0.48); body fat percentage (r, 0.56); pectoral (r, 0.61), mid-axilla (r, 0.69), triceps (r, 0.49), subscapular (r, 0.61), abdominal (r, 0.59), suprailiac (r, 0.55), and medial calf (r, 0.53) skin-fold thickness; mean speed of the training sessions (r, -0.68); and personal best time in a half-marathon (r, 0.69) correlated with race time after bivariate analysis. Body weight (P = 0.0054), pectoral skin-fold thickness (P = 0.0068), and mean speed of the training sessions (P = 0.0041) remained significant after multivariate analysis. Mean running speed during training was related to mid-axilla (r, -0.31), subscapular (r, -0.38), abdominal (r, -0.44), and suprailiac (r, -0.41) skin-fold thickness, the sum of 8 skin-fold thicknesses (r, -0.36); and percent body fat (r, -0.31). It was determined that variables of both anthropometry and training were related to half-marathon race time, and that skin-fold thicknesses were associated with running speed during training. For practical applications, high running speed during training (as opposed to extensive training) may both reduce upper-body skin-fold thicknesses and improve race performance in recreational female half-marathon runners.

  13. In-shoe plantar pressure distribution during running on natural grass and asphalt in recreational runners.

    PubMed

    Tessutti, Vitor; Trombini-Souza, Francis; Ribeiro, Ana Paula; Nunes, Ana Luiza; Sacco, Isabel de Camargo Neves

    2010-01-01

    The type of surface used for running can influence the load that the locomotor apparatus will absorb and the load distribution could be related to the incidence of chronic injuries. As there is no consensus on how the locomotor apparatus adapts to loads originating from running surfaces with different compliance, the objective of this study was to investigate how loads are distributed over the plantar surface while running on natural grass and on a rigid surface--asphalt. Forty-four adult runners with 4+/-3 years of running experience were evaluated while running at 12 km/h for 40 m wearing standardised running shoes and Pedar insoles (Novel). Peak pressure, contact time and contact area were measured in six regions: lateral, central and medial rearfoot, midfoot, lateral and medial forefoot. The surfaces and regions were compared by three ANOVAS (2 x 6). Asphalt and natural grass were statistically different in all variables. Higher peak pressures were observed on asphalt at the central (p<0.001) [grass: 303.8(66.7)kPa; asphalt: 342.3(76.3)kPa] and lateral rearfoot (p<0.001) [grass: 312.7(75.8)kPa; asphalt: 350.9(98.3)kPa] and lateral forefoot (p<0.001) [grass: 221.5(42.9)kPa; asphalt: 245.3(55.5)kPa]. For natural grass, contact time and contact area were significantly greater at the central rearfoot (p<0.001). These results suggest that natural grass may be a surface that provokes lighter loads on the rearfoot and forefoot in recreational runners. Copyright (c) 2008 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  14. A consensus definition of running-related injury in recreational runners: a modified Delphi approach.

    PubMed

    Yamato, Tiê Parma; Saragiotto, Bruno Tirotti; Lopes, Alexandre Dias

    2015-05-01

    Delphi study. To reach a consensus definition of running-related injury in recreational runners through a modified Delphi approach. Many studies have suggested the need for a standardized definition of running-related injury to provide uniformity to injury surveillance in running. We invited 112 researchers from running-related injury studies identified in a previous systematic review to classify words and terms frequently used in definitions of running-related injury in an online form during 3 rounds of study. In the last round, participants were asked to approve or disapprove the consensus definition. We considered an agreement level of at least 75% to be a consensus. Thirty-eight participants agreed to participate in the study. The response rates were 94.7% (n = 36) for the first round, 83.3% (n = 30) for the second round, and 86.7% (n = 26) for the third round. A consensus definition of running-related injury was reached, with 80% of participants approving the following: "Running-related (training or competition) musculoskeletal pain in the lower limbs that causes a restriction on or stoppage of running (distance, speed, duration, or training) for at least 7 days or 3 consecutive scheduled training sessions, or that requires the runner to consult a physician or other health professional." The proposed standardized definition of running-related injury could assist in standardizing the definitions used in sport science research and facilitate between-study comparisons. Future studies testing the validity of the proposed consensus definition, as well as its accurate translation to other languages, are also needed.

  15. Mucosal immunity and upper respiratory tract symptoms in recreational endurance runners.

    PubMed

    Ihalainen, Johanna K; Schumann, Moritz; Häkkinen, Keijo; Mero, Antti A

    2016-01-01

    The present study investigated the effects of a 12-week endurance-training intervention on salivary proteins and upper respiratory tract symptoms (URS) in 25 young men. Saliva samples of 25 recreational male endurance runners (age 34.6 years, body mass index = 23.8 kg·m(-2), peak aerobic capacity = 47.2 mL·kg(-1)·min(-1)) were collected before (PRE) and after (POST) the training intervention, in a fasting state, as well as both before and after a maximal incremental treadmill run. The training consisted of both continuous and interval training sessions, 4-6 times per week based on the polarized training approach. Participants filled in Wisconsin Upper Respiratory Symptom Survey-21 and were retrospectively divided into 2 groups according to whether they reported URS (URS group, n = 13) or not (HEALTHY group, n = 12). Basal salivary immunoglobulin A (sa-sIgA) levels were significantly higher (+70%, p < 0.05) in the HEALTHY group both at PRE and POST whereas no significant differences were observed in salivary immunoglobulin M, salivary immunoglobulin G, lysozyme, or salivary α-amylase activity (sAA). Sa-sIgA concentration at PRE significantly correlated with the number of sick-days (R = -0.755, p < 0.001) in all subjects. The incremental treadmill run acutely increased sAA significantly (p < 0.05) at PRE (200%) and POST (166%) in the HEALTHY group but not in the URS group. This study demonstrated that subjects, who experienced URS during the 12 weeks of progressive endurance training intervention, had significantly lower basal sa-sIgA levels both before and after the experimental endurance training period. In addition to sa-sIgA, acute sAA response to exercise might be a possible determinant of susceptibility to URS in endurance runners.

  16. Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners.

    PubMed

    Mikkola, Jussi; Vesterinen, Ville; Taipale, Ritva; Capostagno, Benoit; Häkkinen, Keijo; Nummela, Ari

    2011-10-01

    The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([V·]O(₂max)), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [V·]O(₂max) (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups < 0.08). All three modes of strength training used concurrently with endurance training were effective in improving treadmill running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance

  17. Training-Load-Guided vs Standardized Endurance Training in Recreational Runners.

    PubMed

    Schumann, Moritz; Botella, Javier; Karavirta, Laura; Häkkinen, Keijo

    2017-03-01

    To compare the effects of a standardized endurance-training program with individualized endurance training modified based on the cumulative training load provided by the Polar training-load feature. After 12 wk of similar training, 24 recreationally endurance-trained men were matched to a training-load-guided (TL, n = 10) or standardized (ST, n = 14) group and continued training for 12 wk. In TL, training sessions were individually chosen daily based on an estimated cumulative training load, whereas in ST the training was standardized with 4-6 sessions/wk. Endurance performance (shortest 1000-m running time during an incremental field test of 6 × 1000 m) and heart-rate variability (HRV) were measured every 4 wk, and maximal oxygen consumption (VO2max) was measured during an incremental treadmill test every 12 wk. During weeks 1-12, similar changes in VO2max and 1000-m time were observed in TL (+7% ± 4%, P = .004 and -6% ± 4%, P = .069) and ST (+5% ± 7%, P = .019 and -8% ± 5%, P < .001). During wk 13-24, VO2max statistically increased in ST only (3% ± 4%, P = .034). The 1000-m time decreased in TL during wk 13-24 (-9% ± 5%, P = .011), but in ST only during wk 13-20 (-3% ± 2%, P = .003). The overall changes in VO2max and 1000-m time during wk 0-24 were similar in TL (+7% ± 4%, P = .001 and -9% ± 5%, P = .011) and ST (+10% ± 7%, P < .001 and -13% ± 5%, P < .001). No between-groups differences in total training volume and frequency were observed. HRV remained statistically unaltered in both groups. The main finding was that training performed according to the cumulative training load led to improvements in endurance performance similar to those with standardized endurance training in recreational endurance runners.

  18. The effects of orthotic intervention on multisegment foot kinematics and plantar fascia strain in recreational runners.

    PubMed

    Sinclair, Jonathan; Isherwood, Josh; Taylor, Paul J

    2015-02-01

    Chronic injuries are a common complaint in recreational runners. Foot orthoses have been shown to be effective for the treatment of running injuries but their mechanical effects are still not well understood. This study aims to examine the influence of orthotic intervention on multisegment foot kinematics and plantar fascia strain during running. Fifteen male participants ran at 4.0 m · s(-1) with and without orthotics. Multisegment foot kinematics and plantar fascia strain were obtained during the stance phase and contrasted using paired t tests. Relative coronal plane range of motion of the midfoot relative to the rearfoot was significantly reduced with orthotics (1.0°) compared to without (2.2°). Similarly, relative transverse plane range of motion was significantly lower with orthotics (1.1°) compared to without (1.8°). Plantar fascia strain did not differ significantly between orthotic (7.1) and nonorthotic (7.1) conditions. This study shows that although orthotics did not serve to reduce plantar fascia strain, they are able to mediate reductions in coronal and transverse plane rotations of the midfoot.

  19. Coronary atherosclerosis burden, but not transient troponin elevation, predicts long-term outcome in recreational marathon runners.

    PubMed

    Möhlenkamp, Stefan; Leineweber, Kirsten; Lehmann, Nils; Braun, Siegmund; Roggenbuck, Ulla; Perrey, Mareike; Broecker-Preuss, Martina; Budde, Thomas; Halle, Martin; Mann, Klaus; Jöckel, Karl-Heinz; Erbel, Raimund; Heusch, Gerd

    2014-01-01

    We determined the prognostic value of transient increases in high-sensitive serum troponin I (hsTnI) during a marathon and its association with traditional cardiovascular risk factors and imaging-based risk markers for incident coronary events and all-cause mortality in recreational marathon runners. Baseline data of 108 marathon runners, 864 age-matched controls and 216 age- and risk factor-matched controls from the general population were recorded and their coronary event rates and all-cause mortality after 6 ± 1 years determined. hsTnI was measured in 74 marathon finishers before and after the race. Other potential predictors for coronary events, i.e., Framingham Risk Score (FRS), coronary artery calcium (CAC) and presence of myocardial fibrosis as measured by magnetic resonance imaging-based late gadolinium enhancement (LGE), were also assessed. An increase beyond the 99 % hsTnI-threshold, i.e., 0.04 μg/L, was observed in 36.5 % of runners. FRS, CAC, or prevalent LGE did not predict hsTnI values above or increases in hsTnI beyond the median after the race, nor did they predict future events. However, runners with versus without LGE had higher hsTnI values after the race (median (Q1/Q3), 0.08 μg/L (0.04/0.09) versus 0.03 μg/L (0.02/0.06), p = 0.039), and higher increases in hsTnI values during the race (median (Q1/Q3), 0.05 μg/L (0.03/0.08) versus 0.02 μg/L (0.01/0.05), p = 0.0496). Runners had a similar cumulative event rate as age-matched or age- and risk factor-matched controls, i.e., 6.5 versus 5.0 % or 4.6 %, respectively. Event rates in runners with CAC scores <100, 100-399, and ≥400 were 1.5, 12.0, and 21.4 % (p = 0.002 for trend) and not different from either control group. Runners with coronary events had a higher prevalence of LGE than runners without events (57 versus 8 %, p = 0.003). All-cause mortality was similar in marathon runners (3/108, 2.8 %) and controls (26/864, 3.0 % or 5/216, 2.4 %, respectively). Recreational marathon runners with

  20. Neuromuscular Adaptations to Same-Session Combined Endurance and Strength Training in Recreational Endurance Runners.

    PubMed

    Schumann, M; Pelttari, P; Doma, K; Karavirta, L; Häkkinen, K

    2016-12-01

    This study examined neuromuscular adaptations in recreational endurance runners during 24 weeks of same-session combined endurance and strength training (E+S, n=13) vs. endurance training only (E, n=14). Endurance training was similar in the 2 groups (4-6x/week). Additional maximal and explosive strength training was performed in E+S always after incremental endurance running sessions (35-45 min, 65-85% HRmax). Maximal dynamic leg press strength remained statistically unaltered in E+S but decreased in E at week 24 (-5±5%, p=0.014, btw-groups at week 12 and 24, p=0.014 and 0.011). Isometric leg press and unilateral knee extension force, EMG of knee extensors and voluntary activation remained statistically unaltered in E+S and E. The changes in muscle cross-sectional (CSA) differed between the 2 groups after 12 (E+S+6±8%, E -5±6%, p<0.001) and 24 (E+S+7±7%, E -6±5%, p<0.001) weeks. 1 000 m running time determined during an incremental field test decreased in E+S and E after 12 (-7±3%, p<0.001 and -8±5%, p=0.001) and 24 (-9±5%, p=0.001 and -13±5%, p<0.001) weeks. Strength training performed always after an endurance running session did not lead to increased maximal strength, CSA, EMG or voluntary activation. This possibly contributed to the finding of no endurance performance benefits in E+S compared to E. © Georg Thieme Verlag KG Stuttgart · New York.

  1. Effects of foot orthoses on Achilles tendon load in recreational runners.

    PubMed

    Sinclair, J; Isherwood, J; Taylor, P J

    2014-09-01

    Achilles tendon pathology is a frequently occurring musculoskeletal disorder in runners. Foot orthoses have been shown to reduce the symptoms of pain in runners but their mechanical effects are still not well understood. This study aimed to examine differences in Achilles tendon load when running with and without orthotic intervention. Twelve male runners ran at 4.0 m·s(-1). Ankle joint moments and Achilles tendon forces were compared when running with and without orthotics. The results indicate that running with foot orthotics was associated with significant reductions in Achilles tendon load compared to without orthotics. In addition to providing insight into the mechanical effects of orthotics in runners, the current investigation suggests that via reductions in Achilles tendon load, foot orthoses may serve to reduce the incidence of chronic Achilles tendon pathologies in runners. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. [Hemodynamic and humoral changes in long-distance athletes].

    PubMed

    Corea, L; Bentivoglio, M; Verdecchia, P; Provvidenza, M; Milia, U; Pollavini, G

    1983-12-01

    Cardiac anatomy and function, and some biohumoral parameters, have been examined in 11 long-distance olympic runners, and in 11 healthy untrained control subjects. Echocardiographic methods and computed reading of tracings were adopted. Long-distance runners were also studied within 2 minutes after the end of a 30 Km race. At rest, the athletes had thicker interventricular septa and, posterior walls, higher left ventricular mass index, larger end-diastolic dimensions, cardiac index and stroke index compared to the untrained subjects (all P less than 0.01). Resting heart rate was lower in runners (P less than 0.01). In runners, competitive exercise test induced significant haemodynamic changes (increases in cardiac index, heart rate, stroke index, ejection fraction [all P less than 0.01], decreases in end-systolic dimensions and peripheral vascular resistance [both P less than 0.01]). After exercise, runners showed massive increases both of norepinephrine and epinephrine serum levels (measured in 4 subjects), an increase, in haematocrit and plasma glucose concentration, and a decrease in plasma potassium concentration (all P less than 0.01). In conclusion, olympic long-distance runners have increased cardiac dimensions and wall thickness at rest as compared with healthy untrained subjects matched for age and resting blood pressure. In the former group, a competitive long-distance test results in marked haemodynamic changes, with massive increase in plasma catecholamine concentration and concomitant reduction in plasma potassium concentration. This combination is potentially hazardous, and warrants further investigation.

  3. Long distance entanglement distribution

    NASA Astrophysics Data System (ADS)

    Broadfoot, Stuart Graham

    Developments in the interdisciplinary field of quantum information open up previously impossible abilities in the realms of information processing and communication. Quantum entanglement has emerged as one property of quantum systems that acts as a resource for quantum information processing and, in particular, enables teleportation and secure cryptography. Therefore, the creation of entangled resources is of key importance for the application of these technologies. Despite a great deal of research the efficient creation of entanglement over long distances is limited by inevitable noise. This problem can be overcome by creating entanglement between nodes in a network and then performing operations to distribute the entanglement over a long distance. This thesis contributes to the field of entanglement distribution within such quantum networks. Entanglement distribution has been extensively studied for one-dimensional networks resulting in "quantum repeater" protocols. However, little work has been done on higher dimensional networks. In these networks a fundamentally different scaling, called "long distance entanglement distribution", can appear between the resources and the distance separating the systems to be entangled. I reveal protocols that enable long distance entanglement distribution for quantum networks composed of mixed state and give a few limitations to the capabilities of entanglement distribution. To aid in the implementation of all entanglement distribution protocols I finish by introducing a new system, composed of an optical nanofibre coupled to a carbon nanotube, that may enable new forms of photo-detectors and quantum memories.

  4. Mechanical Work and Long-Distance Performance Prediction: the Influence of Allometric Scaling

    PubMed Central

    Tartaruga, Marcus Peikriszwili; Brisswalter, Jeanick; Mota, Carlos Bolli; Alberton, Cristine Lima; Gomeñuka, Natalia Andrea; Peyré-Tartaruga, Leonardo Alexandre

    2013-01-01

    The purpose of this study was to examine the effect of allometric scaling on the relationship between mechanical work and long-distance running performance in recreational runners. Fourteen recreational long-distance runners (male, mean ± SD - age: 29 ± 7 years; body mass: 70.0 ± 10.2 kg; body height: 1.71 ± 0.07 m; maximal oxygen uptake: VO2max 52.0 ± 4.9 ml·kg−1·min−1) performed two tests: a continuous incremental test to volitional exhaustion in order to determine VO2max, and a 6-minute running submaximal test at 3.1 m·s−1, during which segments in the sagittal plane were recorded using a digital camera and the internal (Wint), external (Wext) and total (Wtot) mechanic work, in J·kg−1·m−1, was subsequently calculated. The results indicated a significant correlation between mechanical work and performance, however, the strongest correlations were observed when allometric exponents were used (respectively for Wint, Wext and Wtot; non allometric vs. allometric scaling defined by literature (0.75) or determined mathematically (0.49): r = 0.38 vs. r = 0.44 and r = 0.50; r = 0.80 vs. r = 0.83 and r = 0.82; r = 0.70 vs. r = 0.77 and r = 0.78). These results indicate that mechanical work could be used as a predictor of recreational long-distance performance and an allometric model may improve this prediction. PMID:24235986

  5. Prediction of half-marathon race time in recreational female and male runners.

    PubMed

    Knechtle, Beat; Barandun, Ursula; Knechtle, Patrizia; Zingg, Matthias A; Rosemann, Thomas; Rüst, Christoph A

    2014-01-01

    Half-marathon running is of high popularity. Recent studies tried to find predictor variables for half-marathon race time for recreational female and male runners and to present equations to predict race time. The actual equations included running speed during training for both women and men as training variable but midaxillary skinfold for women and body mass index for men as anthropometric variable. An actual study found that percent body fat and running speed during training sessions were the best predictor variables for half-marathon race times in both women and men. The aim of the present study was to improve the existing equations to predict half-marathon race time in a larger sample of male and female half-marathoners by using percent body fat and running speed during training sessions as predictor variables. In a sample of 147 men and 83 women, multiple linear regression analysis including percent body fat and running speed during training units as independent variables and race time as dependent variable were performed and an equation was evolved to predict half-marathon race time. For men, half-marathon race time might be predicted by the equation (r(2) = 0.42, adjusted r(2) = 0.41, SE = 13.3) half-marathon race time (min) = 142.7 + 1.158 × percent body fat (%) - 5.223 × running speed during training (km/h). The predicted race time correlated highly significantly (r = 0.71, p < 0.0001) to the achieved race time. For women, half-marathon race time might be predicted by the equation (r(2) = 0.68, adjusted r(2) = 0.68, SE = 9.8) race time (min) = 168.7 + 1.077 × percent body fat (%) - 7.556 × running speed during training (km/h). The predicted race time correlated highly significantly (r = 0.89, p < 0.0001) to the achieved race time. The coefficients of determination of the models were slightly higher than for the existing equations. Future studies might include physiological

  6. Predictors of individual adaptation to high-volume or high-intensity endurance training in recreational endurance runners.

    PubMed

    Vesterinen, V; Häkkinen, K; Laine, T; Hynynen, E; Mikkola, J; Nummela, A

    2016-08-01

    The aim of this study was to investigate factors that can predict individual adaptation to high-volume or high-intensity endurance training. After the first 8-week preparation period, 37 recreational endurance runners were matched into the high-volume training group (HVT) and high-intensity training group (HIT). During the next 8-week training period, HVT increased their running training volume and HIT increased training intensity. Endurance performance characteristics, heart rate variability (HRV), and serum hormone concentrations were measured before and after the training periods. While HIT improved peak treadmill running speed (RSpeak ) 3.1 ± 2.8% (P < 0.001), no significant changes occurred in HVT (RSpeak : 0.5 ± 1.9%). However, large individual variation was found in the changes of RSpeak in both groups (HVT: -2.8 to 4.1%; HIT: 0-10.2%). A negative relationship was observed between baseline high-frequency power of HRV (HFPnight ) and the individual changes of RSpeak (r = -0.74, P = 0.006) in HVT and a positive relationship (r = 0.63, P = 0.039) in HIT. Individuals with lower HFP showed greater change of RSpeak in HVT, while individuals with higher HFP responded well in HIT. It is concluded that nocturnal HRV can be used to individualize endurance training in recreational runners.

  7. The Effects of Long Distance Running on Preadolescent Children.

    ERIC Educational Resources Information Center

    Covington, N. Kay

    This study investigated the effects of selected physiological variables on preadolescent male and female long distance runners. The trained group was comprised of 20 children between the ages of 8 and 10 who had been running a minimum of 20 miles per week for two months or longer. The control group was made up of 20 children of the same ages who…

  8. Effects of a concurrent strength and endurance training on running performance and running economy in recreational marathon runners.

    PubMed

    Ferrauti, Alexander; Bergermann, Matthias; Fernandez-Fernandez, Jaime

    2010-10-01

    The purpose of this study was to investigate the effects of a concurrent strength and endurance training program on running performance and running economy of middle-aged runners during their marathon preparation. Twenty-two (8 women and 14 men) recreational runners (mean ± SD: age 40.0 ± 11.7 years; body mass index 22.6 ± 2.1 kg·m⁻²) were separated into 2 groups (n = 11; combined endurance running and strength training program [ES]: 9 men, 2 women and endurance running [E]: 7 men, and 4 women). Both completed an 8-week intervention period that consisted of either endurance training (E: 276 ± 108 minute running per week) or a combined endurance and strength training program (ES: 240 ± 121-minute running plus 2 strength training sessions per week [120 minutes]). Strength training was focused on trunk (strength endurance program) and leg muscles (high-intensity program). Before and after the intervention, subjects completed an incremental treadmill run and maximal isometric strength tests. The initial values for VO2peak (ES: 52.0 ± 6.1 vs. E: 51.1 ± 7.5 ml·kg⁻¹·min⁻¹) and anaerobic threshold (ES: 3.5 ± 0.4 vs. E: 3.4 ± 0.5 m·s⁻¹) were identical in both groups. A significant time × intervention effect was found for maximal isometric force of knee extension (ES: from 4.6 ± 1.4 to 6.2 ± 1.0 N·kg⁻¹, p < 0.01), whereas no changes in body mass occurred. No significant differences between the groups and no significant interaction (time × intervention) were found for VO2 (absolute and relative to VO2peak) at defined marathon running velocities (2.4 and 2.8 m·s⁻¹) and submaximal blood lactate thresholds (2.0, 3.0, and 4.0 mmol·L⁻¹). Stride length and stride frequency also remained unchanged. The results suggest no benefits of an 8-week concurrent strength training for running economy and coordination of recreational marathon runners despite a clear improvement in leg strength, maybe because of an insufficient sample size or a short

  9. Changes of Gait Parameters and Lower Limb Dynamics in Recreational Runners with Achilles Tendinopathy

    PubMed Central

    Kim, SungJoong; Yu, JaeHo

    2015-01-01

    This study aimed to clarify the mechanical gait changes caused by achilles tendinopathy by comparing gait parameters and changes in hip, knee, and ankle moments between an experimental group (EG) and a control group (CG). Twenty runners with achilles tendinopathy were included in the EG (male/female: 10/10, age: 27.00 ± 4.63), and 20 CG (male/female: 10/10, age: 27.25 ± 4.33) participants were recruited. Subjects walked a 13-m distance at their normal walking speed 5 times to obtain motion analysis and joint moment data. Gait parameter analysis showed significant differences in double-limb support (EG: 22.65 ± 4.26%, CG: 20.37 ± 4.46%), step length (EG: 0.58 ± 0.0 7m, CG: 0.64 ± 0.08 m), step width (EG: 0.16 ± 0.04 m, CG: 0.14 ± 0.05 m), stride time (EG: 1.09 ± 0.10 second, CG: 1.05 ± 0.08 second), and walking speed (EG: 1.09±0.18 m·s-1, CG: 1.23 ± 0.17 m·s-1) between the 2 groups (p < 0.05). Significant differences were found in hip joint moment for initial contact, mid-stance, terminal stance, and pre-swing phases; knee joint moment for initial contact and pre-swing phases; and ankle joint moment for pre-swing and terminal swing phases (p < 0.05). Gait parameters and hip, knee, and ankle moments were altered in runners with achilles tendinopathy. Thus, clinical features of gait changes should be understood for optimal treatment of achilles tendinopathy; further research is required in this field. Key points A reduction in gait parameters, namely, step length, stride length, and walking speed, and an increase in double-limb support occurs in runners with achilles tendinopathy. A reduction in the hip extension moment occurs during the initial contact, as well as a reduction in the knee flexion moment from the mid-stance to pre-swing phases, a continuous decrease in the knee flexion moment from the early stance phase, and a reduction in the extension moment during the terminal stance phase. A reduction in the ankle plantar flexion moment occurs from

  10. Long-distance running, bone density, and osteoarthritis

    SciTech Connect

    Lane, N.E.; Bloch, D.A.; Jones, H.H.; Marshall, W.H. Jr.; Wood, P.D.; Fries, J.F.

    1986-03-07

    Forty-one long-distance runners aged 50 to 72 years were compared with 41 matched community controls to examine associations of repetitive, long-term physical impact (running) with osteoarthritis and osteoporosis. Roentgenograms of hands, lateral lumbar spine, and knees were assessed without knowledge of running status. A computed tomographic scan of the first lumbar vertebra was performed to quantitate bone mineral content. Runners, both male and female, have approximately 40% more bone mineral than matched controls. Female runners, but not male runners, appear to have somewhat more sclerosis and spur formation in spine and weight-bearing knee x-ray films, but not in hand x-ray films. There were no differences between groups in joint space narrowing, crepitation, joint stability, or symptomatic osteoarthritis. Running is associated with increased bone mineral but not, in this cross-sectional study, with clinical osteoarthritis.

  11. The Effects of Barefoot and Shod Running on Limb and Joint Stiffness Characteristics in Recreational Runners.

    PubMed

    Sinclair, Jonathan; Atkins, Stephen; Taylor, Paul J

    2016-01-01

    The authors aimed to determine the effects of barefoot (BF) and several commercially available barefoot-inspired (BFIS) footwear models on limb and joint stiffness characteristics compared with conventional footwear (CF). Fifteen male participants ran over a force platform at 4.0 m.s(-1), in BF, BFIS, and CF conditions. Measures of limb and joint stiffness were calculated for each footwear. The results indicate that limb and knee stiffness were greater in BF and minimalist BFIS than in CF. CF and more structured BFIS were associated with a greater ankle stiffness compared with BF and minimalist BFIS. These findings serve to provide further insight into the susceptibility of runners to different injury mechanisms as a function of footwear.

  12. Effects of two different knee tape procedures on lower-limb kinematics and kinetics in recreational runners.

    PubMed

    Howe, A; Campbell, A; Ng, L; Hall, T; Hopper, D

    2015-08-01

    The purpose of this study was to compare the effects of Mulligan's tape (MT) and kinesio tape (KT) with no tape (NT) on hip and knee kinematics and kinetics during running. Twenty-nine female recreational runners performed a series of 'run-throughs' along a 10-m runway under the three taping conditions. Two force plates and a 14-camera Vicon motion analysis system (Oxford Metrics, Inc., Oxford, UK) captured kinematic and kinetic data for each dependent variable from ground contact to toe off. Comparisons of each dependent variable under three taping conditions were assessed through Statistical Package for the Social Sciences (SPSS; SPSS, Inc., Chicago, Illinois, USA; P-value < 0.01) using repeated measure analyses of variance. For each dependent variable with a P-value < 0.01, repeated measures with pairwise comparisons and Bonferroni adjustment were conducted to compare the three taping conditions. MT induced a significant reduction in anterior and posterior hip forces, knee flexion angular velocity, knee extensor moments, and hip flexion and extension moments compared with NT and KT (P = 0.001). There was no difference in hip or knee, kinematics or kinetics, between KT and NT (P = 1.000). MT appears to influence hip and knee biomechanics during running in an asymptomatic sample, whereas KT appeared to be biomechanically not different from NT.

  13. Runner's Knee

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Runner's Knee KidsHealth > For Teens > Runner's Knee A A A ... told he had runner's knee. What Is Runner's Knee? Runner's knee is the term doctors use for ...

  14. Long distance tracking of birds

    NASA Technical Reports Server (NTRS)

    Cochran, W. W.

    1972-01-01

    The application of radio telemetry techniques to the long distance tracking of birds is discussed. The types of equipment developed and methods for attachment to a bird are described. The operating range of the radio transmitter receiver system is examined, and methods for acquiring and analyzing the data are explained.

  15. Incidence of Running-Related Injuries Per 1000 h of running in Different Types of Runners: A Systematic Review and Meta-Analysis.

    PubMed

    Videbæk, Solvej; Bueno, Andreas Moeballe; Nielsen, Rasmus Oestergaard; Rasmussen, Sten

    2015-07-01

    No systematic review has identified the incidence of running-related injuries per 1000 h of running in different types of runners. The purpose of the present review was to systematically search the literature for the incidence of running-related injuries per 1000 h of running in different types of runners, and to include the data in meta-analyses. A search of the PubMed, Scopus, SPORTDiscus, PEDro and Web of Science databases was conducted. Titles, abstracts, and full-text articles were screened by two blinded reviewers to identify prospective cohort studies and randomized controlled trials reporting the incidence of running-related injuries in novice runners, recreational runners, ultra-marathon runners, and track and field athletes. Data were extracted from all studies and comprised for further analysis. An adapted scale was applied to assess the risk of bias. After screening 815 abstracts, 13 original articles were included in the main analysis. Running-related injuries per 1000 h of running ranged from a minimum of 2.5 in a study of long-distance track and field athletes to a maximum of 33.0 in a study of novice runners. The meta-analyses revealed a weighted injury incidence of 17.8 (95% confidence interval [CI] 16.7-19.1) in novice runners and 7.7 (95% CI 6.9-8.7) in recreational runners. Heterogeneity in definitions of injury, definition of type of runner, and outcome measures in the included full-text articles challenged comparison across studies. Novice runners seem to face a significantly greater risk of injury per 1000 h of running than recreational runners.

  16. Gonadotropin Pulsatllity in FemaIe Long Distance Runners

    DTIC Science & Technology

    1986-10-24

    8 in Ovarian Follicles 3. Development of the Endometrium 10 B. Gonadotropin Regulation During the 11 Menstrual Cycle 1. overvrew of Gonadotropin...changes in gonadotropin and ovarian steroids throughout the cycle. The development of the ovarian follicle and endometrium are also shown. ’ j...3. Development of the Endometrium During menstruation, bleeding occurs due to a sloughing off of the endometrium from the previous menstrual cycle

  17. The immediate effect of triceps surae myofascial trigger point therapy on restricted active ankle joint dorsiflexion in recreational runners: a crossover randomised controlled trial.

    PubMed

    Grieve, Rob; Cranston, Amy; Henderson, Andrew; John, Rachel; Malone, George; Mayall, Christopher

    2013-10-01

    To investigate the immediate effect on restricted active ankle joint dorsiflexion range of motion (ROM), after a single intervention of myofascial trigger point (MTrP) therapy on latent triceps surae MTrPs in recreational runners. A crossover randomised controlled trial. Twenty-two recreational runners (11 men and 11 women; mean age 24.57; ±8.7 years) with a restricted active ankle joint dorsiflexion and presence of latent MTrPs. Participants were screened for a restriction in active ankle dorsiflexion in either knee flexion (soleus) or knee extension (gastrocnemius) and the presence of latent MTrPs. Participants were randomly allocated a week apart to both the intervention (combined pressure release and 10 s passive stretch) and the control condition. A clinically meaningful (large effect size) and statistically significant increase in ankle ROM in the intervention compared to the control group was achieved, for the soleus (p = 0.004) and the gastrocnemius (p = 0.026). Apart from the statistical significance (p < 0.05), these results are clinically relevant due to the immediate increase in ankle dorsiflexion. These results must be viewed in caution due to the carry-over effect in the RCT crossover design and the combined MTrP therapy approach. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Rethinking the role of fat oxidation: substrate utilisation during high-intensity interval training in well-trained and recreationally trained runners

    PubMed Central

    Hetlelid, Ken J; Plews, Daniel J; Herold, Eva; Laursen, Paul B; Seiler, Stephen

    2015-01-01

    Background Although carbohydrate is the predominant fuel source supporting high-intensity exercise workloads, the role of fat oxidation, and the degree to which it may be altered by training status, is less certain. Methods We compared substrate oxidation rates, using indirect calorimetry, during a high-intensity interval training (HIT) session in well-trained (WT) and recreationally trained (RT) runners. Following preliminary testing, 9 WT (VO2max 71±5 mL/min/kg) and 9 RT (VO2max 55±5 mL/min/kg) male runners performed a self-paced HIT sequence consisting of six, 4 min work bouts separated by 2 min recovery periods on a motorised treadmill set at a 5% gradient. Results WT and RT runners performed the HIT session with the same perceived effort (rating of perceived exertion (RPE) =18.3±0.7 vs 18.2±1.1, respectively), blood lactate (6.4±2.1 vs 6.2±2.5 mmol/L) and estimated carbohydrate oxidation rates (4.2±0.29 vs 4.4±0.45 g/min; effect size (ES) 90% confidence limits (CL)=−0.19±0.85). Fat oxidation (0.64±0.13 vs 0.22±0.16 g/min for WT and RT, respectively) accounted for 33±6% of the total energy expenditure in WT vs 16±6% in RT most likely very large difference in fat oxidation (ES 90% CL=1.74±0.83) runners. Higher rates of fat oxidation had a very large correlation with VO2max (r=0.86; 90% CI (0.7 to 0.94). Conclusions Despite similar RPE, blood lactate and carbohydrate oxidation rates, the better performance by the WT group was explained by their nearly threefold higher rates of fat oxidation at high intensity. PMID:27900134

  19. Renal function abnormalities after marathon run and 16-kilometre long-distance run.

    PubMed

    Mydlík, Miroslav; Derzsiová, Katarína; Bohus, Branislav

    2012-01-01

    Renal functions were investigated in 29 marathon runners and in 20 runners in connection with 16-kilometre long-distance run. Body weight in runners decreased after marathon run in average of 1.3 +/- 0.5 kg and after 16-kilometre long-distance run in average of 1.4 +/- 0.4 kg. Blood pressure decreased after both runs. Total proteinuria and albuminuria significantly increased after both runs. The significant non-glomerular erythrocyturia was found in 9 runners after marathon run and in 3 runners after 16-km long-distance run. Total catalytic activity of serum creatine kinase, and its isoenzyme MB significantly increased after both runs. Increase of isoenzyme MB creatine kinase after runs was lower than 6% of total catalytic activity of creatine kinase. These increases were caused by rhabdomyolysis and were connected with myoglobinuria. Serum myoglobin significantly increased after marathon run and after 16-km run. Serum urea, creatinine, phosphorus and osmolality significantly increased after both runs. Calculated GFR significantly decreased after both runs. FE(Na), FE(Ca), FE(P), FE(OSM) and FE(H2O) significantly decreased after both runs. FE significantly increased after marathon run, but after 16-km run non-significantly decreased. Renal function abnormalities were caused by dehydration, microtraumas in extrarenal urinary tract, protein catabolism, decreased urinary excretion of osmotically active substances, rhabdomyolysis, activation of renin-angiotensin-aldosterone system and other factors. Renal function abnormalities in runners were already not present 2-6 days after marathon run and after 16-kilometre long-distance run and investigated parameters were in normal range or they did not significantly differ from the initial values.

  20. Binding Principle for Long-Distance Anaphors.

    ERIC Educational Resources Information Center

    Choi, Dong-Ik

    1997-01-01

    An analysis of long-distance anaphora, a binding phenomenon in which reflexives find their antecedents outside their local domain, is presented, using data from English, Chinese, Japanese, Korean, Russian, Icelandic, and Italian. It is found that no approach deals with long-distance anaphors exclusively and elegantly. The binding domain…

  1. Gastrointestinal Symptoms of Marathon Runners

    PubMed Central

    Keeffe, Emmet B.; Lowe, Daniel K.; Goss, J. Richard; Wayne, Robert

    1984-01-01

    A survey of 707 participants in the 13th Annual Trail's End Marathon in Seaside, Oregon, showed a high incidence of gastrointestinal disturbances, predominantly of the lower tract, associated with long-distance running. The urge to defecate, both during and immediately after running, occurred in over a third of runners. Bowel movements (35%) and diarrhea (19%) were relatively common after running, and runners occasionally interrupted hard runs or races for bowel movements (18%) or diarrhea (10%). Lower gastrointestinal disturbances were more frequent in women than in men and in younger than in older runners. Awareness of the frequency and nature of gastrointestinal symptoms documented by this survey will assist physicians in evaluating abdominal complaints in runners. PMID:6506684

  2. Gastrointestinal symptoms of marathon runners.

    PubMed

    Keeffe, E B; Lowe, D K; Goss, J R; Wayne, R

    1984-10-01

    A survey of 707 participants in the 13th Annual Trail's End Marathon in Seaside, Oregon, showed a high incidence of gastrointestinal disturbances, predominantly of the lower tract, associated with long-distance running. The urge to defecate, both during and immediately after running, occurred in over a third of runners. Bowel movements (35%) and diarrhea (19%) were relatively common after running, and runners occasionally interrupted hard runs or races for bowel movements (18%) or diarrhea (10%). Lower gastrointestinal disturbances were more frequent in women than in men and in younger than in older runners. Awareness of the frequency and nature of gastrointestinal symptoms documented by this survey will assist physicians in evaluating abdominal complaints in runners.

  3. Effects of Continuous and Interval Training on Running Economy, Maximal Aerobic Speed and Gait Kinematics in Recreational Runners.

    PubMed

    González-Mohíno, Fernando; González-Ravé, José M; Juárez, Daniel; Fernández, Francisco A; Barragán Castellanos, Rubén; Newton, Robert U

    2016-04-01

    The purpose of this study was to evaluate the effects on running economy (RE), V[Combining Dot Above]O2max, maximal aerobic speed (MAS), and gait kinematics (step length [SL] and frequency, flight and contact time [CT]) in recreational athletes, with 2 different training methods, Interval and Continuous (CON). Eleven participants were randomly distributed in an interval training group (INT; n = 6) or CON training group (CON; n = 5). Interval training and CON performed 2 different training programs (95-110% and 70-75% of MAS, respectively), which consisted of 3 sessions per week during 6 weeks with the same external workload (%MAS × duration). An incremental test to exhaustion was performed to obtain V[Combining Dot Above]O2max, MAS, RE, and gait variables (high speed camera) before and after the training intervention. There was a significant improvement (p ≤ 0.05) in RE at 60 and 90% of MAS by the CON group; without changes in gait. The INT group significantly increased MAS and higher stride length at 80, 90, and 100% of MAS and lower CT at 100% of MAS. As expected, training adaptations are highly specific to the overload applied with CON producing improvements in RE at lower percentage of MAS whereas INT produces improvements in MAS. The significantly increased stride length and decreased CT for the INT group are an important outcome of favorable changes in running gait.

  4. Acute neuromuscular and metabolic responses to combined strength and endurance loadings: the "order effect" in recreationally endurance trained runners.

    PubMed

    Taipale, Ritva S; Schumann, Moritz; Mikkola, Jussi; Nyman, Kai; Kyröläinen, Heikki; Nummela, Ari; Häkkinen, Keijo

    2014-01-01

    The study examined the acute neuromuscular and metabolic responses and recovery (24 and 48 h) to combined strength and endurance sessions (SEs). Recreationally endurance trained men (n = 12) and women (n = 10) performed: endurance running followed immediately by a strength loading (combined endurance and strength session (ES)) and the reverse order (SE). Maximal strength (MVC), countermovement jump height (CMJ), and creatine kinase activity were measured pre-, mid-, post-loading and at 24 and 48 h of recovery. MVC and CMJ were decreased (P < 0.05) at post-ES and SE sessions in men. Only MVC decreased in ES and SE women (P < 0.05). During recovery, no order differences in MVC were observed between sessions in men, but MVC and CMJ remained decreased. During recovery in women, a delayed decrease in CMJ was observed in ES but not in SE (P < 0.01), while MVC returned to baseline at 24 h. Creatine kinase increased (P < 0.05) during both ES and SE and peaked in all groups at 24 h. The present combined ES and SE sessions induced greater neuromuscular fatigue at post in men than in women. The delayed fatigue response in ES women may be an order effect related to muscle damage.

  5. Understanding Long-Distance Quantum Correlations

    NASA Astrophysics Data System (ADS)

    Marchildon, L.

    2007-09-01

    The interpretation of quantum mechanics (or, for that matter, of any physical theory) consists in answering the question: How can the world be for the theory to be true? That question is especially pressing in the case of the long-distance correlations predicted by Einstein, Podolsky and Rosen, and rather convincingly established during the past decades in various laboratories. I will review four different approaches to the understanding of long-distance quantum correlations: (i) the Copenhagen interpretation and some of its modern variants; (ii) Bohmian mechanics of spin-carrying particles; (iii) Cramer's transactional interpretation; and (iv) the Hess-Philipp analysis of extended parameter spaces.

  6. The Long-Distance Binding of "ZIJI."

    ERIC Educational Resources Information Center

    Liejiong, XU

    1993-01-01

    Addresses "ziji," notorious long-distance reflexive in Chinese, which can take antecedent infinitively far away. Argues that theories concerned with anaphoric properties should be formed and evaluated on basis of following observations: no barriers can block anaphoric relation; and subjects of any clauses containing reflexive are its…

  7. The Long-Distance Binding of "ZIJI."

    ERIC Educational Resources Information Center

    Liejiong, XU

    1993-01-01

    Addresses "ziji," notorious long-distance reflexive in Chinese, which can take antecedent infinitively far away. Argues that theories concerned with anaphoric properties should be formed and evaluated on basis of following observations: no barriers can block anaphoric relation; and subjects of any clauses containing reflexive are its…

  8. Long-distance interactions in Cyclopean vision.

    PubMed Central

    Kohly, R P; Regan, D

    2001-01-01

    We report on evidence for selective long-distance interactions in Cyclopean binocular vision. When presented with a pair of Cyclopean test bars observers could discriminate trial-to-trial uncorrelated variations in the mean orientation, orientation difference, separation and mean location of the test bars while ignoring random variations in the orientation, width and location of a third bar placed between the two test bars. We propose that the human visual system contains Cyclopean long-distance comparators (i) that compare the outputs of two narrow receptive fields some distance apart while being insensitive to stimuli located between those receptive fields, and (ii) the outputs of which carry orthogonally labelled indicators of orientation difference, mean orientation, separation and mean location. In the evolutionary context, one role for the proposed mechanisms might be to encode information about the silhouettes of animals whose camouflage is broken by the binocular vision of predators. PMID:11209894

  9. Increase in plasma calprotectin during long-distance running.

    PubMed

    Fagerhol, M K; Nielsen, H G; Vetlesen, A; Sandvik, K; Lyberg, T

    2005-01-01

    Running leads to biochemical and hematological changes consistent with an inflammatory reaction to tissue injury. We report changes in the plasma concentration of the leukocyte-derived protein calprotectin after long-distance running. Blood samples were collected from runners before and after a marathon, half-marathon, a 30-km cross-country run, a military ranger-training course and short-term maximal physical exercise until exhaustion, VO2max. Leukocyte counts, plasma calprotectin concentration and calprotectin per neutrophilic granulocyte were assayed using a new method. During the marathon, half-marathon, the 30-km run, the ranger-training course and the VO2max exercise, calprotectin levels increased 96.3-fold, 13.3-fold, 20.1-fold, 7.5-fold and 3.4-fold, respectively. These changes may reflect damage to the tissues or vascular endothelium, causing microthrombi with subsequent activation of neutrophils. These cells are known to phagocytose platelets in microthrombi and may contribute to the prevention of clinical thrombosis. The half-life of calprotectin in plasma was about 5 h. The content of calprotectin per neutrophil remained unchanged during exercise at a level similar to that in healthy blood donors: mean: 25 pg/cell, range 18.8-33.6. A reference interval (mean +/- 2 SD) of 18.6-31.4 pg/cell is suggested.

  10. Acute occlusion of the left iliac artery after long-distance-running.

    PubMed

    Schmidt, O; Thaler, K H; Lang, W

    2001-02-01

    We report a case of spontaneous iliac occlusion in a 44-year-old male patient after long-distance running. Atherogenic risk factors like hypertension, diabetes, hypercholesterolemia and smoking were missing. Spontaneous iliac occlusion is extremely rare and only a few cases have been documented. Angiography showed occlusion of the left iliac artery with collateral flow via the obturator artery to the common femoral artery. Thrombectomy was performed but reocclusion occurred. An iliacofemoral bypass, arterial lysis and bypass thrombectomy was necessary within a few months. At the last follow-up visit two years afterwards the patient was symptom-free. This case indicates that exercise-dependent blood flow disturbances in long-distance-runners could produce changes of the intima.

  11. Long distance coupling of resonant exchange qubits

    NASA Astrophysics Data System (ADS)

    Russ, Maximilian; Burkard, Guido

    We investigate the effectiveness of a microwave cavity as a mediator of interactions between two resonant exchange (RX) qubits in semiconductor quantum dots (QDs) over long distances, limited only by the extension of the cavity. Our interaction model includes the orthonormalized Wannier orbitals constructed from Fock-Darwin states under the assumption of a harmonic QD confinement potential. We calculate the qubit-cavity coupling strength gr in a Jaynes Cummings Hamiltonian, and find that dipole transitions between two states with an asymmetric charge configuration constitute the relevant RX qubit-cavity coupling mechanism. The effective coupling between two RX qubits in a shared cavity yields a universal two-qubit iSWAP-gate with gate times on the order of nanoseconds over distances on the order of up to a millimeter. Funded by ARO through Grant No. W911NF-15-1-0149.

  12. Long distance coupling of resonant exchange qubits

    NASA Astrophysics Data System (ADS)

    Russ, Maximilian; Burkard, Guido

    2015-11-01

    We investigate the effectiveness of a microwave cavity as a mediator of interactions between two resonant exchange (RX) qubits in semiconductor quantum dots (QDs) over long distances, limited only by the extension of the cavity. Our interaction model includes the orthonormalized Wannier orbitals constructed from Fock-Darwin states under the assumption of a harmonic QD confinement potential. We calculate the qubit-cavity coupling strength in a Jaynes-Cummings Hamiltonian and find that dipole transitions between two states with an asymmetric charge configuration constitute the relevant RX qubit-cavity coupling mechanism. The effective coupling between two RX qubits in a shared cavity yields a universal two-qubit iswap gate with gate times on the order of nanoseconds over distances on the order of up to a millimeter.

  13. Optimal architectures for long distance quantum communication

    PubMed Central

    Muralidharan, Sreraman; Li, Linshu; Kim, Jungsang; Lütkenhaus, Norbert; Lukin, Mikhail D.; Jiang, Liang

    2016-01-01

    Despite the tremendous progress of quantum cryptography, efficient quantum communication over long distances (≥1000 km) remains an outstanding challenge due to fiber attenuation and operation errors accumulated over the entire communication distance. Quantum repeaters (QRs), as a promising approach, can overcome both photon loss and operation errors, and hence significantly speedup the communication rate. Depending on the methods used to correct loss and operation errors, all the proposed QR schemes can be classified into three categories (generations). Here we present the first systematic comparison of three generations of quantum repeaters by evaluating the cost of both temporal and physical resources, and identify the optimized quantum repeater architecture for a given set of experimental parameters for use in quantum key distribution. Our work provides a roadmap for the experimental realizations of highly efficient quantum networks over transcontinental distances. PMID:26876670

  14. Optimal architectures for long distance quantum communication.

    PubMed

    Muralidharan, Sreraman; Li, Linshu; Kim, Jungsang; Lütkenhaus, Norbert; Lukin, Mikhail D; Jiang, Liang

    2016-02-15

    Despite the tremendous progress of quantum cryptography, efficient quantum communication over long distances (≥ 1000 km) remains an outstanding challenge due to fiber attenuation and operation errors accumulated over the entire communication distance. Quantum repeaters (QRs), as a promising approach, can overcome both photon loss and operation errors, and hence significantly speedup the communication rate. Depending on the methods used to correct loss and operation errors, all the proposed QR schemes can be classified into three categories (generations). Here we present the first systematic comparison of three generations of quantum repeaters by evaluating the cost of both temporal and physical resources, and identify the optimized quantum repeater architecture for a given set of experimental parameters for use in quantum key distribution. Our work provides a roadmap for the experimental realizations of highly efficient quantum networks over transcontinental distances.

  15. Spectroscopic thermometry for long-distance surveying.

    PubMed

    Tomberg, Teemu; Fordell, Thomas; Jokela, Jorma; Merimaa, Mikko; Hieta, Tuomas

    2017-01-10

    Electronic distance meters are routinely used to accurately determine the distance between two points. To reach relative measurement uncertainties of 10-7, the average temperature along the beam has to be known within 100 mK since it is a key component in determining the refractive index of air. Temperature measurements at this level are extremely challenging over long distances and especially in an outdoor environment. This paper presents a thermometer for accurate temperature measurements over distances up to a few km. The thermometer is based on direct laser absorption spectroscopy of oxygen near 770 nm. The thermometer yields a spatially continuous measurement of air temperature, and it can provide spatially and temporally well-matching data with an actual distance-measuring laser beam. A field measurement campaign at the 864-m Nummela standard baseline demonstrates applicability of the developed thermometer for improving the refractive index compensation of current high-performance electronic distance meters.

  16. 47 CFR 32.5100 - Long distance message revenue.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Long distance message revenue. 32.5100 Section... Long distance message revenue. This account shall include revenue derived from message services that... includes those message services which utilize the public long distance switching network and the basic...

  17. Genetic aspects of athletic performance: the African runners phenomenon.

    PubMed

    Vancini, Rodrigo Luiz; Pesquero, João Bosco; Fachina, Rafael Júlio; Andrade, Marília Dos Santos; Borin, João Paulo; Montagner, Paulo César; de Lira, Claudio Andre Barbosa

    2014-01-01

    The current dominance of African runners in long-distance running is an intriguing phenomenon that highlights the close relationship between genetics and physical performance. Many factors in the interesting interaction between genotype and phenotype (eg, high cardiorespiratory fitness, higher hemoglobin concentration, good metabolic efficiency, muscle fiber composition, enzyme profile, diet, altitude training, and psychological aspects) have been proposed in the attempt to explain the extraordinary success of these runners. Increasing evidence shows that genetics may be a determining factor in physical and athletic performance. But, could this also be true for African long-distance runners? Based on this question, this brief review proposed the role of genetic factors (mitochondrial deoxyribonucleic acid, the Y chromosome, and the angiotensin-converting enzyme and the alpha-actinin-3 genes) in the amazing athletic performance observed in African runners, especially the Kenyans and Ethiopians, despite their environmental constraints.

  18. Genetic aspects of athletic performance: the African runners phenomenon

    PubMed Central

    Vancini, Rodrigo Luiz; Pesquero, João Bosco; Fachina, Rafael Júlio; Andrade, Marília dos Santos; Borin, João Paulo; Montagner, Paulo César; de Lira, Claudio Andre Barbosa

    2014-01-01

    The current dominance of African runners in long-distance running is an intriguing phenomenon that highlights the close relationship between genetics and physical performance. Many factors in the interesting interaction between genotype and phenotype (eg, high cardiorespiratory fitness, higher hemoglobin concentration, good metabolic efficiency, muscle fiber composition, enzyme profile, diet, altitude training, and psychological aspects) have been proposed in the attempt to explain the extraordinary success of these runners. Increasing evidence shows that genetics may be a determining factor in physical and athletic performance. But, could this also be true for African long-distance runners? Based on this question, this brief review proposed the role of genetic factors (mitochondrial deoxyribonucleic acid, the Y chromosome, and the angiotensin-converting enzyme and the alpha-actinin-3 genes) in the amazing athletic performance observed in African runners, especially the Kenyans and Ethiopians, despite their environmental constraints. PMID:24891818

  19. Effect of a herbal yeast food supplement and long-distance running on immunological parameters.

    PubMed Central

    Gmünder, F K; Joller, P W; Joller-Jemelka, H I; Bechler, B; Cogoli, M; Ziegler, W H; Müller, J; Aeppli, R E; Cogoli, A

    1990-01-01

    The effect of a food supplement on immunological parameters of 16 long-distance runners was tested in a randomized, double-blind and placebo-controlled trial. The supplement comprised plasmolysed herbal yeast, malt, honey, and orange juice. No statistically significant differences between the two groups regarding the following variables were detected at three sessions at rest and immediately after a 21 km run: total and differential white blood cell counts, numbers of B- and T-cells and T-subpopulations, concanavalin-A-induced lymphocyte proliferation, serum levels of immunoglobulins, neopterin, IL-2 receptors, beta 2-microglobulin, complement factor b, c4 and c3c, and c1-inactivator. These findings suggest that the effects of the tested food supplement on these parameters are negligible with respect to improvements in the immunological status of long-distance runners. The changes observed immediately after the run had a transient character. In both groups, however, low lymphocyte counts, IgG subclass 2 levels and c1-inactivator levels were noted at rest, which indicate that the immune status of endurance athletes may be affected by training. PMID:2265308

  20. Body Composition and Aerobic Requirements of Male and Female Marathon Runners.

    ERIC Educational Resources Information Center

    Wells, Christine L.; And Others

    This study investigates the physical characteristics, body composition, cardiovascular and pulmonary functions, and aerobic capabilities of male and female long distance runners. Eleven runners volunteered to take tests to determine background information, body fat, oxygen uptake, and running time and pace. Conclusions made from this study…

  1. Wideband Antenna Arraying Over Long Distances

    NASA Astrophysics Data System (ADS)

    Torre Fernandez, A.

    2013-08-01

    Antennas separated by long distances have large delays and delay rates among them. If wide-bandwidth signals are received, frequency domain beamformers based on filter banks can be used to carry out signal combination. A new scheme based on subband delay compensation is proposed in this article. The main advantages of this scheme are the wider field of view of the array, the reduction of distortion in the transfer function, and the simplification of communications among sites. In order to perform coherent combination, the delay and delay rates need to be estimated. In order to do so, an algorithm is devised to estimate the differential phase, delay, and delay rate between two antennas based on the subband signals. This algorithm is first developed for a stationary case, in which the delay rate is zero. The product of subband signals is averaged and an inverse discrete Fourier transform (IDFT) is carried out to yield an estimate of the cross-correlation. For the nonstationary case, first the delay rate is calculated by means of a two-dimensional IDFT, and from that point a function similar to the one in the stationary case is obtained so as to compute the delay and phase offset.

  2. Long Distance Reactor Antineutrino Flux Monitoring

    NASA Astrophysics Data System (ADS)

    Dazeley, Steven; Bergevin, Marc; Bernstein, Adam

    2015-10-01

    The feasibility of antineutrino detection as an unambiguous and unshieldable way to detect the presence of distant nuclear reactors has been studied. While KamLAND provided a proof of concept for long distance antineutrino detection, the feasibility of detecting single reactors at distances greater than 100 km has not yet been established. Even larger detectors than KamLAND would be required for such a project. Considerations such as light attenuation, environmental impact and cost, which favor water as a detection medium, become more important as detectors get larger. We have studied both the sensitivity of water based detection media as a monitoring tool, and the scientific impact such detectors might provide. A next generation water based detector may be able to contribute to important questions in neutrino physics, such as supernova neutrinos, sterile neutrino oscillations, and non standard electroweak interactions (using a nearby compact accelerator source), while also providing a highly sensitive, and inherently unshieldable reactor monitoring tool to the non proliferation community. In this talk I will present the predicted performance of an experimental non proliferation and high-energy physics program. Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE-AC52-07NA27344. Release number LLNL-ABS-674192.

  3. Long-Distance Dispersal of Fungi.

    PubMed

    Golan, Jacob J; Pringle, Anne

    2017-07-01

    Dispersal is a fundamental biological process, operating at multiple temporal and spatial scales. Despite an increasing understanding of fungal biodiversity, most research on fungal dispersal focuses on only a small fraction of species. Thus, any discussion of the dispersal dynamics of fungi as a whole is problematic. While abundant morphological and biogeographic data are available for hundreds of species, researchers have yet to integrate this information into a unifying paradigm of fungal dispersal, especially in the context of long-distance dispersal (LDD). Fungal LDD is mediated by multiple vectors, including meteorological phenomena (e.g., wind and precipitation), plants (e.g., seeds and senesced leaves), animals (e.g., fur, feathers, and gut microbiomes), and in many cases humans. In addition, fungal LDD is shaped by both physical constraints on travel and the ability of spores to survive harsh environments. Finally, fungal LDD is commonly measured in different ways, including by direct capture of spores, genetic comparisons of disconnected populations, and statistical modeling and simulations of dispersal data. To unify perspectives on fungal LDD, we propose a synthetic three-part definition that includes (i) an identification of the source population and a measure of the concentration of source inoculum and (ii) a measured and/or modeled dispersal kernel. With this information, LDD is defined as (iii) the distance found within the dispersal kernel beyond which only 1% of spores travel.

  4. Does polyploidy facilitate long-distance dispersal?

    PubMed Central

    Linder, H. Peter; Barker, Nigel P.

    2014-01-01

    Background and Aims The ability of plant lineages to reach all continents contributes substantially to their evolutionary success. This is exemplified by the Poaceae, one of the most successful angiosperm families, in which most higher taxa (tribes, subfamilies) have global distributions. Due to the old age of the ocean basins relative to the major angiosperm radiations, this is only possible by means of long-distance dispersal (LDD), yet the attributes of lineages with successful LDD remain obscure. Polyploid species are over-represented in invasive floras and in the previously glaciated Arctic regions, and often have wider ecological tolerances than diploids; thus polyploidy is a candidate attribute of successful LDD. Methods The link between polyploidy and LDD was explored in the globally distributed grass subfamily Danthonioideae. An almost completely sampled and well-resolved species-level phylogeny of the danthonioids was used, and the available cytological information was assembled. The cytological evolution in the clade was inferred using maximum likelihood (ML) as implemented in ChromEvol. The biogeographical evolution in the clade was reconstructed using ML and Bayesian approaches. Key Results Numerous increases in ploidy level are demonstrated. A Late Miocene–Pliocene cycle of polyploidy is associated with LDD, and in two cases (the Australian Rytidosperma and the American Danthonia) led to secondary polyploidy. While it is demonstrated that successful LDD is more likely in polyploid than in diploid lineages, a link between polyploidization events and LDD is not demonstrated. Conclusions The results suggest that polyploids are more successful at LDD than diploids, and that the frequent polyploidy in the grasses might have facilitated the extensive dispersal among continents in the family, thus contributing to their evolutionary success. PMID:24694830

  5. 3. Credit JTL Long distance view looking upstream towards New ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Credit JTL Long distance view looking upstream towards New Hampshire; commercial structures in foreground. - Bellows Falls Arch Bridge, Spanning Connecticut River, North Walpole, Cheshire County, NH

  6. Measuring Long-Distance Romantic Relationships: A Validity Study

    ERIC Educational Resources Information Center

    Pistole, M. Carole; Roberts, Amber

    2011-01-01

    This study investigated aspects of construct validity for the scores of a new long-distance romantic relationship measure. A single-factor structure of the long-distance romantic relationship index emerged, with convergent and discriminant evidence of external validity, high internal consistency reliability, and applied utility of the scores.…

  7. Measuring Long-Distance Romantic Relationships: A Validity Study

    ERIC Educational Resources Information Center

    Pistole, M. Carole; Roberts, Amber

    2011-01-01

    This study investigated aspects of construct validity for the scores of a new long-distance romantic relationship measure. A single-factor structure of the long-distance romantic relationship index emerged, with convergent and discriminant evidence of external validity, high internal consistency reliability, and applied utility of the scores.…

  8. 47 CFR 32.5100 - Long distance message revenue.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... terminate beyond the basic service area of the originating wire center and are individually priced. This includes those message services which utilize the public long distance switching network and the basic..., as well as those priced at the basic long distance rates where a discounted toll charge is on a per...

  9. Providing Quality Laboratories to Long-Distance Educational Programs.

    ERIC Educational Resources Information Center

    Gammon, Tammy; Sutton, John

    2003-01-01

    North Carolina State University (UNC) has been on the forefront of long-distance education by offering a Bachelor of Science in Engineering with a Mechatronics Concentration at its remote campus located at UNC Asheville. The program demonstrates that long-distance laboratories are feasible and should not be a stumbling block to offering…

  10. Intelligent monitoring system applied to super long distance telerobotic tasks

    NASA Technical Reports Server (NTRS)

    Wakita, Yujin; Hirai, Shigeoki; Machida, Kazuo

    1994-01-01

    Time delay and small capacity of communication are the primary constraint in super long distance telerobotic systems such as astronautical robotic tasks. Intelligent telerobotics is thought to break this constraint. We aim to realize this super long distance telerobotic system with object handling knowledge base and intelligent monitoring. We will discuss physical and technical factors for this purpose.

  11. Providing Quality Laboratories to Long-Distance Educational Programs.

    ERIC Educational Resources Information Center

    Gammon, Tammy; Sutton, John

    2003-01-01

    North Carolina State University (UNC) has been on the forefront of long-distance education by offering a Bachelor of Science in Engineering with a Mechatronics Concentration at its remote campus located at UNC Asheville. The program demonstrates that long-distance laboratories are feasible and should not be a stumbling block to offering…

  12. Intensive Long Distance Running as a Possible Cause of Multiple Splanchnic Arterial Aneurysms: A Case Report

    PubMed Central

    Jang, Lee Chan; Park, Sung Su

    2016-01-01

    This is a case report that suggests the possible association between multiple splanchnic arterial aneurysms and long-distance running. The clinical features of one patient admitted at Chungbuk National University Hospital for treatment of multiple splanchnic arterial aneurysms were reviewed. A 54-year-old man had a recurrent, intermittent and epigastric pain for 2 months. There was no abnormality in gastroscopy and colonoscopy. An abdominal computed tomography angiography documented calcified superior mesenteric artery (SMA) and splenic artery aneurysms. The patient had a history of recreational long-distance running for over 10 years. His average running time per week was more than 10 hours. There was no evidence of systemic arteritis, connective tissue disorder or infectious process that may have caused the aneurysms. He did not take any drugs. The SMA aneurysm was opened, and the aneurysmal segment of SMA was replaced with a vein graft. The splenic aneurysm was observed. The patient recovered without any sequelae. PMID:27699161

  13. Isolated internal carotid artery dissection in a long-distance runner

    PubMed Central

    Koczewski, Paweł; Gabriel, Marcin; Kociemba, Wojciech

    2016-01-01

    We present a case of internal carotid artery dissection (ICAD) in the precranial segment, which caused binocular visual impairment in a 49-year-old man during a marathon race. The incident lasted 3 h, after which the symptoms resolved. Imaging tests showed internal carotid artery dissection. No ophthalmologic changes were identified. After 6 weeks of ineffective non-invasive treatment the patient underwent vascular surgery – stent implantation into the damaged artery. Detailed diagnostic tests and adequate treatment allowed us to achieve a good clinical result. Upon the suspicion of ICAD it is recommended to extend standard Doppler ultrasound performed with a linear transducer and evaluate the proximal segment of the internal carotid artery with a curved transducer as well. PMID:28194253

  14. Biomechanical and Psychological Analysis of High School, Intercollegiate, and Elite Long-Distance Runners

    ERIC Educational Resources Information Center

    Solorio, Claribel; Hickey, Ann

    2015-01-01

    It is undeniable that efficiency and mentality are crucial to achieving optimal athletic performance during competition. However, development of psychological skills is often neglected, particularly in lower levels of competition. The purpose of this study was to analyze and compare the biomechanical efficiency and psychological skills use among…

  15. Biomechanical and Psychological Analysis of High School, Intercollegiate, and Elite Long-Distance Runners

    ERIC Educational Resources Information Center

    Solorio, Claribel; Hickey, Ann

    2015-01-01

    It is undeniable that efficiency and mentality are crucial to achieving optimal athletic performance during competition. However, development of psychological skills is often neglected, particularly in lower levels of competition. The purpose of this study was to analyze and compare the biomechanical efficiency and psychological skills use among…

  16. Macroecology of habitat choice in long-distance migratory birds.

    PubMed

    Böhning-Gaese, Katrin; Oberrath, Reik

    2003-10-01

    Patterns of habitat choice in ecological communities are not only influenced by present-day selective forces but also by historical processes, such as the biogeographical history of the lineages they are composed of. Nevertheless, it has been very difficult to test historical factors. The possible tropical origin of long-distance migratory birds provides an opportunity for such a test. If habitat choice of long-distance migrants is inherited from their tropical ancestors then Nearctic long-distance migrants might have acquired their habitat choice from Neotropical forest species and European long-distance migrants from African savannah species. Here we use a macroecological approach to show that this hypothesis can be confirmed. Long-distance migrants in the Nearctic are found in forested habitat types, while those in Europe are found in open ones. In comparison, the habitat choice of residents and short-distance migrants (in genera without long-distance migration) does not differ between the Nearctic and Europe. These results demonstrate that habitat choice in temperate bird communities can be explained by the tropical history of long-distance migrants. Thus, habitat choice seems to be shaped not only by local mechanisms, but also by processes acting on much larger spatial and temporal scales.

  17. Specialized common carriers: Long distance alternatives for military installations

    NASA Astrophysics Data System (ADS)

    Klingler, S. L.

    1984-03-01

    Specialized Common Carriers, communications carriers which came into existence offering private line microwave service, are now significant competitors in the long distance telecommunications industry. This thesis provides military installation telecommunications managers with a basic knowledge of how Specialized Common Carriers entered the telecommunications market, what services Specialized Common Carriers offer, and how to obtain these services for a military installation. It includes a case study evaluation of the potential use of long distance services of two of these competing common carriers at Naval Air Station Moffett Field, California. A computer program used to calculate the costs of using these two alternative long distance carriers is included as part of the case study.

  18. 17. Long distance view looking NW towards Manhattan showing access ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Long distance view looking NW towards Manhattan showing access ramps to bridge. Jet Lowe, photographer, 1982. - Brooklyn Bridge, Spanning East River between Park Row, Manhattan and Sands Street, Brooklyn, New York County, NY

  19. Effects of aerobic long distance running training (up to 40 km.day-1) of 1-year duration on blood and endocrine parameters of female beagle dogs.

    PubMed

    Arokoski, J; Miettinen, P V; Säämänen, A M; Haapanen, K; Parviainen, M; Tammi, M; Helminen, H J

    1993-01-01

    The effects of long distance running training on blood parameters, hormone responses and bone growth were studied in young growing dogs. A genetically uniform group of female beagles matched with respect to age and body mass were used. The runner dogs (n = 10) underwent gradually increased running exercise up to 40 km.day-1 on a treadmill with 15 degrees uphill gradient 5 days each week during a period of 1 year, while the littermate control dogs (n = 10) were kept in their cages throughout the study. Low plasma lactate concentrations of the runners measured immediately after the running training indicated the aerobic metabolism of the dogs while running. Significant decreases of blood haemoglobin concentrations (11%), blood erythrocyte number (10%), and erythrocyte packed cell volume (12%) were found in the runner group. Throughout the experiment, the value of thyroxine was slightly lower (13%) in the runners but no changes were found in tri-iodothyronine, free thyroxine, or cortisol serum concentrations. Serum oestradiol concentration at 56 weeks was significantly lower (42%) in the runner group than in the control group but was not as low (27%) at 70 weeks. Somatomedin-C concentration had decreased significantly by 37% at the age of 56 weeks in the runner group but was again at the level of the control dogs at the end of experiment (at 70 weeks). Ulna and radius bone mass as a ratio to the body mass had significantly increased in the runners. It would seem from our study that long distance running has a positive effect on bone growth.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Effects of endurance training only versus same-session combined endurance and strength training on physical performance and serum hormone concentrations in recreational endurance runners.

    PubMed

    Schumann, Moritz; Mykkänen, Olli-Pekka; Doma, Kenji; Mazzolari, Raffaele; Nyman, Kai; Häkkinen, Keijo

    2015-01-01

    This study investigated the effects of endurance training only (E, n = 14) and same-session combined training, when strength training is repeatedly preceded by endurance loading (endurance and strength training (E+S), n = 13) on endurance (1000-m running time during incremental field test) and strength performance (1-repetition maximum (1RM) in dynamic leg press), basal serum hormone concentrations, and endurance loading-induced force and hormone responses in recreationally endurance-trained men. E was identical in the 2 groups and consisted of steady-state and interval running, 4-6 times per week for 24 weeks. E+S performed additional mixed-maximal and explosive-strength training (2 times per week) immediately following an incremental running session (35-45 min, 65%-85% maximal heart rate). E and E+S decreased running time at week 12 (-8% ± 5%, p = 0.001 and -7% ± 3%, p < 0.001) and 24 (-13% ± 5%, p < 0.001 and -9% ± 5%, p = 0.001). Strength performance decreased in E at week 24 (-5% ± 5%, p = 0.014) but was maintained in E+S (between-groups at week 12 and 24, p = 0.014 and 0.011, respectively). Basal serum testosterone and cortisol concentrations remained unaltered in E and E+S but testosterone/sex hormone binding globulin ratio decreased in E+S at week 12 (-19% ± 26%, p = 0.006). At week 0 and 24, endurance loading-induced acute force (-5% to -9%, p = 0.032 to 0.001) and testosterone and cortisol responses (18%-47%, p = 0.013 to p < 0.001) were similar between E and E+S. This study showed no endurance performance benefits when strength training was performed repeatedly after endurance training compared with endurance training only. This was supported by similar acute responses in force and hormonal measures immediately post-endurance loading after the training with sustained 1RM strength in E+S.

  1. Long-distance coherent coupling in a quantum dot array.

    PubMed

    Braakman, F R; Barthelemy, P; Reichl, C; Wegscheider, W; Vandersypen, L M K

    2013-06-01

    Controlling long-distance quantum correlations is central to quantum computation and simulation. In quantum dot arrays, experiments so far rely on nearest-neighbour couplings only, and inducing long-distance correlations requires sequential local operations. Here, we show that two distant sites can be tunnel-coupled directly. The coupling is mediated by virtual occupation of an intermediate site, with a strength that is controlled via the energy detuning of this site. It permits a single charge to oscillate coherently between the outer sites of a triple dot array without passing through the middle, as demonstrated through the observation of Landau-Zener-Stückelberg interference. The long-distance coupling significantly improves the prospects of fault-tolerant quantum computation using quantum dot arrays, and opens up new avenues for performing quantum simulations in nanoscale devices.

  2. Long-distance temporal quantum ghost imaging over optical fibers

    PubMed Central

    Dong, Shuai; Zhang, Wei; Huang, Yidong; Peng, Jiangde

    2016-01-01

    Since the first quantum ghost imaging (QGI) experiment in 1995, many QGI schemes have been put forward. However, the position-position or momentum-momentum correlation required in these QGI schemes cannot be distributed over optical fibers, which limits their large-scale geographical applications. In this paper, we propose and demonstrate a scheme for long-distance QGI utilizing frequency correlated photon pairs. In this scheme, the frequency correlation is transformed to the correlation between the illuminating position of one photon and the arrival time of the other photon, by which QGI can be realized in the time domain. Since frequency correlation can be preserved when the photon pairs are distributed over optical fibers, this scheme provides a way to realize long-distance QGI over large geographical scale. In the experiment, long-distance QGI over 50 km optical fibers has been demonstrated. PMID:27194078

  3. Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

    PubMed Central

    Luna, Natália Mariana Silva; Alonso, Angelica Castilho; Brech, Guilherme Carlos; Mochizuki, Luis; Nakano, Eduardo Yoshio; Greve, Júlia Maria D'Andréa

    2012-01-01

    OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and non-athletes. METHODS: Seventy-five males with a mean age of 30.26 (±6.5) years were divided into three groups: a triathlete group (n = 26), a long-distance runner group (n = 23), and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer. RESULTS: The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180°/s) was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60°/s) was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups. CONCLUSIONS: The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners. PMID:23018298

  4. Isokinetic analysis of ankle and ground reaction forces in runners and triathletes.

    PubMed

    Luna, Natália Mariana Silva; Alonso, Angelica Castilho; Brech, Guilherme Carlos; Mochizuki, Luis; Nakano, Eduardo Yoshio; Greve, Júlia Maria D'Andrea

    2012-09-01

    To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes. Seventy-five males with a mean age of 30.26 (±6.5) years were divided into three groups: a triathlete group (n=26), a long-distance runner group (n = 23), and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer. The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180º/s) was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60º/s) was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups. The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners.

  5. Long distance measurement with femtosecond pulses using a dispersive interferometer.

    PubMed

    Cui, M; Zeitouny, M G; Bhattacharya, N; van den Berg, S A; Urbach, H P

    2011-03-28

    We experimentally demonstrate long distance measurements with a femtosecond frequency comb laser using dispersive interferometry. The distance is derived from the unwrapped spectral phase of the dispersed interferometer output and the repetition frequency of the laser. For an interferometer length of 50 m this approach has been compared to an independent phase counting laser interferometer. The obtained mutual agreement is better than 1.5 μm (3×10(-8)), with a statistical averaging of less than 200 nm. Our experiments demonstrate that dispersive interferometry with a frequency comb laser is a powerful method for accurate and non-incremental measurement of long distances.

  6. Relationship of distance run per week to coronary heart disease risk factors in 8283 male runners. The National Runners' Health Study.

    PubMed

    Williams, P T

    1997-01-27

    Official guidelines from the Centers for Disease Control and Prevention and the American College of Sports Medicine state that every adult should accumulate 30 minutes or more of moderate-intensity physical activity on most, preferably all, days of the week. To examine the dose-response relationship between coronary heart disease (CHD) risk factors and vigorous exercise above the recommended minimum levels to assess whether further benefits accrue. Physician-supplied medical data were compared with reported distance run in a national cross-sectional survey of 8283 male recreational runners. Compared with runners who ran less than 16 km (10 miles) per week, long-distance runners (> or = 80 km/wk) showed an 85% reduced prevalence of high-density lipoprotein cholesterol levels that were clinically low (< 0.9 mmol/L [< 35 mg/dL]), a 2.5-fold increased prevalence of clinically defined high levels of high-density lipoprotein cholesterol (ie, > or = 1.55 mmol/L [> or = 60 mg/dL], the level thought to be protective against CHD), a nearly 50% reduction in hypertension, and more than a 50% reduction in the use of medications to lower blood pressure and plasma cholesterol levels. Estimated age-adjusted 10-year CHD risk was 30% lower in runners who averaged more than 64 km/wk than in those who averaged less than 16 km/wk (42 vs 61 events per 1000 men). Each 16-km incremental increase in weekly distance run up to 64 to 79 km/wk was associated with significant increases in high-density lipoprotein cholesterol levels and significant decreases in adiposity, triglyceride levels, the ratio of total cholesterol to high-density lipoprotein cholesterol level, and estimated CHD risk. Our data (1) suggest that substantial health benefits occur at exercise levels that exceed current minimum guidelines and (2) do not exhibit a point of diminishing return to the health benefits of running at any distance less than 80 km/wk.

  7. 47 CFR 32.5100 - Long distance message revenue.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Long distance message revenue. 32.5100 Section 32.5100 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions For Revenue Accounts §...

  8. 47 CFR 32.5100 - Long distance message revenue.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Long distance message revenue. 32.5100 Section 32.5100 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions For Revenue Accounts §...

  9. 47 CFR 32.5100 - Long distance message revenue.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Long distance message revenue. 32.5100 Section 32.5100 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions For Revenue Accounts §...

  10. 2. Long distance view from the SW of former Cotton ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Long distance view from the SW of former Cotton Yards (now used as a parking lot); Cotton Yard Gates at far right, Red Building and Produce Freight Warehouse in background. - Central of Georgia Railway, Cotton Yard Gates, West Broad Street, Savannah, Chatham County, GA

  11. Perniosis in a long-distance cyclist crossing Mongolia.

    PubMed

    Neal, Andrew J; Jarman, Alison M; Bennett, Timothy G

    2012-01-01

    We report a case of severe perniosis in a long-distance cyclist. This case demonstrates the importance of identifying those at risk of cold-related injuries who are about to embark on extensive travel in cold environments. © 2011 International Society of Travel Medicine.

  12. Long distance movement by a coyote within the Rocky Mountains

    Treesearch

    Jay A. Kolbe; John R. Squires

    2004-01-01

    We documented a long distance movement of a juvenile male coyote (Canis latrines) between February 2002 and February 2003. The radiocollared coyote, last located in west central Montana, U.S.A. traveled ≥310 km to southwestern Alberta, Canada where it was trapped. This is the longest documented movement by a coyote in western North America.

  13. Biochemical Parameters of Orienteers Competing in a Long Distance Race.

    ERIC Educational Resources Information Center

    Mikan, Vladimir; And Others

    1992-01-01

    Measured important biochemical parameters in a group of orienteers two hours before beginning and immediately after an orienteering marathon. Found levels of dehydration. Suggests a drinking regimen which is designed for orienteering races. Concludes that no runner having kidney or liver abnormalities or changes in the urine should be allowed to…

  14. Biochemical Parameters of Orienteers Competing in a Long Distance Race.

    ERIC Educational Resources Information Center

    Mikan, Vladimir; And Others

    1992-01-01

    Measured important biochemical parameters in a group of orienteers two hours before beginning and immediately after an orienteering marathon. Found levels of dehydration. Suggests a drinking regimen which is designed for orienteering races. Concludes that no runner having kidney or liver abnormalities or changes in the urine should be allowed to…

  15. Perception of Health Problems Among Competitive Runners

    PubMed Central

    Jelvegård, Sara; Timpka, Toomas; Bargoria, Victor; Gauffin, Håkan; Jacobsson, Jenny

    2016-01-01

    Background: Approximately 2 of every 3 competitive runners sustain at least 1 health problem each season. Most of these problems are nontraumatic injuries with gradual onset. The main known risk indicator for sustaining a new running-related injury episode is a history of a previous injury, suggesting that behavioral habits are part of the causal mechanisms. Purpose: Identification of elements associated with purposeful interpretations of body perceptions and balanced behavioral responses may supply vital information for prevention of health problems in runners. This study set out to explore competitive runners’ cognitive appraisals of perceived symptoms on injury and illness and how these appraisals are transformed into behavior. Study Design: Cross-sectional study; Level of evidence, 3. Methods: The study population consisted of Swedish middle- and long-distance runners from the national top 15 list. Qualitative research methods were used to categorize interview data and perform a thematic analysis. The categories resulting from the analysis were used to construct an explanatory model. Results: Saturation of the thematic classification required that data from 8 male and 6 female runners (age range, 20-36 years) were collected. Symptoms interpreted to be caused by illness or injury with a sudden onset were found to lead to immediate action and changes to training and competition programs (activity pacing). In contrast, perceptions interpreted to be due to injuries with gradual onset led to varied behavioral reactions. These behavioral responses were planned with regard to short-term consequences and were characterized by indifference and neglect of long-term implications, consistent with an overactivity behavioral pattern. The latter pattern was consistent with a psychological adaptation to stimuli that is presented progressively to the athlete. Conclusion: Competitive runners appraise whether a health problem requires immediate withdrawal from training based on

  16. Long-distance distribution of genuine energy-time entanglement.

    PubMed

    Cuevas, A; Carvacho, G; Saavedra, G; Cariñe, J; Nogueira, W A T; Figueroa, M; Cabello, A; Mataloni, P; Lima, G; Xavier, G B

    2013-01-01

    Any practical realization of entanglement-based quantum communication must be intrinsically secure and able to span long distances avoiding the need of a straight line between the communicating parties. The violation of Bell's inequality offers a method for the certification of quantum links without knowing the inner workings of the devices. Energy-time entanglement quantum communication satisfies all these requirements. However, currently there is a fundamental obstacle with the standard configuration adopted: an intrinsic geometrical loophole that can be exploited to break the security of the communication, in addition to other loopholes. Here we show the first experimental Bell violation with energy-time entanglement distributed over 1 km of optical fibres that is free of this geometrical loophole. This is achieved by adopting a new experimental design, and by using an actively stabilized fibre-based long interferometer. Our results represent an important step towards long-distance secure quantum communication in optical fibres.

  17. Turning points in long distance grandparent-grandchild relationships.

    PubMed

    Bangerter, Lauren R; Waldron, Vincent R

    2014-04-01

    This study examines changes in long-distance relationships between grandparents and their adolescent grandchildren by identifying relational turning points and trajectories. Qualitative analysis of data collected from interviews with grandparents yielded 100 unique turning points. Constant comparative analysis revealed eight distinct categories of relational turning points; Spending Time Together, Family Relational Dynamics, Geographic Distance, Lack of Relational Investment, Use of Technology, Relational Investment, Lack of Free Time, and Grandchild Gaining Independence. These varied in the degree to which they positively or negatively impacted relational closeness. Application of the Retrospective Interview Technique (RIT) yielded five distinctive relational trajectories: Decrease in Closeness, Increase in Closeness, Multidimensional Changes in Closeness, Minimal Changes in Closeness, and Consistent Relational Closeness. The results expose the communicative challenges faced by long-distance-grandparents, the diversity of these relationships, and the ways in which grandparenting bonds change over time. Implications for an enriched understanding of grandparenting relationships and practical applications for families are explored.

  18. Long-distance propagation of forces in a cell.

    PubMed

    Wang, Ning; Suo, Zhigang

    2005-03-25

    A fundamental question in the field of mechanotransduction is how forces propagate inside a cell. Recent experiments have shown that a force of a physiological magnitude, applied via a focal adhesion, can propagate a long distance into the cell. This observation disagrees with existing models that regard the cell as a homogeneous body. We show that this "action at a distance" results from the inhomogeneity in the cell: a prestressed and stiff actin bundle guides the propagation of forces over long distances. Our models highlight the enormous ratios of the prestress and the modulus of the actin bundle to the modulus of the cytoskeleton network. For a normal cell, the models predict that forces propagate over characteristic lengths comparable to the size of the cell. The characteristic lengths can be altered, however, by treatments of the cell. We provide experimental evidence and discuss biological implications.

  19. Long-distance CO(2) signalling in plants.

    PubMed

    Lake, Janice A; Woodward, F Ian; Quick, W Paul

    2002-02-01

    Stomatal numbers are tightly controlled by environmental signals including light intensity and atmospheric CO(2) partial pressure. This requires control of epidermal cell development during the early phase of leaf growth and involves changes in both the density of cells on the leaf surface and the proportion of cells that adopt a stomatal fate. This paper reviews the current understanding of how stomata develop and describes recent advances that have given insights into the regulatory mechanisms involved using mutant Arabidopsis plants that implicates a role for long-chain fatty acids in cell-to-cell communication. Evidence is presented which indicates that long-distance signalling from mature to newly developing leaves forms part of the mechanism by which stomatal development responds to environmental cues. Analysis of mutant plants suggests that the plant hormones abscisic acid, ethylene and jasmonates are implicated in the long-distance signalling pathway and that the action may be mediated by reactive oxygen species.

  20. Ultrafast and fault-tolerant quantum communication across long distances.

    PubMed

    Muralidharan, Sreraman; Kim, Jungsang; Lütkenhaus, Norbert; Lukin, Mikhail D; Jiang, Liang

    2014-06-27

    Quantum repeaters (QRs) provide a way of enabling long distance quantum communication by establishing entangled qubits between remote locations. In this Letter, we investigate a new approach to QRs in which quantum information can be faithfully transmitted via a noisy channel without the use of long distance teleportation, thus eliminating the need to establish remote entangled links. Our approach makes use of small encoding blocks to fault-tolerantly correct both operational and photon loss errors. We describe a way to optimize the resource requirement for these QRs with the aim of the generation of a secure key. Numerical calculations indicate that the number of quantum memory bits at each repeater station required for the generation of one secure key has favorable polylogarithmic scaling with the distance across which the communication is desired.

  1. Long-distance distribution of genuine energy-time entanglement

    PubMed Central

    Cuevas, A.; Carvacho, G.; Saavedra, G.; Cariñe, J.; Nogueira, W.A.T.; Figueroa, M.; Cabello, A.; Mataloni, P.; Lima, G.; Xavier, G.B.

    2013-01-01

    Any practical realization of entanglement-based quantum communication must be intrinsically secure and able to span long distances avoiding the need of a straight line between the communicating parties. The violation of Bell’s inequality offers a method for the certification of quantum links without knowing the inner workings of the devices. Energy-time entanglement quantum communication satisfies all these requirements. However, currently there is a fundamental obstacle with the standard configuration adopted: an intrinsic geometrical loophole that can be exploited to break the security of the communication, in addition to other loopholes. Here we show the first experimental Bell violation with energy-time entanglement distributed over 1 km of optical fibres that is free of this geometrical loophole. This is achieved by adopting a new experimental design, and by using an actively stabilized fibre-based long interferometer. Our results represent an important step towards long-distance secure quantum communication in optical fibres. PMID:24287678

  2. Towards ultra-long-distance distributed fiber optic sensing

    NASA Astrophysics Data System (ADS)

    Wang, Zinan; Jia, Xinhong; Wu, Huijuan; Peng, Fei; Fu, Yun; Rao, Yunjiang

    2017-04-01

    Distributed fiber-optic sensing (DFOS) has drawn great attention in both academic research and industrial applications due to its unique advantages. Recent progress at University of Electronic Science and Technology of China (UESTC) in DFOS, mainly on ultra-long-distance Brillouin optical time-domain analysis (BOTDA) and phase-sensitive optical timedomain reflectometry (Φ-OTDR), is discussed in this paper, including research progress and real-life applications.

  3. Long distance atomic teleportation with as good success as desired

    SciTech Connect

    Mishra, Manoj K.; Prakash, Hari

    2015-09-15

    Long distance atomic teleportation (LDAT) is of prime importance in long distance quantum communication. Scheme proposed by Bose et al. (1999) in principle enables us to have LDAT using cavity decay. However it gives message state dependent fidelity and success rate. Here, using interaction of entangled coherent states with atom–cavity systems and a two-step measurement, we show how, LDAT can be achieved with unit fidelity and as good success as desired under ideal conditions. The scheme is unique in that, the first measurement predicts success or failure. If success is predicted then second measurement gives perfect teleportation. If failure is predicted the message-qubit remains conserved therefore a second attempt may be started. We found that even in presence of decoherence due to dissipation of energy our scheme gives message state independent success rate and almost perfect teleportation in single attempt with mean fidelity of teleportation equal to 0.9 at long distances. However if first attempt fails, unlike ideal case where message-qubit remains conserved with unit fidelity, in presence of decoherence the message-qubit remains conserved to some degree, therefore mean fidelity of teleportation can be increased beyond 0.9 by repeating the process.

  4. Identifying impediments to long-distance mammal migrations.

    PubMed

    Seidler, Renee G; Long, Ryan A; Berger, Joel; Bergen, Scott; Beckmann, Jon P

    2015-02-01

    In much of the world, the persistence of long-distance migrations by mammals is threatened by development. Even where human population density is relatively low, there are roads, fencing, and energy development that present barriers to animal movement. If we are to conserve species that rely on long-distance migration, then it is critical that we identify existing migration impediments. To delineate stopover sites associated with anthropogenic development, we applied Brownian bridge movement models to high-frequency locations of pronghorn (Antilocapra americana) in the Greater Yellowstone Ecosystem. We then used resource utilization functions to assess the threats to long-distance migration of pronghorn that were due to fences and highways. Migrating pronghorn avoided dense developments of natural gas fields. Highways with relatively high volumes of traffic and woven-wire sheep fence acted as complete barriers. At crossings with known migration bottlenecks, use of high-quality forage and shrub habitat by pronghorn as they approached the highway was lower than expected based on availability of those resources. In contrast, pronghorn consistently utilized high-quality forage close to the highway at crossings with no known migration bottlenecks. Our findings demonstrate the importance of minimizing development in migration corridors in the future and of mitigating existing pressure on migratory animals by removing barriers, reducing the development footprint, or installing crossing structures. © 2014 Society for Conservation Biology.

  5. ADAPTIVELY IMPROVING LONG DISTANCE NETWORK TRANSFERS WITH LOGISTICS

    SciTech Connect

    LaBissoniere, D.; Roche, K.

    2007-01-01

    Long distance data movement is an essential activity of modern computing. However, the congestion control mechanisms in the Internet’s Transmission Control Protocol (TCP) severely limit the bandwidth achieved by long distance data transfers. The throughput of such transfers can be improved by applying the logistical technique of breaking a single long distance transfer into multiple shorter transfers. This technique can result in signifi cantly improved throughput while still respecting the shared nature of the Internet by not attempting to circumvent the TCP congestion controls. This technique has been incorporated into an algorithm which attempts to dynamically schedule transfers for optimal throughput. The algorithm couples graph techniques with real-time latency and bandwidth measurements to discover the best path and adaptively respond to network dynamics. The algorithm shows improvements in speed and fl exibility over standard data transfer methods such as FTP. Specifi c transfers tests performed between Oak Ridge National Laboratory and a destination in Sunnyvale, CA show throughput increases by a factor of two.

  6. Distinguishing suspicious actions in long-distance surveillance

    NASA Astrophysics Data System (ADS)

    Hebe, Guy; Chen, Eli; Yitzhaky, Yitzhak

    2014-10-01

    Human action classification distinguishes different human behaviors at a video signal. Suspicious behavior can be defined by the user, and in long distance imaging it may include bending the body during walking or crawling, in contrast to regular walking for instance. When imaging is performed through relatively long distance, some difficulties occur which affect the performances regular action recognition tasks. The degradation sources that include turbulence and aerosols in the atmosphere cause blur and spatiotemporal-varying distortions (image dancing). These effects become more significant as the imaging distance increases and as the sizes of the objects of interest in the image are smaller. The process of action recognition is usually a part of surveillance system that naturally includes a detection of the moving objects as a first step, followed by tracking them in the video sequence. In this study, we first detect and track moving objects in long-distance horizontal imaging, and then we examine dynamic spatio-temporal (motion and shape) characteristics of correctly detected moving objects. According to such characteristics. We construct features that characterize different actions for such imaging conditions, and distinguish suspicious from non-suspicious actions, based on these characteristics.

  7. Long-distance transportation of live isolated lymphatic vessels.

    PubMed

    Gashev, Anatoliy A; Davis, Michael J

    2010-12-01

    We performed experiments to test whether isolated lymphatic vessels would remain viable after overnight long-distance shipment. Freshly isolated segments of rat mesenteric lymphatic vessels were placed into tubes filled by chilled D-MEM/F12 supplemented with antibiotics and shipped via overnight by express mail from College Station, TX to Columbia, MO. Standard physiological and pharmacological tests were performed to investigate the influence of the long-distance transport procedure on the spontaneous contractility of isolated, cannulated, and pressurized rat mesenteric lymphatic vessels. The results demonstrate that normal contractile function of isolated lymphatic vessels can be preserved with long-distance shipping and subsequent overnight recovery if the proper precautions are taken. The method of lymphatic vessel transportation described in this report opens up the opportunity to perform in vitro functional tests on lymphatic tissues harvested and initially processed in a remote location. In addition, the described procedures may expand the options for potential sources of fresh human tissue, harvested during surgery or autopsy and allowed to be available to lymphatic researchers in remote locations.

  8. Renal function, aldosterone, and vasopressin excretion following repeated long-distance running.

    PubMed

    Wade, C E; Dressendorfer, R H; O'Brien, J C; Claybaugh, J R

    1981-04-01

    Renal and endocrine responses were studied in 10 male runners during a 20-day 500-km race. Overnight urine and prerun blood samples were taken prior to running on days 1, 2, 5, 8, 14, 17, and 20. Day 13 followed 70 h of rest. Urine flow rate, osmotic clearance, tubular free water reabsorption, urinary vasopressin excretion rate, and body weight were not significantly changed. Creatinine clearance was constant except for an elevation on day 5. Plasma osmolality was elevated on days 2, 14, and 17. Plasma sodium was increased (P less than 0.05) on days 2 and 13 but reduced on day 20. The percentage of filtered sodium excreted was significantly reduced on all nights following running and elevated on recovery day 13. Urinary aldosterone excretion rate was significantly elevated 162, 117, and 97% on days 5, 8, and 20 and returned to control levels on day 13 after 70 h of rest. These data suggest that in response to repeated long-distance running normal fluid balance is regained within 12 h. However, it is necessary to conserve sodium for at least 24 h after exercise as evidenced by the decrease in the percent filtered sodium excreted and continued elevation of aldosterone excretion.

  9. Modelling long-distance seed dispersal in heterogeneous landscapes.

    SciTech Connect

    Levey, Douglas, J.; Tewlsbury, Joshua, J.; Bolker, Benjamin, M.

    2008-01-01

    1. Long-distance seed dispersal is difficult to measure, yet key to understanding plant population dynamics and community composition. 2. We used a spatially explicit model to predict the distribution of seeds dispersed long distances by birds into habitat patches of different shapes. All patches were the same type of habitat and size, but varied in shape. They occurred in eight experimental landscapes, each with five patches of four different shapes, 150 m apart in a matrix of mature forest. The model was parameterized with smallscale movement data collected from field observations of birds. In a previous study we validated the model by testing its predictions against observed patterns of seed dispersal in real landscapes with the same types and spatial configuration of patches as in the model. 3. Here we apply the model more broadly, examining how patch shape influences the probability of seed deposition by birds into patches, how dispersal kernels (distributions of dispersal distances) vary with patch shape and starting location, and how movement of seeds between patches is affected by patch shape. 4. The model predicts that patches with corridors or other narrow extensions receive higher numbers of seeds than patches without corridors or extensions. This pattern is explained by edgefollowing behaviour of birds. Dispersal distances are generally shorter in heterogeneous landscapes (containing patchy habitat) than in homogeneous landscapes, suggesting that patches divert the movement of seed dispersers, ‘holding’ them long enough to increase the probability of seed defecation in the patches. Dispersal kernels for seeds in homogeneous landscapes were smooth, whereas those in heterogenous landscapes were irregular. In both cases, long-distance (> 150 m) dispersal was surprisingly common, usually comprising approximately 50% of all dispersal events. 5. Synthesis . Landscape heterogeneity has a large influence on patterns of long-distance seed dispersal. Our

  10. Kinanthropometric Profile and Physical Performance of Athletic Track Events in Relation to Different Runners

    ERIC Educational Resources Information Center

    Khan, Zamirullah; ahmed, Naseem; Raja, Waseem Hassan

    2016-01-01

    The purpose of this study was to find out kinanthropometric profile of 20 Athletes of middle distance 800 meters, & long distance runners 5000 meters of Track Event of age 17 years were assessed for the present study. The data of athletes was collected at Athletics Summer Camp 2015 in Kashmir region. The athletes having participation of at…

  11. The Relationship between Running Economy and Biomechanical Variables in Distance Runners

    ERIC Educational Resources Information Center

    Tartaruga, Marcus Peikriszwili; Brisswalter, Jeanick; Peyre-Tartaruga, Leonardo Alexandre; Avila, Aluisio Otavio Vargas; Alberton, Cristine Lima; Coertjens, Marcelo; Cadore, Eduardo Lusa; Tiggemann, Carlos Leandro; Silva, Eduardo Marczwski; Kruel, Luiz Fernando Martins

    2012-01-01

    In this study, we analyzed the relationship between running economy (RE) and biomechanical parameters in a group running at the same relative intensity and same absolute velocity. Sixteen homogeneous male long-distance runners performed a test to determine RE at 4.4 m.s[superscript -1], corresponding to 11.1% below velocity at the ventilatory…

  12. The Relationship between Running Economy and Biomechanical Variables in Distance Runners

    ERIC Educational Resources Information Center

    Tartaruga, Marcus Peikriszwili; Brisswalter, Jeanick; Peyre-Tartaruga, Leonardo Alexandre; Avila, Aluisio Otavio Vargas; Alberton, Cristine Lima; Coertjens, Marcelo; Cadore, Eduardo Lusa; Tiggemann, Carlos Leandro; Silva, Eduardo Marczwski; Kruel, Luiz Fernando Martins

    2012-01-01

    In this study, we analyzed the relationship between running economy (RE) and biomechanical parameters in a group running at the same relative intensity and same absolute velocity. Sixteen homogeneous male long-distance runners performed a test to determine RE at 4.4 m.s[superscript -1], corresponding to 11.1% below velocity at the ventilatory…

  13. Humans as Long-Distance Dispersers of Rural Plant Communities

    PubMed Central

    Auffret, Alistair G.; Cousins, Sara A. O.

    2013-01-01

    Humans are known for their capacity to disperse organisms long distances. Long-distance dispersal can be important for species threatened by habitat destruction, but research into human-mediated dispersal is often focused upon few and/or invasive species. Here we use citizen science to identify the capacity for humans to disperse seeds on their clothes and footwear from a known species pool in a valuable habitat, allowing for an assessment of the fraction and types of species dispersed by humans in an alternative context. We collected material from volunteers cutting 48 species-rich meadows throughout Sweden. We counted 24 354 seeds of 197 species, representing 34% of the available species pool, including several rare and protected species. However, 71 species (36%) are considered invasive elsewhere in the world. Trait analysis showed that seeds with hooks or other appendages were more likely to be dispersed by humans, as well as those with a persistent seed bank. More activity in a meadow resulted in more dispersal, both in terms of species and representation of the source communities. Average potential dispersal distances were measured at 13 km. We consider humans capable seed dispersers, transporting a significant proportion of the plant communities in which they are active, just like more traditional vectors such as livestock. When rural populations were larger, people might have been regular and effective seed dispersers, and the net rural-urban migration resulting in a reduction in humans in the landscape may have exacerbated the dispersal failure evident in declining plant populations today. With the fragmentation of habitat and changes in land use resulting from agricultural change, and the increased mobility of humans worldwide, the dispersal role of humans may have shifted from providers of regular local and landscape dispersal to providers of much rarer long-distance and regional dispersal, and international invasion. PMID:23658770

  14. Generation of distributed W-states over long distances

    NASA Astrophysics Data System (ADS)

    Li, Yi

    2017-08-01

    Ultra-secure quantum communication between distant locations requires distributed entangled states between nodes. Various methodologies have been proposed to tackle this technological challenge, of which the so-called DLCZ protocol is the most promising and widely adopted scheme. This paper aims to extend this well-known protocol to a multi-node setting where the entangled W-state is generated between nodes over long distances. The generation of multipartite W-states is the foundation of quantum networks, paving the way for quantum communication and distributed quantum computation.

  15. High speed, long distance, data transmission multiplexing circuit

    DOEpatents

    Mariotti, Razvan

    1991-01-01

    A high speed serial data transmission multiplexing circuit, which is operable to accurately transmit data over long distances (up to 3 Km), and to multiplex, select and continuously display real time analog signals in a bandwidth from DC to 100 Khz. The circuit is made fault tolerant by use of a programmable flywheel algorithm, which enables the circuit to tolerate one transmission error before losing synchronization of the transmitted frames of data. A method of encoding and framing captured and transmitted data is used which has a low overhead and prevents some particular transmitted data patterns from locking an included detector/decoder circuit.

  16. OBLA is a better predictor of performance than Dmax in long and middle-distance well-trained runners.

    PubMed

    Santos-Concejero, J; Granados, C; Irazusta, J; Bidaurrazaga-Letona, I; Zabala-Lili, J; Tam, N; Gil, S M

    2014-10-01

    The main purpose of this study was to investigate if the lactate threshold estimated by the maximal deviation method (LTDmax) and the onset of blood lactate accumulation speed (LTOBLA) are good correlates of middle- and long-distance running performance in well-trained endurance runners. Eleven long- and eleven middle-distance runners participated in this study. All participants completed a maximal incremental running test on a treadmill to determine maximal physiological variables and velocities corresponding to LTDmax and LTOBLA (4 mmol·L-1 of lactate concentration). The relationships between LTDmax, LTOBLA and the best 10-km (S10km) and 3-km (S3km) race pace were analyzed in the long- and middle distance runners, respectively. The velocities for LTDmax and LTOBLA were 17.0±0.7 km·h-1 and 17.5±1.3 km·h-1 for the long-distance runners and 16.9±1.1 km·h-1 and 17.4±1.3 km·h-1 for the middle-distance runners. A positive linear relationship was found between LTDmax and S10km (r=0.873, P<0.001), as well as between LTOBLA and S10km (r=0.919, P<0.001) in the long-distance runners. Similarly, LTDmax and LTOBLA were significantly correlated with S3km in the middle-distance runners (r=0.825, P<0.01 and r=0.849, P<0.001, respectively). These results indicate that both LTOBLA and LTDmax are highly associated to running performance according to S10km and S3km in well-trained long- and middle-distance runners. Thus, we conclude that competitive middle- and long-distance athletes may find these measures useful to monitor running performance within 3 weeks of laboratory testing.

  17. Long-distance oxygen plasma sterilization: Effects and mechanisms

    NASA Astrophysics Data System (ADS)

    Liu, Hongxia; Chen, Jierong; Yang, Liqing; Zhou, Yuan

    2008-01-01

    The distribution of electrons, ions and oxygen radicals in long-distance oxygen plasma and the germicidal effect (GE) of Escherichia coli on the surface of medical poly(tetrafluoroethylene) (PTFE) film were studied. The quantity of protein leakage and the production of lipid peroxide in bacterial suspension as well as the state of DNA were measured after sterilization to analyse the inactivation mechanisms. The results showed that the concentration of electrons and ions decreased rapidly with increasing the distance from the center of induction coil, which approximated to 0 at 30 cm, whereas the concentration of oxygen radicals reduced slowly, i.e. decreased 30% within 40 cm. GE value reached 3.42 in the active discharge zone (0 cm) and exceeded 3.32 within 40 cm when plasma treatment parameters were set as follows: plasma rf power at 100 W, treatment time at 60 s and oxygen flux at 40 cm 3/min. Fast etching action on cell membrane by electrons, ions and attacking polyunsaturation fatty acid (PUFA) in cell membrane by oxygen radicals are primary reasons of oxygen plasma sterilization in the active discharge and the afterglow zone, respectively. The GE of UV radiation in long-distance oxygen plasma is feebleness.

  18. Long-distance electron transport occurs globally in marine sediments

    NASA Astrophysics Data System (ADS)

    Burdorf, Laurine D. W.; Tramper, Anton; Seitaj, Dorina; Meire, Lorenz; Hidalgo-Martinez, Silvia; Zetsche, Eva-Maria; Boschker, Henricus T. S.; Meysman, Filip J. R.

    2017-02-01

    Recently, long filamentous bacteria have been reported conducting electrons over centimetre distances in marine sediments. These so-called cable bacteria perform an electrogenic form of sulfur oxidation, whereby long-distance electron transport links sulfide oxidation in deeper sediment horizons to oxygen reduction in the upper millimetres of the sediment. Electrogenic sulfur oxidation exerts a strong impact on the local sediment biogeochemistry, but it is currently unknown how prevalent the process is within the seafloor. Here we provide a state-of-the-art assessment of its global distribution by combining new field observations with previous reports from the literature. This synthesis demonstrates that electrogenic sulfur oxidation, and hence microbial long-distance electron transport, is a widespread phenomenon in the present-day seafloor. The process is found in coastal sediments within different climate zones (off the Netherlands, Greenland, the USA, Australia) and thrives on a range of different coastal habitats (estuaries, salt marshes, mangroves, coastal hypoxic basins, intertidal flats). The combination of a widespread occurrence and a strong local geochemical imprint suggests that electrogenic sulfur oxidation could be an important, and hitherto overlooked, component of the marine cycle of carbon, sulfur and other elements.

  19. Long distance laser ultrasonic propagation imaging system for damage visualization

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Ryul; Shin, He-Jin; Chia, Chen Ciang; Dhital, Dipesh; Yoon, Dong-Jin; Huh, Yong-Hak

    2011-12-01

    Wind turbine blade failure is the most prominent and common type of damage occurring in operating wind turbine systems. Conventional nondestructive testing systems are not available for in situ wind turbine blades. We propose a portable long distance ultrasonic propagation imaging (LUPI) system that uses a laser beam targeting and scanning system to excite, from a long distance, acoustic emission sensors installed in the blade. An examination of the beam collimation effect using geometric parameters of a commercial 2 MW wind turbine provided Lamb wave amplitude increases of 41.5 and 23.1 dB at a distance of 40 m for symmetrical and asymmetrical modes, respectively, in a 2 mm-thick stainless steel plate. With this improvement in signal-to-noise ratio, a feasibility study of damage detection was conducted with a 5 mm-thick composite leading edge specimen. To develop a reliable damage evaluation system, the excitation/sensing technology and the associated damage visualization algorithm are equally important. Hence, our results provide a new platform based on anomalous wave propagation imaging (AWPI) methods with adjacent wave subtraction, reference wave subtraction, reference image subtraction, and the variable time window amplitude mapping method. The advantages and disadvantages of AWPI algorithms are reported in terms of reference data requirements, signal-to-noise ratios, and damage evaluation accuracy. The compactness and portability of the proposed UPI system are also important for in-field applications at wind farms.

  20. Metal species involved in long distance metal transport in plants

    PubMed Central

    Álvarez-Fernández, Ana; Díaz-Benito, Pablo; Abadía, Anunciación; López-Millán, Ana-Flor; Abadía, Javier

    2014-01-01

    The mechanisms plants use to transport metals from roots to shoots are not completely understood. It has long been proposed that organic molecules participate in metal translocation within the plant. However, until recently the identity of the complexes involved in the long-distance transport of metals could only be inferred by using indirect methods, such as analyzing separately the concentrations of metals and putative ligands and then using in silico chemical speciation software to predict metal species. Molecular biology approaches also have provided a breadth of information about putative metal ligands and metal complexes occurring in plant fluids. The new advances in analytical techniques based on mass spectrometry and the increased use of synchrotron X-ray spectroscopy have allowed for the identification of some metal-ligand species in plant fluids such as the xylem and phloem saps. Also, some proteins present in plant fluids can bind metals and a few studies have explored this possibility. This study reviews the analytical challenges researchers have to face to understand long-distance metal transport in plants as well as the recent advances in the identification of the ligand and metal-ligand complexes in plant fluids. PMID:24723928

  1. Stress fractures in runners.

    PubMed

    McCormick, Frank; Nwachukwu, Benedict U; Provencher, Matthew T

    2012-04-01

    Stress fractures are a relatively common entity in athletes, in particular, runners. Physicians and health care providers should maintain a high index of suspicion for stress fractures in runners presenting with insidious onset of focal bone tenderness associated with recent changes in training intensity or regimen. It is particularly important to recognize “high-risk” fractures, as these are associated with an increased risk of complication. A patient with confirmed radiographic evidence of a high-risk stress fracture should be evaluated by an orthopedic surgeon. Runners may benefit from orthotics, cushioned sneakers, interval training, and vitamin/calcium supplementation as a means of stress fracture prevention.

  2. Lifting the Runners

    NASA Image and Video Library

    2010-08-25

    Under the unflinching summer sun, workers at NASA Deep Space Network complex in Goldstone, Calif., use a crane to lift a runner segment that is part of major surgery on a giant, 70-meter-wide antenna.

  3. Scorpio and Long-Distance Trade in Mesoamerica

    NASA Astrophysics Data System (ADS)

    Fahmel Beyer, Bernd

    2016-11-01

    This paper establishes a relationship between Scorpio and the astronomical group of the Ciudadela at Teotihuacan, linking them to the city's merchant elite. Its argument is based on a brief discussion of the alacrán and the context in which it appears in Prehispanic documents and art. Human figures with a scorpion-tail are emphasized because of their association with the merchant class and Venus. The iconography used to represent this star takes on many shapes, some of which were related to war. The origin of this symbol can be found on the southern coast of Guatemala, from where cacao was distributed to Oaxaca and the highlands. During the Postclassic the Soconusco was one of the most cherished domains of the Aztec, whose pochteca not only carried out long-distance trade but also had the power to solve or promote diplomatic conflicts.

  4. [MORBIDITY OF SUBMARINE CREW SAILORS IN LONG-DISTANCE CRUISES].

    PubMed

    Myznikov, I L; Burtsev, N N; Bondarenko N V; Khamidullina, A Ya

    2015-01-01

    Morbidity among the personnel of a Kola-based (beyond the Arctic circle) atomic (ASM) and diesel-powered (DSM) submarines in the course of long-distance cruises in different waters of the world ocean was studied. Statistics was collected from the reports of submarine medical officers since 1969. Levels and causes of morbidity were analyzed. According to the data of many years' observations, within the structure of primary diseases of military contractors on cruises the leading place has been occupied by respiratory disorders followed by skin and subcutaneous fat problems, and digestive diseases. Incidence of chronic diseases among ASM and DSM personnel was evaluated. The authors raise the issue of dental care quality provided to submariners.

  5. Rapid, Long-Distance Dispersal by Pumice Rafting

    PubMed Central

    Bryan, Scott E.; Cook, Alex G.; Evans, Jason P.; Hebden, Kerry; Hurrey, Lucy; Colls, Peter; Jell, John S.; Weatherley, Dion; Firn, Jennifer

    2012-01-01

    Pumice is an extremely effective rafting agent that can dramatically increase the dispersal range of a variety of marine organisms and connect isolated shallow marine and coastal ecosystems. Here we report on a significant recent pumice rafting and long-distance dispersal event that occurred across the southwest Pacific following the 2006 explosive eruption of Home Reef Volcano in Tonga. We have constrained the trajectory, and rate, biomass and biodiversity of transfer, discovering more than 80 species and a substantial biomass underwent a >5000 km journey in 7–8 months. Differing microenvironmental conditions on the pumice, caused by relative stability of clasts at the sea surface, promoted diversity in biotic recruitment. Our findings emphasise pumice rafting as an important process facilitating the distribution of marine life, which have implications for colonisation processes and success, the management of sensitive marine environments, and invasive pest species. PMID:22815770

  6. Rapid, long-distance dispersal by pumice rafting.

    PubMed

    Bryan, Scott E; Cook, Alex G; Evans, Jason P; Hebden, Kerry; Hurrey, Lucy; Colls, Peter; Jell, John S; Weatherley, Dion; Firn, Jennifer

    2012-01-01

    Pumice is an extremely effective rafting agent that can dramatically increase the dispersal range of a variety of marine organisms and connect isolated shallow marine and coastal ecosystems. Here we report on a significant recent pumice rafting and long-distance dispersal event that occurred across the southwest Pacific following the 2006 explosive eruption of Home Reef Volcano in Tonga. We have constrained the trajectory, and rate, biomass and biodiversity of transfer, discovering more than 80 species and a substantial biomass underwent a >5000 km journey in 7-8 months. Differing microenvironmental conditions on the pumice, caused by relative stability of clasts at the sea surface, promoted diversity in biotic recruitment. Our findings emphasise pumice rafting as an important process facilitating the distribution of marine life, which have implications for colonisation processes and success, the management of sensitive marine environments, and invasive pest species.

  7. Career Development as a Long-distance Hike

    PubMed Central

    2008-01-01

    Traditional images of achievement do not capture today’s more complex career development realities. Approaching career development as a long-distance expedition can help professionals in addressing the strenuous challenges they face, in seeing that a career can be built in many ways, and in taking a long-term view of their journeys. Skills are like muscles, self-efficacy is like sturdy boots, advancement “how-to’s” are like maps, and mentors are like trail guides. Among the tasks each hiker faces are selecting destinations, navigating through rough terrain and weather, and balancing their packs. To further their hikers’ resilience, departments should pay more attention to the career development ecology, including improving access to qualified trail guides and to alternate paths. PMID:18953615

  8. Long distance quantum communication using continuous variable encoding

    NASA Astrophysics Data System (ADS)

    Li, Linshu; Albert, Victor; Michael, Marios; Muralidharan, Sreraman; Zou, Changling; Jiang, Liang

    Quantum communication enables faithful quantum state transfer between different parties and protocols for cryptographic purposes. However, quantum communication over long distances (>1000km) remains challenging due to optical channel attenuation. This calls for investigation on developing novel encoding schemes that correct photon loss errors efficiently. In this talk, we introduce the generalization of multi-component Schrödinger cat states and propose to encode quantum information in these cat states for ultrafast quantum repeaters. We detail the quantum error correction procedures at each repeater station and characterize the performance of this novel encoding scheme given practical imperfections, such as coupling loss. A comparison with other quantum error correcting codes for bosonic modes will be discussed.

  9. Conflicting evidence about long-distance animal navigation.

    PubMed

    Alerstam, Thomas

    2006-08-11

    Because of conflicting evidence about several fundamental issues, long-distance animal navigation has yet to be satisfactorily explained. Among the unsolved problems are the nature of genetic spatial control of migration and the relationships between celestial and magnetic compass mechanisms and between different map-related cues in orientation and homing, respectively. In addition, navigation is expected to differ between animal groups depending on sensory capabilities and ecological conditions. Evaluations based on modern long-term tracking techniques of the geometry of migration routes and individual migration history, combined with behavioral experiments and exploration of the sensory and genetic mechanisms, will be crucial for understanding the spatial principles that guide animals on their global journeys.

  10. FT and florigen long-distance flowering control in plants.

    PubMed

    Putterill, Joanna; Varkonyi-Gasic, Erika

    2016-10-01

    The great hunt for florigen, the universal, long distance flowering regulator proposed by Chailakhan in the 1930s, resulted in the discovery a decade ago that FT-like proteins fulfilled the predictions for florigen. They are small (∼175 amino acids), globular, phosphatidylethanolamine-binding (PEBP) proteins, phloem-expressed, graft-transmissible and able to move to the shoot apex to act as potent stimulators of flowering in many plants. Genes that regulate Arabidopsis FT protein movement and some features of Arabidopsis FT protein that make it an effective florigen have recently been identified. Although floral promotion via graft transmission of FT has not been demonstrated in trees, FT-like genes have been successfully applied to reducing the long juvenile (pre-flowering) phase of many trees enabling fast track breeding.

  11. Electrical Wiring and Long-Distance Plant Communication.

    PubMed

    Hedrich, Rainer; Salvador-Recatalà, Vicenta; Dreyer, Ingo

    2016-05-01

    Electrical signalling over long distances is an efficient way of achieving cell-to-cell communication in living organisms. In plants, the phloem can be considered as a 'green cable' that allows the transmission of action potentials (APs) induced by stimuli such as wounding and cold. Measuring phloem potential changes and separating them from secondary responses of surrounding tissues can be achieved using living aphids as bioelectrodes. Two glutamate receptor-like genes (GLR3.3 and 3.6) were identified as being involved in the propagation of electrical activity from the damaged to undamaged leaves. However, phloem APs are initiated and propagated independently of these glutamate receptors. Here, we propose new screening approaches to obtain further information on the components required for electrical signalling in phloem cables.

  12. Long-distance practical quantum key distribution by entanglement swapping.

    PubMed

    Scherer, Artur; Sanders, Barry C; Tittel, Wolfgang

    2011-02-14

    We develop a model for practical, entanglement-based long-distance quantum key distribution employing entanglement swapping as a key building block. Relying only on existing off-the-shelf technology, we show how to optimize resources so as to maximize secret key distribution rates. The tools comprise lossy transmission links, such as telecom optical fibers or free space, parametric down-conversion sources of entangled photon pairs, and threshold detectors that are inefficient and have dark counts. Our analysis provides the optimal trade-off between detector efficiency and dark counts, which are usually competing, as well as the optimal source brightness that maximizes the secret key rate for specified distances (i.e. loss) between sender and receiver.

  13. Long-distance teleportation of qubits at telecommunication wavelengths.

    PubMed

    Marcikic, I; de Riedmatten, H; Tittel, W; Zbinden, H; Gisin, N

    2003-01-30

    Matter and energy cannot be teleported (that is, transferred from one place to another without passing through intermediate locations). However, teleportation of quantum states (the ultimate structure of objects) is possible: only the structure is teleported--the matter stays at the source side and must be already present at the final location. Several table-top experiments have used qubits (two-dimensional quantum systems) or continuous variables to demonstrate the principle over short distances. Here we report a long-distance experimental demonstration of probabilistic quantum teleportation. Qubits carried by photons of 1.3 micro m wavelength are teleported onto photons of 1.55 micro m wavelength from one laboratory to another, separated by 55 m but connected by 2 km of standard telecommunications fibre. The first (and, with foreseeable technologies, the only) application of quantum teleportation is in quantum communication, where it could help to extend quantum cryptography to larger distances.

  14. Long distance quantum teleportation in a quantum relay configuration.

    PubMed

    de Riedmatten, H; Marcikic, I; Tittel, W; Zbinden, H; Collins, D; Gisin, N

    2004-01-30

    A long distance quantum teleportation experiment with a fiber-delayed Bell state measurement (BSM) is reported. The source creating the qubits to be teleported and the source creating the necessary entangled state are connected to the beam splitter realizing the BSM by two 2 km long optical fibers. In addition, the teleported qubits are analyzed after 2.2 km of optical fiber, in another laboratory separated by 55 m. Time-bin qubits carried by photons at 1310 nm are teleported onto photons at 1550 nm. The fidelity is of 77%, above the maximal value obtainable without entanglement. This is the first realization of an elementary quantum relay over significant distances, which will allow an increase in the range of quantum communication and quantum key distribution.

  15. Crocodylus acutus (American Crocodile). Long distance juvenile movement

    USGS Publications Warehouse

    Crespo, Rafael; Beauchamp, Jeffrey S.; Mazzotti, Frank; Cherkiss, Michael S.

    2015-01-01

    Crocodylus acutus (American Crocodile) is the most widely distributed New World crocodilian species with its range extending from Peru in the south to the southern tip of peninsular Florida in the north. Crocodylus acutus occupies primarily coastal brackish water habitat, however it also occurs in freshwater to hypersaline habitats (Thorbjarnarson 2010. In Crocodiles. Status Survey and Conservation Action Plan. [Third Edition], American Crocodile Crocodylus acutus, pp. 46–53 S.C. Manolis and C. Stevenson. Crocodile Specialist Group, Darwin). There is limited literature on long distance movements of juvenile crocodilians worldwide and no literature on juvenile crocodiles in Florida. However, adult C. acutus in Florida have been documented to make seasonal movements of 5–15 km from preferred foraging habitat to nesting beaches (Mazzotti 1983. The Ecology of Crocodylus acutus in Florida. PhD Dissertation. The Pennsylvania State University, University Park, Pennsylvania. 161pp), and one adult was documented making a 35 km trip from her nest site to preferred foraging habitat (Cherkiss et. al. 2006. Herpetol. Rev. 38:72–73). Rodda (1984. Herpetologica 40:444–451) reported on juvenile C. acutus movement in Gatun Lake, Panama, and found that juveniles stayed within 1 km of their nest site for the first month. Movements of juvenile Crocodylus porosus (Saltwater Crocodile) in a river system in Northern Australia showed a maximum movement of 38.9 km from a known nest site, with the majority of the crocodiles staying within 15.6 km downstream to 6.8 km upstream (Webb and Messel 1978. Aust. Wildlife Res. 5:263–283). Juvenile movement of Crocodylus niloticus (Nile Crocodile) in Lake Ngezi, Zimbabwe showed crocodiles restricted their movements from 1.0 km up to 4.5 km through the wet and dry seasons (Hutton 1989. Am. Zool. 29:1033–1049). Long distance movements of alligators were recorded for sizes ranging from 28 cm to 361 cm in a coastal refuge in Louisiana, where

  16. Long-distance transport of signals during symbiosis

    PubMed Central

    Xie, Zhi-Ping; Illana, Antonio

    2011-01-01

    Legumes enter nodule symbioses with nitrogen-fixing bacteria (rhizobia), whereas most flowering plants establish symbiotic associations with arbuscular mycorrhizal (AM) fungi. Once first steps of symbiosis are initiated, nodule formation and mycorrhization in legumes is negatively controlled by a shoot-derived inhibitor (SDI), a phenomenon termed autoregulation. According to current views, autoregulation of nodulation and mycorrhization in legumes is regulated in a similar way. CLE peptides induced in response to rhizobial nodulation signals (Nod factors) have been proposed to represent the ascending long-distance signals to the shoot. Although not proven yet, these CLE peptides are likely perceived by leucine-rich repeat (LRR) autoregulation receptor kinases in the shoot. Autoregulation of mycorrhization in non-legumes is reminiscent to the phenomenon of “systemic acquired resistance” in plant-pathogen interactions. PMID:21455020

  17. Long-Distance Water Transport in Aquatic Plants.

    PubMed Central

    Pedersen, O.

    1993-01-01

    Acropetal mass flow of water is demonstrated in two submerged angiosperms, Lobelia dortmanna L. and Sparganium emersum Rehman by means of guttation measurements. Transpiration is absent in truly submerged plants, but the presence of guttation verifies that long-distance water transport takes place. Use of tritiated water showed that the water current arises from the roots, and the main flow of water is channeled to the youngest leaves. This was confirmed by measurement of guttation, which showed the highest rates in young leaves. Guttation rates were 10-fold larger in the youngest leaf of S. emersum (2.1 [mu]L leaf-1 h-1) compared with the youngest leaf of L. dortmanna (0.2 [mu]L leaf-1 h-1). This is probably due to profound species differences in the hydraulic conductance (2.7 x 10-17 m4 Pa-1 s-1 for S. emersum and 1.4 x 10-19 m4 Pa-1 s-1 for L. dortmanna). Estimates derived from the modified Hagen-Poiseuille equation showed that the maximum flow velocity in xylem vessels was 23 to 84 cm h-1, and the required root pressure to drive the flow was small compared to that commonly found in terrestrial plants. In S. emersum long-distance transport of water was shown to be dependent on energy conversion in the roots. The leaves ceased to guttate when the roots were cooled to 4[deg]C from the acclimatization level at 15[deg]C, whereas the guttation was stimulated when the temperature was increased to 25[deg]C. Also, the guttation rate decreased significantly when vanadate was added to the root medium. The observed water transport is probably a general phenomenon in submerged plants, where it can act as a translocation system for nutrients taken up from the rich root medium and thereby assure maximum growth. PMID:12232030

  18. Dynamics of long-distance signaling via plant vascular tissues

    PubMed Central

    Notaguchi, Michitaka; Okamoto, Satoru

    2015-01-01

    Plant vascular systems are constructed by specific cell wall modifications through which cells are highly specialized to make conduits for water and nutrients. Xylem vessels are formed by thickened cell walls that remain after programmed cell death, and serve as water conduits from the root to the shoot. In contrast, phloem tissues consist of a complex of living cells, including sieve tube elements and their neighboring companion cells, and translocate photosynthetic assimilates from mature leaves to developing young tissues. Intensive studies on the content of vascular flow fluids have unveiled that plant vascular tissues transport various types of gene product, and the transport of some provides the molecular basis for the long-distance communications. Analysis of xylem sap has demonstrated the presence of proteins in the xylem transpiration stream. Recent studies have revealed that CLE and CEP peptides secreted in the roots are transported to above ground via the xylem in response to plant–microbe interaction and soil nitrogen starvation, respectively. Their leucine-rich repeat transmembrane receptors localized in the shoot phloem are required for relaying the signal from the shoot to the root. These findings well-fit to the current scenario of root-to-shoot-to-root feedback signaling, where peptide transport achieves the root-to-shoot signaling, the first half of the signaling process. Meanwhile, it is now well-evidenced that proteins and a range of RNAs are transported via the phloem translocation system, and some of those can exert their physiological functions at their destinations, including roots. Thus, plant vascular systems may serve not only as conduits for the translocation of essential substances but also as long-distance communication pathways that allow plants to adapt to changes in internal and external environments at the whole plant level. PMID:25852714

  19. 47 CFR 36.214 - Long distance message revenue-Account 5100.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Long distance message revenue-Account 5100. 36... Revenues and Certain Income Accounts Operating Revenues § 36.214 Long distance message revenue—Account 5100... number of minutes of use for the twelve-month period ending December 31, 2000. (b) Long Distance private...

  20. US long distance fiber optic networks: Technology, evolution and advanced concepts. Volume 2: Fiber optic technology and long distance networks

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The study projects until 2000 the evolution of long distance fiber optic networks in the U.S. Volume 1 is the Executive Summary. Volume 2 focuses on fiber optic components and systems that are directly related to the operation of long-haul networks. Optimistic, pessimistic and most likely scenarios of technology development are presented. The activities of national and regional companies implementing fiber long haul networks are also highlighted, along with an analysis of the market and regulatory forces affecting network evolution. Volume 3 presents advanced fiber optic network concept definitions. Inter-LATA traffic is quantified and forms the basis for the construction of 11-, 15-, 17-, and 23-node networks. Using the technology projections from Volume 2, a financial model identifies cost drivers and determines circuit mile costs between any two LATAs. A comparison of fiber optics with alternative transmission concludes the report.

  1. Analysis of swimming performance in FINA World Cup long-distance open water races.

    PubMed

    Zingg, Matthias Alexander; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald; Knechtle, Beat

    2014-01-02

    Age and peak performance in ultra-endurance athletes have been mainly investigated in long-distance runners and triathletes, but not for long-distance swimmers. The present study investigated the age and swimming performance of elite ultra-distance swimmers competing in the 5-, 10- and 25-km Fédération Internationale de Natation (FINA) World Cup swimming events. The associations of age and swimming speed in elite male and female swimmers competing in World Cup events of 5-, 10- and 25-km events from 2000 to 2012 were analysed using single and multi-level regression analyses. During the studied period, the swimming speed of the annual top ten women decreased significantly from 4.94 ± 0.20 to 4.77 ± 0.09 km/h in 5 km and from 4.60 ± 0.04 to 4.44 ± 0.08 km/h in 25 km, while it significantly increased from 4.57 ± 0.01 to 5.75 ± 0.01 km/h in 10 km. For the annual top ten men, peak swimming speed decreased significantly from 5.42 ± 0.04 to 5.39 ± 0.02 km/h in 5 km, while it remained unchanged at 5.03 ± 0.32 km/h in 10 km and at 4.94 ± 0.35 km/h in 25 km. The age of peak swimming speed for the annual top ten women remained stable at 22.5 ± 1.2 years in 5 km, at 23.4 ± 0.9 years in 10 km and at 23.8 ± 0.9 years in 25 km. For the annual top ten men, the age of peak swimming speed increased from 23.7 ± 2.8 to 28.0 ± 5.1 years in 10 km but remained stable at 24.8 ± 1.0 years in 5 km and at 27.2 ± 1.1 years in 25 km. Female long-distance swimmers competing in FINA World Cup races between 2000 and 2012 improved in 10 km but impaired in 5 and 25 km, whereas men only impaired in 5 km. The age of peak performance was younger in women (approximately 23 years) compared to men (about 25-27 years).

  2. Analysis of swimming performance in FINA World Cup long-distance open water races

    PubMed Central

    2014-01-01

    Background Age and peak performance in ultra-endurance athletes have been mainly investigated in long-distance runners and triathletes, but not for long-distance swimmers. The present study investigated the age and swimming performance of elite ultra-distance swimmers competing in the 5-, 10- and 25-km Fédération Internationale de Natation (FINA) World Cup swimming events. Methods The associations of age and swimming speed in elite male and female swimmers competing in World Cup events of 5-, 10- and 25-km events from 2000 to 2012 were analysed using single and multi-level regression analyses. Results During the studied period, the swimming speed of the annual top ten women decreased significantly from 4.94 ± 0.20 to 4.77 ± 0.09 km/h in 5 km and from 4.60 ± 0.04 to 4.44 ± 0.08 km/h in 25 km, while it significantly increased from 4.57 ± 0.01 to 5.75 ± 0.01 km/h in 10 km. For the annual top ten men, peak swimming speed decreased significantly from 5.42 ± 0.04 to 5.39 ± 0.02 km/h in 5 km, while it remained unchanged at 5.03 ± 0.32 km/h in 10 km and at 4.94 ± 0.35 km/h in 25 km. The age of peak swimming speed for the annual top ten women remained stable at 22.5 ± 1.2 years in 5 km, at 23.4 ± 0.9 years in 10 km and at 23.8 ± 0.9 years in 25 km. For the annual top ten men, the age of peak swimming speed increased from 23.7 ± 2.8 to 28.0 ± 5.1 years in 10 km but remained stable at 24.8 ± 1.0 years in 5 km and at 27.2 ± 1.1 years in 25 km. Conclusion Female long-distance swimmers competing in FINA World Cup races between 2000 and 2012 improved in 10 km but impaired in 5 and 25 km, whereas men only impaired in 5 km. The age of peak performance was younger in women (approximately 23 years) compared to men (about 25–27 years). PMID:24382200

  3. Habitat features and long-distance dispersal modify the use of social information by a long-distance migratory bird.

    PubMed

    Rushing, Clark S; Dudash, Michele R; Marra, Peter P

    2015-11-01

    The processes by which individuals select breeding sites have important consequences for individual tness as well as population- and community-dynamics. Although there is increasing evidence that many animal species use information acquired from conspecics to assess the suitability of potential breeding sites, little is known about how the use of this social information is modified by biotic and abiotic conditions. We used an automated playback experiment to simulate two types of social information, post-breeding public information and pre-breeding location cues, to determine the relative importance of these cues for breeding site selection by a migratory songbird, the American redstart (Setophaga ruticilla). In addition, we used stable hydrogen isotopes to determine the dispersal status of individuals that responded to our experimental treatments and quantify whether long-distance dispersers use different social cues to select breeding sites compared to philopatric individuals. We found that points that received pre-breeding location cue treatments were signi cantly more likely to be settled by redstarts than control points that received no playback. However, we found no evidence the redstarts used post-breeding public information gathered during one season to select breeding sites the following year. Breeding site habitat structure was also a strong predictor of settlement probability, indicating that redstarts modi ed the use of social information based on habitat cues. Furthermore, stable hydrogen isotope signatures from individuals that responded to location cue treatments suggest that long-distance dispersers may rely more heavily on these cues than local recruits. Collectively, these results indicate that redstarts use multiple sources of information to select breeding sites, which could buffer individuals from selecting suboptimal sites when they breed in unfamiliar locations or when habitat quality becomes decoupled from social cues.

  4. Long-Distance Wh-Movement and Long-Distance Wh-Movement Avoidance in L2 English: Evidence from French and Bulgarian Speakers

    ERIC Educational Resources Information Center

    Slavkov, Nikolay

    2015-01-01

    This article investigates spoken productions of complex questions with long-distance wh-movement in the L2 English of speakers whose first language is (Canadian) French or Bulgarian. Long-distance wh-movement is of interest as it can be argued that it poses difficulty in acquisition due to its syntactic complexity and related high processing load.…

  5. Long-Distance Wh-Movement and Long-Distance Wh-Movement Avoidance in L2 English: Evidence from French and Bulgarian Speakers

    ERIC Educational Resources Information Center

    Slavkov, Nikolay

    2015-01-01

    This article investigates spoken productions of complex questions with long-distance wh-movement in the L2 English of speakers whose first language is (Canadian) French or Bulgarian. Long-distance wh-movement is of interest as it can be argued that it poses difficulty in acquisition due to its syntactic complexity and related high processing load.…

  6. Genetic profiles and prediction of the success of young athletes' transition from middle- to long-distance runs: an exploratory study.

    PubMed

    Ben-Zaken, Sigal; Meckel, Yoav; Lidor, Ronnie; Nemet, Dan; Eliakim, Alon

    2013-08-01

    The aim of the study was to assess whether an aerobic-favoring genetic profile can predict the success of a shift from middle- to long-distance running. Thirteen elite middle-distance runners were divided into successful and nonsuccessful groups in their shift toward long-distance runs. All the runners began their training program at the age of 14-15, and after 6-7 years, changed focus and adjusted their training program to fit longer running distances. The participants' personal records in the longer events were set at the age of 25-27, about 3-5 years after the training readjustment took place. The endurance genetic score based on 9 polymorphisms was computed as the endurance genetic distance score (EGDS9). The power genetic distance score (PGDS5) was computed based on 5 power-related genetic polymorphisms. The mean EGDS9 was significantly higher among the successful group than the nonsuccessful group (37.1 and 23.3, respectively, p < .005, effect size 0.75), while the mean PGDS5 was not statistically different between the 2 groups (p = .13). Our findings suggest the possible use of genetic profiles as an added tool for determining appropriate competitive transition and specialization in young athletes involved in early phases of talent development.

  7. Effective long-distance pollen dispersal in Centaurea jacea.

    PubMed

    Albrecht, Matthias; Duelli, Peter; Obrist, Martin K; Kleijn, David; Schmid, Bernhard

    2009-08-25

    Agri-environment schemes play an increasingly important role for the conservation of rare plants in intensively managed agricultural landscapes. However, little is known about their effects on gene flow via pollen dispersal between populations of these species. In a 2-year experiment, we observed effective pollen dispersal from source populations of Centaurea jacea in restored meadows, the most widespread Swiss agri-environment scheme, to potted plants in adjacent intensively managed meadows without other individuals of this species. Potted plants were put in replicated source populations at 25, 50, 100 m and where possible 200 m distance from these source populations. Pollen transfer among isolated plants was prevented by temporary bagging, such that only one isolated plant was accessible for flower visitors at any one time. Because C. jacea is self-incompatible, seed set in single-plant isolates indicated insect mediated effective pollen dispersal from the source population. Seed set was higher in source populations (35.7+/-4.4) than in isolates (4.8+/-1.0). Seed set declined from 18.9% of that in source populations at a distance of 25 m to 7.4% at 200 m. At a distance of 200 m seed set was still significantly higher in selfed plants, indicating long-distance effective pollen dispersal up to 200 m. Analyses of covariance suggested that bees contributed more than flies to this long-distance pollen dispersal. We found evidence that pollen dispersal to single-plant isolates was positively affected by the diversity and flower abundance of neighboring plant species in the intensively managed meadow. Furthermore, the decline of the dispersal was less steep when the source population of C. jacea was large. We conclude that insect pollinators can effectively transfer pollen from source populations of C. jacea over at least 200 m, even when "recipient populations" consisted of single-plant isolates, suggesting that gene flow by pollen over this distance is very likely

  8. Tracking long-distance migration to assess marine pollution impact

    PubMed Central

    Montevecchi, William; Fifield, David; Burke, Chantelle; Garthe, Stefan; Hedd, April; Rail, Jean-François; Robertson, Gregory

    2012-01-01

    Animal tracking provides new means to assess far-reaching environmental impacts. In the aftermath of the Deepwater Horizon explosion in the Gulf of Mexico, a long-distance migrant, the northern gannet (Morus bassanus) suffered the highest oiling among beach-wrecked birds recovered. Analysis of bird-borne tracking data indicated that 25 per cent of their North American population from multiple colonies in eastern Canada migrated to the pollution zone. Findings contrasted sharply with available mark-recapture (band recovery) data. The timing of movement into and out of the Gulf indicates that immature birds would have absorbed most oil-induced mortality. Consequently, one of two outcomes is likely: either a lagged (likely difficult to assess) population decrease, or an undetectable population response buffered by age-related life-history adaptations. Tracking research is especially useful when little information on animal distributions in pollution zones is available, as is the case in the Gulf of Mexico. Ongoing research highlights current risks and conservation concerns. PMID:22012949

  9. Perception's shadow: long-distance synchronization of human brain activity

    NASA Astrophysics Data System (ADS)

    Rodriguez, Eugenio; George, Nathalie; Lachaux, Jean-Philippe; Martinerie, Jacques; Renault, Bernard; Varela, Francisco J.

    1999-02-01

    Transient periods of synchronization of oscillating neuronal discharges in the frequency range 30-80Hz (gamma oscillations) have been proposed to act as an integrative mechanism that may bring a widely distributed set of neurons together into a coherent ensemble that underlies a cognitive act. Results of several experiments in animals provide support for this idea (see, for example, refs 4,5,6,7,8,9,10). In humans, gamma oscillations have been described both on the scalp (measured by electroencephalography and magnetoencephalography) and in intracortical recordings, but no direct participation of synchrony in a cognitive task has been demonstrated so far. Here we record electrical brain activity from subjects who are viewing ambiguous visual stimuli (perceived either as faces or as meaningless shapes). We show for the first time, to our knowledge, that only face perception induces a long-distance pattern of synchronization, corresponding to the moment of perception itself and to the ensuing motor response. A period of strong desynchronization marks the transition between the moment of perception and the motor response. We suggest that this desynchronization reflects a process of active uncoupling of the underlying neural ensembles that is necessary to proceed from one cognitive state to another.

  10. Long distance spin communication in chemical vapour deposited graphene

    PubMed Central

    Kamalakar, M. Venkata; Groenveld, Christiaan; Dankert, André; Dash, Saroj P.

    2015-01-01

    Graphene is an ideal medium for long-distance spin communication in future spintronic technologies. So far, the prospect is limited by the smaller sizes of exfoliated graphene flakes and lower spin transport properties of large-area chemical vapour-deposited (CVD) graphene. Here we demonstrate a high spintronic performance in CVD graphene on SiO2/Si substrate at room temperature. We show pure spin transport and precession over long channel lengths extending up to 16 μm with a spin lifetime of 1.2 ns and a spin diffusion length ∼6 μm at room temperature. These spin parameters are up to six times higher than previous reports and highest at room temperature for any form of pristine graphene on industrial standard SiO2/Si substrates. Our detailed investigation reinforces the observed performance in CVD graphene over wafer scale and opens up new prospects for the development of lateral spin-based memory and logic applications. PMID:25857650

  11. Long-Distance Communication between Laryngeal Carcinoma Cells

    PubMed Central

    Antanavičiūtė, Ieva; Rysevaitė, Kristina; Liutkevičius, Vykintas; Marandykina, Alina; Rimkutė, Lina; Sveikatienė, Renata; Uloza, Virgilijus; Skeberdis, Vytenis Arvydas

    2014-01-01

    Tunneling nanotubes and epithelial bridges are recently discovered new forms of intercellular communication between remote cells allowing their electrical synchronization, transfer of second messengers and even membrane vesicles and organelles. In the present study, we demonstrate for the first time in primary cell cultures prepared from human laryngeal squamous cell carcinoma (LSCC) samples that these cells communicate with each other over long distances (up to 1 mm) through membranous tunneling tubes (TTs), which can be open-ended or contain functional gap junctions formed of connexin 43. We found two types of TTs, containing F-actin alone or F-actin and α-tubulin. In the LSCC cell culture, we identified 5 modes of TT formation and performed quantitative assessment of their electrical properties and permeability to fluorescent dyes of different molecular weight and charge. We show that TTs, containing F-actin and α-tubulin, transport mitochondria and accommodate small DAPI-positive vesicles suggesting possible transfer of genetic material through TTs. We confirmed this possibility by demonstrating that even TTs, containing gap junctions, were capable of transmitting double-stranded small interfering RNA. To support the idea that the phenomenon of TTs is not only typical of cell cultures, we have examined microsections of samples obtained from human LSCC tissues and identified intercellular structures similar to those found in the primary LSCC cell culture. PMID:24945745

  12. Long-distance quantum communication with neutral atoms

    SciTech Connect

    Razavi, Mohsen; Shapiro, Jeffrey H.

    2006-04-15

    The architecture proposed by Duan, Lukin, Cirac, and Zoller (DLCZ) for long-distance quantum communication with atomic ensembles is analyzed. Its fidelity and throughput in entanglement distribution, entanglement swapping, and quantum teleportation is derived within a framework that accounts for multiple excitations in the ensembles as well as loss and asymmetries in the channel. The DLCZ performance metrics that are obtained are compared to the corresponding results for the trapped-atom quantum communication architecture that has been proposed by a team from the Massachusetts Institute of Technology and Northwestern University (MIT and NU). Both systems are found to be capable of high-fidelity entanglement distribution. However, the DLCZ scheme only provides conditional teleportation and repeater operation, whereas the MIT-NU architecture affords full Bell-state measurements on its trapped atoms. Moreover, it is shown that achieving unity conditional fidelity in DLCZ teleportation and repeater operation requires ideal photon-number resolving detectors. The maximum conditional fidelities for DLCZ teleportation and repeater operation that can be realized with nonresolving detectors are 1/2 and 2/3, respectively.

  13. Predictors of psychostimulant use by long-distance truck drivers.

    PubMed

    Williamson, Ann

    2007-12-01

    Two national cross-sectional surveys of fatigue and its effects in long-distance road transport in Australia showed that stimulant use was a common feature of this industry. Between one in five and one in three drivers reported using stimulants at least sometimes, and a significant proportion reported stimulant use as a most helpful fatigue management strategy. This study reanalyzed the surveys with the aim of identifying predictors of stimulant drug use by drivers. The surveys were administered in 1991 (n = 970) and 1998 (n = 1,007) by interview and self-administration. Logistic regression analysis conducted separately for each survey showed that stimulant drug use was twice as likely for drivers who had the greatest problem in managing fatigue and was two to three times more likely for drivers paid on a payment-by-results or contingency-payment basis. Younger, less experienced drivers were also more likely to take drugs. This analysis demonstrates the involvement of external factors, especially productivity-based payment systems, in stimulant drug use by truck drivers; findings were confirmed in two separate surveys conducted 7 years apart. Results highlight the important role of economic and organizational factors in occupational health and safety problems.

  14. Discrimination of individual tigers (Panthera tigris) from long distance roars.

    PubMed

    Ji, An; Johnson, Michael T; Walsh, Edward J; McGee, JoAnn; Armstrong, Douglas L

    2013-03-01

    This paper investigates the extent of tiger (Panthera tigris) vocal individuality through both qualitative and quantitative approaches using long distance roars from six individual tigers at Omaha's Henry Doorly Zoo in Omaha, NE. The framework for comparison across individuals includes statistical and discriminant function analysis across whole vocalization measures and statistical pattern classification using a hidden Markov model (HMM) with frame-based spectral features comprised of Greenwood frequency cepstral coefficients. Individual discrimination accuracy is evaluated as a function of spectral model complexity, represented by the number of mixtures in the underlying Gaussian mixture model (GMM), and temporal model complexity, represented by the number of sequential states in the HMM. Results indicate that the temporal pattern of the vocalization is the most significant factor in accurate discrimination. Overall baseline discrimination accuracy for this data set is about 70% using high level features without complex spectral or temporal models. Accuracy increases to about 80% when more complex spectral models (multiple mixture GMMs) are incorporated, and increases to a final accuracy of 90% when more detailed temporal models (10-state HMMs) are used. Classification accuracy is stable across a relatively wide range of configurations in terms of spectral and temporal model resolution.

  15. Tracking long-distance migration to assess marine pollution impact.

    PubMed

    Montevecchi, William; Fifield, David; Burke, Chantelle; Garthe, Stefan; Hedd, April; Rail, Jean-François; Robertson, Gregory

    2012-04-23

    Animal tracking provides new means to assess far-reaching environmental impacts. In the aftermath of the Deepwater Horizon explosion in the Gulf of Mexico, a long-distance migrant, the northern gannet (Morus bassanus) suffered the highest oiling among beach-wrecked birds recovered. Analysis of bird-borne tracking data indicated that 25 per cent of their North American population from multiple colonies in eastern Canada migrated to the pollution zone. Findings contrasted sharply with available mark-recapture (band recovery) data. The timing of movement into and out of the Gulf indicates that immature birds would have absorbed most oil-induced mortality. Consequently, one of two outcomes is likely: either a lagged (likely difficult to assess) population decrease, or an undetectable population response buffered by age-related life-history adaptations. Tracking research is especially useful when little information on animal distributions in pollution zones is available, as is the case in the Gulf of Mexico. Ongoing research highlights current risks and conservation concerns.

  16. Albatross Long-Distance Navigation: Comparing Adults And Juveniles

    NASA Astrophysics Data System (ADS)

    Åkesson, Susanne; Weimerskirch, Henri

    2005-09-01

    Albatrosses are known for their extreme navigation performance enabling them to locate isolated breeding islands after long-distance migrations across open seas. Little is known about the migration of young albatrosses and how they reach the adults' navigation and foraging skills during the period of immaturity lasting several years and spent permanently flying across the open ocean. We tracked by satellite telemetry the dispersal and migration of 13 juvenile wandering albatrosses from the Crozet Islands during their first year at sea. The young albatrosses covered an average distance of 184,000 km during the first year, restricting their dispersal movement to the unproductive and low wind subtropical Indian Ocean and Tasman Sea. The juveniles initiated the migration by an innate phase of rapid dispersal encoded as a fixed flight direction assisted by southerly winds towards north and northeast. Thereafter each individual restricted its movement to a particular zone of the ocean that will possibly be used until they start breeding 7 10 years later and return in contact with breeding adults. This dispersal in young birds corresponds well with movements observed for adult non-breeding wandering albatrosses. The results show clearly an inherited ability to navigate back to already visited areas in young wandering albatrosses. The juvenile dispersal behaviour and migration at sea suggest a genetically based migration program, encoding navigation to a destination area used throughout the life.

  17. Insulator speckles associated with long-distance chromatin contacts

    PubMed Central

    Buxa, Melanie K.; Slotman, Johan A.; van Royen, Martin E.; Paul, Maarten W.; Houtsmuller, Adriaan B.

    2016-01-01

    ABSTRACT Nuclear foci of chromatin binding factors are, in many cases, discussed as sites of long-range chromatin interaction in the three-dimensional nuclear space. Insulator binding proteins have been shown to aggregate into insulator bodies, which are large structures not involved in insulation; however, the more diffusely distributed insulator speckles have not been analysed in this respect. Furthermore, insulator binding proteins have been shown to drive binding sites for Polycomb group proteins into Polycomb bodies. Here we find that insulator speckles, marked by the insulator binding protein dCTCF, and Polycomb bodies show differential association with the insulator protein CP190. They differ in number and three-dimensional location with only 26% of the Polycomb bodies overlapping with CP190. By using fluorescence in situ hybridization (FISH) probes to identify long-range interaction (kissing) of the Hox gene clusters Antennapedia complex (ANT-C) and Bithorax complex (BX-C), we found the frequency of interaction to be very low. However, these rare kissing events were associated with insulator speckles at a significantly shorter distance and an increased speckle number. This suggests that insulator speckles are associated with long-distance interaction. PMID:27464669

  18. Marking live conifer pollen for long-distance dispersal experiments.

    PubMed

    Williams, Claire G; von Aderkas, Patrick

    2011-01-01

    Long-distance dispersal (LDD) theory requires a method for marking live LDD pollen. Such a method must complement more intensive sampling methods inclusive of molecular cytogenetics, proteomics and genomics. We developed a new method for marking live Pinus taeda pollen using two dyes, rhodamine 123 and aniline blue, dissolved in a sucrose solution. Marked and unmarked pollen were compared with respect to in vitro germination, storage, terminal velocity, and in vivo pollen tube penetration of ovules. We found that: (1) both types of marked pollen retained their capacity for germination, (2) both types of marked pollen had similar aerodynamic properties when compared to unmarked pollen controls, (3) marked pollen retained its germination capacity for 48 h, and (4) of the marked pollen, only the aniline-marked pollen penetrated ovules during pollination. Germination declined rapidly for both types of marked pollen after 48 h and before 37 days at -20°C storage, while unmarked pollen lots retained 93% germination at all stages. This method for marking live P. taeda pollen is feasible for tracing LDD pollen only if released and deposited within 48 h of dye treatment.

  19. Marking live conifer pollen for long-distance dispersal experiments.

    PubMed

    Williams, Claire G; von Aderkas, Patrick

    2011-01-01

    Study of long-distance dispersal (LDD) theory requires a method for marking live LDD pollen. Such a method must complement the more intensive sampling methods involving molecular cytogenetics, proteomics, and genomics. We have developed a new method for marking live Pinus taeda pollen using two dyes, rhodamine 123 and aniline blue, dissolved in a sucrose solution. Marked and unmarked pollen were compared with respect to in vitro germination, storage, terminal velocity and in vivo pollen-tube penetration of ovules. We found that: (1) both types of marked pollen retained their capacity for germination, (2) both types of marked pollen had similar aerodynamic properties as unmarked pollen controls, (3) marked pollen retained its germination capacity for 48 h, and (4) of the marked pollen, only the aniline-marked pollen penetrated ovules during pollination. Germination declined rapidly for both types of marked pollen after 48 h and before 37 days at -20°C storage, while the unmarked pollen lots retained 93% germination at all stages. Our method for marking live P. taeda pollen is feasible for tracing LDD pollen if released and deposited within 48 h of dye treatment.

  20. Insulator speckles associated with long-distance chromatin contacts.

    PubMed

    Buxa, Melanie K; Slotman, Johan A; van Royen, Martin E; Paul, Maarten W; Houtsmuller, Adriaan B; Renkawitz, Rainer

    2016-09-15

    Nuclear foci of chromatin binding factors are, in many cases, discussed as sites of long-range chromatin interaction in the three-dimensional nuclear space. Insulator binding proteins have been shown to aggregate into insulator bodies, which are large structures not involved in insulation; however, the more diffusely distributed insulator speckles have not been analysed in this respect. Furthermore, insulator binding proteins have been shown to drive binding sites for Polycomb group proteins into Polycomb bodies. Here we find that insulator speckles, marked by the insulator binding protein dCTCF, and Polycomb bodies show differential association with the insulator protein CP190. They differ in number and three-dimensional location with only 26% of the Polycomb bodies overlapping with CP190. By using fluorescence in situ hybridization (FISH) probes to identify long-range interaction (kissing) of the Hox gene clusters Antennapedia complex (ANT-C) and Bithorax complex (BX-C), we found the frequency of interaction to be very low. However, these rare kissing events were associated with insulator speckles at a significantly shorter distance and an increased speckle number. This suggests that insulator speckles are associated with long-distance interaction. © 2016. Published by The Company of Biologists Ltd.

  1. Environmental problems of runners.

    PubMed

    Stanitski, C L

    1985-10-01

    By its very nature, running allows for a freedom that many athletic endeavors lack. The ability to run anytime and anywhere may be detrimental in itself, in that it may allow runners to place themselves in environmental circumstances that are unhealthy. Acclimatization to heat, altitude, and air pollution conditions can occur. Rapid changes in environment brought about by travel may lead to lack of recognition of appropriate clothing or running routes. Usual workout intensities and durations may not be appropriate for the specific environment at hand. Runners are advised to recognize the potential for such problems and make adjustments accordingly.

  2. Research of a long distance clock distribution system

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Hanson, K.; Murchadha, A.; Korntheuer, M.; Meures, T.

    2013-03-01

    Ultrahigh-energy neutrinos with energies in excess of 100 PeV from the GZK effect will be studied using a new detector at the South Pole called the Askaryan Radio Array (ARA). The radiofrequency emission which occurs when these particles interact in the glacial ice is detected by an array of antennas spread out over an enormous area, over 100 km2 and embedded in the ice at depths of 200 m to increase sensitivity. Signals from the antennas are digitized by specialized electronics and must be time synchronized with accuracies of order 50 ps or less for event reconstruction to function properly. A system has been proposed which digitizes the impulse waveforms in situ in the ice and sends the data to the surface using high-speed serial links. This requires distribution of a low-jitter clock to each hole but has substantial advantages in cost and power which drive our development effort to realize this technology. Last year we implemented a first version of a long distance clock synchronization system using electrical signaling over CAT5. This year we have updated our solution to optical fiber using high speed transceiver blocks in Spartan 6 FPGAs. The master clock is embedded into the data stream and distributed to the various holes where a phase-locked derivative is recovered. In this way, we have implemented a 1.25 Gbps data link over a bi-directional communication system fulfilling the requirements of the project. This note describes our efforts on the latter solution: technical details as well as methods of maintaining fixed phase difference between two clocks after power cycle and reset.

  3. Long-Distance Phloem Transport of Glucosinolates in Arabidopsis1

    PubMed Central

    Chen, Sixue; Petersen, Bent Larsen; Olsen, Carl Erik; Schulz, Alexander; Halkier, Barbara Ann

    2001-01-01

    Glucosinolates are a large group of plant secondary metabolites found mainly in the order Capparales, which includes a large number of economically important Brassica crops and the model plant Arabidopsis. In the present study, several lines of evidence are provided for phloem transport of glucosinolates in Arabidopsis. When radiolabeled p-hydroxybenzylglucosinolate (p-OHBG) and sucrose were co-applied to the tip of detached leaves, both tracers were collected in the phloem exudates at the petioles. Long-distance transport of [14C]p-OHBG was investigated in wild-type and transgenic 35S::CYP79A1 plants, synthesizing high amounts of p-OHBG, which is not a natural constituent of wild-type Arabidopsis. In both wild-type and 35S::CYP79A1 plants, radiolabeled p-OHBG was rapidly transported from the application site into the whole plant and intact p-OHBG was recovered from different tissues. The pattern of distribution of the radioactivity corresponded to that expected for transport of photoassimilates such as sucrose, and was consistent with translocation in phloem following the source-sink relationship. Radiolabeled p-OHBG was shown to accumulate in the seeds of wild-type and 35S::CYP79A1 plants, where p-OHBG had been either exogenously applied or endogenously synthesized from Tyr in the leaves. p-OHBG was found in phloem exudates collected from cut petioles of leaves from both wild-type and 35S::CYP79A1 plants. Phloem exudates were shown to contain intact glucosinolates, and not desulphoglucosinolates, as the transport form. It is concluded that intact glucosinolates are readily loaded into and transported by the phloem. PMID:11553747

  4. Go long! Predictors of positive relationship outcomes in long-distance dating relationships.

    PubMed

    Dargie, Emma; Blair, Karen L; Goldfinger, Corrie; Pukall, Caroline F

    2015-01-01

    Little is known about long-distance dating relationships. This study aimed to investigate differences between long-distance dating relationships and geographically close relationships and to explore predictors of relationship quality. Participants were 474 women and 243 men in long-distance dating relationships and 314 women and 111 men in geographically close relationships. Few differences existed between long-distance dating relationships and geographically close relationships, while individual and relationship characteristics predicted relationship quality. These results indicate that individuals in long-distance dating relationships are not at a disadvantage and that relationship and individual characteristics predict relationship quality. This knowledge could be a powerful tool for helping those in long-distance dating relationships.

  5. The Runner's High.

    ERIC Educational Resources Information Center

    Sachs, Michael L.

    Research concerning the euphoric state known as "the runner's high" is reviewed in an attempt to determine psychological factors behind the experience. Possible factors include cerebral dominance, relaxation, environmental influences, time and/or distance of run, and absence of personal problems. A list of references and several descriptions of…

  6. Changes in the markers of cardiac damage in men following long-distance and ultra-long-distance running races.

    PubMed

    Yoon, Jin H; Park, Yongbum; Ahn, Jaeki; Shin, Kyung A; Kim, Young J

    2016-03-01

    The aim of this study was to compare pre- and postcompetition markers of cardiac damage in ultraendurance athletes. All the subjects had blood samples collected before starting and immediately after completing the running race, in order to analyze CK, hs-CRP, cTnI, and NT-proBNP. Before starting the marathon, there were no differences between the groups for all of the tests. CK was significantly higher after the 308 km ultra-marathon than after the marathon and the 100 km ultra-marathon (P<0.001). In cTnI, the value after the 100 km ultra-marathon was significantly higher than that after the marathon and 308 km ultra-marathon, respectively (P<0.05, P<0.01). NT-proBNP was significantly higher after the 100 km and 308 km ultra-marathons than after the marathon (P<0.01, P<0.01). Hs-CRP was significantly higher after the 308 km ultra-marathon than after the marathon and the 100 km ultra-marathon (P<0.001). cTnI was expressed after marathon and the 100 km ultra-marathon, and NT-proBNP exceeding the upper reference limit (URL) was expressed in long-distance races such as the 100 km and 308 km ultra-marathons. The highest expression of cTnI and NT-proBNP exceeding the URL was in the 100 km ultra-marathon, which may be caused by a combination of the moderate intensity of the exercise and the long-running distance.

  7. The Interconnectedness of Diet Choice and Distance Running: Results of the Research Understanding the NutritioN of Endurance Runners (RUNNER) Study.

    PubMed

    Turner-McGrievy, Gabrielle M; Moore, Wendy J; Barr-Anderson, Daheia

    2015-10-19

    This study examined differences in diet, particularly vegetarian and vegan, among ultramarathon and other long distance runners. Participants who had completed a half- (HALF), full- (FULL), or ultramarathon (ULTRA) in the past 12 months were recruited to complete an online survey assessing current diet, reason for diet, and other dietary behaviors. A total of 422 participants completed the survey (n=125 ULTRA, n=152 FULL, n=145 HALF). More ULTRA participants were men (63%) (vs. FULL (37%) and HALF (23%)) and ULTRA participants reported significantly more years of running (16.2 ± 13.6) than FULL (12.1 ± 11.1, P<0.05) or HALF (10.6 ± 11.6, P<0.05). Body Mass Index (self-reported height/weight) was significantly higher in HALF (24.3 ± 4.4 kg/m2) vs. FULL (23.1 ± 3.2 kg/m2, P<0.05). ULTRA runners were almost twice as likely to report following a vegan/vegetarian diet than HALF and FULL marathoners combined (B=1.94, 95% CI=1.08, 3.48) and reported following their current diet longer (13.7±15.3 years) than HALF participants (8.6±12.1 years, P=0.01). ULTRA participants more commonly cited environmental concerns whereas HALF and FULL participants cited weight loss or maintenance as a reason for following their current diet. There was no difference in diet quality between ULTRA and other runners but vegan and vegetarian runners had higher diet quality scores than non-vegetarian runners (P<0.001). The findings point to an interconnectedness between long distance running, diet, and diet choice and can help guide nutrition, exercise, and psychology professionals who are working with distance runners.

  8. How do elite endurance runners alter movements of the spine and pelvis as running speed increases?

    PubMed

    Preece, Stephen J; Mason, Duncan; Bramah, Christopher

    2016-05-01

    Elite endurance runners are characterised by their performance ability and higher running economy. However, there is relatively little research aimed at identifying the biomechanical characteristics of this group. This study aimed to understand how motions of the pelvis, lumbar spine and thorax change with speed in a cohort of elite endurance runners (n=14) and a cohort of recreational runners (n=14). Kinematic data were collected during over ground running at four speeds ranging from 3.3 to 5.6ms(-1) and a linear mixed model used to understand the effect of speed on both range of motion and mean sagittal inclination. The results showed the two groups to exhibit similar changes in range of motion as speed was increased, with the most pronounced increases being observed in the transverse plane. However, the adaptation of thorax inclination with speed differed between the two groups. Whereas the recreational runners increased thorax inclination as running speed was increased, elite endurance runners consistently maintained a more upright thorax position. This is the first study to identify specific differences in upper body motions between recreational and elite runners and the findings may have implications for training protocols aimed at improving running performance.

  9. Energy cost of swimming of elite long-distance swimmers.

    PubMed

    Zamparo, P; Bonifazi, M; Faina, M; Milan, A; Sardella, F; Schena, F; Capelli, C

    2005-08-01

    The aim of this study was: (1) to assess the energy cost of swimming (C(s), kJ km(-1)) in a group of male (n = 5) and female (n = 5) elite swimmers specialised in long-distance competitions; (2) to evaluate the possible effect of a 2-km trial on the absolute value of C(s). C(s) was assessed during three consecutive 400-m trials covered in a 50-m pool at increasing speeds (v1, v2, v3). After these experiments the subjects swam a 2-km trial at the 10-km race speed (v2km) after which the three 400-m trials were repeated at the same speed as before (v5 = v1, v6 = v2, v7 = v3). C(s) was calculated by dividing the net oxygen uptake at steady state VO2ss by the corresponding average speed (v, m s(-1)). VO2ss was estimated by using back extrapolation technique from breath-to-breath VO2 recorded during the first 30 s of recovery after each test. C(s) increased (from 0.69 kJ m(-1) to 1.27 kJ m(-1)) as a function of v (from 1.29 m s(-1) to 1.50 m s(-1)), its values being comparable to those measured in elite short distance swimmers at similar speeds. In both groups of subjects the speed maintained during the 2-km trial (v2km) was on the average only 1.2% faster than of v2 and v6 (P>0.05), whereas C(s) assessed at the end of the 2-km trial (v2km) turned out to be 21 +/- 26% larger than that assessed at v2 and v6 (P<0.05); the average stroke frequency (SF, cycles min(-1)) during the 2-km trial turned to be about 6% (P<0.05) faster than that assessed at v2 and v6. At v5, C(s) turned out to be 19 +/- 9% (P<0.05) and 22 +/- 27% (0.1 < P = 0.05) larger than at v1 in male and female subjects (respectively). SF was significantly faster (P<0.05, in male subjects) and the distance per stroke (Ds = v/SF) significantly shorter (P<0.05) in female subjects at v5 and v6 than at v1 and v2. These data suggest that the increase of C(s) found after the 2-km trial was likely related to a decrease in propelling efficiency, since the latter is related to the distance per stroke.

  10. Testing the Limits of Long-Distance Learning: Learning beyond a Three-Segment Window

    ERIC Educational Resources Information Center

    Finley, Sara

    2012-01-01

    Traditional flat-structured bigram and trigram models of phonotactics are useful because they capture a large number of facts about phonological processes. Additionally, these models predict that local interactions should be easier to learn than long-distance ones because long-distance dependencies are difficult to capture with these models.…

  11. 47 CFR 90.266 - Long distance communications on frequencies below 25 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Long distance communications on frequencies below 25 MHz. 90.266 Section 90.266 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... Frequency Bands § 90.266 Long distance communications on frequencies below 25 MHz. (a) The use of any...

  12. 47 CFR 90.266 - Long distance communications on frequencies below 25 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Long distance communications on frequencies below 25 MHz. 90.266 Section 90.266 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... Frequency Bands § 90.266 Long distance communications on frequencies below 25 MHz. (a) The use of any...

  13. Testing the Limits of Long-Distance Learning: Learning beyond a Three-Segment Window

    ERIC Educational Resources Information Center

    Finley, Sara

    2012-01-01

    Traditional flat-structured bigram and trigram models of phonotactics are useful because they capture a large number of facts about phonological processes. Additionally, these models predict that local interactions should be easier to learn than long-distance ones because long-distance dependencies are difficult to capture with these models.…

  14. Long distance, unconditional teleportation of atomic states via complete Bell state measurements.

    PubMed

    Lloyd, S; Shahriar, M S; Shapiro, J H; Hemmer, P R

    2001-10-15

    We propose a scheme for creating and storing quantum entanglement over long distances. Optical cavities that store this long-distance entanglement in atoms could then function as nodes of a quantum network, in which quantum information is teleported from cavity to cavity. The teleportation is conducted unconditionally via measurements of all four Bell states, using a novel method of sequential elimination.

  15. Seasonal Strength Performance and Its Relationship with Training Load on Elite Runners

    PubMed Central

    Balsalobre-Fernández, Carlos; Tejero-González, Carlos M.; del Campo-Vecino, Juan

    2015-01-01

    The aim of this study was to analyze the time-course of force production of elite middle and long-distance runners throughout an entire season and at the end of the off-season, as well as its relationships with training load and hormonal responses. Training load was recorded daily throughout an entire season by measuring and evaluating the session distance (km), training zone and session-RPE in a group of 15 elite middle and long-distance runners (12 men, 3 women; age = 26.3 ± 5.1yrs, BMI = 19.7 ± 1.1). Also, basal salivary-free cortisol levels were measured weekly, and 50-metre sprints, mean propulsive velocity (MPV), mean propulsive power (MPP), repetition maximum (RM) and peak rate of force development (RFD) of half-squats were measured 4 times during the season, and once more after the off-season break. There were no significant variations in force production during the season or after the off-season break, except for the RFD (-30.2%, p = 0.005) values, which changed significantly from the beginning to the end of the season. Significant correlations were found between session-RPE and MPV (r = -0.650, p = 0.004), MPP (r = -0.602, p = 0.009), RM (r = -0.650, p = 0.004), and the 50-metre sprint (r = 0.560, p = 0.015). Meanwhile, salivary-free cortisol correlated significantly with the 50-metre sprint (r = 0.737, p < 0.001) and the RM ( r = -0.514, p = 0.025). Finally, the training zone correlated with the 50-metre sprint (r = -0.463, p = 0.041). Session-RPE, training zone and salivary-free cortisol levels are related to force production in elite middle and long-distance runners. Monitoring these variables could be a useful tool in controlling the training programs of elite athletes. Key points Session-RPE, training zone and salivary free cortisol levels correlate significantly with strength-related variables in middle and long-distance elite runners. A month of active rest during the off-season break is enough to prevent decreases in force production of such

  16. Seasonal strength performance and its relationship with training load on elite runners.

    PubMed

    Balsalobre-Fernández, Carlos; Tejero-González, Carlos M; Del Campo-Vecino, Juan

    2015-03-01

    The aim of this study was to analyze the time-course of force production of elite middle and long-distance runners throughout an entire season and at the end of the off-season, as well as its relationships with training load and hormonal responses. Training load was recorded daily throughout an entire season by measuring and evaluating the session distance (km), training zone and session-RPE in a group of 15 elite middle and long-distance runners (12 men, 3 women; age = 26.3 ± 5.1yrs, BMI = 19.7 ± 1.1). Also, basal salivary-free cortisol levels were measured weekly, and 50-metre sprints, mean propulsive velocity (MPV), mean propulsive power (MPP), repetition maximum (RM) and peak rate of force development (RFD) of half-squats were measured 4 times during the season, and once more after the off-season break. There were no significant variations in force production during the season or after the off-season break, except for the RFD (-30.2%, p = 0.005) values, which changed significantly from the beginning to the end of the season. Significant correlations were found between session-RPE and MPV (r = -0.650, p = 0.004), MPP (r = -0.602, p = 0.009), RM (r = -0.650, p = 0.004), and the 50-metre sprint (r = 0.560, p = 0.015). Meanwhile, salivary-free cortisol correlated significantly with the 50-metre sprint (r = 0.737, p < 0.001) and the RM ( r = -0.514, p = 0.025). Finally, the training zone correlated with the 50-metre sprint (r = -0.463, p = 0.041). Session-RPE, training zone and salivary-free cortisol levels are related to force production in elite middle and long-distance runners. Monitoring these variables could be a useful tool in controlling the training programs of elite athletes. Key pointsSession-RPE, training zone and salivary free cortisol levels correlate significantly with strength-related variables in middle and long-distance elite runners.A month of active rest during the off-season break is enough to prevent decreases in force production of such

  17. Contributions of long-distance dispersal to population growth in colonising Pinus ponderosa populations.

    PubMed

    Lesser, Mark R; Jackson, Stephen T

    2013-03-01

    Long-distance dispersal is an integral part of plant species migration and population development. We aged and genotyped 1125 individuals in four disjunct populations of Pinus ponderosa that were initially established by long-distance dispersal in the 16th and 17th centuries. Parentage analysis was used to determine if individuals were the product of local reproductive events (two parents present), long-distance pollen dispersal (one parent present) or long-distance seed dispersal (no parents present). All individuals established in the first century at each site were the result of long-distance dispersal. Individuals reproduced at younger ages with increasing age of the overall population. These results suggest Allee effects, where populations were initially unable to expand on their own, and were dependent on long-distance dispersal to overcome a minimum-size threshold. Our results demonstrate that long-distance dispersal was not only necessary for initial colonisation but also to sustain subsequent population growth during early phases of expansion.

  18. Interpersonal conflict and health perceptions in long-distance caregiving relationships.

    PubMed

    Bevan, Jennifer L; Vreeburg, Sean K; Verdugo, Sherri; Sparks, Lisa

    2012-08-01

    With job markets expanding globally and life expectancy continually increasing, more demands are being placed on distant relatives to provide care for their aging family members, creating a health care situation known as long-distance caregiving. An online survey explored the relations between negative health perceptions by long-distance caregivers and conflict frequency and conflict strategy usage. The authors observed positive significant relations between distant caregiver negative health perceptions and conflict frequency and usage of the distributive and avoidance conflict strategies. However, they observed no significant associations between distant caregiver negative health perceptions and usage of the two integrative strategies. Implications for long-distance caregiving communication are discussed.

  19. Rapid advance of spring arrival dates in long-distance migratory birds.

    PubMed

    Jonzén, Niclas; Lindén, Andreas; Ergon, Torbjørn; Knudsen, Endre; Vik, Jon Olav; Rubolini, Diego; Piacentini, Dario; Brinch, Christian; Spina, Fernando; Karlsson, Lennart; Stervander, Martin; Andersson, Arne; Waldenström, Jonas; Lehikoinen, Aleksi; Edvardsen, Erik; Solvang, Rune; Stenseth, Nils Chr

    2006-06-30

    Several bird species have advanced the timing of their spring migration in response to recent climate change. European short-distance migrants, wintering in temperate areas, have been assumed to be more affected by change in the European climate than long-distance migrants wintering in the tropics. However, we show that long-distance migrants have advanced their spring arrival in Scandinavia more than short-distance migrants. By analyzing a long-term data set from southern Italy, we show that long-distance migrants also pass through the Mediterranean region earlier. We argue that this may reflect a climate-driven evolutionary change in the timing of spring migration.

  20. Re-creating Recreation.

    ERIC Educational Resources Information Center

    Cohen, Andrew

    1999-01-01

    Discusses the importance of the Architectural and Transportation Barriers Compliance Board guidelines for recreational and sports areas and their ancillary spaces. Examples of how the guidelines affect specific areas are highlighted, such as team seating areas, fitness centers, tennis courts, swimming pools, and locker rooms. (GR)

  1. Regional economic impacts of Grand Canyon river runners.

    PubMed

    Hjerpe, Evan E; Kim, Yeon-Su

    2007-10-01

    Economic impact analysis (EIA) of outdoor recreation can provide critical social information concerning the utilization of natural resources. Outdoor recreation and other non-consumptive uses of resources are viewed as environmentally friendly alternatives to extractive-type industries. While outdoor recreation can be an appropriate use of resources, it generates both beneficial and adverse socioeconomic impacts on rural communities. The authors used EIA to assess the regional economic impacts of rafting in Grand Canyon National Park. The Grand Canyon region of northern Arizona represents a rural US economy that is highly dependent upon tourism and recreational expenditures. The purpose of this research is twofold. The first is to ascertain the previously unknown regional economic impacts of Grand Canyon river runners. The second purpose is to examine attributes of these economic impacts in terms of regional multipliers, leakage, and types of employment created. Most of the literature on economic impacts of outdoor recreation has focused strictly on the positive economic impacts, failing to illuminate the coinciding adverse and constraining economic impacts. Examining the attributes of economic impacts can highlight deficiencies and constraints that limit the economic benefits of recreation and tourism. Regional expenditure information was obtained by surveying non-commercial boaters and commercial outfitters. The authors used IMPLAN input-output modeling to assess direct, indirect, and induced effects of Grand Canyon river runners. Multipliers were calculated for output, employment, and income. Over 22,000 people rafted on the Colorado River through Grand Canyon National Park in 2001, resulting in an estimated $21,100,000 of regional expenditures to the greater Grand Canyon economy. However, over 50% of all rafting-related expenditures were not captured by the regional economy and many of the jobs created by the rafting industry are lower-wage and seasonal. Policy

  2. Long-distance dispersal of eastern spruce budworm in Minnesota (USA) via the atmospheric pathway

    Treesearch

    Brian Sturtevant; Gary Achtemeier; Dean Anderson; Joseph Charney; Barry. Cooke

    2011-01-01

    Long-distance dispersal is thought to play an important role in synchronizing disparate populations of forest insect defoliators, but its importance relative to other factors remains unclear due to the difficulty of quantifying dispersal.

  3. [Evidence of long distance migration of diamondback moth (DBM) Plutella xylostella: a review].

    PubMed

    Xing, Kun; Ma, Chun-Sen; Han, Ju-Cai

    2013-06-01

    As cruciferous plants have been cultivated northwards due to climate warming, diamondback moth (DBM) Plutella xylostella is becoming a major pest in North China. The long distance migration of DBM not only induces its sudden outbreak over extensive areas, but also leads to its insecticide resistance by the spread of resistant genes in large area. To elucidate the long distance migration of DBM is of significance for early warning and decision-making in integrated pest managements. So far, the migration of DBM has not yet been systematically investigated in China. Here, we reviewed the literatures about the long distance migration of DBM at home and abroad, and summarized the related evidence: 1) DBM cannot overwinter in cold regions such as northern Japan, western Canada, and northeast China, where the DBM outbreak is presumed from elsewhere by long distance migration, 2) DBM adults are captured from seas, mountain tops, sea islands, and sky, etc., and the collection of large quantity of DBM presents the powerful direct evidence of DBM long distance migration, 3) the sudden increase of DBM in fields is consistent with the meteorological conditions such as the presence of nocturnal temperature inversion layer and the front passage, suggesting that these meteorological conditions supply suitable backgrounds for the insect migration, 4) the target insect characters identified by vertical insect looking radar is consistent with the measured DBM characters in laboratory and the trapping data from fields, confirming the long distance migration of DBM, 5) the biological characteristics and genetic variations of different DBM populations have no correlations with geographic distance, suggesting the frequent gene flows among the populations in different positions, and 6) the flight test of DBM indicates its long distance flight capacity, and the decreasing fitness of host plants is probably one of the trigger factors for the migration of DBM. Some future research directions

  4. Differences in MCT1 A1470T polymorphism prevalence between runners and swimmers.

    PubMed

    Ben-Zaken, S; Eliakim, A; Nemet, D; Rabinovich, M; Kassem, E; Meckel, Y

    2015-06-01

    Skeletal muscle is the major producer and user of lactate in the body. Therefore, transport of lactate across cells' membrane is of considerable importance. Lactate transport is mediated by proton-linked monocarboxylate transporter (MCT1). The A1470T polymorphism (rs1049434) in MCT1 gene influences lactate transport, with T allele associated with reduction of lactate transport rate and elevation in blood lactate levels. The aim of the current study was to compare allelic and genotype frequencies of MCT1 A1470T polymorphism among Israeli track-and-field athletes, swimmers, and non-athletes. Genomic DNA was extracted from 173 track-and-field athletes (age 17-50), 80 swimmers (age 16-49), and 128 non-athletes (age 19-29). Track-and-field athletes were assigned to three subgroups: long-distance runners, middle-distance runners, and power event athletes. Swimmers were assigned to two subgroups: long-distance swimmers and short-distance swimmers. Genotyping was performed using polymerase chain reaction. T-allele frequency was significantly higher among long-distance swimmers (45%) compared with long- and middle-distance runners (27% and 30%, respectively; P < 0.01). In addition, T-allele frequency was significantly higher among short-distance swimmers (40%) compared with power event athletes (25%, P < 0.01). Overall, T-allele frequency was significantly higher among swimmers (42%) compared with runners (27%, P < 0.001). More research is needed to clarify whether this polymorphism displays advantage for swimming performance.

  5. Injuries and Health Considerations in Ultramarathon Runners.

    PubMed

    Hoffman, Martin D

    2016-02-01

    Ultramarathon runners are a relatively small and unique group of distance runners with somewhat different medical issues than other distance runners. This article outlines some of those differences so that clinicians caring for these runners in the clinic or at competitions might be better prepared.

  6. Long-distance movement factor: a transport function of the potyvirus helper component proteinase.

    PubMed Central

    Cronin, S; Verchot, J; Haldeman-Cahill, R; Schaad, M C; Carrington, J C

    1995-01-01

    Transport of viruses from cell to cell in plants typically involves one or more viral proteins that supply dedicated movement functions. Transport from leaf to leaf through phloem, or long-distance transport, is a poorly understood process with requirements differing from those of cell-to-cell movement. Through genetic analysis of tobacco etch virus (TEV; potyvirus group), a novel long-distance movement factor was identified that facilitates vascular-associated movement in tobacco. A mutation in the central region of the helper component proteinase (HC-Pro), a TEV-encoded protein with previously described activities in aphid-mediated transmission and polyprotein processing, inactivated long-distance movement. This mutant virus exhibited only minor defects in genome amplification and cell-to-cell movement functions. In situ histochemical analysis revealed that the mutant was capable of infecting mesophyll, bundle sheath, and phloem cells within inoculated leaves, suggesting that the long-distance movement block was associated with entry into or exit from sieve elements. The long-distance movement defect was specifically complemented by HC-Pro supplied in trans by a transgenic host. The data indicate that HC-Pro functions in one or more steps unique to long-distance transport. PMID:7780307

  7. Runner's knee injuries.

    PubMed

    Lutter, L D

    1984-01-01

    In our series of running injuries 40% of all injuries have been related to the knee area. Over 20 million people in the United States run on a regular basis. Figures from large running sources show that 60% to 70% of individuals running regularly are injured severely enough to temporarily stop running. The figures are significant, not in the seriousness of the knee injury, but in the fact that seeking treatment for their knee problems. Orthopaedic surgeons, because of their ability to evaluate the entire lower extremity, become the central component for treatment of this large group of injured runners. As has been noted, the underlying biomechanical abnormality must be sought and dealt with or the symptoms return. By identification of the injured structure(s) integrated with biomechanical understanding, treatment can be developed on a rational basis, dealing with acute problems and prevention of future ones.

  8. Grafting of water turbines runner

    SciTech Connect

    Yang, I.T.

    1983-12-01

    It is possible to graft upon or hybridize two different types of water turbines' runner in order to attain more perfect performance to meeting engineering needs. The answer is positive and very interesting, as shown in the research experiment in the Hydromachines Laboratory of Gansu University of Technology. Grafting a group of propeller blades (Ns=440 N.KW) on a Francis turbine runner (Ns=200) with certain boundary conditions in the flow areas, a new hybrid multiplex runner performance has been achieved. Its efficiency curve has been improved at high speed and large flow rate operating conditions that could be able to meet the engineering requirements when the head of the hydropower station is lower than normal. Its unit rotation speed is increased about 25% over that of the Francis. The general performance curve of this hybrid runner will be provided in this paper.

  9. Lower limb dynamics vary in shod runners who acutely transition to barefoot running.

    PubMed

    Hashish, Rami; Samarawickrame, Sachithra D; Powers, Christopher M; Salem, George J

    2016-01-25

    Relative to traditional shod rear-foot strike (RFS) running, habituated barefoot running is associated with a forefoot-strike (FFS) and lower loading rates. Accordingly, barefoot running has been purported to reduce lower-extremity injury risk. Investigations, however, indicate that novice barefoot runners may not innately adopt a FFS. Therefore, the purpose of this study was to examine lower-extremity dynamics of habitually shod runners who acutely transition to barefoot running. 22 recreational RFS runners were included in this investigation. This laboratory controlled study consisted of two visits one-week apart, examining habitually shod, then novice barefoot running. Foot-strike patterns and loading rates were determined using motion analysis and force plates, and joint energy absorption was calculated using inverse dynamics. Of the 22 runners, 8 maintained a RFS, 9 adopted a MFS, and 5 adopted a FFS during novice barefoot running. All runners demonstrated a reduction in knee energy absorption when running barefoot; MFS and FFS runners also demonstrated a significant increase in ankle energy absorption. Runners who maintained a RFS presented with loading rates significantly higher than traditional shoe running, whereas FFS runners demonstrated a significant reduction in loading rate. Mid-foot strikers did not demonstrate a significant change in loading rate. These results indicate that habitually shod RFS runners demonstrate a variety of foot-strike and lower-extremity dynamic responses during the acute transition to barefoot running. Accordingly, explicit instruction regarding foot-strike patterns may be necessary if transitioning to barefoot. Long-term prospective studies are required in order to determine the influence of FFS barefoot running on injury rates.

  10. Testing the limits of long-distance learning: learning beyond a three-segment window.

    PubMed

    Finley, Sara

    2012-01-01

    Traditional flat-structured bigram and trigram models of phonotactics are useful because they capture a large number of facts about phonological processes. Additionally, these models predict that local interactions should be easier to learn than long-distance ones because long-distance dependencies are difficult to capture with these models. Long-distance phonotactic patterns have been observed by linguists in many languages, who have proposed different kinds of models, including feature-based bigram and trigram models, as well as precedence models. Contrary to flat-structured bigram and trigram models, these alternatives capture unbounded dependencies because at an abstract level of representation, the relevant elements are locally dependent, even if they are not adjacent at the observable level. Using an artificial grammar learning paradigm, we provide additional support for these alternative models of phonotactics. Participants in two experiments were exposed to a long-distance consonant-harmony pattern in which the first consonant of a five-syllable word was [s] or [∫] ("sh") and triggered a suffix that was either [-su] or [-∫u] depending on the sibilant quality of this first consonant. Participants learned this pattern, despite the large distance between the trigger and the target, suggesting that when participants learn long-distance phonological patterns, that pattern is learned without specific reference to distance. Copyright © 2012 Cognitive Science Society, Inc.

  11. Ultrasound diagnosis of Achilles tendon pathology in runners.

    PubMed Central

    Maffulli, N; Regine, R; Angelillo, M; Capasso, G; Filice, S

    1987-01-01

    The great upsurge in popularity of running activities has increased the number of athletes presenting with pathology of the Achilles tendon. A clinical and ultrasonic study was performed on 47 middle and long distance runners referred to the Authors with such problems. The results of this study can be grouped as follows: 1. paratendonitis: enlargement of the antero-posterior diameter of the tendon, and hyperechogenicity of Kager's triangle; 2. tendonitis (with or without paratendonitis): thickening of the tendon, with the presence of degenerative nodules; 3. enthesopathy: thickening of the distal part of the tendon, enlargement of the hypoechogenic area behind the tendon itself and microcalcification. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:3325127

  12. Recreation monitoring

    SciTech Connect

    DiGennaro, B.; Merklein, G.H.

    1995-12-31

    Recreational use and recreational facilities are common features at hydropower projects. In fact, the hydropower industry is a major supplier of recreational opportunities contributing to tourism and rural economic growth in many communities across the country, As demands for public recreation have grown, pressure on the hydropower industry to provide more public access and more facilities has increased. This paper looks at recent developments in the FERC licensing and compliance arenas with regard to planning for and monitoring recreation at hydropower facilities. The paper highlights the increased occurrence of recreation monitoring requirements in license articles and discusses methods for complying with such requirements. The paper also looks at how monitoring data can be used to avoid unnecessary developments and to better plan for future recreation use.

  13. Phloem RNA-binding proteins as potential components of the long-distance RNA transport system

    PubMed Central

    Pallas, Vicente; Gómez, Gustavo

    2013-01-01

    RNA-binding proteins (RBPs) govern a myriad of different essential processes in eukaryotic cells. Recent evidence reveals that apart from playing critical roles in RNA metabolism and RNA transport, RBPs perform a key function in plant adaptation to various environmental conditions. Long-distance RNA transport occurs in land plants through the phloem, a conducting tissue that integrates the wide range of signaling pathways required to regulate plant development and response to stress processes. The macromolecules in the phloem pathway vary greatly and include defense proteins, transcription factors, chaperones acting in long-distance trafficking, and RNAs (mRNAs, siRNAs, and miRNAs). How these RNA molecules translocate through the phloem is not well understood, but recent evidence indicates the presence of translocatable RBPs in the phloem, which act as potential components of long-distance RNA transport system. This review updates our knowledge on the characteristics and functions of RBPs present in the phloem. PMID:23675378

  14. Role of cucumovirus capsid protein in long-distance movement within the infected plant.

    PubMed Central

    Taliansky, M E; García-Arenal, F

    1995-01-01

    Direct evidence is presented for a host-specific role of the cucumovirus capsid protein in long-distance movement within infected plants. Cucumber (Cucumis sativus L.) is a systemic host for cucumber mosaic cucumovirus (CMV). Tomato aspermy cucumovirus, strain 1 (1-TAV), multiplied to the levels of CMV (i.e., replicated, moved from cell to cell, and formed infectious particles) in the inoculated leaves of cucumbers but was completely unable to spread systemically. The defective long-distance systemic movement of 1-TAV was complemented by CMV in mixed infections. Coinfection of cucumbers with 1-TAV RNA with various combinations of transcripts from full-length cDNA clones of CMV genomic RNA 1, RNA2, and RNA3 showed that CMV RNA3 alone complemented 1-TAV long-distance movement. We obtained mutants containing mutations in the two open reading frames in CMV RNA3 encoding the 3a protein and the capsid protein (CP), both of which are necessary for cell-to-cell movement of CMV. Complementation experiments with mutant CMV RNA3 showed that only 3a protein mutants, i.e., those with an intact CP, complemented the long-distance movement of 1-TAV in cucumbers. Since CMV and TAV have common systemic host plants, the results presented here are strong evidence for an active, host-specific function of the CPs of these two cucumoviruses for long-distance spread in the phloem. The results also suggest that the plasmodesmata in the vascular system and/or at the boundary between the mesophyll and the vascular system, involved in long-distance movement through the phloem, and those in the mesophyll, involved in cell-to-cell movement, differ functionally. PMID:7815560

  15. Executive overview: welfare aspects of the long distance transportation of animals.

    PubMed

    Adams, David B; Thornber, Peter M; Murray, Gardner

    2008-01-01

    A compendium of papers brings together a range of perspectives on the long distance transportation of animals. The purpose is to assist in the strengthening of global public policies for the protection of animal health and welfare. The audience targeted is the wide range of people involved in shaping sound public policy. Papers cover the history of long distance transportation of animals, the viewpoints of the foremost civil society organisations involved in the long distance transport of animals, how various governments approach public policy on the subject, the implementation of quality management for the transportation of different species of animals in different situations, future directions for quality management, design and engineering of infrastructures, transport safety and animal welfare and the education and training necessary for the successful management of animal welfare during long distance transportation. A seamless connection between animal health and animal welfare is an absolute necessity given the critical importance of animal movements in the spread of infection and the devastation to animal and human welfare produced by infectious disease. A compendium of papers brings together a range of perspectives on the long distance transportation of animals. The purpose is to assist in the strengthening of global public policies for the protection of animal health and welfare. The audience targeted is the wide range of people involved in shaping sound public policy. Papers cover the history of long distance transportation of animals, the viewpoints of the foremost civil society organisations involved in the long distance transport of animals, how various governments approach public policy on the subject, the implementation of quality management for the transportation of different species of animals in different situations, future directions for quality management, design and engineering of infrastructures, transport safety and animal welfare and the

  16. Metabolic and hormonal changes during aerobic exercise in distance runners.

    PubMed

    Fernández-Pastor, V J; Ruiz, M; Diego-Acosta, A M; Avila, C; García, J C; Pérez, F; Guirado, F; Noguer, N

    1999-03-01

    A group of long-distance runners is studied in order to clarify aspects concerning neuroendocrine mechanisms regulating organic adaptation to maximum effort, with special interest in the function of the growth hormone in fat metabolism and the possible use of ketone bodies as an alternative source of energy. A test is designed on a treadmill with a gradient of 3% and progressive increases in speed of 2 Km/h every 10 min, starting at 6 Km/h, and continuing until exhaustion. Masks are worn to enable the breath by breath measurement of expired gases and the subjects are monitored electrocardiographically using V5. For blood sample collection an antecubital vein is catheterized with a system enabling the replacement of the blood volume extracted by means of perfusion with physiological saline solution, and the increasing concentration of hormones in the blood is evaluated. The results obtained, indicate that epinephrine as well as GH hormones increase significatively from 20 min of exercise in runners promoting changes from carbohydrates to lipids as fuels to carry out exercise. The concomitant variations in energy substrates support the former hypothesis of work. Moreover, the muscle could employ acetylCoA originating from acetoacetate as an alternative metabolic source of fuel during maximum effort.

  17. Unconditional security proof of long-distance continuous-variable quantum key distribution with discrete modulation.

    PubMed

    Leverrier, Anthony; Grangier, Philippe

    2009-05-08

    We present a continuous-variable quantum key distribution protocol combining a discrete modulation and reverse reconciliation. This protocol is proven unconditionally secure and allows the distribution of secret keys over long distances, thanks to a reverse reconciliation scheme efficient at very low signal-to-noise ratio.

  18. Phenological differences among selected residents and long-distance migrant bird species in central Europe

    NASA Astrophysics Data System (ADS)

    Bartošová, Lenka; Trnka, Miroslav; Bauer, Zdeněk; Možný, Martin; Štěpánek, Petr; Žalud, Zdeněk

    2014-07-01

    The phenological responses to climate of residents and migrants (short- and long-distance) differ. Although few previous studies have focussed on this topic, the agree that changes in phenology are more apparent for residents than for long-distance migrants. We analysed the breeding times of two selected residents ( Sitta europaea, Parus major) and one long-distance migrant ( Ficedula albicollis) from 1961 to 2007 in central Europe. The timing of the phenophases of all three bird species showed a significant advance to earlier times. Nevertheless, the most marked shift was observed for the long-distance migrant (1.9 days per decade on average in mean laying date with linearity at the 99.9 % confidence level). In contrast, the shifts shown by the residents were smaller (1.6 days for S. europaea and 1.5 days for P. major also on average in mean laying date for both, with linearity at the 95 % confidence level). Spearman rank correlation coefficients calculated for pairs of phenophases of given bird species in 20-year subsamples (e.g. 1961-1980, 1962-1981) showed higher phenological separation between the residents and the migrant. This separation is most apparent after the 1980s. Thus, our results indicate that the interconnections between the studied phenological stages of the three bird species are becoming weaker.

  19. Phenological differences among selected residents and long-distance migrant bird species in central Europe

    NASA Astrophysics Data System (ADS)

    Bartošová, Lenka; Trnka, Miroslav; Bauer, Zdeněk; Možný, Martin; Štěpánek, Petr; Žalud, Zdeněk

    2013-05-01

    The phenological responses to climate of residents and migrants (short- and long-distance) differ. Although few previous studies have focussed on this topic, the agree that changes in phenology are more apparent for residents than for long-distance migrants. We analysed the breeding times of two selected residents (Sitta europaea, Parus major) and one long-distance migrant (Ficedula albicollis) from 1961 to 2007 in central Europe. The timing of the phenophases of all three bird species showed a significant advance to earlier times. Nevertheless, the most marked shift was observed for the long-distance migrant (1.9 days per decade on average in mean laying date with linearity at the 99.9 % confidence level). In contrast, the shifts shown by the residents were smaller (1.6 days for S. europaea and 1.5 days for P. major also on average in mean laying date for both, with linearity at the 95 % confidence level). Spearman rank correlation coefficients calculated for pairs of phenophases of given bird species in 20-year subsamples (e.g. 1961-1980, 1962-1981) showed higher phenological separation between the residents and the migrant. This separation is most apparent after the 1980s. Thus, our results indicate that the interconnections between the studied phenological stages of the three bird species are becoming weaker.

  20. [Onyx embolization for treatment of dural arteriovenous fistula: comparison of long- distance versus routine injection method].

    PubMed

    He, Xiao-Yan; Zhang, Guo-Zhong; Li, Ming-Zhou; Wang, Gang; Liu, Dan; Qi, Song-Tao; Li, Wei-Guang; Feng, Wen-Feng

    2016-03-01

    To compare the efficacy, clinical characteristics, safety, injection time and radiation exposure of Onyx embolization using a long-distance injection method and routine injection method for management of dural arteriovenous fistula (DAVF). The clinical data were retrospectively analyzed in 59 patients with DAVF treated with Onyx embolization using long-distance injection method (28 patients) and routine injection method (31 patients). The efficacy, safety, injection time and radiation exposure during Onyx embolization were compared between the two injections methods. The average radiation dose exposure to the surgeon per procedure was significantly lower in the long-distance injection group than in the routine group. The injection time (P=0.53), injection volume (P=0.78), number of supply arteries (P=0.80), Cognard types (P=0.67), and effect of embolization (P=0.88) were all similar between the two groups. Endovaseular treatment of intracranial DAVF with Onyx embolization using the long-distance injection method is feasible, safe and effective and can reduce the radiation exposure to the surgeon.

  1. Necessity Fuels Creativity: Adapting Long-Distance Collaborative Methods for the Classroom

    ERIC Educational Resources Information Center

    Sopoci Drake, Katie; Larson, Eliza; Rugh, Rachel; Tait, Barbara

    2016-01-01

    Improved technology has made it possible to virtually bridge distance between dance makers, rendering physical location another choreographic device to be manipulated. Long-distance collaboration as an artistic process is not only a fertile new ground for creation and necessary for many practicing dance artists in the field today, but there is…

  2. Arts Go the Distance: Creating a Low-Budget, Long-Distance Collaboration

    ERIC Educational Resources Information Center

    Shafer, John; Brown, George; Boyd, Be; Marino, Danielle; Merritt, Don

    2005-01-01

    The authors' experiments with long-distance arts collaboration in a multiform environment began in July 2002. They consider a multiform environment to be an interactive environment where different audiences experience a shared event from different and mutually exclusive frames of reference. The Dynamic Media Project team members had extensive…

  3. Long-Distance and Proximal Romantic Relationship Satisfaction: Attachment and Closeness Predictors

    ERIC Educational Resources Information Center

    Roberts, Amber; Pistole, M. Carole

    2009-01-01

    Relationship satisfaction was examined in college student long-distance romantic relationships (LDRRs) and geographically proximal romantic relationships (PRRs). LDRR/PRR attachment style proportions and relationship satisfaction were similar. Multiple regression analyses revealed that low attachment avoidance contributed uniquely to high LDRR…

  4. Necessity Fuels Creativity: Adapting Long-Distance Collaborative Methods for the Classroom

    ERIC Educational Resources Information Center

    Sopoci Drake, Katie; Larson, Eliza; Rugh, Rachel; Tait, Barbara

    2016-01-01

    Improved technology has made it possible to virtually bridge distance between dance makers, rendering physical location another choreographic device to be manipulated. Long-distance collaboration as an artistic process is not only a fertile new ground for creation and necessary for many practicing dance artists in the field today, but there is…

  5. Behind-the-Scenes: Designing a Long-Distance Course on Geriatric Interdisciplinary Teaming

    ERIC Educational Resources Information Center

    Welleford, E.; Parham, Iris; Coogle, Constance; Netting, F.

    2004-01-01

    In this paper, the design and development of a long-distance course on geriatric interdisciplinary teaming are presented. The focus is on the conceptualization of the course, followed by details surrounding developing a design team; designing curricular content; deciding delivery methods; scripting; overseeing and editing videos; and determining…

  6. Population genetics strategies to characterize long-distance dispersal of insects

    USDA-ARS?s Scientific Manuscript database

    Population genetics strategies offer an alternative and powerful approach for obtaining information about long-distance movement, and have been widely used for examining patterns and magnitude of insect dispersal over geographic and temporal scales. Such strategies are based on the principle that ge...

  7. Long-Distance and Proximal Romantic Relationship Satisfaction: Attachment and Closeness Predictors

    ERIC Educational Resources Information Center

    Roberts, Amber; Pistole, M. Carole

    2009-01-01

    Relationship satisfaction was examined in college student long-distance romantic relationships (LDRRs) and geographically proximal romantic relationships (PRRs). LDRR/PRR attachment style proportions and relationship satisfaction were similar. Multiple regression analyses revealed that low attachment avoidance contributed uniquely to high LDRR…

  8. Predictors of Satisfaction in Geographically Close and Long-Distance Relationships

    ERIC Educational Resources Information Center

    Lee, Ji-yeon; Pistole, M. Carole

    2012-01-01

    In this study, the authors examined geographically close (GCRs) and long-distance (LDRs) romantic relationship satisfaction as explained by insecure attachment, self-disclosure, gossip, and idealization. After college student participants (N = 536) completed a Web survey, structural equation modeling (SEM) multigroup analysis revealed that the GCR…

  9. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    DOEpatents

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  10. Long-distance dispersal of Red-cockaded Woodpeckers in Texas

    Treesearch

    Richard N. Conner; D. Craig Rudolph; Richard R. Schaefer; Daniel Saenz

    1997-01-01

    The red-cockaded woodpecker (Picoides borealis) is a cooperatively breeding species indigenous to the mature pine forests of the Southeastern United States. Continued loss and fragmentation of the mature forests of the South have increased the isolation of extant woodpecker groups throughout the range of this endangered species. The authors discuss long-distance...

  11. Predictors of Satisfaction in Geographically Close and Long-Distance Relationships

    ERIC Educational Resources Information Center

    Lee, Ji-yeon; Pistole, M. Carole

    2012-01-01

    In this study, the authors examined geographically close (GCRs) and long-distance (LDRs) romantic relationship satisfaction as explained by insecure attachment, self-disclosure, gossip, and idealization. After college student participants (N = 536) completed a Web survey, structural equation modeling (SEM) multigroup analysis revealed that the GCR…

  12. Neuromuscular factors associated with decline in long-distance running performance in master athletes.

    PubMed

    Brisswalter, Jeanick; Nosaka, Kazunori

    2013-01-01

    This review focuses on neuromuscular factors that may affect endurance performance in master athletes. During the last decade, due to the rapid increase in the number of master or veteran participants in endurance sporting competitions, many studies attempted to identify metabolic factors associated with the decrease in endurance, especially long-distance running performance with ageing, focusing on decreases in maximal oxygen consumption. However, neuromuscular factors have been less studied despite the well-known phenomena of strength loss with ageing. For master athletes to perform better in long-distance running events, it is important to reduce muscle fatigue and/or muscle damage, to improve locomotion efficiency and to facilitate recovery. To date, no consensus exists that regular endurance training is beneficial for improving locomotion efficiency, reducing muscle fatigue and muscle damage, and enhancing recovery capacity in master athletes. Some recent studies seem to indicate that master athletes have similar muscle damage to young athletes, but they require a longer recovery time after a long-distance running event. Further analyses of these parameters in master athletes require more experimental and practical interest from researchers and coaches. In particular, more attention should be directed towards the capacity to maintain muscle function with training and the role of neuromuscular factors in long-distance performance decline with ageing using a more cellular and molecular approach.

  13. The Virtual Learning Environment ROODA: An Institutional Project of Long Distance Education

    ERIC Educational Resources Information Center

    Behar, Patricia Alejandra; Leite, Silvia Meirelles

    2006-01-01

    This article describes ROODA (http://www.homer.nuted.edu.ufrgs.br), a virtual learning environment and one of the official Long Distance Education platforms that has been in use since 2005 at the Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil. It is free software that integrates syncronous and assyncronous…

  14. The design of Gaussian beam zoom system in intermediate and long distance measurement

    NASA Astrophysics Data System (ADS)

    Wang, Mengcheng; Zhou, Jian

    2016-10-01

    It is well known that laser possesses high brightness, high coherence, good directivity and other unique properties. In many practical applications, it is necessary to get small light spot in intermediate and long distance. Intermediate and long distance laser measurement demands to minimize the spot radius in order to improve the spatial resolution of the system and signal quality. Therefore, the study of Gaussian beam focusing property has high value for practical applications. In order to achieve intermediate and long distance laser measurement, this paper studies the method to adjust Gaussian beam spot diameter within a certain range after a near-field optical system transformation to improve the signal quality. Based on the fundamental characteristics of the Gaussian beam, this paper deduces the theoretical formula for the position and radius of the Gaussian beam waist and measures them by means of the CCD method. Then Matlab is used to simulate the spot diameter in the far field, and by combining numerical simulation results as well as optimizing the structure of the actual optical system, we make the light spot diameter in the target area fit the requirements of the laser velocimeter in intermediate and long distance measurement.

  15. Kenyan and Ethiopian distance runners: what makes them so good?

    PubMed

    Wilber, Randall L; Pitsiladis, Yannis P

    2012-06-01

    Since the 1968 Mexico City Olympics, Kenyan and Ethiopian runners have dominated the middle- and long-distance events in athletics and have exhibited comparable dominance in international cross-country and road-racing competition. Several factors have been proposed to explain the extraordinary success of the Kenyan and Ethiopian distance runners, including (1) genetic predisposition, (2) development of a high maximal oxygen uptake as a result of extensive walking and running at an early age, (3) relatively high hemoglobin and hematocrit, (4) development of good metabolic "economy/efficiency" based on somatotype and lower limb characteristics, (5) favorable skeletal-muscle-fiber composition and oxidative enzyme profile, (6) traditional Kenyan/Ethiopian diet, (7) living and training at altitude, and (8) motivation to achieve economic success. Some of these factors have been examined objectively in the laboratory and field, whereas others have been evaluated from an observational perspective. The purpose of this article is to present the current data relative to factors that potentially contribute to the unprecedented success of Kenyan and Ethiopian distance runners, including recent studies that examined potential links between Kenyan and Ethiopian genotype characteristics and elite running performance. In general, it appears that Kenyan and Ethiopian distance-running success is not based on a unique genetic or physiological characteristic. Rather, it appears to be the result of favorable somatotypical characteristics lending to exceptional biomechanical and metabolic economy/efficiency; chronic exposure to altitude in combination with moderate-volume, high-intensity training (live high + train high), and a strong psychological motivation to succeed athletically for the purpose of economic and social advancement.

  16. Perception of Health Problems Among Competitive Runners: A Qualitative Study of Cognitive Appraisals and Behavioral Responses.

    PubMed

    Jelvegård, Sara; Timpka, Toomas; Bargoria, Victor; Gauffin, Håkan; Jacobsson, Jenny

    2016-12-01

    Approximately 2 of every 3 competitive runners sustain at least 1 health problem each season. Most of these problems are nontraumatic injuries with gradual onset. The main known risk indicator for sustaining a new running-related injury episode is a history of a previous injury, suggesting that behavioral habits are part of the causal mechanisms. Identification of elements associated with purposeful interpretations of body perceptions and balanced behavioral responses may supply vital information for prevention of health problems in runners. This study set out to explore competitive runners' cognitive appraisals of perceived symptoms on injury and illness and how these appraisals are transformed into behavior. Cross-sectional study; Level of evidence, 3. The study population consisted of Swedish middle- and long-distance runners from the national top 15 list. Qualitative research methods were used to categorize interview data and perform a thematic analysis. The categories resulting from the analysis were used to construct an explanatory model. Saturation of the thematic classification required that data from 8 male and 6 female runners (age range, 20-36 years) were collected. Symptoms interpreted to be caused by illness or injury with a sudden onset were found to lead to immediate action and changes to training and competition programs (activity pacing). In contrast, perceptions interpreted to be due to injuries with gradual onset led to varied behavioral reactions. These behavioral responses were planned with regard to short-term consequences and were characterized by indifference and neglect of long-term implications, consistent with an overactivity behavioral pattern. The latter pattern was consistent with a psychological adaptation to stimuli that is presented progressively to the athlete. Competitive runners appraise whether a health problem requires immediate withdrawal from training based on whether the problem is interpreted as an illness and/or has a

  17. Long-distance communication and signal amplification in systemic acquired resistance

    PubMed Central

    Shah, Jyoti; Zeier, Jürgen

    2013-01-01

    Systemic acquired resistance (SAR) is an inducible defense mechanism in plants that confers enhanced resistance against a variety of pathogens. SAR is activated in the uninfected systemic (distal) organs in response to a prior (primary) infection elsewhere in the plant. SAR is associated with the activation of salicylic acid (SA) signaling and the priming of defense responses for robust activation in response to subsequent infections. The activation of SAR requires communication by the primary infected tissues with the distal organs. The vasculature functions as a conduit for the translocation of factors that facilitate long-distance intra-plant communication. In recent years, several metabolites putatively involved in long-distance signaling have been identified. These include the methyl ester of SA (MeSA), the abietane diterpenoid dehydroabietinal (DA), the dicarboxylic acid azelaic acid (AzA), and a glycerol-3-phosphate (G3P)-dependent factor. Long-distance signaling by some of these metabolites also requires the lipid-transfer protein DIR1 (DEFECTIVE IN INDUCED RESISTANCE 1). The relative contribution of these factors in long-distance signaling is likely influenced by environmental conditions, for example light. In the systemic leaves, the AGD2-LIKE DEFENSE RESPONSE PROTEIN1 (ALD1)-dependent production of the lysine catabolite pipecolic acid (Pip), FLAVIN-DEPENDENT MONOOXYGENASE1 (FMO1) signaling, as well as SA synthesis and downstream signaling are required for the activation of SAR. This review summarizes the involvement and interaction between long-distance SAR signals and details the recently discovered role of Pip in defense amplification and priming that allows plants to acquire immunity at the systemic level. Recent advances in SA signaling and perception are also highlighted. PMID:23440336

  18. Characteristics of lesser prairie-chicken (Tympanuchus pallidicinctus) long-distance movements across their distribution

    USGS Publications Warehouse

    Earl, Julia E.; Fuhlendorf, Samuel D.; Haukos, David A.; Tanner, Ashley M.; Elmore, Dwayne; Carleton, Scott A.

    2016-01-01

    Long-distance movements are important adaptive behaviors that contribute to population, community, and ecosystem connectivity. However, researchers have a poor understanding of the characteristics of long-distance movements for most species. Here, we examined long-distance movements for the lesser prairie-chicken (Tympanuchus pallidicinctus), a species of conservation concern. We addressed the following questions: (1) At what distances could populations be connected? (2) What are the characteristics and probability of dispersal movements? (3) Do lesser prairie-chickens display exploratory and round-trip movements? (4) Do the characteristics of long-distance movements vary by site? Movements were examined from populations using satellite GPS transmitters across the entire distribution of the species in New Mexico, Oklahoma, Kansas, and Colorado. Dispersal movements were recorded up to 71 km net displacement, much farther than hitherto recorded. These distances suggest that there may be greater potential connectivity among populations than previously thought. Dispersal movements were displayed primarily by females and had a northerly directional bias. Dispersal probabilities ranged from 0.08 to 0.43 movements per year for both sexes combined, although these movements averaged only 16 km net displacement. Lesser prairie-chickens displayed both exploratory foray loops and round-trip movements. Half of round-trip movements appeared seasonal, suggesting a partial migration in some populations. None of the long-distance movements varied by study site. Data presented here will be important in parameterizing models assessing population viability and informing conservation planning, although further work is needed to identify landscape features that may reduce connectivity among populations.

  19. Cardiovascular responses to static exercise in distance runners and weight lifters

    NASA Technical Reports Server (NTRS)

    Longhurst, J. C.; Kelly, A. R.; Gonyea, W. J.; Mitchell, J. H.

    1980-01-01

    Three groups of athletes including long-distance runners, competitive and amateur weight lifters, and age- and sex-matched control subjects have been studied by hemodynamic and echocardiographic methods in order to determine the effect of the training programs on the cardiovascular response to static exercise. Blood pressure, heart rate, and double product data at rest and at fatigue suggest that competitive endurance (dynamic exercise) training alters the cardiovascular response to static exercise. In contrast to endurance exercise, weight lifting (static exercise) training does not alter the cardiovascular response to static exercise: weight lifters responded to static exercise in a manner very similar to that of the control subjects.

  20. Cardiovascular responses to static exercise in distance runners and weight lifters

    NASA Technical Reports Server (NTRS)

    Longhurst, J. C.; Kelly, A. R.; Gonyea, W. J.; Mitchell, J. H.

    1980-01-01

    Three groups of athletes including long-distance runners, competitive and amateur weight lifters, and age- and sex-matched control subjects have been studied by hemodynamic and echocardiographic methods in order to determine the effect of the training programs on the cardiovascular response to static exercise. Blood pressure, heart rate, and double product data at rest and at fatigue suggest that competitive endurance (dynamic exercise) training alters the cardiovascular response to static exercise. In contrast to endurance exercise, weight lifting (static exercise) training does not alter the cardiovascular response to static exercise: weight lifters responded to static exercise in a manner very similar to that of the control subjects.

  1. The validity of incremental exercise testing in discriminating of physiological profiles in elite runners.

    PubMed

    Legaz-Arrese, Alejandro; Munguía-Izquierdo, D; Carranza-García, L E; Reverter-Masía, J; Torres-Dávila, C G; Medina-Rodríguez, R E

    2011-06-01

    The goal of this study was to determine whether traditional ergoespirometric incremental exercise testing carried out to the point of exhaustion could be useful in distinguishing the physiological profiles of elite runners that compete in races that lasted about 8 minutes versus those that lasted about 2 hours. Ten male marathon runners (performance time: 2:12:04, coefficient of variation (CV) = 2.33%) and 8 male 3000 m steeplechase runners (performance time: 8:37.83, CV = 2.12%) performed an incremental test on the treadmill (starting speed 10 km·h-1; increments, 2 km·h-1; increment duration, 3 min to exhaustion). Heart rate (HR), VO2, and lactate concentrations were measured at the end of each exercise level. At maximal effort, there were no differences between the groups regarding VO2max and maximal HR; however, the workload time, vVO2max and peak treadmill velocity were significantly higher in the 3000 m steeplechase group (p<0.05). At submaximal effort, there were no significant differences between groups for VO2 (ml·kg-1·min-1), HR, or lactate. Our results show that this type of testing was not sufficient for discriminating the physiological profiles of elite runners who competed in middle-distance versus long-distance events (e.g. in the marathon and the 3000 m steeplechase).

  2. Iron nutritional status in female karatekas, handball and basketball players, and runners.

    PubMed

    Nuviala, R J; Castillo, M C; Lapieza, M G; Escanero, J F

    1996-03-01

    The iron nutritional status was studied in 84 sportswomen (19 karatekas, 20 handball players, 20 basketball players, and 25 middle and long distance runners) and in 82 nonathletic females of similar characteristics (control group). After a 7-day nutritional survey by means of the food weighing method, it was found that iron intake was significantly higher in the handball players (p < 0.05), basketball players (p < 0.01), and runners (p < 0.01) with regard to the control group; the basketball players were the only ones to cover the recommended minimum intake (15 mg/day). The heme iron intake was significantly greater in the handball and basketball players (p < 0.01), who, together with the runners, reached the value of 1.5 mg/day, which is considered to be optimal. In relation to the control group, the karatekas and handball and basketball players had lower levels of serum ferritin, although their iron intake was greater, whereas the runners had higher values that were very similar to those of the control group, due to the iron supplementation they had received. Despite finding a marked prevalence of inadequate iron intake, both in the sportswomen and in the control group, the manifest cases of anemia are relatively scarce. The organic iron stores do not seem to depend exclusively on the iron intake but also on intimate mechanisms of intestinal absorption and diverse causes of iron loss.

  3. A Mismatch Between Athlete Practice and Current Sports Nutrition Guidelines Among Elite Female and Male Middle- and Long-Distance Athletes.

    PubMed

    Heikura, Ida A; Stellingwerff, Trent; Mero, Antti A; Uusitalo, Arja Leena Tuulia; Burke, Louise M

    2017-08-01

    Contemporary nutrition guidelines promote a variety of periodized and time-sensitive recommendations, but current information regarding the knowledge and practice of these strategies among world-class athletes is limited. The aim of this study was to investigate this theme by implementing a questionnaire on dietary periodization practices in national/international level female (n = 27) and male (n = 21) middle- and long-distance runners/race-walkers. The questionnaire aimed to gain information on between and within-day dietary choices, as well as timing of pre- and posttraining meals and practices of training with low or high carbohydrate (CHO) availability. Data are shown as percentage (%) of all athletes, with differences in responses between subgroups (sex or event) shown as Chi-square x(2) when p < .05. Nearly two-thirds of all athletes reported that they aim to eat more food on, or after, hard training days. Most athletes said they focus on adequate fueling (96%) and adequate CHO and protein (PRO) recovery (87%) around key sessions. Twenty-six percent of athletes (11% of middle vs 42% of long-distance athletes [x(2) (1, n = 46) = 4.308, p = .038, phi = 0.3])) reported to undertake training in the fasted state, while 11% said they periodically restrict CHO intake, with 30% ingesting CHO during training sessions. Our findings show that elite endurance athletes appear to execute pre- and post-key session nutrition recovery recommendations. However, very few athletes deliberately undertake some contemporary dietary periodization approaches, such as training in the fasted state or periodically restricting CHO intake. This study suggests mismatches between athlete practice and current and developing sports nutrition guidelines.

  4. Supplementation patterns in marathon runners.

    PubMed

    Nieman, D C; Gates, J R; Butler, J V; Pollett, L M; Dietrich, S J; Lutz, R D

    1989-11-01

    The purpose of the present investigation was to study the use of supplements in a large group of endurance runners (no. = 347) who had participated in the 1987 Los Angeles Marathon. Three-day dietary records were analyzed for nutrient content and supplement usage. The runners' supplementation patterns with respect to demographics, dietary quality, training habits, and race performance were investigated. In general, no significant associations were found between supplement use and the aforementioned variables. Use of supplements, especially vitamins C and E, calcium, and zinc, increased with age (p less than .05). Daily use of at least one type of supplement was reported by 29% of the runners; 48% reported use of at least one type of supplement within the 3-day period.

  5. Steering Compensation for Strong Vertical Refraction Gradients in a Long-Distance Free-Space Optical Communication Link Over Water

    DTIC Science & Technology

    2005-01-01

    Steering compensation for strong vertical refraction gradients in a long-distance free-space optical communication link over water M.R. Suitea...2005 4. TITLE AND SUBTITLE Steering compensation for strong vertical refraction gradients in a long-distance free-space optical communication link...focal-spot wander in a long-distance free-space optical communication link”, Proc. SPIE Int. Soc. Opt. Eng. 5160, 439 (2004) Proc. of SPIE 58921T-10

  6. Operation Recreation

    ERIC Educational Resources Information Center

    Schutz, Jeff; Schutz, Laurie

    2010-01-01

    Parents who have a child with a disability often find that recreational activities can be anything but accessible. Time for recreation is drowned by the priorities of caring for a child's needs, and the "umph" to get out can feel like an insurmountable obstacle. The activities parents love and aspire to share with their child may seem like one…

  7. The Relationship Between Aerobic and Anaerobic Performance in Recreational Runners

    PubMed Central

    GILLEN, ZACHARY M.; WYATT, FRANK B.; WINCHESTER, JASON B.; SMITH, DALTON A.; GHETIA, VIDHI

    2016-01-01

    Research has indicated that combined aerobic and anaerobic training (concurrent training) may improve aerobic performance greater than aerobic training alone. The purpose of this investigation was to establish any associations between aerobic and anaerobic performance. Eleven participants (n = 11, age = 34.1 ± 13 years, VO2max = 58.4 ± 7.8) volunteered for this study. Participants were asked for endurance training experience (4.7 ± 3.7 years) and resistance training experience (4.1 ± 4.6 years). To meet training status, participants were to have a VO2max in the 80th percentile as per ACSM guidelines. The Bruce treadmill test was used to measure aerobic performance. In order to measure anaerobic performance, several tests were completed utilizing a force platform. A Pearson Product R Correlation Coefficient was calculated to determine correlations between variables. The results show significant correlation between VO2max and RFD (r = 0.68). Further analyses utilizing Cohen’s effect size indicated a strong association between VO2max and peak force, as well as running efficiency and peak power, relative peak power, and power endurance. These results indicate an existing possibility that anaerobic performance measures such as RFD may have a positive relationship with aerobic performance measures such as VO2max. Therefore, it may be beneficial to integrate specific training components which focus on improving RFD as a method of improving running performance. PMID:27990224

  8. Temporal changes in long-distance running performance of Asian children between 1964 and 2009.

    PubMed

    Tomkinson, Grant R; Macfarlane, Duncan; Noi, Shingo; Kim, Dae-Yeon; Wang, Zhengzhen; Hong, Ren

    2012-04-01

    Aerobic fitness is considered to be an important marker of current health and even a predictor of future health. The aim of this study was to systematically analyse the available scientific information on temporal changes in maximal long-distance running performance (a widely and long-used marker of aerobic fitness) of Asian children. A systematic review of the scientific literature was undertaken to locate studies explicitly reporting on temporal changes (spanning a minimum of 5 years) in maximal long-distance running of apparently healthy (free from known disease or injury) Asian children aged 9-17 years. Studies were located up to October 2010 via computerized searching of bibliographical databases, reference list searching and personal communication with international experts. Temporal changes were analysed at the country by sex by age by test level using best-fitting linear or polynomial regression models relating the year of testing to long-distance running performances expressed as average running speeds. Changes in means were expressed as percent changes and as standardized effect sizes. Eight studies reporting temporal changes in the long-distance running performance of 23,897,571 children aged 9-17 years from four Asian countries over the period 1964-2009 were included. Overall, there was a large decline in long-distance running performance equivalent to -16.6 ± 1.3% (mean change ± 95% confidence interval) or -1.2 ± 0.1 standard deviations. Temporal changes were generally consistent for different sex and age groups, but not for different countries, with large declines observed for children from China and the Republic of Korea, small declines for children from Japan and very small declines for children from Singapore. There is overwhelming evidence of meaningful declines in the maximal long-distance running performance of Asian children in recent decades, which are probably caused by a network of social, behavioural, physical, psychosocial

  9. Revisiting a runner cavitation repair job

    SciTech Connect

    Witman, J.K.

    1996-05-01

    This article reviews the efforts to repair turbine runner cavitation damage. The particular runner was originally repaired in 1990 with the application of a layer of beaded epoxy to areas of severe cavitation on the suction side of the blades on the upper runner. A year later, the runner was inspected, with no damage to the epoxy. In June of 1994, the runner was again inspected, and this and the most recent inspection shows that the epoxy coating is holding up well. The last inspection did show the beginnings on some erosion of the repair material. Based on this long-term series of inspections, maintenance recommendations are set forth.

  10. Capture of associated targets on chromatin links long-distance chromatin looping to transcriptional coordination

    PubMed Central

    Bourgo, Ryan J.; Singhal, Hari; Greene, Geoffrey L.

    2016-01-01

    Here we describe a sensitive and novel method of identifying endogenous DNA–DNA interactions. Capture of Associated Targets on CHromatin (CATCH) uses efficient capture and enrichment of specific genomic loci of interest through hybridization and subsequent purification via complementary biotinylated oligonucleotide. The CATCH assay requires no enzymatic digestion or ligation, requires little starting material, provides high-quality data, has excellent reproducibility and is completed in less than 24 h. Efficacy is demonstrated through capture of three disparate loci, which demonstrate unique subsets of long-distance chromatin interactions enriched for both enhancer marks and oestrogen receptor-binding sites. In each experiment, CATCH-seq peaks representing long-distance chromatin interactions were centred near the TSS of genes, and, critically, the genes identified as physically interacting are shown to be transcriptionally coexpressed. These interactions could potentially create transcriptional hubs for the regulation of gene expression programmes. PMID:27634217

  11. Long-distance fiber-optic point-sensing systems based on random fiber lasers.

    PubMed

    Wang, Z N; Rao, Y J; Wu, H; Li, P Y; Jiang, Y; Jia, X H; Zhang, W L

    2012-07-30

    We find that the random fiber laser (RFL) without point-reflectors is a temperature-insensitive distributed lasing system for the first time. Inspired by such thermal stability, we propose the novel concept of utilizing the RFL to achieve long-distance fiber-optic remote sensing, in which the RFL offers high-fidelity and long-distance transmission for the sensing signal. Two 100 km fiber Bragg grating (FBG) point-sensing schemes based on RFLs are experimentally demonstrated using the first-order and the second-order random lasing, respectively, to verify the concept. Each sensing scheme can achieve >20 dB optical signal-to-noise ratio (OSNR) over 100 km distance. It is found that the second-order random lasing scheme has much better OSNR than that of the first-order random lasing scheme due to enhanced lasing efficiency, by incorporating a 1455 nm FBG into the lasing cavity.

  12. The Saudi clinical practice guideline for the prophylaxis of venous thromboembolism in long-distance travelers

    PubMed Central

    Al-Hameed, Fahad M.; Al-Dorzi, Hasan M.; Abdelaal, Mohamed A.; Alaklabi, Ali; Bakhsh, Ebtisam; Alomi, Yousef A.; Baik, Mohammad Al; Aldahan, Salah; Schünemann, Holger; Brozek, Jan; Wiercioch, Wojtek; Darzi, Andrea J.; Waziry, Reem; Akl, Elie A.

    2017-01-01

    Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a preventable disease. Long distant travelers are prone to variable degree to develop VTE. However, the low risk of developing VTE among long-distance travelers and which travelers should receive VTE prophylaxis, and what prophylactic measures should be used led us to develop these guidelines. These clinical practice guidelines are the result of an initiative of the Ministry of Health of the Kingdom of Saudi Arabia involving an expert panel led by the Saudi Association for Venous Thrombo Embolism (a subsidiary of the Saudi Thoracic Society). The McMaster University Guideline working group provided the methodological support. The expert panel identified 5 common questions related to the thromboprophylaxis in long-distance travelers. The corresponding recommendations were made following the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. PMID:28042639

  13. Long-distance continuous-variable quantum key distribution by controlling excess noise

    NASA Astrophysics Data System (ADS)

    Huang, Duan; Huang, Peng; Lin, Dakai; Zeng, Guihua

    2016-01-01

    Quantum cryptography founded on the laws of physics could revolutionize the way in which communication information is protected. Significant progresses in long-distance quantum key distribution based on discrete variables have led to the secure quantum communication in real-world conditions being available. However, the alternative approach implemented with continuous variables has not yet reached the secure distance beyond 100 km. Here, we overcome the previous range limitation by controlling system excess noise and report such a long distance continuous-variable quantum key distribution experiment. Our result paves the road to the large-scale secure quantum communication with continuous variables and serves as a stepping stone in the quest for quantum network.

  14. Long-distance super-resolution imaging assisted by enhanced spatial Fourier transform.

    PubMed

    Tang, Heng-He; Liu, Pu-Kun

    2015-09-07

    A new gradient-index (GRIN) lens that can realize enhanced spatial Fourier transform (FT) over optically long distances is demonstrated. By using an anisotropic GRIN metamaterial with hyperbolic dispersion, evanescent wave in free space can be transformed into propagating wave in the metamaterial and then focused outside due to negative-refraction. Both the results based on the ray tracing and the finite element simulation show that the spatial frequency bandwidth of the spatial FT can be extended to 2.7k(0) (k(0) is the wave vector in free space). Furthermore, assisted by the enhanced spatial FT, a new long-distance (in the optical far-field region) super-resolution imaging scheme is also proposed and the super resolved capability of λ/5 (λ is the wavelength in free space) is verified. The work may provide technical support for designing new-type high-speed microscopes with long working distances.

  15. [Health risks of long-distance air travel. Role of the general practitioner].

    PubMed

    Bazex, Jacques; Cabanis, Emmanuel Alain

    2010-06-01

    Air transport is seeing an increase in long-distance flights (12-16 hours average flight time), greater seating capacity, and a higher proportion of elderly, and hence more fragile, passengers. The French Academy of Medicine recommends that medical care be reinforced, particularly on long-distance flights, through the following measures: (i) passengers should be informed in advance of potential risks, through a Passenger's Guide, (ii) all future passengers should be encouraged to seek health advice and information from their general practitioner, (iii) flight crew members should receive training as "in-flight medical correspondents", and (iv) airlines and plane designers should reserve a "medical space" on the plane, equipped with appropriate medical materials.

  16. Transpiration, a prerequisite for long-distance transport of minerals in plants?

    PubMed Central

    Tanner, W.; Beevers, H.

    2001-01-01

    The major “benefit” alleged to accrue from transpiration (the evaporative loss of water from plant surfaces) is that it is essential for the long-distance transport of mineral ions, but the possible interrelation between these two processes has rarely been tested. Transpiration was experimentally dissociated from mineral supply by growing sunflowers (Helianthus anuus) in hydroculture and providing mineral nutrients only during the nights. These plants grew as well as a control group that received nutrients only during the day and transpired 12–15 times more water during the exposure period. It thus appears that convective water transport in the xylem, brought about by root pressure and the resultant guttation, “growth water,” and Münch's phloem counterflow is in itself sufficient for long-distance mineral supply and that transpiration is not required for this function. PMID:11481499

  17. Long-distance fiber sensor system based on the second-order Raman pump and amplification

    NASA Astrophysics Data System (ADS)

    Dong, B.; Hu, J.; Chen, Z.; Yu, C.

    2012-07-01

    We demonstrate a novel technique to realize a long-distance fiber sensor system based on the second-order Raman pump and amplification. With the second-order Raman pump and amplification, a gain spectrum around 1582-nm is achieved. It serves as not only the optical source for the remote fiber sensor but also the filter to intensity modulated the wavelength shift of the fiber sensor. A long-distance fiber strain sensor system is demonstrated by adopting a fiber Fabry-Pérot sensor. Experimental results show that the wavelength shift of the sensor in response to the strain is simultaneously intensity modulated by the steep slope with a high sensitivity, while it is temperature insensitive. With the side gain spectrum served as a quasi-linear filter, the sensor can also be quasi-linearly intensity-modulated.

  18. Process for the Φ130 sapphire window element with long distance and high resolution

    NASA Astrophysics Data System (ADS)

    Xu, Zengqi; Su, Ying; Lei, Jianli; Guo, Rui; Zhang, Feng; Guo, Xinlong; Liu, Xuanmin; Sun, Taohui

    2016-10-01

    With the process test for the choice of materials, the test materials and the molds, the abrasives, the temperature and the different machining process monitoring parameters of the polishing machine, the process method and the quality control technology were figured out for the Φ130 sapphire window element with long distance and high resolution (hereinafter referred to as window element), meantime, the optimum process condition was determined to machine the element. The results were that the high resolution imaging window was processed with the surface roughness Ra of 0.639nm, the transmission distortion of λ/10 (λ=632.8nm), the parallel error of 5″, the resolution of 1.47″ and the focal length of 5 km, which can satisfy the imaging requirements better for the military photoelectric device for sapphire window with long distance and high resolution.

  19. Long-distance continuous-variable quantum key distribution by controlling excess noise

    PubMed Central

    Huang, Duan; Huang, Peng; Lin, Dakai; Zeng, Guihua

    2016-01-01

    Quantum cryptography founded on the laws of physics could revolutionize the way in which communication information is protected. Significant progresses in long-distance quantum key distribution based on discrete variables have led to the secure quantum communication in real-world conditions being available. However, the alternative approach implemented with continuous variables has not yet reached the secure distance beyond 100 km. Here, we overcome the previous range limitation by controlling system excess noise and report such a long distance continuous-variable quantum key distribution experiment. Our result paves the road to the large-scale secure quantum communication with continuous variables and serves as a stepping stone in the quest for quantum network. PMID:26758727

  20. Photo Surfing in Blade Runner

    ERIC Educational Resources Information Center

    Ohler, Jason

    2005-01-01

    This month's "Mining Movies" looks at Blade Runner, Ridley Scott's film set in the year 2019. It is a sad time for Earth, which is in the midst of environmental degradation so severe that other planets are being prepared for colonization. The main source of labor for this preparation work are "replicants," organic robots that look and behave like…

  1. Photo Surfing in Blade Runner

    ERIC Educational Resources Information Center

    Ohler, Jason

    2005-01-01

    This month's "Mining Movies" looks at Blade Runner, Ridley Scott's film set in the year 2019. It is a sad time for Earth, which is in the midst of environmental degradation so severe that other planets are being prepared for colonization. The main source of labor for this preparation work are "replicants," organic robots that look and behave like…

  2. High-accuracy long-distance measurements in air with a frequency comb laser.

    PubMed

    Cui, M; Zeitouny, M G; Bhattacharya, N; van den Berg, S A; Urbach, H P; Braat, J J M

    2009-07-01

    We experimentally demonstrate that a femtosecond frequency comb laser can be applied as a tool for long-distance measurement in air. Our method is based on the measurement of cross correlation between individual pulses in a Michelson interferometer. From the position of the correlation functions, distances of up to 50 m have been measured. We have compared this measurement to a counting laser interferometer, showing an agreement with the measured distance within 2 microm (4x10(-8) at 50 m).

  3. Taking the Flight to the Enemy: Chinese Thinking About Long-Distance and Expeditionary Operations

    DTIC Science & Technology

    2016-07-01

    concept, advanced-attack weapons (e.g., millimeter wave, rail gun, directed energy ); and, 15. Deep-insertion special operations forces.31 The...munitions with greater killing power; • Long-distance electronic warfare capabilities; • Directed energy munitions and weapons like lasers and...General Armaments Department assess U.S. successes with directed energy weapons and point out that: 1. Directed energy weapon systems are diverse in

  4. Effect of clenbuterol on tracheal mucociliary transport in horses undergoing simulated long-distance transportation.

    PubMed

    Norton, J L; Jackson, K; Chen, J W; Boston, R; Nolen-Walston, R D

    2013-01-01

    Pneumonia is observed in horses after long-distance transportation in association with confinement of head position leading to reduction in tracheal mucociliary clearance rate (TMCR). Clenbuterol, a beta-2 agonist shown to increase TMCR in the horse, will ameliorate the effects of a fixed elevated head position on large airway contamination and inflammation in a model of long-distance transportation model. Six adult horses. A cross-over designed prospective study. Horses were maintained with a fixed elevated head position for 48 hours to simulate long-distance transport, and treated with clenbuterol (0.8 μg/kg PO q12h) or a placebo starting 12 hours before simulated transportation. TMCR was measured using a charcoal clearance technique. Data were collected at baseline and 48 hours, and included TMCR, tracheal wash cytology and quantitative culture, rectal temperature, CBC, fibrinogen, and serum TNFα, IL-10, and IL-2 levels. There was a 18-21 day washout between study arms, and data were analyzed using regression analysis and Wilcoxon rank-sum tests. Tracheal mucociliary clearance rate was significantly decreased after transportation in both treatment (P = .002) and placebo (P = .03) groups. There was a significant effect of treatment on TMCR, with the treatment group showing half the reduction in TMCR compared with the placebo group (P = .002). Other significant differences between before- and after-transportation samples occurred for serum fibrinogen, peripheral eosinophil count, quantitative culture, tracheal bacteria, and degenerate neutrophils, though no treatment effect was found. Treatment with clenbuterol modestly attenuates the deleterious effects of this long-distance transportation model on tracheal mucociliary clearance. Copyright © 2013 by the American College of Veterinary Internal Medicine.

  5. Long-distance dispersal of the gypsy moth (Lepidoptera: Lymantriidae) facilitated its initial invasion of Wisconsin.

    PubMed

    Tobin, Patrick C; Blackburn, Laura M

    2008-02-01

    Gypsy moth (Lymantria dispar L.) spread is dominated by stratified dispersal, and, although spread rates are variable in space and time, the gypsy moth has invaded Wisconsin at a consistently higher rate than in other regions. Allee effects, which act on low-density populations ahead of the moving population that contribute to gypsy moth spread, have also been observed to be consistently weaker in Wisconsin. Because a major cause of an Allee effect in the gypsy moth is mate-finding failure at low densities, supplementing low-density populations with immigrants that arrive through dispersal may facilitate establishment and consequent spread. We used local indicator of spatial autocorrelation methods to examine space-time gypsy moth monitoring data from 1996 to 2006 and identify isolated, low-density colonies that arrived through dispersal. We measured the distance of these colonies from the moving population front to show that long-distance dispersal was markedly present in earlier years when Wisconsin was still mainly uninfested. Recently, however, immigrants arriving through long-distance dispersal may no longer be detected because instead of invading uninfested areas, they are now supplementing high-density colonies. In contrast, we observed no temporal pattern in the distance between low-density colonies and the population front in West Virginia and Virginia. We submit that long-distance dispersal, perhaps facilitated through meteorological mechanisms, played an important role in the spread dynamics of the initial Wisconsin gypsy moth invasion, but it currently plays a lesser role because the portion of Wisconsin most susceptible to long-distance immigrants from alternate sources is now heavily infested.

  6. Long Distance Dispersal Potential of Two Seagrasses Thalassia hemprichii and Halophila ovalis.

    PubMed

    Wu, Kuoyan; Chen, Ching-Nen Nathan; Soong, Keryea

    2016-01-01

    The wide distribution of many seagrasses may be attributable to exploitation of currents. However, many species have seeds heavier than seawater, limiting surface floating, and thus, deep water becomes a potential barrier between suitable habitats. In this investigation, we studied the dispersal potential of various life history stages of two species of seagrasses, Thalassia hemprichii and Halophila ovalis, at Dongsha Atoll and Penghu Islands in Taiwan Strait, west Pacific. The adult plants of both species, often dislodged naturally from substrate by waves, could float, but only that of T. hemprichii could float for months and still remain alive and potentially able to colonize new territories. The seedlings of T. hemprichii could also float for about a month once failing to anchor to substrate of coral sand, but that of H. ovalis could not. The fruits and seeds of T. hemprichii could both float, but for too short a duration to enable long distance travel; those seeds released from long floating fruits had low germination rates in our tests. Obviously, their seeds are not adaptive for long distance dispersal. Fruits and seeds of H. ovalis do not float. The potential of animals as vectors was tested by feeding fruits and seeds of both species to a goose, a duck, and two fish in the laboratory. The fruits and seeds of T. hemprichii were digested and could no longer germinate; those of H. ovalis could pass through the digestive tracts and have a much higher germination rates than uningested controls. Therefore, birds could be important vectors for long distance dispersal of H. ovalis. The two seagrasses adopted very different dispersal mechanisms for long distance travel, and both exploited traits originally adaptive for other purposes.

  7. Long-Distance and Frequent Movements of the Flying-Fox Pteropus poliocephalus: Implications for Management

    PubMed Central

    Roberts, Billie J.; Catterall, Carla P.; Eby, Peggy; Kanowski, John

    2012-01-01

    Flying-foxes (Pteropodidae) are large bats capable of long-distance flight. Many species are threatened; some are considered pests. Effective conservation and management of flying-foxes are constrained by lack of knowledge of their ecology, especially of movement patterns over large spatial scales. Using satellite telemetry, we quantified long-distance movements of the grey-headed flying-fox Pteropus poliocephalus among roost sites in eastern Australia. Fourteen adult males were tracked for 2–40 weeks (mean 25 weeks). Collectively, these individuals utilised 77 roost sites in an area spanning 1,075 km by 128 km. Movement patterns varied greatly between individuals, with some travelling long distances. Five individuals travelled cumulative distances >1,000 km over the study period. Five individuals showed net displacements >300 km during one month, including one movement of 500 km within 48 hours. Seasonal movements were consistent with facultative latitudinal migration in part of the population. Flying-foxes shifted roost sites frequently: 64% of roost visits lasted <5 consecutive days, although some individuals remained at one roost for several months. Modal 2-day distances between consecutive roosts were 21–50 km (mean 45 km, range 3–166 km). Of 13 individuals tracked for >12 weeks, 10 moved >100 km in one or more weeks. Median cumulative displacement distances over 1, 10 and 30 weeks were 0 km, 260 km and 821 km, respectively. On average, over increasing time-periods, one additional roost site was visited for each additional 100 km travelled. These findings explain why culling and relocation attempts have had limited success in resolving human-bat conflicts in Australia. Flying-foxes are highly mobile between camps and regularly travel long distances. Consequently, local control actions are likely to have only temporary effects on local flying-fox populations. Developing alternative methods to manage these conflicts remains an important challenge that

  8. Addition of long-distance heart procurement promotes changes in heart transplant waiting list status

    PubMed Central

    Atik, Fernando Antibas; Couto, Carolina Fatima; Tirado, Freddy Ponce; Moraes, Camila Scatolin; Chaves, Renato Bueno; Vieira, Nubia W.; Reis, João Gabbardo

    2014-01-01

    Objective Evaluate the addition of long-distance heart procurement on a heart transplant program and the status of heart transplant recipients waiting list. Methods Between September 2006 and October 2012, 72 patients were listed as heart transplant recipients. Heart transplant was performed in 41 (57%), death on the waiting list occurred in 26 (36%) and heart recovery occurred in 5 (7%). Initially, all transplants were performed with local donors. Long-distance, interstate heart procurement initiated in February 2011. Thirty (73%) transplants were performed with local donors and 11 (27%) with long-distance donors (mean distance=792 km±397). Results Patients submitted to interstate heart procurement had greater ischemic times (212 min ± 32 versus 90 min±18; P<0.0001). Primary graft dysfunction (distance 9.1% versus local 26.7%; P=0.23) and 1 month and 12 months actuarial survival (distance 90.1% and 90.1% versus local 90% and 86.2%; P=0.65 log rank) were similar among groups. There were marked incremental transplant center volume (64.4% versus 40.7%, P=0.05) with a tendency on less waiting list times (median 1.5 month versus 2.4 months, P=0.18). There was a tendency on reduced waiting list mortality (28.9% versus 48.2%, P=0.09). Conclusion Incorporation of long-distance heart procurement, despite being associated with longer ischemic times, does not increase morbidity and mortality rates after heart transplant. It enhances viable donor pool, and it may reduce waiting list recipient mortality as well as waiting time. PMID:25372907

  9. An Assessment of Diarrhea Among Long-Distance Backpackers in the Sierra Nevada.

    PubMed

    Meyer, Derek J; Costantino, Amber; Spano, Susanne

    2017-03-01

    Diarrhea is a common problem among long-distance backpackers, ranging in overall incidence from 11-56% as reported by previous studies on the Appalachian Trail and Long Trail. Differences in age, sex, and regularity of standard backcountry hygiene recommendations and practices have been shown to significantly affect the incidence of diarrhea. No study to date has investigated these trends among long-distance backpackers on the John Muir Trail (JMT) in the Sierra Nevada mountain range of California. Retrospective analysis of online survey data gathered from long-distance backpackers who attempted a JMT trek in 2014. Data were assessed for the significance of variables that might contribute to the incidence and severity of on-trail diarrhea. Of 737 valid responders, 16.4% reported experiencing diarrhea (82% with minimal/mild severity; 18% with significant severity). Regular hand sanitizer use was significantly correlated with more severe diarrhea (P < .05), but had no effect on incidence. Regular hand sanitizer users followed all other recommended hygiene practices as frequently as or better than those not using hand sanitizer regularly. Of all backpackers, 88% filtered or treated their drinking water regularly, with 18% of those reporting diarrhea of any severity. JMT backpackers have a comparatively lower incidence of diarrhea than backpackers on other major long-distance backpacking routes in the United States. Most JMT backpackers follow standard backcountry hygiene recommendations, including regular filtration or treatment of drinking water. No statistical significance was found between the incidence of diarrhea and compliance with standard hygiene recommendations. Regular hand sanitizer use was significantly correlated with more severe diarrhea but was not associated with incidence. There was no significant difference in compliance with standard backcountry hygiene practices between regular and infrequent hand sanitizer users. Copyright © 2017 Wilderness

  10. Long Distance Dispersal Potential of Two Seagrasses Thalassia hemprichii and Halophila ovalis

    PubMed Central

    Wu, Kuoyan; Chen, Ching-Nen Nathan; Soong, Keryea

    2016-01-01

    The wide distribution of many seagrasses may be attributable to exploitation of currents. However, many species have seeds heavier than seawater, limiting surface floating, and thus, deep water becomes a potential barrier between suitable habitats. In this investigation, we studied the dispersal potential of various life history stages of two species of seagrasses, Thalassia hemprichii and Halophila ovalis, at Dongsha Atoll and Penghu Islands in Taiwan Strait, west Pacific. The adult plants of both species, often dislodged naturally from substrate by waves, could float, but only that of T. hemprichii could float for months and still remain alive and potentially able to colonize new territories. The seedlings of T. hemprichii could also float for about a month once failing to anchor to substrate of coral sand, but that of H. ovalis could not. The fruits and seeds of T. hemprichii could both float, but for too short a duration to enable long distance travel; those seeds released from long floating fruits had low germination rates in our tests. Obviously, their seeds are not adaptive for long distance dispersal. Fruits and seeds of H. ovalis do not float. The potential of animals as vectors was tested by feeding fruits and seeds of both species to a goose, a duck, and two fish in the laboratory. The fruits and seeds of T. hemprichii were digested and could no longer germinate; those of H. ovalis could pass through the digestive tracts and have a much higher germination rates than uningested controls. Therefore, birds could be important vectors for long distance dispersal of H. ovalis. The two seagrasses adopted very different dispersal mechanisms for long distance travel, and both exploited traits originally adaptive for other purposes. PMID:27248695

  11. Comment on "Rapid advance of spring arrival dates in long-distance migratory birds".

    PubMed

    Both, Christiaan

    2007-02-02

    Jonzén et al. (Reports, 30 June 2006, p. 1959) proposed that the rapid advance of spring migration dates of long-distance migrants throughout Europe reflects an evolutionary response to climate change. However, most migrants should not advance their migration time because the phenology of their breeding grounds has not changed. It is more likely that migration speed has changed in response to improved environmental circumstances.

  12. Processing classifier-noun agreement in a long distance: an ERP study on Mandarin Chinese.

    PubMed

    Hsu, Chun-Chieh; Tsai, Shu-Hua; Yang, Chin-Lung; Chen, Jenn-Yeu

    2014-10-01

    The classifier system categorizes nouns on a semantic basis. By inserting an object-gap relative clause (RC) between a classifier and its associate noun, we examined how temporary classifier-noun semantic incongruity and long-distance classifier-noun dependency are processed. Instead of a typical N400 effect, a midline anterior negativity was elicited by the temporary semantic incongruity, suggesting that the anticipation of coming words influences semantic processing and that metacognitive processes are involved in resolving the conflict. The lack of reduced P600 effects at the RC marker suggests that classifier-noun mismatch may not be effective in RC prediction. The N400 observed at the head noun suggests that the parser retains the temporary incongruity in the memory and computes the classifier-noun semantic agreement over a long distance. In addition, both successful and unsuccessful long-distance integration elicited P600 effects, supporting the view that P600 indexes more than just syntactic processing. Detailed discussion and implications are provided. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Long-distance dispersal via ocean currents connects Omani clownfish populations throughout entire species range.

    PubMed

    Simpson, Stephen D; Harrison, Hugo B; Claereboudt, Michel R; Planes, Serge

    2014-01-01

    Dispersal is a crucial ecological process, driving population dynamics and defining the structure and persistence of populations. Measuring demographic connectivity between discreet populations remains a long-standing challenge for most marine organisms because it involves tracking the movement of pelagic larvae. Recent studies demonstrate local connectivity of reef fish populations via the dispersal of planktonic larvae, while biogeography indicates some larvae must disperse 100-1000 s kilometres. To date, empirical measures of long-distance dispersal are lacking and the full scale of dispersal is unknown. Here we provide the first measure of long-distance dispersal in a coral reef fish, the Omani clownfish Amphiprion omanensis, throughout its entire species range. Using genetic assignment tests we demonstrate bidirectional exchange of first generation migrants, with subsequent social and reproductive integration, between two populations separated by over 400 km. Immigration was 5.4% and 0.7% in each region, suggesting a biased southward exchange, and matched predictions from a physically-coupled dispersal model. This rare opportunity to measure long-distance dispersal demonstrates connectivity of isolated marine populations over distances of 100 s of kilometres and provides a unique insight into the processes of biogeography, speciation and adaptation.

  14. Long-distance gene flow and adaptation of forest trees to rapid climate change.

    PubMed

    Kremer, Antoine; Ronce, Ophélie; Robledo-Arnuncio, Juan J; Guillaume, Frédéric; Bohrer, Gil; Nathan, Ran; Bridle, Jon R; Gomulkiewicz, Richard; Klein, Etienne K; Ritland, Kermit; Kuparinen, Anna; Gerber, Sophie; Schueler, Silvio

    2012-04-01

    Forest trees are the dominant species in many parts of the world and predicting how they might respond to climate change is a vital global concern. Trees are capable of long-distance gene flow, which can promote adaptive evolution in novel environments by increasing genetic variation for fitness. It is unclear, however, if this can compensate for maladaptive effects of gene flow and for the long-generation times of trees. We critically review data on the extent of long-distance gene flow and summarise theory that allows us to predict evolutionary responses of trees to climate change. Estimates of long-distance gene flow based both on direct observations and on genetic methods provide evidence that genes can move over spatial scales larger than habitat shifts predicted under climate change within one generation. Both theoretical and empirical data suggest that the positive effects of gene flow on adaptation may dominate in many instances. The balance of positive to negative consequences of gene flow may, however, differ for leading edge, core and rear sections of forest distributions. We propose future experimental and theoretical research that would better integrate dispersal biology with evolutionary quantitative genetics and improve predictions of tree responses to climate change. © 2012 Blackwell Publishing Ltd/CNRS.

  15. Long-distance entanglement and quantum teleportation in XX spin chains

    SciTech Connect

    Campos Venuti, L.; Giampaolo, S. M.; Illuminati, F.; Zanardi, P.

    2007-11-15

    Isotropic XX models of one-dimensional spin-1/2 chains are investigated with the aim to elucidate the formal structure and the physical properties that allow these systems to act as channels for long-distance, high-fidelity quantum teleportation. We introduce two types of models: (i) open, dimerized XX chains, and (ii) open XX chains with small end bonds. For both models we obtain the exact expressions for the end-to-end correlations and the scaling of the energy gap with the length of the chain. We determine the end-to-end concurrence and show that model (i) supports true long-distance entanglement at zero temperature, while model (ii) supports 'quasi-long-distance' entanglement that slowly falls off with the size of the chain. Due to the different scalings of the gaps, respectively exponential for model (i) and algebraic in model (ii), we demonstrate that the latter allows for efficient qubit teleportation with high fidelity in sufficiently long chains even at moderately low temperatures.

  16. Feasibility of long-distance heart rate monitoring using transmittance photoplethysmographic imaging (PPGI)

    NASA Astrophysics Data System (ADS)

    Amelard, Robert; Scharfenberger, Christian; Kazemzadeh, Farnoud; Pfisterer, Kaylen J.; Lin, Bill S.; Clausi, David A.; Wong, Alexander

    2015-10-01

    Photoplethysmography (PPG) devices are widely used for monitoring cardiovascular function. However, these devices require skin contact, which restricts their use to at-rest short-term monitoring. Photoplethysmographic imaging (PPGI) has been recently proposed as a non-contact monitoring alternative by measuring blood pulse signals across a spatial region of interest. Existing systems operate in reflectance mode, many of which are limited to short-distance monitoring and are prone to temporal changes in ambient illumination. This paper is the first study to investigate the feasibility of long-distance non-contact cardiovascular monitoring at the supermeter level using transmittance PPGI. For this purpose, a novel PPGI system was designed at the hardware and software level. Temporally coded illumination (TCI) is proposed for ambient correction, and a signal processing pipeline is proposed for PPGI signal extraction. Experimental results show that the processing steps yielded a substantially more pulsatile PPGI signal than the raw acquired signal, resulting in statistically significant increases in correlation to ground-truth PPG in both short- and long-distance monitoring. The results support the hypothesis that long-distance heart rate monitoring is feasible using transmittance PPGI, allowing for new possibilities of monitoring cardiovascular function in a non-contact manner.

  17. Long-distance impact of Iceland plume on Norway's rifted margin.

    PubMed

    Koptev, Alexander; Cloetingh, Sierd; Burov, Evgueni; François, Thomas; Gerya, Taras

    2017-09-04

    Results of a 3D modeling study inspired by recent seismic tomography of the Northern Atlantic mantle suggest that a complex pattern of hot mantle distribution with long horizontal flows originating from the Iceland mantle plume has been the norm in the geological past. In the Northern Atlantic the Iceland plume has a strong long-distance impact on intraplate deformation affecting both onshore and offshore parts of Norway's rifted margin. As a result, this margin is characterized by large magnitude differential topography sustained over at least several tens of Myr. Here we use high-resolution 3D thermo-mechanical modeling to demonstrate that the long-distance plume impact can be explained by its fast lateral propagation controlled by pre-existing lithosphere structures. Numerical models show that these structures strongly affect the style of horizontal flow of plume head material. This results in long-distance propagation of hot material emplaced at the lithosphere-asthenosphere boundary causing long-wavelength anomalies in onshore topography of Norway's rifted margin. Short-wavelength offshore topographic domes are likely caused by joint occurrence of plume-related thermal perturbations and gravitational forces related to plate thickening (ridge push). Our 3D modeling brings together plume impingement, spreading ridge dynamics, and the formation of anomalous intraplate structures offshore Norway in one scenario.

  18. Long-distance proton transfer with a break in the bacteriorhodopsin active site.

    PubMed

    Phatak, Prasad; Frähmcke, Jan S; Wanko, Marius; Hoffmann, Michael; Strodel, Paul; Smith, Jeremy C; Suhai, Sándor; Bondar, Ana-Nicoleta; Elstner, Marcus

    2009-05-27

    Bacteriorhodopsin is a proton-pumping membrane protein found in the plasma membrane of the archaeon Halobacterium salinarium. Light-induced isomerization of the retinal chromophore from all-trans to 13-cis leads to a sequence of five conformation-coupled proton transfer steps and the net transport of one proton from the cytoplasmic to the extracellular side of the membrane. The mechanism of the long-distance proton transfer from the primary acceptor Asp85 to the extracellular proton release group during the O --> bR is poorly understood. Experiments suggest that this long-distance transfer could involve a transient state [O] in which the proton resides on the intermediate carrier Asp212. To assess whether the transient protonation of Asp212 participates in the deprotonation of Asp85, we performed hybrid Quantum Mechanics/Molecular Mechanics proton transfer calculations using different protein structures and with different retinal geometries and active site water molecules. The structural models were assessed by computing UV-vis excitation energies and C=O vibrational frequencies. The results indicate that a transient [O] conformer with protonated Asp212 could indeed be sampled during the long-distance proton transfer to the proton release group. Our calculations suggest that, in the starting proton transfer state O, the retinal is strongly twisted and at least three water molecules are present in the active site.

  19. Efficient utilization of wind power: Long-distance transmission or local consumption?

    NASA Astrophysics Data System (ADS)

    Sun, Yuanzhang; Ma, Xiyuan; Xu, Jian; Bao, Yi; Liao, Siyang

    2017-09-01

    Excess wind power produced in wind-intensive areas is normally delivered to remote load centers via long-distance transmission lines. This paper presents a comparison between long-distance transmission, which has gained popularity, and local energy consumption, in which a fraction of the generated wind power can be locally consumed by energy-intensive industries. First, the challenges and solutions to the long-distance transmission and local consumption of wind power are presented. Then, the two approaches to the utilization of wind power are compared in terms of system security, reliability, cost, and capability to utilize wind energy. Finally, the economic feasibility and technical feasibility of the local consumption of wind power are demonstrated by a large and isolated industrial power system, or supermicrogrid, in China. The coal-fired generators together with the short-term interruptible electrolytic aluminum load in the supermicrogrid are able to compensate for the intermittency of wind power. In the long term, the transfer of high-energy-consumption industries to wind-rich areas and their local consumption of the available wind power are beneficial.

  20. Long-distance gene flow and adaptation of forest trees to rapid climate change

    PubMed Central

    Kremer, Antoine; Ronce, Ophélie; Robledo-Arnuncio, Juan J; Guillaume, Frédéric; Bohrer, Gil; Nathan, Ran; Bridle, Jon R; Gomulkiewicz, Richard; Klein, Etienne K; Ritland, Kermit; Kuparinen, Anna; Gerber, Sophie; Schueler, Silvio

    2012-01-01

    Forest trees are the dominant species in many parts of the world and predicting how they might respond to climate change is a vital global concern. Trees are capable of long-distance gene flow, which can promote adaptive evolution in novel environments by increasing genetic variation for fitness. It is unclear, however, if this can compensate for maladaptive effects of gene flow and for the long-generation times of trees. We critically review data on the extent of long-distance gene flow and summarise theory that allows us to predict evolutionary responses of trees to climate change. Estimates of long-distance gene flow based both on direct observations and on genetic methods provide evidence that genes can move over spatial scales larger than habitat shifts predicted under climate change within one generation. Both theoretical and empirical data suggest that the positive effects of gene flow on adaptation may dominate in many instances. The balance of positive to negative consequences of gene flow may, however, differ for leading edge, core and rear sections of forest distributions. We propose future experimental and theoretical research that would better integrate dispersal biology with evolutionary quantitative genetics and improve predictions of tree responses to climate change. PMID:22372546

  1. Long-Distance Interactions Regulate the Structure and Resilience of Coastal Ecosystems

    NASA Astrophysics Data System (ADS)

    van de Koppel, Johan; van der Heide, Tjisse; Altieri, Andrew H.; Eriksson, Britas Klemens; Bouma, Tjeerd J.; Olff, Han; Silliman, Brian R.

    2015-01-01

    Mounting evidence indicates that spatial interactions are important in structuring coastal ecosystems. Until recently, however, most of this work has been focused on seemingly exceptional systems that are characterized by regular, self-organized patterns. In this review, we document that interactions that operate at long distances, beyond the direct neighborhood of individual organisms, are more common and have much more far-reaching implications for coastal ecosystems than was previously realized. We review studies from a variety of ecosystem types—including cobble beaches, mussel beds, coral reefs, seagrass meadows, and mangrove forests—that reveal a startling interplay of positive and negative interactions between habitats across distances of up to a kilometer. In addition to classical feeding relations, alterations of physical conditions constitute an important part of these long-distance interactions. This entanglement of habitats has crucial implications for how humans manage coastal ecosystems, and evaluations of anthropogenic impact should explicitly address long-distance and system-wide effects before we deem these human activities to be causing little harm.

  2. Long-distance interactions regulate the structure and resilience of coastal ecosystems.

    PubMed

    van de Koppel, Johan; van der Heide, Tjisse; Altieri, Andrew H; Eriksson, Britas Klemens; Bouma, Tjeerd J; Olff, Han; Silliman, Brian R

    2015-01-01

    Mounting evidence indicates that spatial interactions are important in structuring coastal ecosystems. Until recently, however, most of this work has been focused on seemingly exceptional systems that are characterized by regular, self-organized patterns. In this review, we document that interactions that operate at long distances, beyond the direct neighborhood of individual organisms, are more common and have much more far-reaching implications for coastal ecosystems than was previously realized. We review studies from a variety of ecosystem types-including cobble beaches, mussel beds, coral reefs, seagrass meadows, and mangrove forests-that reveal a startling interplay of positive and negative interactions between habitats across distances of up to a kilometer. In addition to classical feeding relations, alterations of physical conditions constitute an important part of these long-distance interactions. This entanglement of habitats has crucial implications for how humans manage coastal ecosystems, and evaluations of anthropogenic impact should explicitly address long-distance and system-wide effects before we deem these human activities to be causing little harm.

  3. Metabolic and hormonal responses to long-distance swimming in cold water.

    PubMed

    Dulac, S; Quirion, A; DeCarufel, D; LeBlanc, J; Jobin, M; Côte, J; Brisson, G R; Lavoie, J M; Diamond, P

    1987-10-01

    The acute effects of long-distance swimming in cold water on selected hormonal and metabolic variables were evaluated on 22 long-distance swimmers (16 males and 6 females) during a 32-km swimming competition (La Traversée Internationale du Lac St-Jean). The water temperature was 18.5 degrees C and the mean performance times were 8 h and 32 min for men (M) and 9 h and 1 min for women (F). The blood samples were withdrawn in the fasting state during the week preceding the event and within 30 min after completion of the race. A positive correlation was obtained, for both groups, between percent body fat and rectal temperature measured at the end of the competition. After the competition, an increase in plasma epinephrine, norepinephrine, cortisol, thyroxine, free fatty acids, lactate, a decrease in glucose and insulin and no change in growth hormone, triiodothyronine, triglycerides, and cholesterol concentrations were observed in both groups. The increase in plasma thyroxine was more pronounced in the slower swimmers while the change in blood cortisol concentrations was higher in the subjects having the most acute decrease in body temperature. Male and female swimmers have a similar metabolic and hormonal response to a long-distance swimming competition in cold water.

  4. Molecular analysis confirms the long-distance transport of Juniperus ashei pollen

    PubMed Central

    Mohanty, Rashmi Prava; Buchheim, Mark Alan; Anderson, James; Levetin, Estelle

    2017-01-01

    Although considered rare, airborne pollen can be deposited far from its place of origin under a confluence of favorable conditions. Temporally anomalous records of Cupressacean pollen collected from January air samples in London, Ontario, Canada have been cited as a new case of long-distance transport. Data on pollination season implicated Juniperus ashei (mountain cedar), with populations in central Texas and south central Oklahoma, as the nearest source of the Cupressacean pollen in the Canadian air samples. This finding is of special significance given the allergenicity of mountain cedar pollen. While microscopy is used extensively to identify particles in the air spora, pollen from all members of the Cupressaceae, including Juniperus, are morphologically indistinguishable. Consequently, we implemented a molecular approach to characterize Juniperus pollen using PCR in order to test the long-distance transport hypothesis. Our PCR results using species-specific primers confirmed that the anomalous Cupressacean pollen collected in Canada was from J. ashei. Forward trajectory analysis from source areas in Texas and the Arbuckle Mountains in Oklahoma and backward trajectory analysis from the destination area near London, Ontario were completed using models implemented in HYSPLIT4 (Hybrid Single-Particle Lagrangian Integrated Trajectory). Results from these trajectory analyses strongly supported the conclusion that the J. ashei pollen detected in Canada had its origins in Texas or Oklahoma. The results from the molecular findings are significant as they provide a new method to confirm the long-distance transport of pollen that bears allergenic importance. PMID:28273170

  5. Feasibility of long-distance heart rate monitoring using transmittance photoplethysmographic imaging (PPGI)

    PubMed Central

    Amelard, Robert; Scharfenberger, Christian; Kazemzadeh, Farnoud; Pfisterer, Kaylen J.; Lin, Bill S.; Clausi, David A.; Wong, Alexander

    2015-01-01

    Photoplethysmography (PPG) devices are widely used for monitoring cardiovascular function. However, these devices require skin contact, which restricts their use to at-rest short-term monitoring. Photoplethysmographic imaging (PPGI) has been recently proposed as a non-contact monitoring alternative by measuring blood pulse signals across a spatial region of interest. Existing systems operate in reflectance mode, many of which are limited to short-distance monitoring and are prone to temporal changes in ambient illumination. This paper is the first study to investigate the feasibility of long-distance non-contact cardiovascular monitoring at the supermeter level using transmittance PPGI. For this purpose, a novel PPGI system was designed at the hardware and software level. Temporally coded illumination (TCI) is proposed for ambient correction, and a signal processing pipeline is proposed for PPGI signal extraction. Experimental results show that the processing steps yielded a substantially more pulsatile PPGI signal than the raw acquired signal, resulting in statistically significant increases in correlation to ground-truth PPG in both short- and long-distance monitoring. The results support the hypothesis that long-distance heart rate monitoring is feasible using transmittance PPGI, allowing for new possibilities of monitoring cardiovascular function in a non-contact manner. PMID:26440644

  6. Study on shortwave infrared long-distance imaging performance based on multiband imaging experiments

    NASA Astrophysics Data System (ADS)

    Junwei, Lang; Yueming, Wang; Xizhong, Xiao; Xiaoqiong, Zhuang; Shengwei, Wang; Jun, Liu; Jianyu, Wang

    2013-04-01

    Balloon-borne or ground-based high resolution long range observation has extensive applications in border monitoring and area surveillance. Performance of long-distance oblique or horizontal imaging systems is closely related to the atmospheric transmittance of the observing spectral band. Compared with visible and near infrared, the shortwave infrared (SWIR) band benefits from less scattering effects, which enables it to provide better quality images under harsh atmospheric conditions. We present a signal-to-noise ratio (SNR) model including atmospheric influences. Based on the model, image SNR was calculated in the spectral range of 0.4 μm to 2.5 μm. In order to validate the imaging performance model of SWIR, a multi-band camera was designed and spectral imaging experiments were conducted. The results clearly demonstrated the advantage of SWIR imaging. The experiments show that the contrast and SNR of SWIR images reduced insignificantly for long distances and under low visibility conditions. This advantage makes SWIR multiband cameras suitable for long-distance remote sensing and for observing through haze.

  7. Three distinct mechanisms of long-distance modulation of gene expression in yeast

    PubMed Central

    Du, Manyu; Zhang, Qian

    2017-01-01

    Recent Hi-C measurements have revealed numerous intra- and inter-chromosomal interactions in various eukaryotic cells. To what extent these interactions regulate gene expression is not clear. This question is particularly intriguing in budding yeast because it has extensive long-distance chromosomal interactions but few cases of gene regulation over-a-distance. Here, we developed a medium-throughput assay to screen for functional long-distance interactions that affect the average expression level of a reporter gene as well as its cell-to-cell variability (noise). We ectopically inserted an insulated MET3 promoter (MET3pr) flanked by ~1kb invariable sequences into thousands of genomic loci, allowing it to make contacts with different parts of the genome, and assayed the MET3pr activity in single cells. Changes of MET3pr activity in this case necessarily involve mechanisms that function over a distance. MET3pr has similar activities at most locations. However, at some locations, they deviate from the norm and exhibit three distinct patterns including low expression / high noise, low expression / low noise, and high expression / low noise. We provided evidence that these three patterns of MET3pr expression are caused by Sir2-mediated silencing, transcriptional interference, and 3D clustering. The clustering also occurs in the native genome and enhances the transcription of endogenous Met4-targeted genes. Overall, our results demonstrate that a small fraction of long-distance chromosomal interactions can affect gene expression in yeast. PMID:28426659

  8. Population genetic structure and long-distance dispersal of a recently expanding migratory bird.

    PubMed

    Ramos, Raül; Song, Gang; Navarro, Joan; Zhang, Ruiying; Symes, Craig T; Forero, Manuela G; Lei, Fumin

    2016-06-01

    Long-distance dispersal events and their derivable increases of genetic diversity have been highlighted as important ecological and evolutionary determinants that improve performances of range-expanding species. In the context of global environmental change, specific dispersal strategies have to be understood and foreseen if we like to prevent general biodiversity impoverishment or the spread of allochthonous diseases. We explored the genetic structure and potential population mixing on the recently range-expanding European bee-eater Merops apiaster. In addition, the species is suspected of harbouring and disseminating the most relevant disease for bees and apiculture, Nosema microsporidia. In agreement with complementary ringing recovery data and morphometric measurements, genetic results on two mitochondrial genes and 12 microsatellites showed a reasonably well-structured population partitioning along its breeding distribution. Microsatellite results indicated that not only did a few birds recently disperse long distance during their return migrations and change their natal breeding areas, but also that a group of allochthonous birds together founded a new colony. Although we did not provide evidence on the direct implication of birds in the widespread of Nosema parasites, our finding on the long-distance dispersal of bird flocks between remote breeding colonies adds concern about the role of European bee-eaters in the spread of such disease at a large, inter-continental scale.

  9. Efficient utilization of wind power: Long-distance transmission or local consumption?

    NASA Astrophysics Data System (ADS)

    Sun, Yuanzhang; Ma, Xiyuan; Xu, Jian; Bao, Yi; Liao, Siyang

    2017-06-01

    Excess wind power produced in wind-intensive areas is normally delivered to remote load centers via long-distance transmission lines. This paper presents a comparison between long-distance transmission, which has gained popularity, and local energy consumption, in which a fraction of the generated wind power can be locally consumed by energy-intensive industries. First, the challenges and solutions to the long-distance transmission and local consumption of wind power are presented. Then, the two approaches to the utilization of wind power are compared in terms of system security, reliability, cost, and capability to utilize wind energy. Finally, the economic feasibility and technical feasibility of the local consumption of wind power are demonstrated by a large and isolated industrial power system, or supermicrogrid, in China. The coal-fired generators together with the short-term interruptible electrolytic aluminum load in the supermicrogrid are able to compensate for the intermittency of wind power. In the long term, the transfer of high-energy-consumption industries to wind-rich areas and their local consumption of the available wind power are beneficial.

  10. Long-Distance Dispersal via Ocean Currents Connects Omani Clownfish Populations throughout Entire Species Range

    PubMed Central

    Claereboudt, Michel R.; Planes, Serge

    2014-01-01

    Dispersal is a crucial ecological process, driving population dynamics and defining the structure and persistence of populations. Measuring demographic connectivity between discreet populations remains a long-standing challenge for most marine organisms because it involves tracking the movement of pelagic larvae. Recent studies demonstrate local connectivity of reef fish populations via the dispersal of planktonic larvae, while biogeography indicates some larvae must disperse 100–1000 s kilometres. To date, empirical measures of long-distance dispersal are lacking and the full scale of dispersal is unknown. Here we provide the first measure of long-distance dispersal in a coral reef fish, the Omani clownfish Amphiprion omanensis, throughout its entire species range. Using genetic assignment tests we demonstrate bidirectional exchange of first generation migrants, with subsequent social and reproductive integration, between two populations separated by over 400 km. Immigration was 5.4% and 0.7% in each region, suggesting a biased southward exchange, and matched predictions from a physically-coupled dispersal model. This rare opportunity to measure long-distance dispersal demonstrates connectivity of isolated marine populations over distances of 100 s of kilometres and provides a unique insight into the processes of biogeography, speciation and adaptation. PMID:25229550

  11. Moving Large Data Sets Over High-Performance Long Distance Networks

    SciTech Connect

    Hodson, Stephen W; Poole, Stephen W; Ruwart, Thomas; Settlemyer, Bradley W

    2011-04-01

    In this project we look at the performance characteristics of three tools used to move large data sets over dedicated long distance networking infrastructure. Although performance studies of wide area networks have been a frequent topic of interest, performance analyses have tended to focus on network latency characteristics and peak throughput using network traffic generators. In this study we instead perform an end-to-end long distance networking analysis that includes reading large data sets from a source file system and committing large data sets to a destination file system. An evaluation of end-to-end data movement is also an evaluation of the system configurations employed and the tools used to move the data. For this paper, we have built several storage platforms and connected them with a high performance long distance network configuration. We use these systems to analyze the capabilities of three data movement tools: BBcp, GridFTP, and XDD. Our studies demonstrate that existing data movement tools do not provide efficient performance levels or exercise the storage devices in their highest performance modes. We describe the device information required to achieve high levels of I/O performance and discuss how this data is applicable in use cases beyond data movement performance.

  12. [Rates of breathing values and kinetics of respiration response in critical patterns of muscular activity in middle and long distance running].

    PubMed

    Volkov, N I; Kornienko, T G; Tambovtseva, R V

    2014-01-01

    Parameters of ventilation influx, ventilation debt and ventilation demand of exercise were calculated on the basis of heart rate dynamics and parameters of external breathing during the testing procedure and recovery of elite runners during of the maximum workout. It was established that all of external breathing values closely reproduce changes of basic parameters of oxygen demand during the exercises at high intensity and duration and can be used for quantification and valuation of exercise loads in sport. During the conducted at the research it was experimentally proved that high level of sporting achievements in middle and long distance running is defined by three major factors of an aerobic exchange in an organism: 1. General ratio of increase in level of pulmonary ventilation (VE), consumption of oxygen (VO2) and allocation of carbon dioxide (CO2); 2. During the expiration--rate and of supply speed of oxygen (O2) from lungs to working muscles; 3. Rate of oxygenation (StO2) and total speed of the blood-groove.

  13. Effects of Strength Training on Running Economy in Highly Trained Runners: A Systematic Review With Meta-Analysis of Controlled Trials.

    PubMed

    Balsalobre-Fernández, Carlos; Santos-Concejero, Jordan; Grivas, Gerasimos V

    2016-08-01

    Balsalobre-Fernández, C, Santos-Concejero, J, and Grivas, GV. Effects of strength training on running economy in highly trained runners: a systematic review with meta-analysis of controlled trials. J Strength Cond Res 30(8): 2361-2368, 2016-The purpose of this study was to perform a systematic review and meta-analysis of controlled trials to determine the effect of strength training programs on the running economy (RE) of high-level middle- and long-distance runners. Four electronic databases were searched in September 2015 (PubMed, SPORTDiscus, MEDLINE, and CINAHL) for original research articles. After analyzing 699 resultant original articles, studies were included if the following criteria were met: (a) participants were competitive middle- or long-distance runners; (b) participants had a V[Combining Dot Above]O2max >60 ml·kg·min; (c) studies were controlled trials published in peer-reviewed journals; (d) studies analyzed the effects of strength training programs with a duration greater than 4 weeks; and (e) RE was measured before and after the strength training intervention. Five studies met the inclusion criteria, resulting in a total sample size of 93 competitive, high-level middle- and long-distance runners. Four of the 5 included studies used low to moderate training intensities (40-70% one repetition maximum), and all of them used low to moderate training volume (2-4 resistance lower-body exercises plus up to 200 jumps and 5-10 short sprints) 2-3 times per week for 8-12 weeks. The meta-analyzed effect of strength training programs on RE in high-level middle- and long-distance runners showed a large, beneficial effect (standardized mean difference [95% confidence interval] = -1.42 [-2.23 to -0.60]). In conclusion, a strength training program including low to high intensity resistance exercises and plyometric exercises performed 2-3 times per week for 8-12 weeks is an appropriate strategy to improve RE in highly trained middle- and long-distance runners.

  14. The psychological benefits of recreational running: a field study.

    PubMed

    Szabo, Attila; Abrahám, Júlia

    2013-01-01

    Running yields positive changes in affect, but the external validity of controlled studies has received little attention in the literature. In this inquiry, 50 recreational runners completed the Exercise-Induced Feeling Inventory (Gauvin & Rejeskí, 1993) before and after a bout of self-planned running on an urban running path. Positive changes were seen in all four measures of affect (p < .001). Multivariate regressions were performed to examine the contribution of four exercise characteristics (i.e., duration of the current run, weekly running time, weekly running distance, and running experience) to the observed changes in affect. The results have revealed that exercise characteristics accounted for only 14-30% of the variance in the recreational runners' affect, in both directions. It is concluded that psychological benefits of recreational running may be linked to placebo (conditioning and/or expectancy) effects.

  15. Therapeutic Recreation

    ERIC Educational Resources Information Center

    Parks and Recreation, 1971

    1971-01-01

    Graphic profiles of (1) the professional membership of the National Therapeutic Recreation Society, (2) state-level employment opportunities in the field, and (3) educational opportunities at U.S. colleges and universities. (MB)

  16. Recreational Fisheries

    EPA Pesticide Factsheets

    Agencies shall, to the extent permitted by law and where practicable, improve the quantity, function, sustainable productivity, and distribution of U.S. aquatic resources for increased recreational fishing opportunities

  17. Long-distance dispersal of plants by vehicles as a driver of plant invasions.

    PubMed

    von der Lippe, Moritz; Kowarik, Ingo

    2007-08-01

    Roadsides are preferential migration corridors for invasive plant species and can act as starting points for plant invasions into adjacent habitats. Rapid spread and interrupted distribution patterns of introduced plant species indicate long-distance dispersal along roads. The extent to which this process is due to species' migration along linear habitats or, alternatively, to seed transport by vehicles has not yet been tested systematically. We tested this by sampling seeds inside long motorway tunnels to exclude nontraffic dispersal. Vehicles transported large amounts of seeds. The annual seed rain caused by vehicles on the roadsides of five different tunnel lanes within three tunnels along a single urban motorway in Berlin, Germany, ranged from 635 to 1579 seeds/m(2)/year. Seeds of non-native species accounted for 50.0% of the 204 species and 54.4% of the total 11,818 seeds trapped inside the tunnels. Among the samples were 39 (19.1%) highly invasive species that exhibit detrimental effects on native biodiversity in some parts of the world. By comparing the flora in the tunnel with that adjacent to the tunnel entrances we confirmed long-distance dispersal events (>250 m) for 32.3% of the sampled species. Seed sources in a radius of 100 m around the entrances of the tunnels had no significant effect on species richness and species composition of seed samples from inside the tunnels, indicating a strong effect of long-distance dispersal by vehicles. Consistently, the species composition of the tunnel seeds was more similar to the regional roadside flora of Berlin than to the local flora around the tunnel entrances. Long-distance dispersal occurred significantly more frequently in seeds of non-native (mean share 38.5%) than native species (mean share 4.1%). Our results showed that long-distance dispersal by vehicles was a routine rather than an occasional mechanism. Dispersal of plants by vehicles will thus accelerate plant invasions and induce rapid changes in

  18. 7 CFR 51.2711 - U.S. Runner Splits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false U.S. Runner Splits. 51.2711 Section 51.2711... STANDARDS) United States Standards for Shelled Runner Type Peanuts Grades § 51.2711 U.S. Runner Splits. “U.S. Runner Splits” consists of shelled Runner type peanut kernels of similar varietal characteristics which...

  19. Half-Marathon and Full-Marathon Runners' Hydration Practices and Perceptions

    PubMed Central

    O'Neal, Eric K.; Wingo, Jonathan E.; Richardson, Mark T.; Leeper, James D.; Neggers, Yasmine H.; Bishop, Phil A.

    2011-01-01

    Context: The behaviors and beliefs of recreational runners with regard to hydration maintenance are not well elucidated. Objective: To examine which beverages runners choose to drink and why, negative performance and health experiences related to dehydration, and methods used to assess hydration status. Design: Cross-sectional study. Setting: Marathon registration site. Patients or Other Participants: Men (n = 146) and women (n = 130) (age = 38.3 ± 11.3 years) registered for the 2010 Little Rock Half-Marathon or Full Marathon. Intervention(s): A 23-item questionnaire was administered to runners when they picked up their race timing chips. Main Outcome Measure(s): Runners were separated into tertiles (Low, Mod, High) based on z scores derived from training volume, expected performance, and running experience. We used a 100-mm visual analog scale with anchors of 0 (never) and 100 (always). Total sample responses and comparisons between tertile groups for questionnaire items are presented. Results: The High group (58±31) reported greater consumption of sport beverages in exercise environments than the Low (42 ± 35 mm) and Mod (39 ± 32 mm) groups (P < .05) and perceived sport beverages to be superior to water in meeting hydration needs (P < .05) and improving performance during runs greater than 1 hour (P < .05). Seventy percent of runners experienced 1 or more incidents in which they believed dehydration resulted in a major performance decrement, and 45% perceived dehydration to have resulted in adverse health effects. Twenty percent of runners reported monitoring their hydration status. Urine color was the method most often reported (7%), whereas only 2% reported measuring changes in body weight. Conclusions: Greater attention should be paid to informing runners of valid techniques to monitor hydration status and developing an appropriate individualized hydration strategy. PMID:22488182

  20. Excessive exercise habits of runners as new signs of hypertension and arrhythmia.

    PubMed

    Kim, Young-Joo; Kim, Chul-Hyun; Park, Kyoung-Min

    2016-08-15

    Excessive exercise may induce arrhythmia, and this risk is higher in middle-aged people. The study aim was to compare the exercise characteristics of middle-aged runners participating in excessive endurance exercise. The subjects of this study were 552 runners (mean age; 49.0±7.4years) without structural heart disease who performed exercise at least twice per week, had consistently exercised for at least three years, and had finished at least five marathons. The arrhythmia runner group (ARG, n=14) and normal runner group (NRG, n=538) were compared with regard to hemodynamic response, cardiorespiratory fitness level, training history, number of finished races, finishing times, and exercise habits. The mean resting systolic (134.0±15.8mmHg) and diastolic (85.8±10.9mmHg) blood pressure values indicated pre-hypertension, while the mean maximal SBP (213.7±27.4mmHg) values indicated exercise-induced hypertension. The VO2max was significantly higher and the maximal DBP was significantly lower in the ARG than in the NRG (p<0.05). Training history was significantly longer in the ARG than in the NRG (p<0.05), while the number of finished marathons, the finishing times in marathons and the exercise frequency per week didn't differ significantly between the two groups. Exercise intensity was significantly higher in the ARG than in the NRG (p<0.01). Middle-aged long-distance runners showed pre-hypertension and exercise-induced hypertension, and the ARG had higher VO2max values, greater exercise intensities, and longer training histories than the NRG. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Comparative analysis between two models of active aging and its influence on body composition, strength levels and quality of life: long-distance runners versus bodybuilders practitioners.

    PubMed

    Latorre-Román, Pedro Ángel; Izquierdo-Sánchez, Jose Manuel; Salas-Sánchez, Jesús; García-Pinillos, Felipe

    2015-04-01

    Objetivo: Analizar la composición corporal, nivel de fuerza y calidad de vida relacionada con la salud (CdV) en deportistas veteranos (mayores de 35 años) en relación a sedentarios (S), y comparar los resultados obtenidos en las mencionadas variables entre dos modelos de práctica deportiva, corredores de fondo (CF) y usuarios de musculación (UM).

  2. Increased urinary 8-hydroxy-2'-deoxyguanosine excretion in long-distance bus drivers in Taiwan.

    PubMed

    Han, Yueh-Ying; Donovan, Maryann; Sung, Fung-Chang

    2010-05-01

    Professional bus drivers are exposed to environments containing air pollution and reactive oxygen species (ROS) that can induce cellular oxidative stress and DNA damage. This study investigated environmental factors associated with oxidative DNA damage in a cohort of long-distance bus drivers. In a comparison study, urinary 8-hydroxydeoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage, was examined in 120 male long-distance bus drivers and 58 male office workers in Taiwan. Multivariate logistic regression was used to analyze association between urinary 8-OHdG levels and environmental factors. Bus drivers had higher urinary 8-OHdG levels (adjusted odds ratio (aOR)=9.4, 95% confidence interval (CI)=3.5-28.2) compared with office workers. Increased urinary 8-OHdG level was significantly related to cigarette smoking (aOR=18.0, 95% CI=7.1-52.1), consumption of energy drinks (aOR=5.0, 95% CI=2.1-12.6), and regular exercise (aOR=3.8, 95% CI=1.5-10.2). A strong exposure-response relationship was found between urinary 8-OHdG and urinary cotinine (p<0.0001). Among nonsmokers, bus drivers (aOR=3.9, 95% CI=1.0-17.7) had higher urinary 8-OHdG than office workers. Among both bus drivers and office workers, those who drank energy drinks (aOR=3.7, 95% CI=1.2-12.2) had higher 8-OHdG levels than those who did not drink energy drinks. Adjusted for smoking, levels of 8-OHdG were increased in long-distance bus drivers exposed to traffic exhaust and ingested energy drinks. Future studies should explore what aspects of energy drinks may contribute to increased urinary 8-OHdG.

  3. Don't kill the messenger: Long-distance trafficking of mRNA molecules.

    PubMed

    Spiegelman, Ziv; Golan, Guy; Wolf, Shmuel

    2013-12-01

    The phloem sap contains numerous macromolecules such as proteins and RNAs, in addition to photoassimilates, amino acids and other small molecules. The transcription profile of messenger RNA (mRNA) molecules in the sieve tubes is unique and does not reflect the transcript profile in the neighboring companion cells. This discovery suggests tight regulation on cell-to-cell movement of mRNA molecules from the companion cells into the sieve tube. Heterografting experiments and RNA-detection methods have provided unequivocal evidence for the trafficking of several specific mRNA molecules between distant organs. Detection of various plant transcripts in their respective plant parasites further confirms this long-distance movement. The finding that several of these trafficked transcripts are involved in the control of developmental processes as well as responses to growth substances or environmental cues has led to a new paradigm that mRNA molecules act as non-cell-autonomous signaling agents operating in the vascular system. Trafficking of these molecules creates a communication network between distant organs that is required for coordinated development of the whole plant under adverse conditions. The generality of this concept, however, is still under debate, because the raison d'être for long-distance movement of mRNA is not clear. In this review we discuss the identity and potential function of phloem-sap mRNA molecules, the factors facilitating RNA transport, and the rationale for their action as long-distance signaling agents in the control of developmental processes.

  4. Efficient Runner Networks for Investment Castings

    SciTech Connect

    GIVLER,RICHARD C.; SAYLORS,DAVID B.

    2000-07-18

    We present a computational method that finds an efficient runner network for an investment casting, once the gate locations have been established. The method seeks to minimize a cost function that is based on total network volume. The runner segments are restricted to lie in the space not occupied by the part itself. The collection of algorithms has been coded in C and runner designs have been computed for several real parts, demonstrating substantial reductions in rigging volume.

  5. Greater performance impairment of black runners than white runners when running in hypoxia.

    PubMed

    Santos-Concejero, J; Tucker, R; Myburgh, K H; Essen-Gustavsson, B; Kohn, T A

    2014-09-01

    This study aimed to compare the response of performance-matched black and white runners during maximal and sub-maximal running in normoxic and hypoxic conditions. 14 well-trained runners (8 black, 6 white) performed 2 incremental maximal exercise tests and 2 fatigue resistance tests at 21% O2 (normoxia) or 14% O2 (hypoxia). Respiratory parameters, heart rate (HR), lactate concentration ([La(-)]) as well as arterial saturation (SpO2) were measured. Enzyme activities and myosin heavy chain content (MHC) were also measured. White runners reached a significantly greater peak treadmill speed and a higher HRmax than black runners in hypoxia (p<0.05). Additionally, White runners achieved a greater time to fatigue than black runners (p<0.05), with black runners displaying a greater decline in performance in hypoxia compared to normoxia (20.3% vs. 13.4%, black vs. white, respectively). However, black runners presented lower [La(-)] and higher SpO2 than white runners in hypoxia (p<0.05). Black runners had a higher proportion of MHC IIa and higher lactate dehydrogenase activity (p<0.05). The greater performance impairment observed in black runners in hypoxia suggests a greater performance sensitivity to this condition, despite the maintenance of physiological variables such as SpO2 and [La (-) ] within a smaller range than white runners.

  6. Damage effects of filaments on non-transparent materials at long distances

    NASA Astrophysics Data System (ADS)

    Diener, Karsten; Borchert, Harmut; Schmitt, Rüdiger; Durand, Magali; Houard, Aurélien; Prade, Bernard; Mysyrowicz, André; Durécu, Anne; Fleury, Didier; Moreau, Bernard; Vasseur, Olivier; Théberge, Francis; Chateauneuf, Marc; Dubois, Jacques

    2011-12-01

    We observed multiple filamentation of a Terawatt fs-laser beam (λ = 800 nm, E = 170 mJ/pulse) after 1 km horizontal propagation in the atmosphere. The interaction of these filaments with the non-transparent targets was studied. The filaments were strong enough to damage the surface of optical windows like Ge and ZnSe even at long distances and under turbulent conditions. The damage effects were analysed by studying the modulation transfer function (MTF), the spectral transmission loss, the ablation depth and the damage threshold. LIBS was applied to estimate the plasma temperature during the interaction process.

  7. Heterosis May Result in Selection Favouring the Products of Long-Distance Pollen Dispersal in Eucalyptus

    PubMed Central

    Costa e Silva, João; Potts, Brad M.; Lopez, Gustavo A.

    2014-01-01

    Using native trees from near the northern and southern extremities of the relatively continuous eastern distribution of Eucalyptus globulus in Tasmania, we compared the progenies derived from natural open-pollination (OP) with those generated from within-region and long-distance outcrossing. Controlled outcrossing amongst eight parents - with four parents from each of the northern and southern regions - was undertaken using a diallel mating scheme. The progeny were planted in two field trials located within the species native range in southern Tasmania, and their survival and diameter growth were monitored over a 13-year-period. The survival and growth performances of all controlled cross types exceeded those of the OP progenies, consistent with inbreeding depression due to a combination of selfing and bi-parental inbreeding. The poorer survival of the northern regional (♀N♂N) outcrosses compared with the local southern regional outcrosses (♀S♂S) indicated differential selection against the former. Despite this mal-adaptation of the non-local ♀N♂N crosses at both southern sites, the survival of the inter-regional hybrids (♀N♂S and ♀S♂N) was never significantly different from that of the local ♀S♂S crosses. Significant site-dependent heterosis was detected for the growth of the surviving long-distance hybrids. This was expressed as mid-parent heterosis, particularly at the more northern planting site. Heterosis increased with age, while the difference between the regional ♀N♂N and ♀S♂S crosses remained insignificant at any age at either site. Nevertheless, the results for growth suggest that the fitness of individuals derived from long-distance crossing may be better at the more northern of the planting sites. Our results demonstrate the potential for early-age assessments of pollen dispersal to underestimate realised gene flow, with local inbreeding under natural open-pollination resulting in selection favouring the products of

  8. Heterosis may result in selection favouring the products of long-distance pollen dispersal in Eucalyptus.

    PubMed

    Costa E Silva, João; Potts, Brad M; Lopez, Gustavo A

    2014-01-01

    Using native trees from near the northern and southern extremities of the relatively continuous eastern distribution of Eucalyptus globulus in Tasmania, we compared the progenies derived from natural open-pollination (OP) with those generated from within-region and long-distance outcrossing. Controlled outcrossing amongst eight parents - with four parents from each of the northern and southern regions - was undertaken using a diallel mating scheme. The progeny were planted in two field trials located within the species native range in southern Tasmania, and their survival and diameter growth were monitored over a 13-year-period. The survival and growth performances of all controlled cross types exceeded those of the OP progenies, consistent with inbreeding depression due to a combination of selfing and bi-parental inbreeding. The poorer survival of the northern regional (♀N♂N) outcrosses compared with the local southern regional outcrosses (♀S♂S) indicated differential selection against the former. Despite this mal-adaptation of the non-local ♀N♂N crosses at both southern sites, the survival of the inter-regional hybrids (♀N♂S and ♀S♂N) was never significantly different from that of the local ♀S♂S crosses. Significant site-dependent heterosis was detected for the growth of the surviving long-distance hybrids. This was expressed as mid-parent heterosis, particularly at the more northern planting site. Heterosis increased with age, while the difference between the regional ♀N♂N and ♀S♂S crosses remained insignificant at any age at either site. Nevertheless, the results for growth suggest that the fitness of individuals derived from long-distance crossing may be better at the more northern of the planting sites. Our results demonstrate the potential for early-age assessments of pollen dispersal to underestimate realised gene flow, with local inbreeding under natural open-pollination resulting in selection favouring the products of

  9. Long-distance quantum information transfer with strong coupling hybrid solid system

    NASA Astrophysics Data System (ADS)

    Zhang, Feng-Yang; Chen, Xin-Yu; Li, Chong; Song, He-Shan

    2015-11-01

    In this paper, we demonstrate how information can be transferred among the long-distance memory units in a hybrid solid architecture, which consists the nitrogen-vacancy (NV) ensemble acting as the memory unit, the LC circuit acting as the transmitter (receiver), and the flux qubit acting as the interface. Numerical simulation demonstrates that the high-fidelity quantum information transfer between memory unit and transmitter (receiver) can be implemented, and this process is robust to both the LC circuit decay and NV ensemble spontaneous emission.

  10. Long-distance transport of phytohormones through the plant vascular system.

    PubMed

    Lacombe, Benoit; Achard, Patrick

    2016-12-01

    Phytohormones are a group of low abundance molecules that activate various metabolic and developmental processes in response to environmental and endogenous signals. Like animal hormones, plant hormones often have distinct source and target tissues, hence ensuring long-range communication at the whole-plant level. Plants rely on various hormone distribution mechanisms depending on the distance and the direction of the transport. Here, we highlight the recent findings on the long-distance movement of plant hormones within the vasculature, from the physiological role to the molecular mechanism of the transport. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Long-Distance Electron Tunneling in Proteins: A New Challenge for Time-Resolved Spectroscopy1

    PubMed Central

    Stuchebrukhov, A. A.

    2010-01-01

    Long-distance electron tunneling is a fundamental process which is involved in energy generation in cells. The tunneling occurs between the metal centers in the respiratory enzymes, typically over distances up to 20 or 30 Å. For such distances, the tunneling time—i.e., the time during which an electron passes through the body of the protein molecule from one metal center to another—is of the order of 10 fs. Here the process of electron tunneling in proteins is reviewed, and a possibility of experimental observation of real-time electron tunneling in a single protein molecule is discussed. PMID:25364214

  12. A one-way quantum amplifier for long-distance quantum communication

    NASA Astrophysics Data System (ADS)

    Elemy, Hany

    2017-05-01

    In this paper, a model for single photon amplification based on cluster-state quantum computation is proposed. A rescaling of the probability amplitudes of a deteriorated qubit in favor of the one-photon component will define the amplifier's gain. Unlike the heralded quantum amplifiers, the probabilistic success of the whole process will not depend on the successful detection of a heralding signal. Instead, the whole procedure will rely upon a single-qubit measurement, which is simpler compared to any two-qubit interaction gate in the heralded quantum amplifiers. The proposed model can be used as a qubit protector against propagation losses in long-distance quantum communication networks.

  13. Master-Slave Locking of Optomechanical Oscillators over a Long Distance

    NASA Astrophysics Data System (ADS)

    Shah, Shreyas Y.; Zhang, Mian; Rand, Richard; Lipson, Michal

    2015-03-01

    Frequency locking and other phenomena emerging from nonlinear interactions between mechanical oscillators are of scientific and technological importance. However, existing schemes to observe such behavior are not scalable over distance. We demonstrate a scheme to couple two independent mechanical oscillators, separated in frequency by 80 kHz and situated far from each other (3.2 km), via light. Using light as the coupling medium enables this scheme to have low loss and be extended over long distances. This scheme is reversible and can be generalized for arbitrary network configurations.

  14. Long-distance root-to-shoot transport of phytochelatins and cadmium in Arabidopsis

    PubMed Central

    Gong, Ji-Ming; Lee, David A.; Schroeder, Julian I.

    2003-01-01

    Phytochelatin synthases (PCS) mediate cellular heavy-metal resistance in plants, fungi, and worms. However, phytochelatins (PCs) are generally considered to function as intracellular heavy-metal detoxification mechanisms, and whether long-distance transport of PCs occurs during heavy-metal detoxification remains unknown. Here, wheat TaPCS1 cDNA expression was either targeted to Arabidopsis roots with the Arabidopsis alcohol dehydrogenase (Adh) promoter (Adh::TaPCS1/cad1-3) or ectopically expressed with the cauliflower mosaic virus 35S promoter (35S::TaPCS1/cad1-3) in the PC-deficient mutant cad1-3. Adh::TaPCS1/cad1-3 and 35S::TaPCS1/cad1-3 complemented the cadmium, mercury, and arsenic sensitivities of the cad1-3 mutant. Northern blot, RT-PCR, and Western blot analyses showed Adh promoter-driven TaPCS1 expression only in roots and thus demonstrated lack of long-distance TaPCS1 mRNA and protein transport in plants. Fluorescence HPLC analyses showed that under Cd2+ stress, no PCs were detectable in cad1-3. However, in Adh::TaPCS1/cad1-3 plants, PCs were detected in roots and in rosette leaves and stems. Inductively coupled plasma atomic emission spectrometer analyses showed that either root-specific or ectopic expression of TaPCS1 significantly enhanced long-distance Cd2+ transport into stems and rosette leaves. Unexpectedly, transgenic expression of TaPCS1 reduced Cd2+ accumulation in roots compared with cad1-3. The reduced Cd2+ accumulation in roots and enhanced root-to-shoot Cd2+ transport in transgenic plants were abrogated by l-buthionine sulfoximine. The presented findings show that (i) transgenic expression of TaPCS1 suppresses the heavy-metal sensitivity of cad1-3, (ii) PCs can be transported from roots to shoots, and (iii) transgenic expression of the TaPCS1 gene increases long-distance root-to-shoot Cd2+ transport and reduces Cd2+ accumulation in roots. PMID:12909714

  15. Mixing of propagules from discrete sources at long distance: comparing a dispersal tail to an exponential

    PubMed Central

    Klein, Etienne K; Lavigne, Claire; Gouyon, Pierre-Henri

    2006-01-01

    Background Rare long distance dispersal events impact the demography and the genetic structure of populations. When dispersal is modelled via a dispersal kernel, one possible characterisation of long-distance dispersal is given by the shape of the tail of the kernel, i.e. its type of decay. This characteristic is known to directly act on the speed and pattern of colonization, and on the spatial structure of genetic diversity during colonization. In particular, colonization waves behave differently depending on whether the kernel decreases faster or slower than an exponential (i.e. is thin-tailed vs. fat-tailed). To interpret and extend published results on the impact of long-distance dispersal on the genetic structure of populations, we examine a classification of dispersal kernels based on the shape of their tails and formally demonstrate qualitative differences among them that can influence the predicted diversity of a propagule pool sampled far from two distinct sources. Results We show that a fat-tailed kernel leads asymptotically to a diverse propagule pool containing a balanced mixing of the propagules from the two sources, whereas a thin-tailed kernel results in all propagules originating from the closest source. We further show that these results hold for biologically relevant distances under certain circumstances, and in particular if the number of propagules is large enough, as would be the case for pollen or seeds. Conclusion To understand the impact of long-distance dispersal on the structure and dynamics of a metapopulation, it might be less important to precisely estimate an average dispersal distance than to determine if the tail of the dispersal kernel is fatter or thinner than that of an exponential function. Depending solely on this characteristic, a metapopulation will behave similarly to an island model with a diverse immigrant pool or to a stepping-stone model with migrants from closest populations. Our results further help to understand why

  16. C/1995 O1 Hale-Bopp: Short and Long Distance activity from a Theoretical Model

    NASA Astrophysics Data System (ADS)

    Capria, Maria Teresa; Coradini, Angioletta; de Sanctis, Maria Cristina

    2002-06-01

    A theoretical model of the nucleus thermal evolutionand differentiation is used to simulatethe evolution along the orbit of the gasand dust emissions of comet Hale-Bopp. The model was already applied to this comet (Capria et al., 2000b): At that time only the results of the observations obtained shortly after the perihelion were available. Now much more data have been published and we present more refined and complete results about the production rates of gasand dust along the orbit and the internal stratigraphy. The results of our model on long distance activity and its explanation are also presented.

  17. Persistent quantum beats and long-distance entanglement from waveguide-mediated interactions.

    PubMed

    Zheng, Huaixiu; Baranger, Harold U

    2013-03-15

    We study photon-photon correlations and entanglement generation in a one-dimensional waveguide coupled to two qubits with an arbitrary spatial separation. To treat the combination of nonlinear elements and 1D continuum, we develop a novel Green function method. The vacuum-mediated qubit-qubit interactions cause quantum beats to appear in the second-order correlation function. We go beyond the Markovian regime and observe that such quantum beats persist much longer than the qubit lifetime. A high degree of long-distance entanglement can be generated, increasing the potential of waveguide-QED systems for scalable quantum networking.

  18. Percent utilization of VO2 max at 5-km competition velocity does not determine time performance at 5 km among elite distance runners.

    PubMed

    Støa, Eva Maria; Støren, Øyvind; Enoksen, Eystein; Ingjer, Frank

    2010-05-01

    The present study investigated to what extent maximum oxygen uptake (VO2 max) and fractional utilization (%VO2 max) in 5-km competition speed correlate with 5-km performance times among elite long distance runners. Eight elite long distance runners with 5-km performance times of 15.10 minutes ( +/- 32 seconds) were tested for VO2 max during an incremental protocol and for %VO2 max during an 8-minute treadmill test at the velocity representing their 5-km seasonal best performance time. There was no correlation between fractional utilization and 5-km performance. The study showed no significant difference between VO2 max obtained during an incremental VO2 max test and %VO2 max when running for 8 minutes at the runner's individual 5-km competition speed. The 5-km time was related to the runner's VO2 max even in a homogenous high-level performance group. In conclusion, the present study found no relationship between fractional utilization and 5-km performance time. Training aiming to increase %VO2 max may thus be of little or no importance in performance enhancement for competitions lasting up to approximately 20 minutes.

  19. Research for visualization of running state of long-distance water transmission pipeline based on OpenGL

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoping; Xu, Xuejun; Liu, Bing; Zhang, Zhendong

    2017-03-01

    The running condition of long distance water pipeline are complicated and changeable, and the lag of water flow is obvious, which is the key technical problem to be solved in the process of regulation and control. According to the present situation of the long-distance water conveyance project, the visualization simulation technology is used to study the operation and management of the long-distance water conveyance pipeline based on OpenGL technology. The system developed in this paper can combine pipeline information, working condition data and relevant data to provide a visualization platform for analysis and decision-making of project management and operation.

  20. Sports-related dermatoses among road runners in Southern Brazil*

    PubMed Central

    Purim, Kátia Sheylla Malta; Leite, Neiva

    2014-01-01

    BACKGROUND Road running is a growing sport. OBJECTIVES: To determine the prevalence of sports-related dermatoses among road runners. METHODS Cross-sectional study of 76 road runners. Assessment was performed by means of a questionnaire, interview, and clinical examination. The chi-square and linear trend tests were used for analysis. RESULTS Most athletes were men (61%), aged 38±11 years, who ran mid- or long-distance courses (60.5%) for 45 to 60 minutes (79%), for a total of 25-64 km (42.1% ) or more than 65 km (18.4%) per week. The most prevalent injuries were blisters (50%), chafing (42.1%), calluses (34.2%), onychomadesis (31.5%), tinea pedis (18.4%), onychocryptosis (14.5%), and cheilitis simplex (14.5%). Among athletes running >64 km weekly, several conditions were significantly more frequent: calluses (p<0.04), jogger's nipple (p<0.004), cheilitis simplex (p<0.05), and tinea pedis (p<0.004). There was a significant association between the weekly running distance and the probability of skin lesions. Of the athletes in our sample, 57% trained before 10 a.m., 86% wore clothing and accessories for sun protection, 62% wore sunscreen, and 19.7% experienced sunburn. Traumatic and environmental dermatoses are common in practitioners of this outdoor sport, and are influenced by the weekly running distance. CONCLUSION In this group of athletes, rashes, blisters, sunburn, and nail disorders were recurrent complaints regardless of running distance. Calluses, athlete's foot, chapped lips, and jogger's nipple predominated in individuals who ran longer routes. PMID:25054745

  1. Predictive Variables of Half-Marathon Performance for Male Runners

    PubMed Central

    Gómez-Molina, Josué; Ogueta-Alday, Ana; Camara, Jesus; Stickley, Christoper; Rodríguez-Marroyo, José A.; García-López, Juan

    2017-01-01

    The aims of this study were to establish and validate various predictive equations of half-marathon performance. Seventy-eight half-marathon male runners participated in two different phases. Phase 1 (n = 48) was used to establish the equations for estimating half-marathon performance, and Phase 2 (n = 30) to validate these equations. Apart from half-marathon performance, training-related and anthropometric variables were recorded, and an incremental test on a treadmill was performed, in which physiological (VO2max, speed at the anaerobic threshold, peak speed) and biomechanical variables (contact and flight times, step length and step rate) were registered. In Phase 1, half-marathon performance could be predicted to 90.3% by variables related to training and anthropometry (Equation 1), 94.9% by physiological variables (Equation 2), 93.7% by biomechanical parameters (Equation 3) and 96.2% by a general equation (Equation 4). Using these equations, in Phase 2 the predicted time was significantly correlated with performance (r = 0.78, 0.92, 0.90 and 0.95, respectively). The proposed equations and their validation showed a high prediction of half-marathon performance in long distance male runners, considered from different approaches. Furthermore, they improved the prediction performance of previous studies, which makes them a highly practical application in the field of training and performance. Key points The present study obtained four equations involving anthropometric, training, physiological and biomechanical variables to estimate half-marathon performance. These equations were validated in a different population, demonstrating narrows ranges of prediction than previous studies and also their consistency. As a novelty, some biomechanical variables (i.e. step length and step rate at RCT, and maximal step length) have been related to half-marathon performance. PMID:28630571

  2. Factors associated with falling asleep at the wheel among long-distance truck drivers.

    PubMed

    McCartt, A T; Rohrbaugh, J W; Hammer, M C; Fuller, S Z

    2000-07-01

    Data on the prevalence and hypothesized predictors of falling asleep while driving were gathered through face-to-face interviews with 593 long-distance truck drivers randomly selected at public and private rest areas and routine roadside truck safety inspections. Hypothesized predictor variables related to drivers' typical work and rest patterns, extent of daytime and night-time drowsiness, symptoms of sleep disorder, measures of driving exposure, and demographic characteristics. A sizeable proportion of long-distance truck drivers reported falling asleep at the wheel of the truck: 47.1% of the survey respondents had ever fallen asleep at the wheel of a truck, and 25.4% had fallen asleep at the wheel in the past year. Factor analysis reduced the large set of predictors to six underlying, independent factors: greater daytime sleepiness; more arduous schedules, with more hours of work and fewer hours off-duty; older, more experienced drivers; shorter, poorer sleep on road; symptoms of sleep disorder; and greater tendency to night-time drowsy driving. Based on multivariate logistic regression, all six factors were predictive of self-reported falling asleep at the wheel. Falling asleep was also associated with not having been alerted by driving over shoulder rumble strips. The results suggest that countermeasures that limit drivers' work hours and enable drivers to get adequate rest and that identify drivers with sleep disorders are appropriate methods to reduce sleepiness-related driving by truck drivers.

  3. Long-distance quantum communication over noisy networks without long-time quantum memory

    NASA Astrophysics Data System (ADS)

    Mazurek, Paweł; Grudka, Andrzej; Horodecki, Michał; Horodecki, Paweł; Łodyga, Justyna; Pankowski, Łukasz; PrzysieŻna, Anna

    2014-12-01

    The problem of sharing entanglement over large distances is crucial for implementations of quantum cryptography. A possible scheme for long-distance entanglement sharing and quantum communication exploits networks whose nodes share Einstein-Podolsky-Rosen (EPR) pairs. In Perseguers et al. [Phys. Rev. A 78, 062324 (2008), 10.1103/PhysRevA.78.062324] the authors put forward an important isomorphism between storing quantum information in a dimension D and transmission of quantum information in a D +1 -dimensional network. We show that it is possible to obtain long-distance entanglement in a noisy two-dimensional (2D) network, even when taking into account that encoding and decoding of a state is exposed to an error. For 3D networks we propose a simple encoding and decoding scheme based solely on syndrome measurements on 2D Kitaev topological quantum memory. Our procedure constitutes an alternative scheme of state injection that can be used for universal quantum computation on 2D Kitaev code. It is shown that the encoding scheme is equivalent to teleporting the state, from a specific node into a whole two-dimensional network, through some virtual EPR pair existing within the rest of network qubits. We present an analytic lower bound on fidelity of the encoding and decoding procedure, using as our main tool a modified metric on space-time lattice, deviating from a taxicab metric at the first and the last time slices.

  4. Ecological specialization to fluctuating resources prevents long-distance migratory raptors from becoming sedentary on islands.

    PubMed

    Gangoso, Laura; López-López, Pascual; Grande, Juan Manuel; Mellone, Ugo; Limiñana, Rubén; Urios, Vicente; Ferrer, Miguel

    2013-01-01

    The adaptive transition between behavioral strategies, such as the shift from migratoriness to sedentariness, remains an outstanding question in evolutionary ecology. Density-dependent variation in the age of first breeding has been proposed as a feasible mechanism through which long-lived migratory birds with deferred sexual maturity should become sedentary to persist on islands. Although this pattern seems to hold for most raptors and herons, a few exceptions have been identified. One of these exceptions is the Eleonora's falcon, a long-distance migratory bird, which shows one of the most peculiar adaptations in the timing of reproduction and food requirements among raptors. Here, we compiled data concerning demography, banding recoveries and satellite tracking of Eleonora's falcons to discuss likely explanations for the exceptional behavior of this insular long-distance migratory species. New data reveal that Eleonora's falcons do return to the natal colonies in their first year and young birds are able to breed. However, in contrast to previous hypothesis, the highly specialized strategy of this and other ecologically similar species, as well as the virtual lack of food during winter at breeding areas prevent them from becoming sedentary on islands. Although the ultimate mechanisms underlying the process of sedentarization remain poorly understood, the evidence provided reveal the existence of important trade-offs associated with ecological specialization that may become particularly relevant in the present context of global change.

  5. Fiber optic cable-based high-resolution, long-distance VGA extenders

    NASA Astrophysics Data System (ADS)

    Rhee, Jin-Geun; Lee, Iksoo; Kim, Heejoon; Kim, Sungjoon; Koh, Yeon-Wan; Kim, Hoik; Lim, Jiseok; Kim, Chur; Kim, Jungwon

    2013-02-01

    Remote transfer of high-resolution video information finds more applications in detached display applications for large facilities such as theaters, sports complex, airports, and security facilities. Active optical cables (AOCs) provide a promising approach for enhancing both the transmittable resolution and distance that standard copper-based cables cannot reach. In addition to the standard digital formats such as HDMI, the high-resolution, long-distance transfer of VGA format signals is important for applications where high-resolution analog video ports should be also supported, such as military/defense applications and high-resolution video camera links. In this presentation we present the development of a compressionless, high-resolution (up to WUXGA, 1920x1200), long-distance (up to 2 km) VGA extenders based on serialized technique. We employed asynchronous serial transmission and clock regeneration techniques, which enables lower cost implementation of VGA extenders by removing the necessity for clock transmission and large memory at the receiver. Two 3.125-Gbps transceivers are used in parallel to meet the required maximum video data rate of 6.25 Gbps. As the data are transmitted asynchronously, 24-bit pixel clock time stamp is employed to regenerate video pixel clock accurately at the receiver side. In parallel to the video information, stereo audio and RS-232 control signals are transmitted as well.

  6. Extremely long-distance seed dispersal by an overfished Amazonian frugivore.

    PubMed

    Anderson, Jill T; Nuttle, Tim; Saldaña Rojas, Joe S; Pendergast, Thomas H; Flecker, Alexander S

    2011-11-22

    Throughout Amazonia, overfishing has decimated populations of fruit-eating fishes, especially the large-bodied characid, Colossoma macropomum. During lengthy annual floods, frugivorous fishes enter vast Amazonian floodplains, consume massive quantities of fallen fruits and egest viable seeds. Many tree and liana species are clearly specialized for icthyochory, and seed dispersal by fish may be crucial for the maintenance of Amazonian wetland forests. Unlike frugivorous mammals and birds, little is known about seed dispersal effectiveness of fishes. Extensive mobility of frugivorous fish could result in extremely effective, multi-directional, long-distance seed dispersal. Over three annual flood seasons, we tracked fine-scale movement patterns and habitat use of wild Colossoma, and seed retention in the digestive tracts of captive individuals. Our mechanistic model predicts that Colossoma disperses seeds extremely long distances to favourable habitats. Modelled mean dispersal distances of 337-552 m and maximum of 5495 m are among the longest ever reported. At least 5 per cent of seeds are predicted to disperse 1700-2110 m, farther than dispersal by almost all other frugivores reported in the literature. Additionally, seed dispersal distances increased with fish size, but overfishing has biased Colossoma populations to smaller individuals. Thus, overexploitation probably disrupts an ancient coevolutionary relationship between Colossoma and Amazonian plants.

  7. Capability of long distance 100  GHz FMCW using a single GDD lamp sensor.

    PubMed

    Levanon, Assaf; Rozban, Daniel; Aharon Akram, Avihai; Kopeika, Natan S; Yitzhaky, Yitzhak; Abramovich, Amir

    2014-12-20

    Millimeter wave (MMW)-based imaging systems are required for applications in medicine, homeland security, concealed weapon detection, and space technology. The lack of inexpensive room temperature imaging sensors makes it difficult to provide a suitable MMW system for many of the above applications. A 3D MMW imaging system based on chirp radar was studied previously using a scanning imaging system of a single detector. The radar system requires that the millimeter wave detector will be able to operate as a heterodyne detector. Since the source of radiation is a frequency modulated continuous wave (FMCW), the detected signal as a result of heterodyne detection gives the object's depth information according to value of difference frequency, in addition to the reflectance of the 2D image. New experiments show the capability of long distance FMCW detection by using a large scale Cassegrain projection system, described first (to our knowledge) in this paper. The system presents the capability to employ a long distance of at least 20 m with a low-cost plasma-based glow discharge detector (GDD) focal plane array (FPA). Each point on the object corresponds to a point in the image and includes the distance information. This will enable relatively inexpensive 3D MMW imaging.

  8. A comprehensive strategy for identifying long-distance mobile peptides in xylem sap.

    PubMed

    Okamoto, Satoru; Suzuki, Takamasa; Kawaguchi, Masayoshi; Higashiyama, Tetsuya; Matsubayashi, Yoshikatsu

    2015-11-01

    There is a growing awareness that secreted pemediate organ-to-organ communication in higher plants. Xylem sap peptidomics is an effective but challenging approach for identifying long-distance mobile peptides. In this study we developed a simple, gel-free purification system that combines o-chlorophenol extraction with HPLC separation. Using this system, we successfully identified seven oligopeptides from soybean xylem sap exudate that had one or more post-transcriptional modifications: glycosylation, sulfation and/or hydroxylation. RNA sequencing and quantitative PCR analyses showed that the peptide-encoding genes are expressed in multiple tissues. We further analyzed the long-distance translocation of four of the seven peptides using gene-encoding peptides with single amino acid substitutions, and identified these four peptides as potential root-to-shoot mobile oligopeptides. Promoter-GUS analysis showed that all four peptide-encoding genes were expressed in the inner tissues of the root endodermis. Moreover, we found that some of these peptide-encoding genes responded to biotic and/or abiotic factors. These results indicate that our purification system provides a comprehensive approach for effectively identifying endogenous small peptides and reinforce the concept that higher plants employ various peptides in root-to-shoot signaling.

  9. Acute phase protein concentrations after limited distance and long distance endurance rides in horses.

    PubMed

    Cywińska, Anna; Szarska, Ewa; Górecka, Renata; Witkowski, Lucjan; Hecold, Mateusz; Bereznowski, Andrzej; Schollenberger, Antoni; Winnicka, Anna

    2012-12-01

    Acute phase proteins (APP) have been described as useful for assessing health in human and animal patients, as they closely reflect the acute phase reaction (APR). In humans and dogs a reaction analogous to APR has also been described after prolonged or strenuous exercise. The aim of this study was to determine, if similar reactions occur in endurance horses after limited and long distance rides. Seventeen horses that successfully completed various distance competitions were tested. Routine haematological and biochemical tests were performed and the concentrations of serum amyloid A (SAA), C-reactive protein (CRP) and haptoglobin were measured. Typical endurance exercise-induced haematological and biochemical changes were observed in all horses, regardless the distance. After long distance rides, the level of SAA markedly increased, but CRP and haptoglobin concentrations remained unchanged. After limited distance rides no changes in the levels of APPs were noted. Exercise-induced APR in horses occurred only after prolonged, strenuous exertion, and differed from APR in inflammation in that only SAA concentration was increased.

  10. SHD digital cinema distribution over a long distance network of Internet2

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Takahiro; Shirai, Daisuke; Fujii, Tatsuya; Nomura, Mitsuru; Fujii, Tetsuro; Ono, Sadayasu

    2003-06-01

    We have developed a prototype SHD (Super High Definition) digital cinema distribution system that can store, transmit and display eight-million-pixel motion pictures that have the image quality of a 35-mm film movie. The system contains a video server, a real-time decoder, and a D-ILA projector. Using a gigabit Ethernet link and TCP/IP, the server transmits JPEG2000 compressed motion picture data streams to the decoder at transmission speeds as high as 300 Mbps. The received data streams are decompressed by the decoder, and then projected onto a screen via the projector. With this system, digital cinema contents can be distributed over a wide-area optical gigabit IP network. However, when digital cinema contents are delivered over long distances by using a gigabit IP network and TCP, the round-trip time increases and network throughput either stops rising or diminishes. In a long-distance SHD digital cinema transmission experiment performed on the Internet2 network in October 2002, we adopted enlargement of the TCP window, multiple TCP connections, and shaping function to control the data transmission quantity. As a result, we succeeded in transmitting the SHD digital cinema content data at about 300 Mbps between Chicago and Los Angeles, a distance of more than 3000 km.

  11. Migratory connectivity and population-specific migration routes in a long-distance migratory bird.

    PubMed

    Trierweiler, Christiane; Klaassen, Raymond H G; Drent, Rudi H; Exo, Klaus-Michael; Komdeur, Jan; Bairlein, Franz; Koks, Ben J

    2014-03-07

    Knowledge about migratory connectivity, the degree to which individuals from the same breeding site migrate to the same wintering site, is essential to understand processes affecting populations of migrants throughout the annual cycle. Here, we study the migration system of a long-distance migratory bird, the Montagu's harrier Circus pygargus, by tracking individuals from different breeding populations throughout northern Europe. We identified three main migration routes towards wintering areas in sub-Saharan Africa. Wintering areas and migration routes of different breeding populations overlapped, a pattern best described by 'weak (diffuse) connectivity'. Migratory performance, i.e. timing, duration, distance and speed of migration, was surprisingly similar for the three routes despite differences in habitat characteristics. This study provides, to our knowledge, a first comprehensive overview of the migration system of a Palaearctic-African long-distance migrant. We emphasize the importance of spatial scale (e.g. distances between breeding populations) in defining patterns of connectivity and suggest that knowledge about fundamental aspects determining distribution patterns, such as the among-individual variation in mean migration directions, is required to ultimately understand migratory connectivity. Furthermore, we stress that for conservation purposes it is pivotal to consider wintering areas as well as migration routes and in particular stopover sites.

  12. Temperate origins of long-distance seasonal migration in New World songbirds.

    PubMed

    Winger, Benjamin M; Barker, F Keith; Ree, Richard H

    2014-08-19

    Migratory species exhibit seasonal variation in their geographic ranges, often inhabiting geographically and ecologically distinct breeding and nonbreeding areas. The complicated geography of seasonal migration has long posed a challenge for inferring the geographic origins of migratory species as well as evolutionary sequences of change in migratory behavior. To address this challenge, we developed a phylogenetic model of the joint evolution of breeding and nonbreeding (winter) ranges and applied it to the inference of biogeographic history in the emberizoid passerine birds. We found that seasonal migration between breeding ranges in North America and winter ranges in the Neotropics evolved primarily via shifts of winter ranges toward the tropics from ancestral ranges in North America. This result contrasts with a dominant paradigm that hypothesized migration evolving out of the tropics via shifts of the breeding ranges. We also show that major lineages of tropical, sedentary emberizoids are derived from northern, migratory ancestors. In these lineages, the winter ranges served as a biogeographic conduit for temperate-to-tropical colonization: winter-range shifts toward the tropics during the evolution of long-distance migration often preceded southward shifts of breeding ranges, the loss of migration, and in situ tropical diversification. Meanwhile, the evolution of long-distance migration enabled the persistence of old lineages in North America. These results illuminate how the evolution of seasonal migration has contributed to greater niche conservatism among tropical members of this diverse avian radiation.

  13. Long-distance dispersal to oceanic islands: success of plants with multiple diaspore specializations

    PubMed Central

    Vargas, Pablo; Arjona, Yurena; Nogales, Manuel; Heleno, Ruben H.

    2015-01-01

    A great number of scientific papers claim that angiosperm diversification is manifested by an ample differentiation of diaspore traits favouring long-distance seed dispersal. Oceanic islands offer an ideal framework to test whether the acquisition of multiple sets of diaspore traits (syndromes) by a single species results in a wider geographic distribution. To this end, we performed floristic and syndrome analyses and found that diplochorous species (two syndromes) are overrepresented in the recipient flora of the Azores in contrast to that of mainland Europe, but not to mainland Portugal. An additional analysis of inter-island colonization showed a general trend of a higher number of islands colonized by species with a single syndrome (monochorous) and two syndromes than species with no syndrome (unspecialized). Nevertheless, statistical significance for differences in colonization is meagre in some cases, partially due to the low proportion of diplochorous species in Europe (244 of ∼10 000 species), mainland Portugal (89 of 2294 species), and the Azores (9 of 148 species), Canaries (17 of 387 lowland species) and Galápagos (18 of 313 lowland species). Contrary to expectations, this first study shows only a very marginal advantage for long-distance dispersal of species bearing multiple syndromes. PMID:26174146

  14. Long-distance movement of phosphate starvation-responsive microRNAs in Arabidopsis.

    PubMed

    Huen, Amanda K; Rodriguez-Medina, Caren; Ho, Angela Y Y; Atkins, Craig A; Smith, Penelope M C

    2017-03-21

    Plant microRNAs are small RNAs that are important for genetic regulation of processes such as plant development or environmental responses. Specific microRNAs accumulate in the phloem during phosphate starvation, and may act as long-distance signalling molecules. We performed quantitative PCR on Arabidopsis hypocotyl micrograft tissues of wild-type and hen1-6 mutants to assess the mobility of several phosphate starvation-responsive microRNA species. In addition to the previously-confirmed mobile species miR399d, the corresponding microRNA* (miR399d*) was identified for the first time as mobile between shoots and roots. Translocation by phosphate-responsive microRNAs miR827 and miR2111a between shoots and roots during phosphate starvation was evident, while their respective microRNA*s were not mobile. The results suggest that long-distance mobility of microRNA species is selective and can occur without the corresponding duplex strand. Movement of miR399d* and root-localised accumulation of miR2111a* opens the potential for persisting microRNA*s to be mobile and functional in novel pathways during phosphate starvation responses. This article is protected by copyright. All rights reserved.

  15. The monarch butterfly genome yields insights into long-distance migration

    PubMed Central

    Zhan, Shuai; Merlin, Christine; Boore, Jeffrey L.; Reppert, Steven M.

    2011-01-01

    SUMMARY We present the draft 273 Mb genome of the migratory monarch butterfly (Danaus plexippus) and a set of 16, 866 protein-coding genes. Orthology properties suggest that the Lepidoptera are the fastest evolving insect order yet examined. Compared to the silkmoth Bombyx mori, the monarch genome shares prominent similarity in orthology content, microsynteny, and protein family sizes. The monarch genome reveals: a vertebrate-like opsin whose existence in insects is widespread; a full repertoire of molecular components for the monarch circadian clockwork; all members of the juvenile hormone biosynthetic pathway whose regulation shows unexpected sexual dimorphism; additional molecular signatures of oriented flight behavior; microRNAs that are differentially expressed between summer and migratory butterflies; monarch-specific expansions of chemoreceptors potentially important for long-distance migration; and a variant of the sodium/potassium pump that underlies a valuable chemical defense mechanism. The monarch genome enhances our ability to better understand the genetic and molecular basis of long-distance migration. PMID:22118469

  16. Repeatability of individual migration routes, wintering sites, and timing in a long-distance migrant bird.

    PubMed

    van Wijk, Rien E; Bauer, Silke; Schaub, Michael

    2016-12-01

    Migratory birds are often faithful to wintering (nonbreeding) sites, and also migration timing is usually remarkably consistent, that is, highly repeatable. Spatiotemporal repeatability can be of advantage for multiple reasons, including familiarity with local resources and predators as well as avoiding the costs of finding a new place, for example, nesting grounds. However, when the environment is variable in space and time, variable site selection and timing might be more rewarding. To date, studies on spatial and temporal repeatability in short-lived long-distance migrants are scarce, most notably of first-time and subsequent migrations. Here, we investigated repeatability in autumn migration directions, wintering sites, and annual migration timing in Hoopoes (Upupa epops), a long-distance migrant, using repeated tracks of adult and first-time migrants. Even though autumn migration directions were mostly the same, individual wintering sites often changed from year to year with distances between wintering sites exceeding 1,000 km. The timing of migration was repeatable within an individual during autumn, but not during spring migration. We suggest that Hoopoes respond to variable environmental conditions such as north-south shifts in rainfall during winter and differing onset of the food availability during spring migration.

  17. Ecological Specialization to Fluctuating Resources Prevents Long-Distance Migratory Raptors from Becoming Sedentary on Islands

    PubMed Central

    Gangoso, Laura; López-López, Pascual; Grande, Juan Manuel; Mellone, Ugo; Limiñana, Rubén; Urios, Vicente; Ferrer, Miguel

    2013-01-01

    Background The adaptive transition between behavioral strategies, such as the shift from migratoriness to sedentariness, remains an outstanding question in evolutionary ecology. Density-dependent variation in the age of first breeding has been proposed as a feasible mechanism through which long-lived migratory birds with deferred sexual maturity should become sedentary to persist on islands. Although this pattern seems to hold for most raptors and herons, a few exceptions have been identified. One of these exceptions is the Eleonora’s falcon, a long-distance migratory bird, which shows one of the most peculiar adaptations in the timing of reproduction and food requirements among raptors. Methodology/Principal Findings Here, we compiled data concerning demography, banding recoveries and satellite tracking of Eleonora’s falcons to discuss likely explanations for the exceptional behavior of this insular long-distance migratory species. Conclusions/Significance New data reveal that Eleonora’s falcons do return to the natal colonies in their first year and young birds are able to breed. However, in contrast to previous hypothesis, the highly specialized strategy of this and other ecologically similar species, as well as the virtual lack of food during winter at breeding areas prevent them from becoming sedentary on islands. Although the ultimate mechanisms underlying the process of sedentarization remain poorly understood, the evidence provided reveal the existence of important trade-offs associated with ecological specialization that may become particularly relevant in the present context of global change. PMID:23626704

  18. Migratory connectivity and population-specific migration routes in a long-distance migratory bird

    PubMed Central

    Trierweiler, Christiane; Klaassen, Raymond H. G.; Drent, Rudi H.; Exo, Klaus-Michael; Komdeur, Jan; Bairlein, Franz; Koks, Ben J.

    2014-01-01

    Knowledge about migratory connectivity, the degree to which individuals from the same breeding site migrate to the same wintering site, is essential to understand processes affecting populations of migrants throughout the annual cycle. Here, we study the migration system of a long-distance migratory bird, the Montagu's harrier Circus pygargus, by tracking individuals from different breeding populations throughout northern Europe. We identified three main migration routes towards wintering areas in sub-Saharan Africa. Wintering areas and migration routes of different breeding populations overlapped, a pattern best described by ‘weak (diffuse) connectivity’. Migratory performance, i.e. timing, duration, distance and speed of migration, was surprisingly similar for the three routes despite differences in habitat characteristics. This study provides, to our knowledge, a first comprehensive overview of the migration system of a Palaearctic-African long-distance migrant. We emphasize the importance of spatial scale (e.g. distances between breeding populations) in defining patterns of connectivity and suggest that knowledge about fundamental aspects determining distribution patterns, such as the among-individual variation in mean migration directions, is required to ultimately understand migratory connectivity. Furthermore, we stress that for conservation purposes it is pivotal to consider wintering areas as well as migration routes and in particular stopover sites. PMID:24430850

  19. Temperate origins of long-distance seasonal migration in New World songbirds

    PubMed Central

    Winger, Benjamin M.; Barker, F. Keith; Ree, Richard H.

    2014-01-01

    Migratory species exhibit seasonal variation in their geographic ranges, often inhabiting geographically and ecologically distinct breeding and nonbreeding areas. The complicated geography of seasonal migration has long posed a challenge for inferring the geographic origins of migratory species as well as evolutionary sequences of change in migratory behavior. To address this challenge, we developed a phylogenetic model of the joint evolution of breeding and nonbreeding (winter) ranges and applied it to the inference of biogeographic history in the emberizoid passerine birds. We found that seasonal migration between breeding ranges in North America and winter ranges in the Neotropics evolved primarily via shifts of winter ranges toward the tropics from ancestral ranges in North America. This result contrasts with a dominant paradigm that hypothesized migration evolving out of the tropics via shifts of the breeding ranges. We also show that major lineages of tropical, sedentary emberizoids are derived from northern, migratory ancestors. In these lineages, the winter ranges served as a biogeographic conduit for temperate-to-tropical colonization: winter-range shifts toward the tropics during the evolution of long-distance migration often preceded southward shifts of breeding ranges, the loss of migration, and in situ tropical diversification. Meanwhile, the evolution of long-distance migration enabled the persistence of old lineages in North America. These results illuminate how the evolution of seasonal migration has contributed to greater niche conservatism among tropical members of this diverse avian radiation. PMID:25092321

  20. Extremely long-distance seed dispersal by an overfished Amazonian frugivore

    PubMed Central

    Anderson, Jill T.; Nuttle, Tim; Saldaña Rojas, Joe S.; Pendergast, Thomas H.; Flecker, Alexander S.

    2011-01-01

    Throughout Amazonia, overfishing has decimated populations of fruit-eating fishes, especially the large-bodied characid, Colossoma macropomum. During lengthy annual floods, frugivorous fishes enter vast Amazonian floodplains, consume massive quantities of fallen fruits and egest viable seeds. Many tree and liana species are clearly specialized for icthyochory, and seed dispersal by fish may be crucial for the maintenance of Amazonian wetland forests. Unlike frugivorous mammals and birds, little is known about seed dispersal effectiveness of fishes. Extensive mobility of frugivorous fish could result in extremely effective, multi-directional, long-distance seed dispersal. Over three annual flood seasons, we tracked fine-scale movement patterns and habitat use of wild Colossoma, and seed retention in the digestive tracts of captive individuals. Our mechanistic model predicts that Colossoma disperses seeds extremely long distances to favourable habitats. Modelled mean dispersal distances of 337–552 m and maximum of 5495 m are among the longest ever reported. At least 5 per cent of seeds are predicted to disperse 1700–2110 m, farther than dispersal by almost all other frugivores reported in the literature. Additionally, seed dispersal distances increased with fish size, but overfishing has biased Colossoma populations to smaller individuals. Thus, overexploitation probably disrupts an ancient coevolutionary relationship between Colossoma and Amazonian plants. PMID:21429923

  1. The monarch butterfly genome yields insights into long-distance migration.

    PubMed

    Zhan, Shuai; Merlin, Christine; Boore, Jeffrey L; Reppert, Steven M

    2011-11-23

    We present the draft 273 Mb genome of the migratory monarch butterfly (Danaus plexippus) and a set of 16,866 protein-coding genes. Orthology properties suggest that the Lepidoptera are the fastest evolving insect order yet examined. Compared to the silkmoth Bombyx mori, the monarch genome shares prominent similarity in orthology content, microsynteny, and protein family sizes. The monarch genome reveals a vertebrate-like opsin whose existence in insects is widespread; a full repertoire of molecular components for the monarch circadian clockwork; all members of the juvenile hormone biosynthetic pathway whose regulation shows unexpected sexual dimorphism; additional molecular signatures of oriented flight behavior; microRNAs that are differentially expressed between summer and migratory butterflies; monarch-specific expansions of chemoreceptors potentially important for long-distance migration; and a variant of the sodium/potassium pump that underlies a valuable chemical defense mechanism. The monarch genome enhances our ability to better understand the genetic and molecular basis of long-distance migration. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Allometric scaling of long-distance seed dispersal by migratory birds.

    PubMed

    Viana, Duarte S; Santamaría, Luis; Michot, Thomas C; Figuerola, Jordi

    2013-05-01

    Migratory birds are often suggested to be important vectors for long-distance dispersal (LDD) of plant and animal propagules. The scale of such dispersal events (hundreds to thousands of kilometers) can influence landscape-level biological processes and species distributions. However, the few vector species studied and the lack of proper integration of their migratory movement in models of LDD has precluded the study of their potential as long-distance biotic dispersers. By means of a mechanistic model parameterized with empirical data, we first investigated the properties of seed dispersal curves generated by migratory birds and then analyzed the effect of bird size on model parameters and consequent seed dispersal patterns. Seed dispersal curves showed in most cases large and heavy tails, resulting in relatively frequent LDD (up to 3.5% of dispersal distances longer than 100 km). Bird size mediated trade-offs between bird movement and seed retention time that, in turn, determined seed dispersal patterns and the potential of each bird species as an LDD vector. Our modeling framework builds on a mechanistic understanding of seed dispersal by migratory birds and may thus be a useful tool to estimate the scale and frequency of bird-mediated, large-scale transport of native, invasive, and pathogenic organisms.

  3. Long-distance fiber optic sensing solutions for pipeline leakage, intrusion, and ground movement detection

    NASA Astrophysics Data System (ADS)

    Nikles, Marc

    2009-05-01

    An increasing number of pipelines are constructed in remote regions affected by harsh environmental conditions where pipeline routes often cross mountain areas which are characterized by unstable grounds and where soil texture changes between winter and summer increase the probability of hazards. Third party intentional interference or accidental intrusions are a major cause of pipeline failures leading to large leaks or even explosions. Due to the long distances to be monitored and the linear nature of pipelines, distributed fiber optic sensing techniques offer significant advantages and the capability to detect and localize pipeline disturbance with great precision. Furthermore pipeline owner/operators lay fiber optic cable parallel to transmission pipelines for telecommunication purposes and at minimum additional cost monitoring capabilities can be added to the communication system. The Brillouin-based Omnisens DITEST monitoring system has been used in several long distance pipeline projects. The technique is capable of measuring strain and temperature over 100's kilometers with meter spatial resolution. Dedicated fiber optic cables have been developed for continuous strain and temperature monitoring and their deployment along the pipeline has enabled permanent and continuous pipeline ground movement, intrusion and leak detection. This paper presents a description of the fiber optic Brillouin-based DITEST sensing technique, its measurement performance and limits, while addressing future perspectives for pipeline monitoring. The description is supported by case studies and illustrated by field data.

  4. Identification of host factors potentially involved in RTM-mediated resistance during potyvirus long distance movement.

    PubMed

    Sofer, Luc; Cabanillas, Daniel Garcia; Gayral, Mathieu; Téplier, Rachèle; Pouzoulet, Jérôme; Ducousso, Marie; Dufin, Laurène; Bréhélin, Claire; Ziegler-Graff, Véronique; Brault, Véronique; Revers, Frédéric

    2017-07-01

    The long distance movement of potyviruses is a poorly understood step of the viral cycle. Only factors inhibiting this process, referred to as "Restricted TEV Movement" (RTM), have been identified in Arabidopsis thaliana. On the virus side, the potyvirus coat protein (CP) displays determinants required for long-distance movement and for RTM-based resistance breaking. However, the potyvirus CP was previously shown not to interact with the RTM proteins. We undertook the identification of Arabidopsis factors which directly interact with either the RTM proteins or the CP of lettuce mosaic virus (LMV). An Arabidopsis cDNA library generated from companion cells was screened with LMV CP and RTM proteins using the yeast two-hybrid system. Fourteen interacting proteins were identified. Two of them were shown to interact with CP and the RTM proteins suggesting that a multiprotein complex could be formed between the RTM proteins and virions or viral ribonucleoprotein complexes. Co-localization experiments in Nicotiana benthamiana showed that most of the viral and cellular protein pairs co-localized at the periphery of chloroplasts which suggests a putative role for plastids in this process.

  5. Effect of long-distance transportation on serum metabolic profiles of steer calves.

    PubMed

    Takemoto, Satoshi; Tomonaga, Shozo; Funaba, Masayuki; Matsui, Tohru

    2017-07-19

    Long-distance transportation is sometimes inevitable in the beef industry because of the geographic separation of major breeding and fattening areas. Long-distance transportation negatively impacts production and health of cattle, which may, at least partly, result from the disturbance of metabolism during and after transportation. However, alteration of metabolism remains elusive in transported cattle. We investigated the effects of transportation on the metabolomic profiles of Holstein steer calves. Non-targeted analysis of serum concentrations of low molecular weight metabolites was performed by gas chromatography mass spectrometry. Transportation affected 38 metabolites in the serum. A pathway analysis suggested that 26, 10, and 10 pathways were affected immediately after transportation, and 3 and 7 days after transportation, respectively. Some pathways were disturbed only immediately after transportation, likely because of feed and water withdrawal during transit. Nicotinate and nicotinamide metabolism, and citric acid cycle were affected for 3 days after transportation, whereas propionate metabolism, phenylalanine and tyrosine metabolism were affected throughout the experiment. Four pathways were not affected immediately after transportation, but were altered thereafter. These results suggested that many metabolic pathways had marked perturbations during transportation. Metabolites such as citric acid, propionate, tyrosine and niacin can be candidate supplements for mitigating transportation-induced adverse effects. © 2017 Japanese Society of Animal Science.

  6. Long-Distance Charge Carrier Funneling in Perovskite Nanowires Enabled by Built-in Halide Gradient.

    PubMed

    Tian, Wenming; Leng, Jing; Zhao, Chunyi; Jin, Shengye

    2017-01-18

    The excellent charge carrier transportation in organolead halide perovskites is one major contributor to the high performance of many perovskite-based devices. There still exists a possibility for further enhancement of carrier transportation through nanoscale engineering, owing to the versatile wet-chemistry synthesis and processing of perovskites. Here we report the successful synthesis of bromide-gradient CH3NH3PbBrxI3-x single-crystalline nanowires (NWs) by a solid-to-solid ion exchange reaction starting from one end of pure CH3NH3PbI3 NWs, which was confirmed by local photoluminescence (PL) and energy dispersive X-ray spectroscopy (EDS) measurements. Due to the built-in halide gradient, the long-distance carrier transportation was driven by the energy funnel, rather than the spontaneous carrier diffusion. Indeed, local PL kinetics demonstrated effective charge carrier transportation only from the high-bandgap bromide-rich region to the low-bandgap iodine-rich region over a few micrometers. Therefore, these halide gradient NWs might find applications in various optoelectronic devices requiring long-distance and directional delivery of excitation energy.

  7. Research on numerical simulation and protection of transient process in long-distance slurry transportation pipelines

    NASA Astrophysics Data System (ADS)

    Lan, G.; Jiang, J.; Li, D. D.; Yi, W. S.; Zhao, Z.; Nie, L. N.

    2013-12-01

    The calculation of water-hammer pressure phenomenon of single-phase liquid is already more mature for a pipeline of uniform characteristics, but less research has addressed the calculation of slurry water hammer pressure in complex pipelines with slurry flows carrying solid particles. In this paper, based on the developments of slurry pipelines at home and abroad, the fundamental principle and method of numerical simulation of transient processes are presented, and several boundary conditions are given. Through the numerical simulation and analysis of transient processes of a practical engineering of long-distance slurry transportation pipeline system, effective protection measures and operating suggestions are presented. A model for calculating the water impact of solid and fluid phases is established based on a practical engineering of long-distance slurry pipeline transportation system. After performing a numerical simulation of the transient process, analyzing and comparing the results, effective protection measures and operating advice are recommended, which has guiding significance to the design and operating management of practical engineering of longdistance slurry pipeline transportation system.

  8. A Grounded Theory of Students' Long-Distance Coping With a Family Member's Cancer.

    PubMed

    Basinger, Erin D; Wehrman, Erin C; Delaney, Amy L; McAninch, Kelly G

    2015-08-01

    In this study, we explore how family members cope with one source of stress-cancer diagnosis and treatment. We suggest that coping away from one's family is characterized by constraints that are not common to proximal coping. We conducted six focus groups with college students (N = 21) at a university in the United States to investigate their long-distance coping experiences and used grounded theory methods to develop a model of college students' long-distance coping. Negotiating the tension between being here (at school) and being there (at home) was central to their experiences. Participants described four manifestations of their negotiation between here and there (i.e., expressing/hiding emotion, longing to care for the patient there/avoiding responsibility here, feeling shock at degeneration there/escaping degeneration by being here, and lacking information from there) and three strategies they used to cope (i.e., being here and withdrawing, being here and doing school, and seeking/not seeking support).

  9. Estuarine crocodiles ride surface currents to facilitate long-distance travel.

    PubMed

    Campbell, Hamish A; Watts, Matthew E; Sullivan, Scott; Read, Mark A; Choukroun, Severine; Irwin, Steve R; Franklin, Craig E

    2010-09-01

    1. The estuarine crocodile (Crocodylus porosus) is the world's largest living reptile. It predominately inhabits freshwater and estuarine habitats, but widespread geographic distribution throughout oceanic islands of the South-east Pacific suggests that individuals undertake sizeable ocean voyages. 2. Here we show that adult C. porosus adopt behavioural strategies to utilise surface water currents during long-distance travel, enabling them to move quickly and efficiently over considerable distances. 3. We used acoustic telemetry to monitor crocodile movement throughout 63 km of river, and found that when individuals engaged in a long-distance, constant direction journey (>10 km day(-1)), they would only travel when current flow direction was favourable. Depth and temperature measurements from implanted transmitters showed that they remained at the water surface during travel but would dive to the river substratum or climb out on the river bank if current flow direction became unfavourable. 4. Satellite positional fixes from tagged crocodiles engaged in ocean travel were overlaid with residual surface current (RSC) estimates. The data showed a strong correlation existed between the bearing of the RSC and that of the travelling crocodile (r(2) = 0.92, P < 0.0001). 5. The study demonstrates that C. porosus dramatically increase their travel potential by riding surface currents, providing an effective dispersal strategy for this species.

  10. Euglossine bees mediate only limited long-distance gene flow in a tropical vine.

    PubMed

    Opedal, Øystein H; Falahati-Anbaran, Mohsen; Albertsen, Elena; Armbruster, W Scott; Pérez-Barrales, Rocío; Stenøien, Hans K; Pélabon, Christophe

    2017-03-01

    Euglossine bees (Apidae: Euglossini) have long been hypothesized to act as long-distance pollinators of many low-density tropical plants. We tested this hypothesis by the analysis of gene flow and genetic structure within and among populations of the euglossine bee-pollinated vine Dalechampia scandens. Using microsatellite markers, we assessed historical gene flow by the quantification of regional-scale genetic structure and isolation by distance among 18 populations, and contemporary gene flow by the estimation of recent migration rates among populations. To assess bee-mediated pollen dispersal on a smaller scale, we conducted paternity analyses within a focal population, and quantified within-population spatial genetic structure in four populations. Gene flow was limited to certain nearby populations within continuous forest blocks, whereas drift appeared to dominate on larger scales. Limited long-distance gene flow was supported by within-population patterns; gene flow was biased towards nearby plants, and significant small-scale spatial genetic structure was detected within populations. These findings suggest that, although female euglossine bees might be effective at moving pollen within populations, and perhaps within forest blocks, their contribution to gene flow on the regional scale seems too limited to counteract genetic drift in patchily distributed tropical plants. Among-population gene flow might have been reduced following habitat fragmentation.

  11. US long distance fiber optic networks: Technology, evolution and advanced concepts. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Over the past two decades, fiber optics has emerged as a highly practical and cost-efficient communications technology. Its competitiveness vis-a-vis other transmission media, especially satellite, has become a critical question. This report studies the likely evolution and application of fiber optic networks in the United States to the end of the century. The outlook for the technology of fiber systems is assessed and forecast, scenarios of the evolution of fiber optic network development are constructed, and costs to provide service are determined and examined parametrically as a function of network size and traffic carried. Volume 1 consists of the Executive Summary. Volume 2 focuses on fiber optic technology and long distance fiber optic networks. Volume 3 develops a traffic and financial model of a nationwide long distance transmission network. Among the study's most important conclusions are: revenue requirements per circuit for LATA-to-LATA fiber optic links are less than one cent per call minute; multiplex equipment, which is likely to be required in any competing system, is the largest contributor to circuit costs; the potential capacity of fiber optic cable is very large and as yet undefined; and fiber optic transmission combined with other network optimization schemes can lead to even lower costs than those identified in this study.

  12. Long-distance aerial dispersal modelling of Culicoides biting midges: case studies of incursions into Australia.

    PubMed

    Eagles, Debbie; Melville, Lorna; Weir, Richard; Davis, Steven; Bellis, Glenn; Zalucki, Myron P; Walker, Peter J; Durr, Peter A

    2014-06-19

    Previous studies investigating long-distance, wind-borne dispersal of Culicoides have utilised outbreaks of clinical disease (passive surveillance) to assess the relationship between incursion and dispersal event. In this study, species of exotic Culicoides and isolates of novel bluetongue viruses, collected as part of an active arbovirus surveillance program, were used for the first time to assess dispersal into an endemic region. A plausible dispersal event was determined for five of the six cases examined. These include exotic Culicoides specimens for which a possible dispersal event was identified within the range of two days--three weeks prior to their collection and novel bluetongue viruses for which a dispersal event was identified between one week and two months prior to their detection in cattle. The source location varied, but ranged from Lombok, in eastern Indonesia, to Timor-Leste and southern Papua New Guinea. Where bluetongue virus is endemic, the concurrent use of an atmospheric dispersal model alongside existing arbovirus and Culicoides surveillance may help guide the strategic use of limited surveillance resources as well as contribute to continued model validation and refinement. Further, the value of active surveillance systems in evaluating models for long-distance dispersal is highlighted, particularly in endemic regions where knowledge of background virus and vector status is beneficial.

  13. Long-distance aerial dispersal modelling of Culicoides biting midges: case studies of incursions into Australia

    PubMed Central

    2014-01-01

    Background Previous studies investigating long-distance, wind-borne dispersal of Culicoides have utilised outbreaks of clinical disease (passive surveillance) to assess the relationship between incursion and dispersal event. In this study, species of exotic Culicoides and isolates of novel bluetongue viruses, collected as part of an active arbovirus surveillance program, were used for the first time to assess dispersal into an endemic region. Results A plausible dispersal event was determined for five of the six cases examined. These include exotic Culicoides specimens for which a possible dispersal event was identified within the range of two days – three weeks prior to their collection and novel bluetongue viruses for which a dispersal event was identified between one week and two months prior to their detection in cattle. The source location varied, but ranged from Lombok, in eastern Indonesia, to Timor-Leste and southern Papua New Guinea. Conclusions Where bluetongue virus is endemic, the concurrent use of an atmospheric dispersal model alongside existing arbovirus and Culicoides surveillance may help guide the strategic use of limited surveillance resources as well as contribute to continued model validation and refinement. Further, the value of active surveillance systems in evaluating models for long-distance dispersal is highlighted, particularly in endemic regions where knowledge of background virus and vector status is beneficial. PMID:24943652

  14. Oxidative and antioxidant status in plasma of runners: effect of oral supplementation with natural antioxidants.

    PubMed

    Di Giacomo, Claudia; Acquaviva, Rosaria; Sorrenti, Valeria; Vanella, Angelo; Grasso, Salvatore; Barcellona, Maria Luisa; Galvano, Fabio; Vanella, Luca; Renis, Marcella

    2009-02-01

    Aerobic exercise increases free radical production as a consequence of enhanced oxygen consumption. If free radical formation exceeds antioxidant capacity, lipids, proteins, and DNA may be oxidized. Oxidative stress is widely recognized as a factor in many degenerative human diseases. The role of dietary antioxidants in protection against disease is a topic of continuing interest. In fact, there is epidemiological evidence correlating a higher intake of nutrients possessing antioxidant abilities with a lower incidence of various human diseases. This study was directed at investigating whether changes in plasma antioxidant capacity and oxidative stress markers occur in voluntary wheel runners, before and after oral supplementation with lycopene and isoflavones. For this purpose, plasma antioxidant capacity and oxidative stress markers were assessed in long distance runners at the end of a 60-minute run. Comparisons were made between runners before and after 60 days of supplementation with lycopene and isoflavones. DNA damage in blood cells of the same samples was also evaluated by comet assay. This investigation shows that oral supplementation with lycopene and soy-derived isoflavones significantly reduced lipid peroxidation and enhanced plasma nonproteic antioxidant defense.

  15. Social Services: Recreation Occupations

    ERIC Educational Resources Information Center

    Rones, Philip L.

    1976-01-01

    Description of recreation services for the elderly in two areas, community recreation and therapeutic recreation, includes employment information for the various levels: Recreation director, supervisor, leader, activity specialist, and aide. (JT)

  16. Recreation Manual.

    ERIC Educational Resources Information Center

    North Dakota Farmers Union, Jamestown. Dept. of Youth Activities.

    Suggestions for recreational activities are outlined in this manual. Instructions are given for games to play in small places, home or party games, paper and pencil games, children's singing games, and dances. Ideas for crafts and special parties are also included. (SW)

  17. Outdoor recreation

    Treesearch

    J. M. Bowker; Ashley Askew; H. Ken Cordell; John C. Bergstrom

    2013-01-01

    Key FindingsBy 2060, the number of southern adults participating in each of 10 different popular outdoor recreation activities is projected to increase. Depending on future demographic, economic, land use, and population changes, the activity demonstrating the least growth in participants is hunting (8–25 percent). The activity projected to...

  18. The impact of footwear and packweight on injury and illness among long-distance hikers.

    PubMed

    Anderson, L Stewart; Rebholz, Casey M; White, Laura F; Mitchell, Patricia; Curcio, Edward P; Feldman, James A; Kahn, Joseph H

    2009-01-01

    To determine the prevalence and predictors of injury and illness among long-distance hikers. This was a cross-sectional study of long-distance hikers (> 500 miles [805 km]) along the Appalachian Trail and Pacific Crest Trails between August and October of 2006. An 8-page survey instrument was made available to hikers at a designated station near the northern terminus of the respective trails. The survey questions were yes/no or multiple choice. Independent variables included packweight, footwear, and type and frequency of water purification. chi(2) tests to compare categorical data and the Cochran-Armitage test for trend were used (P < .05 significant). We used logistic regression to compare the variables concurrently, and significance was determined using likelihood ratio tests. Profile likelihood confidence intervals for the odds ratios are reported. Of the 128 hikers completing surveys that met inclusion criteria, the mean age was 33 years (range = 18-65 years), 94% walked >1500 miles (2400 km), and 70% were male. Using univariate analysis, trends were noted in the proportion of hikers reporting paresthesias and increasing packweight (35% with 10-20 pound [4.5-9 kg] packs, 50% with 21-30 pound [9.5-13.5 kg] packs, and 69% with >31 pound [14 kg] packs [P < .002]), as well as in the proportion of hikers reporting paresthesias and increasing footwear rigidity (29% sandals, 36% running shoes, 42% hiking shoes, and 68% hiking boots [P < .001]). In multivariate analysis compared to sandals, the odds ratio of suffering from paresthesias with running shoes was 1.57 (95% CI 0.3, 12.2), hiking shoes 1.73 (95% CI 0.3, 13.9), and hiking boots 3.9 (95% CI 0.7, 32.1) (P = .16). Compared to 10 to 20 pound (4.5-9 kg) packs, the odds ratios of suffering from paresthesias with 21 to 30 pound (9.5-13.5 kg) packs was 1.5 (95% CI 0.6, 3.9), and for > 31 pounds (14 kg) was 2.2 (CI 0.7, 7.1) (P = .03). Adjusting for footwear and pack weight, only pack weight was significantly

  19. Large-eddy simulations of wind farm production and long distance wakes

    NASA Astrophysics Data System (ADS)

    Eriksson, O.; Nilsson, K.; Breton, S.-P.; Ivanell, S.

    2015-06-01

    The future development of offshore wind power will include many wind farms built in the same areas. It is known that wind farms produce long distance wakes, which means that we will see more occasions of farm to farm interaction, namely one wind farm operating in the wake of another wind farm. This study investigates how to perform accurate power predictions on large wind farms and how to assess the long distance wakes generated by these farms. The focus of this paper is the production's and wake's sensitivity to the extension of the grid as well as the turbulence when using Large-eddy simulations (LES) with pregenerated Mann turbulence. The aim is to determine an optimal grid which minimizes blockage effects and ensures constant resolution in the entire wake region at the lowest computational cost. The simulations are first performed in the absence of wind turbines in order to assess how the atmospheric turbulence and wind profile are evolving downstream (up to 12,000 m behind the position where the turbulence is imposed). In the second step, 10 turbines are added in the domain (using an actuator disc method) and their production is analyzed alongside the mean velocities in the domain. The blockage effects are tested using grids with different vertical extents. An equidistant region is used in order to ensure high resolution in the wake region. The importance of covering the entire wake structure inside the equidistant region is analyzed by decreasing the size of this region. In this step, the importance of the lateral size of the Mann turbulence box is also analyzed. In the results it can be seen that the flow is acceptably preserved through the empty domain if a larger turbulence box is used. The relative production is increased (due to blockage effects) for the last turbines using a smaller vertical domain, increased for a lower or narrower equidistant region (due to the smearing of the wake in the stretched area) and decreased when using a smaller turbulence

  20. Skeletal muscle plasticity with marathon training in novice runners.

    PubMed

    Luden, N; Hayes, E; Minchev, K; Louis, E; Raue, U; Conley, T; Trappe, S

    2012-10-01

    The purpose of this study was to investigate leg muscle adaptation in runners preparing for their first marathon. Soleus and vastus lateralis (VL) biopsies were obtained from six recreational runners (23 ± 1 years, 61 ± 3 kg) before (T1), after 13 weeks of run training (T2), and after 3 weeks of taper and marathon (T3). Single muscle fiber size, contractile function (strength, speed, and power) and oxidative enzyme activity [citrate synthase (CS)] were measured at all three time points, and fiber type distribution was determined before and after the 16-week intervention. Training increased VO(2max) ∼9% (P<0.05). All soleus parameters were unchanged. VL MHC I fiber diameter increased (+8%; P<0.05) from T1 to T2. VL MHC I V(o) (-12%), MHC I power (-22%) and MHC IIa power (-29%) were reduced from T1 to T2 (P<0.05). No changes in VL single fiber contractile properties were observed from T2 to T3. No change was observed in soleus CS activity, whereas VL CS activity increased 66% (P<0.05). Our observations indicate that modest marathon training elicits very specific skeletal muscle adaptations that likely support the ability to perform 42.2 km of continuous running - further strengthening the existing body of evidence for skeletal muscle specificity.

  1. Graduated Compression Stockings for Runners: Friend, Foe, or Fake?

    PubMed Central

    Bovenschen, H. Jorn; te Booij, Mariëlle; van der Vleuten, Carine J. M.

    2013-01-01

    Objective: To assess the effect of graduated compression stockings (GCS) on lower leg volume and leg complaints in runners during and after exercise. Design: Cross-sectional study. Setting: Radboud University Nijmegen Medical Centre and an outdoor running track in Nijmegen, The Netherlands. Patients or Other Participants: Thirteen Dutch trained recreational runners. Intervention(s): Participants used a GCS on 1 leg during running. Main Outcome Measures: (1) Lower leg volume of both legs was measured at baseline, directly after running, and at 5 minutes and 30 minutes after running using a validated perometer. (2) Leg complaints were reported on questionnaires at set intervals. Results: (1) In both experiments, the legs with GCS showed a reduction in mean (± SEM) leg volume directly after running, as compared with the leg without GCS: −14.1 ± 7.6 mL (P = .04) for the 10-km running track and −53.5 ± 17.8 mL (P = .03) for the maximum exercise test. This effect was not observed at 5 and 30 minutes after running. (2) No differences in leg complaints were reported in either experiment. Conclusions: The GCS prevented an increase in leg volume just after the running exercise. However, this result was not accompanied by a reduction in subjective questionnaire-reported leg complaints. The practical consequences of the present findings need further study. PMID:23672387

  2. Long-distance monitoring of physiological and environmental parameters for emergency operators.

    PubMed

    Magenes, Giovanni; Curone, Davide; Lanati, Matteo; Secco, Emanuele L

    2009-01-01

    The recent disaster provoked by the earthquake in middle Italy has pointed out the need for minimizing risks endangering rescuers' lives. An European Project called ProeTEX (Protection e-Textiles: MicroNanoStructured fiber systems for Emergency-Disaster Wear) aims at developing smart garments able to monitor physiological and environmental parameters of emergency operators. The goal is to realize a wearable system detecting health state parameters of the users (heart rate, breathing rate, body temperature, blood oxygen saturation, position, activity and posture) and environmental variables (external temperature, presence of toxic gases and heat flux passing through the garments) and remotely transmitting useful information to the operation manager. This work presents an overview of the main features of the second prototype realized by ProeTEX with particular emphasis to the sensor's body network and the long distance transmission of signals.

  3. Long-distance transport, vacuolar sequestration and transcriptional responses induced by cadmium and arsenic

    PubMed Central

    Mendoza-Cózatl, David G.; Jobe, Timothy O.; Hauser, Felix; Schroeder, Julian I.

    2011-01-01

    Summary Iron, zinc, copper and manganese are essential metals for cellular enzyme functions while cadmium, mercury and the metalloid arsenic lack any biological function. Both, essential and non-essential metals and metalloids are extremely reactive and toxic. Therefore, plants have acquired specialized mechanisms to sense, transport and maintain essential metals within physiological concentrations and to detoxify non-essential metals and metalloids. This review focuses on the recent identification of transporters that sequester cadmium and arsenic in vacuoles and the mechanisms mediating the partitioning of these metal(loid)s between roots and shoots. We further discuss recent models of phloem-mediated long-distance transport, seed accumulation of Cd and As and recent data demonstrating that plants posses a defined transcriptional response that allow plants to preserve metal homeostasis. This research is instrumental for future engineering of reduced toxic metal(loid) accumulation in edible crop tissues as well as for improved phytoremediation technologies. PMID:21820943

  4. Cable bacteria associated with long-distance electron transport in New England salt marsh sediment.

    PubMed

    Larsen, Steffen; Nielsen, Lars Peter; Schramm, Andreas

    2015-04-01

    Filamentous Desulfobulbaceae have been proposed as 'cable bacteria', which electrically couple sulfide oxidation and oxygen reduction in marine sediment and thereby create a centimetre-deep suboxic zone. We incubated New England salt marsh sediment and found long-distance electron transport across 6 mm and 16S rRNA genes identical to those of previously observed cable bacteria in Aarhus Bay sediment incubations. Cable bacteria density in sediment cores was quantified by fluorescence in situ hybridization. In contrast to the coastal, subtidal sediments with short-termed blooms of cable bacteria based on rapidly depleted iron sulfide pools, the salt marsh cable community was based on ongoing sulfate reduction and therefore probably more persistent. Previously observed seasonal correlation between Desulfobulbaceae dominance and extensive reduced sulfur oxidation in salt marshes suggest that cable bacteria at times may have an important role in situ.

  5. Mode-resolved frequency comb interferometry for high-accuracy long distance measurement.

    PubMed

    van den Berg, Steven A; van Eldik, Sjoerd; Bhattacharya, Nandini

    2015-09-30

    Optical frequency combs have developed into powerful tools for distance metrology. In this paper we demonstrate absolute long distance measurement using a single femtosecond frequency comb laser as a multi-wavelength source. By applying a high-resolution spectrometer based on a virtually imaged phased array, the frequency comb modes are resolved spectrally to the level of an individual mode. Having the frequency comb stabilized against an atomic clock, thousands of accurately known wavelengths are available for interferometry. From the spectrally resolved output of a Michelson interferometer a distance is derived. The presented measurement method combines spectral interferometry, white light interferometry and multi-wavelength interferometry in a single scheme. Comparison with a fringe counting laser interferometer shows an agreement within <10(-8) for a distance of 50 m.

  6. Highly Efficient Long-Distance Quantum Communication: a Blueprint for Implementation

    NASA Astrophysics Data System (ADS)

    Li, Linshu; Muralidharan, Sreraman; Kim, Jungsang; Lutkenhaus, Norbert; Lukin, Mikhail; Jiang, Liang

    2015-03-01

    Quantum repeaters provide a way for long distance quantum communication through optical fiber networks. Transmission losses and operation errors are two major challenges to the implementation of quantum repeaters. At each intermediate repeater station, transmission losses can be overcome using either heralded entanglement generation or quantum error correction, while operation errors can be corrected via entanglement purification or quantum error correction. Depending on the mechanisms used to correct loss and operation errors respectively, three generations of quantum repeaters have been proposed. We present a quantitative comparison of different quantum repeater schemes by evaluating the time- and qubit-resource consumed simultaneously. We can identify the most efficient scheme for given technological capabilities, which are characterized by fiber coupling efficiency, local gate fidelity, and local gate speed. Our work provides a roadmap for high-speed quantum networks across continental distances. Linshu and Sreraman contributed equally to this work.

  7. Long-distance transmission of light in a scintillator-based radiation detector

    DOEpatents

    Dowell, Jonathan L.; Talbott, Dale V.; Hehlen, Markus P.

    2017-07-11

    Scintillator-based radiation detectors capable of transmitting light indicating the presence of radiation for long distances are disclosed herein. A radiation detector can include a scintillator layer and a light-guide layer. The scintillator layer is configured to produce light upon receiving incident radiation. The light-guide layer is configured to receive light produced by the scintillator layer and either propagate the received light through the radiation detector or absorb the received light and emit light, through fluorescence, that is propagated through the radiation detector. A radiation detector can also include an outer layer partially surrounding the scintillator layer and light-guide layer. The index of refraction of the light-guide layer can be greater than the index of refraction of adjacent layers.

  8. Does size and buoyancy affect the long-distance transport of floating debris?

    NASA Astrophysics Data System (ADS)

    Ryan, Peter G.

    2015-08-01

    Floating persistent debris, primarily made from plastic, disperses long distances from source areas and accumulates in oceanic gyres. However, biofouling can increase the density of debris items to the point where they sink. Buoyancy is related to item volume, whereas fouling is related to surface area, so small items (which have high surface area to volume ratios) should start to sink sooner than large items. Empirical observations off South Africa support this prediction: moving offshore from coastal source areas there is an increase in the size of floating debris, an increase in the proportion of highly buoyant items (e.g. sealed bottles, floats and foamed plastics), and a decrease in the proportion of thin items such as plastic bags and flexible packaging which have high surface area to volume ratios. Size-specific sedimentation rates may be one reason for the apparent paucity of small plastic items floating in the world’s oceans.

  9. A profile of women participants in five long distance winter sporting events.

    PubMed

    Mischler, J K

    1989-01-01

    Women have been entering long distance winter sports in increasing numbers in Alaska and other states and countries. Much publicity has been given to the success of some. The 1,100 mile Iditarod Sled Dog Race across Alaska has been won by a woman every year since 1985. The Minnesota Beargrease Sled Dog Marathon 500 mile race was won by a woman in 1988. But what of the experience of the average female entrant? This investigation sought to examine the circumstances of each of the women who competed in the Iditarod, Iditaski, Iditabike, Yukon Quest and Beargrease Marathon. Since December 1987, 79 questionnaires were mailed to all of the women participants (past and present) of these events and as of July 1988 the response rate was 58%. Examination of the findings in the areas of age ranges; training/competition miles; types, rates, self-treatment of injuries and protection from cold are reported.

  10. Long-distance plant dispersal to North Atlantic islands: colonization routes and founder effect

    PubMed Central

    Alsos, Inger Greve; Ehrich, Dorothee; Eidesen, Pernille Bronken; Solstad, Heidi; Westergaard, Kristine Bakke; Schönswetter, Peter; Tribsch, Andreas; Birkeland, Siri; Elven, Reidar; Brochmann, Christian

    2015-01-01

    Long-distance dispersal (LDD) processes influence the founder effect on islands. We use genetic data for 25 Atlantic species and similarities among regional floras to analyse colonization, and test whether the genetic founder effect on five islands is associated with dispersal distance, island size and species traits. Most species colonized postglacially via multiple dispersal events from several source regions situated 280 to >3000 km away, and often not from the closest ones. A strong founder effect was observed for insect-pollinated mixed maters, and it increased with dispersal distance and decreased with island size in accordance with the theory of island biogeography. Only a minor founder effect was observed for wind-pollinated outcrossing species. Colonization patterns were largely congruent, indicating that despite the importance of stochasticity, LDD is mainly determined by common factors, probably dispersal vectors. Our findings caution against a priori assuming a single, close source region in biogeographic analyses. PMID:25876627

  11. Daily time budgets of long-distance commuting workers in Tokyo megalopolis.

    PubMed

    Umezaki, M; Ishimaru, H; Ohtsuka, R

    1999-01-01

    In Tokyo Megalopolis, long-distance commuting between residences in the suburbs and work places in the centre of the city was examined. Using a questionnaire, heads of household in two suburbs were asked about the influences of long commuting hours on their daily time budgets. The results showed that on workdays, the workers who spent longer commuting rose and left home for work earlier, and came back home and retired later; accordingly, both time spent on in-home activities on workdays and hours slept on the day before a workday were shorter. Comparison of time budgets between the subjects who work 5 and 6 days per week revealed more vulnerable influences of long commuting hours in the former than the latter. The expected health consequences of these findings are discussed from a biosocial/human ecological viewpoint.

  12. Overcoming Challenges: Breathing Hope Through Teamwork and Long-Distance Thoracic Transplantation.

    PubMed

    Villalon, Ernie

    2016-09-01

    Lung donation and transplantation is increasing in volume annually, yet there continues to be a shortage of available organs for transplant. Despite this shortage, suitable lungs are occasionally not transplanted due to logistical issues. Issues such as time and distance can be a major barrier in deceased donor organ recovery and transplantation. This single case study serves as an example of the teamwork and cooperation that resulted in the successful transplantation of lungs in spite of long-distance logistical issues between the donor and the recipient. All of the members who contributed to this collaboration recognized the need and urgency to overcome these challenges. The organ procurement organization's collaboration with multiple transplant centers across multiple regions resulted in a successful outcome for the lung recipient.

  13. Long distance measurement-device-independent quantum key distribution with entangled photon sources

    SciTech Connect

    Xu, Feihu; Qi, Bing; Liao, Zhongfa; Lo, Hoi-Kwong

    2013-08-05

    We present a feasible method that can make quantum key distribution (QKD), both ultra-long-distance and immune, to all attacks in the detection system. This method is called measurement-device-independent QKD (MDI-QKD) with entangled photon sources in the middle. By proposing a model and simulating a QKD experiment, we find that MDI-QKD with one entangled photon source can tolerate 77 dB loss (367 km standard fiber) in the asymptotic limit and 60 dB loss (286 km standard fiber) in the finite-key case with state-of-the-art detectors. Our general model can also be applied to other non-QKD experiments involving entanglement and Bell state measurements.

  14. [Network system for alpine ambulance using long distance wireless LAN and CATV LAN].

    PubMed

    Nakamura, Masayuki; Yang, Yuying; Kubota, Shoshin; Shimizu, Hiroshi; Miura, Yutaka; Wasaki, Katsumi; Shidama, Yasunari; Takizawa, Masaomi

    2003-01-01

    A network of the emergency telemedicine for mountain climbers in Japan Alps area has been developed. The network consists of 2.4GHz wireless LAN with over 30 km distance to be connected the Cable TV LAN. We confirmed that this network is able to transfer the high quality video and audio signal suitable for the telemedicine between the mountain huts and hospitals. In this paper, we pointed out the shortcomings of wireless LAN system and cable TV network system in use for the telemedicine, and wireless LAN module covered more than 30km and an extension system of upstream frequency bandwidth for Cable TV network. Experiments suggested that a low cost and long distance wireless LAN is useful for mountain climber's emergency telemedicine.

  15. Middle and long distance athletics races viewed from the perspective of complexity.

    PubMed

    García-Manso, Juan M; Martín-González, Juan M; Dávila, Nancy; Arriaza, Enrique

    2005-03-21

    Middle and long distance athletics races behave as power-laws when time (or average speed) and distance are related, thus suggesting the presence of critical phenomena. Power-laws as a function of the athlete's position in the all-time world ranking allows us to define a Performance Index that reveals the existence of possible multifractal structures associated to the natural barriers to that the athletes tend in their evolution towards better results and in pursuit of world records. The new theories of self-organized critical phenomena provide an explanation for the power-law and fractal structures in systems at, or near, their critical points. In this paper we analyse the athletic races using these theories and as a result of this study a new variety of interpretations are posited.

  16. Multi-Reflex Propulsion Systems for Space and Air Vehicles and Energy Transfer for Long Distance

    NASA Astrophysics Data System (ADS)

    Bolonkin, A.

    The purpose of this article is to call attention to the revolutionary idea of light multi-reflection. This idea allows the design of new engines, space and air propulsion systems, storage (of a beam and solar energy), transmitters of energy (to millions of kilometers), creation of new weapons, etc. This method and the main innovations were offered by the author in 1983 in the former USSR. Now the author shows in a series of articles the immense possibilities of this idea in many fields of engineering - astronautics, aviation, energy, optics, direct converter of light (laser beam) energy to mechanical energy (light engine), to name a few. This article considers the multi-reflex propulsion systems for space and air vehicles and energy transmitter for long distances in space.

  17. Long-Distance Axonal Growth from Human Induced Pluripotent Stem Cells After Spinal Cord Injury

    PubMed Central

    Lu, Paul; Woodruff, Grace; Wang, Yaozhi; Graham, Lori; Hunt, Matt; Wu, Di; Boehle, Eileen; Ahmad, Ruhel; Poplawski, Gunnar; Brock, John; Goldstein, Lawrence S. B.; Tuszynski, Mark H.

    2014-01-01

    Human induced pluripotent stem cells (iPSCs) from a healthy 86 year-old male were differentiated into neural stem cells and grafted into adult immunodeficient rats after spinal cord injury. Three months after C5 lateral hemisections, iPSCs survived and differentiated into neurons and glia, and extended tens of thousands of axons from the lesion site over virtually the entire length of the rat central nervous system. These iPSC-derived axons extended through adult white matter of the injured spinal cord, frequently penetrating gray matter and forming synapses with rat neurons. In turn, host supraspinal motor axons penetrated human iPSC grafts and formed synapses. These findings indicate that intrinsic neuronal mechanisms readily overcome the inhibitory milieu of the adult injured spinal cord to extend many axons over very long distances; these capabilities persist even in neurons reprogrammed from very aged human cells. PMID:25123310

  18. Vascular Sap Proteomics: Providing Insight into Long-Distance Signaling during Stress

    PubMed Central

    Carella, Philip; Wilson, Daniel C.; Kempthorne, Christine J.; Cameron, Robin K.

    2016-01-01

    The plant vascular system, composed of the xylem and phloem, is important for the transport of water, mineral nutrients, and photosynthate throughout the plant body. The vasculature is also the primary means by which developmental and stress signals move from one organ to another. Due to practical and technological limitations, proteomics analysis of xylem and phloem sap has been understudied in comparison to accessible sample types such as leaves and roots. However, recent advances in sample collection techniques and mass spectrometry technology are making it possible to comprehensively analyze vascular sap proteomes. In this mini-review, we discuss the emerging field of vascular sap proteomics, with a focus on recent comparative studies to identify vascular proteins that may play roles in long-distance signaling and other processes during stress responses in plants. PMID:27242852

  19. Testing the Münch hypothesis of long distance phloem transport in plants

    PubMed Central

    Knoblauch, Michael; Knoblauch, Jan; Mullendore, Daniel L; Savage, Jessica A; Babst, Benjamin A; Beecher, Sierra D; Dodgen, Adam C; Jensen, Kaare H; Holbrook, N Michele

    2016-01-01

    Long distance transport in plants occurs in sieve tubes of the phloem. The pressure flow hypothesis introduced by Ernst Münch in 1930 describes a mechanism of osmotically generated pressure differentials that are supposed to drive the movement of sugars and other solutes in the phloem, but this hypothesis has long faced major challenges. The key issue is whether the conductance of sieve tubes, including sieve plate pores, is sufficient to allow pressure flow. We show that with increasing distance between source and sink, sieve tube conductivity and turgor increases dramatically in Ipomoea nil. Our results provide strong support for the Münch hypothesis, while providing new tools for the investigation of one of the least understood plant tissues. DOI: http://dx.doi.org/10.7554/eLife.15341.001 PMID:27253062

  20. Mode-resolved frequency comb interferometry for high-accuracy long distance measurement

    PubMed Central

    van den Berg, Steven. A.; van Eldik, Sjoerd; Bhattacharya, Nandini

    2015-01-01

    Optical frequency combs have developed into powerful tools for distance metrology. In this paper we demonstrate absolute long distance measurement using a single femtosecond frequency comb laser as a multi-wavelength source. By applying a high-resolution spectrometer based on a virtually imaged phased array, the frequency comb modes are resolved spectrally to the level of an individual mode. Having the frequency comb stabilized against an atomic clock, thousands of accurately known wavelengths are available for interferometry. From the spectrally resolved output of a Michelson interferometer a distance is derived. The presented measurement method combines spectral interferometry, white light interferometry and multi-wavelength interferometry in a single scheme. Comparison with a fringe counting laser interferometer shows an agreement within <10−8 for a distance of 50 m. PMID:26419282

  1. Testing the Münch hypothesis of long distance phloem transport in plants

    DOE PAGES

    Knoblauch, Michael; Knoblauch, Jan; Mullendore, Daniel L.; ...

    2016-06-02

    Long distance transport in plants occurs in sieve tubes of the phloem. The pressure flow hypothesis introduced by Ernst Münch in 1930 describes a mechanism of osmotically generated pressure differentials that are supposed to drive the movement of sugars and other solutes in the phloem, but this hypothesis has long faced major challenges. The key issue is whether the conductance of sieve tubes, including sieve plate pores, is sufficient to allow pressure flow. We show that with increasing distance between source and sink, sieve tube conductivity and turgor increases dramatically in Ipomoea nil . Our results provide strong supportmore » for the Münch hypothesis, while providing new tools for the investigation of one of the least understood plant tissues.« less

  2. Long-distance measurement-device-independent quantum key distribution with coherent-state superpositions.

    PubMed

    Yin, H-L; Cao, W-F; Fu, Y; Tang, Y-L; Liu, Y; Chen, T-Y; Chen, Z-B

    2014-09-15

    Measurement-device-independent quantum key distribution (MDI-QKD) with decoy-state method is believed to be securely applied to defeat various hacking attacks in practical quantum key distribution systems. Recently, the coherent-state superpositions (CSS) have emerged as an alternative to single-photon qubits for quantum information processing and metrology. Here, in this Letter, CSS are exploited as the source in MDI-QKD. We present an analytical method that gives two tight formulas to estimate the lower bound of yield and the upper bound of bit error rate. We exploit the standard statistical analysis and Chernoff bound to perform the parameter estimation. Chernoff bound can provide good bounds in the long-distance MDI-QKD. Our results show that with CSS, both the security transmission distance and secure key rate are significantly improved compared with those of the weak coherent states in the finite-data case.

  3. Experimental realization of SDA-method for the detection of substance at long distance

    NASA Astrophysics Data System (ADS)

    Trofimov, Vyacheslav A.; Denisov, Anton D.; Tikhomirov, Vasily V.

    2013-10-01

    Nowadays, the detection and identification of dangerous substances at long distance (several metres, for example) by using of THz pulse reflected from the object is an important problem. The main problem with this technique is the absorption of THz energy by water vapor. However, using THz pulsed radiation is possible at distance of some metres as it is well-known. Below we demonstrate possibility of THz signal measuring reflected from a flat metallic mirror placed about 3.2 metres from the parabolic mirror. Investigated object is placed before this mirror. Therefore, at present time our measurements contain features of both transmission and reflection modes. The reflecting mirror is used because of weak averaged power of femtosecond laser. This power is about 1 W. Nevertheless, the laser beam splits many times. Therefore, the averaged power falling on the THz emitter decreases at least 8 times. The pulse duration generated by the femtosecond laser is equal to 68 fs. In this mode of measurements we took measurements for a chocolate brick, cookies, a bag made from thick paperboard, many layers of thin papers (paper napkin for computer monitor). In particular, it should be stressed that a spectrum of the measured signal is highly sensitive to a angle position of the flat mirror. Therefore, at long distance the position of object, that reflects the THz pulse, will influence essentially on the measured spectrum. Other very important features of the measurements with the multilayer of paper are the strong modulation of the spectrum of the reflected signal. As a consequence, we see additional frequencies, which correspond to absorption frequencies of various explosives, in the spectrum of the reflected signal. In fact, these substances are absent in our experiment. The last important result consists of unusual influence of the cookies on the measured signal: it becomes strong modulated. Consequently, cookies act as disordered structures.

  4. Sleepiness, Long Distance Commuting and Night Work as Predictors of Driving Performance

    PubMed Central

    Di Milia, Lee; Rogers, Naomi L.; Åkerstedt, Torbjörn

    2012-01-01

    Few studies have examined the effect of working night shift and long distance commuting. We examined the association between several sleep related and demographic variables, commuting distance, night work and use of mobile phones on driving performance. We used a prospective design to recruit participants and conducted a telephone survey (n = 649). The survey collected demographic and journey details, work and sleep history and driving performance concerning the day the participant was recruited. Participants also completed the Karolinska Sleepiness Scale and the Epworth Sleepiness Scale. Night workers reported significantly more sleepiness, shorter sleep duration and commuting longer distances. Seven variables were significant predictors of lane crossing. The strongest predictor was acute sleepiness (OR = 5.25, CI, 1.42–19.49, p<0.01) followed by driving ≥150 kms (OR = 3.61, CI, 1.66–7.81, p<0.001), obtaining less than 10 hours sleep in the previous 48 hours (OR = 2.58, CI, 1.03–6.46, p<0.05), driving after night shift (OR = 2.19, CI, 1.24–3.88, p<0.001), being <43 years old (OR = 1.95, CI, 1.11–3.41, p<0.05) and using mobile phones during the journey (OR = 1.90, CI, 1.10–3.27, p<0.05). Sleep related variables, long-distance commuting and night work have a major impact on lane crossing. Several interventions should be considered to reduce the level of sleepiness in night workers. PMID:23029278

  5. Long-distance dispersal in a fire- and livestock-protected savanna

    PubMed Central

    Tarazi, Roberto; Sebbenn, Alexandre M; Kageyama, Paulo Y; Vencovsky, Roland

    2013-01-01

    Savannas are highly diverse and dynamic environments that can shift to forest formations due to protection policies. Long-distance dispersal may shape the genetic structure of these new closed forest formations. We analyzed eight microsatellite loci using a single-time approach to understand contemporary pollen and effective seed dispersal of the tropical tree, Copaifera langsdorffii Desf. (Fabaceae), occurring in a Brazilian fire- and livestock-protected savanna. We sampled all adult trees found within a 10.24 ha permanent plot, young trees within a subplot of 1.44 ha and open-pollinated seeds. We detected a very high level of genetic diversity among the three generations in the studied plot. Parentage analysis revealed high pollen immigration rate (0.64) and a mean contemporary pollen dispersal distance of 74 m. In addition, half-sib production was 1.8 times higher than full-sibs in significant higher distances, indicating foraging activity preference for different trees at long distances. There was a significant and negative correlation between diameter at breast height (DBH) of the pollen donor with the number of seeds (r = −0.640, P-value = 0.032), suggesting that pollen donor trees with a higher DBH produce less seeds. The mean distance of realized seed dispersal (recruitment kernel) was 135 m due to the large home range dispersers (birds and mammals) in the area. The small magnitude of spatial genetic structure found in young trees may be a consequence of overlapping seed shadows and increased tree density. Our results show the positive side of closed canopy expansion, where animal activities regarding pollination and seed dispersal are extremely high. PMID:23610640

  6. Expression of an Activated Integrin Promotes Long-Distance Sensory Axon Regeneration in the Spinal Cord.

    PubMed

    Cheah, Menghon; Andrews, Melissa R; Chew, Daniel J; Moloney, Elizabeth B; Verhaagen, Joost; Fässler, Reinhard; Fawcett, James W

    2016-07-06

    After CNS injury, axon regeneration is blocked by an inhibitory environment consisting of the highly upregulated tenascin-C and chondroitin sulfate proteoglycans (CSPGs). Tenascin-C promotes growth of axons if they express a tenascin-binding integrin, particularly α9β1. Additionally, integrins can be inactivated by CSPGs, and this inhibition can be overcome by the presence of a β1-binding integrin activator, kindlin-1. We examined the synergistic effect of α9 integrin and kindlin-1 on sensory axon regeneration in adult rat spinal cord after dorsal root crush and adeno-associated virus transgene expression in dorsal root ganglia. After 12 weeks, axons from C6-C7 dorsal root ganglia regenerated through the tenascin-C-rich dorsal root entry zone into the dorsal column up to C1 level and above (>25 mm axon length) through a normal pathway. Animals also showed anatomical and electrophysiological evidence of reconnection to the dorsal horn and behavioral recovery in mechanical pressure, thermal pain, and ladder-walking tasks. Expression of α9 integrin or kindlin-1 alone promoted much less regeneration and recovery. The study demonstrates that long-distance sensory axon regeneration over a normal pathway and with sensory and sensory-motor recovery can be achieved. This was achieved by expressing an integrin that recognizes tenascin-C, one of the components of glial scar tissue, and an integrin activator. This enabled extensive long-distance (>25 mm) regeneration of both myelinated and unmyelinated sensory axons with topographically correct connections in the spinal cord. The extent of growth and recovery we have seen would probably be clinically significant. Restoration of sensation to hands, perineum, and genitalia would be a significant improvement for a spinal cord-injured patient. Copyright © 2016 CHEAH et al.

  7. Phloem long-distance delivery of FLOWERING LOCUS T (FT) to the apex.

    PubMed

    Yoo, Soo-Cheul; Chen, Cheng; Rojas, Maria; Daimon, Yasufumi; Ham, Byung-Kook; Araki, Takashi; Lucas, William J

    2013-08-01

    Cucurbita moschata FLOWERING LOCUS T-LIKE 2 (hereafter FTL2) and Arabidopsis thaliana (Arabidopsis) FLOWERING LOCUS T (FT), components of the plant florigenic signaling system, move long-distance through the phloem from source leaves to the vegetative apex where they mediate floral induction. The mechanisms involved in long-distance trafficking of FT/FTL2 remain to be elucidated. In this study, we identified the critical motifs on both FT and FTL2 required for cell-to-cell trafficking through mutant analyses using a zucchini yellow mosaic virus expression vector. Western blot analysis, performed on phloem sap collected from just beneath the vegetative apex of C. moschata plants, established that all mutant proteins tested retained the ability to enter the phloem translocation stream. However, immunolocalization studies revealed that a number of these FTL2/FT mutants were defective in the post-phloem zone, suggesting that a regulation mechanism for FT trafficking exists in the post-phloem unloading step. The selective movements of FT/FTL2 were further observed by microinjection and trichome rescue studies, which revealed that FT/FTL2 has the ability to dilate plasmodesmata microchannels during the process of cell-to-cell trafficking, and various mutants were compromised in their capacity to traffic through plasmodesmata. Based on these findings, a model is presented to account for the mechanism by which FT/FTL2 enters the phloem translocation stream and subsequently exits the phloem and enters the apical tissue, where it initiates the vegetative to floral transition.

  8. Long-distance signals positively regulate the expression of iron uptake genes in tobacco roots.

    PubMed

    Enomoto, Yusuke; Hodoshima, Hirotaka; Shimada, Hiroaki; Shoji, Kazuhiro; Yoshihara, Toshihiro; Goto, Fumiyuki

    2007-12-01

    Long-distance signals generated in shoots are thought to be associated with the regulation of iron uptake from roots; however, the signaling mechanism is still unknown. To elucidate whether the signal regulates iron uptake genes in roots positively or negatively, we analyzed the expressions of two representative iron uptake genes: NtIRT1 and NtFRO1 in tobacco (Nicotiana tabacum L.) roots, after shoots were manipulated in vitro. When iron-deficient leaves were treated with Fe(II)-EDTA, the expressions of both genes were significantly reduced; nevertheless iron concentration in the roots maintained a similar level to that in roots grown under iron-deficient conditions. Next, all leaves from tobacco plants grown under the iron-deficient condition were excised. The expression of two genes were quickly reduced below half within 2 h after the leaf excision and gradually disappeared by the end of a 24-h period. The NtIRT1 expression was compared among the plants whose leaves were cut off in various patterns. The expression increased in proportion to the dry weight of iron-deficient leaves, although no relation was observed between the gene expression and the position of excised leaves. Interestingly, the NtIRT1 expression in hairy roots increased under the iron-deficient condition, suggesting that roots also have the signaling mechanism of iron status as well as shoots. Taken together, these results indicate that the long-distance signal generated in iron-deficient tissues including roots is a major factor in positive regulation of the expression of NtIRT1 and NtFRO1 in roots, and that the strength of the signal depends on the size of plants.

  9. Evidence of long distance airborne transport of porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae

    PubMed Central

    Dee, Scott; Otake, Satoshi; Oliveira, Simone; Deen, John

    2009-01-01

    The ability of porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae to be transported over long distances via the airborne route was evaluated. A source population of 300 grow-finish pigs was experimentally inoculated with PRRSV MN-184 and M. hyopneumoniae 232 and over a 50-day period, air samples were collected at designated distances from the source herd using a liquid cyclonic collector. Samples were tested for the presence of PRRSV RNA and M. hyopneumoniae DNA by PCR and if positive, further characterized. Of the 306 samples collected, 4 (1.3%) were positive for PRRSV RNA and 6 (1.9%) were positive for M. hyopneumoniae DNA. The PRRSV-positive samples were recovered 4.7 km to the northwest (NW) of the source population. Four of the M. hyopneumoniae-positive samples were obtained at the NW sampling point; 2 samples at approximately 2.3 km and the other 2 samples approximately 4.7 km from the source population. Of the remaining 2 samples, one sample was obtained at the southeast sampling point and the other at the southwest sampling point, with both locations being approximately 4.7 km from the source. The four PRRSV-positive samples contained infectious virus and were ≥ 98.8% homologous to the MN-184 isolate used to inoculate the source population. All 6 of the M. hyopneumoniae-positive samples were 99.9% homologous to M. hyopneumoniae 232. These results support the hypothesis that long distance airborne transport of these important swine pathogens can occur. PMID:19379664

  10. Evidence of long distance airborne transport of porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae.

    PubMed

    Dee, Scott; Otake, Satoshi; Oliveira, Simone; Deen, John

    2009-01-01

    The ability of porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae to be transported over long distances via the airborne route was evaluated. A source population of 300 grow-finish pigs was experimentally inoculated with PRRSV MN-184 and M. hyopneumoniae 232 and over a 50-day period, air samples were collected at designated distances from the source herd using a liquid cyclonic collector. Samples were tested for the presence of PRRSV RNA and M. hyopneumoniae DNA by PCR and if positive, further characterized. Of the 306 samples collected, 4 (1.3%) were positive for PRRSV RNA and 6 (1.9%) were positive for M. hyopneumoniae DNA. The PRRSV-positive samples were recovered 4.7 km to the northwest (NW) of the source population. Four of the M. hyopneumoniae-positive samples were obtained at the NW sampling point; 2 samples at approximately 2.3 km and the other 2 samples approximately 4.7 km from the source population. Of the remaining 2 samples, one sample was obtained at the southeast sampling point and the other at the southwest sampling point, with both locations being approximately 4.7 km from the source. The four PRRSV-positive samples contained infectious virus and were >/= 98.8% homologous to the MN-184 isolate used to inoculate the source population. All 6 of the M. hyopneumoniae-positive samples were 99.9% homologous to M. hyopneumoniae 232. These results support the hypothesis that long distance airborne transport of these important swine pathogens can occur.

  11. Work stress and recovery measured by urinary catecholamines and cortisol excretion in long distance coach drivers

    PubMed Central

    Sluiter, J. K.; van der Beek, A. J.; Frings-Dresen, M. H.

    1998-01-01

    OBJECTIVES: To evaluate coach drivers' work stress during work and in the course of recovery from work by measurement of urinary catecholamines and cortisol. METHODS: The urinary excretion rate of adrenaline, noradrenaline, and cortisol of 10 coach drivers was studied during a long distance trip of three days and two consecutive days off. Each driver was asked to provide seven urine samples on the working days and six urine samples on the days off. The second day off was considered as the baseline. RESULTS: An occupationally induced disturbance of the circadian rhythmicity was found for adrenaline and noradrenaline but not for cortisol. The mean excretion rates of adrenaline on the first working day and most samples on all working days were higher than the baseline. For both adrenaline and noradrenaline the mean excretion rates on the first day off were lower than the baseline. For cortisol, the mean excretion rate on all working days was higher than the baseline. A trend towards accumulation of cortisol excretion from the first working day to the third working day was found. A backward shift in peak concentrations was found for adrenaline and noradrenaline on the second working day, as was a forward shift in peak concentration of cortisol on both days off. CONCLUSIONS: Long distance coach drivers showed occupationally induced reactivity in rates of urinary excretion of adrenaline, noradrenaline, and cortisol. After the outward journey the rates of excretion of catecholamines did not return to baseline values. The course of recovery in adrenaline excretion after the journey showed a new phenomenon, which has been called "fatigue debt". It is recommended that longer resting times in shuttle bus trips and fixed days off after these kind of trips should be planned. Extensive future research should be focused on the additional relations between fatigue debt and health complaints.   PMID:9764101

  12. Influence of Massive and Long Distance Migration on Parasite Epidemiology: Lessons from the Great Wildebeest Migration.

    PubMed

    Mijele, Domnic; Iwaki, Takashi; Chiyo, Patrick I; Otiende, Moses; Obanda, Vincent; Rossi, Luca; Soriguer, Ramon; Angelone-Alasaad, Samer

    2016-12-01

    Very little is known about the influence of massive and long distance migration on parasite epidemiology. Migration can simultaneously minimize exposure to common parasites in their habitats and increase exposure to novel pathogens from new environments and habitats encountered during migration, while physiological stress during long distance movement can lead to immune suppression, which makes migrants vulnerable to parasites. In this paper, we investigated the diversity, prevalence, parasite load, co-infection patterns and predilection sites of adult gastrointestinal helminths in 130 migrating wildebeests and tested for their relation with animal age, sex and migration time (which also could indicate different migration routes), and compared them with the non-migratory wildebeest. Surprisingly, only four parasite species were found, Oesophagostomum columbianum, Haemonchus placei, Calicophoron raja and Moniezia expansa, which were lower than in non-migratory wildebeest reported in the literature. These parasites were generalists, infecting livestock, and suggests that wildebeest and livestock, because of their interaction during migration, have a cross-infection risk. There was a negative relation between parasites diversity, prevalence and intensity of infection, and host age, which suggests that wildebeests acquire protective immunity against these parasites as they get older. Prevalence and intensity of infection were higher among wildebeest crossing the Mara Bridge (early migrants) compared to those crossing the Serena (late migrants), which suggests that early migrants (or migrants originating from different areas) have varying infection intensities. The prevalence and intensity of infection were higher in males compared to females and may be due to ecological, behavioural, or physiological differences between males and females. Our findings compared to those of previous studies suggest that migration may provide a mechanism to minimize exposure of hosts to

  13. Impaired Long Distance Functional Connectivity and Weighted Network Architecture in Alzheimer's Disease

    PubMed Central

    Liu, Yong; Yu, Chunshui; Zhang, Xinqing; Liu, Jieqiong; Duan, Yunyun; Alexander-Bloch, Aaron F.; Liu, Bing; Jiang, Tianzi; Bullmore, Ed

    2014-01-01

    Alzheimer's disease (AD) is increasingly recognized as a disconnection syndrome, which leads to cognitive impairment due to the disruption of functional activity across large networks or systems of interconnected brain regions. We explored abnormal functional magnetic resonance imaging (fMRI) resting-state dynamics, functional connectivity, and weighted functional networks, in a sample of patients with severe AD (N = 18) and age-matched healthy volunteers (N = 21). We found that patients had reduced amplitude and regional homogeneity of low-frequency fMRI oscillations, and reduced the strength of functional connectivity, in several regions previously described as components of the default mode network, for example, medial posterior parietal cortex and dorsal medial prefrontal cortex. In patients with severe AD, functional connectivity was particularly attenuated between regions that were separated by a greater physical distance; and loss of long distance connectivity was associated with less efficient global and nodal network topology. This profile of functional abnormality in severe AD was consistent with the results of a comparable analysis of data on 2 additional groups of patients with mild AD (N = 17) and amnestic mild cognitive impairment (MCI; N = 18). A greater degree of cognitive impairment, measured by the mini-mental state examination across all patient groups, was correlated with greater attenuation of functional connectivity, particularly over long connection distances, for example, between anterior and posterior components of the default mode network, and greater reduction of global and nodal network efficiency. These results indicate that neurodegenerative disruption of fMRI oscillations and connectivity in AD affects long-distance connections to hub nodes, with the consequent loss of network efficiency. This profile was evident also to a lesser degree in the patients with less severe cognitive impairment, indicating that the potential of resting

  14. Meanings and vulnerability to HIV/AIDS among long-distance truck drivers in Brazil

    PubMed Central

    Magno, Laio; Castellanos, Marcelo Eduardo Pfeiffer

    2016-01-01

    ABSTRACT OBJECTIVE To understand the meanings assigned by long-distance truck drivers to HIV/AIDS and its transmission and prevention, bearing in mind different contexts of vulnerability. METHODS Qualitative research with 22 truck drivers. Semi-structured interviews and participant observation were conducted in highways of the state of Bahia in 2013. We selected male truck drivers, with one year or more of work experience in long-distance routes. We carried out the thematic analysis of the interviews, to identify different contexts of vulnerability. RESULTS The results showed that the insertion of truck drivers in contexts of high social vulnerability (poor working conditions, violence on the roads, and use of alcohol and other drugs) along with the advances in access and effectiveness of treatment for AIDS promote a reduced perception of the risk and severity of this disease. In addition, the notion of “risk group” and the symbolic division between “home space” (protected) and “street space” (unprotected) intensified a restricted and specific use of condoms, guided by the opposition between “woman of the street” (unknown women, prostitutes, among others) and “woman of the house” (wives, girlfriends). CONCLUSIONS The meanings assigned by truckers to AIDS incorporated elements of recent transformations of the expanded social context, such as the development of health technologies (especially anti-retroviral drugs) and the guarantee of free access to treatment in the Brazilian public health system; but also incorporated old elements of social vulnerability context – such as the poor working conditions on Brazilian highways. PMID:28099654

  15. Long-distance communication facilitates cooperation among wild spotted hyaenas, Crocuta crocuta

    PubMed Central

    Gersick, Andrew S.; Cheney, Dorothy L.; Schneider, Jennifer M.; Seyfarth, Robert M.; Holekamp, Kay E.

    2015-01-01

    Calls that catalyse group defence, as in the mobbing of predators, appear to facilitate cooperation by recruiting receivers to act collectively. However, even when such signals reliably precede cooperative behaviour, the extent to which the calls function as recruitment signals is unclear. Calls might simply arouse listeners’ attention, setting off a cascade of independent responses to the threat. By contrast, they might convey information, for example, about signaller identity and the nature of a threat that affects receivers’ decisions to participate. We explored this distinction by investigating a possible long-distance recruitment call used by spotted hyaenas. These social carnivores live in fission–fusion clans and individuals disperse widely within their territories. Putative recruitment calls must therefore attract receivers that are distant from the inciting threat and free to opt out of risky collective aggression. Hyaenas compete with lions over food, and neighbouring clans sometimes engage in violent border clashes. These high-stakes contests are decided based on numerical asymmetries, so hyaenas can only protect critical resources if the dispersed clan can converge quickly at conflict sites. We recorded and analysed whoop bouts produced in multiple contexts and found that bouts produced in response to signs of lion–hyaena conflict had shorter inter-whoop intervals than spontaneous ‘display’ bouts. In subsequent field playback experiments, resting hyaenas were significantly more likely to move in response to ‘recruitment’ bouts with shortened intervals than to otherwise identical ‘display’ bouts. Whereas only stimulus type predicted movement, lower-ranked subjects responded most quickly, perhaps because their feeding opportunities depend on arriving early at any kill site. Results demonstrate that hyaenas possess a signal that can reliably recruit allies across long distances, despite moderating effects of individual circumstances on

  16. Long-distance dispersal of the coconut palm by migration within the coral atoll ecosystem

    PubMed Central

    Harries, Hugh C.; Clement, Charles R.

    2014-01-01

    Background The location of the original home of the coconut palm, Cocos nucifera, and the extent of its natural dispersal are not known. Proponents of a South American origin must explain why it is not indigenous there and why it shows greatest diversity in southern Asia. Conversely, proponents of an Asian origin must explain why there are no Asian Cocoseae and why the closest botanical relative to Cocos is in South America. Both hypotheses share the common problems of how, when, where and in what directions long-distance dispersal occurred. Hypothesis These difficulties are resolved by accepting that C. nucifera originated and dispersed by populating emerging islands of the coral atoll ecosystem, where establishment conditions impose high selection pressures for survival. When lifted by wave action onto virtually sterile, soilless coralline rocks just above sea level and exposed to the full impact of the sun, seednuts must germinate, root and establish vigorous populations. The cavity within the nut augments the buoyancy provided by the thick husk, which in turn protects the embryo and, by delaying germination, simultaneously extends viability while floating and provides a moisture-retentive rooting medium for the young seedling. These adaptations allow coconuts to disperse widely through the coral atoll ecosystem. Conclusions The monthly production of fruit and the long floating duration ensure that viable seednuts are always available in the lagoon to replace those destroyed by hurricanes and tsunamis, or to populate newly emerged coral atolls elsewhere. Long-distance dispersal is secondary, because it was the spontaneous, independent migration of coral polyps on a prolonged geological time scale that generated new coral atolls in new areas where the coconuts would be amongst the earliest inhabitants. The coconut palm became an intermittent, itinerant, pioneer endemic there, and also on suitable beaches on volcanic or large islands and continental coastlines

  17. Optimal energy-utilization ratio for long-distance cruising of a model fish

    NASA Astrophysics Data System (ADS)

    Liu, Geng; Yu, Yong-Liang; Tong, Bing-Gang

    2012-07-01

    The efficiency of total energy utilization and its optimization for long-distance migration of fish have attracted much attention in the past. This paper presents theoretical and computational research, clarifying the above well-known classic questions. Here, we specify the energy-utilization ratio (fη) as a scale of cruising efficiency, which consists of the swimming speed over the sum of the standard metabolic rate and the energy consumption rate of muscle activities per unit mass. Theoretical formulation of the function fη is made and it is shown that based on a basic dimensional analysis, the main dimensionless parameters for our simplified model are the Reynolds number (Re) and the dimensionless quantity of the standard metabolic rate per unit mass (Rpm). The swimming speed and the hydrodynamic power output in various conditions can be computed by solving the coupled Navier-Stokes equations and the fish locomotion dynamic equations. Again, the energy consumption rate of muscle activities can be estimated by the quotient of dividing the hydrodynamic power by the muscle efficiency studied by previous researchers. The present results show the following: (1) When the value of fη attains a maximum, the dimensionless parameter Rpm keeps almost constant for the same fish species in different sizes. (2) In the above cases, the tail beat period is an exponential function of the fish body length when cruising is optimal, e.g., the optimal tail beat period of Sockeye salmon is approximately proportional to the body length to the power of 0.78. Again, the larger fish's ability of long-distance cruising is more excellent than that of smaller fish. (3) The optimal swimming speed we obtained is consistent with previous researchers’ estimations.

  18. Membrane nanotubes facilitate long-distance interactions between natural killer cells and target cells

    PubMed Central

    Chauveau, Anne; Aucher, Anne; Eissmann, Philipp; Vivier, Eric; Davis, Daniel M.

    2010-01-01

    Membrane nanotubes are membranous tethers that physically link cell bodies over long distances. Here, we present evidence that nanotubes allow human natural killer (NK) cells to interact functionally with target cells over long distances. Nanotubes were formed when NK cells contacted target cells and moved apart. The frequency of nanotube formation was dependent on the number of receptor/ligand interactions and increased on NK cell activation. Most importantly, NK cell nanotubes contained a submicron scale junction where proteins accumulated, including DAP10, the signaling adaptor that associates with the activating receptor NKG2D, and MHC class I chain-related protein A (MICA), a cognate ligand for NKG2D, as occurs at close intercellular synapses between NK cells and target cells. Quantitative live-cell fluorescence imaging suggested that MICA accumulated at small nanotube synapses in sufficient numbers to trigger cell activation. In addition, tyrosine-phosphorylated proteins and Vav-1 accumulated at such junctions. Functionally, nanotubes could aid the lysis of distant target cells either directly or by moving target cells along the nanotube path into close contact for lysis via a conventional immune synapse. Target cells moving along the nanotube path were commonly polarized such that their uropods faced the direction of movement. This is the opposite polarization than for normal cell migration, implying that nanotubes can specifically drive target cell movement. Finally, target cells that remained connected to an NK cell by a nanotube were frequently lysed, whereas removing the nanotube using a micromanipulator reduced lysis of these target cells. PMID:20212116

  19. Seroepidemiological Study after a Long-Distance Industrial Outbreak of Legionnaires' Disease▿

    PubMed Central

    Wedege, E.; Bergdal, T.; Bolstad, K.; Caugant, D. A.; Efskind, J.; Heier, H. E.; Kanestrøm, A.; Strand, B. H.; Aaberge, I. S.

    2009-01-01

    Following a long-distance outbreak of Legionnaires' disease from an industrial air scrubber in Norway in 2005, a seroepidemiological study measuring levels of immunoglobulin G (IgG) and IgM antibodies to Legionella pneumophila was performed with a polyvalent enzyme-linked immunosorbent assay. One year after the outbreak, IgG levels in employees (n = 213) at the industrial plant harboring the scrubber and in blood donors (n = 398) from the outbreak county were low but significantly higher (P ≤ 0.002) than those in blood donors (n = 406) from a nonexposed county. No differences in IgM levels among the three groups were found after adjustment for gender and age. Home addresses of the seroresponders in the exposed county clustered to the city of the outbreak, in contrast to the scattering of addresses of the seroresponding donors in the nonexposed county. Factory employees who operated at an open biological treatment plant had significantly higher IgG and IgM levels (P ≤ 0.034) than those working >200 m away. Most of the healthy seroresponders among the factory employees worked near this exposure source. Immunoblotting showed that IgG and IgM antibodies in 82.1% of all seroresponders were directed to the lipopolysaccharide of the L. pneumophila serogroup 1 outbreak strain. In conclusion, 1 year after the long-distance industrial outbreak a small increase in IgG levels of the exposed population was observed. The open biological treatment plant within the industrial premises, however, constituted a short-distance exposure source of L. pneumophila for factory employees working nearby. PMID:19225076

  20. Expression of an Activated Integrin Promotes Long-Distance Sensory Axon Regeneration in the Spinal Cord

    PubMed Central

    Cheah, Menghon; Chew, Daniel J.; Moloney, Elizabeth B.; Verhaagen, Joost; Fässler, Reinhard

    2016-01-01

    After CNS injury, axon regeneration is blocked by an inhibitory environment consisting of the highly upregulated tenascin-C and chondroitin sulfate proteoglycans (CSPGs). Tenascin-C promotes growth of axons if they express a tenascin-binding integrin, particularly α9β1. Additionally, integrins can be inactivated by CSPGs, and this inhibition can be overcome by the presence of a β1-binding integrin activator, kindlin-1. We examined the synergistic effect of α9 integrin and kindlin-1 on sensory axon regeneration in adult rat spinal cord after dorsal root crush and adeno-associated virus transgene expression in dorsal root ganglia. After 12 weeks, axons from C6–C7 dorsal root ganglia regenerated through the tenascin-C-rich dorsal root entry zone into the dorsal column up to C1 level and above (>25 mm axon length) through a normal pathway. Animals also showed anatomical and electrophysiological evidence of reconnection to the dorsal horn and behavioral recovery in mechanical pressure, thermal pain, and ladder-walking tasks. Expression of α9 integrin or kindlin-1 alone promoted much less regeneration and recovery. SIGNIFICANCE STATEMENT The study demonstrates that long-distance sensory axon regeneration over a normal pathway and with sensory and sensory–motor recovery can be achieved. This was achieved by expressing an integrin that recognizes tenascin-C, one of the components of glial scar tissue, and an integrin activator. This enabled extensive long-distance (>25 mm) regeneration of both myelinated and unmyelinated sensory axons with topographically correct connections in the spinal cord. The extent of growth and recovery we have seen would probably be clinically significant. Restoration of sensation to hands, perineum, and genitalia would be a significant improvement for a spinal cord-injured patient. PMID:27383601

  1. Long-distance dispersal of the coconut palm by migration within the coral atoll ecosystem.

    PubMed

    Harries, Hugh C; Clement, Charles R

    2014-03-01

    The location of the original home of the coconut palm, Cocos nucifera, and the extent of its natural dispersal are not known. Proponents of a South American origin must explain why it is not indigenous there and why it shows greatest diversity in southern Asia. Conversely, proponents of an Asian origin must explain why there are no Asian Cocoseae and why the closest botanical relative to Cocos is in South America. Both hypotheses share the common problems of how, when, where and in what directions long-distance dispersal occurred. These difficulties are resolved by accepting that C. nucifera originated and dispersed by populating emerging islands of the coral atoll ecosystem, where establishment conditions impose high selection pressures for survival. When lifted by wave action onto virtually sterile, soilless coralline rocks just above sea level and exposed to the full impact of the sun, seednuts must germinate, root and establish vigorous populations. The cavity within the nut augments the buoyancy provided by the thick husk, which in turn protects the embryo and, by delaying germination, simultaneously extends viability while floating and provides a moisture-retentive rooting medium for the young seedling. These adaptations allow coconuts to disperse widely through the coral atoll ecosystem. The monthly production of fruit and the long floating duration ensure that viable seednuts are always available in the lagoon to replace those destroyed by hurricanes and tsunamis, or to populate newly emerged coral atolls elsewhere. Long-distance dispersal is secondary, because it was the spontaneous, independent migration of coral polyps on a prolonged geological time scale that generated new coral atolls in new areas where the coconuts would be amongst the earliest inhabitants. The coconut palm became an intermittent, itinerant, pioneer endemic there, and also on suitable beaches on volcanic or large islands and continental coastlines.

  2. Postglacial population expansion drives the evolution of long-distance migration in a songbird.

    PubMed

    Milá, Borja; Smith, Thomas B; Wayne, Robert K

    2006-11-01

    The evolution of long-distance migratory behavior from sedentary populations is a central problem in studies of animal migration. Three crucial issues that remain unresolved are: (1) the biotic and abiotic factors promoting evolution of migratory behavior, (2) the geographic origin of ancestral sedentary populations, and (3) the time scale over which migration evolves. We test the role of postglacial population expansions during the Quaternary in driving the evolution of songbird migration against prevailing views favoring the role of intraspecific competition. In contrast to previous attempts to investigate these questions using interspecific phylogenies, we adopt an intraspecific approach and examine the phylogeography of a North American songbird, the chipping sparrow (Spizella passerina), which exhibits both long-distance migratory behavior in temperate North America and sedentary behavior in Mexico and Central America. We show that migratory populations descend from sedentary populations in southern Mexico and that migration has evolved as a result of a northward population expansion into temperate North America since the last glacial maximum 18,000 years ago. Migration appears to have evolved rapidly in some species as populations colonized areas of high seasonality in the temperate zone. The phylogeography of the yellow-eyed junco (Junco phaeonotus), a strictly sedentary species, provides a null model supporting the view that northward range expansions were driven solely by environmental factors and not by a predisposition to evolve migratory behavior. These results provide the strongest evidence to date that historical climate patterns can drive the rapid evolution of avian migration in natural populations, and they suggest a general mechanism for the repeated evolution of migration within and across bird lineages.

  3. Long-distance communication in the HDV ribozyme: insights from molecular dynamics and experiments.

    PubMed

    Veeraraghavan, Narayanan; Bevilacqua, Philip C; Hammes-Schiffer, Sharon

    2010-09-10

    The hepatitis delta virus ribozyme is a small, self-cleaving RNA with a compact tertiary structure and buried active site that is important in the life cycle of the virus. The ribozyme's function in nature is to cleave an internal phosphodiester bond and linearize concatemers during rolling circle replication. Crystal structures of the ribozyme have been solved in both pre-cleaved and post-cleaved (product) forms and reveal an intricate network of interactions that conspire to catalyze bond cleavage. In addition, extensive biochemical studies have been performed to work out a mechanism for bond cleavage in which C75 and a magnesium ion catalyze the reaction by general acid-base chemistry. One issue that has remained unclear in this ribozyme and in other ribozymes is the nature of long-distance communication between peripheral regions of the RNA and the buried active site. We performed molecular dynamics simulations on the hepatitis delta virus ribozyme in the product form and assessed communication between a distal structural portion of the ribozyme-the protonated C41 base triple-and the active site containing the critical C75. We varied the ionization state of C41 in both the wild type and a C41 double mutant variant and determined the impact on the active site. In all four cases, effects at the active site observed in the simulations agree with experimental studies on ribozyme activity. Overall, these studies indicate that small functional RNAs have the potential to communicate interactions over long distances and that wild-type RNAs may have evolved ways to prevent such interactions from interfering with catalysis.

  4. Polar auxin transport in relation to long-distance transport of nutrients in the Charales.

    PubMed

    Raven, John A

    2013-01-01

    This paper examines the significance of the recent demonstration of polar auxin transport (PAT) in the green macroalga Chara (Charophyceae: Charales) and, especially, options for explaining some features of PAT in the Charales. The occurrence of PAT in the Charales shows that PAT originated in the algal ancestors of the embryophytes (liverworts, mosses, hornworts, and vascular plants), although it is not yet known if PAT occurs elsewhere in the Charophyceae or in other algae. While in the embryophytes PAT occurs in parenchymatously constructed structures which commonly also have xylem and phloem (or their bryophyte analogues) as long-distance transport processes in parallel to PAT, in Chara corallina PAT shares the pathway for long-distance transport of nutrients though the parenchymatously constructed nodal complexes and the single giant cells of the internode. The speed of auxin movement of PAT is much more rapid than that attributable to diffusion and of the same order as the rate of cytoplasmic streaming in the giant internodal cells, yet complete inhibition of streaming by the inhibitor cytochalasin H does not slow down auxin transport. Explanations for this phenomenon are sought in the operation of other mechanochemical motors, dynein-tubulin and kinesin-tubulin, as alternatives to the myosin-actin system which powers cytoplasmic streaming. Experiments in which microtubules are disrupted, for example by colchicine, could show if one of the tubulin-based motors is involved. If these motors are involved, some mechanism is needed to amplify the speeds known for the motors to explain the order of magnitude higher speeds seen for auxin transport.

  5. Potential ergogenic activity of grape juice in runners.

    PubMed

    Toscano, Lydiane Tavares; Tavares, Renata Leite; Toscano, Luciana Tavares; Silva, Cássia Surama Oliveira da; Almeida, Antônio Eduardo Monteiro de; Biasoto, Aline Camarão Telles; Gonçalves, Maria da Conceição Rodrigues; Silva, Alexandre Sérgio

    2015-09-01

    Recent studies have indicated that certain food products have ergogenic potential similar to that of sports supplements. The present study aimed to investigate the potential ergogenic effect of integral purple grape juice on the performance of recreational runners. Twenty-eight volunteers of both sexes (age, 39.8 ± 8.5 years; peak oxygen consumption, 43.2 ± 8.5 mL/(kg·min)) were randomized into either a group that received grape juice (grape juice group (GJG), n = 15; 10 mL/(kg·min) for 28 days) or a group that received an isocaloric, isoglycemic, and isovolumetric control beverage (control group (CG), n = 13). A time-to-exhaustion exercise test, anaerobic threshold test, and aerobic capacity test were performed, together with assessments of markers of oxidative stress, inflammation, immune response, and muscle injury, performed at baseline and 48 h after the supplementation protocol. The GJG showed a significant increase (15.3%) in running time-to-exhaustion (p = 0.002) without significant improvements in either anaerobic threshold (3.6%; p = 0.511) or aerobic capacity (2.2%; p = 0.605). In addition, GJG exhibited significant increases in total antioxidant capacity (38.7%; p = 0.009), vitamin A (11.8%; p = 0.016), and uric acid (28.2%; p = 0.005), whereas α-1-acid glycoprotein significantly decreased (20.2%; p = 0.006) and high-sensitivity C-reactive protein levels remained unchanged. In contrast, no significant changes occurred in any of these variables in the CG. In conclusion, supplementation with purple grape juice shows an ergogenic effect in recreational runners by promoting increased time-to-exhaustion, accompanied by increased antioxidant activity and a possible reduction in inflammatory markers.

  6. Renal and cardiovascular responses to water immersion in trained runners and swimmers

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Tatro, D. L.; Rogan, R. B.

    1993-01-01

    The purpose of this study was to determine if fluid-electrolyte, renal, hormonal, and cardiovascular responses during and after multi-hour water immersion were associated with aerobic training. Additionally, we compared these responses in those who trained in a hypogravic versus a 1-g environment. Seventeen men comprised three similarly aged groups: six long-distance runners, five competitive swimmers, and six untrained control subjects. Each subject underwent 5 h of immersion in water [mean (SE)] 36.0 (0.5) degrees C to the neck. Immediately before and at each hour of immersion, blood and urine samples were collected and analyzed for sodium (Na), potassium, osmolality, and creatinine (Cr). Plasma antidiuretic hormone and aldosterone were also measured. Hematocrits were used to calculate relative changes in plasma volume (% delta Vpl). Heart rate response to submaximal cycle ergometer exercise (35% peak oxygen uptake) was measured before and after water immersion. Water immersion induced significant increases in urine flow, Na clearance (CNa), and a 3-5% decrease in Vpl. Urine flow during immersion was greater (P < 0.05) in runners [2.4 (0.4) ml.min-1] compared to controls [1.3 (0.1) ml.min-1]. However, % delta Vpl, CCr, CNa and CH2O during immersion were not different (P > 0.05) between runners, swimmers, and controls. After 5 h of immersion, there was an increase (P < 0.05) in submaximal exercise heart rate of 9 (3) and 10 (3) beats.min-1 in both runners and controls, respectively, but no change (P > 0.05) was observed in swimmers.(ABSTRACT TRUNCATED AT 250 WORDS).

  7. Renal and cardiovascular responses to water immersion in trained runners and swimmers

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Tatro, D. L.; Rogan, R. B.

    1993-01-01

    The purpose of this study was to determine if fluid-electrolyte, renal, hormonal, and cardiovascular responses during and after multi-hour water immersion were associated with aerobic training. Additionally, we compared these responses in those who trained in a hypogravic versus a 1-g environment. Seventeen men comprised three similarly aged groups: six long-distance runners, five competitive swimmers, and six untrained control subjects. Each subject underwent 5 h of immersion in water [mean (SE)] 36.0 (0.5) degrees C to the neck. Immediately before and at each hour of immersion, blood and urine samples were collected and analyzed for sodium (Na), potassium, osmolality, and creatinine (Cr). Plasma antidiuretic hormone and aldosterone were also measured. Hematocrits were used to calculate relative changes in plasma volume (% delta Vpl). Heart rate response to submaximal cycle ergometer exercise (35% peak oxygen uptake) was measured before and after water immersion. Water immersion induced significant increases in urine flow, Na clearance (CNa), and a 3-5% decrease in Vpl. Urine flow during immersion was greater (P < 0.05) in runners [2.4 (0.4) ml.min-1] compared to controls [1.3 (0.1) ml.min-1]. However, % delta Vpl, CCr, CNa and CH2O during immersion were not different (P > 0.05) between runners, swimmers, and controls. After 5 h of immersion, there was an increase (P < 0.05) in submaximal exercise heart rate of 9 (3) and 10 (3) beats.min-1 in both runners and controls, respectively, but no change (P > 0.05) was observed in swimmers.(ABSTRACT TRUNCATED AT 250 WORDS).

  8. The Cooper River Bridge Run Study of low back pain in runners and walkers.

    PubMed

    Woolf, Shane K; Barfield, William R; Nietert, Paul J; Mainous, Arch G; Glaser, John A

    2002-01-01

    Investigations dedicated to examining relationships between low back pain (LBP) and factors specific to running and walking are limited. Current literature suggests runners and walkers may have a lower relative risk for significant LBP. The purpose of this study was to investigate the incidence, prevalence, and possible risk factors for LBP among a group of runners and walkers. A survey was administered to participants who registered for either a 10-kilometer run or 4-mile recreational walk. A total of 539 responses were received. Previous history of LBP was reported by 74% of respondents overall. Prevalence of LBP at the time of survey completion was 13.6%. Low back pain was experienced more frequently by obese runners and by those who reported certain patterns of shoe wear. Regular participation in aerobics correlated with a reduced lifetime risk for LBP. We believe these findings warrant further investigation. This knowledge may benefit not only athletes in training, but other fitness enthusiasts, including casual runners and walkers and those who jog or walk to rehabilitate low back injuries.

  9. The effects of speed and surface compliance on shock attenuation characteristics for male and female runners.

    PubMed

    Dufek, Janet S; Mercer, John A; Griffin, Janet R

    2009-08-01

    The purpose of the study was to examine the effects of running speed and surface compliance on shock attenuation (SA) characteristics for male and female runners. We were also interested in identifying possible kinematic explanations, specifically, kinematics of the lower extremity at foot-ground contact, for anticipated gender differences in SA. Fourteen volunteer recreational runners (7 male, 7 female) ran at preferred and slow speeds on an adjustable bed treadmill, which simulated soft, medium, and hard surface conditions. Selected kinematic descriptors of lower extremity kinematics as well as leg and head peak impact acceleration values were obtained for 10 left leg contacts per subject-condition. Results identified significant SA values between genders across conditions and more specifically, across surfaces for females, with male runners demonstrating a similar trend. Regression modeling to predict SA by gender for surface conditions elicited unremarkable results, ranging from 30.9 to 59.9% explained variance. It appears that surface compliance does affect SA during running; however, the runner's ability to dissipate the shock wave may not be expressly explained by our definition of lower extremity kinematics at contact.

  10. Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water

    USGS Publications Warehouse

    2014-01-01

    Polar bears (Ursus maritimus Phipps, 1774) depend on sea ice for catching marine mammal prey. Recent sea-ice declines have been linked to reductions in body condition, survival, and population size. Reduced foraging opportunity is hypothesized to be the primary cause of sea-ice-linked declines, but the costs of travel through a deteriorated sea-ice environment also may be a factor. We used movement data from 52 adult female polar bears wearing Global Positioning System (GPS) collars, including some with dependent young, to document long-distance swimming (>50 km) by polar bears in the southern Beaufort and Chukchi seas. During 6 years (2004-2009), we identified 50 long-distance swims by 20 bears. Swim duration and distance ranged from 0.7 to 9.7 days (mean = 3.4 days) and 53.7 to 687.1 km (mean = 154.2 km), respectively. Frequency of swimming appeared to increase over the course of the study. We show that adult female polar bears and their cubs are capable of swimming long distances during periods when extensive areas of open water are present. However, long-distance swimming appears to have higher energetic demands than moving over sea ice. Our observations suggest long-distance swimming is a behavioral response to declining summer sea-ice conditions.

  11. Avian population consequences of climate change are most severe for long-distance migrants in seasonal habitats.

    PubMed

    Both, Christiaan; Van Turnhout, Chris A M; Bijlsma, Rob G; Siepel, Henk; Van Strien, Arco J; Foppen, Ruud P B

    2010-04-22

    One consequence of climate change is an increasing mismatch between timing of food requirements and food availability. Such a mismatch is primarily expected in avian long-distance migrants because of their complex annual cycle, and in habitats with a seasonal food peak. Here we show that insectivorous long-distance migrant species in The Netherlands declined strongly (1984-2004) in forests, a habitat characterized by a short spring food peak, but that they did not decline in less seasonal marshes. Also, within generalist long-distance migrant species, populations declined more strongly in forests than in marshes. Forest-inhabiting migrant species arriving latest in spring declined most sharply, probably because their mismatch with the peak in food supply is greatest. Residents and short-distance migrants had non-declining populations in both habitats, suggesting that habitat quality did not deteriorate. Habitat-related differences in trends were most probably caused by climate change because at a European scale, long-distance migrants in forests declined more severely in western Europe, where springs have become considerably warmer, when compared with northern Europe, where temperatures during spring arrival and breeding have increased less. Our results suggest that trophic mismatches may have become a major cause for population declines in long-distance migrants in highly seasonal habitats.

  12. Using a network model to assess risk of forest pest spread via recreational travel

    Treesearch

    Frank H. Koch; Denys Yemshanov; Robert A. Haack; Roger D. Magarey

    2014-01-01

    Long-distance dispersal pathways, which frequently relate to human activities, facilitate the spread of alien species. One pathway of concern in North America is the possible spread of forest pests in firewood carried by visitors to campgrounds or recreational facilities. We present a network model depicting the movement of campers and, by extension, potentially...

  13. Recreational drugs.

    PubMed

    Iven, V G

    1998-04-01

    The war against substance abuse continues in today's society and the sports world often seems to be in the middle of all the attention, especially among the media. New recreational drugs arrive on the scene from time to time, much like GHB, but the predominant substances of abuse continue to be marijuana, cocaine, and alcohol. As research evolves in efforts to stay current and determine any potential performance effects of new substances, the literature has changed very little regarding the more common recreational drug and their effects on athletic participation. New studies are emerging comparing recreational drug use among athletes versus nonathletes. Findings include differences among these groups regarding individual sports, team sports, contact versus noncontact sports, and gender-specific sports. Higher risk-taking behavior contribute to these findings and is known to be more prevalent among an athletic population. Overall, illicit drug use in America in 1996 remained about the same as in 1995 after rising steadily since the early 1990s. About 13 million Americans used drugs at least monthly in 1996, up slightly from 12.8 million in 1995. Teenage drug and alcohol use fell to 9% in 1996, down from 10.9% in 1995. Attempts to recognize the early signs of substance abuse and identify those athletes "at risk" of experimenting with elicit drugs are paramount to the optimal treatment response program. The preparticipation examination remains the best initial format for establishing a sound physician-patient relationship. A thorough history including risk factors, family history, and personnel tendencies toward substance abuse should be obtained followed by an ongoing relationship between the athlete and his team physician. The better rapport between the athlete and team physician, the higher likelihood of early recognition of a developing substance abuse problem. Likewise, the earliest intervention usually leads to the most optimal treatment response.

  14. The design, construction, and operation of long-distance high-voltage electricity transmission technologies.

    SciTech Connect

    Molburg, J. C.; Kavicky, J. A.; Picel, K. C.

    2008-03-03

    This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these

  15. Long Distance Non-Line-of-Sight Ultraviolet Communication Channel Analysis and Experimental Verification

    NASA Astrophysics Data System (ADS)

    Liao, Linchao

    In this thesis, the characteristics of long-distance non-line-of-sight (NLOS) ultraviolet (UV) communication channel are studied through experiment and theoretical analysis. The research focuses on the validation of different channel models, long distance NLOS link loss and received signal energy distribution based on outdoor experiment results and numerous simulations. All the previous research on NLOS UV only considered short communication range scenarios, in which turbulence effects were assumed to be negligible. In fact, with the increasing of communication distance, optical turbulence effects may degrade UV communication performance because the fading irradiance significantly deteriorates the received signal in two aspects: received energy fluctuation and extra path loss. In the beginning, the author conducts a comprehensive outdoor channel measurement from several hundreds meters up to four thousand meters. To the best of our knowledge, this experiment represents the most comprehensive examination of the NLOS UV communication channel at such distances. By reporting experimentally collected data, we illustrate two approaches to measuring path loss. In addition to highlighting practical issues, which is death time, that must be considered when performing such measurement , the data provide validation of a previously reported Monte Carlo multiple-scattering channel model. In addition, we examine the distribution of received photon counts for evidence of the effects of turbulence in the NLOS channel. In this case, however, there is less agreement with predictions from existing turbulence models, suggesting the need for additional research on the refinement of turbulence modeling. For this reason, we then propose a MC channel model to capture the multiple scattering channel behavior under turbulence condition. In addition, we present a serial experimental results and study the characteristic of NLOS UV turbulence channel with farthest distances up to 1 km. Through

  16. ERP effects of the processing of syntactic long-distance dependencies.

    PubMed

    Phillips, Colin; Kazanina, Nina; Abada, Shani H

    2005-03-01

    In behavioral studies on sentence comprehension, much evidence indicates that shorter dependencies are preferred over longer dependencies, and that longer dependencies incur a greater processing cost. However, it remains uncertain which of the various steps involved in the processing of long-distance dependencies is responsible for the increased cost of longer dependencies. Previous sentence comprehension studies using event-related potentials (ERPs) have revealed response components that reflect the construction [J. King, M. Kutas, Who did what and when? Using word- and clause-level ERPs to monitor working memory usage in reading. Journal of Cognitive Neuroscience, 7, (1995) 376-395.] and completion [E. Kaan, A. Harris, E. Gibson, P. Holcomb, The P600 as an index of syntactic integration difficulty. Language and Cognitive Processes, 5, (2000) 159-201.] of long-distance wh-dependencies. This article reports one off-line rating study and one ERP study that manipulated both the presence of wh-dependencies and the length of the dependencies (one clause vs. two clauses), with the aim of clarifying the locus of length-sensitivity and the functional role of associated ERP components. Results of the off-line study confirm that longer wh-dependencies incur greater processing cost. Results of the ERP study indicate that both a sustained anterior negativity that follows the initiation of the wh-dependency and also a late posterior positivity (P600) that marks the completion of the dependency are sensitive to the presence of a wh-dependency, but do not show amplitude variations reflecting the length of the dependency. However, the P600 is delayed when it marks the completion of a longer wh-dependency. This suggests that both the sustained negativity and the P600 reflect length-insensitive aspects of the construction of syntactic dependencies. In addition, an N400 component is elicited in the middle of the two clause wh-dependency, upon encountering a verb with an argument

  17. Bone mineral density and serum testosterone in chronically trained, high mileage 40–55 year old male runners

    PubMed Central

    MacKelvie, K; Taunton, J; McKay, H; Khan, K

    2000-01-01

    Objectives—To identify physical activity that is beneficial for the maintenance of bone strength with increasing age by examining the relation between bone mineral density (BMD) and chronic endurance training in men. BMD at the proximal femur, its subregions, and the lumbar spine, and serum testosterone were compared between two groups of long distance runners with more than 20 years of training experience and non-athletic controls. Methods—Runners (n = 12) were divided into (a) high volume runners (n = 7), running 64–80 km a week, and (b) very high volume runners (n = 5), running more than 95 km a week, and compared with non-athletic male controls, exercising in non-endurance oriented activities two to four times a week. BMD (g/cm2) at the total proximal femur, femoral neck, trochanteric region, and lumbar spine was measured by dual energy x ray absorptiometry. Total testosterone (nmol/l) and free testosterone (pmol/l) in serum were measured by radioimmunoassay from single fasting blood samples. Results—Height, weight, and age (range = 40–55 years) were not significantly different between groups. The high volume runners had significantly higher BMD at the total proximal femur (1.09 (0.17) v 0.94 (0.056)), femoral neck (0.91 (0.16) v 0.78 (0.071)), and trochanteric region (0.85 (0.14) v 0.73 (0.053)) than controls (p<0.05). The differences in BMD for the proximal femur between the very high volume runners and the other two groups were not significant. There was no difference in lumbar spine BMD, total testosterone, or free testosterone between groups. However, there was a significant negative correlation between total testosterone (r = -0.73, p<0.01) and free testosterone (r = -0.79, p<0.005) and running volume in the distance runners. Conclusions—Long term distance running with training volumes less than 80 km a week had a positive effect on BMD of the proximal femur. With running volumes greater than 64 km a week, training was inversely related to

  18. Non-breeding season events influence sexual selection in a long-distance migratory bird.

    PubMed

    Reudink, Matthew W; Marra, Peter P; Kyser, T Kurt; Boag, Peter T; Langin, Kathryn M; Ratcliffe, Laurene M

    2009-05-07

    The study of sexual selection has traditionally focused on events and behaviours immediately surrounding copulation. In this study, we examine whether carry-over effects from the non-breeding season can influence the process of sexual selection in a long-distance migratory bird, the American redstart (Setophaga ruticilla). Previous work on American redstarts demonstrated that overwintering in a high-quality habitat influences spring departure dates from the wintering grounds, advances arrival dates on the breeding grounds and increases apparent reproductive success. We show that the mixed-mating strategy of American redstarts compounds the benefits of overwintering in high-quality winter habitats. Males arriving to breed in Canada from high-quality winter habitats arrive earlier than males from poor-quality habitats, resulting in a lower probability of paternity loss, a higher probability of achieving polygyny and ultimately higher realized reproductive success. Such results suggest that the process of sexual selection may be influenced by events interacting throughout the annual cycle.

  19. Peculiarities of the detection and identification of substance at long distance

    NASA Astrophysics Data System (ADS)

    Trofimov, Vyacheslav A.; Varentsova, Svetlana A.; Trofimov, Vladislav V.; Tikhomirov, Vasily V.

    2014-05-01

    Nowadays, the detection and identification of dangerous substances at long distance (several meters, for example) by using of THz pulse reflected from the object is an important problem. In this report we demonstrate possibility of THz signal measuring reflected from investigated object that is placed before a flat metallic mirror. A distance between the flat mirror and the parabolic mirror this mirror is equal to 3.5 meters. Therefore, at present time our measurements contain features of both transmission and reflection modes. The reflecting mirror is used because of weak average power of used femtosecond laser. Measurements were provided at room temperature and humidity about 60%. The aim of investigation was the detection of a substance in real condition. Chocolate and Cookies were used as samples for identification. We also discuss modified correlation criteria for the detection and identification of various substances using pulsed THz signal in the transmission and reflection mode at short distances of about 30-40 cm. These criteria are integral criteria in time and they are based on the SDA method. Proposed algorithms show both high probability of the substance identification and a reliability of realization in practice. We compare P-spectrum and SDA- methods in the paper and show that P-spectrum method is a partial case of SDAmethod.

  20. Possibility of the detection and identification of substance at long distance at using broad THz pulse

    NASA Astrophysics Data System (ADS)

    Trofimov, Vyacheslav A.; Varentsova, Svetlana A.; Trofimov, Vladislav V.

    2014-10-01

    The spectral properties of THz pulses containing a few cycles reflected from a flat metallic mirror placed at long distance about 3.5 meters from the parabolic mirror are investigated. The samples for analysis were placed before this mirror. Measurements were provided at room temperature of about 18-20° C and humidity of about 70%. The aim of investigation was the detection of a substance under real conditions. At the present time our measurements contain features of both transmission and reflection modes. This leads to a strong modulation of the spectrum and makes difficulties for identification. As samples for our current research we used several neutral substances: paper layers, a thick paper bag, chocolate and cookies. The first problem deals with the detection of common and mismatched spectral properties of samples with paper layers, a thick paper bag and explosives. HMX, PETN and RDX were used as explosive samples. The dependence of the accuracy of identification of samples with paper layers and a thick bag is studied when using short transmitted THz signals with opposite absolute phases as calibration signals. Common and mismatched spectral features of neutral substances: chocolate, cookies and drugs MA, MDMA were investigated by modified integral criteria as well.

  1. Male European eels are highly efficient long distance swimmers: effects of endurance swimming on maturation.

    PubMed

    Burgerhout, Erik; Brittijn, Sebastiaan A; Tudorache, Christian; de Wijze, Daniëlle L; Dirks, Ron P; van den Thillart, Guido E E J M

    2013-11-01

    European eels (Anguilla anguilla) migrate ~6000km towards their spawning area in the Sargasso Sea. Based on the recent discovery that males swim even more efficiently than females, it was predicted that males also would be able to swim ~6000km within six months. Additionally, eels do not mature naturally in captivity due to strong neural inhibition. Earlier, it was hypothesized that swimming exercise is a natural trigger to induce sexual maturation and may even result in full maturation. In the present study two groups of farmed male silver eels were subjected to either endurance swimming or resting for up to 6months. It was found that male eels were able to swim continuously for a total distance of 6670km within 6months. The body weight decrease in swimming and resting males after 6months was similar (<30g) underlining the extreme low energy cost of swimming. In contrast to our expectation long-term swimming did not induce sexual maturation in farmed silver eels, suggesting that swimming alone is not sufficient as a trigger for sexual maturation. In conclusion, male eels are efficient long distance swimmers and likely able to cover the distance to the Sargasso Sea within the expected time span of 6months.

  2. Retention time variability as a mechanism for animal mediated long-distance dispersal.

    PubMed

    Guttal, Vishwesha; Bartumeus, Frederic; Hartvigsen, Gregg; Nevai, Andrew L

    2011-01-01

    Long-distance dispersal (LDD) events, although rare for most plant species, can strongly influence population and community dynamics. Animals function as a key biotic vector of seeds and thus, a mechanistic and quantitative understanding of how individual animal behaviors scale to dispersal patterns at different spatial scales is a question of critical importance from both basic and applied perspectives. Using a diffusion-theory based analytical approach for a wide range of animal movement and seed transportation patterns, we show that the scale (a measure of local dispersal) of the seed dispersal kernel increases with the organisms' rate of movement and mean seed retention time. We reveal that variations in seed retention time is a key determinant of various measures of LDD such as kurtosis (or shape) of the kernel, thinkness of tails and the absolute number of seeds falling beyond a threshold distance. Using empirical data sets of frugivores, we illustrate the importance of variability in retention times for predicting the key disperser species that influence LDD. Our study makes testable predictions linking animal movement behaviors and gut retention times to dispersal patterns and, more generally, highlights the potential importance of animal behavioral variability for the LDD of seeds.

  3. Measuring atomic emission from beacons for long-distance chemical signaling.

    PubMed

    LaFratta, Christopher N; Pelse, Ian; Falla, Jose Luis; Liu, Yi; Palacios, Manuel A; Manesse, Mael; Whitesides, George M; Walt, David R

    2013-10-01

    In an effort to exploit chemistry for information science, we have constructed a system to send a message powered by a combustion reaction. Our system uses the thermal excitation of alkali metals to transmit an encoded signal over long distances. A message is transmitted by burning a methanol-soaked cotton string embedded with combinations of high, low, or zero levels of potassium, rubidium, and/or cesium ions. By measuring the intensities at the characteristic emission wavelengths of each metal in the near-infrared, 19 unique signals can be distinguished. We have built a custom telescope to detect these signals from 1 km away for nearly 10 min. The signal is isotropic, is self-powered, and has a low background. A potential application of this platform is for search and rescue signaling where another layer of information can be transmitted, in addition to the location of the beacon. This work, which seeks to encode and transmit information using chemistry instead of electronics, is part of the new field of "infochemistry".

  4. Very rapid long-distance sea crossing by a migratory bird

    NASA Astrophysics Data System (ADS)

    Alves, José A.; Dias, Maria P.; Méndez, Verónica; Katrínardóttir, Borgný; Gunnarsson, Tómas G.

    2016-11-01

    Landbirds undertaking within-continent migrations have the possibility to stop en route, but most long-distance migrants must also undertake large non-stop sea crossings, the length of which can vary greatly. For shorebirds migrating from Iceland to West Africa, the shortest route would involve one of the longest continuous sea crossings while alternative, mostly overland, routes are available. Using geolocators to track the migration of Icelandic whimbrels (Numenius phaeopus), we show that they can complete a round-trip of 11,000 km making two non-stop sea crossings and flying at speeds of up to 24 m s‑1 the fastest recorded for shorebirds flying over the ocean. Although wind support could reduce flight energetic costs, whimbrels faced headwinds up to twice their ground speed, indicating that unfavourable and potentially fatal weather conditions are not uncommon. Such apparently high risk migrations might be more common than previously thought, with potential fitness gains outweighing the costs.

  5. Intrinsic parameterization of a computational optical system for long-distance displacement structural monitoring

    NASA Astrophysics Data System (ADS)

    Martins, Luís F. Lages; Rebordão, José Manuel N. V.; Ribeiro, Álvaro Silva

    2015-01-01

    We aim at the intrinsic parameterization of a computational optical system applied in long-distance displacement measurement of large-scale structures. In this structural-monitoring scenario, the observation distance established between the digital camera and reference targets, which is composed of the computational optical system, can range from 100 up to 1000 m, requiring the use of long-focal length lenses in order to obtain a suitable sensitivity for the three-dimensional displacement measurement of the observed structure which can be of reduced magnitude. Intrinsic parameterization of long-focal length cameras is an emergent issue since conventional approaches applied for reduced focal length cameras are not suitable mainly due to ill-conditioned matrices in least squares estimation procedures. We describe the intrinsic parameterization of a long-focal length camera (600 mm) by the diffractive optical element method and present the obtained estimates and measurement uncertainties, discussing their contribution for the system's validation by calibration field test and displacement measurement campaigns in a long-span suspension bridge.

  6. Long-distance copropagation of quantum key distribution and terabit classical optical data channels

    NASA Astrophysics Data System (ADS)

    Wang, Liu-Jun; Zou, Kai-Heng; Sun, Wei; Mao, Yingqiu; Zhu, Yi-Xiao; Yin, Hua-Lei; Chen, Qing; Zhao, Yong; Zhang, Fan; Chen, Teng-Yun; Pan, Jian-Wei

    2017-01-01

    Quantum key distribution (QKD) generates symmetric keys between two remote parties and guarantees the keys are not accessible to any third party. Wavelength-division multiplexing between QKD and classical optical communications by sharing the existing fiber-optics infrastructure is highly desired in order to reduce the cost of QKD applications. However, comparing to the light for classical transmission, quantum signals are very weak and easily affected by impairments from classical light, such as the spontaneous Raman-scattering effect. Here, by selecting an optimal wavelength of quantum signals, we significantly reduce the influence of the Raman-scattering effect. In addition, through coherent optical communication technology, we achieve high-speed classical data transmission with relatively low launch powers, thereby further reducing the impairments from classical light. As a result, we realize the multiplexing and long-distance copropagation of QKD and terabit classical data transmission up to 80 km. The data capacity is two orders of magnitude larger than the existing results. Our demonstration verifies the feasibility of QKD and classical communication to share the resources of backbone fiber links and thus taking the utility of QKD a great step forward.

  7. Artemin promotes functional long-distance axonal regeneration to the brainstem after dorsal root crush.

    PubMed

    Wong, Laura Elisabeth; Gibson, Molly E; Arnold, H Moore; Pepinsky, Blake; Frank, Eric

    2015-05-12

    Recovery after a spinal cord injury often requires that axons restore synaptic connectivity with denervated targets several centimeters from the site of injury. Here we report that systemic artemin (ARTN) treatment promotes the regeneration of sensory axons to the brainstem after brachial dorsal root crush in adult rats. ARTN not only stimulates robust regeneration of large, myelinated sensory axons to the brainstem, but also promotes functional reinnervation of the appropriate target region, the cuneate nucleus. ARTN signals primarily through the RET tyrosine kinase, an interaction that requires the nonsignaling coreceptor GDNF family receptor (GFRα3). Previous studies reported limited GFRα3 expression on large sensory neurons, but our findings demonstrate that ARTN promotes robust regeneration of large, myelinated sensory afferents. Using a cell sorting technique, we demonstrate that GFRα3 expression is similar in myelinated and unmyelinated adult sensory neurons, suggesting that ARTN likely induces long-distance regeneration by binding GFRα3 and RET. Although ARTN is delivered for just 2 wk, regeneration to the brainstem requires more than 3 mo, suggesting that brief trophic support may initiate intrinsic growth programs that remain active until targets are reached. Given its ability to promote targeted functional regeneration to the brainstem, ARTN may represent a promising therapy for restoring sensory function after spinal cord injury.

  8. Fitness consequences of short- and long-distance pollinations in Phlox hirsuta, an endangered species.

    PubMed

    Ruane, Lauren G; Dickens, Morgan E; Wall, Morgan E

    2015-10-01

    The persistence of rare and endangered plant species may depend on the distance pollinators travel when dispersing pollen. Pollinations between adjacent plants, which are often genetically similar, can decrease seed set, germination, and/or progeny vigor due to shared S-alleles or inbreeding depression. Interpopulation pollen dispersal is often suggested as a management tool to increase genetic diversity; however, long-distance pollinations also have the potential to decrease fitness. We performed experimental hand pollinations in the field and germination experiments in a growth chamber to determine the effect of intrapopulation pollination distance (1 m, 10 m, and 100 m) on seed set, seed germination, progeny growth, and progeny reproduction in Phlox hirsuta. In addition, we included interpopulation pollinations (6740 m) to determine whether artificial gene flow is a viable management option for this endangered species. Although pollination distance did not affect the number of healthy seeds produced or the likelihood of radicle emergence, it did significantly affect the ability of germinating seeds to successfully produce cotyledons. Outbreeding depression was observed during seed germination and early seedling development. Seedlings resulting from interpopulation pollinations developed more slowly and were less likely to survive to produce cotyledons than seedlings resulting from all three intrapopulation pollination distances. Our results suggest that the success of P. hirsuta does not depend on the distance pollinators travel within populations and that conservation strategies that involve transporting genes between populations can be counterproductive. © 2015 Botanical Society of America.

  9. Building a long distance training program to enhance clinical cancer research capacity in Puerto Rico.

    PubMed

    Appleyard, Caroline B; Antonia, Scott J; Sullivan, Daniel M; Santiago-Cardona, Pedro G; Cáceres, William; Velez, Hector; Torres-Ruiz, Jose A; Wright, Kenneth L

    2014-01-01

    Barriers persist in the development and delivery of effective cancer therapies to under-represented minority populations. In Puerto Rico, cancer is the second leading cause of death, yet cancer research awareness and training opportunities remain somewhat limited on the island. These limitations hinder progress toward decreasing the cancer health disparities that exist within the Puerto Rican population. The predominantly Hispanic population of Puerto Rico is the focus of a partnership between the Ponce Health Sciences University-Medical School and Ponce Research Institute (PHSU) in Ponce, Puerto Rico and the H. Lee Moffitt Cancer Center in Tampa, Florida. The Partnership goals are to reduce these barriers through an integrated, multipronged approach of training and education alongside outreach and research components. This report describes the approaches, successes and challenges of enhancing clinical cancer research capacity on the island and the unique challenges of a partnership between two institutes physically separated by long distances. Once fully developed this model may be exportable to other Latin American countries where the need is even greater.

  10. [Intensive care within the context of military long-distance transport].

    PubMed

    Hossfeld, B; Rohowsky, B; Rödig, E; Lampl, L

    2004-05-01

    Due to the changed task spectrum of the German Federal Armed Forces with participation in international deployments for UN and NATO the concept of Aeromedical Evacuation (MedEvac) gained a new quality for the Air Force as well as for the Medical Corps. The transport of mostly severely injured or critically ill patients requires both, medical equipment which has to be permanently adapted to the national standard, and qualified intensive-care-personnel. At present, the aircrafts used for such deployments are four C-160 Transall, one CL-601 Challenger and two Airbus A310, which, if necessary, can be equipped with one or more intensive-care "patient transportation units" (PTU). Contrary to the two other aircrafts, the CL-601 Challenger is only equipped for the intensive-care transport of one individual patient. The PTU corresponds to the technical equipment of the intensive care unit of a level-1-trauma centre and ensures an intensive-care therapy on highest level also during longer transportation. The work with this equipment, the characteristics of the long-distance air transport and the special situation of the military deployment causes special demands on the qualifications of the assigned personnel. Primarily planned for the repatriation of injured or ill soldiers, in the mean time, this concept is also essential for the medevac of civilian victims after mass casualties worldwide.

  11. An investigation of long-distance propagation of gravity waves under CAWSES India Phase II Programme

    NASA Astrophysics Data System (ADS)

    Parihar, N.; Taori, A.

    2015-05-01

    Coordinated measurements of airglow features from the mesosphere-lower thermosphere (MLT) region were performed at Allahabad (25.5° N, 81.9° E) and Gadanki (13.5° N, 79.2° E), India to study the propagation of gravity waves in 13-27° N latitude range during the period June 2009 to May 2010 under CAWSES (Climate And Weather of Sun Earth System) India Phase II Programme. At Allahabad, imaging observations of OH broadband emissions and OI 557.7 nm emission were made using an all-sky imager, while at Gadanki photometric measurements of OH (6, 2) Meinel band and O2 (0, 1) Atmospheric band emissions were carried out. On many occasions, the nightly observations reveal the presence of similar waves at both locations. Typically, the period of observed similar waves lay in the 2.2-4.5 h range, had large phase speeds (~ 77-331 m s-1) and large wavelengths (~ 1194-2746 km). The images of outgoing long-wave radiation activity of the National Oceanic and Atmospheric Administration (NOAA) and the high-resolution infrared images of KALPANA-1 satellite suggest that such waves possibly originated from some nearby convective sources. An analysis of their propagation characteristics in conjunction with SABER/TIMED temperature profiles and Horizontal Wind Model (HWM 2007) wind estimates suggest that the waves propagated over long distances (~ 1200-2000 km) in atmospheric ducts.

  12. Long-distance communication by specialized cellular projections during pigment pattern development and evolution

    PubMed Central

    Eom, Dae Seok; Bain, Emily J; Patterson, Larissa B; Grout, Megan E; Parichy, David M

    2015-01-01

    Changes in gene activity are essential for evolutionary diversification. Yet, elucidating the cellular behaviors that underlie modifications to adult form remains a profound challenge. We use neural crest-derived adult pigmentation of zebrafish and pearl danio to uncover cellular bases for alternative pattern states. We show that stripes in zebrafish require a novel class of thin, fast cellular projection to promote Delta-Notch signaling over long distances from cells of the xanthophore lineage to melanophores. Projections depended on microfilaments and microtubules, exhibited meandering trajectories, and stabilized on target cells to which they delivered membraneous vesicles. By contrast, the uniformly patterned pearl danio lacked such projections, concomitant with Colony stimulating factor 1-dependent changes in xanthophore differentiation that likely curtail signaling available to melanophores. Our study reveals a novel mechanism of cellular communication, roles for differentiation state heterogeneity in pigment cell interactions, and an unanticipated morphogenetic behavior contributing to a striking difference in adult form. DOI: http://dx.doi.org/10.7554/eLife.12401.001 PMID:26701906

  13. Endemism and long distance dispersal in the waterfleas of Easter Island.

    PubMed

    Damme, Kay Van

    2016-08-22

    Easter Island is known for a depauperate terrestrial and aquatic biota. The discovery of new taxa is unusual, even among the island's micro-invertebrates. A new cladoceran, Ovalona pascua sp. nov. (Crustacea: Cladocera: Anomopoda: Chydoridae), is described from freshwater environments. The chydorid, the only known extant cladoceran on the island, is the dominant aquatic invertebrate in the surface waters. Based on detailed morphological comparison, including a character similarity matrix applied across the species in the genus (12 characters/17 spp), the new taxon is proposed here as an insular endemic with affinities in the East (New World). The revision challenges the theory that invasive zooplankton species were introduced from the subantarctic islands during the 18th century. Human introduction is not the main mechanism through which cladocerans could have arrived on Easter Island. Late Pleistocene - Early Holocene fossils in Cañellas-Boltà et al. (2012) from cores in Rano Raraku Lake are identified here as Daphnia O.F. Müller, 1785 (subgenus Ctenodaphnia Dybowski & Grochowski, 1895). The establishment of Daphnia before human colonization on Easter Island provides strong proof of successful long distance dispersal by ephippia over thousands of kilometers of open sea.

  14. Dengue and chikungunya: long-distance spread and outbreaks in naïve areas

    PubMed Central

    Rezza, Giovanni

    2014-01-01

    Mosquito-borne virus infections, such as dengue and chikungunya, are continuously expanding their geographical range. The dengue virus, which is known to be a common cause of febrile illness in tropical areas of the Old World, is now widespread in the Americas. In most affected areas, all the four dengue virus serotypes have circulated. Recently, small clusters of dengue have been identified also in Southern Europe during the hot season. The chikungunya virus, initially restricted to Central Africa, where is a common cause of sporadic cases or small outbreaks, and Asia, where it is used to cause large epidemics, has recently invaded new territories. After ravaging Indian Ocean Islands and the Indian subcontinent, CHIKV caused an outbreak in north-eastern Italy. Recently, chikungunya has reached the Caribbean, causing for the first time a large epidemic on the American continent. Although Aedes aegypti is the main vector of both viruses, Aedes albopictus, the Asian ‘Tiger’ mosquito, is now playing an increasingly important role, contributing to their spread in temperate climate areas. Hereby, we focus the attention on outbreaks of dengue and chikungunya occurring in previously disease-free areas and discuss factors associated with the long-distance spread of the vector-borne infections, such as mutations increasing viral fitness, climate change, urbanization, and globalization of humans and vectors. PMID:25491436

  15. Waterfowl endozoochory: An overlooked long-distance dispersal mode for Cuscuta (dodder).

    PubMed

    Costea, Mihai; Stefanović, Saša; García, Miguel A; De La Cruz, Susan; Casazza, Michael L; Green, Andy J

    2016-05-01

    Dispersal of parasitic Cuscuta species (dodders) worldwide has been assumed to be largely anthropomorphic because their seeds do not match any previously known dispersal syndrome and no natural dispersal vectors have been reliably documented. However, the genus has a subcosmopolitan distribution and recent phylogeographic results have indicated that at least18 historical cases of long-distance dispersal (LDD) have occurred during its evolution. The objective of this study is to report the first LDD biological vector for Cuscuta seeds. Twelve northern pintails (Anas acuta) were collected from Suisun Marsh, California and the contents of their lowest part of the large intestine (rectum) were extracted and analyzed. Seed identification was done both morphologically and using a molecular approach. Extracted seeds were tested for germination and compared to seeds not subjected to gut passage to determine the extent of structural changes caused to the seed coat by passing through the digestive tract. Four hundred and twenty dodder seeds were found in the rectum of four northern pintails. From these, 411 seeds were identified as Cuscuta campestris and nine as most likely C. pacifica. The germination rate of C. campestris seeds after gut passage was 55%. Structural changes caused by the gut passage in both species were similar to those caused by an acid scarification. Endozoochory by waterbirds may explain the historical LDD cases in the evolution of Cuscuta. This also suggests that current border quarantine measures may be insufficient to stopping spreading of dodder pests along migratory flyways. © 2016 Botanical Society of America.

  16. Long-distance pollen flow assessment through evaluation of pollinator foraging range suggests transgene escape distances

    PubMed Central

    Pasquet, Rémy S.; Peltier, Alexis; Hufford, Matthew B.; Oudin, Emeline; Saulnier, Jonathan; Paul, Lénaic; Knudsen, Jette T.; Herren, Hans R.; Gepts, Paul

    2008-01-01

    Foraging range, an important component of bee ecology, is of considerable interest for insect-pollinated plants because it determines the potential for outcrossing among individuals. However, long-distance pollen flow is difficult to assess, especially when the plant also relies on self-pollination. Pollen movement can be estimated indirectly through population genetic data, but complementary data on pollinator flight distances is necessary to validate such estimates. By using radio-tracking of cowpea pollinator return flights, we found that carpenter bees visiting cowpea flowers can forage up to 6 km from their nest. Foraging distances were found to be shorter than the maximum flight range, especially under adverse weather conditions or poor reward levels. From complete flight records in which bees visited wild and domesticated populations, we conclude that bees can mediate gene flow and, in some instances, allow transgene (genetically engineered material) escape over several kilometers. However, most between-flower flights occur within plant patches, while very few occur between plant patches. PMID:18768793

  17. Long-distance plant dispersal to North Atlantic islands: colonization routes and founder effect.

    PubMed

    Alsos, Inger Greve; Ehrich, Dorothee; Eidesen, Pernille Bronken; Solstad, Heidi; Westergaard, Kristine Bakke; Schönswetter, Peter; Tribsch, Andreas; Birkeland, Siri; Elven, Reidar; Brochmann, Christian

    2015-04-15

    Long-distance dispersal (LDD) processes influence the founder effect on islands. We use genetic data for 25 Atlantic species and similarities among regional floras to analyse colonization, and test whether the genetic founder effect on five islands is associated with dispersal distance, island size and species traits. Most species colonized postglacially via multiple dispersal events from several source regions situated 280 to >3000 km away, and often not from the closest ones. A strong founder effect was observed for insect-pollinated mixed maters, and it increased with dispersal distance and decreased with island size in accordance with the theory of island biogeography. Only a minor founder effect was observed for wind-pollinated outcrossing species. Colonization patterns were largely congruent, indicating that despite the importance of stochasticity, LDD is mainly determined by common factors, probably dispersal vectors. Our findings caution against a priori assuming a single, close source region in biogeographic analyses. Published by Oxford University Press on behalf of the Annals of Botany Company.

  18. Building a Long Distance Training Program to Enhance Clinical Cancer Research Capacity in Puerto Rico

    PubMed Central

    Appleyard, Caroline B.; Antonia, Scott J.; Sullivan, Daniel M.; Santiago-Cardona, Pedro G.; Cáceres, William; Velez, Hector; Torres-Ruiz, Jose A.; Wright, Kenneth L.

    2015-01-01

    Barriers persist in the development and delivery of effective cancer therapies to under-represented minority populations. In Puerto Rico, cancer is the second leading cause of death, yet cancer research awareness and training opportunities remain somewhat limited on the island. These limitations hinder progress toward decreasing the cancer health disparities that exist within the Puerto Rican population. The predominantly Hispanic population of Puerto Rico is the focus of a partnership between the Ponce Health Sciences University-Medical School and Ponce Research Institute (PHSU) in Ponce, Puerto Rico and the H. Lee Moffitt Cancer Center in Tampa, Florida. The Partnership goals are to reduce these barriers through an integrated, multipronged approach of training and education alongside outreach and research components. This report describes the approaches, successes and challenges of enhancing clinical cancer research capacity on the island and the unique challenges of a partnership between two institutes physically separated by long distances. Once fully developed this model may be exportable to other Latin American countries where the need is even greater. PMID:25626061

  19. Satellite tracking reveals long distance coastal travel and homing by translocated estuarine crocodiles, Crocodylus porosus.

    PubMed

    Read, Mark A; Grigg, Gordon C; Irwin, Steve R; Shanahan, Danielle; Franklin, Craig E

    2007-09-26

    Crocodilians have a wide distribution, often in remote areas, are cryptic, secretive and are easily disturbed by human presence. Their capacity for large scale movements is poorly known. Here, we report the first study of post-release movement patterns in translocated adult crocodiles, and the first application of satellite telemetry to a crocodilian. Three large male Crocodylus porosus (3.1-4.5 m) were captured in northern Australia and translocated by helicopter for 56, 99 and 411 km of coastline, the last across Cape York Peninsula from the west coast to the east coast. All crocodiles spent time around their release site before returning rapidly and apparently purposefully to their capture locations. The animal that circumnavigated Cape York Peninsula to return to its capture site, travelled more than 400 km in 20 days, which is the longest homeward travel yet reported for a crocodilian. Such impressive homing ability is significant because translocation has sometimes been used to manage potentially dangerous C. porosus close to human settlement. It is clear that large male estuarine crocodiles can exhibit strong site fidelity, have remarkable navigational skills, and may move long distances following a coastline. These long journeys included impressive daily movements of 10-30 km, often consecutively.

  20. Working Memory in the Processing of Long-Distance Dependencies: Interference and Filler Maintenance.

    PubMed

    Ness, Tal; Meltzer-Asscher, Aya

    2017-05-20

    During the temporal delay between the filler and gap sites in long-distance dependencies, the "active filler" strategy can be implemented in two ways: the filler phrase can be actively maintained in working memory ("maintenance account"), or it can be retrieved only when the parser posits a gap ("retrieval account"). The current study tested whether filler content is maintained during the processing of dependencies. Using a self-paced reading paradigm, we compared reading times on a noun phrase (NP) between the filler and gap sites in object relative clauses, to reading times on an NP between the antecedent and ellipsis sites in ellipsis sentences. While in the former type of dependency a filler by hypothesis can be maintained, in the latter there is no indication for the existence of a dependency prior to the ellipsis site, and hence no maintenance. By varying the amount of similarity-based interference between the antecedent and integration sites, we tested the influence of holding an unresolved dependency on reading times. Significantly increased reading times due to interference were found only in the object relative condition, and not in the ellipsis condition, demonstrating filler maintenance costs. The fact that these costs were measured as an effect on similarity-based interference indicates that the maintained representation of the filler must include at least some of the features shared by the interfering NP.

  1. Some chronobiological and physiological problems associated with long-distance journeys.

    PubMed

    Reilly, Thomas; Waterhouse, Jim; Edwards, Benjamin

    2009-03-01

    Long-distance travel is becoming increasingly common. Whatever the means of transport, any long journey will be associated with "travel fatigue". The symptoms associated with this phenomenon result from a changed routine (particularly sleep lost and meals) and the general disruption caused by travel. Planning any trip well in advance will minimise many of these problems, but some factors are less easy to guard against. These problems include sitting in cramped and uncomfortable conditions and, with flights, the hypoxic environment in the cabin. After arrival at the destination in another country, there can be problems coping with the local language, alterations in food and different customs. If the flight has crossed the equator, then there is likely to be a change in season and natural lighting and, if it has crossed several time zones, there will also be the problem of "jet lag", caused by a transient desynchrony between the "body clock" and the new local time. Moreover, the new environment might differ from the place of departure with regard to ambient temperature and humidity, altitude, natural lighting (including ultraviolet radiation) and pollution. The traveller needs to be aware of these changes before setting off, so that appropriate preparations (clothing, for example) can be made.

  2. Repeated, long-distance migrations by a philopatric predator targeting highly contrasting ecosystems

    PubMed Central

    Lea, James S. E.; Wetherbee, Bradley M.; Queiroz, Nuno; Burnie, Neil; Aming, Choy; Sousa, Lara L.; Mucientes, Gonzalo R.; Humphries, Nicolas E.; Harvey, Guy M.; Sims, David W.; Shivji, Mahmood S.

    2015-01-01

    Long-distance movements of animals are an important driver of population spatial dynamics and determine the extent of overlap with area-focused human activities, such as fishing. Despite global concerns of declining shark populations, a major limitation in assessments of population trends or spatial management options is the lack of information on their long-term migratory behaviour. For a large marine predator, the tiger shark Galeocerdo cuvier, we show from individuals satellite-tracked for multiple years (up to 1101 days) that adult males undertake annually repeated, round-trip migrations of over 7,500 km in the northwest Atlantic. Notably, these migrations occurred between the highly disparate ecosystems of Caribbean coral reef regions in winter and high latitude oceanic areas in summer, with strong, repeated philopatry to specific overwintering insular habitat. Partial migration also occurred, with smaller, immature individuals displaying reduced migration propensity. Foraging may be a putative motivation for these oceanic migrations, with summer behaviour showing higher path tortuosity at the oceanic range extremes. The predictable migratory patterns and use of highly divergent ecosystems shown by male tiger sharks appear broadly similar to migrations seen in birds, reptiles and mammals, and highlight opportunities for dynamic spatial management and conservation measures of highly mobile sharks. PMID:26057337

  3. Long distance dispersal and vertical gene flow in the Caribbean brooding coral Porites astreoides.

    PubMed

    Serrano, Xaymara M; Baums, Iliana B; Smith, Tyler B; Jones, Ross J; Shearer, Tonya L; Baker, Andrew C

    2016-02-22

    To date, most assessments of coral connectivity have emphasized long-distance horizontal dispersal of propagules from one shallow reef to another. The extent of vertical connectivity, however, remains largely understudied. Here, we used newly-developed and existing DNA microsatellite loci for the brooding coral Porites astreoides to assess patterns of horizontal and vertical connectivity in 590 colonies collected from three depth zones (≤10 m, 15-20 m and ≥25 m) at sites in Florida, Bermuda and the U.S. Virgin Islands (USVI). We also tested whether maternal transmission of algal symbionts (Symbiodinium spp.) might limit effective vertical connectivity. Overall, shallow P. astreoides exhibited high gene flow between Florida and USVI, but limited gene flow between these locations and Bermuda. In contrast, there was significant genetic differentiation by depth in Florida (Upper Keys, Lower Keys and Dry Tortugas), but not in Bermuda or USVI, despite strong patterns of depth zonation in algal symbionts at two of these locations. Together, these findings suggest that P. astreoides is effective at dispersing both horizontally and vertically despite its brooding reproductive mode and maternal transmission of algal symbionts. In addition, these findings might help explain the ecological success reported for P. astreoides in the Caribbean in recent decades.

  4. Long distance dispersal and vertical gene flow in the Caribbean brooding coral Porites astreoides

    PubMed Central

    Serrano, Xaymara M.; Baums, Iliana B.; Smith, Tyler B.; Jones, Ross J.; Shearer, Tonya L.; Baker, Andrew C.

    2016-01-01

    To date, most assessments of coral connectivity have emphasized long-distance horizontal dispersal of propagules from one shallow reef to another. The extent of vertical connectivity, however, remains largely understudied. Here, we used newly-developed and existing DNA microsatellite loci for the brooding coral Porites astreoides to assess patterns of horizontal and vertical connectivity in 590 colonies collected from three depth zones (≤10 m, 15–20 m and ≥25 m) at sites in Florida, Bermuda and the U.S. Virgin Islands (USVI). We also tested whether maternal transmission of algal symbionts (Symbiodinium spp.) might limit effective vertical connectivity. Overall, shallow P. astreoides exhibited high gene flow between Florida and USVI, but limited gene flow between these locations and Bermuda. In contrast, there was significant genetic differentiation by depth in Florida (Upper Keys, Lower Keys and Dry Tortugas), but not in Bermuda or USVI, despite strong patterns of depth zonation in algal symbionts at two of these locations. Together, these findings suggest that P. astreoides is effective at dispersing both horizontally and vertically despite its brooding reproductive mode and maternal transmission of algal symbionts. In addition, these findings might help explain the ecological success reported for P. astreoides in the Caribbean in recent decades. PMID:26899614

  5. The impact of increased food availability on survival of a long-distance migratory bird.

    PubMed

    Seward, Adam M; Beale, Colin M; Gilbert, Lucy; Jones, T Hefin; Thomas, Robert J

    2013-01-01

    Temperature-, rainfall- and habitat-driven change in food availability is one likely mechanism by which anthropogenic factors may affect animal population dynamics and species distributions. Long-distance migratory birds must synchronize their migrations with food availability at locations hundreds or thousands of kilometers apart, so changes in the overall abundance of food or the phenology of peaks in food availability may be critical factors influencing annual survival. In this study we used experimental food supplementation at a breeding site to examine and compare the impact of changing food supply on annual survival of adult migratory birds and their offspring. We provided supplemental food to Northern Wheatears (Oenanthe oenanthe) breeding on Fair Isle, UK, to infer the sensitivity of annual survival to increases in natural food availability. Food-supplemented wheatears exhibited higher rates of annual survival than control wheatears, and the strength of this effect varied with age. Food supplementation led to 1.56 times higher annual survival of juveniles and 1.22 times higher survival of adults. Survival of juveniles was related to their own food availability as fledglings, but not to whether their parents were food-supplemented or unfed control adults. This increased survival, combined with increased breeding productivity associated with food supplementation, implies that an increase in natural food availability, of the magnitude simulated in our experiment, would increase the population growth rate of wheatears on Fair Isle from approximately lambda = 0.93 (a contracting population) to lambda = 1.14 (an expanding population).

  6. Using task dynamics to quantify the affordances of throwing for long distance and accuracy.

    PubMed

    Wilson, Andrew D; Weightman, Andrew; Bingham, Geoffrey P; Zhu, Qin

    2016-07-01

    In 2 experiments, the current study explored how affordances structure throwing for long distance and accuracy. In Experiment 1, 10 expert throwers (from baseball, softball, and cricket) threw regulation tennis balls to hit a vertically oriented 4 ft × 4 ft target placed at each of 9 locations (3 distances × 3 heights). We measured their release parameters (angle, speed, and height) and showed that they scaled their throws in response to changes in the target's location. We then simulated the projectile motion of the ball and identified a continuous subspace of release parameters that produce hits to each target location. Each subspace describes the affordance of our target to be hit by a tennis ball moving in a projectile motion to the relevant location. The simulated affordance spaces showed how the release parameter combinations required for hits changed with changes in the target location. The experts tracked these changes in their performance and were successful in hitting the targets. We next tested unusual (horizontal) targets that generated correspondingly different affordance subspaces to determine whether the experts would track the affordance to generate successful hits. Do the experts perceive the affordance? They do. In Experiment 2, 5 cricketers threw to hit either vertically or horizontally oriented targets and successfully hit both, exhibiting release parameters located within the requisite affordance subspaces. We advocate a task dynamical approach to the study of affordances as properties of objects and events in the context of tasks as the future of research in this area. (PsycINFO Database Record

  7. Long-distance pollen flow assessment through evaluation of pollinator foraging range suggests transgene escape distances.

    PubMed

    Pasquet, Rémy S; Peltier, Alexis; Hufford, Matthew B; Oudin, Emeline; Saulnier, Jonathan; Paul, Lénaic; Knudsen, Jette T; Herren, Hans R; Gepts, Paul

    2008-09-09

    Foraging range, an important component of bee ecology, is of considerable interest for insect-pollinated plants because it determines the potential for outcrossing among individuals. However, long-distance pollen flow is difficult to assess, especially when the plant also relies on self-pollination. Pollen movement can be estimated indirectly through population genetic data, but complementary data on pollinator flight distances is necessary to validate such estimates. By using radio-tracking of cowpea pollinator return flights, we found that carpenter bees visiting cowpea flowers can forage up to 6 km from their nest. Foraging distances were found to be shorter than the maximum flight range, especially under adverse weather conditions or poor reward levels. From complete flight records in which bees visited wild and domesticated populations, we conclude that bees can mediate gene flow and, in some instances, allow transgene (genetically engineered material) escape over several kilometers. However, most between-flower flights occur within plant patches, while very few occur between plant patches.

  8. Foliage shedding in deciduous forests lifts up long-distance seed dispersal by wind.

    PubMed

    Nathan, Ran; Katul, Gabriel G

    2005-06-07

    Seed terminal velocity and release height are recognized as key biotic determinants of long-distance dispersal (LDD) of seeds by wind. Yet, potential determinants at the ecosystem level, such as seasonal dynamics in foliage density characterizing many deciduous forests, have received much less attention. We integrated detailed field observations and experiments with a mechanistic wind dispersal model to assess how seasonal variation in foliage density, estimated by leaf-area index (LAI), affects LDD in deciduous forests. We found that the model, previously shown to accurately predict seed dispersal by wind, also reliably describes the effects of LAI variation on wind statistics for a wide range of canopy types. Sparser canopies are characterized by more organized vertical eddy motion that promotes LDD by uplifting seeds to higher elevations where winds are stronger. Yet, sparser canopies are also characterized by reduced mean windspeed aloft. We showed that former effect more than compensates for the latter, i.e., conditions of low LAI are favorable for LDD. This may account for the tendency of many temperate tree species to restrict seed release to either early spring or late fall, when LAI is relatively low. Sensitivity analysis reveals that the typical seasonal variation in LAI can be more important to LDD of seeds by wind than the natural variation in seed terminal velocity. Because our model accurately describes the effects of LAI variation for distinctly different sites, species, and life forms, we suggest that its results reflect a general association between LDD and foliage density dynamics.

  9. The physiology of long-distance migration: extending the limits of endurance metabolism.

    PubMed

    Weber, Jean-Michel

    2009-03-01

    Long-distance migrants have evolved specific adaptations that make their athletic records possible. Unique mechanisms explaining their amazing capacity for endurance exercise have now been uncovered, particularly with respect to energy storage, mobilization, transport and utilization. Birds are champions of migration because flying offers a key compromise: it allows more rapid movement than swimming, but has a lower cost of transport than running. High efficiency for muscle contraction, pointed wings, low wingloading, travelling in V-formations, storing fuel as energy-dense lipids and atrophy of non-essential organs are some of their strategies to decrease the cost of transport. The ability to process lipids rapidly also emerges as a crucial component of the migrant phenotype. High lipid fluxes are made possible by lipoprotein shuttles and fatty acid binding proteins (FABPs) that accelerate lipid transport and by upgrading the metabolic machinery for lipolysis and lipid oxidation. Preparation for long flights can include natural doping on n-3 polyunsaturated fatty acids (n-3 PUFAs) from unique invertebrate diets. Muscle performance is improved by restructuring membrane phospholipids and by activating key genes of lipid metabolism through peroxisome proliferator-activated receptors (PPARs). The physiological secret to long migrations does not depend on a single ;magic' adaptation but on the integration of multiple adjustments in morphology, biomechanics, behavior, nutrition and metabolism. Research on the physiology of migrants improves the fundamental knowledge of exercise biology, but it also has important implications for wildlife conservation, treating obesity and improving the performance of human athletes.

  10. Pipe inspection system by guide wave using a long distance waveguide

    NASA Astrophysics Data System (ADS)

    Murayama, Riichi; Kobayashi, Makiko

    2016-02-01

    Nondestructive inspection of a high-temperature structure is required to guarantee its safety. However, there are no useful sensors for high-temperature structures. Some of them cannot work at temperatures over 50°C. Another concern is that it is too expensive to use. Therefore, a sensing system, which can transmit and receive an ultrasonic wave and travel a long distance using a long waveguide, has been studied. This means that an ultrasonic sensor could be driven at atmospheric temperature. Especially, the work was focused in applying the developed technique to a pipe which is used in a nuclear power plant. Therefore, the best rectangle-shaped wave-guide was studied and tried to wound the waveguide around a pipe to drive as an acoustic source of a guide wave. Finally, L (0,2) and T (0,1)-mode guide wave were detected successfully by devising the shape of the opposite edge of the rectangle shaped waveguide and could detect the reflected signal from an artificial defect machined into a test pipe.

  11. Splicing regulation in spinal muscular atrophy by an RNA structure formed by long-distance interactions.

    PubMed

    Singh, Natalia N; Lee, Brian M; Singh, Ravindra N

    2015-04-01

    Humans carry two copies of the survival motor neuron gene: SMN1 and SMN2. Loss of SMN1 coupled with skipping of SMN2 exon 7 causes spinal muscular atrophy (SMA), a leading genetic disease associated with infant mortality. Our discovery of intronic splicing silencer N1 (ISS-N1) is a promising target, currently in a phase III clinical trial, for an antisense oligonucleotide-mediated splicing correction in SMA. We have recently shown that the first residue of ISS-N1 is locked in a unique RNA structure that we term ISTL1 (internal stem through long-distance interaction-1). Complementary strands of ISTL1 are separated from each other by 279 nucleotides. Using site-specific mutations and chemical structure probing, we confirmed the formation and functional significance of ISTL1. Located in the middle of intron 7, the 3' strand of ISTL1 falls within an inhibitory region that we term ISS-N2. We demonstrate that an antisense oligonucleotide-mediated sequestration of ISS-N2 fully corrects SMN2 exon 7 splicing and restores high levels of SMN in SMA patient cells. These results underscore the therapeutic potential of the regulatory information present in a secondary and high-order RNA structure of a human intron.

  12. Airborne multi-axis DOAS measurements of atmospheric trace gases on CARIBIC long-distance flights

    NASA Astrophysics Data System (ADS)

    Dix, B.; Brenninkmeijer, C. A. M.; Frieß, U.; Wagner, T.; Platt, U.

    2009-11-01

    A DOAS (Differential Optical Absorption Spectroscopy) instrument was implemented and operated onboard a long-distance passenger aircraft within the framework of the CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container). The instrument was designed to keep weight, size and power consumption low and to comply with civil aviation regulations. It records spectra of scattered light from three viewing directions (nadir, 10° above and below horizon) using a miniaturized telescope system. The telescopes are integrated in the main pylon of the inlet system which is mounted at the belly of the aircraft. Fibre bundles transmit light from the telescopes to spectrograph-detector units inside the DOAS container instrument. The latter is part of the removable CARIBIC instrument container, which is installed monthly on the aircraft for a series of measurement flights. During 30 flight operations within three years, measurements of HCHO, HONO, NO2, BrO, O3 and the oxygen dimer O4 were conducted. All of these trace gases except BrO could be analysed with a 30 s time resolution. HONO was detected for the first time in a deep convective cloud over central Asia, while BrO, NO2 and O3 could be observed in tropopause fold regions. Biomass burning signatures over South America could be seen and measurements during ascent and descent provided information on boundary layer trace gas profiles (e.g. NO2 or HCHO).

  13. Airborne multi-axis DOAS measurements of atmospheric trace gases on CARIBIC long-distance flights

    NASA Astrophysics Data System (ADS)

    Dix, B.; Brenninkmeijer, C. A. M.; Frieß, U.; Wagner, T.; Platt, U.

    2009-02-01

    A DOAS (Differential Optical Absorption Spectroscopy) instrument was implemented and operated onboard a long-distance passenger aircraft within the framework of the CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container). The instrument was designed to keep weight, size and power consumption low and to comply with civil aviation regulations. It records spectra of scattered light from three viewing directions (nadir, 10° above and below horizon) using a miniaturized telescope system. The telescopes are integrated in the main pylon of the inlet system which is mounted at the belly of the aircraft. Fibre bundles transmit light from the telescopes to spectrograph-detector units inside the DOAS container instrument. The latter is part of the removable CARIBIC instrument container, which is installed monthly on the aircraft for a series of measurement flights. During 30 flight operations within three years, measurements of HCHO, HONO, NO2, BrO, O3 and the oxygen dimer O4 were conducted. All of these trace gases except BrO could be analysed with a 30 s time resolution. HONO was detected for the first time in a deep convective cloud over central Asia. BrO, NO2 and O3 could be observed in tropopause fold regions, biomass burning signatures over South America could be seen and measurements during ascent and descent provided information on boundary layer trace gas profiles (e.g. NO2 or HCHO).

  14. Distribution of Ophioglossum reticulatum L. in South America. A case of long-distance jump dispersal?

    NASA Astrophysics Data System (ADS)

    Meza Torres, Esteban I.; Cerne, Bibiana; Ulke, Ana G.; Morbelli, Marta A.

    2015-02-01

    The objective of this exploratory work is to test the hypothesis that South American populations of Ophioglossum reticulatum L. derive from Africa. Spores cross the Atlantic transported by wind and arrive in South America in recurrent migration. Three-dimensional (backward and forward) trajectories of spores between Africa and South America were calculated using the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT4). The model showed possible backward trajectories in the low troposphere arriving in South America with probable origin in Northwestern Africa. The results support the hypothesis of long-distance dispersal of the studied species. Including vertical motion in the model runs allowed obtaining valuable and novel information about the migration routes. The trade winds combined with the South American monsoon could be a dispersal vehicle for the disseminules from Northwestern Africa to the eastern slopes of the Andes. As the monsoon is a periodic regional atmospheric circulation pattern, transcontinental migration can be assumed to be a recurring phenomenon that provides genetic exchange and prevents speciation by reproductive isolation. Modelled forward trajectories connect the neotropics with Africa-Madagascar, but they seem to be less effective due to their travelling altitudes. This hypothesis might explain the absence of infraspecific taxa restricted to different geographic locations.

  15. Convergent patterns of long-distance nocturnal migration in noctuid moths and passerine birds.

    PubMed

    Alerstam, Thomas; Chapman, Jason W; Bäckman, Johan; Smith, Alan D; Karlsson, Håkan; Nilsson, Cecilia; Reynolds, Don R; Klaassen, Raymond H G; Hill, Jane K

    2011-10-22

    Vast numbers of insects and passerines achieve long-distance migrations between summer and winter locations by undertaking high-altitude nocturnal flights. Insects such as noctuid moths fly relatively slowly in relation to the surrounding air, with airspeeds approximately one-third of that of passerines. Thus, it has been widely assumed that windborne insect migrants will have comparatively little control over their migration speed and direction compared with migrant birds. We used radar to carry out the first comparative analyses of the flight behaviour and migratory strategies of insects and birds under nearly equivalent natural conditions. Contrary to expectations, noctuid moths attained almost identical ground speeds and travel directions compared with passerines, despite their very different flight powers and sensory capacities. Moths achieved fast travel speeds in seasonally appropriate migration directions by exploiting favourably directed winds and selecting flight altitudes that coincided with the fastest air streams. By contrast, passerines were less selective of wind conditions, relying on self-powered flight in their seasonally preferred direction, often with little or no tailwind assistance. Our results demonstrate that noctuid moths and passerines show contrasting risk-prone and risk-averse migratory strategies in relation to wind. Comparative studies of the flight behaviours of distantly related taxa are critically important for understanding the evolution of animal migration strategies.

  16. FLOWERING LOCUS T protein may act as the long-distance florigenic signal in the cucurbits.

    PubMed

    Lin, Ming-Kuem; Belanger, Helene; Lee, Young-Jin; Varkonyi-Gasic, Erika; Taoka, Ken-Ichiro; Miura, Eriko; Xoconostle-Cázares, Beatriz; Gendler, Karla; Jorgensen, Richard A; Phinney, Brett; Lough, Tony J; Lucas, William J

    2007-05-01

    Cucurbita moschata, a cucurbit species responsive to inductive short-day (SD) photoperiods, and Zucchini yellow mosaic virus (ZYMV) were used to test whether long-distance movement of FLOWERING LOCUS T (FT) mRNA or FT is required for floral induction. Ectopic expression of FT by ZYMV was highly effective in mediating floral induction of long-day (LD)-treated plants. Moreover, the infection zone of ZYMV was far removed from floral meristems, suggesting that FT transcripts do not function as the florigenic signal in this system. Heterografting demonstrated efficient transmission of a florigenic signal from flowering Cucurbita maxima stocks to LD-grown C. moschata scions. Real-time RT-PCR performed on phloem sap collected from C. maxima stocks detected no FT transcripts, whereas mass spectrometry of phloem sap proteins revealed the presence of Cm-FTL1 and Cm-FTL2. Importantly, studies on LD- and SD-treated C. moschata plants established that Cmo-FTL1 and Cmo-FTL2 are regulated by photoperiod at the level of movement into the phloem and not by transcription. Finally, mass spectrometry of florally induced heterografted C. moschata scions revealed that C. maxima FT, but not FT mRNA, crossed the graft union in the phloem translocation stream. Collectively, these studies are consistent with FT functioning as a component of the florigenic signaling system in the cucurbits.

  17. The relationship between testosterone and long-distance calling in wild male chimpanzees

    PubMed Central

    Fedurek, Pawel; Slocombe, Katie E.; Enigk, Drew K.; Emery Thompson, Melissa; Wrangham, Richard W; Muller, Martin N.

    2016-01-01

    Long-distance calling is a common behaviour in animals that has various important social functions. At a physiological level, calling is often mediated by gonadal hormones such as testosterone (T), particularly when its function is linked to intra-sexual competition for mates or territory. T also plays an important role in the development of vocal characteristics associated with dominance in humans. However, the few available studies of T and vocal behaviour in non-human primates suggest that in primates T has less influence on call production than in other animals. We tested this hypothesis by studying the relationship between T concentrations and pant hooting in wild male chimpanzees (Pan troglodytes schweinfurthii) of the Kanyawara community in the Kibale National Park, Uganda. We found three kinds of correlation. Hourly T averages were positively associated with hourly rates of pant-hooting. Monthly T levels were likewise correlated with monthly rates of pant hooting after controlling for other influences such as fission-fusion rates. Finally, males with high T levels had higher peak frequency at the start of the call climax. These results suggest that T affects the production of pant-hoots in chimpanzees. This implies that the pant-hoot call plays a role in male-male competition. We propose that even in cognitively sophisticated species, endocrine mechanisms can contribute to regulating vocal production. PMID:27182103

  18. Long-Distance Delivery of Bacterial Virulence Factors by Pseudomonas aeruginosa Outer Membrane Vesicles

    PubMed Central

    Bomberger, Jennifer M.; MacEachran, Daniel P.; Coutermarsh, Bonita A.; Ye, Siying; O'Toole, George A.; Stanton, Bruce A.

    2009-01-01

    Bacteria use a variety of secreted virulence factors to manipulate host cells, thereby causing significant morbidity and mortality. We report a mechanism for the long-distance delivery of multiple bacterial virulence factors, simultaneously and directly into the host cell cytoplasm, thus obviating the need for direct interaction of the pathogen with the host cell to cause cytotoxicity. We show that outer membrane–derived vesicles (OMV) secreted by the opportunistic human pathogen Pseudomonas aeruginosa deliver multiple virulence factors, including β-lactamase, alkaline phosphatase, hemolytic phospholipase C, and Cif, directly into the host cytoplasm via fusion of OMV with lipid rafts in the host plasma membrane. These virulence factors enter the cytoplasm of the host cell via N-WASP–mediated actin trafficking, where they rapidly distribute to specific subcellular locations to affect host cell biology. We propose that secreted virulence factors are not released individually as naked proteins into the surrounding milieu where they may randomly contact the surface of the host cell, but instead bacterial derived OMV deliver multiple virulence factors simultaneously and directly into the host cell cytoplasm in a coordinated manner. PMID:19360133

  19. Possibility of long-distance heat transport in weightlessness using supercritical fluids.

    PubMed

    Beysens, D; Chatain, D; Nikolayev, V S; Ouazzani, J; Garrabos, Y

    2010-12-01

    Heat transport over large distances is classically performed with gravity or capillarity driven heat pipes. We investigate here whether the "piston effect," a thermalization process that is very efficient in weightlessness in compressible fluids, could also be used to perform long-distance heat transfer. Experiments are performed in a modeling heat pipe (16.5 mm long, 3 mm inner diameter closed cylinder), with nearly adiabatic polymethylmethacrylate walls and two copper base plates. The cell is filled with H2 near its gas-liquid critical point (critical temperature: 33 K). Weightlessness is achieved by submitting the fluid to a magnetic force that compensates gravity. Initially the fluid is isothermal. Then heat is sent to one of the bases with an electrical resistance. The instantaneous amount of heat transported by the fluid is measured at the other end. The data are analyzed and compared with a two-dimensional numerical simulation that allows an extrapolation to be made to other fluids (e.g., CO2, with critical temperature of 300 K). The major result is concerned with the existence of a very fast response at early times that is only limited by the thermal properties of the cell materials. The yield in terms of ratio, injected or transported heat power, does not exceed 10-30% and is limited by the heat capacity of the pipe. These results are valid in a large temperature domain around the critical temperature.

  20. Long-distance dispersal and accelerating waves of disease: empirical relationships.

    PubMed

    Mundt, Christopher C; Sackett, Kathryn E; Wallace, LaRae D; Cowger, Christina; Dudley, Joseph P

    2009-04-01

    Classic approaches to modeling biological invasions predict a "traveling wave" of constant velocity determined by the invading organism's reproductive capacity, generation time, and dispersal ability. Traveling wave models may not apply, however, for organisms that exhibit long-distance dispersal. Here we use simple empirical relationships for accelerating waves, based on inverse power law dispersal, and apply them to diseases caused by pathogens that are wind dispersed or vectored by birds: the within-season spread of a plant disease at spatial scales of <100 m in experimental plots, historical plant disease epidemics at the continental scale, the unexpectedly rapid spread of West Nile virus across North America, and the transcontinental spread of avian influenza strain H5N1 in Eurasia and Africa. In all cases, the position of the epidemic front advanced exponentially with time, and epidemic velocity increased linearly with distance; regression slopes varied over a relatively narrow range among data sets. Estimates of the inverse power law exponent for dispersal that would be required to attain the rates of disease spread observed in the field also varied relatively little (1.74-2.36), despite more than a fivefold range of spatial scale among the data sets.