749 research outputs found
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Emg Signal Spectral Analysis Of Superficial Quadriceps Muscles During Constant Load Submaximal Cycling Exercise [análise Espectral Do Sinal Emg Dos Músculos Superficiais Do Quadríceps Durante Exercício Submáximo De Carga Constante No Cicloergômetro]
No full textThe objective of this study was to investigate possible differences in the EMG signal spectral analysis of the superficial quadriceps muscles, using the techniques short-time Fourier transform (STFT) and continues Wavelet (CWT) db4 type during constant load submaximal cycling exercise. Fourteen male subjects, healthy and physically active (25.8 ± 3.3 years, 82.1 ± 7.3 kg, 181.3 ± 5.5 cm) were submitted to constant load submaximal test (Tcons) with exercise intensity corresponding to 80% of maximum load until voluntary exhaustion. The EMG of the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) of the right leg were recorded throughout the period of the Tcons to obtain the parameters: median frequency (MF), fatigue index EMG (FIslp) and variance of MF. The results showed no statistically significant differences for the variables MF, FIslp and variance of MF in any of the muscles examined in different time periods, when comparing STFT and CWT (P> 0.05). Thus, our findings suggest the use of both analytical techniques in constant load submaximal cycling exercise when the target is to quantify muscle fatigue with EMG spectral indicators.222211220Barria, E.A., Jagadeesh, J.M., Multiresolution estimation of motion using the wavelet transform Proceedings (1994) Spie, 2303 (2), pp. 542-553. , LondonBeck, T.W., Housh, T.J., Johnson, G.O., Weir, J.P., Cramer, J.T., Coburn, J.W., Malek, M.H., Comparison of Fourier and wavelet transform procedures for examining the mechanomyographic and electromyographic frequency domain responses during fatiguing isokinetic muscle actions of the biceps brachii (2005) Journal of Electromyography and Kinesiology, 15 (2), pp. 190-199. , DOI 10.1016/j.jelekin.2004.08.007, PII S105064110400077XBigland-Ritchie, B., Rice, C.L., Garland, S.J., Walsh, M.L., Task-dependent factors in fatigue of human voluntary contractions (1995) Fatigue: Neural and Muscular Mechanisms, pp. 361-380. , GANDEVIA, S.C. et al. New York: Plenum PressBonato, P., Roy, S.H., Knaflitz, M., De Luca, C.J., Time frequency parameters of the surface myoelectric signal for assessing muscle fatigue during cyclic dynamic contractions (2001) IEEE Transactions on Biomedical Engineering, 48 (7), pp. 745-753. , DOI 10.1109/10.930899, PII S0018929401051321Camata, T.V., Lacerda, T.R., Altimari, L.R., Bortolloti, H., Fontes, E.B., Dantas, J.L., Nakamura, F.Y., Moraes, A.C., Association between the electromyographic fatigue threshold and ventilatory threshold (2009) Electromyography and Clinical Neurophysiology, 49 (6-7), pp. 102-108. , LeuvenCamata, T.V., Dantas, J.L., Abrao, T., Brunetto, M.A., Moraes, A.C., Altimari, L.R., Fourier and Wavelet spectral analysis of EMG signals in supramaximal constant load dynamic exercise (2010) Conference Proceedings IEEE Engineering in Medicine and Biology Society, 1 (1), pp. 1364-1367. , Buenos AiresCarneiro, J.G., Gonçalves, E.M., Camata, T.V., Altimari, J.M., MacHado, M.V., Batista, A.R., Guerra Junior, G., Altimari, L.R., Influence of gender on EMG signs of the quadriceps muscles and performance in shortterm high-intensity exercise (2010) Electromyography and Clinical Neurophysiology, 50 (7-8), pp. 326-332. , LeuvenDa Silva, R.A., Lariviere, C., Arsenault, A.B., Nadeau, S., Plamondon, A., The comparison of wavelet- and Fourier-based electromyographic indices of back muscle fatigue during dynamic contractions: Validity and reliability results (2008) Electromyography and Clinical Neurophysiology, 48 (3-4), pp. 147-162Dantas, J.L., Camata, T.V., Brunetto, M.A., Moraes, A.C., Abrão, T., Altimari, L.R., Fourier and Wavelet spectral analysis of EMG signals in isometric and dynamic maximal effort exercise (2010) Conference Proceedings IEEE Engineering in Medicine and Biology Society, 1 (1), pp. 5979-5982. , Buenos AiresDaubechies, I., (1992) Ten Lectures on Wavelets, CBMSNSF Conference Series in Applied Mathematics, , 1 ed., Ed. SIAMDe Luca, C.J., The use of surface electromyography in biomechanics (1997) Journal of Applied Biomechanics, 13 (2), pp. 135-163Flanders, M., Choosing a wavelet for single-trial EMG (2002) Journal of Neuroscience Methods, 116 (2), pp. 165-177. , DOI 10.1016/S0165-0270(02)00038-9, PII S0165027002000389Hermens, H.J., Freriks, B., Disselhorstklug, C., Rau, G., Development of recommendations for SEMG sensors and sensor placement procedures (2000) Journal of Electromyography and Kinesiology, 10 (5), pp. 361-374. , OxfordHostens, I., Seghers, J., Spaepen, A., Ramon, H., Validation of the wavelet spectral estimation technique in Biceps Brachii and Brachioradialis fatigue assessment during prolonged low-level static and dynamic contractions (2004) Journal of Electromyography and Kinesiology, 14 (2), pp. 205-215. , DOI 10.1016/S1050-6411(03)00101-9Hug, F., Laplaud, D., Lucia, A., Grelot, L., A comparison of visual and mathematical detection of the electromyographic threshold during incremental pedaling exercise: A pilot study (2006) Journal of Strength and Conditioning Research, 20 (3), pp. 704-708. , DOI 10.1519/R-17405.1Hummel, A., Laubli, T., Pozzo, M., Schenk, P., Spillmann, S., Klipstein, A., Relationship between perceived exertion and mean power frequency of the EMG signal from the upper trapezius muscle during isometric shoulder elevation (2005) European Journal of Applied Physiology, 95 (4), pp. 321-326. , DOI 10.1007/s00421-005-0014-7Hunter, A.M., St Clair Gibson, A., Lambert, M.I., Nobbs, L., Noakes, T.D., Effects of supramaximal exercise on the electromyographic signal (2003) British Journal of Sports Medicine, 37 (4), pp. 296-299. , DOI 10.1136/bjsm.37.4.296Karlsson, S., Yu, J., Akay, M., Time-frequency analysis of myoelectric signals during dynamic contractions: A comparative study (2000) IEEE Transactions on Biomedical Engineering, 47 (2), pp. 228-238. , DOI 10.1109/10.821766, PII S0018929400008867Knaflitz, M., Bonato, P., Time-frequency methods applied to muscle fatigue assessment during dynamic contractions (1999) Journal of Electromyography and Kinesiology, 9 (5), pp. 337-350. , DOI 10.1016/S1050-6411(99)00009-7, PII S1050641199000097Kumar, D.K., Pah, N.D., Bradley, A., Wavelet Analysis of Surface Electromyography to Determine Muscle Fatigue (2003) IEEE Transactions on Neural Systems and Rehabilitation Engineering, 11 (4), pp. 400-406. , DOI 10.1109/TNSRE.2003.819901Laubli, T., Hermens, H., Sjogaard, G., Neuromuscular assessment of the elderly worker, NEW: A multidisciplinary European research project (2006) European Journal of Applied Physiology, 96 (2), pp. 107-109. , DOI 10.1007/s00421-005-0045-0MacIsaac, D., Parker, P.A., Scott, R.N., The short-time Fourier transform and muscle fatigue assessment in dynamic contractions (2001) Journal of Electromyography and Kinesiology, 11 (6), pp. 439-449. , DOI 10.1016/S1050-6411(01)00021-9, PII S1050641101000219Merletti, R., Rainoldi, A., Farina, D., Surface electromyography for noninvasive characterization of muscle (2001) Exercise and Sport Sciences Reviews, 29 (1), pp. 20-25Ng, J.K.-F., Richardson, C.A., Kippers, V., Parnianpour, M., Bui, B.H., Clinical applications of power spectral analysis of electromyographic investigations in muscle function (1996) Manual Therapy, 1 (2), pp. 99-103. , DOI 10.1054/math.1996.0257Nybo, L., Nielsen, B., Perceived exertion is associated with an altered brain activity during exercise with progressive hyperthermia (2001) Journal of Applied Physiology, 91 (5), pp. 2017-2023Oliveira, A.D.E.S., Goncalves, M., EMG amplitude and frequency parameters of muscular activity: Effect of resistance training based on electromyographic fatigue threshold (2009) Journal of Electromyography and Kinesiology, 19 (2), pp. 295-303. , OxfordSo, R.C., Ng, J.K., Lam, R.W., Lo, C.K., Ng, G.Y., EMG Wavelet analysis of quadriceps muscle during repeated knee extension movement (2009) Medicine and Science in Sports and Exercise, 41 (4), pp. 788-796. , HagerstownSparto, P.J., Parnianpour, M., Barria, E.A., Jagadeesh, J.M., Wavelet analysis of electromyography for back muscle fatigue detection during isokinetic constant-torque exertions (1999) Spine, 24 (17), pp. 1791-1798. , DOI 10.1097/00007632-199909010-00008Troiano, A., Naddeo, F., Sosso, E., Camarota, G., Merletti, R., Mesin, L., Assessment of force and fatigue in isometric contractions of the upper trapezius muscle by surface EMG signal and perceived exertion scale (2008) Gait and Posture, 28 (2), pp. 179-186. , DOI 10.1016/j.gaitpost.2008.04.002, PII S0966636208000994Vitor-Costa, M., Pereira, L.A., Oliveira, R.S., Pedro, R.E., Camata, T.V., Abrao, T., Brunetto, M.A., Altimari, L.R., Fourier and Wavelet spectral analysis of EMG signals in maximal constant load dynamic exercise (2010) Conference Proceedings IEEE Engineering in Medicine and Biology Society, 1 (1), pp. 4622-4625. , Buenos Aire
Anthropometric And Motor Performance Profile Of Elite Futsal Athletes [perfil Antropométrico E De Desempenho Motor De Atletas Paranaenses De Futsal De Elite]
No full textThe purpose of the present study was to identify the anthropometric and motor performance profile of futsal (indoor soccer) athletes in the second and third-placed teams in the Parana state championships (Brazil). Anthropometric (body mass, stature and skinfolds thickness) and motor performance (modified abdominal test, shuttle run, race of 30 m and 40 s) measures were obtained from twenty-seven male athletes (24.7 ± 6.4 years; 73.6 ± 7.6 kg; 174.8 ± 6.6 cm). For data analysis, athletes were grouped according to game positions. ANOVA one-way was used for comparisons between different positions, followed by Scheffé's post hoc test, with p < 0.05. Significant differences were detected in body mass (midfielder < goalkeeper, p < 0.01), stature (midfielder < forward and goalkeeper, p < 0.01) and lean body mass (midfielder < goalkeeper, p < 0.01). No significant differences in motor performance were detected between the athletes studied. The results of this study show that futsal athletes playing in different positions exhibit similar anthropometric and motor performance, in the majority of variables.1017680Altimari, L.R., Okano, A.H., Coelho, C.F., Cyrino, E.S., Efeitos do treinamento de futsal sobre o desempenho motor em atividades predominantemente aeróbias e anaeróbias (1999) Trein Desp, 4, pp. 23-28Cyrino, E.S., Altimari, L.R., Okano, A.H., Coelho, C.F., Efeitos do treinamento de futsal sobre a composição corporal e o desempenho motor de jovens atletas (2002) Rev Bras Ciên Mov, 10, pp. 41-46Freitas, L.A.G., Altimari, L.R., Estudo somatotipológico de atletas de futebol de salão da categoria fraldinha e prémirim (1999) Trein Desp, 4, pp. 29-34Lima, A.M.J., Silva, D.V.G., Souza, A.O.S., Correlação entre as medidas direta e indireta do VO2max em atletas de futsal (2005) Rev Bras Med Esporte, 11 (3), pp. 164-166Queiroga, M.R., Ferreira, S.A., Romanzini, M., Per fil antropométrico de atletas de futsal feminino de alto nível competitivo conforme a função tática desempenhada no jogo (2005) Rev Bras Cineantropom Desempenho Hum, 7 (1), pp. 30-34Goulart, L.F., Dias, R.M.R., Altimari, L.R., Força isocinética de jogadores de futebol categoria sub-20: Comparação entre diferentes posições de jogo (2007) Rev Bras Cineantropom Desempenho Hum, 9 (2), pp. 165-169Wisloff, U., Helgerud, J., Hoff, J., Strength and endurance of elite soc c er players (1998) Med Sci Spor ts E xerc, 30 (3), pp. 462-467Bicalho, E.L.C., Paula, A., Cotta, D.O., (2007) Estudo da diferença do perfil físico de jogadores de futsal por posicionamento em quadra que participaram do campeonato Ipatinguense., , http://www.efdeportes.com/efd104/futsal.htm, Lecturas [revista digital]. Disponível em [2007 jan 11]Soares, B., Tourinho-Filho, H., Análise das distâncias e intensidade dos deslocamentos em uma partida de futsal, nas diferentes posições de jogo (2006) Rev Bras Educ Fis Esp, 20 (2), pp. 93-101Gordon, C.C., Chumlea, W.C., Roche, A.F., Stature, recumbent length, and weight (1988) Anthropometric Standardization Reference Manual., pp. 3-8. , In: Lohman TG, Roche AF, Martorell R, editors. Champaign: Human Kinetics BooksHarrison, G.G., Buskirk, E.R., Carter, L.J.E., Johston, F.E., Lohman, T.G., Pollock, M.L., Skinfold thickness and measurement technique (1988) Anthropometric Standardization Reference Manual., pp. 55-70. , In: Lohman TG, Roche AF, Martorell R, editors. Champaign: Human Kinetics BooksGuedes, D.P., (1994) Composição corporal: Princípios, técnicas e aplicações., , Londrina: APEFSiri, W.E., Body composition from fluid spaces and density (1961) Techniques for measuring body composition., pp. 223-244. , In: Brozek J, Henschel A, editors. Washington: National Academy of ScienceJackson, A.S., Pollock, M.L., Generalized equations for predicting body density of men (1978) Br J Nutr, 40 (3), pp. 497-504(1988) Physical Best: Reston, VA: American Alliance for Health, , A AHPERD. Physical Education, Recreation and DanceMathews, D.K., (1980) Medidas e avaliação em educação física., , Rio de Janeiro: GuanabaraMarins, J.C.B., Giannichi, R.S., (1988) Avaliação e prescrição de atividade física: Guia prático., , Rio de Janeiro: ShapeMatsudo, V.K.R., (2000) Testes em ciência do esporte., , São Caetano do Sul: BuritiDantas, P.M.S., Fernandes Filho, J., Identificação dos perfis, genético, de aptidão física e somatotípico que caracterizam atletas masculinos, de alto rendimento, participantes do futsal adulto, no Brasil (2002) Fitness Perf J, 1 (1), pp. 28-36Silva, M.R., (2004) O goleiro de futsal: Sua evolução junto com as regras., , [Monografia de graduação]. Londrina (PR): Universidade Estadual de LondrinaDias, R.M.R., Santana, W.C., (2006) Tempo de incidência de gols em equipes de diferentes níveis competitivos na copa do mundo de futsal., , http://www.efdeportes.com/efd101/futsal.htm, Lecturas [revista digital]. Disponível em [2007 jan 11]Santana, W.C., (2006) Versatilidade: Um novo paradigma para ensinar futsal., , http://www.pedagogiadofutsal.com.br/texto_010.asp, In: Pedagogia do Futsal [livro online]. Disponível em [2007 abr 10
Spectral Analysis Of Electromyographic Signal In Supramaximal Effort In Cycle Ergometer Using Fourier And Wavelet Transforms: A Comparative Study
No full textObjective. The objective of this study was to compare these methods Fourier (STFT) and Wavelet (WT) transforms to assess muscle fatigue during supramaximal exercise. Methods. Twenty five subjects of both genders (13 men, age = 28.2 ± 2.7 years and 12 women, age = 23.2 ± 2.7 years) performed the Wingate test, during which the electromyographic responses of the superficial muscles of the quadriceps were examined. For analysis we used the STFT and WT transforms, which provided the following variables: median frequency (MF), slope and variance. Results. The results showed no differences (P > 0.05) in MF and slope. However, there were differences for the variance between the analysis (P < 0.05). Conclusion. It seems that both analyzes provide the same physiological parameters, however, the WT transform shows less variance between the results. © 2012 Revista Andaluza de Medicina del Deporte.524852Enoka, R.M., Stuart, D.G., Neurobiology of muscle fatigue (1992) J Appl Physiol., 72, pp. 1631-1648Nybo, L., Nielsen, B., Perceived exertion is associated with an altered brain activity during exercise with progressive hyperthermia (2001) J Appl Physiol., 91, pp. 2017-2023Hummel, A., Laubli, T., Pozzo, M., Schenk, P., Spillmann, S., Klipstein, A., Relationship between perceived exertion and mean power frequency of the EMG signal from the upper trapezius muscle during isometric shoulder elevation (2005) Eur J Appl Physiol., 95, pp. 321-326Laubli, T., Hermens, H., Sjogaard, G., Neuromuscular assessment of the elderly worker, New: A multidisciplinary European research project (2006) Eur J Appl Physiol., 96, pp. 107-109Troiano, A., Naddeo, F., Sosso, E., Camarota, G., Merletti, R., Mesin, L., Assessment of force and fatigue in isometric contractions of the upper trapezius muscle by surface EMG signal and perceived exertion scale (2008) Gait Posture., 28, pp. 179-186Oliveira, S., Gonçalves, M., EMG amplitude and frequency parameters of muscular activity: Effect of resistance training based on electromyographic fatigue threshold (2009) J Electromyogr Kinesiol., 19, pp. 295-303Ng, J.K., Richardson, C.A., Kippers, V., Parnianpour, M., Bui, B.H., Clinical applications of power spectral analysis of electromyographic investigations in muscle function (1996) Man Ther., 1, pp. 99-103Knaflitz, M., Bonato, P., Time-frequency methods applied to muscle fatigue assessment during dynamic contractions (1999) J Electromyogr Kinesiol., 9, pp. 337-350Bonato, P., Roy, S.H., Knaflitz, M., De Luca, C.J., Time-frequency parameters of the surface myoelectric signal for assessing muscle fatigue during cyclic dynamic contractions (2001) IEEE Trans Biomed Eng., 48, pp. 745-753Beck, T.W., Housh, T.J., Johnson, G.O., Weir, J.P., Cramer, J.T., Coburn, J.W., Comparison of fourier and wavelet transform procedures for examining the mechanomyographic and electromyographic frequency domain responses during fatiguing isokinetic muscle actions of the biceps brachii (2005) J Electromyogr Kinesiol., 15, pp. 190-199Dantas, J.L., Camata, T.V., Brunetto, M.A., Moraes, A.C., Abrão, T., Altimari, L.R., Fourier and wavelet spectral analysis of EMG signals in isometric and dynamic maximal effort exercise (2010) Conference Proceedings (IEEE Engineering in Medicine and Biology Society Conf), 1, pp. 5979-5982Camata, T.V., Dantas, J.L., Abrão, T., Brunetto, M.A., Moraes, A.C., Altimari, L.R., Fourier and wavelet spectral analysis of EMG signals in supramaximal constant load dynamic exercise (2010) Conference Proceedings (IEEE Engineering in Medicine and Biology Society Conf), 1, pp. 1364-1367Vitor-Costa, M., Pereira, L.A., Oliveira, R.S., Pedro, R.E., Camata, T.V., Abrão, T., Fourier and wavelet spectral analysis of EMG signals in maximal constant load dynamic exercise (2010) Conference Proceedings (IEEE Engineering in Medicine and Biology Society Conf), 1, pp. 4622-4625Von Tscharner, V., Goepfert, B., Estimation of the interplay between groups of fast and slow muscle fibers of the tibialis anterior and gastrocnemius muscle while running (2006) J Electromyogr Kinesiol., 16, pp. 188-197Sparto, P.J., Parnianpour, M., Barria, E.A., Jagadeesh, J.M., Wavelet analysis of electromyography for back muscle fatigue detection during isokinetic constant-torque exertions (1999) Spine (Phila Pa 1976), 24, pp. 1791-1798Hostens, I., Seghers, J., Spaepen, A., Ramon, H., Validation of the wavelet spectral estimation technique in biceps brachii and brachioradialis fatigue assessment during prolonged low-level static and dynamic contractions (2004) J Electromyogr Kinesiol., 14, pp. 205-215Da Silva, R.A., Lariviere, C., Arsenault, A.B., Nadeau, S., Plamondon, A., The comparison of Wavelet-and Fourier-based electromyographic indices of back muscle fatigue during dynamic contractions: Validity and reliability results (2008) Electromyogr Clin Neurophysiol., 48, pp. 147-162Karlsson, S., Yu, J., Akay, M., Time-frequency analysis of myoelectric signals during dynamic contractions: A comparative study (2000) IEEE Trans Biomed Eng., 47, pp. 228-238Ponorac, N., Matavulj, A., Rajkovaca, Z., Kovacevic, P., The assessment of anaerobic capacity in athletes of various sports (2007) Med Pregl., 60, pp. 427-430Bar-Or, O., The Wingate anaerobic test. An update on methodology, reliability and validity (1987) Sports Med., 4, pp. 381-394Hunter, A.M., St. Clair Gibson, A., Lambert, M.I., Nobbs, L., Noakes, T.D., Effects of supramaximal exercise on the electromyographic signal (2003) Br J Sports Med., 37, pp. 296-299Minahan, C., Wood, C., Strength training improves supramaximal cycling but not anaerobic capacity (2008) Eur J Appl Physiol., 102, pp. 659-666Havenetidis, K., Matsouka, O., Konstadinou, V., Establishment of the highest peak anaerobic power prior to the commencement of the anaerobic wingate test (2003) J Hum Mov Stud., 44, pp. 479-487Merletti, R., Rainoldi, A., Farina, D., Surface electromyography for non-invasive characterization of muscle (2001) Exerc Sport Sci Ver., 29, pp. 20-25Hermens, H.J., Freriks, B., Disselhorst-Klug, C., Rau, G., Development of recommendations for SEMG sensors and sensor placement procedures (2000) J Electromyogr Kinesiol., 10, pp. 361-37
Letter to the editor: Reply to J. J. Child, Crim. L.R. 2010, 12, 924-932
No full textResponds to J.J. Child's article in this issue criticising the conclusions reach by the author in his article "The conflict between the Serious Crime Act 2007 and section 1(4)(b) Criminal Attempts Act 1981 - a missed repeal?", (Crim. L.R. 2010, 6, 483-488)
Some Comments on the Question Whether Co-occurrence Data Should Be Normalized
No full textIn a recent paper in the Journal of the American Society for Information Science and Technology, Leydesdorff and Vaughan assert that raw cocitation data should be analyzed directly, without first applying a normalization like the Pearson correlation. In this report, it is argued that there is nothing wrong with the widely adopted practice of normalizing cocitation data. One of the arguments put forward by Leydesdorff and Vaughan turns out to depend crucially on incorrect multidimensional scaling maps that are due to an error in the PROXSCAL program in SPSS.Multidimensional scaling;Author cocitation analysis;Co-occurrence data;Normalization;PROXSCAL;Pearson correlation
Some Comments on the Question Whether Co-Occurrence Data Should Be Normalized
No full textIn a recent article in JASIST, L. Leydesdorff and L. Vaughan (2006) asserted that raw cocitation data should be analyzed directly, without first applying a normalization such as the Pearson correlation. In this communication, it is argued that there is nothing wrong with the widely adopted practice of normalizing cocitation data. One of the arguments put forward by Leydesdorff and Vaughan turns out to depend crucially on incorrect multidimensional scaling maps that are due to an error in the PROXSCAL program in SPSS.multidimensional scaling;PROXSCAL;Pearson correlation;author cocitation analysis;co-occurrence data;normalization
I. Nota betreffende de bemaling van de Drentsche hoofdvaart, opgemaakt door den ingenieur van den Rijkswaterstaat dr. L.R. Wentholt: II. Nota over het proefheien van houten en ijzeren damwand te Linne, opgemaakt door den ingenieur van den Rijkswaterstaat F. Volker
No full textEisen waaraan gemalen moeten voldoen, beschrijving van de soorten gemalen, aandrijving, ontwerp en exploitatie. Prototyoe proef met ijzeren en houten damwanden bij de sluis te Linne
Effects Of Long-term Creatine Monohydrate Supplementation On Anaerobic Performance Of Trained Young Adults [efeitos Da Suplementação Prolongada De Creatina Mono-hidratada Sobre O Desempenho Anaeróbio De Adultos Jovens Treinados]
No full textThe objective of the present study was to investigate the impact of eight weeks of creatine monohydrate (Crm) supplementation on the anaerobic performance of young trained adults. Twenty-six healthy male physical education students were randomly divided in creatine group (CrG, n = 13; 22.5 ± 2.7 years; 74.9 ± 6.8 kg; 178.5 ± 4.8 cm) and placebo group (PlG, n = 13; 22.9 ± 3.2 years; 71.9 ± 11.3 kg; 178.6 ± 4.0 cm). The subjects received in a double-blind system a Crm or placebo-maltodextrin dose (20 g.d-1 for 5 days and 3 g.d-1 for 51 subsequent days). Both groups had their eating habits and levels of physical fitness previously controlled. The Wingate anaerobic test (WT) was used to evaluate the anaerobic performance before and after the ingestion period of Crm or placebo. The performance indexes assessed were: relative peak power (RPP), relative mean power (RMP), relative total work (RTW) and index of fatigue (IF). ANOVA followed by Tukey post hoc test were used when P<0.05 for statistical treatment. No significant difference in RPP, RMP, RTW or IF was observed after the period of supplementation of Crm (P>0.05). The results of the present study suggest that Crm supplementation does not seem to be an efficient ergogenic resource in high-intensity and short-duration efforts involving a single set.163186190Mesa, J.L., Ruiz, J.R., Gonzalez-Gross, M.M., Gutierrez-Sainz, A., Garzon, M.J.C., Oral creatine supplementation and skeletal muscle metabolism in physical exercise (2002) Sports Med, 32, pp. 903-944Branch, J.D., Effect of creatine supplementation on body composition and performance: A meta-analysis (2003) Int J Sport Nutr Exerc Metab, 13, pp. 198-226Persky, A.M., Rawson, E.S., Safety of creatine supplementation (2007) Subcell Biochem, 46, pp. 275-289Brudnak, M.A., Creatine: Are the benefits worth the risk? (2004) Toxicol Lett, 150, pp. 123-130Pischel, I., Gastner, T., Creatine: Its chemical synthesis, chemistry, and legal status (2007) Subcell Biochem, 46, pp. 291-307Hultman, E., Greenhaff, P.L., Ren, J.M., Soderlund, K., Energy metabolism and fatigue during intense muscle contraction (1991) Biochem Soc Trans, 19, pp. 347-353Allen, D.G., Lamb, G.D., Westerblad, H., Skeletal muscle fatigue: Cellular mechanisms (2008) Physiol Rev, 88, pp. 287-332Balsom, P.D., Söderlund, K., Sjödin, B., Ekblom, B., Skeletal muscle metabolism during short duration high-intensity exercise: Influence of creatine supplementation (1995) Acta Physiol Scand, 154, pp. 303-310Cooke, C.B., Theodorou, A., King, R.F.G.J., Gibbon, W., Frain, M., The effects of a creatine maintenance dosage on muscle metabolites and anaerobic performance (1999) Med Sci Sports Exercise, 31, pp. S354Havenetidis, K., Theodorou, A., Cooke, C.B., King, R.F.G.J., Effects of an acute Cr loading on muscle metabolites and anaerobic performance (2002) Annual Congress of The European College of Sport Science, p. 593. , Atenas, 2002. Proceedings. AtenasVandenberghe, K., van Hecke, P., van Leemputte, M., Vanstapel, F., Hespel, P., Phosphocreatine resynthesis is not affected by creatine loading (1999) Med Sci Sports Exercise, 31, pp. 236-242Bar-Or, O., The Wingate anaerobic test: An update on methodology, reliability and validity (1987) Sports Med, 4, pp. 381-394Havenetidis, K., Matsouka, O., Cooke, C.B., Theodorou, A., The use of varying creatine regimes on sprint cycling (2003) J Sports Sci Med, 2, pp. 88-97Snow, R.J., Murphy, R.M., Factors influencing creatine loading into human skeletal muscle (2003) Exercise Sport Sci Rev, 31, pp. 154-158Position stand: Progression models in resistance training for healthy adults (2002) Med Sci Sports Exerc, 34, pp. 364-380. , American College of Sports MedicineGordon, C.C., Chumlea, W.C., Roche, A.F., Stature, recumbent length, and weight (1988) Anthropometric Standardization Reference Manual, pp. 3-8. , In: Lohman TG, Roche AF, Martorell R., editors, Champaign: Human KineticsHespel, P., Op't eijnde, B., van Leemputte, M., Opposite actions of caffeine and creatine on muscle relaxation time in humans (2002) J Appl Physiol, 92, pp. 513-518Green, A.L., Simpson, E.J., Littlewood, J.J., Macdonald, I.A., Greenhaff, P.L., Carbohydrate ingestion augments creatine retention during creatine feeding in humans (1996) Acta Physiol Scand, 158, pp. 195-202Havenetidis, K., Matsouka, O., Konstadinou, V., Establishment of the highest peak anaerobic power prior to the commencement of the anaerobic Wingate test (2003) J Hum Mov Stud, 44, pp. 479-487Okano, A.H., Dodero, S.R., Coelho, C.F., Gassi, E., Altimari, L.R., Silva, C.C., Efeito da aplicação de diferentes cargas sobre o desempenho motor no teste de Wingate Rev Bras Ciên E Mov, 9, pp. 39-44. , 200Rawson, E.S., Perski, A.M., Price, T.B., Clarkson, P.M., Effects of repeated creatine supplementation on muscle, plasma, and urine creatine levels (2004) J Strength Cond Res, 18, pp. 162-167Narayanan, S., Appleton, H.D., Creatinine: A review (1980) Clin Chem, 26, pp. 1119-1126Barr, S.I., Rideout, C.A., Nutritional considerations for vegetarian athletes (2004) Nutrition, 20, pp. 696-703Odland, L.M., Macdougall, J.D., Tarnopolsky, M.A., Elorriaga, A., Borgmann, A., Effect of oral creatine supplementation on muscle [PCr] and short-term maximum power output (1997) Med Sci Sports Exercise, 29, pp. 216-219Cooke, W.H., Grandjean, P.W., Barnes, W.S., Effect of oral creatine supplementation on power output and fatigue during bicycle ergometry (1995) J Appl Physiol, 78, pp. 670-673Dawson, B., Cutler, M., Moody, A., Lawrence, S., Goodman, C., Randall, N., Effects of oral creatine loading on single and repeated maximal short sprints (1995) Aust J Sci Med Sport, 27, pp. 56-61Snow, R.J., McKenna, M.J., Selig, S.E., Kemp, J., Stathis, C.G., Zhao, S., Effect of creatine supplementation on sprint exercise performance and muscle metabolism (1998) J Appl Physiol, 84, pp. 1667-1673Ledford, A., Branch, J.D., Creatine supplementation does not increase peak power production and work capacity during repetitive wingate testing in women (1999) J Strength Cond Res, 13, pp. 394-399Earnest, C.P., Snell, P.G., Rodriguez, R., Almada, A.L., Mitchell, T.L., The effect of creatine monohydrate ingestion on anaerobic power indices, muscular strength and body composition (1995) Acta Physiol Scand, 153, pp. 207-209Casey, A., Constantin-Teodosiu, D., Howell, S., Hultman, E., Greenhaff, P.L., Creatine ingestion favorably affects performance and muscle metabolism during maximal exercise in humans (1996) Am J Physiol, 271, pp. 31-37Green, J.M., McLester, J.R., Smith, J.E., Mansfield, E.R., The effects of creatine supplementation on repeated upper- and lower-body Wingate performance (2001) J Strength Cond Res, 15, pp. 36-41Tarnopolsky, M.A., Maclennan, D.P., Creatine monohydrate supplementation enhances high-intensity exercise performance in males and females (2000) Int J Sport Nutr Exercise Metab, 10, pp. 452-463Kurosawa, Y., Hamaoka, T., Katsumura, T., Kuwamori, M., Kimura, N., Sako, T., Creatine supplementation enhances anaerobic ATP synthesis during a single 10 sec maximal handgrip exercise (2003) Mol Cell Biochem, 244, pp. 105-112Birch, R., Noble, D., Greenhaff, P.L., The influence of dietary creatine supplementation on performance during repeated bouts of maximal isokinetic cycling in man (1994) Eur J Appl Physiol Occup Physiol, 69, pp. 268-270Havenetidis, K., Cooke, C.B., King, R.F.G.J., Butterly, R., The effect of creatine supplementation on repeated 30 s cycle sprints in man (1995) J Physiol, 483, pp. S122Greenhaff, P.L., Casey, A., Short, A.H., Harris, R., Söderlund, K., Hultman, E., Influence of oral creatine supplementation on muscle orque during repeated bouts of maximal voluntary exercise in man (1993) Clin Sci, 84, pp. 565-571Harris, R.C., Söderlund, K., Hultman, E., Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation (1992) Clin Sci, 83, pp. 367-374Greenhaff, P.L., Bodin, K., Söderlund, K., Hultman, E., Effect of oral creatine supplementation on skeletal muscle phosphocreatine resynthesis (1994) Am J Physiol, 266, pp. 725-730Vandewalle, H., Peres, G., Monod, H., Standard anaerobic exercise tests (1987) Sports Med, 4, pp. 268-289Weinstein, Y., Bediz, C., Dotan, R., Falk, B., Reliability of peak-lactate, heart rate, and plasma volume following the Wingate test (1998) Med Sci Sports Exercise, 30, pp. 1456-1460Prevost, M.C., Nelson, A.G., Morris, G.S., Creatine supplementation enhances intermittent work performance (1997) Res Q Exercise Sport, 68, pp. 233-240Andrews, R., Greenhaff, P.L., Curtis, S., Perry, A., Cowley, A.J., The effect of dietary creatine supplementation on skeletal muscle metabolism in congestive heart failure (1998) Eur Heart J, 19, pp. 617-622Rieu, M., Duvallet, A., Scharapan, L., Thieulart, L., Ferry, A., Blood lactate accumulation in intermittent supramaximal exercise (1988) Eur J Appl Physiol Occup Physiol, 57, pp. 235-242Havenetidis, K., Bourdas, D., Creatine supplementation: Effects on urinary excretion and anaerobic performance (2003) J Sports Med Phys Fitness, 43, pp. 347-35
Enkele nauwkeurigheidsaspekten van de digitale signaalverwerking en mogelijkheden tot signaal-ruisverbetering bij een troposfeer aftastende F.M.-C.W.radar
No full textEen uitgebreide analyse van de meetresultaten van de troposfeerradar is zo tijdrovend, dat deze niet tijdens de meting plaats kan vinden. Om toch een indruk te krijgen van wat gemeten wordt, is de zogenaamde monitor ontwikkeld. Deze moet de meetresultaten binnen de 1 sec. verwerken. Hierbij is de nauwkeurigheid van iets minder belang. Deze signaalverwerking wordt met behulp van een rekenmachine uitgevoerd en het fast fourier transform algoritme is hiervan een belangrijk onderdeel. De nauwkeurigheid van dit algoritme in vaste komma en "block-floating point"-uitvoering is onderzocht in relatie tot de verwachte ingangssignalen. Daarnaast is aandacht besteed aan de mogelijkheden tot verbetering van signaal-ruisverhouding, rekening houdend met de beperkingen opgelegd door eigenschappen van het meetsysteem en de troposfeer.Applied SciencesElectrotechniekTransmissie van Informati
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