929 resultados para Oracle bones.


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The Gallus gallus (chicken) embryo is a central model organism in evolutionary developmental biology. Its anatomy and developmental genetics have been extensively studied and many relevant evolutionary implications have been made so far. However, important questions regarding the developmental origin of the chicken skull bones are still unresolved such that no solid homology can be established across organisms. This precludes evolutionary comparisons between this and other avian model systems in which skull anatomy has evolved significantly over the last millions of years.(...)

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Studies evaluating the mechanical behavior of the trabecular microstructure play an important role in our understanding of pathologies such as osteoporosis, and in increasing our understanding of bone fracture and bone adaptation. Understanding of such behavior in bone is important for predicting and providing early treatment of fractures. The objective of this study is to present a numerical model for studying the initiation and accumulation of trabecular bone microdamage in both the pre- and post-yield regions. A sub-region of human vertebral trabecular bone was analyzed using a uniformly loaded anatomically accurate microstructural three-dimensional finite element model. The evolution of trabecular bone microdamage was governed using a non-linear, modulus reduction, perfect damage approach derived from a generalized plasticity stress-strain law. The model introduced in this paper establishes a history of microdamage evolution in both the pre- and post-yield regions

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Bone defects in revision knee arthroplasty are often located in load-bearing regions. The goal of this study was to determine whether a physiologic load could be used as an in situ osteogenic signal to the scaffolds filling the bone defects. In order to answer this question, we proposed a novel translation procedure having four steps: (1) determining the mechanical stimulus using finite element method, (2) designing an animal study to measure bone formation spatially and temporally using micro-CT imaging in the scaffold subjected to the estimated mechanical stimulus, (3) identifying bone formation parameters for the loaded and non-loaded cases appearing in a recently developed mathematical model for bone formation in the scaffold and (4) estimating the stiffness and the bone formation in the bone-scaffold construct. With this procedure, we estimated that after 3 years mechanical stimulation increases the bone volume fraction and the stiffness of scaffold by 1.5- and 2.7-fold, respectively, compared to a non-loaded situation.

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Myocardial angiogenesis induction with vascular growth factors constitutes a potential strategy for patients whose coronary artery disease is refractory to conventional treatment. The importance of angiogenesis in bone formation has led to the development of growth factors derived from bovine bone protein. Twelve pigs (mean weight, 73 +/- 3 kg) were chosen for the study. In the first group (n = 6, growth factor group) five 100 micrograms boluses of growth factors derived from bovine bone protein, diluted in Povidone 5%, were injected in the lateral wall of the left ventricle. In the second group (n = 6, control group), the same operation was performed but only the diluting agent was injected. All the animals were sacrificed after 28 days and the vascular density of the left lateral wall (expressed as the number of vascular structures per mm2) as well as the area of blood vessel profiles per myocardial area analysed were determined histologically with a computerised system. The growth factor group had a capillary density which was significantly higher than that of the control group: 12.6 +/- 0.9/mm2 vs 4.8 +/- 0.5/mm2 (p < 0.01). The same holds true for the arteriolar density: 1 +/- 0.2/mm2 vs 0.3 +/- 0.1/mm2 (p < 0.01). The surface ratios of blood vessel profiles per myocardial area were 4900 +/- 800 micron 2/mm2 and 1550 +/- 400 micron 2/mm2 (p < 0.01) respectively. In this experimental model, bovine bone protein derived growth factors induce a significant neovascularisation in healthy myocardium, and appear therefore as promising candidates for therapeutic angiogenesis.

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Different cell sources for bone tissue engineering are reviewed. In particular, adult cell source strategies have been based on the implantation of unfractionated fresh bone marrow; purified, culture expanded mesenchymal stem cells, differentiated osteoblasts, or cells that have been modified genetically to express rhBMP. Several limiting factors are mentioned for these strategies such as low number of available cells or possible immunological reaction of the host. Foetal bone cells are presented as an alternative solution and review of actual treatments using these cells is presented. Finally, foetal cells used specifically for bone tissue engineering are characterised and potentially interesting therapeutic options are proposed.

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Les importants progrès dans la qualité et la résolution des images obtenues par «absorptiométrie biphotonique à rayons X» ou DXA ont amélioré certaines modalités existantes et favorisé le développement de nouvelles fonctions permettant d'affiner de manière significative la prise en charge de nos patients dans diverses pathologies. On peut par exemple améliorer la prédiction du risque fracturaire par l'analyse indirecte de la micro et de la macroarchitecture osseuse, rechercher les marqueurs de pathologies associées (recherche de fractures vertébrales ou de fractures fémorales atypiques), ou évaluer le statut métabolique par la mesure de la composition corporelle. Avec les appareils DXA les plus performants, on pourra bientôt déterminer l'âge osseux, estimer le risque cardiovasculaire (par la mesure de la calcification de l'aorte abdominale), ou prédire la progression de l'arthrose articulaire et son évolution après la prise en charge chirurgicale dans la routine clinique. The significant progress on the quality and resolution of the images obtained by "Dual X-ray Absorptiometry" or DXA has permitted on one hand to improve some existing features and on the other to develop new ones, significantly refining the care of our patients in various pathologies. For example, by improving the prediction of fracture risk by indirect analysis of micro- and macro-architecture of the bone, by looking for markers of associated bone diseases (research vertebral fractures or atypical femoral fractures), or by assessing the metabolic status by the measurement of body composition. With the best performing DXA devices we will soon be able, in clinical routine, to determine bone age, to estimate cardiovascular risk (by measuring the calcification of the abdominal aorta) or to predict the progression of joint osteoarthritis and its evolution after surgical management.

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The objective of this study is to show that bone strains due to dynamic mechanical loading during physical activity can be analysed using the flexible multibody simulation approach. Strains within the bone tissue play a major role in bone (re)modeling. Based on previous studies, it has been shown that dynamic loading seems to be more important for bone (re)modeling than static loading. The finite element method has been used previously to assess bone strains. However, the finite element method may be limited to static analysis of bone strains due to the expensive computation required for dynamic analysis, especially for a biomechanical system consisting of several bodies. Further, in vivo implementation of strain gauges on the surfaces of bone has been used previously in order to quantify the mechanical loading environment of the skeleton. However, in vivo strain measurement requires invasive methodology, which is challenging and limited to certain regions of superficial bones only, such as the anterior surface of the tibia. In this study, an alternative numerical approach to analyzing in vivo strains, based on the flexible multibody simulation approach, is proposed. In order to investigate the reliability of the proposed approach, three 3-dimensional musculoskeletal models where the right tibia is assumed to be flexible, are used as demonstration examples. The models are employed in a forward dynamics simulation in order to predict the tibial strains during walking on a level exercise. The flexible tibial model is developed using the actual geometry of the subject’s tibia, which is obtained from 3 dimensional reconstruction of Magnetic Resonance Images. Inverse dynamics simulation based on motion capture data obtained from walking at a constant velocity is used to calculate the desired contraction trajectory for each muscle. In the forward dynamics simulation, a proportional derivative servo controller is used to calculate each muscle force required to reproduce the motion, based on the desired muscle contraction trajectory obtained from the inverse dynamics simulation. Experimental measurements are used to verify the models and check the accuracy of the models in replicating the realistic mechanical loading environment measured from the walking test. The predicted strain results by the models show consistency with literature-based in vivo strain measurements. In conclusion, the non-invasive flexible multibody simulation approach may be used as a surrogate for experimental bone strain measurement, and thus be of use in detailed strain estimation of bones in different applications. Consequently, the information obtained from the present approach might be useful in clinical applications, including optimizing implant design and devising exercises to prevent bone fragility, accelerate fracture healing and reduce osteoporotic bone loss.

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Cf. notice du ms. par Leroquais, Sacramentaires, II, 180-183 n° 366. Les incipit des proses ont été relevés dans la table des incipit. F. 1-6v Calendrier de Paris : 3 janv., en rouge, «Genovefe virg. IX lc.» (1); 22 avr., «Inventio corporis s. Dyonisii sociorumque ejus. Oportune virg. semid.» (2v); 28 mai, en rouge, «Germani ep. Parisiensis semid. Carauni mart. memoria» (3); 25juin, en violet, «Translatio s. Eligii ep.» (3v); en violet, «In prima dominica hujus mensis [augusti] fit d. de cruce» [réception à Notre-Dame d'un fragment de la vraie Croix] (4v); 9 oct., en rouge, «Dyonisii sociorumque ejus duplex» (5v); 28 oct., «Germani ep. Translatio s. Genovefe virg. mart. memoria» (5v); 3 nov. «Marcelli ep. Parisiensis dupl.»; 13 nov., «Gendulphi ep. et conf. [Parisiensis] dupl.»; 26 nov., en violet, «Genovefe virg. de miraculo [ardentium] IX lc.» (6); 4 déc., «Susceptio capillorum b. Marie et capitis b. Dyonisii in ecclesia Parisiensi» (6v). Le calendrier ne contient pas la fête de s. Louis au 25 août (établie en 1298) ni au 17 mai la translation du chef de s. Louis à la Sainte-Chapelle (en 1306); — Ajout du XIVe s. au 30 avr., «Eutropii mart. et conf.» [culte établi à Paris en 1296] (2v); cf. Leroquais, Bréviaires, I, CXII-CXIII, Tableau chronologique des fêtes parisiennes. — Au début de chaque mois, vers sur les jours égyptiaques (éd. Hennig, Traditio, XI (1955), 84 III), sauf celui de janvier (1) qui correspond au premier vers de la série éd. par Riese (Anthol. lat., I2 (1906), 680a); — À la fin de février, vers sur l'année bissextile : «Byssextum sexte martis tenuere kalende...»; cf. ms. Latin 3162, f. 102 (1v); — À la fin de mars, vers sur la date de Pâques : «Post martis nonas ubi sit nova luna requiras...» (2); — Notations astrologiques et de comput, passim. F. 7-353v Temporal, avec parties chantées notées. Incomplet du début par la perte du premier f., il commence dans la prose du premier dimanche de l'Avent : «... [eterna indefici]ens mundi vita...» (7). À remarquer : «dominica IIIa [in Adventu] more ecclesie Parisiensis» (24v); — Cérémonie des Cendres avec rubriques liturgiques (62v-66v); — Dimanche des Rameaux, «congregatis processionibus conventualibus in ecclesia B. Marie, capiceriis portantibus capsam et tribus clericis in albis paratis tres textus, exitur de ecclesia nichil cantando et sic eundum est ad ecclesiam Sancte Genovefe de Monte...» (147); cf. Leroquais, 181; — Dans l'évangile des Rameaux, le Christ est désigné par la lettre L, le narrateur par la lettre C et les autres par la lettre S (153-158); dans les autres évangiles de la Passion (162-186 passim), ces lettres suscrites ont été effacées et remplacées à la mine de plomb de façon sporadique, le Christ étant alors désigné par une croix; — «Oremus pro papa nostro N...» (186v); «... pro christianissimo rege nostro N...» (187); — Parmi les litanies, «s.Stephane... s. Dyonisi...» (191v)..., « s. Lucane... s. Justine... s. Gendulphe... s. Germane...» (199)..., « s. Genovefa...» (201v). — «Incipit ordo misse. Sacerdos primo induat se rocheto dicens : Actiones nostras...» (203v-206); pour les rubriques liturgiques, cf. Leroquais, 181; — Préfaces notées : «Incipiunt prefationes...» (206-210); — Canon de la messe (210-213); pour les rubriques liturgiques, cf. Leroquais, 182; — «In die Re[sur]rectionis» (214); — «In die sancto [Pentecostes]» (262v); — [De sancta Trinitate] (280v); — «Dominica XXVa» (348v); — «In dedicatione ecclesie» (350-353v). La fête du Saint-Sacrement ne figure pas. F. 354-496v Sanctoral, avec parties chantées notées. À noter parmi les saints parisiens : 3 janv., «S. Genovefe virg.» (373v); 22 avr., «Inventio corporis s. Dyonisii, Rustici et Eleuterii» (398v); — 28 mai, «S. Germani ep. Parisiensis» (407v); — 10 juin, «S. Landerici Parisiensis ep.» (410); — 26 juill., «In translatione s. Marcelli» (432); — 11août, «De receptione s. corone...» (443v); —, 4 oct., «Auree virg. [abb. Parisiis]» (480); 9 oct., «In die [s. Dyonisii]», avec octave (481v); — 28oct., «In translatione s. Genovefe» (487); — 3nov., «S. Marcelli Parisiensis ep.», avec octave (489v); — 26 nov., «S. Genovefe de miraculo ardentium» (495); — «De s. Gendulpho. Prosa» (495). F. 497-541 Commun des saints, avec pièces chantées notées. F. 541-559 Messes votives, sans parties notées à l'exception de la messe des morts (551v-556). Aux ff. 546v-547, en marge de la messe «pro amico», deux additions d'une écriture cursive de la fin du XIVe s. précisent : «ducem nostrum et duxissem ejusque prolem». — Prières diverses (556-559). F. 559-563 Rituel de mariage. «Incipit ordo ad sponsam benedicendam. Cum venerint ante valvas ecclesie sponsus et sponsa, accinctus sacerdos alba et stola... auxilium et argentum super scutum positum benedicat dicens : Manda Deus... Tunc aspergatur aqua benedicta et thurificetur et sponsus et sponsa; quo facto sacerdos dicat : Bones genz nos avons faiz les bans III foiz de ces II genz et encore les faison nous, que se il i a nul ne nule qui sache enpeschement par quoi l'un ne puisse avoir l'autre par loi de mariage, si le die. Et re[spon]dent assistentes : Nous ni savons se bien non. Quo audito, accipiat sacerdos manum dexteram sponse et ponat in dextera manu sponsi et dicat... nominandos eos : Vos Marie et vos Jeham vous prometez, fianciez et jurez l'un à l'autre à garder la foi et la loiauté du mariage... Tunc sacerdos tradat anulum sponso et sponsus autem per manum sacerdotis primo in police sponse... dicens... : Marie de cest annel t'espous et de mon cors t'ennor et de douaire qui est devisiez entre mes amis et les tiens. In nomine... Secundo in indice dicens... Tercio in medio dicens : Et Spiritus sancti. Amen... Postea sacerdos extensa manu super illos dicat orationes... Tunc sacerdos centus [sic] sponsum per manum dexteram et sponsam et introducat eos in ecclesiam...» (559-559bis); — Messe de mariage, comportant deux préfaces notées : «Deinde celebratur missa...» (559bis-562v); pour les rubriques liturgiques, cf. Leroquais, 183. — «Missa celebrata, recedant sponsus et sponsa et, ipsis stantibus ante hostium domus illorum presentibus pane et vinum [sic], faciat sacerdos benedictionem super panem dicens : Benedic Domine creaturam... Tunc sponsus mordet in pane, postea sponsa. Item benedictio super vinum... Tunc sponsus bibat, postea sponsa. Quo facto introducit eos sacerdos per manum in domum... Item in sero benedictio thalami... Tunc turificet thalamum, postea sponsum et sponsam sedentes vel jacentes in lecto suo benedicat dicens : Benedic Domine adulescentulos...» (562v-563) (éd. avec variantes par E. Martène, De antiquis Ecclesiae ritibus, II, 374-376, d'après le ms. Latin 859A); même ordo dans le ms. NAL 2649, f. 333-336. F. 563-565v Exorcisme de l'eau et du sel (563-564v). — «Pro Terra sancta» (564v-565). — «Pro rege nostro» (565). — «Benedictio pere et baculi peregrinorum» (565-565v). — «Benedictio crucis... Benedictio novorum fructuum... Benedictio panis» (565v).

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Contient : IRoman des Sept sages ; « Ci commance li livres des VII sages de Rome... Il ot jadis I emperere à Rome, qui ot non Diocliciens ; il ot eu famme... » ; «... aprés l'ampereour fu son fill ampereres tant coume il vesqui. Explicit. Explicit » ; IIMarqués de Rome ; « Ci commance li romanz de Marqués, le filz Chaton. Jadis out I empereeur à Rome, qui avoit non Diocliciens ; li empereres fu mult vieuz hom... » ; « ... et vesquirent ainsint en samble toutes leurs vies. Ici faut li rommanz de Marqués et des VII sages de Rome » ; IIIMiracles de Notre-Dame, en vers, par GAUTIER DE COINCY, incomplets du début. Exemplaire non cité dans l'édition de l'abbé Poquet ; Fragments du Prologue ; Les Miracles de la sainte Vierge, publiés par l'abbé Poquet, 1857, vers 25-30, 62-69, 99-106, 138-142 ; Suite du Prologue, à partir du vers 143 ; Fin du Prologue : « ... La langue GAUTIER DE CHOISI (sic), Qui por s'amor commance einsi » ; Miracle de Théophile : « Por ceus esbatre et deporter... » ; Les Miracles de la sainte Vierge, col. 50 ; « Un biau miracle vos récite... » ; Les Miracles de la sainte Vierge, col. 423 ; « Tenez silence, bones genz... » ; Les Miracles de la sainte Vierge, col. 355 ; « Un biau miracle vos weil dire... » ; Les Miracles de la sainte Vierge, col. 291 ; « [M]es livres me dit et revelle... » ; Les Miracles de la sainte Vierge., col. 475 ; « Ci aprés vell metre en brief... » ; Les Miracles de la sainte Vierge, col. 501 ; « Queque talant avez d'oïr... » ; Les Miracles de la sainte Vierge, col. 511 ; « De l'abesse qui fu enceinte, que Nostre Dame délivra de son enfant en dormant. Une abesse fu jadis, Qui la dame de Paradis... » ; Ulrich, dans Zeitschrift für romanische Philologie, t. VI (1882), p. 334 ; « Un miracle truis d'un provoire... » ; édit. Poquet, col. 323 ; « Un moine fu d'une abahie... » ; édit. Poquet, col. 327 ; « Por plusors cuers plus enflammer... » ; édit. Poquet, col. 341 ; « Un arcevesque ot à Touleste... », texte très abrégé ; édit. Poquet, col. 77 ; « Tuit li miracle Nostre Dame... » ; édit. Poquet, col. 429 ; « Entendez tuit, et cler et lai... » ; édit. Poquet, col. 517 ; « Tant convolante me semont... » ; édit. Poquet, col. 303 ; « Pour ce qu'oiseuse est mort à l'ame... » ; édit. Poquet, col. 523 ; « [C]i fu un clers, un damoisiaux... » ; édit. Poquet, col. 363 ; « Entendez tuit, faites silence... » ; édit. Poquet, col. 443 ; « Des V siaumes de Maria. Un brief miracle vos veil dire, Conter vos veil d'un simple moinne... » ; édit. Poquet, col. 359 ; « Si com mes [livres] me tesmoigne... » ; édit. Poquet, col. 455 ; « A ceus qui aiment doucement... » ; édit. Poquet, col. 493 ; « A la loange de la Virge... » ; texte abrégé, comprenant seulement les 114 premiers vers ; édit. Poquet, col. 481 ; « Queque d'oïr estes en grant... » ; édit. Poquet, col. 505 ; « A Chartres fu ce truis uns clers... » ; édit. Poquet, col. 297 ; « Bien est que nos le bien dions... » ; édit. Poquet, col. 347 ; « Cele en cui prist humanité... », texte incomplet ; édit. Poquet, col. 461 ; « De la nonnein que li chevalliers espoussa. A la gloire la glorieuse, Une merveille merveilleuse... » ; Ulrich, dans Zeitschrift für romanische Philologie, t. VI (1882), p. 339 ; « ... Et serront tant com Dieux dura, Beneoiz soit qui l'endurra. Amen. Amen. Explicit les miracles de Nostre Dame sainte Marie, la douce dame et la beningne » ; IVLa Conception de Notre-Dame, par WACE ; « Ci commance la vie Nostre Damne. El non Dieu, qui nous doint sa grace, Oiiez que nos dit mestre GASCE... » — Le texte est incomplet des 18 derniers vers, et s'arrête (fol. 200 v°, col. 2) à ces mots : « ... Si Jonas en la mer sauva, Les IIII enfanz el feu garda, Bien pout donques [resusciter...] » ; cf La vie de la vierge Marie, de maître Wace, p. p. V. Luzarche, Tours, 1859, p. 90

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« Les Captifs d'Alger » (fol. 2), « La Toison d'or » (fol. 18), « L'Oracle muet » (fol. 26), « La pudeur à la Foire » (fol. 40), « La Matrône de Charenton » (fol. 44), « Les vendanges de la Foire » (fol. 53), représentées par la troupe du sieur Dolet à la Foire Saint-Laurent. 1724. — « Divertissement préparé pour le Roy au voyage de Chantilli, 1724 » (fol. 61), et « La reine des Péris » (fol. 67). — « Arlequin, gentilhomme malgré luy » (fol. 87), « L'ombre de la Foire » (fol. 134), « L'isle de Gougou » (fol. 143), « Magotin » (fol. 167), « Arlequin barbet, pagode et médecin » (fol. 181), « Les trois commères » (fol. 208), « L'arbitre des différents » (fol. 256), représentés par les troupes italiennes du sr Octave, du sr Francisque et de Restiers à la Foire Saint-Germain, et par les comédiens italiens du roy à l'Hôtel de Bourgogne, 1716-1725. — « In memoriam carissimi amici D'Orneval, De Challoup scripsit, 1731, à Paris. »

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ABSTRACT Background: Previous studies have implied that weight-bearing, intense and prolonged physical activities optimize bone accretion during the grow^ing years. The majority of past inquiries have used dual-energy X-ray absorptiometry (DXA) to examine bone strength and hand-wrist radiography to determine skeletal maturity in children. Recently, quantitative ultrasound (QUS) technologies have been developed to examine bone properties and skeletal maturity in a safe, noninvasive and cost-effective manner. Objective: The purpose of this study was to compare bone properties and skeletal maturity in competitive male child and adolescent athletes with minimallyactive, age-matched controls, using QUS technology. >. Methods: In total, 224 males were included in the study. The 115 pre-pubertal boys aged 10-12 years consisted of control, minimally-active children (n=34), soccer players (n=26), gymnasts (n=25) and hockey players (n=30). In addition, the 109 late-pubertal boys aged 14-16 years consisted of control, minimally-active adolescents (n=31), soccer players (n=30), gymnasts (n=17) and hockey players (n=31). The athletic groups were elite level players that predominantly trained year-round. Physical activity, nutrition and sports participation were assessed with various questionnaires. Anthropometries, such as height, weight and relative body fat percentage (BF%) were assessed using standard measures. Skeletal strength and age were evaluated using bone QUS. Lastly, salivary testosterone (sT) concentration was measured using Radioimmunoassay (RIA). Results: Within each age group, there were no significant differences between the activity groups in age and pubertal stage. An age effect was apparent in all variables, as expected. A sport effect was noted in all physical characteristics: the child and adolescent gymnasts were shorter and lighter than other sports groups. Adiposity was greater in the controls and in the hockey players. All child subjects were pubertal stage (fanner) I or II, while adolescent subjects were pubertal stage IV or V. There were no differences in daily energy and mineral intakes between sports groups. In both age groups, gymnasts had a higher training volume than other athletic groups. Bone speed of sound (50s) was higher in adolescents compared with the children. Gymnasts had signifieantly higher radial 50S than controls, hockey and soccer players in both age cohorts. Hockey athletes also had higher radial 50S than controls and soccer players in the child and adolescent groups, respectiyely. Child gymnasts and soccer players had greater tibial 50S compared with the hockey players and control groups. Likewise, adolescent gymnasts and soccer players had higher tibial SoS compared with the control group. No interaction was apparent between age and type of activity in any of the bone measures. » Lastly, maturity as assessed by sT and secondary sex characteristics (Tanner stage) was not different between sports group within each age group. Despite the similarity in chronological age, androgen levels and sexual maturity, differences between activity groups were noted in skeletal maturity. In the younger group, hockey players had the highest bone age while the soccer players had the lowest bone age. In the adolescent group, gymnasts and hockey players were characterized by higher skeletal maturity compared with controls. An interaction between the age and sport type effects was apparent in skeletal maturity, reflecting the fact that among the children, the soccer players were significantly less mature than the rest of the groups, while in the adolescents, the controls were the least skeletally mature. Summary and Conclusions: In summary, radial and tibial SOS are enhanced by the unique loading pattern in each sport (i.e, upper and lower extremities in gymnastics, lower extremities in soccer), with no cumulative effect between childhood and adolescence. That is, the effect of sport participation on bone SOS was apparent already among the young athletes. Enhanced bone properties among athletes of specific sports suggest that participation in these sports can improve bone strength and potential bone health.

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ABSTRACT Introduction The purpose of this study was to assess specific osteoporosis-related health behaviours and physiological outcomes including daily calcium intake, physical activity levels, bone strength, as assessed by quantitative ultrasound, and bone turnover among women between the ages of 18 and 25. Respective differences on relevant study variables, based on dietary restraint and oral contraceptive use were also examined. Methods One hundred women (20.6 ± 0.2 years of age) volunteered to participate in the study. Informed written consent was obtained by all subjects prior to participation. The study and all related procedures were approved by the Brock University Research Ethics Board. Body mass, height, relative body fat, as well as chest, waist and hip circumferences were measured using standard procedures. The 10-item restrained eating subscale of the Dutch Eating Behaviour Questionnaire (DEBQ) was used to assess dietary restraint (van Strien et al., 1986). Daily calcium intake was assessed by the Rapid Assessment Method (RAM) (Hertzler & Frary 1994). Weekly physical activity was documented by the 4-item Godin Leisure-Time Exercise Questionnaire (Godin & Shephard 1985). Bone strength was determined from the speed of sound (SOS) as measured by QUS (Sunlight 7000S). SOS measurements (m/s) were taken of the dominant and non-dominant sides of the distal one third of the radius and the mid-shaft of the tibia. Resting blood samples were collected from all subjects between 9am and 12pm, in order to evaluate the impact of lifestyle factors on biochemical markers of bone turnover. Blood was collected during the early follicular phase of the menstrual cycle (approximately days 1-5) for all subjects. Samples were centrifliged and the serum or plasma was aliquoted into separate tubes and stored at -80°C until analysis. The bone formation markers measured were Osteocalcin (OC), bone specific alkaline phosphatase (BAP) and 25-OH vitamin D. The bone resorption markers measured were the carboxy (CTx) and amino (NTx) terminal telopeptides of type-I collagen crosslinks. All markers were assessed by ELISA. Subjects were divided into high (HDR) and low dietary restrainers (LDR) based on the median DEBQ score, and also into users (BC) and non-users (nBC) of oral contraceptives. A series of multiple one way ANOVA's were then conducted to identify differences between each set of groups for all relevant variables. A two-way ANOVA analysis was used to explore significant interactions between dietary restraint and use of oral contraceptives while a univariate follow-up analysis was also performed when appropriate. Pearson Product Moment Correlations were used to determine relationships among study variables. Results HDR had significantly higher BMI, %BF and circumference measures but lower daily calcium intake than LDR. There were no significant differences in physical activity levels between HDR and LDR. No significant differences were found between BC and nBC in body composition, calcium intake and physical activity. HDR had significantly lower tibial SOS scores than LDR in both the dominant and non-dominant sites. The post-hoc analysis showed that within the non-birth control group, the HDR had significantly lower tibial SOS scores of bone strength when compared to the LDR but Aere were no significant differences found between the two dietary restraint groups for those currently on birth control. HDR had significantly lower levels of OC than LDR and the BC group had lower levels of BAP than the nBC group. Consistently, the follow-up analysis revealed that within those not on birth control, subjects who were classified as HDR had significantly (f*<0.05) lower levels of OC when compared with LDR but no significant differences were observed in bone turnover between the two dietary restraint groups for those currently on birth control. Physical activity was not correlated with SOS scores and bone turnover markers possibly due to the low physical activity variability in this group of women. Conclusion This is the first study to examine the effects of dietary restraint on bone strength and turnover among this population of women. The most important finding of this study was that bone strength and turnover are negatively influenced by dietary restraint independent of relative body fat. In general, the results of the present thesis suggest that dietary restraint, oral contraceptive use, as well as low daily calcium intake and low physical activity levels were widespread behaviours among this population of college-aged women. The young women who were using dietary restraint as a strategy to lose weight, and thus were in the HDR group, despite their higher relative body fat and weight, had lower scores of bone strength and lower levels of markers of bone turnover compared to the low dietary restrainers. Additionally, bone turnover seemed to be negatively affected by oral contraceptives, while bone strength, as assessed by QUS, seemed unaffected by their use in this population of young women. Physical activity (weekly energy expenditure), on the other hand, was not associated with either bone strength or bone tiimover possibly due to the low variability of this variable in this population of young Canadian women.

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The purpose of this study was to compare bone speed of sound (SOS) measured by quantitative ultrasound, circulating levels of IGF- 1 and biochemical markers of bone turnover in pre- (Pr) and post-menarcheal (Po) synchronized swimmers (SS) and controls (NS). Seventy participants were recruited: 8 PrSS, 22 PoSS, 20 PrNS, and 20 PoNS. Anthropometric measures of height, weight, skeletal maturity and percent body fat were taken, and dietary intake evaluated using 24-hour recall. Bone SOS was measured at the distal radius and mid-tibia and blood samples analyzed for IGF-1, osteocalcin, NTx, and 25-OH vitamin D. Results demonstrated maturational effects on bone SOS, IGF-1 and bone turnover (p<0.05), with no differences observed between SS and NS. Main effects were observed for a reduced caloric intake in SS compared to NS (p<0.05). Therefore, SS does not offer additive affects on bone strength but imparts no adverse affects to skeletal health in these athletes.

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Over the last two decades, the prevalence of obesity in the general population has been steadily increasing. Obesity is a major issue in scientific research because it is associated with many health problems, one of which is bone quality. In adult females, adiposity is associated with increased bone mineral density, suggesting that there is a protective effect of fat on bone. However, the association between adiposity and bone strength during childhood is not clear. Thus, the purpose of this study was to compare bone strength, as reflected by speed of sound (SOS), of overweight and obese girls and adolescents with normal-weight age-matched controls. Data from 75 females included normal-weight girls (G-NW; body fat:::; 25%; n = 21), overweight and obese girls (GOW; body fat ~ 28%; n = 19), normal-weight adolescents (A-NW, body fat:::; 25%; n = 13) and overweight and obese adolescents (A-OW; body fat ~ 28%; n = 22). Nutrition was assessed with a 24-hour recall questionnaire and habitual physical activity was measured for one week using accelerometry. Using quantitative ultrasound (QUS; Sunlight Omnisense™), bone SOS was measured at the distal radius and mid-tibia. No differences were found between groups in daily total energy, calcium or vitamin D intake. However, all groups were below the recommended daily calcium intake of 1300 mg (Osteoporosis Canada, 2008). Adolescents were significantly less active than girls (14.7 ± 0.6 vs. 6.3 ± 0.6% active for G and A, respectively). OW accumulated significantly less minutes of moderate-to-very vigorous physical activity per day (MVPA) than NW in both age groups (114 ± 6 vs. 57 ± 5 min/day for NW and OW, i respectively). Girls had significantly lower radial SOS (3794 ± 87 vs. 3964 ± 64 mls for G-NW and A-NW, respectively), and tibial SOS (3678 ± 86 vs. 3878 ± 52 mls for G-NW and A-NW, respectively) than adolescents. Radial SOS was similar in the two adiposity groups within each age group. However, tibial SOS was lower in the two overweight groups (3601 ± 75 mls vs. 3739 ± 134 mls for G-OW and A-OW, respectively) compared with the age-matched normal-weight controls. Body fat percentage negatively correlated with tibial SOS in the study sample as a whole (r = -0.30). However, when split into groups, percent bo~y fat correlated with tibial SOS only in the A-OW group (r = -0.53). MVPA correlated with tibial SOS (r = 0.40), once age was partialed out. In conclusion, in contrast withthe higher bone strength characteristic of obese adult women, overweight and obese girls and adolescents are characterized by low tibial bone strength, as assessed with QUS. The differences between adiposity groups in tibial SOS may be at least partially due to the reduced weight-bearing physical activity levels in the overweight girls and adolescents. However, other factors, such as hormonal influences associated with high body fat may also playa role in reducing bone strength in overweight girls. Further research is required to reveal the mechanisms causing low bone strength in overweight and obese children and adolescents.

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The purpose of this study was to examine the associations between bone speed of sound (SOS) and body composition, osteoporosis-related health behaviours, and socioeconomic status (SES) in adolescent females. A total of 442 adolescent females in grades 9-11 participated. Anthropometric measures of height, body mass, and percent body fat were taken, and osteo-protective behaviours such as oral contraceptive use (OC), physical activity and daily calcium intake were evaluated using self-report questionnaires. Bone SOS was measured by transaxial quantitative ultrasound (QUS) at the distal radius and mid-tibia. The results suggest that fat mass is a significant negative predictor of tibial SOS, while lean mass is positively associated with radial SOS scores and calcium intake was positively associated with tibial SOS scores (p