Biomechanics of Musculoskeletal System Growth and Development

2012 ◽  
pp. 325-358
Author(s):  
David Nuckley
2020 ◽  
Vol 60 (18) ◽  
pp. 2155
Author(s):  
Chris W. Rogers ◽  
Erica K. Gee ◽  
Charlotte F. Bolwell ◽  
Sarah M. Rosanowski

During the past 20 years, there has been a contraction in the New Zealand Thoroughbred industry and, to a lesser extent, within the Standardbred industry. These changes have seen an increasing proportion of the market being associated with fewer larger commercial farms. Many of these farms manage their own mares, and the mares and foals of several clients. This, in turn, has increased the similarity of the management of breeding and young stock within New Zealand. The temperate climate allows the majority of the management of breeding and young stock to be pasture based. The predominant pasture is ryegrass–clover mix that has been demonstrated to provide adequate nutrition for growth and development. The temperate climate also permits management of horses at pasture year round, which is proposed to stimulate development of the musculoskeletal system. Apart from a brief period during weaning, most young stock remain at pasture from birth until the start of yearling preparation. Free access to pasture exercise provides the opportunity to stimulate the musculoskeletal system for the future challenges as a racehorse. The export focus of many of the equine industries heavily influences the management decisions. Despite the availability of good-quality pasture post-weaning, many foals receive up to 50% of the daily dietary energy requirement as concentrates, possibly reflecting the emphasis on early sales as yearlings and the drive to optimise growth. The observations of drench resistance of common internal parasites presents an emerging problem for pasture-based production systems. A large proportion of the Thoroughbred foal crop is exported as yearlings or ready to run 2-year-olds. There is an increasing trend for Standardbreds to be sold as yearlings and this has resulted in changes in the management of Standardbred young stock.


Author(s):  
Randy Moore

Cell and tissue interactions are a basic aspect of eukaryotic growth and development. While cell-to-cell interactions involving recognition and incompatibility have been studied extensively in animals, there is no known antigen-antibody reaction in plants and the recognition mechanisms operating in plant grafts have been virtually neglected.An ultrastructural study of the Sedum telephoides/Solanum pennellii graft was undertaken to define possible mechanisms of plant graft incompatibility. Grafts were surgically dissected from greenhouse grown plants at various times over 1-4 weeks and prepared for EM employing variations in the standard fixation and embedding procedure. Stock and scion adhere within 6 days after grafting. Following progressive cell senescence in both Sedum and Solanum, the graft interface appears as a band of 8-11 crushed cells after 2 weeks (Fig. 1, I). Trapped between the buckled cell walls are densely staining cytoplasmic remnants and residual starch grains, an initial product of wound reactions in plants.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
G. M. Hutchins ◽  
J. S. Gardner

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.


2015 ◽  
Vol 58 ◽  
pp. 61-70 ◽  
Author(s):  
Paul B. Larsen

Ethylene is the simplest unsaturated hydrocarbon, yet it has profound effects on plant growth and development, including many agriculturally important phenomena. Analysis of the mechanisms underlying ethylene biosynthesis and signalling have resulted in the elucidation of multistep mechanisms which at first glance appear simple, but in fact represent several levels of control to tightly regulate the level of production and response. Ethylene biosynthesis represents a two-step process that is regulated at both the transcriptional and post-translational levels, thus enabling plants to control the amount of ethylene produced with regard to promotion of responses such as climacteric flower senescence and fruit ripening. Ethylene production subsequently results in activation of the ethylene response, as ethylene accumulation will trigger the ethylene signalling pathway to activate ethylene-dependent transcription for promotion of the response and for resetting the pathway. A more detailed knowledge of the mechanisms underlying biosynthesis and the ethylene response will ultimately enable new approaches to be developed for control of the initiation and progression of ethylene-dependent developmental processes, many of which are of horticultural significance.


2016 ◽  
Vol 1 (11) ◽  
pp. 81-85
Author(s):  
Melanie Hudson

The Clinical Fellowship Experience is described by the American Speech-Hearing-Language Association (ASHA) as the transition period from constant supervision to independent practitioner. It is typically the first paid professional experience for the new graduate, and may be in a setting with which the new clinician has little or even no significant practical experience. The mentor of a clinical fellow (CF) plays an important role in supporting the growth and development of this new professional in areas that extend beyond application of clinical skills and knowledge. This article discusses how the mentor may provide this support within a framework that facilitates the path to clinical independence.


2000 ◽  
Vol 5 (6) ◽  
pp. 1-7
Author(s):  
Christopher R. Brigham ◽  
James B. Talmage ◽  
Leon H. Ensalada

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, is available and includes numerous changes that will affect both evaluators who and systems that use the AMA Guides. The Fifth Edition is nearly twice the size of its predecessor (613 pages vs 339 pages) and contains three additional chapters (the musculoskeletal system now is split into three chapters and the cardiovascular system into two). Table 1 shows how chapters in the Fifth Edition were reorganized from the Fourth Edition. In addition, each of the chapters is presented in a consistent format, as shown in Table 2. This article and subsequent issues of The Guides Newsletter will examine these changes, and the present discussion focuses on major revisions, particularly those in the first two chapters. (See Table 3 for a summary of the revisions to the musculoskeletal and pain chapters.) Chapter 1, Philosophy, Purpose, and Appropriate Use of the AMA Guides, emphasizes objective assessment necessitating a medical evaluation. Most impairment percentages in the Fifth Edition are unchanged from the Fourth because the majority of ratings currently are accepted, there is limited scientific data to support changes, and ratings should not be changed arbitrarily. Chapter 2, Practical Application of the AMA Guides, describes how to use the AMA Guides for consistent and reliable acquisition, analysis, communication, and utilization of medical information through a single set of standards.


2000 ◽  
Vol 5 (3) ◽  
pp. 4-4

Abstract Lesions of the peripheral nervous system (PNS), whether due to injury or illness, commonly result in residual symptoms and signs and, hence, permanent impairment. The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, divides PNS deficits into sensory and motor and includes pain in the former. This article, which regards rating sensory and motor deficits of the lower extremities, is continued from the March/April 2000 issue of The Guides Newsletter. Procedures for rating extremity neural deficits are described in Chapter 3, The Musculoskeletal System, section 3.1k for the upper extremity and sections 3.2k and 3.2l for the lower limb. Sensory deficits and dysesthesia are both disorders of sensation, but the former can be interpreted to mean diminished or absent sensation (hypesthesia or anesthesia) Dysesthesia implies abnormal sensation in the absence of a stimulus or unpleasant sensation elicited by normal touch. Sections 3.2k and 3.2d indicate that almost all partial motor loss in the lower extremity can be rated using Table 39. In addition, Section 4.4b and Table 21 indicate the multistep method used for spinal and some additional nerves and be used alternatively to rate lower extremity weakness in general. Partial motor loss in the lower extremity is rated by manual muscle testing, which is described in the AMA Guides in Section 3.2d.


2010 ◽  
Author(s):  
Erica Frydenberg ◽  
Krys Kaniasty ◽  
Erica Frydenberg ◽  
Barbara Jones ◽  
Esther Greenglass ◽  
...  

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