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Advances in Adult Dysplasia
Published in K. Mohan Iyer, Hip Joint in Adults: Advances and Developments, 2018
Complete development of the acetabulum is dependent on the continuous mechanical pressure of the well-seated femoral head inside the acetabulum. The triradiate cartilage forms the shape and depth of the acetabulum in response to the moulding effect of the femoral head. On the other hand the secondary growth centres are responsible for fine-tuning of the details. These centres activate after the closure of the triradiate cartilage [7,24].
Abies Spectabilis (D. Don) G. Don (Syn. A. Webbiana Lindl.) Family: Coniferae
Published in L.D. Kapoor, Handbook of Ayurvedic Medicinal Plants, 2017
Pharmacognostical characteristics — Its young stem shows four ridges, of which three are more prominent. In transverse section, some epidermal cells elongate to form multicellular nonglandular hairs. The cortex consists of collenchyma followed by parenchyma. The endodermis and pericycle are distinct. The stele is developed below the ridges. The stem becomes circular after secondary growth. The pericycle forms strands of thick-walled fibers which separate, and stone cells are formed in the intervening parenchyma. The bark shows a thick periderm of 15 to 20 layers of cork cells and a wide zone of phelloderm, whose cells become thick walled and sclerenchymatous. The secondary phloem is represented by concentric tangential bands of fibers, sieve tubes, companion cells, and phloem parenchyma separated by funnel-shaped medullary rays. Cortical bundles, fibers of the pericycle, phloem, and stone cells of the phelloderm are the distinguishing features of the bark.153
The ankle and foot
Published in Ashley W. Blom, David Warwick, Michael R. Whitehouse, Apley and Solomon’s System of Orthopaedics and Trauma, 2017
The skin and soft tissues of the calf and the medial side of the foot are short and underdeveloped. If the condition is not corrected early, secondary growth changes occur in the bones; these are permanent. Even with treatment the foot is liable to be short, the calf may remain thin and a below-knee length discrepancy of less than 2 cm may occur.
Transient Visual Obscurations Without Papilloedema as the Heralding Symptom of Chiasmal Compression
Published in Neuro-Ophthalmology, 2023
Niels A. Ryden, Helena Lam, Casey Judge, Andrew S. Venteicher, Michael S. Lee
His past medical history included type 2 diabetes mellitus, hypertension, and obesity. Following an episode of syncope 10 years previously, brain magnetic resonance imaging (MRI) incidentally identified a 1.0 × 0.8 × 1.1 cm hypo-enhancing pituitary adenoma without close approximation to the optic chiasm (Figure 1). Annual surveillance imaging for 4 years showed no changes. An endocrine work-up demonstrated secondary growth hormone deficiency. He was lost to follow up for 6 years prior to this presentation.
Bio-acoustic signaling; exploring the potential of sound as a mediator of low-dose radiation and stress responses in the environment
Published in International Journal of Radiation Biology, 2022
Bruno F. E. Matarèse, Jigar Lad, Colin Seymour, Paul N. Schofield, Carmel Mothersill
Drought stress and predation constitute two of the major physiological stressors of vascular plants. Under drought stress some plants produce measurable bio-acoustic emissions (De Roo et al. 2016). The mechanisms for generating these signals are not fully understood but may involve the effects of decreasing hydrostatic pressure in xylem, leading to the production of ultrasonic sound emissions variously measured as >20 kHz (Tyree and Dixon 1983) and from 10 to 300 kHz (Laschimke et al. 2006). With rapidly decreasing pressure in the xylem, collapse of bubbles caused by cavitation has been suggested as one mechanism for the generation of sound, but an alternative hypothesis derived to explain the ‘violent acoustic activity’ detected in Ulmus sp. in response to drought stress, is release of energy from the xylem-adherent bubble system that normally contributes to water flow (Laschimke et al. 2006; Zweifel and Zeugin 2008; Gagliano et al. 2012a, 2012b; Gagliano 2013). Respiration and metabolic growth activity of the cambium is another method suggested to be involved (Zweifel and Zeugin 2008). The cambium is the portion between the xylem and phloem where cells are rapidly dividing and is responsible for secondary growth of stems and roots (Zweifel and Zeugin 2008; Schöner et al. 2016). At nighttime when the plant is subject to drought stress, the cambium has increased turgor pressure due to increased respiration. This increased pressure causes greater levels of carbon dioxide to enter the xylem, resulting in more gas bubbles and subsequent acoustic emissions. In the absence of drought stress and consequent xylem cavitation, young corn roots are able to produce clicking sounds under water – the reason for retaining or developing this mechanism is unknown (Schöner et al. 2016). It is apparent that a variety of plant species have developed mechanisms for sound production.