Introduction to the Postconcussion Syndrome
Rolland S. Parker in Concussive Brain Trauma, 2016
The site of noncerebral trauma has been described by the Abbreviated Injury Scale (AIS) (Fearnside & Simson, 2005) as head or neck, face, chest, abdomen or pelvic contents, extremities or pelvic girdle, external. Additional trauma sites are the spinal column and other bones, muscles, fascia, and viscera. One sample of 8-year-old children manifested 26% multiple injuries (Klonoff et al., 1995). The brain and soma interact with profound holistic behavioral and physiological changes. Adaptation is the integrated way in which a person or species copes with its environment: genetic (hereditary), phenotypic (expression of genes in a particular personal history), and stylistic (learning and preferences). It is assumed that TBI interferes with flexibility and capacity to deal with complex and difficult problems. Substantial inability to cope is indicated by later difficulties in school, employment, family relations, and community participation.
Basic Thermal Physiology: What Processes Lead to the Temperature Distribution on the Skin Surface
Kurt Ammer, Francis Ring in The Thermal Human Body, 2019
The terms acclimation and acclimatization are etymologically indistinguishable. Both words have been assigned several and different meanings [146]. The most useful of the assigned meanings, adopted here, would seem to be those of Hart [147] and Eagan [148] who use the term acclimation to describe the adaptive changes that occur within an organism in response to experimentally induced changes in particular climatic factors such as ambient temperature in a controlled environment, and the term acclimatization to describe the adaptive changes that occur within an organism in response to changes in the natural climate [2]. Consequently, acclimatization was defined as the process by which a living organism becomes adapted to a change of climatic environment [145]. Acclimatization is a relatively quick adaptation that occurs within the organism’s lifetime [2]. Traditionally, acclimatization studies in humans have focused on adapting to temperature changes (such as moving from a temperate climate to the tropics), but acclimatization can also occur with a change in altitude, photoperiod and humidity, for instance [145].
Acclimatization
Andrew M. Luks, Philip N. Ainslie, Justin S. Lawley, Robert C. Roach, Tatum S. Simonson in Ward, Milledge and West's High Altitude Medicine and Physiology, 2021
The transient phenomenon of acclimatization must be distinguished from the concept of adaptation, which refers to characteristics present in long-term high altitude residents that have arisen as a result of natural selection working on the gene pool. These characteristics serve to distinguish people born and bred at high altitude from even well-acclimatized lowlanders. There is debate about whether these characteristics are due to environmental factors operating during early growth or due to genetic causes. Recent genetic evidence points to adaptation happening in people resident at high altitude for generations in South America, Tibet, and Ethiopia (Chapter 4). The remainder of this chapter will focus on the issue of acclimatization while issues related to adaptation are discussed in Chapters 4 and 6.
The paradox of adaptive responses and iso-effect per fraction
Published in International Journal of Radiation Biology, 2018
Although tempting, such an axiomatic explanation seems unsatisfactory. The evolutionary concepts of adaptation and selection are frequently invoked to explain a role for adaptive responses, or used as an analogy to illustrate them. Though this invites the expectation that such adaptations are naturally advantageous or beneficial, there is no such formal requirement. Whether a reduced radiation-induced response is beneficial (to the cell, the organism or the species) is not always clear and multiple opposing effects might conceivably occur simultaneously. In practice, adaptive responses have most frequently been defined as: when exposure to radiation prior to a subsequent radiation exposure results in a reduced radiation-induced response of a given endpoint compared to that observed without prior irradiation (the response for the latter dose alone). This definition could provide a clue as to why it is widely considered to be a low-dose phenomenon, since any effect induced by the prior dose might mask a reduced response to the subsequent dose.
From tangled banks to toxic bunnies; a reflection on the issues involved in developing an ecosystem approach for environmental radiation protection
Published in International Journal of Radiation Biology, 2022
Carmel E. Mothersill, Deborah H. Oughton, Paul N. Schofield, Michael Abend, Christelle Adam-Guillermin, Kentaro Ariyoshi, Nicholas A. Beresford, Andrea Bonisoli-Alquati, Jason Cohen, Yuri Dubrova, Stanislav A. Geras’kin, Tanya Helena Hevrøy, Kathryn A. Higley, Nele Horemans, Awadhesh N. Jha, Lawrence A. Kapustka, Juliann G. Kiang, Balázs G. Madas, Gibin Powathil, Elena I. Sarapultseva, Colin B. Seymour, Nguyen T. K. Vo, Michael D. Wood
This statement was designed to address the role of adaptation and evolution. Biota can adapt in response to new stimuli and invoke protective mechanisms that are essentially heritable and conserved, and molecularly predicated, in the interest of survival. Such adaptation could occur in response to environmental exposure to low-dose radiation (Audette-Stuart et al. 2011; Mothersill et al. 2013; Lampe et al. 2017; Beresford et al. 2020b). These processes draw attention to the fact that the current environmental radiation protection regulation adapted from the human framework essentially measures or models dose and compares this to benchmarks below which impacts on individuals (mortality, morbidity, fecundity) likely to lead to population level effects are not anticipated (Howard et al. 2010). This can miss long-term processes playing out over generations in populations. It is difficult for humans to make the conceptual jump from individual-level short-term effects to very long-term ecosystem-level effects.
Menstrual variation in the acute testosterone and cortisol response to laboratory stressors correlate with baseline testosterone fluctuations at a within- and between-person level
Published in Stress, 2021
Christian J. Cook, Phillip Fourie, Blair T. Crewther
Surprisingly, the dynamic activity of the hypothalamic-pituitary-gonadal (HPG) axis, as measured by testosterone, has received much less attention in this work (Lane et al., 2015; Nakamura et al., 2011). This dearth of research could reflect misconceptions regarding the functioning of, and menstrual fluctuations in, testosterone. Among women, androgens like testosterone originate from both HPA and HPG sources (Burger, 2002). There is also considerable proof of negative- and positive-feedback loops, involving multiple chemical, neuropeptide and receptor signals, linking both axes via bidirectional pathways (Acevedo-Rodriguez et al., 2018; Chrousos et al., 1998; Viau, 2002). Hence, the HPG axis can regulate, and be regulated by, the HPA axis in the broader context of stress and fertility. Testosterone can also influence the stress response via cognitive processing, coping mechanisms (Jezova et al., 2019), anti-anxiety and analgesic effects (Edinger & Frye 2005). These complexities serve evolutionary roles by ensuring flexible responding for reproduction, adaptation, and survival.
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