China
Africa
Explore chapters and articles related to this topic
Gamma Spectrometry
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
An important feature of the quality assurance is to have a routine for dealing with non-conformance in the laboratory (such as erroneous handling of data leading to inaccurate reported results), which may or could lead to an event that jeopardizes the quality of the reported data. Therefore, related to this, it is useful to have a plan for preventive actions to ensure minimizing the risk of perturbations or nonconformity. Regular internal and external audits, including both the technical and management aspects should be done.
Nongenetic Determinants of Obesity and Body Fat Topography
Published in Claude Bouchard, The Genetics of Obesity, 2020
James O. Hill, Michael J. Pagliassotti, John C. Peters
When perturbations to the system exceed the capacity of the functional phenotype to compensate via behavioral and metabolic responses, an excess or surfeit of energy exists; this is a situation that must produce changes in body energy stores. The extent and nature of such changes depend on the functional phenotype and, in particular, on the metabolic phenotype, since the latter determines the immediate fate of excess energy and the source of Estored to be used for oxidation. Moreover, the specific changes that occur in Estored will in part determine the new characteristics of the functional phenotype.
Energy in, energy out – and fatigue
Published in Francesco E. Marino, Human Fatigue, 2019
The need for energy storage (e.g., fat) and conversely the capacity to deal with deficits (e.g., food, water) indicate that Homo was adapted to make concessions at various times. One of those concessions must have been to spare energy whenever it was in low supply. As discussed in Chapter 3, fatigue can result from several perturbations, including a lessening in one’s response to or enthusiasm for something, caused by overexposure. This predicts that overexposure to long periods of low energy availability would potentially manifest as fatigue, precisely to avoid unnecessary energy expenditure. If we consider fatigue in this light, it would seem a reasonable suggestion that as energy availability became scarce, avoiding unnecessary physical exertion would be a useful adaptation. The converse of this proposition is that when energy availability is high, the need to conserve energy should be low. However, this does not seem to be the case since it is plainly obvious that a capacity to store energy in the form of fat seems to be much greater than our desire to expend it. As we shall see, the capability to expend energy may indeed be limited and maladapted. In essence, the adaptations required to meet the needs of our larger more expensive brain with high energy demands, fuelled mainly by storage of fat, may in effect be maladaptive in today’s context.
The Effect of Additional Leg Supports in Control of Posture in Sitting
Published in Journal of Motor Behavior, 2023
Adeolu Ademiluyi, Huaqing Liang, Alexander S. Aruin
Furthermore, while the effect of the leg support was seen in the trunk muscles, these muscles showed lesser involvement as compared to the leg muscles. Thus, when ALS support was available, the activation of ES muscles was seen 16% early and it was seen 25% early when PLS was available as compared to FR condition. While using PLS, the participants activated the ES muscle to keep the back in erect posture in preparation of the trunk for the oncoming perturbation. This was contrary to the outcome of a study with sitting subjects applying self-induced perturbations in a vertical plane: muscle activation in ES and RA muscles was similar irrespective of the availability of the leg support (Aruin & Shiratori, 2003). The disagreements between the outcomes of the current and that prior study could be explained by the differences in perturbation properties: horizontal external perturbations were used in the current study while self-induced perturbations in vertical direction were used in that prior study.
Adverse outcome pathways (AOPs) for radiation-induced reproductive effects in environmental species: state of science and identification of a consensus AOP network
Published in International Journal of Radiation Biology, 2022
Knut Erik Tollefsen, Frédéric Alonzo, Nicholas A. Beresford, Dag Anders Brede, Elizabeth Dufourcq-Sekatcheff, Rodolphe Gilbin, Nele Horemans, Selma Hurem, Patrick Laloi, Erica Maremonti, Deborah Oughton, Olivier Simon, You Song, Michael D. Wood, Li Xie, Sandrine Frelon
Reproduction is one of three biological processes (with survival and growth) that are critical for population dynamics. Reproductive disturbances are often the focus of ecological risk assessment as perturbations may impact wildlife populations in the long-term, and consequently affect ecosystem functioning (Anderson and Wild 1994; Dallas et al. 2012). Studies addressing biological effects of chronic radiation in a wide range of non-human species have also shown that reproduction is the most radiosensitive phenotypic endpoint, compared to endpoints such as morbidity and mortality (Garnier-Laplace et al. 2010; Adam-Guillermin et al. 2018). In addition, species sensitivity and resilience to chronic radiation might differ, depending on species physiology and reproduction strategies (e.g. sexual, asexual, parthenogenetic, hermaphroditic, etc.) (Shuryak 2020). To date, developmental disorders and altered reproductive endpoints have been observed following radiation exposure. Although some effects on individual endpoints may appear of minor importance (Kryvokhyzha et al. 2019; Beresford et al. 2020), their combination may lead to ecologically significant consequences such as decrease in population abundance and/or extinction. Moreover, studies to address such reproductive perturbations are particularly relevant in multi-generational exposure scenarios since they may alter the ability of offspring to adapt to environmental stressors and to survive (Lynch 1992; Alonzo et al. 2008; Dutilleul et al. 2015).
Facing Repeated Stressors in a Motor Task: Does it Enhance or Diminish Resilience?
Published in Journal of Motor Behavior, 2021
Yannick Hill, Nico W. Van Yperen, Ruud J. R. Den Hartigh
Collecting time-serial data may indicate both the strength of the deviation from the equilibrium following the stressor (Holling, 1973) and the time it takes the system to return to this level of functioning (Bardy et al., 2002; Scheffer et al., 2009; Schöner et al., 1992). Combining these indices yields the Area Under the Curve (AUC, see Figure 1) which represents the deviation from the level of functioning (Bruneau et al., 2003). In case the perturbation strength increases when repeatedly encountering stressors with the same or a similar magnitude, the stress sensitivity would be said to increase. Thus, if the stress sensitivity increases, while the relaxation time stays stable or vice versa, the AUC would indicate a larger deviation from the level of functioning and thus lower resilience of the system.1 This is in line with the observations of resilience losses in systems during critical slowing down: The systems become more sensitive to minor stressors and/or require more time to return to the previous level of functioning (e.g., Bardy et al., 2002; Scheffer et al., 2009, 2012). In contrast, a decrease in relaxation time or stress sensitivity with repeated stressors, while the other parameter stays stable, would indicate increased resilience.