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Morphometries of Craniofacial Form
Published in D. Dixon Andrew, A.N. Hoyte David, Ronning Olli, Fundamentals of Craniofacial Growth, 2017
Straney (1990) utilized the MAF approach for the study of evolutionary changes in the shape of certain bones (the baculum) in the spiny rat (genus proechimysj. Previous studies have been based on length and width measurements because of the lack of homologous landmarks. Points on the outline (150-350) were digitized and Bookstein’s line skeleton applied. The question that arises is how effective is the line skeleton and its branch points (bifurcations) for capturing the shape variation in the outline. Using the bifurcation intersections as points, a set of 27 inter-landmark distances were computed. To these were added 10 variables computed from the radius or R function of the line skeleton. These 37 variables were then submitted to principal component analysis (PCA). The plot of PC-1 against PC-2 displayed reasonably good discrimination among most of the six groups of Proechimys. At this juncture a second question arose, namely, since the line skeleton was a simplification of the actual shape, how much does the simplification affect group discrimination? To test this, the bacular outlines were also analyzed by Rohlf (1990b) using elliptical Fourier functions or EFFs. (see Section VI.D). The accuracy of the EFF fit with 22 harmonics, in terms of residuals, is not given. Size-standardization with the EFF was not imposed in this case to maintain conformity with the line skeleton data. The PCA results of the EFF coefficients (not amplitudes) were essentially similar to the earlier line skeleton data after a number of transformations so that both approaches were comparable. For example, the PCA axes were standardized to have unit variance. Size played a major part in the group discrimination with the use of EFFs and this, in turn, affected the PC-1 axis.
Back to Stir It Up: Erectile Dysfunction in an Evolutionary, Developmental, and Clinical Perspective
Published in The Journal of Sex Research, 2019
Ylenia Nicolini, Antonella Tramacere, Stefano Parmigiani, Harold Dadomo
Human males lack a baculum (De Tejada, Goldstein, Azadzoi, Krane, & Cohen, 1989) or penile bone (or os penis), a particular bone formed by the ossification of the distal region of the corpora cavernosa and located above the distal end of the urethra (Romer & Parsons, 1962) (see Appendix A in the online supplementary files). Lacking the baculum, human penile erection relies essentially on a coordinated and arranged series of vascular events, a complex of interactions which works at multiple levels for achieving tumescence (Dean & Lue, 2005). The presence of multiple levels of control, from the central nervous system (CNS) to peripheral nerves, is common to many systems important for reproduction, as relying on a single process would make the species vulnerable to extinction (De Tejada et al., 1988).
Long-term exposure of cockroach Blaptica dubia (Insecta: Blaberidae) nymphs to magnetic fields of different characteristics: effects on antioxidant biomarkers and nymphal gut mass
Published in International Journal of Radiation Biology, 2019
Dajana Todorović, Larisa Ilijin, Marija Mrdaković, Milena Vlahović, Aleksandra Filipović, Anja Grčić, Vesna Perić-Mataruga
The induction of oxidative stress in B. dubia nymphs exposed to MFs is reflected by the changes in activity of examined antioxidative enzymes which act in a coordinated manner to counteract oxidative stress generated by high concentrations of ROS inside the gut cell. The key enzymes responsible for the elimination of oxygen radicals are SOD and CAT (Dutta et al. 2016). The enhanced activities of these enzymes in response to MFs are a likely defense against oxidative damage due to the accumulation of ROS (Meng et al. 2009). In the present study, we have shown that long-term exposure (5 months) of B. dubia nymphs to MFs led to significant increases in SOD and CAT activities in the gut tissues independent of the MF type (SMF and ELF MF). Excessive production of free radicals can induce activation of these enzymes in conditions of long-term oxidative stress caused by the MF. The change in SOD activity suggested that MFs induces production of superoxide anion radicals in B. dubia nymphs. This enzyme catalyzes the destruction of these radicals and protects cells against the harmful effects of ROS. At the same time, CAT activity in gut tissues of both SMF and ELF MF nymph groups was also increased, which is consistent with the high activity of SOD under MF stress. Specifically, it is possible that increased SOD activity results in an increased H2O2 concentration and consequently in a further increase in CAT activity. Previous studies have shown that CAT can protect against oxidative stress and extend the lifespan of insects (Melov et al. 2000). The general stress response of B. dubia nymph gut tissues after prooxidative action of both types of MFs was obvious and confirmed the efficiency of the SOD–CAT enzyme pair in the cascade reaction to remove ROS in insects (reviewed in Blagojević and Grubor-Lajšić 2000). Our findings confirm for the first time the importance of SOD and CAT in the antioxidant protection in the gut tissues of B. dubia exposed to long-term MF stress. It is interesting that the increase in SOD activity was significantly greater in the gut tissue of nymphs treated with ELF MF than in the SMF group. This might indicate stronger stressogenic prooxidative effects of ELF MF, that is, the production of more free radicals. Similarly, enhanced activity of these enzymes was also observed in individuals of Baculum extradentatum exposed to SMF (50 mT) or ELF MF (50 Hz, 6 mT; Todorović et al. 2012).