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Entamoeba histolytica is one of the least understood protists in terms of taxa, clone, and kin discrimination/recognition ability. However, the capacity to tell apart same or self (clone/kin) from different or nonself (nonclone/nonkin) has long been demonstrated in pathogenic eukaryotes like Trypanosoma and Plasmodium, free‐living social amebas (Dictyostelium, Polysphondylium), budding yeast (Saccharomyces), and in numerous bacteria and archaea (prokaryotes). Kin discrimination/recognition is explained under inclusive fitness theory; that is, the reproductive advantage that genetically closely related organisms (kin) can gain by cooperating preferably with one another (rather than with distantly related or unrelated individuals), minimizing antagonism and competition with kin, and excluding genetic strangers (or cheaters = noncooperators that benefit from others' investments in altruistic cooperation). In this review, we rely on the outcomes of in vitro pairwise discrimination/recognition encounters between seven Entamoeba lineages to discuss the biological significance of taxa, clone, and kin discrimination/recognition in a range of generalist and specialist species (close or distantly related phylogenetically). We then focus our discussion on the importance of these laboratory observations for E. histolytica's life cycle, host infestation, and implications of these features of the amebas' natural history for human health (including mitigation of amebiasis). [ABSTRACT FROM AUTHOR]

Horizontal gene transfer (HGT) and common descent interact in space and time. Because events of HGT co-occur with phylogenetic evolution, it is difficult to depict evolutionary patterns graphically. Tree-like representations of life's diversification are useful, but they ignore the significance of HGT in evolutionary history, particularly of unicellular organisms, ancestors of multicellular life. Here we integrate the reticulated-tree model, ring of life, symbiogenesis whole-organism model, and eliminative pattern pluralism to represent evolution. Using Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2), a bifunctional enzyme in the glycolytic pathway of amoeba, we illustrate how EhADH2 could be the product of both horizontally acquired features from ancestral prokaryotes (i.e. aldehyde dehydrogenase [ALDH] and alcohol dehydrogenase [ADH]), and subsequent functional integration of these enzymes into EhADH2, which is now inherited by amoeba via common descent. Natural selection has driven the evolution of EhADH2 active sites, which require specific amino acids (cysteine 252 in the ALDH domain; histidine 754 in the ADH domain), iron- and NAD+ as cofactors, and the substrates acetyl-CoA for ALDH and acetaldehyde for ADH. Alternative views invoking “common design” (i.e. the non-naturalistic emergence of major taxa independent from ancestry) to explain the interaction between horizontal and vertical evolution are unfounded. [ABSTRACT FROM AUTHOR]

In Part I of this article (Paz-y-Miño C. & Espinosa, 2004) we discussed how some music principles can be applied to various aspects of aikido training, including stretches, single-person routines to develop balance and mind-body coordination, rolling and falling. Here we expand on this idea and discuss how these principles can also be applied to partnered techniques of neutralization, projections-throws, weapons, breathing exercises, and meditation. Our goal is to provide students and instructors with novel tools for learning and teaching aiki arts. [ABSTRACT FROM AUTHOR]

In this two-part article, we discuss how some music principles can be applied to various aspects of aikido training: Part I - including stretches, single- person routines to develop balance and mind-body coordination, rolling and falling; Part 11 - partnered techniques of neutralization, projections/ throws, weapons, breathing exercises, and meditation. We use simple music notation and a percussion instrument to explain aikido's natural rhythm. Our goal is to provide students and instructors with novel tools for learning and teaching aiki arts. Not only aikido but every martial art-or physical discipline- has its own pace, which the student should discover. Learning to move according to this rhythm will allow the martial artist to adequately match an attack, blend and flow with it, and finally neutralize it. [ABSTRACT FROM AUTHOR]

Aikido, a Japanese martial discipline, has been labeled "the art of the dynamic sphere." Its techniques appear to move the body in a "circular" manner resulting in immobilization or projection of a partner. Here we argue that more than spherical motions, aikido techniques describe swirl-like movements, or spirals, similar to the chamber arrangement of a Nautilus shell. When spiral movements are used in aikido, its techniques become very efficient and gentle. We discuss how the principles of the equiangular spiral can be applied to most aspects of aikido training, including stances and sitting postures, bows, stretching exercises, warm-ups, single-person routines to develop balance and mind/body coordination, rolling and falling, partnered techniques of neutralization, projections/throws, and weapons. Not only aikido but also numerous martial arts include equiangular motions in their fighting routines, although martial artists may not be aware of it. [ABSTRACT FROM AUTHOR]