Tomakomai Komazawa University

The Ulnar Collateral Ligament (UCL) injury is frequently seen in baseball players, it generally causes baseball players to rest for one season or more. In the global context, due to the continuous increase in the number of young people participating in baseball, the proportion of UCL injuries among teenage baseball players has also been increasing. Currently, insufficient attention is paid to UCL injuries in teenage baseball players, which affects their sports experience and career longevity. This study aims to raise awareness among more people about the differences between UCL injuries in teenagers and those in adults, including the risk and severity of the injuries. The purpose is to help adolescent baseball players return to the playing field through appropriate treatment methods and rehabilitation training, to restore their physical functions and the same playing level as before the injury. This not only affects their sports experience but also their sports lifespan. The purpose of this study was to enable more people to understand the severity, risk of injury, rehabilitation training and methods for adolescent UCL injury. Through this study, more people can learn about and pay attention to the UCL injury diseases of adolescent baseball players.

Abstract Many animals reap significant benefits from migration, yet they face high mortality rates during the journey. As the mortality during migration typically operates more strongly on smaller migratory individuals (migrants), small pre‐migrants among migratory animals tend to grow better than larger ones prior to migration, enabling them to attain a larger body size. A common growth strategy for smaller pre‐migrants is extending their growth period compared to larger ones. Although this tactic has been documented in previous studies, the landscape‐scale habitat utilization that allowed smaller pre‐migrants to stay longer prior to migration remains largely unknown. Here, we focused on two distinct riverscape habitats (nursery habitat and transitional habitat) and investigated where smaller pre‐migrants of masu salmon (Oncorhynchus masou) stayed longer than larger ones prior to oceanic migration. We conducted an individual monitoring survey on their habitat utilization in two distinct migration years. We found that in 1 year, smaller pre‐migrants stayed longer in the transitional habitat compared to the nursery habitat, whereas in the other year, they stayed longer in the nursery habitat compared to the transitional habitat. This suggests that smaller pre‐migrants can adjust their duration of stay in each riverscape habitat. Our findings highlight the importance of conserving the entire pre‐migration habitat to enhance the resilience of migratory animals in the face of rapid environmental changes.

Alien species can influence populations of native species through individual-level effects such as predation, competition, and poisoning. For alien species that possess strong defensive chemicals, poisoning is one of the most powerful mechanisms of individual-level effects on native biota. Although toxic alien species could potentially negatively affect survival (lethal effects) or life history traits (sub-lethal effects) of native predators via poisoning, previous studies have mainly focused on acute lethal effects. Thus, delayed effects on predator life history traits have been largely overlooked. To fill this knowledge gap, we conducted laboratory and field experiments to investigate whether toxic alien prey (hatchlings and tadpoles of an invasive toad, Bufo formosus) affect the survival and/or growth and development of a native predatory salamander (larvae of Hynobius retardatus) on Hokkaido, Japan. The laboratory experiment revealed that consumption of a single toad hatchling exerted non-lethal effects on salamanders, but suppressed both salamander growth and development of an ecological phenotype (broad-gape) normally induced by environmental conditions. Furthermore, the field experiment in a natural pond showed that the presence of toad hatchlings and tadpoles resulted in reduced salamander growth (smaller body size) and lower survival of salamanders in the later larval period. The results of the laboratory and field experiments are complementary evidence of the life history impacts of the toxic alien toad on native salamanders. Thus, the poisoning effects of toxic alien species can affect the life history of native predators even if they do not exert acute lethality.

Abstract Understanding the habitat requirements of fishes throughout their life cycle is essential for effective conservation. Despite the growing need to conserve anguillid eels, the current understanding of the ontogenetic habitat shifts during their riverine stages remains limited, particularly for the Japanese eel Anguilla japonica and the Indo‐Pacific eel Anguilla marmorata. Here, changes in habitat use during the riverine stages of these two eel species were investigated in the southern Japan rivers, where they coexist. Eels were classified into total length (TL) classes at 10 cm intervals, and generalized additive models were constructed using these classes as an ordinal, quasi‐continuous explanatory variable. The models showed that the habitat use of the two species changed with growth; both species shifted to deeper and more lentic habitats as they grew larger. Small‐ and mid‐sized (<25 and 25–55 cm in TL, respectively) A. japonica used more lentic habitats with smaller substrates, ranging from sand/silt to cobbles, than small‐ and mid‐sized A. marmorata, which mainly used lotic habitats with cobble and boulder substrates. However, compared with small‐sized conspecifics, mid‐sized A. japonica mainly used habitats with larger substrates, such as pebbles and cobbles, suggesting that the interspecific overlap in habitat use is relatively high for mid‐sized individuals of both species. Large A. marmorata ( 85 cm) mainly used habitats with smaller substrates as they grew larger. The results suggest that using a fine body size classification and including these classes as a quasi‐continuous explanatory variable in habitat models capture gradual changes in habitat use, improving habitat use evaluation of anguillid eels. Preserving the environmental heterogeneity of river habitats in terms of water depth, current velocity and substrate size would facilitate habitat segregation of both conspecifics and allospecifics in the same rivers, thereby promoting the conservation of anguillid eels.

Most carnivores undergo diet shift from smaller to larger prey items during ontogeny. The trophic relationship between a growing carnivore and larger prey is representative of a size-structured predator-prey interaction. The strength of this interaction is, in part, determined by the recruitment of individuals from smaller predatory size classes into larger predatory size classes. Therefore, it is interesting to investigate how larger prey alter the recruitment of smaller predator size classes into larger predator size classes, since this can affect their own future predation risk. Past empirical studies have exclusively documented that large prey reduce predator recruitment by decreasing growth and/or survival of the smaller predators. In this study, we provide empirical evidence of the contrasting pattern: large prey enhance the recruitment of smaller predators into larger predators even though they increase cannibalism mortality of the smaller predators. We have done this here by studying the trophic interaction between predatory salamander larvae Hynobius retardatus and the frog tadpoles Rana pirica that represent their large prey. In a field experiment in which salamander hatchlings were exposed to the presence or absence of large frog tadpoles, we found that more giant salamanders emerged in the presence of frog tadpoles than in their absence. Reassignment of frog tadpoles (to both treatments) in the subsequent experimental period showed that the enhanced emergence of giant salamanders in the presence of frog tadpoles leads to the intensification of salamander predation on the frog tadpoles. In an additional laboratory experiment, to better understand the underlying mechanisms, we manipulated both the presence of frog tadpoles and the occurrence of cannibalism between salamander hatchlings. This experiment revealed that frog tadpoles intensify the cannibalism of salamander larvae during their hatchling stage, thus allowing more salamander larvae to become large-sized predators. Our results suggest that frog tadpoles can inadvertently intensify their own future predation risk by intensifying cannibalistic interactions among predatory salamander hatchlings, thereby enhancing the degree of predator recruitment to a larger size class. Hence, large prey can enhance the recruitment of individuals from small predator size classes into larger predator size classes.

Abstract To manage biological invasions effectively, the impacts of alien species on the demography and traits of native species must be known, but determining those impacts can be challenging. We used a comparative approach to gain insight into the impacts that an alien toad (Bufo japonicus formosus) might have on native Japanese predatory amphibians. We compared the susceptibility of native predator species to alien toad toxins in the alien‐invaded range and the susceptibility of closely related native predator species to the toxins in the alien toad's native range to investigate the impacts of an alien on a native species. Bufo japonicus formosus is native to Honshu, but was recently introduced to Hokkaido and Sado. In laboratory experiments, we compared individual mortality of predators exposed to a toad hatchling between novel predators on the toad‐invaded islands and ecologically similar congeneric or conspecific species on Honshu, where the toad is native. We also compared (1) the percentage of individuals that consumed a toad hatchling and (2) toxin resistance (i.e. survival and growth of individuals after toad consumption) between these two groups of predators, as mechanistic components behind the susceptibility of the predators to the toxic prey. The mortality of Rana pirica from all populations after consumption of a toad hatchling was almost 100%, and that of Hynobius retardatus ranged from 14 to 90%, depending on the population. In contrast, the mortality of Rana ornativentris and Hynobius nigrescens was near 0% regardless of population. These differences between congeneric predators were mostly due to differences in their toxin resistance. These results suggest that the alien toad is a potential threat to the novel amphibian predators on Hokkaido, although they also imply that the novel predators on Hokkaido have the potential to develop toxin resistance through adaptive evolution. However, this counteradaptation may have a higher chance of evolving in H. retardatus than in R. pirica because of differences in their genetic backgrounds.

Sarah B. Franklin, Biological Relatives: IVF, Stem Cells, and the Future of Kinship (Durham, NC, and London: Duke University Press, 2013), pp. 376, $26.95, paperback, ISBN: 978-0-8223-5499-4. - Volume 58 Issue 3

Since the discovery of the “framing effect” by Kahneman and Tversky, the sensitivity of the “framing effect” – its appearance and in some cases its disappearance – has long been an object of study. However there is little agreement as to the reasons for this sensitivity. The “ambiguity-ambivalence hypothesis” (Wang, 2008) aims to systematically explain the sensitivity of this effect by paying particular attention to people’s cue priority: it states that the framing effect occurs when verbal framing is used to compensate for the absence of higher prioritized decision cues. The main purpose of our study is to examine and develop this hypothesis by examining cue priority given differences in people’s “group experience.” The main result is that the framing effect is absent when the choice problem is presented in a group context that reflects the actual size of the group that the participant has had experience with. Thus, in order to understand the choices that people make in life and death decisions, it is important to incorporate the decision maker’s group experience explicitly into the ambiguity-ambivalence hypothesis.

Developed and reported are compact yet efficient correlating basis sets for the (57)La and (89)Ac atoms, missing in the literature. Good performance of these correlating sets is exemplified in molecular applications to diatomic oxides and fluorides.

For 14 actinide atoms from (90)Th to (103)Lr, contracted Gaussian-type function sets are developed for the description of correlations of the 5f, 6d, and 7s electrons. Basis sets for the 6d orbitals are also prepared, since the orbitals are important in molecular environments despite their vacancy in the ground state of some actinides. A segmented contraction scheme is employed for the compactness and efficiency. Contraction coefficients and exponents are so determined as to minimize the deviation from accurate natural orbitals of the lowest term arising from the 5f(n-1)6d(1)7s(2) configuration. The spin-free relativistic effects are considered through the third-order Douglas-Kroll approximation. To test the present correlating sets, all-electron calculations are performed on the ground state of (90)ThO molecule. The calculated spectroscopic constants are in excellent agreement with experimental values.