Some families of group divisible designs

Generalizing methods of constructions of Hadamard group divisible designs due to Bush (1979), some new families of semi-regular or regular group divisible designs are produced. Furthermore, new nonisomorphic solutions for some known group divisible designs are given, together with useful group divisible designs not listed in Clatworthy (1973).     

An island biogeographical approach to the analysis of butterfly community patterns in newly designed parks

We analyzed the butterfly communities in the newly designed city parks (area C), “newly opened habitat islands”, of Tsukuba City, central Japan. The area constituted a natural ecological experiment on the mainland for clarifying the pattern and process of faunal immigration. We compared butterfly communities in area C with those in two other areas in the light of the theory of island biogeography and the concept of generalist/specialist. Our results showed the following: (1) Fewer species were found in area C than in other areas, due largely to the absence of many specialist types, restricted and habitat specialists, and/or low density species in the area. Generalist types, widespread and habitat generalists, and/or high density species predominated in area C. (2) The difference in the species numbers among the three sections within area C could be explained by the habitat structure in and around the respective sections. (3) The densities of many species were low in area C, probably due to its man-modified habitat structure. In particular, several species occurred at extremely low densities in area C, but at high densities in other areas. (4) The internal structure of the habitat island butterfly community in area C was almost perfectly consistent with that of “quasi-equilibrium” communities that appear during the colonization of an island. Our results demonstrate that the synergetic application of the generalist/specialist concept and the island biogeography theory is effective for the understanding of the patterns and structures of habitat island communities.     

Simulated removal trapping considered in connection with actual census data in small mammals

Summary A record of simulated removal trapping of 50 samples drawn fromN=50 under a design has been considered as to how it does contribute to practical censuses of small mammals. It follows that, for ordinary-density populations so far experienced, the removal census based on the theory may frequently lead to quite wrong estimates from single-plot data by the simplest method, and that the maximum likelihood method is doubtless better, but even this method may produce right estimates in about half of the cases, their standard error being of limited availability. Therefore pooling of data from many plots are desirous for such populations.     

Adaptation and validation of the Japanese version of the Gambling Urge Scale

In Japan, accurately assessing and targeting gambling urges is important for the treatment of gambling disorder because people are constantly exposed to external triggers that elicit gambling urges. However, a valid measure that assesses gambling urges has not been adequately established. Therefore, the purpose of this study was to examine the psychometric properties of the Japanese version of the Gambling Urge Scale (GUS-J), which is a well-known valid 6-item instrument in English-speaking countries. Two hundred and thirty-nine participants completed questionnaires, 86 of which met the criteria for a probable gambling disorder. As with the original GUS, the GUS-J was demonstrated to be a one-factor model that accounted for 63.82% of the total item variance, with all items demonstrating loadings of .40 or higher. With regard to reliability, the GUS-J showed good internal consistency (α = .88). Furthermore, validity based on evidence of relationships with other variables, especially convergent and concurrent validity of the GUS-J, were supported by several analyses that examined hypotheses based on previous findings. In conclusion, this study showed that the GUS-J has good psychometric properties as an assessment tool for gambling urges in Japanese people and it will be useful for future clinical practice and research.     

Variation in offspring size within a population of the web-building spiderAgelena limbata

Within a population of the web-building spiderAgelena limbata, the weight of the first instar nymphs ranged from 1.187 to 6.559 mg. Both intraclutch and interclutch variation were recorded. The mean weights were different among clutches and the coefficients of variation within a clutch ranged from 3.3 to 29.2%. Variation in the nymphal weight was certainly derived from variation in the egg weight because there was a high correlation between the two weights. Factors affecting interclutch variation in nymphal weight were examined by multiple regression analysis. Nymphal weight was positively correlated with the body size and food conditions of female parents, and negatively correlated with the clutch size. Among these three factors, the food conditions of female parents had the largest apparent effect on the interclutch variation. The results suggest that females with larger body size and more food produce larger offspring, and that there is a trade-off between offspring size and clutch size. Heavier nymphs had larger body size (carapace width) and may have larger energy reserves. Heavier nymphs survived experimental starvation for a significantly longer period.     

Evolution and physiological consequences of de-alation in crickets

Wing shedding or de-alation is a common phenomenon among crickets. Its significance and effects on other traits were examined based on the results from experiments using artifical or natural de-alation. Artificial de-alation at adult emergence induces rapid egg production and flight muscle histolysis in several species examined. However, natural de-alation does not always shorten the pre-ovipositional period because it does not occur immediately after adult emergence and because oviposition starts before de-alation. In some cases, naturally de-alated females produce more eggs than to intact females during early adult life, but peak ovipositing activity occurs before de-alation. Therefore, retention of the hindwings does not suppress high ovipositing activity in such cases. It appears that de-alation is a result rather than a causal factor in ending migration. Ovarian development and flight muscle histolysis, which can be stimulated by de-alation, are controlled by the jevenile hormone, but the mechanism inducing de-alation remains unknown. The possible factors leading to the evolution of de-alation are discussed.     

How is life history variation generated from the genetic resource allocation?

A simple quantitative genetic model is proposed to explain the observed genetic correlation structure of a bruchid beetleCallosobruchus chinensis in terms of two underlying variables: the resource acquisition and the resource allocation. Heritabilities and genetic correlations among age-specific, fecundities are regarded as consequences of genetic variations of the two variables. Genetic correlations are predominantly positive in both predictions and observations. Nonetheless, comparison between observed and predicted values in heritabilities, genetic correlations, and genetic principal components suggested significant genetic variances both of the resource allocation and the resource acquisition. The prediction of the model is discussed in relation, to experimental tests of trade-off in life history evolution.     

An experimental analysis of the relationship between species combination and community persistence

Among many stabilizing factors for community dynamics, nonlinear biological interactions such as type III functional response have been widely considered to be major characteristics. However, most experimental biological communities employed so far had quite simple structures. Therefore, the possibility that the conclusions in earlier studies were dependent on simple community structure is undeniable. In this study, using a multiple-species experimental community, we evaluated which combinations of component species and what kinds of interspecific interactions allow communities to persist and how these contribute to community persistence. We conducted experimental communities using two species of beans, the adzuki bean (Vigna angularis) and the red kidney bean (Phaseolus vulgaris), two species of bean weevils, the Mexican bean weevil (Zabrotes subfasciatus, Coleoptera: Bruchidae) and adzuki bean weevil (Callosobruchus chinensis, Coleoptera: Bruchidae), and two species of parasitic wasp, Heterospilus prosopidis (Hymenoptera: Braconidae) and Anisopteromalus calandrae (Hymenoptera: Pteromalidae). The outcome of multiple-generation experimental communities was explained by the characteristics of component species obtained from short-term experiments. In our two resources–two herbivores–one carnivore system, the strong density-dependent attack ability of one parasitic wasp species (A. calandrae) led to the extinction of C. chinensis. On the other hand, the weak density-dependent attack ability of the other parasitic wasp species (H. prosopidis) led to system persistence. Our overall results show that, in a multiple-species community, the combination of species itself is more important for community persistence than are the characteristics of the particular species. Received: September 29, 1997 / Accepted: October 5, 1998     

Systems Development and Difficulties in Implementing Procedures for Elder Abuse Prevention Among Private Community General Support Centers in Japan

The present study examines differences in systems development and difficulties in implementing procedures for elder abuse prevention in 1,119 private and 606 public community general support centers under the public long-term care insurance program in Japan. The private community general support centers showed more difficulty implementing procedures than the public community general support centers. Controlling for the type of municipality, progress in systems development did not differ between the private and public community general support centers. Further research should examine how the characteristics of municipal governments are related to systems development in community general support centers.