COMPARISON OF VERTICAL AERIAL PHOTOGRAPHIC AND GROUND CENSUSES OF STELLER SEA LIONS AT AÑO NUEVO ISLAND, JULY 1990-1993

Counts of Steller sea lion ( Eumetopias jubatus ) pups and non-pups (adults and juveniles) from aerial photographs of rookeries at Año Nuevo Island between 1990 and 1993 were significantly higher than those made on the ground. Based on regression of natural logs of photographic counts versus year, the number of pups declined at a rate of −0.099yr while non-pup numbers declined at −0.315/yr. Examination of ground count data for the same period revealed a significant decline in non-pups (−0.139/yr), but no trend was detected in the ground counts of pups. The regression coefficients from photographic and ground counts of non-pups did not differ significantly. Power analyses using the program TRENDS indicated that detectable rates of change in abundance from four annual surveys were much lower for counts of pups than counts of non-pups where sampling precision was based on fits to linear models.     

Aim‐then‐shoot anemotaxis involved in the hopping approach of potato tuberworm moth Phthorimaea operculella toward a sex pheromone source

Male moths locate conspecific females by pheromone‐induced upwind flight maintained by detecting a visual flow, termed optomotor anemotaxis. Their behavioural pattern is characterized by an upwind surge in response to a pheromone stimulus and crosswind casting after odour loss, which is considered to be reset and restarted on receipt of another pheromone pulse. However, pheromone‐stimulated males of the potato tuberworm moth Phthorimaea operculella exhibit a series of short and straight intermittent flights, or hops, when moving upwind. It is unclear whether they navigate by employing the same behavioural pattern and wind detection mechanism as that used by flying moths. To analyze odour‐modulated anemotaxis in male potato tuberworm moths, a flat wind tunnel is constructed to give regular odour stimuli to an insect regardless of its location. Moths are subjected to pheromone pulses of different frequencies to test whether they show a behavioural pattern that is reset and restarted by a pheromone pulse. Moths on the ground are also subjected to crosswind shear to examine their detection of wind direction. Path analyses reveal that males surge upwind when they receive a pheromone pulse and exhibit casting by successive hops when they lose odour. This behavioural pattern appears to be similar to that of flying moths. When the direction of the airflow is switched orthogonally, males adjust their course angle accordingly when they are on the ground. It is suggested that, instead of optomotor anemotaxis, this ‘aim‐then‐shoot’ system aids the detection of wind direction, possibly by mechanosensory means.     

Purification and Characterization of Isocitrate Lyase from Ethanol-grown Euglena gracilis

Isocitrate lyase was purified to homogeneity from ethanol-grown Euglena gracilis. The specific activity was 0.26 μmol/min/mg protein. The molecular mass of the enzyme was calculated to be 380 kDa by gel filtration on a Superose 6 column. The subunit molecular mass of the enzyme was 116 kDa as determined by SDS-polyacrylamide gel electrophoresis. These results showed that the native form of this enzyme was a trimer composed of three identical subunits. The pH optimum for cleavage and condensation reactions was 6.5 and 7.0, respectively. The K_m values for isocitrate, glyoxylate and succinate were 3.8, 1.3 and 7.7 mM, respectively. Isocitrate lyase absolutely required Mg for enzymatic activity. This is the first report of the purification of isocitrate lyase to homogeneity from Euglena gracilis.     

A new method in growth-electrophysiology: Pressurized intra-organ perfusion

Abstract A new experimental system was devised for the simultaneous measurement of elongation rate and the activity of the spatially separate electrogenic ion pumps of a hypocotyl segment excised from a seedling of Vigna unguiculata L. Walp. under enforced intra-organ perfusion by artificial solutions. The pathway of the perfusion medium was apoplastic space, including xylem vessels as main routes. The elongation rate of the segment was highly dependent on the perfusion pressure applied. It was possible to increase the growth rate under pressurized perfusion by 10-30 times as much as that without perfusion. Elongation rate was also dependent on respiration under perfusion, being retarded reversibly by anoxia a few minutes after the activities of the electrogenic ion pumps were stopped. Perfusion pressure had a little influence on the membrane potential (V_px) below a breakdown level (c. 130 kPa). Perfusion of mannitol or sorbitol solution of appropriate concentration reduced the elongation rate reversibly.     

Reproductivity of early males of the temperate paper wasp Polistes rothneyi iwatai

In Polistes paper wasps, haploid early males can mate with early emerging females and leave viable offspring. In contrast, diploid early males are eventually sterile because they contribute triploid offspring via diploid sperm. Clarifying the ploidy of early males is important for determining whether early male production is a reproductive strategy for the species. We examined the mating behavior and the ploidy of early males in the Japanese paper wasp, Polistes rothneyi iwatai van der Vecht. Thirteen early males from four colonies were all diploid. Two of the nine early males (22.2%) attempted to mate with females, but only one individual (11.1%) was successful (the female's spermatheca contained spermatozoa). These results suggest that although most early males of P. rothneyi iwatai do not produce offspring, their mating may be linked to the occasional production of triploid females.     

Effect of metanotal secretion ingestion on oviposition in a tree cricket, Truljalia hibinonis (Orthoptera: Gryllidae)

The female Truljalia hibinonis ingests metanotal secretions of the male during copulation. The effect of ingestion on oviposition behavior was compared between three female groups: females that copulated once with an intact male (a male that had not been manipulated; M group); females that copulated once with a male from which most of the metanotal secretion had been removed (NO group); and females that copulated once with an intact male followed by being artificially supplied with metanotal secretion three times (MS group). There were no obvious differences in female fecundity across the three groups. However, within the MS group, intake of an optimal amount of metanotal secretion increased the number of eggs laid. This effect appeared quickly after ingestion and was most effective on the first bout (eggs laid during the first few days after copulation) after ingestion of the metanotal secretion. In contrast, the number of eggs laid had a negative correlation with the amount of metanotal secretion ingested when the amount exceeded the optimal in this experimental arrangement.     

传承与转译，日本景观教育的追求——“传统造园的传承”与“接轨世界的设计能力”

日本的庭院文化经过长时间发展,已形成独特的景观空间语言。这些空间语言由庭园、公园、广场等城市外部空间传承,而我们需要静下心来理解这掺杂着思想和时代背景的特殊语言体系。日本的景观教育,通过以下课程设置,将空间的语言体系传授给学生们：1）通过测量掌握设计语言的基础,学生通过尺子测量传统空间和现代空间,获得相应的空间感。近年来也通过3D测量技术,掌握更加精细的尺度感。2）材料使日本特有的设计语言更加丰富多变,通过实际接触石材和植物,体验管理和施工,加深学生对材料的理解。3）在学习和实践的基础上,进行与国际和社会接轨的设计。面对当下多领域融合的社会课题,组织建筑、规划、土木等学科的学生们进行展览和交流,并开展相应的实践训练     

Comparative analysis of volatile components from labial glands of male Japanese bumblebees (Bombus spp.)

The volatile components from the labial glands of males of six Japanese bumblebee species were analyzed and compared. Clear species‐specificity was found. Ethyl dodecanoate was identified as the major component from the glands of Bombus (Bombus) hypocrita hypocrita and Bombus (Bombus) hypocrita sapporoensis while dihydrofarnesal and dihydrofarnesol were the major components from Bombus (Bombus) ignitus. Citronellol and trans,trans‐farnesol were found from Bombus (Pyrobombus) ardens ardens and Bombus (Diversobombus) diversus diversus, respectively. trans,trans‐Farnesol was also found from Bombus (Diversobombus) diversus tersatus in Hokkaido. Such differences strongly suggest that these chemicals play an important role in reproductive isolation between sympatric species of Japanese bumblebees.