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To maximize their growth, grazers should shift their behavior to balance the cues from predators and periphyton in the field. As a stream grazer seeks periphyton that are heterogeneously distributed, a shift in its behavior on the basis of the intensity of microalgal cues would be beneficial as it would allow the grazer to feed on more periphyton. Using a caddisfly grazer, Glossosoma larvae, we conducted a laboratory channel experiment with upstream experimental plates having four levels of periphyton abundance (control, low, medium, and high), and we recorded the movement behavior of the larvae. As periphyton abundance increased, both larval crawling time and the total crawling distance to the periphyton patch significantly decreased and the directness of the crawling path significantly increased. That is, larvae crawled in various directions as they approached a relatively low-abundance periphyton patch, whereas they crawled straight to the high-abundance periphyton patch in a short time. The behavior change was likely due to the detection of some microalgal cue, which should intensify with an increase in upstream periphyton abundance. Chemical and visual cues play important roles in the interactions between organisms (Lima 1998; Burks and Lodge 2002). Many studies have established that these cues are involved in predator–prey interactions. By recognizing predator cues, prey can change their life histories, morphologies, activity, and habitat use to avoid predation (McIntosh et al. 1999; Miyasaka et al. 2003; Turner and Montgomery 2003). Likewise, predators can be attracted to food patches by recognizing cues from animal prey

静岡産業大学情報学部では、授業で利用する資料としてデジタルコンテンツを学生に配付したり、課題をデジタルデータとして提出させたりしている教員がいる。しかし、その配付や提出の方法は各教員により異なるため、統一した教材サーバを確立し効率の良い授業展開が行われることが望まれている。当初は商用の外部サーバシステムの利用を考えてみたが、商用であるため有料であり、利用する教員のみならず、学生も課題提出などを行うためには有料アカウント登録をする必要があったり、本学部のコンピュータ演習室に設置されているMacintosh(3室120台)上では利用することができなかったりしたために断念することになった。一方、多くの大学が有料の教育支援システムを導入して、デジタル教材の提供、テスト問題の出題、提出、採点、記録や出席管理等を総合的に行っており私立大学情報教育協会の調査によると、平成20年度には7割の私立大学がこのシステムの導入をする計画を持っている。しかし、本学においては予算的な面などからも高額な有料ソフトを導入することは難しい。そこで、国内の大学でも利用され、事例報告等も多くされているMoodle(ムードル:Modular Object-Oriented Dynamic Learning Environment)を利用することを考えた。Moodleは海外で開発され、オープンソースであるフリーソフトウェアのLMS (Learning Management System)であり、このソフトを本学部の複雑なカリキュラム体系に適合するようにカスタマイズすることで、多くの教員がストレスを感じること無く利用できるシステムを構築することができると思われる。教員がコンピュータに関して初心者であっても、比較的簡単に学生に対して教材の提供を行うことができるシステムを構築できるか検証することにした。

Summary Several herbivorous insects are known to benefit from feeding in groups; however, little is known about (1) the resource conditions under which herbivorous insects perform group feeding and (2) the optimum population size to get any benefits by group feeding, for example, in terms of growth performance. To test the hypotheses that the benefits from group feeding change with resource level and population size, we performed field investigations and an enclosure experiment using the grazer caddisfly larva Micrasema quadriloba . The field investigations revealed aggregated distributions of larvae (indicator of aggregation, I δ =4.1±1.55, aggregated density: 12.7±5.3 individuals per 3.1×3.1 cm 2 (mean±1 SD)) when periphyton was abundant on stream cobbles and random distributions ( I δ =1.0±0.11) when periphyton was scarce. In the enclosure experiment, the relative growth rate (RGR) of the larvae at each population size showed different tendencies at high and low periphyton abundance levels; RGR with abundant periphyton had a convex curve with a peak at intermediate population size, whereas RGR with scarce periphyton decreased linearly with increasing population size. The benefits from group feeding thus changed with resource level; larvae obtained high growth performance by group feeding behavior only when the resource was sufficiently abundant. The present study revealed not only that the optimum group size of larvae increased their growth performance, but also that this optimum group size occurred frequently in the field. We also discuss the mechanisms and benefits of group feeding by case-bearing caddisfly grazers.

The present study investigated whether room temperature (T(a)) cycles around dusk and dawn could influence the circadian rhythm of rectal temperature (T(core)), urinary 6-hydroxymelatonin sulfate during nocturnal sleep, and subjective assessments of sleep in humans. Six female and two male students served as participants. Two different T(a) conditions, cyclic and constant, were established. Two kinds of room temperature were provided to subjects: cyclic T(a) (gradual decrease from 27 degrees C to 24 degrees C between 1800 and 2200 h and gradual increase from 24 degrees C to 27 degrees C between 0300 and 0700 h) and constant T(a) (27 degrees C over 24 h). At cyclic T(a), the circadian nadir of T(core) rhythm was significantly advanced, while T(core) was significantly lower from 2300 to 0200 h and significantly higher from 0600 to 1000 h. The nocturnal concentration of 6-hydroxymelatonin sulfate in the urine during sleep was significantly higher during cyclic T(a). Waking sensation just after rising was significantly better with cyclic T(a). (Skin temperatures in the extremities-T(a)) were significantly higher with cyclic T(a) especially during the evening and night. Our results suggest that gradual change of room temperature in the evening and early morning is important in terms of sleep promotion and fresh awakening. It seems probable that mankind has been evolved to have deeper sleep under the influence of cyclic T(a) around dusk and dawn.

Effects of 17beta-estradiol and p-nonylphenol were examined in the immune and endocrine organs of Japanese quail embryos. The test compounds were injected into the yolk of embryonated eggs. Injection of estrogen resulted in (1) disappearance of lymphoid cells and flattened development of plicae in the bursa of Fabricius, (2) decreased area of thyroid follicles and height of simple cuboidal epithelial cells in the thyroid, (3) increased follicular appearance of the thymus, and (4) development of an ovotestis in male embryos. Injection of nonylphenol did not induce flattened plicae in the bursa of Fabricius or development of an ovotestis in male embryos, but it increased the disappearance of lymphoid cells from the lymphoid follicles in the bursa, decreased the height of simple cuboidal epithelial cells surrounding the thyroid follicle, and increased the follicle-like structure in the thymus in male embryos. These results suggest that nonylphenol has estrogenic effects, but these are low compared to those of estrogen itself.

We investigated the photoperiodic response of serotonin- and galanin (GA)- immunoreactive (ir) cells in the paraventricular organ (PVO) and infundibular nucleus (IF) of the Japanese quail and the interaction of these cells with gonadotropin-releasing hormone (GnRH)-ir neurons in the hypothalamus. Serotonin-ir cells were located in series from the PVO to the IF, and were connected with each other. The number of serotonin-ir cells differed significantly between light and dark phases on the short days (SD), but did not differ between light and dark phases on long days (LD). GA-ir cells were also found in the PVO and IF. The number of GA-ir cells under SD conditions was significantly greater than under LD conditions but did not change diurnally. Both serotonin-ir and GA-ir fibers ran along the GnRH-ir cells in the nucleus commissurae pallii. Serotonin-ir and GA-ir fibers were connected with the GnRH-ir fibers in the external layer of the median eminence (ME). We confirmed that GA-ir fibers were closely associated with serotonin-ir neurons in the PVO and IF. GA-ir neurons have at least 2 routes of regulating GnRH neurons directly, and indirectly via the serotonin-ir cells in the PVO and IF.

Daily variations in plasma melatonin levels in the rainbow trout Oncorhynchus mykiss were studied under various light and temperature conditions. Plasma melatonin levels were higher at mid-dark than those at mid-light under light-dark (LD) cycles. An acute exposure to darkness (2 hr) during the light phase significantly elevated the plasma melatonin to the level that is comparable with those at mid-dark, while an acute exposure to a light pulse (2 hr) during the dark phase significantly suppressed melatonin to the level that is comparable with those at mid-light. Plasma melatonin kept constantly high and low levels under constant darkness and constant light, respectively. No circadian rhythm was seen under both conditions. When the fish were subjected to simulative seasonal conditions (simulative (S)-spring: under LD 13.1:10.9 at 13 degrees C; S-summer: under LD 14.3:9.7 at 16.5 degrees C; S-autumn: under LD 11.3:12.7 at 13 degrees C; S-winter: under LD 10.1:13.9 at 9 degrees C), melatonin levels during the dark phase were significantly higher than those during the light phase irrespective of simulative seasons. The peak melatonin level in each simulative season significantly correlated with temperature but not with the length of the dark phase employed. In addition, the peak melatonin level in S-autumn was significantly higher than those in S-spring although water temperature was the same under these conditions. These results indicate that the melatonin rhythm in the trout plasma is not regulated by an endogenous circadian clock but by combination of photoperiod and water temperature.

The relation between emergence date and the factors concerned in reproduction were studied in the stoneflies Isoperla aizuana (Perlodidae) and Sweltsa sp. (Chloroperlidae) in the laboratory. Individuals emerging earlier had larger adult size and greater adult longevity. Fecundity was also related to emergence date, adult size, and adult longevity. Furthermore, individuals emerging earlier had more days until first effective mating and tended to mate more effectively than later-emerging individuals. The maturity of the reproductive tissue may differ with emergence date. While most of the later-emerging individuals had a lower rate of effective mating, longer-lived and larger size adults mated more effectively in females of Sweltsa sp. The differences in mating character might affect the effectiveness of mating.

1年次で情報リテラシ、2年次でプログラミングの基礎教育を受けた学生が、その後の3学次の情報処理関連科目でどのような成績をとるかを調べた。成績の推移の調査分析にはデータマイニング手法を用いた。すなわち、情報処理関連科目のテスト結果をランク別の学生数の分布で捉え、科目別ランク間の学生の推移数や推移率を算出し、それに基づき相関ルールを抽出し、ルールの分類によってルールの意味を分析する。抽出された幾つかの相関ルールを要約すると、(1) 1、2年でAランクを取れない学生は3年でAランクを取れないこと、(2)大学入学前予備知識のある(職業課程卒)学生が2年でAとCの2つのランクに分かれることである。したがって、学年が上がるにつれてAランクの学生が減る。情報処理技術者(SE)として社会で活躍するには4科目ともAランクであることが望まれる。このような問題を解決するには、科目間での教育の協力方法を改善する必要がある。なお、著者らが担当する科目は情報処理関連科目の一部であるから、全ての科目の成績を反映した相関ルールが得られていると言えない。しかし、授業の進め方などで改善のヒントが他にも多く指摘されたことで、筆者らが提案するデータマイニング手法は、他の科目においても教育方法や講義内容の改善の自己評価手法として役立つように思われる。, This paper reports how many students, who have studied basics of computer literacy at the first grade and programming at the second grade, can master well the advanced computer algorithms and system designs at the third grade or higher. As the means to analyze the student transitions between subject-rank sets, the data mining featured by the following processes has been employed. The first process is to extract association rules to show the main trends of transitions between subject-rank sets from the test data. The second is to categorize the association rules by ranks. The last is to logically analyze the rules by semantics. By summarizing the data mining results, we found the following rules. The first rule shows that the students who could not get A rank at the first and second grades cannot get A rank at the third grade. The second rule shows that the students coming from the business oriented high school keeps the good performance at the first and second grades, but are classified into two groups of ranks A and C at the third grade. As a result, the students of rank A decrease as the grade raises. To solve this problem, we noticed that the collaboration between the subjects must be improved. Since many useful suggestions for better education could be pointed by analyzing the association rules, the authors found that the above mentioned data mining techniques should be used as self-evaluation tools for the other education improvement by the other teachers.

It is well characterized that melanophores in the tail fin of Xenopus laevis tadpoles are directly photosensitive. In order to better understand the mechanism underlying this direct photosensitivity, we performed a retinal analysis of the tail fins and eyes of Xenopus tadpoles at stages 51-56 using high performance liquid chromatography (HPLC). Following the extraction of retinoids by the formaldehyde method, a fraction containing retinal and/or 3,4-didehydroretinal isomers from the first HPLC analysis were collected. These isomers were then reduced by sodium borohydride to convert retinal and/or 3,4-didehydroretinal isomers into the corresponding retinol isomers to prepare for a second HPLC analysis. Peaks of 11-cis and all-trans 3,4-didehydroretinol were detected in the eyes and tail fins containing melanophores, but they were not detected in the tail fins without melanophores. The amounts of 11-cis and all-trans 3,4-didehydroretinol were 27.5 and 5.7 fmol/fin, respectively, and the total quantity of 3,4-didehydroretinal was calculated at approximately 5 x 10(6) molecules/melanophore. These results strongly suggest the presence of 11-cis and all-trans 3,4-didehydroretinal in melanophores of the tadpole tail fin, which probably function as the chromophore of photoreceptive molecules.

Extraretinal photoreceptor cells have been found in the pineal complex and deep brain of a variety of non-mammalian vertebrates. Light signals received by these photoreceptor cells seem to be a potent regulator of diverse physiological responses. Here, the pineal complex and deep brain of the Japanese grass lizard, Takydromus tachydromoides, were immunohistochemically analyzed to localize the photoreceptive molecule (opsin) and the light signal-transducing G-protein (transducin). In addition to the pineal organ and parietal eye constituting the pineal complex, we unexpectedly found a parapineal organ, which is located just below the parietal eye and is morphologically similar to the pineal organ. Both organs had photoreceptor-like cells with outer segments immunostained by anti-rhodopsin and anti-pinopsin antibodies. Neither opsin- nor transducin-like immunoreactivities were detected in the parietal eye with all the antibodies tested in this study, although its morphology resembles that of the la...

Locomotor activity rhythms of the Japanese newt, Cynops pyrrhogaster, were recorded under a semi-natural condition using phototransistor systems. The daily activity rhythm showed a seasonal change: the locomotor activity was mainly diurnal (active during the daytime) from spring to early summer; mainly nocturnal (active during the night-time) from summer to autumn; and showed either a diurnal or nocturnal pattern, depending on the ambient temperature, in winter. To analyze the daily activity in detail, we observed the behavior of a group of newts (three males, three females) throughout 24 h. Four types of behavior (respiration, feeding, mating, and resting on the land) were observed. Each behavior had daily rhythms and showed a seasonal change. The behavior on land showed mainly a nocturnal or bimodal pattern (activity rhythms with two peaks) throughout the year and was more frequently observed in summer. Mating behavior also showed a seasonal change: high activity in spring, with peaks in the early morning and evening, but no activity in summer. Except in winter, feeding and respiratory behavior showed no seasonal changes in either activity period or frequency. Coupling between behavior and the clock seems to be weak in the Japanese newt because of indistinct daily rhythms and frequent phase changes of locomotor activity in water. Physical factors such as humidity and temperature seem to affect strongly the daily activity of the newts.

In the retina of the medaka four kinds of retinal cone photoreceptor cells are arranged in a simple, repeating organizational pattern known as a square mosaic. We found that the distribution of cones in the retina could be easily detected by autofluorescence-emission from the photoreceptor cells without any staining. In tangential sections of the retina, cones were located at a specific position in a crystalline lattice as follows: Double cone pairs display a zigzagging appearance, oriented roughly 90-120 degrees to one another, and single cones were in the center of the square consisting of four double cone pairs. In order to determine the continuity of this regular arrangement on the spherical surface, the distribution of this cone mosaic pattern was examined in central, dorsal, ventral, nasal and caudal areas of the retina. The regular arrangement of cones was confirmed in the whole retina. Double cones and single cones are in their respective lines and these lines form a lattice-work. As a re...

The mudskipper, Periophthalmus modestus, inhabits the intertidal zone and is active on the surface of mud flat during low tides. We investigated relationships between the behavior and environmental variables during low tides from daily and annual aspects. The observation was done in two distant sites where tidal cycles and population densities are different. The emergence of the mudskipper on the surface of the tidelands was influenced by ambient temperature; low temperature inhibited emergence and locomotor activity of the mudskipper. The mudskipper retreated into the mud as the time went on after emersion of the tideland in order to avoid increase of body temperature and desiccation of the epidermis. Therefore, the emergence of the mudskipper seems to be directly suppressed by drying up of the mud surface. There were no differences in the diel and annual changes in the activity pattern between the populations. The emergence exhibited synodic changes in both areas, and it was correlated not with...

Stream grazers have a major impact on food web structure and the productivity of stream ecosystems; however, studies on the longitudinal (upstream versus downstream) and temporal changes in their drift dynamics and resulting distributions remain limited. Here, we investigated the longitudinal and temporal distributions and drift propensity of a trichopteran grazer, the caddisfly, Micrasema quadriloba , during its life cycle in a Japanese stream. The distribution of larvae significantly shifted downstream during the fifth instar larval stage during late winter; with periphyton abundance (i.e. their food source) showing similar shifts downstream. Therefore, our results show that the drift dispersal the caddisfly occurs in response to decline in available food resources (i.e. food-resource scarcity) and an increase in food requirements by growing individuals. Furthermore, our results show that this observed longitudinal shift in larval distribution varies through their life cycle, because the drift dispersal of fifth instar larvae was greater than that of immature larvae. The correlation between periphyton abundance and drift propensity of fourth instar larvae was not statistically significant, whereas that of fifth instar larvae was significantly negative. In conclusion, we detected an ontogenetic shift in drift propensity, which might explain the longitudinal and temporal distributions of this species.

SUMMARY In the pineal organ, two types of ganglion cell exhibit antagonistic chromatic responses to UV and green light, and achromatic responses to visible light. In this study, we histologically characterized UV-sensitive photoreceptor cells that contain a unique non-visual UV pigment, lamprey parapinopsin, in order to elucidate the neural network that is associated with antagonistic chromatic responses. These characteristics were compared with those of lamprey rhodopsin-containing cells, most of which are involved in achromatic responses. RT-PCR analysis revealed that lamprey parapinopsin was expressed in the pineal organ but not in the retina, unlike lamprey rhodopsin,which was expressed in both. Lamprey parapinopsin and lamprey rhodopsin were immunohistochemically localized in the dorsal and ventral regions of the pineal organ, respectively. The two pigments were localized in distinct photoreceptor cells throughout the pineal organ, namely the dorsal and ventral regions as well as the peripheral region, which corresponds to the dorso-ventral border region. The ratio of the number of lamprey parapinopsin-containing cells to lamprey rhodopsin-containing cells around the peripheral region was higher than in the central region. Electron-microscopic analysis revealed that lamprey parapinopsin-containing dorsal cells have outer segments and synaptic ribbons similar to those of ventral photoreceptor cells. However, unlike lamprey rhodopsin-containing cells, lamprey parapinopsin-containing cells connected with each other in a wide area of dorsal and peripheral portions and made direct contact with ganglion cells,mainly in the peripheral portion. These results suggest that UV light information captured by lamprey parapinopsin-containing photoreceptor cells is converged and directly transmitted to chromatic-type ganglion cells in the peripheral region to generate antagonistic chromatic responses.

Thermally comfortable zones in Vietnamese were investigated during winter in Hanoi. The subjects were 21 males (age: 19.7 +/- 0.4 yrs; height: 165 +/- 1.5 cm; body mass: 55.1 +/- 1.1 kg) and 19 females (age: 19.7 +/- 0.4 yrs; height; 155.6 +/- 1.7 cm; body mass: 45.6 +/- 1.3 kg). Each participant entered singly the climatic chamber controlled at 22 degrees C and 40% RH. After 20 min rest, the participant was requested to indicate on a 7-point scale (Table 1) how he or she felt to the room temperature given. Then, the room temperature increased by 1 degrees C over 10 min every 20 min. Just before the rise of the room temperature, the participant judged his or her thermal sensation. More than 90% of the participants felt 24-29 degrees C of the room temperature as "slightly cool", "neutral" and "slightly warm" (Table 2). We defined these sensations as "thermally comfort". These thermally comfortable zones were quite higher than those (20-24 degrees C) recommended by ISO-7730 (1994). We discussed these discrepancies in terms of higher establishment of thermoregulatory set-point in the Vietnamese.

Lower vertebrates can detect UV light with the pineal complex independently of eyes. Electrophysiological studies, together with chromophore extraction analysis, have suggested that the underlying pigment in the lamprey pineal exhibits a bistable nature, that is, reversible photoreaction by UV and visible light, which is never achieved by known UV pigments. Here we addressed the molecular identification of the pineal UV receptor. Our results showed that the long-hypothesized pigment is a lamprey homologue of parapinopsin, which exhibits an absorption maximum at 370 nm, in the UV region. UV light causes cis - trans isomerization of its retinal 2 chromophore, forming a stable photoproduct having an absorption maximum at 515 nm, in the green region. The photoproduct reverts to the original pigment upon visible light absorption, showing photoregeneration of the pigment. In situ hybridization showed that parapinopsin is selectively expressed in the cells located in the dorsal region of the pineal organ. We successfully obtained the hyperpolarizing responses with a maximum sensitivity of ≈380 nm from the photoreceptor cells at the dorsal region, in which the outer segment was clearly stained with anti-parapinopsin antibody. These results demonstrated that parapinopsin is the pineal UV pigment having photointerconvertible two stable states. The bistable nature of the parapinopsin can account for the photorecovery of the pineal UV sensitivity by background green light in the lamprey. Furthermore, we isolated the parapinopsin homologues from fish and frog pineal complexes that exhibit UV sensitivity, suggesting that parapinopsin is a common molecular basis for pineal UV reception in the vertebrate.

The light response of vertebrate visual cells is achieved by light-sensing proteins such as opsin-based pigments as well as signal transduction proteins, including visual arrestin. Previous studies have indicated that the pineal pigment parapinopsin has evolutionally and physiologically important characteristics. Parapinopsin is phylogenetically related to vertebrate visual pigments. However, unlike the photoproduct of the visual pigment rhodopsin, which is unstable, dissociating from its chromophore and bleaching, the parapinopsin photoproduct is stable and does not release its chromophore. Here, we investigated arrestin, which regulates parapinopsin signaling, in the lamprey pineal organ, where parapinopsin and rhodopsin are localized to distinct photoreceptor cells. We found that beta-arrestin, which binds to stimulated G protein-coupled receptors (GPCRs) other than opsin-based pigments, was localized to parapinopsin-containing cells. This result stands in contrast to the localization of visual arrestin in rhodopsin-containing cells. Beta-arrestin bound to cultured cell membranes containing parapinopsin light-dependently and translocated to the outer segments of pineal parapinopsin-containing cells, suggesting that beta-arrestin binds to parapinopsin to arrest parapinopsin signaling. Interestingly, beta-arrestin colocalized with parapinopsin in the granules of the parapinopsin-expressing cell bodies under light illumination. Because beta-arrestin, which is a mediator of clathrin-mediated GPCR internalization, also served as a mediator of parapinopsin internalization in cultured cells, these results suggest that the granules were generated light-dependently by beta-arrestin-mediated internalization of parapinopsins from the outer segments. Therefore, our findings imply that beta-arrestin-mediated internalization is responsible for eliminating the stable photoproduct and restoring cell conditions to the original dark state. Taken together with a previous finding that the bleaching pigment evolved from a non-bleaching pigment, vertebrate visual arrestin may have evolved from a “beta-like” arrestin by losing its clathrin-binding domain and its function as an internalization mediator. Such changes would have followed the evolution of vertebrate visual pigments, which generate unstable photoproducts that independently decay by chromophore dissociation.

A group of the medaka, Oryzias latipes (Cyprinodontidae, orange-red variety, 25 males and 25 females), was kept in an aquarium, which was placed outdoors under natural conditions from December 1984 to January 1986. Locomotor activity at three layers (upper, middle, and lower layers) was recorded with a phototransistor system in each season. In summer, the fish showed typical diurnal activity at all three layers and the activity was greater than in other seasons. However, in autumn and winter, the fish became less active and showed relatively high activity at night at the upper or middle layer and diurnal activity at the lower layer. Nocturnal activity seemed to appear when the water temperature was decreased and the photoperiod was shortened. A free-running activity rhythm was also recorded under continuous darkness (DD) in each season; however, the fish showed clear free-running activity rhythms under DD only in summer.

Thirty-two N-allylamino acids were prepared, and their preventive activity against Fusarium diseases was determined. Esters of N-allyl-glycine and -sarcosine showed a strong effect in preventing yellows of the Japanese radish caused by Fusarium oxysporum f. sp.raphani. These compounds were also effective against Fusarium wilt of tomato by foliage treatment. The preventive activity of N-allylsarcosinates varied insignificantly with the variation of the alcohol moiety of the esters. Although n-dodecyl N-allylsarcosinate was shown to effectively control Fusarium diseases, it did not affect the growth of Fusarium on an agar medium. The preventive effect was dependent on the application time. Enhancement of the peroxidase activity and the accumulation of total phenols were seen in the plants treated with these chemicals.

Forty nine N-substituted-α-aminonitriles were prepared and their preventive activities against Fusarium diseases were determined. Relationships between chemical structure and preventive activity were examined and the systemic movement in plants was investigated with 14C-N-allylaminoacetonitrile. Of the compounds tested, N-sec-butyl-α-aminoisobutyronitrile and N-allylaminoacetonitrile were most effective in controlling yellows of the Japanese radish which were caused by Fusarium oxysporum f. sp. raphani. N-Allylaminoacetonitrile showed remarkable systemic movement and a potent preventive activity against Fusarium wilts of cucumber and tomato not only by the soil drench test but also by the foliar spray assay.

Thirty-two N-allylamino acids were prepared, and their preventive activity against Fusarium diseases was determined. Esters of N-allyl-glycine and -sarcosine showed a strong effect in preventing yellows of the Japanese radish caused by Fusarium oxysporuwn f. sp. raphani. These compounds were also effective against Fusarium wilt of tomato by foliage treatment. The preventive activity of N-allylsarcosinates varied insignificantly with the variation of the alcohol moiety of the esters. Although n-dodecyl N-allylsarcosinate was shown to effectively control Fusarium diseases, it did not affect the growth of Fusarium on an agar medium. The preventive effect was dependent on the application time. Enhancement of the peroxidase activity and the accumulation of total phenols were seen in the plants treated with these chemicals.

Avian gonadal activity is known to be controlled by photoperiods. In male Japa-nese quail, testicular activity is stimulated by long days and inhibited by short days. However, the photoperiodic testicular response of the quail is not completely under-stood. Thus, I investigated it under various photoperiodic conditions.When birds were reared under continuous light (LL) after hatching, they reached maturation in 6 weeks and maintained large testes as long as they were kept under LL. When birds were transferred from LL to a short photoperiod (8L : 16D), their testes showed considerable involution within 2 weeks. However, when birds received the short day treatment for 5 weeks or longer period prior to the long day treatment, their testes showed resistance to involution in the subsequent short day treatment of both young and old birds. Further, when birds were continuously kept under a short photoperiod, they showed spontaneous growth of their testes 12 weeks after hatching. Adult birds, which experienced sexual maturation under the long photoperiod, also showed spontaneous recrudescence of their testes under a short photoperiod after several weeks in the involuted state. These results clearly indicate that a short photoperiod does not always act to inhibit the testes of the Japanese quail. They also suggest that there is a kind of photorefractoriness against short days.

The structure-activity relationships of N-alkylaminoacetonitriles and analogs possessing preventive activity against Fusarium diseases were investigated by the Hansch method. The variation in the preventive activity against yellows of the Japanese radish caused by Fusarium oxysporum f. sp. raphani was shown to be related to the variation in the steric dimension of the N-alkyl group. The amide, carboxylic acid and alcohol derivatives of N-sec-butylamino-acetonitrile were inactive while those of N-allylaminoacetonitrile showed the potent activity.

We have isolated a cDNA clone encoding a deep brain photoreceptive molecule from the hypothalamic cDNA library of the toad, Bufo japonicus. The deduced amino acid sequence showed the highest similarity to that of pinopsin (75^76%) among vertebrate retinal opsins, indicating the expression of toad pinopsin in the deep brain. Antibodies raised against the C- terminal tail of toad pinopsin stained cell bodies and the knob- like structures of the cerebrospinal fluid-contacting neurons in the anterior preoptic nucleus. This region is known to play an important role in breeding behavior, suggesting that toad pinopsin acts as a photosensor for the photoperiodic gonadal response. z 1998 Federation of European Biochemical Societies.