Seedling Growth Form of Oaks

Growth forms of recently-established oak seedlings were comparedamong five species from California and three species from Japan.Evergreen and deciduous species were included, native to a varietyof habitats. Each seedling was grown in a tall tube in orderto measure main root length and was harvested when leaf expansionhad ceased. The effects of light intensity reduced to 5% onseedling growth form were not strong enough to overcome theinnate differences between species. Shoot/root and leaf area/rootweight ratios were smaller in the species from drier environmentswithin each region, though all Californian oaks showed muchgreater root elongation than did the Japanese oaks. Extensiveroot systems combined with small leaf areas would help seedlingssurvival in xeric and open sites. Large leaf areas combinedwith small roots would be profitable for surviving in shadeunder canopy. In oaks of both regions, xeromorphic evergreengrowth forms are clearly distinguished from hygromorphic evergreengrowth forms. Seedling growth form, habitat moisture gradient, California oaks, Japanese oaks, shoot/root ratio     

Atypical Mesothelial Cells Associated With Eosinophilic Pleural Effusions: Nuclear Dna Content and Immunocytochemical Staining Reaction With Epithelial Markers

The nuclear DNA contents of atypical mesothelial cells from five patients who had an eosinophilic pleural effusion (EPE) were studied by the use of DAPI (4′,6-diamidino-2-phenylindole dihydrochloride) DNA staining. Analysis of the nuclear DNA content revealed a polyploid pattern, with a major peak in the tetraploid region. Using an immunocytochemical technique, the atypical mesothelial cells showed a positive reaction for cytokeratin. In contrast carcinoembryonic antigen (CEA) was always negative in these cells. It is suggested that the atypical mesothelial cells with EPE had a higher rate of proliferation than did the normal mesothelial cells.     

日本千曲川河中游成年水生昆虫羽化后的沿边扩散与沿岸植被的关系

Adults of aquatic insects emerge fromstreamslive inthe nearby riparian zone where they can select streamsidevegetations as preferred sites in order to(a)completemetamorphosis,(b)rest while awaiting proper swarmingtime,(c)feedin order to produce eggs,or(d)mate toreproduce[1—3].Most adult aquatic insect dispersal studies have fo-cused on quantifying the degree of upstream move-ment[4,5].Some researchers have shown distinct patternsof upstreammovement related to post-mating ovipositionalbehavior…     

Diversity of drosophilid flies on Kume-jima, a subtropical island: comparison with diversity on Iriomote-jima

The drosophilid fauna was studied on Kume‐jima, a subtropical island located in the central part of the Ryukyu archipelago, and compared with the fauna of Iriomote‐jima located near the south‐western end of the archipelago. The number of species collected from Kume‐jima was 37, much fewer than that recorded from Iriomote‐jima (95 species). The number of subtropical species was particularly reduced on Kume‐jima, possibly owing either to this island being more distantly located from the sources of subtropical species (e.g. Taiwan) than Iriomote‐jima and/or to winter temperature on Kume‐jima being a little lower (by approximately 1.5°C). The number of fungus‐feeders was also much reduced on Kume‐jima, but the number of fruit‐feeders was only slightly reduced. On Kume‐jima, fungi seem to be less abundant because forests are smaller, resulting in a smaller number of fungus‐feeders. Habitat selection and seasonality were analyzed for species collected using “retainer” type traps baited with banana. For species occurring on both islands, habitat selection differed little between the two islands, whereas the seasonality of some species differed markedly between the two islands.     

Effect of leaf surface wetness and wettability on photosynthesis in bean and pea

Leaf surface wetness that occurs frequently in natural environments has a significant impact on leaf photosynthesis. However, the physiological mechanisms for the photosynthetic responses to wetness are not well understood. The responses of leaf CO₂ assimilation rate (A) to 72 h of artificial mist of a wettable (bean; Phaseolus vulgaris) and a non‐wettable species (pea; Pisum sativum) were compared. Stomatal and non‐stomatal limitations to A were investigated. A 28% inhibition of A was observed in the bean leaves as a result of a 16% decrease in stomatal conductance and a 55% reduction in the amount of Rubisco. The decrease of Rubisco was mainly due to its partial degradation. In contrast to the bean leaves, a 22% stimulation of A was obtained in the 72 h mist‐treated pea leaves. Mist treatment increased stomatal conductance by 12.5% and had no effect on the amount of Rubisco. These results indicated that a positive photosynthetic response to wetness occurred only in non‐wettable species and is due to the change in stomatal regulation.     

Some effects of low temperature on the photoperiodic clock in Drosophila triauraria

Abstract. Prior studies revealed that the photoperiodic clock in Drosophila triauraria operates during the scotophase and the processes measuring scotophase are composed of two phases: the A phase which lasts 6–7 h from the onset of the scotophase and the B phase which follows the A phase. In this study the photoperiodic clock in this species was analysed by low-temperature pulses. Low temperature (5C) or a low-temperature (2C) pulse of 3 or 4 h decreased the induction of diapause when applied during the scotophase, but not when applied within the photophase. The low-temperature pulse showed two maxima of the effect, 0–4 h and 8–10 h after the onset of the scotophase, approximately corresponding to the A and B phases, respectively. It is considered that low temperature retards the time measurement processes operating during these phases. In the period which was rather insensitive to the diapause-preventing action of low temperature, i.e. 5-7h after the onset of the scotophase, substances or stimuli accumulated during the A phase may be converted to information required for operation of the machinery in the B phase. Experiments using a combination of low-temperature and light pulses suggested that low-temperature decreases the sensitivity to light, especially in the B phase.     

Hourglass and oscillator expressions of photoperiodic diapause response in the cabbage moth Mamestra brassicae

Abstract. Both oscillator and hourglass features are found in the photoperiodic response that controls the pupal winter diapause of Mamestra brassicae. The expression of oscillatory response to extended long-night cycles is temperature dependent, i.e. circadian resonance appears at 23 and 25^oC but not at 20 and 28^oC. At 20^oC, scanning of extended scotophases by a short light pulse does not reveal any clear circadian rhythmicity. However, a circadian feature of the photoperiodic response is indicated even at 20^oC by a bistability phenomenon, i.e. either one of the two dark periods in symmetrical skeleton photoperiods determines the diapause response depending on the phase angle with the preceding (entraining) light-dark cycles. At 20 and 25^oC, the incidence of diapause increases as a function of the number of light–dark cycles regardless of the cycle length (T) , if T is 24 h or 2 X 24h (with a 12 h light period). A non-diel cycle (r=36h) is less effective, suggesting that disturbance of the circadian organization partly impairs the diapause-inducing function. The inductive effect of a long night is largely affected by temperature, and becomes saturated with eight cycles at 20^oC and 14 cycles at 25^oC. Presumably, an hourglass mechanism measures the dark time, and a circadian component involved in some later sequence of the photoperiodic response may or may not be expressed depending on the mode of interaction between them.     

The relative importance and distribution of Aedes polynesiensis and Ae.aegypti larval habitats in Samoa

Abstract. In preparation for a Filariasis Control programme in Samoa, during 1978 monthly larval surveys of the vector mosquito Aedes polynesiensis were carried out in four study villages in the main island of Upolu. A more extensive survey of larval habitat distribution was then made in twenty-two villages of Upolu and eighteen of Savai'i island, to determine the importance of habitat types according to their abundance, volume of water and whether their productivity was permanent or seasonal. Ae.aegypti larval densities and habitat distribution were also monitored and the occurrence of predatory Toxorhynchites amboinensis larvae in northern Upolu was recorded from forty-one collections. Aedes Breteau and container indices fluctuated with the pattern of rainfall in two coastal villages and an inland bush village, but not in a coconut plantation community. The five main Aedes larval habitat types encountered were: 200 litre water-storage drums, discarded tins and bottles, coconut shells, automobile tyres and treeholes. Aedes immatures occurred perennially in drums and tree holes, but breeding discontinued in tins, bottles and coconut shells during the driest month of July. For Ae.polynesiensis in Upolu the Breteau and container indices of 104.5 ± SD 80.9 and 35.3 ± 12.4 respectively were significantly higher than those in Savai'i: 33.1 ±25.0 and 24.3 ±20.0 respectively. Likewise for Ae.aegypti the Breteau and container indices of 50.8 ± 32.5 and 23.9 ± 15.6, respectively, were also significantly higher than those in Savai'i: 12.7 ± 17.1 and 9.4 ±13.2 respectively. Habitat types greater or lesser importance were determined by plotting the percentage of each type of container utilized for Aedes breeding against the percentage of each type amongst all larva-positive containers. Ae.polynesiensis preferred tree-holes but not water-storage drums. Ae.aegypti preferred drums and tyres; mixed populations of larvae of both species were commonest in these two types of habitat. Ae.polynesiensis occurred in every village. Ae.aegypti was encountered in all twenty-two villages surveyed in Upolu and nine of eighteen villages in Savai'i. Total larval surveys revealed that drums and tree-holes contained the highest numbers of Aedes larvae. The study provided criteria for planning a control programme.