bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in adhesive properties of epithelial cells during early morphogenesis of the mammary gland
Authors: Nanba Daisuke , Nakanishi Yasuo , Hieda Yohki
Published: March 2003

Previous studies have demonstrated that cell adhesion systems are downregulated in epithelial buds at the earliest stages of submandibular gland and hair follicle development, but are restored at subsequent stages. Here it is shown that epithelial cell adhesion systems are also remodeled during early mammary gland development. Immunofluorescence and electron microscopy of the mouse mammary bud demonstrated that cell–cell adhesion systems were hardly detectable, with significant downregulation of expression of desmosomal molecules, but not of E‐cadherin and β‐catenin. Hemidesmosomal structures were also rarely found, although their component molecules were expressed. Differences in cell adhesivity between cells of the mammary bud and those of the overlying epidermis were shown by the finding that the mammary cells formed smaller aggregates than the epidermal cells and were not randomly mixed with the epidermal cells. At subsequent stages, the mammary epithelium restored cell–cell adhesion systems along with de novo expression of tight junction molecules. These data, together with previous findings, indicate that remodeling of epithelial cell adhesion systems is a general feature underlying the early development of several ectoderm‐derived organs and support the idea that segregation and rearrangements of cells are involved in early epithelial morphogenesis.
Analysis of haploid development based on expression patterns of developmental genes in the medaka Oryzias latipes
Authors: Araki Kazuo , Okamoto Hiroyuki , Graveson Ann C. , Nakayama Ichiro , Nagoya Hiroyuki
Published: March 2003

The abnormalities of haploid medaka embryos were characterized by comparative analysis of histologic sections and expression patterns of some developmental marker genes between haploids and diploids to clarify whether medaka haploids are useful for identifying mutants. During gastrulation, an obvious defect was first observed as a delay of epiboly and involution. This delay was shown to be caused not by the perturbation of mesoderm induction, but by widespread cell death and disorganization of cell arrangement in the blastoderm. This disorganization of cell arrangement was also detected in various organs, such as the brain, somite and notochord, at a late developmental stage. Ten days after fertilization, a small head and a short body axis were formed; these changes were also observed in haploid embryos in other species, but their cause is unknown. Based on the expression patterns of HNF3β and goosecoid, it was demonstrated that a short and impotent prechordal plate induced near the marginal zone in haploid embryos was responsible for this defect. However, in these experiments it was also demonstrated that many major organs in haploids, such as the somite and notochord, differentiated incompletely but were present. Therefore, it was concluded that haploid screening is suitable for identifying mutations revealed by an obvious phenotype, such as dorsoventral polarity.
Dissecting planarian central nervous system regeneration by the expression of neural‐specific genes
Authors: Cebrià Francesc , Nakazawa Masumi , Mineta Katsuhiko , Ikeo Kazuho , Gojobori Takashi , Agata Kiyokazu
Published: March 2003

The planarian central nervous system (CNS) can be used as a model for studying neural regeneration in higher organisms. Despite its simple structure, recent studies have shown that the planarian CNS can be divided into several molecular and functional domains defined by the expression of different neural genes. Remarkably, a whole animal, including the molecularly complex CNS, can regenerate from a small piece of the planarian body. In this study, a collection of neural markers has been used to characterize at the molecular level how the planarian CNS is rebuilt. Planarian CNS is composed of an anterior brain and a pair of ventral nerve cords that are distinct and overlapping structures in the head region. During regeneration, 12 neural markers have been classified as early, mid‐regeneration and late expression genes depending on when they are upregulated in the regenerative blastema. Interestingly, the results from this study show that the comparison of the expression patterns of different neural genes supports the view that at day one of regeneration, the new brain appears within the blastema, whereas the pre‐existing ventral nerve cords remain in the old tissues. Three stages in planarian CNS regeneration are suggested.
Lineage of anuran epidermal basal cells and their differentiation potential in relation to metamorphic skin remodeling
Authors: Suzuki Ken‐ichi , Utoh Rie , Kotani Kaori , Obara Masanobu , Yoshizato Katsutoshi
Published: March 2003

The anuran remodels the larval epidermis into the adult one during metamorphosis. Larval and adult epidermal cells of the bullfrog were characterized by determining the presence of huge cytoplasmic keratin bundles and the expression profiles of specific marker genes, namely colα1 (collagen α1 (I)), rlk (larval keratin) and rak (adult keratin). We identified four types of epidermal basal cells: (i) basal skein cells that have keratin bundles and express colα1 and rlk; (ii) rak+‐basal skein cells that have keratin bundles and express colα1, rlk, and rak; (iii) larval basal cells that express rlk and rak; and (iv) adult basal cells that express rak. These traits suggested that these basal cells are on the same lineage in which basal skein cells are the original progenitor cells that consecutively differentiate into rak+‐basal skein cells into larval basal cells, and finally into adult basal cells. To directly verify the differentiation potential of larval basal cells into adult ones, the mono‐layered epidermis composed of larval basal cells was cultured in the presence of aldosterone and thyroid hormone. In this culture, larval basal cells differentiated into adult basal cells that reconstituted the adult epidermis. Thus, it was concluded that larval basal cells are the direct progenitor cells of the adult epidermal stem cells.
Soil nitrogen mineralization rates of rainforests in a matrix of elevations and geological substrates on Mount Kinabalu, Borneo
Authors: Kitayama Kanehiro , Aiba Shin‐Ichiro , Majalap‐Lee Noreen , Ohsawa Masahiko
Published: March 2003

Mt Kinabalu, Borneo, is characterized by a deep elevational gradient and mosaics of geological substrates. We chose a pair of two geological substrates (sedimentary vs ultrabasic) at five altitudes (800, 1400, 2100, 2700 and 3100 m a.s.l.). We investigated soil nitrogen (N) mineralization and nitrification rates using an incubation technique to assay the pattern and control of soil N status in this environmental matrix. In situ net mineralization rates decreased with elevation on both substrates. The decreasing pattern was linear across altitudes on ultrabasic rock, whereas on sedimentary rock it was depressed in the middle slope wet cloud zone. Sedimentary sites in this zone had low soil redox potential values and this anoxic soil condition might be related to slow N mineralization. The in situ rates were significantly greater (P < 0.05, ANOVA) on sedimentary than on ultrabasic rock at the same altitudes except in the cloud zone. Net mineralization rates of the soils that were collected from different elevations and incubated in the same conditions were statistically invariable (P > 0.05) among the original elevations for sedimentary rock, but were variable (P < 0.05) for ultrabasic rock. Those of the soils that were collected from the same elevation and incubated at different elevations decreased significantly across altitudes (P < 0.05) for sedimentary rock, while they were invariable (P > 0.05) for ultrabasic rock. Thus, temperature had stronger effects on net N mineralization on sedimentary rock, whereas inherent soil quality had stronger effects on ultrabasic rock. Controls of soil N mineralization might be different between the two substrates, leading to diverse biogeochemical site conditions on Kinabalu.
Recruitment of fleshy‐fruited species under different shrub species: Control by under‐canopy environment
Authors: KOLLMANN JOHANNES , GRUBB PETER, J.
Published: March 2003

Seedling densities and the mortality of fleshy‐fruited species under 10 European tall‐shrub species and the tree Sorbus aria were analyzed in 10‐year‐old experimental scrub for one growing season. The mean total densities of seedlings of 18 fleshy‐fruited species differed under the different ‘hosts’, being highest under Crataegus monogyna, Viburnum opulus and Rosa canina (24–20 m−2); intermediate under Sorbus aria, Rhamnus catharticus, Cornus sanguinea, Ligustrum vulgare and Juniperus communis (17–12 m−2); and lowest under Euonymus europaeus, Viburnum lantana and Prunus spinosa (10–9 m−2). This ranking was similar for the 11 planted species and for nine bird‐dispersed, non‐planted species which invaded the site, notably Hedera helix and Solanum dulcamara. Within the experimental scrub as a whole mortality of seedlings differed significantly among species, being highest in those with the smallest number of recruits. Mortality ranged from 94% and 89% for Solanum dulcamara and Viburnum opulus to 26% for Hedera helix and Ligustrum vulgare. The mean mortality across all species of seedlings did not differ significantly between host species, although it was slightly higher under Juniperus and Cornus (56%, 53%) and lower under Viburnum lantana and Rhamnus (42%, 41%). In four species, the mortality of seedlings was significantly higher under conspecific adults. Mean topsoil water content after a dry spell was negatively correlated with the diffuse site factor (DSF). The mean density of accumulated seedlings of the most abundant seedling species (Hedera) was positively correlated with the topsoil water content. Densities of other species showed no strong correlations with either topsoil water content or DSF. The probable factors controlling recruitment are discussed.
Ecological significance of root tip rotation for seedling establishment of Oryza sativa L.
Authors: INOUE NAOTO , ARASE TERUO , HAGIWARA MOTOYUKI , AMANO TAKAHISA , HAYASHI TAIICHI , IKEDA RYOICHI
Published: March 2003

How plant seeds secure root penetration into soil to obtain good seedling establishment is one of the basic ecological problems. In this study, seminal root growth was investigated to clarify the cause of varietal difference of seedling establishment in direct seeding of rice in flooded paddy fields, with special reference to root tip rotation. In a field experiment, seedling establishment percentage had a weak correlation with seminal root elongation rate but was not correlated with apparent seedling weight in water, which has been reported to be the cause of floating seedlings resulting in poor seedling establishment. Root tip rotation was analyzed for indoor‐grown seedlings using spectrum analysis: the maximum entropy method (MEM) was used. Maximum entropy method power spectrum analysis clarified that maximum MEM power density (practically corresponds to spiral angle) detected in the frequency range above 0.1 cycles mm‐1 was highly and positively correlated to seedling establishment percentage in the field experiment. Maximum MEM power density in high correlation with seedling establishment was mostly found around frequencies of 0.2 cycles mm–1, which corresponded to 2.0–3.4 cycles of root tip rotation per day. From these results, root tip rotation (circumnutation) with a larger spiral angle was suggested to play an important role in the establishment of rice seedlings on flooded and very soft soil. A possible explanation for why a larger spiral angle was advantageous for seedling establishment is that if buoyancy and seedling weight are constant, a larger pushing force of the seminal root is available without causing floating of a seedling, due to the upward force being a reaction of the seminal root pushing force.
Coexistence of drosophilid flies: Aggregation, patch size diversity and parasitism
Authors: Mitsui Hideyuki , Kimura Masahito T.
Published: March 2003

We carried out field experiments to investigate the coexistence of Drosophila species in domestic and forest areas on the basis of the aggregation model. Three cosmopolitan species Drosophila simulans Sturtevant, Drosophila melanogaster Meigen and Drosophila immigrans Sturtevant, and a native species, Drosophila auraria Peng, emerged abundantly from banana placed at the domestic station, while Drosophila immigrans and five native species, Drosophila lutescens Okada, Drosophila rufa Kikkawa and Peng, Drosophila bizonata Kikkawa and Peng, Drosophila sternopleuralis Okada and Kurokawa and Scaptodrosophila coracina (Kikkawa and Peng), were abundant at the forest station. The present analysis suggests that their coexistence was facilitated by the aggregation mechanism. In the cosmopolitan species, the density of individuals that emerged from patches increased with the increase of patch size, but the relationship between fly density and patch size was not clear in the native species. This difference in distribution patterns between the cosmopolitan and native species is likely to be due to the difference in the female visiting behavior. In the present analysis, however, it was not clear whether patch size diversity facilitated their coexistence or not. The effect of patch size diversity may have been masked, because the effect of aggregation was more prominent. The rate of parasitism by wasps was high in October at the domestic station, and in May and June at the forest station. The present result suggests that the rate of parasitism was density‐dependent, at least at the domestic station, and therefore parasitism facilitates the coexistence of drosophilid species in domestic areas.
Flow rate mediates the competitive influence of a grazing caddisfly on mayflies
Authors: Kuhara Naotoshi , Nakano Shigeru , Miyasaka Hitoshi
Published: March 2003

The Glossosomatid caddisflies, which are stream‐insect grazers, have been found to negatively affect the densities of mayfly grazers through intensive periphyton exploitation. The grazing efficiency of a Glossomatid caddisfly, however, is known to decrease with increasing current velocity. A manipulative field experiment was conducted to test the hypotheses that the presence of Glossosoma sp. decreased the densities of three mayfly grazers, Baetis thermicus, Cinygmula sp. and Paraleptophlebia chocorata, and that the decrease was stronger in slower stream‐flow conditions. The experiment followed a two‐factorial design with flow conditions and Glossosoma densities as the main factors. The periphyton biomass in conditions of reduced Glossosoma density was greater than in natural Glossosoma densities, but was not affected by flow conditions. In partial contradiction of the experimental hypothesis, the experimental reduction in Glossosoma density resulted in a higher density of Baetis, irrespective of flow conditions. The grazing activity of Glossosoma would not be affected by the flow variations that were employed in the present experiment. The reduction in Glossosoma density resulted in higher densities of Cinygmula and Paraleptophlebia only in fast‐flow conditions, a result that did not support the experimental hypotheses. The competitive influence of Glossosoma on these mayflies might be altered by flow conditions causing differences in the resource structure.
Push‐up response of stonefly larvae in low‐oxygen conditions
Authors: Genkai‐Kato Motomi , Nozaki Kentaro , Mitsuhashi Hiromune , Kohmatsu Yukihiro , Miyasaka Hitoshi , Nakanishi Masami
Published: March 2003

Under conditions of low oxygen availability, the larvae of the stonefly Oyamia lugubris McLachlan demonstrate a ‘push‐up’ behavior that is thought to enhance respiratory efficiency. We conducted an experiment to investigate the effect of the oxygen supply on this behavior in winter and summer by using a lotic chamber and natural water. From the experiment, we determined the critical oxygen supply level below which the stonefly larvae are compelled to do push‐ups. There was a small difference in the critical oxygen supply level between the seasons. This result emphasizes that a novel measurement of the oxygen availability, that is, the oxygen supply, could be an important determinant of the distribution of aquatic insects.
A new index of interspecific competition for replacement and additive designs
Authors: Williams A. Christina , McCarthy Brian C.
Published: March 2003

The literature is reviewed to summarize the major indices of interspecific competition used in De Wit replacement experiments. Of the many indices that have been defined, some are less than clear as to their meaning, so interpretations are often difficult to make. In an effort to explore the performance of individual indices and to permit cross‐correlation among indices, a series of hypothetical results in different competition scenarios is created. A standardized notation for all indices is also provided, along with equations and proofs. Nine indices are reviewed and analyzed for their behavior under the hypothetical scenarios and a new index that provides increased clarification and interpretability over other indices is proposed. Relative Yield Total, Aggressivity, and Relative Replacement Rate were shown to be poor measures of competition. Relative Crowding Coefficient has many restrictions to its use. The clearest index that includes two or more species is Relative Yield of Mixture. Indices that describe single species accurately were found to be Relative Yield (RY) and Relative Competition Intensity (RCI), both of which are mathematically convertible. An index introduced here, Change in Contribution (CC), is a single species index that differs from RY and RCI because it takes into account the overall biomass each species contributes.
Non‐symbiotic nitrogen fixation in forest ecosystems
Authors: Son Yowhan
Published: March 2003

Since the first attempts to increase forest growth using nitrogen (N) fixation, biological N fixation has been intensively studied. Numerous studies that focused on symbiotic N fixation and rates were well quantified. However, the rates and importance of non‐symbiotic N fixation in forest ecosystems remains incomplete. In this review, reports of non‐symbiotic N fixation from various studies throughout the world were examined and the ecological significance of non‐symbiotic N fixation in temperate forest ecosystems was investigated. The reported rates of non‐symbiotic N fixation varied greatly, and ranged from < 0.01–5 kg N ha–1year–1. However, an average input of 2–3 kg N ha–1year–1could be expected when all ecosystem components were included. In several studies, non‐symbiotic N fixation seemed to decrease with stand age. Some methodological considerations such as incubation time and conversion factor in the acetylene reduction method were presented. Also, it should be noted that more detailed studies on non‐symbiotic N fixation in boreal and tropical forests are needed to understand the importance of N fixation in these forest ecosystems.
High performance of CO2–temperature gradient chamber newly built for studying the global warming effect on a plant population
Authors: Lee Jae‐Seok , Usami Tetsuyuki , Oikawa Takehisa
Published: March 2003

To study the effect of global warming concomitant with rising CO2 on plant growth under field‐like conditions, a CO2–temperature gradient chamber (CTGC) was created from a standard temperature gradient chamber (TGC). Despite great daily and seasonal changes in ambient air temperature, the gradient of air temperatures was simulated by 5°C warmed conditions at the air outlet, rising at a rate of 1°C at 5 m intervals. Also, CO2 concentrations were linearly increased from the air inlet to the outlet; those at the air inlet and 25 m distance from the air inlet were 372 p.p.m and 756 p.p.m. (doubled), respectively. The CTGC proved successful in biological experiments conducted through a full growth season in 1998. This apparatus will be useful for understanding plant response to simultaneous changes in CO2 and temperature. Being a combination of a TGC and a CO2 gradient chamber, the improved CTGC allows parameters and validation data sets to both be obtained for models contributing to plant growth, species composition, and global carbon flux analysis.
Woody plant establishment during the early stages of volcanic succession on Mount Usu, northern Japan
Authors: Haruki Masahiro , Tsuyuzaki Shiro
Published: March 2003

The establishment patterns of woody plants were investigated on the volcano Usu, 9 years after the 1977–1978 eruptions. The former vegetation was covered by a 1–3 m thick volcanic deposit. Trees producing wind‐dispersed seeds capable of long distance dispersal, such as Populus maximowiczii, Betula platyphylla var. japonica, Salix hultenii var. angustifolia, and Salix sachalinensis, were dominant. Most trees were only 2–4 years old in 1986, suggesting that chances for seedling establishment were restricted. The tree heights did not differ significantly among the species, while lengths of annual shoots differed due to herbivore preferences. Trees were established at higher densities on gravel‐dominated pumice surfaces than on fine‐textured surfaces. Tree density was not greatly affected by the nutrient content of deposits. From 1987 to 1990, tree height increments did not differ between the gravel and non‐gravel areas. Ground surface texture is an important factor in determining seedling establishment in the early stages of volcanic succession, and nutrient status is unimportant.
CENTURY ecosystem model application for quantifying vegetation dynamics in shifting cultivation areas: A case study from Rampa Forests, Eastern Ghats (India)
Authors: Prasad V. Krishna , Kant Yogesh , Badarinath K. V. S.
Published: March 2003

In India, slash and burn agriculture is one of the major factors contributing to deforestation, especially in the hilly north‐eastern region and Eastern Ghats. Studies on vegetation dynamics associated with slash and burn agricultural practices have been intensively studied in the north‐eastern part of India. These have covered semi‐evergreen/evergreen vegetation, but similar studies on tropical mixed dry deciduous ecosystems are not as common. In the present study, we used the CENTURY ecosystem model to study vegetation dynamics in shifting cultivation areas on the mixed dry deciduous forests covering the Eastern Ghats of India. The site‐specific parameters, temperature, precipitation, biomass and nutrient pools were used, and, by collecting information from local management practices, a 12‐year shifting cultivation cycle during a 70‐year period from 1960 to 2030 was simulated. CENTURY estimated a total loss of 239 tonnes carbon (tC) in soil organic matter over the simulation period, and the total nitrogen content of the soil organic matter showed an initial increase followed by a decline (344.3 g m2 during 1960 to less than 318.3 g m2 during 2030). CENTURY estimated that 66 tC ha−1 would be lost from the forest system, reducing the initial forest system carbon level from 118.5 tC ha−1. An increase in productivity from 0.49 tC ha−1 during 1960 to 1.2 tC ha−1 during the initial forest slash and burn in 1962 was observed, but thereafter productivity declined to 0.7 tC ha−1 during the year 2030. Results obtained in other studies of similar types of agricultural practices are also reviewed.
Pine wilt disease as promising causal agent of the mass mortality of Pinus armandii Franch. var. amamiana (Koidz.) Hatusima in the field
Authors: Nakamura Katsunori , Akiba Mitsuteru , Kanetani Seiichi
Published: March 2003

The causal agent of the mass mortality of field populations of Pinus armandii Franch. var. amamiana (Koidz.) Hatusima (PAA) was investigated with special respect to the involvement of pine wilt disease. Wood chips, branches and/or increment cores for detecting the pinewood nematode, feeding marks of the vector insect and environmental stress in the past, respectively, were taken from live and dead PAA trees grown in three locations, Yaku‐shima and Tanega‐shima Islands and a plantation in Kagoshima City, from 1997 to 1998. Five trees died after the spring of 1996 and, of these, four were inhabited by the pinewood nematode. Feeding marks of the vector insects were found on the branches of all dead trees and most of the live trees investigated. These results suggest that the infection of pine wilt disease in PAA trees occurs in the field. Annual ring growth of the sample trees showed neither intervention nor growth reduction, which implies strong environmental stress that may cause mortality in PAA trees.
Distribution and abundance of spotted seals Phoca largha and ribbon seals Phoca fasciata in the southern Sea of Okhotsk
Authors: Mizuno Ayako W. , Wada Akihiko , Ishinazaka Tsuyoshi , Hattori Kaoru , Watanabe Yukiko , Ohtaishi Norioriyuki
Published: March 2003

The distribution and abundance of spotted seals (Phoca largha) and ribbon
seals (Phoca fasciata) were assessed in March and April, 2000,
by aerial line‐transect surveys along the southern edge of the pack ice off the coast
of Hokkaido (southern Sea of Okhotsk), Japan. Five hundred and seventeen spotted
seals and 107 ribbon seals were found on the total 2944 km survey line. Total abundance
was estimated to be 13 653 spotted (95% CI = 6167–30 252) and 2260
ribbon seals (95% CI = 783–6607) in March, and 6545 spotted (95%
CI = 3284–815 644) and 3134 ribbon seals (95% CI = 1247–17
802 512) in April. The pack ice area off Hokkaido had higher densities (0.54 seals
km−2 and 0.58 seals km−2 in March and April, respectively)
of spotted seals than those reported in eastern Sakhalin, whereas densities (0.09
seals km−2 in March and 0.28 seals km−2 in April) of ribbon seals were lower than those in eastern Sakhalin. The large number of spotted seal pups suggests that the study area is an important breeding center. A greater number of female spotted seals with pups tended to be found in the center of larger and rougher floes than in other categories, and they were more abundant in stable pack ice areas. Observations of ribbon seals were limited because the survey period preceded the peak of pupping season. Ribbon seal surveys were also hampered by the inability to fly over the main breeding area between the Shiretoko Peninsula and Kunashiri Island.
Effects of domestication and agronomic selection on phytoalexin antifungal defense in Phaseolus beans
Authors: Lindig‐Cisneros Roberto , Dirzo Rodolfo , Espinosa‐García Francisco J.
Published: March 2003

Systems of wild and cultivated relatives are good experimental systems to test chemical defense theory because they provide closely related varieties that differ in discrete traits. To determine the relationship between resistance and chemical defense diversity among wild, landrace and cultivar accessions of Phaseolus vulgaris, we measured resistance to fungal infection in laboratory and field experiments, quantified phytoalexin diversity, and assessed the effectiveness of phytoalexin mixtures extracted from live tissue. Results show a gradient of resistance to fungal infections between wild, landrace and cultivar varieties. In the laboratory, wild seedlings were more resistant (93% non‐infected) than landrace seedlings (80% non‐infected) and modern cultivar seedlings (68% non‐infected). Under field conditions wild seedlings were more resistant (97% non‐infected) than cultivar seedlings (71% non‐infected). Wild seedlings presented the highest phytoalexin diversity (H′ = 1.11), while those of the landrace presented an intermediate level (H′ = 0.97) and cultivar seedlings presented the lowest diversity (H′ = 0.93). No differences were found in total concentrations. The in vitro inhibitory properties on hyphal growth of the isoflavonoid mixtures produced by individual seedlings showed a similar trend. Our results are consistent with similar gradients in other species of Phaseolus beans and resistance to Colletotrichum sublineolum in sorghum.
Allometry and life history of a forest understory palmPinanga coronata(Arecaceae) on Mount Halimun, West Java
Authors: Kimura Machiko , Simbolon Herwint
Published: March 2003

We studied the allometry and life history of an understory palmPinanga coronata(Arecaceae) in a tropical montane rainforest on Mount Halimun, West Java, Indonesia. When the palm was small, the diameter of the stem increased with the minimum amount of vertical growth needed for new leaves to emerge (juvenile stage). After the base diameter of the stem and the length of the leaves reached a sufficient size (3.5 cm and 207.7 cm, respectively), the palm started to elongate the stem vertically (adult stage). The total mass and area of leaves in the crown increased with increasing stem mass, and approached constant values asymptotically. At the adult stage, the palm increased specific gravity of the lower part of the stem as it grew taller to support the increasing mass of crown and stem. To avoid self‐shading, crown architecture changed as the plant grew larger; leaf blades became longer and narrower and petiole length increased to display leaves efficiently away from the stem. The palm also produced clonal sprouting shoots and formed small clumps. Each clump contained an average of 7.5 shoots. The spatial distribution of the palm was strongly affected by topography, but only minimally affected by light conditions. The architectural adaptation to shaded conditions, effective dispersal of fruits and clonal growth are likely to be the factors that allowP. coronatato be one of the most dominant understory plant species in the study area.
Deer browsing reduces leaf damage by herbivorous insects through an induced response of the host plant
Authors: Shimazaki Aya , Miyashita Tadashi
Published: March 2003

We aimed to demonstrate an indirect relationship between a mammalian herbivore (sika deer) and herbivorous insects on the induced responses of a shared host plant, Viburnum dilatatum. Field studies were conducted at three sites (i.e. two islands and one mainland) and within a deer exclusion area. One island, Kinkazan (Kz) Island, harbored a high density of deer while the other sites (controls) had no deer or very low densities of deer. The deer exclusion area had been established approximately 10 years earlier on Kz. We collected leaves above the browsing line of the deer and measured leaf hardness and tannin concentration. Leaf damage by insects was used as a measure of insect abundance. Leaves collected at Kz were harder than those from one of the control sites and from inside the deer exclusion area, while no difference was detected among the other controls and inside the exclusion area. In contrast, the tannin concentration of leaves from Kz was lower than in leaves from the control site. Leaf damage by herbivorous insects was lower in Kz than the other study sites. In addition, ‘hole’‐type leaf damage tended to be higher inside, rather than outside, the exclusion area. These results suggest the possibility that deer browsing increased leaf hardness, which exerted an indirect negative effect on the herbivorous insects utilizing the common host plant. To our knowledge, this is the first study to provide evidence of indirect negative effects between mammalian herbivores and herbivorous insects sharing a host plant.
Indirect effect of salmon carcasses on growth of a freshwater amphipod, Jesogammarus jesoensis (Gammaridea): An experimental study
Authors: ITO TOMIKO
Published: March 2003

The effect of salmon carcasses on the growth of a freshwater amphipod, Jesogammarus jesoensis (Schellenberg) (Gammaridea, Anisogammaridae), was examined experimentally. Growth rate was determined by rearing juvenile amphipods in four food treatments (‘leaves’, ‘salmon’, ‘leaves and salmon’ and ‘leaves with salmon leachate’) for 20 days. Mass loss and oxygen consumption of the leaves were also measured in the three treatments with leaves. The oxygen consumption rate of leaves was lower in the ‘leaves’ treatment than in either the ‘leaves and salmon’ or ‘leaves with salmon leachate’ treatments, indicating that microbial activity on leaves was enhanced by the presence of salmon carcasses. Mass loss of leaves did not differ between the three treatments with leaves. The growth rate of the amphipods did not differ between the ‘leaves’ and ‘salmon’ treatments, or between the ‘leaves and salmon’ and ‘leaves with salmon leachate’ treatments. Growth rates in the two latter treatments were higher than rates in the ‘leaves’ treatment, but not higher than the rates in the ‘salmon’ treatment. Therefore, it appears likely that consuming leaves fertilized with nutrients from salmon carcasses facilitates growth in this amphipod.
Reduction of geitonogamy: Flower abscission for departure of pollinators
Authors: ITO ERIKO , KIKUZAWA KIHACHIRO
Published: March 2003

Overproduction of flowers increases the attractiveness of a plant to pollinators, but results in increased geitonogamy. In general, flower abscission has been considered to be an event subsequent to the overproduction of flowers. We observed pollinator behavior in Tilia, a self‐incompatible, insect‐pollinated tree. We found that pollinators sequentially visited inflorescences within a tree; however, when they met with flower abortion by abscission, they were apt to move long distances and leave the tree. We propose that plants may utilize flower abscission as a method for regulating the movements of pollinators by disturbing them in order to prevent geitonogamy.
Alarm response of hatchlings of the apple snail, Pomacea canaliculata (Gastropoda: Ampullariidae), to aqueous extracts of other individuals
Authors: ICHINOSE KATSUYA , YUSA YOICHI , YOSHIDA KAZUHIRO
Published: March 2003

We examined how hatchlings of the freshwater snail, Pomacea canaliculata, responded to aqueous extracts of conspecific hatchlings. Three, 3‐day‐old hatchlings were macerated in deionized water (1 mg hatchling per 1 ml water). When 0.5 ml of the aqueous extract was added to a test tube containing 10 hatchlings of the same age and 50 ml of water, the hatchlings in the water began to crawl out of the water within 5 min. The proportion of hatchlings that crawled out of the water approached 0.6–0.9 after 1 h, but gradually decreased to 0.4 after 24 h. The relatedness between the live and the macerated hatchlings had no significant influence on the response. Hatchlings of egg masses obtained either in the laboratory or in the wild responded similarly to aqueous extracts of hatchlings from either egg mass. This suggests that the conditions under which the egg masses were incubated or the conditions that their parents had experienced had no effect on the hatchlings’ response. When compared with experiments reported on other aquatic animals, we consider the behavior of the hatchlings to be an alarm response of escaping from predators.
Fatal methanol poisoning following home distillation of methylated spirits
Authors: Foley Bernard , Rogers Ian R
Published: March 2003

We present the case report of a 47‐year‐old man fatally poisoned by ingestion of a home‐distilled liquor produced from ‘methylated spirits’ containing 5% methanol and 90% ethanol. Classical signs of severe methanol poisoning, including altered conscious state, shock and profound acidosis were manifest at the time of presentation. Despite an ethanol infusion and haemodialysis he was declared brain dead 36 h after arrival at the emergency department.
Setting the benchmark for research in the management of acute pain in emergency departments
Authors: Kelly Anne‐Maree
Published: March 2003

Objective:

The aim of this study was to define the degree of change on a visual analogue scale that corresponded to a clinically meaningful reduction in the level of pain reported by patients experiencing acute pain.

Method:

Secondary analysis of data was performed from prospective, descriptive studies of 152 adults and 73 children presenting to emergency departments with acute pain. At presentation and at 20 min intervals to a maximum of three measurements, patients marked the level of their pain on a 100 mm, non‐hatched visual analogue scale. At each follow up, they also gave a verbal rating of their pain as ‘a lot better’, ‘a little better’, ‘much the same’, ‘a little worse’ or ‘much worse’. Data from the groups reporting that pain was ‘a lot better’ and ‘about the same’ were analysed for mean and median absolute change in visual analogue scale and compared.

Results:

Of 559 pain comparisons, 60 were rated as ‘a lot better’ and 257 as ‘about the same’. The mean absolute change in visual analogue scale for the group reporting that pain was ‘a lot better’ was 24 mm (median = 19 mm, 95% confidence interval = 17–31 mm). For the group reporting that pain was ‘about the same’, the mean visual analogue scale change was 0 mm (median = 0 mm, 95% confidence interval = −1 to 1 mm).

Conclusion:

When evaluating treatments for acute pain, a difference in visual analogue scale pain score of less than about 20 mm is unlikely to be clinically meaningful. Studies should be designed and reported relative to this benchmark rather than the minimum clinically significant difference in visual analogue scale pain score.
Implementation and evaluation of an undergraduate emergency medicine curriculum
Authors: Celenza Antonio , Jelinek George A , Jacobs Ian , Kruk Chris , Graydon Robert , Murray Lindsay
Published: March 2003

Objective:

To describe the implementation and evaluation of an undergraduate course in the first Australian academic emergency medicine unit.

Methods:

A descriptive study of a course involving fifth year medical students at the University of Western Australia was undertaken. Teaching included self‐directed case problem solving, small group tutorials, practical‐skills teaching, clinical attachments and information handouts. Evaluation involved questionnaire scores and written feedback regarding life‐support skills, tutorial teaching, course materials, clinical attachments and the course in general. Some groups of students underwent pre‐course and post‐course examinations.

Results:

Subjective and objective testing showed that student knowledge significantly improved. Feedback was especially positive toward clinical attachments in emergency departments, practical skills tutorials and the case‐based learning method. Students requested longer attachments to emergency departments, and more practical, case‐based, interactive and bedside teaching. Problems encountered included inadequate time for teaching, vagueness about student roles and objectives, and dealing with death for the first time without adequate preparation.

Conclusion:

Undergraduate emergency medicine education should become an essential part of Australian and international undergraduate medical education. Emergency medicine is enjoyable and eminently suitable for problem‐based, interactive and integrated teaching and improves confidence, clinical experience in emergencies, practical skills and teamwork. Improvements include more problem‐based teaching, more practical skills sessions and better definition of student roles. These are general principles that can be applied to other undergraduate courses and to designers of other emergency medicine courses, both undergraduate and postgraduate.
Abdominal Tuberculosis Revisited
Authors: Faylona Jmv , Chung Scs
Published: March 2003

Tuberculosis is still a major problem in Asia. An increase in transglobal migration, ageing patients, socioeconomic deprivation and the acquired immune deficiency syndrome thwart efforts in disease control. With failure to control pulmonary tubercular disease, increasing numbers of cases of extra‐pulmonary tuberculosis, such as abdominal tuberculosis, have been seen. Abdominal tuberculosis remains a diagnostic problem for surgeons. The signs and symptoms of abdominal tuberculosis are non‐specific and there is no specific diagnostic test. Helpful tests would include analysis of ascitic fluid, polymerase chain reaction test, the findings at laparoscopy and endoscopy and histology. Primary treatment is medical with surgery reserved for those patients developing complications. For biliary tuberculosis, a combination of endoscopy, surgery and medical treatment is required.
Hepatocellular carcinoma: Screening and non‐surgical treatment
Authors: Man‐Fung Yuen , Ching‐Lung Lai
Published: March 2003

Hepatocellular carcinoma (HCC) is the second commonest cancer in Hong Kong. Recent advances show that HCC can be derived from hepatocytes and from progenitor oval cells. Those from progenitor oval cells express both hepatocyte and biliary markers and are associated with poorer differentiation, more cellular proliferation, more aggressive clinical course and poorer prognosis. Patients with HCC usually present late and the choice of treatment modalities will be limited. Screening for early subclinical HCC in high‐risk groups is indicated. In patients diagnosed by screening, the clinical parameters were significantly more favourable, with a higher resectability rate, a higher chance of responding to transarterial chemoembolization (TACE) and a better survival. Treatment for HCC at present is still not satisfactory because of the late presentation, low resection rate, the high recurrence/new occurrence rate and the high prevalence of background cirrhosis. Surgical resection remains the first choice of treatment. However, there is a high recurrence rate. Medical treatment for inoperable HCC can be divided into systemic and local/regional therapy. To date, there are relatively few randomized controlled trials. Systemic therapy consists of the use of doxorubicin, alpha‐interferon, tamoxifen or combination therapy. For the local/regional therapy, alcohol injection and TACE with lipiodol are the two commonly used methods. Selective intra‐arterial infusion of 90yttrium has also been described. Randomized controlled trials are urgently needed to assess the efficacy of various medical treatments.

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Biliary‐enteric bypass in unresectable malignant hilar biliary obstruction: Kwong Wah Hospital experience
Authors: Yeung YP , AhChong AK , Wong WC , Yip AWC
Published: March 2003

Objective: To evaluate the efficacy of biliary‐enteric bypass in the palliation of malignant hilar biliary obstruction.

Materials and Methods: Records of 19 patients from 1995 to 1998 were reviewed. There were 13 patients with cholangiocarcinoma and 6 patients with carcinoma of the gallbladder. Single biliary‐enteric bypass had been performed in 13 of the patients; the rest had more than one biliary‐enteric anastomosis.

Results: The 30‐day mortality was 21% (4/19 patients). Bile leakage occurred in 2 patients, leading, in both, to fatality. Excluding the 30‐day mortality, the median survival of patients with carcinoma of the gallbladder and cholangiocarcinoma was 116 days (43–200) and 202 days (47–1207), respectively. The mean hospital stay was 31 days (13–59) and all patients were discharged with their symptoms relieved and a drop in bilirubin of at least two‐thirds their pre‐operative level. The late complication rate was 26.7% (4/15 patients).

Conclusion: Biliary‐enteric bypass is effective in the palliation of symptoms of patients suffering from unresectable hilar biliary obstruction, although it carries considerable mortality and morbidity. Stenting, rather than surgery, should be considered for patients with unresectable gallbladder cancer.
Right atrial thrombosis complicating Hickman catheter placement: A case report and literature review
Authors: Poon Jensen , Poon Ronnie Tung‐Ping
Published: March 2003

We describe a case of right atrial thrombosis complicating Hickman catheter placement in a patient with necrotising pancreatitis. Heparin therapy resulted in the further complication of peripancreatic haemorrhage. Literature on thrombo‐embolic complications after Hickman or Broviac catheter insertion is reviewed, and the optimum position for catheter placement is discussed.
Clinical experience of needle‐laparoscopic cholecystectomy
Authors: Luo Jian , Cai Zhiming , Huang Yuan
Published: March 2003

Forty‐eight cholecystectomy cases were successfully treated at Luohu hospital by needle laparoscopy. The patients were aged 22–69 years and included 36 cases of gallstones, 9 cases of gallbladder polyps, and 3 cases of gallbladder polyps with gallstones. All patients recovered and left hospital 1–3 days postoperatively (average 2.6 ± 0.6 days). There were minimal complications from the surgery and patients recovered quickly. Because the needle laparoscope is more difficult to use than the standard laparoscope, both surgeon and assistant must practise its use, first on cholecystitis cases with minor inflammation, especially in those patients whose gallbladder walls are thinner than 3 mm on ultrasound. Generally, the needle laparoscope is used for inserting titanium clips when the gallbladder is removed. The operation can best be performed by surgeons experienced in laparoscopic cholecystectomy using the standard laparoscope.
Management of overdrainage in cerebrospinal fluid shunting
Authors: Leung Km , Yam Ky , Fong Dawson
Published: March 2003

Objective: To reveal the effectiveness and safety of adding a single slit valve serially to the ventriculoperitoneal shunt system in order to reverse overdrainage.

Materials and Methods: The study is a retrospective review of clinical experience in a regional hospital (Tuen Mun Hospital, Hong Kong). A series of 10 cases are reported. All cases showed evidence of cerebrospinal fluid overdrainage after a ventriculoperitoneal shunt procedure. The advantages and disadvantages of other treatment options are also reviewed.

Results: The symptoms of all six patients who presented symptomatically subsided or improved after the procedure. Nine of the 10 patients had radiological improvement in their postoperative computed tomography scan. No procedure‐related complication occurred.

Conclusion: The early results of such a treatment option appeared safe and rewarding. However, longer term follow up and more experience is needed before the treatment’s efficacy can be proved definitely.
Is the change of bacterial flora after circumcision persistent?
Authors: Wong Wai‐Man , Lau Kwong‐Yau , Wong Che‐Yung , Tsui King‐Yiu , Lau Kwok‐Wai
Published: March 2003

A prospective study of 60 boys who had undergone circumcision in the summer of 1996 was performed at Department of Surgery, Tuen Mun Hospital, Hong Kong. In our previous study in 1996, we showed that there was significant reduction in uropathogens after circumcision in the early postoperative period (up to day 30). In the present longitudinal study, we showed that the change of peri‐urethral bacterial flora after circumcision persists for 18 months after operation in the same group of patients (51 of 60 patients from the previous study were recruited). There was no Staphylococcus aureus colonization in this study. The present study provides circumstantial evidence supporting the idea that circumcision in selected patients may confer long‐term protection from urinary infection.

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Impact of a preoperative programme in the delivery of elective operative service in a district general hospital in Hong Kong
Authors: Lee Kit‐Fai , Li Anthony Chi‐Ngai , Leong Heng‐Tat
Published: March 2003

A preoperative programme (POP) was introduced to improve the efficiency of operative service delivery and to enhance its quality. This paper is a prospective evaluation of a POP from February to July 1999 in the Department of Surgery, Alice Ho Miu Ling Nethersole Hospital. Of 528 bookings for POP, 15.3% of patients failed to attend, 4.9% of patients had their operation cancelled in POP, 70.3% of patients had their operation done as scheduled, while 9.5% did not. Reasons for non‐attendance, for cancellation of operation in POP and for failure of the operation to be done as scheduled were explored. The operation cancellation rate was 11.9%. Without POP, it was expected to be 29.7%. We recommend POP as a means to enhance efficiency and quality.
Supratentorial extraventricular ependymoma: Literature review and case report
Authors: Pang Kai‐Yuen , Ho Wilson Wai‐Shing , Wong Chi‐Keung
Published: March 2003

A 20‐year‐old male underwent surgery for an occipital extraventricular multicystic tumour. The tumour’s histology was high‐grade anaplastic ependymoma. The clinical course, its radiological appearance and the prognosis are discussed.

Chinese Abstract

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