bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomass diversity and stability of food webs in aquatic ecosystems
Authors: Aoki Ichiro , Mizushima Takahisa
Published: March 2003

The diversity–stability hypothesis in ecology asserts that biodiversity begets stability of ecological systems. This hypothesis has been supported by field studies on primary producers in grasslands, in which the interaction between species is mostly competition. As to ecosystems with multitrophic predatory interaction, however, no definite consensus has been arrived at for the relation between trophic diversity and ecosystem stability. The stability index suitable to ecosystems with predatory interaction is given by MacArthur's idea of stability and its formulation by Rutledge et al. More suitable indices of stability (relative conditional entropy) are proposed in this study for the comparison of different ecosystems, and the validity of the diversity–stability hypothesis for food webs (networks of predation) with many trophic compartments in natural aquatic ecosystems is examined. Results reveal that an increase in the biomass diversity of trophic compartments causes an increase in the whole systemic stability of food webs in aquatic ecosystems. Hence, evidence of the whole systemic validity of the diversity–stability hypothesis for natural aquatic ecosystems with ubiquitous multitrophic predatory interaction was obtained for the first time.
Germination and water dispersal of seeds from a threatened plant species Penthorum chinense
Authors: Ikeda Hiroaki , Itoh Kazuyuki
Published: March 2003

To conserve a threatened plant species (Penthorum chinense Pursh) in Japan, seed germination responses to pretreatment (imbibition and/or chilled), temperature and light, and seed dispersal by water were examined. The seeds collected from abandoned paddy fields in a warm temperate region, central Japan, germinated in light (14 h photoperiod; light 22°C, dark 21°C) after a moist‐chilled treatment. After this pretreatment, the seeds germinated well at 10–25°C (optimum temperature 15°C), but did not germinate in darkness even at the optimum temperature. Most of the seeds floated on distilled water, but 20–60% of the seeds that were collected from several populations sank in distilled water, indicating dimorphism in seed dispersal by water. The floating and sunken seeds did not show significant differences in weight and germination rate within a population. The addition of a surface‐active agent in distilled water submerged the seeds, indicating that the buoyancy of the seeds is attributable to an oil coating on the seed surface that enhances the interfacial tension on the seeds. Three times the number of seeds sank in river water collected from a rural area than in distilled water. A greater number of seeds also sank in water that had increasing concentrations of linear alkylbenzenesulfonate, which is a major component of synthetic detergents. This suggests that the water dispersal of this species is suppressed by surface‐active agents, including detergents, in river water.
Seasonal growth and reproductive ecology of two threatened aquatic macrophytes, Blyxa aubertii and B. echinosperma (Hydrocharitaceae), in irrigation ponds of south‐western Japan
Authors: Jiang Meiyi , Kadono Yasuro
Published: March 2003

Ecological life history and reproductive traits of two threatened aquatic macrophytes, Blyxa aubertii L.C. Richard and B. echinosperma (Clarke) Hooker, were studied in irrigation ponds in south‐western Japan. The size of plants varied greatly in both species but reproductive allocation was nearly constant irrespective of plant size at reproductive stage, amounting to 31.8% and 45.9% at maximum in B. aubertii and B. echinosperma, respectively. The number of flowers and total number of seeds produced per individual were associated significantly with plant size. Seeds were produced by self‐pollination both in emerged and submerged cleistogamous flowers and seed set rate of the two species was very high. These traits are considered to be adaptive to unstable environments that are liable to water level fluctuations, such as rice‐fields and irrigation ponds.
Tree shape, forest structure and diversity of drosophilid community: Comparison between boreal and temperate birch forests
Authors: Tanabe Shin‐Ichi , Toda Masanori J. , Vinokurova Alexandra V.
Published: March 2003

Some models, based on the latitudinal variation in sun angle distribution, predict that trees at high latitudes have narrowly conical crowns and constitute simple‐layered forests, whereas trees at low latitudes have shallowly dome‐shaped and form more structurally complex multilayered forests. There is a hypothesis that structurally complex habitats can harbor potentially more species than simple ones. In this study, we examined latitudinal correlations between tree shape, forest structure and diversity in drosophilid communities, comparing boreal and cool‐temperate forests. We selected secondary birch forests with a common canopy tree species, white birch (Betula platyphylla Sukatchev), as study sites. The crown shape of white birch tended to be spherical in the cool‐temperate forest, but narrowly conical in the boreal forest. The foliage structure differed between the two forests. The cool‐temperate forest was characterized by a clearly two‐layered structure, whereas foliage in the boreal forest was less clearly stratified, being distributed somewhat continuously from the ground to the canopy at lower densities. The structural complexity expressed by foliage height diversity was greater in the cool‐temperate forest than in the boreal forest. Various measures of drosophilid diversity were higher in the cool‐temperate forest than in the boreal forest, probably resulting from the impoverishment of the canopy subcommunity in the boreal forest. Thus, a physical environmental factor (i.e. the angle of solar inclination) could be a potentially important factor in structuring latitudinal patterns of sylvan animal communities through changes in plant structure at the individual and community levels.
Forest biomass estimation at regional and global levels, with special reference to China's forest biomass
Authors: Fang Jing‐Yun , Wang Zhang Ming
Published: March 2003

Accurate estimation of forest biomass size and regional distribution is a prerequisite in answering a long‐standing debate on the role of forest vegetation in the regional and global carbon cycle. Appropriate biomass estimation methods and available forest data sources are two key factors for this purpose. Among the estimation methods, the continuous Biomass Expansion Factor (BEF; defined as the ratio of all stand biomass to stem volume or biomass) method is considered to be the best. We applied the continuous BEF to forest inventory data of China and estimated a biomass carbon of 4.6 PgC and a biomass carbon density of 38.4 Mg ha–1. A review of recent literature shows that forest carbon density in major temperate and boreal forest regions in the Northern Hemisphere has a narrow variance ranging from 29 Mg ha−1to 50 Mg ha−1, with a global mean of 36.9 Mg ha−1. This suggests that the forest biomass density in China is closely coincident with the global mean.
Effects of food rewards offered by ant–plantMacarangaon the colony size of ants
Authors: Itino Takao , Itioka Takao , Hatada Aya , Hamid Abang Abdul
Published: March 2003

Myrmecophytes (ant–plants) have special hollow structures (domatia) in which obligate ant partners nest. As the ants live only on the plants and feed exclusively on plant food bodies, sap‐sucking homopterans in the domatia, and/or the homopteran's honeydew, they are suitable for the study of colony size regulation by food. We examined factors regulating ant colony size in four myrmecophyticMacarangaspecies, which have strictly species‐specific association withCrematogastersymbiont ants. Intra‐ and interspecific comparison of the plants showed that the ant biomass per unit food biomass was constant irrespective of plant developmental stage and plant species, suggesting that the ant colony size is limited by food supply. The primary food offered by the plants to the ants was different amongMacarangaspecies. Ants inMacaranga beccarianaandMacaranga bancanarelied on homopterans rather than food bodies, and appeared to regulate the homopteran biomass and, as a consequence, regulate the ants' own biomass. In contrast, ants inMacaranga winkleriandMacaranga trachyphyllarelied primarily on food bodies rather than homopterans, and the plants appeared to manipulate the ant colony size. Per capita plant investment in ants (ant dry weight plant dry weight−1) was different among the fourMacarangaspecies. The homoptera‐dependentM. beccarianaandM. bancanaharbored lower biomass of ants than the food‐body dependentM. winkleri, suggesting that energy loss is involved in the homoptera‐interposing symbiotic system which has one additional trophic level. The plants' investment ratio to the ants generally decreased as plants grew. The evolution of the plant reward‐offering system in ant–plant–homopteran symbioses is discussed with an emphasis on the role of homopterans.
A test of vegetation–environment relationship in serpentine soils of Tuscany, Italy
Authors: Chiarucci Alessandro , Rocchini Duccio , Leonzio Claudio , De Dominicis Vincenzo
Published: March 2003

The present study evaluates the relative importance of environmental factors in affecting the species composition and abundance of the plant communities on ultramafic soils in Tuscany, Italy. We used rigorous sampling techniques to test hypotheses generated from exploratory studies performed previously. Vegetation–environmental relationships were analyzed using 50 plots, each 1 m2, randomly located throughout a 22‐ha area in the Upper Tiber Valley. We confirm that the exchangeable fraction of nickel in the soil is almost never high enough to affect the vegetation. However, physical factors (e.g. substrate setting and elevation) are important in controlling the distribution of plant species. Tree cover (almost exclusively due to the introduced plantation pines) also had a significant affect on the vegetation composition and on soil features such as the C/N ratio. Other important factors significantly related to the gradients in vegetation composition (e.g. rockiness and total soil nitrogen) are interpreted as factors related to the vegetation composition through a positive feedback mechanism.
Towards a theoretical basis for ecosystem conservation
Authors: Rozdilsky Ian Douglas , Chave Jerome , Levin Simon Asagr , Tilman David
Published: March 2003

Humans have altered the environment so severely that extinction events are now occurring at rates unprecedented in modern history. In order to slow this trend, conservation actions must be taken to protect biodiversity, beyond just saving flagship species. Some governmental and conservation organizations have responded by committing to ecosystem conservation but, as yet, there is no coherent strategy for how this can be carried out. This report introduces many of the theoretical aspects that will need to be considered for the development of a coherent ecosystem conservation policy. The approach includes analyzing a hierarchy of interaction‐based local coexistence mechanisms within a regional and historical context. This approach points toward the need for prioritizing sensitive habitats using local interaction models; considering the effects of historical exploitation mechanisms, which are now often missing; and evaluating regional diversity influences further to identify circumstances where system‐wide habitat improvements deserve more emphasis.
An ecosystem organization model explaining diversity at an ecosystem level: Coevolution of primary producer and decomposer
Authors: Yamamura Norio , Yachi Shigeo , Higashi Masahiko
Published: March 2003

Ecological complexity of species interactions and habitat heterogeneity creates and maintains biodiversity at a trophic level in an ecosystem. This biodiversity simultaneously serves as raw material on which selective forces for organizing ecosystems operate. As a result of this organization process, differences in structure and functioning of ecosystems (diversity at ecosystem level) are generated. Although understanding diversity at the ecosystem level has attracted great interest, recent theoretical advances toward this aim have not been fully appreciated yet. Following Higashi
et al. (1993), this report presents a theoretical framework that deals with the organization process of an ecosystem as a consequence of the interactions among its biotic components and their modification of ecological traits. Specifically, the ecosystem organization process of a terrestrial ecosystem is analyzed, including primary producers and decomposers. This model sheds new insight into the differences between temperate and tropical forest ecosystems.
Reduced soil contributes to the anomalous occupation of dwarf communities in N‐richer habitats in a cool‐temperate mire
Authors: Nakamura Takatoshi , Yabe Kazuo , Komatsu Teruyuki , Uemura Shigeru
Published: March 2003

Spatial patterns of the oxidation–reduction potential (Eh) of soil, water level and chemistry were examined in the fen area of the Tohfutsu mire, northern Japan, where horse pasturage has been carried out throughout the growing season every year. The fen vegetation consisted mosaically of communities mono‐ or codominated by Eleocharis kamtschatica, Iris setosa and Carex lyngbyei. The highest

concentration of total dissolved nitrogen of soil water was observed in the dwarf

community dominated by E. kamtschatica with smaller biomass, whereas the nutrient

level was lower in the community monodominated by C. lyngbyei with larger biomass. Principal component analysis denoted well that Eh, N, K, and pH contributed to the differentiation of these communities significantly. During the growing season that was investigated, the highest nitrogen concentration was observed in midsummer, when plants are expected to absorb nutrients intensely, indicating that the supply of dissolved nitrogen far exceeded the nutrient uptake of plants. Multiple habitats with reduced soil were formed by submergence and by an excess of nitrogen due to pasturage, and the soil reduction indirectly inhibited the incursion of species with large biomass at such sites. It was demonstrated that soil Eh contributed to the anomalous pattern of vegetation where the supply of available nitrogen exceeds the uptake by plants.
Roles of food web and heterotrophic microbial processes in upper ocean biogeochemistry: Global patterns and processes
Authors: Rivkin Richard B. , Legendre Louis
Published: March 2003

The growth and dynamics of plankton in the ocean vary with natural cycles, global climate change and the long‐term evolution of ecosystems. The ocean is a large reservoir for CO2 and the food webs in the upper ocean play critical roles in regulating

the global carbon cycle, changes in atmospheric CO2 and associated global

warming. Microheterotrophs are a key component of the upper ocean food webs. Here,

we report on the results of an analysis of the distribution of bacteria and related

properties in the World Ocean. We found that, for the data set as a whole, there

is a significant latitudinal gradient in all field‐measured and computed bacterial

properties, except growth rate. Gradients were, for the most part, driven by an equator‐ward

increase in the Southern Hemisphere. The biomass, rates of production and respiration

and dissolved organic carbon concentrations were significantly higher in the Northern

than the Southern hemispheres. In contrast, growth rates were the same in the two

hemispheres. We conclude that the lower biomass and production in the Southern Hemisphere

reflects greater top‐down control by microbial grazers, which would be due to a lower

abundance or activity of omnivorous zooplankton in the Southern than Northern Hemispheres.

These large spatial differences in dynamics, structure and activity of the bacterial

community and the microbial food web will be reflected in different patterns of carbon

cycling, export and air–sea exchange of CO2 and the potential ability of the ocean to sequester carbon.
Change in body mass in relation to breeding phase in bull‐headed shrikes
Authors: Takagi Masaoki
Published: March 2003

Changes in body mass of both sexes of the bull‐headed shrike, Lanius bucephalus, were investigated over the six breeding phases of this species. Standardized body mass (SBM), which was defined as body mass divided by the length of the tarsus, of the males was relatively constant over the phrases, while the SBM of the females changed drastically. In the females, the SBM during egg‐laying was higher than the SBM in all the other breeding phases. The SBM of the females did not differ between the incubation and early‐nestling phases, and was lowest during the fledgling phase. Mass loss in bull‐headed shrikes did not correspond to an adaptive adjustment of body mass to permit a reduction in the power required for flight in the nestling period. It is likely that incubating females constantly maintain their body mass to invest in parental efforts from the incubating to nestling periods.
Vegetation gradients in relation to temporal fluctuation of environmental factors in Bekanbeushi peatland, Hokkaido, Japan
Authors: Asada Taro
Published: March 2003

The relationship between vegetation gradients and temporal variation of groundwater table depth, groundwater pH and electrical conductivity was studied in Bekanbeushi peatland, northern Japan. These environmental factors were expressed using four statistical parameters: maximum, minimum, mean and standard deviation or coefficient of variation during the growing season. The bog–fen–swamp/marsh gradient was primarily explained by minimum, maximum and mean groundwater table depth and minimum pH. The separation between the bog and the fen by minimum pH was particularly clear. Minimum conductivity was secondarily important for explaining this vegetation gradient. The swamp–marsh gradient was explained by the standard deviation of groundwater table depth. Maximum pH and conductivity were not significant in explaining either of these gradients. This study suggests that parameters that are obtained from the consecutive measurement of environmental factors may have differing significance in explaining vegetation gradients in these peatlands, and values from a single sampling may miss important ecological information.
Measuring the number of co‐dominants in ecological communities
Authors: Kikvidze Zaal , Ohsawa Masahiko
Published: March 2003

We suggest a concept that allows the objective determination of the number of co‐dominants in a community. We define co‐dominants as a subset of species that are more abundant and more uniformly distributed than other species in a given sample. We compare the sample with a model community and use Simpson’s diversity index to estimate the apparent number of co‐dominants. Dominant species determined in this way are responsible for 70–90% of the total measure of abundance in the sample. The statistical significance of the apparent number of co‐dominants may be assessed by a randomization test.
Hoarding of acorns by granivorous mice and its role in the population processes of Pasania edulis (Makino) Makino
Authors: Sone Koichi , Hiroi Sachiko , Nagahama Daisuke , Ohkubo Chiharu , Nakano Eiji , Murao Shun‐ichi , Hata Kunihiko
Published: March 2003

In order to evaluate the role of granivorous mice, Apodemus speciosus Temminck and Apodemus argenteus Temminck, in the regeneration of Pasania edulis (Makino) Makino, an evergreen tree, we conducted field studies examining acorn crops, the population dynamics and hoarding behavior of mice and pre‐ and postdispersal acorn predation in an evergreen broad‐leaved forest dominated by P. edulis in Kagoshima, southern Japan. The study was conducted from 1994 to 2000. Apodemus mice selected sound acorns and hoarded them in the soil after transporting them for distances ranging from 5.4 to 19.9 m. This behavior appeared to be beneficial to the establishment of seedlings of P. edulis. However, the positive effects were negated by a high rate of recovery of the acorns hoarded by the mice. A life‐table analysis of five cohorts of P. edulis indicated that postdispersal predation of acorns by Apodemus mice was a major contributor to annual variation in the number of new seedlings. A considerable number of acorns germinated only in years with a good acorn crop and a low level of resident mice. These results suggest that Apodemus mice are serious acorn predators rather than important dispersers. After germination, acorns were attacked by the acorn borer at a high rate. From these results, we can conclude that acorn production probably makes a smaller contribution to the regeneration of P. edulis than coppice shoot production at the study site.
Ontogenetic change in the diet of the pond frog, Rana nigromaculata
Authors: Hirai Toshiaki
Published: March 2003

I analyzed 478 diet samples of Rana nigromaculata across its natural size range to examine the dietary changes of this species during postmetamorphic ontogeny. As the frogs increased in size, they increased total diet volume, but decreased the number of prey items. Also, individuals ontogenetically increased the mean, minimum and maximum prey volume in the stomach. The mean volume of the major prey taxa consumed by the frogs varied considerably. Small prey, such as ants and dipterans, were found less frequently as the size of the frogs increased, but large prey, such as beetles and orthopterans, were more frequently recovered from larger frogs. These results suggest that ontogenetic diet change should be considered when the structure of an anuran community is investigated using food niche analysis.
Different impacts of two species of aphid‐attending ants with different aggressiveness on the number of emerging adults of the aphid's primary parasitoid and hyperparasitoids
Authors: KANEKO SHUJI
Published: March 2003

The impacts of two species of ants (Lasius niger and Pristomyrmex pungens) attending the cotton aphid (Aphis gossypii) on the number of emerging adults of the aphid's primary parasitoid (Lysiphlebus japonicus) and hyperparasitoids were assessed experimentally at a no‐pesticide mandarin grove. L. japonicus females were observed foraging frequently in aphid colonies attended by either ant species, with more females in P. pungens‐attended than in L. niger‐attended colonies, but rarely in aphid colonies where ants were artificially excluded. Females were less often attacked by P. pungens workers than by L. niger workers, so that they stayed longer and oviposited into more aphids in P. pungens‐attended than in L. niger‐attended colonies. Attendance by each ant species reduced predator numbers in aphid colonies, compared to colonies where ants were absent, although P. pungens was slightly less effective in repelling predators. Therefore, both ant species incidentally protected parasitized aphids from predators. Consequently, L. japonicus‐mummies were abundant in colonies attended by either ant species, with more mummies in P. pungens‐attended colonies, and were scarce in ant‐excluded colonies. The hyperparasitism and predation on L. japonicus larvae within mummies occurred more frequently in P. pungens‐attended than in L. niger‐attended colonies, but mummy predation rate was only 20% in the former. As a result, the number of emerging L. japonicus adults did not differ significantly between aphid colonies attended by the two ant species, but significantly more hyperparasitoids emerged in colonies attended by the relatively less aggressive P. pungens than in colonies attended by L. niger.
Microtopography and distribution of canopy trees in a subtropical evergreen broad‐leaved forest in the northern part of Okinawa Island, Japan
Authors: ENOKI TSUTOMU
Published: March 2003

The spatial distribution of trees in relation to topography was investigated using two topographic indices, slope steepness and slope configuration, in a 4‐ha plot in a subtropical evergreen forest in the northern part of Okinawa Island, Japan. Most species showed an aggregated distribution and patch size was related to various microtopographical features, including small ridges and valleys. In a cluster analysis based on the dissimilarity of each species’ distribution, the species were divided into three major clusters. A significant correlation between the dissimilarity and the distance between each species on the axis of the two topographic indices indicated that species association was, in part, explained by the topographic indices. I suggest that species distributed on steep and concave slopes regenerate depending on disturbances such as landslides on unstable topography, whereas species distributed on ridges and upper slopes regenerate depending on the canopy gap. A number of species that were less abundant in the 4‐ha plot occurred in the riparian area near a stream, where the density of more abundant species was low. The results of this study support the existence of habitat niche divergence related to topography in a subtropical evergreen broad‐leaved forest.
DNA sequence variation in the ITS‐1 rDNA subunit and host relationships in sorghum midge, Stenodiplosis sorghicola (Coquillett) (Diptera: Cecidomyiidae), in Australia
Authors: Congdon Bradley C , Kurniasih  , Franzmann Bernard A , Hardy Adam T
Published: March 2003

Sequence variation in the internal transcribed spacer (ITS‐1) ribosomal DNA subunit was examined for sorghum midge obtained from introduced and native hosts in south‐eastern and central Queensland. No variation was observed relative to host plant or geographical distance for midges collected from two introduced hosts, grain sorghum (Sorghum

bicolor) and Johnson grass (S. halepense); however, sequence differences

were observed between midges from introduced and native hosts and among midges from

a single native host, slender bluegrass (Dichanthium affine). No evidence

was observed of introduced midges on native hosts, or vice versa. These results agree

with previously hypothesised host distributions for native and introduced midges

in Australia, and expand the sample of introduced hosts to include Johnson grass.

They suggest that Stenodiplosis sorghicola, the principal midge infesting

grain sorghum, is also the most common species on Johnson grass. This confirms that

Johnson grass plays a role in the population dynamics of S. sorghicola and suggests that midges originating from Johnson grass may influence levels of infestation in grain sorghum.
Histiostoma papillata sp. n. (Acari: Histiostomatidae), a mite attacking fish in Australia
Authors: Halliday RB , Collins RO
Published: March 2003

Histiostoma papillata sp. n. (Acari: Histiostomatidae) is described from
Victoria, Australia. It was found in the fins and gills of juvenile Murray cod, Maccullochella
peelii peelii (Mitchell), where it appeared to inflict injuries thought to be responsible for the mortality of fish in a diet trial.
Comparison of feeding efficiency, development time and survival of Tasmanian eucalyptus leaf beetle larvae Chrysophtharta bimaculata (Olivier) (Coleoptera: Chrysomelidae) on two hosts
Authors: Baker Susan C , Elek Jane A , Candy Steven G
Published: March 2003

The native Eucalyptus leaf beetle Chrysophtharta bimaculata (Olivier)
(Coleoptera: Chrysomelidae) has become a pest of the introduced, plantation species,
Eucalyptus nitens Maiden in Tasmania, Australia. However, in the field it
prefers to oviposit on the Tasmanian native species, E. regnans F. Muell.
This laboratory study found that the performance of C. bimaculata larvae was
superior on foliage of E. nitens compared with E. regnans. Larval development
was 4 days shorter on E. nitens than on E. regnans foliage. Total food
consumption per larva and relative consumption rates were about 30% lower
while relative growth rates and weight of emergent adults were more than 25%
higher on E. nitens than E. regnans. Efficiency of conversion (ECI)
of fresh food into larval wet weight was 0.26 on E. nitens compared with 0.14
on E. regnans. Mortality of larvae feeding on E. nitens (23%)
was only one third of that on E. regnans (69%), a result of high first
instar mortality on E. regnans. Although the amount of foliage consumed per
larva was lower on E. nitens (0.23 g vs 0.32 g), the differential mortality
meant that the amount of E. nitens consumed per egg batch was 60%
more than that of E. regnans. If these results occurred in the field, then
the same monitored population of C. bimaculata eggs may result in heavier
defoliation of plantation E. nitens than of E. regnans. These data
show that the reported oviposition preference of C. bimaculata for E. regnans in the field cannot be explained by selection of host factors related to superior larval performance.
New species and new record ofTetranychusDufour from Australia, with a key to the major groups in this genus based on females (Acari: Prostigmata: Tetranychidae)
Authors: Flechtmann Carlos HW , Knihinicki Danuta K
Published: March 2003

A new species of spider mite,Tetranychus bundasp. n., is described and illustrated from Australia. It was found damaging the foliage ofDesmodium tortuosum(Sw.) DC. (Fabaceae) in Darwin, Northern Territory. In addition, the geographical range ofTetranychus fijiensisHirst is extended to include Australia. This species was found in the Northern Territory feeding on frangipani (Plumeriasp., Apocynaceae), betel palm (Areca catechuL., Arecaceae) and Macarthur feather palm (Ptychosperma macarthurii[H. Wendl. ex Veitch] (H. Wendl. ex Hook. f., Arecaceae)). Details of the biology ofT. bundasp. n. andT. fijiensisare given. A key to the major groups ofTetranychusDufour of the world, based on females, is presented and species known to occur in Australia are outlined.
A prospective randomized pilot comparison of intranasal fentanyl and intramuscular morphine for analgesia in children presenting to the emergency department with clinical fractures
Authors: Younge Paul A , Nicol Mark F , Kendall Jason M , Harrington Anthony P
Published: March 2003

Abstract

Objective: To evaluate the tolerability and efficacy of intranasal fentanyl analgesia for children.

Methods: A prospective, open‐label, two‐arm pilot study was conducted. Children, aged 3 to 10 years, with clinical limb fractures were randomized to receive 1 μg/kg intranasal fentanyl via nasal spray or 0.2 mg/kg intramuscular morphine. Tolerance to administration, pain scores, rescue analgesia, adverse events and physiological data were recorded at intervals over 30 min.

Results: Forty‐seven children were recruited to the study. Tolerance to administration was better for intranasal fentanyl compared with intramuscular morphine (median scores 1 vs 2; P < 0.001). Pain scores over the trial period were similar in both groups. One child receiving intranasal fentanyl required rescue analgesia. No significant adverse effects were noted.

Conclusions: Intranasal fentanyl provides effective paediatric analgesia comparable to intramuscular morphine and is better tolerated. A larger study is needed to determine dose range and confirm safety.
Hyperammonaemia with normal liver function: An uncommon cause of coma
Authors: Paoloni Richard , Green Tim
Published: March 2003

Abstract

Hyperammonaemia is an uncommon, but well‐described cause of coma. Most cases occur in patients with advanced liver failure. A case of hyperammonaemic coma in a 41‐year‐old woman with normal liver function is presented. Recurrent hyperammonaemia was secondary to a ureterorectal urinary diversion procedure performed during childhood. The pathophysiology, causes and management of hyperammonaemia are reviewed.
Safety of interhospital transport of patients with acute myocardial infarction
Authors: Hooi Herbert
Published: March 2003

Objectives: To describe the rate of complications in patients who undergo interhospital transport in the early stages of acute myocardial infarction and to determine whether instability in the emergency department is a predictor of these complications.

Methods: A retrospective medical record review of patients with proven acute myocardial infarction transferred from Wyong Emergency Department to Gosford Hospital in the period 1994–96 was performed.

Results: Three hundred and twenty‐three patients were transported. Four patients required an unplanned intervention; all four patients suffered hypotension and all had an intravenous nitroglycerin infusion. Three patients required fluid resuscitation and one patient developed supraventricular tachycardia with hypotension, treated by cardioversion. No other complications, cardiac arrest or deaths were recorded. Prior patient instability did not predict three out of four complications during transfer and did not predict any complications in non‐intubated patients.

Conclusion: Medical escort of stabilized non‐intubated patients in the early stages of acute myocardial infarction is probably unnecessary. Further prospective studies are needed to determine which patients with acute myocardial infarction can be safely transported without a medical escort.
Organizing and training the emergency department in the reception of major trauma
Authors: Flavin Brian M , Driscoll Peter A
Published: March 2003

Because mortality from trauma may be avoided, an organized approach to trauma patients is required. The trauma team provides an effective structure within which emergency staff, other medical specialities and paramedical staff resuscitate and treat trauma cases. Training, as individuals and as a team, is necessary. Clear criteria for trauma team calls are often not available, resulting in over‐ and under‐triage, but a minimum amount of information should be provided for the team prior to patient arrival. The team’s performance should be audited regularly to maintain and improve standards.
Slow‐release potassium overdose: Clinical features and the role of whole‐bowel lavage in management
Authors: Whitaker Richard J , Maguire John E
Published: March 2003

Poisoning with slow‐release potassium preparations is reported uncommonly in the medical literature; slow‐release potassium poisoning occurring in a child has not been reported previously. There is potential for death from hyperkalaemia, as well as significant potential morbidity from gastrointestinal side‐effects of the potassium preparations. Treatment of hyperkalaemia is paramount in stabilizing these patients, but previous reports have not strongly supported the role of vigorous gastrointestinal decontamination in the management of this overdose. We report a case of significant slow‐release potassium poisoning in a child, and discuss our management. The literature of slow‐release potassium poisoning is reviewed with an emphasis on the role and safety of gastrointestinal decontamination with whole‐bowel lavage.
Recognition and management of falciparum malaria
Authors: Davis Timothy ME
Published: March 2003

Falciparum malaria is a serious parasitic infection that, if left untreated, can give rise to a range of life‐threatening complications. Prompt recognition depends on a high index of suspicion and a detailed history identifying possible malaria risk factors. Symptoms and signs, apart from periodic fever in some cases, are typically non‐specific. Even in cases of severe falciparum malaria with vital organ involvement, the differential diagnosis can be broad. The gold standard diagnostic test is blood film microscopy but antigen detection tests have become available as an alternative. Other laboratory tests can, together with the history and examination findings, help confirm the diagnosis and provide data relating to the nature and severity of complications. Management of malaria involves prompt administration of effective antimalarial drugs and prevention or amelioration of complications such as coma (cerebral malaria), renal failure and acidosis. Oral treatment is usually given to patients with uncomplicated malaria while therapy should be administered parenterally in severe cases. Conventional drugs such as quinine are still useful but the artemisinin derivatives are rapidly acting antimalarial drugs that are increasingly used as first‐line therapy in tropical countries. Most adjunctive therapies assessed specifically for their effectiveness against complications have proved disappointing but some (such as prophylactic phenobarbitone and exchange transfusion) can complement generic management protocols that remain the cornerstone of intensive care for the severely ill patient with malaria.
Nerve stimulator‐assisted femoral nerve block in the emergency department
Authors: Stella Julian , Ellis Rod , Sprivulis Peter
Published: March 2003

Objective: To describe the technique of femoral nerve block using a nerve stimulator to locate the nerve, and to report the success rate of its use by junior and senior doctors in the emergency department.

Method: Standardized protocol and patient selection criteria were formulated for the performance of femoral nerve block on patients with femoral neck or shaft fractures using a nerve stimulator to locate the femoral nerve and confirm deposition of local anaesthetic agent close to the femoral nerve. Femoral nerve blockade was assessed before and after femoral nerve block by testing for altered sensation in the cutaneous distribution of the femoral nerve. Pain was assessed before and after femoral nerve block using a visual analogue scale. The use of supplementary analgesics was recorded.

Results: A successful femoral nerve block was obtained with the nerve stimulator in 19 of 22 attempts (86%) at femoral nerve block. Success was unrelated to seniority of staff. Femoral nerve block was the only analgesia required in 17 patients (77%). Femoral nerve block was the only analgesia required for 100% for femoral shaft fractures and 75% and 73%, respectively, for extra‐capsular and intracapsular fractures of the femoral neck.

Conclusion: The femoral nerve was accurately located using the nerve stimulator irrespective of seniority of staff performing the procedure. Femoral nerve block using the nerve stimulator was effective analgesia for femoral shaft fractures and the majority of both intra‐ and extra‐capsular femoral neck fractures.
Absence of ice‐cream interference with the adsorption of paracetamol onto activated charcoal
Authors: Teubner David JO
Published: March 2003

Aims: To measure the extent to which the addition of ice‐cream to activated charcoal interferes with its ability to adsorb paracetamol.

Method: Activated charcoal, ice‐cream and both charcoal and ice‐cream were added to stock solutions of paracetamol at both simulated gastric and intestinal pH at charcoal : paracetamol ratios of 3:1, 5:1 and 10:1. The samples were centrifuged and the supernatant assayed for paracetamol concentration.

Results: When the charcoal : paracetamol ratio was 3:1, charcoal alone adsorbed 65% of the available paracetamol, and charcoal with ice‐cream adsorbed 57%. When the ratio was 5:1, charcoal alone adsorbed 92% of the available paracetamol and charcoal with ice‐cream 90%. When the ratio was 10:1, charcoal alone adsorbed 100% of the available paracetamol and charcoal with ice‐cream 99%. The results were independent of pH.

Conclusions: The practice of adding ice‐cream to activated charcoal to improve palatability does not decrease the ability of the charcoal to adsorb paracetamol in vitro, especially if charcoal : drug ratios are above 5:1.
Same‐day X‐ray reporting is not needed in well‐supervised emergency departments
Authors: Sprivulis Peter , Frazer Amanda , Waring Andrew
Published: March 2003

Objective:

To evaluate the efficacy of a missed radiological abnormality follow‐up system in a teaching hospital emergency department.

Methods:

Prospective audit of all reported radiological abnormalities missed by Fremantle Hospital Emergency Department medical staff from 1 January 1997 to 31 December 1998.

Results:

Of 29 724 radiological examination series, 459 abnormalities (1.5%) were not clearly documented as being identified in the medical record. The commonest missed abnormalities were incidental chest findings, distal wrist fractures with minimal or no displacement, radial head fractures and tibial plateau fractures. The most senior doctor undertaking initial film review was a junior medical officer in 242 cases (53%), a registrar in 96 cases (21%), and a consultant in 42 cases (9%). The most senior staff member was unknown in 79 cases (17%). One hundred and twenty‐four missed abnormalities required a change in patient management (0.41% of total examinations, CI 0.34–0.48%). Ninety patients (73%) were referred to the patient’s general practitioner for management. Seventeen patients (14%) returned to the emergency department for management. Thirteen patients (10%) were referred to a specialist clinic and in four cases (3%) the management of the patient was not recorded. No patient required re‐admission to hospital.

Conclusions:

Missed radiological abnormalities in an emergency department with extended‐hours emergency physician supervision can be managed non‐urgently on an outpatient basis. Same‐day reporting of radiographs is not required if adequate follow‐up mechanisms for missed abnormalities exist.
Another cause for bilateral haemorrhagic otorrhoea following trauma
Authors: Swain Andrew , Jeffery Penelope , Hughes Geoffrey , Nowitz Michael
Published: March 2003

Bleeding from the external auditory meatus (haemorrhagic otorrhoea) following head trauma is usually attributed to a basal skull fracture. However, it may also result from unsuspected facial trauma. We describe a case that highlights an usual but important differential diagnosis for bilateral haemorrhagic otorrhoea.
Paediatric sedation in emergency departments: What is our practice?
Authors: Everitt Ian , Younge Paul , Barnett Peter
Published: March 2003

Objectives: The aim of the present study was to document the use of sedation in paediatric patients in emergency departments within Australia and New Zealand.

Methods: A questionnaire was sent to 54 emergency departments throughout Australia and New Zealand.

Results: A total of 45 departments (83%) responded to the survey. Because the adult departments (n = 5) reported few paediatric attendances, they were not included in the analysis. Thirty‐nine of 40 departments (97.5%) reported using sedation in children. Midazolam was used most frequently (77%) for sedation. There was marked variation in the route of delivery and the dose of midazolam used. Ketamine was reported as the most efficacious agent used, but it was used only in 12% of cases. Formal guidelines existed in all paediatric departments but only in 58% of mixed departments, and formal discharge criteria were used in only 52% of all departments. The use of topical anaesthesia in wound closure was reported in only 30% of departments.

Conclusions: There exists wide variation in practice regarding the use of sedation in children in emergency departments throughout Australia and New Zealand. Thus, the development of adequate guidelines, including discharge instructions and the use of topical agents, will improve sedation for children.
Non‐invasive positive pressure ventilation in patients with acute respiratory failure
Authors: Hore Craig T
Published: March 2003

Non‐invasive positive pressure ventilation is an emerging modality in contemporary critical care practice. Perhaps the most widely utilized and familiar form of non‐invasive positive pressure ventilation is mask continuous positive airway pressure. Other common modes include mask Bi‐level positive airway pressure and mask pressure support ventilation. All feature the delivery of positive airway pressure via a mask (full‐face, naso‐oral or nasal), and a patient‐controlled respiratory cycle. The physiological benefits of non‐invasive positive pressure ventilation suggested by a number of studies include improved oxygenation, decreased work of breathing, improved ventilation and perfusion matching, decreased fatigue, and increased minute ventilation. The utilization of non‐invasive positive pressure ventilation has now been reported for a variety of clinical indications. In most, randomized trials are lacking, and the benefits and preferred mode of non‐invasive positive pressure ventilation are still to be elucidated. In general, in patients that are candidates for endotracheal intubation, non‐invasive positive pressure ventilation should be used as a way to possibly avoid endotracheal intubation rather than as an alternative to endotracheal intubation. Whilst the benefit of non‐invasive positive pressure ventilation appears to be established in patients with chronic obstructive airways disease with hypercapnic acute respiratory failure, one of the major unresolved issues is whether one modality is significantly better than the others. Unfortunately, the question of whether Bi‐level positive airway pressure is better than continuous positive airway pressure in this clinical scenario has not been satisfactorily addressed in any large randomized and controlled clinical trial. Further, there is no ‘gold standard’ for predicting success with non‐invasive positive pressure ventilation, although several studies have looked at this aspect.
Unexplained drowsiness and progressive visual loss: Methanol poisoning diagnosed at autopsy
Authors: Weinberg Laurence , Stewart Jonathan , Wyatt Jonathan Paul , Mathew Joseph
Published: March 2003

A patient was admitted to the emergency department with a reduced level of consciousness and deteriorating vision. Her pupils became fixed and dilated and she developed a third nerve palsy with extensor posturing of her limbs. Biochemistry profile showed an increased serum osmolar gap with a raised anion gap metabolic acidosis. Supportive treatment was instituted, but she made no recovery and brainstem death was later confirmed. Post mortem examination and toxicology screen confirmed the cause of death as methanol poisoning leading to cerebral oedema and transtentorial herniation. We highlight some of the diagnostic difficulties associated with treating a patient with a reduced level of consciousness. The clinical and biochemical findings that are critical in establishing a diagnosis of methanol intoxication are discussed. The definitive management of methanol poisoning is reviewed.
Impact of antenatal diagnosis on perinatal management of omphalocele and gastroschisis
Authors: Poon Jensen , Chan Kwong Leung
Published: March 2003

Omphalocele and gastroschisis are rare congenital abnormalities that always present as challenging problems to clinicians. Antenatal diagnosis provides important information for evaluation of prognosis and planning of management of these conditions. In this article, current application of antenatal diagnosis and perinatal management of omphalocele and gastroschisis are reviewed.
Collecting duct carcinoma presenting as a bleeding complicated renal cyst
Authors: Cheung() Man‐Chiu , Lo () Siu‐Hung , Khoo () Ui‐Soon , Tam () Po‐Chor
Published: March 2003

Collecting duct carcinoma is a rare type of renal cell carcinoma. It is usually diagnosed pathologically and carries a poor prognosis. Renal cell carcinoma arising within a cyst is also rare. We report a case of collecting duct carcinoma presenting as a giant, bleeding complicated renal cyst with minimal solid component. The patient had a relatively long survival after nephrectomy.

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Granulomatous mastitis
Authors: Mak Siu‐King , Wong Pik‐Kei , Lee Danny Wai‐Hung , Chan Angus Chi‐Wai
Published: March 2003

Granulomatous mastitis is a rare, benign breast disease that can mimic carcinoma. This report describes the clinical and pathological features of two patients presenting with breast abscesses. Both patients required a drainage procedure for the abscesses before a definite diagnosis could be made. Granulomatous mastitis must also be differentiated from other known causes of granulomatous inflammation such as tuberculosis, which is common in Hong Kong. The management of granulomatous mastitis remains controversial. Surgery alone may not prevent subsequent recurrence. Nevertheless, it is important to have operative specimens examined histologically so that a patient’s prognosis can be better understood.