bluuebunny/crossref_metadata_2025 huggingface dataset:
The distribution of aquatic invertebrate egg masses in relation to physical characteristics of oviposition sites at two Victorian upland streams
Authors: Reich Paul , Downes Barbara J.
Published: August 2003

1. Various physical variables were measured at rocks potentially used by lotic macroinvertebrates as oviposition sites at multiple locations on two occasions along the Acheron and Little Rivers, south‐eastern Australia. The associations between these parameters and the presence/absence and abundance of aquatic insect egg masses were explored as well as the small‐scale distribution of egg masses on individual rocks.

2. Physical features that characterise oviposition sites of 17 different aquatic taxa are presented. No obvious differences in patterns of oviposition site selectivity were apparent between multiple sampling times or locations. For some common taxa, multivariate analyses revealed that measurements of rock size and local current speed were positively related to the likelihood of an egg mass being present. However there were no consistent relationships between the abundance of egg masses and either of these variables.

3. The small‐scale distribution of egg masses on individual rocks revealed patterns in relation to surfaces that clearly differed as oviposition habitat, such as the underside, upstream and downstream surfaces. Presumably, these patterns are the result of small‐scale variation in flow conditions that characterise these particular rock surfaces.

4. The results of this study indicate that the oviposition strategies of a number of aquatic taxa may be reasonably predictable based on measurable physical parameters. These findings have important implications for future studies wanting to incorporate the adult and egg life history stages of lotic insects into studies of population dynamics.
Local disturbance history affects patchiness of benthic river algae
Authors: Matthaei Christoph D. , Guggelberger Cornelia , Huber Harald
Published: August 2003

1. Recent research has shown that high‐flow events in streams leave a small‐scale mosaic of bed patches that have experienced scouring, sediment deposition (fill), or remained stable. Few studies have investigated if this ‘local disturbance history’ contributes to the patchy distribution of benthic organisms in streams and rivers.

2. In the present research, we demonstrate that local disturbance history in a mid‐sized river can have both short‐ and long‐term effects on epilithic algae. Chains buried vertically in the substratum of the river bed (236 in a 800‐m reach) indicated that two floods (return periods ≤1 year) caused a mosaic of bed patches with different disturbance histories. Once after the first and twice after the second flood, we sampled epilithic algae (mainly diatoms) in replicate patches that had been scoured, filled, or remained stable during the respective event. Algal biomass and cell density per substratum area were determined.

3. Three months after the first flood, algal biomass, total diatom density, diatom taxon richness, and densities of six of nine most common taxa were highest in fill patches. Six days after the second flood, biomass was highest in stable patches, indicating a refugium function of these patches. The refugium patches consisted of average‐sized stones, in contrast to previous studies of flood refugia for benthic algae in which these refugia were always large and/or immobile substrata. Four weeks after the second flood, diatoms tended to be most abundant in scour patches. With one exception, these differences between patch types could not be attributed to differences in local near‐bed current velocity or water depth.

4. The effects of disturbance history were more complex than a simple refugium function of stable patches because algal patterns changed with time since the last disturbance, possibly depending on the successional state of the algal mats.
Breakdown of tussock grass in streams along a gradient of agricultural development in New Zealand
Authors: Niyogi Dev K. , Simon Kevin S. , Townsend Colin R.
Published: August 2003

Summary 1. We measured the breakdown rate of tussock grass in 12 New Zealand streams in catchments that provided a gradient of agricultural development. We also examined the microbial and invertebrate communities associated with decomposing tussock litter.

2. Pristine streams in the study had low concentrations of dissolved inorganic nitrogen (<10 μg L−1) and dissolved reactive phosphate (<3 μg L−1), whereas streams in the most developed catchments had high concentrations of nitrate (>2500 μg L−1) and phosphate (35 μg L−1), as well as greater amounts of suspended sediment and fine sediment covering the streambed.

3. Breakdown rate and microbial respiration were significantly related across the sites, and both were positively related to concentrations of nitrate and phosphate. Fungal biomass, measured as ergosterol, was positively related to microbial respiration and was also higher at sites with higher concentrations of nutrients. Total and shredding invertebrates were most abundant at the sites with high nutrient concentrations, but abundance of shredding invertebrates was not significantly related to breakdown rate. Amphipods were the most common shredding invertebrate at most sites, but probably did not contribute greatly to high rates of breakdown in streams in agricultural catchments.

4. With the exception of one site, nutrients from agricultural development appeared to have larger positive effects on litter breakdown than negative effects from sedimentation. Litter breakdown can serve as a functional measure of ecosystem health in streams, but caution should be exercised when a stress, such as land use, can have both positive (nutrients) and negative (sedimentation) effects.
A landscape approach to examining spatial patterns of limnological variables and long‐term environmental change in a southern Canadian lake district
Authors: Quinlan Roberto , Paterson Andrew M. , Hall Roland I. , Dillon Peter J. , Wilkinson Anna N. , Cumming Brian F. , Douglas Marianne S. V. , Smol John P.
Published: August 2003

1. We explored patterns of limnological variables (physical, chemical and biological) with relation to landscape position (expressed as lake order) in 86 study lakes located on shield bedrock in south‐central Ontario, Canada.

2. Using anovas with lake order as the categorical variable, landscape position explained significant amounts of variation in major ion chemistry, physical and catchment characteristics, hypolimnetic oxygen, and community composition in algal (diatom, chrysophyte) and invertebrate (chironomid) assemblages preserved in surficial sediments. Several nutrient variables (TP, total phosphorus and TN, total nitrogen) and dissolved organic carbon did not have significant relationships with lake order.

3. The strongest relationships with lake order (as a fraction of variation explained in anovas) included silica concentrations (r2 = 0.40) and SO4 (r2 = 0.29) concentrations, surface area (r2 = 0.50) and hypolimnetic oxygen (r2 = 0.29).

4. Bedrock geology (carbonate metasedimentary versus non‐carbonate bedrock) had strong influences on spatial gradients of pH and major ion chemistry. It was difficult to separate geological influences from spatial influences on limnological variables in this study, as drainage patterns in the region are highly influenced by surface features of underlying geological formations because of the very thin glacial till or exposed bedrock that exists in most catchments.

5. Patterns of limnological variables indicated that low‐order, headwater lakes had the lowest concentrations of major ions, and, from algal inferences of pH change, had been most susceptible to acidic deposition. High‐order, downstream lakes were larger and deeper, and had higher concentrations of hypolimnetic oxygen, indicating that optimal lake trout habitat was primarily located in high‐order lakes.

6. Variance partitioning analyses indicated that lake order as a metric of landscape position explained comparable portions of community variation in algal and invertebrate assemblages compared with geographic position (latitude, longitude) and Cartesian coordinate position (e.g. x, y, x2, y2, etc.) metrics. Lake order explained more community variation in chironomid assemblages compared with other landscape metrics, possibly because of the strong relationships between lake order and lake morphometry variables.
Interspecific interference and the functional response of four species of carnivorous stoneflies
Authors: Elliott J.M.
Published: August 2003

1. A previous study compared the functional responses to their prey and intraspecific interference in mature larvae ofPerlodes microcephalus,Isoperla grammatica,Dinocras cephalotesandPerla bipunctata. The present study extends this work by assessing interspecific interference between pairs of these species in equal numbers (one, two or three larvae per species) to provide total predator densities of two, four or six larvae.Baetislarvae as prey were replaced as they were eaten, and their density per predator was varied between 20 and 200 larvae.

2. The number of prey eaten by each competing species increased curvilinearly with prey density, the relationship being well described by a Type II model. Of the two constants in the model, handling time varied considerably between species, mean values being shortest forPerlodes,slightly higher forIsoperla,and much higher forDinocrasandPerla. It was not affected significantly either by predator density or the identity of the competing species.

3. Attack rate also varied between species and decreased with predator density. This decrease was slight forPerlodes,and also forDinocrasandPerlain competition withIsoperla. The decrease inDinocrasandPerlawas similar to that for intraspecific interference.

4. The decrease in attack rate was described by a convex curve forPerlodeswith the other three species and forDinocras/PerlawithIsoperla,but by a concave curve (negative power function) forIsoperlacompeting with the other three species, and for bothDinocrasandPerlain competition withPerlodes. Prey consumption also decreased with predator density, the severity of competition with different species reflecting that for attack rate.

5. A comparison with previous results for intraspecific interference showed that the latter was dominant forPerlodesin all contests and forDinocrasorPerlacompeting withIsoperla,whilst interspecific interference dominated forIsoperlain all contests and forDinocrasandPerlacompeting withPerlodes. Both types of interference were applicable to competition betweenDinocrasandPerla.Isoperlawas the least, andPerlodesthe most, aggressive of the four species withDinocrasandPerlaintermediate.
Toxin production of cyanobacteria is increased by exposure to zooplankton
Authors: Jang Min‐Ho , Ha Kyong , Joo Gea‐Jae , Takamura Noriko
Published: August 2003

1. Cyanobacterial toxin production in response to direct and indirect zooplankton feeding activity was examined using four strains of Microcystis aeruginosa, of which three were previously reported to be toxic to zooplankton and one non‐toxic. Direct (Microcystis cultured with zooplankton) and indirect effects (Microcystis cultured with filtered zooplankton culture media, ZCMF) were tested for the zooplankton species, Moina macrocopa, Daphnia magna or D. pulex.

2. With direct exposure to zooplankton, increased mass‐specific microcystin productions occurred in all Microcystis strains, with mean microcystin concentrations up to five times greater (61.5–177.3 μg g−1 dry cell) than the controls.

3. With indirect exposure, mass‐specific microcystin production increased over controls in three strains of M. aeruginosa. Mean maximum concentrations of microcystin during the experiment were 92.6–125.7 μg g−1 dry cell.

4. These results suggest that several strains of Microcystis aeruginosa increased toxin production in response to direct and indirect exposure to herbivorous zooplankton of several species, and support the hypothesis that this response is an induced defence mediated by the release of info‐chemicals from zooplankton.
Stay cool: habitat selection of a cyclopoid copepod in a north temperate oligotrophic lake
Authors: Makino Wataru , Yoshida Takehito , Sakano Hiroyuki , Ban Syuhei
Published: August 2003

1. We studied the vertical distributions of Cyclops cf. sibiricus in Lake Toya, a north temperate oligotrophic lake. During the winter circulation period, their distribution was vertically homogeneous both day and night. During the summer stratification period, C. cf. sibiricus stayed below the thermocline. Diel vertical migration (DVM) was pronounced in advanced developmental stages, although the upper limit of the migration became deeper as the thermocline gradually descended. This seasonal change was observed throughout the 4‐year study period, implying that thermal structure is the primary determinant of C. cf. sibiricus distribution.

2. In a field experiment, C. cf. sibiricus incubated in the summer epilimnion, which most of the population never experience, developed faster and grew better than in their original habitat. We consider that trans‐thermocline DVM would not have evolved because of possible disadvantages such as the cost of migration offset the benefit observed in the field experiment. The rapid temperature change at the thermocline may act as a swimming‐cost estimator for the copepod.

3. Low food availability in deep water during the summer stratification period seemed to determine the lower limit of C. cf. sibiricus distribution, and the copepod minimised the risks of predation by fish via DVM. These results suggest that C. cf. sibiricus modified their distribution seasonally to obtain maximum benefit in terms of individual fitness.
Ontogenetic shifts in habitat use by the endangered Roanoke logperch (Percina rex)
Authors: Rosenberger Amanda , Angermeier Paul L.
Published: August 2003

1. Conservation of the federally endangered Roanoke logperch (Percina rex, Jordan and Evermann) necessitates protection of habitat that is critical for all age classes. We examined habitat use patterns of individual logperch to determine: (1) if age classes of logperch in the Nottoway and Roanoke Rivers exhibit habitat selectivity, (2) if age classes differ in habitat use, and (3) if ontogenetic patterns of habitat use differ between the Roanoke and Nottoway river populations.

2. In the summers of 2000 and 2001, we observed 17 young‐of‐year (YOY) logperch [<4 cm total length (TL)], 13 subadult logperch (4–8 cm TL), and 49 adult logperch (>8 cm TL) in the upper Roanoke River, and 40 subadult and 39 adult logperch in the Nottoway River, Virginia.

3. All size classes of Roanoke logperch demonstrated habitat selectivity and logperch used a wide range of habitats in the Roanoke and Nottoway rivers during ontogeny. Habitat use by logperch varied among age classes and between rivers.

4. In the Roanoke River, adult and subadult logperch primarily preferred run and riffle habitat, often over gravel substrate. Subadults were found in lower water velocities and slightly more embedded microhabitats than adults. YOY logperch were found in shallow, stagnant backwaters and secondary channels. In the Nottoway River, both adult and subadult logperch were found over sand and gravel in deep, low‐velocity pools and runs. Subadults were observed in slightly more silted, lower velocity habitat than adults. Shifts in habitat use were more distinct between age classes in the Roanoke River than the Nottoway River.

5. Successful conservation of this species will involve sound understanding of spatial variation in habitat use over logperch life history and preservation of the ecological processes that preserve required habitat mosaics.
Conversion of leaf litter to secondary production by a shredding caddis‐fly
Authors: González J.M. , Graça M.A.S.
Published: August 2003

Summary 1. The aim of this study was to estimate the amount of leaf litter ingested by the shredder caddis‐fly Sericostoma vittatum in a small stream in central Portugal. The study combined field data on population dynamics and laboratory experiments to determine the effect of temperature (9, 12, 15 and 18 °C), leaf species (Alnus glutinosa, Castanea sativa, Populus × canadensis and Quercus andegavensis) and animal mass on growth and consumption rates of the larvae.

2. Sericostoma vittatum had two overlapping cohorts, each of which needed about 1 year to complete development. Mean annual density and biomass were 115 individuals m−2 and 83 mg m−2, respectively. Secondary production was 0.44 g m−2 year−1 and production/biomass ratio was 4.9–5 year−1.

3. Consumption rates of larvae increased with temperature up to the optimal temperature for growth which varied between 13.7 and 16.7 °C depending on the diet.

4. Consumption rate was positively related to larval mass but growth rate was negatively related with larval mass. Larvae fed on A. glutinosa and P. × canadensis had higher consumption and growth rates than those fed on C. sativa or Q. andegavensis.

5. Annual leaf litter consumption by S. vittatum was estimated as 14–22 g m−2 depending on the diet. No relationship was observed between the amount of detritus consumed by the population of this caddis‐fly in the field and either water temperature, the stock of detritus on the stream bottom, or larval abundance. Instead, the temporal dynamics of leaf litter consumption by S. vittatum were controlled by its life history.

6. This study highlights the influence of factors such as animal size and water temperature on the invertebrate energetics. Models explaining how these variables affect invertebrate production efficiency may be very important for obtaining accurate estimates of the role of shredders in the energy flow across stream ecosystems.
Predator‐induced phenotypic plasticity in the exotic cladoceran Daphnia lumholtzi
Authors: Dzialowski Andrew R. , Lennon Jay T. , O'Brien W.J. , Smith Val H.
Published: August 2003

1. The exotic cladoceran Daphnia lumholtzi has recently invaded freshwater systems throughout the United States. Daphnia lumholtzi possesses extravagant head spines that are longer than those found on any other North American Daphnia. These spines are effective at reducing predation from many of the predators that are native to newly invaded habitats; however, they are plastic both in nature and in laboratory cultures. The purpose of this experiment was to better understand what environmental cues induce and maintain these effective predator‐deterrent spines. We conducted life‐table experiments on individual D. lumholtzi grown in water conditioned with an invertebrate insect predator, Chaoborus punctipennis, and water conditioned with a vertebrate fish predator, Lepomis macrochirus.

2. Daphnia lumholtzi exhibited morphological plasticity in response to kairomones released by both predators. However, direct exposure to predator kairomones during postembryonic development did not induce long spines in D. lumholtzi. In contrast, neonates produced from individuals exposed to Lepomis kairomones had significantly longer head and tail spines than neonates produced from control and Chaoborus individuals. These results suggest that there may be a maternal, or pre‐embryonic, effect of kairomone exposure on spine development in D. lumholtzi.

3. Independent of these morphological shifts, D. lumholtzi also exhibited plasticity in life history characteristics in response to predator kairomones. For example, D. lumholtzi exhibited delayed reproduction in response to Chaoborus kairomones, and significantly more individuals produced resting eggs, or ephippia, in the presence of Lepomis kairomones.
In situexperiments on the effects of increased sediment loads on littoral rocky shore communities in Lake Tanganyika, East Africa
Authors: Donohue Ian , Verheyen Erik , Irvine Kenneth
Published: August 2003

1. Twoin situexperiments investigated the responses to artificially increased sediment loads of the gastropod and fish communities, and of the whole benthos, of the rocky shores of Lake Tanganyika. Sediments were emptied once onto randomly selected quadrats using SCUBA, with control quadrats receiving no addition of sediment. Quadrats were monitored up to 6 months after sediment addition.

2. While the abundance ofLavigeria grandis(Mollusca; Gastropoda) was reduced greatly by the addition of sediment, low abundance and biomass of the whole gastropod community on sediment‐impacted quadrats 6 months after sediment addition suggests more general impacts of inundation in the longer term.

3. Benthic invertebrate communities inundated by sediment had significantly fewer individuals and numbers of taxa than control communities. No significant community recovery was recorded on sediment‐impacted quadrats within the timescale of the experiment. A short‐term period of high turbidity brought about by the emptying of sediments onto sediment‐impacted quadrats also caused severe decreases in benthic invertebrate abundance on controls 10 days after sediment addition. This suggests that even short‐term pulses of sediment may have significant detrimental effects on littoral communities.

4. Although significant impacts of sediment on fish community dynamics were found, and a significant reduction in the number of benthic algivorous species was recorded immediately after sediment addition, littoral fish communities showed strong resistance overall to the addition of sediments. This apparent resistance, however, may be a consequence of the small scale at which the experiment took place. Littoral fish communities were also shown to be more dynamic than indicated previously.
Midsummer spatial variation in methane efflux from stands of littoral vegetation in a boreal meso‐eutrophic lake
Authors: Kankaala Paula , Mäkelä Suvi , Bergström Irina , Huitu Eeva , Käki Tiina , Ojala Anne , Rantakari Miitta , Kortelainen Pirkko , Arvola Lauri
Published: August 2003

1. Spatial variation of methane (CH4) efflux from the littoral zone of a meso‐eutrophic boreal lake was studied with a closed‐chamber technique for three summer days in 22 vegetation stands, consisting of three emergent and three floating‐leaved species.

2. Between‐species differences in CH4 emission were significant. The highest emissions were measured from the emergent Phragmites australis stands (0.5–1.7 mmol m−2 h−1), followed by Schoenoplectus lacustris > Equisetum fluviatile > Nuphar lutea > Sparganium gramineum > Potamogeton natans. Within‐species differences between stands were not significant.

3. In P. australis stands, the stand‐specific mean CH4 emission was significantly correlated with solar radiation, probably indicating the role of effective pressurised ventilation on CH4 fluxes. The proportion of net primary production emitted as CH4 was significantly higher in P. australis stands (7.4%) than in stands of S. lacustris and E. fluviatile (both 0.5%).

4. In N. lutea stands, CH4 efflux was negatively correlated with the mean fetch and positively with the percentage cover of leaves on the water surface. There were no differences in CH4 efflux between intact N. lutea leaves and those grazed by coleopteran Galerucella nymphaeae. In S. graminaeum and P. natans stands, CH4 effluxes were not related to any of the measured environmental variables.

5. For all vegetation stands, the biomass above water level explained about 60% of the observed spatial variation in CH4 emission, indicating the important role of plants as gas conduits and producers of substrates for methanogens in the anoxic sediment.
Substratum stability associated with the riverine macrophyte Justicia americana
Authors: Fritz Ken M. , Feminella Jack W.
Published: August 2003

1. Patches of stable substratum in streams may be important refugia for benthic organisms during scouring floods. Streambed stone stability, packing and embeddedness were assessed within and adjacent to beds of the macrophyte Justicia americana in five Alabama streams.

2. The force needed to dislodge stones and embeddedness was about two times lower outside Justicia beds than within them. Significant positive correlations between stone stability and (i) degree of embeddedness, and (ii) the abundance of binding rhizomes and the presence of attached roots indicate that Justicia may physically modify the local streambed, indirectly enhancing substratum stability and reducing flow, thereby increasing sand deposition.

3. Despite higher stability (i.e. physical refugia during bed‐moving spates) within Justicia beds, the abundance of epilithic plants (moss and Podostemum ceratophyllum) and pleurocerid snails (Elimia spp.) was similar both inside and outside the macrophyte beds. Several physical characteristics within macrophyte beds, such as low light, reduced current and increased sand intrusion, may create suboptimal conditions for benthic organisms in these habitats.

4. Additional work is needed to determine if Justicia biogenically enhances substratum stability or if its presence merely reflects patches of stable substratum within the streambed. Regardless of the mechanism, there is an association between Justicia beds and streambed characteristics.
Six years of submerged plant community dynamics in a freshwater tidal wetland
Authors: Capers Robert S.
Published: August 2003

1. The dynamics of a submerged plant community were studied for 6 years in a freshwater tidal wetland. The degree and nature of change at several spatial scales (quadrat, transect and overall community) was determined, and the implications for community stability were assessed.

2. A high degree of change was recorded in 1 m2 quadrats, and this was reflected in 10 m2 transects as well. In quadrats, mean species richness changed every year. Species richness changed in >60% of quadrats each year. Stem number changed by as many as several 100 stems per quadrat from one year to the next.

3. Richness varied more among quadrats than among transects and varied less at the community level than among either quadrats or transects. Greater stability at the spatial scale of the whole community was reflected in high scores on the Jaccard and Morasita–Horn indices and Kendall's coefficient of concordance.

4. Although most of the submerged species were perennials, persistence at the local scale was low, and 4‐year persistence exceeded 50% for only one species. Change in abundance was largely independent among the species.

5. In the face of great small‐scale changes, species remain in the community (and the community persists) because of high recruitment rates.
The concepts of ‘plant functional types’ and ‘functional diversity’ in lake phytoplankton – a new understanding of phytoplankton ecology?
Authors: Weithoff Guntram
Published: August 2003

1. This is a discussion of the applicability to the phytoplankton of the concepts of ‘plant functional types’ (PFTs) and ‘functional diversity’ (FD), which originated in terrestrial plant ecology.

2. Functional traits driving the performance of phytoplankton species reflect important processes such as growth, sedimentation, grazing losses and nutrient acquisition.

3. This paper presents an objective, mathematical way of assigning PFTs and measuring FD. Ecologists can use this new approach to investigate general hypotheses [e.g. the intermediate disturbance hypothesis (IDH), the insurance hypothesis and synchronicity phenomena] as, for example, in its original formulation the IDH makes its predictions based on FD rather than species diversity.
A comparative study of the dispersal of 10 species of stream invertebrates
Authors: Elliott J. M.
Published: August 2003

1. Apart from downstream dispersal through invertebrate drift, few quantitative data are available to model the dispersal of stream invertebrates, i.e. the outward spreading of animals from their point of origin or release. The present study provides comparative data for 10 species, using two independent methods: unmarked animals in six stream channels built over a stony stream and marked animals in the natural stream. Experiments were performed in April and June 1973 and 1974, with initial numbers of each species varying from 20 to 80 in the stream channels and 20 to 60 for marked animals.

2. Results were the same for marked invertebrates and those in the channels. Dispersal was not density‐dependent; the number of dispersing animals was a constant proportion of the initial number for each species. The relationship between upstream or downstream dispersal distance and the number of animals travelling that distance was well described by an inverse power function for all species (exponential and log models were poorer fits). Results varied between species but were similar within species for the 4 months, and therefore were unaffected by variations in mean water velocity (range 0.04–0.35 m s−1) or water temperature (range 6.7–8.9 °C in April, 12.1–14.8 °C in June).

3. Species were arranged in order, according to their dispersal abilities. Three carnivores (Perlodes, Rhyacophila, Isoperla) dispersed most rapidly (70–91% in 24 h, maximum distances 9.5–13.5 m per day), followed by two species (Protonemura, Rhithrogena) in which about half their initial numbers dispersed (50–51% in 24 h, 7.5–8 m per day), and four species (Ecdyonurus, Hydropsyche, Gammarus, Baetis) in which less than half dispersed (33–40% in 24 h, 5.5–7 m per day). Dispersal was predominantly upstream for all nine species. Few larvae (20%) of Potamophylax dispersed, with similar maximum upstream and downstream distances of 3.5 m per day. The mean time spent drifting downstream was known for seven species from previous studies, and correlated positively with their dispersal distances. Therefore, the species formed a continuum from rapid to very slow dispersers. These interspecific differences should be considered when evaluating the role of dispersal in the maintenance of genetic diversity in stream invertebrates, and in their ability to colonise or re‐colonise habitats.
Microcomputer systems: what to look for and where to go for help*
Authors: BURTON PAUL F.
Published: August 2003

This paper attempts to summarize the microcomputer hardware and software situation for libraries and information services. There is a wide choice of hardware available, capable of supporting both single, stand‐alone systems and networked services, and a growing range of software. Funding will continue to be a major influence on what can be achieved but within budgetary limits a great deal can be done to improve or extend services to users through the implementation of microcomputer systems.
A core list of periodicals for health–care management libraries
Authors: COOK SUE
Published: August 2003

This paper illustrates the increasing importance of management in the health service and suggests 91 Periodicals as a potential core list for librarians.
The Medical Research Council's Union Catalogue of Books by ISBN
Authors: MOULD SHEILA
Published: August 2003

The setting up and development of a Union Catalogue of Books by ISBN amongst some Medical Research Council (MRC) Libraries is described and discussed. The list has proved valuable as a location tool for inter‐library lending.
Selecting and implementing and integrated library system for the WHO Library, Geneva
Authors: RUFF BERYL , AVRIEL DEBORAH
Published: August 2003

This paper gives a management overview of the process and problems associated with selecting and implementing an integrated library system suitable for the special requirements of WHO, Geneva. Emphasis is given to defining the needs of the parent organization as well as identifying the objectives of the Library's computerization programme. The necessity of staff involvement in evaluating and testing the software within the Library as part of the selection process is also considered. Lessons learnt from the negotiating process with the vendor are indicated and the problems of implementation are summarized. Initial reactions and future developments are mentioned in conclusion.
Information for occupational medicine, occupational health and related fields: some results of a study
Authors: WOOD F. E. , RUBIN V. , THOMAS S.
Published: August 2003

This study, funded by the British Library, aimed to identify requirements for occupational health information and to propose improvements to the current UK situation. Only those results relating to occupational health physicians and occupational health nurses are reported here. Methods employed included structured interviews, which were used to establish the pattern of information use and elicit views on information provision, literature searches and visits to relevant organizations. Findings were that respondents preferred to ask for information rather than seeking it in publications; reading and attending meetings and courses were the main methods of keeping up to date; use of the abstracting and indexing publications, online services and Prestel was low; and toxicity information presented problems especially for the physicians. It is suggested that more effective information handling could be promoted in basic and continuing professional education, by the provision of guides to sources of information and by improved alerting services.
Journals as a support to health management in Europe: an initial approach to a ‘core list’
Authors: THURIAUX M. C. , WEISS P. , PERRY C. M. , VALCHEV A. S.
Published: August 2003

The principle of a core list of journals in support of documentation and information for health managers is presented, together with a preliminary list of 32 journals.
The Story of Calibre
Authors: BERENRDT LADY FRANCES
Published: August 2003

The aims, history and development of Calibre – a lending service of unabridged books recorded on to standard cassettes for the visually and physically handicapped unable to read normal print – are described. Details are given of membership, staffing, how books and readers are selected and the recent computerization. The recent development of bulk loans of cassettes for delivery via housebound readers' services is an exciting extension ofthe service.
Medical tradition and medical libraries in Japan
Authors: GROEN FRANCES
Published: August 2003

This article provides a brief overview of the development of indigenous medical information resources and medical libraries in Japan. The stimulation to investigate the development of Japanese medical information sources and medical libraries was provided by the opportunity to participate in the 5th International Congress on Medical Librarianship, Tokyo, 1985.
The NHS Regional Librarians Group
Authors: FORREST MAUREEN , CARMEL MICHAEL
Published: August 2003

A brief account of the origins, organization and work of the National Health Service Regional Librarians Group.
Interlending of audio–visual materials: a neglected national resource for medical and health libraries
Authors: CORNISH GRAHAM P.
Published: August 2003

Although the UK has an inter library lending system of outstanding efficiency this does not extend to non‐print media. The work of the National Committee on Regional Library Cooperation towards improving the situation is described including the development of documentation systems to support interlending. The paucity of bibliographic sources for audio‐visual materials and the problems which still remain are discussed, and the comparatively favourable position of medical and health services libraries outlined.
Recent developments in American medical libraries and at the Institute for Scientific Information*
Authors: HAGUE HOWARD
Published: August 2003

This paper describes a visit to the eastern United States of America in November 1985. The tour commenced with a users' conference hosted by the Institute for Scientific Information and seven other major libraries were visited. Key features and recent developments are outlined briefly.
The scientific and clinical literature of AIDS: development, bibliographic control and retrieval
Authors: ROBERTS SARAT , SHEPHERD LOUISE , WADE JENNY
Published: August 2003

The objective of thispaper is to provide a review of the development of the literature of the acquired immunodeficiency syndrome (AIDS) and the methods by which it can be accessed. We first survey the development of bibliographic tools (printed indexes, current‐awareness lists and online databases) and journals in parallel with the progress of research in this fast‐moving subject. A chronological approach has been used in order to emphasize the ways in which bibliographic control methods and publishing in the field have kept pace with scientific developments. There follows a guide to accessing online databases, and an overview of monographs, conference proceedings, guidelines and other official publications. Finally, there are notes on statistical sources. An appendix gives additional details of bibliographic tools and journals, and lists books, selected conference proceedings and official guidelines. No attempt has been made to discuss literature and information services for the lay audience or sufferers from HIV‐infection/AIDS, as this is a specialist area that requires separate consideration.
Health for all by the year 2000: information targets. National goals–no national focus?
Authors: SHARP DAVID
Published: August 2003

A brief analysis of some of the targets published in the World Health Organization's document on health for all provides evidence that consumer health information is intended to play a significant role in improving the nation's health but that although there is a growing interest in consumer health information provision in the UK there is still no overall national strategy for its development. A number of goals which such a strategy might embrace are identified to stimulate debate from which it is hoped more positive action will ensue.
Searching EMBASE: do the results justify the cost?
Authors: COLLINS ANNE M. K. , GASS STEVEN
Published: August 2003

The cost of the Excerpta Medica abstracting journals was giving cause for concern and it was decided to cancel the subscription and to evaluate the online database as an alternative source of information. This paper describes the background to the decision to cancel and the evaluation that was curried out at the University of Leeds Medical and Dental Library.
Replacement of scientific journals with microfiche in a small specialist library
Authors: GRAINGER FELICITY
Published: August 2003

The experimental replacement of certain printed journals with microfiche in a small specialist library is described. The reasons for choosing this format, the selection of titles, the problems encountered, the reactions of users and the effects of the experiment on library policy are discussed. Possible future plans are indicated.
Orientation and training of preclinical medical students in the use of the library*
Authors: STRICKLAND‐HODGE B.
Published: August 2003

The importance of library instruction for medical students is emphasized. Previous work is discussed and brief descriptions of programmes and methods used in the USA and New Zealand are described.

Research has recently been carried out into British practice, specifically with regard to library orientation and training for preclinical medical students. Librarians were canvassed for their opinions using a postal questionnaire Interviews were also carried out, with teaching staff and medical students. Results indicate that no standard approach is possible and a variety of techniques are helpful. It is concluded that orientation of students is vital, but should be short, conducted with small groups and initially should concentrate on basic information only. Additional training should only be carried out in cases of speciJic need, for example completion of a tutor set project.
The relationship between dental aesthetic index (DAI) and perceptions of aesthetics, function and speech amongst secondary school children in Ibadan, Nigeria
Authors: Onyeaso C. O. , Aderinokun G. A.
Published: August 2003

Objective. The purpose of the study was to investigate the relationship between a professionally derived index, the Dental Aesthetic Index, and some indications for orthodontic treatment as perceived by potential patients.

Methods. An epidemiological survey of 614 secondary school students, 327 males (53·3%) and 287 females (46·7%) was carried out in Ibadan, Nigeria. Children aged 12–18 years (mean age, 14·9 ± 2·9 SD) were randomly selected, none of them had received previous orthodontic treatment. One examiner assessed the students using the Dental Aesthetic Index (DAI). Subjects were also asked to complete a questionnaire consisting of three questions concerning appearance, function, and speech, using a 5‐point Likert scale.

Results. Weak but statistically significant correlations were found for subjective assessments of appearance of teeth and the DAI (r = 0·174; P < 0·01) and between biting/chewing and appearance of teeth (r = 0·095; P < 0·05). Statistically significant correlations were found between appearance of teeth and speech (r = 0·148; P < 0·01) and biting/chewing and speech. The last showed the strongest correlation (r = 0·268; P < 0·01).

Conclusion. The study has shown weak but significant correlation between DAI and children's perceptions of the appearance of their teeth. We recommend further study involving both DAI and Index of Orthodontic Treatment Need (IOTN) for comparison in the Nigerian population.
Tooth agenesis: a report of missing molars in two generations
Authors: Kau C. H. , Hunter M. L. , Lewis B. , Knox J.
Published: August 2003

Summary. A recent review has suggested that tooth agenesis is becoming more evident in society, though it is not known whether this observation is related to better detection methods and patient awareness or whether there is a real trend towards an increase in prevalence. In this paper we report developmental absence of permanent molars in two generations, and discuss the possible clinical implications of this pattern of tooth agenesis.
Relative analgesia and general dental practitioners: attitudes and intentions to provide conscious sedation for paediatric dental extractions
Authors: Freeman R. , Carson P.
Published: August 2003

Aim. To examine the attitudes and intentions of general dental practitioners (GDPs) who work within the remit of the National Health Service (NHS) to provide relative analgesia (RA) for paediatric extractions.

Methods. All 45 GDPs working within the boundaries of one Trust were asked to complete a questionnaire to assess demography, etc., intention and attitudes to provide RA for paediatric extractions.

Results. Ninety‐eight per cent of GDPs took part. All GDPs worked within the NHS. Twenty‐nine per cent of GDPs stated that they had RA equipment available in their practices and 68% stated that they discussed RA as treatment alternative. Eighty‐seven per cent referred their paediatric extraction cases for dental general anaesthesia. The behavioural intention was predicted by total attitude score and the availability of RA equipment in the practice (R2 = 0·97, F(37,5) = 260·11, P < 0·001). Total attitude was predicted by clinical competency, few financial worries or time concerns and the availability of RA equipment (R2 = 0·91, F(38,4) = 106·21, P < 0·001).

Conclusions. This study suggests that GDPs’ concerns of clinical competence and costs have an inhibiting effect upon their intention to provide RA for paediatric extractions. These concerns must be addressed by planners and policy makers if there is to be a shift from hospital‐based DGA to surgery‐based RA services for paediatric extractions.
Cutaneous horn occurring on the lip of a child
Authors: Souza L. N. , Martins C. R. , De Paula A. M. B.
Published: August 2003

Cutaneous horn is a relatively uncommon lesion consisting of keratotic material resembling that of an animal horn. This kind of lesion is more common in Caucasians and in older age groups. The primary lesion underlying the horny material may be benign, premalignant or malignant. The treatment of choice is an excisional biopsy with a narrow margin, because of the possibility of malignancy. The material must be submitted for histopathological evaluation. The first reported case of cutaneous horn arising on the vermillion border of the lower lip in a black child is presented.
Treatment outcome in subgroups of uncooperative child dental patients: an exploratory study
Authors: Arnrup K. , Broberg A. G. , Berggren U. , Bodin L.
Published: August 2003

Objectives.The principal aims of this study were to evaluate the treatment outcome in subgroups of uncooperative child dental patients and to test the validity of these subgroups, which were based on fear and personality characteristics.

Design.An exploratory, intervention study using quantified questionnaire, interview and observation data.

Sample and methods.Eighty‐six 4 to 12‐year‐old uncooperative child dental patients (of whom 81 were divided retrospectively into four subgroups) and their accompanying parents were followed up during treatment at a specialist paediatric dental clinic in Sweden. Treatment was based on behaviour management techniques, supported by nitrous oxide/oxygen sedation if necessary. At baseline, parents answered a questionnaire including questions on child dental and general fear, temperament and behaviour, and parental dental fear, emotional stress, locus of control, parenting efficacy and attitudes to dental care, some of which were repeated post‐treatment. The treating dentist rated child behaviour according to the acceptance of a maximum of 14 treatment steps at each visit.

Results.Approximately 90% of all children managed to undergo the dental treatment. Child dental fear and parental emotional stress decreased during treatment. Externalizing, impulsive children showed lower acceptance. In fearful, inhibited children, integrated use of sedation appeared to facilitate acceptance. Validity of the subgroups characterized as ‘fearful, extrovert, outgoing’, ‘fearful, inhibited’ and ‘externalizing, impulsive’ was supported, while heterogeneity within the group of ‘non‐fearful, extrovert, outgoing’ children made validation difficult.

Conclusion.Fear and personality characteristics may serve as diagnostic aids when planning treatment of uncooperative child dental patients. Controlled outcome studies using differentiated treatment methods for children with different fear and personality profiles are needed.
Premature exfoliation of primary molars related to the use of formocresol in a multivisit pulpotomy technique: a case report
Authors: Hunter M. L.
Published: August 2003

Since its introduction in 1904, formocresol has become one of the most widely studied dental medicaments. In the United Kingdom, it is the preferred primary tooth pulpotomy medicament of the majority of Specialists in Paediatric Dentistry [1]. Reports of adverse effects resulting from its clinical use are rare. This paper presents a case of premature exfoliation of primary molars that may be related to the use of formocresol in a multivisit pulpotomy technique.
Unusual manifestations in X‐linked Amelogenesis Imperfecta
Authors: Lykogeorgos T. , Duncan K. , Crawford P. J. M. , Aldred M. J.
Published: August 2003

This paper describes a female with X‐linked amelogenesis imperfecta (XAI). This case is unusual in having taurodontism, pulpal calcifications, coronal defects prior to tooth eruption and unerupted teeth. These findings have been reported in some cases of autosomal dominant and autosomal recessive AI but have not previously been documented in XAI.