bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of different concentrations of levobupivacaine for post‐operative epidural analgesia
Authors: Dernedde M. , Stadler M. , Bardiau F. , Boogaerts J. 
Published: July 2003

Background:  The relative effects of the mass, volume and concentration of local anaesthetic solution used for epidural anaesthesia and analgesia are still under debate. Clinical studies have shown discrepancies, probably because of limited consideration of total dose.Methods:  This prospective, randomized and blinded study evaluated the spread, the quality of post‐operative analgesia and the incidence of side‐effects of continuous thoracic epidural levobupivacaine 15 mg/h in three different concentrations: 1.5 mg/ml, 10 ml/h (n = 26), 5 mg/ml, 3 ml/h (n = 33) or 7.5 mg/ml, 2 ml/h (n = 31). The following variables were registered within 48 h: sensory block, pain scores, rescue morphine consumption, motor blockade, haemodynamics, sedation, nausea and vomiting, and patient satisfaction.Results:  The three groups were similar with regard to demographics, quality of analgesia, morphine consumption, and satisfaction rate. The upper level of sensory block was two segments higher in the 1.5 mg/ml group. Motor blockade in the lower limbs was low in the three groups. Haemodynamic profile was more stable in the higher concentration groups compared with the 1.5 mg/ml patient group (P < 0.001). Nausea was more frequent in the 1.5 mg/ml group (P = 0.02).Conclusion:  The same dose of levobupivacaine provides an equal quality of analgesia in low or high volume continuous thoracic epidural infusion with reduced haemodynamic instability and nausea in the low volume/high concentration groups.
Quantification of induced resistance against Phytophthora species expressing GFP as a vital marker: β‐aminobutyric acid but not BTH protects potato and Arabidopsis from infection
Authors: Si‐Ammour Azeddine , Mauch‐Mani Brigitte , Mauch Felix 
Published: July 2003

SUMMARYInduced resistance was studied in the model pathosystem Arabidopsis‐Phytophthora brassicae (formerly P. porri) in comparison with the agronomically important late blight disease of potato caused by Phytophthora infestans. For the quantification of disease progress, both Phytophthora species were transformed with the vector p34GFN carrying the selectable marker gene neomycine phosphotransferase (nptII) and the reporter gene green fluorescent protein (gfp). Eighty five per cent of the transformants of P. brassicae and P. infestans constitutively expressed GFP at high levels at all developmental stages both in vitro and in planta. Transformants with high GFP expression and normal in vitro growth and virulence were selected to quantify pathogen growth by measuring the in planta emitted GFP fluorescence. This non‐destructive monitoring of the infection process was applied to analyse the efficacy of two chemical inducers of disease resistance, a functional SA‐analogue, benzothiadiazole (BTH), and β‐aminobutyric acid (BABA) which is involved in priming mechanisms of unknown nature. BABA pre‐treatment (300 µm) via soil drench applied 24 h before inoculation completely protected the susceptible Arabidopsis accession Landsberg erecta (Ler) from infection with P. brassicae. A similar treatment with BTH (330 µm) did not induce resistance. Spraying the susceptible potato cultivar Bintje with BABA (1 mm) 2 days before inoculation resulted in a phenocopy of the incompatible interaction shown by the resistant potato cultivar Matilda while BTH (1.5 mm) did not protect Bintje from severe infection. Thus, in both pathosystems, the mechanisms of induced resistance appeared to be similar, suggesting that the Arabidopsis‐P. brassicae pathosystem is a promising model for the molecular analysis of induced resistance mechanisms of potato against the late blight disease.
Root‐knot nematode parasitism and host response: molecular basis of a sophisticated interaction
Authors: Abad Pierre , Favery Bruno , Rosso Marie‐Noëlle , Castagnone‐Sereno Philippe 
Published: July 2003

SUMMARYTaxonomy: Eukaryota; Metazoa; Nematoda; Chromadorea; order Tylenchida; Tylenchoidea; Heteroderidae; genus Meloidogyne. Physical properties: Microscopic‐non‐segmented worms. Meloidogyne species can reproduce by apomixis, facultative meiotic parthenogenesis or obligate mitotic parthenogenesis. Obligate biotrophic parasites inducing the re‐differentiation of plant cells into specialized feeding cells. Hosts: Meloidogyne spp. can infest more than 3000 plant species including vegetables, fruit trees, cereals and ornamental flowers. Symptoms: Root swellings called galls. Alteration of the root vascular system. Disease control: Cultural control, chemical control, resistant cultivars. Agronomic importance: Major threat to agriculture in temperate and tropical regions.
Alternaria spp.: from general saprophyte to specific parasite
Authors: Thomma Bart P. H. J. 
Published: July 2003

SUMMARY Alternaria species are mainly saprophytic fungi. However, some species have acquired pathogenic capacities collectively causing disease over a broad host range. This review summarizes the knowledge on pathogenic strategies employed by the fungus to plunder the host. Furthermore, strategies employed by potential host plants in order to ward off an attack are discussed.Taxonomy: Alternaria spp. kingdom Fungi, subkingdom Eumycotera, phylum Fungi Imperfecti (a non‐phylogenetic or artificial phylum of fungi without known sexual stages whose members may or may not be related; taxonomy does not reflect relationships), form class Hypomycetes, Form order Moniliales, form family Dematiaceae, genus Alternaria. Some species of Alternaria are the asexual anamorph of the ascomycete Pleospora while others are speculated to be anamorphs of Leptosphaeria.Host Range: Most Alternaria species are common saprophytes that derive energy as a result of cellulytic activity and are found in a variety of habitats as ubiquitous agents of decay. Some species are plant pathogens that cause a range of economically important diseases like stem cancer, leaf blight or leaf spot on a large variety of crops. Latent infections can occur and result in post‐harvest diseases or damping‐off in case of infected seed.Useful Website: <http://ag.arizona.edu/PLP/alternaria/online.htm>
Cross‐protection in Arabidopsis against crucifer tobamovirus Cg by an attenuated strain of the virus
Authors: Kurihara Yukio , Watanabe Yuichiro 
Published: July 2003

SUMMARYCross‐protection is a procedure that has been utilized to protect crops against virulent strains of viruses by pre‐treatment with closely related attenuated strains of the virus. We constructed a mutant of crucifer tobamovirus Cg, which is analogous to L11A, an attenuated strain of Tomato mosaic virus‐L (ToMV‐L). This mutant, named CgYD, caused few disease symptoms and could spread throughout Arabidopsis thaliana Col‐0 plants. Initial infection with CgYD was shown to efficiently cross‐protect against a challenge with wild‐type Cg. Thus, we have established in Arabidopsis a powerful system for investigating mechanisms of cross‐protection. Using this system, we showed that cross‐protection was not overcome, even if a higher concentration of the virion, or purified virion RNA, were used in the challenge. We also demonstrated that cross‐protection requires that the second virus be very similar in sequence to Cg, which is a characteristic of RNA silencing. However the RNA dependent RNA polymerase SDE1/SGS2 associated with post‐transcriptional gene silencing was not required for cross‐protection.
Identification of cytokinins produced by the plant parasitic nematodes Heterodera schachtii and Meloidogyne incognita
Authors: De Meutter Jan , Tytgat Tom , Witters Erwin , Gheysen Greetje , Van Onckelen Henri , Gheysen Godelieve 
Published: July 2003

SUMMARYThe presence of different types of cytokinins was analysed in exudates and lysates of stage‐2 juveniles of Heterodera schachtii and Meloidogyne incognita and in mixed stages of Caenorhabditis elegans. For all species, cytokinins were detected in lysates and exudates in which benzyladenine and zeatin‐type cytokinins were the most prominent forms. The production of cytokinins by Meloidogyne was much higher than by Heterodera, and the detected levels were in a range which interfered with the physiological activities of the host plant. The presence of 5‐methoxy‐N,N‐dimethyltryptamine hydrogen oxalate did not affect hormone production by H. schachtii, whereas resorcinol slightly stimulated hormone production by M. incognita. The exuded cytokinins may play a role in feeding site induction, more particularly in cell cycle activation and in establishing the feeding site as a nutrient sink.
Quality of Care for Older Persons at the Dawn of the Third Millennium
Authors: Reuben David B. , Shekelle Paul G. , Wenger Neil S. 
Published: July 2003

During the past quarter century, researchers, providers, insurers, and governmental agencies have devoted considerable effort to improving and standardizing the quality of health care provided to older persons. Because older persons differ from younger persons as a result of their life expectancy, disease prevalence and comorbidity, social resources, goals of treatment, and preferences for care, defining and measuring quality of care has been more difficult for this age group. Nevertheless, several decades of research have led to reliable, although imperfect, methods of measuring quality, including those for geriatric conditions.Using these measurement approaches, a variety of studies using different patient populations and sampling strategies have consistently identified deficiencies in quality of care provided to older persons. Moreover, efforts to improve quality of care for older persons have been difficult to design, implement, and sustain. Some have been successful, including having effects on outcome measures, but have not made the transition from research to clinical settings. Others have used quality improvement methods to improve the care of diseases (e.g., diabetes mellitus, congestive heart failure) that commonly affect older persons. However, the lack of alignment of incentives between providers and insurers for most older persons is a major barrier to this approach. In addition, there is no concerted effort among providers, regulatory agencies, and insurers to move the quality‐of‐care agenda for most Medicare recipients. Despite substantial progress in defining and measuring high‐quality care for older persons, the goal of ensuring that older persons receiving such care remains a distant hope.
Disruption of a longitudinal pattern in environmental factors and benthic fauna by a glacial tributary
Authors: Knispel S. , Castella E. 
Published: July 2003

SUMMARY 1. In the upper Rhône catchment (Swiss Alps), modifications in the longitudinal pattern of environmental conditions and the benthic macroinvertebrate fauna were investigated in a glacier‐fed stream (Rhône) at its confluence with a smaller glacier‐fed tributary (Mutt) in June, August and September 1998. The distance to the source glacier was greater for the Mutt than for the Rhône.2. Environmental conditions were harsher for the biota in the main stream upstream of the confluence than in the tributary. The tributary upstream of the confluence was characterised by higher taxonomic richness and abundance of the zoobenthos than the Rhône upstream.3. Although environmental conditions in the main stream were little modified by the tributary, the fauna was richer and more diverse below the confluence. During the period of ice melt, colonisation from the Mutt led to the occurrence of faunal elements atypical of glacial streams in the main glacial stream upstream of the confluence, where water temperature remains below 4 °C.4. Although contributing an average of only 10% to the Rhône discharge, the Mutt tributary is suggested to be the faunal driver of the system.
Sources of organic carbon supporting the food web of an arid zone floodplain river
Authors: Bunn Stuart E. , Davies Peter M. , Winning Michelle 
Published: July 2003

SUMMARY 1. Many Australian inland rivers are characterised by vast floodplains with a network of anastomosing channels that interconnect only during unpredictable flooding. For much of the time, however, rivers are reduced to a string of disconnected and highly turbid waterholes. Given these features, we predicted that aquatic primary production would be light‐limited and the riverine food web would be dependent on terrestrial carbon from floodplain exchanges and direct riparian inputs.2. To test these predictions, we measured rates of benthic primary production and respiration and sampled primary sources of organic carbon and consumers for stable isotope analysis in several river waterholes at four locations in the Cooper Creek system in central Australia.3. A conspicuous band of filamentous algae was observed along the shallow littoral zone of the larger waterholes. Despite the high turbidity, benthic gross primary production in this narrow zone was very high (1.7–3.6 g C m−2 day−1); about two orders of magnitude greater than that measured in the main channel.4. Stable carbon isotope analysis confirmed that the band of algae was the major source of energy for aquatic consumers, ultimately supporting large populations of crustaceans and fish. Variation in the stable carbon and nitrogen isotope signatures of consumers suggested that zooplankton was the other likely major source.5. Existing ecosystem models of large rivers often emphasise the importance of longitudinal or lateral inputs of terrestrial organic matter as a source of organic carbon for aquatic consumers. Our data suggest that, despite the presence of large amounts of terrestrial carbon, there was no evidence of it being a significant contributor to the aquatic food web in this floodplain river system.
Is water temperature an adequate predictor of recruitment success in cyprinid fish populations in lowland rivers?
Authors: Nunn A. D. , Cowx I. G. , Frear P. A. , Harvey J. P. 
Published: July 2003

SUMMARY 1. Higher than average ambient water temperature in the first year of life may be responsible for strong cohorts of adult cyprinid fish. Whilst temperature explains much of the variation in year‐class strength (YCS), however, it is not the only influential factor as high temperature does not inevitably yield strong year‐classes. Furthermore, years in which a strong year‐class is prevalent in one species do not necessarily result in strong year‐classes in other coexisting species, suggesting other biotic and abiotic factors are important in regulating recruitment success.2. The relationships between water temperature, river discharge, the position of the Gulf Stream, 0‐group fish growth and recruitment success (YCS) were examined in three cyprinid fish species in an English lowland river, using a 15‐year data set.3. Mean length of 0‐group fish at the end of the summer was positively correlated with water temperature (cumulative degree‐days >12 °C) and negatively correlated with river discharge (cumulative discharge‐days above basal discharge rate). Water temperature was negatively correlated with river discharge.4. YCS was positively correlated with mean 0‐group fish length at the end of the summer and with the position of the North Wall of the Gulf Stream.5. ’Critical periods’ (i.e. periods in the first summer of life when fish may be more susceptible to increases in river discharge) were difficult to discern because of interannual variations in river discharge relative to the timing of fish hatching. YCS of roach and chub was most strongly correlated with discharge in the period from June to September inclusive, while YCS of dace was most significantly correlated with discharge in August.6. River discharge (rather than water temperature) may be the key factor in determining YCS, either directly (through discharge‐induced mortality) or indirectly (via reduced growth at lower water temperatures, discharge‐associated increases in energy expenditure or reduced food availability). It could be that, in effect, water temperature determines potential YCS while discharge determines realised YCS.
Zooplankton responses to predation by larval bluegill: an enclosure experiment
Authors: Rettig J. E. 
Published: July 2003

SUMMARY 1. Larval fish are gape‐limited predators that forage on prey of specific sizes, and thus may be expected to differentially affect members of a zooplankton community, possibly altering the size‐structure or species composition.2. I used an enclosure experiment to look at the effect of predation by larval bluegill on the dynamics of two zooplankton communities, one dominated by large‐bodied individuals and the other by small‐bodied individuals. Enclosures containing these zooplankton received a zero, low, medium, or high density of larval bluegill predators.3. Increasing larval density had a negative effect on zooplankton abundance and abundance declined similarly in the large‐bodied and small‐bodied communities.4. Zooplankton size‐structure, as estimated by the length of the average zooplankton, increased and then decreased during the experiment, decreasing faster at higher larval fish densities. When zooplankton size‐structure was estimated as the length of the average cladoceran, size‐structure declined in the large‐bodied but not in the small‐bodied community and the greatest decline in size‐structure was seen in the medium and high larval density treatments.5. Ordination of each community using multidimensional scaling (MDS) indicated that the trajectory of change in species composition differed between the presence and absence of larval fish. In both communities, the degree of response by individual taxa depended on the density of bluegill larvae. This effect on zooplankton abundance, size‐structure and community composition suggests that larval fish may make an important contribution to zooplankton dynamics in many lakes and ponds.
Do fish regulate phytoplankton in shallow eutrophic Northeast Brazilian reservoirs?
Authors: Lazzaro Xavier , Bouvy Marc , Ribeiro‐Filho Rinaldo A. , Oliviera Vanildo S. , Sales Leonardo T. , Vasconcelos André R. M. , Mata Maurício R. 
Published: July 2003

SUMMARY 1. In a comparative study, we examined the potential for fish to structure planktonic food webs in shallow mesotrophic to hypereutrophic Northeast Brazilian reservoirs. The food webs were dominated by three guilds of fish (facultative piscivores, generalist planktivores and omnivores), small herbivorous zooplankton and bloom‐forming cyanobacteria, with few littoral macrophytes.2. A principal component's analysis on data from 13 reservoirs (27 sampling dates in 1995–99) revealed that euphotic depth, the relative density of phytoplankton (i.e. the percentage of overall phytoplankton density) represented by cyanobacteria, and the relative biomass of fish (i.e. percentage of overall biomass) represented by omnivores and facultative piscivores, explained most of the variance in the data. Physico‐chemical conditions, lake morphometry and rainfall were secondary factors.3. Phytoplankton was related to fish guild structure. Chlorophyll concentration increased with total phosphorus and the relative biomass of omnivorous fish, decreased with the relative biomass of facultative piscivores, but was unrelated to the biomass and mean body size of herbivorous zooplankton. Chlorophyll concentration and the densities of filamentous and colonial cyanobacteria decreased with the ratio of the biomass of facultative piscivores to that of omnivores (FP : OM).4. We propose two complementary mechanisms for the observed relationships between fish and phytoplankton. At a low biomass of facultative piscivores, juvenile zooplanktivorous fishes may induce a trophic cascade on zooplankton in the littoral zone. Regardless of piscivore biomass, piscivores and omnivores may regulate phytoplankton via multichannel omnivory because of the predominance of omnivorous or detritivorous foraging behaviour.5. Manipulative experiments are needed to explore further whether, depending on priorities in the use of the reservoir, fisheries management could alter the FP : OM ratio either to enhance fish yields or to reduce phytoplankton densities and cyanobacterial blooms.
Temperature effects on chemical signalling in a predator–prey system
Authors: Lass S. , Spaak P. 
Published: July 2003

SUMMARY 1. We investigated the effect of temperature on chemical signalling in a predator–prey model system (planktivorous fish and Daphnia galeata). Life‐history changes in Daphnia in response to chemical cues (kairomones) derived from fish have become a paradigm for chemically induced anti‐predator defences.2. As temperature can affect both predator and prey, we carried out two experiments to disentangle these effects. In order to test for temperature effects on the predator, we kept prey at a single temperature and exposed them to kairomones from fish exposed to two different temperatures. Daphnia exhibited a higher intrinsic rate of population increase (r) when exposed to fish kairomones produced at high rather than low temperature. Assuming a positive correlation between r (because of an earlier maturation and/or increased clutch sizes) and kairomone concentration, our results suggest that kairomone production increases with rising temperature.3. In the second experiment, to study the influence of temperature on the prey, Daphnia were kept at two different temperatures and exposed to fish kairomones produced at one constant temperature. We found no interaction between the effects of fish kairomone and temperature on Daphnia life history, suggesting that temperature does not directly alter life‐history responses to fish kairomones.4. Our results suggest that temperature influences Daphnia life history through its effects on fish kairomone concentration, but that temperature does not affect the strength of the response of Daphnia to the presence of fish.
Small‐scale patterns of genetic variation in the mayfly Bungona narilla (Ephemeroptera: Baetidae) in rainforest streams, south‐east Queensland
Authors: Hughes Jane M. , Hillyer Mia , Bunn Stuart E. 
Published: July 2003

SUMMARY 1. Genetic structure of the mayfly Bungona narilla was examined using allozymes and a section of the cytochrome oxidase I gene.2. The study had two major aims. The first was to determine whether patterns of genetic variation in mitochondrial DNA were similar to those found previously for allozymes, i.e. that more variation was evident among pools within a single stream than among streams. The mitochondrial DNA results were similar to those reported previously for allozymes, supporting the idea that larvae within any particular pool were unrepresentative of the total population and may result from a few matings.3. The second aim was to test the hypothesis that the variation among pools within a stream was greater after dry periods than after wet periods. This was because after wet periods, larvae would have greater opportunity for mixing because of movement among pools. This hypothesis was partly supported by the mitochondrial DNA data but not by the allozyme data, in which variation among pools was extremely low on both sampling occasions. The reasons for this difference are unclear.