bluuebunny/crossref_metadata_2025_split huggingface dataset:
A structured health needs assessment tool: acceptability and effectiveness for health visiting
Authors: Cowley Sarah , Houston Anna M. 
Published: June 2003

Background. There is, nominally at least, a universal health visiting service in Great Britain, although the frequency of contacts may be severely restricted. Debates about whether home visiting should be universal or selective, therefore, focus on whether health visitors should use professional judgement or structured assessment tools to target attention within their caseload. Research attention has focused mainly on unstructured needs assessments and professional judgment or the development of assessment tools, so that the views of practitioners using structured instruments and their clients are not known.Methods. A two‐phase qualitative study examined the acceptability and effectiveness of a structured health needs assessment tool (HNAT) implemented in London. Views about the tool were elicited from 30 health visitors through telephone interview, and then 21 assessments were observed and tape‐recorded; 19 clients were interviewed after the event. Data were evaluated for adequate coverage of views across the target population and analysed using the framework approach.Findings. A range of views were expressed, but the HNAT caused anxiety and distress to, particularly, the most vulnerable clients. The structured format of the tool appeared to encourage the health visitors to question instead of listen. It did not help to identify all the needs and intruded into normal practice in an insensitive and unhelpful way.Limitations. This study investigated only one form of structured HNAT. These are commonly used to prioritize undifferentiated needs of clients who have been offered an unsolicited, health promoting service. Our findings therefore do not apply to validated instruments used for screening or specific diagnostic purposes where a client has requested help with a problem.Conclusions. Given the problems in use and potential for harm, this form of structured assessment tool appears unsuitable for routine use to determine the intensity of health visiting contacts.
Post‐ice age recolonization and differentiation of Fucus serratus L. (Phaeophyceae; Fucaceae) populations in Northern Europe
Authors: Coyer J. A. , Peters A. F. , Stam W. T. , Olsen J. L. 
Published: June 2003

AbstractThe seaweed Fucus serratus is hypothesized to have evolved in the North Atlantic and present populations are thought to reflect recolonization from a southern refugium since the last glacial maximum 18 000–20 000 years bp. We examined genetic structure across several spatial scales by analysing seven microsatellite loci in populations collected from 21 localities throughout the species’ range. Spatial auto‐correlation analysis of seven microsatellite loci revealed no evidence for spatial clustering of alleles on a scale of 100 m despite limited gamete dispersal in F. serratus of ≈ 2 m from parental individuals. Pairwise θ analysis suggested that the minimal panmictic unit for F. serratus was between 0.5 and 2 km. Isolation by distance was significant along some contiguous coastlines. Population differentiation was strong within the Skagerrak–Kattegat–Baltic Seas (SKB) (global θ= 0.17) despite a short history of ≈ 7500 years. A neighbour‐joining tree based on Reynold's distances computed from the microsatellite data revealed a central assemblage of populations on the Brittany Peninsula surrounded by four well‐supported clusters consisting of the SKB, the North Sea (Ireland, Helgoland), and two populations from the northern Spanish coast. Samples from Iceland and Nova Scotia were most closely aligned with northwest Sweden and Brittany, respectively. When sample sizes were standardized (N = 41), allelic diversity was twofold higher for Brittany populations than for populations to the north and threefold higher than southern populations. The Brittany region may be a refugium or a recolonized area, whereas the Spanish populations most likely reflect present‐day edge populations that have undergone repeated bottlenecks as a consequence of thermally induced cycles of recolonization and extinction.
Calibrating phylogenetic species formation in a threatened insect using DNA from historical specimens
Authors: Goldstein Paul Z. , Desalle Rob 
Published: June 2003

AbstractMuseum specimens from the late 19th and early 20th centuries were surveyed for the single nucleotide polymorphism identified previously and used to diagnose populations of the federally threatened Northeastern Beach Tiger Beetle Cicindela d. dorsalis (Coleoptera: Carabidae). Widespread polymorphism was revealed throughout the historical range of this species, suggesting a relatively recent anthropogenic character fixation event associated with the extinction and fragmentation of populations. Implications for the phylogenetic species criterion and for the reintroduction of individuals to formerly occupied sites are discussed.
Effects of Wolbachia on mtDNA variation in two fire ant species
Authors: Dewayne Shoemaker D. , Keller Gwen , Ross Kenneth G. 
Published: June 2003

Abstract Wolbachia are endosymbiotic bacteria that infect arthropods. As they are maternally transmitted, the spread of Wolbachia variants within host populations may affect host mtDNA evolution. We sequenced a portion of the mitochondrial cytochrome oxidase I gene from numerous individuals of two Wolbachia‐infected fire ant species, Solenopsis invicta and S. richteri, to determine how these bacteria influence patterns of mtDNA variation. As predicted, there was a strong association between Wolbachia strain and host mtDNA lineage within and between these fire ant species. However, there was no consistent association between the presence of Wolbachia and a reduction in mtDNA diversity. Moreover, patterns of mtDNA variation within Wolbachia‐infected populations did not differ consistently from neutral expectations, despite our prediction that strong positive selection acting on Wolbachia influences the evolutionary dynamics of other cytoplasmic genomes. Specifically, while values of Tajima's D consistently were less than zero for all six samples of fire ants harbouring Wolbachia, MacDonald–Kreitman tests suggested that the patterns of variation were different from those expected under neutrality in only two of the samples. We conclude that these neutrality tests do not unambiguously reveal a clear effect of Wolbachia infection on patterns of mtDNA variation and substitution in fire ants. Finally, consistent with an earlier study, our data revealed the presence of two divergent mtDNA haplotype lineages and Wolbachia strains within S. invicta. Recognition of these two lineages has important consequences for interpreting patterns of mtDNA evolution and genetic differentiation between conspecific social forms of this species.
Population genetics of an invasive species, Heracleum mantegazzianum: implications for the role of life history, demographics and independent introductions
Authors: Walker N. F. , Hulme P. E. , Hoelzel A. R. 
Published: June 2003

AbstractThe population genetic structure of an invasive, nonindigenous riparian weed (Heracleum mantegazzianum) in the northeast of England was investigated using microsatellite DNA markers. Data were used to assess the size and frequency of introductions into three catchments and the subsequent spread. We sampled 13 populations, including a remote population (Perivale, London) for comparison. Five loci were screened and considerable variation was found. Results revealed greater overall variation between populations from different catchments than those in the same catchment, and suggested the generation of population structure in the relatively short time since the initial introduction. Between‐catchment variation may reflect population structure generated by local founders as the species spread and may indicate a large initial founder population at the time of the introduction into Britain, or multiple introductions. Within‐catchment variation was consistent with expectations based on the water‐borne dispersal of seeds in this species, and the relatively small dispersal range of likely pollinators. Independent introductions stand out in some cases as exceptions to the general pattern. Taken together the results are consistent with a relatively large initial founder population, and the subsequent spread of the species in local founder populations, followed by some level of inbreeding within local populations and novel introductions in some localities.
Landscape location affects genetic variation of Canada lynx (Lynx canadensis)
Authors: Schwartz M. K. , Mills L. S. , Ortega Y. , Ruggiero L. F. , Allendorf F. W. 
Published: June 2003

AbstractThe effect of a population's location on the landscape on genetic variation has been of interest to population genetics for more than half a century. However, most studies do not consider broadscale biogeography when interpreting genetic data. In this study, we propose an operational definition of a peripheral population, and then explore whether peripheral populations of Canada lynx (Lynx canadensis) have less genetic variation than core populations at nine microsatellite loci. We show that peripheral populations of lynx have fewer mean numbers of alleles per population and lower expected heterozygosity. This is surprising, given the lynx's capacity to move long distances, but can be explained by the fact that peripheral populations often have smaller population sizes, limited opportunities for genetic exchange and may be disproportionately affected by ebbs and flows of species’ geographical range.
Temporal Variation in Cleanerfish and Client Behaviour: Does It Reflect Ectoparasite Availability?
Authors: Côté Isabelle M. , Molloy Philip P. 
Published: June 2003

AbstractWe tested the importance of ectoparasites as the proximate cause of cleaning interactions by comparing the activity of Caribbean cleaning gobies (Elacatinus evelynae) and of their clients during three daily periods (early morning, midday, and late afternoon) in which ectoparasite availability varied naturally. Emergence from the benthos of gnathiid isopod larvae, the main target of cleaning goby predation, was higher at night, when cleaners were inactive, than during the day. As a result, overall ectoparasite loads on client fish tended to be higher in the morning. Inspection bouts by cleaning gobies were longest in the morning, but also at midday when ectoparasite availability on clients was lower. Client fish were observed at cleaning stations most often in the afternoon, when they harboured few ectoparasites, but they were more likely to adopt incitation poses, which increase the likelihood of being cleaned, in the morning than later in the day. Most cleaner and client behaviours therefore did not change predictably in response to natural diurnal variation in ectoparasite availability. Our study suggests that the ultimate and proximate causes of cleaning behaviour need not necessarily coincide.
Age Differences in the Response of Willow Tits (Parus montanus) to Conspecific Alarm Calls
Authors: Rajala Mari , Rätti Osmo , Suhonen Jukka 
Published: June 2003

AbstractPredation is an important mortality factor in wintering birds. To counter this, birds produce alarm calls in the presence of predators which serve to warn conspecifics. In social hierarchical bird flocks, adults survive the winter better than juveniles and therefore survival strategies probably vary with social status. This study examined the differential responses to alarm calls by free‐living willow tits, Parus montanus, in dominance‐structured winter flocks in Finland. To explore the age‐dependent differences in response to conspecific alarm calls, a series with three alarm calls was played to focal adults and juveniles while they sat in the middle section of a spruce branch. Immediately after the playback, juvenile willow tits moved more often, flew longer distances and changed branches more often than did adults. Previous mammal studies have shown that juveniles are more likely to flee than adults after hearing conspecific alarm calls. The current study demonstrates that similar age‐dependent responses to conspecific alarm calls occur in birds also. These findings reflect an increased vulnerability to predators or lack of experience of young birds.
Antipredator Tactics of Amphibious Sea‐Snakes (Serpentes, Laticaudidae)
Authors: Shine Richard , Bonnet Xavier , Cogger Harold G. 
Published: June 2003

AbstractBecause the antipredator behavior that an animal displays depends upon the context in which it encounters the predator, apparent interspecific differences in antipredator tactics may result from ecological rather than behavioral differences among taxa. We approached 127 free‐ranging laticaudid sea‐snakes on small islands in Noumea Lagoon, New Caledonia, prodded the animals midbody, and recorded their responses. One species (Laticauda colubrina) usually remained immobile (relying on crypsis) whereas another (L. laticaudata) generally fled. However, multivariate analysis shows that the two species actually responded in very similar ways to any given stimulus; the species differed overall because colubrina was generally encountered on land during the day whereas laticaudata was more often encountered in the ocean at night. Thus, apparent interspecific differences in antipredator responses were secondary consequences of interspecific differences in the times and places that predators were encountered. Snakes were more likely to flee rather than remain immobile when rapid locomotion was possible (i.e. juveniles rather than adults; in water rather than on land) and pursuit by a predator was difficult (i.e. at night rather than during the day). These patterns suggest that snakes adjust their antipredator tactics in ways that maximize the chances of surviving the encounter, although the remarkable docility of these highly venomous snakes remains puzzling.
Deterministic Plio‐Pleistocene extinctions in the European cool‐temperate tree flora
Authors: Svenning Jens‐Christian 
Published: June 2003

AbstractExtinctions have been important in the shaping of modern phytogeographic patterns. A classic example is the heavy Plio‐Pleistocene losses that have caused Europe to have a depauperate temperate tree flora compared to eastern North America and eastern Asia. To investigate the mechanisms involved in this extinction event, I test the hypothesis that the present European status (extinct, relictual, or widespread) of cool‐temperate tree genera found in Pliocene Europe is predictable from their modern climatic requirements. As a prerequisite for this analysis, I test for genus‐level conservatism in climatic requirements by comparing congeneric values across Europe, eastern Asia and North America, and find strong evidence hereof. I find a high degree of ecological determinism in the fate of European Pliocene tree genera, still widespread taxa being more tolerant of cold growing season and winter temperatures than extinct and relictual taxa, and relictual taxa being more drought tolerant than extinct taxa.
How should environmental stress affect the population dynamics of disease?
Authors: Lafferty Kevin D. , Holt Robert D. 
Published: June 2003

abstractWe modelled how stress affects the population dynamics of infectious disease. We were specifically concerned with stress that increased susceptibility of uninfected hosts when exposed to infection. If such stresses also reduced resources, fecundity and/or survivorship, there was a reduction in the host carrying capacity. This lowered the contact between infected and uninfected hosts, thereby decreasing transmission. In addition, stress that increased parasite mortality decreased disease. The opposing effects of stress on disease dynamics made it difficult to predict the response of disease to environmental stress. We found analytical solutions with negative, positive, convex and concave associations between disease and stress. Numerical simulations with randomly generated parameter values suggested that the impact of host‐specific diseases generally declined with stress while the impact of non‐specific (or open) diseases increased with stress. These results help clarify predictions about the interaction between environmental stress and disease in natural populations.
Dopamine‐dependent cytotoxicity of tetrahydrobiopterin: a possible mechanism for selective neurodegeneration in Parkinson's disease
Authors: Choi Hyun Jin , Kim Seong Who , Lee So Yeon , Hwang Onyou 
Published: June 2003

AbstractParkinson's disease is a neurodegenerative disorder associated with selective loss of dopaminergic neurons in the substantia nigra. While the underlying cause of this cell death is poorly understood, oxidative stress is thought to play a role. We have previously shown that tetrahydrobiopterin (BH4), an obligatory co‐factor for tyrosine hydroxylase (TH), exerts selective toxicity on dopamine‐producing cells and that this is prevented by antioxidants. This study shows that BH4‐induced dopaminergic cell death is primarily mediated by dopamine, evidenced by findings that (i) BH4 toxicity is increased in proportion to cellular dopamine content; (ii) non‐dopaminergic cells become susceptible to BH4 upon exposure to dopamine; and (iii) depletion of dopamine attenuates BH4 toxicity in dopamine‐producing cells. BH4 causes lipid peroxidation, suggesting involvement of oxidative stress but the toxicity does not require enzymatic oxidation of dopamine. Instead, it seems to involve formation of quinone product(s) because (i) the cell death is attenuated by exposure to or induction of quinone reductase and (ii) BH4‐treated cells show increased formation of protein‐bound quinones, which is inhibited by thiol antioxidants. These data taken together suggest that the presence of both BH4 and dopamine is important in rendering dopaminergic cells vulnerable and that this involves formation of reactive dopamine quinone products.
Dopaminergic neuronal loss and motor deficits inCaenorhabditis elegansoverexpressing human α‐synuclein
Authors: Lakso Merja , Vartiainen Suvi , Moilanen Anu‐Maarit , Sirviö Jouni , Thomas James H. , Nass Richard , Blakely Randy D. , Wong Garry 
Published: June 2003

AbstractOverexpression of human α‐synuclein in model systems, including cultured neurons, drosophila and mice, leads to biochemical and pathological changes that mimic synucleopathies including Parkinson's disease. We have overexpressed both wild‐type (WT) and mutant alanine53→threonine (A53T) human α‐synuclein by transgenic injection intoCaenorhabditis elegans. Motor deficits were observed when either WT or A53T α‐synuclein was overexpressed with a pan‐neuronal or motor neuron promoter. Neuronal and dendritic loss were accelerated in all three sets ofC. elegansdopaminergic neurons when human α‐synuclein was overexpressed under the control of a dopaminergic neuron or pan‐neuronal promoter, but not with a motor neuron promoter. There were no significant differences in neuronal loss between overexpressed WT and A53T forms or between worms of different ages (4 days, 10 days or 2 weeks). These results demonstrate neuronal and behavioral perturbations elicited by human α‐synuclein inC. elegansthat are dependent upon expression in specific neuron subtypes. This transgenic model inC. elegans, an invertebrate organism with excellent experimental resources for further genetic manipulation, may help facilitate dissection of pathophysiologic mechanisms of various synucleopathies.
Differential effect of nitric oxide on glutathione metabolism and mitochondrial function in astrocytes and neurones: implications for neuroprotection/neurodegeneration?
Authors: Gegg M. E. , Beltran B. , Salas‐Pino S. , Bolanos J. P. , Clark J. B. , Moncada S. , Heales S. J. R. 
Published: June 2003

AbstractPrimary culture rat astrocytes exposed to the long acting nitric oxide donor (Z)‐1‐[2‐aminoethyl)‐N‐(2‐ammonioethyl)amino]diazen‐1‐ium‐1,2‐diolate (DETA‐NO) for 24 h approximately double their concentration of glutathione (GSH) and show no sign of cell death. In contrast, GSH was depleted by 48%, and significant loss of mitochondrial respiratory chain complex activity and cell death were observed in primary culture rat neurones subjected to DETA‐NO for 18 h. Northern blot analysis suggested that mRNA amounts of both subunits of glutamate‐cysteine ligase (GCL), the rate‐limiting enzyme in GSH synthesis, were elevated in astrocytes following nitric oxide (NO) exposure. This correlated with an increase in astrocytic GCL activity. Neurones on the other hand did not exhibit increased GCL activity when exposed to NO. In addition, the rate of GSH efflux was doubled and γ‐glutamyltranspeptidase (γ‐GT) activity was increased by 42% in astrocytes treated with NO for 24 h. These results suggest that astrocytes, but not neurones, up‐regulate GSH synthesis as a defence mechanism against excess NO. It is possible that the increased rate of GSH release and activity of γ‐GT in astrocytes may have important implications for neuroprotection in vivo by optimizing the supply of GSH precursors to neurones in close proximity.
Synergistic inhibitory effect of ascorbic acid and acetylsalicylic acid on prostaglandin E2 release in primary rat microglia
Authors: Fiebich Bernd L. , Lieb Klaus , Kammerer Norbert , Hüll Michael 
Published: June 2003

AbstractAscorbic acid (vitamin C) has been suggested to protect cerebral tissue in a variety of pathophysiological situations such as head trauma, ischemia or Alzheimer's disease. Most of these protective actions have been attributed to the antioxidative capacity of ascorbic acid. Besides the presence of elevated levels of oxygen radicals, prostaglandins produced by neurones and microglial cells seem to play an important role in prolonged tissue damage. We investigated whether ascorbic acid alone inhibits prostaglandin E2 (PGE2) synthesis and may augment the inhibitory effect of acetylsalicylic acid on prostaglandin synthesis. Ascorbic acid dose‐dependently inhibited PGE2 synthesis in lipopolysaccharide‐treated primary rat microglial cells (IC50 = 3.70 µm). In combination with acetylsalicylic acid (IC50 = 1.85 µm), ascorbic acid augmented the inhibitory effect of acetylsalicylic acid on PGE2 synthesis (IC50 = 0.25 µm in combination with 100 µm ascorbic acid). Ascorbic acid alone or in combination with acetylsalicylic acid did not inhibit cyclooxygenase‐2 (COX‐2) protein synthesis but inhibited COX‐2 enzyme activity. Our results show that ascorbic acid and acetylsalicylic acid act synergistically in inhibiting PGE2 synthesis, which may help to explain a possible protective effect of ascorbic acid in various brain diseases.
Exaggerated effect of fluvoxamine in heterozygote serotonin transporter knockout mice
Authors: Montañez Sylvia , Owens W. Anthony , Gould Georgianna G. , Murphy Dennis L. , Daws Lynette C. 
Published: June 2003

AbstractClearance rates for serotonin (5‐HT) in heterozygote (+/–) and homozygote (–/–) serotonin transporter (5‐HTT) knockout (KO) mice have not been determined in vivo. Moreover, the effect of selective serotonin reuptake inhibitors (SSRIs) on 5‐HT clearance in these mice has not been examined. In this study, the rate of clearance of exogenously applied 5‐HT was measured in the CA3 region of the hippocampus of anesthetized mice using high‐speed chronoamperometry. Compared with wild‐type mice, the maximal rate of 5‐HT clearance from extracellular fluid (ECF) was decreased in heterozygotes and more markedly so in KO mice. Heterozygote mice were more sensitive to the 5‐HT uptake inhibitor, fluvoxamine, resulting in longer clearance times for 5‐HT than in wild‐type mice; as expected, the KO mice were completely unresponsive to fluvoxamine. There were no associated changes in norepinephrine transporter density, nor was there an effect of the norepinephrine uptake inhibitor, desipramine, on 5‐HT clearance in any genotype. Thus, adaptive changes in the norepinephrine transport system do not occur in the CA3 region of hippocampus as a consequence of 5‐HTT KO. These data highlight the potential of the heterozygote 5‐HTT mutant mice to model the dynamic in vivo consequences of the human 5‐HTT polymorphism.