bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential effects of drugs interacting with autonomic transmitters on responses of rat vas deferens to field stimulation
Authors: Boselli C. , Grana E.
Published: March 2003

1 Frequency–response curves (0.1–30 Hz) were obtained in the epididymal portion of rat vas deferens. At low frequencies (0.1–1 Hz), the parameters evaluated were the first twitch and the fourth twitch at each frequency. The responses to trains of stimuli at intermediate (2–5 Hz) and high (10–30 Hz) frequencies were biphasic consisting of phase I (the first rapid phase of tetanus) and of phase II (the secondary slowly developing one).  2 Prazosin inhibited the first and the fourth twitch but not when the frequency was <1 Hz. Suramin inhibited the first twitch while substantially depressing the fourth one. The combination of prazosin and suramin almost completely abolished all the twitches evoked by a train of stimuli at low frequencies. Nifedipine left almost unaltered the first twitch while markedly depressing the fourth one, especially at relatively high frequency (1 Hz). Verapamil was devoid of any inhibitory action. Papaverine depressed the first twitch while only at the highest concentration used (1×10−4
m) markedly inhibited the fourth one. Chloroethylclonidine (CEC) depressed the first twitch and increased the fourth.  3 When intermediate (2–5 Hz) and high (10–30 Hz) frequencies are considered, prazosin and suramin partially inhibited both phase I and phase II, while in combination they almost completely abolished both phases. Nifedipine and verapamil selectively suppressed phase II, leaving phase I unaffected. Papaverine completely abolished both phase I and phase II. CEC was able to completely abolish phase I but increased phase II.  4 These results suggest that the response to the first twitch of a train at low frequency is prevailingly noradrenergic, prazosin‐sensitive, while when the twitches are close enough (i.e. at 1 Hz) a summation of stimuli takes place and a predominant purinergic component, both suramin‐ and nifedipine‐sensitive, becomes evident.  5 At high frequencies, both phases are due to the concomitant release of noradrenaline and adenosine triphosphate (ATP). The noradrenergic component of phase I is nifedipine‐insensitive and CEC‐sensitive, resembling the pharmacological profile of the endogenously released noradrenaline by single pulse, while that of phase II, nifedipine‐sensitive and CEC‐insensitive, is similar to that produced by exogenously applied noradrenaline.
Effects of clofilium on cardiovascular tissues from normo‐ and hypertensive rats
Authors: Nand Vinita , Doggrell Sheila A.
Published: March 2003

1 The overall aim was to test whether clofilium has some potential as a positive inotrope for heart failure. We used Wistar Kyoto normotensive rats (WKY) and spontaneously hypertensive rats (SHRs) and studied the effects of clofilium on isolated blood vessels, left ventricular action potentials and left ventricular contractility.  2 Clofilium at ≤10−6 m had no effect on WKY portal vein contractions and at ≤3×10−4 m had no effect on WKY or SHR quiescent mesenteric and intralobar pulmonary arteries.  3 Clofilium at 10−7–10−5 m prolonged the WKY left ventricular action potentials and with 10−6 and 10−5 m this included after‐depolarizations.  4 Clofilium at ≤3×10−5 m augmented the peak force, prolonged the contractions and did not cause arrhythmias in the absence and presence of isoprenaline on left ventricle strips from 12‐month‐old WKY.  5 The 12‐month‐old SHR has hypertrophy of the left ventricle with reduced peak force and prolongation of relaxation. The effects of clofilium on 12‐month‐old SHR left ventricle contractility were similar to those in the age‐matched WKY.6 In summary, clofilium has positive inotropic effects on the rat left ventricle that are maintained in hypertrophy. Clofilium does not have effects on blood vessels that would be detrimental in heart failure. Clofilium prolongs the rat left ventricle action potential and causes after‐depolarizations. The pro‐arrhythmic potential of clofilium, however, makes it unlikely that it could be used as a positive inotrope in the treatment of heart failure.
Role of endothelium in ischaemia‐induced myocardial dysfunction of isolated working hearts: cardioprotection by activation of adenosine A2A receptors
Authors: Maddock H. L. , Broadley K. J. , Bril A. , Khandoudi N.
Published: March 2003

1 This study aimed to determine the role of the vascular endothelium on recovery of contractile function following global low‐flow ischaemia of guinea‐pig isolated working hearts and the effects of adenosine analogues on this recovery.

2 Guinea‐pig isolated spontaneously beating or paced working hearts were set up and coronary flow (CF), aortic output (AO) (as an index of cardiac function), heart rate (HR), left ventricular pressure (LVP) and dP/dt max recorded. The endothelium was either intact or removed by a blast of oxygen.

3 In spontaneously beating hearts, low‐flow ischaemia for 30 min reduced CF and cardiac contractility (LVP, dP/dt max) but not AO. On reperfusion, CF, LVP and dP/dt max recovered, while AO fell precipitously followed by a gradual recovery, indicative of myocardial stunning. The effects of ischaemia did not differ between endothelium‐intact and ‐denuded hearts, indicating no role of the endothelium in the changes observed.

4 The adenosine analogues, N6‐cyclopentyladenosine (CPA, A1 selective), 5'‐N‐ethylcarboxamidoadenosine (NECA, two‐fold A2 selective over A1) and 2‐p‐((carboxyethyl)‐phenethylamino)‐5'carboxamidoadenosine (CGS21680, A2A selective) were infused (3 × 10−7 M) from 10 min into the 30‐min low‐flow ischaemia of denuded hearts and during reperfusion.

5 CGS21680 increased CF and improved the postischaemic functional recovery, as measured by the AO. NECA and CPA were not cardioprotective. The A2A selective antagonist, ZM241385, attenuated the coronary vasodilatation by CGS21680 and abolished the improved recovery of AO on reperfusion.

6 Reperfusion of paced working hearts caused a dramatic fall in AO which failed to recover. Infusion of CGS21680 from 15 min into the ischaemic period produced vasodilatation but failed to restore AO, presumably because the ischaemic damage was irreversible.

7 Thus, the endothelium plays no role in myocardial dysfunction following low‐flow global ischaemia and reperfusion of guinea‐pig working hearts. The A2A adenosine receptor‐selective agonist but not the non‐selective A2 receptor agonist, NECA, attenuated ischaemia‐ and reperfusion‐induced stunning. This was attributed to increased CF and was independent of the endothelium.
The phytogeography of European and Mediterranean heath species (Ericoideae, Ericaceae): a quantitative analysis
Authors: Ojeda Fernando , Arroyo Juan , Marañón Teodoro
Published: March 2003

The geographic ranges of heath species in Europe and the Mediterranean and their relationships with environmental (climatic and ecogeographic) variables and biological features are analysed by means of multivariate methods. In particular, twinspan classifications into floristic elements and floristic regions, DCA floristic ordinations, CCA environment‐constrained ordinations and CCA biology‐constrained ordinations are carried out. Results of the analyses show a correspondence with conventional regionalization analyses based on broader criteria, and less correspondence with numerical analyses of other taxonomic groups at a similar scale. This lack of fit depends on the particular history and ecology of the taxonomic groups under study. A number of climatic (temperature and water stress) and geographic (coast length) variables are associated with different types of heaths according to their geographical ranges (continental, Mediterranean, Atlantic). Biological features of heaths account for a small part of the variation in range, but the association of temperate heaths with a preference for acid soils, of Mediterranean heaths with pubescence, and of Atlantic heaths with plant height is of interest. Heath species richness throughout Europe and the Mediterranean is analysed by multiple regression analyses and, apart from a strong influence of area size, a significant effect of water conditions, temperature and proximity to sea is detected. The area with the highest heath species richness is Western Mediterranean. Additional classification, ordination and multiple regression analyses of heaths in the Iberian Peninsula (Spain and Portugal, the areas with the highest heath diversity) revealed similar patterns to those found in Europe and the Mediterranean. The effect of heterogeneity of the studied units at this latter scale is removed in the Iberian analysis because of the relative homogeneity of the units considered at this scale.
Distribution patterns and insular biogeography of South Asian raptor communities
Authors: Thiollay Jean‐Marc
Published: March 2003

Ten diurnal raptor communities (Falconiformes) were studied in continental and peninsular situations, and on landbridge and oceanic islands of various sizes, from Southern India to Southern Vietnam and from Sri Lanka to Java. An index of abundance was derived from 1‐km2 sample plots. A consistent decrease of species richness occurred from continent to peninsulas and to large landbridge islands, then more abruptly to oceanic islands. The impoverishment process was much faster for open habitat raptors than for forest species, and for rarest and most specialized raptors than for common and more generalist species. Large taxa survived on islands as well as smaller species. Specific habitat requirements, historical factors and forest fragmentation were probably more important determinants of community composition than land area itself. An insular syndrome was documented in forest species on islands, including significant examples of habitat niche expansion, interspecific segregation and density compensation. Some cases suggested that interspecific competition was involved. Such relaxation of habitat and density constraints may enhance the survival probability of these species on islands.
Floristic affinities of an inselberg archipelago in the southern Namib desert—relic of the past, centre of endemism or nothing special?
Authors: Burke A , Jürgens N , Seely M. K
Published: March 2003

The floral composition of an inselberg archipelago in the southern Namib desert was investigated with regard to species diversity, geographic range of the species, habitat niches, seed dispersal abilities and plant herbivore defence. Although no endemic species were found, the archipelago forms an extreme and often isolated outlier for a large number of species in their distribution area. The hypothesis is proposed that the isolated extreme habitat allowed survival of relic populations due to low immigration rate and low competition. The high proportion of species favouring long‐range dispersal might explain the lack of endemic species as well as the large contribution of species at their distributional boundary.
Possible latitudinal clines in Antarctic intertidal and subtidal zone communities encrusting ephemeral hard substrata
Authors: Barnes D. K. A. , Arnold R. J.
Published: March 2003

Aim Encrusting faunal communities on rocks were examined from Southern Ocean intertidal and subtidal (6 m) zones to investigate potential change with latitude.

Location The site locations were South Georgia (54°S [sub‐Antarctic]), Signy Island (60.5°S [maritime Antarctic]) and Adelaide Island (68°S [high Antarctic]).

Methods The number of taxa, degree of colonization and bryozoan growth and mortality were measured.

Results The communities present were relatively simple in terms of composition and interactions. Spirorbid polychaetes (Annelida) and cheilostomatid bryozoans were the principal components. The community simplicity and dominance of unitary (compared to colonial) fauna increased with latitude. Mean annual mortality of subtidal cheilostomatids also significantly increased with latitude. The number of bryozoan species and potential aspects of community complexity increased with latitude. The growth of the bryozoan Inversiula nutrix increased with latitude reversing the general trend of decreased growth rate.

Conclusions These findings suggest that disturbance may significantly increase with latitude within the Southern Ocean. The apparent reversal of typical latitudinal growth trends is probably a result of classical island biogeography, with species decreasing away from a centre of high diversity.
Greta's Garbo: stranded seeds and fruits from Greta Beach, Christmas Island, Indian Ocean
Authors: Green P. T.
Published: March 2003

AimTo describe the species composition of stranded seeds and fruits drifted by ocean currents to Christmas Island, Indian Ocean.

LocationChristmas Island, Indian Ocean.

MethodsFrequent visual searches along the strand line of the island's few accessible beaches over a 4‐year period 1988–92, with most effort concentrated on Greta Beach, on the east coast.

ResultsThe collection contained not fewer than sixty‐three species in forty‐nine genera and twenty‐nine families. Leguminous seeds were by far the most common (especially Caesalpinia bonduc (L.) Roxb., Dioclea spp., Entada spp., Erythrina spp. and Mucunagigantea (Willd.) DC.), but Calophyllum inophyllum L., Guettarda speciosa L., Hernandia ovigera L., Heritiera littoralis Aiton and Terminalia catappa L. were also common.

Main conclusionsOnly about one‐third of species recorded in the drift flora are native to the island, and most disseminules stranded on the island are probably not locally derived. The most likely distant sources of drift disseminules are probably the southern Indonesian islands and Sumatra, with most disseminules probably arriving via the Timor and Arafura Seas between Indonesia and Australia. However, some disseminules may originate from as far east as the Moluccas and the east coast of Kalimantan. The majority of species recorded in the drift flora are not native to the island, and yet some of these were encountered frequently and displayed a high degree of viability on arrival (e.g. Dioclea hexandra (Ralph) Mabb., Erythrina fusca Loureiro and Mucuna gigantea (Willd.) DC.). Several possible reasons for the failure of many drift species to establish on the island are discussed.
Evidence for reticulate palaeogeography: beetle diversity linked to connection‐disjunction cycles of the Gibraltar strait
Authors: Palmer Miquel , Cambefort Yves
Published: March 2003

Aim Dispersal barriers between areas within some regions have appeared and disappeared throughout evolutionary time. Here we describe the distributional patterns displayed by three taxa living in such kind of regions. These patterns can be better explained considering a reticulated rather than a hierarchically branched palaeogeography.

Location Western Mediterranean.

Methods The taxa studied are Misolampus (Coleoptera, Tenebrionidae), Tentyria (Coleoptera, Tenebrionidae) and Thorectes (Coleoptera, Geotrupidae). All them are flightless and show a high degree of endemicity. The individual pattern of area relationships was determined separately for each genus by Brooks Parsimony Analysis (BPA). A theoretical general area cladogram was constructed based on the palaeogeographical history of the region. Finally, the general area cladogram is reconciled with the individual ones.

Results The ancestor of Misolampus probably was North African. Land dispersal toward the Iberian Peninsula is proposed. Speciation within Iberia is related to specific vicariance events, and the presence of insular (Balearic Islands) populations is explained by sea‐surface or, more probably, human‐mediated dispersal. The ancestor of Tentyria was Iberic. The proposed hypothesis to explain the current species distribution mainly relies on the occurrence of specific vicariance events. However, the occurrence of some sea‐surface dispersal event is not discarded. Almost all possible vicariance events can be recognized in the first clade of the Thorectes genus. There is evidence for dispersal between Africa and Europe at different dates and in both directions. In spite of some uncertainties, the appearance of the second Thorectes clade can also be explained by the occurrence of specific historical events. An ancient dispersal toward the eastern Mediterranean and several dispersal events during the Messinian seem likely.

Main conclusions The same historical events have specific outcomes in every tree (even in every branch within a tree) depending on the ability for dispersal and speciation of each taxon. Connection‐disjunction cycles of dispersal barriers have acted as diversity producers.
Modelling the potential effects of climate change on calcareous grasslands in Atlantic Europe
Authors: Duckworth J. C. , Bunce R. G. H. , Malloch A. J. C.
Published: March 2003

Aim This study aims to assess the sensitivity of calcareous grassland vegetation to climate change and to indicate the most probable direction of change.

Location The study area was a region of Britain, Ireland, France and Spain, centred on the Bay of Biscay, which was defined using a land classification based on climatic criteria.

Methods Vegetation was sampled in the field, with additional data collected on soils, climate, management and land cover. The vegetation samples were ordinated by detrended correspondence analysis in order to explore the main gradients present and as a basis for modelling changes. Environmental data were summarized by ordination techniques, with the scores generated used to predict the current vegetation score on the first two ordination axes by multiple regression. The model was then manipulated to represent a 2 °C increase in temperature and resulting shifts in the vegetation samples in terms of their species composition assessed.

Results There was a good general agreement between the original vegetation ordination axis scores and those predicted by the model, the latter of which were based on environmental data alone. Following a 2 °C increase in temperature, the predicted changes in the ordination space were demonstrated to be subtle, consisting of small shifts towards vegetation associated with warmer conditions, representing distances 100 km or less on the ground.

Main conclusions The models are simple but nevertheless provide a useful basis for the investigation of potential vegetation change. The shifts in the ordination space represent more minor changes than those predicted in previous studies. This suggests that the potential for major change is lower when environmental factors such as soil and management are considered in addition to climate. The potential for change is also reduced when vegetation is considered as a whole rather than on an individual species basis, due to both interspecific interactions and interactions with environmental factors acting as constraints.
Biogeography and climatic differentiation of two annual species of Teesdalia R. Br. (Brassicaceae)
Authors: Hoffmann Matthias H.
Published: March 2003

Aim

The two annual species of Teesdalia R. Br. occupy nearly exclusive ranges. Autecological data on T. nudicaulis (L.) R. Br., taken from the literature, are compared with data obtained from a climatic analysis of the general distributional range of the species. This paper addresses the question of whether the observed autecological characteristics of the species (local scale) are reflected in the data obtained from the climatic analysis (global scale). Furthermore, the marked biogeographical differentiation of the two annual species of Teesdalia R. Br. is investigated.

Location

The genus Teesdalia is naturally distributed in Europe and North Africa.

Methods

The number of occurrences of the species along climatic gradients is calculated. The data are primarily presented in frequency diagrams (FDs) exhibiting the number of occupied grid cells along the climatic gradients. The temperature–precipitation diagrams (TPDs) are derived from the FDs to illustrate the monthly climate spaces of the species. The climate spaces of the species in the course of the year are shown in the climatic mean diagram (CMD). Each type of diagram illustrates distinctive characteristics of the species’ ranges.

Results

Autecological studies of T. nudicaulis show that distinctive thermal and hydric (autumn and spring) conditions are necessary for optimal germination and fruit set. The significance of these two seasons is also reflected in the climatic analysis of the species’ range. Despite their importance, the results of the autecological study are not sufficient to explain the whole range of the species. It seems that additional factors, such as low temperatures, but also higher or lower amounts of precipitation at temperatures similar to those observed locally, may be limiting in other parts of the range. The three types of diagram shed light on factors affecting the geographical differentiation of the two annual species. However, the biology and ecology of T. coronopifolia (J. P. Bergeret) Thell. are not well enough known to trace evolutionary pathways of this biogeographical differentiation.

Main conclusions

Local ecological or biological studies are necessary for a better understanding of the species’ ranges. Results of local studies concerning the influence of climate on the species’ ranges may be tested at a global level using the methodology presented here. The diagrams provide a framework for analyses of geographical differentiations of species and the formulation of locally testable hypotheses for comparative biogeographical studies.
Participation of species with different zoogeographical ranks in the formation of local faunas: a case study
Authors: Vilenkin B. YA. , Chikatunov V. I.
Published: March 2003

Aim

To find out how common the earlier explored regularity is in numerical relationships among co‐occurring species with various zoogeographical rank.

Location

The distribution of 284 species of Scarabaeoidea beetles in 20 biotic provinces of Israel and the Sinai Peninsula is considered. This Eastern Mediterranean territory is a part of the Levant area.

Methods

All species are allocated to one of three groups with different zoogeographical rank. These are the Levantine endemics (E), Regional (R) and Ubiquitous (U) species. Relationships among the numbers of species of each group were analysed with the use of multiple and ordinary regression. Similarity between faunas of resulting sets of provinces was analysed using the of chi‐square test.

Results

The numbers of E‐ and R‐species in each province are statistically independent, while the number of U‐species increases linearly with an increase in the E‐ and/or R‐species number. Two linear regressions appear in the coordinates: ln (E + 1) − R. These regressions unify nine and seven provinces, respectively. The faunas of two sets of provinces differed significantly. Two fringe provinces, which were present within the territory considered only by small parts of their respective zoogeographical units, as well as two provinces with heavily destroyed habitats, fall out of the regression lines. The number of E‐species increases in a south–north direction. The area of maximum diversity is assumed to be somewhat north of the Israeli state border. Success of the invading E‐species is discussed from the standpoint of Van Valen's (1973) Red Queen Theory.

Main conclusions

Species persisting together are not selected by chance. In our case, three zoogeographical ranks correspond to three grades of species’ ranges. Different ranges are assumed to have different species’ fitness. The present faunas have formed in the two sets of provinces in similar but independent ways.
Holocene palaeoenvironments of salt lakes in the Darling Anabranch region, south‐western New South Wales, Australia
Authors: Cupper Matthew L. , Drinnan Andrew N. , Thomas Ian
Published: March 2003

Aim

Fossil pollen preserved within small salt lake basins in the Australian interior is used to reconstruct mid‐ to late Holocene vegetation. The study aims to identify the origin of problems such as woodland decline and salinization within present ecosystems.

Location

Warrananga and Tooperoopna salt lakes, south‐western New South Wales, Australia.

Methods

Pollen, carbonized particle and sedimentological analyses of cores taken from salt lakes.

Results

Prior to c. 4500 years ago, the region supported a dense cover of Casuarinaceae woodlands. It is possible that the subhumid zone species Allocasuarina luehmannii comprised some of the Casuarinaceae element. In the late Holocene, A. luehmannii disappeared from the record and chenopodiaceous low shrublands expanded. About 2000 years ago, Callitris representation decreased. Woodland contraction also occurred after European settlement.

Main conclusions

Increasing aridity or greater seasonal variation in the climate during the late Holocene caused a contraction of woodland vegetation. Increased proportions of Chenopodiaceae may indicate soil salinization around the basins. A decrease in Callitris was possibly due to heightened severity or frequency of drought events after 2000 years ago. Decline in woodland pollen in the uppermost samples is explained by the preferential clearing of Callitris glaucophylla, Callitris gracilis and Casuarina pauper for timber and their limited regeneration because of browsing by stock and rabbits.
Biogeography and evolutionary history of Hyperolius species: application of molecular phylogeny
Authors: Wieczorek Ania M. , Drewes Robert C. , Channing Alan
Published: March 2003

Aim

We propose a phylogeny of selected Hyperolius species (Anura: Hyperoliidae), based on mtDNA sequence data and parsimony analysis. This phylogeny was used to interpret the historical biogeography of the genus in Africa.

Location

Samples were collected throughout the distribution of Hyperolius in Africa.

Methods

We compiled distributional maps of all species, summarized historical changes in vegetation and climate in Africa since the late Cretaceous, and used these in combination to identify historical factors that may have contributed to speciation in these frogs. A phylogeny for Hyperolius was derived from mtDNA sequence data and interpreted in terms of climatic and vegetation changes in Africa.

Main conclusions

Lowland rainforest is proposed to have been the ancestral habitat of Hyperolius. The expansion of savannah and reduction of lowland rainforest were identified as important factors in the differentiation of the more basal species. Finally, the development of the Rift Valley system played an important role in the speciation of derived species with relatively limited distributions.
Towards a more general species–area relationship: diversity on all islands, great and small
Authors: Lomolino  , Weiser
Published: March 2003

Aim

To demonstrate a new and more general model of the species–area relationship that builds on traditional models, but includes the provision that richness may vary independently of island area on relatively small islands (the small island effect).

Location

We analysed species–area patterns for a broad diversity of insular biotas from aquatic and terrestrial archipelagoes.

Methods

We used breakpoint or piecewise regression methods by adding an additional term (the breakpoint transformation) to traditional species–area models. The resultant, more general, species–area model has three readily interpretable, biologically relevant parameters: (1) the upper limit of the small island effect (SIE), (2) an estimate of richness for relatively small islands and (3) the slope of the species–area relationship (in semi‐log or log–log space) for relatively large islands.

Results

The SIE, albeit of varying magnitude depending on the biotas in question, appeared to be a relatively common feature of the data sets we studied. The upper limit of the SIE tended to be highest for species groups with relatively high resource requirements and low dispersal abilities, and for biotas of more isolated archipelagoes.

Main conclusions

The breakpoint species–area model can be used to test for the significance, and to explore patterns of variation in small island effects, and to estimate slopes of the species–area (semi‐log or log–log) relationship after adjusting for SIE. Moreover, the breakpoint species–area model can be expanded to investigate three fundamentally different realms of the species–area relationship: (1) small islands where species richness varies independent of area, but with idiosyncratic differences among islands and with catastrophic events such as hurricanes, (2) islands beyond the upper limit of SIE where richness varies in a more deterministic and predictable manner with island area and associated, ecological factors and (3) islands large enough to provide the internal geographical isolation (large rivers, mountains and other barriers within islands) necessary forin situspeciation.
Biogeography and ecology of paedomorphosis in Triturus alpestris (Amphibia, Caudata)
Authors: Denoël M. , Duguet R. , Dzukic G. , Kalezic M. , Mazzotti S.
Published: March 2003

Aim

Paedomorphosis is an evolutionary change in which larval structures are retained in adult animals. In newts and salamanders, this heterochronic process is widely represented and concerns the retention of gill slits. We want to find out whether ecological and geographical determinants may be associated with paedomorphosis in the Alpine newt Triturus alpestris.

Location

Europe.

Methods

Determination of the main characteristics of all known aquatic sites containing paedomorphic Alpine newt individuals.

Results

Although metamorphs are common in Europe, paedomorphs are only found at the southern margin of the geographical range of the species: mainly in Italy and in the Balkans. They were recorded in eighty‐seven aquatic sites. No single trend was outlined for the analysed ecological parameters of the aquatic and terrestrial habitats (e.g. altitude, maximum water depth, drying and presence of forest).

Main conclusions

Contrary to the first models of paedomorphosis, the main traits of aquatic and terrestrial habitat do not explain the occurrence of paedomorphs in natural populations. Although they were found in favourable aquatic habitats surrounded by hostile terrestrial landscapes, they also exist in temporary waters located at proximity of appropriate terrestrial environments. These results support models predicting paedomorphosis in varied environments, but require complementary investigations on the costs and benefits of the alternative ontogenetic pathways. On the other hand, the southern limitation of the heterochronic phenomenon suggests a genetic basis for paedomorphosis in the studied species.
Ecosystem function and species loss – a microcosm study
Authors: Scarff Fiona R. , Bradley J. Stuart
Published: March 2003

There are too many kinds of organisms to be able to study and manage each, yet the loss of a single species can sometimes unravel an ecosystem. Such `fusewire species'– critical in the same sense that an electrical fuse can cut out a whole circuit – would be a rewarding focus for research and management effort. However, this approach can only be effective if these `fusewires' represent but a small proportion of the number of species in the system.

Aim

To demonstrate methods for measuring what proportion of the species in a system are critical to ecosystem function.

Methods

The prevalence of fusewire species was measured in manipulative experiments on an aquatic microcosm.

Results

No single genus deletion caused changes in key characteristics of the system.

Main conclusions

Comparison of these results with other published studies shows that the proportion of critical fusewire species varies amongst different ecosystems. The oxidation pond microcosms were shown to contain no single species indispensable to system function. They appear to be ill‐suited to a management strategy which focuses on priority eukaryote species. However, a single study provides no evidence that this result is general or even typical of other kinds of ecosystems; it is presented here as an empirical model. Other methods of investigation are available; they are less experimentally rigorous but more practical. These could provide important guidance in planning an approach to management in a particular ecosystem.
Predictors of deforestation in the Brazilian Amazon
Authors: Laurance William F. , Albernaz Ana K. M. , Schroth Götz , Fearnside Philip M. , Bergen Scott , Venticinque Eduardo M. , Da Costa Carlos
Published: March 2003

Aim and Location

We assessed the effects of biophysical and anthropogenic predictors on deforestation in Brazilian Amazonia. This region has the world's highest absolute rates of forest destruction and fragmentation.

Methods

Using a GIS, spatial data coverages were developed for deforestation and for three types of potential predictors: (1) human‐demographic factors (rural‐population density, urban‐population size); (2) factors that affect physical accessibility to forests (linear distances to the nearest paved highway, unpaved road and navigable river), and (3) factors that may affect land‐use suitability for human occupation and agriculture (annual rainfall, dry‐season severity, soil fertility, soil waterlogging, soil depth). To reduce the effects of spatial autocorrelation among variables, the basin was subdivided into >1900 quadrats of 50 × 50 km, and a random subset of 120 quadrats was selected that was stratified on deforestation intensity. A robust ordination analysis (non‐metric multidimensional scaling) was then used to identify key orthogonal gradients among the ten original predictor variables.

Results

The ordination revealed two major environmental gradients in the study area. Axis 1 discriminated among areas with relatively dense human populations and highways, and areas with sparse populations and no highways; whereas axis 2 described a gradient between wet sites having low dry‐season severity, many navigable rivers and few roads, and those with opposite values. A multiple regression analysis revealed that both factors were highly significant predictors, collectively explaining nearly 60% of the total variation in deforestation intensity (F2,117=85.46, P < 0.0001). Simple correlations of the original variables were highly concordant with the multiple regression model and suggested that highway density and rural‐population size were the most important correlates of deforestation.

Mainconclusions

These trends suggest that deforestation in the Brazilian Amazon is being largely determined by three proximate factors: human population density, highways and dry‐season severity, all of which increase deforestation. At least at the spatial scale of this analysis, soil fertility and waterlogging had little influence on deforestation activity, and soil depth was only marginally significant. Our findings suggest that current policy initiatives designed to increase immigration and dramatically expand highway and infrastructure networks in the Brazilian Amazon are likely to have important impacts on deforestation activity. Deforestation will be greatest in relatively seasonal, south‐easterly areas of the basin, which are most accessible to major population centres and where large‐scale cattle ranching and slash‐and‐burn farming are most easily implemented.
Biogeographical research on European species of the lichen genusPhysconia
Authors: Otte Volker , Esslinger Theodore L. , Litterski Birgit
Published: March 2003

AbstractAim The (world) distribution of the European species ofPhysconiaPoelt (Lichenes: Physciaceae) [exceptPh. distorta(With.) J. R. Laundon andPh.americanaEssl.] was investigated. The study was complemented by data on the ecological behaviour of the species.

Location The location of the study is the whole world with a local emphasis on Europe.

Methods The geographical distribution of the lichen species under consideration was investigated from collection data of herbaria and field studies in a databank. Additional data were taken from existing literature and critically considered. Distribution maps were created with ArcView GIS. The distribution patterns are expressed as three‐dimensional areal formulas, regarding zonal distribution, altitudinal range and oceanity of the species distributions, using the method ofMeuselet al. (1965).

Results The distribution patterns of the tenPhysconiataxa considered are represented in detailed maps and expressed as three‐dimensional areal formulas. The ecological behaviour was discussed.Physconia muscigenaandPh. perisidiosaare species of bipolar distribution type, the other species are holarctic types.Physconia detersaandPh. enteroxanthaoccur in both Eurasia and North America, the remaining species (Ph.griseassp.grisea,Ph. griseassp.lilacina,Ph. petraea,Ph. servitii,Ph. subpulverulentaandPh.venusta) are pure Old world taxa with a much more limited distribution.The majority of the EuropeanPhysconiataxa are distributed meridionally to submeridionally and occur preferentially in suboceanic areas.

Main conclusions Some of the species under consideration have a wide distribution, nevertheless they show clear affinities to ecological conditions that influence their distribution patterns. A number of species show not only zonal and regional restrictions, but also affinities to the western climatic type. The Mediterranean is the centre of diversity of the genusPhysconiain Europe.
From optimism to pessimism. A case study of a psychiatric patient
Authors: Hellzen Ove , Asplund Kenneth , Gilje Fredricka , Sandman Per‐olof , Norberg Astrid
Published: March 2003

• This article focuses on the results of a single case study which illuminates an understanding of phases in nursing care for a patient in a psychiatric setting in Sweden.

• The focus of this study is a 50‐year‐old man who showed progressive deterioration from increased motor activity to oral, sexual, destructive and aggressive actions.

• Data collection using five methods occurred during a 21‐month period. Results of the content analysis processes identified four distinct but non‐discrete phases of the patient's complex condition.

• Medical and nursing care was categorized in three approaches: optimistic, strategic and resigned.

• The results raise the question of whether there is action that is without any meaning as an expression of the patient's wishes, thoughts and feelings.

• It seems clear that the patient in this study felt really angry and in despair. However, during moments of lucidity, he also indicated that he felt this was not an authentic expression of his ‘real’ self. His experience was that of a splintered world.
An investigation into the information obtained by patients undergoing gastroscopy investigations
Authors: Clements  , Melby
Published: March 2003

• The benefits of informing patients before undergoing surgery or other investigative procedures are clearly demonstrated in the literature.

• This study aimed to determine the amount and type of information given to patients before, during and after undergoing gastroscopy investigations.

• A survey approach incorporating structured interviews and structured observation was utilized.

• There were statistically significant differences between the information acquired by younger and older patients prior to, but not during or after, the procedure.

• Nurses appear to be the most important source of information for older patients while the information leaflet was perceived as the most important source of information for younger patients.
Nurses' perceptions of gross self‐neglect amongst older people living in the community
Authors: ADAMS JOHN , JOHNSON JULIA
Published: March 2003

• Self‐neglect in older people has an established medical literature but receives surprisingly little attention in the nursing literature.

• Hospital and community nurses were interviewed using a semistructured questionnaire.

• All the nurses were able to identify patients who had shown features of `gross self‐neglect'.

• Poor nutrition was a prominent feature: links with the literature are explored.
The wider implications of an audit of care plan documentation
Authors: GRIFFITHS  , HUTCHINGS
Published: March 2003

•This article describes how the results of an audit of district nursing care plan documentation have been used to inform practice development in a community trust.

•The principle aim of the audit was to discover whether the evaluation of patient care was being adequately recorded in nursing care plans.

•To establish this, four commonly occurring areas of district nursing work were selected and an ideal assessment of care developed from the available evidence. The areas were: the management of leg ulceration, bath care, pressure area care and catheter care.

•Data capture forms were developed to record whether the features of an ideal assessment of these four areas of care were reflected in the written evaluation of that care.

•The results of the audit demonstrated that the evaluation of care was often inadequately recorded, which reflected poor written documentation of the initial nursing assessment.

•The implications of the findings of the audit for practice development in the four areas of care are discussed.
A review of the literature on the prevention of suicide through interventions in Accident and Emergency Departments
Authors: REPPER JULIE
Published: March 2003

• In order to inform the development of a specialist `suicide prevention nurse' to work in an Accident and Emergency department (A&E), a review of literature in the area was undertaken.

• Priority was given to papers describing well specified interventions with a carefully defined client group. Only eight such studies were identified and, although they do have clear implications for practice, they provide inadequate information regarding the targeting of all clients at risk of suicide.

• The review was therefore broadened to include all UK literature on suicide and parasuicide at population and individual levels. Three distinct groups of A&E attendees at particular risk of suicide were identified: patients attending A&E following deliberate self‐harm; attendees with specific physical problems, and attendees with a known history of mental health problems.

• The needs of each of these groups are described, with their implications for the role of a `suicide prevention nurse' in A&E.

• In conclusion, action to reduce suicide needs to be taken at all levels of the organization and the role of the suicide prevention nurse needs to include support, training and development as well as specific time limited therapy with a highly targeted group of patients at specific risk.
Looking out for the patient and ourselves – the process of family integration into the ICU
Authors: HUPCEY JUDITH E.
Published: March 2003

• As more intensive care units (ICU) are adopting the policy of unrestricted family visiting, families are playing an increasing role in the unit. This role may be restricted to being involved in discussions and decisions related to the patient or may entail a caregiving role.

• This study examined how families and nurses interact to increase or decrease the family's involvement in the ICU, how nurses maintain control, how families remain on guard, endure and find their niche in the ICU.

• The techniques of grounded theory were used to develop a model of the process of family integration into the ICU.

• This model was developed around the core variable of `looking out for the patient – looking out for ourselves'.

• The perspectives of ICU nurses, families and ICU patients in the process of looking out for the patient while they look out for themselves are discussed, as well as nurses maintaining the position of power and families remaining on guard and enduring the ICU experience.
Nutritional care of the patient: nurses' knowledge and attitudes in an acute care setting
Authors: KOWANKO INGE , SIMON STEPHEN , WOOD JACQUELIN
Published: March 2003

• Concern is growing about the occurrence of malnutrition in hospitals throughout the developed world. Reduced involvement of nurses in patients' nutritional care may be one of the contributing factors.

• This study explored nurses' attitudes and knowledge about nutrition and food service in hospital.

• Semi‐structured interviews were conducted with seven nurses from the internal medical service of a large Australian acute care hospital.

• Analysis of the interview transcripts revealed that many nurses lacked the in‐depth knowledge needed to give proper nutritional care to their patients.

• Although nurses considered nutritional care to be important many had difficulty in raising its priority above other nursing activities, as a result of time constraints and multitasking issues.

• Several problems relating to food service arrangements were also highlighted.

• The findings suggest a need to raise nurses' awareness of the importance of nutrition in patient outcome.

• This study provides information which will guide in‐service nurse education programs about nutrition, and suggests strategies for practice and organizational change.
Studying the careers of nurse diplomates: the importance of branch‐specific questionnaires
Authors: Hardyman Rachel , Tingle Alison
Published: March 2003

• Questionnaire design is considered in the context of a longitudinal panel study focusing on the careers of people qualifying from all four branches of the UK nurse diploma course.

• Separate, but comparable, questionnaires were developed for each branch in order to produce information which reflected the differences between branches, and the experiences of the cohort as a whole.

• This approach ensured that participants from the smaller branches did not feel their interests and concerns were overshadowed by those of the largest (adult) branch, as is often the case during the diploma course’s Common Foundation Programme.

• The elements that needed to be tailored to each branch emerged during a three‐stage piloting process used to develop and test the questionnaires.

• Differences were found between branches in their use of terminology; in certain issues being more relevant to some branches than others; and in questions which concerned all branches benefiting from the inclusion of branch‐specific examples.

• The effectiveness of this approach to questionnaire design is borne out by the study’s high response rates.
Reflections on intuition and expertise
Authors: Perry Margaret A.
Published: March 2003

• Reflective practice now appears firmly established in the English speaking world of professional nursing practice and development. Outside this linguistic context, however, the concept seems less well‐known.

• This paper describes an experience drawn from clinical practice and education in French‐speaking Switzerland followed by explicit reflection grounded in questions generated by Johns’ model for structured reflection. Thus, a concept well‐described in the English‐language literature underpins an innovative approach to a French‐language clinical teaching situation.

• The professional implications of this situation are explored through meaningful reflection providing new insight into familiar circumstances as they relate to the nurse tutor’s role.

• This exploration is followed by a critical approach to the experience and the subsequent structured reflection in order to address relationships between intuition and expertise and self‐awareness through reflection.

• A hermeneutic perspective provides additional insight into the nurse–patient relationship where both come to the situation with their own ‘pre‐understandings’. Individual horizons thus endorse a new understanding going beyond taken‐for‐granted meanings.