bluuebunny/crossref_metadata_2025_split huggingface dataset:
Psychosocial factors and diabetes‐related outcomes following diagnosis of Type 1 diabetes in adults: The Edinburgh Prospective Diabetes Study
Authors: Taylor M. D. , Frier B. M. , Gold A. E. , Deary I. J. 
Published: March 2003

AbstractAims  To examine prospectively the relationships between psychosocial variables and diabetes‐related outcomes in adults with newly diagnosed Type 1 diabetes.Methods  A total of 84 adults (48 male) with a median (range) age of 30.8 (17–51) years with newly diagnosed Type 1 diabetes were recruited for the study. Shortly after initial diagnosis each participant's personality, cognitive ability, and recent psychiatric distress were assessed. At 4 months (n = 69) and at 12 months (n = 66) after diagnosis diabetes‐related outcomes were measured, including each respondent's knowledge of diabetes, satisfaction with diabetes treatment and diabetes‐related quality of life. Glycated haemoglobin (HbA1c) was recorded at each clinic attendance.Results  Social class (Spearman's correlation r = −0.30 and −0.28, respectively, P < 0.05) and scores on the National Adult Reading Test (r = 0.38 and 0.36, respectively, P < 0.01) were consistently associated with knowledge of diabetes at 4 months and at 12 months after diagnosis. Hierarchical regression revealed that alcohol consumption recorded at diagnosis and knowledge of diabetes at 4 months were independent predictors of glycaemic control at 12 months (adjusted r2 = 0.16). Total scores on the Diabetes Treatment Satisfaction Questionnaire (DTSQ) at 12 months were significantly predicted by age at diagnosis (adjusted r2 = 0.08). High neuroticism at diagnosis was consistently associated with poorer self‐reported diabetes quality of life at 4 months and at 12 months after diagnosis (rs between −0.30 and −0.39, P < 0.05).Conclusions  Long‐standing psychosocial factors have a significant influence on self‐reported outcomes during the 12 months following diagnosis of Type 1 diabetes but may not be reliable predictors of glycaemic control. Further follow‐up is necessary to determine the longer‐term predictors of objective (e.g. glycaemic control) and subjective (e.g. quality of life) indicators of coping in people with diabetes.
Bioclimatic discriminant capacity of terrestrial mammal faunas
Authors: Fernández Manuel Hernández 
Published: March 2003

AbstractA new method of environmental inference is presented. This method uses the climatic restriction index (CRI) for each mammal species, based on its geographical range within different climatic regimes, and a set of calculated summary indexes known as the bioclimatic spectrum. Analysis of 50 faunas throughout the world shows that terrestrial mammal communities are effective tools for accurate climatic inference at large spatial scale. The results also indicate that the use of entire mammalian fauna is the best inference system, followed by those based on separate groups such as Insectivora, Rodentia, micromammals and macromammals. Removing Chiroptera from the analysis does not change the results significantly. Bioclimatic analysis appears to be a good method for environmental interpretation. This new method ensures a high qualitative precision. It provides an empirical model for mammal community characterization that must be taken into account for palaeoclimatic reconstructions of continental environments.
Inter‐hemispheric synchrony of forest fires and the El Niño‐Southern Oscillation
Authors: Kitzberger Thomas , Swetnam Thomas W. , Veblen Thomas T. 
Published: March 2003

AbstractFire histories were compared between the south‐western United States and northern Patagonia, Argentina using both documentary records (1914–87 and 1938–96, respectively) and tree‐ring reconstructions over the past several centuries. The two regions share similar fire–climate relationships and similar relationships of climatic anomalies to the El Niño–Southern Oscillation (ENSO). In both regions, El Niño events coincide with above‐average cool season precipitation and increased moisture availability to plants during the growing season. Conversely, La Niña events correspond with drought conditions. Monthly patterns of ENSO indicators (southern oscillation indices and tropical Pacific sea surface temperatures) preceding years of exceptionally widespread fires are highly similar in both regions during the 20th century. Major fire years tend to follow the switching from El Niño to La Niña conditions. El Niño conditions enhance the production of fine fuels, which when desiccated by La Niña conditions create conditions for widespread wildfires. Decadal‐scale patterns of fire occurrence since the mid‐17th century are highly similar in both regions. A period of decreased fire occurrence in both regions from c. 1780–1830 coincides with decreased amplitude and/or frequency of ENSO events. The interhemispheric synchrony of fire regimes in these two distant regions is tentatively interpreted to be a response to decadal‐scale changes in ENSO activity. The ENSO–fire relationships of the south‐western USA and northern Patagonia document the importance of high‐frequency climatic variation to fire hazard. Thus, in addition to long‐term trends in mean climatic conditions, multi‐decadal scale changes in year‐to‐year variability need to be considered in assessments of the potential influence of climatic change on fire regimes.
Elevation gradients of diversity for rodents and bats in Oaxaca, Mexico
Authors: SÁnchez‐Cordero VÍctor 
Published: March 2003

Abstract1 This study documents patterns of rodent and bat diversity related to abiotic and biotic factors along elevational gradients in the Sierra Mazateca (640–2600 m a.s.l.) and Sierra Mixteca (700–3000 m a.s.l.) in Oaxaca, Mexico.2 The two transects share similar faunas: 17 and 23 rodent species were captured in the sierras Mazateca and Mixteca, respectively, 14 of which occurred on both transects. Rodent species richness was similar in the wet season and the dry season along both transects. Rodent species richness peaked at 1025–1050 m in tropical semi‐deciduous forest on both transects. Endemic species were restricted to high‐elevation habitats.3 Sixteen and 17 bat species were captured in the sierras Mazateca and Mixteca, respectively; 11 occurred on both transects. Bat species richness was higher in the wet season than in the dry season in the Sierra Mazateca. Bat species richness peaked at 1850 m in pine–oak forest in the Sierra Mazateca, and at 750 m and 1050 m in tropical semi‐deciduous forest in the Sierra Mixteca, decreasing abruptly at higher elevations on both transects.4 Patterns of trophic diversity of rodents and bats coincided with those of species richness on each transect. Species richness increased with increasing habitat diversity; increased with increasing rainfall and productivity; increased with increasing resource diversity; and increased in areas with high rates of speciation (rodents only).5 The need for conservation action in Oaxaca is urgent and proponents should promote establishment of protected areas linking lowland habitats with high species richness to high‐elevation habitats harbouring large numbers of endemic forms.
Mapping the biomass of Bornean tropical rain forest from remotely sensed data
Authors: Foody Giles M. , Cutler Mark E. , McMorrow Julia , Pelz Dieter , Tangki Hamzah , Boyd Doreen S. , Douglas Ian 
Published: March 2003

AbstractThe biomass and biomass dynamics of forests are major uncertainties in our understanding of tropical environments. Remote sensing is often the only practical means of acquiring information on forest biomass but has not always been used successfully. Here the conventional approaches to the estimation of forest biomass from remotely sensed data were evaluated relative to techniques based on the application of artificial neural networks. Together these approaches were used to estimate and map the biomass of tropical forests in north‐eastern Borneo from Landsat TM data. The neural networks were found to be particularly suited to the application. A basic multi‐layer perceptron network, for example, provided estimates of biomass that were strongly correlated with those measured in the field (r = 0.80). Moreover, these estimates were more strongly correlated with biomass than those derived from 230 conventional vegetation indices, including the widely used normalized difference vegetation index (NDVI).
Pantropical dynamics of ‘intact’ rain forest canopy texture
Authors: Weishampel John F. , Godin Jason R. , Henebry Geoffrey M. 
Published: March 2003

AbstractAside from deforestation and selective logging, mature tropical rain forests appear to be in a state of near‐term flux. At plot scales over a 20‐year period, forest inventory data (representing areas < 750 ha) have shown stands to be accumulating above‐ground biomass pantropically while displaying signs of increasing turnover. To assess whether or not such disequilibrium is manifest at broader spatial scales (i.e. coarser grain sizes and larger extents), we performed a change detection analysis of landscape texture (i.e. the organization of reflective properties), in satellite images of closed‐canopy tropical rain forests considered to be anthropically undisturbed. Here we show that fractal properties of pixel spectral values depicting low and high levels of photosynthetic activity underwent significant shifts from the 1970s to the 1980s. Following expectations for aggrading forests, canopy texture became more random throughout the tropics. Although subject to periodic disturbance events such as natural exogenic perturbations and/or synchronous die‐off, which should produce no consistent trend, these forested landscapes across the globe exhibited similar dynamics at fine temporal (decadal) intervals. Such biophysical changes (representing areas > 1000 000 ha) directly affect atmospheric boundary layer conditions and could have implications with respect to biodiversity and carbon cycling in these systems.
Does precipitation variability increase from mesic to xeric biomes?
Authors: Davidowitz Goggy 
Published: March 2003

AbstractDesert precipitation is often characterized as more variable than precipitation in nondesert biomes. However, empirical support for this generalization is lacking. I analysed precipitation variability in five desert and four nondesert biomes that represent a xeric to mesic gradient in the South‐western United States, using data from 328 weather stations, for a total of 18 337 station‐years. I examined precipitation variability at two temporal scales: among years and among months, within years. Each of these scales was analysed for annual precipitation, summer precipitation and winter precipitation for a total of 18 separate analyses. Overall, precipitation variability does increase as precipitation decreases. However, I found little support for the generalization that desert precipitation is more variable than precipitation in nondeserts. At most time scales, many south‐western American desert biomes are no more variable than nondesert biomes. The level of variability is highly dependent on which desert biome is under study, where in the biome a particular site is located, and what time scale is used to measure variability. Certain desert sites are in fact more variable than nondesert sites, in some cases by as much as fivefold. However, and perhaps more importantly, each desert biome includes many sites that are no more variable, across many or all time scales, than sites in the grassland or pine forest biomes. These results emphasize the importance of measuring variability for each study site of interest and caution against extrapolating from a few sites to biomes or gradients in general. Implications for the study of adaptations to environmental variability are discussed.
The effects of productivity and seasonality on life history: comparing age at maturity among moose (Alces alces) populations
Authors: Ferguson Steven H. 
Published: March 2003

AbstractThe productivity hypothesis in respect of an animal species’ geographical range predicts that whereas higher productivity at the equatorial periphery of a species’ range favours superior competitors, lower productivity at the centre of a species’ range favours high reproduction and reduced competitive traits. I test whether life‐history patterns follow this hypothesis, using demographic data from 15 Canadian moose (Alces alces) populations. Two models are contrasted; the first assumes that intraspecific variation in age at maturity is explained proximately by density and juvenile mortality. Age at maturity was found to increase with decreasing juvenile mortality (P = 0.01) and increasing density (P = 0.006). To test the productivity hypothesis, the second model additionally included primary productivity and seasonality as geographical explanatory variables that would ultimately influence age at maturity via juvenile mortality and density. Path analysis indicated that including productivity and seasonality improved the model predictions of variation in age at maturity (Ra20.56 and 0.85). In bivariate comparisons, seasonality was negatively associated (P = 0.01) with age at maturity. In the best model, however, primary productivity was the environmental variable that explained 25% of the variance in age at maturity, and forest cover replaced seasonality as an explanatory variable. The positive association between primary productivity and age at maturity is consistent with the productivity hypothesis. Relative to populations that lived at the centre of the species’ range (51°N), moose populations living in relatively high productivity and low seasonality environments (equatorial periphery of species’ range; 48°N) experienced less juvenile mortality, more variable year‐to‐year density, higher relative density and slower life history (slower growth rate, later age at maturity, lower fecundity).
The global distribution of cultivable lands: current patterns and sensitivity to possible climate change
Authors: Ramankutty Navin , Foley Jonathan A. , Norman John , McSweeney Kevin 
Published: March 2003

AbstractAim This study makes quantitative global estimates of land suitability for cultivation based on climate and soil constraints. It evaluates further the sensitivity of croplands to any possible changes in climate and atmospheric CO2 concentrations.Location The location is global, geographically explicit.Methods The methods used are spatial data synthesis and analysis and numerical modelling.Results There is a cropland ‘reserve’ of 120%, mainly in tropical South America and Africa. Our climate sensitivity analysis indicates that the southern provinces of Canada, north‐western and north‐central states of the United States, northern Europe, southern Former Soviet Union and the Manchurian plains of China are most sensitive to changes in temperature. The Great Plains region of the United States and north‐eastern China are most sensitive to changes in precipitation. The regions that are sensitive to precipitation change are also sensitive to changes in CO2, but the magnitude is small compared to the influence of direct climate change. We estimate that climate change, as simulated by global climate models, will expand cropland suitability by an additional 16%, mainly in the Northern Hemisphere high latitudes. However, the tropics (mainly Africa, northern South America, Mexico and Central America and Oceania) will experience a small decrease in suitability due to climate change.Main conclusions There is a large reserve of cultivable croplands, mainly in tropical South America and Africa. However, much of this land is under valuable forests or in protected areas. Furthermore, the tropical soils could potentially lose fertility very rapidly once the forest cover is removed. Regions that lie at the margins of temperature or precipitation limitation to cultivation are most sensitive to changes in climate and atmospheric CO2 concentration. It is anticipated that climate change will result in an increase in cropland suitability in the Northern Hemisphere high latitudes (mainly in developed nations), while the tropics will lose suitability (mainly in developing nations).
Assessing the vulnerability of species richness to anthropogenic climate change in a biodiversity hotspot
Authors: Midgley G.F. , Hannah L. , Millar D. , Rutherford M.C. , Powrie L.W. 
Published: March 2003

ABSTRACTAim  To compare theoretical approaches towards estimating risks of plant species loss to anthropogenic climate change impacts in a biodiversity hotspot, and to develop a practical method to detect signs of climate change impacts on natural populations.Location  The Fynbos biome of South Africa, within the Cape Floristic Kingdom.Methods  Bioclimatic modelling was used to identify environmental limits for vegetation at both biome and species scale. For the biome as a whole, and for 330 species of the endemic family Proteaceae, tolerance limits were determined for five temperature and water availability‐related parameters assumed critical for plant survival. Climate scenarios for 2050 generated by the general circulation models HadCM2 and CSM were interpolated for the region. Geographic Information Systems‐based methods were used to map current and future modelled ranges of the biome and 330 selected species. In the biome‐based approach, predictions of biome areal loss were overlayed with species richness data for the family Proteaceae to estimate extinction risk. In the species‐based approach, predictions of range dislocation (no overlap between current range and future projected range) were used as an indicator of extinction risk. A method of identifying local populations imminently threatened by climate change‐induced mortality is also described.Results  A loss of Fynbos biome area of between 51% and 65% is projected by 2050 (depending on the climate scenario used), and roughly 10% of the endemic Proteaceae have ranges restricted to the area lost. Species range projections suggest that a third could suffer complete range dislocation by 2050, and only 5% could retain more than two thirds of their range. Projected changes to individual species ranges could be sufficient to detect climate change impacts within ten years.Main conclusions  The biome‐level approach appears to underestimate the risk of species diversity loss from climate change impacts in the Fynbos Biome because many narrow range endemics suffer range dislocation throughout the biome, and not only in areas identified as biome contractions. We suggest that targeted vulnerable species could be monitored both for early warning signs of climate change and as empirical tests of predictions.
Patterns of within‐species body size variation of birds: strong evidence for Bergmann's rule
Authors: Ashton Kyle G. 
Published: March 2003

ABSTRACTAim The aim of this study is to test whether Bergmann's rule, a general intraspecific tendency towards larger body size in cooler areas and at higher latitudes, holds for birds throughout the world.Location This study includes information on species of birds from throughout the world.Methods I gathered data on body size variation from the literature and used two general meta‐analytical procedures to test the validity of Bergmann's rule in birds: a modified vote‐counting approach and calculation of overall effect sizes. Related species may show similar body size trends, thus I performed all analyses using nonphylogenetic and phylogenetic methods. I used tests of phylogenetic signal for each data set to decide which type of statistical analysis (nonphylogenetic or phylogenetic) was more appropriate.Results The majority of species of birds (76 of 100 species) are larger at higher latitudes, and in cooler areas (20 of 22 species). Birds show a grand mean correlation coefficient of +0.32 for body size and latitude, and −0.81 for body size and temperature, both significant trends. Sedentary species show stronger body size trends in some, but not all, analyses. Neither males nor females consistently have stronger body size trends. Additionally, the strength of body size trends does not vary with latitude or body mass.Conclusions Bergmann's rule holds for birds throughout the world, regardless of whether temperature or latitude (as a proxy) is used. Previous studies have suggested that Bergmann's rule is stronger for sedentary than migratory species, males than females and temperate than tropical taxa. I did not find strong support for any of these as general themes for birds, although few studies of tropical taxa have been conducted. The processes responsible for Bergmann's rule remain somewhat of a black box; however, fasting endurance is probably a more important factor than the traditional hypothesis of heat conservation.
A probabilistic approach to the use of pollen indicators for plant attributes and biomes: an application to European vegetation at 0 and 6 ka
Authors: Gachet S. , Brewer S. , Cheddadi R. , Davis B. , Gritti E. , Guiot J. 
Published: March 2003

ABSTRACTAim This paper presents a probabilistic method for the characterization of pollen taxa using attributes, and for the reconstitution of past biomes. The probabilities are calculated on the basis of European floristic and pollen databases sufficiently large and exhaustive to provide robust estimates.Location The analysis is based on data from approximately 1000 sites throughout Europe.Method We use all the pollen data from the European Pollen Database (EPD), which contains about 50 000 pollen assemblages distributed across Europe and covering the period from the Last Glacial Maximum to the present. Using existing floras, each pollen taxon has been characterized by allocating one or more modes of several attributes, chosen according to the biogeography and phenology of the taxon. With this information, conditional probabilities are defined, representing the chance of a given attribute mode occurring in a given pollen spectrum, when the taxa assemblage is known. The concept of co‐occurrence is used to provide a greater amount of information to compensate for difficulties in the identification of pollen grains, allowing a better interpretation when there is little diversity in the pollen assemblage.Results The method has been validated using a dataset of modern samples against existing methods of biome classification and remote sensing data. An application is proposed in which the new method is used to produce biomes for pollen data 6000 years ago. This confirms previous results showing an extension of the deciduous forest to the north, east and south, explained by milder winters in western and northern Europe, and cooler and wetter climate in the Mediterranean region.Conclusion The results show the new method to be efficient, reliable and flexible and to be an improvement over the previous method of biomization. They will be used to test simulations of earth system models running on periods with climate significantly different from the present day, enabling a robust test of the validity of applying these models to the future.