bluuebunny/crossref_metadata_2025_split huggingface dataset:
Managing heterogeneity: the importance of grazing and environmental variation on post‐fire succession in heathlands
Authors: VANDVIK VIGDIS , HEEGAARD EINAR , MÅREN INGER ELISABETH , AARRESTAD PER ARILD 
Published: February 2005

Summary

Semi‐natural habitats have been shaped by human disturbance regimes for centuries. Spatially and temporally heterogeneous land‐use practices, such as cutting, burning, grazing and turf‐cutting, have resulted in complex mosaic landscapes that are of high priority for conservation in Europe. Contemporary conservation subjects these systems to management regimes that are generally less diverse, in terms of disturbances and fine‐scale temporal and spatial variability, than traditional land use, but the ecological consequences of these simplifications are unclear.
We investigated the interactive effects of fire and grazing on plant species composition and diversity along local environmental (moisture) gradients in coastal heathlands. A replicated series of post‐fire successions (n = 12) was initiated in three heathland habitats and the areas subjected to two grazing regimes. Floristic and environmental data were recorded in permanent plots over a 5‐year period. Community data were analysed using multivariate ordination techniques (principal components analysis, partial redundancy analyses, and principal response curves) and generalized linear models.
Fire induced strong successional trends in the species composition of the heathlands. These trends differed among heathland habitats, and with grazing. Strong interactions between fire, habitat and grazing implied that the effect of grazing on the successional dynamics differed among habitats. Species diversity decreased in the first year after fire but increased beyond the pre‐fire levels during succession. This trend was not affected by local environment or grazing, although there were main effect differences in diversity between environments and grazing regimes.
Synthesis and applications. Our results demonstrate that the two management practices do not have simple additive effects within the semi‐natural system studied, as grazing created ecological opportunities for additional sets of species, increased variability among habitats, and added complexity to the post‐fire successional dynamics. In order to preserve diversity, conservation management should thus aim to preserve the level of complexity of the traditional management regimes, both in terms of the actual disturbances (e.g. fire and grazing) as well as the spatial scales at which they are applied. Further, the considerable change in these effects along the local environmental gradient brings into question the efficiency of general management prescriptions, and indicates that local environmental variability should be taken into account in the conservation of semi‐natural habitats.
Assessing the value of roadless areas in a conservation reserve strategy: biodiversity and landscape connectivity in the northern Rockies
Authors: CRIST MICHELE R. , WILMER BO , APLET GREGORY H. 
Published: February 2005

Summary

Roadless areas on United States Department of Agriculture (USDA) Forest Service lands hold significant potential for the conservation of native biodiversity and ecosystem processes, primarily because of their size and location. We examined the potential increase in land‐cover types, elevation representation and landscape connectivity that inventoried roadless areas would provide in a northern Rockies (USA) conservation reserve strategy, if these roadless areas received full protection.
For the northern Rocky Mountain states of Montana, Wyoming and Idaho, USA, we obtained GIS data on land‐cover types and a digital elevation model. We calculated the percentage of land‐cover types and elevation ranges of current protected areas (wilderness, national parks and national wildlife refuges) and compared these with the percentages calculated for roadless and protected areas combined. Using five landscape metrics and corresponding statistics, we quantified how roadless areas, when assessed with current protected areas, affect three elements of landscape connectivity: area, isolation and aggregation.
Roadless areas, when added to existing federal‐protected areas in the northern Rockies, increase the representation of virtually all land‐cover types, some by more than 100%, and increase the protection of relatively undisturbed lower elevation lands, which are exceedingly rare in the northern Rockies. In fact, roadless areas protect more rare and declining land‐cover types, such as aspen, whitebark pine, sagebrush and grassland communities, than existing protected areas.
Synthesis and applications. Landscape metric results for the three elements of landscape connectivity (area, isolation and aggregation) demonstrate how roadless areas adjacent to protected areas increase connectivity by creating larger and more cohesive protected area ‘patches.’ Roadless areas enhance overall landscape connectivity by reducing isolation among protected areas and creating a more dispersed conservation reserve network, important for maintaining wide‐ranging species movements. We advocate that the USDA Forest Service should retain the Roadless Area Conservation Rule and manage roadless areas as an integral part of the conservation reserve network for the northern Rockies.
The kangaroo conundrum: home range studies and implications for land management
Authors: VIGGERS K. L. , HEARN J. P. 
Published: February 2005

Summary

The movement of native herbivores onto agricultural land is a key management issue world‐wide as they may compete with domestic livestock for pasture and contribute to overgrazing and soil erosion. Eastern grey kangaroos Macropus giganteus are viewed as a problem species in temperate south‐eastern Australia, where high‐density populations in reserves encroach on nearby farmland.
This study examined home range size and use in M. giganteus across different types of land use and in relation to population density and pasture availability.
Farmland adjacent to either radiata pine plantations or reserves supporting high‐density populations of M. giganteus was subject to frequent incursions by kangaroos moving onto farmland to rest or graze. However, animals from reserves moved on average only 135 m onto farms.
Home ranges of M. giganteus were significantly smaller in the reserves than in farm study sites where population densities were lower. At reserve sites, home range size was limited by higher population densities and limited opportunity for dispersal across surrounding open farmland because of a lack of cover. Home range size was not affected by resource availability.
Where suitable vegetation cover occurred on farmland (e.g. woodland remnants or scrub), M. giganteus occurred as resident or roving small mobs. This may be seen by farmers as a disincentive to preserve remnant vegetation as it can provide habitat for unwanted native wildlife.
Home range attributes of M. giganteus suggest the species could be controlled by culling. However, recolonization occurs quickly and little is known of dispersal.
Synthesis
and
applications. Population density, presence of cover and reluctance to disperse across cleared landscapes are key factors influencing kangaroo home range size and use of adjacent farmland. Currently, little incentive exists for farmers to preserve remnant vegetation, as it may be regarded as providing habitat for unwanted or ‘pest’ kangaroos. Given the potential importance of remnant vegetation on private land for the conservation of plants and other species of wildlife, government incentives and compensation programmes may be required to limit land clearing on farms and to encourage improved pasture management.
Adaptive restoration of sand‐mined areas for biological conservation
Authors: CUMMINGS JASON , REID NICK , DAVIES IAN , GRANT CARL 
Published: February 2005

Summary

Adaptive management approaches to ecological restoration are current best practice. The usefulness of such an approach was tested in this study by implementing repeated experiments that examined restoration options for derelict sand mine sites dominated by Imperata cylindrica. Reclamation of degraded land that is dominated by I. cylindrica is a common problem throughout the tropics.
Initially, the hypothesized barrier to regeneration was limited seedling establishment because of I. cylindrica competition. After burning the grassland, woody weed control and planting of seedlings were implemented in factorial combination.
Seedling survival 28 months after planting averaged 26%, with < 1% of all seedlings establishing to a height > 1 m. The hypothesis that a transition barrier comprising solely biotic interactions restricted regeneration of native woody cover was rejected after seedlings and natural regeneration failed to thrive in this experiment.
A revised hypothesis, that the transition barrier comprised a combination of abiotic limitations (soil deficiencies) and biotic interactions (Wallabia bicolor browsing and I. cylindrica competition), was developed. A second experiment tested this hypothesis by removing W. bicolor (fencing), slashing the I. cylindrica, adding organic mulch and planting a mixture of native pioneer and secondary successional woody species in factorial combination.
Seedling survival was 61% in the second experiment and mulching significantly enhanced the survival and growth of all planted species. Planting alone reduced the regeneration of I. cylindrica after slashing. Native woody cover establishment was maximized by planting seedlings in mulched treatments.
Synthesis and applications. Taken together, these experiments support the hypothesis that there is a barrier restricting regeneration of native woody cover, and the barrier probably comprises both abiotic and biotic components. By adopting an adaptive management approach to the ecological restoration of sites, significant insights into their management requirements have been gained, supporting the current best practice restoration framework. Insights gained through monitoring and adaptation will be used to update the reserve plan of management, enhancing restoration of this severely degraded area and promoting connectivity of native woody cover within the conservation estate.
Numerical analysis of surface and fossil pollen spectra from northern Fennoscandia
Authors: Bennett K. D. , Hicks S. 
Published: February 2005

AbstractAim  Determination of the main directions of variance in an extensive data base of annual pollen deposition, and the relationship between pollen data from modified Tauber traps and palaeoecological data.Location  Northern Finland and Norway.Methods  Pollen analysis of annual samples from pollen traps and contiguous high‐resolution samples from a peat sequence. Numerical analysis (principal components analysis) of the resulting data.Results  The main direction of variation in the trap data is due to the vegetation region in which each trap is located. A secondary direction of variation is due to the annual variability of pollen production of some of the tree taxa, especially Betula and Pinus. This annual variability is more conspicuous in ‘absolute’ data than it is in percentage data which, at this annual resolution, becomes more random. There are systematic differences, with respect to peat‐forming taxa, between pollen data from traps and pollen data from a peat profile collected over the same period of time.Main conclusions  Annual variability in pollen production is rarely visible in fossil pollen samples because these cannot be sampled at precisely a 12‐month resolution. At near‐annual resolution sampling, it results in erratic percentage values which do not reflect changes in vegetation. Profiles sampled at near annual resolution are better analysed in terms of pollen accumulation rates with the realization that even these do not record changes in plant abundance but changes in pollen abundance. However, at the coarser temporal resolution common in most fossil samples it does not mask the origin of the pollen in terms of its vegetation region. Climate change may not be recognizable from pollen assemblages until the change has persisted in the same direction sufficiently long enough to alter the flowering (pollen production) pattern of the dominant trees.
Bioclimatic analysis of disjunct populations of the giant burrowing frog, Heleioporus australiacus
Authors: Penman T. D. , Mahony M. J. , Towerton A. L. , Lemckert F. L. 
Published: February 2005

AbstractAim  A bioclimatic analysis of the giant burrowing frog was conducted to determine if the northern and southern populations have distinct climatic profiles and to determine if the disjunction in the species records is a result of a climatically unsuitable area.Location  The study utilized records throughout the species range in south‐eastern Australia.Methods  The bioclim package was used to examine the climatic envelope of the species, as well as envelopes for the southern and northern populations. Principal components analysis (PCA) was used in an attempt to refine the model.Results  The package predicted the observed gap between the populations as climatically suitable in all of the models. The northern populations were found in warmer and wetter sites than the southern populations. River valleys and coastal lowlands were generally unsuitable climatically for the species.Main conclusions  The area of the observed disjunction is climatically suitable for both the northern and southern populations. Large river valleys appear to have played a significant role in determining the distribution of the species. PCA was used successfully to alter the model, however further research is needed to determine which is the most accurate approach.
Waveguide sidewall roughness measurement on full wafers by SEM‐based stereoscopy
Authors: BONY A. , HEID A. , TAKAKURA Y. , SATZKE K. , MEYRUEIS P. 
Published: February 2005

SummaryWe present a technique aiming at sidewall roughness measurement on integrated optical silica waveguides using a scanning electron microscope. The technique uses the principles of stereoscopy to retrieve sidewall topography. Practical implementation details and first results are provided.
Imaging the substructure of antibodies with tapping‐mode AFM in air: the importance of a water layer on mica
Authors: THOMSON N. H. 
Published: February 2005

SummaryMonoclonal antibodies (immunoglobulin G; IgG) against the N‐terminal domain of the A subunit of DNA gyrase have been imaged using tapping‐mode atomic force microscopy under ambient conditions on hydrophilic mica surfaces. The familiar tri‐nodal submolecular resolution of IgG (i.e. 50‐kDa resolution) has been achieved when operating the microscope with the tip predominantly in the attractive force regime. Under common laboratory conditions of about 40% relative humidity, the resolution of this substructure was not achieved owing to motion of the antibodies on the surface and/or image distortion from tip–sample instabilities. Reproducible imaging of the tri‐nodal antibody substructure was achieved by desiccating the samples for extended periods of time (1 week or more) before imaging. This effect is attributed to the presence of a humidity‐dependent thin water layer (a few molecules or nanometres thick), which has been observed previously using the surface force apparatus and scanning polarization force microscopy. Desiccation of the mica surfaces allowed enough water to be removed from the mica surface to prevent this effect. Degradation in the image quality over the imaging period of an hour or two was observed, owing to re‐adsorption of water under the ambient laboratory conditions.
Radon track imaging in CR‐39 plastic detectors using confocal scanning laser microscopy
Authors: PETFORD N. , WERTHEIM D. , MILLER J. A. 
Published: February 2005

SummaryConfocal scanning laser microscopy (CSLM) has been used to provide the first images of radon track populations in two external CR‐39 plastic detectors. Measurements of variables including track area distribution and estimates of the angle of track inclination (dip) derived from surface CSLM sections are presented. CSLM depth slices, combined with three‐dimensional (3D) visualization techniques, provide a new, non‐destructive way of examining the 2D and 3D geometry of the etched tracks within solid‐state nuclear track detectors that may prove useful in complementing existing optical microscopy methods.
Characterization of ultrafine coal fly ash particles by energy‐filtered TEM
Authors: CHEN Y. , SHAH N. , HUGGINS F. E. , HUFFMAN G. P. , DOZIER A. 
Published: February 2005

SummaryIn this study, energy‐filtered transmission electron microscopy is demonstrated to be a valuable tool for characterizing ultrafine coal fly ash particles, especially those particles encapsulated in or associated with carbon. By examining a series of elemental maps (K‐edge maps of C and O, and L‐edge maps of Si, Al, Ti and Fe) recorded using the three‐window method, considerable numbers of titanium and iron species with sizes from several nanometres to submicrometre were shown to be present, typically as oxides dispersed in the carbonaceous matrix. Crystalline phases, such as rutile and iron‐rich oxide spinel, were also identified from electron diffraction patterns and high‐resolution TEM images. Information about these ultrafine coal fly ash particles regarding their size, morphology, elemental composition and distribution, and crystalline phases, which has not been available previously in conventional ash studies, should be useful in toxicological studies and related environmental fields.
New technique for in‐situ measurement of backscattered and secondary electron yields for the calculation of signal‐to‐noise ratio in a SEM
Authors: SIM K. S. , WHITE J. D. 
Published: February 2005

SummaryThe quality of an image generated by a scanning electron microscope is dependent on secondary emission, which is a strong function of surface condition. Thus, empirical formulae and available databases are unable to take into account actual metrology conditions. This paper introduces a simple and reliable measurement technique to measure secondary electron yield (δ) and backscattered electron yield (η) that is suitable for in‐situ measurements on a specimen immediately prior to imaging. The reliability of this technique is validated on a number of homogenous surfaces. The measured electron yields are shown to be within the range of published data and the calculated signal‐to‐noise ratio compares favourably with that estimated from the image.
A method for automated detection of gene expression required for the establishment of a digital transcriptome‐wide gene expression atlas
Authors: CARSON J. P. , EICHELE G. , CHIU W. 
Published: February 2005

SummaryAcquiring information about the expression of a gene in different cell populations and tissues can provide key insight into the function of the gene. A high‐throughputin situhybridization (ISH) method was recently developed for rapid and reproducible acquisition of gene expression patterns in serial tissue sections at cellular resolution. Characterizing and analysing expression patterns on thousands of sections requires efficient methods for locating cells and estimating the level of expression in each cell. Such cellular quantification is an essential step in both annotating and quantitatively comparing high‐throughput ISH results. Here we describe a novel automated and efficient methodology for performing this quantification on postnatal mouse brain.
The use of rhodamine 6G and fluorescence microscopy in the evaluation of phospholipid‐based polymeric biomaterials
Authors: WANG J‐H. , BARTLETT J. D. , DUNN A. C. , SMALL S. , WILLIS S. L. , DRIVER M. J. , LEWIS A. L. 
Published: February 2005

SummaryA technique is described that allows the staining and subsequent visualization of polymers that contain the phosphorylcholine (PC) group. These materials are useful as bulk materials or coatings for the fabrication of medical devices. The staining method employs rhodamine 6G, which can be simply and rapidly applied to the polymer coating and imaged using fluorescence microscopy. The specificity of the staining for the PC polymers makes this technique suitable for the evaluation of a wide range of substrates and provides qualitative information on coating uniformity, coverage and morphology. It can be used to examine the durability of, and defects in, the coating. Statistical analysis of the fluorescent intensity by measuring the pixel value during imaging can allow for the method to be used as a quality control tool.
Longitudinal Left Ventricular Myocardial Dysfunction Assessed by 2D Colour Tissue Doppler Imaging in a Dog with Systemic Hypertension and Severe Arteriosclerosis
Authors: Nicolle A. P. , Carlos Sampedrano C. , Fontaine J. J. , Tessier‐Vetzel D. , Goumi V. , Pelligand L. , Pouchelon J.‐L. , Chetboul V. 
Published: February 2005

SummaryA 12‐year‐old sexually intact male Vendée Griffon Basset was presented for acute pulmonary oedema. Severe systemic systolic arterial hypertension (SAH) was diagnosed (290 mmHg). Despite blood and abdominal ultrasound tests, the underlying cause of the systemic hypertension could not be determined, and primary SAH was therefore suspected. Conventional echocardiography showed eccentric left ventricular hypertrophy with normal fractional shortening. Despite this apparent normal systolic function, 2D colour tissue Doppler imaging (TDI) identified a marked longitudinal systolic left ventricular myocardial alteration, whereas radial function was still preserved. Three months later, the dog underwent euthanasia because of an acute episode of distal aortic thromboembolism. Necropsy revealed severe aortic and iliac arteriosclerosis. SAH related to arteriosclerosis is a common finding in humans, but has not been previously described in dogs. Moreover, its consequence on longitudinal myocardial function using TDI has never been documented before in this species.
Characteristics of patients with delayed diagnosis of infectious pulmonary tuberculosis
Authors: PHOA Lee‐Lan , TELEMAN Monica D. , WANG Yee‐Tang , CHEE Cynthia B. E. 
Published: February 2005

Objective:  The aim of this study was to identify patient and disease characteristics associated with delayed diagnosis of infectious pulmonary tuberculosis (TB).Methodology:  A retrospective analysis of 375 adult patients with culture‐positive pulmonary TB and cough, treated at the Singapore Tuberculosis Control Unit (TBCU) in 2000, was carried out using data extracted from the TB notification registry and clinical records of the TBCU. Demographic, social, clinical and disease characteristics of patients with reported cough of duration less than, and exceeding, the median duration for the study population were compared.Results:  The median duration of cough reported at TB notification was 4 weeks (range, 1–156 weeks). By multivariate analysis, patients with cough > 4 weeks were more likely to be < 65 years old (adjusted odds ratio (OR), 1.8; 95% CI, 1.1–2.9; P = 0.02), of Chinese ethnicity (adjusted OR, 2.0; 95% CI, 1.2–3; P = 0.004), more likely to be sputum acid‐fast bacilli smear‐positive (adjusted OR, 1.7; 95% CI, 1.1–2.7; P = 0.016), and to have weight loss (adjusted OR, 2.6; 95% CI, 1.7–4; P < 0.01).Conclusion:  Further studies are needed to identify the possible reasons for delayed diagnosis of TB among those < 65 years old, in the Chinese population in Singapore.