bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent geodetic unrest at Santorini Caldera, Greece
Authors: Newman Andrew V. , Stiros Stathis , Feng Lujia , Psimoulis Panos , Moschas Fanis , Saltogianni Vasso , Jiang Yan , Papazachos Costas , Panagiotopoulos Dimitris , Karagianni Eleni , Vamvakaris Domenikos 
Published: March 2012

After approximately 60 years of seismic quiescence within Santorini caldera, in January 2011 the volcano reawakened with a significant seismic swarm and rapidly expanding radial deformation. The deformation is imaged by a dense network of 19 survey and 5 continuous GPS stations, showing that as of 21 January 2012, the volcano has extended laterally from a point inside the northern segment of the caldera by about 140 mm and is expanding at 180 mm/yr. A series of spherical source models show the source is not migrating significantly, but remains about 4 km depth and has expanded by 14 million m3since inflation began. A distributed sill model is also tested, which shows a possible N‐S elongation of the volumetric source. While observations of the current deformation sequence are unprecedented at Santorini, it is not certain that an eruption is imminent as other similar calderas have experienced comparable activity without eruption.
Identifying reliable traits across laboratory mouse exploration arenas: A meta-analysis
Authors: Galsworthy Michael , Madani Rime , Lipp Hans-Peter 
Published: March 2012

AbstractThis study is a meta-analysis of 367 mice from a collection of behaviour neuroscience and behaviour genetic studies run in the same lab in Zurich, Switzerland. We employed correlation-based statistics to confirm and quantify consistencies in behaviour across the testing environments. All 367 mice ran exactly the same behavioural arenas: the light/dark box, the null maze, the open field arena, an emergence task and finally an object exploration task. We analysed consistency of three movement types across those arenas (resting, scanning, progressing), and their relative preference for three zones of the arenas (home, transition, exploration). Results were that 5/6 measures showed strong individual-differences consistency across the tests. Mean inter-arena correlations for these five measures ranged from +.12 to +.53. Unrotated principal component factor analysis (UPCFA) and Cronbach’s alpha measures showed these traits to be reliable and substantial (32-63% of variance across the five arenas). UPCFA loadings then indicate which tasks give the best information about these cross-task traits. One measure (that of time spent in “intermediate” zones) was not reliable across arenas. Conclusions centre on the use of individual differences research and behavioural batteries to revise understandings of what measures in one task predict for behaviour in others. Developing better behaviour measures also makes sound scientific and ethical sense.
Feature Detection in Radio Astronomy using the Circle Hough Transform
Authors: Hollitt C. , Johnston-Hollitt M. 
Published: March 2012

AbstractWhile automatic detection of point sources in astronomical images has experienced a great degree of success, less effort has been directed towards the detection of extended and low-surface-brightness features. At present, existing telescopes still rely on human expertise to reduce the raw data to usable images and then to analyse the images for non-pointlike objects. However, the next generation of radio telescopes will generate unprecedented volumes of data making manual data reduction and object extraction infeasible. Without developing new methods of automatic detection for extended and diffuse objects such as supernova remnants, bent-tailed galaxies, radio relics and halos, a wealth of scientifically important results will not be uncovered. In this paper we explore the response of the Circle Hough Transform to a representative sample of different extended circular or arc-like astronomical objects. We also examine the response of the Circle Hough Transform to input images containing noise alone and inputs including point sources.
Transverse Mixing of Simulated Piscicides in Small Montane Streams
Authors: Brown Peter J. , Ard Jenifer L. , Zale Alexander V. 
Published: March 2012

AbstractThorough mixing of piscicides into receiving waters is important for efficient and effective fish eradication. However, no guidance exists for the placement of drip stations with respect to mixing. Salt (NaCl) was used as a tracer to measure the mixing rates of center versus edge applications in riffle–pool, straight, and meandering sections of montane streams. The tracer was applied at either the center or the edge of a channel and measured with a conductivity meter across a downstream grid to determine the distances at which transverse mixing was complete. No advantage was accrued by applying piscicides in different types of channels because transverse mixing distance did not differ among them. However, mixing distance was significantly shorter at center applications. Chemicals entering a stream at the center of the channel mixed thoroughly within 10 stream widths, whereas chemicals entering a stream channel at the edge mixed thoroughly within 20 stream widths.
Influence of applied compressive stress on the hysteresis curves and magnetic domain structure of grain-oriented transverse Fe–3%Si steel
Authors: Perevertov O , Schäfer R 
Published: March 2012

Abstract
The influence of an applied compressive stress on the hysteresis curve and domain structure in conventional (1 1 0) [0 0 1] Fe–3%Si steel cut transverse to the rolling direction is studied. Quasistatic hysteresis loops under compressive stress up to 75 MPa were measured. The magnetic domains and magnetization processes were observed by longitudinal Kerr microscopy at different levels of stress. It is shown that the bulk hysteresis loop can be described with a good accuracy by the action of an effective field, which is the product of the stress and a function of magnetization. Domain observations have shown that the reasons for the effective field are demagnetizing fields due to the disappearance of supplementary domains along [0 1 0] and [1 0 0] at low fields and different domain systems in different grains at moderate fields. The latter are caused by differences in grain sensitivity to stress depending on the degree of misorientation. A decrease in the effective field above 1 T is connected with a transformation of all grains into the same domain system—the column pattern.
Zinc nitride films prepared by reactive RF magnetron sputtering of zinc in nitrogen containing atmosphere
Authors: Jiang Nanke , Georgiev Daniel G , Jayatissa Ahalapitiya H , Collins Robert W , Chen Jie , McCullen Erik 
Published: March 2012

Abstract
Zinc nitride films were deposited on glass or silicon substrates by reactive magnetron RF sputtering of zinc in N2–Ar ambient. The deposition conditions were optimized in terms of substrate temperature and N2/Ar sputtering gas ratio, and representative films were then studied by structure, optical and spectroscopy techniques, and electrical measurements. Spectroscopic ellipsometry and spectrophotometry measurements revealed that the material has a direct band gap close to 1.26 eV. Hall effect and resistivity measurements indicated n-type conductivity with a very high carrier concentration of about1021 cm−3, mobility of up to 90 cm2 V−1 s−1, and resistivity of ∼10−3 Ω cm. X-ray photoelectron spectroscopy spectra clearly showed the existence of not only Zn–N bonding but also of a fraction of N–N bonding configurations, together with an oxidized surface. According to energy-dispersive x-ray spectroscopy analysis, the as-deposited films were almost stoichiometric and contained only a small fraction of oxygen.
Cathode erosion in a high-pressure high-current arc: calculations for tungsten cathode in a free-burning argon arc
Authors: Nemchinsky Valerian 
Published: March 2012

Abstract
The motion of an evaporated atom of the cathode material in a near-cathode plasma is considered. It is shown that the evaporated atom is ionized almost instantly. The created ion, under the influence of a strong electric field existing in the cathode proximity, has a high probability of returning to the cathode. A small fraction of evaporated atoms are able to diffuse away from the cathode to the region where they are involved in plasma flow and lose their chance to return to the cathode. The fraction of the total evaporated atoms, which do not return to the cathode, the escape factor, determines the net erosion rate. In order to calculate this factor, the distributions of the plasma parameters in the near-cathode plasma were considered. Calculations showed that the escape factor is on the order of a few per cent. Using experimental data on the plasma and cathode temperatures, we calculated the net erosion rate for a free-burning 200 A argon arc with a thoriated tungsten cathode. The calculated erosion rate is close to 1 µg s−1, which is in agreement with available experimental data.
First Report of Erysiphe knautiae (Erysiphales) on Lomelosia caucasica (Caucasian Pincushion Flower) in North America
Authors: Dugan Frank M. 
Published: March 2012

Erysiphe knautiae (Erysiphales) is reported for the first time in North America on Lomelosia caucasica (Caucasian Pincushion Flower, Dipsacaceae). Accepted for publication 7 January 2012. Published 27 February 2012.
Effects of Soybean Leaf and Plant Age on Susceptibility to Initiation of Infection by Phakopsora pachyrhizi
Authors: Bonde M. R. , Nester S. E. , Berner D. K. 
Published: March 2012

To help resolve the question of relationship of soybean leaf and plant age to susceptibility to infection by Phakopsora pachyrhizi, we inoculated 50-day-old plants of cv. Williams 82 with a suspension at 3 × 103 urediniospores/ml, placed in growth chambers under a range of temperature conditions, and later examined for number of lesions. In addition, plants ranging in age from 20 days to 79 days were inoculated, placed in a greenhouse, and examined by leaf for number of lesions. Results showed that Williams 82 did not vary in susceptibility among leaves at different positions regardless of temperature, or among leaves at different positions (up to 11 trifoliolates) on individual plants ranging in age from 20 to 79 days at inoculation. However, on a per-plant basis, there was a gradual decrease in numbers of lesions as plants increased in age at inoculation. For example, whereas 37 lesions/cm2 leaf area were produced on 20-day-old plants, only 10 were produced on 79-day-old plants. Although the study does not rule out the possibility that there might be cultivar dependent differences in age response, it does strengthen the possibility that older plants are less susceptible, and that the increase in disease observed in the field during fall months may be due to an increase in favorability of the environment for disease or increase in inoculum pressure. Accepted for publication 23 November 2011. Published 27 February 2012.
Significant soil acidification across northern China's grasslands during 1980s–2000s
Authors: Yang Yuanhe , Ji Chengjun , Ma Wenhong , Wang Shifeng , Wang Shaopeng , Han Wenxuan , Mohammat Anwar , Robinson David , Smith Pete 
Published: March 2012

AbstractAnthropogenic acid deposition may lead to soil acidification, with soil buffering capacity regulating the magnitude of any soil pH change. However, little evidence is available from large‐scale observations. Here, we evaluated changes in soil pH across northern China's grasslands over the last two decades using soil profiles obtained from China's Second National Soil Inventory during the 1980s and a more recent regional soil survey during 2001–2005. A transect from the central‐southern Tibetan Plateau to the eastern Inner Mongolian Plateau, where Kriging interpolation provided robust predictions of the spatial distribution of soil pH, was then selected to examine pH changes during the survey period. Our results showed that soil pH in the surface layer had declined significantly over the last two decades, with an overall decrease of 0.63 units (95% confidence interval = 0.54–0.73 units). The decline of soil pH was observed in both alpine grasslands on the Tibetan Plateau and temperate grasslands on the Inner Mongolian Plateau. Soil pH decreased more intensively in low soil carbonate regions, while changes of soil pH showed no significant associations with soil cation exchange capacity. These results suggest that grassland soils across northern China have experienced significant acidification from the 1980s to 2000s, with soil carbonates buffering the increase in soil acidity. The buffering process may induce a large loss of carbon from soil carbonates and thus alter the carbon balance in these globally important ecosystems.
Investigating fine‐scale spatio‐temporal predator–prey patterns in dynamic marine ecosystems: a functional data analysis approach
Authors: Embling Clare B. , Illian Janine , Armstrong Eric , van der Kooij Jeroen , Sharples Jonathan , Camphuysen Kees C. J. , Scott Beth E. 
Published: March 2012

Summary1. Spatial management of marine ecosystems requires detailed knowledge of spatio‐temporal mechanisms linking physical and biological processes. Tidal currents, the main driver of ecosystem dynamics in temperate coastal ecosystems, influence predator foraging ecology by affecting prey distribution and ecology. The mechanistic links between tidal currents and how they influence predator–prey behaviour and interactions at a fine scale are poorly understood.2. Studies of fine‐scale changes in oceanography, prey and predator behaviour with tidal currents require repeated surveys of the same location over brief time‐scales. Such data are highly temporally and spatially autocorrelated and require appropriate analytical tools.3. We used functional data analysis (FDA), specifically functional principal component analysis (FPCA), to analyse repeated, fine‐scale, survey data collected in the North Sea. FPCA was used to explore the relationship between the behaviour of an important North Sea prey species (sandeel Ammodytes spp.) and a vulnerable surface‐foraging predator (black‐legged kittiwake Rissa tridactyla) with fine‐scale tidally driven changes in bio‐physical characteristics (temperature stratification and maximum subsurface chlorophyll concentration).4. The FPCA indicated that sandeels were aggregated close to the surface at maximum ebb (ME) currents. Surface‐feeding kittiwakes were also found in highest numbers during ME in locations of both high subsurface chlorophyll concentration and shallow sandeel aggregations. We suggest that the combination of a well‐stratified water column with the movement of tidal currents over uneven topography results in surface aggregations of sandeels which kittiwakes exploit.5. Synthesis and applications. Functional Data Analysis provides a useful tool for examining spatio‐temporal patterns in natural ecosystems. In combination with fine‐scale repeated survey design, we identified the importance of tide in driving prey behaviour and hence predator foraging behaviour. This has implications both for critical marine habitat identification for Marine Protected Area selection and for fisheries stock assessments. We therefore recommend that tidal aspects should be taken into account when designing marine surveys in temperate coastal ecosystems both to ensure the best identification of critical marine habitat and to improve the accuracy of fish stock assessments.
Tree recruitment of European tree species at their current upper elevational limits in the Swiss Alps
Authors: Vitasse Yann , Hoch Günter , Randin Christophe F. , Lenz Armando , Kollas Chris , Körner Christian 
Published: March 2012

AbstractAim  The physical and physiological mechanisms that determine tree‐line position are reasonably well understood, but explanations for tree species‐specific upper elevational limits below the tree line are still lacking. In addition, once these uppermost positions have been identified, questions arise over whether they reflect past expansion events or active ongoing recruitment or even upslope migration. The aims of this study were: (1) to assess current tree recruitment near the cold‐temperature limit of 10 major European tree species in the Swiss Alps, and (2) to rank species by the extent that their seedlings and saplings exceed the elevational limit of adult trees, possibly reflecting effects of the recent climate warming.Location  Western and eastern Alps of Switzerland.Methods  For each species, occurrences were recorded along six elevational transects according to three size classes from seedlings to adult trees in 25‐m‐elevation steps above and below their regional upper elevational limit. Two methods were used to compare upper elevational limits between seedlings, saplings and adults within species. First, we focused on the uppermost occurrence observed in each life stage for a given species within each studied region; and second, we predicted their upper distribution range using polynomial models fitted to presence/absence data.Results  Species exhibited a clear ranking in their elevational limit. Regional differences in species limits (western versus eastern Swiss Alps) could largely be attributed to regional differences in temperature. Observed and predicted limits of each life stage showed that all species were represented by young individuals in the vicinity of the limit of adult trees. Moreover, tree recruitment of both seedlings and saplings was detected and predicted significantly beyond adult tree limits in most of the species. Across regions, seedlings and saplings were on average found at elevations 73 m higher than adult trees.Main conclusions  Under current conditions, neither seed dispersal nor seedling establishment constitutes a serious limitation of recruitment at the upper elevational limits of major European trees. The recruits found beyond the adult limits demonstrate the potential for an upward migration of trees in the Alps in response to ongoing climate warming.
Nestedness in island faunas: novel insights into island biogeography through butterfly community profiles of colonization ability and migration capacity
Authors: Dennis Roger L. H. , Hardy Peter B. , Dapporto Leonardo 
Published: March 2012

AbstractAim  To relate variation in the migration capacity and colonization ability of island communities to island geography and species island occupancy.Location  Islands off mainland Britain and Ireland.Methods  Mean migration (transfer) capacity and colonization (establishment) ability (ecological indices), indexed from 12 ecological variables for 56 butterfly species living on 103 islands, were related to species nestedness, island and mainland source geography and indices using linear regression models, RLQ analysis and fourth‐corner analysis. Random creation of faunas from source species, rank correlation and rank regression were used to examine differences between island and source ecological indices, and relationships to island geography.Results  Island butterfly faunas are highly nested. The two ecological indices related closely to island occupancy, nestedness rank of species, island richness and geography. The key variables related to migration capacity were island area and isolation; for colonization ability they were area, isolation and longitude. Compared with colonization ability, migration capacity was found to correlate more strongly with island species occupancy and species richness. For island faunas, the means for both ecological indices decreased, and variation increased, with increasing island species richness. Mean colonization ability and migration capacity values were significantly higher for island faunas than for mainland source faunas, but these differences decreased with island latitude.Main conclusions  The nested pattern of butterfly species on islands off mainland Britain and Ireland relates strongly to colonization ability but especially to migration capacity. Differences in colonization ability among species are most obvious for large, topographically varied islands. Generalists with abundant multiple resources and greater migration capacity are found on all islands, whereas specialists are restricted to large islands with varied and long‐lived biotopes, and islands close to shore. The inference is that source–sink dynamics dominate butterfly distributions on British and Irish islands; species are capable of dispersing to new areas, but, with the exception of large and northern islands, facilities (resources) for permanent colonization are limited. The pattern of colonization ability and migration capacity is likely to be repeated for mainland areas, where such indices should provide useful independent measures for assessing the conservation status of faunas within spatial units.
Changes in coexistence mechanisms along a long‐term soil chronosequence revealed by functional trait diversity
Authors: Mason Norman W. H. , Richardson Sarah J. , Peltzer Duane A. , de Bello Francesco , Wardle David A. , Allen Robert B. 
Published: March 2012

Summary1. Functional trait diversity can reveal mechanisms of species coexistence in plant communities. Few studies have tested whether functional diversity for foliar traits related to resource‐use strategy increases or decreases with declining soil phosphorus (P) in forest communities.2. We quantified tree basal area and four foliar functional traits (i.e. nitrogen (N), phosphorus (P), thickness and tissue density) for all woody species along the c. 120 000 year Franz Josef soil chronosequence in cool temperate rain forest, where strong shifts occur in light and soil nutrient availability (i.e. total soil P declines from 805 to 100 mg kg−1). We combined the abundance and trait data in functional diversity indices to quantify trait convergence and divergence, in an effort to determine whether mechanisms of coexistence change with soil fertility.3. Relationships between species trait means and total soil N and P were examined using multiple regression, with and without weighting of species abundances. We used Rao’s quadratic entropy to quantify functional diversity at the plot scale, then compared this with random expectation, using a null model that randomizes abundances across species within plots. Taxonomic diversity was measured using Simpson’s Diversity. Relationships between functional and taxonomic diversity and total soil P were examined using jackknife linear regression.4. Leaf N and P declined and leaf thickness and density increased monotonically with declining total soil P along the sequence; these relationships were unaffected by abundance weighting of species in the analyses. Inclusion of total soil N did not improve predictions of trait means. All measures of diversity calculated from presence/absence data were unrelated to total soil N and P. There was no evidence for a relationship between Rao values using quantitative abundances and total soil P. However, there was a strong positive relationship between Rao, expressed relative to random expectation, and total soil P, indicating trait convergence of dominant species as soil P declined.5. Synthesis: Our results demonstrate that at high fertility locally dominant species differ in resource‐use strategy, but as soil fertility declines over the long term, dominant species increasingly converge on a resource‐retentive strategy. This suggests that differentiation in resource‐use strategy is required for coexistence at high‐fertility but not in low‐fertility ecosystems.