bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Ways of Specifying Data Edits
Authors: Petrakos George , Conversano Claudio , Farmakis Gregory , Mola Francesco , Siciliano Roberta , Stavropoulos Photis 
Published: December 2004

SummaryData editing is the process by which data that are collected in some way (a statistical survey for example) are examined for errors and corrected with the help of software. Edits, the logical conditions that should be satisfied by the data, are specified by subject-matter experts with a procedure which could be tedious and could lead to mistakes with practical implications. To render the process of edit specification more efficient we provide a new step—the definition of the so-called abstract data model of a survey—which describes the structure of the phenomenon that is studied in a survey. The existence of this model enables experts to identify all combinations of variables which should be checked by edits and to avoid the definition of conflicting edits. Furthermore, we introduce an automatic data validation strategy—TREEVAL—that consists of fast tree growing to derive automatically the functional form of edits and of a statistical criterion to clean the incoming data. The TREEVAL strategy is cast within a total quality management framework. The application of the methodologies proposed is demonstrated with the help of a real life application.
Production of external mycelium by ectomycorrhizal fungi in a norway spruce forest was reduced in response to nitrogen fertilization
Authors: Nilsson Lars Ola , Wallander Håkan 
Published: December 2004

Summary

A field study was carried out to evaluate the influence of N fertilization on the growth of the external mycelium of ectomycorrhizal (EM) fungi in a Norway spruce forest in SW Sweden.
Nylon mesh bags filled with sand were buried in the soil for 6–18 months and the ingrowth of mycelium was used as an estimate of EM mycelial growth. Root‐isolated, trenched plots were used to estimate background growth of saprotrophic fungi.
Mycelial growth of EM fungi in N‐treated plots was reduced to c. 50% of that in nonfertilized plots. Local addition of apatite stimulated the EM mycelial growth in N‐treated plots.
The negative influence of N on the growth of external EM mycelium observed earlier in laboratory studies was confirmed in the present field study. The growth of EM mycelia was not directly related to N concentration in the soil but rather to the N status of the trees, although other factors induced by the N treatment may also have influenced EM mycelial growth.
Changes in leaf hydraulic conductance during leaf shedding in seasonally dry tropical forest
Authors: Brodribb T. J. , Holbrook N. M. 
Published: December 2004

Summary

The hydraulic conductance of leaves (kleaf) was examined to determine whether this little understood component of the water transport pathway plays a role in governing leaf phenology of two deciduous dry forest trees (Calycophyllum candidissimum and Rhedera trinervis).
kleaf was monitored in parallel with stem hydraulic conductivity (Kstem) during the transition from wet to dry season. The relationships between declining photosynthetic quantum yield during senescence and declining kleaf and Kstem were compared.
Divergent patterns were observed in the response of Kstem to seasonal drying; however, the behaviour of kleaf was essentially similar in both species. Large (five‐ to ten‐fold) decreases in leaf hydraulic conductance occurred before, and during the later stages of leaf senescence. During senescence, declining kleaf, which continued until leaves were ultimately shed, was associated with a concomitant decline in quantum yield.
We conclude that, in these species, the loss of hydraulic conductance of the leaf vascular system is linked to, and possibly responsible for, the loss of photosynthetic capacity during leaf senescence.
Inter‐ and intraspecific variation of homologous hydrophobin (H1) gene sequences amongXanthoriaspp. (lichen‐forming ascomycetes)
Authors: Scherrer Sandra , Honegger Rosmarie 
Published: December 2004

SummaryInter‐ and intra‐specific variability of the hydrophobin geneH1was investigated in a range ofXanthoriaspecies collected in their natural habitat.On Southern blots theXEH1probe (fromXanthoria ectaneoides) hybridized under standard conditions to the genomic DNA ofXanthoria calcicola, Xanthoria parietinaandXanthoria flammea. The correspondingH1genes in these and additional species (Xanthoria turbinata, Xanthoriaspp.), and ribosomal gene regions (ITS 1 and 2, 5.8S rDNA) were amplified with polymerase chain reaction, sequenced and similarities calculated. Restriction fragment length polymorphism and cleaved amplified polymorphic sequence analyses provided molecular tools for species delimitation.Ribosomal gene data were largely in parallel with the hydrophobinH1sequence data, the protein‐codingH1sequence being even more variable as the noncoding rDNA regions.Very low intraspecific variation was detected in theH1gene ofX. parietinasamples collected on four continents, with the highest variability occurring among Mediterranean samples.Xanthoria ectaneoidesfrom Brittany, France, andX. calcicolaappear to be coastal and inland forms of the same fungal species but differ from SicilianX. ectaneoides. The AfricanX. flammeaandX. turbinataare related to theX. parietinacluster.
Differential heavy metal tolerance of Arabidopsis halleri and Arabidopsis thaliana: a leaf slice test
Authors: Cho Misuk , Chardonnens Agnes N. , Dietz Karl‐Josef 
Published: December 2004

Summary

Here, a short‐term leaf tissue tolerance test was designed to determine the distinct Zn‐, Cd‐ and Ni‐tolerance levels for leaves of the Zn‐hyperaccumulating plant Arabidopsis halleri compared with Arabidopsis thaliana.
Leaf slices were incubated in different metal concentrations for 2 h. Quantum yield of photosystem II was used as a parameter dependent on heavy metal concentrations in the incubation medium.
The half effective concentration values (EC50) showed that A. halleri was extremely tolerant to Zn (EC50 » 1 m), whereas A. thaliana had an EC50 of only 2.5 mm. For Cd, the EC50 values were 40 mm and 1.9 mm for A. halleri and A. thaliana, respectively. No differential tolerance was observed for Ni between the two species. Determination of heavy metal uptake by leaf slices under the same conditions revealed decreased uptake rates for A. halleri, suggesting that low metal influx from the apoplast, probably combined with efficient intracellular compartmentation, constitutes the mechanistic basis for Zn‐ and Cd‐hyperaccumulation. It is also shown that pre‐exposure of A. halleri with Zn during growth affects tolerance in the subsequent leaf slice test.
The leaf slice test presented here provides a quick and reliable method for estimating heavy metal tolerance levels in individual plants.
Expression of the OsPI1 gene, cloned from rice roots using cDNA microarray, rapidly responds to phosphorus status
Authors: Wasaki Jun , Yonetani Ryoma , Shinano Takuro , Kai Motoshi , Osaki Mitsuru 
Published: December 2004

Summary

Plants have developed several methods of adapting to conditions of low phosphorus (P). However, details of the regulation of the gene expression system that responds to P status of plants is unknown. Here, a phosphorus limitation inducible novel gene was isolated and characterized to provide further information of plant adaptation to low P.
Rice plants (Oryza sativa) were grown hydroponically with or without P. A novel gene was isolated by cDNA microarray analysis and designated as OsPI1 (Oryza sativaPhosphate‐limitation Inducible Gene 1). mRNA accumulation was examined by Northern blot and quantitative real time PCR.
The OsPI1 gene was rapidly induced by phosphate starvation in both shoots and roots. When phosphate was supplied to phosphate‐deficient plants, the OsPI1 transcripts rapidly disappeared. OsPI1 cDNA consisted of 375 bp and contained several small open reading frames (ORFs). The OsPI1 gene shows the same characteristics as the TPSI1/Mt4 family (the phosphate starvation inducible novel gene family).
It is suggested that OsPI1 acts as riboregulator, that is, it binds with other molecules under phosphate starvation and regulates their function.
Early neural activity in Necker‐cube reversal: Evidence for low‐level processing of a gestalt phenomenon
Authors: Kornmeier Jürgen , Bach Michael 
Published: December 2004

AbstractNormally we experience the visual world as stable. Ambiguous figures provide a fascinating exception: On prolonged inspection, the “Necker cube” undergoes a sudden, unavoidable reversal of its perceived front‐back orientation. What happens in the brain when spontaneously switching between these equally likely interpretations? Does neural processing differ between an endogenously perceived reversal of a physically unchanged ambiguous stimulus and an exogenously caused reversal of an unambiguous stimulus? A refined EEG paradigm to measure such endogenous events uncovered an early electrophysiological correlate of this spontaneous reversal, a negativity beginning at 160 ms. Comparing across nine electrode locations suggests that this component originates in early visual areas. An EEG component of similar shape and scalp distribution, but 50 ms earlier, was evoked by an external reversal of unambiguous figures. Perceptual disambiguation seems to be accomplished by the same structures that represent objects per se, and to occur early in the visual stream. This suggests that low‐level mechanisms play a crucial role in resolving perceptual ambiguity.
Stimulus modality, perceptual overlap, and the go/no‐go N2
Authors: Nieuwenhuis Sander , Yeung Nick , Cohen Jonathan D. 
Published: December 2004

AbstractStimuli that elicit a prepotent but incorrect response are typically associated with an enhanced electrophysiological N2 that is thought to index the operation of a control process such as inhibition or conflict detection. However, recent studies reporting the absence of the N2 modulation in go/no‐go tasks involving auditory stimuli challenge this view: It is not clear why inhibition or conflict detection should be sensitive to the modality of the stimulus. Here we present electrophysiological data from a go/no‐go task suggesting that the relative size of the N2 modulation in visual and auditory tasks depends on the perceptual overlap between the go and no‐go stimuli. Stimuli that looked similar but sounded different were associated with a typical visual N2 modulation and the absence of an auditory N2 modulation, consistent with previous findings. However, when we increased the perceptual overlap between the auditory stimuli, a large no‐go N2 was observed. These findings are discussed in terms of existing hypotheses of the N2, and clarify why previous studies have not found an N2 modulation in auditory go/no‐go tasks.
Awareness of sleepiness when driving
Authors: Horne James A. , Baulk Stuart D. 
Published: December 2004

AbstractThe extent to which sleepy drivers are aware of sleepiness has implications for the prevention of sleep‐related crashes, especially for drivers younger than 30 years old who are most at risk. Using a real car interactive simulator, we report on EEG, subjective sleepiness, and lane drifting (sleepiness‐related driving impairment) from 38 sleep‐restricted, healthy young adults undergoing nontreatment control conditions from three (unpublished) investigations using the same experimental protocols for assessing various drinks intended to alleviate sleepiness. Participants drove 2 h during midafternoon under monotonous conditions. For all studies, subjective sleepiness and EEG activity indicative of sleepiness were highly correlated, with both changing concomitantly, along with lane drifting. Drivers had knowledge of their physiological sleepiness. There were indications that sugar content of these drinks may additionally affect sleepiness.
Re‐creating Semi‐natural Communities: Vacuum Harvesting and Hand Collection of Seed on Calcareous Grassland
Authors: Stevenson Mark J. , Ward Lena K. , Pywell Richard F. 
Published: December 2004

AbstractAgricultural set‐aside and compensation land provide restoration ecologists with opportunities to re‐create semi‐natural habitats. Restoration sites often have high soil fertility and inadequate seed banks of desirable species. Sowing additional seed is a proven method for establishing chalk grassland vegetation. If seed of local provenance is required, it may be collected by hand or by using specialized machines. Ultimately, the mix collected must provide seed suitable for recreating vegetation similar to that of the donor site. We examine the ability of a vacuum machine to meet this requirement by comparison with hand collection, and we discuss possible effects on invertebrates. Microscope analysis and glasshouse and field trials were used to compare the abundance of seed of different species in harvested mixes with the vegetation composition of the donor site. Seed heads of individual species were examined to determine the number of viable seeds per head and attack rates by phytophagous insects. The mix contained seed of over half the species recorded on the donor site. The seed of taller, more common species was overrepresented in the mix, at the expense of some smaller, mat‐forming plants. After one season, however, the vegetation of the field trial plots was of the same type as that of the donor site, although the proportions of the constituent species differed slightly and certain species were absent. Mechanical collection is more efficient than hand collection. Endophagous invertebrates are unlikely to be affected by the machine. Seed collection requires a combination of methods, precise timing, and careful planning to provide a full range of species and to minimize impacts on plant and invertebrate populations.
Constructed Crevasses and Land Gain in the Mississippi River Delta
Authors: Boyer Mark E. , Harris James O. , Turner R. Eugene 
Published: December 2004

AbstractExtensive land loss, which is mostly wetland loss, has taken place during this century in the Mississippi River delta and other river deltas. Our purpose was to evaluate the effectiveness of constructing “artificial” crevasses, or cuts in the natural levee, made by the U.S. Fish and Wildlife Service in the Delta National Wildlife Refuge (DNWR) to slow or reverse this type of land loss. Land growth of the crevasses was determined from aerial photographs and was related to crevasse‐site characteristics. The newly constructed crevasses create emergent wetlands after 2 years of subaqueous growth at about 4.7 ha/year and an average cost of $21,377 per crevasse. The present total cost per hectare declines with age as new land builds, and it will equal $48 per hectare if all the open water in the receiving ponds fills in. At these rates, the net land loss rates in the DNWR measured from 1958 to 1978 would be compensated for by the building of 63 crevasses, 24 of which are already in place.
Experiments on Ion Cyclotron Waves
Authors: Hooke W. M. , Tenney F. H. , Brennan M. H. , Hill H. M. , Stix T. H. 
Published: December 2004

Experiments have been performed on the generation of ion cyclotron waves and their propagation into a magnetic beach. The experiments were carried out on the B-66 machine, which is currently a magnetic mirror device. Studies of the production of neutrons have provided evidence for the absorption of the energy of these waves via ion cyclotron damping.
Microwave phase-shift measurements have now been made, and the addition of electron density completes the list of parameters required for direct comparison of experimental and theoretical dispersion relations. The experimental data yield a smooth monotonic relation between density and frequency which is qualitatively similar to that predicted by theory. There are, however, unexplained quantitative differences.
Wave propagation into the magnetic beach region was observed with a single turn rf magnetic probe. The variation of the amplitude of these waves in the magnetic beach is in qualitative agreement with the theory of ion cyclotron wave propagation and cyclotron damping.
Ethics, values and behaviours: comparison of three case studies examining the paucity of leadership in government
Authors: Kakabadse Andrew , Korac‐Kakabadse Nada , Kouzmin Alexander 
Published: December 2004

Three societies with similar initiatives for public service re‐configuration and reform – the UK, Canada and Australia – are examined to highlight the many‐faceted issues of public service ethics and the different approaches these governments have taken to re‐building public trust and enhancing public service ethics in times of rapid change. These efforts for re‐building an ethical public service are scrutinized according to four criteria for effectively leading change. Changes of public service values are also analysed as well as their implications for public servants.Effectively, applied leadership is identified as the pillar of ethical practice – emphasizing the need for quality leadership development through on‐the‐job experience. Although legislation and codification are seen as necessary for building an ethical infrastructure that can help employees out of encountered dilemmas, the way forward is seen as nurturing an environment of trust and vigilance in which ethics are promoted through exemplary behaviour of leaders and employees alike.
Towards a literacy of fusion: new times, new teaching and learning?
Authors: Millard Elaine 
Published: December 2004

AbstractThis paper seeks to widen discussion about which forms of literacy are most appropriate for the education of children in the twenty‐first century. It outlines the current debate about the changes to children's literacy practices, which are described as being prompted on the one hand by the pervasive influence in society of new technologies, and on the other by the extent of pupils' engagement with popular culture. Using a single example, representative of a number of classroom action research studies devised by the author in which children's own interests were used to motivate writing, she argues that what is required from teachers is a transformative pedagogy. This would allow children's cultural interest to be merged with the school requirements into what is described as aliteracy of fusion. The paper ends with an outline of the aspects of learning to which a teacher working to create such forms of literacy would need to attend.
Interpreting Statistical Evidence by using Imperfect Models: Robust Adjusted Likelihood Functions
Authors: Royall Richard , Tsou Tsung-Shan 
Published: December 2004

SummaryThe strength of statistical evidence is measured by the likelihood ratio. Two key performance properties of this measure are the probability of observing strong misleading evidence and the probability of observing weak evidence. For the likelihood function associated with a parametric statistical model, these probabilities have a simple large sample structure when the model is correct. Here we examine how that structure changes when the model fails. This leads to criteria for determining whether a given likelihood function is robust (continuing to perform satisfactorily when the model fails), and to a simple technique for adjusting both likelihoods and profile likelihoods to make them robust. We prove that the expected information in the robust adjusted likelihood cannot exceed the expected information in the likelihood function from a true model. We note that the robust adjusted likelihood is asymptotically fully efficient when the working model is correct, and we show that in some important examples this efficiency is retained even when the working model fails. In such cases the Bayes posterior probability distribution based on the adjusted likelihood is robust, remaining correct asymptotically even when the model for the observable random variable does not include the true distribution. Finally we note a link to standard frequentist methodology—in large samples the adjusted likelihood functions provide robust likelihood-based confidence intervals.
Diagnostics for Dependence within Time Series Extremes
Authors: Ledford Anthony W. , Tawn Jonathan A. 
Published: December 2004

SummaryThe analysis of extreme values within a stationary time series entails various assumptions concerning its long- and short-range dependence. We present a range of new diagnostic tools for assessing whether these assumptions are appropriate and for identifying structure within extreme events. These tools are based on tail characteristics of joint survivor functions but can be implemented by using existing estimation methods for extremes of univariate independent and identically distributed variables. Our diagnostic aids are illustrated through theoretical examples, simulation studies and by application to rainfall and exchange rate data. On the basis of these diagnostics we can explain characteristics that are found in the observed extreme events of these series and also gain insight into the properties of events that are more extreme than those observed.
On-Line Inference for Hidden Markov Models via Particle Filters
Authors: Fearnhead Paul , Clifford Peter 
Published: December 2004

SummaryWe consider the on-line Bayesian analysis of data by using a hidden Markov model, where inference is tractable conditional on the history of the state of the hidden component. A new particle filter algorithm is introduced and shown to produce promising results when analysing data of this type. The algorithm is similar to the mixture Kalman filter but uses a different resampling algorithm. We prove that this resampling algorithm is computationally efficient and optimal, among unbiased resampling algorithms, in terms of minimizing a squared error loss function. In a practical example, that of estimating break points from well-log data, our new particle filter outperforms two other particle filters, one of which is the mixture Kalman filter, by between one and two orders of magnitude.
The psychophysiology of anxiety disorder: Fear memory imagery
Authors: Cuthbert Bruce N. , Lang Peter J. , Strauss Cyd , Drobes David , Patrick Christopher J. , Bradley Margaret M. 
Published: December 2004

AbstractPsychophysiological response to fear memory imagery was assessed in specific phobia, social anxiety disorder, panic disorder with agoraphobia, post‐traumatic stress disorder (PTSD), and healthy controls. Heart rate, skin conductance, and corrugator muscle were recorded as participants responded to tone cues signaling previously memorized descriptor sentences. Image contents included personal fears, social fears, fears of physical danger, and neutral (low arousal) scenes. Reactions to acoustic startle probes (eyeblink) were assessed during recall imagery and nonsignal periods. Participants were significantly more reactive (in physiology and report of affect) to fear than neutral cues. Panic and PTSD patients were, however, less physiologically responsive than specific phobics and the socially anxious. Panic and PTSD patients also reported the most anxiety and mood symptoms, and were most frequently comorbidly depressed. Overall, physiological reactivity to sentence memory cues was greatest in patients with focal fear of specific objects or events, and reduced in patients characterized by generalized, high negative affect.