bluuebunny/crossref_metadata_2025_split huggingface dataset:
Salinity stress adaptation competence in the extremophile Thellungiella halophila in comparison with its relative Arabidopsis thaliana
Authors: Gong Qingqiu , Li Pinghua , Ma Shisong , Indu Rupassara S. , Bohnert Hans J. 
Published: November 2005

SummaryIn stark contrast to Arabidopsis, a related species, Thellungiella halophila (Thellungiella salsuginea; salt cress), displays extreme tolerance to high salinity, low humidity and freezing. High nucleotide sequence identity permits the use of tools developed for Arabidopsis for Thellungiella transcript profiling, for which a microarray platform with >25 000 DNA elements (70‐mer oligonucleotides) was used. Microarray transcript profiling and intensity analysis, quantitative RT‐PCR, and metabolite profiles define genes and pathways that showed shared and divergent responses to salinity stress in the two species. Shared responses are exemplified by 40% of the regulated genes functioning in confining ribosomal functions, photosynthesis and cell growth, as well as activating osmolyte production, transport activities and abscisic acid‐dependent pathways. An additional 60% of regulated genes distinguished Thellungiella from Arabidopsis. Analysis of the differences showed that Arabidopsis exhibited a global defense strategy that required bulk protein synthesis, while Thellungiella induced genes functioning in protein folding, post‐translational modification and protein redistribution. At 150 mm NaCl, Thellungiella maintained unimpeded growth. Transcript intensity analyses and metabolite profiles supported the microarray results, pointing towards a stress‐anticipatory preparedness in Thellungiella.
Seed survival and predation of Anoda cristata in soyabean crops
Authors: PURICELLI E , FACCINI D , ORIOLI G , SABBATINI M R 
Published: November 2005

Summary Anoda cristata is a troublesome annual broad‐leaved weed in summer crops in the rolling Pampa in Argentina; seeds are the only source of regeneration of this species. Seed persistence or depletion is the result of survival and loss processes, including predation. The objective of this study was to determine survival at two burial depths in undisturbed soil and predation rates of A. cristata seeds in soyabean crops in different rotations and tillage systems. Survival was discontinuous and decreased to 25% after 35 months, after which no further reduction in survival was observed to the end of the experiment at 96 months. No differences in seed survival between seeds placed on the soil surface and buried 5 cm below the soil surface were found at 80 months, but at later times survival was lower for seeds placed on the soil surface. Predation rates ranged between 0.3% day−1 and 6.7% day−1. Of the models tested, a polynomial regression of the rate of predation with time gave the best representation of seed predation. From January to July, predation was higher in non‐tillage plots in the wheat/soyabean rotation. There was no significant difference in predation rates between tillage systems in the soyabean monoculture and no difference between planting densities. Higher crop residue levels in non‐tillage plots in the wheat/soyabean rotation was the dominant factor influencing seed predation, probably because such habitat favours the presence of seed predators.
Germination response of Orobanche seeds subjected to conditioning temperature, water potential and growth regulator treatments
Authors: SONG W J , ZHOU W J , JIN Z L , CAO D D , JOEL D M , TAKEUCHI Y , YONEYAMA K 
Published: November 2005

SummaryBroomrapes (Orobanche spp.) are parasitic weeds that cause significant losses of crop yield. Experiments were conducted to investigate the seed response to the artificial germination stimulant GR24 in three species of Orobanche subjected to preconditioning under various temperatures, water potentials and with plant growth regulators. The highest germination percentages were observed in Orobanche ramosa, Orobanche aegyptiaca and Orobanche minor seeds conditioned at 18°C for 7 days followed by germination stimulation at 18°C. With the increase of the conditioning period (7, 14, 21 and 28 days), the germination percentage of O. ramosa and O. aegyptiaca progressively decreased. When conditioned at −2 MPa, the germination percentage was lower than at 0 and −1 MPa, especially at 13 and 28°C. Orobanche minor seeds could retain relatively high germination if conditioned at 18, 23 or 28°C, even after significantly extended conditioning periods (up to 84 days). GA3 (30–100 mg L−1), norflurazon and fluridone (10–100 mg L−1), and brassinolide (0.5–1.0 mg L−1) increased seed germination, while 0.01 mg L−1 uniconazole significantly reduced germination rates of all three Orobanche spp. The promotional effects of GA3 and norflurazon and the inhibitory effect of uniconazole were evident, even when they were treated for 3 days. Germination of Orobanche seeds was much lower when the unconditioned seeds were directly exposed to GR24 at 10−6 m. This early GR24‐induced inhibition was however alleviated or even eliminated by the inclusion of GA3 or norflurazon (10–50 mg L−1) in the conditioning medium. On the contrary, the inclusion of uniconazole increased the inhibitory effect of GR24, particularly in the case of O. ramosa.
Differences in the molecular basis of resistance to the cyclohexanedione herbicide sethoxydim in Lolium multiflorum
Authors: WHITE G M , MOSS S R , KARP A 
Published: November 2005

SummaryResistance to the cyclohexanedione (CHD) herbicide sethoxydim was investigated in two UK Lolium multiflorum populations, Yorks A2 and PYL. Resistance screening experiments demonstrated a qualitative difference in the responses of the two populations to sethoxydim, suggesting that the molecular basis of resistance between them was different. After treatment, Yorks A2 plants were either alive (78% of sample tested) or dead (22% tested) but plants of the PYL population showed two further intermediate categories of response. The level of acetyl‐CoA carboxylase (ACCase) insensitivity directly correlated with the degree of resistance at the whole plant level, indicating that the molecular basis of resistance is associated with differences in ACCase sensitivity in each population. Direct sequencing of the carboxyl transferase domain of the ACCase gene showed that an Ile‐418‐Leu substitution in the L. multiflorum chloroplastic ACCase (GenBank accession number AY710293) confers resistance to sethoxydim in Yorks A2. This corresponds to amino acid residue 1781 in the Alopecurus myosuroides full ACCase sequence. This is the first report of this mutation in this L. multiflorum, which has also been reported in four other grass‐weeds, including L. rigidum. However, no amino acid substitutions were found to be specifically associated with the resistant phenotypes in the PYL population and the molecular basis of resistance in this population remains to be resolved.
An assessment of genetic diversity within and between populations of Phalaris minor using ISSR markers
Authors: McROBERTS N , SINCLAIR W , McPHERSON A , FRANKE A C , SAHARAN R P , MALIK R K , SINGH S , MARSHALL G 
Published: November 2005

SummaryIntra‐ and inter‐sample similarities for four populations of the annual grass weed Phalaris minor from Haryana state, India, were examined using inter‐simple sequence repeat (ISSR) DNA markers. Levels of polymorphism within and between populations were low in comparison with values reported from other grassy weed species. Analysis of inter‐population similarities allowed a partial differentiation of the four populations and of pairs of populations classified by cropping system. Analysis of the intra‐population similarity data showed a weak but consistent and statistically significant negative correlation between the molecular similarity of seedlings and the physical distance between their mother plants over distances up to 40 m (the maximum separation tested) in all four populations. The consistency of the observed relationship between molecular similarity and physical separation, and the differences in cultivation practices at the four sites, suggested that the relationship may be a result of localized out‐crossing, rather than an effect of localized seed rain. The results of the analyses are discussed in relation to the potential for evolution of multiple traits in the weed in response to changes in the wheat production system in the region.
Localized bullous pemphigoid: a commonly delayed diagnosis
Authors: Tran Julie T. , Mutasim Diya F. 
Published: November 2005

AbstractLocalized bullous pemphigoid is a rare clinical variant of bullous pemphigoid. We report three cases of localized bullous pemphigoid in which the diagnosis was delayed because the presentation simulated other local vesicular or bullous diseases. Localized bullous pemphigoid differs from the generalized form by its more benign course. Early diagnosis will help avoid unnecessary and costly treatment for unrelated conditions.
Genetic robustness and selection at the protein level for synonymous codons
Authors: Archetti M. 
Published: November 2005

Abstract
Synonymous codons are neutral at the protein level, therefore natural selection at the protein level should have no effect on their frequencies. Synonymous codons, however, differ in their capacity to reduce the effects of errors: after mutation, certain codons keep on coding for the same amino acid or for amino acids with similar properties, while other synonymous codons produce very different amino acids. Therefore, the impact of errors on a coding sequence (genetic robustness) can be measured by analysing its codon usage. I analyse the codon usage of sequenced nuclear and cytoplasmic genomes and I show that there is an extensive variation in genetic robustness at the DNA sequence level, both among genomes and among genes of the same genome. I also show theoretically that robustness can be adaptive, that is natural selection may lead to a preference for codons that reduce the impact of errors. If selection occurs only among the mutants of a codon (e.g. among the progeny before the adult phase), however, the codons that are more sensitive to the effects of mutations may increase in frequency because they manage to get rid more easily of deleterious mutations. I also suggest other possible explanations for the evolution of genetic robustness at the codon level.
Slow response of plant species richness to habitat loss and fragmentation
Authors: Helm Aveliina , Hanski Ilkka , Pärtel Meelis 
Published: November 2005

AbstractWe examined the response of vascular plant species richness to long‐term habitat loss and fragmentation of Estonian calcareous grasslands (alvars). The current number of habitat specialist species in 35 alvars was not explained by their current areas and connectivities but it was explained by their areas and connectivities 70 years ago (R2 = 0.27). We estimated the magnitude of extinction debt in local communities by assuming an equilibrium species richness in 14 alvars that had lost only a small amount of area and by applying this model to the remaining alvars, in which the average area has declined from 3.64 km2 in the 1930s to 0.21 km2 at present. The extinction debt estimated for individual alvars was around 40% of their current species number. Our conclusions are applicable to temperate grasslands in general, which have lost much area because of agricultural intensification and cessation of traditional management.
Quantifying the extinction vortex
Authors: Fagan William F. , Holmes E. E. 
Published: November 2005

AbstractWe developed a database of 10 wild vertebrate populations whose declines to extinction were monitored over at least 12 years. We quantitatively characterized the final declines of these well‐monitored populations and tested key theoretical predictions about the process of extinction, obtaining two primary results. First, we found evidence of logarithmic scaling of time‐to‐extinction as a function of population size for each of the 10 populations. Second, two lines of evidence suggested that these extinction‐bound populations collectively exhibited dynamics akin to those theoretically proposed to occur in extinction vortices. Specifically, retrospective analyses suggested that a population size ofnindividuals within a decade of extinction was somehow less valuable to persistence than the same population size was earlier. Likewise, both year‐to‐year rates of decline and year‐to‐year variability increased as the time‐to‐extinction decreased. Together, these results provide key empirical insights into extinction dynamics, an important topic that has received extensive theoretical attention.
Intergenerational Mobility under Private vs. Public Education*
Authors: Davies James B. , Zhang Jie , Zeng Jinli 
Published: November 2005

AbstractIntergenerational earnings mobility is analyzed in a model where human capital is produced using schooling and parental time. In steady states more mobile societies have less inequality, but in the short run higher mobility may result from an increase in inequality. Starting from the same inequality, mobility is higher under public than under private education. A rise in income shocks, for example due to increased returns to ability, or a switch from public to private schooling both increase inequality. However, increased shocks raise mobility in the short run and do not affect it in the long run, whereas an increased role for private schooling reduces mobility in both the short and long run. That these differences may help to identify the source of changes in inequality, and other real‐world implications, are illustrated in a brief discussion of time trends and cross‐country differences.
Stick, Carrot and Skill Acquisition*
Authors: Filges Trine , Larsen Birthe 
Published: November 2005

AbstractWe evaluate the impact of specially designed youth unemployment programmes (YUPs), intended to provide young unemployed unskilled workers with skills. If unemployment among skilled workers is lower than among unskilled workers, YUPs imply that unemployment falls. However, YUPs potentially crowd out ordinary training. We set up an equilibrium matching model with endogenous skill choice and examine the impact of an increase in programme participation. We derive a condition for crowding out of ordinary training, as well as a condition for an increase in the skilled labour force and thereby reduced unemployment. The impact of YUPs on welfare and wage dispersion is also considered.
New‐Keynesian Models and Monetary Policy: A Re‐examination of the Stylized Facts*
Authors: Söderström Ulf , Söderlind Paul , Vredin Anders 
Published: November 2005

AbstractUsing an empirical New‐Keynesian model with optimal discretionary monetary policy, we estimate key parameters—the central bank's preference parameters; the degree of forward‐looking behavior in the determination of inflation and output; and the variances of inflation and output shocks—to match some broad characteristics of U.S. data. The parameterization we obtain implies a small concern for output stability but a large preference for interest rate smoothing, and a small degree of forward‐looking behavior in price‐setting but a large degree of forward‐looking in the determination of output. Our methodology also allows us to carefully examine the consequences of alternative parameterizations and to provide intuition for our results.
Economic Implications of Alternative Allocation Schemes for Emission Allowances*
Authors: Böhringer Christoph , Lange Andreas 
Published: November 2005

AbstractFor reasons of political feasibility, emission trading systems may have to rely on free initial allocation of emission allowances in order to ameliorate adverse production and employment effects in dirty industries. Against the background of an emerging European‐wide emission trading system, we examine the trade‐off between such compensation and economic efficiency under output‐based and emissions‐based allocation rules. We show that the emissions‐based allocation rule is more costly than the output‐based rule in terms of maintaining output and employment in energy‐intensive industries. When the international allowance price increases, the inferiority of emissions‐based allocation vis‐à‐vis output‐based allocation becomes more pronounced, as emission subsidies drastically restrict efficiency gains from international trade in emission allowances.
Healthcare librarians and learner support: a review of competences and methods
Authors: Robinson Lyn , Hilger‐Ellis Julia , Osborne Liz , Rowlands Jane , Smith Janet M. , Weist Anne , Whetherly June , Phillips Ray 
Published: November 2005

AbstractObjectives:London Health Libraries (LHL) are undertaking a project in order to develop the role of their library and knowledge services staff in supporting learners within the NHS in the London area (LHL Learner Support Project). This paper reports on the first phase of the project.Methodology:A literature analysis was carried out to provide guidance on the skills and competences needed for library and knowledge staff to perform this function.Results:A variety of competences are identified, and structured in a model incorporating both training skills and general professional competencies. Library and knowledge staff will themselves need to have a high‐level of information literacy and to be active lifelong learners.Conclusions:A ‘blended learning’ approach, involving e‐learning together with other methods, is identified as the most appropriate way for skills to be acquired.
Using mobile technologies to give health students access to learning resources in the UK community setting
Authors: Walton Graham , Childs Susan , Blenkinsopp Elizabeth 
Published: November 2005

AbstractObjectives:  This article describes a project which explored the potential for mobile technologies to give health students in the community access to learning resources. The purpose included the need to identify possible barriers students could face in using mobile technologies. Another focus was to assess the students perceptions of the importance of being able to access learning resources in the community.Methods:  This 1‐year project used two main approaches for data collection. A review of the literature on mobile technologies in the health context was conducted. This was used in a systematic way to identify key issues and trends. The literature review was used to inform the design and production of a questionnaire. This was distributed to and completed by a group of community health students at Northumbria University, UK. The questionnaire was piloted and there was a 100% completion rate with 49 returned forms.Results:  The literature review indicated that most mobile technology applications were occurring in the US. At the time of the review the most prevalent mobile technologies were PDAs, laptops, WAP phones and portable radios with use being concentrated around doctors in the acute sector. A range of advantages and disadvantages to the technology were discovered. Mobile technologies were mainly being used for clinical rather than learning applications. The students showed a low level of awareness of the technology but placed great importance to accessing learning resources from the community.Conclusions:  Significant development and changes are taking place in mobile technologies. Since the data collection for this work was completed in 2004 podcasting and videocasting have become significant in mobile learning for health professionals. Librarians will need to address the relevance and implications of m‐learning for their practice. Care and consideration needs to be given on the time and resources librarians allocate for the necessary development work around mobile technologies. Collaboration and partnership working will be most effective approach for librarians wishing to integrate their services with m‐learning technologies.
The Vertical Hydraulic Conductivity of an Aquitard at Two Spatial Scales
Authors: Hart David J. , Bradbury Kenneth R. , Feinstein Daniel T. 
Published: November 2005

AbstractAquitards protect underlying aquifers from contaminants and limit recharge to those aquifers. Understanding the mechanisms and quantity of ground water flow across aquitards to underlying aquifers is essential for ground water planning and assessment. We present results of laboratory testing for shale hydraulic conductivities, a methodology for determining the vertical hydraulic conductivity (Kv) of aquitards at regional scales and demonstrate the importance of discrete flow pathways across aquitards. A regional shale aquitard in southeastern Wisconsin, the Maquoketa Formation, was studied to define the role that an aquitard plays in a regional ground water flow system. Calibration of a regional ground water flow model for southeastern Wisconsin using both predevelopment steady‐state and transient targets suggested that the regional Kv of the Maquoketa Formation is 1.8 × 10−11 m/s. The core‐scale measurements of the Kv of the Maquoketa Formation range from 1.8 × 10−14 to 4.1 × 10−12 m/s. Flow through some additional pathways in the shale, potential fractures or open boreholes, can explain the apparent increase of the regional‐scale Kv. Based on well logs, erosional windows or high‐conductivity zones seem unlikely pathways. Fractures cutting through the entire thickness of the shale spaced 5 km apart with an aperture of 50 microns could provide enough flow across the aquitard to match that provided by an equivalent bulk Kv of 1.8 × 10−11 m/s. In a similar fashion, only 50 wells of 0.1 m radius open to aquifers above and below the shale and evenly spaced 10 km apart across southeastern Wisconsin can match the model Kv.
Extending Electromagnetic Methods to Map Coastal Pore Water Salinities
Authors: Greenwood Wm. Jason , Kruse Sarah , Swarzenski Peter 
Published: November 2005

AbstractThe feasibility of mapping pore water salinity based on surface electromagnetic (EM) methods over land and shallow marine water is examined in a coastal wetland on Tampa Bay, Florida. Forward models predict that useful information on seabed conductivity can be obtained through <1.5 m of saline water, using floating EM‐31 and EM‐34 instruments from Geonics Ltd. The EM‐31 functioned as predicted when compared against resistivity soundings and pore water samples and proved valuable for profiling in otherwise inaccessible terrain due to its relatively small size. Experiments with the EM‐34 in marine water, however, did not reproduce the theoretical instrument response. The most effective technique for predicting pore water conductivities based on EM data entailed (1) computing formation factors from resistivity surveys and pore water samples at representative sites and (2) combining these formation factors with onshore and offshore EM‐31 readings for broader spatial coverage. This method proved successful for imaging zones of elevated pore water conductivities/salinities associated with mangrove forests, presumably caused by salt water exclusion by mangrove roots. These zones extend 5 to 10 m seaward from mangrove trunks fringing Tampa Bay. Modeling indicates that EM‐31 measurements lack the resolution necessary to image the subtle pore water conductivity variations expected in association with diffuse submarine ground water discharge of fresher water in the marine water of Tampa Bay. The technique has potential for locating high‐contrast zones and other pore water salinity anomalies in areas not accessible to conventional marine‐ or land‐based resistivity arrays and hence may be useful for studies of coastal‐wetland ecosystems.