bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conflicting patterns of mitochondrial and nuclear DNA diversity in Phylloscopus warblers
Authors: BENSCH STAFFAN , IRWIN DARREN E. , IRWIN JESSICA H. , KVIST LAURA , ÅKESSON SUSANNE 
Published: October 2005

AbstractMolecular variation is often used to infer the demographic history of species, but sometimes the complexity of species history can make such inference difficult. The willow warbler, Phylloscopus trochilus, shows substantially less geographical variation than the chiffchaff, Phylloscopus collybita, both in morphology and in mitochondrial DNA (mtDNA) divergence. We therefore predicted that the willow warbler should harbour less nuclear DNA diversity than the chiffchaff. We analysed sequence data obtained from multiple samples of willow warblers and chiffchaffs for the mtDNA cytochrome b gene and four nuclear genes. We confirmed that the mtDNA diversity among willow warblers is low (π = 0.0021). Sequence data from three nuclear genes (CHD‐Z, AFLP‐WW1 and MC1R) not linked to the mitochondria demonstrated unexpectedly high nucleotide diversity (π values of 0.0172, 0.0141 and 0.0038) in the willow warbler, on average higher than the nucleotide diversity for the chiffchaff (π values of 0.0025, 0.0017 and 0.0139). In willow warblers, Tajima's D analyses showed that the mtDNA diversity, but not the nuclear DNA diversity, has been reduced relative to the neutral expectation of molecular evolution, suggesting the action of a selective sweep affecting the maternally inherited genes. The large nuclear diversity seen within willow warblers is not compatible with processes of neutral evolution occurring in a population with a constant population size, unless the long‐term effective population size has been very large (Ne > 106). We suggest that the contrasting patterns of genetic diversity in the willow warbler may reflect a more complex evolutionary history, possibly including historical demographic fluctuations or historical male‐biased introgression of nuclear genes from a differentiated population of Phylloscopus warblers.
Comparative population structure of Cynopterus fruit bats in peninsular Malaysia and southern Thailand
Authors: CAMPBELL POLLY , SCHNEIDER CHRISTOPHER J. , ADNAN ADURA M. , ZUBAID AKBAR , KUNZ THOMAS H. 
Published: October 2005

AbstractThe extent to which response to environmental change is mediated by species‐specific ecology is an important aspect of the population histories of tropical taxa. During the Pleistocene glacial cycles and associated sea level fluctuations, the Sunda region in Southeast Asia experienced concurrent changes in landmass area and the ratio of forest to open habitat, providing an ideal setting to test the expectation that habitat associations played an important role in determining species’ response to the opportunity for geographic expansion. We used mitochondrial control region sequences and six microsatellite loci to compare the phylogeographic structure and demographic histories of four broadly sympatric species of Old World fruit bats in the genus, Cynopterus. Two forest‐associated species and two open‐habitat generalists were sampled along a latitudinal transect in Singapore, peninsular Malaysia, and southern Thailand. Contrary to expectations based on habitat associations, the geographic scale of population structure was not concordant across ecologically similar species. We found evidence for long and relatively stable demographic history in one forest and one open‐habitat species, and inferred non‐coincident demographic expansions in the second forest and open‐habitat species. Thus, while these results indicate that Pleistocene climate change did not have a single effect on population structure across species, a correlation between habitat association and response to environmental change was supported in only two of four species. We conclude that interactions between multiple factors, including historical and contemporary environmental change, species‐specific ecology and interspecific interactions, have shaped the recent evolutionary histories of Cynopterus fruit bats in Southeast Asia.
DnaA coordinates replication initiation and cell cycle transcription in Caulobacter crescentus
Authors: Hottes Alison K. , Shapiro Lucy , McAdams Harley H. 
Published: October 2005

SummaryThe level of DnaA, a key bacterial DNA replication initiation factor, increases during the Caulobacter swarmer‐to‐stalked transition just before the G1/S transition. We show that DnaA coordinates DNA replication initiation with cell cycle progression by acting as a global transcription factor. Using DnaA depletion and induction in synchronized cell populations, we have analysed global transcription patterns to identify the differential regulation of normally co‐expressed genes. The DnaA regulon includes genes encoding several replisome components, the GcrA global cell cycle regulator, the PodJ polar localization protein, the FtsZ cell division protein, and nucleotide biosynthesis enzymes. In cells depleted of DnaA, the G1/S transition is temporally separated from the swarmer‐to‐stalked cell differentiation, which is normally coincident. In the absence of DnaA, the CtrA master regulator is cleared by proteolysis during the swarmer‐to‐stalked cell transition as usual, but DNA replication initiation is blocked. In this case, expression of gcrA, which is directly repressed by CtrA, does not increase in conjunction with the disappearance of CtrA until DnaA is subsequently induced, showing that gcrA expression requires DnaA. DnaA boxes are present upstream of many genes whose expression requires DnaA, and His6‐DnaA binds to the promoters of gcrA, ftsZ and podJ in vitro. This redundant control of gcrA transcription by DnaA (activation) and CtrA (repression) forms a robust switch controlling the decision to proceed through the cell cycle or to remain in the G1 stage.
Evidence for novel processing of the anaerobically inducible dicistronic focA‐pfl mRNA transcript in Escherichia coli
Authors: Sawers R. Gary 
Published: October 2005

SummaryThe anaerobically inducible dicistronic focA‐pfl operon is transcribed from three co‐ordinately regulated promoters that are located 5′ of the operon. Remarkably, the 5′ ends of four further highly abundant operon‐internal transcripts are located within the focA gene, with a fifth transcript mapping in the intergenic region between focA and pfl. The findings of this study demonstrate that the bulk of these five operon‐internal transcripts are the result of processing. Processing was independent of the broad‐spectrum endoribonucleases associated with mRNA turnover and still occurred when the upstream regulatory region of the operon was replaced with two different heterologous promoters recognized by Escherichia coli core RNA polymerase, including the tetP promoter. However, when the T7Φ10 promoter was introduced upstream of the focA‐pfl operon, mainly full‐length transcript and a minor amount of two processing products were observed. T7 RNA polymerase mutants that exhibit reduced elongation speed did not restore the wild‐type transcript‐processing pattern. Moreover, processing was independent of focA translation. Taken together, these data suggest that processing of the focA‐pfl transcripts occurs by a novel mechanism that might require the action of E. coli core RNA polymerase.
A mutation affecting ASCORBATE PEROXIDASE 2 gene expression reveals a link between responses to high light and drought tolerance
Authors: ROSSEL JAN BART , WALTER PHILIPPA B. , HENDRICKSON LUKE , CHOW WAH SOON , POOLE ANDREW , MULLINEAUX PHILIP M. , POGSON BARRY J. 
Published: October 2005

ABSTRACTMolecular analyses of plants have revealed a number of genes whose expression changes in response to high light (HL), including the H2O2 scavenger, ASCORBATE PEROXIDASE 2 (APX2). We carried out a screen in Arabidopsis thaliana for lesions that alter HL‐induced expression of APX2 to identify components in abiotic stress signalling pathways. High light was used as it can be instantaneously applied or removed and accurately measured. We identified a number of alx mutations causing altered APX2 expression. Here we describe the gain‐of‐function mutant, alx8, which has constitutively higher APX2 expression and higher levels of foliar abscisic acid (ABA) than wild type. In fact, exogenous ABA increased APX2 expression and the APX2 promoter contains ABA response elements. Furthermore, we have shown that HL stress increases ABA in wild‐type plants, implicating ABA in the regulation of HL‐inducible genes. The alx8 mutant is drought tolerant, exhibits improved water‐use efficiency and a number of drought‐tolerance genes are upregulated. Additionally, alx8 demonstrates the complexity of ABA‐dependent and ABA‐independent transcriptional networks as some components in both pathways are upregulated in alx8. This study provides evidence for common steps in drought and HL stress response pathways.
Using continuous stable isotope measurements to partition net ecosystem CO2 exchange
Authors: ZHANG JIANMIN , GRIFFIS TIMOTHY J. , BAKER JOHN M. 
Published: October 2005

ABSTRACTEcosystem‐scale estimation of photosynthesis and respiration using micrometeorological techniques remains an important, yet difficult, challenge. In this study, we combined micrometeorological and stable isotope methods to partition net ecosystem CO2 exchange (FN) into photosynthesis (FA) and respiration (FR) in a corn–soybean rotation ecosystem during the summer 2003 corn phase. Mixing ratios of 12CO2 and 13CO2 were measured continuously using tunable diode laser (TDL) absorption spectroscopy. The dynamics of the isotope ratio of ecosystem respiration (δR), net ecosystem CO2 exchange (δN) and photosynthetic discrimination at the canopy scale (Δcanopy) were examined. During the period of full canopy closure, FN was partitioned into photosynthesis and respiration using both the isotopic approach and the conventional night‐time‐derived regression methodology. Results showed that δR had significant seasonal variation (−32 to −11‰) corresponding closely with canopy phenology. Daytime δN typically varied from −12 to −4‰, while Δcanopy remained relatively constant in the vicinity of 3‰. Compared with the regression approach, the isotopic flux partitioning showed more short‐term variations and was considerably more symmetric about FN. In this experiment, the isotopic partitioning resulted in larger uncertainties, most of which were caused by the uncertainties in δN and the daytime estimate of δR. By sufficiently reducing these uncertainties, the tunable diode laser (TDL)–micrometeorological technique should yield a better understanding of the processes controlling photosynthesis, respiration and ecosystem‐scale discrimination.
Genetic caste determination in Pogonomyrmex harvester ants imposes costs during colony founding
Authors: Schwander T. , Cahan S. Helms , Keller L. 
Published: October 2005

Abstract
Some populations of Pogonomyrmex harvester ants comprise genetically differentiated pairs of interbreeding lineages. Queens mate with males of their own and of the alternate lineage and produce pure-lineage offspring which develop into queens and inter-lineage offspring which develop into workers. Here we tested whether such genetic caste determination is associated with costs in terms of the ability to optimally allocate resources to the production of queens and workers. During the stage of colony founding, when only workers are produced, queens laid a high proportion of pure-lineage eggs but the large majority of these eggs failed to develop. As a consequence, the number of offspring produced by incipient colonies decreased linearly with the proportion of pure-lineage eggs laid by queens. Moreover, queens of the lineage most commonly represented in a given mating flight produced more pure-lineage eggs, in line with the view that they mate randomly with the two types of males and indiscriminately use their sperm. Altogether these results predict frequency-dependent selection on pairs of lineages because queens of the more common lineage will produce more pure-lineage eggs and their colonies be less successful during the stage of colony founding, which may be an important force maintaining the coexistence of pairs of lineages within populations.
Host use of a hemiparasitic plant: no trade-offs in performance on different hosts
Authors: Ahonen R. , Puustinen S. , Mutikainen P. 
Published: October 2005

AbstractTo examine putative specialization of a hemiparasitic plant to the most beneficial host species, we studied genetic variation in performance and trade-offs between performance on different host species in the generalist hemiparasite, Rhinanthus serotinus. We grew 25 maternal half-sib families of the parasite on Agrostis capillaris and Trifolium pratense and without a host in a greenhouse. Biomass and number of flowers of the parasite were the highest when grown on T. pratense. There were significant interactions between host species and R. serotinus seed-family indicating that the differences in performance on the two hosts and without a host varied among the families. However, we found no significant negative correlations between performance of R. serotinus on the host species or between performance on the two hosts and autotrophic performance. Thus, the genetic factors studied here are not likely to affect the evolution of specialization of R. serotinus to the most beneficial host.
Early complication of pediatric central venous cannulation
Authors: WADDINGTON MARK S , MULLINS GEOFFREY C. 
Published: October 2005

SummaryWe describe a case of hemothorax following central venous catheter (CVC) insertion in an infant. Presumably injury occurred as a result of perforation with the dilator. Strategies to reduce the risk of complications and possible factors influencing the unsatisfactory delay in diagnosis, including the role of ’Fixation Error’, are discussed.
Acute pancreatitis induced by short‐term propofol administration
Authors: GOTTSCHLING SVEN , LARSEN REINHARD , MEYER SASCHA , GRAF NORBERT , REINHARD HARALD 
Published: October 2005

SummaryThe incidence of a drug‐induced pancreatitis is rare and so far more than 85 different drugs have been reported to have induced pancreatitis. Some case reports consider a relationship between propofol and acute pancreatitis. However, in these cases a number of different drugs were coadministered, thus preventing a clear causal link being established. We report a case of a drug‐induced acute pancreatitis that was most likely triggered by a single dosage of propofol. It occurred in a young girl who underwent elective magnetic resonance imaging. She developed pancreatitis within hours after exposure to propofol. Other possible triggers, e.g. gallstones or infection were ruled out. Physicians should consider pancreatitis as a potentially life‐threatening adverse event associated with propofol sedation, which is nowadays extensively used.
Pain management in the neonatal intensive care unit: a national survey in Italy
Authors: LAGO PAOLA , GUADAGNI ANNAMARIA , MERAZZI DANIELE , ANCORA GINA , BELLIENI CARLO VALERIO , CAVAZZA ALESSANDRA ,   THE PAIN STUDY GROUP OF THE ITALIAN SOCIETY OF NEONATOLOGY
Published: October 2005

SummaryBackground : This study assessed current medical practice in preventative analgesia and sedation for invasive procedures in neonatal intensive care units (NICU) in Italy.Methods : A questionnaire was sent to level II and III Italian NICUs to investigate pain management, pharmacological treatment and the use of pain scores during invasive procedures.Main outcome measures were the extent to which analgesia and sedation are currently used for invasive procedures in Italian neonatal units.Results : The rate of response to the questionnaire was 88%. Written guidelines were available on acute pain control in 25% of the NICUs, and on prolonged pain control in 50%. Routine use of preventative pharmacological and nonpharmacological measures for painful procedures ranged from 13% for elective tracheal intubation to 68% for chest tube insertion. Thirty‐six percent of NICUs routinely use sedation with opioids for mechanical ventilation; 14% prevent distress and pain for tracheal suctioning, 44% for heel lancing, 50% for venepuncture and percutaneous venous catheter insertion; 58% use analgesia before lumbar puncture. Validated pain assessment scores were used by 19% of NICUs.Conclusions : The need for adequate analgesia is still underestimated. Further information on the safety of analgesics in neonatology is imperative, as is an adequate education of physicians and nurses on the use of pain control guidelines as part of the standard of care in the NICU.
Ultrasound‐guided interscalene brachial plexus block in a child with femur fibula ulna syndrome
Authors: JAN VAN GEFFEN GEERT , TIELENS LUC , GIELEN MATHIEU 
Published: October 2005

SummaryUltrasound‐guided interscalene brachial plexus block is described in a 7‐year‐old child with femur fibula ulna syndrome. It is suggested that ultrasound is a useful tool in situations where nerve stimulation for nerve localization cannot be used.
Australian evidence on the determinants and impact of takeover resistance
Authors: Maheswaran Krishnan , Pinder Sean 
Published: October 2005

AbstractIn the present paper, we examine the determinants and impact of target bid resistance on the wealth of target shareholders and the takeover process in Australia. We find that bid resistance increases target shareholder wealth in the post‐announcement period and that the probability of bid hostility increases with the target's size, decreases with the target's performance and is unrelated to the size of the premium offered by the bidder. We also find that bid hostility decreases the probability of bid success, increases the probability of bid revision and has no effect on the probability of competing bidders entering the market.
Disclosure regulation and information risk
Authors: Poskitt Russell 
Published: October 2005

AbstractThe present paper examines the impact of the Corporations Law Reform Act 1994 on information‐based trading in Australian Stock Exchange‐listed stocks. Results show that information‐based trading is higher in the post‐reform period, particularly for lower capitalization stocks. Further analysis shows that this is caused by a fall in turnover and rise in the number of slow trading days. After controlling for these factors, the reform is found to have no impact on information‐based trading. Interestingly, the volume of price‐sensitive disclosures is found to have no impact on either the level of information‐based trading or market spreads.
Economic benefits of enterprise resource planning systems: some empirical evidence
Authors: Matolcsy Zoltan P. , Booth Peter , Wieder Bernhard 
Published: October 2005

AbstractThe present study provides empirical evidence on the economic benefits of enterprise resource planning (ERP) systems. We use a modified value chain approach and identify several ratios for each component of the value chain to reflect improvements as a result of the adoption of ERP systems. These financial ratios are tracked for 2 years for a group of companies that adopted ERP systems versus a group of companies that did not adopt ERP. Both univariate and multivariate statistics are used to test for differences. The key result of the present study is that the adoption of ERP systems leads to sustained operational efficiencies and improved overall liquidity. In addition, some support is found for increased profitability 2 years after the adoption of ERP and for improvements in accounts receivable management.
Closing call auctions and liquidity
Authors: Aitken Michael , Comerton‐Forde Carole , Frino Alex 
Published: October 2005

AbstractThe present paper examines the impact of closing call auctions on liquidity. It exploits the natural experiment offered by the introduction of a closing call auction on the Australian Stock Exchange on 10 February 1997. The introduction of the closing call auction is associated with a reduction in trading volume at the close of continuous trading. However, bid‐ask spreads during continuous trading are largely unaffected by the introduction of the closing call auction. Therefore, closing call auctions consolidate liquidity at a single point in time without having any adverse effect on the cost of trading.
Disease resistance conferred by the expression of a gene encoding a synthetic peptide in transgenic cotton (Gossypium hirsutum L.) plants
Authors: Rajasekaran Kanniah , Cary Jeffrey W. , Jaynes Jesse M. , Cleveland Thomas E. 
Published: October 2005

SummaryFertile, transgenic cotton plants expressing the synthetic antimicrobial peptide, D4E1, were produced through Agrobacterium‐mediated transformation. PCR products and Southern blots confirmed integration of the D4E1 gene, while RT‐PCR of cotton RNA confirmed the presence of D4E1 transcripts. In vitro assays with crude leaf protein extracts from T0 and T1 plants confirmed that D4E1 was expressed at sufficient levels to inhibit the growth of Fusarium verticillioides and Verticillium dahliae compared to extracts from negative control plants transformed with pBI‐d35SΩ‐uidA‐nos (CGUS). Although in vitro assays did not show control of pre‐germinated spores of Aspergillus flavus, bioassays with cotton seeds in situ or in planta, inoculated with a GFP‐expressing A. flavus, indicated that the transgenic cotton seeds inhibited extensive colonization and spread by the fungus in cotyledons and seed coats. In planta assays with the fungal pathogen, Thielaviopsis basicola, which causes black root rot in cotton, showed typical symptoms such as black discoloration and constriction on hypocotyls, reduced branching of roots in CGUS negative control T1 seedlings, while transgenic T1 seedlings showed a significant reduction in disease symptoms and increased seedling fresh weight, demonstrating tolerance to the fungal pathogen. Significant advantages of synthetic peptides in developing transgenic crop plants that are resistant to diseases and mycotoxin‐causing fungal pathogens are highlighted in this report.
Engineering a root‐specific, repressor‐operator gene complex
Authors: Kim Tehryung , Balish Rebecca S. , Heaton Andrew C. P. , McKinney Elizabeth C. , Dhankher Om Parkash , Meagher Richard B. 
Published: October 2005

SummaryStrong, tissue‐specific and genetically regulated expression systems are essential tools in plant biotechnology. An expression system tool called a ‘repressor‐operator gene complex’ (ROC) has diverse applications in plant biotechnology fields including phytoremediation, disease resistance, plant nutrition, food safety, and hybrid seed production. To test this concept, we assembled a root‐specific ROC using a strategy that could be used to construct almost any gene expression pattern. When a modified E. coli lac repressor with a nuclear localization signal was expressed from a rubisco small subunit expression vector, S1pt::lacIn, LacIn protein was localized to the nuclei of leaf and stem cells, but not to root cells. A LacIn repressible Arabidopsis actin expression vector A2pot was assembled containing upstream bacterial lacO operator sequences, and it was tested for organ and tissue specificity using β‐glucuronidase (GUS) and mercuric ion reductase (merA) gene reporters. Strong GUS enzyme expression was restricted to root tissues of A2pot::GUS/S1pt::lacIn ROC plants, while GUS activity was high in all vegetative tissues of plants lacking the repressor. Repression of shoot GUS expression exceeded 99.9% with no evidence of root repression, among a large percentage of doubly transformed plants. Similarly, MerA was strongly expressed in the roots, but not the shoots of A2pot::merA/S1pt::lacIn plants, while MerA levels remained high in both shoots and roots of plants lacking repressor. Plants with MerA expression restricted to roots were approximately as tolerant to ionic mercury as plants constitutively expressing MerA in roots and shoots. The superiority of this ROC over the previously described root‐specific tobacco RB7 promoter is demonstrated.