bluuebunny/crossref_metadata_2025 huggingface dataset:
Inactivation of the 20S proteasome in Streptomyces lividans and its influence on the production of heterologous proteins
Authors: Hong Bin , Wang Lifei , Lammertyn Elke , Geukens Nick , Van Mellaert Lieve , Li Yuan , Anné Jozef
Published: September 2005

Proteasomes are self-compartmentalizing proteases first discovered in eukaryotes but also occurring in archaea and in bacteria belonging to the order Actinomycetales. In bacteria, proteasomes have so far no known function. In order to evaluate the influence of the 20S proteasome on the production of heterologous proteins by Streptomyces lividans TK24, the production of a number of heterologous proteins, including soluble human tumour necrosis factor receptor II (shuTNFRII) and salmon calcitonin (sCT), was compared with the wild-type TK24, a proteasome-deficient mutant designated PRO41 and a strain complemented for the disrupted proteasome genes (strain PRO41R). S. lividans cells lacking intact proteasome genes are phenotypically indistinguishable from the wild-type or the complemented strain containing functional proteasomes. Using the expression and secretion signals of the subtilisin inhibitor of Streptomyces venezuelae CBS762.70 (Vsi) for shuTNFRII and those of tyrosinase of Streptomyces antibioticus (MelC1) for the production of sCT, both proteins were secreted in significantly higher amounts in the strain PRO41 than in the wild-type S. lividans TK24 or the complemented strain PRO41R. However, the secretion of other heterologous proteins such as shuTNFRI was not enhanced in the proteasome-deficient strain. This suggests that S. lividans TK24 can degrade some heterologous proteins in a proteasome-dependent fashion. The proteasome-deficient strain may therefore be useful for the efficient production of these heterologous proteins.
The MAP kinase Hog1p differentially regulates stress-induced production and accumulation of glycerol and d-arabitol in Candida albicans
Authors: Kayingo Gerald , Wong Brian
Published: September 2005

Candida albicansproduces and accumulates large amounts of the polyolsd-arabitol and glycerol in culture, and/or in infected mammalian tissues. However, the effects of environmental stresses on production and accumulation of these polyols, and the means by which polyol production and accumulation are regulated have not been studied.C. albicansgrown in glucose at 30 °C (i) produced maximal amounts of glycerol within 6 h, (ii) produced maximal amounts ofd-arabitol and ribitol within 12 h, and (iii) released most of these polyols into the extracellular environment.C. albicansresponded to osmotic and citric acid stress by producing and accumulating more glycerol, and to temperature and oxidative stresses by producing mored-arabitol. The increase in intracellular glycerol was proportional to extracellular osmolarity, suggesting that glycerol functions as an osmolyte. The MAP kinase Hog1p is required for wild-type glycerol production in several fungal species subjected to osmotic stress, but it is not known if Hog1p plays a role in regulatingd-arabitol production. Therefore, twoC. albicans hog1null mutants were constructed and tested for the ability to produce glycerol andd-arabitol in response to environmental stresses. The ability to grow and produce glycerol when exposed to osmotic or citric acid stresses, and to produced-arabitol when exposed to oxidative stress, was partially dependent on Hog1p, but the ability to produced-arabitol when exposed to temperature stress was Hog1p independent. These results imply that multiple pathways regulate glycerol andd-arabitol synthesis inC. albicans.
Calcium influences cellular and extracellular product formation during biofilm-associated growth of a marine Pseudoalteromonas sp.
Authors: Patrauchan M. A. , Sarkisova S. , Sauer K. , Franklin M. J.
Published: September 2005

Bacteria undergo a variety of physiological changes following a switch from planktonic growth to surface-associated biofilm growth. Here, it is shown that biofilm development of a marine isolate, Pseudoalteromonas sp. 1398, results in global changes in its cytosolic and extracellular proteomes. Calcium influences these proteome responses, and affects the amount of surface-associated biomass and extracellular matrix material produced by Pseudoalteromonas sp. 1398. Four extracellular proteins, characterized by N-terminal sequencing, showed increased abundances, while one protein, flagellin, showed reduced abundance at higher [Ca2+]. Immunoblotting and transmission-electron-microscopy analysis confirmed that higher [Ca2+] and surface-associated growth results in the repression of flagella production. Two-dimensional gel electrophoresis (2DGE) studies combined with cluster analysis of global proteome responses demonstrated that Ca2+ had a greater regulatory influence on Pseudoalteromonas sp. growing in biofilms than on planktonic cultures. Approximately 22 % of the total cytosolic proteins resolved by 2DGE had differing abundances in response to a switch from planktonic growth to surface-associated growth when the cells were cultivated in 1 mM Ca2+. At higher [Ca2+] this number increased to 38 %. Fifteen cellular proteins that were differentially expressed in response to biofilm growth and/or Ca2+ were analysed by N-terminal sequencing and/or MS/MS. These proteins were identified as factors involved in cellular metabolic functions, putative proteases and transport proteins, although there were several proteins that had not been previously characterized. These results indicate that Ca2+ causes global changes in matrix material, as well as in cellular and extracellular protein profiles of Pseudoalteromonas sp. 1398. These changes are more pronounced when the bacterium grows in biofilms than when it grows in planktonic culture.
Molecular and serological evidence of Pneumocystis circulation in a social organization of healthy macaques (Macaca fascicularis)
Authors: Demanche Christine , Wanert Fanélie , Barthélemy Mathieu , Mathieu Jérôme , Durand-Joly Isabelle , Dei-Cas Eduardo , Chermette René , Guillot Jacques
Published: September 2005

Simian populations represent valuable models for understanding the epidemiology of human pneumocystosis. The present study aims to describe the circulation ofPneumocystisorganisms within a social organization of healthy crab-eating macaques (Macaca fascicularis) living in a natural setting in France. Animals were followed for up to 2 years. Deep nasal swab and blood samples were collected monthly from each animal under general anaesthesia. Environmental air was sampled for a 1 week period every month in the park where the macaques dwelt.PneumocystisDNA was detected by nested-PCR of mitochondrial large subunit rRNA (mtLSU) gene in nasal swab and air samples. Anti-PneumocystisIgG antibodies were detected in serum samples by indirect immuno-fluorescence assay.PneumocystisDNA was detected in 168 of 500 swab samples examined (33·6 %). The number of macaques with detectablePneumocystisDNA was highly variable from one month to another. Positive detection ofPneumocystisDNA was not related to the detection of serum anti-Pneumocystisantibody. During the second year of the study,PneumocystisDNA was amplified more frequently from unweaned macaques than from adults or subadults. The mtLSU sequence showed marked polymorphism with eightPneumocystissequence types representing two distinct groups. On the whole, a constant and intensive circulation ofPneumocystisorganisms within the community was observed. However, the implication of the various members of the colony was probably different and several levels of colonization byPneumocystismay occur in immunocompetent macaques.
Characterization of chaperonin 10 (Cpn10) from the intestinal human pathogen Entamoeba histolytica
Authors: van der Giezen Mark , León-Avila Gloria , Tovar Jorge
Published: September 2005

Entamoeba histolyticais the causative agent of amoebiasis, a poverty-related disease that kills an estimated 100 000 people each year.E. histolyticadoes not contain ‘standard mitochondria’, but harbours mitochondrial remnant organelles called mitosomes. These organelles are characterized by the presence of mitochondrial chaperonin Cpn60, but little else is known about the functions and molecular composition of mitosomes. In this study, a gene encoding molecular chaperonin Cpn10 – the functional partner of Cpn60 – was cloned, and its structure and expression were characterized, as well as the cellular localization of its encoded protein. The 5′ untranslated region of the gene contains all of the structural promoter elements required for transcription in this organism. The amoebic Cpn10, like Cpn60, is not significantly upregulated upon heat-shock treatment. Computer-assisted protein modelling, and specific antibodies against Cpn10 and Cpn60, suggest that both proteins interact with each other, and that they function in the same intracellular compartment. Thus,E. histolyticaappears to have retained at least two of the key molecular components required for the refolding of imported mitosomal proteins.
The sigma factor RpoS is required for stress tolerance and environmental fitness of Pseudomonas fluorescens Pf-5
Authors: Stockwell Virginia O. , Loper Joyce E.
Published: September 2005

Many micro-organisms exist in natural habitats that are subject to severe or dramatically fluctuating environmental conditions. Such is the case for bacteria inhabiting plant surfaces, where they are exposed to UV irradiation, oxygen radicals, and large fluctuations in temperature and moisture. This study focuses on the role of RpoS, a central regulator of stationary-phase gene expression in bacterial cells, in stress response and environmental fitness of Pseudomonas fluorescens Pf-5. Strain Pf-5 is a rhizosphere-inhabiting bacterium that suppresses plant diseases caused by several plant-pathogenic fungi and oomycetes. Previous studies demonstrated that rpoS was required for osmotic and oxidative stress resistance of Pf-5. The results of this study demonstrate a role for rpoS in tolerance of Pf-5 to freezing, starvation, UV irradiation and desiccation stress. In field studies, an rpoS mutant was compromised in rhizosphere colonization of plants in dry soil, whereas similar rhizosphere populations were established by Pf-5 and an rpoS mutant in well-irrigated soils. RpoS is a key determinant in stress response and environmental fitness of the rhizosphere bacterium P. fluorescens Pf-5.
Noncomplementing diploidy resulting from spontaneous zygogenesis in Escherichia coli
Authors: Gratia Jean-Pierre
Published: September 2005

With the aim of understanding sexual reproduction and phenotypic expression, a novel type of mating recently discovered inEscherichia coliwas investigated. Termed spontaneous zygogenesis (or Z-mating), it differs from F-mediated conjugation. Its products proved phenotypically unstable, losing part of the phenotype for which they were selected. Inactivation of a parental chromosome in the zygote is strongly suggested by fluctuation tests, respreading experiments, analysis of reisolates, and segregation of non-viable cells detected by epifluorescence staining. Some phenotypically haploid subclones were interpreted as stable noncomplementing diploids carrying an inactivated co-replicating chromosome. Pedigree analysis indicated that the genetic composition of such cells consisted of parental genomes or one parental plus a recombinant genome. Inactivation of a chromosome carrying a prophage resulted in the disappearance of both the ability to produce phage particles and the immunity to superinfection. Phage production signalled transient reactivation of such a chromosome and constituted a sensitive test for stable noncomplementing diploidy. Chromosome inactivation thus appears to be a spontaneous event in bacteria.
Identification of pathogen-specific genes through microarray analysis of pathogenic and commensal Neisseria species
Authors: Stabler Richard A. , Marsden Gemma L. , Witney Adam A. , Li Yanwen , Bentley Stephen D. , Tang Christoph M. , Hinds Jason
Published: September 2005

The release of the complete genome sequences of Neisseria meningitidis MC58 and Z2491 along with access to the sequences of N. meningitidis FAM18 and Neisseria gonorrhoeae FA1090 allowed the construction of a pan-Neisseria microarray, with every gene in all four genomes represented. The microarray was used to analyse a selection of strains including all N. meningitidis serogroups and commensal Neisseria species. For each strain, genes were defined as present, divergent or absent using gack analysis software. Comparison of the strains identified genes that were conserved within N. meningitidis serogroup B strains but absent from all commensal strains tested, consisting of mainly virulence-associated genes and transmissible elements. The microarray was able to distinguish between pilin genes, pilC orthologues and serogroup-specific capsule biosynthetic genes, and to identify dam and drg genotypes. Previously described N. meningitidis genes involved in iron response, adherence to epithelial cells, and pathogenicity were compared to the microarray analysis. The microarray data correlated with other genetic typing methods and were able to predict genotypes for uncharacterized strains and thus offer the potential for a rapid typing method. The subset of pathogen-specific genes identified represents potential drug or vaccine targets that would not eliminate commensal neisseriae and the associated naturally acquired immunity.
The tcrB gene is part of the tcrYAZB operon conferring copper resistance in Enterococcus faecium and Enterococcus faecalis
Authors: Hasman Henrik
Published: September 2005

The plasmid-localized tcrB (transferable copper-resistance gene B) gene from Enterococcus faecium was identified to be part of an operon called the tcrYAZB operon, which has a genetic organization similar to the copYZAB copper-homeostasis gene cluster from Enterococcus hirae. Putative promoter (P
tcr
)- and repressor-binding sites highly similar to the E. hirae cop-promoter region were identified upstream of the tcrYAZB genes. The P
tcr
promoter was cloned in both the absence and the presence of the proximal repressor-encoding tcrY gene into a promoter-probe vector. Induction of the promoter was shown in liquid growth medium containing increasing concentrations of copper sulphate. To determine the growth advantage conferred by the tcrYAZB genes in a copper environment, a tcr-deletion mutant was isolated, and its growth was compared with that of its copper-resistant ancestor (strain A17sv1) in sublethal concentrations of copper sulphate. A competition assay using these two isogenic strains showed that copper sulphate concentrations of 3 mmol l−1 and above are sufficient to select for copper resistance.
Desferrioxamine E produced by Streptomyces griseus stimulates growth and development of Streptomyces tanashiensis
Authors: Yamanaka Kazuki , Oikawa Hiroaki , Ogawa Hiro-omi , Hosono Kuniaki , Shinmachi Fumie , Takano Hideaki , Sakuda Shohei , Beppu Teruhiko , Ueda Kenji
Published: September 2005

The authors previously reported that interspecific stimulatory events between Streptomyces species for antibiotic production and/or morphological differentiation mediated by putative diffusible metabolites take place at a high frequency. This paper reports the isolation and characterization of a substance produced by Streptomyces griseus that stimulates the growth and development of Streptomyces tanashiensis. The substance was purified from the culture supernatant of S. griseus by using anion-exchange chromatography, gel filtration chromatography and reverse-phase HPLC. FAB-MS and NMR analyses of the purified preparation indicated the substance to be desferrioxamine E (synonym: nocardamine), a siderophore that is widely produced by Streptomyces species and related organisms. Similar stimulatory effects on the growth and development of S. tanashiensis were exerted by desferrioxamine E produced by another actinomycete strain, but not by other siderophores tested, including ferrichrome and nocobactin and free ferric ion. An exogenous supply of desferrioxamine E stimulated secondary metabolite formation and/or morphological differentiation in various actinomycete strains. Disruption of the desferrioxamine biosynthesis gene cluster in Streptomyces coelicolor A3(2) abolished the production of desferrioxamine E and the activity to stimulate the growth and differentiation of S. tanashiensis. The S. coelicolor mutant showed impaired growth and development on Bennett's/glucose agar medium, but it was rescued by the exogenous supply of desferrioxamine E. These results indicate that desferrioxamines play an important role in streptomycete physiology. Similar to several pathogenic bacteria and fungi, S. tanashiensis may be defective in the production of siderophores; however, it can utilize the siderophores excreted by other organisms.
Identification and expression of a host-recognized antigen, FspA, from Flavobacterium psychrophilum
Authors: Crump Elizabeth M. , Burian Ján , Allen Philippe D. , Kay William W.
Published: September 2005

Flavobacterium psychrophilumis the aetiological agent of rainbow trout fry syndrome, an economically important disease of immature salmonid fish for which there is no vaccine. Convalescent serum from the host, rainbow trout (Oncorhynchus mykiss), reacted strongly with a ∼20 kDa,Flavobacterium-specific protein antigen (subsequently named FspA) fromF. psychrophilum. Protein-enriched, detergent-partitioned samples were separated by two-dimensional gel electrophoresis and the protein target was excised, proteolytically cleaved and the resulting peptides analysed by MS. Quadrupole-time-of-flight MS was used to generate a fragmented peptide spectrum. The resulting peptide sequences were then used to design degenerate PCR primers to amplify the gene (fspA) of interest: 612 bp encoding 203 aa, including a putative 19 aa N-terminal signal sequence which predicted a processed 19 303·6 Da protein. FspA proved to be unique and only homologous to two unspecified sequences reported fromFlavobacterium johnsoniae, although weakly homologous to aYersinia pseudotuberculosisadhesin. An amplified gene fragment (537 bp, encoding 179 aa) was further cloned into an expression vector, expressed as a ∼30 kDa N-terminal fusion protein and found to retain its strong reactivity with host serum antibodies. These results suggest that the surface-localized FspA may be an important subunit vaccine candidate antigen againstF. psychrophilum.
Ala160 and His116 residues are involved in activity and specificity of apyrase, an ATP-hydrolysing enzyme produced by enteroinvasive Escherichia coli
Authors: Sarli Serena , Nicoletti Mauro , Schippa Serena , Del Chierico Federica , Santapaola Daniela , Valenti Piera , Berlutti Francesca
Published: September 2005

The virulence plasmid-carried apy (phoN2) gene of Shigella and related enteroinvasive Escherichia coli (EIEC) encodes apyrase, an ATP-diphosphohydrolase belonging to class A of the non-specific acid phosphatases (A-NSAPs). Apyrase and A-NSAPs share three domains of conserved amino acids (domains D1–D3) containing residues forming the putative active site of apyrase. In spite of their similarity, apyrase and A-NSAPs show different substrate specificity, apyrase being able to hydrolyse nucleotide tri- and diphosphates, but not monophosphates, as well as p-nitrophenyl phosphate (pNPP), while A-NSAPs are also active towards monophosphates and pNPP. In this paper, to get further insights into the structure–function relationship of apyrase, a random and site-directed mutagenesis of the apy gene of EIEC strain HN280 was conducted. Results indicate that amino acids located within the D2 and D3 conserved domains (Ser157 and Arg192, respectively) as well as residues located in the N-terminal (Ser97) and C-terminal (Glu233) domains are required for enzyme activity. Surprisingly, Ala160, located near the D2 domain and considered to be important for enzyme specificity, is required for enzyme activity, as its substitution with Thr led to the inactivation of enzyme activity. Furthermore, residue His116 is involved in apyrase specificity, since the H116L apyrase mutant shows substrate specificity resembling that of A-NSAPs.
The clpB gene of Bifidobacterium breve UCC 2003: transcriptional analysis and first insights into stress induction
Authors: Ventura Marco , Kenny John G. , Zhang Ziding , Fitzgerald Gerald F. , van Sinderen Douwe
Published: September 2005

The so-called clp genes, which encode components of the Clp proteolytic complex, are widespread among bacteria. The Bifidobacterium breve UCC 2003 genome contains a clpB gene with significant homology to predicted clpB genes from other members of the Actinobacteridae group. The heat- and osmotic-inducibility of the B. breve UCC 2003 clpB homologue was verified by slot-blot analysis, while Northern blot and primer extension analyses showed that the clpB gene is transcribed as a monocistronic unit with a single promoter. The role of a hspR homologue, known to control the regulation of clpB and dnaK gene expression in other high G+C content bacteria was investigated by gel mobility shift assays. Moreover the predicted 3D structure of HspR provides further insight into the binding mode of this protein to the clpB promoter region, and highlights the key amino acid residues believed to be involved in the protein–DNA interaction.
Novel surface layer protein genes in Bacillus sphaericus associated with unusual insertion elements
Authors: Pollmann Katrin , Raff Johannes , Schnorpfeil Michaela , Radeva Galina , Selenska-Pobell Sonja
Published: September 2005

The surface layer (S-layer) protein genes of the uranium mining waste pile isolateBacillus sphaericusJG-A12 and of its relativeB. sphaericusNCTC 9602 were analysed. The almost identical N-termini of the two S-layer proteins possess a unique structure, comprising three N-terminal S-layer homologous (SLH) domains. The central parts of the proteins share a high homology and are related to the S-layer proteins ofB. sphaericusCCM 2177 and P-1. In contrast, the C-terminal parts of the S-layer proteins of JG-A12 and NCTC 9602 differ significantly between each other. Surprisingly, the C-terminal part of the S-layer protein of JG-A12 shares a high identity with that of the S-layer protein ofB. sphaericusCCM 2177. In both JG-A12 and NCTC 9602 the chromosomal S-layer protein genes are followed by a newly identified putative insertion element comprising three ORFs, which encode a putative transposase, a putative integrase/recombinase and a putative protein containing a DNA binding helix–turn–helix motif, and the S-layer-protein-like gene copiessllA(9602) orsllB(JG-A12). Interestingly, bothB. sphaericusstrains studied were found to contain an additional, plasmid-located and silent S-layer protein gene with the same sequence assllAandsllB. The primary structures of the corresponding putative proteins are almost identical in both strains. The N-terminal and central parts of these S-layer proteins share a high identity with those of the chromosomally encoded functional S-layer proteins. Their C-terminal parts, however, differ significantly. These results strongly suggest that the S-layer protein genes have evolved via horizontal transfer of genetic information followed by DNA rearrangements mediated by mobile elements.
The Term Structure of Implicit Discount Rates in Security Valuation
Authors: Garrod Neil , Valentincic Aljosa
Published: September 2005

Abstract:  A reformulation of the residual income model is used to generate estimates of discount rates implicit in UK security prices. The terminal value of the infinite valuation model is incorporated into the coefficient on current earnings. By varying the length of the forecast horizon, different combinations of implicit discount rates are revealed that allow the estimation of time‐variant costs of equity. Results indicate no specific pattern of discount rates, thus revealing neither myopia on short‐term earnings nor excessive optimism on long(er)‐term earnings. Surprisingly, there is weak evidence that if any myopia exists, it is concentrated in larger and lower price‐earnings firms.
Earnings Conservatism, Litigation and Contracting: The Case of Cross‐Listed Firms
Authors: Huijgen Carel , Lubberink Martien
Published: September 2005

Abstract:  We compare earnings conservatism of UK companies cross‐listed in the US to that of UK companies without a US‐listing. We expect that conservatism will be more pronounced for cross‐listed firms than for firms with a UK listing only, because the cross‐listed firms face a stricter enforcement regime. Furthermore, cross‐listed firms may use a listing on a US exchange to signal high‐quality reporting to investors. Using a matched‐pairs research design, we find that earnings of UK cross‐listed firms are significantly more conservative than earnings of UK firms without a US listing. Moreover, cross listed firms display particularly high levels of conservatism during the early years of their cross‐listing. This indicates that firms use earnings conservatism to commit to highly demanding reporting requirements and in doing so communicate a perception of investor care.
A Comparison of Earnings Management Between KSE Firms and KOSDAQ Firms
Authors: Yoon Soon Suk
Published: September 2005

Abstract:  This study investigates differences in earnings management practices of Korea Stock Exchange (KSE) firms and KOSDAQ (a Korean version of the NASDAQ market) firms during the period of 1996–1997. A sample of 1,256 KSE and 577 KOSDAQ firm‐year observations is used to compare earnings management practices of firms listed in the two different stock exchanges. The results of the study reveal that KOSDAQ firms tend to more actively manipulate earnings to avoid losses than KSE firms. KOSDAQ firms generally tend to increase reported earnings more aggressively than KSE firms when their operating cash flows are poor, and play down their reported earnings more when their operating cash flows are exceptionally good. The results of the study are quite robust in the sense that more aggressive earnings management practices of KOSDAQ firms persist even when operating cash flows are controlled.
The Impact of Mandated Cash Flow Disclosure on Bid‐Ask Spreads
Authors: Frino Alex , Jones Stewart
Published: September 2005

Abstract:  This study provides evidence that mandatory cash flow disclosure required by Approved Australian Accounting Standard AASB 1026, Statement of Cash Flows(June 1992) was associated with a decline in bid‐ask spreads following the introduction of the regulation, even after controlling for changes in trading volume and price volatility. More pronounced decreases in bid‐ask spreads were associated with firms having lower correlations between reported CFO and estimates of CFO using balance sheet reconstructions. We conclude that mandatory cash flow disclosure reduces information asymmetry across market participants.
The Provision of Company Benefits in the UK
Authors: Collard David , Godwin Michael , Hudson John
Published: September 2005

Abstract:  A theoretical analysis argues that a company will provide benefits if they are worth more to the employee than income equal to the net amount it is costing the firm to provide the benefit. Because the individual is being denied choice, other things being equal he/she would prefer the income. But the firm may be able to provide a benefit‐wage package which compensates the individual because of (i) tax advantages, (ii) economies of scale in purchasing or (iii) production function advantages. The empirical work focuses on benefit provision in the UK.
Voluntary Disclosure of Bad News
Authors: Suijs Jeroen
Published: September 2005

Abstract:  This paper shows that in a voluntary disclosure environment entailing both a fixed disclosure cost and a variable proprietary cost, partial disclosure equilibria may arise in which firms voluntarily disclose bad private information to the public. Furthermore, it is shown that such equilibria may arise more frequently as the threat of incuring proprietary cost increases and/or the proprietary cost itself increases.
The Relevance of Analysts’ Earnings Forecasts in Japan
Authors: Covrig Vicentiu , Low Buen Sin
Published: September 2005

Abstract:  This study examines the role of financial analysts in equity valuation in Japan by comparing the relevance of financial analysts’ earnings forecasts, over financial statement information, to investors’ decisions. We find that the value‐relevance of a set of accounting variables is very modest, but the incremental contribution of analysts’ forecasts is very significant. This is in line with the expectation that the skill and expertise of analysts are more valuable in markets with poor financial disclosure, such as Japan. We also find that the importance of the financial statements increases over time while the importance of the analysts’ forecasts does not change. We also provide evidence of the effect of Japanese corporate groupings, keiretsu, on the informativeness of accounting signals and earnings forecasts. The results show that the contribution of accounting variables to valuation is lower for keiretsu firms, which supports the exclusionary hypothesis that companies which are a part of keiretsu, disclose less information than do non‐keiretsu companies. The analysts’ forecasts are equally important for investors in both types of firms.
Evaluating the Performance of Ethical and Non‐ethical Funds: A Matched Pair Analysis
Authors: Kreander N. , Gray R.H. , Power D.M. , Sinclair C.D.
Published: September 2005

Abstract:  This paper studies the performance of 60 European funds from four countries. The paper extends the UK matched pair approach for fund evaluation developed by Mallin et al. (1995) to a European setting. The findings suggest that there is no difference between ethical and non‐ethical funds according to the performance measures employed. Neither type of fund displayed any ability to time the market. Finally, the results indicate that the management fee is a significant explanatory variable for the Jensen measure as Chen et al. (1992) and Grinblatt and Titman (1994) suggested.
The Opening, Short, Medium and Long Term Performance of Canadian Unit Trust Initial Public Offerings (IPOs)
Authors: Boabang Francis
Published: September 2005

Abstract:  This paper investigates the initial pricing and performance of Canadian unit trust IPOs over a three‐ to four‐year period and then draws implications for the efficiency of the Canadian market. Overall, the results confirm the following: in the short term, unit trust IPOs are underpriced and outperform the Canadian market; in the medium term, IPOs are fairly priced and neither outperform nor underperform the Canadian market; and in the long term, IPOs are fairly priced but underperform the Canadian market. In addition, our results confirm that the size of underpricing is related to ex‐ante uncertainty about the value of the issue. Ex‐ante uncertainty proxies, namely total risk, exchange listing, relative bid‐ask spread, and relative volume of initial trade, all explain the size of underpricing. When the effects of these factors are controlled, the results confirm that Canadian unit trust IPOs are indeed overpriced in the short term but underpriced in the long term. We conclude that the Canadian unit trust IPO market appears to be inefficient in the short and long term, but over the medium, the market appears to be efficient.
Financial Modernization in US Banking Markets: A Local or Global Event?
Authors: Akhigbe Aigbe , Frye Melissa B. , Whyte Ann Marie
Published: September 2005

Abstract:  We test the hypothesis that the passage of the Financial Services Modernization Act (FSMA) of 1999 has spillover effects cross‐nationally, using a sample of US, non‐US transactional (Australian, Canadian, and UK), and relationship (German, Japanese, Dutch, and Swiss) banks. Our results suggest that financial modernization in the US has limited cross‐national effects. We find strong evidence that US banks were affected favorably. Although we detect some evidence of significant reactions by banks in certain countries, a closer examination reveals that the reaction is most likely attributable to events in the respective countries during the event period. We do find, however, that non‐US transactional banks have been more likely to elect financial holding company status compared to relationship banks, suggesting they are positioning themselves to exploit the expanded opportunity set created by the FSMA. Nonetheless, the majority of elections have been made by US banks. In general, the results suggest that the respective banking markets are efficient in filtering events that are largely country‐specific with only limited implications for other international banks.
Comparing the Impact of News: A Tale of Three Health Care Sectors
Authors: Ewing Bradley T. , Kruse Jamie B. , Thompson Mark A.
Published: September 2005

Abstract:  This paper examines the impact of news on the volatility of equity returns in three sectors of the health care industry – health care service providers, producers of drugs and supplies, and third‐party payors. The news impact is found to be asymmetric in that bad news (i.e., a negative shock) has a significantly greater effect on volatility than good news. Intra‐industry differences in health care equity market performance are documented and are consistent with the fundamental attributes of these sectors including the degree of price and cost pressures facing firms, the physical capital requirements of firms, the search behavior of health care customers, and the presence of alternative market opportunities.
Corporate Dividend Policy:  The Views of British Financial Managers
Authors: Dhanani Alpa
Published: September 2005

Abstract:  Using a survey approach, this paper examines the importance and relevance of the various theories of dividend policy for UK companies. Further, it evaluates the extent to which corporate characteristics such as size and industry influence managerial responses to the survey. In general, the results support dividend hypotheses relating to signalling and ownership structure, in preference to those about capital structure and investment decisions and agency issues. At a more detailed level, the cross sectional analysis reveals important differences between managers’ responses, based on company size, industry sector, growth opportunities, ownership structure and information asymmetry.
Are grazing increaser species better tolerators than decreasers? An experimental assessment of defoliation tolerance in eight British grassland species
Authors: DEL‐VAL EK , CRAWLEY MICHAEL J.
Published: September 2005

The importance of tolerance to herbivory for plant survival has long been recognized, but capacity for regrowth following recurrent defoliation has rarely been studied.

A glasshouse experiment was conducted with eight grassland species. We chose both species favoured under herbivory (increasers) and those that become scarce (decreasers) and manipulated the ontogeny of the plant when first clipped, as well as frequency (up to eight times) and intensity of clipping.

Plant survival was high (88%) but both frequency and intensity of clipping increased plant mortality in all species investigated (P < 0.05). Immature plants showed the highest mortality (15.9%).

Plant biomass mirrored mortality with immature plants again the most affected. As expected, control plants were largest and plants experiencing 100% biomass removal smallest. Clipping frequency was also significant, but the effect was not linear and plants that were clipped more than twice were more dramatically affected.

Biomass compensation showed species‐specific responses that were significantly related to an a priori definition of species status in the grassland: increaser species had significantly higher compensation ability after recurrent defoliation than decreaser species.

Tolerance to herbivory has been viewed as a marginal strategy for plant survival, but our results suggest that it plays an important role in explaining abundance and distribution of plant species in environments with recurrent defoliation.

Plants do not always respond linearly to environmental pressures (such as repeated defoliation) and cannot therefore be predicted by studies considering only the lower end of the possible intensities. Understanding the effects of environmental pressures on plant fitness requires the study of a broader range of intensities, at different ontogenic stages and consideration of possible response thresholds.
The hare, the tortoise and the crocodile: the ecology of angiosperm dominance, conifer persistence and fern filtering
Authors: COOMES DAVID A. , ALLEN ROBERT B. , BENTLEY WARREN A. , BURROWS LARRY E. , CANHAM CHARLES D. , FAGAN LAURA , FORSYTH DAVID M. , GAXIOLA‐ALCANTAR AURORA , PARFITT ROGER L. , RUSCOE WENDY A. , WARDLE DAVID A. , WILSON DEBORAH J. , WRIGHT ELAINE F.
Published: September 2005

Angiosperm trees often dominate forests growing in resource‐rich habitats, whereas conifers are generally restricted to less productive habitats. It has been suggested that conifers may be displaced by angiosperms except where competition is less intense, because conifer seedlings are inherently slow growing, and are outpaced by faster‐growing angiosperm species. Here we investigate whether competition with ferns and deeply shading trees also contributes to a failure of conifers to regenerate in resource‐rich habitats.

We examined how changes in soil nutrient availability and drainage affected vegetation along the retrogressive stages of a soil chronosequence in southern New Zealand. Vegetation composition shifted from angiosperm‐tree dominance on ‘recent’ alluvial terraces (< 24 ky), via coniferous‐tree dominance on older marine terraces (79–121 ky), to coniferous‐shrub dominance on the oldest marine terraces (291 ky). Soil drainage deteriorated along the sequence, and N : Pleavesand N : Psoilindicate increasing P‐limitation. Conifer species appear to be adapted to persistence on infertile and poorly drained soils.

The floor of the relatively fertile alluvial forests was deeply shaded (∼1% light transmission) by dense groves of tree‐ferns and ground‐ferns, and by large‐leaved subcanopy trees. Few seedlings of any type were found on the forest floor, even in tree‐fall gaps, and establishment was restricted to rotting logs and tree‐fern trunks. Angiosperms were particularly successful at colonizing these raised surfaces.

Less shade was cast by the conifer‐dominated forests on infertile marine terraces (∼5% light transmission), which lacked tall ferns. There were many opportunities for conifer establishment, with high seedling densities recorded on the forest floor and on logs. By contrast, angiosperm seedlings were mainly restricted to logs.

Our results suggest that several mechanisms act in concert to reduce regeneration opportunities for conifers in productive habitats. In particular, we suggest that tall ferns and deep shade are responsible for a restriction of regeneration opportunities in relatively productive forests in New Zealand, diminishing the opportunities for conifers to escape the competitive effects of fast‐growing angiosperms. Thus ‘crocodiles’ may alter the outcome of the race between ‘hares’ and ‘tortoises’.
Differential genetic influences on competitive effect and response in Arabidopsis thaliana
Authors: F. CAHILL JAMES , KEMBEL STEVEN W. , GUSTAFSON DANNY J.
Published: September 2005

Competition plays an important role in structuring populations and communities, but our understanding of the genetic basis of competitive ability is poor. This is further complicated by the fact that plants can express both competitive effect (target plant influence upon neighbour growth) and competitive response (target plant growth as a function of a neighbour) abilities, with these ecological characteristics potentially being independent.

Using the model plant species Arabidopsis thaliana, we investigated patterns of intraspecific variation in competitive effect and response abilities and their relationships to other plant traits and resource supply rates.

Both competitive effect and response were measured for 11 genotypes, including the Columbia ecotype and 10 derived mutant genotypes. Plants were grown alone, with intragenotypic competition, and with intergenotypic competition in a replicated blocked design with high nutrient and low nutrient soil nutrient treatments. We quantified competitive effect and response on absolute and per‐gram bases.

Competitive effect and response varied among genotypes, with the relative competitive abilities of genotypes consistent across fertilization treatments. Overall, high rates of fertilization increased competitive effect and competitive response abilities of all genotypes. Both competitive effect and response were correlated with neighbour biomass, though genotype‐specific traits also influenced competitive response.

At the genotype level, there was no correlation between competitive effect and response in either fertilization treatment. Overall patterns in competitive response appeared consistent among inter‐ and intragenotypic competition treatments, indicating that a target genotype's response to competition was not driven by the genetic identity of the competitor.

These findings indicate that within A. thaliana, there is the potential for differential selection on competitive effect and response abilities, and that such selection may influence different sets of plant traits. The concept of a single competitive ability for a given plant is not supported by these data, and we suggest continued recognition of these dual competitive abilities is essential to understanding the potential role of competition in influencing intra‐ and interspecific processes.
Seed limitation in a Panamanian forest
Authors: SVENNING JENS‐CHRISTIAN , WRIGHT S. JOSEPH
Published: September 2005

The role of seed limitation in tropical forests remains uncertain owing to the scarcity of experimental evidence. We performed seed addition experiments to assess seed limitation for 32 shade‐tolerant tropical forest species and monitored the natural seed rain of 25 of these species for 17 years.

One, two or five seeds were sown into 0.0079‐m2plots for large‐ (n = 5 species), medium‐ (n = 5) and small‐seeded species (n = 22), respectively. The experiment was replicated at 69 sites, placed in groups of three at 23 locations. Seedling establishment was evaluated after 1 and 2 years in paired seed addition and control plots. Natural seedling emergence and understorey plant density were also measured.

Median natural seed rain was 0.31 seeds m−2 year−1per focal species.

Seed addition enhanced seedling establishment in 31 and 26 of the 32 species after 1 and 2 years, respectively. Mean number of focal species’ seedlings after 2 years was 0.002 seedlings in control plots and 0.12, 0.37 and 0.60 seedlings in seed addition plots for large‐, medium‐ and small‐seeded species, respectively.

A 25 seeds added treatment increased seedling establishment by ≥ 2.0‐fold over the five seeds added treatment after 2 years.

Community‐wide recruitment and understorey plant density were strongly seed‐limited. The natural density of understorey plants averaged 12 plants m−2and was significantly less than for seedlings of the single focal species in plots with ≥ 2 seeds added 2 years earlier.

The number of established seedlings per seed added was independent of seed size.

Treatment (adding zero or five seeds), species identity and location all affected seedling establishment for the 11 small‐seeded species represented at all sites, with treatment and its interactions accounting for 86% of the explained variation.

Our results suggest that seed limitation plays a dominant role in seedling recruitment and understorey plant community assembly in tropical forests. Although strong seed limitation may set the stage for species‐neutral community assembly, the species differences in seedling establishment rate and its spatial variation demonstrate an important role for species‐specific processes.
A mechanistic model for secondary seed dispersal by wind and its experimental validation
Authors: SCHURR FRANK M. , BOND WILLIAM J. , MIDGLEY GUY F. , HIGGINS STEVEN I.
Published: September 2005

Secondary seed dispersal by wind, the wind‐driven movement of seeds along the ground surface, is an important dispersal mechanism for plant species in a range of environments.

We formulate a mechanistic model that describes how secondary dispersal by wind is affected by seed traits, wind conditions and obstacles to seed movement. The model simulates the movement paths of individual seeds and can be fully specified using independently measured parameters.

We develop an explicit version of the model that uses a spatially explicit representation of obstacle patterns, and also an aggregated version that uses probability distributions to model seed retention at obstacles and seed movement between obstacles. The aggregated version is computationally efficient and therefore suited to large‐scale simulations. It provides a very good approximation of the explicit version (R2 > 0.99) if initial seed positions vary randomly relative to the obstacle pattern.

To validate the model, we conducted a field experiment in which we released seeds of seven South African Proteaceae species that differ in seed size and morphology into an arena in which we systematically varied obstacle patterns. When parameterized with maximum likelihood estimates obtained from independent measurements, the explicit model version explained 70–77% of the observed variation in the proportion of seeds dispersed over 25 m and 67–69% of the observed variation in the direction of seed dispersal.

The model tended to underestimate dispersal rates, possibly due to the omission of turbulence from the model, although this could also be explained by imprecise estimation of one model parameter (the aerodynamic roughness length).

Our analysis of the aggregated model predicts a unimodal relationship between the distance of secondary dispersal by wind and seed size. The model can also be used to identify species with the potential for long‐distance seed transport by secondary wind dispersal.

The validated model expands the domain of mechanistic dispersal models, contributes to a functional understanding of seed dispersal, and provides a tool for predicting the distances that seeds move.