bluuebunny/crossref_metadata_2025 huggingface dataset:
America's economic decline: Evidence and explanations
Authors: Hart Jeffrey A.
Published: April 2007

Changes in international competitiveness since World War II have favored Germany and Japan over France, the United States, and Britain. This applies to competitiveness in general, but is examined in three specific industries: steel, automobiles, and semiconductors. Explanations of changes in competitiveness often focus on economic and cultural variables, but an examination of the three industries shows that a better explanation can be found in the way in which each country organizes its state and society. State‐societal arrangements influence competitiveness mainly through their impact on the speed of diffusion of new technologies. The disparate cases of Germany (strong business and labor, weak government) and Japan (strong business and government, weak labor) suggest that there is more than one path to competitiveness. The literature on competitiveness has focused too much on Japan, and therefore on state industrial policies, as the key to increasing competitiveness. The German case shows that increased competitiveness is possible with a relatively weak state, but only if there is a major commitment to upgrading the skill levels of the work force. © 1995 John Wiley & Sons, Inc.
Financial rewards and company ownership: An examination of reward practices in Ireland
Authors: Gunnigle Patrick , Foley Kieran , Morley Michael
Published: April 2007

This article examines the influence of company ownership on the level at which pay is determined in Ireland and on the kinds of payment systems used. U.S. and U.K. multinational companies (MNCs), the two largest foreign investors in Ireland, are the focus of the analysis. Although the evidence points to the national level as the key level at which pay is determined, U.S. and U.K. MNCs operating in Ireland tend to follow the practices of their headquarters, rather than those of the host country. Evidence also suggests that foreign MNCs are much more likely to utilize nonstandard, variable payment systems than indigenous organizations. © 1995 John Wiley & Sons, Inc.
Massive Urban renewal under emergency
Authors: Mendoza Enrique Cabrero , Gault David Arellano
Published: April 2007

The management challenge entailed in Mexico City's massive urban renewal effort following the 1985 earthquake went well beyond organizing relief and reconstruction tasks. A collective action agency successfully avoided a political crisis by enlisting grass‐roots participation and mobilizing dozens of public, private, and volunteer organizations in a swiftly executed joint undertaking. © 1995 John Wiley & Sons, Inc.
Mobilizing social development through music
Authors: Fischer Tania , Dantas Marcelo
Published: April 2007

The Olodum Cultural Group describes itself as a nongovernmental organization that combines a variety of profit‐making show business activities with wide‐ranging nonprofit programs addressed to cultural, social, and political action. Show business activities, music production and recording, dance, and theater presentations build on Olodum's research on Afro‐Bahian origins, history, and customs, which serve as a rich source of new artistic themes and rhythms. Social and political action programs are focused on highlighting the identity of the Black population of Maciel–Pelourinho, a district of the city of Salvador that UNESCO has declared to be a heritage of humankind but is inhabited largely by social cast‐offs, prostitutes, transvestites, and drug addicts. Olodum also grows its own talent by operating a “Creative School,” where district children enroll in courses that range from Black identity and human rights to the performing arts. Additionally, Olodum campaigns include curbing police violence, cooperation with AIDS prevention, city clean‐up drives, and representing Maciel–Pelourinho in world events. © 1995 John Wiley & Sons, Inc.
International business education of the United States in the 1990s: Accredited vs. nonaccredited schools
Authors: Kwok Chuck C. Y.
Published: April 2007

This article reports the status of the international business education in the United States as of the 1990s and examines the differences between AACSB accredited and nonaccredited business schools regarding the various aspects of internationalization. The overall conclusions are that along all dimensions significant progress has been made regarding internationalization. Accredited schools have progressed further than nonaccredited schools. Nevertheless, many of the schools have not aimed very high or made major changes in structures, operations, incentives, or requirements of their college to accommodate internationalization. © 1995 John Wiley & Sons, Inc.
An assessment of Colombian managers' perceptions of international strategic alliances
Authors: Arbeláez Harvey , Culpan Refik
Published: April 2007

This article reports the results of a survey of Colombian managers concerning their perceptions of strategic alliances with foreign firms. The survey focuses in particular on partner selection and the managerial expectations from such partnerships, as well as the potential difficulties involved in developing interfirm linkages. The survey of Colombian managers shows that international strategic alliances are considered a viable approach to building a competitive advantage, especially in domestic markets, either through acquiring Western technology or marketing know‐how. However, the survey results also suggest that a number of obstacles need to be overcome. The important considerations in partner selection, competence building through strategic alliances, and dealing with potential problems in establishing interfirm partnerships are discussed. © 1995 John Wiley & Sons, Inc.
Competitiveness in information technology service exports
Authors: Thompson Donna M.
Published: April 2007

The US service export base is expanding rapidly as firms seek to penetrate international markets in search of growth opportunities. This article explores mechanisms that a sample of 67 US‐based information technology (IT) firms use to export their services to one selected market, Mexico. A correlation analysis revealed that most firms adapt and extend existing IT services for the Mexican market, and consider cultural understanding imperative to successful operations in Mexico. The results also found that firms use a variety of business arrangements (joint ventures, licensing) and a wide array of contract vehicles (time and materials, firm fixed price). © 1995 John Wiley & Sons, Inc.
An alternative approach to expatriate allowances: An “international citizen”
Authors: Freeman Kimberly A. , Kane Jeffrey S.
Published: April 2007

Competitive advantages for an organization that may be realized through the use of expatriates often are diminished due to excessive compensation and the costs associated with expatriate failure. This article addresses an approach for determining expatriate allowances that uses a worldwide standard as the basis for establishing such allowances. It also provides the philosophy and rationale behind such an approach and differentiates it from traditional “balance sheet” or parent‐country equivalency approaches. The relative merits of this approach are systematically assessed using a set of objectives for international compensation. © 1995 John Wiley & Sons, Inc.
Is the country manager an endangered species?
Authors: Birkinshaw Julian
Published: April 2007

The role of the country manager in the multinational corporation has changed substantially in recent years in both North America and Europe. Where the country manager previously held full responsibility for the national operations, frequently the role is now reduced to that of spokesperson and figurehead. This article describes four generic country management functions that were identified in a recent study of 15 multinationals, and describes the structural and environmental contingencies associated with each. The future role of the country manager is also assessed. © 1995 John Wiley & Sons, Inc.
Trends in international business thought and literature: Job insecurity: Emerging social roles of the 90s
Authors: Jacobson Dan
Published: April 2007

Job insecurity is a societal problem of global concern that is not likely to abate in the foreseeable future. The proportion of the population subjected to some degree of job insecurity is considerably larger than the number of workers who actually experience job loss. To date, the problem, despite its damaging consequences, has not been adequately studied. In particular, scholars have ignored the impact of the external environment. This leaves open a field of interesting questions concerning the relationships between cultural and other factors and the experience of job insecurity. Such factors may have important effects on the way individuals respond to job insecurity in different countries. © 1995 John Wiley & Sons, Inc.
International joint ventures in the United States: An examination of factors related to their effectiveness
Authors: Zeira Yoram , Parker Barbara
Published: April 2007

The increasing popularity of international joint ventures (IJVs) and their high failure rate prompted this examination of pre‐ and postincorporation factors related to IJV effectiveness. Interviews with IJV CEOs, and the findings from a questionnaire administered to CEOs of 81 IJVs in the United States, suggest which pre‐ and postincorporation factors can be important to IJVs' effectiveness. Why these factors are important, and how they interact with other factors in the general context of IJV experiences are also explored in this article. © 1995 John Wiley & Sons, Inc.
Asymmetric expectations: Cross‐national coalitions in a Japanese transplant in Italy
Authors: Bonazzi Giuseppe , Botti Hope Finney
Published: April 2007

This article is a study of the experience of a Japanese production unit transplanted to Italy. It employs the concepts of “Fordism” and “lean production” which are well known in industrial sociology and management studies. The article shows how the interplay of the owner's nationality with the local managerial and organizational characteristics of the firm resulted in a production and market crisis, and how following a series of cross‐cultural misunderstandings, a new system of trust relations evolved permitting the firm's transition to lean production. © 1995 John Wiley & Sons, Inc.
Perceptions about managerial advancement in the people's republic of China
Authors: Solt Michael E.
Published: April 2007

Cultural differences are evident in the managerial advancement strategies of People's Republic of China managers. Using the findings of prior research for comparison, PRC managers were found to be similar to Hong Kong mangers in not valuing highly the strategies preferred by US managers that emphasize individual achievement. Yet PRC managers differ from the Hong Kong managers in terms of the extent to which information control/networking strategies meet ethical approval. The findings here support the implications of prior studies: awareness of cultural differences is necessary in order to understand managerial behavior and achieve success in international business transactions. © 1995 John Wiley & Sons, Inc.
The species, sex, and stage specificity of a
Caenorhabditis
sex pheromone
Authors: Chasnov J. R. , So W. K. , Chan C. M. , Chow K. L.
Published: April 2007

Four species in the ELEGANS group of subgenus the
Caenorhabditis
are distinguished by two very different mating systems: androdioecy in
C. elegans
and
Caenorhabditis briggsae
with males and self-fertilizing hermaphrodites and dioecy in
Caenorhabditis remanei
and
Caenorhabditis
sp. strain CB5161 with males and females. Using chemotaxis assays, we demonstrate that females secrete a potent sex pheromone that attracts males from a distance, whereas hermaphrodites do not. The female sex pheromone is not species-specific, with males of all four species attracted to both the
C. remanei
and
Caenorhabditis
sp. female sex pheromones. The pheromone is, however, sex-specific, with only females secreting the pheromone and attracting only males. Furthermore, the sex pheromone is stage-specific, with female secretion and male detection of the pheromone beginning near adulthood. Females lose their attractiveness immediately after mating but regain it several hours after mating ceases. Finally, the female somatic gonad is required for sex-pheromone production, and the male-specific cephalic neurons (CEM) are required for male response.
Insulin receptors in β-cells are critical for islet compensatory growth response to insulin resistance
Authors: Okada Terumasa , Liew Chong Wee , Hu Jiang , Hinault Charlotte , Michael M. Dodson , Kr̈tzfeldt Jan , Yin Catherine , Holzenberger Martin , Stoffel Markus , Kulkarni Rohit N.
Published: April 2007

Insulin and insulin-like growth factor 1 (IGF1) are ubiquitous growth factors that regulate proliferation in most mammalian tissues including pancreatic islets. To explore the specificity of insulin receptors in compensatory β-cell growth, we examined two models of insulin resistance. In the first model, we used liver-specific insulin receptor knockout (LIRKO) mice, which exhibit hyperinsulinemia without developing diabetes due to a compensatory increase in β-cell mass. LIRKO mice, also lacking functional insulin receptors in β-cells (βIRKO/LIRKO), exhibited severe glucose intolerance but failed to develop compensatory islet hyperplasia, together leading to early death. In the second model, we examined the relative significance of insulin versus IGF1 receptors in islet growth by feeding high-fat diets to βIRKO and β-cell-specific IGF1 receptor knockout (βIGFRKO) mice. Although both groups on the high-fat diet developed insulin resistance, βIRKO, but not βIGFRKO, mice exhibited poor islet growth consistent with insulin-stimulated phosphorylation, nuclear exclusion of FoxO1, and reduced expression of Pdx-1. Together these data provide direct genetic evidence that insulin/FoxO1/Pdx-1 signaling is one pathway that is crucial for islet compensatory growth response to insulin resistance.
Public health interventions and epidemic intensity during the 1918 influenza pandemic
Authors: Hatchett Richard J. , Mecher Carter E. , Lipsitch Marc
Published: April 2007

Nonpharmaceutical interventions (NPIs) intended to reduce infectious contacts between persons form an integral part of plans to mitigate the impact of the next influenza pandemic. Although the potential benefits of NPIs are supported by mathematical models, the historical evidence for the impact of such interventions in past pandemics has not been systematically examined. We obtained data on the timing of 19 classes of NPI in 17 U.S. cities during the 1918 pandemic and tested the hypothesis that early implementation of multiple interventions was associated with reduced disease transmission. Consistent with this hypothesis, cities in which multiple interventions were implemented at an early phase of the epidemic had peak death rates ≈50% lower than those that did not and had less-steep epidemic curves. Cities in which multiple interventions were implemented at an early phase of the epidemic also showed a trend toward lower cumulative excess mortality, but the difference was smaller (≈20%) and less statistically significant than that for peak death rates. This finding was not unexpected, given that few cities maintained NPIs longer than 6 weeks in 1918. Early implementation of certain interventions, including closure of schools, churches, and theaters, was associated with lower peak death rates, but no single intervention showed an association with improved aggregate outcomes for the 1918 phase of the pandemic. These findings support the hypothesis that rapid implementation of multiple NPIs can significantly reduce influenza transmission, but that viral spread will be renewed upon relaxation of such measures.
Symmetry matters for the electronic structure of core complexes from
Rhodopseudomonas palustris
and
Rhodobacter sphaeroides
PufX
−
Authors: Richter M. F. , Baier J. , Prem T. , Oellerich S. , Francia F. , Venturoli G. , Oesterhelt D. , Southall J. , Cogdell R. J. , Köhler J.
Published: April 2007

Low-temperature (1.4 K), single-molecule fluorescence-excitation spectra have been recorded for individual reaction center–light-harvesting 1 complexes from
Rhodopseudomonas palustris
and the PufX
−
strain of
Rhodobacter sphaeroides
. More than 80% of the complexes from
Rb. sphaeroides
show only broad absorption bands, whereas nearly all of the complexes from
Rps. palustris
also have a narrow line at the low-energy end of their spectrum. We describe how the presence of this narrow feature indicates the presence of a gap in the electronic structure of the light-harvesting 1 complex from
Rps. palustris
, which provides strong support for the physical gap that was previously modeled in its x-ray crystal structure.
The alanine-rich XAO peptide adopts a heterogeneous population, including turn-like and polyproline II conformations
Authors: Schweitzer-Stenner Reinhard , Measey Thomas J.
Published: April 2007

The solution structure of the hepta-alanine polypeptide Ac-X
2
A
7
O
2
-NH
2
(XAO) has been a matter of controversy in the current literature. On one side of the argument is a claim that the peptide adopts a mostly polyproline II (PPII) structure, with a <20% population of β conformations at room temperature [Shi Z, Olson CA, Rose GA, Baldwin RL, Kallenbach NR (2002)
Proc Natl Acad Sci USA
99:9190–9195], whereas the other side of the argument insists that the peptide exists as an ensemble of conformations, including multiple β-turn structures [Makowska J, Rodziewicz-Motowidlo S, Baginska K, Vila JA, Liwo A, Chmurzynski L, Scheraga HA (2006)
Proc Natl Acad Sci USA
103:1744–1749]. We have used an excitonic coupling model to simulate the amide I band of the FTIR, vibrational circular dichroism, and isotropic and anisotropic Raman spectra of XAO, where, for each residue, the backbone dihedral angle φ was constrained by using the reported
3
J
CαHNH
values and a modified Karplus relation. The best reproduction of the experimental data could only be achieved by assuming an ensemble of conformations, which contains various β-turn conformations (≈26%), in addition to β-strand (≈23%) and PPII (≈50%) conformations. PPII is the dominant conformation in segments not involved in turn formations. Most of the residues were found to sample the bridge region connecting the PPII and right-handed helix troughs in the Ramachandran plot, which is part of the very heterogeneous ensemble of conformations generally termed type IV β-turn.
Network of coregulated spliceosome components revealed by zebrafish mutant in recycling factor p110
Authors: Trede Nikolaus S. , Medenbach Jan , Damianov Andrey , Hung Lee-Hsueh , Weber Gerhard J. , Paw Barry H. , Zhou Yi , Hersey Candace , Zapata Agustin , Keefe Matthew , Barut Bruce A. , Stuart Andrew B. , Katz Tammisty , Amemiya Chris T. , Zon Leonard I. , Bindereif Albrecht
Published: April 2007

The spliceosome cycle consists of assembly, catalysis, and recycling phases. Recycling of postspliceosomal U4 and U6 small nuclear ribonucleoproteins (snRNPs) requires p110/SART3, a general splicing factor. In this article, we report that the zebrafish
earl grey
(
egy
) mutation maps in the
p110
gene and results in a phenotype characterized by thymus hypoplasia, other organ-specific defects, and death by 7 to 8 days postfertilization. U4/U6 snRNPs were disrupted in
egy
mutant embryos, demonstrating the importance of p110 for U4/U6 snRNP recycling
in vivo
. Surprisingly, expression profiling of the
egy
mutant revealed an extensive network of coordinately up-regulated components of the spliceosome cycle, providing a mechanism compensating for the recycling defect. Together, our data demonstrate that a mutation in a general splicing factor can lead to distinct defects in organ development and cause disease.
Identification of mouse Duffy Antigen Receptor for Chemokines (Darc) as a BMD QTL gene
Authors: Edderkaoui Bouchra , Baylink David J. , Beamer Wesley G. , Wergedal Jon E. , Porte Ryan , Chaudhuri Asok , Mohan Subburaman
Published: April 2007

It is now well known that bone mineral density (BMD) variance is determined by both genetic and environmental factors. Accordingly, studies in human and animal models have revealed evidence for the presence of several quantitative trait loci (QTL) that contribute to BMD variations. However, the identification of BMD QTL genes remains a big challenge. In the current study, we focused our efforts to identify the BMD candidate gene in chromosome 1 (Chr 1) QTL that was detected from a cross involving high BMD CAST/EiJ (CAST) and low BMD C57BL/6J (B6) mice. To this end, we have combined several approaches including: (1) fine mapping the BMD QTL in Chr 1 of the B6.CAST F2 female mice using a large number of polymorphic markers; (2) the generation of congenic sublines of mice by repeated backcrossing of CAST with B6 mice and phenotype characterization; (3) expression profiling genes in the QTL region; and (4) SNP analyses to identify the mouse Duffy Antigen Receptor for Chemokines (Darc) as a candidate gene for Chr 1 BMD QTL2. We verified the involvement of the Darc protein in BMD variation by evaluating the skeletal phenotype of Darc-knockout mice and congenic sublines of mice carrying small chromosomal segments from CAST BMD QTL. Based on the findings that Darc-antibody blocked formation of multinucleated osteoclasts in vitro and that Darc from CAST binds chemokines, known to regulate osteoclast formation, with reduced affinity compared with Darc from B6 mice, we conclude that Darc regulates BMD negatively by increasing osteoclast formation, and that the genetic association between Darc gene polymorphism and BMD variations in humans merits investigation.
Fast-X on the Z: Rapid evolution of sex-linked genes in birds
Authors: Mank Judith E. , Axelsson Erik , Ellegren Hans
Published: April 2007

Theoretical work predicts natural selection to be more efficient in the fixation of beneficial mutations in X-linked genes than in autosomal genes. This “fast-X effect” should be evident by an increased ratio of nonsynonymous to synonymous substitutions (dN/dS) for sex-linked genes; however, recent studies have produced mixed support for this expectation. To make an independent test of the idea of fast-X evolution, we focused on birds, which have female heterogamety (males ZZ, females ZW), where analogous arguments would predict a fast-Z effect. We aligned 2.8 Mb of orthologous protein-coding sequence of zebra finch and chicken from 172 Z-linked and 4848 autosomal genes. Zebra finch data were in the form of EST sequences from brain cDNA libraries, while chicken genes were from the draft genome sequence. The dN/dS ratio was significantly higher for Z-linked (0.110) than for all autosomal genes (0.085; P = 0.002), as well as for genes linked to similarly sized autosomes 1–10 (0.0948; P = 0.04). This pattern of fast-Z was evident even after we accounted for the nonrandom distribution of male-biased genes. We also examined the nature of standing variation in the chicken protein-coding regions. The ratio of nonsynonymous to synonymous polymorphism (pN/pS) did not differ significantly between genes on the Z chromosome (0.104) and on the autosomes (0.0908). In conjunction, these results suggest that evolution proceeds more quickly on the Z chromosome, where hemizygous exposure of beneficial nondominant mutations increases the rate of fixation.
Rapid evolution of an X-linked microRNA cluster in primates
Authors: Zhang Rui , Peng Yi , Wang Wen , Su Bing
Published: April 2007

MicroRNAs (miRNAs) are a growing class of small RNAs (about 22 nt) that play crucial regulatory roles in the genome by targeting mRNAs for cleavage or translational repression. Most of the identified miRNAs are highly conserved among species, indicating strong functional constraint on miRNA evolution. However, nonconserved miRNAs may contribute to functional novelties during evolution. Recently, an X-linked miRNA cluster was reported with multiple copies in primates but not in rodents or dog. Here we sequenced and compared this miRNA cluster in major primate lineages including human, great ape, lesser ape, Old World monkey, and New World monkey. Our data indicate rapid evolution of this cluster in primates including frequent tandem duplications and nucleotide substitutions. In addition, lineage-specific substitutions were observed in human and chimpanzee, leading to the emergence of potential novel mature miRNAs. The expression analysis in rhesus monkeys revealed a strong correlation between miRNA expression changes and male sexual maturation, suggesting regulatory roles of this miRNA cluster in testis development and spermatogenesis. We propose that, like protein-coding genes, miRNA genes involved in male reproduction are subject to rapid adaptive changes that may contribute to functional novelties during evolution.
Sebacina vermifera Promotes the Growth and Fitness of Nicotiana attenuata by Inhibiting Ethylene Signaling
Authors: Barazani Oz , von Dahl Caroline C. , Baldwin Ian T.
Published: April 2007

Sebacina vermifera, a growth-promoting endophytic fungus, significantly increases Nicotiana attenuata's growth but impairs both its herbivore resistance and its accumulation of the costly, jasmonic acid (JA)-regulated defense protein, trypsin proteinase inhibitor (TPI). To determine if the fungi's growth-promoting effects can be attributed to lower TPI-related defense costs, we inoculated transformed N. attenuata plants silenced in their ability to synthesize JA, JA-isoleucine, and TPI by antisense (lipoxygenase 3 [as-lox3] and Thr deaminase [as-td]) and inverted repeat (ir-tpi) expression, and found that inoculation promoted plant growth as in untransformed wild-type plants. Moreover, herbivore-elicited increases in JA and JA-isoleucine concentrations did not differ between inoculated and uninoculated wild-type plants. However, inoculation significantly reduced the morphological effect of 1-aminocyclopropane-1-carboxylic acid on wild-type seedlings in a triple response assay, suggesting that ethylene signaling was impaired. Furthermore, S. vermifera failed to promote the growth of N. attenuata plants transformed to silence ethylene production (1-aminocyclopropane-1-carboxylic acid oxidase [ir-aco]). Inoculating wild-type plants with S. vermifera decreased the ethylene burst elicited by applying Manduca sexta oral secretions to mechanical wounds. Accordingly, oral secretion-elicited transcript levels of the ethylene synthesis genes NaACS3, NaACO1, and NaACO3 in inoculated plants were significantly lower compared to these levels in uninoculated wild-type plants. Inoculation accelerated germination in wild-type seeds; however, uninoculated wild-type seeds germinated as rapidly as inoculated seeds in the presence of the ethylene scrubber KMnO4. In contrast, neither inoculation nor KMnO4 exposure influenced the germination of ir-aco seeds. We conclude that S. vermifera increases plant growth by impairing ethylene production independently of JA signaling and TPI production.
Induction of Isoforms of Tetrapyrrole Biosynthetic Enzymes, AtHEMA2 and AtFC1, under Stress Conditions and Their Physiological Functions in Arabidopsis
Authors: Nagai Satoshi , Koide Masumi , Takahashi Shigekazu , Kikuta Akihiro , Aono Mitsuko , Sasaki-Sekimoto Yuko , Ohta Hiroyuki , Takamiya Ken-ichiro , Masuda Tatsuru
Published: April 2007

In the tetrapyrrole biosynthetic pathway, isoforms of glutamyl-tRNA reductase (HEMA2) and ferrochelatase1 (FC1) are mainly expressed in nonphotosynthetic tissues. Here, using promoter-β-glucuronidase constructs, we showed that the expressions of Arabidopsis (Arabidopsis thaliana) HEMA2 (AtHEMA2) and FC1 (AtFC1) were induced in photosynthetic tissues by oxidative stresses such as wounding. Transcript levels and β-glucronidase activity were rapidly induced within 30 min, specifically in the wound area in a jasmonate-independent manner. Transcriptome analysis of wound-specific early inducible genes showed that AtHEMA2 and AtFC1 were coinduced with hemoproteins outside plastids, which are related to defense responses. Ozone fumigation or reagents generating reactive oxygen species induced the expression of both genes in photosynthetic tissues, suggesting that reactive oxygen species is involved in the induction. Since cycloheximide or puromycin induced the expression of both genes, inhibition of cytosolic protein synthesis is involved in the induction of these genes in photosynthetic tissues. The physiological functions of AtHEMA2 and AtFC1 were investigated using insertional knockout mutants of each gene. Heme contents of the roots of both mutants were about half of that of the respective wild types. In wild-type plants, heme contents were increased by ozone exposure. In both mutants, reduction of the ozone-induced increase in heme content was observed. These results suggest the existence of the tetrapyrrole biosynthetic pathway controlled by AtHEMA2 and AtFC1, which normally functions for heme biosynthesis in nonphotosynthetic tissues, but is induced in photosynthetic tissues under oxidative conditions to supply heme for defensive hemoproteins outside plastids.
SIZ1-Mediated Sumoylation of ICE1 ControlsCBF3/DREB1AExpression and Freezing Tolerance inArabidopsis
Authors: Miura Kenji , Jin Jing Bo , Lee Jiyoung , Yoo Chan Yul , Stirm Vicki , Miura Tomoko , Ashworth Edward N. , Bressan Ray A. , Yun Dae-Jin , Hasegawa Paul M.
Published: April 2007

SIZ1 is a SUMO E3 ligase that facilitates conjugation of SUMO to protein substrates. siz1-2 and siz1-3 T-DNA insertion alleles that caused freezing and chilling sensitivities were complemented genetically by expressing SIZ1, indicating that the SIZ1 is a controller of low temperature adaptation in plants. Cold-induced expression of CBF/DREB1, particularly of CBF3/DREB1A, and of the regulon genes was repressed by siz1. siz1 did not affect expression of ICE1, which encodes a MYC transcription factor that is a controller of CBF3/DREB1A. A K393R substitution in ICE1 [ICE1(K393R)] blocked SIZ1-mediated sumoylation in vitro and in protoplasts identifying the K393 residue as the principal site of SUMO conjugation. SIZ1-dependent sumoylation of ICE1 in protoplasts was moderately induced by cold. Sumoylation of recombinant ICE1 reduced polyubiquitination of the protein in vitro. ICE1(K393R) expression in wild-type plants repressed cold-induced CBF3/DREB1A expression and increased freezing sensitivity. Furthermore, expression of ICE1(K393R) induced transcript accumulation of MYB15, which encodes a MYB transcription factor that is a negative regulator of CBF/DREB1. SIZ1-dependent sumoylation of ICE1 may activate and/or stabilize the protein, facilitating expression of CBF3/DREB1A and repression of MYB15, leading to low temperature tolerance.
The Balance between Protein Synthesis and Degradation in Chloroplasts Determines Leaf Variegation inArabidopsis yellow variegatedMutants
Authors: Miura Eiko , Kato Yusuke , Matsushima Ryo , Albrecht Verónica , Laalami Soumaya , Sakamoto Wataru
Published: April 2007

An Arabidopsis thaliana leaf-variegated mutant yellow variegated2 (var2) results from loss of FtsH2, a major component of the chloroplast FtsH complex. FtsH is an ATP-dependent metalloprotease in thylakoid membranes and degrades several chloroplastic proteins. To understand the role of proteolysis by FtsH and mechanisms leading to leaf variegation, we characterized the second-site recessive mutation fu-gaeri1 (fug1) that suppressed leaf variegation of var2. Map-based cloning and subsequent characterization of the FUG1 locus demonstrated that it encodes a protein homologous to prokaryotic translation initiation factor 2 (cpIF2) located in chloroplasts. We show evidence that cpIF2 indeed functions in chloroplast protein synthesis in vivo. Suppression of leaf variegation by fug1 is observed not only in var2 but also in var1 (lacking FtsH5) and var1 var2. Thus, suppression of leaf variegation caused by loss of FtsHs is most likely attributed to reduced protein synthesis in chloroplasts. This hypothesis was further supported by the observation that another viable mutation in chloroplast translation elongation factor G also suppresses leaf variegation in var2. We propose that the balance between protein synthesis and degradation is one of the determining factors leading to the variegated phenotype in Arabidopsis leaves.
The DELLA Domain of GA INSENSITIVE Mediates the Interaction with the GA INSENSITIVE DWARF1A Gibberellin Receptor ofArabidopsis
Authors: Willige Björn C. , Ghosh Soumya , Nill Carola , Zourelidou Melina , Dohmann Esther M.N. , Maier Andreas , Schwechheimer Claus
Published: April 2007

Gibberellic acid (GA) promotes seed germination, elongation growth, and flowering time in plants. GA responses are repressed by DELLA proteins, which contain an N-terminal DELLA domain essential for GA-dependent proteasomal degradation of DELLA repressors. Mutations of or within the DELLA domain of DELLA repressors have been described for species including Arabidopsis thaliana, wheat (Triticum aestivum), maize (Zea mays), and barley (Hordeum vulgare), and we show that these mutations confer GA insensitivity when introduced into the Arabidopsis GA INSENSITIVE (GAI) DELLA repressor. We also demonstrate that Arabidopsis mutants lacking the three GA INSENSITIVE DWARF1 (GID1) GA receptor genes are GA insensitive with respect to GA-promoted growth responses, GA-promoted DELLA repressor degradation, and GA-regulated gene expression. Our genetic interaction studies indicate that GAI and its close homolog REPRESSOR OF ga1-3 are the major growth repressors in a GA receptor mutant background. We further demonstrate that the GA insensitivity of the GAI DELLA domain mutants is explained in all cases by the inability of the mutant proteins to interact with the GID1A GA receptor. Since we found that the GAI DELLA domain alone can mediate GA-dependent GID1A interactions, we propose that the DELLA domain functions as a receiver domain for activated GA receptors.
Effect of Phosphorus on Survival of
Escherichia coli
in Drinking Water Biofilms
Authors: Juhna Talis , Birzniece Dagne , Rubulis Janis
Published: April 2007

The effect of phosphorus addition on survival of
Escherichia coli
in an experimental drinking water distribution system was investigated. Higher phosphorus concentrations prolonged the survival of culturable
E. coli
in water and biofilms. Although phosphorus addition did not affect viable but not culturable (VBNC)
E. coli
in biofilms, these structures could act as a reservoir of VBNC forms of
E. coli
in drinking water distribution systems.
Salivaricin P, One of a Family of Two-Component Antilisterial Bacteriocins Produced by Intestinal Isolates of
Lactobacillus salivarius
Authors: Barrett Eoin , Hayes Maria , O'Connor Paula , Gardiner Gillian , Fitzgerald Gerald F. , Stanton Catherine , Ross R. Paul , Hill Colin
Published: April 2007

Lactobacillus salivarius
DPC6005, a porcine intestinal isolate, produces a two-component bacteriocin, salivaricin P, with homology to ABP-118 produced by a human probiotic
L. salivarius
strain. Indeed, molecular characterization revealed that while the peptides Sln1 and ABP-118α are identical, their companion peptides (Sln2 and ABP-118β, respectively) differ by two amino acids. This observation suggests that two-component bacteriocins may be a common feature of intestinal
L. salivarius
strains.
Evaluation of Two Surface Sampling Methods for Detection of
Erwinia herbicola
on a Variety of Materials by Culture and Quantitative PCR
Authors: Buttner Mark P. , Cruz Patricia , Stetzenbach Linda D. , Cronin Tracy
Published: April 2007

This research was designed to evaluate surface sampling protocols for use with culture and quantitative PCR (QPCR) amplification assay for detection of the gram-negative bacterial biothreat simulant
Erwinia herbicola
on a variety of surface materials. Surfaces selected for evaluation were wood laminate, glass and computer monitor screens, metal file cabinets, plastic arena seats, nylon seat cushions, finished concrete flooring, and vinyl tile flooring. Laboratory and test chamber studies were performed to evaluate two sampling methods, a sponge and a macrofoam swab, for detection of
E. herbicola
on surface materials. In laboratory trials, seven materials were inoculated with a known concentration of
E. herbicola
cells and samples were collected from the surfaces of the materials to determine sampling efficiencies. Culture analysis was ineffective for assessing
E. herbicola
collection efficiency because very few culturable cells were obtained from surface samples. QPCR demonstrated that
E. herbicola
DNA was present in high concentrations on all of the surface samples, and sampling efficiencies ranged from 0.7 to 52.2%, depending on the sampling method and the surface material. The swab was generally more efficient than the sponge for collection of
E. herbicola
from surfaces. Test chamber trials were also performed in which
E. herbicola
was aerosolized into the chamber and allowed to settle onto test materials. Surface sampling results supported those obtained in laboratory trials. The results of this study demonstrate the capabilities of QPCR to enhance the detection and enumeration of biocontaminants on surface materials and provide information on the comparability of sampling methods.
Regulation of Caffeate Respiration in the Acetogenic Bacterium
Acetobacterium woodii
Authors: Dilling Sabrina , Imkamp Frank , Schmidt Silke , Müller Volker
Published: April 2007

The anaerobic acetogenic bacterium
Acetobacterium woodii
can conserve energy by oxidation of various substrates coupled to either carbonate or caffeate respiration. We used a cell suspension system to study the regulation and kinetics of induction of caffeate respiration. After addition of caffeate to suspensions of fructose-grown cells, there was a lag phase of about 90 min before caffeate reduction commenced. However, in the presence of tetracycline caffeate was not reduced, indicating that de novo protein synthesis is required for the ability to respire caffeate. Induction also took place in the presence of CO
2
, and once a culture was induced, caffeate and CO
2
were used simultaneously as electron acceptors. Induction of caffeate reduction was also observed with H
2
plus CO
2
as the substrate, but the lag phase was much longer. Again, caffeate and CO
2
were used simultaneously as electron acceptors. In contrast, during oxidation of methyl groups derived from methanol or betaine, acetogenesis was the preferred energy-conserving pathway, and caffeate reduction started only after acetogenesis was completed. The differential flow of reductants was also observed with suspensions of resting cells in which caffeate reduction was induced prior to harvest of the cells. These cell suspensions utilized caffeate and CO
2
simultaneously with fructose or hydrogen as electron donors, but CO
2
was preferred over caffeate during methyl group oxidation. Caffeate-induced resting cells could reduce caffeate and also
p
-coumarate or ferulate with hydrogen as the electron donor.
p
-Coumarate or ferulate also served as an inducer for caffeate reduction. Interestingly, caffeate-induced cells reduced ferulate in the absence of an external reductant, indicating that caffeate also induces the enzymes required for oxidation of the methyl group of ferulate.
Clonothrix fuscaRoze 1896, a Filamentous, Sheathed, Methanotrophic γ-Proteobacterium
Authors: Vigliotta Giovanni , Nutricati Eliana , Carata Elisabetta , Tredici Salvatore M. , De Stefano Mario , Pontieri Paola , Massardo Domenica Rita , Prati Maria Vittoria , De Bellis Luigi , Alifano Pietro
Published: April 2007

Crenothrix polysporaCohn 1870 andClonothrix fuscaRoze 1896 are two filamentous, sheathed microorganisms exhibiting complex morphological differentiation, whose phylogeny and physiology have been obscure for a long time due to the inability to cultivate them. Very recently, DNA sequencing data from unculturedC. polyspora-enriched material have suggested thatCrenothrixis a methane-oxidizing γ-proteobacterium (39). In contrast, the possible ecological function ofC. fusca, originally considered a developmental stage ofC. polyspora, is unknown. In this study, temporal succession of two filamentous, sheathed microorganisms resembling Cohn'sCrenothrixand Roze'sClonothrixwas observed by analyzing the microbial community of an artesian well by optical microscopy. Combined culture-based and culture-independent approaches enabled us to assignC. fuscato a novel subgroup of methane-oxidizing γ-proteobacteria distinct from that ofC. polyspora. This assignment was supported by (i) methane uptake and assimilation experiments, (ii) ultrastructural data showing the presence inC. fuscacytoplasm of an elaborate membrane system resembling that of methanotrophic γ-proteobacteria, and (iii) sequencing data demonstrating the presence in its genome of a methanol dehydrogenase α subunit-encoding gene (mxaF) and a conventional particulate methane mono-oxygenase α subunit-encoding gene (pmoA) that is different from the unusualpmoA(u-pmoA) ofC. polyspora.
Chlamydomonas reinhardtii
CNX1E Reconstitutes Molybdenum Cofactor Biosynthesis in
Escherichia coli
Mutants
Authors: Llamas Ángel , Tejada-Jimenez Manuel , González-Ballester David , Higuera José Javier , Schwarz Guenter , Galván Aurora , Fernández Emilio
Published: April 2007

We have isolated and characterized the
Chlamydomonas reinhardtii
genes for molybdenum cofactor biosynthesis, namely,
CNX1G
and
CNX1E
, and expressed them and their chimeric fusions in
Chlamydomonas
and
Escherichia coli
. In all cases, the wild-type phenotype was restored in individual mutants as well as in a
CNX1G CNX1E
double mutant. Therefore, CrCNX1E is the first eukaryotic protein able to complement an
E. coli moeA
mutant.
Barrier Activity in
Candida albicans
Mediates Pheromone Degradation and Promotes Mating
Authors: Schaefer Dana , Côte Pierre , Whiteway Malcolm , Bennett Richard J.
Published: April 2007

Mating in
Candida albicans
and
Saccharomyces cerevisiae
is regulated by the secretion of peptide pheromones that initiate the mating process. An important regulator of pheromone activity in
S. cerevisiae
is barrier activity, involving an extracellular aspartyl protease encoded by the
BAR1
gene that degrades the alpha pheromone. We have characterized an equivalent barrier activity in
C. albicans
and demonstrate that the loss of
C. albicans BAR1
activity results in opaque
a
cells exhibiting hypersensitivity to alpha pheromone. Hypersensitivity to pheromone is clearly seen in halo assays; in response to alpha pheromone, a lawn of
C. albicans
Δ
bar1
mutant cells produces a marked zone in which cell growth is inhibited, whereas wild-type strains fail to show halo formation.
C. albicans
mutants lacking
BAR1
also exhibit a striking mating defect in
a
cells, but not in α cells, due to overstimulation of the response to alpha pheromone. The block to mating occurs prior to cell fusion, as very few mating zygotes were observed in mixes of Δ
bar1
a
and α cells. Finally, in a barrier assay using a highly pheromone-sensitive strain, we were able to demonstrate that barrier activity in
C. albicans
is dependent on Bar1p. These studies reveal that a barrier activity to alpha pheromone exists in
C. albicans
and that the activity is analogous to that caused by Bar1p in
S. cerevisiae
.
Role of SP65 in Assembly of the
Dictyostelium discoideum
Spore Coat
Authors: Metcalf Talibah , van der Wel Hanke , Escalante Ricardo , Sastre Leandro , West Christopher M.
Published: April 2007

Like the cyst walls of other protists, the spore coat of
Dictyostelium discoideum
is formed de novo to protect the enclosed dormant cell from stress. Spore coat assembly is initiated by exocytosis of protein and polysaccharide precursors at the cell surface, followed by the infusion of nascent cellulose fibrils, resulting in an asymmetrical trilaminar sandwich with cellulose filling the middle layer. A molecular complex consisting of cellulose and two proteins, SP85 and SP65, is associated with the inner and middle layers and is required for proper organization of distinct proteins in the outer layer. Here we show that, unlike SP85 and other protein precursors, which are stored in prespore vesicles, SP65 is, like cellulose, synthesized just in time. By tagging the SP65 locus with green fluorescent protein, we find that SP65 is delivered to the cell surface via largely distinct vesicles, suggesting that separate delivery of components of the cellulose-SP85-SP65 complex regulates its formation at the cell surface. In support of previous in vivo studies, recombinant SP65 and SP85 are shown to interact directly. In addition, truncation of SP65 causes a defect of the outer layer permeability barrier as seen previously for SP85 mutants. These observations suggest that assembly of the cellulose-SP85-SP65 triad at the cell surface is biosynthetically regulated both temporally and spatially and that the complex contributes an essential function to outer layer architecture and function.
Flagellar Motility and Structure in the Hyperthermoacidophilic Archaeon
Sulfolobus solfataricus
Authors: Szabó Zalán , Sani Musa , Groeneveld Maarten , Zolghadr Benham , Schelert James , Albers Sonja-Verena , Blum Paul , Boekema Egbert J. , Driessen Arnold J. M.
Published: April 2007

Flagellation in archaea is widespread and is involved in swimming motility. Here, we demonstrate that the structural flagellin gene from the crenarchaeaon
Sulfolobus solfataricus
is highly expressed in stationary-phase-grown cells and under unfavorable nutritional conditions. A mutant in a flagellar auxiliary gene,
flaJ
, was found to be nonmotile. Electron microscopic imaging of the flagellum indicates that the filaments are composed of right-handed helices.
Molecular Interaction between Lipoteichoic Acids and
Lactobacillus delbrueckii
Phages Depends on
d
-Alanyl and α-Glucose Substitution of Poly(Glycerophosphate) Backbones
Authors: Räisänen Liisa , Draing Christian , Pfitzenmaier Markus , Schubert Karin , Jaakonsaari Tiina , von Aulock Sonja , Hartung Thomas , Alatossava Tapani
Published: April 2007

Lipoteichoic acids (LTAs) have been shown to act as bacterial counterparts to the receptor binding proteins of LL-H, LL-H host range mutant LL-H-a21, and JCL1032. Here we have used LTAs purified by hydrophobic interaction chromatography from different phage-resistant and -sensitive strains of
Lactobacillus delbrueckii
subsp.
lactis.
Nuclear magnetic resonance analyses revealed variation in the degree of α-glucosyl and
d
-alanyl substitution of the 1,3-linked poly(glycerophosphate) LTAs between the phage-sensitive and phage-resistant strains. Inactivation of phages was less effective if there was a high level of
d
-alanine residues in the LTA backbones. Prior incubation of the LTAs with α-glucose-specific lectin inhibited the LL-H phage inactivation. The overall level of decoration or the specific spatial combination of α-glucosyl-substituted,
d
-alanyl-substituted, and nonsubstituted glycerol residues may also affect phage adsorption.