bluuebunny/crossref_metadata_2025 huggingface dataset:
Animal Model for Cholesteatoma Induced in the Gerbil: Will the Profiles of Differentiation/Growth‐Regulatory Markers be Similar to the Clinical Situation?
Authors: Choufani Georges , Roper Nicolas , Delbrouck Carine , Hassid Sergio , Gabius Hans‐Joachim
Published: March 2007

Introduction: Cholesteatoma is a benign tumor of the middle ear characterized by an aggressive and invasive potential. The only current treatment being surgery, it is important to have access to a reliable animal model to study and better understand cholesteatoma pathogenesis. Our study aimed to examine the biological validity of the most common experimental model of cholesteatoma: the Mongolian gerbil.

Material and Methods: We have induced cholesteatoma by surgical ligature of the gerbil's external auditory duct. Quantitative comparison of eight biological markers involved in inflammation (macrophage migration inhibitory factor [MIF]), cell differentiation (retinoic acid receptors‐α, ‐β, and ‐γ), and cell adhesion/apoptosis (galectins‐1, ‐3, ‐7, and ‐8). The immunohistochemical staining was quantified by computer‐assisted microscopy.

Results: Two immunohistochemical parameters were determined in sections. The labeling index (LI) represents the percentage of tissue area specifically stained, and the mean optical density (MOD) denotes the staining intensity index. The LI reveals statistically significant differences for each marker tested. The MOD also shows statistically significant differences except for MIF (P = .259).

Conclusion: From the panel of markers, the majority of staining parameters was statistically significantly different between sections of the animal model and clinical specimen. These data do not support the concept of complete validity of the popular animal model.
Flexible Laryngoscopy‐Guided Pharyngeal pH Monitoring in Infants
Authors: Ulualp Seckin O. , Rodriguez Sarah , Holmes‐Wright Camysha N.
Published: March 2007

Objective: To evaluate flexible laryngoscopy‐guided pharyngeal pH probe monitoring as an alternative accurate and practical pharyngeal pH probe placement technique to eliminate the need for radiographs and esophageal manometry for pharyngeal pH monitoring in infants with extraesophageal reflux disease (EERD).

Materials and Methods: Infants with suspected laryngopharyngeal acid reflux (LPR) who underwent pharyngoesophageal pH monitoring were included. Data analysis included description of the flexible laryngoscopy‐guided pharyngoesophageal pH monitoring technique and pharyngoesophageal pH monitoring findings, including the number of acid reflux episodes and percent acid exposure time.

Results: Six infants (3 boys, 3 girls, age range, 2 wk–7.5 mo) with suspected LPR underwent pharyngoesophageal pH monitoring. Flexible laryngoscopy was used, under direct vision, to guide pH probe placement in the laryngopharyngeal region. The esophageal pH probe was located 5 cm distal to the pharyngeal pH probe. All infants tolerated the procedure. Of the six infants, four had pharyngeal acid reflux, and six had esophageal acid reflux. The number of acid reflux episodes ranged from 4 to 81 in the pharynx and from 5 to 173 in the esophagus. The percentage of acid exposure time was between 0% and 1.2% in the pharynx and between 0.1% and 1.5% in the esophagus.

Conclusion: With the aid of flexible laryngoscopy, a pH probe can be placed in the laryngopharyngeal region in infants undergoing pharyngeal pH monitoring. Findings documented that not all esophageal acid reflux reach the pharynx. Flexible laryngoscopy‐guided pharyngeal pH probe placement can be used to detect LPR in infants with EERD.
Learning by doing
Authors: Durrani Shiraz
Published: March 2007

Purpose – The purpose of this paper is to examine the changes in the way information management is taught at the Department of Applied Social Science (DASS) in the context of a fast‐changing world situation. It looks at the way reflective learning is being incorporated in teaching and provides some details of projects and modules which incorporate reflective learning in teaching and learning programmes. Design/methodology/approach – The paper examines the changing global situation to which a university education needs to respond. It then focuses on the information field and gives details of the way in which some new projects and modules are being developed to meet new challenges. Findings – As this is ongoing work, a final analysis is not possible at this stage. External evaluation of the Quality Leaders Project (QLP) will provide further assessment of this approach and responses from employers and students will further inform the direction of this approach. Practical implications – The paper highlights the need for change in the teaching of information management. Changes in curricula and learning practices at universities and direct intervention through pilot projects can offer one solution. The experience gained has the potential of developing a new teaching model with lifelong learning at its core. Originality/value – This paper brings ideas and practices from teaching, learning and management to the information sector. It will be of interest to a number of professions: teaching, management, lifelong learning and information as well as political activists and organisations whose learning needs are largely ignored in the mainstream education systems.
Quality assurance: a study of the primary poultry producers' perspective
Authors: Manning L. , Baines R.N. , Chadd S.A.
Published: March 2007

Purpose

Quality assurance (QA) is considered to be a proven mechanism for delivering quality of product and service. This paper seeks to analyse how poultry producers view the benefits of the implementation of QA mechanisms in the poultry supply chain.

Design/methodology/approach

Initially, an information audit was undertaken to examine the recent developments in the area of research. The second stage involved qualitative and quantitative primary research. The poultry producers' attitudes were collected by means of a questionnaire. Attitudes were studied on two occasions. The data obtained from the study was analysed by a comparison of two means and then calculating the standard error of the difference in means.

Findings

This research has demonstrated that producers are primarily complying with farm assurance standards in order to maintain market access. In general, they have to date seen no other organisational or financial benefit of compliance other than continuing to supply their retail customers.

Research limitations/implications

Limitations concerning sample size, and possible skewing of respondent responses are discussed.

Originality/value

This research is of academic value and of value to those working in the food supply chain.
Nutritional profile of pizza commonly consumed in Bahrain
Authors: Musaiger Abdulrahman O. , D'souza Varghese Reshma , Al‐Jedah Jassim H.
Published: March 2007

Purpose

This paper seeks to determine the proximate, mineral, sterol composition, and fatty acid profile of pizzas commonly consumed in Bahrain.

Design/methodology/approach

Five different types of pizza were purchased from various food outlets in Manama city, the capital of Bahrain. Proximate composition was determined by measuring the moisture, ash, fat, protein (N × 6.25), crude fiber, and carbohydrate content. The elements Ca, Mg, Na, Fe, Zn, Cu, and Mn were measured using the flame system, while fatty acids were analyzed by gas liquid chromatography (GLC) as their methyl esters, and sterols in the extracted fat were determined quantitatively by GLC.

Findings

On a fresh weight basis the dishes contained 47.50‐63.22 per cent w/w moisture, 8.25‐13.45 per cent w/w protein (N × 6.25), 8.43‐11.35 per cent w/w fat, and 11.76‐28.75 per cent w/w carbohydrates. The energy value ranged from 187.43‐259.60kcal (784.20‐1,086.18kJ)/100g, while a significant variation in the fiber and ash content was not observed. Of the minerals tested sodium (4,301.0‐5,315.3ppm), calcium (1,431.3‐2,143.2ppm), iron (9.10‐22.712ppm), and zinc (10.85‐17.65ppm) were the most prominent, while potassium, magnesium, and manganese were considerably lower. Analysis of sterol composition showed that cholesterol (9.87‐20.91mg/100g) and β‐sitosterol (5.91‐9.65mg/100g) were the most prominent sterols, whilst the presence of campesterol and stigmasterol was low. The main fatty acids present were oleic (22.10‐32.40mg/100g) and palmitic acid (24.0‐26.7mg/100g), while considerable amount of linoleic, stearic, and myristic acids were also present.

Originality/value

Despite the popular misconception regarding the nutritional value of fast foods like pizzas, the pizza commonly consumed in Bahrain could be a considerable source of nutrition and make nutritional contribution to the diet, if eaten in moderation.
An assessment of food consumption within urban households in Osun State, Nigeria
Authors: Funke Olumakaiye Montunrayo
Published: March 2007

Purpose

Malnutrition affects one out of every three individuals living in developing countries. This disturbing state of affairs causes untold suffering. Little attention has been paid to the general food consumption within households in the developing countries. This study therefore aims to focus on the food consumption of urban households in Osun State, Nigeria.

Design/methodology/approach

One‐hundred‐and‐fifty‐eight nuclear households were purposively selected, which contained an average of four to six household members. Structured interview Schedule was used to collect information on the socioeconomic characteristics of the respondents, while a chart designed to collect information on daily individual food intake was also used. Statistical techniques like frequency count and percentage were used in data quantification of socioeconomic characteristics, while food composition table was used to analyse the Recommended Dietary Allowance met by the respondents.Findings – The results indicated that the body mass index (BMI) of women between the age range of 21 and 40 was 17.89, which implied mild malnutrition, while women who are 40 years and above had BMI of 18.64 which was marginal, whereas, their male counterparts of the same age ranges were normal with BMI of 23.69 and 20.81, respectively. Other age groups in the households had relatively normal BMI.

Research limitations/implications

The limitation of the research was that it only assessed nuclear households in urban areas. Future study could include extended and polygamous households in both urban and rural areas.

Originality/value

This research established the facts that women of reproductive age tend towards being malnourished as a result of inadequate nutrients intake and this could be corrected through effective nutrition education.
The practical aspects of British companies establishing and developing business in Poland
Authors: Adams Nigel
Published: March 2007

Purpose

The purpose of this case study is to provide information on the practical aspects of British companies establishing and developing business in Poland.

Design/methodology/approach

The case study is based on the author's experience, assisting and working with British companies to establish businesses that have developed successfully in Poland.

Findings

Investing in Poland has been a success story for Beck & Pollitzer Engineering Ltd. The move to Poland has been in line with the European market expansion strategy of the company and has benefited from developing business operations in a market with high growth potential. The access to qualified and comparatively cheap labour force in Poland has reduced the overall cost of the investment. Moreover, the market access to the Russian buyers via the Polish company has provided an additional value‐added to the British company.

Research limitations/implications

The single case study and related managerial experience give company specific information that is difficult to be generalised.

Practical implications

Shows that a medium‐sized British company can succeed in a volatile foreign market.

Originality/value

The case study provides a manager's perspective of a company's expansion into the dynamic Polish market.
Consumer attitudes and behaviors associated with direct‐to‐consumer prescription drug marketing
Authors: Friedman Michael , Gould James
Published: March 2007

Purpose

This article seeks to examine attitudes about direct‐to‐consumer advertising (DTCA) of prescription drugs to final users (referred to as consumers in this paper).

Design/methodology/approach

A national telephone survey was carried out of 300 consumers that had seen a doctor in the last six months.

Findings

Consumer awareness of DTCA continues at a very high level (96 percent) among the adult consumer population. However, the majority of consumers (53 percent) disagreed somewhat or strongly with the statement “I like seeing advertisements directed to consumers for prescription drugs.” The majority of consumers (69 percent) agree strongly or somewhat that DTCA does not provide adequate information on the risks and benefits of advertised products. It appears that the use of DTCA by pharmaceutical companies is not stimulating nearly the information‐gathering response reported in past studies.

Research limitations/implications

Small sample size makes this survey exploratory.

Practical implications

This negativism may impair the usefulness of this type of advertising in the future. As television, magazine, radio, and other traditional media become less important, the internet may become an important channel for the growth of DTCA. Given the growing negativism of consumers, it is clear that significant changes in DTCA practices are necessary. Without significant changes, DTCA may become impractical or even prohibited.

Originality/value

The article adds to longitudinal data on consumer attitudes towards DTCA. It is hoped that this study will suggest areas for subsequent research and will elaborate on the practical consequences of DTCA and its implications for public health and welfare.
The Mindcam methodology: perceiving through the native's eye
Authors: Starr Richard G. , Fernandez Karen V.
Published: March 2007

Purpose

Consumer researchers and marketing practitioners increasingly appreciate the potential of videography to generate better insights into consumers' behaviours. The purpose of this paper is to introduce the Mindcam research methodology as an addition to the videographers tool‐kit, which uniquely records and interprets videographic data from a first‐person perspective.

Design/methodology/approach

The philosophical rationale for collecting observational data from the informant's perspective is presented. A full description is provided of an innovative research method that allows market researchers to observe, record and interpret consumers' experiences from the informants' literal and figurative viewpoints. The technical and ethical issues that should be addressed when using this methodology are specified.

Findings

Observational research presently shapes and edits data as it is collected, filtering others' behaviour through the researcher's perspective to generate interpretive insights. Recording consumers' lived reality, from their own unedited perspective, allows the consumer experience to be re‐lived by the researcher. This assists in generating a negotiated interpretation of the consumer's reality. Findings are not constrained by the researcher's perspective of the informants' reality.

Originality/value

This new method integrates own‐perspective videography with post‐hoc visual elicitation, thereby generating informant‐driven perspectives of their own lived consumption reality. Dual‐mode presentation of the data (original experience with the informant's interpretation) enables viewers to judge the truthfulness of the interviewer‐informant negotiated interpretation of the informant's lived consumption reality. Enough information is provided for others to employ the Mindcam method in their own research.
A framework for evaluating knowledge‐mapping tools
Authors: Driessen Samuel , Huijsen Willem‐Olaf , Grootveld Marjan
Published: March 2007

Purpose

This article describes the knowledge‐mapping framework the authors designed based on their theoretical and practical research on knowledge mapping. It also shows the practical use of the Framework for companies interested in knowledge‐mapping tools.

Design/methodology/approach

In the first place the authors position their research in the context of knowledge management and knowledge‐mapping research and practice. An example of their practical research on knowledge mapping is given as a preliminary step to describe their knowledge‐mapping framework. The use of this framework is illustrated. Finally, the authors validate their framework against a number of commercially available tools with knowledge‐mapping functionality.

Findings

The authors found that their framework is useful, insightful and robust when applied to new knowledge‐mapping tools/functionality.

Research limitations/implications

The important issue how to embed knowledge‐mapping tools in organizations is not considered to be in the scope of this article.

Practical implications

Based on concrete examples the authors illustrate the practical implications of their knowledge‐mapping framework for companies. The Framework can be used for defining knowledge‐mapping tool requirements, the assessment and comparison of commercial tools, and the assessment of available knowledge in an organization.

Originality/value

Knowledge mapping and its use have been a research issue for some time. Companies have also adopted knowledge‐mapping tools to support and stimulate knowledge sharing in their organizations and to help employees find the expertise they are looking for. But no research has been done on how to help companies decide what kind of knowledge‐mapping tool they need or how any tools they already have can be combined in a knowledge‐mapping tool. This article describes a unique and new Framework the authors devised to help companies do just that.
The impact of e‐resources at Bournemouth University 2004/2006
Authors: Beard Jill , Dale Penny , Hutchins Jonathan
Published: March 2007

Purpose

The purpose of this paper is to survey the impact of electronic resources on the learning and teaching community of Bournemouth University.

Design/methodology/approach

Action research was used over a two‐year period, with the results from one academic school were compared the following year with the results from two other schools.

Findings

The findings in the paper show how the use of, and enthusiasm for, electronic resources is widespread amongst students and staff.

Originality/value

The paper demonstrates the effectiveness and value in using action research to assess service offerings.
Purchaser‐provider interaction in UK public health: improving stakeholder cooperation
Authors: Carruthers Janet , Rod Michel , Ashill Nicholas J.
Published: March 2007

Purpose

The purpose of this paper is to examine the bases of positive relations between suppliers and purchasers of healthcare services. In doing so, it examines the nature of cooperation between the providers of healthcare services (hospitals) and those who commission and purchase healthcare on behalf of patients (regional health authorities) and makes specific recommendations as to how cooperation can be better realized.

Design/methodology/approach

The paper employs a qualitative interview approach for gathering and analyzing major stakeholder (provider and purchaser) perceptions of their interorganizational relations and how these interactions impact on the quest of the healthcare provider to meet the needs of the community they serve.

Findings

The paper identifies and groups relevant variables into four major themes or “core categories” that characterize purchaser‐provider stakeholder cooperation. These themes represent provider and purchaser views on those factors characterising stakeholder relationships within the purchaser‐provider dyad. This is followed by a number of suggestions as to how to improve the nature of cooperation between these stakeholders.

Practical implications

Extending practitioners' understanding of the nature of these inter‐related factors may lead to better insights of how interorganizational relations and partnerships might be managed more proactively throughout the healthcare value chain. Strategies to foster stakeholder cooperation are also suggested.

Originality/value

In the extant literature, there is a paucity of research that has illustrated multi‐stakeholder perspectives in the public sector. This paper explores the perceptions of two main stakeholders in public healthcare to map and assess management issues influencing purchaser‐provider cooperation.
Destination image and destination personality
Authors: Hosany Sameer , Ekinci Yuksel , Uysal Muzaffer
Published: March 2007

Purpose

To examine the contentious relationship between brand image and brand personality in the context of tourism destinations.

Design/methodology/approach

The paper reviews the literature on brand (destination) image, brand (destination) personality and identifies examples of definitional inconsistencies and instances where the terms brand image and brand personality are used interchangeably. Two studies were carried out to investigate the relationship between the two constructs. Data were analysed using canonical correlation.

Findings

Results indicate that destination image and destination personality are related concepts. Canonical correlation analyses reveal that the emotional component of destination image captures the majority of variance on destination personality dimensions.

Research limitations/implications

Academics must pay particular attention at distinguishing between brand image and brand personality, since, failure to do so, will hinder research progress and result in poor conceptual developments.

Practical implications

Destination marketers can focus on the commonality between destination image and destination personality in order to communicate unique destination features and to influence tourist behavior.

Originality/value

This paper fills a gap in the generic branding literature by adopting an empirical stance at delineating the relationship between brand image and brand personality in the context of tourism destinations.
Exploring consumers' responses to service providers' positive affective displays
Authors: Gountas Sandra , Ewing Michael T. , Gountas John I.
Published: March 2007

Purpose

To discuss the importance of the relationship between service providers' positive affective displays, the value of a “real” smile within the consumers' perception of authentic service delivery and how these relate to satisfaction and future intentions.

Design/methodology/approach

The literature review discusses underpinning theory concerning the role of expressive display in service provision. In particular the importance of authenticity is explored through qualitative and quantitative research in an extended duration service setting. The quantitative data are analysed using SPSS and path modelling (AMOS).

Findings

The findings indicate a strong positive relationship between affective displays (including the “real” smile), overall service satisfaction and life satisfaction.

Research limitations/implications

The study advances existing research and raises suggestions for future research including how personality differences may affect the service provider's ability to interact with their customers appropriately.

Practical implications

The wider implications for marketing practitioners are concerned with the services marketing mix. The authors suggest ways that managers may improve interactive service standards.

Originality/value

The literature reveals no other study that has quantified the value of a “real” smile within expressive display.
Social capital as a club good: the case of ethnic communities and entrepreneurship
Authors: Galbraith Craig S. , Rodriguez Carlos L. , Stiles Curt H.
Published: March 2007

Purpose

The purpose of this paper is to offer the economic theory of clubs as a potential unifying paradigm for the study of ethnic economies and social capital.

Design/methodology/approach

The paper examines the basic concepts of club theory, and reviews the empirical literature. It then applies club theory to the notion of social capital within the context of ethnic communities. It is argued that although various sociological frameworks of social capital and social networks have provided powerful descriptive models of ethnic and immigrant population behaviors, social capital needs to be examined from an economic perspective to increase prescriptive capabilities.

Findings

Using club theory the paper conceptualizes the benefits derived from an ethnic grouping – among which social capital can be considered the most important – as a “club” good, supplied at the co‐ethnic level and demanded by the various key stakeholders within an ethnic community. While these benefits are at least partially non‐rivalrous, they have clear characteristics of excludability and therefore form a “pseudo‐public” good. Four propositions are then offered regarding the behavior of ethnic entrepreneurs who draw from these important ethnic resources.

Originality/value

This paper offers a new way to examine social capital within ethnic communities. It also provides an economic foundation to begin analyzing optimal economic and social structures within these communities.
IGF2 gene characterization and association with rib eye area in beef cattle
Authors: Goodall J. J. , Schmutz S. M.
Published: March 2007

Insulin‐like growth factor 2 (IGF2) is an imprinted gene expressed in most tissues affecting lean muscle content in mice, pigs and cattle. We previously identified the bovine IGF2 c.‐292C>T SNP in the non‐translated exon 2. Using this SNP, we demonstrated biallelic expression of IGF2 after birth. Seven alternatively spliced mRNA transcripts of IGF2 were expressed among 15 tissues. An IGF2 pseudogene (ψIGF2) was identified with sequence identical to at least IGF2 exons 2 and 3 without the intervening intron. The biallelic expression of this c.‐292C>T SNP was associated with an increase in rib eye area (REA) in two populations of cattle, with the C.‐292C allele associated with a 10% increase. A significant association with per cent fat was found in one of the populations.
Population structure of the freshwater flatworm Crenobia alpina (Dana): old lineages and low gene flow
Authors: Brändle Martin , Heuser Roland , Marten Andreas , Brandl Roland
Published: March 2007

Aim  The freshwater flatworm Crenobia alpina lives almost exclusively in headwaters of mountainous areas and is supposed to be a glacial relict. We examined genetic diversity within and between populations of C. alpina in order to determine the taxonomic status of purported subspecies and to understand large‐scale biogeographical patterns of glacial relicts.

Location  Central Europe.

Methods  We analysed mitochondrial DNA sequences and polymorphic allozyme loci of C. alpina populations across its range in central Europe. Sequences were compared using parsimony, minimum evolution and maximum likelihood. Allozymes were analysed using traditional as well as Bayesian estimates of F statistics.

Results  We found considerable divergence between haplotypes. For each of the two lineages occurring throughout central Europe, allozymes showed considerable differentiation between populations and a strong isolation by distance effect. Hence populations are effectively isolated even across rather small spatial scales.

Main conclusions  There is strong evidence that C. alpina is a complex of distinct lineages or cryptic species that date back to the late Miocene. The separation of lineages may be associated with the formation of deep valleys at the end of the Messinian Crisis.
Literature review of nursing practice in managing obesity in primary care: developments in the UK
Authors: Brown Ian , Psarou Aitkaterini
Published: March 2007

Aims and objectives. To review empirical studies reporting primary care nursing practice in relation to obesity management for adults in the UK; to place these in the context of policy and professional developments.

Background. Obesity is recognized as a public health problem in many parts of the world. The UK has a well‐developed system of primary care nursing with experience of initiatives to tackle obesity.

Methods. Searches of electronic databases supplemented by hand‐searching of identified leads and key journals. Data extracted and analysed following methods for an integrative literature review.

Findings. Eleven empirical studies were reviewed. Obesity management developed as part of the role of general practice nurses after 1990. Nurses’ role has been mainly in providing one‐to‐one support to within surgery or clinic consultations; and to a lesser extent group based support sessions. The interventions could be characterized as general oral advice about nutrition and lifestyle. There was no evidence of positive outcomes for patients from these interventions. In some contexts, oral advice extended to calorie deficit diets and more developed referral options about physical activity. Two studies examined outcomes of practice following attempts to implement evidence‐based protocols. The evidence of outcomes from these is mixed. At best, perhaps 10% of patients entering a nurse led support programme may achieve a clinically significant weight loss.

Conclusions. There is potential in primary care nursing to help patients manage obesity but caution is needed. Despite practice developments in the UK the outcomes for patients remain unclear.

Relevance to clinical practice. It is important to follow a structured programme in supporting patients with weight loss within an holistic assessment of their needs.
Phylogeography of the white‐breasted nuthatch (Sitta carolinensis): diversification in North American pine and oak woodlands
Authors: SPELLMAN GARTH M. , KLICKA JOHN
Published: March 2007

Pine and oak woodlands are common North American floral communities with distinct regional species composition. The white‐breasted nuthatch (Aves: Sitta carolinensis) is a common resident bird of North American pine and oak woodlands, and is distributed continentally across the highly disjunct distribution of these woodlands. We propose three historical hypotheses to explain the evolution of the white‐breasted nuthatch in its principal habitat. (i) The species evolved in situ in the regional pine–oak communities and the isolation of populations in these regions is captured in cryptic genetic variation. (ii) Migration of individuals between regions is frequent enough to maintain the widespread distributions and prevent regional divergence. (iii) The species have recently expanded to occupy their current distributions and an insufficient amount of time has passed for divergence to occur. Phylogenetic analysis of mitochondrial DNA (ND2 gene) variation (N = 216) in the white‐breasted nuthatch reveals four reciprocally monophyletic clades concordant with the distribution of the regional North American pine and oak woodlands, and supports hypothesis 1 of in situ evolution of populations in the regional pine and oak communities. Within‐clade population structure and demographic history are also discussed.
In vivo and ex vivo comparative transcriptional profiling of invasive and non‐invasive Candida albicans isolates identifies genes associated with tissue invasion
Authors: Thewes Sascha , Kretschmar Marianne , Park Hyunsook , Schaller Martin , Filler Scott G. , Hube Bernhard
Published: March 2007

The human pathogenic fungus Candida albicans can cause a wide range of infections and invade multiple organs. To identify C. albicans genes that are expressed during invasion of the liver, we used genome‐wide transcriptional profiling in vivo and ex vivo. By analysing the different phases of intraperitoneal infection from attachment to tissue penetration in a time‐course experiment and by comparing the profiles of an invasive with those of a non‐invasive strain, we identified genes and transcriptional pattern which are associated with the invasion process. This includes genes involved in metabolism, stress, and nutrient uptake, as well as transcriptional programmes regulating morphology and environmental sensing. One of the genes identified as associated with liver invasion was DFG16, a gene crucial for pH‐dependent hyphal formation, correct pH sensing, invasion at physiological pH and systemic infection.
Domain swapping reveals that the C‐ and N‐terminal domains of DnaG and DnaB, respectively, are functional homologues
Authors: Chintakayala Kiran , Larson Marilynn A. , Grainger William H. , Scott David J. , Griep Mark A. , Hinrichs Steven H. , Soultanas Panos
Published: March 2007

The bacterial primase (DnaG)–helicase (DnaB) interaction is mediated by the C‐terminal domain of DnaG (p16) and a linker that joins the N‐ and C‐terminal domains (p17 and p33 respectively) of DnaB. The crystal and nuclear magnetic resonance structures of p16 from Escherichia coli and Bacillus stearothermophilus DnaG proteins revealed a unique structural homology with p17, despite the lack of amino acid sequence similarity. The functional significance of this is not clear. Here, we have employed a ‘domain swapping’ approach to replace p17 with its structural homologue p16 to create chimeras. p33 alone hydrolyses ATP but exhibits no helicase activity. Fusing p16 (p16‐p33) or DnaG (G‐p33) to the N‐terminus of p33 produced chimeras with partially restored helicase activities. Neither chimera interacted with DnaG. The p16‐p33 chimera formed hexamers while G‐p33 assembled into tetramers. Furthermore, G‐p33 and DnaB formed mixed oligomers with ATPase activity better than that of the DnaB/DnaG complex and helicase activity better than the sum of the individual DnaB and G‐p33 activities but worse than that of the DnaB/DnaG complex. Our combined data provide direct evidence that p16 and p17 are not only structural but also functional homologues, albeit their amino acid composition differences are likely to influence their precise roles.
TraA, TraC and TraD autorepress two divergent quorum‐regulated promoters near the transfer origin of the Ti plasmid of Agrobacterium tumefaciens
Authors: Cho Hongbaek , Winans Stephen C.
Published: March 2007

Whole‐genome transcriptional profiling experiments were performed to identify the complete set of TraR‐regulated genes in isogenic A. tumefaciens strains containing an octopine‐type or nopaline‐type Ti plasmid. Most of the known TraR‐regulated genes as well as a number of new inducible genes were identified. Surprisingly, some known members of this regulon showed both weaker induction and weak levels of expression than we had predicted based upon earlier studies. In particular, traA was expressed at surprisingly weak levels. Genetic analysis showed that the traAFBH operon is repressed by formation of a putative relaxosome at oriT consisting the TraA, TraC and TraD. These proteins also repressed the divergent traCDGyci operon. TraA was essential for oriT processing, and both TraC and TraD were necessary for the efficient processing, although some processing occurred in their absence. Likewise, Ti plasmid conjugation required TraA, TraF and TraG, and occurred at reduced levels in the absence of TraC or TraD. TraA preferentially acted in cis in repressing the traA and traC promoters and in the processing of oriT, which explains the very high activity of plasmid‐borne traA–lacZ fusions reported in previous studies.
Deciphering regulatory mechanisms for secondary metabolite production in the myxobacterium Sorangium cellulosum So ce56
Authors: Rachid Shwan , Gerth Klaus , Kochems Irene , Müller Rolf
Published: March 2007

Sorangium cellulosum strains produce approximately 50% of the biologically active secondary metabolites known from myxobacteria. These metabolites include several compounds of biotechnological importance such as the epothilones and chivosazols, which, respectively, stabilize the tubulin and actin skeletons of eukaryotic cells. S. cellulosum is characterized by its slow growth rate, and natural products are typically produced in low yield. In this study, biomagnetic bead separation of promoter‐binding proteins and subsequent inactivation experiments were employed to identify the chivosazol regulator, ChiR, as a positive regulator of chivosazol biosynthesis in the genome‐sequenced strain So ce56. Overexpression of chiR under the control of T7A1 promoter in a merodiploid mutant resulted in fivefold overproduction of chivosazol in a kinetic shake flask experiment, and 2.5‐fold overproduction by fermentation. Using quantitative reverse transcription PCR and gel shift experiments employing heterologously expressed ChiR, we have shown that transcription of the chivosazol biosynthetic genes (chiA–chiF) is directly controlled by this protein. In addition, we have demonstrated that ChiR serves as a pleiotropic regulator in S. cellulosum, because mutant strains lack the ability to develop into regular fruiting bodies.
A tale of two dead ends: origin of a potential new gene and a potential new transposable element
Authors: Clutterbuck A. John
Published: March 2007

An article in this issue of Molecular Microbiology by Cultrone et al. describes how a non‐autonomous helitron element could arise from its autonomous parent transposon by deletion followed by readthrough into an adjacent gene and its promoter, thus providing a mechanism for distribution of a specifically regulated promoter sequence around the genome, where it would have the potential to evolve new functions.
Modulation of host pH during the wheat–Fusarium culmorum interaction and its influence on the production and activity of pectolytic enzymes
Authors: Aleandri M. P. , Magro P. , Chilosi G.
Published: March 2007

The effect on ambient pH of Fusarium culmorum during its growth on mineral medium and in apoplastic fluids from infected wheat seedlings, and the effect on the production and activity of the enzymes pectin lyase (PNL) and polygalacturonase (PG), were investigated. Fungal development on a weakly buffered mineral medium in the pH range 5·0–8·0, with pectin as the sole carbon source, led to pronounced alkalinization, reaching values above 8·0. The increase in ambient pH was accompanied by enhancement of total PNL activity. Pectin lyase secretion was detected at pH 5·0 as a single isoenzyme. An additional isoenzyme was apparent during the increase in medium pH. Polygalacturonase was detected as a single isoenzyme only during early growth on medium buffered at pH 5·0. At this stage, the initial medium pH of 5·0, corresponding to the optimum pH for PG activity, appeared to be the most suitable for the activation of early production of this enzyme. During growth in acidified yeast extract medium the fungus secreted ammonia and increased medium pH. Similarly, in apoplastic fluids from inoculated seedlings the concomitant ammonia accumulation and rise in pH were recorded. This trend was accompanied by an increase in PNL, which could therefore function at close to its optimal pH. The results suggest that during infection of wheat seedlings by F. culmorum, pH modulation can lead to PNL production and activity, thus promoting colonization of host tissue.
Genotype‐isolate interaction for resistance to black stem in sunflower (Helianthus annuus)
Authors: Darvishzadeh R. , Dechamp‐Guillaume G. , Hewezi T. , Sarrafi A.
Published: March 2007

Two experiments were undertaken to determine the partial resistance of sunflower genotypes to seven isolates of Phoma macdonaldii. In the first experiment, 28 genotypes, including recombinant inbred lines and their parents, M6 mutant lines developed by gamma irradiation, and some genotypes from different geographical origins, were used. The experiment consisted of a split‐plot design with three replications, each with 12 seedlings per genotype per isolate, in controlled conditions. Seven days after inoculation, plantlets were scored on a 1–9 scale for percentage necrotic area. Highly significant differences were observed among genotypes, isolates and their interactions. The presence of a differential interaction between genotypes and P. macdonaldii isolates was confirmed in a second experiment using 12 genotypes representing large variability for partial resistance to P. macdonaldii isolates, as identified in the first experiment. Inbred lines B454/03, ENSAT‐B5 and LC1064C were the most susceptible sunflower genotypes, whereas two American lines SDR19 and SDR18 presented high partial resistance to all P. macdonaldii isolates studied. The least and most aggressive isolates were MA6 and MP3, respectively. Isolates interacted differentially with sunflower genotypes. This study identified two genotypes (AS613 and PAC2) presenting specific resistance to isolate MP8. The results also showed a wide range of isolate‐nonspecific partial resistances among the lines tested. The information presented here could assist sunflower breeders to choose parents of crosses for breeding of durable resistance to phoma black stem disease.
Aggressiveness of Phytophthora infestans and phenotypic analysis of resistance in wild Petota accessions in Ecuador
Authors: Chacón M. G. , Andrade‐Piedra J. L. , Gessler C. , Forbes G. A.
Published: March 2007

The aggressiveness of four Phytophthora infestans isolates collected from wild and cultivated potato species (sect. Petota) and the level of resistance of nine Petota species were assessed in the highland tropics of Ecuador. For this, isolates of P. infestans were inoculated on whole plants of Petota species in the field and net house and six epidemiological components – infection frequency (IF), incubation period (IP), latent period (LP), lesion size (LS), lesion growth rate (LGR), and relative area under the lesion expansion curve (RAULEC) – were measured during a single infection cycle. Additionally, host specificity was determined by testing for a significant host by pathogen interaction using the same components. The results showed significant differences among isolates of the EC‐1 clonal lineage for IP, IF, and RAULEC. Significant differences among isolates were not found for the other components measured. There were significant differences in resistance among the accessions of Petota hosts tested. RAULEC, LGR, LP, and LS were in general more adequate in differentiating among the more resistant and more susceptible accessions but the importance of each component varied with host species. There was slight and inconsistent evidence for the existence of host specificity in some isolates of Petota hosts. IP was the only component for which a significant host by isolate interaction was observed and in most cases the isolates had the greatest aggressiveness on their hosts of origin.
Genetic structure and spatial distribution of the mycoparasite Sphaerellopsis filum on Melampsora larici‐epitea in a short‐rotation coppice willow planting
Authors: Bayon C. , Pei M. H. , Ruiz C. , Hunter T.
Published: March 2007

AFLP analysis was used to examine the genetic structure of the mycoparasite Sphaerellopsis filum on willow rust Melampsora larici‐epitea using two sets of samples of a willow clone in a short‐rotation coppice planting. The first set was collected from a plot (short strip) in 1998, 1999 and 2000 and the second from another plot (long strip) in 2000. In all, 228 S. filum isolates were typed, 139 AFLP loci scored and 54 AFLP genotypes identified. In the short strip, genotypes sampled in 1998 were no longer detected in subsequent years and genotype diversity fluctuated (0·25–0·68) over the years, indicating that migration had a major impact on the genotype structure. Two distinct groups (average Nei and Li's similarity coefficient between the groups = 0·047) were identified. The group B genotypes were sampled only in 2000. Within the groups, the average similarities were > 0·96. Both the index of association test and the parsimony tree length permutation test suggest that there was a significant clonality in group A while recombination cannot be ruled out in group B. Localized clusters of AFLP genotypes were detected using the software SaTScan that is based on the spatial scan statistic. Possible mechanisms involved in the spread of S. filum in willow coppice plantations are discussed.
Potential physical and chemical barriers to infection by the burrowing nematode Radopholus similis in roots of susceptible and resistant banana (Musa spp.)
Authors: Wuyts N. , Lognay G. , Verscheure M. , Marlier M. , De Waele D. , Swennen R.
Published: March 2007

Resistance in banana roots against the burrowing nematode Radopholus similis has been correlated in the past with the phenylpropanoid pathway of secondary metabolism, but quantitative chemical analyses to support histological data are lacking. Therefore, healthy and infected roots of two susceptible (Grande naine and Obino l’ewai) and three resistant cultivars (Yangambi km5, Pisang jari buaya and Calcutta 4) were extracted and chemically analysed for their lignin content and phenylpropanoid profile using a quantitative lignin assay, high performance liquid chromatography and liquid chromatography/mass spectrometry. Through histochemical staining phenylpropanoids were localized in root tissue. Compared to the susceptible cultivars, the resistant cultivars had constitutively significantly higher levels of lignin in the vascular bundle and cell‐wall bound ferulic acid esters in the cortex. Infection‐induced lignification was observed in the vascular bundles of all cultivars. The catecholamine dopamine was identified as a major metabolite in banana roots. Levels varied from 2·8 to 8·4 mg per g root fresh weight and were significantly higher in the resistant cultivars. Other compounds, tentatively identified as anthocyanidin‐related, were present in high quantities and may, besides dopamine, make up the substrates for polyphenol oxidation products in necrotic tissue.
Do cuckoos choose nests of great reed warblers on the basis of host egg appearance?
Authors: CHERRY M. I. , BENNETT A. T. D. , MOSKÁT C.
Published: March 2007

Prevailing theory assumes cuckoos lay at random among host nests within a population, although it has been suggested that cuckoos could choose large nests and relatively active pairs within host populations. We tested the hypothesis that egg matching could be improved by cuckoos choosing nests in which host eggs more closely match their own, by assessing matching and monitoring nest fate in great reed warblers naturally or experimentally parasitized by eggs of European cuckoos. A positive correlation between cuckoo and host egg visual features suggests that cuckoos do not lay at random within a population, but choose nests and this improves egg matching: naturally parasitized cuckoo eggs were more similar to host eggs as perceived by humans and as measured by spectrophotometry. Our results suggest a hitherto overlooked step in cuckoo–host evolutionary arms races, and have nontrivial implications for the common experimental practice of artificially parasitizing clutches.