bluuebunny/crossref_metadata_2025 huggingface dataset:
Building information modelling demystified: does it make business sense to adopt BIM?
Authors: Aranda‐Mena Guillermo , Crawford John , Chevez Agustin , Froese Thomas
Published: June 2009

Purpose

The purpose of this paper is to inform project management practice on the business benefits of building information modelling (BIM) adoption.

Design/methodology/approach

BIM needs to compete against well‐ingrained methods to deliver projects in a fragmented and rather traditional industry. This paper investigates 47 value propositions for the adoption of BIM under a multiple case study investigation carried out in Australia and Hong Kong. The selected case study projects included a range of public (1) and private (4) sector building developments of small and large‐scale. Findings are coded, interpreted and synthesised in order to identify the challenges and business drivers, and the paper focuses mainly on challenges and benefits for architectural and engineering consultants, contractors and steel fabricators. As a condition for the selection criteria all case studies had to be collaborating by sharing BIM data between two or more consultants/stakeholders. As practices cannot afford to ignore BIM, this paper aims to identify those immediate business drivers as to provoke debate amongst the professional and academic community.

Findings

Shared understanding on business drivers to adopt BIM for managing the design and construction process of building projects raging from small commercial to high‐rise.

Originality/value

The originality of the research reported in this paper is that it breaks from a proliferating series of articles on BIM as industry “aspiration” and as a “marketing” statement. The elicited drivers for BIM underwent industry, academic and peer validation.
New approaches in project performance evaluation techniques
Authors: Bower Douglas C. , Finegan Andrew D.
Published: June 2009

Purpose

The purpose of this paper is to describe a Doctor of Project Management research study including summary of the literature review, the application of the combination of case study, survey and theory building research methodologies, key research findings and potential areas for future research.

Design/methodology/approach

The research investigates the reasons for the limited adoption of earned value management (EVM) as a project performance evaluation technique. It proposes new extensions to this technique that will be beneficial to project management practitioners. The multifaceted research approach incorporates the following elements: a review of previous and current literature on EVM; a survey of project management practitioners on their practices and attitudes towards EVM; analysis of the known challenges of the EVM technique; development of techniques to address and resolve the EVM challenges; consolidation of those techniques into a single framework and implementation model; and validation of that framework and model through multiple methods.

Findings

The research confirms that EVM can be greatly enhanced and simplified though three key initiatives: include the cost assurance (i.e. risk transfer) provided by procurement contracts; measure project achievement and progress on the completion of each phase, rather than monthly; and combine the above into a simplified, single model.

Originality/value

This paper provides practitioners with an insight into how EVM can be enhanced and applied in project management organisations. In particular, the integrated PAVA technique should be particularly useful to projects using the rolling wave approach, as its recognition of phases provides a framework for short‐ and long‐term planning.
Investigating the deployment of project management
Authors: Yatim Faysal , Bredillet Christophe N. , Ruiz Philippe
Published: June 2009

Purpose

The purpose of this paper is to provide a summary description of the doctoral thesis investigating the field of project management (PM) deployment. Researchers will be informed of the current contributions within this topic and of the possible further investigations and researches. The decision makers and practitioners will be aware of a set of tools addressing the PM deployment with new perspectives.

Design/methodology/approach

Research undertaken with the thesis is based on quantitative methods using time series statistics (time distance analysis) and comparative and correlation analysis aimed to better define and understand the PM deployment within and between countries or groups.

Findings

The results suggest a project management deployment index (PMDI) to objectively measure the PM deployment based on the concept of certification. A proposed framework to empirically benchmark the PM deployment between countries by integrating the PMDI time series with the two dimensional comparative analysis of Sicherl. The correlation analysis within Hoftsede cultural framework shows the impact of the national culture dimensions on the PM deployment. The forecasting model shows a general continual growth trend of the PM deployment, with continual increase in the time distance between the countries.

Research limitations/implications

The PM researchers are offered an empirical quantification on which they can construct further investigations and understanding of this phenomenon. The number of possible units that can be studied offers wide possibilities to replicate the thesis work. New researches can be undertaken to investigate further the contribution of other social or economical indicators, or to refine and enrich the definition of the PMDI indicator.

Practical implications

These results have important implications on the PM deployment approaches. The PMDI measurements and time series comparisons facilitate considerably the measurement and benchmarking between the units (e.g. countries) and against targets, while the readiness setting of the studied unit (in terms of development and cultural levels) impacts the PM deployment within this country.

Originality/value

This paper provides a summary of cutting‐edge research work in the studied field of PM deployment and a link to the published works that researchers can use to help them understand the thesis research as well as how it can be extended.
Islamic finance: regulatory framework – challenges lying ahead
Authors: Alexakis Christos , Tsikouras Alexandros
Published: June 2009

Purpose

The purpose of this paper is to provide an overview of the regulatory framework and key regulatory institutions and industry associations in Islamic finance today and highlight areas that merit increased attention.

Design/methodology/approach

A wide range of bibliography was reviewed, with particular focus on the standards published by the Islamic Financial Services Board and the Accounting and Auditing Organization for Islamic Financial Institutions. Regulatory topics of particular interest in the Islamic financial world are reviewed. An overview of the main Islamic regulatory institutions is provided. The paper ends with a set of hypotheses requiring further research.

Findings

The paper finds that the growth of the Islamic finance sector may be impacted by the: increased involvement in Islamic finance by Western regulators, as well as credit rating agencies; existence of sound accounting procedures; increased protection of stakeholders of Islamic Financial Institutions.

Originality/value

This paper provides useful information on the current status of the regulatory framework in Islamic finance and highlights areas for further research for academics and professionals alike.
China's exchange rate policy and fiscal expansion
Authors: McKinnon Ronald I.
Published: June 2009

Purpose

The purpose of this paper is to present an overview of China's exchange rate policy and fiscal expansion.

Design/methodology/approach

This paper is a reprint of a Financial Times online forum contribution dated 10 February 2009.

Findings

The paper finds that there is a good economic rationale for China's wanting to keep the yuan/dollar rate stable.

Originality/value

This “perspective” piece written by a Professor of Economics is brought to a wider readership via its inclusion in Journal of Chinese Economic and Foreign Trade Studies.
Competitiveness changes in China's quality vegetable exports post‐WTO
Authors: Liu Xue , Revell Brian J.
Published: June 2009

Purpose

The purpose of this paper is to examine patterns of recent change in China's international export trade in high quality fresh‐vegetables between 2002 and 2005 since its WTO membership and some of the underlying determinants that will determine its future export opportunities.

Design/methodology/approach

A trade‐shares accounting and decomposition approach is adopted which enables the sources of change in China's aggregate export market shares be identified in terms of both structural effects (SEs) through the share‐shifts in world trade of its major trading partners and performance effects (PEs) of changes in China's penetration of individual markets.

Findings

China's underlying comparative advantage in labour‐intensive products such as fresh vegetables is reflected in the positive PE of its increase in share of world trade since WTO membership. There has been an emerging re‐orientation in its trade shares from E Asia to SE Asia, and to further penetration into the Russian Federation and US markets, but little overall evidence of significant enhanced penetration of developed country markets.

Research limitations/implications

The methodology, whilst identifying the predominant sources of dynamic changes in trade shares, does not explain or model the causes of such developments. However, as such it is useful in focussing attention on where significant changes have taken place and hence where further research into modelling such bi‐lateral or multilateral trade flows would be fruitful. Originality/value – Hitherto competitiveness studies have tended to focus either on aggregate trade flows, or at the broad sectoral level such as agriculture. Those in relation to China have also tended to be of a predictive nature in assessing the potential WTO impact on China's trade and agriculture. This study addresses China's actual trade performance at the product category and individual product level, and examines the strategic implications for China's fresh produce export sector. It also assesses whether the initial expectations of positive gains in exporting fresh vegetables have been realised thus far, and what adjustments in China's global trading patterns have emerged in this sector.
An empirical evaluation of export demand in China
Authors: Kumar Saten
Published: June 2009

Purpose– The purpose of this paper is to estimate the export demand equation for China with appropriate specification that incorporates exchange rate in the relative price variable. Design/methodology/approach – Alternative time series techniques such as general to specific and Johansen maximum likelihood are used with annual data from 1974‐2004. The augmented Dicky–Fuller and Elliot–Rothenberg–Stock methods are also employed to test the time series properties of the variables. Findings – The paper confirms that there is a cointegration relationship between real exports, real income and relative prices in China. The long‐run income elasticity is around 1.3 and the relative price elasticity is around −1.5. In addition, the export demand functions are temporally stable in China. Research limitations/implications – The structural breaks and trade shock analysis were ignored because that would have made this paper much longer. Practical implications – The results imply that exports are an engine of growth in China. China's exports are competitive in the international market and it has the option to devalue its currency to promote export earnings. However, the paper argues that in current global economic crises, trade promotion policies such as subsidies, tax exceptions and special credit lines should be encouraged. Originality/value – The paper assesses the magnitudes of export elasticities with a specification that includes exchange rate in relative price variable.
How can China build purchase alliances in the world market of resource commodities?
Authors: Song Yuhua , Li Feng
Published: June 2009

Purpose

The purpose of this paper is to study China's strategy of purchasing resource commodities in international markets, what the Chinese government can do to change the current disorderly import system and how China can build purchase alliances to win in international bargaining.

Design/methodology/approach

A narrative inquiry is used to analyze China's strategy of purchasing resource commodities in international markets, and a game theory model is employed to study different manufacturers’ attitudes toward united negotiation and purchase alliances and the influence of government regulation on their attitude.

Findings

The paper finds that the “paradox of China's great market” in importing resource commodities is due to the constant increase of China's demand and China's disorderly import system. Government regulation will influence manufacturers’ attitudes toward united negotiation and purchase alliances. Purchase alliances may be the only effective strategy that can help China avoid price risk in international markets, because Chinese corporations cannot control foreign mines and the Chinese futures market cannot mature in a limited, short period.

Research limitations/implications

The analysis in the paper lacks sufficient theory and experiences. The game theory model is very simple and is not directly linked with purchase alliances. Owing to literature constraints, there are few foreign experiences about building purchase alliances.

Practical implications

This paper advises the Chinese government and corporations what to do about the high import price of resource commodities and how to build purchase alliances to win in international bargaining, for example improving import regulations, recomposing the united negotiation group, forming a responsibility system and so on.

Originality/value

The paper forms an integrated agenda for China to build purchase alliances for importing resource commodities, and most policies could be carried out by the Chinese government immediately.
A comparison of distilled spirit consumption patterns in the United Kingdom and the United States
Authors: Meloche Martin S. , Stanton John L.
Published: June 2009

Purpose

The purpose of this paper is to show academics and practitioners the practical uses of syndicated data. Toward this end, an analysis of the distilled spirits industry in the USA and the UK is undertaken.

Design/methodology/approach

The approach adopted draws on secondary data analysis using syndicated data to draw some preliminary conclusions and uses further analysis to support these conclusions.

Findings

The paper supports the usefulness of syndicated data when used creatively across different studies. It also points out the changing direction of distilled spirit consumption within the USA and the UK.

Practical implications

This use of syndicated data helps the academic develop a fuller understanding of the key research questions and gives the practitioner a higher degree of confidence in the direction they take and in the future they anticipate.

Originality/value

This paper emphasises the usefulness of syndicated data.
Theoretical analysis of local search strategies to optimize network communication subject to preserving the total number of links
Authors: Mitavskiy Boris , Rowe Jonathan , Cannings Chris
Published: June 2009

Purpose

A variety of phenomena such as world wide web, social or business networks, interactions are modelled by various kinds of networks (such as the scale free or preferential attachment networks). However, due to the model‐specific requirements one may want to rewire the network to optimize the communication among the various nodes while not overloading the number of channels (i.e. preserving the number of edges). The purpose of this paper is to present a formal framework for this problem and to examine a family of local search strategies to cope with it.

Design/methodology/approach

This is mostly theoretical work. The authors use rigorous mathematical framework to set‐up the model and then we prove some interesting theorems about it which pertain to various local search algorithms that work by rerouting the network.

Findings

This paper proves that in cases when every pair of nodes is sampled with non‐zero probability then the algorithm is ergodic in the sense that it samples every possible network on the specified set of nodes and having a specified number of edges with nonzero probability. Incidentally, the ergodicity result led to the construction of a class of algorithms for sampling graphs with a specified number of edges over a specified set of nodes uniformly at random and opened some other challenging and important questions for future considerations.

Originality/value

The measure‐theoretic framework presented in the current paper is original and rather general. It allows one to obtain new points of view on the problem.
Meta‐learning approach to gene expression data classification
Authors: Feres de Souza Bruno , Soares Carlos , de Carvalho André C.P.L.F.
Published: June 2009

Purpose

The purpose of this paper is to investigate the applicability of meta‐learning to the problem of algorithm recommendation for gene expression data classification.

Design/methodology/approach

Meta‐learning was used to provide a preference order of machine learning algorithms, based on their expected performances. Two approaches were considered for such: k‐nearest neighbors and support vector machine‐based ranking methods. They were applied to a set of 49 publicly available microarray datasets. The evaluation of the methods followed standard procedures suggested in the meta‐learning literature.

Findings

Empirical evidences show that both ranking methods produce more interesting suggestions for gene expression data classification than the baseline method. Although the rankings are more accurate, a significant difference in the performances of the top classifiers was not observed.

Practical implications

As the experiments conducted in this paper suggest, the use of meta‐learning approaches can provide an efficient data driven way to select algorithms for gene expression data classification.

Originality/value

This paper reports contributions to the areas of meta‐learning and gene expression data analysis. Regarding the former, it supports the claim that meta‐learning can be suitably applied to problems of a specific domain, expanding its current practice. To the latter, it introduces a cost effective approach to better deal with classification tasks.
GAOC 2008 conference issue: accounting's role in organizational change
Authors: Bell Jan , Hoque Zahirul
Published: June 2009

Purpose

The purpose of this paper is to introduce and review papers incorporated into this special issue of the first biennial conference of the Global Accounting and Organisational Change.

Design/methodology/approach

A textual analytical approach is adopted to review the selected papers.

Findings

A variety of themes emerge from the subject papers, including institutionalisation of organizational and accounting processes, top management and employee support for effective change processes, employee resistance to change, determinants of change, and economies of scale.

Practical implications

Findings reported in this special issue will provide organizational practitioners with better understandings of the effectiveness of the change process.

Originality/value

Findings reported here will enhance the theoretical understandings of the adoption and successful implementation of organizational innovations including accounting.
Five easy pieces: a case study of cost management as organizational change
Authors: Ansari Shahid , Bell Jan
Published: June 2009

Purpose

The primary purpose of this paper is to merge two traditions in management accounting change – design theory and action research – to explain findings from a case study of introducing a cost leadership initiative.

Design/methodology/approach

This paper is an example of action research in which design theory explains events related to the implementation of a strategic cost leadership initiative at Shell Gabon, a Royal Dutch Shell unit in West Africa.

Findings

The evidence shows that technical accounting changes are, in the final analysis, change management exercises. Implementing change requires thinking as a designer and employing the logic of conjecture rather than scientific deductive or inductive reasoning. Successful implementation requires conjuring an image of a future reality that does not currently exist and making that image persuasive by connecting it with the values of the organizational participants.

Research limitations/implications

This case study provides five key lessons for future designers of accounting change. Implementers should: understand the mental models of organizational participants; show respect for the cultural values of the organization they are working in; meaningfully engage organizational participants; use structured processes to unfold change; and be ready to seize new opportunities and discard old game plans when necessary. The case study also reveals gaps in existing change management models and behavioural accounting theories.

Originality/value

This paper offers design theory as an alternative way of viewing organizational change and offers criteria for evaluating the use of design as a process and for assessing the value of the implemented change.
Performance management, budgeting, and legitimacy‐based change in educational organisations
Authors: Fowler Carolyn
Published: June 2009

Purpose

The purpose of this paper is to document the types of and any changes in the budgeting and performance management practices of New Zealand primary educational organisations and explain why they occurred using an institutional theory framework. In doing so, it will provide an understanding of past budgeting and performance measurement and reporting practice, as well as consider the policy implications for the contemporary public‐provided primary education system.

Design/methodology/approach

The paper uses a historical archival‐based case study approach.

Findings

The historical evidence suggests that from 1844 until 1859 budgeting and performance management practices in educational organisations changed as the provision and control of education moved from not‐for‐profit community‐based organisations to become a predominantly public function. The budgeting, inspection and performance management practices and changes observed in the primary education providers were directly related to their need to obtain legitimacy and procure resources.

Practical implications

The detailed information regarding historical budgeting and performance management practices provides rich background material for researchers as well as suggesting that split responsibility and control between the community and government for education creates a tension between the two controlling bodies.

Originality/value

This paper is the first study of internal accounting and performance reporting practices in a mid‐nineteenth century New Zealand education context.
Making development accountable
Authors: Ochoki Nyamori Robert
Published: June 2009

Purpose

The purpose of this paper is to describe and critically evaluate the systems of accounting and accountability for the Constituency Development Fund (CDF) in Kenya. It suggests a new framework of accounting and accountability that places the goals and aspirations expressed in public discourse at the centre of accountability.

Design/methodology/approach

The theoretical insights of Bourdieu and Foucault are mobilized so as to tease out the nature of power relations between the various fields associated with the CDF in Kenya. The study analyses newspaper commentaries as text for identifying the main themes associated with the management of the CDF in Kenya.

Findings

The paper finds that the CDF's systems of accounting and accountability are skewed towards the needs of centralized national planning and development, contrary to its expressed aim of bringing about citizens' participation in development.

Research limitations/implications

Use of newspaper commentaries and reports does not necessarily represent the views of the majority of the people of Kenya.

Practical implications

A new framework is suggested which places the goals and aspirations of public discourse at the centre of accounting with the various capitals suggested by these goals and aspirations forming the dimensions on which the CDF can be accounted for. Novel forms of accounting and accountability are suggested which include presentation of CDF implementation and results at public forums where the managers of CDF can be interrogated on the basis of the goals and aspirations expressed in public discourse.

Originality/value

Study of the CDF systems of accounting and accountability is a unique contribution to accounting for development in developing countries.
Sydney water sector change and industrial water management
Authors: Egan Matthew
Published: June 2009

Purpose

The purpose of this paper is to explain three phases of modernisation change in the Sydney water sector from the early 1980s to 2007 and comments on how those phases of change are likely to be impacting the nascent development of water management processes in Sydney‐based water consuming organisations.

Design/methodology/approach

A framework of modernisation reform in the Sydney water sector has been determined through literature review.

Findings

This paper demonstrates that only moderate modernisation reform occurred in the Sydney water sector in the period from the early 1980s to 2007 tempered by water scarcity and a thrust to sustainability. As a result of these reforms, it is argued that water management processes in water consuming organisations are likely to have accelerated into the early 2000s.

Research limitations/implications

This paper calls for empirical research to understand why organisations in the Sydney region have recently developed water management practices.

Practical implications

This paper contributes to an understanding of the impact of modernisation reform in the Sydney water sector from the early 1980s to 2007 and provides insight into the factors driving water management practices in water consuming organisations.

Originality/value

This paper provides public sector and environmental management researchers with an examination of modernisation reform in the Sydney water sector and relates this to the development of water management objectives in water consuming organisations.
Bleeding peptic ulcer – time trends in incidence, treatment and mortality in Sweden
Authors: SADIC J. , BORGSTRÖM A. , MANJER J. , TOTH E. , LINDELL G.
Published: June 2009

Background  The incidence of peptic ulcer disease was expected to decrease following the introduction of acid inhibitors and Helicobacter pylori eradication.

Aim  To analyse possible changes in the incidence of bleeding peptic ulcer, treatment and mortality over time.

Methods  Residents of Malmö hospitalized for bleeding gastric or duodenal ulcer disease during 1987–2004 were identified in hospital databases (n = 1610). The material was divided into 6‐year periods to identify changes over time. All patients who had been submitted to emergency surgery (n = 137) were reviewed.

Results  The incidence rate for bleeding gastric or duodenal ulcers decreased by one half in males and by one‐third in females and emergency operations decreased significantly (9.2%, 7.5% and 5.7% during the three time periods, respectively (P < 0.05). The post‐operative mortality tended to decrease (9.7, 2.4 and 3.7%, respectively) and the 30‐day mortality rates in the whole material were 1.2%, 3.6% and 3.4% during the different time periods.

Conclusion  The incidence of bleeding gastric and duodenal ulcer disease has decreased markedly. Operative treatment has been replaced by endoscopic treatment. The bleeding ulcer‐related mortality was less than 4% and has not changed over time.
Database of cattle candidate genes and genetic markers for milk production and mastitis
Authors: Ogorevc J. , Kunej T. , Razpet A. , Dovc P.
Published: June 2009

A cattle database of candidate genes and genetic markers for milk production and mastitis has been developed to provide an integrated research tool incorporating different types of information supporting a genomic approach to study lactation, udder development and health. The database contains 943 genes and genetic markers involved in mammary gland development and function, representing candidates for further functional studies. The candidate loci were drawn on a genetic map to reveal positional overlaps. For identification of candidate loci, data from seven different research approaches were exploited: (i) gene knockouts or transgenes in mice that result in specific phenotypes associated with mammary gland (143 loci); (ii) cattle QTL for milk production (344) and mastitis related traits (71); (iii) loci with sequence variations that show specific allele‐phenotype interactions associated with milk production (24) or mastitis (10) in cattle; (iv) genes with expression profiles associated with milk production (207) or mastitis (107) in cattle or mouse; (v) cattle milk protein genes that exist in different genetic variants (9); (vi) miRNAs expressed in bovine mammary gland (32) and (vii) epigenetically regulated cattle genes associated with mammary gland function (1). Fourty‐four genes found by multiple independent analyses were suggested as the most promising candidates and were further in silico analysed for expression levels in lactating mammary gland, genetic variability and top biological functions in functional networks. A miRNA target search for mammary gland expressed miRNAs identified 359 putative binding sites in 3′UTRs of candidate genes.
Effects of ultraviolet radiation on human cutaneous nerve fibres
Authors: Rodriguez A. L. , Stefani F. S. , De Oliveira Praes C. E. , Piaceski A. , Oliveira M. P. , Martins P. , Da Silva V. D. , Bonorino C. , Bauer M. E.
Published: June 2009

Due to an increasing number of skin diseases as a result of exposure to ultraviolet (UV) radiation, it is necessary to evaluate the effectiveness of new skin care formulations with broad‐spectrum sunscreens.

Objectives:  This study aims to assess the status of nerve fibres in healthy human skin, to quantify effects of UV radiation on nerve endings, and to evaluate neuroprotective effects of new skin care formulations against UV exposure damage.

Methods:  Samples were obtained from 34 female patients enrolled for plastic surgery and were immediately treated (10 min) with three emulsions: Cream 1, Cream 2 (placebo) and a sunscreen with sun protection factor 15 (SPF15). Control samples and those treated with the cream emulsions were exposed to UVA and UVB for 60 min. Nerve fibres were identified by immunofluorescence using a monoclonal antibody (anti‐human CD56/NCAM). Cell damage was assessed by image analysis.

Results:  Several cellular nervous structures were identified in the skin samples, including free nerve endings. UVA and UVB significantly decreased (40–60%) density of nerve endings in the control samples and those treated with placebo (Cream 2) or SPF15 (all P < 0.001). Cream 1 completely blocked effects of UV radiation on nerve endings (P > 0.05 vs. control).

Conclusions:  Quantification of cell damage induced by UV radiation provides useful information for identification of new skin care compounds with neuroprotective properties.
Attention deficit hyperactivity disorder in pre‐school children: current findings, recommended interventions and future directions
Authors: Daley D. , Jones K. , Hutchings J. , Thompson M.
Published: June 2009

This paper outlines the presentation, aetiology and treatment of attention deficit hyperactivity disorder (ADHD) in pre‐school children. A review of current parenting training interventions demonstrates that there is good evidence for their efficacy in reducing symptoms of ADHD in pre‐school children, and three interventions are evaluated: The new forest parent training programme (NFPP); the triple P – positive parenting programme and the incredible years parent training programme (IY). The evaluation of the NFPP provides strong evidence demonstrating its effectiveness for pre‐school children with ADHD, while the efficacy of the Triple – P and the IY programme have, to date, only been demonstrated on children with conduct problems and co‐morbid ADHD. It is suggested that parent training should be the first choice treatment for pre‐school children presenting signs of ADHD, and medication introduced only for those children where parent training is not effective. Few moderators of outcome have been identified for these interventions, with the exception of parental ADHD. Barriers to intervention and implementation fidelity will need to be addressed to achieve high levels of attendance, completion and efficacy. The IY programme is a good model for addressing fidelity issues and for overcoming barriers to intervention. The future directions for parent training are also discussed.
Gastrointestinal nematode infection interferes with experimental allergic airway inflammation but not atopic dermatitis
Authors: Hartmann S. , Schnoeller C. , Dahten A. , Avagyan A. , Rausch S. , Lendner M. , Bocian C. , Pillai S. , Loddenkemper C. , Lucius R. , Worm M. , Hamelmann E.
Published: June 2009

Background
Some helminth infections are negatively associated with the prevalence of allergic disorders, arguing for a modulation of allergic reactions by the parasites, depending on the worm species, intensity and phase of infection and the type of disease.

Objective
The aim of this study was to analyse the influence of a chronic infection with the gastrointestinal nematode Heligmosomoides polygyrus, in a murine model of allergic airway disease and of atopic dermatitis (AD), respectively.

Methods
Mice were infected with H. polygyrus and systemically sensitized with the model allergen ovalbumin. Subsequently, the animals were challenged with the allergen either via the airways for induction of airway disease, or via skin patches for induction of dermatitis.

Results
Mice concomitantly infected with H. polygyrus showed diminished eosinophil and lymphocyte recruitment into the lungs and decreased allergen‐specific IgE levels when compared with sensitized and airway challenged controls. In addition, animals showed a trend towards reduced airway hyper‐reactivity. In contrast, no significant differences in the severity of eczematous skin lesions were observed between infected and control animals in the AD model. Although H. polygyrus infection reduced CD8+ and CD4+ T‐cell infiltration into the skin and production of allergen‐specific IgE, mast cell recruitment was significantly increased in worm‐infected mice in the dermatitis model. The worm infection was associated with significantly elevated numbers of Foxp3+ regulatory T cells (Treg) in peribronchial lymph nodes in H. polygyrus‐infected sensitized and airway challenged mice. In contrast, Treg cells were basically absent in eczematous skin and their number was not increased in skin‐draining lymph nodes of mice with experimental dermatitis.

Conclusion
Infection with the gastrointestinal nematode used in our study leads to significant inhibition of mucosa‐associated but not cutaneous allergic reactions, pointing to a site specificity of the immunomodulation exerted by helminths. This finding might be an important aspect for future considerations of helminths for treatment of allergic diseases.
Clinical and genetic heterogeneity of congenital adrenal hypoplasia due to NR0B1 gene mutations
Authors: Landau Zohar , Hanukoglu Aaron , Sack Joseph , Goldstein Nurit , Weintrob Naomi , Eliakim Alon , Gillis David , Sagi Michal , Shomrat Ruth , Kosinovsky Elka Bella , Anikster Yair
Published: June 2009

Introduction  X‐linked adrenal hypoplasia congenita (AHC) is a rare disorder caused by mutations or complete deletion of the NR0B1 gene that encodes the DAX‐1 protein, an orphan member of the nuclear receptor superfamily. AHC is characterized by adrenal insufficiency in infancy and early childhood. Later, hypogonadotropic hypogonadism (HH) manifests as pubertal failure.

Patients and methods  We evaluated the clinical, endocrine and molecular characteristics of 12 AHC patients from 5 families diagnosed between 1984 and 2007 in Israel.

Results  Most of the boys (10/12) presented with signs of adrenal insufficiency such as salt wasting and failure to thrive during the neonatal period. Aldosterone deficiency usually preceded cortisol deficiency requiring early mineralocorticoid therapy. Serum cortisol levels in the first weeks of life varied from very low to high levels (<2·76 to >1776 nmol/l). Five boys showed signs of precocious sexual development during infancy and childhood, including enlargement of the penis and testes. In four patients the initial diagnoses were erroneous. Molecular analysis of the NR0B1 gene identified point mutations in six patients including a novel splice site mutation in one patient and his family (IVS1‐1G→C). Contiguous gene deletion was found in six patients from two families who manifested impaired mental development.

Conclusions  In X‐linked AHC caused by different molecular defects in NR0B1 gene, the clinical spectrum of the disease is quite variable and precocious sexual development is a prominent feature. Genetic testing is indicated in boys presenting with salt‐wasting with or without cortisol deficiency if congenital adrenal hyperplasia has been ruled out.
Xylem hydraulic safety margins in woody plants: coordination of stomatal control of xylem tension with hydraulic capacitance
Authors: Meinzer Frederick C. , Johnson Daniel M. , Lachenbruch Barbara , McCulloh Katherine A. , Woodruff David R.
Published: June 2009

1. The xylem pressure inducing 50% loss of hydraulic conductivity due to embolism (P50) is widely used for comparisons of xylem vulnerability among species and across aridity gradients. However, despite its utility as an index of resistance to catastrophic xylem failure under extreme drought, P50 may have no special physiological relevance in the context of stomatal regulation of daily minimum xylem pressure and avoidance of hydraulic failure under non‐extreme conditions. Moreover, few studies of hydraulic architecture have accounted for the buffering influence of tissue hydraulic capacitance on daily fluctuations in xylem pressure in intact plants.

2. We used data from 104 coniferous and angiosperm species representing a range of woody growth forms and habitat types to evaluate trends in three alternative xylem hydraulic safety margins based on features of their stem xylem vulnerability curves and regulation of daily minimum stem water potential (Ψstem min) under non‐extreme conditions: (i) Ψstem min − P50, (ii) Ψstem min − Pe, the difference between Ψstem min and the threshold xylem pressure at which loss of conductivity begins to increase rapidly (Pe) and (iii) Pe − P50, an estimate of the steepness of the vulnerability curve between Pe and P50. Additionally, we assessed relationships between xylem capacitance, species‐specific set‐points for daily minimum stem water potential and hydraulic safety margins in a subset of species for which relevant data were available.

3. The three types of hydraulic safety margin defined increased with decreasing species‐specific set‐points for Ψstem min, suggesting a diminishing role of stem capacitance in slowing fluctuations in xylem pressure as Ψstem min became more negative. The trends in hydraulic safety were similar among coniferous and angiosperm species native to diverse habitat types.

4. Our results suggest that here is a continuum of relative reliance on different mechanisms that confer hydraulic safety under dynamic conditions. Species with low capacitance and denser wood experience greater daily maximum xylem tension and appear to rely primarily on xylem structural features to avoid embolism, whereas in species with high capacitance and low wood density avoidance of embolism appears to be achieved primarily via reliance on transient release of stored water to constrain transpiration‐induced fluctuations in xylem tension.
Pollination networks of oil‐flowers: a tiny world within the smallest of all worlds
Authors: Bezerra Elisângela L.S. , Machado Isabel C. , Mello Marco A. R.
Published: June 2009

1.
 In the Neotropics, most plants depend on animals for pollination. Solitary bees are the most important vectors, and among them members of the tribe Centridini depend on oil from flowers (mainly Malpighiaceae) to feed their larvae. This specialized relationship within ‘the smallest of all worlds’ (a whole pollination network) could result in a ‘tiny world’ different from the whole system. This ‘tiny world’ would have higher nestedness, shorter path lengths, lower modularity and higher resilience if compared with the whole pollination network.

2.
 In the present study, we contrasted a network of oil‐flowers and their visitors from a Brazilian steppe (‘caatinga’) to whole pollination networks from all over the world.

3.
 A network approach was used to measure network structure and, finally, to test fragility. The oil‐flower network studied was more nested (NODF = 0·84, N = 0·96) than all of the whole pollination networks studied. Average path lengths in the two‐mode network were shorter (one node, both for bee and plant one‐mode network projections) and modularity was lower (M = 0·22 and four modules) than in all of the whole pollination networks. Extinctions had no or small effects on the network structure, with an average change in nestedness smaller than 2% in most of the cases studied; and only two species caused coextinctions. The higher the degree of the removed species, the stronger the effect and the higher the probability of a decrease in nestedness.

4.
 We conclude that the oil‐flower subweb is more cohesive and resilient than whole pollination networks. Therefore, the Malpighiaceae have a robust pollination service in the Neotropics. Our findings reinforce the hypothesis that each ecological service is in fact a mosaic of different subservices with a hierarchical structure (‘webs within webs’).
Predicting the impact of stage‐specific harvesting on population dynamics
Authors: Carslake David , Townley Stuart , Hodgson David J.
Published: June 2009

1.
 Perturbation analyses of population projection matrices predict the response of a population’s growth rate to changes in lifestage‐specific vital rates. Such predictions have been widely used in population management but their reliability remains hotly debated.

2.
 We grew replicate populations of the water flea Daphnia magna in controlled, density‐independent conditions and subjected treatment populations to harvesting of the largest lifestage. We predicted the growth rate of treatment populations using sensitivity analysis (a linear approximation), and transfer function analysis (TFA; which captures nonlinear responses) applied to projection matrix models parameterized from the control populations.

3.
 When perturbation analyses considered only the direct effect of harvesting on adult survival, the growth rate of harvested populations (averaging 0·051) was significantly overestimated (average of 0·112) by TFA and non‐significantly underestimated (average of 0·012) by sensitivity.

4.
 When the indirect effects of harvesting on other vital rates were accounted for in a structured perturbation, TFA gave accurate predictions (average growth rate of 0·068), while sensitivity gave significant underestimates (average of −0·043).

5.
 Our results demonstrate two crucial sources of error that may influence predictions of the impacts of demographic perturbations on population dynamics. First, impacts of stage‐specific harvesting are inherently nonlinear, hence predictions based on sensitivity must be treated with caution. Second, stage‐specific perturbations can change non‐target demographic rates, even in the absence of adaptation.

6.
 Population managers should consider both nonlinear and indirect effects of perturbations when designing management interventions. We encourage the development of methods to assess the robustness of predictions to unforeseen perturbation structures and indirect harvesting impacts.
Growth properties of 16 non‐pioneer rain forest tree species differing in sapling architecture
Authors: Aiba Masahiro , Nakashizuka Tohru
Published: June 2009

1. Sapling architecture may be an important determinant of performance traits, such as light interception and height growth, but few studies have examined the direct relationship between sapling architecture and growth properties. To study this relationship and the potential for strategic diversification, we analysed the growth properties in saplings of 16 Bornean tree species that differ in architecture.

2. Annual net production significantly differed amongst species and was positively correlated with total above‐ground dry mass, total leaf area and crown area. In contrast, the net assimilation rate was weakly but negatively correlated with these architectural traits. The net assimilation rate was virtually independent of leaf size and specific leaf area. Relationships between sapling architecture and relative growth rate in mass were weak.

3. The relative growth rate in height did not significantly differ amongst species, although their total dry mass, a proxy for extension cost, varied fourfold across species for a given sapling height. This is because the proportional increase in net production with total dry mass, which is based on a larger total leaf area and larger crown area, cancelled out the higher extension cost. All architectural traits, including leaf size and specific leaf area, failed to predict height growth rate.

4. Synthesis. Relative growth rates in both mass and height were relatively independent of sapling architecture. Of the architectural traits, leaf size, specific leaf area and stem diameter were poor predictors of growth properties, even though they were considered functionally important. These results clearly reject the classic hypothesis that architectural variation leads to a trade‐off between height growth and light interception, at least for the species that are under shaded conditions. However, functional variation ranging from species with high net production and low net assimilation rates (in saplings of equal height) to species with the opposite traits, which was accompanied by architectural variation in total dry mass and related size factors, may be important for the coexistence of these tree species. The possibility that small total dry mass may be advantageous in height growth under well‐lit conditions should be examined in future studies.