bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations of the Scottish elections 2007
Authors: Lock Russell , Storer Tim , Harvey Natalie , Hughes Conrad , Sommerville Ian
Published: May 2008

Purpose

The purpose of this paper is to provide an observational examination of the recent Scottish elections, within which an e‐counting system was employed to manage the increased complexity of the Scottish electoral system for the first time.

Design/methodology/approach

Observations of an ethnographic nature, supplemented by written documentation used for both training and public consumption during the Scottish election process.

Findings

It was found that the voting system for the Scottish elections had not received sufficient review or testing prior to the election; further that the design choices imposed by the DRS software did not support the actions of its users efficiently enough, or justify confidence in the dependability of the system.

Practical implications

That the deployment of e‐counting systems requires careful consideration; many of the issues raised in this paper are similar to those of the official Scottish Elections Review, to which our team provided input.

Originality/value

The Scottish elections were the first to allow members of the public to register as election observers, accredited by the Electoral Commission. As such, the Scottish elections represented the first large‐scale opportunity to observe such processes for the academic community.
Stakeholder enfranchisement
Authors: Elliman Tony , Taylor Simon
Published: May 2008

Purpose

The purpose of this paper is to clearly identify a problem area in participation and indicate the potential for technology and eParticipation research as a response to the problem.

Design/methodology/approach

The approach taken within the paper is to develop a hypothetical argument illustrating deficiencies in the current UK approach to public participation and the use of expert evidence in consultation processes. The argument is developed using traffic analysis as an exemplar of such expert input to planning enquiries.

Findings

The literature indicates the current confrontation needs to be replaced by a process that supports informative communication and learning; treats citizens fairly and empowers them to have genuine impact on the decisions. Based on the hypothesis that the capability to re‐organise and present the same data in different forms and contexts enables information technology (IT) to bridge gap between different stakeholder groups the paper proposes the development of a collaborative approach to traffic assessment.

Practical implications

Such an enhanced process with appropriate IT support – SIRTASS – will enable planning activities achieve better decisions with greater community and citizen acceptance. If applied as a general approach there is the potential to significantly improve the speed and quality of the current UK system.

Originality/value

This paper is part of the debate about lack of participation and points to a particular area where research could make a significant contribution.
Resource configuration and creative practices of community entrepreneurs
Authors: Jarl Borch Odd , Førde Anniken , Rønning Lars , Kluken Vestrum Ingebjørg , Agnete Alsos Gry
Published: May 2008

Purpose

This paper aims to focus on the role of the community entrepreneur and the process of community entrepreneurship. It seeks to emphasize the social context as critical for gaining access to the resources needed by a community venture and elaborates on the action pattern of the community entrepreneur towards raising critical resources from the environment.

Design/methodology/approach

The analysis is based on a longitudinal field study of community entrepreneurs in four Norwegian rural municipalities. The data consists of interviews, observations, and documents.

Findings

Community entrepreneurs create local arenas and thereby facilitate cooperative entrepreneurial action, through bridging social capital. The actors are part of these community contexts and are involved in a range of reciprocal relations. Thus, the actors' creative practices toward the community have to run parallel with the resource configuration process.

Research limitations/implications

Future studies may provide a broader empirical platform in different communities, and take part in the process for a longer time period. One may also develop comparative studies focusing on the basic resource platform, the action pattern, and the performance of the different social ventures.

Practical implications

A major finding is that government support should be flexible and develop tools “tailored” to the characteristics of the rural communities. The combined resources of the entrepreneurs, social networks, and more formal institutions create more ambitious results.

Originality/value

The paper contributes to the field of entrepreneurship by studying community entrepreneurs and their entrepreneurial ventures. Further, an integration of a resource configuration approach and a practice‐oriented approach gives an increased understanding to the community venture creation process.
Membertou First Nation indigenous people succeeding as entrepreneurs
Authors: Johnstone Harvey
Published: May 2008

Purpose

This paper seeks to link the extraordinary success of an aboriginal community called Membertou First Nation to the literature of entrepreneurship and small‐ and medium‐sized enterprises.

Design/methodology/approach

The paper recounts the remarkable case of the people of Membertou First Nation who have been very successful in the area of economic development. It then considers their objective to further promote entrepreneurship within in the community.

Findings

The literature informs us that fast growing firms contribute disproportionately to job creation, wealth creation, and longer term support systems of local economies. The paper suggests that some of the unique circumstances that would appear to favor efforts to raise rates of new firm formation may ultimately constrain growth.

Research limitations/implications

The findings are limited by the unique circumstances operating within Canada and may not apply to other situations. Moreover, as Membertou First Nation is an urban‐based reserve it faces a different set of opportunities and constraints than rural‐based communities within Canada.

Originality/value

At one level, the story of Membertou First Nation is inspirational. But, this paper identifies some of the unique challenges and barriers faced by First Nations people pursuing opportunities as entrepreneurs. Challenges include issues of political stability; the need to respect the value placed upon community, conservation and sustainability by the culture the limited access to traditional sources of capital and other possible barriers. It attempts to foresee some potential barriers and underscore the real complexity of issues that arise when development and entrepreneurship are linked.
Oil and gas and the Inuvialuit people of the Western Arctic
Authors: Dana Leo‐Paul , Meis‐Mason Aldene , Anderson Robert B.
Published: May 2008

Purpose

To learn how Inuvialuit people feel about the oil and gas activities on their land.

Design/methodology/approach

Interviews were administered to a stratified sample, on Inuvialuit land. Participants included: Inuvialuit elders; entrepreneurs; public servants; employees of the private sector; managers of oil companies; unemployed persons; housewives; the mayor of Inuvik; and the first aboriginal woman leader in Canada.

Findings

It was reported that oil and gas industry activities are having a positive impact on the regional economy, creating indirect as well as direct financial benefits for the Inuvialuit among others. However, some residents qualified their support saying that they are in favour of continued activity only if benefits filter to them as opposed to being enjoyed only by oil companies and migrant employees. Concern was also expressed for the environment and for the threat that development brings to wildlife upon which people rely on as a food source.

Research limitations/implications

This study should have a longitudinal follow‐up.

Practical implications

While oil and gas exploration and the building of a pipeline may have economic advantages, this might have social, cultural and environment costs for the Inuvialuit.

Originality/value

The paper illustrates how oil and gas activities on Inuvialuit land will transform the lives of these people.
Contextualising social enterprise in New Zealand
Authors: Grant Suzanne
Published: May 2008

Purpose

Social enterprise in New Zealand is still in its infancy, with no recognised framework to inform knowledge of current or future developments. In this exploratory paper, the aim is to consider four influences which are shaping the development of social enterprise in New Zealand.

Design/methodology/approach

A critical‐appreciative lens utilising Habermas' concepts of the lifeworld and system informs the consideration of these influences.

Findings

Four distinct cultural and historical influences are proposed as contributing to the scope and “flavour” of social enterprise developing in New Zealand: socio‐cultural norms, e.g. “Kiwi ingenuity”; the neoliberal reforms initiated by successive governments during the 1980s; Crown settlements in relation to breaches of the principles of 1840 Treaty of Waitangi; New Zealanders' as international citizens.

Originality/value

The paper shows how feedback and dialogue across the sectors, at local, national and international levels, is now required to determine how other scholars, practitioners and policy makers perceive this proposed initial framework.
Leadership in the NHS: what can hospitals learn from Gerry Robinson – the programme?
Authors: Towill Denis R.
Published: May 2008

Purpose

The purpose of this succinct discussion paper is to dissect the recent excellent BBC2 TV series to put on record those emergent lessons from which NHS hospitals may well learn. The emphasis is on development of a framework and culture for health care delivery innovation from within.

Design/methodology/approach

This short paper, one of a series, extracts the key emerging issues and learning opportunities from the perspective of hospital practice as observed from the logistician viewpoint.

Findings

Opinion regarding the outcomes of the documentary has been divided both within the health care sector and the public domain. However, it did raise debate and identified issues about leadership which could be relevant for any large organisation within the world and particularly within health care.

Originality/value

The first of these series of papers is brief, to the point, and highly relevant for health care delivery at an international level.
Defining competencies for hospital management
Authors: Pillay Rubin
Published: May 2008

Purpose

The purpose of this paper is to address the problem of providing managers in both the public and private sectors with the requisite competencies to help address efficiency, effectiveness and responsiveness in the delivery of health services.

Design/methodology/approach

A cross sectional survey using a self administered questionnaire was conducted among hospital managers in South Africa. Respondents were asked to rate the level of importance that each proposed competency had in their job and to indicate their perceptions about the adequacy of health management training programs in South Africa.

Findings

Hospital managers in both sectors feel that people management and self management skills are the most valuable for the efficient and effective management of hospitals, followed by “hard management skills” and skills related to the ability to think strategically. Specific skills or knowledge related to health care delivery were perceived to be least important. Public sector managers were also more likely to seek future training, and were also more adamant about the need for future management development programs.

Originality/value

This research provides the evidence that there is a great need, as well as a significant demand, for a degree program in health management at South African institutions. The findings will be useful in the conceptualization, design and delivery of health management programs aimed at enhancing current and future management and leadership capacity in the health sector.
Standardization of management systems in Spanish care homes
Authors: Heras Iñaki , Cilleruelo Ernesto , Iradi Jon
Published: May 2008

Purpose

The purpose of this article is to give a brief introduction to the global phenomenon of standardization of management systems and to analyze the case of Spanish care homes.

Design/methodology/approach

Observation and interviews were conducted with top and middle managers, consultants and employees of UNE 158001 certified Spanish care homes. The paper analyzes the impact of UNE 158001 standards for residential homes for the elderly, the only specific standard for care homes that has been enacted by a European standardization body.

Findings

Those homes which have implemented and certified the UNE 158001 standard point out that the application of this standard has not been difficult, thanks to the prior implementation of the ISO 9001:2000 standard, and also due to the fact that most of the requirements laid down by the UNE 158001 standard were already deemed to be customary according in their systems, with only some “minor” requirements needing change. The reasons behind the implementation the UNE 158001 standard were varied. Thus, some representatives of residential care homes pointed out that the standard was implemented in order to improve the efficiency of the home and/or improve the quality of the service provided. On the other hand, however, there were representatives who claimed that implementing UNE 158001 serves essentially a business purpose – in other words, of an image conveyed on the market.

Originality/value

The paper provides a useful up‐to‐date conceptual overview for the different agencies interested in the sector, including managers, public administrators and consultants. In addition, the paper provides information for future developments in the sector.
Myoblasts from affected and non‐affected FSHD muscles exhibit morphological differentiation defects
Authors: Barro Marietta , Carnac Gilles , Flavier Sébastien , Mercier Jacques , Vassetzky Yegor , Laoudj‐Chenivesse Dalila
Published: May 2008

Facioscapulohumeral dystrophy (FSHD) is a muscular hereditary disease with a prevalence of 1 in 20,000 caused by a partial deletion of a subtelomeric repeat array on chromosome 4q. However, very little is known about the pathogenesis as well as the molecular and biochemical changes linked to the progressive muscle degeneration observed in these patients. Several studies have investigated possible pathophysiological pathways in FSHD myoblasts and mature muscle cells but some of these reports were apparently in contradiction. The discrepancy between these studies may be explained by differences between the sources of myoblasts. Therefore, we decided to thoroughly analyze affected and unaffected muscles from patients with FSHD in terms of vulnerability to oxidative stress, differentiation capacity and morphological abnormalities. We have established a panel of primary myoblast cell cultures from patients affected with FSHD and matched healthy individuals. Our results show that primary myoblasts are more susceptible to an induced oxidative stress than control myoblasts. Moreover, we demonstrate that both types of FSHD primary myoblasts differentiate into multi‐nucleated myotubes, which present morphological abnormalities. Whereas control myoblasts fuse to form branched myotubes with aligned nuclei, FSHD myoblasts fuse to form either thin and branched myotubes with aligned nuclei or large myotubes with random nuclei distribution. In conclusion, we postulate that these abnormalities could be responsible for muscle weakness in patients with FSHD and provide an important marker for FSHD myoblasts.
Foetal hepatocyte transplantation in a vascularized AV‐Loop transplantation model in the rat
Authors: Fiegel H. C. , Pryymachuk G. , Rath S. , Bleiziffer O. , Beier J. P. , Bruns H. , Kluth D. , Metzger R. , Horch R. E. , Till H. , Kneser U.
Published: May 2008

The use of foetal liver cells (FLC) in the context of hepatic tissue engineering might permit efficientin vitroexpansion and cryopreservation in a cell bank. A prerequisite for successful application of bioartificial liver tissue is sufficient initial vascularization. In this study, we evaluated the transplantation of fibrin gel‐immobilized FLC in a vascularized arterio‐veno‐venous (AV)‐loop model. FLC were isolated from embryonic/foetal (ED 16) rat livers and were enriched by using magnetic cell sorting (MACS). After cryopreservation, FLC were labelled by pkh‐26. Cells were transplanted in a fibrin matrix into a subcutaneous chamber containing a microsurgically created AV‐loop in the femoral region of the recipient rat. The chambers were explanted after 14 days. Subcutaneous implants without an AV‐loop and cell‐free implants served as controls. Fluorescence microscopy of the constructs was used to identify pkh‐26+‐ donor cells. Characterization was performed by RT‐PCR and immunhistology (IH) for CK‐18 and CD31. Transplantation of FLC using the AV‐loop permitted aneo‐tissue formation in the fibrin matrix. A high‐density vascularization was observed in the AV‐loop constructs as shown by CD31 IH. Viable foetal donor cells were detected which expressed CK‐18. FLC can be successfully used for heterotopic transplantation. Fibrin matrix permits rapid blood vessel ingrowth from the AV‐loop and supports engraftment of FLC. It is therefore an appropriate environment for hepatocyte transplantation in combination with microsurgical vascularization strategies. Transplantation of fibrin gel‐immobilized FLC may be a promising approach for the development of highly vascularizedin vivotissue‐engineering‐based liver support systems.
Intron‐1 rs3761548 is related to the defective transcription of Foxp3 in psoriasis through abrogating E47/c‐Myb binding
Authors: Shen Z. , Chen L. , Hao F. , Wang G. , Fan P. , Liu Y.
Published: May 2008

Foxp3 is a master transcription factor (TF) for development and function of CD4+CD25+Foxp3+ regulatory T cells (Treg cells) and is critical for the transcription of target genes. But the transcriptional regulation of Foxp3 itself has not been fully understood until now. Here, we aimed to demonstrate the hypothesis that upstream single nucleotide polymorphism(s) (SNPs) of Foxp3 was/were responsible for the defective transcription of Foxp3 in psoriasis and to explore the mechanism behind this hypothesis. In this study, SNP of large sample was investigated for risk analysis. Mature algorithms, electrophoretic mobility shift and chromatin immunoprecipitation assays were used to identify TF binding site variations. Loss‐of‐function and overexpression assays and cell cycle blocker assay were performed to identify when and what kind of possible roles the candidate factors play. Our results showed that intron‐1 rs3761548 was correlated with a significant susceptibility to psoriasis. The rs3761548 contributed to the decreased resting Foxp3 transcription and impaired acceleration of Foxp3 transcription levels after stimulation in psoriatic patients with genotype AA. We analysed and demonstrated potent new E47/c‐Myb ‐dependent regulation elements in rs3761548, oppositely controlling Foxp3 gene transcription at G1 and G2/M phases of Treg cells in psoriatic patients. For patients with rs3761548 AA, the polymorphism causes loss of bindings to the E47 and c‐Myb factors, leading to defective transcription of Foxp3 gene. Further identification of the networks and molecular mechanisms underlying Foxp3 transcription may provide new insights into Foxp3 transcriptional regulation and alternative therapeutic strategies to improve characteristics of autoimmune disorders.
IL‐24: a classic cytokine and/or a potential cure for cancer?
Authors: Kreis S. , Philippidou D. , Margue C. , Behrmann I.
Published: May 2008

IL‐24, a member of the IL‐10 family of cytokines, is produced by monocytes and Th2 cells. Interestingly, immune cells do not appear to express specific IL‐24 receptor chains (IL‐20R1/IL‐20R2 and IL‐22R/IL‐20R2), it is therefore unlikely that IL‐24 has classical immune‐modulating properties. Skin, on the other hand, seems to represent a major target tissue for IL‐24 and related cytokines such as IL‐19, ‐20, and ‐22. However, the initial interest in IL‐24 did not arise from its physiological signalling properties through its cognate receptors but rather because of its tentative ability to selectively kill different cancer cells. In an attempt to further investigate the signalling events underlying the IL‐24‐induced cancer cell death, we found that melanoma cell lines did not react in the expected and previously described way. Using several different forms and delivery modes of IL‐24, we were unable to detect any apoptosis‐inducing properties of this cytokine in melanoma cells. In the present ‘Point of view’ we will briefly summarizse these findings and put them in context of published reports stating that IL‐24 might be a long sought after treatment for several types of cancer.
Connexin expression and gap junctional coupling in human cumulus cells: contribution to embryo quality
Authors: Wang H.‐X. , Tong D. , El‐Gehani F. , Tekpetey F. R. , Kidder G. M.
Published: May 2008

Gap junctional coupling among cumulus cells is important for oogenesis since its deficiency in mice leads to impaired folliculogenesis. Multiple connexins (Cx), the subunits of gap junction channels, have been found within ovarian follicles in several species but little is known about the connexins in human follicles. The aim of this study was to determine which connexins contribute to gap junctions in human cumulus cells and to explore the possible relationship between connexin expression and pregnancy outcome from in vitro fertilization (IVF). Cumulus cells were obtained from IVF patients undergoing intra‐cytoplasmic sperm injection (ICSI). Connexin expression was examined by RT‐PCR and confocal microscopy. Cx43 was quantified by immunoblotting and gap junctional coupling was measured by patch‐clamp electrophysiology. All but 5 of 20 connexin mRNAs were detected. Of the connexin proteins detected, Cx43 forms numerous gap junction‐like plaques but Cx26, Cx30, Cx30.3, Cx32 and Cx40 appeared to be restricted to the cytoplasm. The strength of gap junctional conductance varied between patients and was significantly and positively correlated with Cx43 level, but neither was correlated with patient age. Interestingly, Cx43 level and intercellular conductance were positively correlated with embryo quality as judged by cleavage rate and morphology, and were significantly higher in patients who became pregnant than in those who did not. Thus, despite the presence of multiple connexins, Cx43 is a major contributor to gap junctions in human cumulus cells and its expression level may influence pregnancy outcome after ICSI.
Temperature-Dependent Parasitic Relationship between
Legionella pneumophila
and a Free-Living Amoeba (
Acanthamoeba castellanii
)
Authors: Ohno Akira , Kato Naoyuki , Sakamoto Ryota , Kimura Soichiro , Yamaguchi Keizo
Published: May 2008

We analyzed the effects of temperature on the interaction of
Legionella pneumophila
with
Acanthamoeba castellanii
. At <20°C, overexpression of type 1 metacaspase, a stimulator of
A. castellanii
encystation, was associated with a reduced number of bacteria within amoeba. At low temperatures,
A. castellanii
seems to eliminate
L. pneumophila
by encystation and digestion.
Multichromosomal Genome Structure and Confirmation of Diazotrophy in Novel Plant-Associated
Burkholderia
Species
Authors: Martínez-Aguilar Lourdes , Díaz Rafael , Peña-Cabriales Juan José , Estrada-de los Santos Paulina , Dunn Michael F. , Caballero-Mellado Jesús
Published: May 2008

Pulsed-field gel electrophoresis and 16S rRNA hybridization experiments showed that multichromosome genome structures and very large genome sizes (6.46 to 8.73 Mb) are prevalent in novel plant-associated
Burkholderia
species.
15
N
2
isotope dilution assays revealed unambiguous diazotrophy in these novel species.
nifH
gene sequence analysis, often used to determine phylogenetic relatedness among diazotrophs, showed tight clusters of
Burkholderia
species, which were clearly distinct from those of other diazotrophs.
Membrane-Bound Pyrroloquinoline Quinone-Dependent Dehydrogenase in
Gluconobacter oxydans
M5, Responsible for Production of 6-(2-Hydroxyethyl) Amino-6-Deoxy-
l
-Sorbose
Authors: Yang Xue-Peng , Wei Liu-Jing , Lin Jin-Ping , Yin Bo , Wei Dong-Zhi
Published: May 2008

A membrane-bound protein purified from
Gluconobacter oxydans
M5 was confirmed to be a pyrroloquinoline quinone-dependent
d
-sorbitol dehydrogenase. Gene disruption and complementation experiments demonstrated that this enzyme is responsible for the oxidation of 1-(2-hydroxyethyl) amino-
1
-deoxy-
d
-sorbitol (1NSL) to 6-(2-hydroxyethyl) amino-6-deoxy-
l
-sorbose (6NSE), which is the precursor of an antidiabetic drug, miglitol.
Competitive Oxidation of Volatile Fatty Acids by Sulfate- and Nitrate-Reducing Bacteria from an Oil Field in Argentina
Authors: Grigoryan Aleksandr A. , Cornish Sabrina L. , Buziak Brenton , Lin Shiping , Cavallaro Adriana , Arensdorf Joseph J. , Voordouw Gerrit
Published: May 2008

Acetate, propionate, and butyrate, collectively referred to as volatile fatty acids (VFA), are considered among the most important electron donors for sulfate-reducing bacteria (SRB) and heterotrophic nitrate-reducing bacteria (hNRB) in oil fields. Samples obtained from a field in the Neuquén Basin, western Argentina, had significant activity of mesophilic SRB, hNRB, and nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB). In microcosms, containing VFA (3 mM each) and excess sulfate, SRB first used propionate and butyrate for the production of acetate, which reached concentrations of up to 12 mM prior to being used as an electron donor for sulfate reduction. In contrast, hNRB used all three organic acids with similar kinetics, while reducing nitrate to nitrite and nitrogen. Transient inhibition of VFA-utilizing SRB was observed with 0.5 mM nitrite and permanent inhibition with concentrations of 1 mM or more. The addition of nitrate to medium flowing into an upflow, packed-bed bioreactor with an established VFA-oxidizing SRB consortium led to a spike of nitrite up to 3 mM. The nitrite-mediated inhibition of SRB led, in turn, to the transient accumulation of up to 13 mM of acetate. The complete utilization of nitrate and the incomplete utilization of VFA, especially propionate, and sulfate indicated that SRB remained partially inhibited. Hence, in addition to lower sulfide concentrations, an increase in the concentration of acetate in the presence of sulfate in waters produced from an oil field subjected to nitrate injection may indicate whether the treatment is successful. The microbial community composition in the bioreactor, as determined by culturing and culture-independent techniques, indicated shifts with an increasing fraction of nitrate. With VFA and sulfate, the SRB genera
Desulfobotulus
,
Desulfotignum
, and
Desulfobacter
as well as the sulfur-reducing
Desulfuromonas
and the NR-SOB
Arcobacter
were detected. With VFA and nitrate,
Pseudomonas
spp. were present. hNRB/NR-SOB from the genus
Sulfurospirillum
were found under all conditions.
Effect of Subtherapeutic Administration of Antibiotics on the Prevalence of Antibiotic-Resistant
Escherichia coli
Bacteria in Feedlot Cattle
Authors: Alexander T. W. , Yanke L. J. , Topp E. , Olson M. E. , Read R. R. , Morck D. W. , McAllister T. A.
Published: May 2008

Antibiotic-resistant
Escherichia coli
in 300 feedlot steers receiving subtherapeutic levels of antibiotics was investigated through the collection of 3,300 fecal samples over a 314-day period. Antibiotics were selected based on the commonality of use in the industry and included chlortetracycline plus sulfamethazine (TET-SUL), chlortetracycline (TET), virginiamycin, monensin, tylosin, or no antibiotic supplementation (control). Steers were initially fed a barley silage-based diet, followed by transition to a barley grain-based diet. Despite not being administered antibiotics prior to arrival at the feedlot, the prevalences of steers shedding TET- and ampicillin (AMP)-resistant
E. coli
were >40 and <30%, respectively. Inclusion of TET-SUL in the diet increased the prevalence of steers shedding TET- and AMP-resistant
E. coli
and the percentage of TET- and AMP-resistant
E. coli
in the total generic
E. coli
population. Irrespective of treatment, the prevalence of steers shedding TET-resistant
E. coli
was higher in animals fed grain-based compared to silage-based diets. All steers shed TET-resistant
E. coli
at least once during the experiment. A total of 7,184 isolates were analyzed for MIC of antibiotics. Across antibiotic treatments, 1,009 (13.9%), 7 (0.1%), and 3,413 (47.1%)
E. coli
isolates were resistant to AMP, gentamicin, or TET, respectively. In addition, 131 (1.8%) and 143 (2.0%) isolates exhibited potential resistance to extended-spectrum β-lactamases, as indicated by either ceftazidime or cefpodoxime resistance. No isolates were resistant to ciprofloxacin. The findings of the present study indicated that subtherapeutic administration of tetracycline in combination with sulfamethazine increased the prevalence of tetracycline- and AMP-resistant
E. coli
in cattle. However, resistance to antibiotics may be related to additional environmental factors such as diet.
Coordinated Regulation of Cold-Induced Changes in Fatty Acids with Cardiolipin and Phosphatidylglycerol Composition among Phospholipid Species for the Food Pathogen
Listeria monocytogenes
Authors: Mastronicolis S. K. , Arvanitis N. , Karaliota A. , Magiatis P. , Heropoulos G. , Litos C. , Moustaka H. , Tsakirakis A. , Paramera E. , Papastavrou P.
Published: May 2008

We present here the structural identification of four phospholipid (Phl) classes in
Listeria monocytogenes
, the fatty acid (FA) composition for each individual Phl species, and a description of cold-induced FA changes. Cardiolipin (48.5%) and phosphatidylglycerol (18.1%) are dominated by anteiso-FA, and the previously recognized branched FA chain shortening by cold was observed singularly in these Phls. Phosploaminolipid (19.9%) and phosphatidylinositol, (9.1%) are significantly different, containing significant amounts of straight-chain FA. These findings are supported by nuclear magnetic resonance analysis.
Development of a Denaturing High-Performance Liquid Chromatography Method for Detection of Protist Parasites of Metazoans
Authors: Troedsson Christofer , Lee Richard F. , Stokes Vivica , Walters Tina L. , Simonelli Paolo , Frischer Marc E.
Published: May 2008

Increasingly, diseases of marine organisms are recognized as significant biotic factors affecting ecosystem health. However, the responsible disease agents are often unknown and the discovery and description of novel parasites most often rely on morphological descriptions made by highly trained specialists. Here, we describe a new approach for parasite discovery, utilizing denaturing high-performance liquid chromatography (DHPLC) reverse-phase ion-paring technology. Systematic investigations of major DHPLC variables, including temperature, gradient conditions, and target amplicon characteristics were conducted to develop a mechanistic understanding of DNA fragment separation by DHPLC. As a model system, 18S rRNA genes from the blue crab (
Callinectes sapidus
) and a parasitic dinoflagellate
Hematodinium
sp. were used. Binding of 18S rRNA gene PCR amplicons to the DNA separation column in the presence of triethylammonium acetate (TEAA) was inversely correlated with temperature and could be predicted based on the estimated DNA helicity of the PCR amplicon. Amplicons of up to 498 bp were resolved as single chromatographic peaks if they had high (>95%) DNA helicity. Amplicons that differed by as few as 2 bp could be resolved. Separation of 18S rRNA gene PCR amplicons was optimized by simultaneous manipulation of both temperature and solvent gradients. The optimal conditions included targeting regions of high DNA helicity (>95%), temperatures in the range of 57 to 63°C, and a linear acetonitrile gradient from 13.75 to 17.5% acetonitrile in 0.1 M TEAA (55 to 70% buffer B) over a 9-min period. Under these conditions, amplicons from a variety of parasites and their hosts can be separated and detected by DHPLC.
Detection and Discovery of Crustacean Parasites in Blue Crabs (
Callinectes sapidus
) by Using 18S rRNA Gene-Targeted Denaturing High-Performance Liquid Chromatography
Authors: Troedsson Christofer , Lee Richard F. , Walters Tina , Stokes Vivica , Brinkley Karrie , Naegele Verena , Frischer Marc E.
Published: May 2008

Recently, we described a novel denaturing high-performance liquid chromatography (DHPLC) approach useful for initial detection and identification of crustacean parasites. Because this approach utilizes general primers targeted to conserved regions of the 18S rRNA gene, a priori genetic sequence information on eukaryotic parasites is not required. This distinction provides a significant advantage over specifically targeted PCR assays that do not allow for the detection of unknown or unsuspected parasites. However, initial field evaluations of the DHPLC assay suggested that because of PCR-biased amplification of dominant host genes it was not possible to detect relatively rare parasite genes in infected crab tissue. Here, we describe the use of a peptide nucleic acid (PNA) PCR hybridization blocking probe in association with DHPLC (PNA-PCR DHPLC) to overcome inherent PCR bias associated with amplification of rare target genes by use of generic primers. This approach was utilized to detect infection of blue crabs (
Callinectes sapidus
) by the parasitic dinoflagellate
Hematodinium
sp. Evaluation of 76 crabs caught in Wassaw Sound, GA, indicated a 97% correspondence between detection of the parasite by use of a specific PCR diagnostic assay and that by use of PNA-PCR DHPLC. During these studies, we discovered one crab with an association with a previously undescribed protist symbiont. Phylogenetic analysis of the amplified symbiont 18S rRNA gene indicated that it is most closely related to the free-living kinetoplastid parasite
Procryptobia sorokini
. To our knowledge, this is the first report of this parasite group in a decapod crab and of this organism exhibiting a presumably parasitic life history.
Abundance, Depth Distribution, and Composition of Aerobic Bacteriochlorophyll
a
-Producing Bacteria in Four Basins of the Central Baltic Sea
Authors: Salka Ivette , Moulisová Vladimíra , Koblížek Michal , Jost Günter , Jürgens Klaus , Labrenz Matthias
Published: May 2008

The abundance, vertical distribution, and diversity of aerobic anoxygenic phototrophic bacteria (AAP) were studied at four basins of the Baltic Sea. AAP were enumerated by infrared epifluorescence microscopy, and their diversity was analyzed by using
pufM
gene clone libraries. In addition, numbers of CFU containing the
pufM
gene were determined, and representative strains were isolated. Both approaches indicated that AAP reached maximal abundance in the euphotic zone. Maximal AAP abundance was 2.5 × 10
5
cells ml
−1
(11% of total prokaryotes) or 1.0 × 10
3
CFU ml
−1
(9 to 10% of total CFU). Environmental
pufM
clone sequences were grouped into 11 operational taxonomic units phylogenetically related to cultivated members of the
Alpha
-,
Beta
-, and
Gammaproteobacteria
. In spite of varying
pufM
compositions, five clones were present in all libraries. Of these,
Jannaschia
-related clones were always found in relative abundances representing 25 to 30% of the total AAP clones. The abundances of the other clones varied. Clones potentially affiliated with typical freshwater
Betaproteobacteria
sequences were present at three Baltic Sea stations, whereas clones grouping with
Loktanella
represented 40% of the total cell numbers in the Gotland Basin. For three alphaproteobacterial clones, probable
pufM
phylogenetic relationships were supported by 16S rRNA gene analyses of Baltic AAP isolates, which showed nearly identical
pufM
sequences. Our data indicate that the studied AAP assemblages represented a mixture of marine and freshwater taxa, thus characterizing the Baltic Sea as a “melting pot” of abundant, polyphyletic aerobic photoheterotrophic bacteria.
Facilitation of Robust Growth of
Prochlorococcus
Colonies and Dilute Liquid Cultures by “Helper” Heterotrophic Bacteria
Authors: Morris J. Jeffrey , Kirkegaard Robin , Szul Martin J. , Johnson Zackary I. , Zinser Erik R.
Published: May 2008

Axenic (pure) cultures of marine unicellular cyanobacteria of the
Prochlorococcus
genus grow efficiently only if the inoculation concentration is large; colonies form on semisolid medium at low efficiencies. In this work, we describe a novel method for growing
Prochlorococcus
colonies on semisolid agar that improves the level of recovery to approximately 100%.
Prochlorococcus
grows robustly at low cell concentrations, in liquid or on solid medium, when cocultured with marine heterotrophic bacteria. Once the
Prochlorococcus
cell concentration surpasses a critical threshold, the “helper” heterotrophs can be eliminated with antibiotics to produce axenic cultures. Our preliminary evidence suggests that one mechanism by which the heterotrophs help
Prochlorococcus
is the reduction of oxidative stress.
Diversity Surveys and Evolutionary Relationships of
aoxB
Genes in Aerobic Arsenite-Oxidizing Bacteria
Authors: Quéméneur Marianne , Heinrich-Salmeron Audrey , Muller Daniel , Lièvremont Didier , Jauzein Michel , Bertin Philippe N. , Garrido Francis , Joulian Catherine
Published: May 2008

A new primer set was designed to specifically amplify ca. 1,100 bp of
aoxB
genes encoding the As(III) oxidase catalytic subunit from taxonomically diverse aerobic As(III)-oxidizing bacteria. Comparative analysis of AoxB protein sequences showed variable conservation levels and highlighted the conservation of essential amino acids and structural motifs. AoxB phylogeny of pure strains showed well-discriminated taxonomic groups and was similar to 16S rRNA phylogeny.
Alphaproteobacteria
-,
Betaproteobacteria
-, and
Gammaproteobacteria
-related sequences were retrieved from environmental surveys, demonstrating their prevalence in mesophilic As-contaminated soils. Our study underlines the usefulness of the
aoxB
gene as a functional marker of aerobic As(III) oxidizers.
Use of Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy To Identify Microbial Metabolic Products on Carbonate Mineral Surfaces
Authors: Bullen Heather A. , Oehrle Stuart A. , Bennett Ariel F. , Taylor Nicholas M. , Barton Hazel A.
Published: May 2008

This paper demonstrates the use of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to detect microbial metabolic products on carbonate mineral surfaces. By creating an ATR-FTIR spectral database for specific organic acids using ATR-FTIR spectroscopy we were able to distinguish metabolic acids on calcite surfaces following
Escherichia coli
growth. The production of these acids by
E. coli
was verified using high-performance liquid chromatography with refractive index detection. The development of this technique has allowed us to identify microbial metabolic products on carbonate surfaces in nutrient-limited cave environments.
Saccharomyces cerevisiae
Grx6 and Grx7 Are Monothiol Glutaredoxins Associated with the Early Secretory Pathway
Authors: Izquierdo Alicia , Casas Celia , Mühlenhoff Ulrich , Lillig Christopher Horst , Herrero Enrique
Published: May 2008

Saccharomyces cerevisiae
Grx6 and Grx7 are two monothiol glutaredoxins whose active-site sequences (CSYS and CPYS, respectively) are reminiscent of the CPYC active-site sequence of classical dithiol glutaredoxins. Both proteins contain an N-terminal transmembrane domain which is responsible for their association to membranes of the early secretory pathway vesicles, facing the luminal side. Thus, Grx6 localizes at the endoplasmic reticulum and Golgi compartments, while Grx7 is mostly at the Golgi. Expression of
GRX6
is modestly upregulated by several stresses (calcium, sodium, and peroxides) in a manner dependent on the Crz1-calcineurin pathway. Some of these stresses also upregulate
GRX7
expression under the control of the Msn2/4 transcription factor. The N glycosylation inhibitor tunicamycin induces the expression of both genes along with protein accumulation. Mutants lacking both glutaredoxins display reduced sensitivity to tunicamycin, although the drug is still able to manifest its inhibitory effect on a reporter glycoprotein. Grx6 and Grx7 have measurable oxidoreductase activity in vivo, which is increased in the presence of tunicamycin. Both glutaredoxins could be responsible for the regulation of the sulfhydryl oxidative state at the oxidant conditions of the early secretory pathway vesicles. However, the differences in location and expression responses against stresses suggest that their functions are not totally overlapping.
Purification and Characterization of Bacteriophage P22 Xis Protein
Authors: Mattis Aras N. , Gumport Richard I. , Gardner Jeffrey F.
Published: May 2008

The temperate bacteriophages λ and P22 share similarities in their site-specific recombination reactions. Both require phage-encoded integrase (Int) proteins for integrative recombination and excisionase (Xis) proteins for excision. These proteins bind to core-type, arm-type, and Xis binding sites to facilitate the reaction. λ and P22 Xis proteins are both small proteins (λ Xis, 72 amino acids; P22 Xis, 116 amino acids) and have basic isoelectric points (for P22 Xis, 9.42; for λ Xis, 11.16). However, the P22 Xis and λ Xis primary sequences lack significant similarity at the amino acid level, and the linear organizations of the P22 phage attachment site DNA-binding sites have differences that could be important in quaternary intasome structure. We purified P22 Xis and studied the protein in vitro by means of electrophoretic mobility shift assays and footprinting, cross-linking, gel filtration stoichiometry, and DNA bending assays. We identified one protected site that is bent approximately 137 degrees when bound by P22 Xis. The protein binds cooperatively and at high protein concentrations protects secondary sites that may be important for function. Finally, we aligned the
attP
arms containing the major Xis binding sites from bacteriophages λ, P22, L5, HP1, and P2 and the conjugative transposon Tn
916
. The similarity in alignments among the sites suggests that Xis-containing bacteriophage arms may form similar structures.
NrdI Essentiality for Class Ib Ribonucleotide Reduction in
Streptococcus pyogenes
Authors: Roca Ignasi , Torrents Eduard , Sahlin Margareta , Gibert Isidre , Sjöberg Britt-Marie
Published: May 2008

The
Streptococcus pyogenes
genome harbors two clusters of class Ib ribonucleotide reductase genes,
nrdHEF
and
nrdF
*
I
*
E
*, and a second stand-alone
nrdI
gene, designated
nrdI2
. We show that both clusters are expressed simultaneously as two independent operons. The NrdEF enzyme is functionally active in vitro, while the NrdE*F* enzyme is not. The NrdF* protein lacks three of the six highly conserved iron-liganding side chains and cannot form a dinuclear iron site or a tyrosyl radical. In vivo, on the other hand, both operons are functional in heterologous complementation in
Escherichia coli
. The
nrdF
*
I
*
E
* operon requires the presence of the
nrdI
* gene, and the
nrdHEF
operon gained activity upon cotranscription of the heterologous
nrdI
gene from
Streptococcus pneumoniae
, while neither
nrdI
* nor
nrdI
2 from
S. pyogenes
rendered it active. Our results highlight the essential role of the flavodoxin NrdI protein in vivo, and we suggest that it is needed to reduce met-NrdF, thereby enabling the spontaneous reformation of the tyrosyl radical. The NrdI* flavodoxin may play a more direct role in ribonucleotide reduction by the NrdF*I*E* system. We discuss the possibility that the
nrdF
*
I
*
E
* operon has been horizontally transferred to
S. pyogenes
from
Mycoplasma
spp.
Formate as the Main Branch Point for Methylotrophic Metabolism in
Methylobacterium extorquens
AM1
Authors: Crowther Gregory J. , Kosály George , Lidstrom Mary E.
Published: May 2008

In serine cycle methylotrophs, methylene tetrahydrofolate (H
4
F) is the entry point of reduced one-carbon compounds into the serine cycle for carbon assimilation during methylotrophic metabolism. In these bacteria, two routes are possible for generating methylene H
4
F from formaldehyde during methylotrophic growth: one involving the reaction of formaldehyde with H
4
F to generate methylene H
4
F and the other involving conversion of formaldehyde to formate via methylene tetrahydromethanopterin-dependent enzymes and conversion of formate to methylene H
4
F via H
4
F-dependent enzymes. Evidence has suggested that the direct condensation reaction is the main source of methylene H
4
F during methylotrophic metabolism. However, mutants lacking enzymes that interconvert methylene H
4
F and formate are unable to grow on methanol, suggesting that this route for methylene H
4
F synthesis should have a significant role in biomass production during methylotrophic metabolism. This problem was investigated in
Methylobacterium extorquens
AM1. Evidence was obtained suggesting that the existing deuterium assay might overestimate the flux through the direct condensation reaction. To test this possibility, it was shown that only minor assimilation into biomass occurred in mutants lacking the methylene H
4
F synthesis pathway through formate. These results suggested that the methylene H
4
F synthesis pathway through formate dominates assimilatory flux. A revised kinetic model was used to validate this possibility, showing that physiologically plausible parameters in this model can account for the metabolic fluxes observed in vivo. These results all support the suggestion that formate, not formaldehyde, is the main branch point for methylotrophic metabolism in
M. extorquens
AM1.
Rad50 Is Not Essential for the Mre11-Dependent Repair of DNA Double-Strand Breaks inHalobacteriumsp. Strain NRC-1
Authors: Kish A. , DiRuggiero J.
Published: May 2008

The genome of the halophilic archaeonHalobacteriumsp. strain NRC-1 encodes homologs of the eukaryotic Mre11 and Rad50 proteins, which are involved in the recognition and end processing of DNA double-strand breaks in the homologous recombination repair pathway. We have analyzed the phenotype ofHalobacteriumdeletion mutants lackingmre11and/orrad50after exposure to UV-C radiation, an alkylating agent (N-methyl-N′-nitro-N-nitrosoguanidine), and γ radiation, none of which resulted in a decrease in survival of the mutant strains compared to that of the background strain. However, a decreased rate of repair of DNA double-strand breaks in strains lacking themre11gene was observed using pulsed-field gel electrophoresis. These observations led to the hypothesis that Mre11 is essential for the repair of DNA double-strand breaks inHalobacterium, whereas Rad50 is dispensable. This is the first identification of a Rad50-independent function for the Mre11 protein, and it represents a shift in theArchaeaaway from the eukaryotic model of homologous recombination repair of DNA double-strand breaks.