bluuebunny/crossref_metadata_2025 huggingface dataset:
An externally tunable bacterial band-pass filter
Authors: Sohka Takayuki , Heins Richard A. , Phelan Ryan M. , Greisler Jennifer M. , Townsend Craig A. , Ostermeier Marc
Published: June 2009

The current paradigm for tuning synthetic biological systems is through re-engineering system components. Biological systems designed with the inherent ability to be tuned by external stimuli will be more versatile. We engineered
Escherichia coli
cells to behave as an externally tunable band-pass filter for enzyme activity and small molecules. The band's location can be positioned within a range of 4 orders of magnitude simply by the addition of compounds to the growth medium. Inclusion in the genetic network of an enzyme-substrate pair that functions as an attenuator is a generalizable strategy that enables this tunability. The genetic circuit enabled bacteria growth to be patterned in response to chemical gradients in nonintuitive ways and facilitated the isolation of engineered allosteric enzymes. The application of this strategy to other biological systems will increase their utility for biotechnological applications and their usefulness as a tool for gaining insight into nature's underlying design principles.
Natural colonization and adaptation of a mosquito species in Galápagos and its implications for disease threats to endemic wildlife
Authors: Bataille Arnaud , Cunningham Andrew A. , Cedeño Virna , Patiño Leandro , Constantinou Andreas , Kramer Laura D. , Goodman Simon J.
Published: June 2009

Emerging infectious diseases of wildlife have been recognized as a major threat to global biodiversity. Endemic species on isolated oceanic islands, such as the Galápagos, are particularly at risk in the face of introduced pathogens and disease vectors. The black salt-marsh mosquito (
Aedes taeniorhynchus
) is the only mosquito widely distributed across the Galápagos Archipelago. Here we show that this mosquito naturally colonized the Galápagos before the arrival of man, and since then it has evolved to represent a distinct evolutionary unit and has adapted to habitats unusual for its coastal progenitor. We also present evidence that
A. taeniorhynchus
feeds on reptiles in Galápagos in addition to previously reported mammal and bird hosts, highlighting the important role this mosquito might play as a bridge-vector in the transmission and spread of extant and newly introduced diseases in the Galápagos Islands. These findings are particularly pertinent for West Nile virus, which can cause significant morbidity and mortality in mammals (including humans), birds, and reptiles, and which recently has spread from an introductory focus in New York to much of the North and South American mainland and could soon reach the Galápagos Islands. Unlike Hawaii, there are likely to be no highland refugia free from invading mosquito-borne diseases in Galápagos, suggesting bleak outcomes to possible future pathogen introduction events.
Blockage of receptor for advanced glycation end products prevents development of cardiac dysfunction in db/db type 2 diabetic mice
Authors: Nielsen Jan M. , Kristiansen Steen B. , Nørregaard Rikke , Andersen Claus L. , Denner Larry , Nielsen Torsten T. , Flyvbjerg Allan , Bøtker Hans E.
Published: June 2009

Aims

Activation of the receptor for advanced glycation end products (RAGE) is associated with long‐term complications in diabetes mellitus. In this study, we tested whether RAGE activation in the diabetic myocardium is implicated in the development of cardiac dysfunction.

Methods and results

Using MRI and conductance catheter techniques, we evaluated cardiac function in a type 2 diabetic mouse model (db/db), and assessed the effect of blocking RAGE with a RAGE antibody. Gene expressions were evaluated in samples of myocardial tissue. Diabetic db/db mice demonstrated an accelerated age‐dependent deterioration in cardiac function associated with altered expression of genes related to cardiac structure and function. Blockage of RAGE signalling prevented the reduction in systolic function (preload recruitable stroke work: 109.8 ± 13.8 vs. 94.5 ± 14.9 mmHg/µL, P = 0.04) and development of increased LV diastolic chamber stiffness (0.18 ± 0.05 vs. 0.27 ± 0.07 mmHg, P = 0.01). The cardiac expression of collagen (col1a1) was reduced by approximately 45% and the expression of myosin was switched from the foetal isoform (MHCβ) to the adult isoform (MHCα).

Conclusion

Activation of RAGE is a significant pathogenetic mechanism for the development of cardiac dysfunction in type 2 diabetes. The underlying mechanisms involve not only the passive biophysical properties of the myocardium but also myocyte function.
Growth of Bacillus subtilis and Spore Germination in Soil Observed by a Fluorescent-antibody Technique
Authors: Siala A. , Gray T. R. G.
Published: June 2009

Vegetative bacteria of Bacillus subtilis placed in contact with an acid forest soil initially declined in number but grew after the development of fungal hyphae. Growth did not occur in sterile soil, nor in alkaline forest soil unless fungal growth was stimulated. Spores of B. subtilis would not germinate in the same acid forest soil unless fungal growth took place, and hardly germinated at all in the alkaline soil. Roots of seedlings of Pinus sylvestris inhibited both vegetative growth and spore germination. These results are consistent with the observed distribution of vegetative bacteria and spores of B. subtilis in forest soils.
Viability and Electron Microscope Studies of Phages T3 and T7 Subjected to Freeze-drying, Freeze-thawing and Aerosolization
Authors: Cox C. S. , Harris W. J. , Lee J.
Published: June 2009

Phages T3 and T7 were freeze-dried, freeze-thawed or aerosolized. Freeze-drying and aerosolization caused dehydration and resulted in a loss of viability due mainly to one factor, loss of tails. However, the extent of loss of viability and tails was critically dependent upon the manner of rehydration, slow rehydration being best for the preservation of the head-tail complex and viability. Slow freezing (at about 1 °C/min), but fairly rapid thawing (at about 200 °C/min), resulted in marked loss of viability of T7 but only slight loss for T3, through causes other than loss of tails or lysis. Collection of aerosols of T3 and T7 by impinger resulted in much lower viabilities than were obtained by subsonic impaction (e.g. about 10 and 80 % respectively).

The results indicate that the dehydration induced by freeze-drying and aerosolization did not cause loss of viability, but that loss of viability occurred during rehydration. Dehydration of T3 and T7 did not appear to occur during slow freezing (at about 1 °C/min). Mechanisms different from those operating through shear stresses induced by freeze-drying and aerosolization caused loss of viability when T3 and T7 were slowly frozen at about 1 °C/min.
Further Studies with Lipoamide Dehydrogenase Mutants of Escherichia coli
k12
Authors: Guest J. R. , Creaghan I. T.
Published: June 2009

The immunological properties of ten lipoamide dehydrogenase mutants of Escherichia coli were investigated with antiserum raised against purified lipoamide dehydrogenase. Seven mutants were CRM+ (cross-reacting material present) as they contained lipoamide dehydrogenase proteins exhibiting either complete or partial immunological identity with the wild-type protein. This indicates that at least seven of the mutations affect the lipoamide dehydrogenase structural gene (lpd). The remaining three mutants (CRM-) contained no detectable cross-reacting protein. None of the lpd mutations were sensitive to any of three different amber-suppressors. Genetic analysis by P1-transduction showed that all the lpd mutant sites were clustered very near the distal gene (aceF) of the ace region which specifies the dehydrogenase (aceE) and transacetylase (aceF) components of the pyruvate dehydrogenase multienzyme complex. Calculations based on the recombination frequency between an aceF mutant and the nearest lpd mutant site support the conclusion that apart from the possible presence of a regulatory element, the aceF and lpd genes are contiguous.
Polymorphism in a Flagellar-shape Mutant of Salmonella typhimurium
Authors: Iino T. , Oguchi Tomoko , Kuroiwa T.
Published: June 2009

A flagellar-shape mutant, designated ‘polymorphous’, was isolated from a normal flagella strain of Salmonella typhimurium. The mutant produces normal flagella in phase 1 and polymorphous flagella in phase 2. The polymorphous flagella are either straight or possess one of the four distinct wave-forms, namely M, S, N or C, when observed with an electron microscope after negative staining with phosphotungstic acid or uranyl acetate. Conversions between the four wave-forms were found to be brought about mainly by a change in the degree of twisting of longitudinal strands around the axis of a flagella filament, without marked change in the relative lengths of the outermost and innermost strands.

The major fraction of the polymorphous mutant flagella showed the N-form under any conditions of specimen preparation. The remaining four forms appeared as minor fractions in various proportions. Specimens fixed with formalin showed less pronounced polymorphism than unfixed ones. Negative staining with uranyl acetate was more effective than with phosphotungstic acid for observing polymorphism. Even though more than one form appeared among the polymorphous flagella, each individual flagellum comprised a single form except for a rare coexistence of S and N. The same form of flagella tended to coexist in a bacterium in a heteromorphously flagellated cell population.

It was concluded that the conformation and arrangement of the flagellin molecules responsible for wave-form result from strong mutual interactions between the neighbouring molecules along the flagellar filaments and also, to a lesser extent, between the neighbouring filaments in a flagellar bundle, as well as being influenced by the physico-chemical environment.
Ultrastructural Studies on Sporulation in Wild-type and White Colony Mutants of Streptomyces coelicolor
Authors: McVITTIE ANNE
Published: June 2009

Summary: Examination of thin sections of sporulating wild-type colonies revealed new structural details of the development of the sporulation-septum walls. Spores with very thick (about 75 nm) three-layered walls were seen in spore preparations.

Of the sporulation defective (whi) mutants examined, whiDI6 was defective in spore-wall thickening while whiF99 was defective in rounding up and produced rod-shaped, thick-walled spores. A third mutant (whi-92) showed occasional abnormality in sporulation-septum spacing and produced immature as well as mature spores. One mutant (whi-53) produced only a few spores, all structurally normal. In two whiE mutants, structural abnormalities in spores were absent or rare.
The Mode of Action of Polyene Antibiotics; Induced Potassium Leakage in Candida albicans
Authors: HAMMOND S. M. , LAMBERT P. A. , KLIGER B. N.
Published: June 2009

Summary: With a liquid membrane potassium-sensitive electrode it was shown that lethal concentrations of the polyene antibiotics amphotericin B, candicidin and nystatin caused leakage of 90% of non-bound potassium ions from Candida albicans. Accurate and rapid determinations of rates of potassium leakage were made directly in suspensions of Candida. Leakage patterns for the three polyenes were very similar, suggesting a common site of action. Differences were noted in the rates of potassium efflux with organisms from cultures of differing ages.
Studies on the Formation of Bacitracin by Bacillus licheniformis: Effect of Glucose
Authors: HAAVIK H. I.
Published: June 2009

Summary: The production of bacitracin by Bacillus licheniformis closely paralleled growth in a synthetic medium without glucose. Glucose inhibited bacitracin production during the first hours of growth, whereas growth was not affected. Bacitracin was produced mainly during the later stages of growth. Formation of bacitracin was apparently not under catabolite repression control by glucose since the inhibitory effect of glucose upon the early bacitracin production was prevented by neutralizing the culture fluid with CaCO3. The inhibitory effect of glucose may be due to the low pH created by its metabolism.

Addition of 0.5% glucose markedly increased the maximum titre of bacitracin. This stimulation could also be due to the effect of glucose metabolism upon the pH of the medium. The observation that peptide antibiotics are produced mainly after growth is not always true; in appropriate media they might also be produced during the phase of rapid growth.
Isolation and Properties of Cytochrome a Deficient Mutants of Bacillus subtilis
Authors: TABER H.
Published: June 2009

Summary: Three classes of cytochrome a deficient mutants of Bacillus subtilis have been isolated. These classes were defined by concentration ratios of cytochromes a, b and c relative to the parent strain, and by responses to non-fermentable substrates. The cytochrome deficiencies were not due to blocks in haem biosynthesis or to failure of the control mechanisms which alter the respiratory chain during growth of B. subtilis. Mutational loss of cytochrome a did not reduce proportionately the rate of oxygen consumption by late exponential phase cells, although exponential growth rates were generally lower than the parent strain. The cytochrome system of wild-type B. subtilis appears to contain cytochromes a (or a+a3), b, c, c1, and o. A previously unreported absorption maximum at 617 nm was discovered, which was elevated in some of the cytochrome a deficient mutants. In these mutants, a new maximum also appeared at 627 nm.
Mycoplasma verecundum, a New Species Isolated from Bovine Eyes
Authors: GOURLAY R. N. , LEACH R. H. , HOWARD C. J.
Published: June 2009

Summary: Two similar micro-organisms with the characteristics of the order Mycoplas-matales were isolated from the eyes of calves with conjunctivitis. Both isolates produced only a slight pH decrease in broth and did not ferment glucose or hydrolyse arginine or urea -- hence they were almost undetectable by fluid cultures. Other biological characters included sterol dependence, indicative of the genus Mycoplasma, production of film and spots, growth at low temperature (20°C) or low pH (4.7), and failure to reduce tetrazolium. The two strains were serologically indistinguishable from each other, but distinct from known bovine and other Mycoplasma species tested. Because of their distinct biological and serological characteristics they are proposed as forming a separate new species, Mycoplasma verecundum, with strain 107 (nctc10145) as the type strain.
Adhesion of Dextran to Streptococcus muttans
Authors: KELSTRUP J. , FUNDER-NIELSEN T. D.
Published: June 2009

Summary: Fifteen strains of Streptococcus mutans were agglutinated by 5 to 50 ng Leuco-nostoc dextran/ml, and one by 500 ng/ml. Competitive inhibition of the agglutination by sugars or sugar alcohols suggested that the spatial arrangement of the HOC(3)H and O(1) groups were important in the dextran but that the dextran receptor is not identical with the dextran reactive site of glucosyl transferase. Periodate oxidation of the dextran, with or without subsequent borohydride reduction, prevented agglutination, again implicating the C3 group. Pretreatment of dextran with cyclohexyl-isocyanide or of S. mutans with 4.0 m-urea, 0.01 m-EDTA or 0.1 % sodium dodecyl sulphate prevented agglutination; the last three reagents dispersed organisms already agglutinated. Ca2+ or Mg2+ reversed the effect of EDTA. Exposure of bacteria to 60°C or to papain for a few minutes impaired agglutination, so the dextran receptor site may be protein.
Homeopathic Treatment ofArabidopsis thalianaPlants Infected withPseudomonas syringae
Authors: Shah-Rossi Devika , Heusser Peter , Baumgartner Stephan
Published: June 2009

Homeopathic basic research is still in the screening phase to identify promising model systems that are adapted to the needs and peculiarities of homeopathic medicine and pharmacy. We investigated the potential of a common plant-pathogen system, Arabidopsis thaliana infected with the virulent bacteria Pseudomonas syringae, regarding its response towards a homeopathic treatment. A. thaliana plants were treated with homeopathic preparations before and after infection. Outcome measure was the number of P. syringae bacteria in the leaves of A. thaliana, assessed in randomized and blinded experiments. After a screening of 30 homeopathic preparations, we investigated the effect of Carbo vegetabilis 30x, Magnesium phosphoricum 30x, Nosode 30x, Biplantol (a homeopathic complex remedy), and Biplantol 30x on the infection rate in five or six independent experiments in total. The screening yielded significant effects for four out of 30 tested preparations. In the repeated experimental series, only the homeopathic complex remedy Biplantol induced a significant reduction of the infection rate (p = 0.01; effect size, d = 0.38). None of the other four repeatedly tested preparations (Carbo vegetabilis 30x, Magnesium phosphoricum 30x, Nosode 30x, Biplantol 30x) yielded significant effects in the overall evaluation. This phytopathological model yielded a small to medium effect size and thus might be of interest for homeopathic basic research after further improvement. Compared to Bion (a common SAR inducer used as positive control), the magnitude of the treatment effect of Biplantol was about 50%. Thus, homeopathic formulations might have a potential for the treatment of plant diseases after further optimization. However, the ecological impact should be investigated more closely before widespread application.
Ride the wavelet: A multiscale analysis of genomic contexts flanking small insertions and deletions
Authors: Kvikstad Erika M. , Chiaromonte Francesca , Makova Kateryna D.
Published: June 2009

Recent studies have revealed that insertions and deletions (indels) are more different in their formation than previously assumed. What remains enigmatic is how the local DNA sequence context contributes to these differences. To investigate the relative impact of various molecular mechanisms to indel formation, we analyzed sequence contexts of indels in the non protein- or RNA-coding, nonrepetitive (NCNR) portion of the human genome. We considered small (≤30-bp) indels occurring in the human lineage since its divergence from chimpanzee and used wavelet techniques to study, simultaneously for multiple scales, the spatial patterns of short sequence motifs associated with indel mutagenesis. In particular, we focused on motifs associated with DNA polymerase activity, topoisomerase cleavage, double-strand breaks (DSBs), and their repair. We came to the following conclusions. First, many motifs are characterized by unique enrichment profiles in the vicinity of indels vs. indel-free portions of the genome, verifying the importance of sequence context in indel mutagenesis. Second, only limited similarity in motif frequency profiles is evident flanking insertions vs. deletions, confirming differences in their mutagenesis. Third, substantial similarity in frequency profiles exists between pairs of individual motifs flanking insertions (and separately deletions), suggesting “cooperation” among motifs, and thus molecular mechanisms, during indel formation. Fourth, the wavelet analyses demonstrate that all these patterns are highly dependent on scale (the size of an interval considered). Finally, our results depict a model of indel mutagenesis comprising both replication and recombination (via repair of paused replication forks and site-specific recombination).
The consequences of genetic drift for bacterial genome complexity
Authors: Kuo Chih-Horng , Moran Nancy A. , Ochman Howard
Published: June 2009

Genetic drift, which is particularly effective within small populations, can shape the size and complexity of genomes by affecting the fixation of deleterious mutations. In Bacteria, assessing the contribution of genetic drift to genome evolution is problematic because the usual methods, based on intraspecific polymorphisms, can be thwarted by difficulties in delineating species' boundaries. The increased availability of sequenced bacterial genomes allows application of an alternative estimator of drift, the genome-wide ratio of replacement to silent substitutions in protein-coding sequences. This ratio, which reflects the action of purifying selection across the entire genome, shows a strong inverse relationship with genome size, indicating that drift promotes genome reduction in bacteria.
Metabolic Pathways Involved in Cold Acclimation Identified by Integrated Analysis of Metabolites and Transcripts Regulated by DREB1A and DREB2A
Authors: Maruyama Kyonoshin , Takeda Migiwa , Kidokoro Satoshi , Yamada Kohji , Sakuma Yoh , Urano Kaoru , Fujita Miki , Yoshiwara Kyouko , Matsukura Satoko , Morishita Yoshihiko , Sasaki Ryosuke , Suzuki Hideyuki , Saito Kazuki , Shibata Daisuke , Shinozaki Kazuo , Yamaguchi-Shinozaki Kazuko
Published: June 2009

DREB1A/CBF3 and DREB2A are transcription factors that specifically interact with a cis-acting dehydration-responsive element (DRE), which is involved in cold- and dehydration-responsive gene expression in Arabidopsis (Arabidopsis thaliana). Overexpression of DREB1A improves stress tolerance to both freezing and dehydration in transgenic plants. In contrast, overexpression of an active form of DREB2A results in significant stress tolerance to dehydration but only slight tolerance to freezing in transgenic plants. The downstream gene products for DREB1A and DREB2A are reported to have similar putative functions, but downstream genes encoding enzymes for carbohydrate metabolism are very different between DREB1A and DREB2A. We demonstrate that under cold and dehydration conditions, the expression of many genes encoding starch-degrading enzymes, sucrose metabolism enzymes, and sugar alcohol synthases changes dynamically; consequently, many kinds of monosaccharides, disaccharides, trisaccharides, and sugar alcohols accumulate in Arabidopsis. We also show that DREB1A overexpression can cause almost the same changes in these metabolic processes and that these changes seem to improve freezing and dehydration stress tolerance in transgenic plants. In contrast, DREB2A overexpression did not increase the level of any of these metabolites in transgenic plants. Strong freezing stress tolerance of the transgenic plants overexpressing DREB1A may depend on accumulation of these metabolites.
The impact of ethanol plants on cropland values in the great plains
Authors: Henderson Jason , Gloy Brent A.
Published: June 2009

Purpose

Corn ethanol plants consume large amounts of corn and their location has the potential to alter local crop prices and surrounding agricultural land values. The purpose of this paper is to analyze the local economic impact of ethanol plant locations on farmland values.

Design/methodology/approach

The relationship between ethanol plant location and agricultural land prices is examined using data obtained from the Agricultural Credit Survey administered by the Federal Reserve Bank of Kansas City.

Findings

The findings indicate that ethanol plant location has had an impact on land values. The portion of land price changes attributable to location is consistent with previous estimates of basis changes associated with ethanol plant location.

Originality/value

The paper finds that land markets appear to be rationally adjusting to the location of ethanol plants.
Regional differences in agricultural profitability, government payments, and farmland values
Authors: Mishra Ashok K. , Moss Charles B. , Erickson Kenneth W.
Published: June 2009

Purpose

The purpose of this paper is to use the DuPont expansion to examine those factors underlying differences in (rates of) return on different crop portfolios over space (ten regions) and time (1960‐2004). The paper also estimates the impact of government payments on farmland values through its impact on farm profitability.

Design/methodology/approach

Businesses use the DuPont model to analyze the profitability of a business. This model includes three components: net profit margin, asset turnover, and financial leverage (or assets to equity). It is based on the relationships among these three components and is expressed as a product of ratios. For the purposes of the current study, accrued capital gains from (total) returns are excluded to focus on cash returns “cash flow”. Returns from current income are a “cash flow” available in the short run to pay financial obligations. Furthermore, returns from capital gains are not liquid; they are gains in wealth fully captured as capital gains/losses only in the longer term. Following the DuPont approach, the effect of government payments on farm asset values is equal to the sum of the effect of government payments on profit margins plus the effect of government payments on the asset turnover ratio.

Findings

The analysis focuses on agricultural profitability in the ten Economic Research Service (ERS) regions. By comparing the components of the DuPont expansion, profitability differences over time are analyzed. The results indicate that one cause of low profitability in the Corn Belt and Mountain regions is a perpetually low profit margin while the evidence for other regions supports lower asset efficiency. Results show that government payments impact the profit margin and affect value of farm assets in particular farmland values but not asset turnover ratio.

Originality/value

The use of DuPont expansion factor in agriculture is original and really helps us to understand the factors driving profitability in agriculture. Another innovation (originality) in this paper is the theoretical model that connects the DuPont expansion factor, government payments and its impact on farmland values.
Farm credit member‐borrowers' preferences for patronage payments
Authors: Briggeman Brian , Jorgensen Quatie
Published: June 2009

Purpose

Many associations in the Farm Credit System, which are financial cooperatives, pay their member‐borrowers a cash patronage payment based on the amount of loan volume with the association. In today's competitive lending environment, some Farm Credit associations have offered lower interest rates on new loans but these new member‐borrowers have to forgo their cash patronage payment to receive this new, lower‐interest rate loan. The purpose of this paper is to identify Farm Credit member‐borrowers' preferences for patronage refunds received as a cash payment versus lower fixed real estate interest rates.

Design/methodology/approach

Preferences for patronage refunds or lower fixed interest rates are elicited from Farm Credit Services of East Central Oklahoma member‐borrowers via conjoint analysis.

Findings

Results show that member‐borrowers strongly prefer patronage refunds compared to lower fixed interest rates.

Originality/value

This paper fulfills a need to better understand patronage refund programs within the Farm Credit System.
Design basis and hydrodynamic performance analysis of single‐screw extruders. II – viscous power loss
Authors: Demiryürek Oğuz , Koç Erdem
Published: June 2009

Purpose

The purpose of this paper is to investigate the design dimensions in pressure or metering region of a single‐screw extruder by determining viscous power loss. The paper is the second part of a series.

Design/methodology/approach

Viscous power loss formed in the extruder screw channel and the radial clearance is determined and evaluated in terms of non‐dimensional parameters in order to obtain a theoretical model.

Findings

The theoretical model developed is capable of estimating the viscous power loss in the extruder metering region. With the model developed, extruder geometry and viscous power loss under different operating conditions can be predicted.

Originality/value

This paper offers a quick and easy opportunity to examine the viscous power loss in the extruder.
Tribological characteristics at running‐in of repaired tractor engines using friction modifiers
Authors: Nikolov Mitko I. , Gospodinova Nina N. , Pavlov Dimitar J. , Dimitrov Mitko S.
Published: June 2009

Purpose

The purpose of this paper is to determine and compare the tribological characteristics (weight wear and friction moment) of a friction couple C45/C330 at running‐in with motor oil SAE 30 and different friction modifiers of copper oleate and zinc oleate.

Design/methodology/approach

Friction couples are tested using the model “roller‐sector” and they are lubricated with oil SAE 30 and two other samples of SAE 30 containing 0.6 per cent copper oleate and 0.6 per cent zinc oleate, respectively. Graphic dependencies are drawn for the weight wear of the sectors, rollers and couples; as well as for the running‐in moment, the friction moments at the end of the loading and at the end of the test.

Findings

The weight wear, running‐in moment and friction moments are evaluated for friction with SAE 30 as reference and oils containing copper oleate and zinc oleate as friction modifiers. The best performing material is the oil with zinc oleate.

Originality/value

From a practical point of view this paper offers a new idea about a friction modifier – zinc oleate. Data for tribological characteristics and suitable concentration in the oil composition are given in the paper.
An exploratory qualitative and quantitative analysis of Six Sigma in service organizations in Singapore
Authors: Chakrabarty Ayon , Kay Chuan Tan
Published: June 2009

Purpose

The purpose of this paper is to develop a conceptual framework to facilitate widening the scope of Six Sigma implementation in service organizations.

Design/methodology/approach

Using grounded theory methodology, this study develops theory for Six Sigma implementation in service organizations. The study involves a questionnaire survey and case studies to understand and build a conceptual framework. The survey is conducted in service organizations in Singapore and is exploratory. The case studies involved three service organizations which implement Six Sigma. The objective is to explore and understand the issues highlighted by the survey and the literature.

Findings

The findings confirm the inclusion of critical success factors, critical‐to‐quality characteristics, and set of tools and techniques as observed from the literature. In the case of key performance indicators (KPI), there are different interpretations about it in the literature and also by industry practitioners. Some literature explains KPIs as performance metrics whereas some feel it as key process input or output variables, which is similar to interpretations by practitioners of Six Sigma. The responses of “not relevant” and “unknown to us” as reasons for not implementing Six Sigma show the need for understanding specific requirements of service organizations.

Originality/value

Though much theoretical description is available about Six Sigma, there has been limited rigorous academic research on it. This gap is far more pronounced about Six Sigma implementation in service organizations, where the theory is not yet mature. Identifying this need, the paper contributes by going through theory building exercise and developing a conceptual framework to understand the issues involving its implementation in service organizations.
China's social assistance: in need of closer coordination
Authors: Zhang Haomiao
Published: June 2009

Purpose

This paper aims to analyze the three issues about China's social assistance programs and put forward some suggestions separately.

Design/methodology/approach

Qualitative research, mainly using documentary analysis.

Findings

The paper finds that China's urban and rural social assistance, minimum living standard security and special assistance programs, China's social assistance and the other parts of social security such as social insurance and social welfare are in need of closer coordination.

Originality/value

This paper presents a valuable idea about the need for the coordination of China's social assistance programs.
Explaining the continuation of technical college nursing training in Germany
Authors: di Luzio Gaia
Published: June 2009

Purpose

In Germany, basic nursing training still takes place at technical colleges. This type of training lacks standardisation, leaving considerable freedom to colleges and their providers. The purpose of this paper is to identify the reasons for the continuation of technical college training for nurses in Germany.

Design/methodology/approach

The paper adopts an actor‐based approach which restricts the notion of “actor” to the level of organisations. The interplay between these actors is put in a context in which institutions maintain traditional structures of training. The study employs the method of document analysis. The method of analysis is qualitative content analysis.

Findings

The investigation shows that it is an interplay between key actors involved in a conflict over nurses’ education which, together with institutions, is responsible for the persistence of technical college‐based nursing training as the standard basic qualification. The relevant institutions are those regulating the health professions and institutions to which a model of ancillary nursing work is oriented. These are in turn embedded in the German system of health care provision and the corporatist health care governance. The study exposes several cross‐relationships between actor‐based and institutional explanatory factors.

Research limitations/implications

The empirical study is limited to the extent that it excludes the micro‐level of nursing work. It provides a framework for comparative research on educational standards in health care in that it pins down specific variables.

Originality/value

The paper develops a framework for analysing the reasons for the continuation of national educational standards of health professions despite a general European process of changing these standards.
The exclusion and marginalisation of immigrants in the Danish welfare society
Authors: Andersen John , Elm Larsen Jørgen , Hornemann Møller Iver
Published: June 2009

Purpose

The purpose of this paper is to discuss and theorise the links and possible dilemmas posed by the politics of redistribution and the politics of recognition taking the case of Denmark as the point of departure.

Design/methodology/approach

The empirical observations in this paper consist of the political and discursive climate around legislation on ethnic minority matters, information from the Danish Statistical Bureau, the “Danish Level of Living Survey”, and the experiences from Danish urban districts which have a high concentration of immigrants.

Findings

Since the 1990s, the political discourse has changed with the emergence of right‐wing, anti‐immigration populism seriously affecting immigrants’ and refugees’ legal rights and their possibilities for socio‐cultural and socio‐economic inclusion. On the one hand, these changes have been driven by a strong “work first” discourse which has led to a reduction of the duration and level of social benefits, and increased poverty. On the other hand, other policy changes have been more inclusive examples being education policy, active labour market policy measures and innovative empowerment programmes in deprived urban districts.

Practical implications

Social innovation – here defined as the ability to organise bottom linked collective action/empowerment (including efficient political representation) – is a condition for reaching sustainable democratic and social development. But without more far‐reaching changes in the socio‐cultural and socio‐economic opportunity structures based on universal welfare principles and which also clearly address structural ethnic discrimination in all spheres of the social fabric, local empowerment and recognition strategies are likely to fail.

Originality/value

The paper addresses a crucial issue in the Danish and other European societies in relation to the exclusion and marginalisation of immigrants. The value of the paper is that it integrates different theoretical approaches to inclusion and exclusion of immigrants and employs different empirical material (quantitative and qualitative) to both underpin, discuss and challenge these theoretical approaches.
Marginalization and health: children's asthma on the Texas‐Mexico border
Authors: Grineski Sara E.
Published: June 2009

Purpose

The purpose of this paper is to investigate children's vulnerability to asthma and its relationship with marginalized locations. More specifically, the effects of zip code level social predictors on children's asthma and their conditionality on location in the Texas‐Mexico border region are explored. The border region is perhaps the most marginalized in the USA.

Design/methodology/approach

Data for analysis comes from the State of Texas and the US Bureau of the Census. Negative binomial regression models are used to predict asthma hospitalizations using a set of social predictors. Then, interaction effects are used to test if social predictors are conditional on border location.

Findings

Within the state of Texas, location in a metropolitan area, location along the US‐Mexico border, percent Hispanic, percent African American and percent Native American are positive and significant predictors of asthma hospitalizations; social class is negative and significant. The effects of proportion of Hispanics who were foreign born, median year of home construction, and percent of homes with inadequate heating are conditional on a zip code's location relative to the US‐Mexico border, with the slopes being steeper in border locations. Findings in general suggest that locational and social factors intersect in marginalized places (i.e. border regions of Texas) to create vulnerability to asthma hospitalizations.

Research limitations/implications

This study is conducted solely in the USA.

Originality/value

As sociologists continue to consider space as a factor in health inequalities, this paper demonstrates the utility of considering space as operating at more than one scale.
Initial online trust formation: the role of company location and web assurance
Authors: Fisher Richard , Zoe Chu S.
Published: June 2009

Purpose

Prior research suggests that significant impediments to the growth in electronic commerce exist, particularly in relation to international exchanges. This paper aims to investigate the respective roles of vendor location (domestic vs international) and web assurance seals in the development of initial trusting beliefs about a vendor's web site, and to determine whether these beliefs ultimately influence online purchase intentions.

Design/methodology/approach

A model is developed and tested using a controlled laboratory experiment in which 181 subjects are randomly allocated to one of six web site treatments corresponding to two possible locations of the web site vendor (domestic vs international) and three web assurance states (no Web seal vs TRUSTe seal vs WebTrust seal). Data are analysed using ANCOVA and multiple regression analysis.

Findings

As hypothesised, the results suggest that geographical location does appear to influence the formation of initial trusting beliefs (perceived trustworthiness) about a vendor's websites. In contrast, web assurance seals, in general, were found to have little influence on trusting beliefs; and accountants' seals, in particular, were found to be equally ineffective as those issued by other providers. Overall, trusting beliefs were seen to strongly influence online purchase intentions.

Research limitations/implications

Future research aimed at evaluating the relative effectiveness of various trust‐building mechanisms applicable to international vendors is warranted, as is research advancing the understanding of why assurance seals appear to be ineffective as trust‐building mechanisms. The implications of using students as surrogates for online consumers and other limitations inherent in experimental analyses ought to be considered in interpreting the study's findings.

Practical implications

The study's findings indicate that international vendors ought to consider implementing targeted trust‐building mechanisms to compensate for being at a competitive disadvantage to their domestic counterparts. Suggested strategies are discussed in the paper. In relation to assurance seals, results suggest that the accounting profession can no longer assume to successfully leverage off its reputation for trustworthiness and integrity in extending its claims to expertise into new markets.

Originality/value

No previous study has examined the role of vendor location in the development of initial trusting beliefs. In relation to web assurance, previous studies have produced conflicting results and employed a range of research models. This study attempts to address these concerns through the use of a comprehensive and integrated theoretical model.
The comparative role of banking in binary and Islamic economy
Authors: Shakespeare Rodney , Harahap Sofyan
Published: June 2009

Purpose

The purpose of this paper is to set out the role of banking in a binary and Islamic economy.

Design/methodology/approach

By comparison, the paper shows that the main requirements for such an economy, although superficially similar, differ from the realities of “free market” finance capitalism. The paper goes on to explain how, in a binary and Islamic economy, commercial banks would be the means by which interest‐free loans, coming from the central bank and ummah and directed at various forms of productive capacity, would be introduced.

Findings

There is no difficulty in using the banking system to introduce the binary and Islamic economy. However, a paradigm issue is involved.

Practical implications

The central bank‐issued interest‐free loans implemented through the commercial banking system loans serve the ends of both binary and Islamic economics in that they enhance the real economy and forward social and economic justice.

Originality/value

The paper shows how use of these loans is a new concept with a power to change the whole of the economy and society in a beneficial way.
Israeli teachers' perceptions of mentoring effectiveness
Authors: Shapira‐Lishchinsky Orly
Published: June 2009

Purpose

The purpose of this paper is to identify Israeli teachers' perceptions about the relationships between mentoring styles and team culture and the effect of these relationships on mentoring effectiveness.

Design/methodology/approach

The sample consisted of 169 Israeli teachers from 22 science and technology teams in junior high schools. Four mentoring styles and four dimensions of team culture are examined. Data analysis is carried out on an individual level, whilst taking into consideration the influence of the entire team.

Findings

Meaning attribution style influences the perception of mentoring effectiveness in every team culture. Contrary to the expected outcome, the “fit” between the other mentoring styles and team culture has no significant bearing on mentoring effectiveness.

Research limitations/implications

The self‐reported instrument is vulnerable to a same‐source bias. However, since the focus of this paper is teachers' perceptions of their specific mentors' effectiveness, rather than mentoring effectiveness in practice, it seems to be a suitable tool. In addition, the study sample is limited to science and technology teams, However, it appears that these findings can be generalised beyond these teams, since the study variables, which have a general psychological character, have been used previously in other fields.

Practical implications

These findings will be able to assist supervisors in recruiting and assigning suitable mentors, thus contributing to school effectiveness.

Originality/value

The paper contributed to the design of a model that explains mentoring effectiveness. This model raises doubts regarding the perception that “fit” between mentoring styles and team culture is necessary for improving mentoring effectiveness.
A case study of leadership development in action: the UJIA Ashdown Fellowship 2000‐2007
Authors: Winston Lira
Published: June 2009

Purpose

The United Jewish Israel Appeal Ashdown Fellowship was launched in 2000 with the aim of creating high quality leadership for educational organisations in the British Jewish community. It sought to develop talented and committed people who demonstrated leadership potential. The purpose of this paper is to record the narrative of the programme, its strengths and challenges and to lay out some issues for thinking about the next phase.

Design/methodology/approach

A survey was sent to the graduates of the programme to ascertain their assessment of its impact.

Findings

Key factors which helped the development of the programme were secure funding, a stable board and professional staff, an emphasis on making fellows feel valued, and access to some of the best people within the academic field of leadership and management and within Jewish education.

Originality/value

The paper presents a case study of leadership development in practice.
Study on the cultural communication preferences of teachers
Authors: Kocabaş İbrahim
Published: June 2009

Purpose

The purpose of this paper is to look at the communication preferences of teachers on the basis of high‐ and low‐context distinction.

Design/methodology/approach

In total, 275 teachers employed in primary schools in Elazığ, Malatya, and Diyarbakır provinces were chosen as the sample group. Cultural communication scale‐Turkish scale developed by Erdem was applied to measure communication tendencies of teachers.

Findings

At the end of the paper, during which high‐ and low‐context dimensions are treated separately, high‐context communication tendencies of teachers are found to be more dominant than their low‐context communication tendencies. Communication tendencies have also been compared in terms of demographic variables and it is evident that variables such as marital status, education level, income level, age, and employment period have resulted in differences in communication tendencies.

Originality/value

The paper presents a study on the cultural communication preferences of teachers from a Turkish perspective.
Success in an introductory operations research course
Authors: Abdulrahman Yousef Darwish
Published: June 2009

Purpose

The purpose of this paper is to examine the influence of a number of factors such as high school major, high school score, gender, Stat105, Maths I, Maths II grades, and grade point average (GPA) on students' academic performance in an introductory operations research (OR) course at the department of Business Administration – College of Business and Economics at the UAE University.

Design/methodology/approach

All students who completed the introductory OR course during the fall and spring semesters of the academic years 2005/2006 and 2006/2007 were chosen. Collected data were analyzed using correlation and stepwise multiple regression.

Findings

The results indicate that significant correlations exist between OR grade and GPA, maths I grade, maths II grade, and stat 105 grade. Results also show that there is statistically significant difference between the performance, measured by grade, in OR of males and females. There is also statistically significant difference in performance in OR between students majoring in art and those majoring in science in high school. Regression analysis indicates that GPA is the most significant predictor of students' performance in the OR course.

Originality/value

This paper is first study to examine the influence of a number of factors on students' performance in the OR course in the developing countries in general and the UAE in particular. It has implications for both decision makers and academicians.