bluuebunny/crossref_metadata_2025 huggingface dataset:
Ex vivo gene delivery of GDNF using primary astrocytes transduced with a lentiviral vector provides neuroprotection in a rat model of Parkinson's disease
Authors: Ericson Cecilia , Georgievska Biljana , Lundberg Cecilia
Published: November 2005

Astrocytes are, as normal constituents of the brain, promising vehicles for ex vivo gene delivery to the central nervous system. In the present study, we have used a lentiviral vector encoding glial cell line‐derived neurotrophic factor (GDNF) to transduce rat‐derived primary astrocytes, in order to evaluate their potential for long‐term transgene expression in vivo and neuroprotection in a rat model of Parkinson's disease. Following transplantation of GDNF‐transduced astrocytes to the intact striatum, the level of released GDNF was 2.93 ± 0.28 ng/mg tissue at 1 week post‐grafting, reduced to 0.42 ± 0.12 ng/mg tissue at 4 weeks, and thereafter was maintained at this level throughout the experiment (12 weeks; 0.53 ± 0.068 ng/mg tissue). Similarly, grafting to the substantia nigra (SN) resulted in a significant overexpression of GDNF (∼0.20 ng/mg tissue) at 1 week. Intact animals receiving transplants of GDNF‐transduced astrocytes displayed an increased contralateral turning (5.39 ± 1.19 turns/min) in the amphetamine‐induced rotation test, which significantly correlated with the GDNF tissue levels measured in the striatum, indicating a stimulatory effect of GDNF on the dopaminergic function. Transplantation of GDNF‐transduced astrocytes to the SN 1 week prior to an intrastriatal 6‐hydroxydopamine lesion provided a significant protection of nigral tyrosine hydroxylase‐positive cells. By contrast, when the cells were transplanted to the striatum, the level of released GDNF was not sufficient to rescue the striatal fibers and, hence, to protect the nigral dopaminergic neurons. Overall, our results suggest that genetically modified astrocytes expressing GDNF can provide neuroprotection in a rat model of Parkinson's disease following transplantation to the SN.
The pregnancies of women with Type 2 diabetes: poor outcomes but opportunities for improvement
Authors: Roland J. M. , Murphy H. R. , Ball V. , Northcote‐Wright J. , Temple R. C.
Published: December 2005

Aim  To compare the outcomes of Type 1 and Type 2 diabetic pregnancies and identify risk factors for poor outcome of Type 2 pregnancies

Methods  The data from all (389 Type 1 and 146 Type 2) pre‐gestational diabetic pregnancies from 10 UK hospitals were collected prospectively.

Results  The Type 2 mothers were less likely to have documented pre‐pregnancy counselling (28.7 vs. 40.5%; P < 0.05) or be taking folic acid at conception (21.9 vs. 36.4%; P < 0.001) than Type 1 mothers. The percentage of pregnancies having a serious adverse outcome was higher in Type 2 patients (16.4 vs. 6.4%; P = 0.002). Congenital abnormalities (12.3% in Type 2 vs. 4.4% in Type 1; P = 0.002) accounted for most of this difference. The HbA1c of the Type 2 patients was similar to that of the Type 1 with mean first trimester HbA1c of 7.22 and 7.35%, respectively (P = 0.5). Treatment with oral hypoglycaemic agents [odds ratio (OR), 1.8; 95% confidence interval (CI), 1.0–3.3; P = 0.04], body mass index (OR, 1.09; 95% CI, 1.01–1.18; P = 0.02) and folic acid supplementation (OR, 0.3; 95% CI, 0.09–1.0; P = 0.04) were all independently associated with congenital malformation.

Conclusion  Type 2 diabetic pregnancies are characterized by poor pre‐pregnancy planning, inadequate folic acid supplementation and treatment with oral hypoglycaemic agents, all of which may contribute to the serious adverse outcomes affecting one in six Type 2 diabetic pregnancies. These remediable aspects of the pre‐pregnancy care of women with Type 2 diabetes provide opportunities for improving the outcome towards that of women with Type 1 diabetes.
Reflecting on the think‐aloud method for evaluating e‐learning
Authors: Cotton Deborah , Gresty Karen
Published: December 2005

E‐learning is increasingly being used in higher education settings, yet research examining how students use e‐resources is frequently limited. Some previous studies have used the think‐aloud method (an approach with origins in cognitive psychology) as an alternative to the more usual questionnaire or focus groups, but there is little discussion in the educational literature about the advantages and disadvantages of this approach. In this paper, we discuss our experience of using the think‐aloud method in a recent study, and we reflect on its potential contribution as a research method. A number of concerns about the method arose during our study, including the level of guidance given to participants, observer influence, and the complexity of data analysis. We conclude, however, that the richness of the data collected outweighs these constraints, and that the think‐aloud method has the potential to enhance research in this field.
Teachers’ private theories and their design of technology‐based learning
Authors: Churchill Daniel
Published: December 2005

This study explores the private theories of four vocational education teachers in Singapore who have engaged in the design of technology‐based learning for their own classes. The understanding of teachers’ private theories is important in the context of contemporary educational reforms, which emphasise the shift towards student‐centred practices and technology integration. As teachers learn to change strategies and utilise technology, they might also need to transform aspects of their private theories that could impede effective technology integration and lead them to continue with outdated educational practice. This study aims to understand and explicate areas of private theories that impede the effective design of student‐centred technology‐based learning. The final outcome of the study was a set of propositions for readers to examine for the possible application in their own environments.
Does mere exposure enhance positive evaluation, independent of stimulus recognition? A replication study in Japan and the USA1
Authors: ISHII KEIKO
Published: December 2005

Abstract:  In order to examine whether the mere exposure effect, the finding that exposure to a stimulus enhances a positive evaluation of it, occurs in Japan as well as in the USA, a test was carried out using a novel auditory stimulus. Japanese and American people were asked to listen to repeatedly presented Tagalog (the native Filipino language) utterances. They were then asked to estimate their liking for each utterance and whether they recognized it as one presented during the first exposure stage. The mere exposure effect was found in both cultures. Further, it resulted from only exposure frequency, not recognition. Implications for preference and the role of culture are discussed.
Reticulon 1‐C/neuroendocrine‐specific protein‐C interacts with SNARE proteins
Authors: Steiner Pascal , Kulangara Karina , Sarria J. C. Floyd , Glauser Liliane , Regazzi Romano , Hirling Harald
Published: December 2005

Reticulons are proteins of neuroendocrine cells localized primarily to the endoplasmic reticulum membrane. Despite their implication in cellular processes like apoptosis or axonal regeneration, their intracellular molecular function is still largely unknown. Here, we show that reticulon 1‐C can be detected in a protein complex of 150–200 kDa, and that a number of soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (SNARE) proteins, i.e. syntaxin 1, syntaxin 7, syntaxin 13 and VAMP2, can be co‐immunoprecipitated with reticulon 1‐C. Moreover, it localizes to a nocodazole‐sensitive, but calreticulin‐negative domain of the endoplasmic reticulum. Finally, overexpression in PC12 cells of a reticulon 1‐C fragment which binds to SNAREs, significantly enhances human growth hormone secretion. These results suggest that reticulons are involved in vesicle trafficking events, including regulated exocytosis.
Nitrotyrosine as a marker for peroxynitrite‐induced neurotoxicity: the beginning or the end of the end of dopamine neurons?
Authors: Kuhn Donald M. , Sakowski Stacey A. , Sadidi Mahdieh , Geddes Timothy J.
Published: December 2005

This review examines the involvement of nitrotyrosine as a marker for peroxynitrite‐mediated damage in the dopamine neuronal system. We propose that the dopamine neuronal phenotype can influence the cytotoxic signature of peroxynitrite. Dopamine and tetrahydrobiopterin are concentrated in dopamine neurons, and both are essential for their proper neurochemical function. It is not well appreciated that dopamine and tetrahydrobiopterin are also powerful blockers of peroxynitrite‐induced tyrosine nitration. What is more, the reaction of peroxynitrite with either dopamine or tetrahydrobiopterin forms chemical species (i.e. o‐quinones and pterin radicals, respectively) whose cytotoxic effects may be manifested far earlier than nitrotyrosine formation in the course of dopamine neuronal damage. A better understanding of how the dopamine neuronal phenotype modulates the effects of reactive nitrogen species could reveal early steps in drug‐ and disease‐induced damage to the dopamine neuron and form the basis for rational, protective therapies.
The insulin‐like growth factor mRNA binding‐protein IMP‐1 and the Ras‐regulatory protein G3BP associate with tau mRNA and HuD protein in differentiated P19 neuronal cells
Authors: Atlas Roee , Behar Leah , Elliott Evan , Ginzburg Irith
Published: December 2005

Tau mRNA is axonally localized mRNA that is found in developing neurons and targeted by an axonal localization signal (ALS) that is located in the 3′UTR of the message. The tau mRNA is trafficked in an RNA–protein complex (RNP) from the neuronal cell body to the distal parts of the axon, reaching as far as the growth cone. This movement is microtubule‐dependent and is observed as granules that contain tau mRNA and additional proteins. A major protein contained in the granule is HuD, an Elav protein family member, which has an identified mRNA binding site on the tau 3′UTR and stabilizes the tau message and several axonally targeted mRNAs. Using GST‐HuD fusion protein as bait, we have identified four proteins contained within the tau RNP, in differentiated P19 neuronal cells. In this work, we studied two of the identified proteins, i.e. IGF‐II mRNA binding protein 1 (IMP‐1), the orthologue of chick β‐actin binding protein‐ZBP1, and RAS‐GAP SH3 domain binding protein (G3BP). We show that IMP‐1 associates with HuD and G3BP‐1 proteins in an RNA‐dependent manner and binds directly to tau mRNA. We also show an RNA–dependent association between G3BP‐1 and HuD proteins. These associations are investigated in relation to the neuronal differentiation of P19 cells.
Kainic acid‐induced status epilepticus alters GABAA receptor subunit mRNA and protein expression in the developing rat hippocampus
Authors: Laurén H. B. , Lopez‐Picon F. R. , Korpi E. R. , Holopainen I. E.
Published: December 2005

Kainic acid‐induced status epilepticus leads to structural and functional changes in inhibitory GABAA receptors in the adult rat hippocampus, but whether similar changes occur in the developing rat is not known. We have used in situ hybridization to study status epilepticus‐induced changes in the GABAAα1–α5, β1–β3, γ1 and γ2 subunit mRNA expression in the hippocampus of 9‐day‐old rats during 1 week after the treatment. Immunocytochemistry was applied to detect the α1, α2 and β3 subunit proteins in the control and treated rats. In the saline‐injected control rats, the α1 and α4 subunit mRNA expression significantly increased between the postnatal days 9–16, whereas those of α2, β3 and γ2 subunits decreased. The normal developmental changes in the expression of α1, α2, β3 and γ2 subunit mRNAs were altered after the treatment. The immunostainings with antibodies to α1, α2 and β3 subunits confirmed the in situ hybridization findings. No neuronal death was detected in any hippocampal subregion in the treated rats. Our results show that status epilepticus disturbs the normal developmental expression pattern of GABAA receptor subunit in the rat hippocampus during the sensitive postnatal period of brain development. These perturbations could result in altered functional and pharmacological properties of GABAA receptors.
Anti‐CD11d antibody treatment reduces free radical formation and cell death in the injured spinal cord of rats
Authors: Bao Feng , Dekaban Gregory A. , Weaver Lynne C.
Published: December 2005

Treatment with a monoclonal antibody (mAb) against the CD11d subunit of the leukocyte integrin CD11d/CD18 after spinal cord injury (SCI) decreases intraspinal inflammation and oxidative damage, improving neurological function in rats. In this study we tested whether the anti‐CD11d mAb treatment reduces intraspinal free radical formation and cell death after SCI. Using clip‐compression SCI in rats, reactive oxygen species (ROS) generated in injured spinal cord were detected using 2′,7′‐dichlorofluorescin‐diacetate and hydroethidine as fluorescent probes. ROS in the injured cord increased significantly after SCI; anti‐CD11d mAb treatment significantly reduced this ROS formation. Immunohistochemistry and western blotting were employed to assess the effects of anti‐CD11d mAb treatment on spinal cord expression of gp91Phox (a subunit of NADPH oxidase producing superoxide) on formation of 4‐hydroxynonenal (HNE, indicating lipid peroxidation) and on expression of caspase‐3. We also assessed effects on cell death, determined by cell morphology. The expression of gp91Phox, formation of HNE, and cell death increased after SCI. Anti‐CD11d mAb treatment clearly attenuated these responses. In conclusion, anti‐CD11d mAb treatment significantly reduces intraspinal free radical formation caused by infiltrating leukocytes after SCI, thereby reducing secondary cell death. These effects likely underlie tissue preservation and improved neurological function that result from the mAb treatment.
Pricing Pension Insurance: The Proposed Levy Structure for the Pension Protection Fund*
Authors: McCarthy David , Neuberger Anthony
Published: November 2005

The UK Pension Protection Fund (PPF), established by the 2004 Pensions Act to protect beneficiaries of defined benefit pension schemes when the sponsor becomes insolvent and the scheme is underfunded, is required to finance itself through a levy on participating schemes. In July 2005, the PPF issued a consultative document setting out its proposal for the structure of the levy. In this paper, we provide a critique of the proposal and, in particular, its heavy reliance on securing levy income from the weakest schemes. We propose an alternative structure for the levy that recognises the limits on capacity to pay and also mitigates some other undesirable features of the proposal.
Customer Behavior in an Online Ordering Application: A Decision Scoring Model*
Authors: Boyer Kenneth K. , Hult G. Tomas M.
Published: December 2005

This research presents the development of behavioral scoring models to predict future customer purchases in an online ordering application. Internet retailing lowers many barriers for customers switching between retailers for repeat purchases; thus, retaining existing customers is a key challenge for achieving profitability. Survey data were collected from 1,089 online customers of two companies. The subjective survey data were then used to predict purchases over the ensuing 12 months based on data from the company databases. The analysis illustrates the general applicability of predictive models of future customer purchases while also demonstrating the need to develop specific models tailored for an individual company's operating and marketing environment. The models provide insight on how companies can target marketing dollars more effectively and allocate investment across multiple operational areas for maximum return. The research answers a call for rigorous research in the area of predictive marketing, an area in which many companies are excelling but where there is a scarcity of detailed knowledge regarding application of such models.
The State of State Budget Research
Authors: RUBIN IRENE
Published: November 2005

This essay examines the research on state budgeting that has appeared in Public Budgeting & Finance since its founding, with a view to summarizing the key themes and outlining what we have yet to learn. It also offers some suggestions for future research strategies, how to pick topics and cases, and theorize about the findings. The goal is not to utilize theories from other fields which may or may not be relevant to budgeting, but to theorize about what we know and get to a deeper level of understanding.
Monomorphic Ventricular Tachycardia Due to Brugada Syndrome Successfully Treated by Hydroquinidine Therapy in a 3‐Year‐Old Child
Authors: PROBST VINCENT , EVAIN STEPHANE , GOURNAY VERONIQUE , MARIE ALLOUIS , SCHOTT JEAN‐JACQUES , BOISSEAU PIERRE , LE MAREC HERVE
Published: November 2005

Mutations in the SCN5A gene can cause Brugada syndrome, a genetically inherited form of idiopathic ventricular fibrillation. We describe the case of a 3‐year‐old child with a structurally normal heart presenting with monomorphic ventricular tachycardia. Her electrocardiogram suggested a Brugada syndrome and the diagnosis was confirmed by the identification of a Brugada syndrome in her mother and in two other family members. Genetic study led to the identification of a c.2516T→C SCN5A mutation. The child was treated with quinidine therapy without recurrence of arrhythmic events for a time period of 16 months.
Effect of Misreported Family History on Mendelian Mutation Prediction Models
Authors: Katki Hormuzd A.
Published: December 2005

Summary People with familial history of disease often consult with genetic counselors about their chance of carrying mutations that increase disease risk. To aid them, genetic counselors use Mendelian models that predict whether the person carries deleterious mutations based on their reported family history. Such models rely on accurate reporting of each member's diagnosis and age of diagnosis, but this information may be inaccurate. Commonly encountered errors in family history can significantly distort predictions, and thus can alter the clinical management of people undergoing counseling, screening, or genetic testing. We derive general results about the distortion in the carrier probability estimate caused by misreported diagnoses in relatives. We show that the Bayes factor that channels all family history information has a convenient and intuitive interpretation. We focus on the ratio of the carrier odds given correct diagnosis versus given misreported diagnosis to measure the impact of errors. We derive the general form of this ratio and approximate it in realistic cases. Misreported age of diagnosis usually causes less distortion than misreported diagnosis. This is the first systematic quantitative assessment of the effect of misreported family history on mutation prediction. We apply the results to the BRCAPRO model, which predicts the risk of carrying a mutation in the breast and ovarian cancer genes BRCA1 and BRCA2.
Once Upon a Time in Volcán, Costa Rica: Integrating Values into Watershed Management and Poverty Alleviation
Authors: Chapman Mollie
Published: November 2005

The purposes of this article are twofold. One is to make recommendations on a possible course of action for a small town in Costa Rica. The other is to examine the relationship between policy and values, in search of a method of integrating values into policy decisions that can be more broadly applied. The method uses narratives to define common values and science and economics to apply these values most efficiently. The process of defining values through narratives uses a relation‐based organizing framework through which trust can be built and empowerment attained.
Effects of Exchange Rate Regime on IMF Program Participation
Authors: Trudel Robert
Published: November 2005

This article investigates the effect of a domestic policy choice, the exchange rate regime, on countries’ interaction with an international institution, their participation in International Monetary Fund (IMF) lending agreements. I hypothesize that the effect of the level of international reserves on a country's probability of participation in an IMF program depends on the exchange rate regime. A low level of international reserves threatens unfavorable economic and political outcomes only in countries that maintain a fixed exchange rate regime. The level of reserves may thus be a significant determinant of participation in IMF programs only for countries that maintain a fixed exchange rate regime. I use a dynamic univariate probit model of IMF program participation to assess empirically the effect of reserves in countries that maintain fixed, intermediate, and floating exchange rate regimes. The empirical results support my hypothesis: reserves have a significant effect only in countries that maintain a fixed exchange rate.
AlPO4 Coating on Alumina/Mullite Fibers as a Weak Interface in Fiber‐Reinforced Oxide Composites‡
Authors: Bao Yahua , Nicholson Patrick S.
Published: December 2005

A sol of amorphous aluminum orthophosphate (AlPO4) nano particles (30–100 nm) was synthesized by co‐precipitation of Al3+ and HPO42− with urea at 95°C. A narrow particle size distribution was achieved when [Al3+]≤0.1M. The isoelectric point of the synthesized powder is pH∼4.7. Alumina/mullite fibers (Nextel™ 720) were pretreated with cationic polyelectrolyte to render them of opposite charge to the AlPO4 particles, and the latter were then coated by electrostatic‐attraction dipcoating. A uniform, continuous coating formed after several cycles, and its effectiveness as the weak layer between the fibers and the Al2O3 matrix of a hot‐pressed composite was reported. Significant fiber pullout was noted.
Effects of Nb Doping and Segregation on the Grain Boundary Plane Distribution in TiO2
Authors: Pang Ying , Wynblatt Paul
Published: December 2005

Orientation imaging microscopy has been used to investigate the effects of Nb doping on the grain boundary plane distributions in TiO2 (rutile). By comparing the grain boundary plane distribution of the undoped material with theoretical estimates of grain boundary energy anisotropy of pure rutile, it is possible to show that the frequency of grain boundary planes is inversely correlated with grain boundary energy. In the case of Nb‐doped material, this inverse correlation can also be demonstrated by a comparison of grain boundary plane frequency with measurements of surface energy anisotropy. In addition, by comparing the grain boundary plane distribution of doped and undoped materials with previous measurements of Nb grain boundary segregation in TiO2 as a function of grain boundary plane orientation, it is possible to explain the changes in grain boundary plane distribution which result from doping.
Proportions of melanocyte stimulating hormone‐immunoreactive cells in the adenohypophysis of Silky fowl and hyperpigmentation‐free cockerels
Authors: NISHIMURA Shotaro , SHIMODA Hitomi , OSHIMA Ichiro , ONO Yoshitaka , OKANO Kaoru , ISHIBASHI Akira , TABATA Shoji , IWAMOTO Hisao
Published: November 2005

Alpha‐melanocyte stimulating hormone (α‐MSH) is one of the main regulators for melanocytes, and the adenohypophysis is one of the major tissues for the synthesis of this hormone. The Silky fowl is a characteristic breed of chicken with hyperpigmentation throughout the body. The involvement of the adenohypophysis in the hyperpigmentation of this breed is not known. In the present study, the proportion of melanocyte stimulating hormone‐immunopositive cells (MSH cells) in the adenohypophysis was immunocytochemically compared between Silky, Red Cornish × New Hampshire (RN) crossbred and Japanese bantam cockerels at 15 weeks of age. After the body and gland were weighed, the adenohypophyseal cells were enzymatically dispersed and immunostained for α‐MSH, and the immunopositive MSH cells were counted. The weights of the body and adenohypophysis were heaviest in the RN crossbred, followed by the Silky and lightest in the bantam cockerels. In contrast, the ratio between adenohypophysis and bodyweight was much larger in the Silky and the bantam than in the RN crossbreed (P < 0.05). The population of MSH cells in the adenohypophysis was larger in the Silky (14.3%) than in the RN crossbreed (8.0%) and the bantam (8.1%) cockerels (P < 0.05). From these results, it was concluded that prepubertal Silky cockerel have numerous MSH cells in the adenohypophysis suggesting a relationship to hyperpigmentation.
SENSORY TEXTURE PROFILING AND DEVELOPMENT OF STANDARD RATING SCALES FOR POUNDED YAM
Authors: OTEGBAYO BOLANLE , AINA JOHNSON , SAKYI‐DAWSON ESTHER , BOKANGA MPOKO , ASIEDU ROBERT
Published: November 2005

This study evaluated sensory texture profile analysis (STPA) as an objective method for characterizing the texture attributes of “pounded yam,” a popular dish in West Africa made by peeling yam, boiling, pounding and kneading it into a glutinous dough. Panelists were carefully selected and trained to assess the texture attributes of pounded yam. Standard rating scales were developed from local foods that are common in Nigeria, and the foods were used as descriptors to exemplify the texture attributes being assessed. Reproducible and consistent results were obtained. It is thus concluded that STPA can be used as an objective method for evaluating the texture attributes of pounded yam.
MOISTURE REDISTRIBUTION AND TEXTURAL CHANGES IN STORED MODEL SANDWICHES
Authors: BARRETT ANN , CARDELLO ARMAND , MAGUIRE PAUL , PELEG MICHA
Published: November 2005

Moisture migration and instrumental and sensory texture changes were determined in model cheese sandwich structures in which bread water activity was varied by glycerol level. Sandwiches and components were evaluated both after assembly and 4‐week ambient storage by uniaxial compression and mathematical description of stress‐strain relationships, assessment of sensory characteristics by a trained panel, correspondence between predicted and actual stress‐strain relationships, and mass‐balance analysis of moisture migration between cheese, bread crumb and bread crust. Textural changes occurred as a result of both aging and moisture migration, and the accuracy of fitted “predicted” stress‐strain relationships of the composites varied according to the extent of moisture migration. Sensory assessments of key textural attributes of sandwich composites and components, before and after storage, were significantly correlated with measured mechanical parameters.
Spontaneous magnetization of ferromagnets
Authors: Kraftmakher Yaakov
Published: November 2005

Computer-controlled experiments are described for observing hysteresis loops of a ferromagnet over a wide temperature range, including its Curie point, and for determining the temperature dependence of the spontaneous magnetization. A nickel-based alloy, Monel 400, is used as the sample.
Visualization of induced electric fields
Authors: van Deursen A. P. J.
Published: November 2005

A cylindrical electrolytic tank between a set of Helmholtz coils provides a classroom demonstration of induced, nonconservative electric fields. The field strength is measured by a sensor consisting of a pair of tiny spheres immersed in the liquid. The sensor signal depends on position, frequency, and orientation. A low resistance copper ring strongly modifies the magnetic field inside and increases the field outside; the electric field changes accordingly. A metallic ring with a small gap can be used to measure the behavior of the electric field in the vicinity of windings around a transformer core. The measured results are consistent with simple models.
Evidence for a One-Allele Assortative Mating Locus
Authors: Ortíz-Barrientos Daniel , Noor Mohamed A. F.
Published: December 2005

Theoretical models have shown that speciation with gene flow can occur readily via a “one-allele mechanism,” where the spread of the same allele within both of two diverging species reduces their subsequent hybridization. Here we present direct genetic evidence for such an allele in
Drosophila pseudoobscura
. Alleles conferring high or low assortative mating in
D. pseudoobscura
produce the same effects when inserted into
D. persimilis
. This observation suggests that the type of genetic variation that is most conducive to controversial modes of speciation with gene flow, such as reinforcement or sympatric speciation, is present in nature.
Characterization of the
Bacillus subtilis
Spore Morphogenetic Coat Protein CotO
Authors: McPherson D. C. , Kim H. , Hahn M. , Wang R. , Grabowski P. , Eichenberger P. , Driks A.
Published: December 2005

Bacillus spores are protected by a structurally and biochemically complex protein shell composed of over 50 polypeptide species, called the coat. Coat assembly in
Bacillus subtilis
serves as a relatively tractable model for the study of the formation of more complex macromolecular structures and organelles. It is also a critical model for the discovery of strategies to decontaminate
B. anthracis
spores. In
B. subtilis
, a subset of coat proteins is known to have important roles in assembly. Here we show that the recently identified
B. subtilis
coat protein CotO (YjbX) has an especially important morphogenetic role. We used electron and atomic force microscopy to show that CotO controls assembly of the coat layers and coat surface topography as well as biochemical and cell-biological analyses to identify coat proteins whose assembly is CotO dependent.
cotO
spores are defective in germination and partially sensitive to lysozyme. As a whole, these phenotypes resemble those resulting from a mutation in the coat protein gene
cotH
. Nonetheless, the roles of CotH and CotO and the proteins whose assembly they direct are not identical. Based on fluorescence and electron microscopy, we suggest that CotO resides in the outer coat (although not on the coat surface). We propose that CotO and CotH participate in a late phase of coat assembly. We further speculate that an important role of these proteins is ensuring that polymerization of the outer coat layers occurs in such a manner that contiguous shells, and not unproductive aggregates, are formed.
Importance of Tetramer Formation by the Nitrogen Assimilation Control Protein for Strong Repression of Glutamate Dehydrogenase Formation in
Klebsiella pneumoniae
Authors: Rosario Christopher J. , Bender Robert A.
Published: December 2005

The nitrogen assimilation control protein (NAC) from
Klebsiella pneumoniae
is a very versatile regulatory protein. NAC activates transcription of operons such as
hut
(histidine utilization) and
ure
(urea utilization), whose products generate ammonia. NAC also represses the transcription of genes such as
gdhA
, whose products use ammonia. NAC exerts a weak repression at
gdhA
by competing with the binding of a lysine-sensitive activator. NAC also strongly represses transcription of
gdhA
(about 20-fold) by binding to two separated sites, suggesting a model involving DNA looping. We have identified negative control mutants that are unable to exert this strong repression of
gdhA
expression but still activate
hut
and
ure
expression normally. Some of these negative control mutants (e.g., NAC
86ter
and NAC
132ter
) delete the C-terminal domain, thought to be required for tetramerization. Other negative control mutants (e.g., NAC
L111K
and NAC
L125R
) alter single amino acids involved in tetramerization. In this work we used gel filtration to show that NAC
86ter
and NAC
L111K
are dimers in solution, even at high concentration (NAC
WT
is a tetramer). Moreover, using a combination of DNase I footprints and gel mobility shifts assays, we showed that when NAC
WT
binds to two adjacent sites on a DNA fragment, NAC
WT
binds as a tetramer that bends the DNA fragment significantly. NAC
L111K
binds to such a fragment as two independent dimers without inducing the strong bend. Thus, NAC
L111K
is a dimer in solution or when bound to DNA. NAC
L111K
(typical of the negative control mutants) is wild type for every other property tested: (i) it activates transcription at
hut
and
ure
; (ii) it competes with the lysine-sensitive activator for binding at
gdhA
; (iii) it binds to the same sites at the
hut
,
ure
,
nac
, and
gdhA
promoters as NAC
WT
; (iv) the relative affinity of NAC
L111K
for these sites follows the same order as NAC
WT
(
ure
>
gdhA
>
nac
>
hut
); (v) it induces the same slight bend as dimers of NAC
WT
; and (vi) its DNase I footprints at these sites are indistinguishable from those of NAC
WT
(except for features ascribed to tetramer formation). The only two phenotypes we know for negative control mutants of NAC are their inability to tetramerize and their inability to cause the strong repression of
gdhA
. Thus, we propose that in order for NAC
WT
to exert the strong repression, it must form a tetramer that bridges the two sites at
gdhA
(similar to other DNA looping models) and that the negative control mutants of NAC, which fail to tetramerize, cannot form this loop and thus fail to exert the strong repression at
gdhA
.
Role of the
Pseudomonas fluorescens
Alginate Lyase (AlgL) in Clearing the Periplasm of Alginates Not Exported to the Extracellular Environment
Authors: Bakkevig Karianne , Sletta Håvard , Gimmestad Martin , Aune Randi , Ertesvåg Helga , Degnes Kristin , Christensen Bjørn Erik , Ellingsen Trond E. , Valla Svein
Published: December 2005

Alginate is an industrially widely used polysaccharide produced by brown seaweeds and as an exopolysaccharide by bacteria belonging to the genera
Pseudomonas
and
Azotobacter
. The polymer is composed of the two sugar monomers mannuronic acid and guluronic acid (G), and in all these bacteria the genes encoding 12 of the proteins essential for synthesis of the polymer are clustered in the genome. Interestingly, 1 of the 12 proteins is an alginate lyase (AlgL), which is able to degrade the polymer down to short oligouronides. The reason why this lyase is associated with the biosynthetic complex is not clear, but in this paper we show that the complete lack of AlgL activity in
Pseudomonas fluorescens
in the presence of high levels of alginate synthesis is toxic to the cells. This toxicity increased with the level of alginate synthesis. Furthermore, alginate synthesis became reduced in the absence of AlgL, and the polymers contained much less G residues than in the wild-type polymer. To explain these results and other data previously reported in the literature, we propose that the main biological function of AlgL is to degrade alginates that fail to become exported out of the cell and thereby become stranded in the periplasmic space. At high levels of alginate synthesis in the absence of AlgL, such stranded polymers may accumulate in the periplasm to such an extent that the integrity of the cell is lost, leading to the observed toxic effects.
The ClgR Protein Regulates Transcription of theclpPOperon inBifidobacterium breveUCC 2003
Authors: Ventura Marco , Zhang Ziding , Cronin Michelle , Canchaya Carlos , Kenny John G. , Fitzgerald Gerald F. , van Sinderen Douwe
Published: December 2005

Fiveclpgenes (clpC,clpB,clpP1,clpP2, andclpX), representing chaperone- and protease-encoding genes, were previously identified inBifidobacterium breveUCC 2003. In the present study, we characterize theB. breveUCC 2003clpPlocus, which consists of two paralogous genes, designatedclpP1andclpP2, whose deduced protein products display significant similarity to characterized ClpP peptidases. Transcriptional analyses showed that theclpP1andclpP2genes are transcribed in response to moderate heat shock as a bicistronic unit with a single promoter. The role of aclgRhomologue, known to control the regulation ofclpPgene expression inStreptomyces lividansandCorynebacterium glutamicum, was investigated by gel mobility shift assays and DNase I footprint experiments. We show that ClgR, which in its purified form appears to exist as a dimer, requires a proteinaceous cofactor to assist in specific binding to a 30-bp region of theclpPpromoter region. In pull-down experiments, a 56-kDa protein copurified with ClgR, providing evidence that the two proteins also interact in vivo and that the copurified protein represents the cofactor required for ClgR activity. The prediction of the ClgR three-dimensional structure provides further insights into the binding mode of this protein to theclpP1promoter region and highlights the key amino acid residues believed to be involved in the protein-DNA interaction.
Genetic Requirements for Potassium Ion-Dependent Colony Spreading inBacillus subtilis
Authors: Kinsinger Rebecca F. , Kearns Daniel B. , Hale Marina , Fall Ray
Published: December 2005

Undomesticated strains ofBacillus subtilisexhibit extensive colony spreading on certain soft agarose media: first the formation of dendritic clusters of cells, followed by spreading (pellicle-like) growth to cover the entire surface. These phases of colonization are dependent on the level of potassium ion (K+) but independent of flagella, as verified with a mutant with ahaggene replacement; this latter finding highlights the importance of sliding motility in colony spreading. Exploring the K+requirement, directed mutagenesis of the higher-affinity K+transporter KtrAB, but not the lower-affinity transporter KtrCD, was found to inhibit surface colonization unless sufficient KCl was added. To identify other genes involved in K+-dependent colony spreading, transposon insertion mutants in wild-type strain 3610 were screened. Disruption of genes for pyrimidine (pyrB) or purine (purD,purF,purH,purL,purM) biosynthetic pathways abolished the K+-dependent spreading phase. Consistent with a requirement for functional nucleic acid biosynthesis, disruption of purine synthesis with the folic acid antagonist sulfamethoxazole also inhibited spreading. Other transposon insertions disrupted acetoin biosynthesis (thealsSgene), acidifying the growth medium, glutamine synthetase (theglnAgene), and two surfactin biosynthetic genes (srfAA,srfAB). This work identified four classes of surface colonization mutants with defective (i) potassium transport, (ii) surfactin formation, (iii) growth rate or yield, or (iv) pH control. Overall, the ability ofB. subtilisto colonize surfaces by spreading is highly dependent on balanced nucleotide biosynthesis and nutrient assimilation, which require sufficient K+ions, as well as growth conditions that promote sliding motility.
Coexpression Patterns of σBRegulators inBacillus subtilisAffect σBInducibility
Authors: Zhang Shuyu , Reeves Adam , Woodbury Robyn L. , Haldenwang W. G.
Published: December 2005

RsbT is an essential component of the pathway that activates theBacillus subtilisσBtranscription factor in response to physical stress.rsbTis located within an operon that includes the genes for its principal negative regulator (RsbS) and the stress pathway component that it activates (RsbU), as immediate upstream and downstream neighbors. In the current work we demonstrate that RsbT's ability to function is strongly influenced by coexpression with these adjoining genes. WhenrsbTis expressed at a site displaced fromrsbSandrsbU, RsbT accumulates but it is unable to activate σBfollowing stress. RsbT activity is restored ifrsbTis cotranscribed at the alternative site with the genes that normally abut it. Additionally, anrsbSallele whose product allows constitutively high RsbT-dependent σBactivity displays this activity inrsbSmerodiploid strains only when cotranscribed withrsbTand is recessive to a wild-typersbSallele only if the wild-typersbSgene is not cotranscribed with anrsbTgene of its own. The data suggest that RsbS and RsbT are synthesized in equivalent amounts and interact coincidently with their synthesis to form stable regulatory complexes that maintain RsbT in a state from which it can be stress activated.
Inhibition of
Bacillus subtilis scoC
Expression by Multicopy
senS
Authors: Kawachi Eiji , Abe Sadanobu , Tanaka Teruo
Published: December 2005

The
Bacillus subtilis aprE
gene, which encodes the extracellular alkaline protease, is regulated by many positive and negative transcriptional regulators. SenS is one such positive regulator consisting of 65 amino acids. We found that the
senS
gene on a multicopy plasmid, pSEN24, caused an increase in
aprE
expression in strains carrying the upstream region of
aprE
up to −340 with respect to the transcription initiation site but not in a strain carrying the region up to −299, which is within the binding site of the negative regulator ScoC (Hpr). Epistatic analysis showed that the pSEN24 effect was lost in a
scoC
-deleted mutant. In accordance with these results, the
scoC
transcription level as assayed by a
scoC-lacZ
fusion and Northern analysis was greatly reduced in the cells carrying pSEN24. From these results we conclude that multicopy
senS
enhances
aprE
expression by suppressing the transcription of
scoC
.
RANKING FUZZY NUMBER BASED ON LEXICOGRAPHIC SCREENING PROCEDURE
Authors: WANG MIAO-LING , WANG HSIAO-FAN , LIN CHIH-LUNG
Published: December 2005

Fuzzy numbers are used for representing the numerical quantities in a vague environment. Their ranking order has been an important issue for application purposes. Most of the existing ranking methods transform a fuzzy number into a real number based on certain criteria. There is yet no method that can always give a satisfactory solution. This study pointed out that it cannot be avoided for different fuzzy numbers to be corresponding to the same real number by any type of ranking functions. Therefore, sequential screening approach would be necessary for a complete order of fuzzy numbers. We summarize the properties for a sufficient and necessary set of ranking criteria. Then, based on the ranking order of these criteria, a Lexicographical Screening Procedure is proposed, which has shown to be promising in ranking fuzzy number with efficient computation and ease of understanding. Six counterexamples of the existing methods were used for comparison.
ESTIMATING THE MINIMUM ENTROPY OF CHINESE AND JAPANESE LANGUAGES
Authors: REN FUJI , YEN KANG
Published: December 2005

The study of minimum entropy of a natural language has been an interesting research subject. For English, great progress has been made, but few reports on other languages have been found in literature. Based on two hypotheses on the conservation of information quantity, we proposed a method which can be used to estimate the minimum entropy of characters in natural languages. With a large quantity of translation corpus, this method enables us to estimate the minimum entropy without calculating the probability. Besides, as the scale of translation corpus increases, the fluctuation of the ratio between character quantities in any two languages becomes negligible. In this paper, we apply this method to the study of two languages of a large character total — Japanese and Chinese.
WHAT CHARACTERIZES SUCCESSFUL IT PROJECTS
Authors: KARLSEN JAN TERJE , ANDERSEN JEANETTE , BIRKELY LIVE S. , ØDEGÅRD ELISE
Published: December 2005

This paper presents empirical research aimed at studying what characterizes successful information technology (IT) projects. There are often doubts about what characterizes project success and who actually defines it. In this paper, we have reviewed the literature and present significant contributions to the discussion of what characterizes successful IT projects. Furthermore, a survey was conducted in Norway to collect data on successful IT projects. Research results show that the five most important success criteria are: (1) the IT system works as expected and solves the problems, (2) satisfied users, (3) the IT system has high reliability, (4) the solution contributes to improved efficiency and competitive power, and (5) the IT system realizes strategic, tactical and operational objectives.
FUZZY LINEAR PROGRAMMING FOR DECISION MAKING AND PLANNING UNDER UNCERTAINTY
Authors: VASANT PANDIAN M.
Published: December 2005

In this paper, the S-curve membership function methodology is used in a real life industrial problem of mix product selection. This problem occurs in the chocolate manufacturing industry whereby a decision maker, analyst and implementer play important roles in making decisions in an uncertain environment. As analysts, we try to find a solution with a higher level of satisfaction for the decision maker to make a final decision. This problem of mix product selection is considered because all the coefficients such as objective, technical and resource variables are fuzzy. This is considered as one of the sufficiently large problem involving 29 constraints and 8 variables. A decision maker can identify which vagueness (α) is suitable for achieving satisfactory optimal revenue. The decision maker can also suggest to the analyst some possible and practicable changes in fuzzy intervals for improving the satisfactory revenue. This interactive process has to go on among the analyst, the decision maker and the implementer until an optimum satisfactory solution is achieved and implemented.
CLASSIFYING CREDIT CARD ACCOUNTS FOR BUSINESS INTELLIGENCE AND DECISION MAKING: A MULTIPLE-CRITERIA QUADRATIC PROGRAMMING APPROACH
Authors: SHI YONG , PENG YI , KOU GANG , CHEN ZHENGXIN
Published: December 2005

A major challenge in credit card portfolio management is to classify and predict credit cardholders' behaviors in a reliable precision because cardholders' behaviors are rather dynamic in nature. This is crucial for creditors because it allows them to take proactive actions and minimize charge-off and bankruptcy losses. Although the methods used in the area of credit portfolio management have improved significantly, the demand for alternative and sophisticated analytical tools is still strong.

The objective of this paper is to propose a multiple criteria quadratic programming (MCQP) to classify credit card accounts for business intelligence and decision making. MCQP is intended to predict credit cardholders' behaviors from a nonlinear perspective that is justifiable because both the objective functions and constraints in credit card accounts classification may be nonlinear. Using a real-life credit card dataset from a major US bank, the MCQP method is compared with popular and similar classification methods: linear discriminant analysis, decision tree, multiple criteria linear programming, support vector machine, and neural network. The results indicate that MCQP is a promising business intelligence method in credit card portfolio management.
Low Temperature Growth GaAs on Ge
Authors: Knuuttila L. , Lankinen A. , Likonen J. , Lipsanen H. , Lu X. , McNally P. , Riikonen J. , Tuomi T.
Published: December 2005

In this work, low temperature growth of GaAs epitaxial layers on Ge substrates by metalorganic vapor phase epitaxy has been studied. The experiments show that a growth temperature of 530°C and a V/III ratio of 3.5 result in smooth GaAs surfaces. Atomic force micrographs do not show any anti-phase boundaries on the surface of GaAs grown on a misoriented substrate. X-ray diffraction curves show that the layer tilt is reduced as the growth temperature is lowered. Synchrotron X-ray topography reveals very low threading dislocation densities of 300 cm-2 for the GaAs epitaxial layers. Additionally, no misfit dislocations are observed. If a single layer is deposited at low temperature, secondary ion mass spectrometry shows a considerably reduced arsenic diffusion into Ge. When an additional layer is deposited at higher temperature on top of the initial low temperature layer, a substantial increase for the deep concentration-dependent arsenic diffusion is found.