bluuebunny/crossref_metadata_2025_split huggingface dataset:
Websites as educational motivators for adults with learning disability
Authors: Johnson Rachel , Hegarty John R. 
Published: August 2003

AbstractAdults with learning disability pose an educational challenge for teachers and support workers. They frequently have limited skills in reading and writing, and may find it difficult to pay attention to topics of little interest to them. Nevertheless, they can be keen to use new technology, and often have hobbies and interests that are catered for on the Internet. This article describes a project aimed to highlight the advantages and weaknesses of web‐based learning for adults with learning disability, and to suggest improvements. Eight students with mild to moderate learning disability were helped to find websites related to their interests, and supported in creating multimedia work linked to those sites. Results showed the powerfully motivating effect of the websites for students, but highlighted the access difficulties posed by websites for such students. Further work in this area is needed, to develop strategies for exploiting the motivating effect of websites, and to improve the accessibility of sites for people with low literacy levels.
Adaptive navigation support in educational hypermedia: the role of student knowledge level and the case for meta‐adaptation
Authors: Brusilovsky Peter 
Published: August 2003

AbstractAdaptive hypermedia is an alternative to the traditional “one‐size‐fits‐all” approach in the development of hypermedia systems. Adaptive hypermedia (AH) systems build a model of the goals, preferences, and knowledge of each individual user, and use this model throughout the interaction with the user, in order to adapt to the needs of that user. Adaptive navigation support is a specific group of adaptive hypermedia techniques that become especially popular in educational hypermedia systems. This paper provides a brief overview of main adaptive navigation support techniques and analyzes the results of most representative empirical studies of these techniques. It demonstrates an evidence that different known techniques work most efficiently in different context. In particular, the studies summarized in the paper have provided evidence that users with different knowledge level of the subject may appreciate different adaptive navigation support technologies. The paper argues that more empirical studies are required to help the developers of adaptive hypermedia systems in selecting most relevant adaptation technologies. It also attempts to build a case for meta‐adaptive hypermedia systems, ie, systems that are able to adapt the very adaptation technology to the given user and context.
Adaptive web‐based learning: accommodating individual differences through system's adaptation
Authors: Magoulas George D. , Papanikolaou Yparisia , Grigoriadou Maria 
Published: August 2003

AbstractThe idea of developing educational hypermedia systems for the Web is very challenging, and demands the synergy of computer science and instructional science. The paper builds on theories from instructional design and learning styles to develop a design rational and guidelines for adaptive web‐based learning systems that use individual differences as a basis of system's adaptation. Various examples are provided to illustrate how instructional manipulations with regards to content adaptation and presentation, and adaptive navigation support, as well as the overall degree of system adaptation, are guided by educational experiences geared towards individual differences.
Reviews: 9
Authors: Deeson Eric 
Published: August 2003

Rudestam, Kjell & Schoenholtz‐Read, Judith ed (2002) Handbook of online learning Sage (Thousand Oaks CA & London) ISBN 0‐7619‐2403‐5 460 pp £35 (boards £69) http://www.sagepub.co.uk

info@sagepub.co.uk
Human Resource Management and Individualisation in Australian Labour Law
Authors: Mitchell Richard , Fetter Joel 
Published: August 2003

By tradition, Australian industrial relations have been regulated by industrial awards and collective agreements made by, or under the auspices of, industrial tribunals. The central parties to these agreements and awards were employers and trade unions. The individual employment contract between employer and employee was subject to these collective arrangements, which, generally speaking, set the minimum floor of employment conditions from which the parties could not derogate. In common with other countries, there was a strong push for ‘deregulation’ of the labour market throughout the 1980s and the 1990s in Australia. In 1996, the Liberal/National Party Coalition conservative government introduced new federal labour laws that permitted employers and employees to enter individualised employment relationships by excluding the operation of much collective regulation from their affairs. The present paper explores the supposed rationales for this legal development, and outlines the legal conditions that are imposed upon this statutory individualisation process. It also examines the evidence in order to address certain questions: ‘How effective has the individualisation process been in Australia?’; ‘Explicitly or implicitly, what sort of employment system outcomes were envisaged?’; ‘What forms of flexibility has it been able to introduce into the employment relationship?’; and ‘To what extent has it been able to promote a “high performance” HRM agenda in Australian workplaces?’
Ecological Theology: Roots in Tradition, Liturgical and Ethical Practice for Today
Authors: Ruether Rosemary Radford 
Published: August 2003

AbstractOften it is claimed that themes occasionally present in Christianity such as anthropocentrism, ecological alienation, and redemption as a world‐escaping disembodied immortality, translated directly into large‐scale abuse of nature and subsequent ecological crisis. Such a view is too simplistic, however. Instead the present environmental and ecological crisis may be primarily traced to cultural, economic, and technological developments of the last 500 years. Indeed, within Christian monasticism, ecofeminism, covenantal ethics, and cosmic christology, one finds ample resources for the transformation of human attitudes towards nature and a brighter ecological future.
Ecology Needs Theology
Authors: Siegenthaler David 
Published: August 2003

AbstractA primary purpose of theology is the explication of the relationship of Creation to the transcendent for the sake of responsible action in the world. Environmental policy arenas need a perspective that can take them beyond a more limited utilitarianism. Ecology needs theology. We can appreciate to a much greater extent today than we could a generation ago that all theologies are products of particular people within particular social, cultural, historical, geographical situations. To do theology adequately, it is clearer now that many perspectives must be considered—both within and outside one's own tradition. Theology must be conversational. One's assertions of values and proposed actions must be weighed against the assertions of others. Only through such engagement will theology be meaningful to lives that must be lived with integrity in a world of manifold ambiguities. That world is the whole world in which human community is sustained and to which human beings are responsible. The practical effects of theological engagement will be to help us all find a better “common good” than may be obtained otherwise.
Globalization in Light of Luther's Eucharistic Economic Ethics
Authors: Moe‐Lobeda Cynthia 
Published: August 2003

AbstractThis article suggests that Christ “filling all things,” and abiding in a special way in the assembly of believers, offers moral agency for faithful response to economic structures that gravely threaten Earth's regenerative capacities. That claim is explored through Luther's theology of Christ indwelling creation held together with his eucharistic economic ethics, his call to certain practices, his refusal to minimize the pervasiveness of human sin, and his insistence that in brokenness and defeat the saving God is present and calls forth power. The trends designated by the term “globalization,” as used in this essay, are clarified. Dangers posed to the Earth community by that constellation of trends are illustrated.
Ecclesial DNA
Authors: Murphy George L. 
Published: August 2003

AbstractWe discuss here the metaphor of church DNA which has been used in arguments against Called to Common Mission. Consideration of the role of the genetic material in biological organisms enables us to suggest what it might mean to say that the DNAs of different Christian traditions are or are not compatible. As plants or animals belong to the same species if they can propagate their kind, church bodies can be said to be compatible if their inter‐communion furthers the church's mission to make disciples. Some ways in which ecumenical agreements might make this possible are considered.
Polar Localization of CheA
2
in
Rhodobacter sphaeroides
Requires Specific Che Homologs
Authors: Martin Angela C. , Nair Usha , Armitage Judith P. , Maddock Janine R. 
Published: August 2003

ABSTRACT

Rhodobacter sphaeroides
is a motile bacterium that has multiple chemotaxis genes organized predominantly in three major operons (
che
Op
1
,
che
Op
2
, and
che
Op
3
). The chemoreceptor proteins are clustered at two distinct locations, the cell poles and in one or more cytoplasmic clusters. One intriguing possibility is that the physically distinct chemoreceptor clusters are each composed of a defined subset of specific chemotaxis proteins, including the chemoreceptors themselves plus specific CheW and CheA proteins. Here we report the subcellular localization of one such protein, CheA
2
, under aerobic and photoheterotrophic growth conditions. CheA
2
is predominantly clustered and localized at the cell poles under both growth conditions. Furthermore, its localization is dependent upon one or more genes in
che
Op
2
but not those of
che
Op
1
or
che
Op
3
. In
E. coli
, the polar localization of CheA depends upon CheW. The
R. sphaeroides che
Op
2
contains two
cheW
genes. Interestingly, CheW
2
is required under both aerobic and photoheterotrophic conditions, whereas CheW
3
is not required under aerobic conditions but appears to play a modest role under photoheterotrophic conditions. This suggests that
R. sphaeroides
contains at least two distinct chemotaxis complexes, possibly composed of proteins dedicated for each subcellular location. Furthermore, the composition of these spatially distinct complexes may change under different growth conditions.
Performance of Standard Phenotypic Assays for TonB Activity, as Evaluated by Varying the Level of Functional, Wild-Type TonB
Authors: Larsen Ray A. , Chen Gregory J. , Postle Kathleen 
Published: August 2003

ABSTRACTThe ability of gram-negative bacterial cells to transport cobalamin and iron-siderophore complexes and their susceptibility to killing by some bacteriophages and colicins are characteristics routinely used to assay mutations of proteins in the TonB-dependent energy transduction system. These assays vary greatly in sensitivity and are subject to perturbation by overexpression of TonB and, perhaps, other proteins that contribute to the process. Thus, the choice of assay and the means by which a potential mutant is expressed can greatly influence the interpretation and recognition of a given mutant. In the present study, we expressed TonB at several different quantified levels in cells that were then subjected to a panel of assays. Our results suggest that it is reasonable to regard the assays as having windows of sensitivity. Thus, while no single assay satisfactorily spans the potential range of TonB activity, it is evident that certain assays are better suited for resolving small deviations from wild-type levels of activity, with others most useful when activity levels are very low. It is apparent from the results that the application of all possible assays to the characterization of new mutants will yield the most meaningful results.
Role of
Pseudomonas putida tol-oprL
Gene Products in Uptake of Solutes through the Cytoplasmic Membrane
Authors: Llamas María A. , Rodríguez-Herva José J. , Hancock Robert E. W. , Bitter Wilbert , Tommassen Jan , Ramos Juan L. 
Published: August 2003

ABSTRACT

Proteins of the Tol-Pal (Tol-OprL) system play a key role in the maintenance of outer membrane integrity and cell morphology in gram-negative bacteria. Here we describe an additional role for this system in the transport of various carbon sources across the cytoplasmic membrane. Growth of
Pseudomonas putida tol-oprL
mutant strains in minimal medium with glycerol, fructose, or arginine was impaired, and the growth rate with succinate, proline, or sucrose as the carbon source was lower than the growth rate of the parental strain. Assays with radiolabeled substrates revealed that the rates of uptake of these compounds by mutant cells were lower than the rates of uptake by the wild-type strain. The pattern and amount of outer membrane protein in the
P. putida tol-oprL
mutants were not changed, suggesting that the transport defect was not in the outer membrane. Consistently, the uptake of radiolabeled glucose and glycerol in spheroplasts was defective in the
P. putida tol-oprL
mutant strains, suggesting that there was a defect at the cytoplasmic membrane level. Generation of a proton motive force appeared to be unaffected in these mutants. To rule out the possibility that the uptake defect was due to a lack of specific transporter proteins, the PutP symporter was overproduced, but this overproduction did not enhance proline uptake in the
tol-oprL
mutants. These results suggest that the Tol-OprL system is necessary for appropriate functioning of certain uptake systems at the level of the cytoplasmic membrane.
Rod Shape Determination by the
Bacillus subtilis
Class B Penicillin-Binding Proteins Encoded by
pbpA
and
pbpH
Authors: Wei Yuping , Havasy Teresa , McPherson Derrell C. , Popham David L. 
Published: August 2003

ABSTRACT

The peptidoglycan cell wall determines the shape and structural integrity of a bacterial cell. Class B penicillin-binding proteins (PBPs) carry a transpeptidase activity that cross-links peptidoglycan strands via their peptide side chains, and some of these proteins are directly involved in cell shape determination. No
Bacillus subtilis
PBP with a clear role in rod shape maintenance has been identified. However, previous studies showed that during outgrowth of
pbpA
mutant spores, the cells grew in an ovoid shape for several hours before they recovered and took on a normal rod shape. It was postulated that another PBP, expressed later during outgrowth, was able to compensate for the lack of the
pbpA
product, PBP2a, and to guide the formation of a rod shape. The
B. subtilis pbpH
(
ykuA
) gene product is predicted to be a class B PBP with greatest sequence similarity to PBP2a. We found that a
pbpH-lacZ
fusion was expressed at very low levels in early log phase and increased in late log phase. A
pbpH
null mutant was indistinguishable from the wild-type, but a
pbpA pbpH
double mutant was nonviable. When
pbpH
was placed under the control of an inducible promoter in a
pbpA
mutant, viability was dependent on
pbpH
expression. Growth of this strain in the absence of inducer resulted in conversion of the cells from rods to ovoid/round shapes and lysis. We conclude that PBP2a and PbpH play redundant roles in formation of a rod-shaped peptidoglycan cell wall.
A Rhamnogalacturonan Lyase in the
Clostridium cellulolyticum
Cellulosome
Authors: Pagès Sandrine , Valette Odile , Abdou Laetitia , Bélaïch Anne , Bélaïch Jean-Pierre 
Published: August 2003

ABSTRACT

Clostridium cellulolyticum
secretes large multienzymatic complexes with plant cell wall-degrading activities named cellulosomes. Most of the genes encoding cellulosomal components are located in a large gene cluster:
cipC
-
cel
48
F
-
cel
8
C-cel
9
G-cel
9
E
-
orfX
-
cel
9
H-cel
9
J-man
5
K-cel
9
M
. Downstream of the
cel
9
M
gene, a new open reading frame was discovered and named
rgl
11
Y
. Amino acid sequence analysis indicates that this gene encodes a multidomain pectinase, Rgl11Y, containing an N-terminal signal sequence, a catalytic domain belonging to family 11 of the polysaccharide lyases, and a C-terminal dockerin domain. The present report describes the biochemical characterization of a recombinant form of Rgl11Y. Rgl11Y cleaves the α-
l
-Rha
p
-(1→4)-α-
d
-Gal
p
A glycosidic bond in the backbone of rhamnogalacturonan I (RGI) via a β-elimination mechanism. Its specific activity on potato pectic galactan and rhamnogalacturonan was found to be 28 and 3.6 IU/mg, respectively, indicating that Rgl11Y requires galactan decoration of the RGI backbone. The optimal pH of Rgl11Y is 8.5 and calcium is required for its activity. Rgl11Y was shown to be incorporated in the
C. cellulolyticum
cellulosome through a typical cohesin-dockerin interaction. Rgl11Y from
C. cellulolyticum
is the first cellulosomal rhamnogalacturonase characterized.
Transcriptional Pausing in the
Bacillus subtilis pyr
Operon In Vitro: a Role in Transcriptional Attenuation?
Authors: Zhang Hesheng , Switzer Robert L. 
Published: August 2003

ABSTRACT

The genes encoding the enzymes of pyrimidine nucleotide biosynthesis (
pyr
genes) are regulated in
Bacillus subtilis
and many other bacterial species by transcriptional attenuation. When UMP or UTP is bound to the PyrR regulatory protein, it binds to
pyr
mRNA at specific sequences and secondary structures in the RNA. Binding to this site prevents formation of an antiterminator stem-loop in the RNA and permits formation of a downstream terminator, leading to reduced expression of the
pyr
genes lying downstream from the terminator. The functioning of several other transcriptional attenuation systems has been shown to involve transcriptional pausing; this observation stimulated us to use single-round transcription of
pyr
genes to test for formation of paused transcripts in vitro. Using templates with each of the three known
B. subtilis pyr
attenuation sites, we identified one major pause site in each in which the half-life of the paused transcript was increased four- to sixfold by NusA. In each case pausing at the NusA-stimulated site prevented formation of a complete antiterminator stem-loop, while it resulted in increased time for a PyrR binding loop to form and for PyrR to bind to this loop. Thus, the pausing detected in vitro is potentially capable of playing a role in establishing the correct timing for
pyr
attenuation in vivo. With two of three
pyr
templates the combination of NusA with PyrR markedly stimulated termination of transcription at the normal termination sites. This suggests that NusA, by stabilizing pausing, plays a role in termination of
pyr
transcription in vivo.
Dependence of
Helicobacter pylori
Urease Activity on the Nickel-Sequestering Ability of the UreE Accessory Protein
Authors: Benoit Stéphane , Maier Robert J. 
Published: August 2003

ABSTRACT

The
Helicobacter pylori ureE
gene product was previously shown to be required for urease expression, but its characteristics and role have not been determined. The UreE protein has now been overexpressed in
Escherichia coli
, purified, and characterized, and three altered versions were expressed to address a nickel-sequestering role of UreE. Purified UreE formed a dimer in solution and was capable of binding one nickel ion per dimer. Introduction of an extra copy of
ureE
into the chromosome of mutants carrying mutations in the Ni maturation proteins HypA and HypB resulted in partial restoration of urease activity (up to 24% of the wild-type levels). Fusion proteins of UreE with increased ability to bind nickel were constructed by adding histidine-rich sequences (His-6 or His-10 to the C terminus and His-10 as a sandwich fusion) to the UreE protein. Each fusion protein was overexpressed in
E. coli
and purified, and its nickel-binding capacity and affinity were determined. Each construct was also expressed in wild-type
H. pylori
and in
hypA
and
hypB
mutant strains for determining in vivo urease activities. The urease activity was increased by introduction of all the engineered versions, with the greatest Ni-sequestering version (the His-6 version) also conferring the greatest urease activity on both the
hypA
and
hypB
mutants. The differences in urease activities were not due to differences in the amounts of urease peptides. Addition of His-6 to another expressed protein (triose phosphate isomerase) did not result in stimulation of urease, so urease activation is not related to the level of nonspecific protein-bound nickel. The results indicate a correlation between
H. pylori
urease activity and the nickel-sequestering ability of the UreE accessory protein.
Regulation of Sialic Acid Catabolism by the DNA Binding Protein NanR in
Escherichia coli
Authors: Kalivoda Kathryn A. , Steenbergen Susan M. , Vimr Eric R. , Plumbridge Jacqueline 
Published: August 2003

ABSTRACT

All
Escherichia coli
strains so far examined possess a chromosomally encoded
nanATEK-yhcH
operon for the catabolism of sialic acids. These unique nine-carbon sugars are synthesized primarily by higher eukaryotes and can be used as carbon, nitrogen, and energy sources by a variety of microbial pathogens or commensals. The gene
nanR
, located immediately upstream of the operon, encodes a protein of the FadR/GntR family that represses
nan
expression in
trans
. S1 analysis identified the
nan
transcriptional start, and DNA footprint analysis showed that NanR binds to a region of ∼30 bp covering the promoter region. Native (nondenaturing) polyacrylamide gel electrophoresis, mass spectrometry, and chemical cross-linking indicated that NanR forms homodimers in solution. The region protected by NanR contains three tandem repeats of the hexameric sequence GGTATA. Gel shift analysis with purified hexahistidine-tagged or native NanR detected three retarded complexes, suggesting that NanR binds sequentially to the three repeats. Artificial operators carrying different numbers of repeats formed the corresponding number of complexes. Among the sugars tested that were predicted to be products of the
nan
-encoded system, only the exogenous addition of sialic acid resulted in the dramatic induction of a chromosomal
nanA
-
lacZ
fusion or displaced NanR from its operator in vitro. Titration of NanR by the
nan
promoter region or artificial operators carrying different numbers of the GGTATA repeat on plasmids in this fusion strain supported the binding of the regulator to target DNA in vivo. Together, the results indicate that GGTATA is important for NanR binding, but the precise mechanism remains to be determined.