bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development: it's about time
Authors: Elman Jeff 
Published: July 2003

Abstract Traditionally, research has been defined as being about development if it focuses on behaviors that occur during development, without reference either to what precedes or follows, or – more importantly – the mechanisms that drive change. This perspective has been challenged by two new approaches: dynamical systems, and connectionism, both of which have as core goals the explanation of change. Interestingly, these approaches have also been seen by many as being at odds with one another, for reasons that are in part valid, and in part superficial. Recent developments in both approaches suggest that a convergence is occurring, although much remains to be done before a true unification can take place.
Different is good: connectionism and dynamic systems theory are complementary emergentist approaches to development
Authors: Smith Linda B. , Samuelson Larissa K. 
Published: July 2003

AbstractConnectionist and dynamic systems approaches to development are similar in that they are both emergentist theories that take a very different perspective from more traditional symbolic systems. Moreover, they are both based on similar mathematical principles. Nevertheless, connectionism and dynamic systems differ in the approach they take to the study of development. We argue that differences between connectionist and dynamic systems approaches in terms of the basic components of the models, what they see as the object of study, how they view the nature of knowledge and their notions of developmental change mean that they each stand to make different and unique contributions to a more complete theory of development. We present an example from our work on how children learn to learn words that illustrates the complementary nature of connectionist and dynamic systems theories.
Comparisons of developmental modeling frameworks and levels of analysis in cognition: connectionist and dynamic systems theories deserve attention, but don’t yet explain attention
Authors: Cowan Nelson 
Published: July 2003

Abstract In this article, an investigator who is outside of the connectionist / dynamic systems (CD) tradition, but is sympathetic to many of its theoretical stances, considers whether these are separate approaches and what the two approaches mean for the development of information processing. It is argued that these approaches have not been defined in the target articles of this special issue narrowly enough to make them clearly separate approaches. Rather, they appear to emphasize different aspects of a common approach. It is also suggested that they do not form an overarching theory of development but do form an important theoretical approach at one level of analysis. In particular, one may sometimes, but not always, have to get into nonlinear interactions between faculties of the mind to predict and explain behavior. Finally, an attempt is made to challenge the CD approach to become more global by confronting the issue of how attention and conscious awareness should be represented in these models, and how the development of them may occur. Evidence of changes in automatic and attention‐related parameters of processing may provide a scaffolding upon which better CD models can be constructed.
‘I'd Like to Read Fluorescently’— Year 7 Pupils' Developing Views of Reading and Their Progress
Authors: Pearson Sue 
Published: July 2003

Previous research has suggested that children making transitions from one setting into another have to adjust to new sets of expectations and different cultural contexts for teaching and learning. In particular, they have to redefine for themselves ‘what counts as literacy’. In this article, Sue Pearson, a past President of NASEN, an experienced teacher and currently a lecturer at Leeds University, reports on her investigations into whether similar adjustments may be required of some pupils as they start secondary school.The recommendations at the end of this article are based on interviews with 24 11 to 12 year‐olds and are of direct relevance to practitioners in primary and secondary schools and to parents and family members. Sue Pearson uses pupils' perceptions to raise important issues about the nature of the support that pupils experiencing difficulties in literacy require as they make the transfer from Year 6 to Year 7.
Scientific collaboratories in higher education: exploring learning style preferences and perceptions of technology
Authors: Sonnenwald Diane H. , Li Bin 
Published: August 2003

AbstractScientific collaboratories hold the promise of providing students access to specialized scientific instruments, data and experts, enabling learning opportunities perhaps otherwise not available. However, evaluation of scientific collaboratories in higher education has lagged behind their development. We conducted a repeated‐measures study that provided data regarding social interaction learning styles and perceptions of a scientific collaboratory system from 40 university science students working face‐to‐face and remotely. Students with a strong competitive learning style preference or who worked with a student with a strong competitive learning style reported a slightly more positive perception of the relative advantage, compatibility and complexity of the collaboratory system. Students with a strong individualistic learning style preference or who worked with a student with a strong individualistic learning style reported a more negative perception of the observability of the system. No relationships were found between students’ cooperative learning style preference and their perceptions of the system after using it face‐to‐face or remotely.
Reviews: 4
Authors: Christian‐Carter Judith 
Published: August 2003

Garrison, D R & Anderson, Terry (2003) E‐learning in the 21st Century RoutledgeFalmer (London & New York) ISBN 0‐335‐20791‐X 109 pp £17.99 (boards £55) http://www.tandf.co.uk

enquiry@tandf.co.uk
Reviews: 8
Authors: Hartley James 
Published: August 2003

O’Neill, Harold F & Perez, Ray ed (2003) Technology applications in education Erlbaum (Mahwah NJ (& Eurospan, London)) ISBN 0‐8058‐3649‐7 372 pp $79.95 boards http://www.erlbaum.com

orders@erlbaum.com

http://www.eurospan.co.uk

orders@eurospan.co.uk
Reviews: 11
Authors: Kirschner Paul 
Published: August 2003

Vrasidas, Charalambos & Glass, Gene ed (2002) Distance education and distributed learning Information Age (Greenwich CT) ISBN 1‐931576‐88‐2 231 pp $29.95 (boards $63.24) http://www.infoagepub.com

orders@infoagepub.com
Concepts of special educational need
Authors: Wedell Klaus 
Published: July 2003

Editor's note.
This article first appeared in ‘Education Today’ in 1981. At that time issues of classification and categorisation of children with special educational needs were being debated in many countries, and in England an enquiry into the education of children with disabilities had recommended the abolition of categories of disability in favour of the concept of special educational need (DES, 1978). Today, as the government consults on the reintroduction of disability categories, it seems appropriate to reconsider this concept and the thinking that led to its adoption. The use of the male pronoun has been retained in this article for fluency of reading. ‘He’ and ‘his’ should be understood as ‘he or she’ and ‘his or her’. The article is reprinted with the kind permission of the College of Teachers –http://www.collegeofteachers.ac.uk.
The labelling approach to deviance
Authors: Rains Prudence M. , Kitsuse John L. , Duster Troy , Freidson Eliot 
Published: July 2003

Editor's note.
In the 1970s Professor Nicholas Hobbs directed a comprehensive study on child classification while Provost at Vanderbilt University in the USA. Though neglected in recent years his 1975 edited text, ‘Issues in the Classification of Children’, remains a relevant and important source of thinking about categorisation. Given the current policy interest in categories of special educational need it seems appropriate to reconsider some of these ideas. The following article originally appeared as Chapter 4 from Volume One of the Hobbs text. It is reprinted here with the kind permission of the Hobbs family. The American spellings and style in this article have been altered for consistency with house style, as has the format of the references list.
Contexts, relationship quality, and family value socialization: The case of parent–school ideological fit in Israel
Authors: Knafo Ariel 
Published: August 2003

AbstractParent–school ideological fit is studied as the context of parent–child relationships and socialization. It was hypothesized that parents’ choice of school environments that promote values consistent with parents’ values is related to a better parent–child relationship and facilitates socialization. Participants were 589 Israeli families with religious, traditional, and nonreligious parents, whose adolescent children attended either religious or nonreligious schools. Most parents chose high–fit contexts—that is, schools that fit their own values. Parents in high–fit contexts exhibited relatively higher levels of value consistency, but lower levels of value discussion with their children. Value conflict with parents was lower in high–fit contexts, and the relationship with the father, but not with the mother, was warmer and closer. Accuracy of perception and acceptance of parental values, and parent–child value congruence were higher in high fit contexts, an effect partially mediated by relationship characteristics. The relevance of fit for family relationships, socialization, and school adaptation is discussed.
Drilling in the Cathedral
Authors: Rasmussen Larry 
Published: August 2003

AbstractUtilitarianism, alienation, consumerism, and oppression are major forces endangering Earth's well‐being. Over and against these morally and ecologically destructive forces are practices and ideas rooted and nourished in both ancient and modern religio‐moral institutions and traditions. As powerful voices of faith calling the present to account, sacramentalism, mysticism, asceticism, and prophetic liberative practices offer Earth‐honoring ways of life that draw from shared wells and deep‐running waters.
So That He Might Fill All Things: Comprehending the Cosmic Love of Christ
Authors: Santmire H. Paul 
Published: August 2003

AbstractWhat does Jesus Christ have to do with the starry skies above and the good earth under our feet? Although theological discussions of cosmic and ecological issues have often been developed in dialogue with the natural sciences, “cosmic christology” is itself intrinsically a theological theme. In response to the cosmic vision of Ephesians, this paper explores the contributions of two contemporary theologians who have developed cosmic christologies, Colin Gunton and Jürgen Moltmann, and then seeks to build critically on their achievements by reclaiming Luther's ubiquity christology and by calling upon the Johannine witness to Christ as the light and the shepherd of the cosmos.
Mutation in the
relA
Gene of
Vibrio cholerae
Affects In Vitro and In Vivo Expression of Virulence Factors
Authors: Haralalka Shruti , Nandi Suvobroto , Bhadra Rupak K. 
Published: August 2003

ABSTRACT

The
relA
gene product determines the level of (p)ppGpp, the effector nucleotides of the bacterial stringent response that are also involved in the regulation of other functions, like antibiotic production and quorum sensing. In order to explore the possible involvement of
relA
in the regulation of virulence of
Vibrio cholerae
, a
relA
homolog from the organism (
relA
VCH
) was cloned and sequenced. The
relA
VCH
gene encodes a 738-amino-acid protein having functions similar to those of other gram-negative bacteria, including
Escherichia coli
. A Δ
relA
::
kan
allele was generated by replacing ∼31% of the open reading frame of wild-type
relA
of
V. cholerae
El Tor strain C6709 with a kanamycin resistance gene. The
V. cholerae relA
mutant strain thus generated, SHK17, failed to accumulate (p)ppGpp upon amino acid deprivation. Interestingly, compared to the wild type, C6709, the mutant strain SHK17 exhibited significantly reduced in vitro production of two principal virulence factors, cholera toxin (CT) and toxin-coregulated pilus (TCP), under virulence gene-inducing conditions. In vivo experiments carried out in rabbit ileal loop and suckling mouse models also confirmed our in vitro results. The data suggest that (p)ppGpp is essential for maximal expression of CT and TCP during in vitro growth, as well as during intestinal infection by virulent
V. cholerae
. Northern blot and reverse transcriptase PCR analyses indicated significant reduction in the transcript levels of both virulence factors in the
relA
mutant strain SHK17. Such marked alteration of virulence phenotypes in SHK17 appears most likely to be due to down regulation of transcript levels of
toxR
and
toxT
, the two most important virulence regulatory genes of
V. cholerae.
In SHK17, the altered expression of the two outer membrane porin proteins, OmpU and OmpT, indicated that the
relA
mutation most likely affects the ToxR-dependent virulence regulatory pathway, because it had been shown earlier that ToxR directly regulates their expression independently of ToxT.
Mutant Analysis of the
Escherichia coli
FhuA Protein Reveals Sites of FhuA Activity
Authors: Endriß Franziska , Braun Michael , Killmann Helmut , Braun Volkmar 
Published: August 2003

ABSTRACT

The FhuA outer membrane protein of
Escherichia coli
actively transports ferrichrome, albomycin, and rifamycin CGP 4832, and confers sensitivity to microcin J25, colicin M, and the phages T1, T5, and φ80. Guided by the FhuA crystal structure and derived predictions on how FhuA might function, mutants were isolated in the cork domain (residues 1 to 160) and in the β-barrel domain (residues 161 to 714). Deletion of the TonB box (residues 7 to 11) completely inactivated all TonB-dependent functions of FhuA. Fixation of the cork to turn 7 of the barrel through a disulfide bridge between introduced C27 and C533 residues abolished ferrichrome transport, which was restored by reduction of the disulfide bond. Deletion of residues 24 to 31, including the switch helix (residues 24 to 29), which upon binding of ferrichrome to FhuA undergoes a large structural transition (17 Å) and exposes the N terminus of FhuA (TonB box) to the periplasm, reduced FhuA transport activity (79% of the wild-type activity) but conferred full sensitivity to colicin M and the phages. Duplication of residues 23 to 30 or deletion of residues 13 to 20 resulted in FhuA derivatives with properties similar to those of FhuA with a deletion of residues 24 to 31. However, a frameshift mutation that changed QSEA at positions 18 to 21 to KKAP abolished almost completely most of FhuA's activities. The conserved residues R93 and R133 among energy-coupled outer membrane transporters are thought to fix the cork to the β-barrel by forming salt bridges to the conserved residues E522 and E571 of the β-barrel. Proteins with the E522R and E571R mutations were inactive, but inactivity was not caused by repulsion of R93 by R522 and R571 and of R133 by R571. Point mutations in the cork at sites that move or do not move upon the binding of ferrichrome had no effect or conferred only slightly reduced activities. It is concluded that the TonB box is essential for FhuA activity. The TonB box region has to be flexible, but its distance from the cork domain can greatly vary. The removal of salt bridges between the cork and the barrel affects the structure but not the function of FhuA.
Detachment of
Actinobacillus actinomycetemcomitans
Biofilm Cells by an Endogenous β-Hexosaminidase Activity
Authors: Kaplan Jeffrey B. , Ragunath Chandran , Ramasubbu Narayanan , Fine Daniel H. 
Published: August 2003

ABSTRACT

When cultured in broth, fresh clinical isolates of the gram-negative periodontal pathogen
Actinobacillus actinomycetemcomitans
form tenaciously adherent biofilm colonies on surfaces such as plastic and glass. These biofilm colonies release adherent cells into the medium, and the released cells can attach to the surface of the culture vessel and form new colonies, enabling the biofilm to spread. We mutagenized
A. actinomycetemcomitans
clinical strain CU1000 with transposon IS
903
φ
kan
and isolated a transposon insertion mutant that formed biofilm colonies which were tightly adherent to surfaces but which lacked the ability to release cells into the medium and disperse. The transposon insertion in the mutant strain mapped to a gene, designated
dspB
, that was predicted to encode a secreted protein homologous to the catalytic domain of the family 20 glycosyl hydrolases. A plasmid carrying a wild-type
dspB
gene restored the ability of biofilm colonies of the mutant strain to disperse. We expressed
A. actinomycetemcomitans
DspB protein engineered to contain a hexahistidine metal-binding site at its C terminus in
Escherichia coli
and purified the protein by using Ni affinity chromatography. Substrate specificity studies performed with monosaccharides labeled with 4-nitrophenyl groups showed that DspB hydrolyzed the 1→4 glycosidic bond of β-substituted
N
-acetylglucosamine, which is consistent with the known functions of other family 20 glycosyl hydrolases. When added to culture medium, purified DspB protein, but not heat-inactivated DspB, restored the ability of the mutant strain to release cells and disperse. DspB protein also caused the detachment of cells from preformed biofilm colonies of strain CU1000 grown attached to plastic and the disaggregation of highly autoaggregated clumps of CU1000 cells in solution. We concluded that
dspB
encodes a soluble β-
N
-acetylglucosaminidase that causes detachment and dispersion of
A. actinomycetemcomitans
biofilm cells.
DapE Can Function as an Aspartyl Peptidase in the Presence of Mn
2+
Authors: Broder Daniel H. , Miller Charles G. 
Published: August 2003

ABSTRACT

Extracts of a multiply peptidase-deficient (
pepNABDPQTE iadA iaaA
)
Salmonella enterica
serovar Typhimurium strain contain an aspartyl dipeptidase activity that is dependent on Mn
2+
. Purification of this activity followed by N-terminal sequencing of the protein suggested that the Mn
2+
-dependent peptidase is DapE (
N
-succinyl-
l
,
l
-diaminopimelate desuccinylase). A
dapE
chromosomal disruption was constructed and transduced into a multiply peptidase-deficient (MPD) strain. Crude extracts of this strain showed no aspartyl peptidase activity, and the strain failed to utilize Asp-Leu as a leucine source. The
dapE
gene was cloned into expression vectors in order to overproduce either the native protein (DapE) or a hexahistidine fusion protein (DapE-His
6
). Extracts of a strain carrying the plasmid overexpresssing native DapE in the MPD
dapE
background showed a 3,200-fold elevation of Mn
2+
-dependent aspartyl peptidase activity relative to the MPD

dapE
+

strain. In addition, purified DapE-His
6
exhibited Mn
2+
-dependent peptidase activity toward aspartyl dipeptides. Growth of the MPD strain carrying a single genomic copy of
dapE
on Asp-Leu as a Leu source was slow but detectable. Overproduction of DapE in the MPD
dapE
strain allowed growth on Asp-Leu at a much faster rate. DapE was found to be specific for N-terminal aspartyl dipeptides: no N-terminal Glu, Met, or Leu peptides were hydrolyzed, nor were any peptides containing more than two amino acids. DapE is known to bind two divalent cations: one with high affinity and the other with lower affinity. Our data indicate that the form of DapE active as a peptidase contains Zn
2+
in the high-affinity site and Mn
2+
in the low-affinity site.
In Vivo and In Vitro Evidence that TtgV Is the Specific Regulator of the TtgGHI Multidrug and Solvent Efflux Pump of
Pseudomonas putida
Authors: Rojas Antonia , Segura Ana , Guazzaroni María Eugenia , Terán Wilson , Hurtado Ana , Gallegos María Trinidad , Ramos Juan L. 
Published: August 2003

ABSTRACT

The TtgGHI efflux pump of
Pseudomonas putida
DOT-T1E plays a key role in the innate and induced tolerance of this strain to aromatic hydrocarbons and antibiotics. The
ttgGHI
operon is expressed constitutively from two overlapping promoters in the absence of solvents and at a higher level in their presence, but not in response to antibiotics. Adjacent to the
ttgGHI
operon is the divergently transcribed
ttgVW
operon. In TtgV-deficient backgrounds, although not in a TtgW-deficient background, expression of the
ttgGHI
and
ttgVW
operons increased fourfold. This suggests that TtgV represses expression from the
ttgG
promoters and controls its own. TtgW plays no major role in the regulation of expression of these promoters. Primer extension revealed that the divergent
ttgG
and
ttgV
promoters overlap, and mobility shift assays indicated that TtgV binds to this region with high affinity. DNaseI footprint assays revealed that TtgV protected four DNA helical turns that include the −10 and −35 boxes of the
ttgV
and
ttgG
promoters.
Expression of the
Pseudomonas putida
OCT Plasmid Alkane Degradation Pathway Is Modulated by Two Different Global Control Signals: Evidence from Continuous Cultures
Authors: Dinamarca M. Alejandro , Aranda-Olmedo Isabel , Puyet Antonio , Rojo Fernando 
Published: August 2003

ABSTRACT

Expression of the genes of the alkane degradation pathway encoded in the
Pseudomonas putida
OCT plasmid are subject to negative and dominant global control depending on the carbon source used and on the physiological status of the cell. We investigated the signals responsible for this control in chemostat cultures under conditions of nutrient or oxygen limitation. Our results show that this global control is not related to the growth rate and responds to two different signals. One signal is the concentration of the carbon source that generates the repressing effect (true catabolite repression control). The second signal is influenced by the level of expression of the cytochome
o
ubiquinol oxidase, which in turn depends on factors such as oxygen availability or the carbon source used. Since under carbon limitation conditions the first signal is relieved but the second signal is not, we propose that modulation mediated by the cytochrome
o
ubiquinol oxidase is not classical catabolite repression control but rather a more general physiological control mechanism. The two signals have an additive, but independent, effect, inhibiting induction of the alkane degradation pathway.
PorA Represents the Major Cell Wall Channel of the Gram-Positive BacteriumCorynebacterium glutamicum
Authors: Costa-Riu Noelia , Burkovski Andreas , Krämer Reinhard , Benz Roland 
Published: August 2003

ABSTRACTThe cell wall of the gram-positive bacteriumCorynebacterium glutamicumcontains a channel (porin) for the passage of hydrophilic solutes. The channel-forming polypeptide PorA is a 45-amino-acid acidic polypeptide with an excess of four negatively charged amino acids, which is encoded by the 138-bp geneporA.porAwas deleted from the chromosome ofC.glutamicumwild-type strain ATCC 13032 to obtain mutant ATCC 13032ΔporA. Southern blot analysis demonstrated thatporAwas deleted. Lipid bilayer experiments revealed that PorA was not present in the cell wall of the mutant strain. Searches within the known chromosome ofC. glutamicumby using National Center for Biotechnology Information BLAST and reverse transcription-PCR showed that no other PorA-like protein is encoded on the chromosome or is expressed in the deletion strain. TheporAdeletion strain exhibited slower growth and longer growth times than theC. glutamicumwild-type strain. Experiments with different antibiotics revealed that the susceptibility of the mutant strain was much lower than that of the wild-typeC. glutamicumstrain. The results presented here suggest that PorA represents a major hydrophilic pathway through the cell wall and thatC. glutamicumcontains cell wall channels which are not related to PorA.