bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual role of the adenovirus pVI C terminus as a nuclear localization signal and activator of the viral protease
Authors: Honkavuori K. S. , Pollard B. D. , Rodriguez M. S. , Hay R. T. , Kemp G. D.
Published: October 2004

Adenain, the protease produced by adenovirus, is regulated by formation of a heterodimer with an 11 aa peptide derived from the C terminus of another adenoviral protein, pVI. Here, the role of the basic motif KRRR, which is conserved in pVI sequences from human adenovirus serotypes, was investigated. It was shown that this motif is less important than the N- or C-terminal regions in the formation of the adenain–peptide heterodimer and in the activity of the subsequent complex. This motif, however, acted as a nuclear localization signal that was capable of targeting heterologous proteins to the nucleus, resulting in a distinctive intranuclear distribution consisting of discrete foci, which is similar to that found for pVI during adenovirus infection.
Tula hantavirus infection of Vero E6 cells induces apoptosis involving caspase 8 activation
Authors: Li Xiao-Dong , Kukkonen Sami , Vapalahti Olli , Plyusnin Alexander , Lankinen Hilkka , Vaheri Antti
Published: October 2004

Hantaviruses are known to cause two severe human diseases: haemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. The mechanisms of pathogenesis of these two diseases are progressively becoming understood. Recently, two hantaviruses, Hantaan and Prospect Hill were reported to cause programmed cell death of Vero E6 cells. This study shows that Tula hantavirus (TULV) infection efficiently triggers an apoptotic programme in infected Vero E6 cells, and that the replication of TULV is required for the activation of caspase 3 and the cleavage of poly (ADP-ribose) polymerase, two molecular hallmarks of apoptosis. The enforced treatment of infected Vero E6 cells with tumour necrosis factor alpha (TNF-α), but not interferon alpha (IFN-α), advanced the time course of apoptosis. Furthermore, caspase 8 was activated on day 4 post-infection, the same day when caspase 3 was activated. TNF receptor 1 was induced during a late stage of TULV infection. These data suggest that, unlike during influenza A virus infection, TNF-α, but not type I IFN-α/β, may contribute significantly to apoptosis in a synergistic manner with TULV propagation. Interestingly, pretreatment with a broad-spectrum caspase inhibitor, z-VAD-fmk, efficiently inhibited apoptosis of TULV-infected Vero E6 cells. Taken together, these results suggest that TULV replication initiates a typical apoptotic programme involving caspase 8 activation.
Identification of putative atypical scrapie in sheep in Portugal
Authors: Orge Leonor , Galo Alexandre , Machado Carla , Lima Carla , Ochoa Cristina , Silva João , Ramos Manuel , Simas J. Pedro
Published: October 2004

Experimental transmission of bovine spongiform encephalopathy to sheep has prompted the implementation of a surveillance plan of scrapie in small ruminants by the European Union in all member states. Since its start over 30 000 animals have been tested, and the first seven cases of sheep with detectable PrPres deposition in the central nervous system have been identified in Portugal. Notably, the pattern of PrPres distribution in the brainstem was different from that previously described for scrapie and consistent in all seven animals. Moreover, the profile of the electrophoretic mobility of PrPres after proteinase K treatment was equivalent in all cases analysed but distinct from that observed for scrapie. Notably, four animals had genotypes rarely associated with scrapie, including one animal homozygous for A136R154R171. There were no cases found to exhibit vacuolation, a pattern of PrPres distribution or PrPres electrophoretic mobility corresponding to scrapie. These data reveal a putative atypical scrapie strain in Portugal not linked to specific Prnp genotypes.
Evidence for hepatitis E virus quasispecies
Authors: Grandadam Marc , Tebbal Soraya , Caron Mélanie , Siriwardana Mahinda , Larouze Bernard , Koeck Jean Louis , Buisson Yves , Enouf Vincent , Nicand Elisabeth
Published: October 2004

The genetic diversity of hepatitis E virus (HEV) has been extensively analysed during the last decade. Most sporadic and epidemic HEV strains are distributed into genotypes or groups. Nevertheless, few studies have looked at the polymorphism of HEV strains isolated from a given outbreak. A serum bank collected in Tanefdour, Algeria, during an acute hepatitis epidemic (1986–1987), retrospectively confirmed as hepatitis E, was analysed. Of the 69 serum samples collected within an 8-week period, 23 were positive for both partial ORF1 (replicase gene) and ORF2 (capsid gene) sequences. Inter- and intra-patient diversities were assessed by RFLP, and by sequencing a 448 bp sequence corresponding to ORF2. RFLP analysis distinguished three profiles: A (18/23), B (3/23) and C (2/23). Most isolates (18/23) shared 99·7–100 % sequence identity and the remainder showed 1–1·3 % divergence. HEV intra-patient diversity was studied using 12 isolates (seven displaying the major RFLP profile and five displaying minor RFLP profiles). For 9 of 12 isolates, additional intra-patient heterogeneity was revealed by RFLP analysis of 100 clones from each isolate and sequence diversity ranging from 0·11 to 3·4 %. These data strongly support the quasispecies organization of HEV during epidemics and could explain the adaptable behaviour of the virus in the host–pathogen interrelations.
Complete genome sequence of Mycoreovirus-1/Cp9B21, a member of a novel genus within the family Reoviridae, isolated from the chestnut blight fungus Cryphonectria parasitica
Authors: Suzuki Nobuhiro , Supyani S. , Maruyama Kazuyuki , Hillman Bradley I.
Published: October 2004

Mycoreovirus 1 (MYRV-1) is the type species of the newly described genus Mycoreovirus of the large virus family Reoviridae. The virus was isolated from a hypovirulent strain (9B21) of the chestnut blight fungus, Cryphonectria parasitica. A previous study showed that double-shelled particles introduced to fungal spheroplasts resulted in stably infected colonies. Of the 11 double-stranded RNA genomic segments (S1–S11), the three largest (S1–S3) were sequenced previously and shown to have moderate levels of similarity to the homologous segments of mammal-pathogenic coltiviruses (Eyach virus and Colorado tick fever virus) and another fungus-infecting reovirus, Mycoreovirus 3 of Rosellinia necatrix strain W370 (MYRV-3/RnW370). The sequences of the remaining segments (S4–S11) are reported here. All of the segments have single ORFs on their positive strands and the terminal sequences 5′-GAUCA----GCAGUCA-3′ are conserved among currently and previously sequenced segments. Oligo-cap analysis showed that the positive strands of the genomic segments are capped, whereas the negative strands are not. Similarities among the four evolutionarily related viruses include low or moderate levels of amino acid sequence identity (14·7–34·2 %) and isoelectric points among equivalent polypeptides, e.g. proteins encoded by segments S4 and S5 of the four viruses. Phylogenetic analysis indicated that MYRV-1/Cp9B21 is related more closely to MYRV-3/RnW370 than to the coltiviruses. An interesting dissimilarity is found in codon-choice pattern among the four viruses, i.e. MYRV-1/Cp9B21 segments have a lower frequency of [XYG+XYC] than corresponding segments of the other viruses, suggesting a possible adjustment of virus codon usage to their host environments.
Identification of a conserved linear epitope at the N terminus of the rabies virus glycoprotein
Authors: Mansfield K. L. , Johnson N. , Fooks A. R.
Published: October 2004

A novel, linear B-cell epitope has been identified at the N terminus of the rabies virus (RABV) glycoprotein. Screening of a phage-display library demonstrated that two glycoprotein-specific mAbs recognized a conserved sequence, WxxxDI, which aligned between aa 14 and 19 of the mature glycoprotein. Screening of truncated glycoprotein fragments with both mAbs confirmed the location of the epitope in the N-terminal region. Alignment of amino acid sequences from a range of RABV isolates indicated that the site was conserved in most viruses. Alignment with representatives of other lyssaviruses suggested that it is conserved within phylogroup I, which includes the European bat lyssaviruses, but not phylogroup II. A 12 aa synthetic peptide of this epitope was recognized by both mAbs and sera from a subset of rabies-vaccinated dogs. In a multimeric form, the peptide could induce an epitope-specific response following immunization in rabbits and mice.
Translation of hepatitis B virus (HBV) surface proteins from the HBV pregenome and precore RNAs in Semliki Forest virus-driven expression
Authors: Zajakina Anna , Kozlovska Tatyana , Bruvere Ruta , Aleksejeva Jekaterina , Pumpens Paul , Garoff Henrik
Published: October 2004

Hepatitis B virus (HBV) pregenome RNA (pgRNA) serves as a translation template for the HBV core (HBc) protein and viral polymerase (Pol). HBV precore RNA (pcRNA) directs the synthesis of the precore (preC) protein, a precursor of the hepatitis B e antigen (HBeAg). pgRNA and pcRNA were expressed in the Semliki Forest virus (SFV) expression system. Besides the HBc and preC proteins, there was revealed the synthesis of all three forms of HBV surface (HBs) proteins: long (LHBs), middle (MHBs) and short (SHBs), the start codons of which are located more than 1000 nt downstream of the HBc and preC start codons. Moreover, other HBV templates, such as 3′-truncated pgRNA lacking 3′ direct repeat and Pol mRNA, both carrying internally the HBs sequences, provided the synthesis of three HBs protein forms in the SFV-driven expression system. Maximal production of the HBs was provided by Pol mRNA, while HBc- and preC-producing templates showed relatively low internal translation of the HBs. These data allow the proposal of a ribosome leaky scanning model of internal translation initiation for HBs proteins. The putative functional role of such exceptional synthesis of the HBs proteins from the pgRNA and pcRNA templates in the natural HBV infection process needs further evaluation.
Gene prediction and verification in a compact genome with numerous small introns
Authors: Tenney Aaron E. , Brown Randall H. , Vaske Charles , Lodge Jennifer K. , Doering Tamara L. , Brent Michael R.
Published: October 2004

The genomes of clusters of related eukaryotes are now being sequenced at an increasing rate, creating a need for accurate, low-cost annotation of exon–intron structures. In this paper, we demonstrate that reverse transcription-polymerase chain reaction (RT–PCR) and direct sequencing based on predicted gene structures satisfy this need, at least for single-celled eukaryotes. The TWINSCAN gene prediction algorithm was adapted for the fungal pathogen Cryptococcus neoformans by using a precise model of intron lengths in combination with ungapped alignments between the genome sequences of the two closely related Cryptococcus varieties. This approach resulted in ∼60% of known genes being predicted exactly right at every coding base and splice site. When previously unannotated TWINSCAN predictions were tested by RT–PCR and direct sequencing, 75% of targets spanning two predicted introns were amplified and produced high-quality sequence. When targets spanning the complete predicted open reading frame were tested, 72% of them amplified and produced high-quality sequence. We conclude that sequencing a small number of expressed sequence tags (ESTs) to provide training data, running TWINSCAN on an entire genome, and then performing RT–PCR and direct sequencing on all of its predictions would be a cost-effective method for obtaining an experimentally verified genome annotation.
An active murine transposon family pair: Retrotransposition of “master” MusD copies and ETn trans-mobilization
Authors: Ribet David , Dewannieux Marie , Heidmann Thierry
Published: October 2004

The ETn (Early Transposon) elements are among the most active murine mobile sequences, being responsible for a series of mutations by insertion in vivo. Yet they are noncoding, and it had long been suspected that ETn are mobilized in trans by coding-competent elements, most probably from the closely related MusD family of LTR-retrotransposons. A genome-wide in silico search for coding-competent MusD elements identified a total of nine such copies, which we cloned and marked to test their transpositional activity, using an ex vivo assay in heterologous cells. Three copies were found to be autonomous for transposition, with each gag, pro, and pol MusD gene absolutely required for mobility. These active MusD copies specifically trigger retrotransposition of marked ETn elements with high efficiency, by complementation in trans. Characterization of the structures of de novo transposed MusD and ETn marked elements, as well as of their integration sites, disclosed canonical retroviral-like retrotransposition, with 6-bp target site duplications common to both elements. These results highlight the parasitic molecular strategies that are used by the ETn elements for their mobility, and unambiguously identify their “master genes.”
Ψ-Φ: Exploring the outer limits of bacterial pseudogenes
Authors: Lerat Emmanuelle , Ochman Howard
Published: October 2004

Because bacterial chromosomes are tightly packed with genes and were traditionally viewed as being optimized for size and replication speed, it was not surprising that the early annotations of sequenced bacterial genomes reported few, if any, pseudogenes. But because pseudogenes are generally recognized by comparisons with their functional counterparts, as more genome sequences accumulated, many bacterial pathogens were found to harbor large numbers of truncated, inactivated, and degraded genes. Because the mutational events that inactivate genes occur continuously in all genomes, we investigated whether the rarity of pseudogenes in some bacteria was attributable to properties inherent to the organism or to the failure to recognize pseudogenes. By developing a program suite (called Ψ-Φ, for Ψ-gene Finder) that applies a comparative method to identify pseudogenes (attributable both to misannotation and to nonrecognition), we analyzed the pseudogene inventories in the sequenced members of the Escherichia coli/Shigella clade. This approach recovered hundreds of previously unrecognized pseudogenes and showed that pseudogenes are a regular feature of bacterial genomes, even in those whose original annotations registered no truncated or otherwise inactivated genes. In Shigella flexneri 2a, large proportions of pseudogenes are generated by nonsense mutations and IS element insertions, events that seldom produce the pseudogenes present in the other genomes examined. Almost all (>95%) pseudogenes are restricted to only one of the genomes and are of relatively recent origin, suggesting that these bacteria possess active mechanisms to eliminate nonfunctional genes.
An egr-1 (zif268) Antisense Oligodeoxynucleotide
Infused Into the Amygdala Disrupts Fear Conditioning
Authors: Malkani Seema , Wallace Karin J. , Donley Melanie P. , Rosen Jeffrey B.
Published: October 2004

Studies of gene expression following fear conditioning have demonstrated
that the inducible transcription factor, egr-1, is increased in the
lateral nucleus of the amygdala shortly following fear conditioning. These
studies suggest that egr-1 and its protein product Egr-1 in the
amygdala are important for learning and memory of fear. To directly test this
hypothesis, an egr-1 antisense oligodeoxynucleotide (antisense-ODN)
was injected bilaterally into the amygdala prior to contextual fear
conditioning. The antisense-ODN reduced Egr-1 protein in the amygdala and
interfered with fear conditioning. A 250-pmole dose produced an 11% decrease
in Egr-1 protein and reduced long-term memory of fear as measured by freezing
in a retention test 24 h after conditioning, but left shock-induced freezing
intact. A larger 500-pmole dose produced a 25% reduction in Egr-1 protein and
significantly decreased both freezing immediately following conditioning and
freezing in the retention test. A nonsense-ODN had no effect on postshock or
retention test freezing. In addition, 500 pmole of antisense-ODN infused prior
to the retention test in previously trained rats did not reduce freezing,
indicating that antisense-ODN did not suppress conditioned fear behavior.
Finally, rats infused with 500 pmole of antisense-ODN displayed unconditioned
fear to a predator odor, demonstrating that unconditioned freezing was
unaffected by the antisense-ODN. The data indicate that the egr-1
antisense-ODN interferes with learning and memory processes of fear without
affecting freezing behavior and suggests that the inducible transcription
factor Egr-1 within the amygdala plays important functions in long-term
learning and memory of fear.
Retrieval Does Not Induce Reconsolidation of Inhibitory Avoidance Memory
Authors: Cammarota Martín , Bevilaqua Lia R.M. , Medina Jorge H. , Izquierdo Iván
Published: October 2004

It has been suggested that retrieval during a nonreinforced test induces
reconsolidation instead of extinction of the mnemonic trace. Reconsolidation
would preserve the original memory from the labilization induced by its
nonreinforced recall through a hitherto uncharacterized mechanism requiring
protein synthesis. Given the importance that such a process would have in
terms of maintaining, as part of the animal behavioral repertoire, a learned
response that has been devalued by experience, we analyzed its existence for
the memory associated with a one-trial, step-down inhibitory avoidance task
(IA), a memory whose consolidation and extinction require protein synthesis in
the CA1 region of the dorsal hippocampus (CA1) and involve the participation
of the basolateral amygdala (BLA) and entorhinal cortex (ENT). Rats were
trained in IA, and 24 h later they were submitted either to a pure
reactivation session (retrieval without stepping down), which was unable by
itself to initiate extinction of the avoidance response, or to a second
training session. Fifteen minutes before or 3 h after either the reactivation
or the retraining sessions, animals were infused with the protein synthesis
inhibitor anisomycin (ANI) into CA1, BLA, or ENT. Contrary to the prediction
of the reconsolidation hypothesis, none of these treatments affected
subsequent memory retention. Because reconsolidation is regarded to be a
direct consequence of retrieval, one would expect that, when given before a
retention test or a pure reactivation session, enhancers of memory expression
should permanently improve retention and, therefore, facilitate retrieval both
in that and in subsequent sessions. Using two well-known retrieval enhancers,
noradrenaline and adrenocorticotropin1-24, we could not find any
evidence suggestive of reconsolidation. Hence, our results indicate that there
is no retrieval-induced, protein synthesis-dependent process that would cause
reconsolidation of IA memory.
CB1 Cannabinoid Receptors Modulate Kinase and Phosphatase Activity During Extinction of Conditioned Fear in Mice
Authors: Cannich Astrid , Wotjak Carsten T. , Kamprath Kornelia , Hermann Heike , Lutz Beat , Marsicano Giovanni
Published: October 2004

Cannabinoid receptors type 1 (CB1) play a central role in both short-term
and long-term extinction of auditory-cued fear memory. The molecular
mechanisms underlying this function remain to be clarified. Several studies
indicated extracellular signal-regulated kinases (ERKs), the
phosphatidylinositol 3-kinase with its downstream effector AKT, and the
phosphatase calcineurin as potential molecular substrates of extinction
behavior. To test the involvement of these kinase and phosphatase activities
in CB1-dependent extinction of conditioned fear behavior, conditioned
CB1-deficient mice (CB1-/-) and wild-type littermates
(CB1+/+) were sacrificed 30 min after recall of fear memory, and
activation of ERKs, AKT, and calcineurin was examined by Western blot analysis
in different brain regions. As compared with CB1+/+, the
nonreinforced tone presentation 24 h after auditory-cued fear conditioning led
to lower levels of phosphorylated ERKs and/or calcineurin in the basolateral
amygdala complex, ventromedial prefrontal cortex, dorsal hippocampus, and
ventral hippocampus of CB1-/-. In contrast, higher levels of
phosphorylated p44 ERK and calcineurin were observed in the central nucleus of
the amygdala of CB1-/-. Phosphorylation of AKT was more pronounced
in the basolateral amygdala complex and the dorsal hippocampus of
CB1-/-. We propose that the endogenous cannabinoid system modulates
extinction of aversive memories, at least in part via regulation of the
activity of kinases and phosphatases in a brain structure-dependent
manner.
Facilitation of Fear Extinction by D-Cycloserine: Theoretical and Clinical Implications
Authors: Richardson Rick , Ledgerwood Lana , Cranney Jacquelyn
Published: October 2004

Anxiety disorders are among the most common psychological disturbances in the industrialized world. Current behavioral therapy procedures for these disorders are somewhat effective, but their efficacy could be substantially improved. Because these procedures are largely based on the process of extinction, manipulations that enhance extinction may lead to improvements in treatment effectiveness. We review the evidence that D-cycloserine (DCS), a partial NMDA agonist, facilitates extinction of learned fear in rats. Although only a few studies have examined the effects of DCS on extinction of learned fear, this work suggests that this drug may have a number of potential clinical benefits. In addition, attempts at interpreting this research illustrate our limited understanding of the processes involved in extinction.
Like Extinction, Latent Inhibition of Conditioned Fear in Mice Is Blocked by Systemic Inhibition of L-Type Voltage-Gated Calcium Channels
Authors: Barad Mark , Blouin Ashley M. , Cain Chris K.
Published: October 2004

Having recently shown that extinction of conditioned fear depends on L-type
voltage-gated calcium channels (LVGCCs), we have been seeking other protocols
that require this unusual induction mechanism. We tested latent inhibition
(LI) of fear, because LI resembles extinction except that cue exposures
precede, rather than follow, cue-shock pairing. Systemic injections of two
LVGCC inhibitors, nifedipine and diltiazem, before pre-exposure blocked LI
completely with no evidence of state-dependent learning. The results indicate
that extinction and LI share a common molecular requirement and may support
the notion that LI, like extinction, is a form of inhibitory learning.
Facilitation of Memory for Extinction of Drug-Induced Conditioned Reward: Role of Amygdala and Acetylcholine
Authors: Schroeder Jason P. , Packard Mark G.
Published: October 2004

These experiments examined the effects of posttrial peripheral and intra-amygdala injections of the cholinergic muscarinic receptor agonist oxotremorine on memory consolidation underlying extinction of amphetamine conditioned place preference (CPP) behavior. Male Long-Evans rats were initially trained and tested for an amphetamine (2 mg/kg) CPP. Rats were subsequently given limited extinction training, followed by immediate posttrial peripheral or intrabasolateral amygdala injections of oxotremorine. A second CPP test was then administered, and the amount of time spent in the previously amphetamine-paired and saline-paired apparatus compartments was recorded. Peripheral (0.07 or 0.01 mg/kg) or intra-amygdala (10 ηg/0.5μL) postextinction trial injections of oxotremorine facilitated CPP extinction. Oxotremorine injections that were delayed 2 h posttrial training did not enhance CPP extinction, indicating a time-dependent effect of the drug on memory consolidation processes. The findings indicate that memory consolidation for extinction of approach behavior to environmental stimuli previously paired with drug reward can be facilitated by posttrial peripheral or intrabasolateral amygdala administration of a cholinergic agonist.
Factors Regulating the Effects of Hippocampal Inactivation on Renewal of Conditional Fear After Extinction
Authors: Corcoran Kevin A. , Maren Stephen
Published: October 2004

After extinction of fear to a Pavlovian conditional stimulus (CS),
contextual stimuli come to regulate the expression of fear to that CS. There
is growing evidence that the context dependence of memory retrieval after
extinction involves the hippocampus. In the present experiment, we examine
whether hippocampal involvement in memory retrieval after extinction is
related to the history of CS presentations in the context used for retrieval
testing. We used infusions of muscimol to inactivate the dorsal hippocampus
(DH) during postextinction retrieval tests that were conducted in contexts
that differed in their history of CS presentations in that context. We found
that DH inactivation affected the context-dependent retrieval of extinction
(i.e., renewal) when testing occurred in a context that had no history of CS
exposure, but not in a context that reliably predicted the CS. These results
are discussed in terms of theories regarding the role of the hippocampus in
contextual memory retrieval.
Problematizing religious truth: Implications for public education
Authors: Rosenblith Suzanne , Priestman Scott
Published: October 2004

The question motivating this paper is whether or not there can be standards governing the evaluation of truth claims in religion. In other areas of study — such as physics, math, history, and even value‐laden realms like morality — there is some widespread agreement as to what constitutes good thinking. If such a standard existed in religion, then our approach to teaching religion would need to change. This paper, however, is a prelude to examining such a question. In it, we briefly explore whether or not religion should even be included in public education. After concluding that it should be, we then look at whether we should pursue questions of truth in discussing religion or whether truth should be bracketed. If matters of truth are bracketed, what is lost? If questions of truth are pursued in our public school classrooms, what standards of evaluation should be applied to them?
The corporatizing and privatizing of schooling: A call for grounded critical praxis
Authors: Bell McKenzie Kathryn , Joseph Scheurich James
Published: October 2004

Our review of Henry Giroux's Stealing Innocence, Alex Molnar's Giving Kids the Business, and Kenneth Saltman's Collateral Damage describes how these authors assess the problems posed by contemporary corporate influences on public schools and considers the solutions they offer to counter those influences. We also examine Henry Levin's edited collection Privatizing Education, in which various authors address research on privatization in schooling. In our analysis of this book, we highlight the underlying themes of the wide‐ranging chapters. Next, we critique all four books, focusing primarily on the books by Giroux, Molnar, and Saltman. We suggest that these three authors provide a somewhat totalized and ahistorical portrait of contemporary corporate influences on schooling and offer a solution that depends on teachers acting as democratic revolutionaries, though there is no realistic possibility that teachers today would take on this role. In contrast, we call for a critical theory and practice that is grounded both in a more complex understanding of the current historical context and also in a dialogical engagement with students, teachers, parents, and other community members.
Stability of Spatial Equilibrium*
Authors: Tabuchi Takatoshi , Zeng Dao‐Zhi
Published: October 2004

Abstract.  Asymptotic stability of equilibrium is often difficult to know when the number of variables exceeds four, since all eigenvalues of the Jacobian matrix are not analytically solvable. However, we obtain stability conditions for a general class of migration dynamics without computing eigenvalues. We show that a spatial equilibrium is stable in the presence of strong congestion diseconomies, but unstable in the presence of strong agglomeration economies. We also show existence of a stable equilibrium in the case of negligible interregional externalities, which is applicable to club goods, local public goods, and new economic geography.
The Impact of Migration on Wages: Empirical Evidence from French Youth*
Authors: Détang‐Dessendre Cécile , Drapier Carine , Jayet Hubert
Published: October 2004

Abstract.  This paper deals with the impact of migration on wages. We introduce a spatial dimension into the job search framework, so that the agent faces neither the same job offer distribution nor the same search costs when looking for a job inside his local labor market. This is in comparison to the agent searching outside his local labor market, where migration costs are a factor. We estimate wage equations in which we introduce the decision to migrate as a binary choice, and later as a polychotomic choice (stayer/mover from provinces to Paris/mover from provinces to provinces). We find no selection effect for people with low levels of education, and a positive selection effect for highly educated migrants. When we distinguish the migration destination for highly educated from provinces, we find a hierarchical effect, that is, the selection effect is higher for men who migrate to Paris than for those who migrate to other provinces.
A Reexamination of Output Convergence in the U.S. States: Toward Which Level(s) are they Converging?
Authors: Choi Chi‐Young
Published: October 2004

Abstract.  This paper reexamines the issue of output convergence among the 48 states in the continental United States. Implementing multiple panel data techniques to state per capita output during the period 1929–2001 reveals little evidence of stochastic convergence in all 48 states, but some evidence among collections of states at the regional level. This observation may suggest that output convergence in the United States has proceeded among geographically neighboring states rather than among distant states, notwithstanding the nearly complete integration of product and factor markets. Our findings appear to be robust to a subsample analysis, although the intensity of convergence varies with the choice of output measure and deflator. Industrial structures and geographic proximity are considered as potential explanations for the regional pattern of output growth dynamics.
The Pricing of Delivery Services*
Authors: Basu Amiya , Ingene Charles A. , Mazumdar Tridib
Published: October 2004

Abstract.  Due to spatial separation between points of distribution and consumption, a vital feature of retailing is the provision of delivery services by customers, retailers, or transport intermediaries. Some store retailers, many Internet retailers, and most transport intermediaries use a multizone pricing plan or a generalized N‐zone menu plan. We extend spatial pricing theory to encompass multizone plans. We prove that the optimal number of zones varies with the level of demand relative to the spatial dispersion of customers, and with the cost of implementing a zonal plan. We show that a small number of zones capture almost all the profit attainable with a spatially discriminatory plan.
Migration, Frictional Unemployment, and Welfare‐Improving Labor Policies*
Authors: Sato Yasuhiro
Published: October 2004

Abstract.  Studies have suggested that there exists job search and recruiting friction in urban areas. This paper constructs a two‐sector (rural and urban) model involving this factor and investigates how it affects migration and what the optimal policies should be. An analysis shows that frictional urban unemployment brings about intersector wage differentials and that an economy almost always has distortion in the absence of government intervention. Tax and subsidy policies that remove the distortion are explored. Setting urban wages appropriately is also shown to attain the optimum. Finally, we explore the criterion to judge whether changing urban wages as a policy, such as the minimum wage law, enhances social welfare.
Towards equality: the voices of young disabled people in Disability Rights Commission research
Authors: WILSON LOUCA‐MAI
Published: October 2004

Increased participation and success in education for disabled people will improve their social inclusion and benefit society in general. In this article Louca‐Mai Wilson discusses Disability Rights Commission research on education and its implications for policy and practice. Research findings are considered in relation to the need for the voices of young disabled people to be heard in research, policy and planning. A key finding was that young disabled people want to be regarded and treated as equal to their peers, with the same rights of access and educational opportunity. But schools and educational establishments vary in their willingness and capacity to address and remove existing access barriers. Inclusion is a key issue for many young disabled people; many feel isolated at school and college and often have lower expectations about their future than their non‐disabled peers. Inclusive practice and participation are key to ensuring that disability equality in education is achieved.
Hearing children's voices in the early years
Authors: MORTIMER HANNAH
Published: October 2004

In this article Hannah Mortimer explores how even very young children can be consulted and included when planning for their education and needs. This allows early years practitioners to ensure that the children they support have equal opportunities, feel involved and successful in their learning and play, and are given activities and interventions to suit their interests and strengths. Various approaches are described here for including young children with special educational needs (SEN) and other disabilities in their foundation stage education. These include observation and interpretation, talk‐through approaches, play‐based assessment and intervention, use of art‐work, role play and stories, welcome profiles and personal records, increasing all children's awareness of SEN and developing inclusive and enjoyable approaches for everybody.
Resilience: a study of risk and protective factors from the perspective of young people with experience of local authority care
Authors: DEARDEN JACKIE
Published: October 2004

As part of a review of services in one local authority, young people aged 13–19 with experience of local authority care were asked to provide their views of what makes a difference to them. As Jackie Dearden makes clear in this article, young people consistently reported on themes collated from previous research into resilience and identified factors which were most and least helpful. The compelling personal accounts draw attention to what services could do to increase protective factors which include interest of carers, access to facilities, taking bullying seriously, a clear sense of a positive future and adults who listen. Additionally, positive change occurred most often after significant changes in circumstances, especially transition phases, providing turning points for some young people. Such personal stories present a powerful perspective that would be hard for service providers to ignore. This raises the question of how local authorities are routinely consulting with vulnerable young people.
Racial Discrimination by Low-Prejudiced Whites
Authors: Vanman Eric J. , Saltz Jessica L. , Nathan Laurie R. , Warren Jennifer A.
Published: October 2004

We investigated the relationship of implicit racial prejudice to discriminatory behavior. White university students chose the best of three applicants (two were White and one was Black) for a prestigious teaching fellowship. They then completed the Implicit Association Test (IAT), a measure of implicit racial bias. Three weeks later, participants completed a second implicit measure of racial bias by viewing photos of Whites and Blacks while facial electromyography (EMG) was recorded from sites corresponding to the muscles used in smiling and frowning. Analyses revealed that bias in cheek EMG activity was related to the race of the chosen applicant, whereas bias on the IAT was not. Motivations to control prejudiced reactions were not related to EMG activity or the race of the applicant chosen, but were related to IAT bias. The findings indicate that facial EMG can be used as an implicit measure of prejudice related to discrimination.
Skimming the Surface
Authors: Lane Sean M. , Schooler Jonathan W.
Published: October 2004

It has become almost a maxim that “talking through” a problem is advantageous. Contrary to this wisdom, studies from numerous domains have demonstrated that describing one's thought processes or analyzing a judgment may, in some circumstances, actually impair performance. The two experiments reported here built upon prior work by examining the effect of verbalization on the retrieval of analogies. Participants read a series of 16 short stories. Later, they were presented with 8 test stories and indicated whether these stories were analogies of the stories they had read previously. Each test story shared the same deep structure with one prior story and only surface characteristics with another prior story. Half of the participants completed the test while thinking aloud, and half did not think aloud. In both experiments, participants who thought aloud were more likely to retrieve surface matches and less likely to retrieve true analogies than participants who did not verbalize their thoughts during the test.
Is Consciousness a Gradual Phenomenon?
Authors: Sergent Claire , Dehaene Stanislas
Published: October 2004

Several theories of the neural correlates of consciousness assume that there is a continuum of perception, associated with a gradual change in the intensity of brain activation. But some models, considering reverberation of neural activity as necessary for conscious perception, predict a sharp nonlinear transition between unconscious and conscious processing. We asked participants to evaluate the visibility of target words on a continuous scale during the attentional blink, which is known to impede explicit reports. Participants used this continuous scale in an all-or-none fashion: Targets presented during the blink were either identified as well as targets presented outside the blink period or not detected at all. We suggest that a stochastic nonlinear bifurcation in neural activity underlies the all-or-none perception observed during the attentional blink.
Which Route to Recovery?
Authors: Lustig Cindy , Konkel Alex , Jacoby Larry L.
Published: October 2004

New learning often interferes with the production of older, previously learned responses. However, the original responses usually appear to spontaneously recover and regain their dominance after a delay. This article takes a new approach to questions of interference and recovery by examining performance on immediate and delayed tests using direct or indirect instructions. Direct instructions asked participants to deliberately retrieve the original responses, and indirect instructions allowed them to respond on a more automatic basis, using whatever response came to mind first. Results suggest that interference and recovery may have their largest effects via relatively automatic influences on memory, such as the accessibility of new versus original information. This finding adds a new perspective to classic theories of interference and recovery, and may also inform current understanding of performance in populations (e.g., older adults) that often rely predominantly on automatic memory processing.
A Sex Difference in the Specificity of Sexual Arousal
Authors: Chivers Meredith L. , Rieger Gerulf , Latty Elizabeth , Bailey J. Michael
Published: October 2004

Sexual arousal is category-specific in men; heterosexual men are more aroused by female than by male sexual stimuli, whereas homosexual men show the opposite pattern. There is reason to believe that female sexual arousal is organized differently. We assessed genital and subjective sexual arousal to male and female sexual stimuli in women, men, and postoperative male-to-female transsexuals. In contrast to men, women showed little category specificity on either the genital or the subjective measure. Both heterosexual and homosexual women experienced strong genital arousal to both male and female sexual stimuli. Transsexuals showed a category-specific pattern, demonstrating that category specificity can be detected in the neovagina using a photoplethysmographic measure of female genital sexual arousal. In a second study, we showed that our results for females are unlikely to be explained by ascertainment biases. These findings suggest that sexual arousal patterns play fundamentally different roles in male and female sexuality.
Impairment in Holistic Face Processing Following Early Visual Deprivation
Authors: Grand Richard Le , Mondloch Catherine J. , Maurer Daphne , Brent Henry P.
Published: October 2004

Unlike most objects, faces are processed holistically: They are processed as a whole rather than as a collection of independent features. We examined the role of early visual experience in the development of this type of processing of faces by using the composite-face task, a measure of holistic processing, to test patients deprived of visual experience during infancy. Visually normal control subjects showed the expected composite-face effect: They had difficulty perceiving that the top halves of two faces were the same when the top halves were aligned with different bottom halves. Performance improved when holistic processing was disrupted by misaligning the top and bottom halves. Deprived patients, in contrast, showed no evidence of holistic processing, and in fact performed significantly better than control subjects when top and bottom halves were aligned. These findings suggest that early visual experience is necessary to set up or maintain the neural substrate that leads to holistic processing of faces.
False Memories in Children
Authors: Dewhurst Stephen A. , Robinson Claire A.
Published: October 2004

Memory illusions in children of three age groups (5-, 8-, and 11-year-olds) were investigated using a modified version of the Deese-Roediger-McDermott (DRM) procedure. Children from each age group falsely recalled nonpresented items related to the study lists. However, the nature of the intrusions varied across the different groups. The 5-year-olds were more likely to falsely recall words that rhymed with the studied items than to recall unrelated items, whereas the 11-year-olds were more likely to falsely recall words that were semantically related to the list theme than to produce either rhyming or unrelated intrusions. Intrusions made by the 8-year-olds were equally likely to be semantic, rhyming, or unrelated to study items. The results are consistent with the notion of a developmental shift from phonological to semantic associations, leading to qualitatively different memory distortions in children of different ages.
Effort for Payment
Authors: Heyman James , Ariely Dan
Published: October 2004

The standard model of labor is one in which individuals trade their time and energy in return for monetary rewards. Building on Fiske's relational theory (1992), we propose that there are two types of markets that determine relationships between effort and payment: monetary and social. We hypothesize that monetary markets are highly sensitive to the magnitude of compensation, whereas social markets are not. This perspective can shed light on the well-established observation that people sometimes expend more effort in exchange for no payment (a social market) than they expend when they receive low payment (a monetary market). Three experiments support these ideas. The experimental evidence also demonstrates that mixed markets (markets that include aspects of both social and monetary markets) more closely resemble monetary than social markets.
Construct Validity of Raven's Advanced Progressive Matrices for African and Non‐African Engineering Students in South Africa
Authors: Rushton J. Philippe , Skuy Mervyn , Bons Trudy Ann
Published: October 2004

We test the hypothesis that the Raven's Advanced Progressive Matrices has the same construct validity in African university students as it does in non‐African students by examining data from 306 highly select 17‐ to 23‐year olds in the Faculties of Engineering and the Built Environment at the University of the Witwatersrand (177 Africans, 57 East Indians, 72 Whites; 54 women, 252 men). Analyses were made of the Matrices scores, an English Comprehension test, the Similarities subscale from the South African Wechsler Adult Intelligence Scale, end‐of‐year university grades, and high‐school grade point average. Out of the 36 Matrices problems, the African students solved an average of 23; East Indian students, 26; and White students, 29 (p<.001), placing them at the 60th, 71st, and 86th percentiles, respectively, and yielding IQ equivalents of 103, 108, and 118 on the 1993 US norms. The same pattern of group differences was found on the Comprehension Test, the Similarities subscale, university course grades, and high‐school grade‐point average. The items on the Matrices ‘behaved’ in the same way for the African students as they did for the non‐African students, thereby indicating the test's internal validity. Item analyses, including a confirmatory factor analysis, showed that the African/non‐African difference was most pronounced on the general factor of intelligence. Concurrent validity was demonstrated by correlating the Matrices with the other measures, both individually and in composite. For the African group, the meanr=.28,p<.05, and for the non‐African group, the meanr=.27,p<.05. Although the intercepts of the regression lines for the two groups were significantly different, their slopes were not. The results imply that scores on the Raven's Matrices are as valid for Africans as they are for non‐Africans.
The Use of Safety Suitability Tests for The Assessment of Immigrant and Majority Group Job Applicants
Authors: Te Nijenhuis Jan , Van Der Flier Henk
Published: October 2004

Safety jobs, meaning jobs where employees are responsible for the safety of customers, other employees and/or public in general are of special importance for our present society and deserve continued attention from I/O psychologists. The central question addressed in this study is whether the scores on safety suitability tests are comparable for immigrants and majority group members. Use was made of test data on first‐generation immigrants (N=786) and majority group members (N=584) who applied for blue collar jobs at the Dutch Railways and at regional bus companies. The tests used measured selective attention, attentional speed, continuous attention, perceptual‐motor ability and general mental ability. Immigrants' mean scores are systematically below the level of the mean scores of the majority group. The tests appear to have a strong dimensional comparability between the different groups. There is very little indication of test bias. The increasing number of immigrants and the increase of safety jobs pose challenges for selection psychologists. It is suggested that continued use of safety suitability tests is needed to keep the number of safety accidents at a minimum.
Permanent Employee Attitudes Toward Temporary Employment
Authors: Wheeler Anthony R. , Buckley M. Ronald
Published: October 2004

The present study investigated the attitudes that a sample of permanent state employees working in the United States (n=100) held toward temporary employment. A simultaneous regression analysis revealed that certain demographic variables differentially predicted attitude scores for the sample. The researchers found that age, level of education, and household size predicted attitudes toward temporary employment. A full inter‐item correlation matrix for the attitudinal measure including internal reliability estimates and descriptive statistics for all variables measured used in the study is included, and the simultaneous regression results are reported.