bluuebunny/crossref_metadata_2025 huggingface dataset:
A Plasmodium Gene Family Encoding Maurer's Cleft Membrane Proteins: Structural Properties and Expression Profiling
Authors: Sam-Yellowe Tobili Y. , Florens Laurence , Johnson Jeffrey R. , Wang Tongmin , Drazba Judith A. , Le Roch Karine G. , Zhou Yingyao , Batalov Serge , Carucci Daniel J. , Winzeler Elizabeth A. , Yates John R.
Published: May 2004

Upon invasion of the erythrocyte cell, the malaria parasite remodels its environment; in particular, it establishes a complex membrane network, which connects the parasitophorous vacuole to the host plasma membrane and is involved in protein transport and trafficking. We have identified a novel subtelomeric gene family in Plasmodium falciparum that encodes 11 transmembrane proteins localized to the Maurer's clefts. Using coimmunoprecipitation and shotgun proteomics, we were able to enrich specifically for these proteins and detect distinct peptides, allowing us to conclude that four to 10 products were present at a given time. Nearly all of the Pfmc-2tm genes are transcribed during the trophozoite stage; this narrow time frame of transcription overlaps with the specific stevor and rif genes that are differentially expressed during the erythrocyte cycle. The description of the structural properties of the proteins led us to manually reannotate published sequences, and to detect potentially homologous gene families in both P. falciparum and Plasmodium yoelii yoelii, where no orthologs were predicted uniquely based on sequence similarity. These basic proteins with two transmembrane domains belong to a larger superfamily, which includes STEVORs and RIFINs.
Complete MHC Haplotype Sequencing for Common Disease Gene Mapping
Authors: Stewart C. Andrew , Horton Roger , Allcock Richard J.N. , Ashurst Jennifer L. , Atrazhev Alexey M. , Coggill Penny , Dunham Ian , Forbes Simon , Halls Karen , Howson Joanna M.M. , Humphray Sean J. , Hunt Sarah , Mungall Andrew J. , Osoegawa Kazutoyo , Palmer Sophie , Roberts Anne N. , Rogers Jane , Sims Sarah , Wang Yu , Wilming Laurens G. , Elliott John F. , de Jong Pieter J. , Sawcer Stephen , Todd John A. , Trowsdale John , Beck Stephan
Published: May 2004

The future systematic mapping of variants that confer susceptibility to common diseases requires the construction of a fully informative polymorphism map. Ideally, every base pair of the genome would be sequenced in many individuals. Here, we report 4.75 Mb of contiguous sequence for each of two common haplotypes of the major histocompatibility complex (MHC), to which susceptibility to >100 diseases has been mapped. The autoimmune disease-associated-haplotypes HLA-A3-B7-Cw7-DR15 and HLA-A1-B8-Cw7-DR3 were sequenced in their entirety through a bacterial artificial chromosome (BAC) cloning strategy using the consanguineous cell lines PGF and COX, respectively. The two sequences were annotated to encompass all described splice variants of expressed genes. We defined the complete variation content of the two haplotypes, revealing >18,000 variations between them. Average SNP densities ranged from less than one SNP per kilobase to >60. Acquisition of complete and accurate sequence data over polymorphic regions such as the MHC from large-insert cloned DNA provides a definitive resource for the construction of informative genetic maps, and avoids the limitation of chromosome regions that are refractory to PCR amplification.
The Norwegian Archive, Library and Museum Authority – our role in a society based on knowledge and culture
Authors: Hindal Sidsel , Harriet Wyller Elin
Published: May 2004

This paper describes a new unitary organization, set up for the purpose of developing and coordinating the resources in libraries, museums and archives in Norway. First, we give a brief introduction to the main aims for archives, libraries and museums as we view them in our country, followed by an outline of the main objectives of the Norwegian Archive, Library and Museum Authority. Next we give an overview of the national strategies for preserving digital culture outlined in various official documents. In the last part we outline our international profile and some of our intentions, although these have not yet been implemented in an official strategic plan.
Racial differences in library anxiety among graduate students
Authors: Jiao Qun G. , Onwuegbuzie Anthony J. , Bostick Sharon L.
Published: May 2004

This study compared the five subscale scores and total scale scores of the Library Anxiety Scale from 135 Caucasian‐American and 45 African‐American graduate students. Findings indicated that the Caucasian‐American sample reported significantly higher levels of library anxiety associated with three of the five subscales than did the African‐American sample. A canonical discriminant analysis also revealed significant differences between the two racial groups, with Caucasian‐American graduate students reporting significantly higher levels of library anxiety associated with the same three subscales than their African‐American counterparts. These findings suggest that race appears to be a predictor of library anxiety levels. The implications of the findings on academic library services and future research are discussed.
MAI: MetaOPAC Azalai Italiano
Authors: De Robbio Antonella , Rossi Paola
Published: May 2004

MetaOPAC Azalai Italiano (MAI) is a virtual union catalogue of Italian libraries developed through co‐operation between the Italian Library Association and the Consorzio Interuniversitario Lombardo per l'Elaborazione Automatica. This paper presents the components of MetaOPAC Azalai Italiano and the organisational, management, planning and implementation tools developed by the team since 1999. MAI provides access to Italian OPACs, offering a directory and metasearch functionality. The search engine, Azalai, performs metasearching. The architecture of the system, the search engine and converter, is based on a database of Italian OPACs. Three different interfaces, designed for specific types of users, provide access to the system. Members of the MAI Editorial Board are responsible for keeping the database updated and this automatically generates the Directory of Italian Online Catalogues. MAI is divided into five distinct sections, integrated with a range of tools and services intended for different categories of user.
Snakes and ladders: towards a post‐maturity evaluation index of integrated library system ownership
Authors: Myhill Martin
Published: May 2004

Although the integrated library system increasingly dominates the information activities of library staff and users, there are very few objective measures available by which to evaluate its medium to long‐term impact. This article moves towards the production of a simple, numerical index of ILS evaluation. It applies a variety of context‐dependent evaluation methods to the different phases of the ILS lifecycle culminating in a draft index of evaluation. Although this methodology and index should not be regarded as a finished product, it should act as a useful starting point for further comparative studies, particularly those that seek simple ways to incorporate relevant, less‐subjective criteria into the ILS evaluation process.
Government goals and entrepreneurship education – an investigation at a Grande Ecole in France
Authors: Klapper Rita
Published: May 2004

Across the European Union there has been an increase in the number of programmes and initiatives aiming to promote small business and entrepreneurship. In line with this general trend, enterprise creation and entrepreneurship are increasingly recognised as vital for French post‐industrial society, yet France is lagging behind Spain, the UK, Italy and the USA in terms of enterprise creation. This article discusses entrepreneurship education and the role of the Grandes Ecoles. Draws on primary research into student attitudes to entrepreneurs and entrepreneurship and concludes that both societal and educational aspects as well as the creation of entrepreneurial environment at a management school are key to promoting an entrepreneurial student population.
Application of value delivery system (VDS) and performance benchmarking in flexible business process reengineering
Authors: Kam‐Chuen Yung Winco , Ting‐Hong Chan Danny
Published: May 2004

The new management concept of flexible business process reengineering (FBPR) may be defined as a methodology that combines the best of three management tools – positioning, continuous improvement and business process reengineering (PIR). Employing all three management tools to a sufficient degree could enhance the effectiveness of an improvement project compared to the conventional BPR methodology. The changes could be slightly less “radical” than conventional BPR, but in exchange, it is a relatively less risky strategy and can facilitate continuous learning and improvement. To maximize the organization's competitiveness through the application of FBPR, it is important to establish a value delivery system (VDS) to increase the project's effectiveness and to employ performance benchmarking to determine the performance gap. Using a case study, this paper illustrates the essentiality and the application of VDS and performance benchmarking during the implementation of FBPR.
Focused cellular manufacturing: an alternative to cellular manufacturing
Authors: Al‐Mubarak Fahad , Khumawala Basheer M. , Canel Cem
Published: May 2004

This paper is aimed at comparing cellular manufacturing with focused cellular manufacturing. We define focused cellular manufacturing as a layout scheme that groups components by end‐items and forms cells of machines to fabricate and assemble end‐items. It is not classified as a cellular manufacturing layout since it does not attempt to take advantage of process similarities. It also is not classified as a flow shop since there are no machines dedicated to individual operations and the machines are not arranged in a series. In addition, this research includes batching and assemble times in its criteria which few researchers in this area have done. The results indicate that the focused cellular manufacturing scheme has a batching advantage. This advantage out‐weighed the set‐up time reduction advantage of the cellular manufacturing scheme for average end‐item completion times and average work‐in‐process inventory levels. The cellular manufacturing scheme overcame the batching advantage only when there were small batch sizes or large set‐up time magnitudes.
College Art Association 92nd Annual Conference
Authors: Vecchiola Rina
Published: May 2004

Reports some of the topics covered at the 92nd Annual Conference of the College Art Association held in Seattle, February 2004, where several sessions addressed the issues involved with the iintroduction of digital technologies in the teaching of art history.
Crossing Boundaries: Collecting and Collaborating Globally A Conference Report on Fiesole 2004
Authors: Hughes Carol
Published: May 2004

Outlines some of the topics addressed at the sixth annual Fiesole Collection Development Retreat Series, entitled "Crossing Boundaries: Collecting and Collaborating Globally", held in March 2004. The conference covered issues in international scholarship, shared preservation and collection strategies, and funding.
Professional Library & Information Associations Should Rise to the Challenge of Promoting Open Access and Lead by Example
Authors: Morrison Heather
Published: May 2004

Focuses on an initiative of the Association of Research Library’s Scholarly Publishing and Academic Resources Coalition in giving leadership for providing open access to scholarly information, determining this as the most effective means of advancing scholarly research. Addresses some of the reasons for opening up access to library literature, issues and challenges, and gives some examples of library associations that are already providing open access to their publications.
Diagnosing the distance
Authors: Jacobs Glenda
Published: May 2004

Identifies and analyses the unique communication challenges arising from the employment of mobile service engineers, in whose supervision and work conditions, it is argued, are combined the disadvantages of both remote and face‐to‐face communication management contexts, without the advantages of either. The paper therefore begins by examining closely the communication dynamics that distinguish this “dispersed” work situation from others and make it particularly challenging, and then suggests a model for diagnosing what organisations might do to overcome these challenges.
Modelling the communication dynamics of uninspired leadership
Authors: Leipzig John S.
Published: May 2004

Change in the leadership of an organization comes from the edges of an organization in which organizational players are engaged in a struggle with uninspired core leaders. Revolutionary transformations and inspired leadership occur at precise times and places within an organization. This article explores the communication strategies employed by uninspired leaders in attempts to maintain control of the organizational core and suggests that uninspired leadership is the normative state for organizational core leadership. The author, through an extensive first person narrative, explored a lifetime of experiences within academic administration and offers ten life lessons that led to the development of the model of uninspired leadership as well as the components and rationale for that model.
Internal communication audits: a case study
Authors: Quinn Dennis , Hargie Owen
Published: May 2004

On 4 April 2002 the Police Service for Northern Ireland (PSNI) officially took over from the Royal Ulster Constabulary (RUC). This historic symbolic change of name arose from the Belfast Agreement, the subsequent Patten Commission and a long period of consultation and persuasion. Like so many UK police organisations the RUC had exhibited evidence that it recognised the need to address the issue of internal communications but had not been involved in any in‐depth assessment of its internal communications, nor did it have a written internal communications strategy. The use of communication audits had also been limited. By applying a validated audit methodology, this paper examines the position internal communications had within the RUC. Using a triangulation approach, the research encompassed structured interviews, the international communication audit questionnaire, and a critical incident approach. The results showed a general dissatisfaction in respect of communication and specific dissatisfaction in relation to particular areas of the organisation. The implications of the findings for the fledgling PSNI and other police organisations are discussed in the context of the role of communication strategies.
Prader–Willi syndrome resulting from an unbalanced translocation: characterization by array comparative genomic hybridization
Authors: Klein OD , Cotter PD , Albertson DG , Pinkel D , Tidyman WE , Moore MW , Rauen KA
Published: May 2004

Prader–Willi syndrome (PWS) is caused by lack of expression of paternally inherited genes on chromosome 15q11→15q13. Most cases result from microdeletions in proximal chromosome 15q. The remainder results from maternal uniparental disomy of chromosome 15, imprinting center defects, and rarely from balanced or unbalanced chromosome rearrangements involving chromosome 15. We report a patient with multiple congenital anomalies, including craniofacial dysmorphology, microcephaly, bilateral cryptorchidism, and developmental delay. Cytogenetic analysis showed a de novo 45,XY,der(5)t(5;15)(p15.2;q13), ‐15 karyotype. In effect, the proband had monosomies of 5p15.2→pter and 15pter→15q13. Methylation polymerase chain reaction analysis of the promoter region of the SNRPN gene showed only the maternal allele, consistent with the PWS phenotype. The proband's expanded phenotype was similar to other patients who have PWS as a result of unbalanced translocations and likely reflects the contribution of the associated monosomy. Array comparative genomic hybridization (array CGH) confirmed deletions of both distal 5p and proximal 15q and provided more accurate information as to the size of the deletions and the molecular breakpoints. This case illustrates the utility of array CGH in characterizing complex constitutional structural chromosome abnormalities at the molecular level.
Bronchiectasis in adult patients: an expression of heterozygosity for CFTR gene mutations?
Authors: Casals T , De‐Gracia J , Gallego M , Dorca J , Rodríguez‐Sanchón B , Ramos MD , Giménez J , Cisteró‐Bahima A , Olveira C , Estivill X
Published: May 2004

While all patients with cystic fibrosis (CF) have mutations in both CFTR alleles, often only one CFTR change is detected in patients with other lung disorders. The aim of this study was to investigate whether heterozygosity for CFTR mutations could be a determinant risk factor in the development of bronchiectasis in adult patients. We have performed the CFTR gene analysis in a cohort of 55 bronchiectasis adult patients with unknown etiology. The 5T variant (TG)m and the M470V polymorphisms were also analyzed. A general population in which the same molecular analysis was previously performed was used as the control group. The mutational spectrum of patients was also compared with that found in our CF population. CFTR mutations/variants were found in 20 patients (36%), 14 with only one mutant gene (25%). All six patients colonized by Staphilococcus aureus presented with at least one CFTR change (p = 0.001). No statistical significance was observed between patients with and without mutations for other clinical features. The 5T variant was found in four patients. Additionally, 90% of patients with mutations had the more functional M470 allele (p < 0.001). These results suggest the involvement of the CFTR gene in bronchiectasis of unknown etiology in adult patients.
Candidate genes for recessive non‐syndromic mental retardation on chromosome 3p (MRT2A)*
Authors: Higgins JJ , Pucilowska J , Lombardi RQ , Rooney JP
Published: May 2004

A mild type of autosomal recessive, non‐syndromic mental retardation (NSMR) is linked to loci on chromosome 3p. This report delimits the MRT2A minimal critical region to 4.2 Mb between loci D3S3630 and D3S1304. This interval contains nine genes (IL5RA, TRNT1, LRRN1, SETMAR, SUMF1, ITPR1, BHLHB2, EDEM, and MRPS36P1). The results suggest that a mutation does not exist in these genes and that an unknown transcript in the region contributes to the cognitive deficits in NSMR.
Ecological anachronisms in the recruitment of temperate light‐demanding tree species in wooded pastures
Authors: BAKKER E. S. , OLFF H. , VANDENBERGHE C. , DE MAEYER K. , SMIT R. , GLEICHMAN J. M. , VERA F. W. M.
Published: May 2004

Light‐demanding trees and thorny shrubs in temperate plant communities may reflect adaptations to now‐extinct large grazers, such as aurochs and tarpans, rendering these adaptations ecological anachronisms.

We explored the ecological functions of plant traits of Quercus robur and Prunus spinosa in areas grazed by cattle and horses, the domesticated descendants of aurochs and tarpans. Specifically, we tested the hypothesis that grazing induces a shifting mosaic of grassland, shrub thickets and woodlands through the key process of associational resistance: the protection of palatable young trees by thorny shrubs.

An exclosure experiment with transplanted Q. robur seedlings revealed that Q. robur grew best in grassland exclosures and on the edge of thorny shrub thickets, which may be viewed as an optimal balance between sufficient protection from large herbivores and sufficient light availability.

A cross‐site comparison of four floodplain woodlands in north‐western Europe showed that Q. robur can regenerate in the presence of large herbivores through spatial association with P. spinosa. However, we found that expansion of P. spinosa shrubs and Q. robur coincided with periods of low rabbit abundance and not with livestock density. From this, it appears that the process of associational resistance does not work with rabbits.

Synthesis and applications. With extensive grazing by large (domesticated) grazers in temperate floodplains, a shifting mosaic of grassland, shrubs and trees may develop that has high conservation value. Palatable, light‐demanding Q. robur seedlings can successfully regenerate in spiny P. spinosa shrubs through associational resistance. This process does not offer protection from abundant small herbivores, such as rabbits, that can inhibit the recruitment of shrubs and trees in this mosaic vegetation. In floodplain meadows frequent flooding may be an efficient way to reduce rabbit populations, with dry conditions in summer and wet in winter. When floodplain meadows are combined with adjacent higher grounds, large herbivores can escape the floods through migration.
Modelling integrated weed management of an invasive shrub in tropical Australia
Authors: BUCKLEY YVONNE M. , REES MARK , PAYNTER QUENTIN , LONSDALE MARK
Published: May 2004

Where biocontrol programmes for invasive plants are in place, only one‐third are fully successful. Integrated weed management (IWM) emphasizes the use of several complementary control measures.

We used models of increasing complexity to determine which parameters affect site occupancy of an invasive shrub, Mimosa pigra, in tropical Australia. Two introduced biocontrol agents have spatial effects on both plant fecundity and the probability of recolonization after senescence. We incorporated biocontrol effects into IWM models with small‐scale disturbance, such as grazing and pig‐rooting, and large‐scale disturbance, such as mechanical control, herbicide and fire. The models were parameterized from experimental and field data.

The models indicated that reduction in fecundity is not the most important impact of biocontrol; rather it is defoliation at the edges of stands, allowing grasses to out‐compete M. pigra seedlings. We demonstrated that biocontrol alone is only successful at low levels of small‐scale disturbance and seedling survival and, even then, current biocontrol agents would take decades to reduce a stand to < 5% site occupancy.

Our model predicts the most successful IWM strategy to be an application of herbicide in year 1, mechanical control + fire in year 2 and herbicide in year 3, with reduction of small‐scale disturbance where possible. The addition of biocontrol improves the success of this strategy.

Synthesis and applications. Ascertaining how control measures, including biological methods, will influence persistence of an invasive requires models of the target species’ dynamics and its ecosystem. As in previous applications of this model, disturbance is the most important regulator of population size in M. pigra; moderate to high levels of small‐scale disturbance promotes M. pigra occupancy. We have shown that IWM can control M. pigra and that biocontrol is an effective part of this strategy. Reductions in fecundity alone are unlikely to control invasive leguminous shrubs. However, biocontrol agents affect the probability of recolonization after senescence and enhance control. Our recommended 3‐year treatment programme (herbicide : mechanical control + fire : herbicide, with biocontrol) is justifiable in terms of the biology of the system, making it more likely to be acted upon by risk‐averse farmers and land managers.
The effect of patch size and separation on bumblebee foraging in oilseed rape: implications for gene flow
Authors: CRESSWELL JAMES E. , OSBORNE JULIET L.
Published: May 2004

Theory predicts that the susceptibility of patches of plants to gene flow mediated by incoming pollinators will depend on the length of pollinator residence (the number of flowers visited during a bout in a patch). We sought to determine whether pollinator residence is sufficiently sensitive to patch size and separation to influence levels of gene flow significantly. We studied oilseed rapeBrassica napusas an exemplar of a conventional animal‐pollinated plant and as a species where there is a risk of genetic escape from genetically modified (GM) varieties.

We determined pollinator residence in 36 patches created by mowing an agricultural field of flowering oilseed rape. Each square patch had an edge length of 1, 2, 3, 4, 5 or 10 m. Patches were separated by either 9 m or 18 m from the border of a large unmown area of crop. We used the residence of bumblebees (Bombusspp.) to solve a model of bumblebee‐mediated gene flow.

Bumblebee residence increased significantly with patch area, but did not depend on the separation distance of the patch from the large areas of crop. Even in the largest patches, bees visited onlyc. 60 of thec. 1 × 105flowers before leaving.

If bumblebees were the sole pollinators, the model predicted that 4–8% of the seed produced by the smaller patches (c. 80–320 plants) had fathers outside the patch, whereas in the larger patches (720–8000 plants) the prediction was 2–4%. Nevertheless, larger patches should produce the greatest number of seeds with extrinsic paternity.

Synthesis and applications. Our observations demonstrate that susceptibility to pollinator‐mediated gene flow is liable to decrease systematically as the size of plant patches increases. These findings can inform the management of genetic diversity in and among small or fragmented populations. If the patch size–gene flow relationship that we observed applies to larger scales, the model could estimate gene flow between GM crops and volunteer or feral populations in agricultural landscapes.
Invasive ecotypes tolerate herbivory more effectively than native ecotypes of the Chinese tallow tree Sapium sebiferum
Authors: ROGERS WILLIAM E. , SIEMANN EVAN
Published: May 2004

The evolution of increased competitive ability (EICA) hypothesis proposes that exotic plants often become invasive because they have evolved reduced allocation to defence and increased allocation to growth and reproduction in response to low herbivore loads. Previous studies with Chinese tallow tree Sapium sebiferum support EICA predictions of invasive North American ecotypes displaying rapid growth, poorly defended leaves and considerable compensation after defoliation. In contrast, native Asian ecotypes are comparatively slow growing with highly defended leaves and are negatively impacted by mechanical leaf damage. The effects of root damage on the different ecotypes are unknown.

We conducted a full‐factorial pot experiment designed to assess the effects of soil fertility, competition with ryegrass Lolium multiflorum and mechanical root damage on Sapium seedlings derived from seed collections obtained in the ancestral range (native Chinese ecotype) and introduced range (invasive Texas ecotype).

The results, consistent with EICA predictions, revealed that Chinese ecotypes were negatively affected by severing roots, while Texas ecotypes were able to compensate for root damage.

Fertilization increased growth of Chinese ecotypes, but did not reduce the negative effects of root damage enough to allow the seedlings to compensate completely. Competition increased the stem height growth of Chinese ecotypes, but did not affect shoot or root mass. Texas ecotypes were not significantly affected by any experimental treatments.

Synthesis and applications. The results of this study are consistent with previous studies indicating that invasive Sapium has undergone a shift away from possessing costly herbivore defences to producing relatively inexpensive tissues that are capable of rapidly compensating for damage. Evolutionary change is increasingly being recognized as an important factor contributing to the success of exotic plant invaders. Understanding that herbivory tolerance and the compensatory capacity for damage may differ between native and introduced plant ecotypes will be essential for implementing effective control strategies for problematic invasive species.
A new species of Megatherium (Mammalia: Xenarthra: Megatheriidae) from the Pleistocene of Sacaco and Tres Ventanas, Peru
Authors: Pujos François , Salas Rodolfo
Published: May 2004

Megatherium urbinai sp. nov. is a new megatheriine ground sloth from Pleistocene beds of the Sacaco area and Tres Ventanas Cave, Peru. This new species is referred to the genus Megatherium based primarily on humeral, femoral, and astragalar morphology. It is characterized by various features, such as a strongly reduced metacarpal‐carpal‐complex (MCC) and a reduced, oval scaphoid facet of the MCC located at the medial extremity of the bone that does not contact without the McII facet. The distal side of the unciform bears an undivided articular surface for the metacarpals III–V. The lateral femoral margin is nearly rectilinear and the tibia and fibula do not fuse distally. The astragalus is oriented more medially, the navicular is in a medial position, the ectocuneiform articulates with MtIII–IV, and the MtIV is more inclined laterally than in M. tarijense and M. americanum. M. urbinai is one of the smallest Megatherium species known along with M. altiplanicum. It has the most marked torsion of the pes for the genus. It extends the palaeogeographic distribution of the genus in South America. It is phylogenetically close to other Andean megatheriines and is less specialised than M. tarijense, and does not belong to the clade constituted by [M. altiplanicum + M. americanum].
A multivariate taxonomic analysis of the Late Carboniferous vertebrate ichnofauna of Alveley, southern Shropshire, England
Authors: Tucker Lauren , Smith M. Paul
Published: May 2004

A diverse Late Carboniferous (Westphalian D; Moscovian) vertebrate ichnofaunal assemblage from the Alveley Member (Salop Formation, Warwickshire Group) of Alveley, southern Shropshire, UK, is a significant example of an early, transitional tetrapod community. Positive tetrapod footprint casts (convex hyporeliefs) within fine‐ and medium‐grained sandstone red‐beds were formed subaqueously in an alluvial floodplain setting. A statistical analysis of this material, the first using multivariate techniques on Late Palaeozoic trackways, has been undertaken to determine the ichnospecific diversity and morphological variation within the ichno‐assemblage. Nine ichnotaxa have been identified, following a study of more than 200 trackways. These include the amniote ichnogenera Dimetropus Romer and Price, 1940, Ichniotherium Pohlig, 1885 and Hyloidichnus Gilmore, 1927, but there is a dominance of trackways of the ichnogenus Limnopus Marsh, 1894, which represent stem‐lissamphibian ‘temnospondyls’. Following statistical analysis, the ichnogenera Limnopus and Batrachichnus are subsumed as ichnosubgenera under the senior available name Limnopus. The Alveley ichnofaunal assemblage provides significant range extensions for a number of amniote and stem‐lissamphibian trackmakers from the latest Carboniferous or Permian down into the mid‐Late Carboniferous. It also marks a key transitional stage in the evolution of tetrapod communities, from the ‘amphibian’ grade assemblages of the Carboniferous to the more terrestrial, amniote‐dominated communities of the Early Permian.
Systematics of Upper Cretaceous calloporid bryozoans with primitive spinose ovicells
Authors: Ostrovsky Andrew N. , Taylor Paul D.
Published: May 2004

The majority of fossil and Recent cheilostome bryozoans brood their larvae in ovicells. These double‐walled, hood‐like skeletal structures are thought to have arisen through modification of spines belonging to the zooid distal of the maternal zooid. Support for this hypothesis comes from the existence of ovicells constructed of multiple spines in a few Upper Cretaceous species belonging to two groups, microporids and cribrimorphs. Here we report the discovery of similar multispinose ovicells in a third group, calloporids, which are closely related to primitive cheilostomes that do not brood their larvae. The genus Distelopora Lang, 1915 from the Cenomanian (‘Chalk Marl’) of Cambridge is taken out of synonymy and shown to comprise the type species (D. bipilata) and two new species (D. langi and D. spinifera) of multiserial calloporids. Between 5 and 15 spine bases are arranged in a crescent on the gymnocyst of the zooid distal of each maternal (egg‐producing) zooid in Distelopora. This indicates the presence of an ovicell formed by a cage of basally articulated spines. Similar ovicells represented by 18–19 spine bases occur in a uniserial calloporid from the German Campanian Allantopora krauseae Voigt and Schneemilch, 1986, which is made the type species of the new genus Unidistelopora. Another calloporid from the Cambridge Cenomanian has ovicells constructed by two claw‐like, flattened, non‐articulated and laterally juxtaposed spines. Described as Gilbertopora larwoodi gen. et sp. nov., this multiserial species provides a link between Distelopora and more typical cheilostome ovicells. The spines forming primitive ovicells provide a good example of exaptations, co‐opted from their original function protecting the polypide of the distal zooid.
The basicranium of dicynodonts (Synapsida) and its use in phylogenetic analysis
Authors: Surkov Mikhail V. , Benton Michael J.
Published: May 2004

Current phylogenetic hypotheses for the dicynodonts conflict, probably because the characters used, especially those of the jaws and facial region, show considerable convergence. Characters of the braincase and basipterygoid articulation of the Late Permian–Middle Triassic dicynodonts Diictodon, Dicynodon, Kingoria, Lystrosaurus, Rechnisaurus, and 14 other genera, may have phylogenetic value. Parsimony analysis and the character compatability permutation test suggest, at the highest possible confidence level, that the data set contains significant hierarchical structure, interpreted as a result of phylogeny. The most parsimonious tree broadly agrees with all recent hypotheses on the relationships among dicynodonts. However, it conflicts with the recent suggestion that Lystrosaurus is part of a clade of Middle–Late Triassic dicynodonts, but supports the basal position of Kingoria. The use of Eodicynodon as an outgroup does not perturb the parsimonious relationship of the included taxa. Topological constraints reveal that phylogenetic hypotheses based only on basicranial characters are not robust. Characters of the basipterygoid articulation and inner braincase have high consistency and retention indices, which suggests that the main evolutionary transformations in the dicynodont basicranium occurred within these structures.
Chitinozoan biostratigraphy of the basal Wenlock Series (Silurian) Global Stratotype Section and Point
Authors: Mullins Gary L. , Aldridge Richard J.
Published: May 2004

Diverse and abundant assemblages of chitinozoans allow the recognition of the upper part of the Margachitina margaritana Biozone in the uppermost Llandovery and lowermost Wenlock series of the Hughley Brook section. The Cingulochitina bouniensis and Salopochitina bella biozones are identified in the lower part of the Buildwas Formation, Wenlock Series. The chitinozoan data indicate that the base of the Wenlock Series most probably correlates with a level in the upper centrifugus or lower murchisoni graptolite biozones. Chitinozoans also indicate that the base of the riccartonensis graptolite Biozone may occur within the Buildwas Formation and not the overlying Coalbrookdale Formation.
Language on the Verge of Death: On Language and Language Criticism in Badenheim 1939 by Aharon Appelfeld
Authors: Shacham Chaya
Published: May 2004

The question of language became a central issue in writing after the Holocaust, especially for those for whom the years of the Second World War were formative in both their personal lives and their becoming writers. The Hebrew writer Aharon Appelfeld is one of them. This study focuses on the problem of language and language criticism in Appelfeld's novella Badenheim 1939 (1975). Language is in fact the covert theme of the novella. The work, which describes the last summer in an Austrian resort before the deportation of its Jews to Poland, is replete with metalanguage whose purpose is to draw the reader's attention to the language and its status in the work. The essay follows and analyses the effects on language made by the characters’ experiences (weakening, loss of meaning, loss of referents in the new reality and the new era in Badenheim) and suggests that the meeting point of the murderers and victims is in language corruption and distortion. The study furthermore suggests that from the novella springs the unspoken accusation against the Jewish vacationers of unintentional collaboration with the murderers by conniving in the ‘laundering’ of the language, which in turn contributed to the coming catastrophe. Central to the explorations of the essay is the possibility of linking Appelfeld's criticism of language with Karl Krause's critical stance on language contamination and doublespeak implied in the work.
Pocket Books to Global Beat: Andrei Voznesensky, Kazuko Shiraishi, Michael Horovitz
Authors: Robert Lee A.
Published: May 2004

The Beat Movement has long been thought to centre only as an American cultural phenomenon and in key names like Jack Kerouac, Allen Ginsberg, Lawrence Ferlinghetti and Gregory Corso, and with William Burroughs as a presiding dark mentor. This essay argues for a far wider contextual understanding. It looks to Beat currents in the African American poetry of LeRoi Jones/Imamu Baraka, Ted Joans and Bob Kaufman, a circuit of Beat‐influenced women like Diane Di Prima and Anne Waldman, and a US multicultural arena to include Oscar Zeta Acosta and Maxine Hong Kingston. Most of all it analyses the Beat impact beyond America in three prime names: Andrei Voznesensky as leading 1960s–1970s Russian dissident poet, Kazuko Shiraishi as longtime vintage Tokyoite jazz‐and‐poetry ‘bad girl’, and Michael Horovitz as British counter‐culture voice. In these three Beat acquires a global reach, a force of vision, a poetics, well beyond Greenwich Village or City Lights Bookshop, San Francisco. It also links the local, miniaturist Pocket Poets series established by Ferlinghetti with his own Pictures of a Gone World (1955) to Beat writings which can best be thought at once national and transnational. Given this larger cultural context, the essay analyzes a relevant body of verse by Vosnesensky, Shiraishi and Horovitz, with particular attention given to vision, image, the shaping language each poet gives to Beat heritage inaugurated far from their own beginnings.
Role of the Otx1 gene in cell differentiation of mammalian cortex
Authors: Pantò Maria Rosita , Zappalà Agata , Tuorto Francesca , Cicirata Federico
Published: May 2004

This study analyses by immunohistochemical methods the effects of the deletion of the Otx1 gene on 12 areas of the cerebral cortex and on neurons expressing Ca‐binding proteins (CaBP), such as parvalbumin (Pv) and calbindin‐D28K (Cb). We found that the deletion of the Otx1 gene modified differently the various cortical areas. The decrease in cortical thickness ranged from 29.35 to 9.85% and the reduction in cellular population from 35.90 to 3.65% in the different cortical areas. The influence of the Otx1 gene concerns all cortical layers with variable effects on different cortical areas. The cellular population of cerebral cortex considered as a whole was reduced by 20.67%, Pv‐positive (Pv+) cells by 58.01% and Cb‐positive (Cb+) cells by 51.54%. The quantitative distribution of Pv+ and Cb+ cells varied independently in the different cortical areas. Topographic analysis of CaBP cells in Otx1‐null mice (Otx1−/−) showed that Pv+ cells were principally distributed in layers IV and V and Cb+ cells in layers V and VI. Given that in the development of wild‐type mice both cell types first appear in deep layers and later spread to superficial ones, the segregation of CaBP neurons in inner layers of Otx1−/− animals is an index of the immaturity of the cerebral cortex of these animals. This study showed that the Otx1 gene has a more complex role than previously reported, as it is involved in the maturation and differentiation of various cerebral cortices, and, specifically, in the development of CaBP cells.
Functional expression of connexin57 in horizontal cells of the mouse retina
Authors: Hombach Sonja , Janssen‐Bienhold Ulrike , Söhl Goran , Schubert Timm , Büssow Heinrich , Ott Thomas , Weiler Reto , Willecke Klaus
Published: May 2004

Horizontal cells are interneurons of the vertebrate retina that exhibit strong electrical and tracer coupling but the identity of the channel‐forming connexins has remained elusive. Here we show that horizontal cells of the mouse retina express connexin57 (Cx57). We have generated Cx57‐deficient mice by replacing the Cx57 coding region with a lacZ reporter gene, expressed under control of the endogenous Cx57 promoter. These mice were fertile and showed no obvious anatomical or behavioural abnormalities. Cx57 mRNA was expressed in the retina of wild‐type littermates but was absent from the retina of Cx57‐deficient mice. Previously reported results that the Cx57 gene was very weakly expressed in several other mouse tissues turned out to be unspecific. Cx57 mRNA is abundantly expressed in the retina and weakly in the thymus of adult mice but absent in all other adult tissues tested, including brain. Furthermore, Cx57 is expressed in embryonic kidney at E16.5 to E18.5 days post‐conception, as indicated by the pattern of lacZ expression. Within the retina, lacZ signals were assigned exclusively to horizontal cells based on co‐localization with cell‐type‐specific marker proteins. Microinjection of Neurobiotin into horizontal cells of isolated retinae revealed less than 1% of tracer coupling in Cx57‐deficient retinae compared with wild‐type controls. Cx57 is the first connexin identified in mammalian horizontal cells and the first connexin whose expression is apparently restricted to only one type of neuron.
Increased MAP kinase activity in Alzheimer's and Down syndrome but not in schizophrenia human brain
Authors: . Swatton Jane E , Sellers Lynda A. , Faull Richard L.M. , Holland Anthony , Iritani Shuji , Bahn Sabine
Published: May 2004

Introduction

Abnormal phosphorylation of tau is a feature of Alzheimer's disease (AD), which develops prematurely in Down syndrome (DS) patients. Cognitive impairment is also recognized as a clinical characteristic of schizophrenia, which does not appear to be associated with tau‐aggregate formation. Several kinases can phosphorylate tau in cell‐free assays. Here we show increased activity of mitogen‐activated protein kinases (MAPKs) (including ERK1/2, SAPKs and p38) in post mortem AD and DS brains, which could not be accounted for by expression changes. In contrast, glycogen synthase kinase‐3 activity (GSK‐3αβ) was reduced significantly. Examination of tau in AD and DS using antibodies selective for MAPK phosphorylation sites showed increased immunoreactivity. In addition, phosphorylation of S199, reportedly a selective substrate for cyclin‐dependent kinase‐5 (cdk5) or GSK‐3αβ was only observed in AD samples, which showed a concomitant increase in the expression of p25, the enhancing cofactor for cdk5 activity. However, in schizophrenia brain, MAPK‐phosphorylated tau was unchanged compared to matched controls, despite similar expression levels to those in AD. The activities of the MAPKs and GSK‐3αβ were also unchanged. These data demonstrate that in AD and DS, enhanced MAPK activity, which has an established role in regulating neuronal plasticity and survival, can account for irregular tau phosphorylation, and that the molecular processes involved in these neurodegenerative disorders are distinct from those in schizophrenia. These data also question the significance of GSK‐3αβ, as much previous work carried out in vitro has placed this kinase as a favoured candidate for involvement in the pathological phosphorylation of tau.
Effects of hypocretin2‐saporin and antidopamine‐β‐hydroxylase‐saporin neurotoxic lesions of the dorsolateral pons on sleep and muscle tone
Authors: Blanco‐Centurion Carlos , Gerashchenko Dmitry , Salin‐Pascual Rafael J. , Shiromani Priyattam J.
Published: May 2004

The hypocretin neurons have been implicated in regulating sleep‐wake states as they are lost in patients with the sleep disorder narcolepsy. Hypocretin (HCRT) neurons are located only in the perifornical region of the posterior hypothalamus and heavily innervate pontine brainstem neurons, such as the locus coeruleus (LC), which have traditionally been implicated in promoting arousal. It is not known how the hypocretin innervation of the pons regulates sleep‐wake states as pontine lesions have never been shown to increase sleep. It is likely that in previous studies specific neurons were not lesioned. Therefore, in this study, we applied saporin‐based neurotoxins to the dorsolateral pons and monitored sleep in rats. Anti‐dopamine‐β‐hydroxylase‐saporin killed the LC neurons but sleep was affected only during a two hour light‐dark transition period. Application of hypocretin2‐saporin killed fewer LC neurons relative to other adjacent neurons. This occurred because the LC neurons possess the hypocretin receptor 1 but the ligand hypocretin 2 binds to this receptor with less affinity relative to the hypocretin receptor 2. The hypocretin2‐saporin lesioned rats compared to controls had increased sleep during the dark period and displayed increased limb movements during REM sleep. None of the lesioned rats had sleep onset REM sleep periods or cataplexy. We conclude that the hypocretin innervation to the pons functions to awaken the animal when the lights turn off (via its innervation of the LC), sustains arousal and represses sleep during the rest of the night (via a wider innervation of other pontine neurons), and modulates muscle tone.
Suppression of a slow post‐spike afterhyperpolarization by calcineurin inhibitors
Authors: Vogalis F. , Harvey J. R. , Furness J. B.
Published: May 2004

A subset of myenteric neurons in the intestine (AH neurons) generate prolonged (>5 s) post‐spike afterhyperpolarizations (slow AHPs) that are insensitive to apamin and tetraethylammonium. Generation of slow AHPs depends critically on Ca2+ entry and intracellular release of Ca2+ from stores, which then leads to the activation of a K+ conductance that underlies the slow AHP (gsAHP). Slow AHPs are inhibited by stimulation of the cAMP/protein kinase A (PKA) pathway, suggesting that phosphorylation of the K+‐channels that mediate the gsAHP (KsAHP‐channels) is responsible for suppression of slow AHPs and possibly for the repolarization phase of slow AHPs. In the present study, we investigated the possibility that the rising phase of the slow AHP is mediated by dephosphorylation of KsAHP‐channels by calcineurin (CaN), a Ca2+‐calmodulin‐dependent protein phosphatase, leading to an increase in gsAHP and activation of the associated current IsAHP. Slow AHPs and IsAHP were recorded using conventional recording techniques, and we tested the actions of two inhibitors of CaN, FK506 and cyclosporin A, and also the effect of the CaN autoinhibitory peptide applied intracellularly, on these events. We report here that all three treatments inhibited the slow AHP and IsAHP (>70%) without significantly affecting the ability of neurons to fire action potentials. In addition, the slow AHP and IsAHP were suppressed by okadaic acid, an inhibitor of protein phosphatases 1 and 2A. Our results indicate that activation of the gsAHP that underlies the post‐depolarization slow AHPs in AH neurons is mediated by the actions CaN and non‐Ca2+‐dependent phosphatases.