bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation‐based investigations of fishery changes as affected by the scale and design of artificial habitats
Authors: Sayer M. D. J. , Magill S. H. , Pitcher T. J. , Morissette L. , Ainsworth C.
Published: November 2005

Preliminary field observations on a large‐scale multi‐reef artificial reef system in Scotland indicated that the provision of artificial habitat of varying design alters the numbers and types of fishes present in areas where they were previously largely absent. These modifications could, in time, be highly beneficial to any programme of fishery enhancement, protection or restoration but only where the scale of habitat manipulation was relevant to the target fisheries. Ecosystem simulations provide a theoretical basis on which to conduct examinations of habitat manipulation at scales that could not be tested empirically. In the present study, a series of ecosystem models was constructed based on broad‐scale simulations for the west coast of Scotland in order to examine the potential consequences to selected fisheries of different scales and types of intervention using artificial reefs. Initialized with a large‐scale mass‐balance model, a number of smaller‐scale dynamic ecosystem simulations covered management situations that encompassed habitat type and reef design for open, restricted and closed fisheries. Spatial simulations examined the presence and absence of artificial habitat with natural reefs and marine protected areas (MPAs) under realistic environmental situations. The simulated trends supported preliminary field observations that artificial habitats would support similar biotic aggregations to natural reefs. Designs that maximized the reef edge as a function of the total reef volume were more productive for some of the functional groups examined compared with larger single deployments of identical area. Increasing the area of artificial habitat did result in improvements to some of the fisheries. The behaviour of some functional groups, however, highlighted the limitations of the broad‐scale primary model to smaller‐scale investigation. Future simulations used to inform management decision at the sub‐regional level would require evidence‐based revision to improve their relevance.
Spatial variation in population dynamics of juvenile Atlantic salmon: implications for conservation and management
Authors: Armstrong J. D.
Published: November 2005

Application of habitat models for predicting expected local densities of Atlantic Salmon Salmo salar in healthy populations has been hampered by a lack of generality in their fit to data from different systems. It is believed that this problem results at least in part from difficulties of effectively integrating factors that act across a range of spatial and temporal scales. Here, as an aid to developing more robust modelling and sampling methodologies, a simple process‐based model for local‐scale dynamics of Atlantic salmon juveniles is developed from first principles by integrating contemporary understanding of self‐thinning, density‐dependent growth and dispersal. The aim is to present a readily understood structure to illustrate the links between spawning and stocking strategies, habitat, migration and fish production. Based on this structure, contemporary understanding of the more complex biological processes that affect density, growth and habitat are discussed in relation to some of the key requirements of managers, including stocking for rehabilitation, assessment of predation impact and development of strategies for sampling populations effectively when deriving habitat‐production models. A major conclusion is that more structured, integrated research is required to provide the basic variables needed to model links between local and global scale habitat and fish production effectively. Nevertheless, application of the current understanding of the biology of Atlantic salmon should be of great benefit to managers in extracting key information from field surveys.
A novel 3‐dimensional culture system as an in vitro model for studying oral cancer cell invasion
Authors: Duong Hai S. , Le Anh D. , Zhang Qunzhou , Messadi Diana V.
Published: November 2005

Tissue microenvironment plays a critical role in tumour growth and invasion. This study established a novel 3‐dimensional (3‐D) cell invasion model for direct microscopic observation of oral cancer cell invasion into the underlying basement membrane and connective tissue stroma. A multilayer cell construct was developed using the OptiCell chamber, consisting of a lower layer of oral mucosa fibroblasts embedded in collagen gel and an overlaying upper layer of oral cancer cells. The two layers are separated by a basement membrane composed of reconstituted extracellular matrix. To verify the applicability of the cell invasion model, multilayer cell constructs of oral squamous cell carcinoma and oral mucosal fibroblasts were exposed to extrinsic urokinase‐type plasminogen activator (uPA) or plasminogen activator inhibitor (PAI‐1), which are known effectors of cell migration. In addition, the constructs were exposed to both normoxic and hypoxic culture conditions. Microscopic study showed that the presence of uPA enhanced cell invasion, while PAI‐1 inhibited cell migration. Western blot and zymographic analysis demonstrated that hypoxia up‐regulated uPA and matrix metalloproteinases (MMPs) expression and activity; conversely, PAI‐1 level was down‐regulated in response to hypoxic challenge as compared to normoxic condition. Our results indicated that the novel 3‐D invasion model could serve as an excellent in vitro model to study cancer cell invasion and to test conditions or mediators of cellular migration.
Abnormal expression of bcl‐2 and bax in rat tongue mucosa during the development of squamous cell carcinoma induced by 4‐nitroquinoline 1‐oxide
Authors: Ribeiro Daniel A. , Salvadori Daisy M. F. , Marques Mariângela E. A.
Published: November 2005

4‐Nitroquinoline 1‐oxide (4NQO)‐induced rat tongue carcinogenesis is a useful model for studying oral squamous cell carcinoma. The aim of this study was to investigate the expression of bcl‐2 and bax during tongue carcinogenesis induced by 4NQO. Male Wistar rats were distributed into three groups of 10 animals each and treated with 50 ppm 4NQO solution through their drinking water for 4, 12 or 20 weeks. Ten animals were used as negative control. Although no histological changes were induced in the epithelium after 4 weeks of carcinogen exposure, bcl‐2 and bax were over‐expressed (P < 0.01) in all layers of the ‘normal’ epithelium. The expression levels were the same in all layers of epithelium for both the antibodies used (bcl‐2 or bax). In dysplastic lesions at 12 weeks following carcinogen administration, the levels of bcl‐2 and bax expression did not increase when compared to negative control with the immunoreactivity for bcl‐2 being restricted to the superficial layer of epithelium. In well‐differentiated squamous cell carcinoma induced after 20 weeks of treatment with 4NQO, bcl‐2 was expressed in some cells of tumour islands. On the other hand, immunostaining for bax was widely observed at the tumour nests. The labelling index for bcl‐2 and bax showed an increase (P < 0.05) after only 4 weeks of 4NQO administration. In conclusion, our results suggest that abnormalities in the apoptosis pathways are associated with the development of persistent clones of mutated‐epithelial cells in the oral mucosa. Bcl‐2 and bax expression appears to be associated with a risk factor in the progression of oral cancer.
Neoplastic transformation and angiogenesis in the thymus of transgenic mice expressing SV40 T and t antigen under an l‐pyruvate kinase promoter (SV12 mice)
Authors: Nabarra Bernadette , Pontoux Christiane , Godard Cecile , Osborne‐Pellegrin Mary , Ezine Sophie
Published: November 2005

Using several techniques, we have assessed morphological characteristics of a malignant thymic tumour in SV12 transgenic (Tg) mice expressing SV40 T and t antigens under control of an L‐PK promoter. We describe the development of a carcinoma originating from thymic hyperplasia and followed by the formation of a benign tumour composed chiefly of medullary epithelial cells expressing the transgene and of lymphocytes, a pathology very rarely reported in mice. Our study of the SV12 Tg mice represents the first description of a model of a pure malignant thymic tumour associated with extensive angiogenesis maintained in numerous descendants. The formation of a large tumoral neovascular network, observed here, has never been described in human and/or experimental thymic tumours. Tumoral transformation and angiogenesis are demonstrated by immunolabelling with antibodies against various cytokeratins (CKs) of different molecular weights, vascular endothelial cell markers and VEGF/receptor‐2 (Flk‐1) present on the neovascular endothelial cells. Different points raised by the originality of this model are discussed. These include the medullary nature of the cells expressing the SV40 transgene and their relationship with the tumoral development. The subset of different molecular weight CK components and their modifications are also considered, as well as the presence of type IV epithelial cells, progenitors of medullary epithelial cells. Finally, the cell signals involved in angiogenesis and the possible action of an angiogenic factor, probably secreted by the tumoral cells themselves, are discussed.
The haemotoxicity of mitomycin in a repeat dose study in the female CD‐1 mouse
Authors: Molyneux Gemma , Gibson Frances M. , Gordon‐Smith Edward C. , Pilling Andrew M. , Liu Kai Chiu , Rizzo Sian , Sulsh Susan , Turton John A.
Published: November 2005

Mitomycin (MMC), like many antineoplastic drugs, induces a predictable, dose‐related, bone marrow depression in man and laboratory animals; this change is generally reversible. However, there is evidence that MMC may also cause a late‐stage or residual bone marrow injury. The present study in female CD‐1 mice investigated the haematological and bone marrow changes induced by MMC in a repeat dose study lasting 50 days. Control and MMC‐treated mice were dosed intraperitoneally on eight occasions over 18 days with vehicle, or MMC at 2.5 mg/kg, autopsied (n = 6–12) at 1, 7, 14, 28, 42 and 50 days after the final dose and haematological changes investigated. Femoral nucleated bone marrow cell counts and levels of apoptosis were also evaluated and clonogenic assays carried out; serum levels of FLT3 ligand (FL) were assessed. At day 1 post‐dosing, MMC induced significant reductions in RBC, Hb and haematocrit (HCT) values, and there were decreases in reticulocyte, platelet, and femoral nucleated cell counts (FNCC); neutrophil, lymphocyte and monocyte values were also significantly reduced. On days 7 and 14 post‐dosing, all haematological parameters showed evidence of a return towards normal values, but at these times, and at day 28, values for RBC and FNCC remained significantly reduced in comparison with controls. At days 42 and 50 post‐dosing, many haematological parameters in MMC‐treated mice had returned to control levels; however, there remained evidence of late‐stage effects on RBC, Hb and HCT values, and FNCC also continued to be significantly decreased. Results for granulocyte‐macrophage colony‐forming units and erythroid colonies showed a profound decrease immediately post‐dosing, but a return to normal values was evident at day 50. Serum FL concentrations demonstrated very significant increases in the immediate post‐dosing period, but a return to normal was seen at day 50 post‐dosing; a relatively similar pattern was seen in the number of apoptotic femoral marrow nucleated cells. The histopathological examination of kidney tissues from MMC animals at day 42 and 50 post‐dosing showed evidence of hydronephrosis with cortical glomerular/tubular atrophy and degeneration. It is therefore concluded that MMC administered on eight occasions over 18 days to female CD‐1 mice at 2.5 mg/kg induced profound changes in haematological and bone marrow parameters in the immediate post‐dosing period with a return to normal levels at day 50 post‐dosing; however, there was evidence of mild but significant late‐stage/residual effects on RBC and FNCC, and on cells of the erythroid lineage in the bone marrow.
Aberrant expression of E‐cadherin and β‐catenin in association with transforming growth factor‐β1 in urinary bladder lesions in humans after the Chernobyl accident
Authors: Romanenko Alina , Morimura Keiichirou , Kinoshita Anna , Wanibuchi Hideki , Vozianov Alexander , Fukushima Shoji
Published: November 2005

This study examines the molecular pathways of cell–cell communication in chronic inflammatory processes associated with long‐term low‐dose urinary bladder exposure to ionizing radiation in people without major disease living more than 19 years in radio‐contaminated areas of Ukraine after the Chernobyl accident. Patterns of components of the E‐cadherin/β‐catenin complex, and transforming growth factor‐β1 (TGF‐β1) and inducible nitric oxide synthase (iNOS) expression were immunohistochemically evaluated in urinary bladder biopsies from 52 males with benign prostate hyperplasia and 8 females with chronic cystitis (group 1). For comparison, 25 males and 6 females living in non‐contaminated areas of Ukraine were also investigated (group 2). Fourteen patients with primary urothelial carcinomas, which were operated on before the Chernobyl accident, were included as a carcinoma group. Chronic proliferative atypical cystitis (‘Chernobyl cystitis’) was observed in group 1 patients. Foci of dysplasia and carcinoma in situ were found in 51 (85%) and 34 (57%) of the 60 cases, respectively. Chronic cystitis with areas of dysplasia was detected in only 4 (13%) cases of 31 group 2 patients. Statistically significant differences in immunohistochemical scores for TGF‐β1 in the urothelium and lamina propria, iNOS in the urothelium and both β‐catenin and E‐cadherin in the cytoplasm were observed between groups 1 and 2 with marked expression in group 1. Furthermore, TGF‐β1 overexpression and alteration in E‐cadherin/β‐catenin complexes in bladder urothelium might play a crucial role in urinary bladder carcinogenesis in humans exposed to long‐term low‐dose ionizing radiation. (Cancer Sci 2005)
Comparison of enhancing effects of different goitrogen treatments in combination with β‐estradiol‐3‐benzoate for establishing a rat two‐stage thyroid carcinogenesis model to detect modifying effects of estrogenic compounds
Authors: Takizawa Tamotsu , Imai Toshio , Ueda Makoto , Onodera Hiroshi , Hirose Masao
Published: November 2005

With the aim of establishing a sensitive model for the detection of weak effects of endocrine disrupting chemicals on thyroid carcinogenesis, thyrotrophic and tumor‐promoting influences of β‐estradiol‐3‐benzoate (EB) in combination with representative antithyroidal agents (goitrogens), sulfadimethoxine (SDM), propylthiouracil (PTU), potassium perchlorate (PPC), iopanoic acid (IOP) or an iodine‐deficient diet were evaluated in a short‐term (7‐day) experiment without N‐bis(2‐hydroxypropyl)nitrosamine (DHPN) initiation and a long‐term (30‐week) experiment with DHPN initiation in ovariectomized F344 rats. In the short‐term experiment, the most remarkable thyrotrophic effects were found in the PTU‐treated group, followed by the SDM and PPC cases. EB treatment alone caused slight increases in thyroidal weights but no apparent morphological changes. Concomitant treatment with EB and antithyroidal agents enhanced the changes in thyroid weights, histopathological findings and/or serum thyroid hormone levels in the SDM (30 and 100 p.p.m), PTU (5 and 30 p.p.m) and PPC (100 p.p.m), IOP (30 and 100 mg/kg) or iodine‐deficient diet groups. In the long‐term experiment after DHPN initiation, EB alone slightly increased small numbers of animals with follicular hyperplasias, adenomas and adenocarcinomas. Simultaneous treatment with antithyroidal chemicals was associated with an increase in the incidences of focal hyperplasias, adenomas and/or adenocarcinomas. The enhancement was most remarkable with PTU (5 p.p.m), followed by PTU (2 p.p.m), SDM (100 p.p.m) and PPC (100 p.p.m). The results showed that EB has only a marginal promoting effect on DHPN‐induced rat thyroid carcinogenesis and that antithyroidal chemicals, particularly PTU, are effective as copromoting agents. (Cancer Sci2005)
The performance of STA‐Liatest D‐dimer assay in out‐patients with suspected pulmonary embolism
Authors: Ghanima W. , Abdelnoor M. , Mowinckel M.‐C. , Sandset P. M.
Published: November 2005

Several studies have shown that d‐dimer can reliably rule out pulmonary embolism (PE) in out‐patients. However, various assays have different sensitivities and specificities to detect thrombosis. Our aim was to evaluate the performance of STA‐Liatest D‐Di in out‐patients referred for suspected PE in a prospective outcome study. 495 consecutive patients referred to Østfold Hospital Trust‐Fredrikstad, Norway for suspected PE between February 2002 and December 2003, were recruited in a study evaluating a decision‐based algorithm combining clinical probability (CP), d‐dimer, and multi‐slice computer tomography (MSCT). d‐dimer was performed as a first step test. No further testing was carried out in patients with d‐dimer ≤0·4 mg/l and low/intermediate CP. The remaining patients proceeded to MSCT. All patients were followed up for 3 months to assess the 3‐month thromboembolic risk. The final cohort consisted of 432 patients. PE was diagnosed in 102 (23%) patients. At a d‐dimer cut‐off point of 0·4 mg/l the tests had the highest sensitivity (100%) and specificity (36%). It safely ruled out PE in 120 (28%) patients. Kappa‐coefficients for comparisons versus VIDAS and Asserachrom showed good concordance. STA‐Liatest is a reliable and effective assay that can safely rule out PE in out‐patients with a performance comparable with that of enzyme‐linked immunosorbent assay‐based d‐dimer levels.
Global assessment of coral bleaching and required rates of adaptation under climate change
Authors: DONNER SIMON D. , SKIRVING WILLIAM J. , LITTLE CHRISTOPHER M. , OPPENHEIMER MICHAEL , HOEGH‐GULDBERG OVE
Published: November 2005

Elevated ocean temperatures can cause coral bleaching, the loss of colour from reef‐building corals because of a breakdown of the symbiosis with the dinoflagellate Symbiodinium. Recent studies have warned that global climate change could increase the frequency of coral bleaching and threaten the long‐term viability of coral reefs. These assertions are based on projecting the coarse output from atmosphere–ocean general circulation models (GCMs) to the local conditions around representative coral reefs.

Here, we conduct the first comprehensive global assessment of coral bleaching under climate change by adapting the NOAA Coral Reef Watch bleaching prediction method to the output of a low‐ and high‐climate sensitivity GCM. First, we develop and test algorithms for predicting mass coral bleaching with GCM‐resolution sea surface temperatures for thousands of coral reefs, using a global coral reef map and 1985–2002 bleaching prediction data. We then use the algorithms to determine the frequency of coral bleaching and required thermal adaptation by corals and their endosymbionts under two different emissions scenarios.

The results indicate that bleaching could become an annual or biannual event for the vast majority of the world's coral reefs in the next 30–50 years without an increase in thermal tolerance of 0.2–1.0°C per decade. The geographic variability in required thermal adaptation found in each model and emissions scenario suggests that coral reefs in some regions, like Micronesia and western Polynesia, may be particularly vulnerable to climate change. Advances in modelling and monitoring will refine the forecast for individual reefs, but this assessment concludes that the global prognosis is unlikely to change without an accelerated effort to stabilize atmospheric greenhouse gas concentrations.
Distributions of tree species along point bars of 10 rivers in the south‐eastern US Coastal Plain
Authors: Robertson Kevin M.
Published: November 2005

Aim  To determine the degree to which rivers within the south‐eastern US Coastal Plain show a predictable spatial distribution of floodplain tree species along each point bar of river bends in relation to elevation and/or soil texture, as seen on the Bogue Chitto River, Louisiana, USA. Also, to understand spatial patterns of tree species on land created during river‐bend migration, and to interpret which physical characteristics of rivers predict this pattern of vegetation.

Location  The south‐eastern US Coastal Plain.

Methods  Ten randomly selected rivers within a portion of the region were studied. At each of 10 river bends per river, a census of trees and shrubs was taken and elevation and soil texture were measured at upstream, mid‐ and downstream locations along the forest–point bar margin. To identify physical characteristics of rivers that are predictive of patterns of tree species along point bars, aerial photographs, hydrographs and field data were analysed.

Results  Tree species composition varied predictably among the three point bar locations, corresponding to an elevation gradient on each bar, on seven of 10 rivers. Species occupying a given point bar location on one river usually occupied the same location on other rivers, in accordance with species‐elevation associations identified in past studies of floodplain forests. Multivariate analysis of river characteristics suggested that rivers failing to show the expected pattern were those with relatively low stream energy and geomorphic dynamics and/or those with hydrological regimes altered by upstream dams.

Main conclusions  A distinct pattern of streamside forest community structure is related to fluvial geomorphic processes characterizing many rivers within the south‐eastern US Coastal Plain. Characteristics of rivers required to promote the predicted pattern of tree species include a single, meandering channel with point bars; an intermediate level of stream energy; a natural hydrological regime; and location in a biome where a large number of tree species are capable of colonizing point bars.
Proximate sources of marine biodiversity
Authors: Briggs John C.
Published: November 2005

When temperature and other kinds of barrier divide formerly continuous populations and confine them to more restricted geographical areas, there is an evolutionary reaction that will, over time, result in the formation of endemic species. In such cases, an allopatric speciation process is considered to have taken place because reproductive isolation was caused by physical means instead of by natural selection. In contrast, when populations exist in a very high‐diversity area and remain undivided by physical events, they exhibit a tendency to speciate by means of sympatry (or parapatry). This process, sometimes called competitive or ecological speciation, does involve reproductive isolation by means of natural selection. Populations that exist in geographical provinces bounded by physical barriers add to the overall diversity through the production of endemic species. This increase by species packing is relatively slow due to the very gradual tempo of the allopatric speciation process. Populations existing in centres of origin add to the general diversity through the production of species that are dominant in terms of their ability to spread over large parts of the world. It is proposed that such species are usually formed by sympatric speciation, a process that can bec.20 times faster than species formation by allopatry. It is not suggested that sympatry is exclusive to centres of origin, nor that allopatry is confined to peripheral provinces. Both processes are widespread, but there do appear to be distinctive geographical concentrations. Considering that numbers of widespread species produced by centres of origin may eventually become subdivided by barriers, and thus give rise to descendants by allopatry, it is difficult to say how much of our present species diversity has come from one source or the other. Both speciation by sympatry from centres of origin and speciation by allopatry in peripheral provinces appear to be important sources of marine biodiversity.
The austral cordgrass Spartina densiflora Brong.: its taxonomy, biogeography and natural history
Authors: Bortolus Alejandro
Published: November 2005

Aim  During the last 20 years, the austral cordgrass Spartina densiflora has been recorded aggressively invading estuarine environments in the USA, Spain and Morocco. Whereas this species is one of the three most widely distributed worldwide, it is among the least studied within the genus. The objective of this work is to integrate baseline information about the taxonomy, global distribution, centre of origin, and general ecology of S. densiflora in native and invaded marshes worldwide in order to help to strengthen management efforts currently directed at controlling or eradicating it from locations where it has been introduced.

Location  World‐wide.

Methods  I review, update and discuss relevant information about S. densiflora published in peer‐reviewed papers, including those in journals with limited international distribution. I also review theses and major technical reports containing critical up‐to‐date information.

Results  This work indicates that, although S. densiflora remains in need of thorough scientific attention, key information on its taxonomy, distribution and invasive biology has been overlooked because it was published in languages other than English, and/or in journals with restricted distribution.

Main conclusions  Spartina densiflora seems to have originated along the east coast of South America; today, however, many other regions worldwide serve as donors for this invasive species, including Chile, the USA, Spain and Morocco. Spartina densiflora is a bioengineer organism, tolerant of a broad spectrum of environmental conditions and able to re‐shape the structure of invaded communities not just in mudflats, but also on sandy, muddy, and rocky shores as well as on cobble beaches. Only by integrating local‐scale research conducted in different geographical regions will we be able to understand the between‐site variations of its biological cycle, which in turn will aid in the design of more effective conservation strategies.
A spontaneous genomic deletion in Listeria ivanovii identifies LIPI‐2, a species‐specific pathogenicity island encoding sphingomyelinase and numerous internalins
Authors: Domínguez‐Bernal Gustavo , Müller‐Altrock Stefanie , González‐Zorn Bruno , Scortti Mariela , Herrmann Petra , Monzó Héctor J. , Lacharme Lizeth , Kreft Jürgen , Vázquez‐Boland José A.
Published: November 2005

Listeria ivanovii differs from the human pathogen Listeria monocytogenes in that it specifically affects ruminants, causing septicaemia and abortion but not meningo‐encephalitis. The genetic characterization of spontaneous L. ivanovii mutants lacking the virulence factor SmcL (sphingomyelinase) led us to identify LIPI‐2, the first species‐specific pathogenicity island from Listeria. Besides SmcL, this 22 kb chromosomal locus encodes 10 internalin (Inl) proteins: i‐InlB1 and ‐B2 are large/surface‐associated Inls similar to L. monocytogenes InlB; i‐InlE to –L are small/excreted (SE)‐Inls, i‐InlG being a tandem fusion of two SE‐Inls. Except i‐inlB1, all LIPI‐2 inl genes are controlled by the virulence regulator, PrfA. LIPI‐2 is inserted into a tRNA locus and is unstable – half of it deleting at ≈10−4 frequency with a portion of contiguous DNA. The spontaneous mutants were attenuated in vivo in mice and lambs and showed impaired intracellular growth and apoptosis induction in bovine MDBK cells. Targeted knock‐out mutations associated the virulence defect with LIPI‐2 genes. The region between the core genome loci ysnB‐tRNAarg and ydeI flanking LIPI‐2 contained different gene complements in the different Listeria spp. and even serovars of L. monocytogenes, including remnants of the PSA bacteriophage int gene in serovar 4b, indicating it is a hot spot for horizontal genome diversification. LIPI‐2 is conserved in L. ivanovii ssp. ivanovii and londoniensis, suggesting an early acquisition during the species’ evolution. LIPI‐2 is likely to play an important role in the pathogenic and host tropism of L. ivanovii.
Deglycosylation of human glycoconjugates by the sequential activities of exoglycosidases expressed by Streptococcus pneumoniae
Authors: King Samantha J. , Hippe Karen R. , Weiser Jeffrey N.
Published: November 2005

Streptococcus pneumoniae produces three surface‐associated exoglycosidases; a neuraminidase, NanA, a β‐galactosidase, BgaA, and a β‐N‐acetylglucosaminidase, StrH. the proposed functions of NanA, which removes terminal sialic acid, include revealing receptors for adherence, affecting the function of glycosylated host clearance molecules, modifying the surface of other bacteria coinhabiting the same niche, and providing a nutrient source. However, it is unclear whether following desialylation S. pneumoniae can further deglycosylate human targets through the activity of BgaA or StrH. We demonstrate that NanA, BgaA and StrH act sequentially to remove sialic acid, galactose and N‐acetylglucosamine and expose mannose on human glycoproteins that bind to the pneumococcus and protect the airway. In addition, both BgaA and NanA were shown to contribute to the adherence of unencapsulated pneumococci, to human epithelial cells. Despite these findings, triple exoglycosidase mutants colonized mice as well as their parental strains, suggesting that any effect of these genes on colonization and disease may be host species‐specific. These studies highlight the importance of considering the complete ability of S. pneumoniae to deglycosylate human targets and suggest that in addition to NanA, BgaA and StrH also contribute to pneumococcal colonization and/or pathogenesis.
Fossil fluid reservoir beneath a duplex fault structure within the Central Range of Taiwan: implications for fluid leakage and lubrication during earthquake rupturing process
Authors: Chan Yu‐Chang , Okamoto Kazuaki , Yui Tzen‐Fu , Iizuka Yoshiyuki , Chu Hao‐Tsu
Published: November 2005

In order to understand the kinematics which likely facilitated the speedy rupturing process of the 1999 Mw 7.6 Taiwan Chi‐Chi earthquake, we examined exposed rocks in the Taiwan Slate belt, where the pressure and temperature conditions most resembled the hypocentre of the Chi‐Chi earthquake, i.e. sub‐greenschist facies. Field observations and composition analyses of the silicified vein‐rich zones beneath the duplex structure suggest that impermeable slate layers may serve as cap rocks for confining deep‐seated fluids. These fluids most likely come from the Taiwan metamorphic complex at deeper depths by the dehydration and decarbonation reactions (or partial melting). In addition, the gouge zone of a link fault above the detachment also indicates the presence of overpressured fluids during faulting. It is probable that episodic leakage of the confined fluid reservoirs may provide essential fluids for fault lubrication during earthquake ruptures.
Have volcanoes already passed their zenith influencing the ozone layer?
Authors: Halmer Martina M.
Published: November 2005

Earth's ozone layer is only a very small part of the atmosphere, but its intact abundance is most important to the vitality of human beings. Observations have shown that especially after the plinian eruption of Pinatubo volcano in 1991 the ozone layer showed a dramatic depletion. Could a similar hypothetic eruption in the future cause an equal effective destruction of ozone while considering the increasing reduction of man‐made halogens in the stratosphere after the Montreal protocol in 1987?
Evidence for remnants of ancient ice‐rich deposits: Mangala Valles outflow channel, Mars
Authors: Levy Joseph S. , Head James W.
Published: November 2005

High‐resolution spacecraft data reveal the presence of a distinctive unit on the upper reaches of the floor of Mangala Valles, an ancient outflow channel on Mars. In contrast to abundant evidence for scour, intense erosion, and hydrodynamic shaping typical of the floors and margins of Mangala and other outflow channels, this unit is smooth‐surfaced, has cuspate margins, is superposed on the scoured valley floor, and is extensively pitted. We interpret this unit to be the sublimation lag deposit derived from an ice thermal boundary layer on the aqueous flood that formed the outflow channel system, and the remnant of floodwaters trapped in channel lows. This interpretation further supports the likelihood that climate conditions at the time of emplacement were similar to the hyper‐arid cold desert conditions of today. Frozen floodwaters from the ancient martian subsurface could still be preserved in these deposits, representing attractive and accessible exobiological exploration objectives.
Bottom‐simulating reflections and geothermal gradients across the western Svalbard margin
Authors: Vanneste Maarten , Guidard Stéphanie , Mienert Jürgen
Published: November 2005

Seismic reflection data reveal prominent bottom‐simulating reflections (BSRs) within the relatively young (<0.78 Ma) sediments along the West Svalbard continental margin. The potential hydrate occurrence zone covers an area of c. 1600 km2. The hydrate accumulation zone is bound by structural/tectonic features (Knipovich Ridge, Molloy Transform Fault, Vestnesa Ridge) and the presence of glacigenic debris lobes inhibiting hydrate formation upslope. The thickness of the gas‐zone underneath the BSR varies laterally, and reaches a maximum of c. 150 ms. Using the BSR as an in‐situ temperature proxy, geothermal gradients increase gradually from 70 to 115 °C km−1 towards the Molloy Transform Fault. Anomalies only occur in the immediate vicinity of normal faults, where the BSR shoals, indicating near‐vertical heat/fluid flow within the fault zones. Amplitude analyses suggest that sub‐horizontal fluid migration also takes place along the stratigraphy. As the faults are related to the northwards propagation of the Knipovich Ridge, long‐term disturbance of hydrate stability appears related to incipient rifting processes.
Palaeoenvironmental turnover across the Palaeocene/Eocene boundary at the Stratotype section in Dababiya (Egypt) based on benthic foraminifera
Authors: Alegret Laia , Ortiz Silvia , Arenillas Ignacio , Molina Eustoquio
Published: November 2005

The Global Stratotype Section and Point for the Palaeocene/Eocene (P/E) boundary was defined at Dababiya Quarry (Egypt) at the base of the carbon isotope excursion (CIE). We present the first detailed analysis of Palaeocene–Eocene benthic foraminifera from Dababiya, in order to infer the palaeoenvironmental turnover across the P/E boundary. At Dababiya, the CIE coincides with a major turnover in foraminiferal assemblages; the last occurrence of Angulogavelinella avnimelechi, at the base of the CIE, may be correlated to the main phase of extinction of deep‐sea benthic foraminifera. Benthic foraminifera indicate that stressful conditions such as oxygen deficiency, carbonate dissolution, and changes in food supply, persisted at the sea floor over most of the CIE interval. The main phase of recovery of benthic foraminifera is recorded c. 250 cm above the P/E boundary, and it may be linked to increased productivity and oxygenation at the sea floor.
Unusual occurrence of glauconite in a shallow lagoonal environment (Lower Cretaceous, northern Aquitaine Basin, SW France)
Authors: El Albani Abderrazzak , Meunier Alain , Fürsich Franz
Published: November 2005

Some minerals are considered to be representative of specific natural environments. Among them glauconite is considered to be formed in marine deep platform conditions. However, the term glauconitic is misused to designate green minerals formed in marine outer‐shelf environments. X‐ray diffraction, scanning electron microscopy and energy‐dispersive X‐ray analyses of individual green materials were carried out leading to the identification of glauconite in the Purbeckian facies. Green glauconite grains predominantly occur as burrow fills and occasionally as faecal pellet replacements. Two depositional environments have been identified from bottom to top of the succession: (1) an argillaceous dolomitic lagoonal sediment formed in saline, shallow water; (2) a marl‐limestone alternation deposited in a brackish water estuary. The crystallochemical properties of the glauconites change abruptly. These findings show that glauconite may form in coastal environments and not only in mid‐shelf to upper deep water platform environments as classically assumed. Moreover, the glauconite composition changes with the chemical conditions imposed by the local environment.
Fluid‐mediated modification of garnet interiors under ultrahigh‐pressure conditions
Authors: Perchuk Alexei L. , Burchard Michael , Maresch Walter V. , Schertl Hans‐Peter
Published: November 2005

We report the results of a novel experimental study on eclogitic garnets with abundant inclusions of clinozoisite, quartz and rutile subjected to temperatures (T) of 800–1100 °C and a pressure (P) of 4 GPa, representative of ultrahigh‐pressure (UHP) metamorphic terranes such as the Kokchetav massif, Saxonian Erzgebirge, etc. The experiments reveal extremely rapid recrystallization and partial melting of garnet interiors controlled by fluids liberated from the breakdown of the hydrous mineral inclusions. The traditional assumption that inclusions of minerals and primary fluid inclusions should be representative of the peak or even earlier metamorphic history cannot be strictly applied in this case. We argue that inclusions in UHP garnets may mirror P–T conditions postdating growth of the host crystal or even P–T conditions never actually experienced by the rock itself. The above modification of garnet interiors produces a typical patchy microstructure that occurs in natural eclogitic garnet from the diamond‐bearing UHP Kokchetav massif.
Protein‐ and energy‐mediated targeting of chloroplast outer envelope membrane proteins
Authors: Hofmann Nancy R. , Theg Steven M.
Published: November 2005

While the import of nuclear‐encoded chloroplast proteins is relatively well studied, the targeting of proteins to the outer membrane of the chloroplast envelope is not. The insertion of most outer membrane proteins (OMP) is generally considered to occur without the utilization of energy or proteinaceous components. Recently, however, proteins have been shown to be involved in the integration of outer envelope protein 14 (OEP14), whose outer membrane insertion was previously thought to be spontaneous. Here we investigate the insertion of two proteins fromPhyscomitrella patens, PpOEP64‐1 and PpOEP64‐2 (formerly known as PpToc64‐1 and PpToc64‐2), into the outer membrane of chloroplasts. The association of PpOEP64‐1 with chloroplasts was not affected by chloroplast pre‐treatments. Its insertion into the membrane was affected, however, demonstrating the importance of measuring insertion specifically in these types of assays. We found that the insertion of PpOEP64‐1, PpOEP64‐2 and two other OMPs, OEP14 and digalactosyldiacylglycerol synthase 1 (DGD1), was reduced by either nucleotide depletion or proteolysis of the chloroplasts. Integration was also inhibited in the presence of an excess of an imported precursor protein. In addition, OEP14 competed with the insertion of the OEP64s and DGD1. These data demonstrate that the targeting of several OMPs involves proteins present in chloroplasts and requires nucleotides. Together with previous reports, our data suggest that OMPs in general do not insert spontaneously.
The BME3 (Blue Micropylar End 3) GATA zinc finger transcription factor is a positive regulator of Arabidopsis seed germination
Authors: Liu Po‐Pu , Koizuka Nobuya , Martin Ruth C. , Nonogaki Hiroyuki
Published: November 2005

In many plant species, seed dormancy is broken by cold stratification, a pre‐chilling treatment of fully imbibed seeds. Although the ecological importance of seed response to cold temperature is well appreciated, the mechanisms underlying the physiological changes during cold stratification is unknown. Here we show that the GATA zinc finger protein expressed in Arabidopsis seeds during cold stratification plays a critical role in germination. Characterization of an enhancer‐trap population identified multiple lines that exhibited β‐glucuronidase (GUS) expression in the micropylar end of the seed (named Blue Micropylar End, BME lines). One of these lines, BME3, had a T‐DNA insertion site in the 5′ upstream region of a GATA‐type zinc finger transcription factor gene (termed BME3‐ZF). The BME3‐ZF mRNA accumulated in seeds during cold stratification. Characterization of the BME3‐ZF promoter indicated that this gene was activated specifically in the embryonic axis, which was still enclosed by the endosperm. The zinc finger gene knockout plants produced seeds exhibiting deeper dormancy, which showed reduced response to cold stratification. The ungerminated knockout seeds exhibited testa rupture, but failed to penetrate the endosperm layer. Application of gibberellic acid (GA3) rescued impaired germination of knockout seeds without cold stratification, indicating that the normal GA signal transduction pathway is present in the knockout mutants. Expression of GA20‐oxidase and GA3‐oxidase genes was greatly reduced in the knockout seeds, suggesting the potential involvement of the zinc finger protein in GA biosynthesis. These results suggest that the GATA zinc finger protein is a positive regulator of seed germination.
Single amino acid variation in barley 14‐3‐3 proteins leads to functional isoform specificity in the regulation of nitrate reductase
Authors: Sinnige Mark P. , Roobeek Ilja , Bunney Tom D. , Visser Antonie J.W.G. , Mol Jos N.M. , de Boer Albertus H.
Published: November 2005

The highly conserved family of 14‐3‐3 proteins function in the regulation of a wide variety of cellular processes. The presence of multiple 14‐3‐3 isoforms and the diversity of cellular processes regulated by 14‐3‐3 suggest functional isoform specificity of 14‐3‐3 isoforms in the regulation of target proteins. Indeed, several studies observed differences in affinity and functionality of 14‐3‐3 isoforms. However, the structural variation by which isoform specificity is accomplished remains unclear. Because other reports suggest that specificity is found in differential expression and availability of 14‐3‐3 isoforms, we used the nitrate reductase (NR) model system to analyse the availability and functionality of the three barley 14‐3‐3 isoforms. We found that 14‐3‐3C is unavailable in dark harvested barley leaf extract and 14‐3‐3A is functionally not capable to efficiently inhibit NR activity, leaving 14‐3‐3B as the only characterized isoform able to regulate NR in barley. Further, using site directed mutagenesis, we identified a single amino acid variation (Gly versus Ser) in loop 8 of the 14‐3‐3 proteins that plays an important role in the observed isoform specificity. Mutating the Gly residue of 14‐3‐3A to the alternative residue, as found in 14‐3‐3B and 14‐3‐3C, turned it into a potent inhibitor of NR activity. Using surface plasmon resonance, we show that the ability of 14‐3‐3A and the mutated version to inhibit NR activity correlates well with their binding affinity for the 14‐3‐3 binding motif in the NR protein, indicating involvement of this residue in ligand discrimination. These results suggest that both the availability of 14‐3‐3 isoforms as well as binding affinity determine isoform‐specific regulation of NR activity.
PIF1 is regulated by light‐mediated degradation through the ubiquitin‐26S proteasome pathway to optimize photomorphogenesis of seedlings in Arabidopsis
Authors: Shen Hui , Moon Jennifer , Huq Enamul
Published: November 2005

Light signals perceived by the phytochrome (phy) family of sensory photoreceptors control multiple aspects of plant development. Recently, PIF1, a phy‐interacting basic helix‐loop‐helix (bHLH) transcription factor, has been shown to negatively regulate facets of the photomorphogenesis of seedlings. Moreover, the transcriptional activation activity of PIF1 is reduced in a phy‐dependent manner. In this study we use the luciferase (LUC) activity of the LUC–PIF1 fusion protein as an indicator of the stability of PIF1 in various light conditions. We found that the activity of LUC–PIF1 in both transient and stable transgenic lines is rapidly reduced in light, while the LUC‐only control is stable under the same conditions, suggesting that PIF1 is degraded in response to light. Fluence‐rate response curves indicate that PIF1 degradation is very sensitive to the quality and quantity of light. The half‐life of PIF1 is about 16 min under 10 μmol m−2 sec−1 red light. PIF1 reaccumulates in the subsequent dark period after light‐induced degradation, signifying that PIF1 not only functions in the dark and during the transition from etiolated to de‐etiolated growth, but may also function during diurnal cycles. Inhibitors of the 26S proteasome increased the stability of PIF1, indicating that degradation of PIF1 is mediated by the ubiquitin‐26S proteasome pathway. Further, de novo protein synthesis is not required for degradation of PIF1, as the presence of cycloheximide does not prevent degradation of PIF1 in the light. Taken together, these results suggest that the light signals perceived by phys induce the degradation of PIF1 and other phy‐interacting factors to optimize photomorphogenesis.
LEAFY, TERMINAL FLOWER1 and AGAMOUS are functionally conserved but do not regulate terminal flowering and floral determinacy in Impatiens balsamina
Authors: Ordidge Matthew , Chiurugwi Tinashe , Tooke Fiona , Battey Nick H.
Published: November 2005

In Impatiens balsamina a lack of commitment of the meristem during floral development leads to the continuous requirement for a leaf‐derived floral signal. In the absence of this signal the meristem reverts to leaf production. Current models for Arabidopsis state that LEAFY (LFY) is central to the integration of floral signals and regulates flowering partly via interactions with TERMINAL FLOWER1 (TFL1) and AGAMOUS (AG). Here we describe Impatiens homologues of LFY, TFL1 and AG (IbLFY, IbTFL1 and IbAG) that are highly conserved at a sequence level and demonstrate homologous functions when expressed ectopically in transgenic Arabidopsis. We relate the expression patterns of IbTFL1 and IbAG to the control of terminal flowering and floral determinacy in Impatiens. IbTFL1 is involved in controlling the phase of the axillary meristems and is expressed in axillary shoots and axillary meristems which produce inflorescences, but not in axillary flowers. It is not involved in maintaining the terminal meristem in either an inflorescence or indeterminate state. Terminal flowering in Impatiens appears therefore to be controlled by a pathway that uses a different integration system than that regulating the development of axillary flowers and branches. The pattern of ovule production in Impatiens requires the meristem to be maintained after the production of carpels. Consistent with this morphological feature IbAG appears to specify stamen and carpel identity, but is not sufficient to specify meristem determinacy in Impatiens.
Cultural awareness among Queensland undergraduate occupational therapy students
Authors: Rasmussen Tanya M. , Lloyd Chris , Wielandt Trish
Published: November 2005

Aim:  Australia's cultural diversity generates substantial challenges and implications for students and health‐care professionals. This study investigated the cultural perceptions and self‐rated level of cultural competence of undergraduate occupational therapy students in Queensland, Australia.

Results:  Two hundred and ninety‐three students completed the Cultural Awareness Questionnaire. The findings indicated that the majority of students have a positive attitude towards cultural differences and influences on occupational therapy services. Students also recognised the importance of cultural awareness and highlighted the need for increased incorporation of cultural information and experience throughout the undergraduate course.

Conclusion:  The implications of this study are discussed with reference to the future academic planning of culturally sensitive occupational therapy course and fieldwork experiences.