bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterisation of dry and mucoid colonies isolated from Australian rhizobial inoculant strains for Medicago species
Authors: McInnes A. , Holford P. , Thies J. E.
Published: April 2005

The presence of dry and mucoid colonies in cultures of rhizobial strains used in the production of commercial Australian inoculants is of concern for quality assurance because of the possibility of altered capacity for nodulation and nitrogen fixation by the different colony types. In this study, single colony isolates obtained from dry and mucoid colonies present in commercial cultures of Sinorhizobium meliloti were investigated to identify stability in culture, genetic identity and changes in exopolysaccharide (EPS) production, nodulation and nitrogen fixation. The 2 strains studied were WSM688 and WSM826 (Australian inoculant strains for annual and perennial medics, respectively), both of which produced only mucoid colonies on agar media when originally isolated from nodules. Dry and mucoid single colony isolates from the ‘mother cultures’ of the 2 strains exhibited stable colony phenotypes during successive subculturing in our laboratory and were shown to be most closely related to S. meliloti using 16S rRNA partial sequencing. All isolates produced at least 1 of 3 exopolysaccharides (succinoglycan, EPS II and K antigen) that are required for successful nodulation of Medicago species by S. meliloti strains, as indicated by nodulation of host legumes. Strain WSM826 isolates probably produce succinoglycan, as shown by similarity to the succinoglycan-producing strain Rm1021 in a calcofluor binding assay. In contrast to published work, there was no evidence that loss of mucoidy in dry colony isolates of either strain was associated with the presence of an insertion sequence element in the expR gene that inhibits EPS II production. For strain WSM688, dry and mucoid isolates were identical by PCR fingerprinting and showed a similar capacity to nodulate and fix nitrogen with the target host legume M. truncatula in glasshouse tests. In contrast, strain WSM826 mucoid isolates produced PCR fingerprints that were different from each other and from the WSM826 dry colony isolates. Dry and mucoid colonies may have arisen from substantial genetic change or through contamination of cultures by other S. meliloti strains. One WSM826 mucoid isolate (826-3) produced significantly lower shoot dry weight when inoculated onto both the target host M. sativa and non-target host M. truncatula, even though the capacity to nodulate both hosts was retained. This suggests that this isolate was affected in its nitrogen fixation capacity. Further research is required to identify the origin and extent of colony variation in commercial S. meliloti cultures.
Increased yield and persistence of several annual medic species and Medicago sativa by inoculation with selected strains of Sinorhizobium meliloti and S. medicae
Authors: Evans P. M. , Howieson J. G. , Nutt B. J.
Published: April 2005

A broad range of genotypes of Medicago sativa, and annual medics including M. polymorpha, M. tornata and M. littoralis were inoculated with strains of Sinorhizobium meliloti or S. medicae of differing effectiveness for symbiotic N2 fixation then sown at 4 field locations. Dry matter production over 2 seasons was strongly related to plant density, which in turn was related to symbiotic effectiveness. Eighteen months after sowing at Esperance, Western Australia, lucerne inoculated with strain WSM922 showed 79% higher plant density and 43% more production than control strain CC169. At Broomehill, no significant differences existed in dry matter production between lucerne cultivars inoculated with strains WSM922, WSM826 and U45. Across all lucerne genotypes, inoculation with WSM922 outyielded those inoculated with CC169 by 99%. At Jerramungup, the difference in yield between these 2 inoculant strains was 44%. Results were consistent with those previously obtained under controlled conditions and emphasised the necessity to remain aware of the symbiotic requirements of newly produced cultivars. An analysis of nodule occupancy at 1 site using PCR-RAPDs revealed the dominance of a particular rhizobial strain (WSM922) in uninoculated plots which had become colonised over 3 seasons. The necessity for separate inoculant species of Sinorhizobium in Australia to satisfy the symbiotic requirements of the acid and alkaline groups of medics was reaffirmed.
Effects of hypothermic liquid storage and cryopreservation on basal and induced plasma membrane phospholipid disorder and acrosome exocytosis in boar spermatozoa
Authors: Guthrie H. D. , Welch G. R.
Published: April 2005

Flow cytometry was utilised to determine whether short-term (Day 1) or long-term hypothermic liquid storage (Day 5), or cryopreservation of boar spermatozoa (1) caused changes in plasma membrane phospholipid disorder (MPLD) and acrosome exocytosis (AE), indicative of an advanced stage of capacitation or acrosome status, and (2) facilitated or inhibited the induction of capacitation and the acrosome reaction. Merocyanine with Yo-Pro-1 and peanut agglutinin–fluorescein isothiocyanate with propidium iodide were used to identify MPLD and AE, respectively, in viable spermatozoa. The incidence of basal sperm MPLD and AE in fresh semen was very low (1.1 and 2.2%, respectively) and was increased (P < 0.05) only a small amount in Day 5 and cryopreserved semen (3–8%). Compared to no bicarbonate, incubation with bicarbonate increased MPLD, but the response was greatest (P < 0.05) in fresh sperm (52.3%) compared with Day 1 (36.6%), Day 5 (13.9%) and cryopreserved sperm (13.6%). Incubation with calcium ionophore A23187 increased AE in spermatozoa, but the response was less (P < 0.05) for fresh (34%) and cryopreserved (27%) semen than for Day 1 (45%) and Day 5 (57%) semen. In summary, hypothermic liquid storage and cryopreservation of boar spermatozoa did not advance capacitation or acrosome status in viable spermatozoa, but did alter their responses to induction of capacitation and the acrosome reaction.
Global archaeological evidence for proboscidean overkill
Authors: Surovell Todd , Waguespack Nicole , Brantingham P. Jeffrey
Published: April 2005

One million years ago, proboscideans occupied most of Africa, Europe, Asia, and the Americas. Today, wild elephants are only found in portions of sub-Saharan Africa and South Asia. Although the causes of global Pleistocene extinctions in the order Proboscidea remain unresolved, the most common explanations involve climatic change and/or human hunting. In this report, we test the overkill and climate-change hypotheses by using global archaeological spatiotemporal patterning in proboscidean kill/scavenge sites. Spanning ≈1.8 million years, the archaeological record of human subsistence exploitation of proboscideans is preferentially located on the edges of the human geographic range. This finding is commensurate with global overkill, suggesting that prehistoric human range expansion resulted in localized extinction events. In the present and the past, proboscideans have survived in refugia that are largely inaccessible to human populations.
The Membrane-anchoring Domain of Epidermal Growth Factor Receptor Ligands Dictates Their Ability to Operate in Juxtacrine Mode
Authors: Dong Jianying , Opresko Lee K. , Chrisler William , Orr Galya , Quesenberry Ryan D. , Lauffenburger Douglas A. , Wiley H. Steven
Published: April 2005

All ligands of the epidermal growth factor (EGF) receptor (EGFR) are synthesized as membrane-anchored precursors. Previous work has suggested that some ligands, such as EGF, must be proteolytically released to be active, whereas others, such as heparin-binding EGF-like growth factor (HB-EGF) can function while still anchored to the membrane (i.e., juxtacrine signaling). To explore the structural basis for these differences in ligand activity, we engineered a series of membrane-anchored ligands in which the core, receptor-binding domain of EGF was combined with different domains of both EGF and HB-EGF. We found that ligands having the N-terminal extension of EGF could not bind to the EGFR, even when released from the membrane. Ligands lacking an N-terminal extension, but possessing the membrane-anchoring domain of EGF, still required proteolytic release for activity, whereas ligands with the membrane-anchoring domain of HB-EGF could elicit full biological activity while still membrane anchored. Ligands containing the HB-EGF membrane anchor, but lacking an N-terminal extension, activated EGFR during their transit through the Golgi apparatus. However, cell-mixing experiments and fluorescence resonance energy transfer studies showed that juxtacrine signaling typically occurred in trans at the cell surface, at points of cell-cell contact. Our data suggest that the membrane-anchoring domain of ligands selectively controls their ability to participate in juxtacrine signaling and thus, only a subclass of EGFR ligands can act in a juxtacrine mode.
Expression of membrane type 1 matrix metalloproteinase in papillomavirus-positive cells: role of the human papillomavirus (HPV) 16 and HPV8 E7 gene products
Authors: Smola-Hess Sigrun , Pahne Jenny , Mauch Cornelia , Zigrino Paola , Smola Hans , Pfister Herbert J.
Published: April 2005

Matrix metalloproteinases (MMPs) degrade extracellular matrix. They are involved in cellular proliferation, migration, angiogenesis, invasion and metastasis. MT-1 MMP, a membrane-bound MMP, is expressed in carcinomas of the uterine cervix in vivo. This type of cancer is associated with human papillomavirus (HPV) infection. Here it was shown that keratinocytes transformed with HPV16 or HPV18 in vitro, and HPV-positive cervical carcinoma cell lines, constitutively expressed MT-1 MMP. Expression of the E7 protein from the mucosal and cutaneous high-risk types HPV16 and HPV8, but not from the cutaneous low-risk type HPV1, was sufficient to induce MT-1 MMP expression in primary human keratinocytes and HaCaT cells. As a consequence, MMP-2 was activated. MT-1 MMP expression might play a role in the HPV life cycle by promoting proliferation of host cells and might contribute to their invasive phenotype during malignant progression.
A functional CD8+ cell assay reveals individual variation in CD8+ cell antiviral efficacy and explains differences in human T-lymphotropic virus type 1 proviral load
Authors: Asquith Becca , Mosley Angelina J. , Barfield Anna , Marshall Sara E. F. , Heaps Adrian , Goon Peter , Hanon Emmanuel , Tanaka Yuetsu , Taylor Graham P. , Bangham Charles R. M.
Published: April 2005

The CD8+lymphocyte response is a main component of host immunity, yet it is difficult to quantify its contribution to the control of persistent viruses. Consequently, it remains controversial as to whether CD8+cells have a biologically significant impact on viral burden and disease progression in infections such as human immunodeficiency virus-1 and human T-lymphotropic virus type I (HTLV-I). Experiments to ascertain the impact of CD8+cells on viral burden based on CD8+cell frequency or specificity alone give inconsistent results. Here, an alternative approach was developed that directly quantifies the impact of CD8+lymphocytes on HTLV-I proviral burden by measuring the rate at which HTLV-I-infected CD4+cells were cleared by autologous CD8+cellsex vivo. It was demonstrated that CD8+cells reduced the lifespan of infected CD4+cells to 1 day, considerably shorter than the 30 day lifespan of uninfected cellsin vivo. Furthermore, it was shown that HTLV-I-infected individuals vary considerably in the rate at which their CD8+cells clear infected cells, and that this was a significant predictor of their HTLV-I proviral load. Forty to 50 % of between-individual variation in HTLV-I proviral load was explained by variation in the rate at which CD8+cells cleared infected cells. This novel approach demonstrates that CD8+cells are a major determinant of HTLV-I proviral load. This assay is applicable to quantifying the CD8+cell response to other viruses and malignancies and may be of particular importance in assessing vaccines.
Complete genome sequences of two new variants of Grapevine rupestris stem pitting-associated virus and comparative analyses
Authors: Meng Baozhong , Li Caihong , Wang Weizhou , Goszczynski Dariusz , Gonsalves Dennis
Published: April 2005

Grapevine rupestris stem pitting-associated virus (GRSPaV), a member of the genus Foveavirus within the family Flexiviridae, is the putative causal agent of the disease Rupestris stem pitting (RSP) of grapevines. GRSPaV comprises a family of variants whose pathological characteristics have not been determined. Recently, many of the indicator ‘St George’ plants (Vitis rupestris) used throughout the world to index RSP tested positive for GRSPaV. This finding questions the validity of past biological indexing results. In this work, a representative genomic region of GRSPaV was first sequenced from ten ‘St George’ plants from two sources and it was demonstrated that nine of them carried a new variant, GRSPaV-SG1. The genomes of GRSPaV-SG1 and GRSPaV-BS from ‘Bertille Seyve 5563’ plants were sequenced, revealing a genome structure identical to that of GRSPaV-1. It was demonstrated experimentally that infection of ‘St George’ plants with GRSPaV-SG1 is asymptomatic and thus it is proposed that GRSPaV-SG1 infection should not have interfered with the outcome of past indicator indexing. This represents the first attempt to link a GRSPaV variant with pathological properties.
Promoting innovation in aid of industrial development: the Singaporean experience
Authors: Goh Andrew L.S.
Published: April 2005

Purpose

The purpose of this article is to examine, appraise and highlight the significance of promoting innovation in aid of industrial development.

Design/methodology/approach

A comprehensive range of published literature is critiqued first to understand why industrial development constitutes a major objective of a country's economic strategy and government policy. Then, through a theoretical review of industrial policy works, relevant issues (e.g. how efficient industrial development sustains economic growth) are highlighted for discussion. For instance, the importance of private sector‐led industrial development and the need to adopt a primary focus on innovation‐driven industrial policy.

Findings

By drawing lessons from the developed world, the article explains why industrial policy‐making must address the pursuit of innovation as a prime mover of economic development; and further outlines the role of government in innovation‐driven industrial policy. As a case study, evolutionary perspectives of Singapore's industrialisation process are elaborated to illustrate a government's role in industrial policy‐making.

Research limitations/implications

Future research could provide better guidance to address new emergent challenges of industrial policy‐making.

Practical implications

The discussion on industrial policy issues raised in this article is expected to be of interest to policy makers, industry planners, academic researchers and business practitioners.

Originality/value

This article offers insights into effective industrial policy‐making for developing nations that may help to transform their economies.
Primary cell culture from gill explants of rainbow trout
Authors: Fernandes M. N. , Eddy F. B. , Penrice W. S.
Published: April 2005

Primary cultures of gill cells were initiated from gill filament explants of rainbow trout, Oncorhynchus mykiss. The explants were cultured in Leibovitz l‐15 medium with 5, 10 or 20% foetal calf serum (FCS) and l‐glutamine. The attachment efficiency was serum‐dependent though increased FCS concentration did not stimulate further outgrowth of cells. The explants produced cell outgrowth 24 h after attachment as a sheet of cells which exhibited characteristics of gill pavement epithelial cells as indicated by surface microridges revealed by scanning electron micrographs. There was high proliferation for the first 14 days then a stable plateau for 30 days followed by a decline phase from 45 days. Following removal of cells, the explants produced further cell outgrowth which was especially active at the proliferation phase (14 days). Removal of these cells caused the explants to produce a further proliferation of cells reaching confluence in 10–14 days. After the third cell removal cell outgrowth from explants showed migratory activity but did not develop to resemble gill epithelial cells. The use of gill explants to establish primary cultures of fish gill cells has advantages which include longevity of the culture and successive proliferations from explants which could provide a useful tool for the investigation of long‐term processes in cellular biology and reduce the number of culture preparations.
Orientation and Growth of Grains in Copper‐Activated Hot‐Pressed Hexagonal Boron Nitride
Authors: Hubäĉek Milan , Ueki Masanori , Sató Tadao
Published: April 2005

Hexagonal boron nitride powder was hot pressed in an environment of metallic copper. When compared with a copper‐free system, the sintered body exposed to the copper was composed of substantially thicker grains having an unusual arrangement, consisting of preferred alignment of (0001) basal planes parallel to the pressure axis. The character of the orientation of the boron nitride grains substantially influenced the mechanical strength of the ceramics. The difference in the orientation of the grains is explained by the interaction between copper atoms and boron nitride crystals selectively occurring on the (0001) basal planes of the latter.
Quantification of cell‐cycle distribution and mitotic index in Hydra by flow cytometry
Authors: Ulrich H. , Tárnok A.
Published: April 2005

Abstract.  The applicability of flow cytometry (FCM) to analyse cell‐cycle distribution and mitotic cells in Hydra oligactis and Hydra vulgaris is demonstrated. The freshwater polyps H. vulgaris and H. oligactis are well‐accepted animal models for studying cell proliferation, regeneration and differentiation. Disintegrated animals were labelled for FCM analysis according to the method of Nuesse et al. [(1990) Flow cytometric analysis of G1 and G2/M‐phase subpopulations in mammalian cell nuclei using side scatter and DNA content measurements. Cytometry 11, 813]. Proliferation and regeneration experiments, in the absence or presence of the oligopeptide head activator, were quantified. Cell‐cycle analysis of different parts of the animals shows low proliferation in the head region and high proliferation in the gastric and foot regions. Cell‐cycle analysis of different parts of Hydra, comparison of H. oligactis and H. vulgaris, as well as pharmacological treatment, yielded results that are in agreement with prior microscopic analysis. Our results demonstrate that FCM is an appropriate technique for quantifying proliferation in this animal model. It can be used for basic research on development, regeneration and differentiation as well as for innovative drug investigation and toxicology studies.
Cellular quiescence induced by contact inhibition or serum withdrawal in C3H10T1/2 cells
Authors: Gos M. , Miloszewska J. , Swoboda P. , Trembacz H. , Skierski J. , Janik P.
Published: April 2005

Abstract.  Either confluence or serum withdrawal may cause growth arrest of cultured non‐transformed cells. Here, we compared sparsely populated and confluent C3H10T1/2 cells with and without serum‐containing medium. The following proliferation‐relevant end points were examined: cell‐cycle distribution, Ki‐67 antigen presence, the level of the von Hippel‐Lindau (VHL) protein, and gene expression, determined using a microarray approach. In sparse/logarithmic cultures, the fraction of cells in G0/G1 phase increased from 55 to 85% following serum withdrawal. Moreover, the fraction of Ki‐67 positive cells dropped from 89 to 47%. In confluent cultures, the majority of cells (80%) were in G0/G1 phase and only 25–30% were Ki‐67 positive, regardless of serum presence. In both serum‐deprived and contact‐inhibited cultures, significant and distinct changes in gene expression were observed. Serum deprivation of sparsely cultured cells resulted in significant over‐expression of several transcription factors, while confluent cells showed elevated expression of genes coding for Wnt6, uPar, Tdag51, Egr1, Ini1a and Mor1. These results indicate that contact inhibition and serum withdrawal lead to cellular quiescence through distinct genetic and molecular mechanisms.
Coherence methods in mapping AVO anomalies and predicting P‐wave and S‐wave impedances
Authors: Barnola A.‐S. , White R.E.
Published: April 2005

Filters for migrated offset substacks are designed by partial coherence analysis to predict ‘normal’ amplitude variation with offset (AVO) in an anomaly free area. The same prediction filters generate localized prediction errors when applied in an AVO‐anomalous interval. These prediction errors are quantitatively related to the AVO gradient anomalies in a background that is related to the minimum AVO anomaly detectable from the data. The prediction‐error section is thus used to define a reliability threshold for the identification of AVO anomalies. Coherence analysis also enables quality control of AVO analysis and inversion. For example, predictions that are non‐localized and/or do not show structural conformity may indicate spatial variations in amplitude–offset scaling, seismic wavelet or signal‐to‐noise (S/N) ratio content. Scaling and waveform variations can be identified from inspection of the prediction filters and their frequency responses. S/N ratios can be estimated via multiple coherence analysis.

AVO inversion of seismic data is unstable if not constrained. However, the use of a constraint on the estimated parameters has the undesirable effect of introducing biases into the inverted results: an additional bias‐correction step is then needed to retrieve unbiased results. An alternative form of AVO inversion that avoids additional corrections is proposed. This inversion is also fast as it inverts only AVO anomalies. A spectral coherence matching technique is employed to transform a zero‐offset extrapolation or near‐offset substack into P‐wave impedance. The same technique is applied to the prediction‐error section obtained by means of partial coherence, in order to estimate S‐wave velocity to P‐wave velocity (VS/VP) ratios. Both techniques assume that accurate well ties, reliable density measurements and P‐wave and S‐wave velocity logs are available, and that impedance contrasts are not too strong. A full Zoeppritz inversion is required when impedance contrasts that are too high are encountered. An added assumption is made for the inversion to the VS/VP ratio, i.e. the Gassmann fluid‐substitution theory is valid within the reservoir area. One synthetic example and one real North Sea in‐line survey illustrate the application of the two coherence methods.
Common variants in the ATP‐sensitive K+channel genesKCNJ11(Kir6.2) andABCC8(SUR1) in relation to glucose intolerance: population‐based studies and meta‐analyses1
Authors: Van Dam R. M. , Hoebee B. , Seidell J. C. , Schaap M. M. , De Bruin T. W. A. , Feskens E. J. M.
Published: April 2005

Aims To evaluate the relation between common variants in the ATP‐sensitive K+channel genes and glucose intolerance.

Methods We conducted a meta‐analysis of reported association studies in Caucasian populations for common variants in theABCC8(exons 16 and 18) and theKCNJ11(E23K) gene and examined sources of heterogeneity in the results. The meta‐analysis was based on 7768–10216 subjects (depending on the gene variant), and included two new population‐based studies in the Netherlands with 725 cases and 742 controls.

Results For theKCNJ11variant, the summary odds ratio (OR) for glucose intolerance was 1.12 (1.01–1.23,P = 0.03) for the EK genotype and 1.44 (1.17–1.78,P = 0.0007) for the KK genotype, as compared with the EE genotype. For theABCC8exon 16 variant, the OR was 1.06 (0.94–1.19,P = 0.34) for ct and 0.93 (0.71–1.20,P = 0.56) for tt, as compared with the cc genotype. ForABCC8exon 18, the OR was 1.20 (0.97–1.49, P = 0.10) for CT/TT, as compared with the CC genotype. Studies of theABCC8variants that were published first or had smaller sample sizes (for the exon 18 variant) showed stronger associations, which may indicate publication bias. For theABCC8exon 18 and theKCNJ11variant, associations were stronger for studies of clinical diabetes than newly detected glucose intolerance. The population attributable risk for clinical Type 2 diabetes was 6.2% for theKCNJ11KK genotype and 10.1% for theKCNJ11EK and KK genotype combined.

Conclusions The commonKCNJ11E23K gene variant, but not theABCC8exon 16 or exon 18 variant, was consistently associated with Type 2 diabetes.
Offshoring: Value Creation through Economic Change
Authors: Farrell Diana
Published: April 2005

abstract  In this essay, I analyse the economic and managerial dimensions of offshoring, drawing from recent research by the McKinsey Global Institute. I argue that offshoring, like other forms of trade, creates enormous value for both companies and the economy as a whole. However, in the case of countries with less flexible labour markets such as Germany, findings are more nuanced. While the potential cost savings for companies from offshoring appear impressive, our research suggests that companies are leaving billions of dollars behind when they offshore. We propose several ways companies could make capital‐labour trade‐offs to create new markets and services. By maximizing gains from offshoring, companies can both cut costs and generate revenue. Given the benefits offshoring, the challenge is how to make the transition to a global economy less painful for workers and increase the participation in the wealth creation. Hence, I also identify options to help policymakers and companies manage the changes offshoring requires.
Bayesian Analysis of Single-Molecule Experimental Data
Authors: Kou S. C. , Sunney Xie X. , Liu Jun S.
Published: April 2005

Recent advances in experimental technologies allow scientists to follow biochemical processes on a single-molecule basis, which provides much richer information about chemical dynamics than traditional ensemble-averaged experiments but also raises many new statistical challenges. The paper provides the first likelihood-based statistical analysis of the single-molecule fluorescence lifetime experiment designed to probe the conformational dynamics of a single deoxyribonucleic acid (DNA) hairpin molecule. The conformational change is initially treated as a continuous time two-state Markov chain, which is not observable and must be inferred from changes in photon emissions. This model is further complicated by unobserved molecular Brownian diffusions. Beyond the simple two-state model, a competing model that models the energy barrier between the two states of the DNA hairpin as an Ornstein–Uhlenbeck process has been suggested in the literature. We first derive the likelihood function of the simple two-state model and then generalize the method to handle complications such as unobserved molecular diffusions and the fluctuating energy barrier. The data augmentation technique and Markov chain Monte Carlo methods are developed to sample from the posterior distribution desired. The Bayes factor calculation and posterior estimates of relevant parameters indicate that the fluctuating barrier model fits the data better than the simple two-state model.
Discrete Time Modelling of Disease Incidence Time Series by Using Markov Chain Monte Carlo Methods
Authors: Morton Alexander , Finkenstädt Bärbel F.
Published: April 2005

A stochastic discrete time version of the susceptible–infected–recovered model for infectious diseases is developed. Disease is transmitted within and between communities when infected and susceptible individuals interact. Markov chain Monte Carlo methods are used to make inference about these unobserved populations and the unknown parameters of interest. The algorithm is designed specifically for modelling time series of reported measles cases although it can be adapted for other infectious diseases with permanent immunity. The application to observed measles incidence series motivates extensions to incorporate age structure as well as spatial epidemic coupling between communities.
Financial markets can go mad: evidence of irrational behaviour during the South Sea Bubble1
Authors: DALE RICHARD S. , JOHNSON JOHNNIE E. V. , TANG LEILEI
Published: April 2005

This paper explores investor behaviour during the South Sea Bubble—the first major speculative boom and bust on the stock markets. Previous literature debates whether investors during this episode acted rationally. Newly acquired data involving parallel markets for the South Sea Company's stock and subscription receipts are analysed, and widening valuation gaps are observed between these substitutable financial instruments. Rational explanations do not prove adequate, and the anomalies are explained by the biased decision‐making of investors, and their tendency to view financial markets as wagering markets. The implications of these findings for the current debate on rationality in financial markets are identified.
Differential infant and child mortality in three Dutch regions, 1812–19091
Authors: VAN POPPEL FRANS , JONKER MARIANNE , MANDEMAKERS KEES
Published: April 2005

New micro‐level data have recently become available for three provinces of The Netherlands for the period 1812–1912, which allow the study of the evolution of socio‐economic differentials in infant and childhood mortality. The authors found significant differences in the levels of infant mortality by social group between the three provinces, and a wide variety in the pattern of social inequality. This showed the importance of the regional environment for the level of infant mortality in the nineteenth century. Contrary to expectations, strong social differences were also observed in neonatal mortality. Being born in an urban environment did not have a strong effect on survival during the first year of birth.
Working‐class consumer credit in the UK, 1925–60: the role of the check trader1
Authors: O'CONNELL SEAN , REID CHRIS
Published: April 2005

This article provides fresh insights into working‐class credit by examining the history of check trading. It explains the system's origins, and its dependence on a series of relationships involving check traders and their agents, retailers, and customers. Data from the market leader— Provident Clothing and Supply Co. Ltd—is analysed to explore the scale and scope of the sector, and to examine its history from the early 1920s to the 1960s. Check trading was both an important and controversial supplier of credit to working‐class families, and the article explores criticisms of the system, and the reason for its popularity.
ANKERSMIT AND HISTORICAL REPRESENTATION1
Authors: ZAMMITO JOHN
Published: April 2005

Historical debate is a semantic quarrel not about the exact meaning of words, but about the past. (HR:62)

In Historical Representation Frank Ankersmit seeks a juste milieu between postmodern theory and historical practice. But he still insists that the meaning of a historical representation “is not found, but made in and by [the] text.” Thus “there will be nothing, outside the text itself, that can govern or check [the conceptualization].” Accordingly, “a (historical) representation itself cannot be interpreted as one large (true or false) description. I would not hesitate to say that this—and nothing else—is the central problem in the philosophy of history.” On the other hand, he affirms that “a historical representation‘is about’a certain part of the past,” that historical debate is a “semantic quarrel not about the exact meaning of words, but about the past.” Everything hinges on how to grasp this idea of “aboutness.”

I propose an alternative reading of postpositivist philosophy of science in hopes of reaching the juste milieu. The issue is whether colligatory concepts in history have a more radically constructed character than theoretical terms in natural‐scientific theory, and whether, as with the latter, they can make intersubjective claims to warrant. My view is that colligatory concepts in historical representations can be conceived to refer in roughly the same way that theoretical terms do in natural‐scientific theories.

All the problems I find in Ankersmit's approach come to the fore in his fruitful analogy to portrait painting. First, the personality the portrait evokes is not restricted to the representation, but is of the sitter. We are offered insight not (merely) into painting but into an actual character. That is, there is a cognitive, not simply an aesthetic, dimension to representation. Historical terms pick out something intersubjectively affirmable in reality, and discrimination is possible among rival versions. The question is how to regard—to explain and to evaluate—these underdetermined objects of consideration, not to preclude them by stipulation.
HISTORY AND DYNAMICS: MARRIAGE OR MÉSALLIANCE?
Authors: Bonneuil Noël
Published: April 2005

Historical Dynamics: Why States Rise and Fall. By Peter Turchin.
The natural history of white coat hypertension during pregnancy
Authors: Brown Mark A. , Mangos George , Davis Greg , Homer Caroline
Published: April 2005

Objective  White coat hypertension (WCH) is a common phenomenon with a long term prognosis intermediate between those with true hypertension and true normotension. The natural history of this phenomenon throughout pregnancy remains unknown. We assessed the likelihood of women with an initial diagnosis of WCH developing pre‐eclampsia (PE) as their pregnancy progressed.

Design  Prospective observational study.

Setting  St George Hospital, a teaching and University hospital.

Population  Two hundred and forty‐one pregnant women with an early pregnancy diagnosis of essential hypertension (EH).

Methods  Eighty‐six women had this diagnosis (EH) confirmed pre‐pregnancy by 24‐hour ambulatory blood pressure monitoring (ABPM) or repeated automated home blood pressure (BP) self‐measurement. The remaining 155 underwent 24‐hour ABPM in early pregnancy to establish their diagnosis. Women found to have WCH did not receive antihypertensives during their pregnancy, whereas those with confirmed EH received oxprenolol or methyldopa. Women with WCH had repeated 24‐hour ABPM and/or BP assessments in a pregnancy day assessment unit until delivery.

Main outcome measure  The development of PE in women with WCH or EH.

Results  The overall prevalence of WCH was 32%. Half retained this phenomenon throughout pregnancy and had good pregnancy outcomes. Forty percent developed (benign) gestational hypertension and also had good pregnancy outcomes while 8% developed proteinuric PE, significantly fewer than in women with confirmed EH (22%), P= 0.008. No BP parameter at study entry permitted discrimination between those women with WCH who retained this phenomenon and those who developed GH or PE.

Conclusion  WCH is a common phenomenon in pregnant women who appear to have EH according to routine BP measurement early in pregnancy. Antihypertensives may be withheld from this group initially and they can be advised they will have better pregnancy outcomes than women with true EH. However, continued monitoring throughout pregnancy remains important to detect the small group of white coat hypertensives who develop PE.
Prediction of congenital toxoplasmosis by polymerase chain reaction analysis of amniotic fluid
Authors: Thalib L. , Gras L. , Romand S. , Prusa A. , Bessieres M.‐H. , Petersen E. , Gilbert R.E. ,   for the European Multicentre Study on Congenital Toxoplasmosis (EMSCOT)
Published: April 2005

Objective  To determine the accuracy of polymerase chain reaction (PCR) analysis of amniotic fluid for fetal toxoplasmosis according to clinical predictors of outcome and study centre.

Design  Prospective cohort study.

Setting  Nine European centres.

Population  Women with suspected toxoplasma infection identified by prenatal screening.

Methods  Logistic regression was used to examine the effects of gestational age at maternal seroconversion, treatment and timing of amniocentesis, on PCR accuracy, and to calculate the post‐test probability of congenital toxoplasmosis.

Main outcome measures  Infants had congenital toxoplasmosis if specific IgG persisted beyond 11.5 months. Uninfected infants had undetectable IgG in the absence of anti‐toxoplasma treatment.

Results  Of 593 PCR results, 64 were positive (57 confirmed infected), and 529 were negative (23 confirmed infected). The likelihood ratio for a positive PCR result decreased significantly with trimester at seroconversion, but did not change significantly for a negative result. Weak associations were detected between sensitivity and, inversely, with specificity, and gestational age at maternal seroconversion. There was no significant association between sensitivity and centre, type or duration of treatment, or timing of amniocentesis. Specificity differed significantly between centres (P < 0.001). The change in pre‐ to post‐test probability of infection was maximal for a positive PCR after first trimester seroconversion, affecting 1% of women tested, and a negative PCR after third trimester seroconversion, affecting half the women tested.

Conclusions  Prediction of the risk of congenital toxoplasmosis should combine estimates of test accuracy and maternal–fetal transmission, which take account of the gestational age at which the mother seroconverted. Local laboratory standards will affect the generalisability of these results.
VARIATION IN THE LUMBAR SPINE OF THE MATURE EWE: A DESCRIPTIVE STUDY
Authors: Lori David N. , MacLeay Jennifer M. , Turner A. Simon
Published: April 2005

The purpose of this descriptive study was to characterize the variation in the lumbar spine of the mature ewe. Ventrodorsal and lateral radiographs of the lumbar spine from 216 mature (4–7‐year‐old) Rambouillet–Columbia cross ewes were examined. Criteria evaluated included the number and orientation of lumbar vertebrae and transverse processes. Observations for fusion of the last lumbar vertebrae with the sacrum and any visible variability seen in transverse processes and ribs were also included. Forty‐one percent of the mature ewes had six and 59% had seven lumbar vertebrae. In addition, 7% had abnormal formations at either the first or last lumbar vertebra. Variations seen were the first lumbar vertebra having one rib and one transverse process (7/216, 3%), apparent fusion of the last lumbar vertebra to the sacrum (5/216, 2%) or apparent fusion of one or both of the transverse processes of the last lumbar vertebra to the pelvis (2/216, 1%).
A REVIEW OF SMALL ANIMAL IMAGING PLANAR AND PINHOLE SPECT γ CAMERA IMAGING
Authors: Peremans Kathelijne , Cornelissen Bart , Van Den Bossche Bieke , Audenaert Kurt , Van de Wiele Christophe
Published: April 2005

Scintigraphy (positron emission tomography (PET) or single photon emission computed tomography (SPECT) techniques) allows qualitative and quantitative measurement of physiologic processes as well as alterations secondary to various disease states. With the use of specific radioligands, molecular pathways and pharmacokinetic processes can be investigated. Radioligand delivery can be (semi)quantified in the region of interest in cross‐sectional and longitudinal examinations, which can be performed under the same conditions or after physiologic or pharmacologic interventions. Most preclinical pharmacokinetic studies on physiological and experimentally altered physiological processes are performed in laboratory animals using high‐resolution imaging systems. Single photon emission imaging has the disadvantage of decreased spatial and temporal resolution compared with PET. The advantage of SPECT is that equipment is generally more accessible and commonly used radionuclides have a longer physical half‐life allowing for investigations over a longer time interval. This review will focus on single photon emission scintigraphy. An overview of contemporary techniques to measure biodistribution and kinetics of radiopharmaceuticals in small animal in vivo is presented. Theoretical as well as practical aspects of planar γ camera and SPECT pinhole (PH) imaging are discussed. Current research is focusing on refining PH SPECT methodology, so specific regarding technical aspects and applications of PH SPECT will be reviewed.
Regeneration of gated carbon nanotube field emission
Authors: Hsu David S. Y. , Shaw Jonathan L.
Published: April 2005

We report large increases in field emission current when operating carbon nanotubes in substantial pressures of hydrogen, especially when the nanotubes were contaminated. We have previously demonstrated two different configurations of integrally gated carbon nanotube field emitter arrays (cNTFEAs), CNTs grown inside microfabricated gate apertures with and without silicon posts. Salient features of these in situ grown microgated cNTFEAs include the absence of electrical arcing, low operating voltage, and enhancing effect of some residual ambient gases. Operating both configurations of cNTFEAs without special precleaning in greater than 10−5Torr hydrogen produced orders of magnitude enhancement in emission. For a cNTFEA intentionally degraded by oxygen, the operation in hydrogen resulted in a 340-fold increase in emission current at constant gate voltage. The results suggested a dependence on atomic hydrogen produced from the interaction between emission electrons and molecular hydrogen. The observed emission enhancement could be due to a surface dipole formation, hydrogen doping, or removal of oxygen-containing surface species.
Electron field emission from carbon nanotubes on porous alumina
Authors: Lysenkov D. , Abbas H. , Müller G. , Engstler J. , Budna K. P. , Schneider J. J.
Published: April 2005

We have synthesized carbon nanotubes by chemical vapor deposition using ferrocene as single source organometallic precursor both on commercial (Anodisc®) and electrochemically etched porous alumina templates. Carbon nanotubes of about 20nm diameter and some μm in length appeared apart on the alumina membranes. Integral field emission measurements of these cathodes were performed in a diode configuration with luminescent screen. High emitter number densities of at least 10000∕cm2 and current densities up to 32mA∕cm2 were obtained at an electric field of 7.2V∕μm. Cathode processing at pressures in the range from 10−7to5×10−4mbar resulted in improved current stability measured over 18h. High resolution emitter distributions obtained with the field emission scanning microscope yielded up to 62000emitters∕cm2 at 23V∕μm. Single emitter investigations showed Fowler–Nordheim behavior up to 1μA and current limits up to 12μA in dc operation. Reversible switching between different emission states was also observed. Possible explanations of these phenomena and their impact for applications will be discussed.
Open-System Coral Ages Reveal Persistent Suborbital Sea-Level Cycles
Authors: Thompson William G. , Goldstein Steven L.
Published: April 2005

Sea level is a sensitive index of global climate that has been linked to Earth's orbital variations, with a minimum periodicity of about 21,000 years. Although there is ample evidence for climate oscillations that are too frequent to be explained by orbital forcing, suborbital-frequency sea-level change has been difficult to resolve, primarily because of problems with uranium/thorium coral dating. Here we use a new approach that corrects coral ages for the frequently observed open-system behavior of uranium-series nuclides, substantially improving the resolution of sea-level reconstruction. This curve reveals persistent sea-level oscillations that are too frequent to be explained exclusively by orbital forcing.
Toward Ecosystems Oceanography
Authors: Cury Philippe
Published: April 2005

Marine Ecosystems and Climate Variation
.
Nils Chr. Stenseth, Geir Ottersen, James W. Hurrell, and Andrea Belgrano, Eds.
. Oxford University Press, Oxford, 2004. 266 pp. $124.50, £68. ISBN 0-19-850748-8.

Using a series of case studies on the relations among top predators, fish populations, and climate change, the contributors present conceptual approaches to the study of environmental effects on marine populations.
A Convergent Enantioselective Route to Structurally Diverse 6-Deoxytetracycline Antibiotics
Authors: Charest Mark G. , Lerner Christian D. , Brubaker Jason D. , Siegel Dionicio R. , Myers Andrew G.
Published: April 2005

Complex antibiotics based on natural products are almost invariably prepared by semisynthesis, or chemical transformation of the isolated natural products. This approach greatly limits the range of accessible structures that might be studied as new antibiotic candidates. Here we report a short and enantioselective synthetic route to a diverse range of 6-deoxytetracycline antibiotics. The common feature of this class is a scaffold of four linearly fused rings, labeled A through D. We targeted not a single compound but a group of structures with the D ring as a site of structural variability. A late-stage, diastereoselective C-ring construction was used to couple structurally varied D-ring precursors with an AB precursor containing much of the essential functionality for binding to the bacterial ribosome. Five derivatives were synthesized from benzoic acid in yields ranging from 5 to 7% over 14 to 15 steps, and a sixth, (-)-doxycycline, was synthesized in 8.3% yield over 18 steps.
Treasures from a Golden Age
Authors: Wurtz Robert
Published: April 2005

Brain and Visual Perception
The Story of a 25-Year Collaboration.
By David H. Hubel and Torsten N. Wiesel
. Oxford University Press, New York, 2004. 737 pp. $49.50, £29.99. ISBN 0-19-517618-9.

The authors survey their long-running and rewarding research on the brain and its development through a collection of papers they published between 1958 and 1983 accompanied by an overall introduction, comments on each paper, and a final summary.
Alternative Splicing Produces Two Endoglucanases with One or Two Carbohydrate-Binding Modules in
Mucor circinelloides
Authors: Baba Yuko , Shimonaka Atsushi , Koga Jinichiro , Kubota Hidetoshi , Kono Toshiaki
Published: April 2005

We previously cloned three endoglucanase genes,
rce1
,
rce2
, and
rce3
, that were isolated from
Rhizopus oryzae
as the first cellulase genes from a member of the subdivision Zygomycota. In this study, two cDNAs homologous to the
rce1
gene, designated the
mce1
and
mce2
cDNAs, were cloned from
Mucor circinelloides
, a member of the subdivision Zygomycota. The
mce1
cDNA encoded an endoglucanase (family 45 glycoside hydrolase) having one carbohydrate-binding module (CBM), designated MCE1, and the
mce2
cDNA encoded the same endoglucanase having two tandem repeated CBMs, designated MCE2. The two cDNAs contained the same sequences but with a 147-bp insertion. The corresponding genomic
mce
gene consisted of four exons. The
mce1
cDNA was created from exons 1, 3, and 4, and the
mce2
cDNA was created from exons 1, 2, 3, and 4. These results indicate that the
mce1
and
mce2
cDNAs were created from one genomic
mce
gene by alternative splicing. MCE1 and MCE2, purified to apparent homogeneity from the culture supernatant of
M. circinelloides
, had molecular masses of 43 and 47 kDa, respectively. The carboxymethyl cellulase specific activity of MCE2 was almost the same as that of MCE1, whereas the Avicelase specific activity of MCE2 was two times higher than that of MCE1. Furthermore, MCE2, whose two tandem CBMs might be more effective for degradation of crystalline cellulose than one CBM, was secreted only at an early culture stage when crystalline cellulose was abundant.
Global Gene Expression Responses to Cadmium Toxicity in
Escherichia coli
Authors: Wang Anyou , Crowley David E.
Published: April 2005

Genome-wide analysis of temporal gene expression profiles in
Escherichia coli
following exposure to cadmium revealed a shift to anaerobic metabolism and induction of several stress response systems. Disruption in the transcription of genes encoding ribosomal proteins and zinc-binding proteins may partially explain the molecular mechanisms of cadmium toxicity.