Selection pressure-driven evolution of the Epstein-Barr virus-encoded oncogene LMP1 in virus isolates from southeast Asia

The geographically constrained distribution of Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) in southeast Asian populations suggests that both viral and host genetics may influence disease risk. Although susceptibility loci have been mapped within the human genome, the role of viral genetics in the focal distribution of NPC remains an enigma. Here we report a molecular phylogenetic analysis of an NPC-associated viral oncogene, LMP1, in a large panel of EBV isolates from southeast Asia and from Papua New Guinea, Africa, and Australia, regions of the world where NPC is and is not endemic, respectively. This analysis revealed that LMP1 sequences show a distinct geographic structure, indicating that the southeast Asian isolates have evolved as a lineage distinct from those of Papua New Guinea, African, and Australian isolates. Furthermore, a likelihood ratio test revealed that the C termini of the LMP1 sequences of the southeast Asian lineage are under significant positive selection pressure, particularly at some sites within the C-terminal activator regions. We also present evidence that although the N terminus and transmembrane region of LMP1 have undergone recombination, the C-terminal region of the gene has evolved without any history of recombination. Based on these observations, we speculate that selection pressure may be driving the LMP1 sequences in virus isolates from southeast Asia towards a more malignant phenotype, thereby influencing the endemic distribution of NPC in this region.

Ultrastructure, aggregation-state, and crystal growth of biogenic nanocrystalline sphalerite and wurtzite

In this study, we investigated the size, submicrometer-scale structure, and aggregation state of ZnS formed by sulfate-reducing bacteria (SRB) in a SRB-dominated biofilm growing on degraded wood in cold (Tsimilar to8degreesC), circumneutral-pH (7.2-8.5) waters draining from an abandoned, carbonate-hosted Pb-Zn mine. High-resolution transmission electron microscope (HRTEM) data reveal that the earliest biologically induced precipitates are crystalline ZnS nanoparticles 1-5 nm in diameter. Although most nanocrystals have the sphalerite structure, nanocrystals of wurtzite are also present, consistent with a predicted size dependence for ZnS phase stability. Nearly all the nanocrystals are concentrated into 1-5 mum diameter spheroidal aggregates that display concentric banding patterns indicative of episodic precipitation and flocculation. Abundant disordered stacking sequences and faceted, porous crystal-aggregate morphologies are consistent with aggregation-driven growth of ZnS nanocrystals prior to and/or during spheroid formation. Spheroids are typically coated by organic polymers or associated with microbial cellular surfaces, and are concentrated roughly into layers within the biofilm. Size, shape, structure, degree of crystallinity, and polymer associations will all impact ZnS solubility, aggregation and coarsening behavior, transport in groundwater, and potential for deposition by sedimentation. Results presented here reveal nanometer- to micrometer-scale attributes of biologically induced ZnS formation likely to be relevant to sequestration via bacterial sulfate reduction (BSR) of other potential contaminant metal(loid)s, such as Pb2+, Cd2+, As3+ and Hg2+, into metal sulfides. The results highlight the importance of basic mineralogical information for accurate prediction and monitoring of long-term contaminant metal mobility and bioavailability in natural and constructed bioremediation systems. Our observations also provoke interesting questions regarding the role of size-dependent phase stability in biomineralization and provide new insights into the origin of submicrometer- to millimeter-scale petrographic features observed in low-temperature sedimentary sulfide ore deposits.

Surveillance as a technique of power in physical education

This paper analyses surveillance as a technique of power in the culture of physical education, including its impact upon the health of teachers. Additionally, gendered aspects of surveillance are investigated because physical education is an important location in and through which bodies are inscribed with gendered identities. The embodied nature of physical educators' work renders the body as particularly significant in patterns of privilege and domination. The research was guided by Michel Foucault's work and poststructural feminist perspectives on the importance of power in social life. At nine schools across two international research sites, the functioning of surveillance was evidenced through the multi-directional workings of power in top-down, lateral, and bottom-up configurations. Data indicated that surveillance occurred on, through and about bodies. It had a strong gender dimension as the male gaze inscribed both female teachers' and students' bodies with value and competence. In terms of teachers' health, as well as responses to surveillance on a physical and emotional level, the workings of power were also influential in shaping teachers' identities.

Recurrence of Helicobacter pylori infection in adults with intellectual disability

Although Helicobacter pylori infection is very common among particular groups of adults with intellectual disability, the rate of recurrence (reinfection or recrudescence) is unknown in this population. Thirty-six months after successful treatment of H. pylori, 28 adults with intellectual disability were retested using the faecal antigen test. Six (21%) of 28 patients tested positive, giving an approximate yearly recurrence rate of 7%, a rate considerably higher than that in the general popu-lation (

Effects of Helicobacter pylori eradication among adults with intellectual disability

Background Compared to the general population, Helicobacter pylori infection is more common among adults with intellectual disability (ID) and is associated with greater levels of disability, maladaptive behaviour, and institutionalization. Little information exists about the effects of eradication therapy in this group, so we aimed to evaluate: (1) success of a standard H. pylori eradication protocol; (2) frequency of side-effects; and (3) impact of eradication on level of functional ability and maladaptive behaviour. Method A cohort of adults with ID underwent assessment of their levels of function and maladaptive behaviour, medical history, physical examination, and H. pylori testing using serology and faecal antigen tests. Some received standard H. pylori eradication therapy. Twelve months later, participants underwent repeat assessment, were grouped by change in H. pylori status and compared. Results Of 168 participants, 117 (70%) were currently infected with H. pylori at baseline, and 96 (82%) of the 117 were given standard H. pylori eradication therapy. The overall eradication rate was 61% but 31% reported side-effects. Institutional status of the participants, their level of behaviour or function, and number of comorbid medical conditions were not associated with failure of eradication. There were no statistically significant differences in level of behaviour or function, ferritin, or weight between the groups in whom H. pylori was eradicated or stayed positive. Conclusion Adults with ID have lower H. pylori eradication and higher side-effect rates than the general population. Levels of maladaptive behaviour and disability did not improve with eradication and thus greater levels of maladaptive behaviour or disability appear to be risk factors for, rather than consequences of, H. pylori infection.

Alcohol, wine, and risk of epithelial ovarian cancer

Moderate alcohol intake can influence sex hormone levels and affect ovarian function as well as increasing breast cancer risk. This suggests that alcohol might also influence ovarian cancer risk. We have evaluated this among 696 Australian women with histologically confirmed epithelial ovarian cancer and 786 cancer-free control women, selected at random from the electoral roll. Sociodemographic information and a detailed reproductive history were collected in a face-to-face interview, and information about diet and alcohol consumption was obtained from a food frequency questionnaire. Logistic regression was used to calculate adjusted odds ratios (OR) and 95% confidence intervals (95% CI). Overall, 59% of women drank

Metamorphosis of a scleractinian coral in response to microbial biofilms

Microorganisms have been reported to induce settlement and metamorphosis in a wide range of marine invertebrate species. However, the primary cue reported for metamorphosis of coral larvae is calcareous coralline algae (CCA). Herein we report the community structure of developing coral reef biofilms and the potential role they play in triggering the metamorphosis of a scleractinian coral. Two-week-old biofilms induced metamorphosis in less than 10% of larvae, whereas metamorphosis increased significantly on older biofilms, with a maximum of 41% occurring on 8-week-old microbial films. There was a significant influence of depth in 4- and 8-week biofilms, with greater levels of metamorphosis occurring in response to shallow-water communities. Importantly, larvae were found to settle and metamorphose in response to microbial biofilms lacking CCA from both shallow and deep treatments, indicating that microorganisms not associated with CCA may play a significant role in coral metamorphosis. A polyphasic approach consisting of scanning electron microscopy, fluorescence in situ hybridization (FISH), and denaturing gradient gel electrophoresis (DGGE) revealed that coral reef biofilms were comprised of complex bacterial and microalgal communities which were distinct at each depth and time. Principal-component analysis of FISH data showed that the Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Cytophaga-Flavobacterium of Bacteroidetes had the largest influence on overall community composition. A low abundance of Archaea was detected in almost all biofilms, providing the first report of Archaea associated with coral reef biofilms. No differences in the relative densities of each subdivision of Proteobacteria were observed between slides that induced larval metamorphosis and those that did not. Comparative cluster analysis of bacterial DGGE patterns also revealed that there were clear age and depth distinctions in biofilm community structure; however, no difference was detected in banding profiles between biofilms which induced larval metamorphosis and those where no metamorphosis occurred. This investigation demonstrates that complex microbial communities can induce coral metamorphosis in the absence of CCA.

Symptoms and diagnosis of borderline, early and advanced epithelial ovarian cancer

Objective. To document symptoms associated with borderline, early and advanced ovarian cancer and identify personal characteristics associated with early versus late diagnosis. Methods. Information concerning symptoms and diagnosis history was available from 811 women with ovarian cancer who took part in an Australian case–control study in the early 1990s. Women were classified into three groups for comparison based on their diagnosis: borderline, early (stage I–II) and advanced (stage III–IV) invasive cancer. Results. Sixteen percent of women with borderline tumors, 7% with early cancer and 4% with advanced cancer experienced no symptoms before diagnosis (P < 0.0001). Among women with symptoms, abdominal pain (44%) or swelling (39%) were most frequently reported; an abdominal mass (12%) and gynecological symptoms (12%) were less common. Compared to advanced stage cancer, women with early stage cancer were more likely to report an abdominal mass or urinary symptoms but less likely to report gastrointestinal problems or general malaise. General malaise and ‘other’ symptoms were least common in borderline disease. Older women, and those with higher parity or a family history of breast or ovarian cancer, were more likely to be diagnosed at an advanced stage of disease. Conclusions. Women who experience persistent or recurrent abdominal symptoms, particularly swelling and/or pain should be encouraged to seek medical attention and physicians should be alert to the possibility of ovarian cancer even in the absence of an abdominal mass. Further information about the prevalence of these symptoms in the general population is essential to assist physicians in patient management.

Geochemistry of late Archaean stromatolites from Zimbabwe: evidence for microbial life in restricted epicontinental seas

We report comprehensive trace element and Sr-isotope data for microbial carbonates from the Archaean Mushandike limestone, Masvingo Greenstone Belt, Zimbabwe. The stromatolites have very coherent REE + Y patterns and share the essential shale-normalised characteristics of other Archaean marine precipitates (positive La and Gd anomalies, absence of a negative Cc anomaly and a strongly superchondritic Y/Ho ratio). Mixing models constrain the maximum amount of shale contamination to 0.25-1% and calculated detritus-free carbonate REE + Y systematics require precipitation from seawater. In terms of light-REE over heavy-REE depletion, however, the studied samples are very different from all other known Archaean marine precipitates. In shale-normalised plots, the Mushandike samples yield a negative slope. A very restricted, regional input source of the dissolved load is indicated because normalisation with locally occurring tonalite gneiss REE + Y data yields a pattern closely resembling typical shale-normalised Archaean marine chemical sediments. The disappearance of a negative Eu anomaly when patterns are normalised with local tonalite gneiss strengthens this interpretation. Sr-isotope ratios are strongly correlated with trace element contents and ratios, which explains the modest scatter in Sr-isotope ratios as representing (minor) clastic contamination. Importantly, even the least contaminated samples have very radiogenic initial Sr-87/Sr-86 ratios (0.7184) implying Sr input from an ancient high Rb/Sr source, such as the early Archaean gneisses of south-central Zimbabwe. A local ancient (3.5-3.8 Ga) source is also indicated by previously published Pb-isotope datasets for the Mushandike stromatolites. This is entirely compatible with the occurrence of 3.7-3.8 Ga zircons in quartzites and metapelites from comparably old greenstone belts within less than 150 km of the studied locality. Comparison of the Pb-isotope ratios of the Mushandike stromatolites with 2.7 and 2.6 Ga old stromatolites from the neighbouring, Belingwe Greenstone Belt demonstrates differences in initial isotope composition that relate to the extent of exchange with the open ocean. The development of numerous basins on old continental crust, with water masses variably restricted from the open ocean. suggests a lack of strong vertical topography on this late Archaean craton. (C) 2004 Elsevier B.V. All rights reserved.

Rare earth element geochemistry of Late Devonian reefal carbonates, canning basin, Western Australia: Confirmation of a seawater REE proxy in ancient limestones

Rare earth element and yttrium (REE+Y) concentrations were determined in 49 Late Devonian reefal carbonates from the Lennard Shelf, Canning Basin, Western Australia. Shale-normalized (SN) REE+Y patterns of the Late Devonian samples display features consistent with the geochemistry of well-oxygenated, shallow seawater. A variety of different ancient limestone components, including microbialites, some skeletal carbonates (stromatoporoids), and cements, record seawater-like REE+Y signatures. Contamination associated with phosphate, Fe-oxides and shale was tested quantitatively, and can be discounted as the source of the REE+Y patterns. Co-occurring carbonate components that presumably precipitated from the same seawater have different relative REE concentrations, but consistent REE+Y patterns. Clean Devonian early marine cements (n = 3) display REE+Y signatures most like that of modern open ocean seawater and the highest Y/Ho ratios (e.g., 59) and greatest light REE (LREE) depletion (average Nd-SN/Yb-SN = 0.413, SD = 0.076). However, synsedimentary cements have the lowest REE concentrations (e.g., 405 ppb). Non-contaminated Devonian microbialite samples containing a mixture of the calcimicrobe Renalcis and micritic thrombolite aggregates in early marine cement (n = 11) have the highest relative REE concentrations of tested carbonates (average total REE = 11.3 ppm). Stromatoporoid skeletons, unlike modern corals, algae and molluscs, also contain well-developed, seawater-like REE patterns. Samples from an estuarine fringing reef have very different REE+Y patterns with LREE enrichment (Nd-SN/Yb-SN > 1), possibly reflecting inclusion of estuarine colloidal material that contained preferentially scavenged LREE from a nearby riverine input source. Hence, Devonian limestones provide a proxy for marine REE geochemistry and allow the differentiation of co-occurring water masses on the ancient Lennard Shelf. Although appropriate partition coefficients for quantification of Devonian seawater REE concentrations from out data are unknown, hypothetical Devonian Canning Basin seawater REE patterns were obtained with coefficients derived from modern natural proxies and experimental values. Resulting Devonian seawater patterns are slightly enriched in LREE compared to most modem seawaters and suggest higher overall REE concentrations, but are very similar to seawaters from regions with high terrigenous inputs. Our results suggest that most limestones should record important aspects of the REE geochemistry of the waters in which they precipitated, provided they are relatively free of terrigenous contamination and major diagenetic alteration from fluids with high, non-seawater-like REE contents. Hence, we expect that many other ancient limestones will serve as seawater REE proxies, and thereby provide information on paleoceanography, paleogeography and geochemical evolution of the oceans. Copyright (C) 2004 Elsevier Ltd.

Canonical valuation of options in the presence of stochastic volatility

Proposed by M. Stutzer (1996), canonical valuation is a new method for valuing derivative securities under the risk-neutral framework. It is non-parametric, simple to apply, and, unlike many alternative approaches, does not require any option data. Although canonical valuation has great potential, its applicability in realistic scenarios has not yet been widely tested. This article documents the ability of canonical valuation to price derivatives in a number of settings. In a constant-volatility world, canonical estimates of option prices struggle to match a Black-Scholes estimate based on historical volatility. However, in a more realistic stochastic-volatility setting, canonical valuation outperforms the Black-Scholes model. As the volatility generating process becomes further removed from the constant-volatility world, the relative performance edge of canonical valuation is more evident. In general, the results are encouraging that canonical valuation is a useful technique for valuing derivatives. (C) 2005 Wiley Periodicals, Inc.

Enrichment, isolation and characterisation of ruminal bacteria that degrade non-protein amino acids from the tropical legume Acacia angustissima

Acacia angustissima has been proposed as a protein supplement in countries where low quality forages predominate. A number of non-protein amino acids have been identified in the leaves of A. angustissima and these have been linked to toxicity in ruminants. The non-protein amino acid 4-n-acetyl-2,4-diaminobutyric acid (ADAB) has been shown to be the major amino acid in the leaves of A. angustissima. The current study aimed to identify micro-organisms from the rumen environment capable of degrading ADAB by using a defined rumen-simulating media with an amino acid extract from A. angustissima. A mixed enrichment culture was obtained that exhibited substantial ADAB-degrading ability. Attempts to isolate an ADAB-degrading micro-organism were carried out, however no isolates were able to degrade ADAB in pure culture. This enrichment culture was also able to degrade the non-protein amino acids diaminobutyric acid (DABA) and diaminopropionic acid (DAPA) which have structural similarities to ADAB. Two isolates were obtained which could degrade DAPA. One isolate is a novel Grain-positive rod (strain LPLR3) which belongs to the Firmicutes and is not closely related to any previously isolated bacterium. The other isolate is strain LPSR1 which belongs to the Gammaproteobacteria and is closely related (99.93% similar) to Klebsiella pneumoniae subsp. ozaenae. The studies demonstrate that the rumen is a potential rich source of undiscovered micro-organisms which have novel capacities to degrade plant secondary compounds. (c) 2005 Elsevier B.V. All rights reserved.

Height, age at menarche, and risk of epithelial ovarian cancer

Objective: We hypothesized that the hormonal changes of adolescence influence ovarian cancer risk particularly in younger women. We investigated this possibility by examining the relationship between ovarian cancer and adult height and age at menarche as both factors reflect pubertal hormonal levels. Methods: Participants were a population-based sample of women with incident ovarian cancer (n = 794) and control women randomly selected from the Australian Electoral Roll (n = 855). The women provided comprehensive reproductive and lifestyle data during a standard interview. Results: Although neither height nor age at menarche was significantly related to the risk of ovarian cancer overall, increasing height was associated with increasing risk of the subgroup of mucinous borderline ovarian cancer (odds ratio, 5.3; 95% confidence interval, 1.5-19.1 for women 175 cm compared with women < 160 cm, P-trend = 0.02). Similarly, later age at menarche was associated with increasing risk of mucinous borderline cancers (odds ratio, 3.8; 95% confidence interval, 1.3-11.4 for those with age at menarche >= 44 years compared with those < 12 years, P-trend = 0.003). Women with mucinous borderline cancers were significantly younger than the women diagnosed with invasive cancers (mean 44 versus 57 years; P < 0.0001). Conclusions: Development of mucinous borderline ovarian cancers, predominantly diagnosed in women ages under 50 years, seems to be associated with age at menarche and attained adult height. These results are consistent with our original hypothesis that pubertal levels of reproductive hormones and insulin-like growth factor-I influence ovarian cancer risk in younger women.