Benthic foraminifera show some resilience to ocean acidification in the northern Gulf of California, Mexico.

The version on PEARL: Corrected proofs are Articles in Press that contain the authors' corrections. Final citation details, e.g., volume/issue number, publication year and page numbers, still need to be added and the text might change before final publication. Although corrected proofs do not have all bibliographic details available yet, they can already be cited using the year of online publication and the DOI , as follows: author(s), article title, journal (year), DOIExtensive CO2 vents have been discovered in the Wagner Basin, northern Gulf of California, where they create large areas with lowered seawater pH. Such areas are suitable for investigations of long-term biological effects of ocean acidification and effects of CO2 leakage from subsea carbon capture storage. Here, we show responses of benthic foraminifera to seawater pH gradients at 74-207m water depth. Living (rose Bengal stained) benthic foraminifera included Nonionella basispinata, Epistominella bradyana and Bulimina marginata. Studies on foraminifera at CO2 vents in the Mediterranean and off Papua New Guinea have shown dramatic long-term effects of acidified seawater. We found living calcareous benthic foraminifera in low pH conditions in the northern Gulf of California, although there was an impoverished species assemblage and evidence of post-mortem test dissolution

A Minimal Model of Signaling Network Elucidates Cell-to-Cell Stochastic Variability in Apoptosis

Signaling networks are designed to sense an environmental stimulus and adapt to it. We propose and study a minimal model of signaling network that can sense and respond to external stimuli of varying strength in an adaptive manner. The structure of this minimal network is derived based on some simple assumptions on its differential response to external stimuli. We employ stochastic differential equations and probability distributions obtained from stochastic simulations to characterize differential signaling response in our minimal network model. We show that the proposed minimal signaling network displays two distinct types of response as the strength of the stimulus is decreased. The signaling network has a deterministic part that undergoes rapid activation by a strong stimulus in which case cell-to-cell fluctuations can be ignored. As the strength of the stimulus decreases, the stochastic part of the network begins dominating the signaling response where slow activation is observed with characteristic large cell-to-cell stochastic variability. Interestingly, this proposed stochastic signaling network can capture some of the essential signaling behaviors of a complex apoptotic cell death signaling network that has been studied through experiments and large-scale computer simulations. Thus we claim that the proposed signaling network is an appropriate minimal model of apoptosis signaling. Elucidating the fundamental design principles of complex cellular signaling pathways such as apoptosis signaling remains a challenging task. We demonstrate how our proposed minimal model can help elucidate the effect of a specific apoptotic inhibitor Bcl-2 on apoptotic signaling in a cell-type independent manner. We also discuss the implications of our study in elucidating the adaptive strategy of cell death signaling pathways.Comment: 9 pages, 6 figure

Diagnostic and preventive service trends in private general practice: 1983-1984 to 1998-1999

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: Aggregate trends have indicated increases in the provision of diagnostic and preventive services but there have been few reports based on their component sub-categories. The aims of this study were to investigate time trends in the provision of sub-categories of diagnostic and preventive services across a 15-year period. Methods: A random sample of Australian dentists was surveyed by mailed questionnaire in 1983-1984, 1988-1989, 1993-1994 and 1998-1999 (response rates 71-75 per cent). Data were weighted to provide representative estimates for the age by sex distribution of private general practitioners in 1983, 1988, 1993 and 1998. Results: Rates per visit were higher, Poisson regression, P<0.05, in 1998-1999 compared to baseline for examinations, radiographs, prophylaxis and topical fluoride. Diagnostic and preventive service rates varied by age of patient: compared to patients aged 65+ years, examinations were higher among children aged <5 years to adults aged 25-44 years, radiographs were lower among children <5 years and 5-11 years but higher among adults aged from 18-24 years to 45-64 years, prophylaxis services were lower among children <5 years but higher among adolescents 12-17 years to adults aged 45-64 years, while topical fluoride was higher among children 5-11 years and adolescents 12-17 years. Conclusions: Examination, radiograph, prophylaxis, and topical fluoride rates increased over the study period. While examination rates increased for both children and adults, and prophylaxis rates increased for adolescents and adults, rates for radiographs and topical fluoride only increased for adults. Agespecific changes in service rates over time indicate the effect of changing oral health status and population demographics on service provision.DS Brennan, AJ Spence

Neurotrophic Effect of Citrus 5-Hydroxy-3,6,7,8,3′,4′-Hexamethoxyflavone: Promotion of Neurite Outgrowth via cAMP/PKA/CREB Pathway in PC12 Cells

5-Hydroxy-3,6,7,8,3′,4′-hexamethoxyflavone (5-OH-HxMF), a hydroxylated polymethoxyflavone, is found exclusively in the Citrus genus, particularly in the peels of sweet orange. In this research, we report the first investigation of the neurotrophic effects and mechanism of 5-OH-HxMF in PC12 pheochromocytoma cells. We found that 5-OH-HxMF can effectively induce PC12 neurite outgrowth accompanied with the expression of neuronal differentiation marker protein growth-associated protein-43(GAP-43). 5-OH-HxMF caused the enhancement of cyclic AMP response element binding protein (CREB) phosphorylation, c-fos gene expression and CRE-mediated transcription, which was inhibited by 2-naphthol AS-E phosphate (KG-501), a specific antagonist for the CREB-CBP complex formation. Moreover, 5-OH-HxMF-induced both CRE transcription activity and neurite outgrowth were inhibited by adenylate cyclase and protein kinase A (PKA) inhibitor, but not MEK1/2, protein kinase C (PKC), phosphatidylinositol 3-kinase (PI3K) or calcium/calmodulin-dependent protein kinase (CaMK) inhibitor. Consistently, 5-OH-HxMF treatment increased the intracellular cAMP level and downstream component, PKA activity. We also found that addition of K252a, a TrKA antagonist, significantly inhibited NGF- but not 5-OH-HxMF-induced neurite outgrowth. These results reveal for the first time that 5-OH-HxMF is an effective neurotrophic agent and its effect is mainly through a cAMP/PKA-dependent, but TrKA-independent, signaling pathway coupling with CRE-mediated gene transcription. A PKC-dependent and CREB-independent pathway was also involved in its neurotrophic action

Feasibility of quality of life assessment in patients with upper gastrointestinal tract cancer

Quality of life (QOL) is an important outcome after treatment for upper gastrointestinal tract cancer but few studies report good accrual and subsequent attrition is usually high. This study investigated the feasibility of a nurse-led service to obtain longitudinal QOL assessments and explored how clinical and sociodemographic factors influence patients' need for help to complete questionnaires. Fully informed patients were invited into the study. Baseline hospital assessments were scheduled by telephone and thereafter by post unless patients' health indicated the need for a home visit. In all, 128 out of 140 (91%) baseline QOL assessments were performed. Follow-up questionnaire completion was good, with 114 patients (89%) completing all but one of the expected assessments. At baseline, 41 (32%) patients required a lot of help to complete questionnaires. Patients requiring help were more likely to be undergoing palliative treatment than treatment aimed at cure (68 vs 33%; odds ratio 3.48, P < 0.01). Patients' with advanced stage cancer of the upper gastrointestinal tract receiving palliative treatment require dedicated staff to ensure good compliance with longitudinal QOL data collection. It is essential to budget for this in clinical trails. © 2003 Cancer Research UK

The Discovery of Two New Satellites of Pluto

Pluto's first known moon, Charon, was discovered in 1978 (Christy 1978) and has a diameter about half that of Pluto (Buie 1992,Young 1994, Sicardy 2005), which makes it larger relative to its primary than any other moon in the Solar System. Previous searches for other satellites around Pluto have been unsuccessful (Stern 1991, Stern 1994, Stern 2003), but they were not sensitive to objects <=150 km in diameter and there are no fundamental reasons why Pluto should not have more satellites (Stern 1994). Here we report the discovery of two additional moons around Pluto, provisionally designated S/2005 P1 (hereafter P1) and S/2005 P2 (hereafter P2), which makes Pluto the first Kuiper belt object (KBO) known to have multiple satellites. These new satellites are much smaller than Charon (diameter~1200 km), with P1 ranging in diameter from 60-165 km depending on the surface reflectivity, and P2 about 20% smaller than P1. Although definitive orbits cannot be derived, both new satellites appear to be moving in circular orbits in the same orbital plane as Charon, with orbital periods of ~38 days (P1) and ~25 days (P2). The implications of the discovery of P1 and P2 for the origin and evolution of the Pluto system, and for the satellite formation process in the Kuiper belt, are discussed in a companion paper (Stern 2006).Comment: Preprint of a paper accepted for publication in the journal Natur