Tectonically-driven oxidant production in the hot biosphere

Genomic reconstructions of the common ancestor to all life have identified genes involved in H2O2 and O2 cycling. Commonly dismissed as an artefact of lateral gene transfer after oxygenic photosynthesis evolved, an alternative is a geological source of H2O2 and O2 on the early Earth. Here, we show that under oxygen-free conditions high concentrations of H2O2 can be released from defects on crushed silicate rocks when water is added and heated to temperatures close to boiling point, but little is released at temperatures <80 °C. This temperature window overlaps the growth ranges of evolutionary ancient heat-loving and oxygen-respiring Bacteria and Archaea near the root of the Universal Tree of Life. We propose that the thermal activation of mineral surface defects during geological fault movements and associated stresses in the Earth’s crust was a source of oxidants that helped drive the (bio)geochemistry of hot fractures where life first evolved

Exposure-age constraints on the extent, timing and rate of retreat of the last Irish Sea ice stream

We report 23 cosmogenic isotope exposure ages (10Be and 36Cl) relating to the maximum extent and deglaciation chronology of the Irish Sea Ice Stream (ISIS), which drained the SW sector of the last British-Irish Ice Sheet. These show that the ISIS failed to reach the Preseli Hills of North Pembrokeshire yet extended southwards to impinge on northern Isles of Scilly (50°N) during the last glacial maximum. Four samples from western Anglesey demonstrate deglaciation of the southern Irish Sea Basin by c. 20-18 ka, and two from the Llŷn Peninsula in northwest Wales, if valid, suggest deglaciation by c. 23-22 ka followed by gradual oscillatory northwards retreat of the ice margin for over 3000 years. An alternative interpretation of our data suggests that ice reached Scilly as late as 22-21 ka then retreated 450 km northwards within the following three millennia, possibly in response to sea level rise and/or intrinsic reorganisation within the last British-Irish Ice Sheet. Samples from upland source areas of the ISIS in NW England and SW Scotland produced exposure ages ≤14.3 ka, suggesting possible persistence of ice in such areas into the Lateglacial Interstade of 14.7-12.9 ka

Prevalence of motor deficiencies and their relationship with federal expenditures for prosthesis, orthetics and other equipment in the Brazilian states in 2010

The objective of this study was to know the prevalence of full motor difficulty (MD) (walking or climbing stairs) and according to degrees (mild, moderate, severe) in the Brazilian states and in the country; present the federal expenditures on prostheses, orthotics and materials (OPM) related to such difficulty; and verify the correlation between the prevalence of disabilities and public expenditures on OPM. Population data was used from every major city in Brazil, obtained from the IBGE website, and OPM expenditures related to MD, extracted from the DATASUS website in 2010. Data was analyzed through the prevalence of MD and OPM expenses related to MD. We used the Stata 11 software for the implementation of the Spearman correlation test with a significance level of 5%. The prevalence of MD in Brazil in the year of 2010 was 6.91%; ranging from 8.63% (state of Alagoas) to 5.28% (state of Tocantins). The expenditures on OPM varied according to the state, and these expenditures were proportional to the prevalence of MD in the cities of the states of Acre and Piauí (orthotics); Pernambuco (prostheses), and Acre and Maranhão (equipment). The correlation between the amount spent and the prevalence of MD was inverse in the cities of the states of Espírito Santo, Minas Gerais, Paraná, Rio Grande do Sul, Santa Catarina and São Paulo (orthotics); Espírito Santo, Minas Gerais, Paraná, Rio Grande do Sul, Santa Catarina and São Paulo (prostheses); and Espírito Santo, Minas Gerais, Rio Grande do Sul and São Paulo (equipment).O objetivo deste estudo foi conhecer a prevalência de dificuldade motora (DM) (caminhar ou subir degraus) total e segundo graus (leve, moderada, grave) nos estados brasileiros e no país; apresentar os gastos federais com próteses, órteses e equipamentos (OPM) relacionados a essa dificuldade; e verificar a existência de correlação entre as prevalências de DM e gasto público com as OPM. Foram usados dados populacionais de todas as cidades do Brasil, obtidos a partir do site do IBGE, e gastos com OPM relacionados à DM, extraídos do site do DATASUS, de 2010. Os dados foram analisados por meio de prevalências de DM e gastos com OPM relacionados à DM. Utilizou-se o programa Stata 11 para execução do teste de correlação de Spearman com nível de significância de 5%. A prevalência de DM no Brasil no ano de 2010 foi de 6,91%, variando de 8,63% (AL) a 5,28% (TO). Os gastos com OPM variaram segundo os estados e foram proporcionais à prevalência de DM nas cidades dos estados do AC e PI (órteses), PB (próteses), e AC e MA (equipamentos). A correlação entre valor investido e prevalência de DM foi inversa nas cidades dos estados de ES, MG, PR, RS, SC e SP (órteses); ES, MG, PR, RS, SC e SP (próteses); e ES, MG, RS e SP (equipamentos).El objetivo de este estudio fue conocer la prevalencia de dificultad motora (DM) (caminar o subir escaleras) total y segundo grados (leve, moderada, severa) en los estados brasileños y en el país; presentar los gastos federales con prótesis, órtesis y equipos (OPM) relacionados con esta dificultad; y verificar la existencia de correlación entre las prevalencias de DM y el gasto público con los OPM. Se utilizaron datos de poblaciones de todas las ciudades del Brasil, obtenidos del sitio web del IBGE, y gastos con OPM relacionados a la DM, extraídos del sitio web del DATASUS, de 2010. Los datos fueron analizados por medio de prevalencias de DM y gastos con OPM relacionados con la DM. Se utilizó el programa Stata 11 para la ejecución de la prueba de correlación de Spearman con nivel de significancia del 5%. La prevalencia de DM en Brasil en el año 2010 fue de 6,91%, variando del 8,63% (AL) hasta el 5,28% (TO). Los gastos con OPM variaron según los estados y fueron proporcionales a la prevalencia de DM en las ciudades de los estados del PI (órtesis), PB (prótesis) y AC y MA (equipos). La correlación entre el monto invertido y prevalencia de DM fue el inverso en las ciudades de los estados de ES, MG, PR, RS, SC y SP (órtesis); ES, MG, PR, RS, SC, y SP (prótesis); y ES, MG, RS y SP (equipos)

Using remote sensing to forecast forage quality for cattle in the dry savannas of northeast Australia

In the dry savannas of northeast Australia, forage quality is just as important for cattle production as forage quantity. The seasonal trend of forage quality is broadly predictable by land managers, but it is more difficult to predict the point when quality—which depends on local climate, management, and pasture condition—falls below the requirement for animal maintenance. In this study we use statistical modelling to forecast how forage quality might change at the crucial time of year, i.e., as the summer wet season transitions to the dry winter. We do this with the aid of historical information associated with a long-term cattle-grazing trial in the dry savannas. We combined multiple years of two measures of forage quality (dietary crude protein and in vivo dry-matter digestibility; respectively DCP and DMD) and ground cover information (specifically the ratio of ‘green grass’ cover to ‘dead (i.e., non-photosynthetic) grass’ cover, derived from an archive of Landsat satellite imagery) into a linear mixed model that explicitly considered the correlations with time and between variables. DCP and DMD were estimated by near-infrared spectroscopy of fresh faecal samples; values did not have to be temporally coincident with the satellite imagery. With the end of May considered a nominal decision-point, we forecast monthly averages of forage quality for June to August, over a 12-year period at the study site. Over all months and all years, the median absolute error of the forecasts was DCP = 0.86%, and DMD = 0.95%. The remote sensing information served as a correlated, oft-sampled covariate that helped to guide the forecasts of forage quality. We propose summarising the forecasts (and their uncertainty) as a near-real-time graphical tool for decision-support. Such a product could potentially benefit cattle-grazing enterprises in the northeast of Australia, enabling more timely management of herds through the dry season

Simulating Radiating and Magnetized Flows in Multi-Dimensions with ZEUS-MP

This paper describes ZEUS-MP, a multi-physics, massively parallel, message- passing implementation of the ZEUS code. ZEUS-MP differs significantly from the ZEUS-2D code, the ZEUS-3D code, and an early "version 1" of ZEUS-MP distributed publicly in 1999. ZEUS-MP offers an MHD algorithm better suited for multidimensional flows than the ZEUS-2D module by virtue of modifications to the Method of Characteristics scheme first suggested by Hawley and Stone (1995), and is shown to compare quite favorably to the TVD scheme described by Ryu et. al (1998). ZEUS-MP is the first publicly-available ZEUS code to allow the advection of multiple chemical (or nuclear) species. Radiation hydrodynamic simulations are enabled via an implicit flux-limited radiation diffusion (FLD) module. The hydrodynamic, MHD, and FLD modules may be used in one, two, or three space dimensions. Self gravity may be included either through the assumption of a GM/r potential or a solution of Poisson's equation using one of three linear solver packages (conjugate-gradient, multigrid, and FFT) provided for that purpose. Point-mass potentials are also supported. Because ZEUS-MP is designed for simulations on parallel computing platforms, considerable attention is paid to the parallel performance characteristics of each module. Strong-scaling tests involving pure hydrodynamics (with and without self-gravity), MHD, and RHD are performed in which large problems (256^3 zones) are distributed among as many as 1024 processors of an IBM SP3. Parallel efficiency is a strong function of the amount of communication required between processors in a given algorithm, but all modules are shown to scale well on up to 1024 processors for the chosen fixed problem size.Comment: Accepted for publication in the ApJ Supplement. 42 pages with 29 inlined figures; uses emulateapj.sty. Discussions in sections 2 - 4 improved per referee comments; several figures modified to illustrate grid resolution. ZEUS-MP source code and documentation available from the Laboratory for Computational Astrophysics at http://lca.ucsd.edu/codes/currentcodes/zeusmp2

Flash heating boosts the potential for mechanochemical energy sources for subglacial ecosystems

Subglacial environments harbour a diversity of microbial ecosystems capable of influencing biogeochemical cycles. However, the darkness and isolation of subglacial environments limit the energy sources available for microbial metabolism. A recently recognised energy source for these microbes in wet-based regions is the rock-water reactions that occur after the mechanical fracturing of glacial bedrock. These mechanochemical reactions produce H2 and H2O2 at 0°C from reactions with mineral surface defects (Si• and SiO•) and release Fe from within the mineral structures, providing electron donors and acceptors for microbial metabolism. However, the production of H2O2 and H2 may be underestimated as temperatures at rock abrasion sites can increase substantially above 0°C as glaciers “slip and grind” rocks, potentially accelerating the rates of mechanochemical reactions. Despite this, the effect of rapid heating on subsequent low-temperature mechanochemical reactions has yet to be examined. Here, we investigate H2, H2O2, and Fe production during low-temperature (0 °C) incubations of water with a range of ground rocks and minerals following “flash heating” to 30, 60, or 121 °C. We show that transient increases (as little as 5–10 min of heating) to moderate temperatures (30 or 60 °C) can significantly increase the rate of H2 production, while short-term heating to 121 °C generates larger bursts of H2. In addition, pyrite is easily crushed, potentially releasing large quantities of Fe2+ into subglacial systems and promoting mechanochemical reactions due to the resulting large surface area (10× larger than other materials). We provide the first evidence for H2 production from water reactions with crushed pyrite and suggest that crushed pyrite has a greater influence on subglacial H2O2 production than silicates. We conclude that electron donors in the form of Fe2+ and H2 bursts can be produced in subglacial ecosystems, which may be coupled to substantial concentrations of H2O2 produced from crushed pyrite. This suggests that rock–water mechanochemical reactions may be a greater source of energy for subglacial environments than previously recognised

Education and National Development

The New England Regional Meeting of the Comparative and International Education Society was held on the campus of Springfield College on April 29, 1977. The Conference was co-sponsored by the Division of Community Education, Springfield College, and the Center for International Education, University of Massachusetts. The theme of the conference was Education and National Development. The papers delivered ranged in topics from a global perspective to the use of ethnic and multicultural education to assist in national development. Case studies of specific cultural areas highlight the conference. The papers provided a format for discussing and recording the experiences and research endeavors of the participants. A total of fourteen papers were delivered. This publication contains the papers delivered at the Conference

Impact of left ventricular ejection fraction on clinical outcomes after left main coronary artery revascularization

Aim: To evaluate the impact of left ventricular ejection fraction (LVEF) on 3-year outcomes in patients with left main coronary artery disease (LMCAD) undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in the EXCEL trial. Methods and results: The EXCEL trial randomized patients with LMCAD to PCI with everolimus-eluting stents (n = 948) or CABG (n = 957). Among 1804 patients with known baseline LVEF, 74 (4.1%) had LVEF <40% [heart failure with reduced ejection fraction (HFrEF)], 152 (8.4%) LVEF 40–49% [heart failure with mid-range ejection fraction (HFmrEF)] and 1578 (87.5%) LVEF ≥50% (heart failure with preserved ejection fraction). Patients with HFrEF vs. HFmrEF vs. preserved LVEF experienced a longer postoperative hospital stay (9.0 vs. 7.0 vs. 6.0 days, P = 0.02) with greater peri-procedural complications after CABG, while hospital stay after PCI was unaffected by LVEF (1.5 vs. 2.0 vs. 1.0 days, P = 0.20). The composite primary endpoint of death, stroke, or myocardial infarction at 3 years was 29.3% (PCI) vs. 27.6% (CABG) in patients with HFrEF, 16.2% vs. 15.0% in patients with HFmrEF, and 14.5% vs. 14.6% in those with preserved LVEF, respectively (Pinteraction = 0.90). Smoothing spline analysis demonstrated that the 3-year risk of all-cause death increased when LVEF decreased, both in patients undergoing CABG and PCI. Conclusion: In the EXCEL trial, the composite rate of death, stroke or myocardial infarction at 3 years was significantly higher in patients with HFrEF compared with HFmrEF or preserved LVEF, driven by an increased rate of all-cause death. No significant differences after PCI vs. CABG were observed among patients with HFrEF, HFmrEF and preserved LVEF. Longer-term follow-up could provide important insights on differences in clinical outcomes that might emerge over time. Clinical Trial Registration: ClinicalTrials.gov ID NCT01205776

Topographic variation in soil erosion and accumulation determined with meteoric ¹⁰Be:Soil erosion and accumulation determined with meteoric 10Be

Understanding natural soil redistribution processes is essential for measuring the anthropogenic impact on landscapes. Although meteoric beryllium-10 (10Be) has been used to determine erosion processes within the Pleistocene and Holocene, fewer studies have used the isotope to investigate the transport and accumulation of the resulting sediment. Here we use meteoric 10Be in hilltop and valley site soil profiles to determine sediment erosion and deposition processes in the Christina River Basin (Pennsylvania, USA). The data indicate natural erosion rates of 14 to 21 mm 10−3yr and soil ages of 26 000 to 57 000 years in hilltop sites. Furthermore, valley sites indicate an alteration in sediment supply due to climate change (from the Pleistocene to the Holocene) within the last 60 000 years and sediment deposition of at least 0.5-2 m during the Wisconsinan glaciation. The change in soil erosion rate was most likely induced by changes in geomorphic processes; probably solifluction and slope wash during the cold period, when ice advanced into the mid latitudes of North America. This study shows the value of using meteoric10Be to determine sediment accumulation within the Quaternary and quantifies major soil redistribution occurred under natural conditions in this region

The mating-specific Gα interacts with a kinesin-14 and regulates pheromone-induced nuclear migration in budding yeast

As a budding yeast cell elongates toward its mating partner, cytoplasmic microtubules connect the nucleus to the cell cortex at the growth tip. The Kar3 kinesin-like motor protein is then thought to stimulate plus-end depolymerization of these microtubules, thus drawing the nucleus closer to the site where cell fusion and karyogamy will occur. Here, we show that pheromone stimulates a microtubule-independent interaction between Kar3 and the mating-specific Gα protein Gpa1 and that Gpa1 affects both microtubule orientation and cortical contact. The membrane localization of Gpa1 was found to polarize early in the mating response, at about the same time that the microtubules begin to attach to the incipient growth site. In the absence of Gpa1, microtubules lose contact with the cortex upon shrinking and Kar3 is improperly localized, suggesting that Gpa1 is a cortical anchor for Kar3. We infer that Gpa1 serves as a positional determinant for Kar3-bound microtubule plus ends during mating. © 2009 by The American Society for Cell Biology