Quantifying the global volcanic CO2 output from subaerial volcanism is key for a better understanding of rates and mechanisms of carbon cycling in and out of our planet and their consequences for the ...long‐term evolution of Earth's climate over geological timescales. Although having been the focus of intense research since the early 1990s, and in spite of recent progress, the global volcanic CO2 output remains inaccurately known. Here we review past developments and recent progress and examine limits and caveats of our current understanding and challenges for future research. We show that CO2 flux measurements are today only available for ~100 volcanoes (cumulative measured flux, 44 Tg CO2/year), implying that extrapolation is required to account for the emissions of the several hundred degassing volcanoes worldwide. Recent extrapolation attempts converge to indicate that persistent degassing through active crater fumaroles and plumes releases ~53–88 Tg CO2/year, about half of which is released from the 125 most actively degassing subaerial volcanoes (36.4 ± 2.4 Tg CO2/year from strong volcanic gas emitters, Svge). The global CO2 output sustained by diffuse degassing via soils, volcanic lakes, and volcanic aquifers is even less well characterized but could be as high as 83 to 93 Tg CO2/year, rivaling that from the far more manifest crater emissions. Extrapolating these current fluxes to the past geological history of the planet is challenging and will require a new generation of models linking subduction parameters to magma and volatile (CO2) fluxes.
Key Points
Progress in determining subaerial volcanic CO2 flux has been significant
Challenges remain with regard to extrapolations through time and global coverage of measurements and with regard to diffuse tectonic degassing and dynamic nature of volcanic degassing
Volcanic and tectonic contributions are <2% of current anthropogenic contributions
Abstract
The global carbon dioxide (CO
2
) flux from subaerial volcanoes remains poorly quantified, limiting our understanding of the deep carbon cycle during geologic time and in modern Earth. Past ...attempts to extrapolate the global volcanic CO
2
flux have been biased by observations being available for a relatively small number of accessible volcanoes. Here, we propose that the strong, but yet unmeasured, CO
2
emissions from several remote degassing volcanoes worldwide can be predicted using regional/global relationships between the CO
2
/S
T
ratio of volcanic gases and whole-rock trace element compositions (e.g., Ba/La). From these globally linked gas/rock compositions, we predict the CO
2
/S
T
gas ratio of 34 top-degassing remote volcanoes with no available gas measurements. By scaling to volcanic SO
2
fluxes from a global catalogue, we estimate a cumulative “unmeasured” CO
2
output of 11.4 ± 1.1 Mt/yr (or 0.26 ± 0.02·10
12
mol/yr). In combination with the measured CO
2
output of 27.4 ± 3.6 Mt/yr (or 0.62 ± 0.08·10
12
mol/yr), our results constrain the time-averaged (2005–2015) cumulative CO
2
flux from the Earth’s 91 most actively degassing subaerial volcanoes at 38.7 ± 2.9 Mt/yr (or 0.88 ± 0.06·10
12
mol/yr).
Using Fresnel zone plates made with our robust nanofabrication processes, we have successfully achieved 10 nm spatial resolution with soft x-ray microscopy. The result, obtained with both a ...conventional full-field and scanning soft x-ray microscope, marks a significant step forward in extending the microscopy to truly nanoscale studies.
Plasmonic structures can provide deep-subwavelength electromagnetic fields that are useful for enhancing light–matter interactions. However, because these localized modes are also dissipative, ...structures that offer the best compromise between field confinement and loss have been sought. Metallic wedge waveguides were initially identified as an ideal candidate but have been largely abandoned because to date their experimental performance has been limited. We combine state-of-the-art metallic wedges with integrated reflectors and precisely placed colloidal quantum dots (down to the single-emitter level) and demonstrate quantum-plasmonic waveguides and resonators with performance approaching theoretical limits. By exploiting a nearly 10-fold improvement in wedge-plasmon propagation (19 μm at a vacuum wavelength, λvac, of 630 nm), efficient reflectors (93%), and effective coupling (estimated to be >70%) to highly emissive (∼90%) quantum dots, we obtain Ag plasmonic resonators at visible wavelengths with quality factors approaching 200 (3.3 nm line widths). As our structures offer modal volumes down to ∼0.004λvac 3 in an exposed single-mode waveguide–resonator geometry, they provide advantages over both traditional photonic microcavities and localized-plasmonic resonators for enhancing light–matter interactions. Our results confirm the promise of wedges for creating plasmonic devices and for studying coherent quantum-plasmonic effects such as long-distance plasmon-mediated entanglement and strong plasmon–matter coupling.
Decades of intensive agricultural production with excessive application of P fertilizer have resulted in the accumulation of P in soils, threatening water bodies in most industrialized countries with ...eutrophication. In our study, we elucidated the risk of P loss of German agricultural soils by transforming provided monitoring data of plant-available P determined by the calcium-acetate-lactate (PCAL) and double-lactate method (PDL) into the degree of phosphorus saturation (DPS). As water-soluble phosphorus (WSP) is correlated to DPS, we derived a pedotransfer function (PTF) between PCAL and WSP for different soil types. Considering all soils together resulted in WSP=0.1918×PCAL (R2=0.80, n=54). Subsequently, risk parameters DPS and EPC0 were calculated from PCAL and PDL monitoring data (n>337,000) by using the determined PTF and soil type-independent correlations with WSP, as published in an earlier study. Calculated DPS values from monitoring data indicated high risks of dissolved P loss for >76% of German arable soils. Recent suggestions by the Association of German Agricultural Analytical and Research Institutes (VDLUFA) to reduce recommended PCAL levels are crucial for the reduction of P loss risks in the future. The accuracy of predicted DPS and EPC0 values by CAL and other methods used in Europe to estimate plant-available P is limited by the soil type-dependency of these methods. Consequently, we recommend considering WSP as an agri-environmental soil P test across Europe. Our results indicate that a WSP level in soils can be defined that constitutes a reasonable compromise between the securing of agronomic production and the fulfillment of environmental goals.
Display omitted
•Accomplishment of the first DPS risk map for German arable soils•High risks of P losses were derived for 76% of monitoring data (n>337,000).•Hitherto recommended P levels in soils are in conflict with environmental goals.•Recommended reduction of P levels is crucial to lower future risks of P losses.•For future P-monitoring WSP is recommended as agri-environmental soil P test in Europe.
Abstract
Data collection of mechanical parameters from compressive tests play a fundamental role in FE modelling of bone tissues or the developing and designing of bone implants, especially referring ...to osteoporosis or other forms of bone loss. A total of 43 cylindrical samples (Ø8 × 16 mm) were taken from 43 freshly frozen proximal femora using a tenon cutter. All femora underwent BMD measurement and additionally apparent- and relative- and bulk density (ρ
app
, ρ
r
, ρ
b
) were determined using samples bordering the compressive specimen on the proximal and distal regions. All samples were classified as "normal", "osteopenia" and "osteoporosis" based on the DEXA measurements. Distal apparent density was most suitable for predicting bone strength and BMD. One novel aspect is the examination of the plateau stress as it describes the stress at which the failure of spongious bone progresses. No significant differences in mechanical properties (compressive modulus E; compressive stress σ
max
and plateau stress σ
p
) were found between osteopenic and osteoporotic bone. The results suggest that already in the case of a known osteopenia, actions should be taken as they are applied in the case of osteoporosis A review of the literature regarding extraction and testing methods illustrates the urgent need for standardized biomechanical compressive material testing.
Information on the relationship between levels of particulate matter (PM) smaller than 2.5μm and mortality rates in Europe is relatively sparse because of limited availability of PM2.5 measurement ...data. Even less information is available on the health effects attributable to PM2.5–10, especially for North-West Europe.
To investigate the relationship between various PM size fractions and daily mortality rates.
Daily concentrations of PM from the Dutch National Ambient Air Quality Monitoring Network as well as all cause and cause-specific mortality rates in the Netherlands were obtained for the period 2008–2009. Poisson regression analysis using generalized additive models was used, with adjustment for potential confounding including long-term and seasonal trends, influenza incidence, meteorological variables, day of the week, and holidays.
Different measures of PM (PM2.5, PM10 and PM2.5–10) were analysed.
PM10 and PM2.5 levels were statistically significantly (p<0.05) associated with all cause and cause-specific deaths. For example, a 10μg/m3 increase in previous day PM was associated with 0.8% (95% CI 0.3–1.2) excess risk in all cause mortality for PM2.5 and a 0.6% (CI 0.2–1.0) excess risk for PM10. No appreciable associations were observed for PM2.5–10. Effects of PM10, and PM2.5 were insensitive to adjustment for PM2.5–10, and vice-versa. PM10 and PM2.5 were too highly correlated to disentangle their independent effects.
PM10 and PM2.5 both were significantly associated with all cause and cause-specific mortality. We were unable to demonstrate significant effects for PM2.5–10, possibly due to the lower temporal variability and the higher exposure misclassification in PM2.5–10 compared to PM10 or PM2.5. The lack of effects of PM2.5–10 in our study should therefore not be interpreted as an indication that PM2.5–10 can be considered harmless.
•European studies on the effects of PM2.5 on daily mortality are still relatively limited.•For the entire Netherlands (population 16million) significant associations with PM2.5 are found.•Effects of PM2.5 could not be disentangled from effects of PM10 due to their high correlation.•Daily variability in levels in the coarse fraction was found to be low in the Netherlands.
The human genome encompasses some 2,000 proteins that utilize adenosine 5-triphosphate (ATP) in one way or another and some 500 of these are protein-tyrosine and protein-serine / threonine kinases ...(PTKs & PSTKs). Substrate phosphorylation by these enzymes is natures predominant molecular way of organizing cellular signal transduction and regulating biochemical processes in general. It is not surprising, therefore, that abnormal phosphorylation of cellular proteins is a hallmark of disease and that there has been a growing interest in the use of kinase inhibitors as drugs. In fact the search for such agents has recently culminated in the approval of the first kinase inhibitor drugs for medical use. Although it has been demonstrated exhaustively that potent and structurally diverse ATP-antagonistic small molecule kinase inhibitors can be found through mass screening and structure-guided design, the question of biochemical, cellular, and in vivo selectivity of such inhibitors remains much less clear. Here the medicinal chemistry of kinase inhibitors is reviewed critically with particular emphasis on target selectivity and specificity. Approaches based on chemical genomics, combinatorial target-guided ligand as sembly, computational chemistry, and structural biology techniques, which aim at classifying both inhibitors and kinase targets, are given special emphasis. The various strategies in which differences in biochemical mechanism of kinase function can be exploited in order to attain selective inhibition are also discussed. Furthermore, recent developments in the design of inhibitors to selected individual validated therapeutic kinase targets, including cell cycle kinases and receptor PTKs, etc. are summarised.
Statistical methods for identifying adaptive mutations from population genetic data face several obstacles: assessing the significance of genomic outliers, integrating correlated measures of ...selection into one analytic framework, and distinguishing adaptive variants from hitchhiking neutral variants. Here, we introduce SWIF(r), a probabilistic method that detects selective sweeps by learning the distributions of multiple selection statistics under different evolutionary scenarios and calculating the posterior probability of a sweep at each genomic site. SWIF(r) is trained using simulations from a user-specified demographic model and explicitly models the joint distributions of selection statistics, thereby increasing its power to both identify regions undergoing sweeps and localize adaptive mutations. Using array and exome data from 45 ‡Khomani San hunter-gatherers of southern Africa, we identify an enrichment of adaptive signals in genes associated with metabolism and obesity. SWIF(r) provides a transparent probabilistic framework for localizing beneficial mutations that is extensible to a variety of evolutionary scenarios.
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