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The Pantanal region of Brazil is the largest seasonally flooded tropical grassland and, according to local chamber measurements, a substantial CH4 source. CH4 emissions from wetlands have recently become of heightened interest because global atmospheric 13CH4 data indicate they may contribute to the resumption of atmospheric CH4 growth since 2007. We have regularly measured vertical atmospheric profiles for 2 years in the center of the Pantanal with the objectives to obtain an estimate of CH4 emissions using an atmospheric approach, and provide information about flux seasonality and its relation to controlling factors. Boundary layer‐free troposphere differences observed in the Pantanal are large compared to other wetlands. Total emissions based on a planetary boundary layer budgeting technique are 2.0–2.8 TgCH4 yr−1 (maximum flux ∼0.4 gCH4 m−2 d−1) while those based on a Bayesian inversion using an atmospheric transport model are ∼3.3 TgCH4 yr−1. Compared to recent estimates for Amazonia (∼41 ± 3 TgCH4 yr−1, maximum flux ∼0.3 gCH4 m−2 d−1) these emissions are not that large. Our Pantanal data suggest a clear flux seasonality with CH4 being released in large amounts just after water levels begin to rise again after minimum levels have been reached. CH4 emissions decline substantially once the maximum water level has been reached. While predictions with prognostic wetland CH4 emission models agree well with the magnitude of the fluxes, they disagree with the phasing. Our approach shows promise for detecting and understanding longer‐term trends in CH4 emissions and the potential for future wetlands CH4 emissions climate feedbacks. Plain Language Summary: CH4 emissions contribute substantially to greenhouse warming and atmospheric concentrations continue to grow rapidly. Increases in emissions from wetlands may contribute. We have measured regularly vertical CH4 concentration profiles over the Pantanal, the largest tropical seasonally flooded grasslands, to provide an estimate of these emissions and to determine seasonal cycle. Our estimates are similar to earlier estimates based on direct flux measurements on the ground. Fluxes vary strongly seasonally. They are largest during the rise of water levels and decrease before maximum levels have been reached. Our data show that longer‐term vertical profile measurements could provide an answer whether wetland emissions are changing. Key Points: Large CH4 boundary layer‐free troposphere differences over Pantanal wetlands revealed by vertical atmospheric CH4 profile dataAccording to atmospheric data, CH4 flux is large during the early expansion phase of the inundated area and weakens at peak extentPrognostic global wetlands CH4 emission models have limited skill regarding seasonality of Pantanal emissions [ABSTRACT FROM AUTHOR]

Abstract: It was suggested in a recent article that sunspots drive decadal variation in Amazon River flow. This conclusion was based on a novel time series decomposition method used to extract a decadal signal from the Amazon River record. We have extended this analysis back in time, using a new hydrological proxy record of tree ring oxygen isotopes (δ18OTR). Consistent with the findings of Antico and Torres, we find a positive correlation between sunspots and the decadal δ18OTR cycle from 1903 to 2012 (r = 0.60, p < 0.001). However, the relationship does not persist into the preceding century and even becomes weakly negative (r = −0.30, p = 0.11, 1799–1902). This result casts considerable doubt over the mechanism by which sunspots are purported to influence Amazon hydrology. [ABSTRACT FROM AUTHOR]

Recent analyses of Amazon runoff and gridded precipitation data suggest an intensification of the hydrological cycle over the past few decades in the following sense: wet season precipitation and peak river runoff (since ∼1980) as well as annual mean precipitation (since ∼1990) have increased, while dry season precipitation and minimum runoff have slightly decreased. There has also been an increase in the frequency of anomalously severe floods and droughts. To provide context for the special issue on Amazonia and its forests in a warming climate we expand here on these analyses. The contrasting recent changes in wet and dry season precipitation have continued and are generally consistent with changes in catchment-level peak and minimum river runoff as well as a positive trend of water vapor inflow into the basin. Consistent with the river records, the increased vapor inflow is concentrated to the wet season. Temperature has been rising by 0.7°C since 1980 with more pronounced warming during dry months. Suggestions for the cause of the observed changes of the hydrological cycle come from patterns in tropical sea surface temperatures (SSTs). Tropical and North Atlantic SSTs have increased rapidly and steadily since 1990, while Pacific SSTs have shifted during the 1990s from a positive Pacific Decadal Oscillation (PDO) phase with warm eastern Pacific temperatures to a negative phase with cold eastern Pacific temperatures. These SST conditions have been shown to be associated with an increase in precipitation over most of the Amazon except the south and southwest. If ongoing changes continue, we expect forests to continue to thrive in those regions where there is an increase in precipitation with the exception of floodplain forests. An increase in flood pulse height and duration could lead to increased mortality at higher levels of the floodplain and, over the long term, to a lateral shift of the zonally stratified floodplain forest communities. Negative effects on forests are mainly expected in the southwest and south, which have become slightly drier and hotter, consistent with tree mortality trends observed at the RAINFOR Amazon forest plot network established in the early 1980s consisting of approximately 150 regularly censused 1ha plots in intact forests located across the whole basin. [ABSTRACT FROM AUTHOR]

Two major droughts in the past decade had large impacts on carbon exchange in the Amazon. Recent analysis of vertical profile measurements of atmospheric CO2 and CO by Gatti et al. (2014) suggests that the 2010 drought turned the normally close-to-neutral annual Amazon carbon balance into a substantial source of nearly 0.5 PgC/yr, revealing a strong drought response. In this study, we revisit this hypothesis and interpret not only the same CO2/CO vertical profile measurements but also additional constraints on carbon exchange such as satellite observations of CO, burned area, and fire hot spots. The results from our CarbonTracker South America data assimilation system suggest that carbon uptake by vegetation was indeed reduced in 2010 but that the magnitude of the decrease strongly depends on the estimated 2010 and 2011 biomass burning emissions. We have used fire products based on burned area (Global Fire Emissions Database version 4), satellite-observed CO columns (Infrared Atmospheric Sounding Interferometer), fire radiative power (Global Fire Assimilation System version 1), and fire hot spots (Fire Inventory from NCAR version 1), and found an increase in biomass burning emissions in 2010 compared to 2011 of 0.16 to 0.24 PgC/yr. We derived a decrease of biospheric uptake ranging from 0.08 to 0.26 PgC/yr, with the range determined from a set of alternative inversions using different biomass burning estimates. Our numerical analysis of the 2010 Amazon drought results in a total reduction of carbon uptake of 0.24 to 0.50 PgC/yr and turns the balance from carbon sink to source. Our findings support the suggestion that the hydrological cycle will be an important driver of future changes in Amazonian carbon exchange. [ABSTRACT FROM AUTHOR]

The article presents research on the variability of magnetization transfer-sensitized balanced steady-state free precession imaging. It relates that a three-dimensional imaging technique for magnetization transfer ratio (MTR) imaging has been proposed using a balanced steady-state free precession protocol with modified radiofrequency pulses. It explains that optimal balanced steady-state free precession MTR protocol parameters were derived for maximum stability and reproducibility. It says that the technique offers variability and reproducibility.

Positive aboveground biomass trends have been reported from old-growth forests across the Amazon basin and hypothesized to reflect a large-scale response to exterior forcing. The result could, however, be an artefact due to a sampling bias induced by the nature of forest growth dynamics. Here, we characterize statistically the disturbance process in Amazon old-growth forests as recorded in 135 forest plots of the RAINFOR network up to 2006, and other independent research programmes, and explore the consequences of sampling artefacts using a data-based stochastic simulator. Over the observed range of annual aboveground biomass losses, standard statistical tests show that the distribution of biomass losses through mortality follow an exponential or near-identical Weibull probability distribution and not a power law as assumed by others. The simulator was parameterized using both an exponential disturbance probability distribution as well as a mixed exponential–power law distribution to account for potential large-scale blowdown events. In both cases, sampling biases turn out to be too small to explain the gains detected by the extended RAINFOR plot network. This result lends further support to the notion that currently observed biomass gains for intact forests across the Amazon are actually occurring over large scales at the current time, presumably as a response to climate change. [ABSTRACT FROM AUTHOR]

It is generally accepted that signal formation in balanced steady-state free precession (bSSFP) is a simple function of relaxation times and flip angle only. This can be confirmed for fluids, but for more complex substances, magnetization transfer (MT) can lead to a considerable loss of steady-state signal. Thus, especially in tissues, the analytical description of bSSFP requires a revision to fully take observed effects into account. In the first part of this work, an extended bSSFP signal equation is derived based on a binary spin-bath model. Based on this new model of bSSFP signal formation, quantitative MT parameters such as the fractional pool size, corresponding magnetization exchange rates, and relaxation times can be explored. In the second part of this work, model parameters are derived in normal appearing human brain. Factors that may influence the quality of the model, such as B1 field inhomogeneities or off-resonances, are discussed. Overall, good correspondence between parameters derived from two-pool bSSFP and common quantitative MT models is observed. Short repetition times in combination with high signal-to-noise ratios make bSSFP an ideal candidate for the acquisition of high resolution isotropic quantitative MT maps, as for the human brain, within clinically feasible acquisition times. Magn Reson Med 60:691-700, 2008. © 2008 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

We use an inverse method to estimate the global-scale pattern of the air-sea flux of natural CO2, i.e., the component of the CO2 flux due to the natural carbon cycle that already existed in preindustrial times, on the basis of ocean interior observations of dissolved inorganic carbon (DIC) and other tracers, from which we estimate ΔCgasex, i.e., the component of the observed DIC that is due to the gas exchange of natural CO2. We employ a suite of 10 different Ocean General Circulation Models (OGCMs) to quantify the error arising from uncertainties in the modeled transport required to link the interior ocean observations to the surface fluxes. The results from the contributing OGCMs are weighted using a model skill score based on a comparison of each model's simulated natural radiocarbon with observations. We find a pattern of air-sea flux of natural CO2 characterized by outgassing in the Southern Ocean between 44°S and 59°S, vigorous uptake at midlatitudes of both hemispheres, and strong outgassing in the tropics. In the Northern Hemisphere and the tropics, the inverse estimates generally agree closely with the natural CO2 flux results from forward simulations of coupled OGCM-biogeochemistry models undertaken as part of the second phase of the Ocean Carbon Model Intercomparison Project (OCMIP-2). The OCMIP-2 simulations find far less air-sea exchange than the inversion south of 20°S, but more recent forward OGCM studies are in better agreement with the inverse estimates in the Southern Hemisphere. The strong source and sink pattern south of 20°S was not apparent in an earlier inversion study, because the choice of region boundaries led to a partial cancellation of the sources and sinks. We show that the inversely estimated flux pattern is clearly traceable to gradients in the observed ΔCgasex, and that it is relatively insensitive to the choice of OGCM or potential biases in ΔCgasex. Our inverse estimates imply a southward interhemispheric transport of 0.31 ± 0.02 Pg C yr-1, most of which occurs in the Atlantic. This is considerably smaller than the 1 Pg C yr-1 of Northern Hemisphere uptake that has been inferred from atmospheric CO2 observations during the 1980s and 1990s, which supports the hypothesis of a Northern Hemisphere terrestrial sink. [ABSTRACT FROM AUTHOR]

Compares skin physiology in children and adults through the use of bioengineering methods. Differences in physiologic parameters of the skin in children and adults; Measurement of cutaneous blood perfusion; Variation in stratum corneum hydration in the outer layers.

Presents information on a study which compared the influence of different moisturizers on skin hydration and mechanics by various non-invasive test methods. Types of oil-in-water emulsions applied during the treatment; Details of measuring methods; Results and discussion.

It was the aim of our studies to estimate predictively the individual eczema risk for persons due to repetitive contact with washing-active substances, by a barrier function test on clinically healthy skin over 2 weeks. Within the scope of the study 3 groups with different atopy scores were compared. As washing solutions, 0.1 m SLS and a slightly acid soap-free washing emulsion were used in comparison to tap water. Prior to the 1st washing procedure, on days 3, 5, 8, 10, and 12, the transepidermal water loss, the horny layer moisture, and the skin blood flow were measured as parameters of barrier function, as well as the inflammatory reaction. The results prove that the atopy score has only limited validity as a predictive method for the acceptance of washing-active substances. The repetitive washing test, however, seems to be more adequate for evaluating the individual barrier function as well as the eczema risk. Irritation by a washing procedure may be greatly influenced by choice of the washing solution. [ABSTRACT FROM AUTHOR]

Damage to the skin following the repeated use of 2 different wash solutions was investigated. Stratum corneum capacitative resistance, stratum corneum lipids, transepidermal water loss, skin surface pH, laser Doppler flow and skin reddening were determined. All skin function parameters already showed a marked change after a single wash (e.g., the median of TEWL values increased by more than 0.5 g/m² h). Repetitive washing for 1 week led to a further deterioration of TEWL and corneometry values (e.g., TEWL increased for about 2.9 g/m² h after repetitive washing with sodium Lauryl sulfate). The rate of skin function regeneration after repetitive washing was unaltered compared to regeneration after a single wash. The surfactants used showed quantitatively differing effects on corneometry, TEWL and laser Doppler flow (e.g., after repetitive washing with Geliderm, the median of TEWL values increased only up to 1.55 g/m² h). However, damage arising from repetitive washing could not be completely prevented by the selection of a mild surfactant. Skin function regeneration showed no difference with the 2 surfactants used. [ABSTRACT FROM AUTHOR]

This article explores the significance of the zein test in the classification of cationic tensides. The corn cob protein zein can be used as an in vitro model for the determination of the proteolytic activity of a test substance. Nitrogen released by protcolysis is the evaluative parameter. The zein test is considered a readily transferable model where irritant effects of anionic tensides on human skin are to be predicted. It is assumed that the irritant potential of anionic tensides depends on the chain length of the substituent.