Climate models suggest that enhanced greenhouse gas concentrations and aerosols have major impacts on the land energy and water cycles, and in particular on evapotranspiration (ET). Here we analyze ...how the main external drivers of ET (incident solar radiation and precipitation) vary regionally, using recent data from a eddy‐covariance flux tower network (FLUXNET) and a multi‐model re‐analysis (GSWP‐2). Trends in radiation (global “dimming” and “brightening”) are expected to impact ET only in regions where ET correlates with radiation. In central Europe this correlation is particularly strong, and trends derived from weighing lysimeters and river‐basin water budgets follow trends in radiation. In central North America the correlation is weak, and trends in precipitation rather than radiation explain trends in ET. Our results reconcile previous hypotheses by demonstrating the strongly regional and temporal differentiation of trends in evaporation.
To study interactions of airborne pathogens, e.g. Aspergillus (A.) fumigatus with upper and lower respiratory tract epithelial and immune cells, we set up a perfused 3D human bronchial and small ...airway epithelial cell system. Culturing of normal human bronchial or small airway epithelial (NHBE, SAE) cells under air liquid interphase (ALI) and perfusion resulted in a significantly accelerated development of the lung epithelia associated with higher ciliogenesis, cilia movement, mucus-production and improved barrier function compared to growth under static conditions. Following the accelerated differentiation under perfusion, epithelial cells were transferred into static conditions and antigen-presenting cells (APCs) added to study their functionality upon infection with A. fumigatus. Fungi were efficiently sensed by apically applied macrophages or basolaterally adhered dendritic cells (DCs), as illustrated by phagocytosis, maturation and migration characteristics. We illustrate here that perfusion greatly improves differentiation of primary epithelial cells in vitro, which enables fast-track addition of primary immune cells and significant shortening of experimental procedures. Additionally, co-cultured primary DCs and macrophages were fully functional and fulfilled their tasks of sensing and sampling fungal pathogens present at the apical surface of epithelial cells, thereby promoting novel possibilities to study airborne infections under conditions mimicking the in vivo situation.
Simulations of climate over the Last Millennium (850-1850 CE) have been incorporated into the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3). The drivers of climate over ...this period are chiefly orbital, solar, volcanic, changes in land use/land cover and some variation in greenhouse gas levels. While some of these effects can be easily defined, the reconstructions of solar, volcanic and land use-related forcing are more uncertain. We describe here the approach taken in defining the scenarios used in PMIP3, document the forcing reconstructions and discuss likely implications.
Ecosystems and the atmosphere: This review describes the state of understanding the processes involved in the exchange of trace gases and aerosols between the earth's surface and the atmosphere. The ...gases covered include NO, NO2, HONO, HNO3, NH3, SO2, DMS, Biogenic VOC, O3, CH4, N2O and particles in the size range 1 nm–10 μm including organic and inorganic chemical species. The main focus of the review is on the exchange between terrestrial ecosystems, both managed and natural and the atmosphere, although some new developments in ocean–atmosphere exchange are included. The material presented is biased towards the last decade, but includes earlier work, where more recent developments are limited or absent.
New methodologies and instrumentation have enabled, if not driven technical advances in measurement. These developments have advanced the process understanding and upscaling of fluxes, especially for particles, VOC and NH3. Examples of these applications include mass spectrometric methods, such as Aerosol Mass Spectrometry (AMS) adapted for field measurement of atmosphere–surface fluxes using micrometeorological methods for chemically resolved aerosols. Also briefly described are some advances in theory and techniques in micrometeorology.
For some of the compounds there have been paradigm shifts in approach and application of both techniques and assessment. These include flux measurements over marine surfaces and urban areas using micrometeorological methods and the up-scaling of flux measurements using aircraft and satellite remote sensing. The application of a flux-based approach in assessment of O3 effects on vegetation at regional scales is an important policy linked development secured through improved quantification of fluxes. The coupling of monitoring, modelling and intensive flux measurement at a continental scale within the NitroEurope network represents a quantum development in the application of research teams to address the underpinning science of reactive nitrogen in the cycling between ecosystems and the atmosphere in Europe.
Some important developments of the science have been applied to assist in addressing policy questions, which have been the main driver of the research agenda, while other developments in understanding have not been applied to their wider field especially in chemistry-transport models through deficiencies in obtaining appropriate data to enable application or inertia within the modelling community. The paper identifies applications, gaps and research questions that have remained intractable at least since 2000 within the specialized sections of the paper, and where possible these have been focussed on research questions for the coming decade.
Purpose: The purpose of this qualitative study was to explore how stroke patients with unilateral spatial neglect experience; (a) performance in activities of daily living; (b) alterations in bodily ...perceptions; and (c) personal hopes and expectations, looking at the period between stroke onset and discharge from inpatient rehabilitation.
Materials and methods: We conducted individual semi-structured interviews with 7 (5 men, 2 women, mean age 69 years) consecutively sampled participants. All interviews were transcribed verbatim and analyzed using thematic analysis.
Findings: Participants' experiences were captured in three over-arching themes: "unawareness of neglect," "emergent awareness for neglect-related difficulties," and "comparing the new life with the old one." Findings showed that participants progressed from initial unawareness to emergent awareness for their neglect-related difficulties over the course of rehabilitation. Comparing their current life situation with the one before their stroke triggered feelings of uncertainty and regret, with associated decreased pleasure in meaningful activities.
Conclusions: This study informs health professionals regarding personal experiences of orientation in and reorganization of life of stroke patients with unilateral spatial neglect. The findings highlight that being aware of neglect-related deficits is a prerequisite for using coping strategies and incorporating them in daily life. Possible therapeutic strategies that fit the current stage of recovery and level of awareness are discussed.
IMPLICATIONS FOR REHABILITATION
Symptoms of unilateral spatial neglect and anosognosia are most common after right hemispheric stroke, both being predictors of poorer functional outcome during rehabilitation.
Patients' regaining some awareness of their impairments is a prerequisite for successful treatment and for engagement in neglect-specific interventions.
Health care providers should carefully examine the "state of awareness" of the patient and adapt their therapeutic approach accordingly.
This check should frequently be repeated over the course of rehabilitation, as awareness changes at different paces for each patient.
The EMEP/EEA guidebook 2009 for agricultural emission inventories reports an average ammonia (NH3) emission factor (EF) by volatilisation of 55% of the applied total ammoniacal nitrogen (TAN) content ...for cattle slurry, and 35% losses for pig slurry, irrespective of the type of surface or slurry characteristics such as dry matter content and pH. In this review article, we compiled over 350 measurements of EFs published between 1991 and 2011. The standard slurry application technique during the early years of this period, when a large number of measurements were made, was spreading by splash plate, and as a result reference EFs given in many European inventories are predominantly based on this technique. However, slurry application practices have evolved since then, while there has also been a shift in measurement techniques and investigated plot sizes. We therefore classified the available measurements according to the flux measurement technique or measurement plot size and year of measurement. Medium size plots (usually circles between 20 to 50 m radius) generally yielded the highest EFs. The most commonly used measurement setups at this scale were based on the Integrated Horizontal Flux method (IHF or the ZINST method (a simplified IHF method)). Several empirical models were published in the years 1993 to 2003 predicting NH3 EFs as a function of meteorology and slurry characteristics (Menzi et al., 1998; Søgaard et al., 2002). More recent measurements show substantially lower EFs which calls for new measurement series in order to validate the various measurement approaches against each other and to derive revised inputs for inclusion into emission inventories.
Methanol is the second most abundant volatile organic compound in the troposphere and plays a significant role in atmospheric chemistry. While there is consensus about the dominant role of living ...plants as the major source and the reaction with OH as the major sink of methanol, global methanol budgets diverge considerably in terms of source/sink estimates reflecting uncertainties in the approaches used to model, and the empirical data used to separately constrain these terms. Here we compiled micrometeorological methanol flux data from eight different study sites and reviewed the corresponding literature in order to provide a first cross-site synthesis of the terrestrial ecosystem-scale methanol exchange and present an independent data-driven view of the land-atmosphere methanol exchange. Our study shows that the controls of plant growth on the production, and thus the methanol emission magnitude, and stomatal conductance on the hourly methanol emission variability, established at the leaf level, hold across sites at the ecosystem-level. Unequivocal evidence for bi-directional methanol exchange at the ecosystem scale is presented. Deposition, which at some sites even exceeds methanol emissions, represents an emerging feature of ecosystem-scale measurements and is likely related to environmental factors favouring the formation of surface wetness. Methanol may adsorb to or dissolve in this surface water and eventually be chemically or biologically removed from it. Management activities in agriculture and forestry are shown to increase local methanol emission by orders of magnitude; they are however neglected at present in global budgets. While contemporary net land methanol budgets are overall consistent with the grand mean of the micrometeorological methanol flux measurements, we caution that the present approach of simulating methanol emission and deposition separately is prone to opposing systematic errors and does not allow taking full advantage of the rich information content of micrometeorological flux measurements.
Introduction It is well known that transcranial direct current stimulation (tDCS) is capable of modulating cortical excitability. However, a source of growing concern has been the observed ...inter-individual variability of tDCS responses, and more recently, the intra-individual variability over repeated expositions. Few studies have investigated the reproducibility of tDCS effects over repeated sessions by assessing whether individuals respond in a predictable manner. The findings of these investigations showed to be inconsistent, and lack control groups to determine whether variability was related to the measuring tool (i.e. TMS). Objective The main objective of this study was to determine inter- and intra-individual variability of anodal tDCS (atDCS) effects on primary motor cortex (M1) excitability when applied over multiple sessions. In addition, we assessed whether tDCS response consistency was dependent on the stimulation parameters (i.e. current intensities). Subjects & methods Twelve subjects participated in a randomized crossover counterbalanced study, in which they received atDCS over M1 in three separate conditions (2 mA, 1 mA, sham) each repeated three times separated by 48 h. tDCS was delivered using a standard montage with the active electrode centered over M1 and the reference over the right supra-orbital area. Motor evoked potentials were recorded before and after stimulation (up to 30 min). Time and day of testing was maintained consistent within participants. To estimate the reliability of tDCS effects across multiple sessions, the Intra-class Correlation Coefficient (ICC) was calculated. Results AtDCS significantly increased cortical excitability at the group level in all sessions, except for the 1 mA condition. The ICC revealed fair to good reliability of tDCS effects. Given the distribution of individual responses showed important variability for the sham condition, we established a cut-off value based on this data to classify responses and to track individual changes across sessions for all conditions. Using this value, an intra-individual consistent response pattern was observed only in the 2 mA condition. Conclusion 2 mA anodal tDCS results in consistent intra- and inter-individual increases of M1 excitability.
Tower CO2 flux measurements from 20 European grasslands in the EUROGRASSFLUX data set covering a wide range of environmental and management conditions were analyzed with respect to their ...ecophysiological characteristics and CO2 exchange (gross primary production, P(g), and ecosystem respiration, R(e)) using light-response function analysis. Photosynthetically active radiation (Q) and top-soil temperature (T(s)) were identified as key factors controlling CO2 exchange between grasslands and the atmosphere at the 30-min scale. A nonrectangular hyperbolic light-response model P(Q) and modified nonrectangular hyperbolic light-temperature-response model P(Q, T(s)) proved to be flexible tools for modeling CO2 exchange in the light. At night, it was not possible to establish robust instantaneous relationships between CO2 evolution rate rn and environmental drivers, though under certain conditions, a significant relationship r(n)=r(0) e(k)T(T)s was found using observation windows 7-14 days wide. Principal light-response parameters--apparent quantum yield, saturated gross photosynthesis, daytime ecosystem respiration, and gross ecological light-use efficiency, epsilon= P(g)/Q, display patterns of seasonal dynamics which can be formalized and used for modeling. Maximums of these parameters were found in intensively managed grasslands of Atlantic climate. Extensively used semi-natural grasslands of southern and central Europe have much lower production, respiration, and light-use efficiency, while temperate and mountain grasslands of central Europe ranged between these two extremes. Parameters from light-temperature-response analysis of tower data are in agreement with values obtained using closed chambers and free-air CO2 enrichment. Correlations between light-response and productivity parameters provides the possibility to use the easier to measure parameters to estimate the parameters that are more difficult to measure. Gross primary production (P(g)) of European grasslands ranges from 1700 g CO2 m-2 year-1 in dry semi-natural pastures to 6900 g CO2 m-2 year-1 in intensively managed Atlantic grasslands. Ecosystem respiration (R(e)) is in the range 1800 < R(e) < 6000 g CO2 m-2 year-1. Annual net ecosystem CO2 exchange (NEE) varies from significant net uptake (>2400 g CO2 m-2 year-1) to significant release (<-600 g CO2 m-2 year-1), though in 15 out of 19 cases grasslands performed as net CO2 sinks. The carbon source was associated with organic rich soils, grazing, and heat stress. Comparison of P(g), R(e), and NEE for tower sites with the same characteristics from previously published papers obtained with other methods did not reveal significant discrepancies. Preliminary results indicate relationships of grassland P(g) and R(e) to macroclimatic factors (precipitation and temperature), but these relationships cannot be reduced to simple monofactorial models.
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