Optimizing a dynamic fossil fuel CO2 emission model with CTDAS (CarbonTracker Data Assimilation Shell, v1.0) for an urban area using atmospheric observations of CO2, CO, NOx, and SO2

We present a modelling framework for fossil fuel CO2 emissions in an urban environment, which allows constraints from emission inventories to be combined with atmospheric observations of CO2 and its co-emitted species CO, NOx , and SO2. Rather than a static assignment of average emission rates to each unit area of the urban domain, the fossil fuel emissions we use are dynamic: they vary in time and space in relation to data that describe or approximate the activity within a sector, such as traffic density, power demand, 2m temperature (as proxy for heating demand), and sunlight and wind speed (as proxies for renewable energy supply). Through inverse modelling, we optimize the relationships between these activity data and the resulting emissions of all species within the dynamic fossil fuel emission model, based on atmospheric mole fraction observations. The advantage of this novel approach is that the optimized parameters (emission factors and emission ratios, N D 44) in this dynamic emission model (a) vary much less over space and time, (b) allow for a physical interpretation of mean and uncertainty, and (c) have better defined uncertainties and covariance structure. This makes them more suited to extrapolate, optimize, and interpret than the gridded emissions themselves. The merits of this approach are investigated using a pseudo-observation-based ensemble Kalman filter inversion set-up for the Dutch Rijnmond area at 1km-1km resolution. We find that the fossil fuel emission model approximates the gridded emissions well (annual mean differences < 2 %, hourly temporal r2 D 0:21-0.95), while reported errors in the underlying parameters allow a full covariance structure to be created readily. Propagating this error structure into atmospheric mole fractions shows a strong dominance of a few large sectors and a few dominant uncertainties, most notably the emission ratios of the various gases considered. If the prior emission ratios are either sufficiently well-known or well constrained from a dense observation network, we find that including observations of co-emitted species improves our ability to estimate emissions per sector relative to using CO2 mole fractions only. Nevertheless, the total CO2 emissions can be well constrained with CO2 as the only tracer in the inversion. Because some sectors are sampled only sparsely over a day, we find that propagating solutions from day-to-day leads to largest uncertainty reduction and smallest CO2 residuals over the 14 consecutive days considered. Although we can technically estimate the temporal distribution of some emission categories like shipping separate from their total magnitude, the controlling parameters are difficult to distinguish. Overall, we conclude that our new system looks promising for application in verification studies, provided that reliable urban atmospheric transport fields and reasonable a priori emission ratios for CO2 and its co-emitted species can be produced

Angiotensin administration stimulates renal 11β-hydroxysteroid dehydrogenase activity in healthy men

Angiotensin administration stimulates renal 11β-hydroxysteroid dehydrogenase activity in healthy men.BackgroundWe examined whether acute administration of angiotensin modulates the activity of 11β-hydroxysteroid dehydrogenase (11βHSD), the intracellular enzyme catalyzing the interconversion between the hormonally active cortisol and inactive cortisone.MethodsTwenty-one male healthy subjects were examined after 1week of a low- and high-salt diet (50 and 200mmol/day, respectively). Separate infusions of angiotensin I (Ang I) and II (Ang II) were administered, both at rates of 4 and 8ng/kg/min. The ratios of tetrahydrocortisol + allotetrahydrocortisol/tetrahydrocortisone (THF + allo-THF/THE) and of free cortisol/free cortisone (UFF/UFE) in urine were measured as indices of overall 11βHSD set point and activity of renal 11βHSD type 2, respectively. Glomerular filtration rate (GFR) was measured by constant infusion of 125I-iothalamate.ResultsAng I and Ang II infusion dose-dependently increased mean arterial blood pressure (MAP) and plasma aldosterone, and decreased plasma renin activity (PRA) and GFR at both diets. Ang I and Ang II infusion resulted in a dose-dependent decrease in the excretion of UFF, UFE, and of the UFF/UFE ratio at both diets, without changing the urinary (THF + allo-THF)/THE ratio. Salt restriction did not affect these 11βHSD variables, but was accompanied by a decrease in UFF and UFE excretion.ConclusionThis study suggests that acute angiotensin administration stimulates the activity of 11βHSD type 2 in human kidney. Angiotensin might therefore exert a dual effect on the mineralocorticoid receptor (i.e., an indirect agonistic effect by increasing aldosterone availability and a direct or indirect antagonistic effect by stimulation of renal 11βHSD type 2 activity)

The acceptance and voice quality of a new voice prosthesis ‘Vega High performance’:a feasibility study

Background: The Provox Vega High Performance (PVHP) is a newly developed voice prosthesis (VP) with an aim to achieve a longer and more predictable lifetime.Objectives: This feasibility study aims to assess patient acceptance of the PVHP VP, evaluate adverse events, voice quality, and device lifetime. Methods: Laryngectomized patients previously using a Provox Vega or ActiValve Light were included. Acceptance and voice outcomes were evaluated at two-time points with a 2-week interval. Baseline measurements were taken with the standard VP, followed by placement of the PVHP for the 2-week assessment. Results: Fifteen participants completed the study, with thirteen being initial Vega-users. PVHP acceptance was 87% 2 weeks after placement. Median device lifetime for all VPs was 64 d (range 14–370). In the subgroup without periprosthetic leakage, the median device lifetime was 101 d (range 31–370). Acceptance dropped to 40% after device failure. Voice quality did not differ between PVHP and baseline VP. The most reported adverse event was PVHP valve stickiness (46%). Conclusion and significance: Acceptance of the PVHP is largely dependent on device lifetime, decreasing from 87% to 40% after leakage or replacement. Voice quality remains consistent across different VPs. Developing a long-lasting VP remains a challenge.</p

The acceptance and voice quality of a new voice prosthesis ‘Vega High performance’:a feasibility study

Background: The Provox Vega High Performance (PVHP) is a newly developed voice prosthesis (VP) with an aim to achieve a longer and more predictable lifetime.Objectives: This feasibility study aims to assess patient acceptance of the PVHP VP, evaluate adverse events, voice quality, and device lifetime. Methods: Laryngectomized patients previously using a Provox Vega or ActiValve Light were included. Acceptance and voice outcomes were evaluated at two-time points with a 2-week interval. Baseline measurements were taken with the standard VP, followed by placement of the PVHP for the 2-week assessment. Results: Fifteen participants completed the study, with thirteen being initial Vega-users. PVHP acceptance was 87% 2 weeks after placement. Median device lifetime for all VPs was 64 d (range 14–370). In the subgroup without periprosthetic leakage, the median device lifetime was 101 d (range 31–370). Acceptance dropped to 40% after device failure. Voice quality did not differ between PVHP and baseline VP. The most reported adverse event was PVHP valve stickiness (46%). Conclusion and significance: Acceptance of the PVHP is largely dependent on device lifetime, decreasing from 87% to 40% after leakage or replacement. Voice quality remains consistent across different VPs. Developing a long-lasting VP remains a challenge.</p

The acceptance and voice quality of a new voice prosthesis ‘Vega High performance’:a feasibility study

Background: The Provox Vega High Performance (PVHP) is a newly developed voice prosthesis (VP) with an aim to achieve a longer and more predictable lifetime.Objectives: This feasibility study aims to assess patient acceptance of the PVHP VP, evaluate adverse events, voice quality, and device lifetime. Methods: Laryngectomized patients previously using a Provox Vega or ActiValve Light were included. Acceptance and voice outcomes were evaluated at two-time points with a 2-week interval. Baseline measurements were taken with the standard VP, followed by placement of the PVHP for the 2-week assessment. Results: Fifteen participants completed the study, with thirteen being initial Vega-users. PVHP acceptance was 87% 2 weeks after placement. Median device lifetime for all VPs was 64 d (range 14–370). In the subgroup without periprosthetic leakage, the median device lifetime was 101 d (range 31–370). Acceptance dropped to 40% after device failure. Voice quality did not differ between PVHP and baseline VP. The most reported adverse event was PVHP valve stickiness (46%). Conclusion and significance: Acceptance of the PVHP is largely dependent on device lifetime, decreasing from 87% to 40% after leakage or replacement. Voice quality remains consistent across different VPs. Developing a long-lasting VP remains a challenge.</p

The acceptance and voice quality of a new voice prosthesis ‘Vega High performance’:a feasibility study

Background: The Provox Vega High Performance (PVHP) is a newly developed voice prosthesis (VP) with an aim to achieve a longer and more predictable lifetime.Objectives: This feasibility study aims to assess patient acceptance of the PVHP VP, evaluate adverse events, voice quality, and device lifetime. Methods: Laryngectomized patients previously using a Provox Vega or ActiValve Light were included. Acceptance and voice outcomes were evaluated at two-time points with a 2-week interval. Baseline measurements were taken with the standard VP, followed by placement of the PVHP for the 2-week assessment. Results: Fifteen participants completed the study, with thirteen being initial Vega-users. PVHP acceptance was 87% 2 weeks after placement. Median device lifetime for all VPs was 64 d (range 14–370). In the subgroup without periprosthetic leakage, the median device lifetime was 101 d (range 31–370). Acceptance dropped to 40% after device failure. Voice quality did not differ between PVHP and baseline VP. The most reported adverse event was PVHP valve stickiness (46%). Conclusion and significance: Acceptance of the PVHP is largely dependent on device lifetime, decreasing from 87% to 40% after leakage or replacement. Voice quality remains consistent across different VPs. Developing a long-lasting VP remains a challenge.</p

The combined effect of elevation and meteorology on potato crop dynamics : a 10-year study in the Gamo Highlands, Ethiopia

Potato (Solanum tuberosum L.) is an important crop in the Gamo Highlands in Ethiopia. The region is characterised by a complex topography with large inter-annual weather variations, where potatoes grow in a range of altitudes between 1,600 and 3,200 m above sea level (a.s.l.). Traditional large-scale crop modelling studies only crudely represent the effect of complex topography, misrepresenting spatial variability in meteorology and potato growth in the region. Here, we investigate how weather influenced by topography affects crop growth. We used the Weather Research and Forecasting (WRF) model to simulate weather in relation to topography in coarse (54 km × 54 km) and fine (2 km × 2 km) resolution domains. The first has a resolution similar to those used by large-scale crop modelling studies that only crudely resolve the horizontal and vertical spatial effects of topography. The second realistically represents the most important topographical variations. The weather variables modelled in both the coarse and fine resolution domains are given as input to the GECROS model (Genotype-by-Environment interaction on CROp growth Simulator) to simulate the potato growth. We modelled potato growth from 2001 to 2010 and studied its inter-annual variability. This enabled us to determine for the first time in Ethiopia how variations in weather are linked to crop dynamics as a function of elevation at a fine resolution. We found that due to its finer representation of topography, weather and crop growth spatio-temporal variations were better represented in the fine than in the coarse resolution domain. The magnitude of crop growth variables such as Leaf Area Index (LAI) and Length of the Growing Season (LGS) obtained with weather from the coarse resolution domain were unrealistically low, hence unacceptable. Nevertheless, the resulting potato yields in the coarse resolution domain were comparable with the yields from the fine resolution domain. We explain this paradoxical finding in terms of a compensating effect, as the opposite effects of temperature and precipitation on yield compensated for each other along the major potato growing transect in the Gamo Highlands. These offsetting effects were also dependent on the correct estimations of the LGS, LAI. We conclude that a well-resolved representation of complex topography is crucial to realistically model meteorology and crop physiology in tropical mountainous areas

Increased water-use efficiency and reduced CO2 uptake by plants during droughts at a continental-scale

Severe droughts in the Northern Hemisphere cause a widespread decline of agricultural yield, the reduction of forest carbon uptake, and increased CO2 growth rates in the atmosphere. Plants respond to droughts by partially closing their stomata to limit their evaporative water loss, at the expense of carbon uptake by photosynthesis. This trade-off maximizes their water-use efficiency (WUE), as measured for many individual plants under laboratory conditions and field experiments. Here we analyse the 13C/12C stable isotope ratio in atmospheric CO2 to provide new observational evidence of the impact of droughts on the WUE across areas of millions of square kilometres and spanning one decade of recent climate variability. We find strong and spatially coherent increases in WUE along with widespread reductions of net carbon uptake over the Northern Hemisphere during severe droughts that affected Europe, Russia and the United States in 2001–2011. The impact of those droughts on WUE and carbon uptake by vegetation is substantially larger than simulated by the land-surface schemes of six state-of-the-art climate models. This suggests that drought-induced carbon–climate feedbacks may be too small in these models and improvements to their vegetation dynamics using stable isotope observations can help to improve their drought response

The CarbonTracker Data Assimilation System for CO2 and delta C-13 (CTDAS-C13 v1.0):retrieving information on land-atmosphere exchange processes

To improve our understanding of the global carbon balance and its representation in terrestrial biosphere models, we present here a first dual-species application of the CarbonTracker Data Assimilation System (CTDAS). The system's modular design allows for assimilating multiple atmospheric trace gases simultaneously to infer exchange fluxes at the Earth surface. In the prototype discussed here, we interpret signals recorded in observed carbon dioxide (CO2) along with observed ratios of its stable isotopologues (CO2)-C-13/(CO2)-C-12 (delta C-13). The latter is in particular a valuable tracer to untangle CO2 exchange from land and oceans. Potentially, it can also be used as a proxy for continent-wide drought stress in plants, largely because the ratio of (CO2)-C-13 and (CO2)-C-12 molecules removed from the atmosphere by plants is dependent on moisture conditions. The dual-species CTDAS system varies the net exchange fluxes of both (CO2)-C-13 and CO2 in ocean and terrestrial biosphere models to create an ensemble of (CO2)-C-13 and CO2 fluxes that propagates through an atmospheric transport model. Based on differences between observed and simulated (CO2)-C-13 and CO2 mole fractions (and thus delta C-13) our Bayesian minimization approach solves for weekly adjustments to both net fluxes and isotopic terrestrial discrimination that minimizes the difference between observed and estimated mole fractions. With this system, we are able to estimate changes in terrestrial delta C-13 exchange on seasonal and continental scales in the Northern Hemisphere where the observational network is most dense. Our results indicate a decrease in stomatal conductance on a continent-wide scale during a severe drought. These changes could only be detected after applying combined atmospheric CO2 and delta C-13 constraints as done in this work. The additional constraints on surface CO2 exchange from delta C-13 observations neither affected the estimated carbon fluxes nor compromised our ability to match observed CO2 variations. The prototype presented here can be of great benefit not only to study the global carbon balance but also to potentially function as a data-driven diagnostic to assess multiple leaf-level exchange parameterizations in carbon-climate models that influence the CO2, water, isotope, and energy balance

Study protocol for a randomized controlled trial : prophylactic swallowing exercises in head-and-neck cancer patients treated with (chemo)radiotherapy (PRESTO trial)

Background: Dysphagia is a common and serious complication after (chemo)radiotherapy (CRT) for head-and-neck cancer (HNC) patients. Prophylactic swallowing exercises (PSE) can have a significantly positive effect on post-treatment swallowing function. However, low adherence rates are a key issue in undermining this positive effect. This current randomized trial will investigate the effect of adherence-improving measures on patients' swallowing function, adherence and quality of life (QOL). Methods: This ongoing trial will explore the difference in adherence and swallowing-related outcome variables during and after PSE in HNC patients performing the same therapy schedule, receiving different delivery methods. One hundred and fifty patients treated in various hospitals will be divided into three groups. Group 1 performs PSE at home, group 2 practices at home with continuous counseling through an app and group 3 receives face-to-face therapy by a speech and language pathologist. The exercises consist of tongue-strengthening exercises and chin-tuck against resistance with effortful swallow. The Iowa Oral Performance Instrument and the Swallowing Exercise Aid are used for practicing. Patients are evaluated before, during and after treatment by means of strength measurements, swallowing and QOL questionnaires. Discussion: Since low adherence rates undermine the positive impact of PSE on post-treatment swallowing function, there is need to develop an efficient PSE protocol maximizing adherence rates