Flux footprint models are often used for interpretation of flux tower measurements, to estimate position and size of surface source areas, and the relative contribution of passive scalar sources to ...measured fluxes. Accurate knowledge of footprints is of crucial importance for any upscaling exercises from single site flux measurements to local or regional scale. Hence, footprint models are ultimately also of considerable importance for improved greenhouse gas budgeting. With increasing numbers of flux towers within large monitoring networks such as FluxNet, ICOS (Integrated Carbon Observation System), NEON (National Ecological Observatory Network), or AmeriFlux, and with increasing temporal range of observations from such towers (of the order of decades) and availability of airborne flux measurements, there has been an increasing demand for reliable footprint estimation. Even though several sophisticated footprint models have been developed in recent years, most are still not suitable for application to long time series, due to their high computational demands. Existing fast footprint models, on the other hand, are based on surface layer theory and hence are of restricted validity for real-case applications. To remedy such shortcomings, we present the two-dimensional parameterisation for Flux Footprint Prediction (FFP), based on a novel scaling approach for the crosswind distribution of the flux footprint and on an improved version of the footprint parameterisation of Kljun et al. (2004b). Compared to the latter, FFP now provides not only the extent but also the width and shape of footprint estimates, and explicit consideration of the effects of the surface roughness length. The footprint parameterisation has been developed and evaluated using simulations of the backward Lagrangian stochastic particle dispersion model LPDM-B (Kljun et al., 2002). Like LPDM-B, the parameterisation is valid for a broad range of boundary layer conditions and measurement heights over the entire planetary boundary layer. Thus, it can provide footprint estimates for a wide range of real-case applications. The new footprint parameterisation requires input that can be easily determined from, for example, flux tower measurements or airborne flux data. FFP can be applied to data of long-term monitoring programmes as well as be used for quick footprint estimates in the field, or for designing new sites.
EAU Guidelines on Prostate Cancer Aus, G.; Abbou, C.C.; Bolla, M. ...
European urology,
10/2005, Letnik:
48, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The first summary of the European Association of Urology (EAU) guidelines on prostate cancer was published in 2001. These guidelines have been continuously updated since many important changes ...affecting the clinical management of patients with prostate cancer have occurred over the past years. The aim of this paper is to present a summary of the 2005 update of the EAU guidelines on prostate cancer.
A literature review of the new data has been performed by the working panel. The guidelines have been updated and level of evidence/grade of recommendation added to the text. This enables readers to better understand the quality of the data forming the basis of the recommendations.
A full version is available at the EAU Office or at
www.uroweb.org. Systemic prostate biopsies under ultrasound guidance is the preferred diagnostic method and the use of periprostatic injection of a local anaesthetic can significantly reduce pain/discomfort associated with the procedure. Active treatment (surgery or radiation) is mostly recommended for patients with localized disease and a long life expectancy with radical prostatectomy being the only treatment evaluated in a randomized controlled trial. Follow-up is at large based on prostate specific antigen (PSA) and a disease-specific history with imaging only indicated when symptoms occur. Cytotoxic therapy has become an option for selected patients with hormone refractory prostate cancer.
The knowledge in the field of prostate cancer is rapidly changing. These EAU guidelines on prostate cancer summarize the most recent findings and put them into clinical practice.
► Sky conditions impact on diffuse light and gross primary production. ► Positive linear relation between diffuse fraction and effective quantum efficiency. ► Trade-off between efficiency and ...magnitude of light available for photosynthesis. ► Annual GPP response positive to aerosols, negative to optically thick clouds.
The role of different sky conditions on diffuse PAR fraction (
ϕ), air temperature (
T
a
), vapor pressure deficit (vpd) and GPP in a deciduous forest is investigated using eddy covariance observations of CO
2 fluxes and radiometer and ceilometer observations of sky and PAR conditions on hourly and growing season timescales. Maximum GPP response occurred under moderate to high PAR and
ϕ and low vpd. Light response models using a rectangular hyperbola showed a positive linear relation between
ϕ and effective quantum efficiency (
α
=
0.023
ϕ
+
0.012,
r
2
=
0.994). Since PAR and
ϕ are negatively correlated, there is a tradeoff between the greater use efficiency of diffuse light and lower vpd and the associated decrease in total PAR available for photosynthesis. To a lesser extent, light response was also modified by vpd and
T
a
. The net effect of these and their relation with sky conditions helped enhance light response under sky conditions that produced higher
ϕ. Six sky conditions were classified from cloud frequency and
ϕ data: optically thick clouds, optically thin clouds, mixed sky (partial clouds within hour), high, medium and low optical aerosol. The frequency and light responses of each sky condition for the growing season were used to predict the role of changing sky conditions on annual GPP. The net effect of increasing frequency of thick clouds is to decrease GPP, changing low aerosol conditions has negligible effect. Increases in the other sky conditions all lead to gains in GPP. Sky conditions that enhance intermediate levels of
ϕ, such as thin or scattered clouds or higher aerosol concentrations from volcanic eruptions or anthropogenic emissions, will have a positive outcome on annual GPP, while an increase in cloud cover will have a negative impact. Due to the
ϕ/PAR tradeoff and since GPP response to changes in individual sky conditions differ in sign and magnitude, the net response of ecosystem GPP to future sky conditions is non-linear and tends toward moderation of change.
This study compares the CO2 exchange of a natural bog forest, and of a bog drained for forestry in the pre-Alpine region of southern Germany. The sites are separated by only 10 km, they share the ...same soil formation history and are exposed to the same climate and weather conditions. In contrast, they differ in land use history: at the Schechenfilz site a natural bog-pine forest (Pinus mugo ssp. rotundata) grows on an undisturbed, about 5 m thick peat layer; at Mooseurach a planted spruce forest (Picea abies) grows on drained and degraded peat (3.4 m). The net ecosystem exchange of CO2 (NEE) at both sites has been investigated for 2 years (July 2010–June 2012), using the eddy covariance technique. Our results indicate that the drained, forested bog at Mooseurach is a much stronger carbon dioxide sink (−130 ± 31 and −300 ± 66 g C m−2 a−1 in the first and second year, respectively) than the natural bog forest at Schechenfilz (−53 ± 28 and −73 ± 38 g C m−2 a−1). The strong net CO2 uptake can be explained by the high gross primary productivity of the 44-year old spruces that over-compensates the two-times stronger ecosystem respiration at the drained site. The larger productivity of the spruces can be clearly attributed to the larger plant area index (PAI) of the spruce site. However, even though current flux measurements indicate strong CO2 uptake of the drained spruce forest, the site is a strong net CO2 source when the whole life-cycle since forest planting is considered. It is important to access this result in terms of the long-term biome balance. To do so, we used historical data to estimate the difference between carbon fixation by the spruces and the carbon loss from the peat due to drainage since forest planting. This rough estimate indicates a strong carbon release of +134 t C ha−1 within the last 44 years. Thus, the spruces would need to grow for another 100 years at about the current rate, to compensate the potential peat loss of the former years. In contrast, the natural bog-pine ecosystem has likely been a small but stable carbon sink for decades, which our results suggest is very robust regarding short-term changes of environmental factors.
Purpose
To establish whether bipolar transurethral resection of tumours (bTURB) on the lateral bladder wall is superior to monopolar transurethral resection (mTURB) of such tumours. To our knowledge, ...this is the first prospective randomised study, which defines complete resection depending on obturator jerk as primary endpoint.
Methods
In a prospective, randomised, single centre study, 52 patients with newly diagnosed or recurrent bladder tumour on the lateral bladder wall were enrolled and randomised to undergo mTURB or bTURB; 44 patients were eligible for analysis, of whom 21 underwent mTURB and 23 bTURB. Any differences between the two techniques related to the incidence of unwanted stimulation of the obturator nerve and subsequent adductor spasms were evaluated. All procedures were carried out under laryngeal mask anaesthesia without obturator nerve block (ONB) and without drug-induced relaxation.
Results
Baseline characteristics of the two study groups did not differ statistically significantly. The success rate defined as complete resection of the bladder tumour without any clinically relevant adductor spasm was 61.9% in the monopolar group and 82.6% in the bipolar group (
p
= 0.18).
Conclusions
Complete, undisturbed resection of tumours of the lateral bladder wall is feasible with mTURB and bTURB. Adductor spasms due to obturator jerk can occur suddenly with the risk of bladder perforation. We therefore support ONB when using spinal anaesthesia and drug-induced relaxation when using general anaesthesia when performing TURB on the lateral bladder wall.
Flux footprint functions estimate the location and relative importance of passive scalar sources influencing flux measurements at a given receptor height. These footprint estimates strongly vary in ...size, depending on receptor height, atmospheric stability, and surface roughness. Reliable footprint calculations from, e.g., Lagrangian stochastic models or large-eddy simulations are computationally expensive and cannot readily be computed for long-term observational programs. To facilitate more accessible footprint estimates, a scaling procedure is introduced for flux footprint functions over a range of stratifications from convective to stable, and receptor heights ranging from near the surface to the middle of the boundary layer. It is shown that, when applying this scaling procedure, footprint estimates collapse to an ensemble of similar curves. A simple parameterisation for the scaled footprint estimates is presented. This parameterisation accounts for the influence of the roughness length on the footprint and allows for a quick but precise algebraic footprint estimation.
The footprint of a turbulent flux measurement defines its spatial context. With the onset of long-term flux measurement sites over forests and other inherently inhomogeneous areas, and the ...development of the FLUXNET program, the need for flux footprint estimations has grown dramatically. This paper provides an overview of existing footprint modeling approaches in the critical light of hindsight and discusses their respective strengths and weaknesses. The second main objective of this paper is to establish a formal connection between micrometeorological measurements of scalar fluxes and their mass conservation equation, in a surface–vegetation–atmosphere volume. An important focus is to identify the limitations of the footprint concept and to point out situations where the application of footprint models may lead to erroneous conclusions, as much as to demonstrate its utility and power where warranted. Finally, a perspective on the current state-of-the-art of footprint modeling is offered, with a list of challenges and suggestions for future directions.
The availability of nitrogen represents a key constraint on carbon cycling in terrestrial ecosystems, and it is largely in this capacity that the role of N in the Earth's climate system has been ...considered. Despite this, few studies have included continuous variation in plant N status as a driver of broad-scale carbon cycle analyses. This is partly because of uncertainties in how leaf-level physiological relationships scale to whole ecosystems and because methods for regional to continental detection of plant N concentrations have yet to be developed. Here, we show that ecosystem CO₂ uptake capacity in temperate and boreal forests scales directly with whole-canopy N concentrations, mirroring a leaf-level trend that has been observed for woody plants worldwide. We further show that both CO₂ uptake capacity and canopy N concentration are strongly and positively correlated with shortwave surface albedo. These results suggest that N plays an additional, and overlooked, role in the climate system via its influence on vegetation reflectivity and shortwave surface energy exchange. We also demonstrate that much of the spatial variation in canopy N can be detected by using broad-band satellite sensors, offering a means through which these findings can be applied toward improved application of coupled carbon cycle-climate models.
We measured annual C storage, or net ecosystem production (NEP), from 1999 to 2003 in an aspen-dominated, mixed-deciduous forest in Michigan, USA. Measurements of the annual production of above- and ...below-ground live and dead mass, foliar herbivory, and soil respiration were used to develop biometric estimates of NEP (NEP
B). Eddy-covariance measurements made above the canopy were used to construct meteorological estimates of NEP (NEP
M). Over the 5-year study period, C stored annually in live mass (above- and below-ground wood) averaged 2.13
Mg
C
ha
−1
year
−1, while annual detritus production (fine roots, leaf litter, woody debris) averaged 4.35
Mg
C
ha
−1
year
−1. Fine root inputs were the largest component (41%) of annual net primary production.
The forest was a consistent C sink, with annual NEP ranging from 0.80 to 1.98
Mg
C
ha
−1
year
−1, comparable in magnitude to other eastern North American forests. When annual NEP
B and NEP
M were compared in a given year, they differed from each other by 13–148%. However, when compared over 5 years, these independent estimates of C storage converged to within 1% of each other. Differences between same-year biometric and meteorological NEP estimates were explained in part by a lag between late-season net canopy photosynthesis and C allocated to tree growth the following spring. Weekly assessments of bole radial growth in 2001 and 2002 indicated that woody mass growth began prior to positive net canopy photosynthesis in the spring and that >25% of annual photosynthetic C assimilation occurred after growth had stopped in the autumn. Thus, while the temporal separation between photosynthesis and growth reduced agreement between annual NEP
B and NEP
M estimates, these metrics converged over several years. These results suggest that the allocation of recent photosynthate to storage carbohydrates, rather than to immediate growth, may obscure the relationship between shorter term, annual biometric and meteorological C storage estimates. Moreover, the 5-year convergence of biometric and meteorological NEP estimates serves as an important cross-validation, demonstrating that both approaches can yield accurate forest C storage assessments.
Summary
Montane grasslands of Central Europe are expected to be exposed to strong warming and to altered precipitation patterns, suggesting that biosphere–atmosphere–hydrosphere exchange of carbon ...(C) and nitrogen (N) compounds may be vulnerable to future climatic conditions. By transferring small lysimeters along an altitudinal gradient, we assessed the impact of climate change conditions on soil–atmosphere exchange of methane (CH4) and nitrous oxide (N2O) as well as on ammonium (NH4+) and nitrate (NO3−) in soil water in extensively managed montane grassland in southern Germany. Lysimeter transfer to lower altitude increased air and soil temperatures by more than 2°C and reduced summer precipitation as well as soil moisture throughout the year compared with a control transfer within the high altitude site. This simulation of climate change conditions almost doubled the CH4 sink strength from −0.11 to −0.19 g C m−2 year−1, which appeared to be mainly related to improved gas diffusion after reduced soil moisture. Mean NH4+ and NO3− concentrations in soil water (0.05 mg NH4+–N l−1 and 0.08 mg NO3−–N l−1) and N2O emissions (approximately 0.03 g N m−2 year−1) remained small and unaffected by climate change simulation. Our study suggests that expected climate change conditions will have positive effects on the non‐CO2 greenhouse gas balance in extensively managed montane grassland because of increased net CH4 uptake in soil. For N2O emission, we conclude that potential effects of management changes may override the small effects of simulated climate change on N2O emissions observed in this study.
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