1,193 research outputs found
Extracting Urban Morphology for Atmospheric Modeling from Multispectral and SAR Satellite Imagery
This paper presents an approach designed to derive an urban morphology map from satellite data while aiming to minimize the cost of data and user interference. The approach will help to provide updates to the current morphological databases around the world. The proposed urban morphology maps consist of two layers: 1) Digital Elevation Model (DEM) and 2) land cover map. Sentinel-2 data was used to create a land cover map, which was realized through image classification using optical range indices calculated from image data. For the purpose of atmospheric modeling, the most important classes are water and vegetation areas. The rest of the area includes bare soil and built-up areas among others, and they were merged into one class in the end. The classification result was validated with ground truth data collected both from field measurements and aerial imagery. The overall classification accuracy for the three classes is 91â%. TanDEM-X data was processed into two DEMs with different grid sizes using interferometric SAR processing. The resulting DEM has a RMSE of 3.2 meters compared to a high resolution DEM, which was estimated through 20 control points in flat areas. Comparing the derived DEM with the ground truth DEM from airborne LIDAR data, it can be seen that the street canyons, that are of high importance for urban atmospheric modeling are not detectable in the TanDEM-X DEM. However, the derived DEM is suitable for a class of urban atmospheric models. Based on the numerical modeling needs for regional atmospheric pollutant dispersion studies, the generated files enable the extraction of relevant parametrizations, such as Urban Canopy Parameters (UCP).Peer reviewe
The Structure of Isothermal, Self-gravitating Gas Spheres for Softened Gravity
A theory for the structure of isothermal, self-gravitating gas spheres in
pressure equilibrium in a softened gravitational field is developed. The one
parameter spline softening proposed by Hernquist & Katz (1989) is used. We show
that the addition of this extra scale parameter implies that the set of
equilibrium solutions constitute a one-parameter family, rather than the one
and only one isothermal sphere solution for Newtonian gravity. We demonstrate
the perhaps somewhat surprising result that for any finite choice of softening
length and temperature, it is possible to deposit an arbitrarily large mass of
gas in pressure equilibrium and with a non-singular density distribution inside
of r_0 for any r_0 > 0. The theoretical predictions of our models are compared
with the properties of the small, massive, quasi-isothermal gas clumps which
typically form in numerical Tree-SPH simulations of 'passive' galaxy formation
of Milky Way sized galaxies. We find reasonable agreement despite the neglect
of rotational support in the models. We comment on whether the hydrodynamical
resolution in our numerical simulation of galaxy formation is sufficient, and
finally we conclude that one should be cautious, when comparing results of
numerical simulations involving gravitational softening and hydrodynamical
smoothing, with reality.Comment: 22 pages Latex + 12 figure
Adenine, guanine and pyridine nucleotides in blood during physical exercise and restitution in healthy subjects
Maximal physical exertion is accompanied by increased degradation of purine nucleotides in muscles with the products of purine catabolism accumulating in the plasma. Thanks to membrane transporters, these products remain in an equilibrium between the plasma and red blood cells where they may serve as substrates in salvage reactions, contributing to an increase in the concentrations of purine nucleotides. In this study, we measured the concentrations of adenine nucleotides (ATP, ADP, AMP), inosine nucleotides (IMP), guanine nucleotides (GTP, GDP, GMP), and also pyridine nucleotides (NAD, NADP) in red blood cells immediately after standardized physical effort with increasing intensity, and at the 30th min of rest. We also examined the effect of muscular exercise on adenylate (guanylate) energy chargeâAEC (GEC), and on the concentration of nucleosides (guanosine, inosine, adenosine) and hypoxanthine. We have shown in this study that a standardized physical exercise with increasing intensity leads to an increase in IMP concentration in red blood cells immediately after the exercise, which with a significant increase in Hyp concentration in the blood suggests that Hyp was included in the IMP pool. Restitution is accompanied by an increase in the ATP/ADP and ADP/AMP ratios, which indicates an increase in the phosphorylation of AMP and ADP to ATP. Physical effort applied in this study did not lead to changes in the concentrations of guanine and pyridine nucleotides in red blood cells
Projecting the impacts of the bioeconomy on Nordic land use and freshwater quality and quantity-An overview
This paper synthesizes a five-year project (BIOWATER) that assessed the effects of a developing bioeconomy on Nordic freshwaters. We used a catchment perspective and combined several approaches: comparative analyses of long-term data sets from well-monitored catchments (agricultural, with forestry, and near pristine) across Fennoscandia, catchment biogeochemical modelling and ecosystem services assessment for integration. Various mitigation measures were also studied. Benchmark Shared Socio-economic Pathways were downscaled and articulated in dialogue with national stakeholder representatives leading to five Nordic Bioeconomy Pathways (NBPs) describing plausible but different trajectories of societal development towards 2050.These were then used for catchment modelling and ecosystem service assessment. Key findings from the work synthesized here are: (a) The monitoring results from 69 catchments demonstrate that agricultural lands exported an order of magnitude more nutrients than natural catchments (medians 44 vs 4 kg P km-2 y-1 and 1450 vs 139 kg N km-2 y-1) whilst forests were intermediate (7 kg P km-2 y-1 and 200 kg N km-2 y-1). (b) Our contrasting scenarios led to substantial differences in land use patterns, which affected river flow as well as nutrient loads in two of the four modelled catchments (Danish Odense angstrom and Norwegian Skuterud), but not in two others (Swedish catchment C6 and Finnish Simojoki). (c) Strongly contrasting scenarios (NBP1 maximizing resource circularity versus NBP5 maximizing short-term profit) were found to lead to similar monetary estimates of total societal benefits, though for different underlying reasons - a pattern similar across the six studied Nordic catchments. (d) The ecological status of small to medium sized rivers in agricultural landscapes benefitted greatly from an increase in riparian forest cover from 10 % to 60 %. Riparian buffer strips, constructed wetlands, rewetting of ditched peatlands, and similar nature-based solutions optimize natural biogeochemical processes and thus can help in mitigating negative impacts of intensified biomass removal on water quality
Physical properties and small-scale structure of the Lyman-alpha forest: Inversion of the HE 1122-1628 UVES spectrum
We study the physical properties of the Lyman-alpha forest by applying the
inversion method described by Pichon et al. (2001) to the high resolution and
high S/N ratio spectrum of the z_em=2.40 quasar HE 1122-1628 obtained during
Science Verification of UVES at the VLT. We compare the column densities
obtained with the new fitting procedure with those derived using standard Voigt
profile methods. The agreement is good and gives confidence in the new
description of the Lyman-alpha forest as a continuous field as derived from our
method. We show that the observed number density of lines with logN>13 and 14
is, respectively, 50 and 250 per unit redshift at z~2. We study the physical
state of the gas, neglecting peculiar velocities, assuming a relation between
the overdensity and the temperature. T=Tbar * rho^(2beta). There is an
intrinsic degeneracy between the parameters beta and Tbar. We demonstrate that,
at a fixed beta, the temperature at mean density, Tbar, can be uniquely
extracted however. While applying the method to HE 1122-1628, we conclude that
for 0.2<beta<0.3, 6000<Tbar<15000 K at z~2. We investigate the small scale
structure of strong absorption lines using the information derived from the
Lyman-beta, Lyman-gamma and Civ profiles. Introducing the Lyman-beta line in
the fit allows us to reconstruct the density field up to rho~10 instead of 5
for the Lyman-alpha line only. There may be small velocity shifts ~10km.s^{-1}
between the peaks in the Civ and Hi density profiles. Although the statistics
is small, it seems that Civ/Hi and n_HI are anti-correlated. This could be a
consequence of the high sensitivity of the Civ/Hi ratio to temperature. The
presence of associated Ovi absorption, with similar profile, confirms that the
gas is photo-ionized and at a temperature of T~10^5 K.Comment: 15 pages, 21 figures, accepted for publication in A&A. Quoted results
from other papers in section 4.2 have been modifie
Influence of forest management changes and reuse of peat production areas on water quality in a northern river
In Northern Finland, the most significant land use challenges are related to bioenergy production from peat extraction and forest biomass. Increasing societal demand for bioenergy may increase production rates. However, environmental impacts of peat extraction are of increasing concern, which has led to a decline in production, thereby freeing up these areas for other uses. Using storylines for different societal futures and process-based models (PERSiST and INCA), we simulated the effect of simultaneous land use change and climate change on water quality (phosphorus, nitrogen and suspended sediments concentration). Conversion of peat extraction areas to arable land, together with climate change, may pose a risk for deterioration of ecological status. On the other hand, continuous forestry may have positive impacts on water quality. Suspended sediment concentrations in the river do not exceed water quality requirements for salmonids, but nitrogen concentrations may exceed threshold values especially during high flows. A storyline emphasizing sustainable development in energy pro-duction led to the best outcome in terms of water protection
When fragments link : a bibliometric perspective on the development of fragment-based drug discovery
Fragment-based drug discovery (FBDD) is a highly interdisciplinary field, rich in ideas integrated from pharmaceutical sciences, chemistry, biology, and physics, among others. To enrich our understanding of the development of the field, we used bibliometric techniques to analyze 3642 publications in FBDD, complementing accounts by key practitioners. Mapping its core papers, we found the transfer of knowledge from academia to industry. Co-authorship analysis showed that universityâindustry collaboration has grown over time. Moreover, we show how ideas from other scientific disciplines have been integrated into the FBDD paradigm. Keyword analysis showed that the field is organized into four interconnected practices: library design, fragment screening, computational methods, and optimization. This study highlights the importance of interactions among various individuals and institutions from diverse disciplines in newly emerging scientific fields. We study the organizational aspects of the development of fragment-based drug discovery (FBDD), using tools from bibliometrics
Tracing the Warm Hot Intergalactic Medium in the local Universe
We present a simple method for tracing the spatial distribution and
predicting the physical properties of the Warm-Hot Intergalactic Medium (WHIM),
from the map of galaxy light in the local universe. Under the assumption that
biasing is local and monotonic we map the ~ 2 Mpc/h smoothed density field of
galaxy light into the mass density field from which we infer the spatial
distribution of the WHIM in the local supercluster. Taking into account the
scatter in the WHIM density-temperature and density-metallicity relation,
extracted from the z=0 outputs of high-resolution and large box size
hydro-dynamical cosmological simulations, we are able to quantify the
probability of detecting WHIM signatures in the form of absorption features in
the X-ray spectra, along arbitrary directions in the sky. To illustrate the
usefulness of this semi-analytical method we focus on the WHIM properties in
the Virgo Cluster region.Comment: 16 pages 11 Figures. Discussion clarified, alternative methods
proposed. Results unchanged. MNRAS in pres
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