111 research outputs found
Potential climate change impacts on the water balance of subcatchments of the River Spree, Germany
Lusatia is considered one of the driest regions of Germany. The climatic water balance is negative even under current climate conditions. Due to global climate change, increased temperatures and a shift of precipitation from summer to winter are expected. Therefore, it is of major interest whether the excess water in winter can be stored and to which extent it is used up on increasing evapotranspiration.
Thus, this study focuses on estimating potential climate change impacts on the water balance of two subcatchments of the River Spree using the Soil and Water Integrated Model (SWIM). Climate input was taken from 100 realisations each of two scenarios of the STatistical Analogue Resampling scheme STAR assuming a further temperature increase of 0 K (scenario A) and 2 K by the year 2055 (scenario B) respectively. Resulting from increased temperatures and a shift in precipitation from summer to winter actual evapotranspiration is supposed to increase in winter and early spring, but to decrease in later spring and early summer. This is less pronounced for scenario A than for scenario B. Consequently, also the decrease in discharge and groundwater recharge in late spring is lower for scenario A than for scenario B. The highest differences of runoff generation and groundwater recharge between the two scenarios but also the highest ranges within the scenarios occur in summer and early autumn. It is planned to estimate potential climate change for the catchments of Spree, Schwarze Elster and Lusatian Neisse
Potential climate change impacts on the water balance of subcatchments of the River Spree, Germany
Lusatia is considered one of the driest regions of Germany. The climatic
water balance is negative even under current climate conditions. Due to
global climate change, increased temperatures and a shift of precipitation
from summer to winter are expected. Therefore, it is of major interest
whether the excess water in winter can be stored and to which extent it is
used up on increasing evapotranspiration.
Thus, this study focuses on estimating potential climate change impacts on
the water balance of two subcatchments of the River Spree using the Soil and
Water Integrated Model (SWIM). Climate input was taken from 100 realisations
each of two scenarios of the STatistical Analogue Resampling scheme STAR
assuming a further temperature increase of 0 K (scenario A) and 2 K by the
year 2055 (scenario B) respectively. Resulting from increased temperatures
and a shift in precipitation from summer to winter actual evapotranspiration
is supposed to increase in winter and early spring, but to decrease in later
spring and early summer. This is less pronounced for scenario A than for
scenario B. Consequently, also the decrease in discharge and groundwater
recharge in late spring is lower for scenario A than for scenario B. The
highest differences of runoff generation and groundwater recharge between
the two scenarios but also the highest ranges within the scenarios occur in
summer and early autumn. It is planned to estimate potential climate change
for the catchments of Spree, Schwarze Elster and Lusatian Neisse
Development of a backward-mode photoacoustic microscope using a Fabry-Perot sensor
Optical-resolution photoacoustic microscopy (PAM) has been shown to enable the acquisition of high resolution (μm) functional and anatomical images. For backward-mode operation, conventional piezoelectric ultrasound transducers need to be placed far away from the signal source due to their opacity and size. This can result in reduced acoustic sensitivity. Planar Fabry-Perot polymer film interferometer (FPI) sensors have the potential to overcome this limitation since they are transparent to the excitation wavelength, can be placed immediately adjacent to the signal source for high acoustic sensitivity, and offer a broadband frequency response (0 –50 MHz). In this study, we present a high frame rate, backward-mode OR-PAM system based on a planar FPI ultrasound sensor. A ns-pulsed laser provides excitation pulses (<200 nJ, maximum pulse repetition frequency = 200 kHz, 532 nm) to generate photoacoustic waves that are detected using a planar FPI sensor interrogated at 765-781 nm. For backwardmode operation and highest acoustic sensitivity, the excitation and interrogation beams are coaxially aligned and rasterscanned. The optical transfer function of the sensor, the spatial resolution and the detection sensitivity were determined to characterise the set-up. Images of a leaf phantom and first in vivo images of zebrafish larvae were acquired. This approach will enable fast 3D OR-PAM with high resolution and high sensitivity for functional and molecular imaging applications. FPI-based ultrasound detection also has the potential to enable dual-mode optical- and acousticresolution PAM and the integration of photoacoustic imaging with purely optical modalities such as multi-photon microscopy
The fluvial architecture of buried floodplain sediments of the Weiße Elster River (Germany) revealed by a novel method combination of drill cores with two‐dimensional and spatially resolved geophysical measurements
The complex and non-linear fluvial river dynamics are characterized by repeated periods of fluvial erosion and re-deposition in different parts of the floodplain. Understanding the fluvial architecture (i.e. the three-dimensional arrangement and genetic interconnectedness of different sediment types) is therefore fundamental to obtain well-based information about controlling factors. However, investigating the fluvial architecture in buried floodplain deposits without natural exposures is challenging. We studied the fluvial architecture of the middle Weiße Elster floodplain in Central Germany, an extraordinary long-standing archive of Holocene flooding and landscape changes in sensitive loess-covered Central European landscapes. We applied a novel systematic approach by coupling two-dimensional transects of electrical resistivity tomography (ERT) measurements and closely spaced core drillings with spatially resolved measurements of electromagnetic induction (EMI) of larger floodplain areas at three study sites. This allowed for (i) time and cost-efficient core drillings based on preceding ERT measurements and (ii) spatially scaling up the main elements of the fluvial architecture, such as the distribution of thick silt-clay overbank deposits and paleochannel patterns from the floodplain transects to larger surrounding areas. We found that fine-grained sand and silt-clay overbank deposits overlying basal gravels were deposited during several periods of intensive flooding. Those were separated from each other by periods of reduced flooding, allowing soil formation. However, the overbank deposits were severely laterally eroded before and during each sedimentation period. This was probably linked with pronounced meandering or even braiding of the river. Our preliminary chronological classification suggests that first fine-grained sedimentation must have occurred during the Early to Middle Holocene, and the last phase of lateral erosion and sedimentation during the Little Ice Age. Our study demonstrates the high archive potential of the buried fluvial sediments of the middle Weiße Elster floodplain and provides a promising time and cost-effective approach for future studies of buried floodplain sediments
A backward-mode optical-resolution photoacoustic microscope for 3D imaging using a planar Fabry-Pérot sensor
Optical-resolution photoacoustic microscopy (OR-PAM) combines high spatial resolution and strong absorption-based contrast in tissue, which has enabled structural and spectroscopic imaging of endogenous chromophores, primarily hemoglobin. This makes OR-PAM an important tool for preclinical vascular research. Conventional piezoelectric ultrasound transducers often need to be placed far away from the signal source due to their opacity, which results in reduced acoustic sensitivity. Optical ultrasound sensors are an alternative as their transparency allows them to be positioned close to the sample for minimal source-detector distances. In this work, a backward-mode OR-PAM system based on a planar Fabry-Pérot ultrasound sensor and coaxially aligned excitation and interrogation beams was developed. Two 3D imaging modes, using raster-scanning for enhanced image quality or continuous-scanning for fast imaging, were implemented and tested on a leaf skeleton phantom. In fast imaging mode, a scan-rate of 100,000 A-lines/s could be achieved. In raster-scanning mode, 3D images of a zebrafish embryo were acquired in vivo. The transparency of the FP sensor in the visible and near-infrared wavelength region makes it potentially suitable for combined functional and molecular imaging using OR-PAM and multi-photon fluorescence microscopy
Bismuth coating of non-tunneled haemodialysis catheters reduces bacterial colonization: a randomized controlled trial
Background. Haemodialysis (HD) catheter-related blood stream infections are a major cause of morbidity and mortality in patients with acute and chronic renal failure
Microsystem Technology for Ambient Assisted Living (AAL)
AbstractAAL is certainly an application area with sensor as well as actuator needs. Some of the requirements can be fulfilled by state of the art technology; some areas however still need a lot of R&D efforts for potential applications in homes. The contribution describes two areas of interest and actual development: One is the topic of robust fire detection; the other domain is fall detection. For both application areas one has to understand both the state of the art and the drawbacks of the current solutions. One can state clearly that there is a huge potential for the development of new microsystems. Still one has to keep in mind that usage in elderly homes also requires consent and cooperation of the users which is the focus of the user centered design principle
Ethnobotany in the Nepal Himalaya
<p>Abstract</p> <p>Background</p> <p>Indigenous knowledge has become recognized worldwide not only because of its intrinsic value but also because it has a potential instrumental value to science and conservation. In Nepal, the indigenous knowledge of useful and medicinal plants has roots in the remote past.</p> <p>Methods</p> <p>The present study reviews the indigenous knowledge and use of plant resources of the Nepal Himalayas along the altitudinal and longitudinal gradient. A total of 264 studies focusing on ethnobotany, ethnomedicine and diversity of medicinal and aromatic plants, carried out between 1979 and 2006 were consulted for the present analysis. In order to cross check and verify the data, seven districts of west Nepal were visited in four field campaigns.</p> <p>Results</p> <p>In contrast to an average of 21–28% ethnobotanically/ethnomedicinally important plants reported for Nepal, the present study found that up to about 55% of the flora of the study region had medicinal value. This indicates a vast amount of undocumented knowledge about important plant species that needs to be explored and documented. The richness of medicinal plants decreased with increasing altitude but the percentage of plants used as medicine steadily increased with increasing altitude. This was due to preferences given to herbal remedies in high altitude areas and a combination of having no alternative choices, poverty and trust in the effectiveness of folklore herbal remedies.</p> <p>Conclusion</p> <p>Indigenous knowledge systems are culturally valued and scientifically important. Strengthening the wise use and conservation of indigenous knowledge of useful plants may benefit and improve the living standard of poor people.</p
Anti-SARS-CoV-2 antibody-containing plasma improves outcome in patients with hematologic or solid cancer and severe COVID-19: a randomized clinical trial
Patients with cancer are at high risk of severe coronavirus disease 2019 (COVID-19), with high morbidity and mortality. Furthermore, impaired humoral response renders severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines less effective and treatment options are scarce. Randomized trials using convalescent plasma are missing for high-risk patients. Here, we performed a randomized, open-label, multicenter trial (https://www.clinicaltrialsregister.eu/ctr-search/trial/2020-001632-10/DE) in hospitalized patients with severe COVID-19 (n = 134) within four risk groups ((1) cancer (n = 56); (2) immunosuppression (n = 16); (3) laboratory-based risk factors (n = 36); and (4) advanced age (n = 26)) randomized to standard of care (control arm) or standard of care plus convalescent/vaccinated anti-SARS-CoV-2 plasma (plasma arm). No serious adverse events were observed related to the plasma treatment. Clinical improvement as the primary outcome was assessed using a seven-point ordinal scale. Secondary outcomes were time to discharge and overall survival. For the four groups combined, those receiving plasma did not improve clinically compared with those in the control arm (hazard ratio (HR) = 1.29; P = 0.205). However, patients with cancer experienced a shortened median time to improvement (HR = 2.50; P = 0.003) and superior survival with plasma treatment versus the control arm (HR = 0.28; P = 0.042). Neutralizing antibody activity increased in the plasma cohort but not in the control cohort of patients with cancer (P = 0.001). Taken together, convalescent/vaccinated plasma may improve COVID-19 outcomes in patients with cancer who are unable to intrinsically generate an adequate immune response
- …