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  • 11
    Language: German
    In: Grundwasser, 3/2012, Vol.17(1), pp.1-1
    Keywords: Environmental Sciences ; Geography;
    ISSN: 1430-483X
    E-ISSN: 1432-1165
    Source: Springer (via CrossRef)
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  • 12
    Language: English
    In: The Journal of Urology, April 2016, Vol.195(4), pp.e744-e745
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.juro.2016.02.613 Byline: Michael Avallone, Peter Dietrich, Shanta Shepherd, Mona Lalehzari, R. Corey O'Connor, Michael Guralnick Author Affiliation: Milwaukee, WI Article Note: (footnote) Source of Funding: None
    Keywords: Medicine
    ISSN: 0022-5347
    E-ISSN: 1527-3792
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  • 13
    Language: English
    In: Journal of Hydrology, March 2016, Vol.534, pp.113-123
    Description: The ongoing transition from fossil fuels to alternative energy source provision has resulted in increased geothermal uses as well as storage of the shallow subsurface. Existing approaches for exploration of shallow subsurface geothermal energy storage often lack the ability to provide information concerning the spatial variability of thermal storage parameters. However, parameter distributions have to be known to ensure that sustainable geothermal use of the shallow subsurface can take place – especially when it is subject to intensive usage. In this paper, we test a temperature decay time approach to obtain , direct, qualitative, spatial high-resolution information about the distribution of thermal storage capabilities of the shallow subsurface. To achieve this, temperature data from a high-resolution Fibre-Optic-Distributed-Temperature-Sensing device, as well as data from conventional Pt -temperature-sensors were collected during a heat injection test. The latter test was used to measure the decay time of temperature signal dissipation of the subsurface. Signal generation was provided by in-aquifer heating with a temperature self-regulating electric heating cable. Heating was carried out for 4.5 days. After this, a cooling period of 1.5 weeks was observed. Temperature dissipation data was also compared to Direct-Push-derived high-resolution (hydro-)geological data. The results show that besides hydraulic properties also the bedding and compaction state of the sediment have an impact on the thermal storage capability of the saturated subsurface. The temperature decay time approach is therefore a reliable method for obtaining information regarding the qualitative heat storage capability of heterogeneous aquifers for the use with closed loop system geothermal storage systems. Furthermore, this approach is advantageous over other commonly used methods, e.g. soil-sampling and laboratory analysis, as even small changes in (hydro-)geological properties lead to strong variances in observed heat-storage capabilities at the investigated case study site. By using fibre-optic-thermometers, nearly every requested spatial resolution can be achieved and easily be adjusted to the needs of actual test sites for shallow geothermal storage exploration.
    Keywords: Distributed-Temperature-Sensing ; Shallow Subsurface Thermal-Storage ; Shallow Geothermal Exploration ; Direct-Push in Situ Investigations ; Geography
    ISSN: 0022-1694
    E-ISSN: 1879-2707
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  • 14
    Language: English
    In: Journal of Contaminant Hydrology, 2011, Vol.122(1), pp.1-15
    Description: Measuring contaminant flow rates at control cross sections is the most accurate method to evaluate natural attenuation processes in the saturated subsurface. In most instances, point scale measurement is the method of choice due to practical reasons and cost factors. However, at many field sites, the monitoring network is too sparse for a reliable estimation of contaminant and groundwater flow rates. Therefore, integral pumping tests have been developed as an alternative. In this study, we compare mass flow rates obtained by integral pumping test results and point scale data. We compare results of both methods with regard to uncertainties due to estimation errors and mass flow estimations based on two different point scale networks. The differences between benzene and groundwater flow rate estimates resulting from point scale samples and integral pumping tests were 6.44% and 6.97%, respectively, demonstrating the applicability of both methods at the site. Point scale-based data, especially with use of cost efficient Direct-Push technique, can be applied to show the contaminant distribution at a site and may be followed by a denser point scale network or an integral method. Nevertheless, a combination of both methods decreases uncertainties.
    Keywords: Integral Pumping Test ; Point Scale Measurements ; Cstream ; Mass Flow Rate ; Btex ; Direct-Push ; Engineering ; Environmental Sciences ; Geography
    ISSN: 0169-7722
    E-ISSN: 1873-6009
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  • 15
    Language: English
    In: Environmental Earth Sciences, 2014, Vol.72(5), pp.1357-1366
    Description: Landslide activity is largely controlled by changes in soil properties, particularly soil moisture and the corresponding changes in pore pressure within the vadose zone. While knowledge of changes in soil conditions is of utmost importance for the prediction of landslides, it is difficult to obtain reliable information on the field scale. A possibility of filling that information gap is the monitoring of changes in soil properties by time-lapse electromagnetic induction (EMI) data. Given the relative stability of soil properties, changes in apparent electric conductivity (ECa) are mainly related to changes in soil water content and its mineralization. Thus, we use time-lapse ECa data over a nine-month period from different investigation depths (0.75, 1.5, 3, and 6 m) to separate areas with different temporal behavior of soil properties. However, working with time-lapse EMI data raised the comparability problem since the recoded ECa is also affected by several day-specific survey conditions (e.g., instrument temperature, operator). Consequently, the reproducibility of accurate ECa measurements is difficult due to potential dynamic shifts which hinders a direct comparing. We introduce in this study a straightforward method for comparability of ECa values from different time steps by normalization of data ranges assuming that the majority of shifts of measured data originate from field calibration. We identify the intensity of spatial changes by means of the standard deviation (SD) as an indication for the intensity of soil properties variability. To obtain the temporal changes and its progression over time, we separate the dynamic signal from the background. A two-layer system could be identified: one shallow more dynamic layer with an east–west-oriented structure and a deeper, more stationary layer with a north–south-oriented structure. The ECa dynamics of the shallow layer is related to the altitude ( R 2  = 0.84) while the deeper dynamics follow a different regime. The decreasing of ECa dynamics with depth was consistent with the decreasing of SWC dynamics observed by previous studies.
    Keywords: EMI time-lapse monitoring and normalization ; ECa calibration issues ; Landslide monitoring ; Proximal soil sensing
    ISSN: 1866-6280
    E-ISSN: 1866-6299
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  • 16
    In: Ground Water, May 2012, Vol.50(3), pp.450-456
    Description: Detailed information on vertical variations in hydraulic conductivity () is essential to describe the dynamics of groundwater movement at contaminated sites or as input data used for modeling. values in high vertical resolution should be determined because tends to be more continuous in the horizontal than in the vertical direction. To determine in shallow unconsolidated sediments and in the vertical direction, the recently developed direct‐push injection logger can be used. The information obtained by this method serves as a proxy for and has to be calibrated to obtain quantitative values of measured vertical profiles. In this study, we performed direct‐push soil sampling, sieve analyses and direct‐push slug tests to obtain values in vertical high resolution. Using the results of direct‐push slug tests, quantitative values obtained by the direct‐push injection logger could be determined successfully. The results of sieve analyses provided lower accordance with the logs due to the inherent limitations of the sieving method.
    Keywords: Hydrogeology ; Environmental Geology ; Aquifers ; Central Europe ; Elbe River ; Europe ; Experimental Studies ; Germany ; Granulometry ; Ground Water ; Hydraulic Conductivity ; Injection ; Measurement ; Mobility ; Pirna Germany ; Pollution ; Preferential Flow ; Sampling ; Saxony Germany ; Sediments ; Soils ; Unconsolidated Materials ; Variations;
    ISSN: 0017-467X
    E-ISSN: 1745-6584
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  • 17
    Language: English
    In: Journal of Plant Nutrition and Soil Science, June 2012, Vol.175(3), pp.345-354
    Description: Today rapid survey methods of proximal soil sensing (PSS) provide an increasing number of different and highly resolved data. These multidimensional data sets can lead to multilayered and complex maps of parameters which are only indirectly related to soil properties and soil functions. However, in applications usually just one clear elementary map is required. It is of increasing importance to tackle this problem utilizing a cluster algorithm for the synthesis and reduction of multidimensional input variables. The cluster algorithm provides a partitioning of the investigated site whereby the units are characterized by the statistics of the PSS data. Therefore, the question that arises is how suitable is the suggested partitioning in terms of the delineation of different soil units. In this study, we investigate the suitability of cluster partitioning through a case study at a medium‐scale test site (≈ 50 000 m). Two common PSS methods: electromagnetic induction (EMI) and gamma spectrometry (GS) will be employed to create a data set for partitioning by a K‐means cluster. The result of the cluster analysis is a delineation of three different parts. In contrast to previous studies, we evaluate the generated partitions by independent soil properties such as grain size, horizon thickness, and color of stratified randomly taken soil samples. The soil analyses show that one of three clusters significantly differs from the others in terms of grain‐size distribution and horizon thickness. The partitioning of the other two clusters could not be confirmed by the considered soil parameters. Nevertheless, the case study demonstrates the combination of different PSS data by K‐means clustering as a potential approach for site partitioning. An evaluation of the results of the cluster analysis through the collection and analysis of soil samples is highly recommended.
    Keywords: Site Partitioning ; Proximal Soil Sensing ; Rapid Soil Survey ; Cluster Analysis ; Emi ; Gamma Spectrometry ; Site‐Specific Crop Management Sscm
    ISSN: 1436-8730
    E-ISSN: 1522-2624
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  • 18
    Language: English
    In: Journal of Applied Geophysics, November 2015, Vol.122, pp.210-217
    Description: Systematic decomposition and evaluation of existing sensor systems as well as the optimal design of future generations of direct push probes are of high importance for optimized geophysical experiments since the employed equipment is a constrain on the data space. Direct push technologies became established methods in the field of geophysical, geotechnical, hydrogeological, and environmental sciences for the investigation of the near subsurface. By using direct push sensor systems it is possible to measure in-situ parameters with high vertical resolution. Such information is frequently used for quantitative geophysical model calibration of interpretation of geotechnical and hydrological subsurface conditions. Most of the available direct push sensor systems are largely based on empirical testing and consecutively evaluated under field conditions. Approaches suitable to identify specific characteristics and problems of direct push sensor systems have not been established, yet. We develop a general systematic approach for the classification, analysis, and optimization of direct push sensor systems. First, a classification is presented for different existing sensor systems. The following systematic description, which is based on the conceptual decomposition of an existing sensor system into subsystems, is a suitable way to analyze and explore the transfer behavior of the system components and therefore of the complete system. Also, this approach may serve as guideline for the synthesis and the design of new and optimized direct push sensor systems.
    Keywords: Direct Push (Dp) ; Optimized Experimental Design ; Subsurface Characterization ; Sensor System ; System Analysis ; Measurement Modeling ; Engineering
    ISSN: 0926-9851
    E-ISSN: 1879-1859
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  • 19
    Language: English
    In: Ground Water, Nov-Dec, 2012, Vol.50, p.935(8)
    Description: To purchase or authenticate to the full-text of this article, please visit this link: http://onlinelibrary.wiley.com/doi/10.1111/j.1745-6584.2012.00948.x/abstract Byline: Falk Handel(1), Peter Dietrich(2) Knowledge of site-specific contaminant transport processes is an essential requirement for performing various tasks concerning the protection and management of groundwater resources. However, prediction of their behavior is often difficult, especially in heterogeneous aquifers because of the lack of information about flow- and transport-governing subsurface structures and parameters. Hence, stochastic approaches have been developed and frequently used. However, extensive modeling studies on sedimentary structures have shown that consideration of hydrogeological subunits and their distribution can be essential for transport modeling. A case study from the intensely investigated Lauswiesen site is used to demonstrate that more accurate predictions are possible with improved knowledge of deterministic structures. Results of this case study using direct-push injection logging (DPIL) provide a more reliable characterization of hydraulic conductivity than sieve and flow meter data. Author Affiliation: (1)Institute for Groundwater Management, Technical University of Dresden, Bergstra[sz]e 66, D-01069 Dresden, Germany (2)Center of Applied Geoscience, University of Tubingen, Sigwartstra[sz]e 10, D-72076 Tubingen, Germany Correspondence: (*) UFZ, Helmholtz Centre for Environmental Research, Department of Monitoring and Exploration Technologies (MET), Permoserstra[sz]e 15, D-04318 Leipzig, Germany; (49) 35146342557; falk.haendel@ufz.de Received June 2011, accepted April 2012.
    Keywords: Hydrogeology -- Case Studies ; Hydrogeology -- Analysis ; Hydrogeology -- Models ; Water Resource Management -- Case Studies ; Water Resource Management -- Analysis ; Water Resource Management -- Models ; Aquifers -- Case Studies ; Aquifers -- Analysis ; Aquifers -- Models ; Groundwater -- Case Studies ; Groundwater -- Analysis ; Groundwater -- Models ; Sedimentary Structures -- Case Studies ; Sedimentary Structures -- Analysis ; Sedimentary Structures -- Models
    ISSN: 0017-467X
    Source: Cengage Learning, Inc.
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  • 20
    Language: English
    In: Gut, July 2018, Vol.67(7), pp.1328-1341
    Description: Sorafenib is the only effective therapy for advanced hepatocellular carcinoma (HCC). Combinatory approaches targeting mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK)- and phosphatidylinositol-4,5-bisphosphate-3-kinase (PI3K)/protein-kinase B(AKT) signalling yield major therapeutic improvements. RAS proteins regulate both RAF/MAPK and PI3K/AKT signalling. However, the most important RAS isoform in carcinogenesis, Kirsten rat sarcoma (KRAS), remains unexplored in HCC. Human HCC tissues and cell lines were used for expression and functional analysis. Sorafenib-resistant HCC cells were newly generated. RNA interference and the novel small molecule deltarasin were used for KRAS inhibition both in vitro and in a murine syngeneic orthotopic HCC model. Expression of wild type KRAS messenger RNA and protein was increased in HCC and correlated with extracellular-signal regulated kinase (ERK) activation, proliferation rate, advanced tumour size and poor patient survival. Bioinformatic analysis and reporter assays revealed that KRAS is a direct target of microRNA-622. This microRNA was downregulated in HCC, and functional analysis demonstrated that KRAS-suppression is the major mediator of its inhibitory effect on HCC proliferation. KRAS inhibition markedly suppressed RAF/ERK and PI3K/AKT signalling and proliferation and enhanced apoptosis of HCC cells in vitro and in vivo. Combinatory KRAS inhibition and sorafenib treatment revealed synergistic antitumorigenic effects in HCC. Sorafenib-resistant HCC cells showed elevated KRAS expression, and KRAS inhibition resensitised sorafenib-resistant cells to suppression of proliferation and induction of apoptosis. KRAS is dysregulated in HCC by loss of tumour-suppressive microRNA-622, contributing to tumour progression, sorafenib sensitivity and resistance. KRAS inhibition alone or in combination with sorafenib appears as novel promising therapeutic strategy for HCC.
    Keywords: Hepatocellular Carcinoma ; Molecular Mechanisms ; Antineoplastic Agents -- Therapeutic Use ; Carcinoma, Hepatocellular -- Metabolism ; Liver Neoplasms -- Metabolism ; Micrornas -- Metabolism ; Niacinamide -- Analogs & Derivatives ; Phenylurea Compounds -- Therapeutic Use ; Proto-Oncogene Proteins P21(Ras) -- Physiology
    ISSN: 00175749
    E-ISSN: 1468-3288
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