62 research outputs found

    Changes in physical-thermal properties of soil related to very shallow geothermal systems in urban areas

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    In the near future the population living in urban areas is expected to increase. This worldwide trend will lead to a high concentrations of infrastructures in confined areas, whose impact on land use and shallow subsurface must be well evaluated. Since shallow geothermal energy resource is becoming increasingly important as renewable energy resource, due to its huge potential in providing thermal energy for residential and tertiary buildings and in contributing to reduce greenhouse gas emission, the number of installed geothermal systems is expected to continue to rise in the near future. However, a leading question concerns the short and long-term effect of an intensive thermal use of the shallow subsurface for heat generation, cooling and thermal energy storage. From an environmental and technical point of view, changes on ground temperatures can influence the physical-thermal properties of soil and groundwater as well as their chemical and biological features. In this study the preliminary results of ITER Project are presented. This project, funded by European Union, focuses on improving heat transfer efficiency of very shallow geothermal systems, as horizontal collector systems or special forms (i.e. helix system), interesting the first 2 m of depth from ground level. Given the heterogeneity of sedimentary deposits in alluvial plain and the uncertainties related to the estimation of thermal parameters for unconsolidated material affected by thermal use, physical-thermal parameters (i.e. moisture content, bulk density, thermal conductivity...) where determined in laboratory for sand, clay and loamy sand samples. In addition, preliminary results from a field test site located within an urban area will be also shown. The main aim is to improve our knowledge of heat transfer process in the soil body in order (i) to create a reference database to compare subsequently the impact of temperature variations on the same properties and (ii) to provide reliable data for model parameterizatio

    Efficient and Specific Analysis of Red Blood Cell Glycerophospholipid Fatty Acid Composition

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    Red blood cell (RBC) n-3 fatty acid status is related to various health outcomes. Accepted biological markers for the fatty acid status determination are RBC phospholipids, phosphatidylcholine, and phosphatidyletholamine. The analysis of these lipid fractions is demanding and time consuming and total phospholipid n-3 fatty acid levels might be affected by changes of sphingomyelin contents in the RBC membrane during n-3 supplementation. We developed a method for the specific analysis of RBC glycerophospholipids. The application of the new method in a DHA supplementation trial and the comparison to established markers will determine the relevance of RBC GPL as a valid fatty acid status marker in humans. Methyl esters of glycerophospholipid fatty acids are selectively generated by a two step procedure involving methanolic protein precipitation and base-catalysed methyl ester synthesis. RBC GPL solubilisation is facilitated by ultrasound treatment. Fatty acid status in RBC glycerophospholipids and other established markers were evaluated in thirteen subjects participating in a 30 days supplementation trial (510 mg DHA/d). The intra-assay CV for GPL fatty acids ranged from 1.0 to 10.5% and the inter-assay CV from 1.3 to 10.9%. Docosahexaenoic acid supplementation significantly increased the docosahexaenoic acid contents in all analysed lipid fractions. High correlations were observed for most of the mono- and polyunsaturated fatty acids, and for the omega-3 index (r = 0.924) between RBC phospholipids and glycerophospholipids. The analysis of RBC glycerophospholipid fatty acids yields faster, easier and less costly results equivalent to the conventional analysis of RBC total phospholipids

    Prediction of Groundwater Flow and Transport Processes in an Urban Area: A Combined Approach of Field Testing and Numerical Modeling

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    Drinking water supply in urban areas is challenging due to different kinds of water use and potential groundwater contamination. We investigate an area where drinking water production is close to different contaminated sites. The study site is characterized by a high complexity of the tectonic and geological setting with a gravel and a karstic aquifer. The two aquifers are partly connected, partly disconnected by an aquitard. To avoid drinking water contamination, artificial groundwater recharge with surface water into the gravel aquifer is used to create a hydraulic barrier between the contaminated sites and the water abstraction wells. Trace compounds, that were found in former times in the surface water but not nowadays, are still detected in the extracted drinking water. Different studies have been performed such as numerical modeling, intensive groundwater monitoring and investigation of drilling cores to get a differentiated overview of the distribution of the contaminants. Back-diffusion from the matrix due to changing hydraulic boundary was stated to be the reason for the actual distribution of the contaminants. In a first approach due to the lack of experimental data or evidence from field measurements, the permeabilities of the karstic aquifer were assumed as homogeneous. In our study, we seek to identify the flow and transport processes within the system including the fracture network in a combined approach of field work and 3D modeling with FEFLOW. During a field campaign we acquired water samples for the analysis of stable water isotopes as well as organic and inorganic compounds. Furthermore, tritium and helium samples were taken to estimate water ages and to determine the flow through the fracture networks. A combination of existing and recently obtained data was used to build and validate a 3D flow and transport model. The simulation of different scenarios such as the water flow for varying injection and extraction rates as well as particle transport from different sources is carried out. To investigate the effect of subsurface heterogeneity, PEST, an independent parameter estimation and uncertainty analysis software, was used. With the calibrated model we will be able to optimize the operational conditions of artificial recharge and drinking water production especially at the boundaries of the production field. Hence, we can provide guidelines for an improved water resource management

    Multicenter Evaluation of a 0-Hour/1-Hour Algorithm in the Diagnosis of Myocardial Infarction With High-Sensitivity Cardiac Troponin T

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    Study objectiveWe aim to prospectively validate the diagnostic accuracy of the recently developed 0-h/1-h algorithm, using high-sensitivity cardiac troponin T (hs-cTnT) for the early rule-out and rule-in of acute myocardial infarction.MethodsWe enrolled patients presenting with suspected acute myocardial infarction and recent (<6 hours) onset of symptoms to the emergency department in a global multicenter diagnostic study. Hs-cTnT (Roche Diagnostics) and sensitive cardiac troponin I (Siemens Healthcare) were measured at presentation and after 1 hour, 2 hours, and 4 to 14 hours in a central laboratory. Patient triage according to the predefined hs-cTnT 0-hour/1-hour algorithm (hs-cTnT below 12 ng/L and Δ1 hour below 3 ng/L to rule out; hs-cTnT at least 52 ng/L or Δ1 hour at least 5 ng/L to rule in; remaining patients to the “observational zone”) was compared against a centrally adjudicated final diagnosis by 2 independent cardiologists (reference standard). The final diagnosis was based on all available information, including coronary angiography and echocardiography results, follow-up data, and serial measurements of sensitive cardiac troponin I, whereas adjudicators remained blinded to hs-cTnT.ResultsAmong 1,282 patients enrolled, acute myocardial infarction was the final diagnosis for 213 (16.6%) patients. Applying the hs-cTnT 0-hour/1-hour algorithm, 813 (63.4%) patients were classified as rule out, 184 (14.4%) were classified as rule in, and 285 (22.2%) were triaged to the observational zone. This resulted in a negative predictive value and sensitivity for acute myocardial infarction of 99.1% (95% confidence interval [CI] 98.2% to 99.7%) and 96.7% (95% CI 93.4% to 98.7%) in the rule-out zone (7 patients with false-negative results), a positive predictive value and specificity for acute myocardial infarction of 77.2% (95% CI 70.4% to 83.0%) and 96.1% (95% CI 94.7% to 97.2%) in the rule-in zone, and a prevalence of acute myocardial infarction of 22.5% in the observational zone.ConclusionThe hs-cTnT 0-hour/1-hour algorithm performs well for early rule-out and rule-in of acute myocardial infarction

    Dynamics of Immune System Gene Expression upon Bacterial Challenge and Wounding in a Social Insect (Bombus terrestris)

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    The innate immune system which helps individuals to combat pathogens comprises a set of genes representing four immune system pathways (Toll, Imd, JNK and JAK/STAT). There is a lack of immune genes in social insects (e.g. honeybees) when compared to Diptera. Potentially, this might be compensated by an advanced system of social immunity (synergistic action of several individuals). The bumble bee, Bombus terrestris, is a primitively eusocial species with an annual life cycle and colonies headed by a single queen. We used this key pollinator to study the temporal dynamics of immune system gene expression in response to wounding and bacterial challenge

    Articulating the effect of food systems innovation on the Sustainable Development Goals

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    Acknowledgments MH, DM-D, JP, JRB, AH, GDB, CMG, CLM, and KR acknowledge funding from the Commonwealth Scientific and Industrial Research Organisation. PKT, BMC, AJ, and AML acknowledge funding from the CGIAR Research Program on Climate Change, Agriculture and Food Security, which is supported by the CGIAR Trust Fund and through bilateral funding agreements. PP acknowledges funding from the German Federal Ministry of Education and Research for the BIOCLIMAPATHS project.Peer reviewedPublisher PD

    Diverse molecular causes of unsolved autosomal dominant tubulointerstitial kidney diseases

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    Autosomal Dominant Tubulointerstitial Kidney Disease (ADTKD) is caused by mutations in one of at least five genes and leads to kidney failure usually in mid adulthood. Throughout the literature, variable numbers of families have been reported, where no mutation can be found and therefore termed ADTKD-not otherwise specified. Here, we aim to clarify the genetic cause of their diseases in our ADTKD registry. Sequencing for all known ADTKD genes was performed, followed by SNaPshot minisequencing for the dupC (an additional cytosine within a stretch of seven cytosines) mutation of MUC1. A virtual panel containing 560 genes reported in the context of kidney disease (nephrome) and exome sequencing were then analyzed sequentially. Variants were validated and tested for segregation. In 29 of the 45 registry families, mutations in known ADTKD genes were found, mostly in MUC1. Sixteen families could then be termed ADTKD-not otherwise specified, of which nine showed diagnostic variants in the nephrome (four in COL4A5, two in INF2 and one each in COL4A4, PAX2, SALL1 and PKD2). In the other seven families, exome sequencing analysis yielded potential disease associated variants in novel candidate genes for ADTKD; evaluated by database analyses and genome-wide association studies. For the great majority of our ADTKD registry we were able to reach a molecular genetic diagnosis. However, a small number of families are indeed affected by diseases classically described as a glomerular entity. Thus, incomplete clinical phenotyping and atypical clinical presentation may have led to the classification of ADTKD. The identified novel candidate genes by exome sequencing will require further functional validation
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