417 research outputs found
In-situ-Vergleichstest fĂźr Sensoren zur Matrixpotentialmessung
Wassergehalt und Matrixpotenzial sind zentrale bodenhydrologische Zustandsvariablen. Zur in-situ Messung dieser GrĂśĂen im Freiland bietet der Markt eine zunehmende Vielzahl von konkurrierenden Systemen und Technologien an. Zur Messung des Matrixpotentials existiert allerdings bis heute kein Sensorsystem, das mit Zuverlässigkeit und Genauigkeit das Matrixpotential Ăźber den gesamten Feuchtebereich messen kann. Zur PrĂźfung der Messcharakteristik von Bodenfeuchtesensoren hat ein Konsortium von 10 Institutionen im Jahr 2016 Ăźber mehrere Monate eine Vergleichsstudie auf einer homogenisierten Testfläche durchgefĂźhrt. Die Fläche war ca. 60 m2 groĂ, natĂźrlichen meteorologischen Bedingungen ausgesetzt und wurde von Vegetation freigehalten. In einem Raster von 0,5 m Weite wurden 15 verschiedene Systeme zur Messung der Bodenfeuchte und 13 verschiedene Systeme zur Messung des Matrixpotenzials in jeweils vierfacher Wiederholung in 0,2 m Tiefe installiert. In diesem Beitrag sollen spezifisch die Ergebnisse der Matrixpotentialmessungen diskutiert werden, deren Technologie auf direkter Druckmessung (Tensiometer T4, T5, T8 der Fa. UMS), Messungen der dielektrischen Eigenschaften (MPS-1, MPS-2 und MPS-6 der Fa. Decagon Devices) bzw. Messungen der Wärmedissipation (pF-Meter, TensioMark der Fa. EcoTech) beruhen. Wir diskutieren die Ergebnisse hinsichtlich der absoluten Lage und Variabilität der Signale, der Reaktionszeiten auf schnelle Feuchteänderungen und auf Temperaturschwankungen. Die Studie zeigte ferner, wie komplex die Probleme einer Vergleichsstudie im Feld generell sind. Trotz groĂer Sorgfalt bei der Versuchsanlage konnte z.B. die Homogenitätsannahme nur fĂźr eine initiale Periode von wenigen Wochen aufrecht gehalten werden. Ein Starkregenereignis mit InfiltrationsĂźberschuss fĂźhrte zur Bildung von Bodenkrusten und oberflächlichen Umverteilungsnetzwerken, und damit zu kleinskaliger Heterogenität der oberen Randbedingung. Generell wirft dies Fragen auf in Hinblick auf die Aussagekraft einzelner Sensorenwerte in Freilandstudien
Concordance of KRAS/BRAF Mutation Status in Metastatic Colorectal Cancer before and after Anti-EGFR Therapy
Anti-EGFR targeted therapy is a potent strategy in the treatment of metastatic colorectal cancer (mCRC) but activating mutations in the KRAS gene are associated with poor response to this treatment. Therefore, KRAS mutation analysis is employed in the selection of patients for EGFR-targeted therapy and various studies have shown a high concordance between the mutation status in primary CRC and corresponding metastases. However, although development of therapy related resistance occurs also in the context of novel drugs such as tyrosine kinase-inhibitors the effect of the anti-EGFR treatment on the KRAS/BRAF mutation status itself in recurrent mCRC has not yet been clarified. Therefore, we analyzed 21âmCRCs before/after anti-EGFR therapy and found a pre-/posttherapeutic concordance of the KRAS/BRAF mutation status in 20 of the 21 cases examined. In the one discordant case, further analyses revealed that a tumor mosaicism or multiple primary tumors were present, indicating that anti-EGFR therapy has no influence on KRAS/BRAF mutation status in mCRC. Moreover, as the preselection of patients with a KRASwt genotype for anti-EGFR therapy has become a standard procedure, sample sets such ours might be the basis for future studies addressing the identification of potential anti-EGFR therapy induced genetic alterations apart from KRAS/BRAF mutations
Global assessment of manure management policies and practices
In 2014 an assessment of livestock manure policies was performed in 34 countries in Asia, Africa and
Latin America, followed by an in-depth assessment of manure management practices in Bangladesh, Viet Nam, Ethiopia, Malawi, Argentina and Costa Rica. The assessments revealed the key barriers for improving integrated manure management and identified six opportunities for actual practice changes to improve manure related policies as well as farm practices with the overall objective of improving food security while mitigating methane emissions at the same tim
Molecular Epidemiology of Anthrax Cases Associated with Recreational Use of Animal Hides and Yarn in the United States
To determine potential links between the clinical isolate to animal products and their geographic origin, we genotyped (MLVA-8, MVLA-15, and canSNP analysis) 80 environmental and 12 clinical isolates and 2 clinical specimens from five cases of anthrax (California in 1976 [nâ=â1], New York in 2006 [nâ=â1], Connecticut in 2007 [nâ=â2], and New Hampshire in 2009[nâ=â1]) resulting from recreational handling of animal products. For the California case, four clinical isolates were identified as MLVA-8 genotype (GT) 76 and in the canSNP A.Br.Vollum lineage, which is consistent with the Pakistani origin of the yarn. Twenty eight of the California isolates were in the A.Br.Vollum canSNP lineage and one isolate was in the A.Br. 003/004 canSNP sub-group. All 52 isolates and both clinical specimens related to the New York and Connecticut cases were MLVA-8 GT 1. The animal products associated with the NY and CT cases were believed to originate from West Africa, but no isolates from this region are available to be genotyped for comparison. All isolates associated with the New Hampshire case were identical and had a new genotype (GT 149). Isolates from the NY, CT and NH cases diverge from the established canSNP phylogeny near the base of the A.Br.011/009. This report illustrates the power of the current genotyping methods and the dramatically different epidemiological conditions that can lead to infections (i.e., contamination by a single genotype versus widespread contamination of numerous genotypes). These cases illustrate the need to acquire and genotype global isolates so that accurate assignments can be made about isolate origins
Soil water retention and hydraulic conductivity measured in a wide saturation range
Soil hydraulic properties (SHPs), particularly soil water retention
capacity and hydraulic conductivity of unsaturated soils, are among the key
properties that determine the hydrological functioning of terrestrial
systems. Some large collections of SHPs, such as the UNSODA and HYPRES
databases, have already existed for more than 2 decades. They have provided an
essential basis for many studies related to the critical zone. Today,
sample-based SHPs can be determined in a wider saturation range and with
higher resolution by combining some recently developed laboratory methods.
We provide 572 high-quality SHP data sets from undisturbed, mostly central
European samples covering a wide range of soil texture, bulk density and
organic carbon content. A consistent and rigorous quality filtering ensures
that only trustworthy data sets are included. The data collection contains
(i)Â SHP data, which consist of soil water retention and hydraulic conductivity data,
determined by the evaporation method and supplemented by retention data
obtained by the dewpoint method and saturated conductivity measurements;
(ii)Â basic soil data, which consist of particle size distribution determined by sedimentation
analysis and wet sieving, bulk density and organic carbon content; and (iii)Â metadata, which include the coordinates of the sampling locations. In
addition, for each data set, we provide soil hydraulic parameters for the
widely used van GenuchtenâMualem model and for the more advanced
PetersâDurnerâIden model. The data were originally collected to develop and
test SHP models and associated pedotransfer functions. However, we expect
that they will be very valuable for various other purposes such as
simulation studies or correlation analyses of different soil properties to
study their causal relationships. The data are available at
https://doi.org/10.5880/fidgeo.2023.012 (Hohenbrink et al.,
2023).</p
Experiencing mindfulness meditationâa client narrative perspective
The study was based on the non-participant involvement of the researcher in four six-to-eight weeks' mindfulness meditation training courses led by chartered psychologists. The participants suffered from stress/sleeplessness, depression or agoraphobia in the presented cases. They were selected on the basis of recommendations by the psychologist who was the course instructor, who described them as positive and suitable. The participants wrote diaries on a weekly basis, and they were interviewed at the beginning, middle and end of the course. An in-depth analysis of three individual cases will be presented in the form of narratives constructed from their own words. The narratives demonstrate the unique and embodied changes of the individual participant's experiences during the training course. The purpose was to illustrate richly what happens and how changes happen during these weeks of learning and practicing mindfulness meditation. It is not the intention to give evidence about the effectiveness of mindfulness meditation in general, but to present the whats and hows of cases where mindfulness meditation appears to improve quality of life, health and well-being
Soil moisture and matric potential-an open field comparison of sensor systems
Soil water content and matric potential are central hydrological state variables. A large variety of automated probes and sensor systems for state monitoring exist and are frequently applied. Most applications solely rely on the calibration by the manufacturers. Until now, there has been no commonly agreed-upon calibration procedure. Moreover, several opinions about the capabilities and reliabilities of specific sensing methods or sensor systems exist and compete. A consortium of several institutions conducted a comparison study of currently available sensor systems for soil water content and matric potential under field conditions. All probes were installed at 0.2mb.s. (metres below surface), following best-practice procedures. We present the set-up and the recorded data of 58 probes of 15 different systems measuring soil moisture and 50 further probes of 14 different systems for matric potential. We briefly discuss the limited coherence of the measurements in a cross-correlation analysis. The measuring campaign was conducted during the growing period of 2016. The monitoring data, results from pedophysical analyses of the soil and laboratory reference measurements for calibration are published in Jackisch et al. (2018, https://doi.org/10.1594/PANGAEA.892319)
Trauman myÜtätuntoisen todistamisen harjoittamisen hyÜty turvallisuustutkimuksen alalla
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