Stable hydrogen isotope ratios in the clay fraction of soil

Die Untersuchung der natürlichen Häufigkeit von stabilen Isotopen des Wasserstoffs (H) in organischen Substanzen hat neue Erkenntnisse für die ökologische Forschung, die forensischen Wissenschaften und die Paläoklimatologie hervorgebracht. Frühere Studien haben gezeigt, dass das ²H/¹H-Isotopenverhältnis (δ²H) von nicht-austauschbarem H (δ²H$_{n}$) des Bodens und der demineralisierten organischen Bodensubstanz mit dem δ²H-Wert des lokalen Niederschlags in Zusammenhang steht. Bisher haben methodische Schwierigkeiten bei der Entfernung von austauschbarem H in der Tonfraktion des Bodens die Untersuchung einer ähnlichen Beziehung zwischen den δ²H$_{n}$-Werten der Tonfraktionen des Bodens und dem δ²H-Wert des lokalen Niederschlags erschwert. Das übergeordnete Ziel meiner Arbeit besteht darin, die δ²H$_{n}$-Werte von Tonfraktionen im Boden durch die Trennung von austauschbarem und nicht-austauschbarem H mittels Dampfäquilibrierung zu bestimmen und deren Einflussfaktoren zu untersuchen. Zu diesem Zweck habe ich (1) die Dampfäquilibrierungsmethode angepasst. Dies war erforderlich, um den Einfluss der klassischen Behandlung zur Separation von Tonfraktionen, einschließlich der Entfernung von dithionitlöslichem Eisen, organischer Substanz, Karbonaten und Salzen, auf die δ²H$_{n}$-Werte von Tonmineralen zu testen. Anschließend habe ich (2) untersucht, ob es eine globale Korrelation zwischen den δ²H-Werten des lokalen Niederschlags und den δ²H$_{n}$-Werten von Oberbodentonfraktionen gibt. Der Ansatz der Dampfäquilibrierung erfordert den Gleichgewichtsfraktionsfaktor zwischen dem H des Dampfes und dem austauschbaren H der Probe (α$_{ex‑w}$), der nicht bekannt ist. Daher habe ich (3) eine experimentelle Methode zur Bestimmung der probenspezifischen α$_{ex‑w}$-Werte entwickelt. Ich verwendete die Tonminerale Kaolinit, Illit, Montmorillonit und Vermiculit sowie Oberbodenproben von 24 Standorten auf fünf Kontinenten. Bei allen Proben wurden die Tonfraktionen separiert. Die δ²H$_{n}$-Werte wurden mittels Dampfäquilibrierung und Pyrolyse-Elementaranalysator-Isotopenverhältnis-Massenspektrometrie bestimmt. Darüber hinaus wurden die Oberbodenproben chemisch charakterisiert, einschließlich der Konzentrationen von H, C$_{org}$, N, Na, Mg, Al, K, Ca, Fe und Fe$_{d}$ sowie der potenziellen Kationenaustauschkapazität. Die klassische Tonseparierung veränderte die δ²H$_{n}$-Werte von fünf verschiedenen Tonmineralien nicht wesentlich. Die δ²H$_{n}$-Werte der Tonfraktionen aus verschiedenen Regionen der Welt reichten von ‑167 ± 1 ‰ für eine nordsibirische Probe bis ‑44 ± 4 ‰ in Westkenia für α$_{ex‑w}$ = 1 und von -191 ± 5 bis -81 ± 5 ‰ für α$_{ex‑w}$ = 1,08. Die δ²H-Werte des lokalen Jahresniederschlags korrelierten signifikant mit den δ²H$_{n}$-Werten der Tonfraktionen (r = 0,88 für α$_{ex‑w}$ = 1 und 0,65 für α$_{ex‑w}$ = 1,08, p < 0,001). Ein multiples Regressionsmodell, das zusätzlich zu den δ²H-Werten des saisonalen Niederschlags auch die Hangneigung als mögliches Maß für die allochthone Tonakkumulation einbezog, erklärte 86 % und 89 % der beobachteten Variation der δ²H-Werte der Tonfraktionen für α$_{ex‑w}$ = 1 bzw. 1,08. Die α$_{ex‑w}$-Werte von sieben Tonmineralen reichten von 1,071 bis 1,140 und von 19 Oberbodentonfraktionen von 0,885 bis 1,216. Die α$_{ex‑w}$-Bestimmungsmethode funktionierte nicht für Kaolinit, wahrscheinlich wegen seines geringen austauschbarem H-Gehalts. Der α$_{ex‑w}$-Wert der Oberbodentonfraktionen korrelierte mit dem Tongehalt des Bodens (r = 0,63, p = 0,004), der lokalen Jahresmitteltemperatur (r = 0,68, p = 0,001) und den δ²H-Werten des lokalen Niederschlags (r = 0,72, p < 0,001), was die unterschiedliche Tonmineralogie unter verschiedenen klimatischen Verwitterungsregimen widerspiegelt. Meine Ergebnisse zeigen, dass die δ²H$_{n}$-Werte des Oberbodens als eine Mischung aus isotopisch schwereren H der organischen Bodensubstanz und isotopisch leichteren H der Tonfraktionen beschrieben werden können. Die δ²H$_{n}$-Werte der Tonfraktionen im Boden werden von den δ²H-Werten der lokalen Niederschläge beeinflusst. Wenn die klimatisch beeinflusste Mineralogie berücksichtigt wird, können unbekannte Bodenproben dem global variierenden δ²H Niederschlagswerten zugeordnet werden. Die vorgeschlagene α$_{ex‑w}$-Bestimmungsmethode kann verwendet werden, um die Unsicherheit der Dampfäquilibrierung zur Bestimmung der δ²H$_{n}$-Werte von hygroskopischen Proben zu verringern

Clinical proteomics for precision medicine: the bladder cancer case

Precision medicine can improve patient management by guiding therapeutic decision based on molecular characteristics. The concept has been extensively addressed through the application of –omics based approaches. Proteomics attract high interest, as proteins reflect a “real-time” dynamic molecular phenotype. Focusing on proteomics applications for personalized medicine, a literature search was conducted to cover: a) disease prevention, b) monitoring/ prediction of treatment response, c) stratification to guide intervention and d) identification of drug targets. The review indicates the potential of proteomics for personalized medicine by also highlighting multiple challenges to be addressed prior to actual implementation. In oncology, particularly bladder cancer, application of precision medicine appears especially promising. The high heterogeneity and recurrence rates together with the limited treatment options, suggests that earlier and more efficient intervention, continuous monitoring and the development of alternative therapies could be accomplished by applying proteomics-guided personalized approaches. This notion is backed by studies presenting biomarkers that are of value in patient stratification and prognosis, and by recent studies demonstrating the identification of promising therapeutic targets. Herein, we aim to present an approach whereby combining the knowledge on biomarkers and therapeutic targets in bladder cancer could serve as basis towards proteomics- guided personalized patient management

Stable hydrogen isotope ratios in crystal water of clay minerals

Hydrogen is the most abundant element in the Universe. But the utilization of the H isotopic composition (δH-2 value) of soil to elucidate biogeochemical processes or to serve as a palaeo climate proxy is still in its infancy. In our research, we will focus on the δH-2 value of nonexchangeable H in the clay fraction of soils. The δH-2 value of structural H in clay minerals – mainly from C-poor subsoils - has been studied since the 1970s. The δH-2 value of clay minerals mainly depends on (a) the average δH-2 value of ambient water at the site and time of formation, and on (b) the size of the equilibrium isotopic fractionation factor between water and clay mineral at the temperature of formation. In our research, we will focus on the δH-2 value of nonexchangeable H in the clay fraction of soils. Only nonexchangeable H in in structural water of minerals preserves its inherited δH-2 value and does not exchange with water at temperatures usually occurring in soil environments at the Earth’s surface. Nonexchangeable H is bound in crystal water, which integrates the δH-2 value of soil water over several millennia. This is in turn determined by palaeoclimatic variations of the precipitation’s δH-2 signal with distinguishable shifts e.g., from Pleistocene to Holocene. For a global data set, Ruppenthal (2014) reported a close correlation of bulk soil δH-2 values with those of the mean local precipitation and confirmed this for organic matter, while the clay fraction of soils was up to now not studied. We will adapt a steam equilibration method with water vapor of known H isotopic composition – formerly applied by Ruppenthal (2014) on SOM and bulk soil – to clay fractions and compare our results to the hitherto used heating treatments (200-250°C) under vacuum. We expect that the δH-2 signal of the clay fraction of Bt horizons will serve to differentiate soils developed in different climatic epochs (e.g., Holocene, last interstadial, last interglacial) by analyzing dated palaeo soil samples. To test the hypothesis that there is a similar global regression line of the δH-2 values in structural water of clay as up to now reported for bulk soils and soil organic matter, we will analyze the clay fraction in a global set of soil samples

Equilibrium isotope fractionation factors of H exchange between steam and soil clay fractions

Rationale Steam equilibration overcomes the problem of the traditional measurements of H isotope compositions, which leave an arbitrary amount of adsorbed water in the sample, by controlling for the entire exchangeable H pool, including adsorbed water and hydroxyl-H. However, the use of steam equilibration to determine nonexchangeable stable H isotope compositions in environmental media (expressed as δ2Hn values) by mathematically eliminating the influence of exchangeable H after sample equilibration with waters of known H-isotopic composition requires the knowledge of the equilibrium isotope fractionation factor between steam-H and exchangeable H of the sample (αex-w), which is frequently unknown. Methods We developed a new method to determine the αex-w values for clay minerals, topsoil clay fractions, and mica by manipulating the contributions of exchangeable H to the total H pool via different degrees of post-equilibration sample drying. We measured the δ2H values of steam-equilibrated mineral and soil samples using elemental analyzer-pyrolysis-isotope ratio mass spectrometry. Results The αex-w values of seven clay minerals ranged from 1.071 to 1.140, and those of 19 topsoil clay fractions ranged from 0.885 to 1.216. The αex-w value of USGS57 biotite, USGS58 muscovite, and of cellulose was 0.965, 0.871, and 1.175, respectively. The method did not work for kaolinite, because its small exchangeable H pool did not respond to the selected drying conditions. Structurally different mineral groups such as two- and three-layer clay minerals or mica showed systematically different αex-w values. The αex-w value of the topsoil clay fractions correlated with the soil clay content (r = 0.63, P = 0.004), the local mean annual temperature (r = 0.68, P = 0.001), and the δ2H values of local precipitation (r = 0.72, P < 0.001), likely to reflect the different clay mineralogy under different weathering regimes. Conclusions Our new αex-w determination method yielded realistic results in line with the few previously published values for cellulose. The determined αex-w values were similar to the widely assumed values of 1.00–1.08 in the literature, suggesting that the adoption of one of these values in steam equilibration approaches is appropriate

Urinary CE-MS peptide marker pattern for detection of solid tumors

Urinary profiling datasets, previously acquired by capillary electrophoresis coupled to mass-spectrometry were investigated to identify a general urinary marker pattern for detection of solid tumors by targeting common systemic events associated with tumor-related inflammation. A total of 2,055 urinary profiles were analyzed, derived from a) a cancer group of patients (n = 969) with bladder, prostate, and pancreatic cancers, renal cell carcinoma, and cholangiocarcinoma and b) a control group of patients with benign diseases (n = 556), inflammatory diseases (n = 199) and healthy individuals (n = 331). Statistical analysis was conducted in a discovery set of 676 cancer cases and 744 controls. 193 peptides differing at statistically significant levels between cases and controls were selected and combined to a multi-dimensional marker pattern using support vector machine algorithms. Independent validation in a set of 635 patients (293 cancer cases and 342 controls) showed an AUC of 0.82. Inclusion of age as independent variable, significantly increased the AUC value to 0.85. Among the identified peptides were mucins, fibrinogen and collagen fragments. Further studies are planned to assess the pattern value to monitor patients for tumor recurrence. In this proof-of-concept study, a general tumor marker pattern was developed to detect cancer based on shared biomarkers, likely indicative of cancer-related features

Kants Theorie der Geschichte

An der Schwelle zum 19. Jahrhundert schuf Kant eine Reihe kürzerer Werke zu geschichtsphilosophischen Fragen, in denen er über Verlauf und Ziel der menschlichen Geschichte nachdenkt. Anliegen dieses Beitrags ist es, unter Rückgriff auf Reinhart Kosellecks semantische Untersuchungen, die Weiche für die immer wieder bezweifelte Rückbindung der Kantischen Geschichtsphilosophie an die erkenntnistheoretische ‚kopernikanischen Wende‘ aus der Kritik der reinen Vernunft zu stellen. Schließlich wird damit ein neues Licht auf den Kantischen Fortschrittsbegriff und die Idee einer Weltrepublik geworfen.On the threshold of the 19th century Kant produced a number of short works on questions dealing with the history of philosophy and reflecting about the goals of human history. Linking the Kantian history of philosophy to the epistemological turn in Kant’s Critique of Pure Reason has always been a problematic issue. This paper focusses on paving the way for this task by reference to Koselleck's semantic studies. Thus, a new light will be shed both to the Kantian concept of progress and the idea of a world republic

Non‐exchangeable stable hydrogen isotope ratios in clay minerals and soil clay fractions: A method test

Stable hydrogen isotope ratios (δ$^{2}$H values) in structural hydroxyl groups of pedogenic clay minerals are inherited from the surrounding water at the time of their formation. Only non-exchangeable H preserves the environmental forensic and paleoclimate information (δ$^{2}$H$_{n}$ value). To measure δ$^{2}$H$_{n}$ values in structural H of clay minerals and soil clay fractions, we adapted a steam equilibration method by accounting for high hygroscopicity. Our δ$^{2}$H$_{n}$ values for USGS57 biotite (−95.3 ± SD 0.9‰) and USGS58 muscovite (30.7 ± 1.4‰) differed slightly but significantly from the reported δ$^{2}$H values (−91.5 ± 2.4‰ and −28.4 ± 1.6‰), because the minerals contained 1.1%–4.4% of exchangeable H. The low SD of replicate measurements (n = 3) confirmed a high precision. The clay separation method including destruction of Fe oxides, carbonates and soil organic matter, and dispersion did not significantly change the δ$^{2}$H$_{n}$ values of five different clay minerals. However, we were unable to remove all organic matter from the soil clay fractions resulting in an estimated bias of 1‰ in two samples and 15‰ in the carbon-richest sample. Our results demonstrate that δ$^{2}$H$_{n}$ values of structural H of clay minerals and soil clay fractions can be reliably measured without interference from atmospheric water and the method used to separate the soil clay fraction

Stable hydrogen isotope ratios in soil organic matter

Stable H isotope ratios are a promising indicator of OM transformation processes (Schimmelmann et al., 2006). δ2H values of bulk organic matter and of specific organic compounds can be used as ecological tracer and forensic tool if the proportion of H that readily exchanges with ambient moisture is accounted for (Wassenaar &amp; Hobson, 1998). There are a few reports about the H isotope ratios in plant-soil systems illustrating that there is little knowledge of the controls of the isotopic composition of the non-exchangeable H fraction of bulk OM (Schimmelmann et al., 2006; Ruppenthal et al., 2015). The increasingly closer relationship between δ2H values of rainfall and of non-exchangeable H in OM (δ2Hn) in the order, plant – plant litter (above- and belowground) – soil along a climatic gradient (Ruppenthal et al., 2015) suggests that decomposition influences δ2Hn values in OM in a systematic way. However, there are knowledge gaps concerning the fractionation factors and the extent of incorporation of ambient water-H into the nonexchangeable fraction of H in OM during decomposition. Our research will focus on the mechanisms responsible for the strong correlation between δ2H values in rainfall and δ2Hn values of SOM. Therefore, our study aims to investigate (1) the incorporation of ambient water-H into the nonexchangeable H fraction in OM during decomposition by heterotrophic bacteria as model organisms and quantify apparent fractionation factors, (2) the extent of incorporation of ambient water into the nonexchangeable H fraction of OM by the soil microbial community under laboratory conditions, and (3) the extent to which H is incorporated into nonexchangeable OM pool from ambient water during decomposition of aboveground litter under field conditions. We will work with microcosms using two bacteria species and determine decomposition rates of litter. Steam equilibration (Ruppenthal et al., 2015) and TC/EA-IRMS are used as analytical tools. We expect that different decomposition rates because of differences in litter quality will be reflected by the extent of H incorporation from ambient water into the nonexchangeable H fraction of the products. Additionally, different litter types enriched in 2H will be buried in soil of forest stands. We hypothesize that the incorporation of 2H-depleted ambient water into 2H-enriched nonexchangeable H fraction of OM will depend on litter type, soil moisture/ temperature, and the heterotrophic activity during the experiment

MSc-FH in Life Sciences Fachgebiet Industrial Life Sciences startet im September 2009: FH – HES

The field of specialization denominated Industrial Life Sciences is one branch within the MSc in Life Sciences program of the Swiss Universities of Applied Sciences. It encompasses seven specializations, offered on four campuses and covers analytical sciences, chemistry, biotechnology, industrial pharmacy and parts of medicinal technologies/biomedical engineering. The program aims at the development of competencies which enable graduates to take further scientific and technical as well as management responsibilities within the context of an industrial environment. The master thesis is an essential element of the program. It is always integrated into a project of applied research and/or development which is, whenever possible, part of a collaboration with an industrial partner