SHYPFIT 2.0 – Software zur Anpassung hydraulischer Funktionen an Messdaten

SHYPFIT 2.0 ist ein Werkzeug zur Anpassung von hydraulischen Funktionen an Messdaten, in dem folgende Innovationen umgesetzt wurden: (1) Sichere Schätzung des globalen Optimums für hydraulische Funktionen ohne Angabe von Anfangsschätzwerten, (2) Elimination von systematischen Schätzfehlern nahe Sättigung, (3) Gewichtete simultane Schätzung der Retentions- und Leitfähigkeitsfunktion, (4) Auswahl aus einer Vielzahl von Retentions- und Leitfähigkeitsmodellen, darunter das Free-Form-Modell von Iden und Durner (2007). Das Programm wird ab 2010 über die Websei-ten des Instituts für Geoökologie in Braunschweig frei downloadbar sein. Features des Programms sind ferner in der Auswertungssoftware des Labor-Verdunstungs-Systems HYPROP™ der Fa. UMS München implementiert

Replikation im mobilen Pflegeassistenzsystem MARIKA

Mit dem derzeitigen demografischen Wandel nimmt auch die Bedeutung der häuslichen Gesundheitspflege stark zu. Professionelle Pflegedienste unterliegen dabei einer gesetzlichen Dokumentationspflicht. Die Dokumentation von Pflegeaktivitäten ist eine sehr zeitaufwendige Tätigkeit und nimmt bis zu 40% der täglichen Arbeitszeit in Anspruch. Durch automatische Dokumentation ist es möglich, das Pflegepersonal zu unterstützen, so dass letztendlich mehr Zeit für die eigentlichen Pflegetätigkeiten bleibt. Das in dieser Arbeit vorgestellte Projekt MARIKA beschäftigt sich mit der Entwicklung einer globalen Pflegedokumentations- und Koordinationsplattform. Diese soll das Pflegepersonal durch automatische Aufzeichnung der erbrachten Pflegetätigkeiten unterstützen. Durch Rückschlüsse aus der Analyse und Auswertung dokumentierter Tätigkeiten kann die Planung täglicher Arbeitsabläufe verbessert und die Auslastung vorhandener Ressourcen optimiert werden. Ein Kernbestandteil des Systems bilden Geräte für den ambulanten mobilen Pflegeeinsatz. Nach Aufzeichnung der erbrachten Pflegetätigkeiten werden die aufgezeichneten Daten zwischen den Komponenten des Systems repliziert. Für den Einsatz in verteilten Datenbanksystemen mit mobilen Teilnehmern werden spezielle Replikationsverfahren vorgestellt

Prediction of the absolute hydraulic conductivity function from soil water retention data

For modeling flow and transport processes in the soil–plant–atmosphere system, knowledge of the unsaturated hydraulic properties in functional form is mandatory. While much data are available for the water retention function, the hydraulic conductivity function often needs to be predicted. The classical approach is to predict the relative conductivity from the retention function and scale it with the measured saturated conductivity, Ks. In this paper we highlight the shortcomings of this approach, namely, that measured Ks values are often highly uncertain and biased, resulting in poor predictions of the unsaturated conductivity function. We propose to reformulate the unsaturated hydraulic conductivity function by replacing the soil-specific Ks as a scaling factor with a generally applicable effective saturated tortuosity parameter τs and predicting total conductivity using only the water retention curve. Using four different unimodal expressions for the water retention curve, a soil-independent general value for τs was derived by fitting the new formulation to 12 data sets containing the relevant information. τs was found to be approximately 0.1. Testing of the new prediction scheme with independent data showed a mean error between the fully predicted conductivity functions and measured data of less than half an order of magnitude. The new scheme can be used when insufficient or no conductivity data are available. The model also helps to predict the saturated conductivity of the soil matrix alone and thus to distinguish between the macropore conductivity and the soil matrix conductivity.</p

Nitrogen release from different polymer‐coated urea fertilizers in soil is affected by soil properties

The use of urea as nitrogen (N) fertilizer in agriculture needs to consider environmental, economic and resource conservation aspects because of low N-use efficiency (NUE). Polymer-coated urea (PCU) offers an effective way to improve the NUE of urea and to reduce its environmental trade-offs. However, we lack information on the impact of climate and soil properties on N release from PCU. Therefore, this study was performed to quantify the effects of soil texture, moisture and temperature on the release kinetics of N from PCU. We designed a test system for soil incubation experiments and investigated three fertilizers with different release patterns, five topsoils, three moisture levels and two temperatures over 48 days. We analysed the concentrations of inorganic N (NH$_{4}$$^{+}$ – N and NO$_{3}$$^{-}$ - N) in the soil and estimated N release rates using the unified Richards model. Soil texture did not change the N release patterns, but release rates varied significantly among the investigated soils. Changes in soil moisture for a given soil had no effect on N release from PCU and urea when fertilizers were incorporated into the soil at conditions supportive of crop growth. Lowering soil temperatures, however, decreased N release rates from PCU by 16%–49% but only in silt loam and not in sandy loam. We conclude that PCU improves the N residence time in soil, but predictions on N release from PCU must be adapted to the prevailing environmental conditions and cannot be generalized across differently textured soils

Local Solute Sinks and Sources Cause Erroneous Dispersion Fluxes in Transport Simulations with the Convection–Dispersion Equation

The convection–dispersion equation (CDE) is the most widely used model for simulating the transport of dissolved substances in porous media. The dispersion term in the CDE lumps molecular diffusion and hydromechanical dispersion into an effective diffusive solute flux. This is possible by describing hydrodynamic dispersion with Fick’s first law of diffusion. We critically analyzed this concept for specific water flow situations where the solute concentration is locally increased by processes like root water uptake or water evaporation. The local accumulation of solutes in these situations leads to high concentration gradients and a dispersive solute flux component opposite to the direction of the water flux. This is physically wrong because it assumes that molecules or ions are moving against the flow direction by dispersion. The aim of this study was to investigate the magnitude of the resulting error by means of numerical modeling. We simulated solute transport from a groundwater table to a bare soil surface during steadystate evaporation using the HYDRUS-1D code. The simulations showed that in the region where dissolved substances accumulate due to the transition from liquid water to vapor, the resulting incorrect dispersive flux against the mean transport direction can reach the same order of magnitude as the convective solute flux. Under such conditions, application of the CDE is questionable

Bestimmung mikrobieller Aktivität in Böden mittels IR – Thermographie

Die mikrobielle Aktivität in Böden wird in der Regel an abgeschlossenen Bodenproben anhand der Bodenatmung oder des Energieumsatzes erfasst (z.B. Respirometer, Kalorimeter). Diese Verfahren können jedoch nur punktuelle Aussagen zur mikrobiellen Aktivität, und damit z.B. zu Belastungen von Böden mit Umwelt-chemikalien liefern. In diesem Beitrag stellen wir ein Verfahren vor, das die Bestimmung flächenhafter mikrobieller Aktivität anhand von räumlich und zeitlich hoch aufgelöster Infrarot(IR)- Thermographie erlaubt. Erste Versuche zeigen, dass dieses Verfahren generell möglich ist. Mögliche andere Einflussgrößen für die Oberflächentemperatur, wie z.B. Evaporation, müssen ausgeschlossen oder bei der Auswertung berücksichtigt werden

Bestimmung der Evaporationsrate von Bodenoberflächen mittels Thermographie

Die aktuellen Evaporationsraten von Bodenoberflächen lassen sich durch aufeinander folgende Wägungen bestimmen. Diese Methode hat zwei Nachteile (i) sie ist nur an kontrollierten Bodenmonolithen auf der Labor- und Lysimeterskala möglich und (ii) sie liefert nur ein über die gesamte Bodenoberfläche integriertes Signal, es gibt somit keine Information über eine räumlich variable Evaporationsrate. In diesem Beitrag stellen wir ein Verfahren vor, das die Evaporationsrate mittels Thermographie räumlich und zeitlich hochaufgelöst ermittelt. Ein erster Versuch zeigt, dass dieses Verfahren prinzipiell anwendbar ist. Allerdings spielen die Substrateigenschaften eine große Rolle, sodass eine jeweilige Kalibrierung notwendig ist

Chimeric Antigen Receptor T-Cell Therapy in Paediatric B-Cell Precursor Acute Lymphoblastic Leukaemia : Curative Treatment Option or Bridge to Transplant?

Chimeric antigen receptor T-cell therapy (CAR-T) targeting CD19 has been associated with remarkable responses in paediatric patients and adolescents and young adults (AYA) with relapsed/refractory (R/R) B-cell precursor acute lymphoblastic leukaemia (BCP-ALL). Tisagenlecleucel, the first approved CD19 CAR-T, has become a viable treatment option for paediatric patients and AYAs with BCP-ALL relapsing repeatedly or after haematopoietic stem cell transplantation (HSCT). Based on the chimeric antigen receptor molecular design and the presence of a 4-1BB costimulatory domain, tisagenlecleucel can persist for a long time and thereby provide sustained leukaemia control. "Real-world" experience with tisagenlecleucel confirms the safety and efficacy profile observed in the pivotal registration trial. Recent guidelines for the recognition, management and prevention of the two most common adverse events related to CAR-T - cytokine release syndrome and immune-cell-associated neurotoxicity syndrome - have helped to further decrease treatment toxicity. Consequently, the questions of how and for whom CD19 CAR-T could substitute HSCT in BCP-ALL are inevitable. Currently, 40-50% of R/R BCP-ALL patients relapse post CD19 CAR-T with either CD19(-) or CD19(+) disease, and consolidative HSCT has been proposed to avoid disease recurrence. Contrarily, CD19 CAR-T is currently being investigated in the upfront treatment of high-risk BCP-ALL with an aim to avoid allogeneic HSCT and associated treatment-related morbidity, mortality and late effects. To improve survival and decrease long-term side effects in children with BCP-ALL, it is important to define parameters predicting the success or failure of CAR-T, allowing the careful selection of candidates in need of HSCT consolidation. In this review, we describe the current clinical evidence on CAR-T in BCP-ALL and discuss factors associated with response to or failure of this therapy: product specifications, patient- and disease-related factors and the impact of additional therapies given before (e.g., blinatumomab and inotuzumab ozogamicin) or after infusion (e.g., CAR-T re-infusion and/or checkpoint inhibition). We discuss where to position CAR-T in the treatment of BCP-ALL and present considerations for the design of supportive trials for the different phases of disease. Finally, we elaborate on clinical settings in which CAR-T might indeed replace HSCT.Peer reviewe

Magnetic fields during the early stages of massive star formation - I. Accretion and disk evolution

We present simulations of collapsing 100 M_\sun mass cores in the context of massive star formation. The effect of variable initial rotational and magnetic energies on the formation of massive stars is studied in detail. We focus on accretion rates and on the question under which conditions massive Keplerian disks can form in the very early evolutionary stage of massive protostars. For this purpose, we perform 12 simulations with different initial conditions extending over a wide range in parameter space. The equations of magnetohydrodynamics (MHD) are solved under the assumption of ideal MHD. We find that the formation of Keplerian disks in the very early stages is suppressed for a mass-to-flux ratio normalised to the critical value \mu below 10, in agreement with a series of low-mass star formation simulations. This is caused by very efficient magnetic braking resulting in a nearly instantaneous removal of angular momentum from the disk. For weak magnetic fields, corresponding to \mu > 10, large-scale, centrifugally supported disks build up with radii exceeding 100 AU. A stability analysis reveals that the disks are supported against gravitationally induced perturbations by the magnetic field and tend to form single stars rather than multiple objects. We find protostellar accretion rates of the order of a few 10^-4 M_\sun yr^-1 which, considering the large range covered by the initial conditions, vary only by a factor of ~ 3 between the different simulations. We attribute this fact to two competing effects of magnetic fields. On the one hand, magnetic braking enhances accretion by removing angular momentum from the disk thus lowering the centrifugal support against gravity. On the other hand, the combined effect of magnetic pressure and magnetic tension counteracts gravity by exerting an outward directed force on the gas in the disk thus reducing the accretion onto the protostars.Comment: 22 pages, 17 figures, accepted for publication in MNRAS, updated to final versio