Understanding heterogeneities of flow paths for agricultural practice

Heterogeneous flow processes, especially preferential flow, facilitate the influx of contaminants (and nutrients) through the soil into the groundwater. With a combination of soil physical, soil chemical and soil geophysical methods we investigate the susceptibility of selected soils for such flow processes on agricultural fields in Lower Saxony. Investigations are performed within the EU Interreg project TOPSOIL which investigates opportunities to improve surface and groundwater quality as well as water management strategies under the consideration of climate adaptation challenges. The project addresses the transport behavior of percolation water in the unsaturated zone, the migration of nitrogen and veterinary pharmaceuticals in soils, and elaborates - together with different stakeholders (e.g. farmers, water supply companies) - common strategies to minimize the migration of these substances into the groundwater. We present results of a first soil scientific and soil geophysical census using radiometry and electrical conductivity which shows the heterogeneity of the site with regard to conductivity and radiation. We used the CMD explorer for electromagnetic mapping (horizontal and vertical dipoles, intercoil spacing of 1.48/2.82/4.49 m, investigation depths of appr. 0 - 6 m). The radiometry detector comprised five sodium-iodide crystals each with a volume of 4 litres. The spectral data are evaluated for potassium, uranium (Bi-214), thorium (T-208) and total counts. The geophysical measurements were used to generally differentiate areas of different soil properties. These areas were sampled for soil physics and soil chemistry (ram coring at 48 sites, 0 - 2 m) with the aim of determining the variability of the transport behavior on a field scale

Transitions Induced by the Discreteness of Molecules in a Small Autocatalytic System

Autocatalytic reaction system with a small number of molecules is studied numerically by stochastic particle simulations. A novel state due to fluctuation and discreteness in molecular numbers is found, characterized as extinction of molecule species alternately in the autocatalytic reaction loop. Phase transition to this state with the change of the system size and flow is studied, while a single-molecule switch of the molecule distributions is reported. Relevance of the results to intracellular processes are briefly discussed.Comment: 5 pages, 4 figure

Anomalous Higgs Couplings

We review the effects of new effective interactions on the Higgs boson phenomenology. New physics in the electroweak bosonic sector is expected to induce additional interactions between the Higgs doublet field and the electroweak gauge bosons leading to anomalous Higgs couplings as well as to anomalous gauge-boson self-interactions. Using a linearly realized $SU(2)_L \times U(1)_Y$ invariant effective Lagrangian to describe the bosonic sector of the Standard Model, we review the effects of the new effective interactions on the Higgs boson production rates and decay modes. We summarize the results from searches for the new Higgs signatures induced by the anomalous interactions in order to constrain the scale of new physics in particular at CERN LEP and Fermilab Te vatron colliders.Comment: 35 pages, latex using epsfig.sty psfig.sty and axodraw.sty, 16 postscript figure

A double parton scattering background to Higgs boson production at the LHC

The experimental capability of recognizing the presence of b quarks in complex hadronic final states has addressed the attention towards final states with b\bar{b} pairs for observing the production of the Higgs boson at the LHC, in the intermediate Higgs mass range.We point out that double parton scattering processes are going to represent a sizeable background to the process.Comment: 9 pages, 2 figure

Healing relationships and the existential philosophy of Martin Buber

The dominant unspoken philosophical basis of medical care in the United States is a form of Cartesian reductionism that views the body as a machine and medical professionals as technicians whose job is to repair that machine. The purpose of this paper is to advocate for an alternative philosophy of medicine based on the concept of healing relationships between clinicians and patients. This is accomplished first by exploring the ethical and philosophical work of Pellegrino and Thomasma and then by connecting Martin Buber's philosophical work on the nature of relationships to an empirically derived model of the medical healing relationship. The Healing Relationship Model was developed by the authors through qualitative analysis of interviews of physicians and patients. Clinician-patient healing relationships are a special form of what Buber calls I-Thou relationships, characterized by dialog and mutuality, but a mutuality limited by the inherent asymmetry of the clinician-patient relationship. The Healing Relationship Model identifies three processes necessary for such relationships to develop and be sustained: Valuing, Appreciating Power and Abiding. We explore in detail how these processes, as well as other components of the model resonate with Buber's concepts of I-Thou and I-It relationships. The resulting combined conceptual model illuminates the wholeness underlying the dual roles of clinicians as healers and providers of technical biomedicine. On the basis of our analysis, we argue that health care should be focused on healing, with I-Thou relationships at its core

Eine neue Methode zur in-situ Bestimmung von präferentiellen Fließwegen von Wasser im Boden

Böden zeigen in der Regel, auch auf sehr kleinem Raum, eine große Variabilität der hydraulischen Eigenschaften. Diese Eigenschaften, aber auch verschiedene Rand- und Anfangsbedingungen oder andere Bodeneigenschaften, können zu einer räumlich und zeitlich unterschiedlichen Verlagerung von Wasser und damit transportierten Stoffen führen (preferential flow). Diese präferentiellen Flüsse werden in der Regel nicht bei der Vorhersage des Wasser- und Stofftransportes berücksichtigt und können daher starke Abweichungen vom prognostizierten Wasser- und Stofftransport verursachen. Präferentielle Flüsse sind an eine bestimmte räumliche Skala gebunden. Auf der Profilskala auftretende präferentielle Flüsse können i. d. R. nicht an Stechzylinderproben im Labor gemessen werden. Deshalb wird eine neue Feldmethode vorgestellt, bei der präferentiell fließendes Wasser in-situ detektiert werden kann. Mit Hilfe einer Beregnungsanlage wird Wasser mit einer konstanten Rate auf einer Fläche von ca. 8 m2 verregnet. Wassergehalte und –spannungen werden mit TDR-Sonden und Tensiometern kurz unter der Bodenoberfläche gemessen. Die Einstellung des Fließgleichgewichtes kann an der Konstanz der Wassergehalte und –spannungen detektiert werden. Die gleichmäßige, kurzzeitige Verregnung eines Salztracers wird durch die Messung der elektrischen Leitfähigkeit des Bodenwassers mit den TDR-Sonden erfasst werden. Mit Hilfe dieses Pulses können lokale Fließgeschwindigkeiten und somit präferentielle Fließwege aufgezeigt werden. Untermauert werden die Ergebnisse des Beregnungsversuches mit weiteren in-Situ- und Labormessungen der hydraulischen Leitfähigkeit und Simulationsmodellen. Mit der vorgestellten Methode konnten präferenzielle Wasserflüsse im Boden auch bei unterschiedlichen Anfangs- und Randbedingung beobachtet werden und so zu einem besseren Prozessverständnis beitragen

Yukawa Corrections to Top Quark Production at the LHC in Two- Higgs-Doublet Models

The O(alpha m_t^2/m_W^2) corrections to top quark pair production by gluon-gluon fusion at the LHC are calculated in two-Higgs-doublet models. We find that the correction to the cross-section can exceed about -10% for certain parameter values.Comment: 16-page text in LaTex. uuencoded file for Fig.1-6 will be sent separatel

QCD and Yukawa corrections to single-top-quark production via q qbar -> t bbar

We calculate the O(alpha_s) and O(alpha_W m_t^2/M_W^2) corrections to the production of a single top quark via the weak process q qbar -> t bbar at the Fermilab Tevatron and the CERN Large Hadron Collider. An accurate calculation of the cross section is necessary in order to extract |V_tb| from experiment.Comment: LaTeX, 13 pages, replaced with version to appear in Phys. Rev.

Einfluss CCS-bedingter Zuflüsse auf die CO2-Konzentrationen in Böden - Anforderungen aus Sicht des Bodenschutzes

Im Rahmen des vom Umweltbundesamt finanzierten Projektes (Ufo-Förderkenn¬zeichen: 3709 72 402) wurden potentielle Auswirkungen von CCS bedingten CO2-Zuflüssen auf das Ökosystem Boden beleuchtet. Dazu wurden bisher publizierte Ergebnisse hinsichtlich potentieller Wege des CCS-CO2 in den Boden, Einfluss¬faktoren der CO2-Konzentration im Boden sowie Auswirkungen hoher CO2-Gehalte auf Bodenlebewesen und Bodenfunktionen zusammengestellt und ausgewertet. Aufgrund der Heterogenität der Böden, der zeitlichen Variabilität der Boden¬zustände, sowie der nicht vorhersagbaren Rand¬bedingungen wird vorgeschlagen, mittels deterministischer Prozessmodelle maximal zulässige Flussdichten aus dem Untergrund (im Sinne von „Critical Loads“) abzuschätzen