Das chemische Klima des Riesenbecker Osning in den Messjahren 1988 und 1998

Depositionsmessungen imRiesenbeckerOsning (nordwestlicher TeutoburgerWald) führen in den Messjahren 1988 und 1998 zum Ergebnis eines Ammonium-betonten chemischen Klimas. Der Depositionstyp wird für 1998 über die Berechnung der Gesamtsäuredeposition exakt quantifiziert: Der Ammonium-Anteil an der Säurebelastung beträgt im Freilandniederschlag 71%, im Waldniederschlag 87%. Das so typisierte chemische Klima fügt sich ein in einen „Gülle-belt“, der sich von der niederländischen Grenze im Raum Kleve über das Münsterland nach Nordosten bis in das südlicheWeser-Ems-Gebiet Niedersachsens erstreckt.Das Ammonium-Nitrat-Verhältnis seiner Messstationen liegt durchweg über dem Indikator für den Einfluss der Massentierhaltung (NH4-N/NO3-N M 1,5). Die Gesamtstickstoffbelastung überschreitet deutlich den kritischen Depositionsgrenzwert für Nadelwälder. Langfristig führt dies zu einer Ökosystemdrift hin zu nitrophilen Waldgesellschaften, im ursprünglich oligotrophen Riesenbecker Osning angezeigt durch die invasive Einbürgerung eines stickstoffbedürftigen Bioindikators der Krautschicht, dem Kletternden Lerchensporn (Ceratocapnos claviculata).Deposition measures in the Riesenbecker Osning (north-west Teutoburg Forest) resulted during the measuring years 1988 and 1998 in a chemical climate characterised by ammonia. The deposition type for 1998 is quantified exactly by the calculation of the total acid deposition: Acid load by precipitation in the Riesenbecker Osning area is for the most part fixed to indirect acidification by ammonia that is approximately 71% of the precipitation on open ground and 87% of the throughfall. The so typified chemical climate fits in a „liquid manure belt“ extending fromthe border to the Netherlands (area of Kleve) across the Münsterland to the north-east until the southern Weser-Ems-area of Lower Saxony. The ammonia-nitrate-ratio of its measuring stations lies entirely over the indicator value for the influence of large-scale animal husbandry (NH4-N/NO3-N M 1,5). The total nitrogen load exceeds the critical load for coniferous forests and in the long term gives rise towards an ecosystemdrift into a nitrophile forest community, indicated in the originally oligotrophic Riesenbecker Osning by the invasive naturalization of the nitrophile forest layer plant species Ceratocapnos claviculata

Measurements of hillslope debris flow impact pressure on obstacles

We present measurements of hillslope debris flow impact pressures on small obstacles. Two impact sensors have been installed in a real-scale experimental site where 50m3 of water-saturated soil material are released from rest. Impact velocities vary between 2 and 13m/s; flow heights between 0.3 and 1.0m. The maximum impact pressures measured over 15 events represent between 2 and 50 times the equivalent static pressures. The measurements reveal that quadratic velocity-dependent formulas can be used to estimate impact pressures. Impact coefficients C are constant from front to tail and range between 0.4 < C < 0.8 according to the individual events. The pressure fluctuations to depend on the sensor size and are between 20% and 60% of the mean pressure values. Our results suggest that hazard guidelines for hillslope debris flows should be based on quadratic velocity-dependent formula

Unique gene structure and paralogy define the 7D-cadherin family

Cadherins are Ca2+-dependent transmembrane glycoproteins crucial for cell-cell adhesion in vertebrates and invertebrates. Classification of this superfamily due to their phylogenetic relationship is currently restricted to three major subfamilies: classical, desmosomal and protocadherins. Here we report evidence for a common phylogenetic origin of the kidney-specific Ksp- (Cdh16) and the intestine-specific LI-cadherin (Cdh17). Both genes consist of 18 exons and the positions of their exon-intron boundaries as well as their intron phases are perfectly conserved. We found an extensive paralogy of more than 40 megabases in mammals as well as teleost fish species encompassing the Ksp- and LI-cadherin genes. A comparable paralogy was not detected for other cadherin gene loci. These findings suggest that the Ksp- and LI-cadherin genes originated by chromosomal duplication early during vertebrate evolution and support our assumption that both proteins are paralogues within a separate cadherin family that we have termed 7D-cadherins

FAUNA BURUANA. Genus PAEDERUS FABRICIUS (Co1. Staph.)

abstract not availabl

Experimental investigation of forces along anchors subjected to dynamic loading under tension and compression in field tests

Full-scale field tests of dynamic rockfall have been performed on a flexible SPIDER Avalanche System to study the dynamic force distribution along the foundations under dynamic loading. Therefore, an anchor to measure dynamic tensile forces and a pile to measure dynamic compressive forces were each equipped with strain gauges. Furthermore, a static pull loading test with load steps of one-minute duration was performed on the anchor to highlight the difference between dynamic and static loading. Effective kinetic energies applied on the net of the SPIDER Avalanche System range from 25 to 492 kJ with impact velocities between 17 and 25 m/s. The results show that the dynamic forces close to the pile- and anchor head are higher and that they are decreasing with increasing distance of pile and anchor. However, the dynamic tensile force distribution is non-linear over the length of the anchor, whereas the dynamic compressive force distribution is linear along the pile length. The comparison of static and dynamic tensile forces shows that dynamic tensile forces are depleted within a shorter distance of the anchor compared to the static tensile forces. Dynamic tensile forces present 25% less in value than the static tensile forces

Numerical modeling using an elastoplastic-adhesive discrete element code for simulating hillslope debris flows and calibration against field experiments

This paper presents a discrete-element-based elastoplastic-adhesive model which is adapted and tested for producing hillslope debris flows. The numerical model produces three phases of particle contacts: elastic, plastic and adhesive. A parametric study was conducted investigating the effect of model parameters and inclination angle on flow height, velocity and pressure, in order to define the most sensitive parameters to calibrate. The model capabilities of simulating different types of cohesive granular flows were tested with different ranges of flow velocities and heights. The basic model parameters, the microscopic basal friction (ϕb) and ratio between stiffness parameters √k1/k2, were calibrated using field experiments of hillslope debris flows impacting a pressure-measuring sensor. Simulations of 50 m3 of material were carried out on a channelized surface that is 41 m long and 8 m wide. The calibration process was based on measurements of flow height, flow velocity and the pressure applied to a sensor. Results of the numerical model matched those of the field data in terms of pressure and flow velocity well while less agreement was observed for flow height. Those discrepancies in results were due in part to the deposition of material in the field test, which is not reproducible in the model. Results of best-fit model parameters against selected experimental tests suggested that a link might exist between the model parameters and the initial conditions of the tested granular material (bulk density and water and fine contents). The good performance of the model against the full-scale field experiments encourages further investigation by conducting lab-scale experiments with detailed variation in water and fine content to better understand their link to the model's parameters

Inclusión: una respuesta frente a la diversidad en las aulas : El preceptor como articulador de instancias y actores institucionales

El presente trabajo trata acerca del rol del preceptor como un articulador de las múltiples instancias institucionales, buscando un mejor aprovechamiento de los recursos humanos, profesionales y materiales, en el contexto de la problemática de la inclusión con calidad frente a las nuevas formas de diversidad en las aulas. Se analiza para ello una propuesta pedagógica del Colegio Nacional Rafael Hernández (UNLP) durante el año 2014, que refiere a una situación detectada en un grupo de ingresantes al primer año por parte de una preceptora. Se observaron ciertas discontinuidades entre lo escolar y lo familiar, en el caso de una estudiante cuyos padres no habían alcanzado el nivel medio en su escolaridad, lo que requirió un abordaje multidisciplinario que vinculara subjetivamente los espacios escolares, tanto en el ámbito privado y familiar, como así también los espacios institucionales. La escuela, como portadora de los significados y lenguajes, que permitan construir nuevas herramientas intelectuales, brindando la posibilidad de representaciones del mundo que mediaticen su acción en él (a través de la acción reflexiva sobre el mundo) supone, necesariamente, una vinculación subjetiva previa y un conocimiento reflexivo, que se oponen a la concepción bancaria de la educación descripta por Paulo Freire.Colegio Nacional "Rafael Hernández

Numerical modeling of shallow landslide impacts on flexible protection systems and its validation with full scale testing

Innovative flexible protection barriers against shallow landslides, made from high tensile steel meshes, demanded the development of numerical models for the different mesh types accompanied with 1:1 scale prototype field testing. To generate the barrier model, a special Discrete Element had to be developed that represents the chain link type of steel mesh. It was crucial that it includes the complex out-of-plane height of the mesh that accomodates the local high deformations of the net. The filling process of the barrier is simulated using OpenFOAM, taking the fluid-structure interaction with high deformations into account. In addition to the shear thinning behaviour of the mud, the turbulence in form of a large eddy simulation can be introduced, having regard to the interaction with the complex geometry and free surface by a Dynamic Mixed Model approach for the subgrid scales. The model is validated with 1:1 scale tests where shots of 50 m3 of mud travel down a 40 m long slope and hit the barrier

Practical guide for debris flow and hillslope debris flow protection nets and its application in case studies

Debris flows and hillslope debris flows endanger people and infrastructures. Technical protection measures are important elements in addition to spatial planning (adapted use of space like hazard maps) and organizational measures (warning systems, emergency plan, evacuation). Additional to other rigid protection measures flexible debris flow nets and hillslope debris flow nets were developed in 2008, and 2010 respectively. Such flexible barriers consist of an interception surface of netting spanned between horizontal support ropes including energy devices and posts for large span width. Since then, they are available on the market worldwide. Many projects were successfully installed and already filled by debris flow events. After more than ten years of experience and demonstrating that these measures work against debris flow and hillslope debris flow, they are fully accepted as possible measures for integral protection against debris flow. To provide planners and engineers the experience and know-how of these flexible protection nets, a practical guide was initiated by the Swiss Federal Roads Office (FEDRO) and Swiss Federal Office for the Environment (FOEN). Two case studies with planned and installed flexible nets, in one case for a debris flow and in the other case for a hillslope debris flow, are presented