Cellular and nuclear morphology…and calcium signaling: revealing the interplay between structure and function
Peter von der Bengtson
- Poster presentation: Calcium plays a pivotal role in relaying electrical signals of the cell to subcellular compartments, such as the nucleus. Since this one ion type is used by the cell for many processes a neuron needs to establish finely tuned calcium pathways in order to be able to differentiate multiple tasks, [1-3].
While it is known that neurons can actively change their shape upon neuronal activity, [4-7], we here present novel findings of activity-regulated nuclear morphology, [8,9]. With the help of an experimental and computational modeling approach, we show that hippocampal neurons can change the previously spherical shape of their nuclei to complex and infolded morphologies. This morphology regulation is demonstrated to be regulated by NMDA-receptor gated calcium, while synaptic and extra-synaptic NMDA-receptors elicit opposing effects on nuclear morphology, .
The structural alterations of the cell nucleus have significant effects on nuclear calcium dynamics. Compartmentalization of the nucleus, due to membrane infoldings, changes calcium frequencies, amplitudes and spatial distributions, [8,10]. Since these parameters have been shown to control downstream events towards gene transcription, [11,12], the results elucidate the cellular control of nuclear function with the help of morphology modulation. With respect to processes downstream of calcium, we show that histone H3 phosphorylation is closely linked to nuclear morphology. Investigating the nuclear morphologies of hippocampal neurons, two major classes were identified [9,10]. One class contains non-infolded nuclei that have the function of calcium signal integrators, while the other class contains highly infolded nuclei, which function as frequency detectors of nuclear calcium, .
Extending this interdisciplinary approach of investigating structure/function relationships in neurons, the effects of cellular morphology – as well as the morphology of the endoplasmic reticulum and other organelles – on neuronal calcium signals is currently being investigated. This endeavor makes use of highly detailed, three-dimensional models of neuronal calcium dynamics, including the three-dimensional morphology of the cell and its organelles.
Monitoring soil erosion in the Souss basin, Morocco, with a multiscale object-based remote sensing approach using UAV and satellite data
Klaus Daniel Peter
Johannes B. Ries
Ali Aït Hssaïne
- This article presents a multiscale approach for detecting and monitoring soil erosion phenomena (i.e. gully erosion) in the agro-industrial area around the city of Taroudannt, Souss basin, Morocco. The study area is characterized as semi-arid with an annual average precipitation of 200 mm. Water scarcity, high population dynamics and changing land use towards huge areas of irrigation farming present numerous threats to sustainability. The agro-industry produces citrus fruits and vegetables in monocropping, mainly for the European market. Badland areas strongly affected by gully erosion border the agricultural areas as well as residential areas. To counteract the significant loss of land, land-leveling measures are attempted to create space for plantations and greenhouses. In order to develop sustainable approaches to limit gully growth the detection and monitoring of gully systems is fundamental. Specific gully sites are monitored with unmanned aerial vehicle (UAV) taking small-format aerial photographs (SFAP). This enables extremely high-resolution analysis (SFAP resolution: 2-10 cm) of the actual size of the gully channels as well as a detailed continued surveillance of their growth. Transferring the methodology on a larger scale using Quickbird satellite data (resolution: 60 cm) leads to the possibility of a large-scale analysis of the whole area around the city of Taroudannt (Area extent: ca. 350 km²). The results will then reveal possible relationships of gully growth and agro-industrial management and may even illustrate further interdependencies. The main objective is the identification of areas with high gully-erosion risk due to non-sustainable land use and the development of mitigation strategies for the study area.
The do`s and don`ts of teaching English at the college/university level Papers from the third Chełm symposium held in april 2003), ed by Grzegorz Kleparski, NKJO-Chełm publishers, 2003, pp. 93, ISBN 83-911683-5-2.
Mind, language and metaphor : Euroconference on consciousness and the imagination, Kerkrade (the Netherlands), april 20-24, 2002.
Pedro J. Chamizo Dominguez
Carmen M. Bretones Callejas
Report on the British Council sponsored conference held in 20-22 of may 2001 in Chełm : "the pitfalls of teaching grammar, lexis and Anglo-Saxon culture at a college level"
Grzegorz A. Kleparski
Report on 34th conference of the "Societas Linguistica Europea" : language study in Europe at the turn of the millennium. Towards the integration of cognitive, historical und cultural approaches to language, Katholieke Universiteit Leuven, Belgium, august 28-31, 2001.
Grzegorz A. Kleparski
A demonstrator for the Micro-Vertex-Detector of the CBM experiment
- CMOS sensors are the most promising candidates for the Micro-Vertex-Detector (MVD) of the CBM experiment at GSI, as they provide an unprecedented compromise between spatial resolution, low material budget, adequate radiation tolerance and readout speed. To study the integration of these sensors into a detector module, a so-called MVD-demonstrator has been developed. The demonstrator and its in-beam performance will be presented and discussed in this work.
A modification of the mixed form of Richards equation and its application in vertically inhomogeneous soils
- Recently, new soil data maps were developed, which include vertical soil properties like soil type. Implementing those into a multilayer Soil-Vegetation-Atmosphere-Transfer (SVAT) scheme, discontinuities in the water content occur at the interface between dissimilar soils. Therefore, care must be taken in solving the Richards equation for calculating vertical soil water fluxes. We solve a modified form of the mixed (soil water and soil matric potential based) Richards equation by subtracting the equilibrium state of soil matrix potential ψE from the hydraulic potential ψh. The sensitivity of the modified equation is tested under idealized conditions. The paper will show that the modified equation can handle with discontinuities in soil water content at the interface of layered soils.
Status of the Micro Vertex Detector of the Compressed Baryonic Matter Experiment
Rita De Masi
Franz M. Wagner
- The CBM experiment will investigate heavy-ion collisions at beam energies from 8 to 45 AGeV
at the future accelerator facility FAIR. The goal of the experiment is to study the QCD phase
diagram in the vincinity of the QCD critical point. To do so, CBM aims at measuring rare probes
among them open charm. In order to identify those rare and short lived particles despite the
rich combinatorial background generated in heavy ion collisions, a micro vertex detector (MVD)
providing an unprecedented combination of high rate capability and radiation hardness, very light
material budget and excellent granularity is required. In this work, we will discuss the concept of
this detector and summarize the status of the R&D.
Sepsis 2012 : Paris, France, 7 - 9 November 2012 ; meeting abstracts