Hardwarearchitektur für einen universellen LDPC Decoder

Im vorliegenden Beitrag wird eine universelle Decoderarchitektur für einen Low-Density Parity-Check (LDPC) Code Decoder vorgestellt. Anders als bei den in der Literatur häufig beschriebenen Architekturen für strukturierte Codes ist die hier vorgestellte Architektur frei programmierbar, so dass jeder beliebige LDPC Code durch eine Änderung der Initialisierung des Speichers für die Prüfmatrix mit derselben Hardware decodiert werden kann. Die größte Herausforderung beim Entwurf von teilparallelen LDPC Decoder Architekturen liegt im konfliktfreien Datenaustausch zwischen mehreren parallelen Speichern und Berechnungseinheiten, wozu ein Mapping und Scheduling Algorithmus benötigt wird. Der hier vorgestellte Algorithmus stützt sich auf Graphentheorie und findet für jeden beliebigen LDPC Code eine für die Architektur optimale Lösung. Damit sind keine Wartezyklen notwendig und die Parallelität der Architektur wird zu jedem Zeitpunkt voll ausgenutzt

Earthworm communities in an agroforest system: Impact of tree rows on the distribution in grassland and cropped land

Agroforest systems are highly discussed as new and innovative land use systems for arable land in temperate regions. They are recommended due to their beneficial impact on several ecosystem functions and for the general diversification of the cultured landscapes. Tree rows, known as alley cropping systems, are one of the most frequent applications. In May 2016 earthworm communities were sampled in an agroforest system in Reiffenhausen south of Göttingen using an electrical extraction system. Asking for the impact of tree rows on the spatial distribution of earthworms, sampling was done in distances of 0, 1, and 4.5m from the alleys (willow on grassland and poplar on cropland). Also grassland and cropland with no trees were sampled as a control. At Reiffenhausen we obtained 6 different species covering all ecological groups of earthworms. Abundances indicated a step gradient for earthworm numbers in the combination of poplar with cropland with decreasing numbers with increasing distance. However, the gradient was not indicated for willow rows on grassland. An effect of hypnotized earthworm supporting factors like litter entry and shading couldn’t be fully confirmed. More data is needed to value agroforest systems for their impact on key organisms and key functions of soil biota

Räumliche Verteilung mikrobieller Bodeneigenschaften in verschiedenen Agroforstsystemen in Deutschland

In den letzten Dekaden konnte frequentiert gezeigt werden, dass Managementpraktiken sowohl Qualität und Quantität pflanzlicher Residuen als auch Aktivität und Diversität von Bodenmikroorganismen beeinflussen. Vor dem Hintergrund nachhaltiger Landnutzung stellen Agroforstsysteme als Kombination aus Bäumen/Sträuchern und Ackerkulturen/Grünland innerhalb eines Landbausystems einen multifunktionalen Ansatz dar. Denn Bäume beeinflussen durch Veränderungen des Mikroklimas und des C-Eintrags direkt das Bodenmilieu und besitzen damit Auswirkungen auf von Bodenorganismen herbeigeführten Ökosystemleistungen (z.B. Abbau organischer Substanz, Nährstoffversorgung, C-Sequestrierung). Dennoch wurden derartige Effekte auf die mikrobielle Aktivität/Diversität und räumliche Variation nur spärlich untersucht. Wir postulieren, dass Unterschiede abiotischer und biotischer Faktoren mit zunehmender Distanz von Baumstreifen die Aktivität und Diversität von Bodenmirkoorganismen beeinflussen. Dafür wurden Oberböden in zwei Tiefen (0-5, 5-20 cm) in unterschiedlichen silvo-arablen und silvo-pastoralen Agroforstsystemen in Deutschland in den Baumstreifen sowie in verschiedenen Distanzen von den Baumstreifen beprobt. An den Bodenproben wurden Corg- und Nt-Gehalte, mikrobielle Biomasse (CMik, NMik), Ergosterol, mikrobielle Residuen (Aminozucker) und pH-Werte bestimmt. Die Ergebnisse zeigen, dass die Baumstreifen mikrobielle Indizes beeinflussen. So hat die Etablierung der Agroforstsysteme an einigen Standorten unter den Bäumen in 0-5 cm Bodentiefe bereits zu einer signifikanten Erhöhung der Corg- und Nt-Gehalte geführt. Gleichfalls konnten erhöhte Cmik-, Nmik- und Ergosterolgehalte beobachtet werden. Darüber hinaus weisen wichtige mikrobiologische Quotienten Unterschiede auf. So deuten signifikant erhöhte Cmik-zu-Corg- und Ergosterol-zu-Cmik-Quotienten auf eine verbesserte C-Nutzungseffizienz beziehungsweise einen erhöhten Anteil saprotropher Pilze an der mikrobiellen Biomasse unter den Bäumen hin. Ferner wird der Einfluss abiotischer Faktoren (z.B. pH, Tongehalt) auf die räumliche Verteilung der mikrobiellen Parameter und die Problematik der Bestimmung der Effekte bei hoher Bodenvariabilität in Agroforstsystemen und Acker-/Grünlandkontrollflächen aufgezeigt

Shell model description of normal parity bands in odd-mass heavy deformed nuclei

The low-energy spectra and B(E2) electromagnetic transition strengths of 159Eu, 159Tb and 159Dy are described using the pseudo SU(3) model. Normal parity bands are built as linear combinations of SU(3) states, which are the direct product of SU(3) proton and neutron states with pseudo spin zero (for even number of nucleons) and pseudo spin 1/2 (for odd number of nucleons). Each of the many-particle states have a well-defined particle number and total angular momentum. The Hamiltonian includes spherical Nilsson single-particle energies, the quadrupole-quadrupole and pairing interactions, as well as three rotor terms which are diagonal in the SU(3) basis. The pseudo SU(3) model is shown to be a powerful tool to describe odd-mass heavy deformed nuclei.Comment: 11 pages, 2 figures, Accepted to be published in Phys. Rev.

Inter-band B(E2) transition strengths in odd-mass heavy deformed nuclei

Inter-band B(E2) transition strengths between different normal parity bands in 163Dy and 165Er are described using the pseudo-SU(3) model. The Hamiltonian includes Nilsson single-particle energies, quadrupole-quadrupole and pairing interactions with fixed, parametrized strengths, and three extra rotor terms used to fine tune the energy spectra. In addition to inter-band transitions, the energy spectra and the ground state intra-band B(E2) strengths are reported. The results show the pseudo-SU(3) shell model to be a powerful microscopic theory for a description of the normal parity sector in heavy deformed odd-A nuclei.Comment: 4 figures, 2 table

Pseudospin symmetry and its approximation in real nuclei

The origin of pseudospin symmetry and its broken in real nuclei are discussed in the relativistic mean field theory. In the exact pseudospin symmetry, even the usual intruder orbits have degenerate partners. In real nuclei, pseudospin symmetry is approximate, and the partners of the usual intruder orbits will disappear. The difference is mainly due to the pseudo spin-orbit potential and the transition between them is discussed in details. The contribution of pseudospin-orbit potential for intruder orbits is quite large, compared with that for pseudospin doublets. The disappearance of the pseudospin partner for the intruder orbit can be understood from the properties of its wave function.Comment: 10 pages, 3 figure

CREB-Induced Inflammation Is Important for Malignant Mesothelioma Growth

Malignant mesothelioma (MM) is an aggressive tumor with no treatment regimen. Previously we have demonstrated that cyclic AMP response element binding protein (CREB) is constitutively activated in MM tumor cells and tissues and plays an important role in MM pathogenesis. To understand the role of CREB in MM tumor growth, we generated CREB-inhibited MM cell lines and performed in vitro and in vivo experiments. In vitro experiments demonstrated that CREB inhibition results in significant attenuation of proliferation and drug resistance of MM cells. CREB-silenced MM cells were then injected into severe combined immunodeficiency mice, and tumor growth in s.c. and i.p. models of MM was followed. We observed significant inhibition in MM tumor growth in both s.c. and i.p. models and the presence of a chemotherapeutic drug, doxorubicin, further inhibited MM tumor growth in the i.p. model. Peritoneal lavage fluids from CREB-inhibited tumor-bearing mice showed a significantly reduced total cell number, differential cell counts, and pro-inflammatory cytokines and chemokines (IL-6, IL-8, regulated on activation normal T cell expressed and secreted, monocyte chemotactic protein-1, and vascular endothelial growth factor). In vitro studies showed that asbestos-induced inflammasome/inflammation activation in mesothelial cells was CREB dependent, further supporting the role of CREB in inflammation-induced MM pathogenesis. In conclusion, our data demonstrate the involvement of CREB in the regulation of MM pathogenesis by regulation of inflammation

The pseudo-spin symmetry in Zr and Sn isotopes from the proton drip line to the neutron drip line

Based on the Relativistic continuum Hartree-Bogoliubov (RCHB) theory, the pseudo-spin approximation in exotic nuclei is investigated in Zr and Sn isotopes from the proton drip line to the neutron drip line. The quality of the pseudo-spin approximation is shown to be connected with the competition between the centrifugal barrier (CB) and the pseudo-spin orbital potential (PSOP). The PSOP depends on the derivative of the difference between the scalar and vector potentials $dV/dr$. If $dV/dr = 0$, the pseudo-spin symmetry is exact. The pseudo-spin symmetry is found to be a good approximation for normal nuclei and to become much better for exotic nuclei with highly diffuse potential, which have $dV/dr \sim 0$. The energy splitting of the pseudo-spin partners is smaller for orbitals near the Fermi surface (even in the continuum) than the deeply bound orbitals. The lower components of the Dirac wave functions for the pseudo-spin partners are very similar and almost equal in magnitude.Comment: 22 pages, 9figure