Isolation and Physical Mapping of the Mitochondrial Chromosome From the Zygomycete Mucor Racemosus.

Mitochondria were isolated from Mucor racemosus and DNA was purified from these organelles by cesium chloride/ethidium bromide isopycnic centrifugation. Examination of mitochondrial DNA samples with a transmission electron microscope revealed a circular mitochondrial chromosome approximately 63.8 kbp in length. Summation of restriction fragments of mitochondrial DNA separated by agarose gel electrophoresis yielded a comparable value of 63.4 kbp for the size of the intact molecule. Electrophoretic mobility and stoichiometry were determined for restriction fragments generated using nine different restriction enzymes. A physical map was deduced from single and double digestions of mitochondrial DNA with several of the restriction enzymes. The locations of the large and small ribosomal RNA genes were mapped and found to be contained in reverse orientation within a repeated region of the mitochondrial genome. This construction yields two populations of mitochondrial DNA molecules, possibly generated through a homologous recombination mechanism

Workflow-Management-Systeme in virtuellen Unternehmen

Virtuelle Unternehmen stellen ein Instrument zur Bewältigung der sprunghaft angestiegenen wirtschaftlichen Dynamik dar. Ausgehend von dem Begriff Virtualität interpretiert der vorliegende Beitrag virtuelle Unternehmen als eine spezielle Ausprägung virtueller Organisationen. Vier Definitionsmerkmale sind konstituierend für das Konzept der virtuellen Unternehmung. Diese Merkmale dienen außerdem zur Identifikation von Problemen und Risiken in diesem Bereich und zeigen, daß dem Konzept der virtuellen Unternehmung die Prozeßorientierung als organisatorisches Gestaltungsprinzip zugrunde liegt. Für die DV-Unterstützung prozeßorientierter Organisationsstrukturen gelten Workflow-Systeme als besonders geeignet. In virtuellen Unternehmen kann der durch Workflow-Systeme entstehende Nutzen unternehmensübergreifend ausgeschöpft werden. Darüber hinaus wird der Zusammenschluß zu einer virtuellen Unternehmung durch die Kopplung von Workflow-Systemen direkt gefördert. Das zwischenbetriebliche Workflow-Phasenmodell zeigt, wie man bei der Kopplung von Unternehmen über interoperable Workflow-Systeme vorgehen sollte. Konkrete Ansatzpunkte, Nutzenpotentiale und Probleme bei der Unterstützung von virtuellen Unternehmen durch Workflow-Systeme lassen sich wiederum anhand der vier Definitionsmerkmale virtueller Unternehmen herleiten

Nonthermal Plasma Synthesis and Plasmonic Properties of Doped Silicon and Titanium Nitride Nanocrystals

University of Minnesota Ph.D. dissertation. September 2017. Major: Mechanical Engineering. Advisor: Uwe Kortshagen. 1 computer file (PDF); viii, 90 pages.This work examines the nonthermal plasma synthesis of phosphorus and boron doped silicon and titanium nitride nanocrystals. The localized surface plasmon resonance (LSPR) of these materials was investigated. Titanium nitride has a plasmon resonance in the visible and near infrared, like gold nanorods, making it a viable alternative to gold for biological applications like photothermal therapy treatments. Titanium nitride is less expensive and more temperature stable than gold as well as biocompatible. The nonthermal plasma synthesis route is a continuous production method that eliminates the need for long processing and morphology modification steps required for gold nanorod production. The plasmon resonance, composition, and particle uniformity of the titanium nitride was found to be very dependent on the flow rate of ammonia during synthesis. Doped silicon has a plasmon resonance further into the infrared region and a tunable absorption controlled by the substitutional doping concentration in the nanocrystals. The presence of the plasmon absorption was used as a diagnostic tool to understand dopant behavior in doped silicon. The plasmon behavior supports the hypothesis of a uniform doping profile for phosphorus dopants and surface doping profile for boron dopants in silicon nanocrystals

Changes in Dopamine-sensitive Adenylate Cyclase Activity in Salivary Glands of Feeding Female Lone Star Ticks Amblyomma Americanum (L.)

This study was designed to determine the importance of the enzyme adenylate cyclase in the salivary glands of female lone star ticks Amblyomma americanum (L.), as this enzyme catalyses� the production of intracellular cyclic AMP, a molecule known to play a key role in the fluid secretory process of feeding female ixodid ticks.Entomolog

Eameses' Exhibition Architecture 1959-1965

Wissenschaftliches Kolloquium vom 19. bis 22. April 2007 in Weimar an der Bauhaus-Universität zum Thema: ‚Die Realität des Imaginären. Architektur und das digitale Bild

Hairpin RNAs and Retrotransposon LTRs Effect RNAi and Chromatin-Based Gene Silencing

The expression of short hairpin RNAs in several organisms silences gene expression by targeted mRNA degradation. This RNA interference (RNAi) pathway can also affect the genome, as DNA methylation arises at loci homologous to the target RNA in plants. We demonstrate in fission yeast that expression of a synthetic hairpin RNA is sufficient to silence the homologous locus in trans and causes the assembly of a patch of silent Swi6 chromatin with cohesin. This requires components of the RNAi machinery and Clr4 histone methyltransferase for small interfering RNA generation. A similar process represses several meiotic genes through nearby retrotransposon long terminal repeats (LTRs). These analyses directly implicate interspersed LTRs in regulating gene expression during cellular differentiation

Evidence for direct contact between the RPA3 subunit of the human replication protein A and single-stranded DNA

Replication Protein A is a single-stranded (ss) DNA-binding protein that is highly conserved in eukaryotes and plays essential roles in many aspects of nucleic acid metabolism, including replication, recombination, DNA repair and telomere maintenance. It is a heterotrimeric complex consisting of three subunits: RPA1, RPA2 and RPA3. It possesses four DNA-binding domains (DBD), DBD-A, DBD-B and DBD-C in RPA1 and DBD-D in RPA2, and it binds ssDNA via a multistep pathway. Unlike the RPA1 and RPA2 subunits, no ssDNA-RPA3 interaction has as yet been observed although RPA3 contains a structural motif found in the other DBDs. We show here using 4-thiothymine residues as photoaffinity probe that RPA3 interacts directly with ssDNA on the 3′-side on a 31 nt ssDNA