Role of the irr protein in the regulation of iron metabolism in Rhodobacter sphaeroides

In Rhizobia the Irr protein is an important regulator for iron-dependent gene expression. We studied the role of the Irr homolog RSP_3179 in the photosynthetic alpha-proteobacterium Rhodobacter sphaeroides. While Irr had little effect on growth under iron-limiting or non-limiting conditions its deletion resulted in increased resistance to hydrogen peroxide and singlet oxygen. This correlates with an elevated expression of katE for catalase in the Irr mutant compared to the wild type under non-stress conditions. Transcriptome studies revealed that Irr affects the expression of genes for iron metabolism, but also has some influence on genes involved in stress response, citric acid cycle, oxidative phosphorylation, transport, and photosynthesis. Most genes showed higher expression levels in the wild type than in the mutant under normal growth conditions indicating an activator function of Irr. Irr was however not required to activate genes of the iron metabolism in response to iron limitation, which showed even stronger induction in the absence of Irr. This was also true for genes mbfA and ccpA, which were verified as direct targets for Irr. Our results suggest that in R. sphaeroides Irr diminishes the strong induction of genes for iron metabolism under iron starvation

Composition of M,N-adhesive Categories with Application to Attribution of Graphs

This paper continues the work on M,N-adhesive categories and shows some important composition properties for these categories. We present a new concept of attributed graphs and show that the corresponding category is M,N-adhesive. As a consequence, we inherit all nice properties for M,N-adhesive systems such as the Local Church-Rosser Theorem, the Parallelism Theorem, and the Concurrency Theorem for this type of attributed graphs

Solid-State Excitation Laser for Laser-Ultrasonics

The inspection speed of laser-ultrasonics compared with conventional ultrasonic testing is limited by the pulse repetition rate of the excitation laser. The maximum pulse repetition rate reported up to now for CO2-lasers, which are presently used for nearly all systems, is in the range of 400 Hz. In this paper a new approach based on a diode-pumped solid-state laser is discussed, which is currently being developed. This new excitation laser is designed for a repetition rate of 1 kHz and will operate at a mid-IR wavelength of 3.3 m. The higher repeti-tion rate enables a higher inspection speed, whereas the mid-IR wavelength anticipates a better coupling efficiency. The total power for pumping the laser crystals is transported via flexible optical fibres to the compact laser head, thus allowing operation on a robot arm. The laser head consists of a master oscillator feeding several lines of power amplifiers and in-cludes nonlinear optical wavelength conversion by an optical parametric process. It is char-acterized by a modular construction which provides optimal conditions for operation at high average power as well as for easy maintenance. These features will enable building reliable, long-lived, rugged, smart laser ultrasonic systems in futur

AIDS and the Artist's Call to Action

Artists have lent their voices to many activist initiatives, and the AIDS crisis of the 1980s and 1990s was no exception. Largely, the art created during this era was propaganda, though some works were a reflection on living under the iron grip of AIDS. Artists and their work pushed for information and education to be dispersed throughout the community to combat the climate of fear and misinformation surrounding the AIDS crisis. These artists explored what HIV/AIDS is, who lives with AIDS, and who is ready to act up (a common sentiment throughout the musical, Rent). Through their work, these artivists advocate/ed for a group of people whose voices were largely unheard and chronicle society for the future (Bottinelli).Honors Collegemonographi

Das römische Gebäude in der Harlach bei Burgsalach, Landkreis Weißenburg-Gunzenhausen. Mit Studien zu Toranlagen, Peristylbauten, Kastellarchitekturen, Unterkunfts- und Amtsgebäuden sowie zu nordafrikanischen Gsur

Das römische Steingebäude in der Harlach bei Burgsalach gehört zu den bemerkenswertesten Bauten am Obergermanisch-Raetischen Limes. Nach einer Einführung zum römischen Burgsalach und in die Forschungsgeschichte des Bauwerks folgt eine detaillierte Baubeschreibung. Der Grundriss des Gebäudes ist Ergebnis einer ausgefeilten Bauplanung. Welche Funktion hatte das Gebäude in der Harlach? War es ein Kleinkastell (castellum; praesidium; castra)? Die ältere Forschung bezeichnete es fälschlicherweise als burgus und verglich es mit vermeintlich vergleichbaren nordafrikanischen Gebäuden („Gsur“). Eines dieser Gsur, Gasr Duib, wird inschriftlich als „centenarium“ bezeichnet, was für den Burgsalacher Bau übernommen wurde. Ebenso wurden eine Datierung in die erste Hälfte des 3. Jahrhunderts n. Chr. und die Errichtung durch eine Abteilung der nordafrikanischen Legio III Augusta daraus abgeleitet. Die archäologische Beweislage hierfür ist aber äußerst dürftig. Zudem darf das Burgsalacher Gebäude nicht in eine Entwicklungslinie vom mittelkaiserzeitlichen Militärlager hin zur spätrömischen Kleinfestung positioniert werden. Im Folgenden wird auf die Ähnlichkeit mit anderen antiken Peristylbauten wie z. B. Peristylhäusern hingewiesen. Viele Gebäude mit Innenhof in Stadt und Land, auch am Limes, wurden von der Forschung als Unterkunftshäuser (praetoria) identifiziert. Auch von der Größe her wäre es gut möglich, das Burgsalacher Gebäude so zu deuten. In Obernburg am Main konnte ein Steinbau mit peristylem Innenhof als Benefiziarierstation identifiziert werden, ein Amtsgebäude für Soldaten mit Sonderfunktionen. Auch dies wäre eine mögliche Deutung für den Burgsalacher Bau

FERNANDO DÍAZ MENDOZA [Material gráfico]

DEDICADA A SU AMIGO JOSÉ BETANCORCopia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

Noise in laser speckle correlation and imaging techniques

We study the noise of the intensity variance and of the intensity correlation and structure functions measured in light scattering from a random medium in the case when these quantities are obtained by averaging over a finite number N of pixels of a digital camera. We show that the noise scales as 1/N in all cases and that it is sensitive to correlations of signals corresponding to adjacent pixels as well as to the effective time averaging (due to the finite sampling time) and spatial averaging (due to the finite pixel size). Our results provide a guide to estimation of noise level in such applications as the multi-speckle dynamic light scattering, time-resolved correlation spectroscopy, speckle visibility spectroscopy, laser speckle imaging etc.Comment: submitted 14 May 201