Toxic Effects of cis- and trans-Diamminedichloroplatinum (II) in uvrD mutants of Escherichia coli

Author Institution: Department of Biological Sciences, Bowling Green State UniversityExcision repair has been shown to be the major pathway for repair of damage in DNA caused by cis and trans-diamminedichloridoplatinum(II) (DDP) in Escherichia coli. The effects of limiting excision repair on resistance to DDP was determined using three uvrD mutants of E. coli having different defects in the UvrD protein, DNA helicase II. Excision repair is limited because the UvrD protein function is necessary for catalytic activity of the UvrABC nuclease. The compound ds-DDP was more toxic than trans-DDP in decreasing survival of exposed bacteria and transforming ability of treated plasmid DNA. Repair of chromosomal DNA damaged with DDP was dependent on uvrD function as both compounds were more toxic to uvrD mutants than to isogenic wild-type bacteria. The transforming ability of plasmids treated withtrans-DDP was also decreased further when competent bacteria were deficient in the UvrD gene function, whereas, plasmid DNA treated with cis- DDP had similar transforming ability in bothw#rD mutant and wild-type cells. Repair of ds-DDP modified plasmid DNA in competent bacteria was inefficient and therefore did not require UvrD function

Groupoids and Wreath Products of Musical Transformations: a Categorical Approach from poly-Klumpenhouwer Networks

Transformational music theory, pioneered by the work of Lewin, shifts the music-theoretical and analytical focus from the "object-oriented" musical content to an operational musical process, in which transformations between musical elements are emphasized. In the original framework of Lewin, the set of transformations often form a group, with a corresponding group action on a given set of musical objects. Klumpenhouwer networks have been introduced based on this framework: they are informally labelled graphs, the labels of the vertices being pitch classes, and the labels of the arrows being transformations that maps the corresponding pitch classes. Klumpenhouwer networks have been recently formalized and generalized in a categorical setting, called poly-Klumpenhouwer networks. This work proposes a new groupoid-based approach to transformational music theory, in which transformations of PK-nets are considered rather than ordinary sets of musical objects. We show how groupoids of musical transformations can be constructed, and an application of their use in post-tonal music analysis with Berg's Four pieces for clarinet and piano, Op. 5/2. In a second part, we show how groupoids are linked to wreath products (which feature prominently in transformational music analysis) through the notion of groupoid bisectionsComment: 16 pages, 9 figures; comments welcom

The Schr\"odinger operator on an infinite wedge with a tangent magnetic field

We study a model Schr\"odinger operator with constant magnetic field on an infinite wedge with Neumann boundary condition. The magnetic field is assumed to be tangent to a face. We compare the bottom of the spectrum to the model spectral quantities coming from the regular case. We are particularly motivated by the influence of the magnetic field and the opening angle of the wedge on the spectrum of the model operator and we exhibit cases where the bottom of the spectrum is smaller than in the regular case. Numerical computations enlighten the theoretical approach

Durability of Pinus elliottii wood impregnated with quebracho colorado (Schinopsis balansae) bio-protectives

Some wood preservatives have a warning due to environmental restrictions and risks to man health. The aim of this study is to determine the performance of non impregnated and impregnated wood with a CCA salt and a bio-protective made from “quebracho colorado”, when facing the action of fungi responsible for white rot decay by Pycnoporus sanguineus and brown rot attack by Gloeophyllum se-piarium.  Wood samples were impregnated with different solutions by vacuum-pressure method. The design was in complete blocks at random with fi ve repetitions. The treatments were T0: non impreg-nated blank sample; impregnated T1: CCA; T2 Colatan IPG-F, T3: Colatan IPG-C, T4: Colatan IPG-C, with retentions of: 6, 18, 9 and 25 kg m-3 respectively. The variable was wood weight loss. Preservative CCA and bio-protective Colatan IPG-C increased the resistance to fungal degradation in lab assay, changing from non-resistance to very resistant (Findlay criterion), guaranteeing the biodegradation process inhibition

Controlling Light Through Optical Disordered Media : Transmission Matrix Approach

We experimentally measure the monochromatic transmission matrix (TM) of an optical multiple scattering medium using a spatial light modulator together with a phase-shifting interferometry measurement method. The TM contains all information needed to shape the scattered output field at will or to detect an image through the medium. We confront theory and experiment for these applications and we study the effect of noise on the reconstruction method. We also extracted from the TM informations about the statistical properties of the medium and the light transport whitin it. In particular, we are able to isolate the contributions of the Memory Effect (ME) and measure its attenuation length

A Quantitative Spectrographic Study of Magnesium Contamination in Calcium Oxalate Precipitates

Chemists have attempted quantitative spectrographic analysis repeatedly since 1863 when Miller first conducted his experiments. De Gramont added considerable information in a series of papers of about 1907. Leonard and Pollock, and Hartley also published much material about the same time. These methods depend on comparison with a standard of the same composition, containing the same elements. Gerlack and Schweitzer have recently developed a system which depends on comparison with lines of some other element which occur very nearby. The method used in our determinations is based on the earlier work

Minimally invasive mitral valve surgery: State-of-the-art and our experience

The minimally invasive approach is becoming the standard-of-care for surgery of the mitral valve. As any less invasive strategy, it entails an increased surgical complexity. Standard-of-care mitral repair using the totally videoscopic approach is indeed reproducible; however, few specific data on patients with complex mitral valve disease are available in the published literature. The purpose of the present paper is to provide an overview of the current state-of-the-art in minimally invasive cardiac surgery, and a summary of recent evidence on the topic, with particular regard to the surgical techniques and comparisons with conventional surgery. The experience of the GVM Care and Research network in the field is also briefly reported