Kinetic Studies of DNA Repair Enzyme ALKBH2

The genomes of living organisms are under constant bombardment from various sources, including chemical modification stemming from processes within the organisms themselves or from exogenous agents, and from radiation. These sources of genomic damage may induce structural changes in the genome’s most basic functional units, the nucleotides that comprise DNA. Damage to an organism’s DNA may result in the production of dysfunctional or nonfunctional proteins. Failure to repair such damage may result in the compounding of successive mutations within the organism’s genome, the pathogenesis of cancer and various genetic disorders in humans. To ensure their viability, organisms have developed unique defense mechanisms to combat genetic damage. Among these mechanisms are repair pathways that allow for the enzymatic correction of DNA lesions. The human ALKBH2 protein (ABH2), an α‐ketoglutarate/Fe(II)-dependent dioxygenase, represents one such DNA repair enzyme. ABH2 represents a relatively novel and potentially fruitful subject for cancer research. ABH2 repairs alkylation damage in DNA through oxidative demethylation, displaying relative specificity for 1- methyladenine (m1A) and 3-methylcytosine (m3C) lesions. In addition to understanding how enzymatic repair systems correct certain DNA defects, it is important to thoroughly analyze the factors that influence the functioning of these catalytic protein complexes and the conditions that allow these systems to function optimally. While several studies have already independently examined the factors associated with ABH2 enzyme functioning, a comprehensive analysis of these determinants has yet to be conducted. The purpose of this project is to determine how variations in several known factors required for the functioning of this enzyme affects its kinetics. Completion of this project provided an in-depth analysis of the effect that changes in α-ketoglutarate, iron (II), ascorbic acid, pH, and temperature have on the correction of m1A, and m3C DNA lesions by the ABH2 repair enzyme. The results indicate that the optimal operating conditions for ABH2 may differ from what has been previously reported in the literature on this subject

Effects of Douglas fir stand age on soil chemical properties, nutrient dynamics, and enzyme activity: A case study in Northern Apennines, Italy

The aim of this study was to determine the effect of a Douglas fir plantation along a stand chronosequence in the North Apennine (Italy) on soil carbon and nitrogen stocks, as well as on soil chemical and biochemical properties involved in the nutrients biogeochemical cycle. In 2014, three sites of Douglas fir stands, aged 80, 100, and 120 years, were selected in Vallombrosa forest to study the dynamics of soil nutrients in the ecosystem. Along the Douglas fir chronosequence, general evidence of surface element accumulation was found, including a conspicuous increase of alkaline element with respect to Al, which was attributed to the increase of soil pH along the Douglas fir stand age classes. A general increase of specific enzyme activity (per unit of organic carbon) and functional diversity were observed in the epipedon of the Douglas fir stand over 100 years of age. Moreover, the (chitinase + leucine aminopeptidase) to acid phosphatase ratio progressively increased from 0.15 to 0.31 in the epipedon of the chrononsequence, while the -glucosidase to (chitinase + leucine aminopeptidase) ratio decreased from 1.45 to 0.83, suggesting nitrogen limitation with respect to carbon. In fact, the soil carbon stock progressively increased along the chronosequence, in the epipedon from 17 to 53 Mg C ha(-1) and in the endopedon from 17 to 37 Mg C ha(-1). Conversely, the soil nitrogen stock increased from 1.2 to 2.4 Mg N ha(-1), but not over the 100-year-old stand class. In conclusion, soil organic matter accumulation became sufficient to define the umbric horizon in the Northern Apennines when the Douglas fir plantation reached the age of 100 years. Over this age class of plants, a limitation of soil nitrogen may occur, affecting enzyme activities regulating the biogeochemical cycle of nutrients

GaN LNAs for Robust Receiving Systems in Radar and Space Applications

In this contribution a series of integrated circuits and methodologies, purposely developed for application in microwave receiving subsystems, will be presented. The integrated circuits, realized in GaN integrated technologies by different suppliers, find their applications in telecom systems as well as in RADAR ones, mainly for space-based apparatuses. The respective performance, as well as the key design methods will be presented in the contribution for bandwidths ranging from S-Band up to K-Band

A particle model of rolling grain ripples under waves

A simple model is presented for the formation of rolling grain ripples on a flat sand bed by the oscillatory flow generated by a surface wave. An equation of motion is derived for the individual ripples, seen as "particles", on the otherwise flat bed. The model account for the initial apperance of the ripples, the subsequent coarsening of the ripples and the final equilibrium state. The model is related to physical parameters of the problem, and an analytical approximation for the equilibrium spacing of the ripples is developed. It is found that the spacing between the ripples scale with the square-root of the non-dimensional shear stress (the Shields parameter) on a flat bed. The results of the model are compared with measurements, and reasonable agreement between the model and the measurements is demonstrated.Comment: 9 pages incl. figures. Revised versio

Seismically induced ground effects of the 1805, 1930 and 1980 earthquakes in the Southern Apennines (Italy

Seismically induced environmental effects (in particular, surfacefaults, ground cracks, slope failures, liquefaction, soil compaction, hydrological changes, tsunamis) are assumed to provide fundamentalinformation on the earthquake size and its intensity field, crucial for a more efficient seismic hazard assessment. Accordingly, this study is aimed at substantiating this assumption by showing that the knowledge about ground effects acquired in recent earthquakes, when combined with that illustrated in historical documents, allows to buildan improved picture of historic seismic events, with respect to that usually provided by the solely damage-based macroseismic scales. In this perspective, the environmental effects are analysed and cataloguedof three of the most ruinous earthquakes in Southern Italy of the last two centuries: the July 26,1805, Molise event (XI MCS, M 6.8), the July 23, 1930, Irpinia event (X MCS, M 6.7), and the November 23, 1980 Campania-Basilicata event (X MSK, Ms 6.9). The distribution of the earthquake environmental effects, in particular their distance from the known or supposed causative fault, has been investigated to obtain a more detailed and comprehensive picture of the macroseismic field, a key parameter in seismic hazard assessment and seismic zonation. KEY WORDS: historical seismicity, intensity, ground effects, earthquak

Una arquitectura basada en XML para la integración de negocios de pequeñas y medianas empresas (PyMEs)

Las Pequeñas y Medianas Empresas (PyMEs) deben hacer grandes esfuerzos para sobrevivir en una economía globalizada que las obliga a ser más competentes y eficientes. En muchos casos estas empresas deben trabajar en conjunto para lograr ventajas que individualmente no les sería posible conseguir. En este trabajo presentamos una arquitectura basada en agentes XML mediante la cual los sistemas de información de las PyMEs, que son heterogéneos por lo general, pueden interactuar entre sí para llevar adelante un pedido de compra de mercaderías en conjunto. Esta asociación de compras les permite aprovechar ofertas y/o negociar con los proveedores mejores condiciones logrando ventajas en precios, formas de pago, plazos de entrega, etc. La arquitectura está basada en tres agentes de software con funciones diferentes (local, mediador y del proveedor) que intercambian documentos XML entre ellos para llevar a cabo el proceso de compra, el cual se realiza actualmente de manera manual.Eje: Ingeniería de softwareRed de Universidades con Carreras en Informática (RedUNCI