Plasma-Treated Water Affects Listeria Monocytogenes Vitality and Biofilm Structure

Plasma-generated compounds (PGCs) such as plasma-processed air (PPA) or plasma-treated water (PTW) offer an increasingly important alternative for the control of microorganisms in hard-to-reach areas found in several industrial applications including the food industry. To this end, we studied the antimicrobial capacity of PTW on the vitality and biofilm formation of Listeria monocytogenes, a common foodborne pathogen

Functional Classification of Genome-Scale Metabolic Networks

We propose two strategies to characterize organisms with respect to their metabolic capabilities. The first, investigative, strategy describes metabolic networks in terms of their capability to utilize different carbon sources, resulting in the concept of carbon utilization spectra. In the second, predictive, approach minimal nutrient combinations are predicted from the structure of the metabolic networks, resulting in a characteristic nutrient profile. Both strategies allow for a quantification of functional properties of metabolic networks, allowing to identify groups of organisms with similar functions. We investigate whether the functional description reflects the typical environments of the corresponding organisms by dividing all species into disjoint groups based on whether they are aerotolerant and/or photosynthetic. Despite differences in the underlying concepts, both measures display some common features. Closely related organisms often display a similar functional behavior and in both cases the functional measures appear to correlate with the considered classes of environments. Carbon utilization spectra and nutrient profiles are complementary approaches toward a functional classification of organism-wide metabolic networks. Both approaches contain different information and thus yield different clusterings, which are both different from the classical taxonomy of organisms. Our results indicate that a sophisticated combination of our approaches will allow for a quantitative description reflecting the lifestyles of organisms

Local and global modes of drug action in biochemical networks

It becomes increasingly accepted that a shift is needed from the traditional target-based approach of drug development to an integrated perspective of drug action in biochemical systems. We here present an integrative analysis of the interactions between drugs and metabolism based on the concept of drug scope. The drug scope represents the set of metabolic compounds and reactions that are potentially affected by a drug. We constructed and analyzed the scopes of all US approved drugs having metabolic targets. Our analysis shows that the distribution of drug scopes is highly uneven, and that drugs can be classified into several categories based on their scopes. Some of them have small scopes corresponding to localized action, while others have large scopes corresponding to potential large-scale systemic action. These groups are well conserved throughout different topologies of the underlying metabolic network. They can furthermore be associated to specific drug therapeutic properties

MetaPath Online: a web server implementation of the network expansion algorithm

We designed a web server for the analysis of biosynthetic capacities of metabolic networks. The implementation is based on the network expansion algorithm and the concept of scopes. For a given network and predefined external resources, called the seed metabolites, the scope is defined as the set of products which the network is in principle able to produce. Through the web interface the user can select a variety of metabolic networks or provide his or her own list of reactions. The information on the organism-specific networks has been extracted from the KEGG database. By choosing an arbitrary set of seed compounds, the user can obtain the corresponding scopes. With our web server application we provide an easy to use interface to perform a variety of structural and functional network analyses. Problems that can be addressed using the web server include the calculation of synthesizing capacities, the visualization of synthesis pathways, functional analysis of mutant networks or comparative analysis of related species. The web server is accessible through http://scopes.biologie.hu-berlin.de

Sovereign Latin American Eurobonds

This research study evaluated statistically the importance of bond structure, financing activity, and issuer characteristics to the relative yield spread for fixed-rate Latin American Sovereign Eurobonds. Higher grade issuers pay a relatively higher spread to borrow long-term funds and for larger issues; the findings are consistent with the notion of a term structure "liquidity" premium and a "market congestion" premium. Low-grade countries obviously pay a higher spread than countries assigned a better international credit rating. However, low-grade countries pay a relatively higher spread to borrow shorter term funds and for the inclusion of a call option; the findings are consistent with a term structure "crisis-at-maturity" and the higher probability that low-grade countries will later find it advantageous to refinance a fixed-rate bond. Sovereign borrowers appear to achieve lower relative yield spreads by repeatedly issuing securities. Although the sovereign Eurobond market has increased in importance during the last two decades, the growth has not proven consistent. Investors seek safety over yield during periods of economic contraction, and adverse region-specific events

My Shadowland

https://digitalcommons.library.umaine.edu/mmb-vp/5593/thumbnail.jp

Latin American credit ratings, the New Basel Capital Accord and portfolio risk

Commercial banks are required by regulation to maintain capital that varies with the perceived risk ofbanking assets. The risk-based capital rule initially introduced by the Bank for International Settlements in 1988 is under revision. This study provides an empirical analysis of proposed capital risk-weights for a sample of global assets. We apply a diffusion-based methodology for assessing the value-at-risk (VaR) of a portfolio offixedincome securities comparable to those now issued and likely to be issued for the foreseeable future by firms in Latin America. This is accomplished by simultaneously simulating both the future environment in which financial instruments will be valued and the credit rating of specific firms. This paper applies a simulation model to assess correlated market, basis and credit risk for both individual bonds and a portfolio ofbonds of similar initial credit quality. Interest rate or market risk is relatively more important for high-grade bonds issued by strong companies from developed countries. Basis risk and credit risk are more important for companies from countries whose sovereign debt is rated lower medium-grade and low-grade