MultiMetEval: comparative and multi-objective analysis of genome-scale metabolic models

Comparative metabolic modelling is emerging as a novel field, supported by the development of reliable and standardized approaches for constructing genome-scale metabolic models in high throughput. New software solutions are needed to allow efficient comparative analysis of multiple models in the context of multiple cellular objectives. Here, we present the user-friendly software framework Multi-Metabolic Evaluator (MultiMetEval), built upon SurreyFBA, which allows the user to compose collections of metabolic models that together can be subjected to flux balance analysis. Additionally, MultiMetEval implements functionalities for multi-objective analysis by calculating the Pareto front between two cellular objectives. Using a previously generated dataset of 38 actinobacterial genome-scale metabolic models, we show how these approaches can lead to exciting novel insights. Firstly, after incorporating several pathways for the biosynthesis of natural products into each of these models, comparative flux balance analysis predicted that species like Streptomyces that harbour the highest diversity of secondary metabolite biosynthetic gene clusters in their genomes do not necessarily have the metabolic network topology most suitable for compound overproduction. Secondly, multi-objective analysis of biomass production and natural product biosynthesis in these actinobacteria shows that the well-studied occurrence of discrete metabolic switches during the change of cellular objectives is inherent to their metabolic network architecture. Comparative and multi-objective modelling can lead to insights that could not be obtained by normal flux balance analyses. MultiMetEval provides a powerful platform that makes these analyses straightforward for biologists. Sources and binaries of MultiMetEval are freely available from https://github.com/PiotrZakrzewski/MetEv​al/downloads

The Relationship Between Alcohol Symptoms and Consumption Among Older Drinkers

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66310/1/j.1530-0277.1996.tb01104.x.pd

Political connections and corporate financial decision making

This paper investigates whether and how political connections influence managerial financial decisions. Our study reveals that those firms that have a politician on its board of directors are highly leveraged, use more long-term debt, hold large excess cash and are associated with low quality financial reporting compared to their non-connected counterparts. These effects escalate with the strength of the connected politician and whether he or his party is in power. The winning party effect is observed to be stronger than victory by the politician himself. Overall, our paper provides strong evidence that political connection is a two-edged sword. It is indeed a valuable resource for connected firms, but it comes at a cost of higher agency problems

Gestão de operações na prática: as empresas e os desafios de contexto concorrencial

O presente artigo tem por objetivo apresentar os resultados de uma pesquisa levada a efeito junto a empresas de manufatura que operam em regime de concorrência. A pesquisa foi dirigida a busca de evidências referentes à utilização de ferramentas e metodologias de gestão de operações, considerando seus vários aspectos e também a pluralidade de autores e pesquisadores que tratam desse assunto. Para formar uma base teórica para subsidiar a análise e apresentação das conclusões, foi feita uma breve revisão da bibliografia, buscando enfocar as contribuições de alguns autores principais e as estruturas de análise por eles sugerida. O resultado foi um quadro representativo das práticas verificadas. Configurando um contexto sistêmico de análise, dentro do qual podem ser visualizadas, claramente, as relações de causa-efeito entre as ações gerenciais (estratégicas e do dia a dia) e a realidade de contexto concorrencial enfrentada em cada caso.<br>This paper outlines the results of a survey conducted involving manufacturing firms, operating in a competitive context. The survey was done to collect evidences about the use of modern operations management methodologies and tools, considering the various aspects and contributions of several authors. To compose a theoretical basis as a support for analysis and conclusions, this paper presents a brief comments about a bibliographic revision, involving some contributions of the main authors and the structure of analysis being suggested. The results obtained presents a very illustrative framework of the practices addopted by the firms, virtually a systemic context analysis, that allows to view clearly the cause-effects relationships between the managerial actions (strategic and day-to-day) and the reality of its concurrent'tal context

Determinants of the entrepreneurial gender gap in Latin America

This paper identifies a set of factors associated with the decision to become an entrepreneur and the variables that account for the gender gap in entrepreneurial activity in Latin America. We estimate logit models for entrepreneurial activity under three different definitions of an entrepreneur. We also estimate the gender gap by using Fairlie’s decomposition method. Depending on the definition of entrepreneur used, the overall gender gap varies from 4 to 13 % points. Differences in observable characteristics explain between 23 and 38 % of the total gender gap. The factors that explain both entrepreneurial activity and gender gap are: education, risk tolerance; own car as primary means of transportation; work satisfaction; and parent business ownership. Variables such as age, access to loans, and need for achievement are significantly associated with entrepreneurial activity, but they play a negligible role in explaining the gender gap