Doubly autoparallel structure on the probability simplex

On the probability simplex, we can consider the standard information geometric structure with the e- and m-affine connections mutually dual with respect to the Fisher metric. The geometry naturally defines submanifolds simultaneously autoparallel for the both affine connections, which we call {\em doubly autoparallel submanifolds}. In this note we discuss their several interesting common properties. Further, we algebraically characterize doubly autoparallel submanifolds on the probability simplex and give their classification

A Morbidity Submodel of Infectious Diseases

Numbers of sick persons with infectious diseases in a country can be estimated by the morbidity submodel of infectious diseases. The input of the model is the population structure of the country and the outputs are numbers of sick, deaths and prevalence rates of infectious diseases. The model makes use of three disease specific rates which are assumed to be constant across developed countries, namely morbidity rate, recovery rate, and death rate per capita. For this paper values of these three rates were calculated from Japanese survey data describing disease specific prevalence rate, death rate, and duration of stay. The outputs of the model are in good agreement with WHO statistics from Japan and other developed countries

Phase ordering in coupled noisy bistable systems on scale-free networks

We study a system consisting of diffusively coupled noisy bistable elements on a scale-free random network. This system exhibits an order-disorder phase transition as the noise intensity is varied. The phase ordering process takes place consecutively and in order of the degrees, reflecting strong degree heterogeneity of the scale-free network. A nonlinear Fokker-Planck equation describing the network dynamics is derived under mean-field approximation of the network, and is used to explain the phase ordering dynamics of the system

An Approach to Building a Universal Health Care Model: Morbidity Model of Degenerative Diseases

There have been many different approaches to building health care models. Because of these differences, it is sometimes difficult to relate the developed models to each other. We have therefore first defined the submodels of the health care system and clarified the relation of our approach to studies already undertaken. The submodels also show the steps in building the health care model. The first step was to construct the morbidity model of degenerative diseases. The validity of the model was tested for various countries, using statistics from the World Health Organization. The fit of the model to empirical data was satisfactory. The model was applied to an international comparison and estimation of trends in degenerative diseases. The study showed the feasibility of this type of approach in health planning

Analysis and Future Estimation of Medical Demands Using a Health Care Simulation Model: A Case Study of Japan

A method of building a universal health care model was proposed in RM-77-006 (Kaihara, et al., An Approach to Building a Universal Health Care Model). This method is based on the calculation of essential parameters of health care from ordinary statistics. The essential parameters proposed in the previous report were population structure, morbidity rate, recovery rate, death rate, patient registration rate and awareness rate. The method was applied successfully to the analysis of medical demands at the national level of Japan. The results showed that in the past 15 years the awareness rate was the most important factor which contributed to the increase of the patients. But in the future, the model predicted that the change of population structure will be the main cause of the increase of the number of patients in Japan

Engineering Corynebacterium glutamicum for isobutanol production

The production of isobutanol in microorganisms has recently been achieved by harnessing the highly active 2-keto acid pathways. Since these 2-keto acids are precursors of amino acids, we aimed to construct an isobutanol production platform in Corynebacterium glutamicum, a well-known amino-acid-producing microorganism. Analysis of this host’s sensitivity to isobutanol toxicity revealed that C. glutamicum shows an increased tolerance to isobutanol relative to Escherichia coli. Overexpression of alsS of Bacillus subtilis, ilvC and ilvD of C. glutamicum, kivd of Lactococcus lactis, and a native alcohol dehydrogenase, adhA, led to the production of 2.6 g/L isobutanol and 0.4 g/L 3-methyl-1-butanol in 48 h. In addition, other higher chain alcohols such as 1-propanol, 2-methyl-1-butanol, 1-butanol, and 2-phenylethanol were also detected as byproducts. Using longer-term batch cultures, isobutanol titers reached 4.0 g/L after 96 h with wild-type C. glutamicum as a host. Upon the inactivation of several genes to direct more carbon through the isobutanol pathway, we increased production by ∼25% to 4.9 g/L isobutanol in a ∆pyc∆ldh background. These results show promise in engineering C. glutamicum for higher chain alcohol production using the 2-keto acid pathways

High-flux isobutanol production using engineered Escherichia coli: a bioreactor study with in situ product removal

Promising approaches to produce higher alcohols, e.g., isobutanol, using Escherichia coli have been developed with successful results. Here, we translated the isobutanol process from shake flasks to a 1-L bioreactor in order to characterize three E. coli strains. With in situ isobutanol removal from the bioreactor using gas stripping, the engineered E. coli strain (JCL260) produced more than 50 g/L in 72 h. In addition, the isobutanol production by the parental strain (JCL16) and the high isobutanol-tolerant mutant (SA481) were compared with JCL260. Interestingly, we found that the isobutanol-tolerant strain in fact produced worse than either JCL16 or JCL260. This result suggests that in situ product removal can properly overcome isobutanol toxicity in E. coli cultures. The isobutanol productivity was approximately twofold and the titer was 9% higher than n-butanol produced by Clostridium in a similar integrated system

3-Methyl-1-butanol production in Escherichia coli: random mutagenesis and two-phase fermentation

Interest in producing biofuels from renewable sources has escalated due to energy and environmental concerns. Recently, the production of higher chain alcohols from 2-keto acid pathways has shown significant progress. In this paper, we demonstrate a mutagenesis approach in developing a strain of Escherichia coli for the production of 3-methyl-1-butanol by leveraging selective pressure toward l-leucine biosynthesis and screening for increased alcohol production. Random mutagenesis and selection with 4-aza-d,l-leucine, a structural analogue to l-leucine, resulted in the development of a new strain of E. coli able to produce 4.4 g/L of 3-methyl-1-butanol. Investigation of the host’s sensitivity to 3-methyl-1-butanol directed development of a two-phase fermentation process in which titers reached 9.5 g/L of 3-methyl-1-butanol with a yield of 0.11 g/g glucose after 60 h