L. plantarum,L. fermentum,and B. breve Beads Modified the Intestinal Microbiota and Alleviated the Inflammatory Response in High-Fat Diet–Fed Mice

Probiotics and Antimicrobial Proteins - This paper aims to study the effects of compound microbe-based beads on changes in the intestinal microbiota and alleviation of high-fat (HF)...     

Feller processes: the next generation in modeling. Brownian motion, Lévy processes and beyond

We present a simple construction method for Feller processes and a framework for the generation of sample paths of Feller processes. The construction is based on state space dependent mixing of Lévy processes. Brownian Motion is one of the most frequently used continuous time Markov processes in applications. In recent years also Lévy processes, of which Brownian Motion is a special case, have become increasingly popular. Lévy processes are spatially homogeneous, but empirical data often suggest the use of spatially inhomogeneous processes. Thus it seems necessary to go to the next level of generalization: Feller processes. These include Lévy processes and in particular brownian motion as special cases but allow spatial inhomogeneities. Many properties of Feller processes are known, but proving the very existence is, in general, very technical. Moreover, an applicable framework for the generation of sample paths of a Feller process was missing. We explain, with practitioners in mind, how to overcome both of these obstacles. In particular our simulation technique allows to apply Monte Carlo methods to Feller processes.     

Nodulation and nitrogen-fixation byHippophaë rhamnoides L. in the field

Summary 1. The extent of nodulation and nitrogen fixation by a population ofHippophaë rhamnoides bushes occurring on a sand dune system on the east coast of England has been studied.2. Nodules were found on all plants (the latter ranged from 3 to 16 years in age) and using the isotope N¹⁵ it was confirmed that these nodules fixed nitrogen. The nodules on the youngest plants were most active in fixation but because of the greater total nodule mass older plants fixed the largest quantities of nitrogen.3. Large increases in total nitrogen (i.e. soil plus plant nitrogen) occurred with increase in age of the plants, such nitrogen increases ranging from 27 kg per hectare per annum in the presence of bushes 0 to 3 years old to 179 kg per hectare per annum in the presence of bushes 13 to 16 years old.4. The N¹⁵-technique indicated that a proportion of the nitrogen accumulated was due to fixation byHippophaë but nitrogen contributions from other sources could not be ruled out.5. The levels of nitrate-nitrogen and ammonium-nitrogen in the soil underHippophaë showed a marked seasonal variation, increasing to a maximum in the winter and to a minimum in the summer. These levels were in general inversely related to the level of average monthly rainfall. Because of the low levels of combined nitrogen in the soil during the summer months it seems unlikely that combined nitrogen should markedly inhibit fixation in this situation.