Рассматривается лин ейное дифференциаль ное уравнение с обобщенн ым потенциаломLu(t)+(u,F)g(t)=f(t), t∈S. Исследуются обобщен ные граничные услови я, при которых существует е динственное решение (в зависимостиF, g). Анало гично исследуется и стохастическое урав нение.
Authors:M. Tóth-Markus, I. Magyar, K. Kardos, L. Bánszky and A. Maráz
In this study the role of different yeast strains in the production of volatile flavour components of Tokaji Aszú wine was tested. The effect of a Saccharomyces cerevisiae starter and that of the typical endogenous Candida stellata strain as well as spontaneous fermentation were studied and compared. For the fast comparison of aroma profile, a solid phase microextraction (SPME) sampling and a GC-MS separation and identification were used. Thirty of the present compounds were selected to characterise the changes of flavour. Significant differences were found between wines fermented with different yeast strains. Application of a Saccharomyces cerevisiae starter alone accelerated the fermentation but this caused only little change in the aroma profile and content. Candida stellata contributed weakly to the production of aroma, especially to that of the longer carbon chain ethyl esters. Characteristic compounds of aged wine were detected in bottle aged Tokaji Aszú. The change of aroma profile as a function of bottle storage time was studied. The concentrations of vitispirane, trimethyl dihydronaphtalene, 2-phenylethanol and diethyl succinate increased in the course of ageing time, while those of 3-methyl-butyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and ethyl dodecanoate decreased.
Authors:L.-M. Haag, A. Fischer, B. Otto, U. Grundmann, A. A. Kühl, U. B. Göbel, S. Bereswill and Markus M. Heimesaat
Campylobacter (C.) jejuni is among the leading bacterial agents causing enterocolitis worldwide. Despite the high prevalence of C. jejuni infections and its significant medical and economical consequences, intestinal pathogenesis is poorly understood. This is mainly due to the lack of appropriate animal models. In the age of 3 months, adult mice display strong colonization resistance (CR) against C. jejuni. Previous studies underlined the substantial role of the murine intestinal microbiota in maintaining CR. Due to the fact that the host-specific gut flora establishes after weaning, we investigated CR against C. jejuni in 3-week-old mice and studied intestinal and extra-intestinal immunopathogenesis as well as age dependent differences of the murine colon microbiota. In infant animals infected orally immediately after weaning C. jejuni strain B2 could stably colonize the gastrointestinal tract for more than 100 days. Within six days following infection, infant mice developed acute enterocolitis as indicated by bloody diarrhea, colonic shortening, and increased apoptotic cell numbers in the colon mucosa. Similar to human campylobacteriosis clinical disease manifestations were self-limited and disappeared within two weeks. Interestingly, long-term C. jejuni infection was accompanied by distinct intestinal immune and inflammatory responses as indicated by increased numbers of T- and B-lymphocytes, regulatory T-cells, neutrophils, as well as apoptotic cells in the colon mucosa. Strikingly, C. jejuni infection also induced a pronounced influx of immune cells into extra-intestinal sites such as liver, lung, and kidney. Furthermore, C. jejuni susceptible weaned mice harbored a different microbiota as compared to resistant adult animals. These results support the essential role of the microflora composition in CR against C. jejuni and demonstrate that infant mouse models resemble C. jejuni mediated immunopathogenesis including the characteristic self-limited enterocolitis in human campylobacteriosis. Furthermore, potential clinical and immunological sequelae of chronic C. jejuni carriers in humans can be further elucidated by investigation of long-term infected infant mice. The observed extraintestinal disease manifestations might help to unravel the mechanisms causing complications such as reactive arthritis or Guillain-Barré syndrome.
Authors:B. Otto, L.-M. Haag, A. Fischer, R. Plickert, A. A. Kühl, U. B. Göbel, Markus M. Heimesaat and S. Bereswill
Campylobacter jejuni is one of the predominant causes for foodborne bacterial infections worldwide. We investigated whether signaling of C. jejuni-lipoproteins and -lipooligosaccharide via Toll-like-receptor (TLR) -2 and -4, respectively, is inducing intestinal and extra-intestinal immune responses following infection of conventional IL-10-/- mice with chronic colitis. At day 3 following oral infection, IL-10-/- mice lacking TLR-2 or TLR-4 harbored comparable C. jejuni strain ATCC 43431 loads in their colon. Interestingly, infected TLR-4-/- IL-10-/- mice displayed less compromized epithelial barrier function as indicated by lower translocation rates of live gut commensals into mesenteric lymphnodes (MLNs), and exhibited less distinct B lymphocyte responses in their colonic mucosa as compared to naïve IL-10-/- controls. Furthermore, in extra-intestinal compartments such as MLNs and spleens, abundance of myeloid cells was less distinct whereas relative percentages of activated T helper cells and cytotoxic T cells were higher in spleens and dendritic cells more abundant in MLNs of infected IL-10-/- animals lacking TLR-4 as compared to IL-10-/- controls. Taken together, in conventionally colonized IL-10-/- mice, TLR-4, but not TLR-2, is involved in mediating extra-intestinal pro-inflammatory immune responses following C. jejuni infection. Thus, conventional IL-10-/- mice are well suited to further dissect mechanisms underlying Campylobacter infections in vivo.