• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1560-1568
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• 2013

Salmonella, a main cause of foodborne diseases, encounters a variety of environmental stresses and overcomes the stresses by multiple resistance strategies. One of the general responses to hyperosmotic stress is to import or produce compatible solutes so that cells maintain fluid balance and protect proteins and lipids from denaturation. The ProP and ProU systems are the main transport systems for compatible solutes. The OsmU system, recently identified as a third osmoprotectant transport system, debilitates excessive growth as well by reducing production of trehalose. We studied a fourth putative osmoprotectant transport system, YehZYXW, with high sequence similarity with the OsmU system. A Salmonella strain lacking YehZ, a predicted substrate-binding protein, did not suffer from hyperosmolarity but rather grew more rapidly than the wild type regardless of glycine betaine, an osmoprotectant, suggesting that the YehZYXW system controls bacterial growth irrespective of transporting glycine betaine. However, the growth advantage of ${\Delta}yehZ$ was not attributable to an increase in OtsBA-mediated trehalose production, which is responsible for the outcompetition of the ${\Delta}osmU$ strain. Overexpressed YehZ in trans was capable of deaccelerating bacterial growth vice versa, supporting a role of YehZ in dampening growth. The expression of yehZ was increased in response to nutrient starvation, acidic pH, and the presence of glycine betaine under hyperosmotic stress. Identifying substrates for YehZ will help decipher the role of the YehZYXW system in regulating bacterial growth in response to environmental cues.

• Bulletin of the Korean Mathematical Society
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• v.21 no.2
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• pp.99-106
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• 1984

J. Yeh has recently introduced the concept of conditional Wiener integrals which are meant specifically the conditional expectation E$^{w}$ (Z vertical bar X) of a real or complex valued Wiener integrable functional Z conditioned by the Wiener measurable functional X on the Wiener measure space (A precise definition of the conditional Wiener integral and a brief discussion of the Wiener measure space are given in Section 2). In [3] and [4] he derived some inversion formulae for conditional Wiener integrals and evaluated some conditional Wiener integrals E$^{w}$ (Z vertical bar X) conditioned by X(x)=x(t) for a fixed t>0 and x in Wiener space. Thus E$^{w}$ (Z vertical bar X) is a real or complex valued function on R$^{1}$. In this paper we shall be concerned with the random vector X given by X(x) = (x(s$_{1}$),..,x(s$_{n}$ )) for every x in Wiener space where 0=s$_{0}$ $_{1}$<..$_{n}$ =t. In Section 3 we will evaluate some conditional Wiener integrals E$^{w}$ (Z vertical bar X) which are real or complex valued functions on the n-dimensional Euclidean space R$^{n}$ . Thus we extend Yeh's results [4] for the random variable X given by X(x)=x(t) to the random vector X given by X(x)=(x(s$_{1}$).., x(s$_{n}$ )).

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1647-1651
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• 2004

The follicles (1.8 to 7.8 mm in diameter) were recovered from the ovaries in marketed pigs and the number of granulosa cells, the diameter of oocytes obtained from different development stages of the follicles and follicular fluid levels were determined. Correlations between size measurements and cell counts as well as the diameter of antral follicles and oocytes were also investigated. The results indicated that, while expanding in size, follicle numbers decreased with a greater atretic proportion. Granulosa cells increased in numbers continuously and remained unchanged beyond the size of 200 ${mm}^3$ in non-atretic follicles, whereas a sudden drop of granulosa counts was observed in atretic follicles. Follicular fluid, on the other hand, linearly increased its volume with follicle size and differed little between those of non-atretic and atretic follicles. Diameters of oocytes in non-atretic follicles increased to its maximum when follicles expanded to 150 ${mm}^3$ and maintained its size during later follicular expansion. It is concluded that, for in vitro culture, the optimal size of porcine follicle should be between 150 to 180 ${mm}^3$if they are collected from pre-pubertal gilts of marketing size slaughtered in an abattoir.