The mechanisms used by Shiga toxin (Stx)-producing Escherichia coli to adhere to epithelial cells are incompletely understood. Two cosmids from an E. coli O157:H7 DNA library contain an adherence-conferring chromosomal gene encoding a protein similar to iron-regulated gene A (IrgA) of Vibrio cholerae (M. B. Goldberg, S. A. Boyko, J. R. Butterton, J. A. Stoebner, S. M. Payne, and S. B. Calderwoo...

A dynamic, closed-chamber infrared gas analysis (IRGA) system (DC-1: CIRAS-1, PP-Systems, Hitchin, U.K.) was compared with three other systems for measuring soil CO(2) efflux: the soda lime technique (SL), the eddy correlation technique (EC), and another dynamic, closed-chamber IRGA system (DC-2: LI-6250, Li-Cor, Inc., Lincoln, NE). Among the four systems, the DC-1 systematically gave the highe...

Rice cold tolerance at the germination stage is important in Rio Grande do Sul (RS) where temperatures below 15°C prevent or reduce germination and plant establishment in early sowings. The present study aimed at identifying an adequate method for cold tolerance evaluation of the rice germination stage and at verifying the variability among 24 rice genotypes of different origins. Cold tolerance...

We address the problem of the high-frequency correction of water vapour fluxes measured by eddy covariance with a closed-path infrared gas analyser (IRGA). Different transfer functions are compared and evaluated at a forested (Vielsalm, Belgium) and an agricultural (Lonzée, Belgium) site. Classical functions, usually applied to correct CO2 fluxes (Gaussian, Lorentzian), are found to be unsuited...

This paper presents evidence for the existence in extracts from porcine non-antral gastric tissue of a peptide capable of causing substantial rises of plasma immunoreactive gastrin levels in a dose dependent manner and of stimulation of gastric acid and pepsin secretion. Obtained data show that the peptide is basic and that its gastrin releasing properties are at least partially resistant to at...

This paper presents evidence for the existence in extracts from porcine non-antral gastric tissue of a peptide capable of causing substantial rises of plasma immunoreactive gastrin levels in a dose dependent manner and of stimulation of gastric acid and pepsin secretion. Obtained data show that the peptide is basic and that its gastrin releasing properties are at least partially resistant to at...

Iron toxicity is a major nutritional disorder in rice plants, especially flooded areas. The use of alternative crop management practices, such as soil drainage, may mitigate negative impacts iron toxicity, since aeration that follows drainage can oxidize and precipitate potentially toxic Fe+2 into Fe3+. This study aimed to evaluate the impact water on agronomical physiological parameters plants...

Whole-plant photosynthetic rate of rose (cv. Kardinal) was measured with an open system consisting of a computer-controlled data acquisition system and an infrared gas analyzer (IRGA). The system was used to monitor diurnal patterns of whole-plant gas exchange in response to environmental variables and a model to simulate this was constructed. A model for leaf photosynthesis was calibrated and ...