Improving the microbiological safety of perishable foods is currently a major preoccupation in the food industry. The aim of this study was to investigate the inactivation of three major food pathogens (Listeria monocytogenes [LSD 105-1], Escherichia coli O157:H7 [ATCC 35150], and Salmonella enterica serotype Enteritidis ATCC [13047]) by dynamic high pressure (DHP) in order to evaluate its potential as a new alternative for the cold pasteurization of milk. The effectiveness of DHP treatment against L. monocYtogenes, E. coli O157:H7, and Salmonella Enteritidis was first evaluated in 0.01 M phosphate-buffered saline (PBS) at pH 7.2 as a function of applied pressure (100, 200, and 300 MPa) and of the number of passes (1, 3, and 5) at 25 degrees C. A single pass at 100 MPa produced no significant inactivation of the three pathogens, while increasing the pressure up to 300 MPa or the number of passes to five increased inactivation. From an initial count of 8.3 log CFU/ml, complete inactivation of viable L. monocytogenes was achieved after three successive passes at 300 MPa, while 200-MPa treatments with three and five passes completely eliminated viable Salmonella Enteritidis and E. coli O157:H7, respectively. The effectiveness of DHP for the inactivation of these pathogens was compared to that of hydrostatic high pressure (HHP) using the same pressure (200 MPa, single pass at 25 degrees C). In general, two additional log reductions in viable count were obtained with DHP DHP was less effective against L. monocytogenes and E. coli O157:H7 in raw milk than in PBS. After five passes at 200 MPa, an 8.3-log reduction was obtained for E. coli O157:H7, while a reduction of about 5.8 log CFU/ml was obtained for L. monocytogenes exposed to 300 MPa for five passes. Exposing milk or buffer samples to mild heating (45 to 60 degrees C) prior to dynamic pressurization enhanced the lethal effect of DHP The inactivation of pathogens also depended on the initial bacterial concentration. The highest reduction was obtained when the bacterial load did not exceed 10(5) CFU/ml. In conclusion, DHP was shown to be very effective for the destruction of the tested pathogens. It offers a promising alternative for the cold pasteurization of milk and possibly other liquid foods.
This article reports on the effects of a family literacy program for first graders that had three main characteristics: (1) book reading with parents that adapts parental intervention to the child’s gradually increasing skills in reading during the school year, (2) support for writing activities, and (3) enjoyable home activities complementing the in-class teaching. The 108 participants were assigned to two treatment conditions: Workshop and Control. Pre- and post-test group comparisons indicate that the workshop program has a positive effect on the children’s performance in both reading and writing. Children produced longer texts and used better vocabulary, sentence structure and spelling. This study provides new data supporting the utility of family literacy programs by demonstrating their positive effect on writing. This confirms the importance of connecting reading and writing activities in family literacy at the beginning of learning and that parents should be invited by the teacher to intervene in these two areas rather than only in reading.
This article presents the results of a study designed to evaluate the impact of an in-class service model on the achievement of students at risk of school failure. The model, which included collaborative consultation, cooperative teaching, parent involvement, and strategic and adapted instruction was implemented for 1 school year in 13 different schools. Significant effects were found on writing scores for students at risk and on reading and mathematics scores for general education students. No significant treatment effects were detected for students with learning disabilities. The findings confirm the benefits of the in-class service model for some students and the need to pursue further research in order to achieve better results for the lowest achievers in the classroom.
Dé partement d'é tudes sur l'enseignement et l'apprentissage, Faculté des sciences de l'é ducation, Université Laval, Qué bec, Canada Given the problems experienced by hearing-impaired individuals in learning the written language, a pedagogical approach was tested. The study examined the links between the development of representations of alphabetic system and the results in reading and writing of first graders. In the study, there were 31 hearing-impaired children and 25 hearing ones. Invented spelling was measured three times during the school year. Reading and writing tests were given at the end of the year. The results obtained revealed a similarity between the learning profile of the hearing-impaired children and that of the hearing children. It also demonstrated the importance of the work done through invented spelling, among the hearing-impaired children. Thus, like their hearing peers, hearing-impaired children are able to use procedures to process the written word based on the alphabetic principle, but continuous supportimplying invented spelling constantly adjusted to the progression of their representations must be provided.It has often been reported that the reading ability of many hearing-impaired students does not go beyond a fourth grade level (Allen, 1986;Kelly, 1995; Gallaudet Research Institute, 2003). This levelling-off, which prevents them from reaching a functional writing level, probably takes root much earlier. Thus, for many years now, the study of foundations of written language learning and reading comprehension has been a central element of the research conducted by the GRIES (Groupe de recherche et d'intervention auprès des enfants sourds, Université Laval). Similarly, a pedagogical approach focused on hearing-impaired children's entry into the writing process has been developed and tested. This approach strongly emphasises the interaction between reading and writing and the development of representations of the writing system. It targets the development of reading autonomy in the initial months of the formal learning of the written language.
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