19 resultados para 1012
em University of Connecticut - USA
Resumo:
The reference librarian's task is to translate the patron's question into one that can be answered with the library's resources. The first element of that task is to know what the patron wants; the second is to know what resources the library has and how to use them. Reference librarians must learn continuously throughout their careers, both because new resources become available, but also because patrons present questions requiring new resources. This article will focus on how to determine what kind of information the patron needs through the reference interview.
Resumo:
The issue of how to respond to the diverse academic needs of students is one of the central challenges of teaching. This project studied how preservice teachers develop an awareness of the needs of academically diverse learners and how they intend to implement and/or modify instruction to meet those needs. Participants all came from one university. As part of the design of the study, the participants were surveyed to investigate (a) their attitudes and beliefs towards academically diverse learners; (b) the teaching practices they would utilize in response to academic diversity in their classrooms; and (c) the confidence they have in their abilities to identify and address these various needs in their classrooms. Several strategies including activities to enhance creativity, cooperative learning, individual instruction, problem-solving activities, and projects were considered noteworthy for the ratings by the preservice teachers as appropriate for all students. Small differences were found based on the preservice teachers' year of placement in the School of Education, indicating that as students progress through this program, they may learn more about different techniques and when and for whom they are appropriate; however, differences across groups were not statistically significant. Results also indicated that across the different years in the program, preservice teachers did not have very high or very low confidence in addressing these issues in their own classrooms. Each grouping fell around the middle level of confidence.
Resumo:
BACKGROUND: Clostridium perfringens type A food poisoning is caused by enterotoxigenic C. perfringens type A isolates that typically possess high spore heat-resistance. The molecular basis for C. perfringens spore heat-resistance remains unknown. In the current study, we investigated the role of small, acid-soluble spore proteins (SASPs) in heat-resistance of spores produced by C. perfringens food poisoning isolates. RESULTS: Our current study demonstrated the presence of all three SASP-encoding genes (ssp1, 2 and 3) in five surveyed C. perfringens clinical food poisoning isolates. beta-Glucuronidase assay showed that these ssp genes are expressed specifically during sporulation. Consistent with these expression results, our study also demonstrated the production of SASPs by C. perfringens food poisoning isolates. When the heat sensitivities of spores produced by a ssp3 knock-out mutant of a C. perfringens food poisoning isolate was compared with that of spores of the wild-type strain, spores of the ssp3 mutant were found to exhibit a lower decimal reduction value (D value) at 100 degrees C than exhibited by the spores of wild-type strain. This effect was restored by complementing the ssp3 mutant with a recombinant plasmid carrying wild-type ssp3, suggesting that the observed differences in D values between spores of wild-type versus ssp3 mutant was due to the specific inactivation of ssp3. Furthermore, our DNA protection assay demonstrated that C. perfringens SASPs can protect DNA from DNase I digestion. CONCLUSION: The results from our current study provide evidences that SASPs produced by C. perfringens food poisoning isolates play a role in protecting their spores from heat-damage, which is highly significant and relevant from a food safety perspective. Further detailed studies on mechanism of action of SASPs from C. perfringens should help in understanding the mechanism of protection of C. perfringens spores from heat-damage.
Resumo:
To prevent leaf senescence of young transplants or excised shoots during storage under dark and cold conditions, the cytokinin biosynthetic gene isopentenyl transferase (ipt) was placed under the control of a cold-inducible promoter cor15a from Arabidopsis thaliana and introduced into Petunia x hybrida 'Marco Polo Odyssey' and Dendranthema x grandiflorum (chrysanthemum) 'Iridon'. Transgenic cor15a-ipt petunia and chrysanthemum plants and excised leaves remained green and healthy during prolonged dark storage (4 weeks at 25 degrees C) after an initial exposure to a brief cold-induction period (4 degrees C for 72 h). However, cor15a-ipt chrysanthemum plants and excised leaves that were not exposed to a cold-induction period, senesced under the same dark storage conditions. Regardless of cold-induction treatment, leaves and plants of non-transformed plants senesced under prolonged dark storage. Analysis of ipt expression indicated a marked increase in gene expression in intact transgenic plants as well as in isolated transgenic leaves exposed to a short cold-induction treatment prior to dark storage. These changes correlated with elevated concentrations of cytokinins in transgenic leaves after cold treatment. Cor15a-ipt transgenic plants showed a normal phenotype when grown at 25 degrees C.
Resumo:
This paper analyzes interbank markets under currency boards. Under such an environment, problematic endogeneity issues common to other monetary regimes do not arise. Using daily data from the interbank markets in Bulgaria and Lithuania we show, that contrary to the existing literature, overnight interest rates tend to decrease towards the end of the reserve holding period. Empirical results are supported by a finite horizon heterogeneous agents model showing that interest rates tend to decrease in the case of excess aggregate reserves in the banking system. Results contrast with Quir'os and Mendiz'abal (2006) who find that interest rates should be increasing regardless of the outstanding aggregate liquidity in the market. We also show that responsiveness of banks to interest rate changes diminishes as the end of reserve holding period approaches. Under certain circumstances this could lead to multiple equilibria with increasing or decreasing interest rates.