A scheme is described for the fractionation of pea (Pisum sativum) albumin proteins. By using this scheme, two closely related major albumin proteins have been isolated and purified to homogeneity. The larger protein, designated PMA-L, has Mr approximately 53 000 and consists of two 25 000-Mr subunits, whereas the smaller, PMA-S, has Mr approximately 48 000 and contains two 24 000-Mr subunits. There was no evidence of mixed dimers of the two subunit sizes, despite their close homology as judged by immunological crossreaction, amino acid composition, N-terminal amino acids, tryptic-peptide mapping and CNBr-cleavage products. Both proteins contained significant amounts of sulphur amino acids. The proteins were shown to be located in the soluble cytosol fraction of cotyledon cells and are not significantly degraded on seed germination. Preliminary screening indicates the presence of homologous major albumin proteins in at least three different, though closely related, legume species.
The seeds of pea (Pisum sativum L.) contain several proteins in the albumin solubility fraction that are significant components of total cotyledonary protein (5-10%) and are accumulated in developing seeds concurrently with storage-protein synthesis. One of these proteins, of low Mr and designated 'Psa LA', has been purified, characterized and sequenced. Psa LA has an Mr of 11000 and contains polypeptides of Mr 6000, suggesting that the protein molecules are dimeric. The amino acid sequence contains 54 residues, with a high content (10/54) of asparagine/aspartate. It has no inhibitory action towards trypsin or chymotrypsin, and is distinct from the inhibitors of those enzymes found in pea seeds, nor does it inhibit hog pancreatic alpha-amylase. The protein contains no methionine, but significant amounts of cysteine (four residues per polypeptide), suggesting a possible role as a sulphur storage protein. However, its sequence is not homologous with low-Mr (2S) storage proteins from castor bean (Ricinus communis) or rape (Brassica napus). Psa LA therefore represents a new type of low-Mr seed protein.
Virtual Classroom (VC) learning approaches have recently drawn considerable attention because they have the potential to encourage student engagement to ensure active and collaborative learning. Although research on online learning has gained visibility in recent times, VC learning has not received notable attention, especially in Gulf countries like the United Arab Emirates (UAE). The study examines students’ perception and experience of VC in a university in UAE during the COVID-19 pandemic in terms of its necessity and helpfulness. This research also examines the situational pressure of VC and aims to explain the reasons for its desirability and inevitability. As a current learning space beyond the conventional face-to-face classroom learning, VC learning is available in various forms and quality depending on creating opportunities for the learners’ participation. However, there are issues with VC practice too. Our analysis of survey data (N = 334) leads to portraying autonomous learning freedom in different learning environments in VC. We argue that students may resort to VC not because of its proven effectiveness but because of the necessity to continue addressing their learning needs. This study contributes to the general understanding of the online and traditional in-person classroom learning and virtual learning resources in the teaching of English as a globally desired language.
Bangladesh ELT situation has been deteriorating for the last four decades. Regional and national projects including ELTIP and EIA proved to be futile in improving this situation, especially, in the Bangladesh rural primary schools with almost 0% properly trained English teachers to implement the current CLT curriculum. This article investigates the on-going poor health-status of CLT at randomly selected schools of northern Bangladesh through delving into the research gaps linked with the ELT practitioners’ own English proficiency, their training needs, motivation and teaching skills; their perception on the instructional module; and perception of the YLs of English in Bangladesh. This enquiry uses a mixed method involving a questionnaire survey, semi-structured interview with ELT teachers, teacher trainers, head-teachers and lesson observation followed by a workshop and informal discussion with 100 participants from all ELT stake-holders to validate the findings of the earlier questionnaire survey. The findings conclude that ineffective and lack of teacher training, non-availability of English subject teacher, unproductive instructional materials, unhelpful learning environment, learners’ socio-economic background, teachers’ poor competence in English and knowledge of CLT methods are responsible for this deterioration. It recommends that implementation of a rigorous teacher training program for CLT to produce English subject teachers for each school, production of a pedagogically user-friendly instructional module for CPD, a culture-oriented teaching-learning environment and a program of regular guidance and supervision by CLT experts would address the gaps prevailing in the ELT (and CLT) situation at the rural primary schools of Bangladesh.
The success of the Communicative Language Teaching (CLT) approach at primary schools of Bangladesh has recently been questioned seriously. No measures have yet been taken to remedy the apprehended failure of CLT programs in the country. This inquiry focuses on the perils of pupils in the forms of shaming, failure, and fear for the tyranny of the current CLT curriculum. A mixed research method was used to conduct a comprehensive analysis of the learners’ situation through a questionnaire survey with participation of 211 CLT practitioners, an FGD with 12 participants and semi-structured interviews with 15 English learners. Along with lack of teacher empowerment mechanisms, other challenges for young learners (YLs) included problem of enduring class rules, their inability to cope with difficult texts, fear of failure in lessons, tests, and physical and psychological sufferings inflicted on them during, before and after the delivery of the lessons. The findings reveal the need of a modified CLT curriculum with provisions for innovative pedagogy, learner care and learner empowerment. Provisions for use of L1 Bangla in lesson delivery, inclusion of learner culture and local context in the teaching-learning of English are recommended to ensure expected outcomes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.