The b iosynthesis of histidine: imidazoleglycerol phosphate, imidazoleacteol phosphate, and histidinol phosphate

This is a report on the isolation and characterization of D-erythro-imidazoleglycerol phosphate (IGP), imidazoleacetol phosphate (IAP), and L-histidinol phosphate, which are accumulated in the mycelia of several of these mutants

Science for Place-based Socioecological Management: Lessons from the Maya Forest (Chiapas and Petén)

The role humans should play in conservation is a pervasive issue of debate in environmental thinking. Two long-established poles of this debate can be identified on a preservation-sustainable use continuum. At one extreme are use bans and natural science-based, top-down management for preservation. At the other extreme is community-based, multidisciplinary management for sustainable resource use and livelihoods. In this paper, we discuss and illustrate how these two strategies have competed and conflicted in conservation initiatives in the Maya forest (MF) of the Middle Usumacinta River watershed (Guatemala and Mexico). We further argue that both extremes have produced unconvincing results in terms of the region’s sustainability. An alternative consists of sustainability initiatives based on place-based and integrated-knowledge approaches. These approaches imply a flexible combination of disciplines and types of knowledge in the context of nature-human interactions occurring in a place. They can be operationalized within the framework of sustainability science in three steps: 1) characterize the contextual circumstances that are most relevant for sustainability in a place; 2) identify the disciplines and knowledge(s) that need to be combined to appropriately address these contextual circumstances; and 3) decide how these disciplines and knowledge can be effectively combined and integrated. Epistemological flexibility in the design of analytic and implementation frameworks is key. Place-based and integrative-knowledge approaches strive to deal with local context and complexity, including that of human individuals and cultures. The success of any sustainability initiative will ultimately depend on its structural coupling with the context in which it is applied

J.R.R. Tolkien and Old English Studies: An Appreciation

Some scholars argue that Tolkien did not fulfil some of his responsibilities during his thirty- four years as an Oxford Professor, in that he spent the bulk of his research time on his imaginative writings, thereby depriving scholarship of valuable works he - or other holders of his Chairs — might have produced. This paper leaves posterity to judge this issue, but in assessing Tolkien’s contribution to Old English studies, it will argue that one of them - his 1936 British Academy lecture, “Beowulf: The Monsters and the Critics” - has had more influence than most of the products of his critics, and that many Old English scholars owe much to his inspiration

Interactions in Lambdoid Bacteriophage Populations

The lambdoid bacteriophages are ideal subjects for the study of populational interactions at the molecular level because they do not mutually exclude one another in mixed infection of the same host cell. Previous work done in this laboratory using the lambdoid phage pairs λ-434 hy mi and λ-∅80 have demonstrated a density-dependent reduction in progeny yield per infected cell (burst size) as a function of increasing multiplicity of infection (m.o.i.). The λ cI gene which codes for the repress or molecule has been demonstrated to be the cause of the interaction in the λ-434 hy mi phage pair. The purpose of this research was to determine if the λ cI gene is also responsible for the interaction observed in the λ-∅80 phage pair. The λ cII gene which also functions in an immunity specific manner was also considered as a source of interaction. The experiments were conducted using the mutant phages λcI857 and 434 hy cII68, a hybrid phage consisting of the 434 immunity region in an otherwise λ genome. By comparing the lines generated on a log-log plot of burst size versus m.o.i. it is possible to determine whether these phages deficient in the λ cI or cII genes produced results similar to the interaction observed in the wild type phage pairs. If the interaction is seen to be eliminated by the use of a mutant phage, then the interaction is dependent upon the gene that is deficient in that mutant phage. The results of this study indicate that the interaction observed in the λ-∅80 phage pair is not dependent upon the λ cI or cII genes. Neither mutant phage alleviated the density-dependent decrease in burst size. This suggests that some vegetative gene is responsible for the observed interaction. It is postulated that the most likely candidates are the DNA replication genes (O and P) and the gene (Q) which controls late phage transcriptions

After The Protests: A Campus Racial Climate Case Study of the Perception and Curricular Responses For Institutional Reforms, Following the Black Students’ Demands For Interventions at the University of Missouri-Columbia

This qualitative method single case study explores the phenomenon of a racially tense campus climate at the University of Missouri Columbia, a Predominantly White Midwestern Institution. At the forefront of the media regarding student and athlete protests, leading to the resignation of senior level administrators, African American students put forth eight demands to their administrators. Included, was the creation and implementation of a required racial awareness and inclusion curriculum. The study explores the perceptions of the institutional response to an exceptional campus racial climate issue and the process of formulating and participating in a diversity training course and a semester long course centered around race. Also, to understand how participants perceived this curricular intervention to have addressed their discontinuities in race and racism and contributed to organizational change, and institutional reform. This study addresses a gap in our understanding of the aftermath of such events, the institutional process of responding to them, addresses an understudied area of divergent participant perceptions, by exploring how student’s demands were implemented as institutional interventions, and by understanding their perceptions of building a required racial awareness and inclusion curriculum. Four-emergent themes: Process of Curricular Reform Implementation, Towards Combating Discontinuities of Intergroup Relations in American Society at Mizzou through Education, Required or Optional Racial Awareness Curriculum to Elicit Institutional Reforms, and Perceptions about the Institutional Response/Curricular Reform Efforts to Change Mizzou’s Campus Racial Climate. Hence, I developed a framework for considerations: Towards Implementing a Race and Identity-focused Inclusive Curriculum, for practitioners/educators desirous of implementing said curriculum

Postmortem changes in meat quality and myofibrillar protein degradation in turkey breast muscle

The purpose of this research was to evaluate the effect of elevated carcass temperature in combination with rapidly declining pH or with postrigor muscle on turkey breast meat quality. Two groups of twelve turkey carcasses with similar ultimate pH values were selected based on 15 min postmortem (PM) breast muscle pH (rapid-glycolyzing (RG), pH 6.0). One side of each carcass was held near 40°C and immersion chilling was delayed until 110 min PM (DC), while the other side was chilled at 20 min PM (IC). Raw breast meat quality was assessed using measurements of colour and protein extractability, while quality characteristics of cooked product were assessed using cook yield and torsion gelometry. The extractability and degradation of 10 specific proteins was monitored using SDS-PAGE and Western blotting. Additionally, holding postrigor turkey breast meat at 40°C was evaluated as a model for mimicking changes due to rapid PM glycolysis. Sarcoplasmic and myofibrillar protein extractability was reduced for breast samples from RG and DC carcasses as well as for postrigor meat held at 40°C (P < 0.05). All colour values ('L*a*b*') increased for DC ground breast meat. Strain at fracture for breast meat gels was lower for RG samples. Both stress and strain at fracture and cook yield were reduced for DC breast meat gels. The reduction in meat quality measurements was additive for RG samples that were delay-chilled. Densitometry of Western blot analyses revealed that the extractability of glycogen phosphorylase, creatine kinase, and M-protein was reduced for RG or DC samples. Increased myosin degradation was observed for samples from either RG or DC carcasses with up to 20% of myosin degraded in RG/DC samples. Nebulin degradation was also more extensive in RG samples than for controls. Heating postrigor breast increased myosin degradation, however, differences in the banding pattern of myosin fragments compared to samples from RG carcasses were observed. These results provide conclusive evidence that rapid PM glycolysis and delayed chilling have detrimental effects on turkey breast meat quality. The association of postmortem protein degradation with meat of reduced quality merits further investigations into the relationship between postmortem proteolytic activity and meat quality