Studies in Protein Synthesis: The Relationship of Energy Intake to Protein Metabolism

Studies have been carried out on rats to determine the nature of the relationship between the level of energy intake and protein metabolism. The experimental studies are described in five sections, summarised as follows Section 1. The influence of previous energy level on the in vitro uptake of 35S-methionine into the proteins of rat liver and muscle, 1. Rats were maintained on a diet of adequate protein content, to which had been added increasing energy increments in the form of fat, and after fasting overnight were then killed 12-14 hours or 18-20 hours later. 2. The uptake of methionine into liver and diaphragm proteins increased linearly with increasing levels of energy intake. 3. The conclusion to be drawn from this series of experiments is that previous energy intake exerts a prolonged action on protein metabolism in both liver and muscle. Section 2. The influence of previous energy intake on the in vitro incorporation of 14C-glycine into liver proteins. 1. A study was made of the influence of the energy content of diets (both protein-free and protein-containing) on the in vitro uptake of 14-C-glycine into rat liver proteins. In this instance, a comparison was made between rats which were in a post-absorptive state for 12 hours and those which had just been fed a protein meal. 2. The uptake of isotope increased as the energy content of the preceding diet rose; the influence of energy level was greater when the previous diet contained protein. 3. Since energy level exerts its greatest effect within the first hour of incubation, it is suggested that the differences in 14C-glycine incorporation may be due to differences in the rate of penetration of isotope into the cell; it is not possible from such experiments to determine whether protein synthesis per se is affected by energy level. Section 3. The influence of previous energy level on the in vivo incorporation of 14C-glycine into liver protein. 1. Rats were maintained on the same dietary regimes as those described in Section 2 and were sacrificed 3 and 6 hours after the injection of 14C-glycine. 2. The only circumstance in which the energy level in the preceding diet affected protein synthesis was in the case of the group fasting after a normal protein intake. In contrast, the energy level of the diet did not affect the uptake of glycine when the rats had been fed a protein-free diet or when the rats were in the absorptive state after a protein meal. 3. The conclusion has been drawn that differences in energy content of the diet exert their main effect on protein utilisation in the post-absorptive state and not at the time when tissues are being flooded with amino acids from the gut. Section 4. The effect of previous energy intake on the adenosine nucleotide pattern of rat liver. 1. Rats were maintained on diets either containing protein or free from protein and providing different energy levels. 2. In the post-absorptive state, the ATP/ADP ratio was found to improve when the energy content of the preceding diet was raised. Such an improvement in the ratio was obliterated when protein was fed 2 hours prior to sacrifice. 3. A difference in nucleotide pattern was still apparent even when a meal was interposed between the last energy supplement and sacrifice; again, the feeding of protein before death altered the pattern. 4. The results were interpreted to mean that the enhanced ATP/ADP ratio observed with increasing energy intakes may well regulate the incorporation of amino acids into protein and consequently the change of nucleotide pattern on feeding protein could account for the lack of influence of energy intake during the phase of absorption. Section 5. The influence of energy intake on PAH synthesis by liver slices in vitro. 1. Liver slices from rats which had been fed on the same dietary regimes as above were incubated with p-amino benzoic acid and glycine. 2. When the results are expressed in terms of the DNA content, the effect of protein and energy intake appears to increase the synthesis in the protein-fed group in the post-absorptive state. 3. When the results are expressed per mg. wet weight, it would appear that no differences exist between the various dietary fators. The fact that differences are no longer apparent has been taken to mean that energy level has no effect on PAH synthesis independent of changes in protein (i.e. enzyme) content. 5. It has been concluded that PAH peptide bond synthesis is not a suitable model system for the study of the effects of energy level on protein synthesis

The effect of carbon arc radiations on certain components of the blood in children

While acting as a resident Medical Officer in the Royal Hospital for Sick Children, Edinburgh, the writer was very much impressed by the general improvement he saw in certain cases attending the Artificial Heliotherapy Department of the hospital.These cases were Bent to the department, not suffering from any definite disease, but labelled "General Debility ", "Anaemia ", "Post-operative debility ", "Debility from chronic sepsis ", etc.The beneficial effects of Heliotherapy in Rickets, Surgical Tuberculosis and other definite diseases are well known and have been most thoroughly investigated by hosts of observers. However it occurred to the writer to investigate a series of such children and find out whether the beneficial effects of the Heliotherapy could be accounted for, by any changes in certain components of their blood.The selected children were all of a type so very common in any large medical out -patient department of a city hospital. The type of child represented is well known to all pediatricians. It is the child of the poorer hospital class, probably living in one of the worst quarters of the city, inefficiently clothed, under nourished but yet not showing any of the clinical manifestations of rickets. There is usually a long history of chronic ill -health. The child is said to sleep badly, eat little, is easily tired, looks pale and is under average weight and height. When examined no definite disease is found but what usually strikes one is the very bad posture of these children probably from an undernourished muscular system. The child is usually labelled general debility or some such term and given a tonic. Previous to artificial heliotherapy, there usually was little improvement with this treatment unless the children were sent to the country or seaside (natural heliotherapy).Now, however, these children make up a large percentage of the children attending the Heliotherapy Dept, as outpatients and their improvement is most encouraging to all those interested in the use of artificial heliotherapy. The investigation aimed at finding out if any changes in certain components of the blood in these children could account for their improvement.The components investigated were the Red Blood Corpuscles, the White Blood Corpuscles, the Haemoglobin content and the Platelets. The Calcium and phosphorus concentrations in the blood were also estimated at intervals in case any change in these important inorganic constituents of the blood could cause the effect noted.All of these children showed such a marked improvement in colour along with the other manifestations, that the writer was hopeful some important changes could be demonstrated in the blood components investigated, to account for the great change in the/ 5. the child's health. It was with this idea that the investigation was carried out, and though the results obtained are not as convincing as was hoped, yet they are so uniform that in the writer's mind, it is certain that Actinotherapy has a very definite therapeutic action on a blood of poor qualities, the latter being due more to the nourishment of the individual than to any definite organic disease.May not most of these children be suffering from an insufficiency of some vitamin, either A, D or some other not yet isolated, and that sunlight has the same effect here as in Vitamin D insufficiency

The Frames Behind the Games: Player's Perceptions of Prisoner's Dilemma, Chicken, Dictator, and Ultimatum Games

The tension between cooperative and competitive impulses is an eternal issue for every society. But how is this problem perceived by individual participants in the context of a behavioral games experiment? We first assess individual differences in players’ propensity to cooperate in a series of experimental games. We then use openended interviews with a subset of those players to investigate the various concepts (or ‘frames’) they used when thinking about self-interested and cooperative actions. More generally, we hope to raise awareness of player’s perceptions of experimental environments to inform both the design and interpretation of experiments and experimental data.Laboratory Experiment, Frames, Selfishness, Cooperation

Unheralded Historian: Mary Sheldon Barnes and Primary Source Material in History Books

ABSTRACT UNHERALDED HISTORIAN: MARY SHELDON BARNES AND PRIMARY SOURCE MATERIAL IN HISTORY BOOKS by James A. Chisholm, Jr. In the latter part of the nineteenth century, Mary Sheldon Barnes emerged as a leading historical methods professor and history textbook author. Although men dominated the field, she wrote several articles and books alone or with her husband Earl Barnes about primary source materials and teaching. She lived during an era in United States history when education was evolving. Students studied traditional subjects such as grammar, mathematics, and Latin using rote memorization. Students who failed to learn classroom material faced varying degrees of punishment from teachers. Classroom pedagogy in the nineteenth century was teacher-focused and teachers often employed a considerable amount of physical fear. Mary Sheldon Barnes developed her pedagogy and writing style using scientific history and German seminary style classrooms. As a teacher, she taught in a normal school, gender specific college, and a co-educational institution of higher learning and these experiences impacted her pedagogy. Barnes rejected the regimented, teacher-centered, memorization/recitation pedagogy of the nineteenth century. She preferred a teaching style that provided more student-centered, discussion-oriented history pedagogy. This study utilizes biography as a format to explore Mary Sheldon Barnes as a pioneer teacher and author. Following her death, history textbook authors turned away from source material textbooks back to traditional chronological design and ignored her contributions to social education history. This dissertation provides an examination of her life and explores its influence on contemporary textbooks and pedagogy

Early psychosocial stress predicts extra-pair copulations

Cheating on a mate, known as an extra-pair copulation (EPC), is considered unacceptable by most individuals. Nonetheless many individuals engage in such risky behaviors. Because individuals with high, as opposed to low, levels of early psychosocial stress are more risk prone and more likely to engage in opportunistic matings, we predicted that individuals reporting EPCs, one of many types of opportunistic mating (e.g., one-night stand, consecutive short-term relationships etc), have higher levels of early psychosocial stress than those who do not. Two types of EPCs were examined: EPC-self (EPC-S), having sex with someone other than one's mate, and EPC-other (EPC-O), having sex with someone else's mate. In a sample of 229 women and 161 men, significantly higher levels of early psychosocial stress were found amongst those reporting an EPC-S than those reporting none, irrespective of EPC-Os. Furthermore, the more EPC-Ss men, but not women, reported the higher their early psychosocial stress. Early psychosocial stress was not associated with EPC-Os irrespective of EPC-Ss. Participants were also classified into one of four groups (no EPCs, EPC-O only, EPC-S only, or EPC-S&O) which significantly interacted with early psychosocial stress. Results are discussed from adaptationist and mechanist perspectives and why early psychosocial stress was higher in individuals reporting EPC-Ss irrespective of EPC-Os, but not EPC-Os irrespective of EPC-Ss, than those not reporting the EPC of interest

Bodies in space/bodies in motion/bodies in character : adolescents bear witness to Anne Frank.

Situated at the intersection of research on Holocaust education and embodied literacies this study examines how an arts-based instructional approach engaged middle school learners in developing empathetic perspectives on the Anne Frank narrative. We addressed the research question: What can adolescents who are using their bodies to gain empathy with Anne Frank teach us about embodied literacies? Digital images and video were used to generate a multimodal analytic method that combined focus group interviewing with the Semiotic Photo Response Protocol and Visual Discourse Analysis. Analyses of performance and visual arts texts illustrated how students layered their understandings as they recast meanings across sign systems. As students engaged their bodies in space, in motion, and in character, they learned about the socio-historical and emotional contexts in which Anne lived. These findings suggest that arts-integrated and embodied learning opportunities may support students’ sensemaking about complex narratives

“She’s Definitely the Artist One”: How Learner Identities Mediate Multimodal Composing

Multimodal composing can activate literacy practices and identities not typically privileged in verbocentric English classrooms, and students’ identities as particular kinds of learners (e.g., “visual artist”) may propel—or limit—their engagement in classroom work, including in multimodal composing. Although researchers have studied the ways multimodal projects can evidence literacy learning and have argued that identity is negotiated, improvisational, and hybrid, they have offered few sustained analyses of the processes by which identities evolve during and across multimodal composing tasks. By examining how students position themselves and one another as particular kinds of learners over time, researchers can better understand the ways in which multimodal tasks help students explore new skills and roles or reify old ones. Drawing on an approach to discourse analysis from the linguistic anthropology of education, we trace the pathways of three 12th graders’ learner identities across two events as they worked in a group to compose visual responses to literary texts for their English class. We examine how one student’s robust identity as an artist emerged in tandem with the devaluing of other participants’ artist identities. Seven weeks later, these positionings led her to act as the painting’s primary author and other students to act in increasingly perfunctory ways. We call for teachers and researchers to consider how students’ identities—interacting with factors such as the teacher’s expectations for group work and the affordances of particular media and materials for collaboration—drive students’ participation in and ownership of multimodal compositions

Flowdown of the TMT astrometry error budget(s) to the IRIS design

TMT has defined the accuracy to be achieved for both absolute and differential astrometry in its top-level requirements documents. Because of the complexities of different types of astrometric observations, these requirements cannot be used to specify system design parameters directly. The TMT astrometry working group therefore developed detailed astrometry error budgets for a variety of science cases. These error budgets detail how astrometric errors propagate through the calibration, observing and data reduction processes. The budgets need to be condensed into sets of specific requirements that can be used by each subsystem team for design purposes. We show how this flowdown from error budgets to design requirements is achieved for the case of TMT's first-light Infrared Imaging Spectrometer (IRIS) instrument.Comment: 8 pages, 4 figures. Proceeding of SPIE, Astronomical Telescopes and Instrumentation 201