Three great american disinflations

In this paper, we examine three famous episodes of deliberate deflation (or disinflation) in U.S. history, including episodes following the Civil War, World War I, and the Volcker disinflation of the early 1980s. These episodes were associated with widely divergent effects on the real economy, which we attribute both to differences in the policy actions undertaken, and to the transparency and credibility of the monetary authorities. We attempt to account for the salient features of each episode within the context of a stylized DSGE model. Our model simulations indicate how a more predictable policy of gradual deflation could have helped avoid the sharp post-WWI depression. But our analysis also suggests that the strong argument for gradualism under a transparent monetary regime becomes less persuasive if the monetary authority lacks credibility; in this case, an aggressive policy stance (as under Volcker) can play a useful signalling role by making a policy shift more apparent to private agents. JEL Classification: E31, E32, E5

Three Great American Disinflations

In this paper, we examine three famous episodes of deliberate deflation (or disinflation) in U.S. history, including episodes following the Civil War, World War I, and the Volcker disinflation of the early 1980s. These episodes were associated with widely divergent effects on the real economy, which we attribute both to differences in the policy actions undertaken, and to the transparency and credibility of the monetary authorities. We attempt to account for the salient features of each episode within the context of a stylized DSGE model. Our model simulations indicate how a more predictable policy of gradual deflation could have helped avoid the sharp post-WWI depression. But our analysis also suggests that the strong argument for gradualism under a transparent monetary regime becomes less persuasive if the monetary authority lacks credibility; in this case, an aggressive policy stance (as under Volcker) can play a useful signalling role by making a policy shift more apparent to private agents.DSGE Model, Credibility, Deflation

Effects of Population Size and Density On Pollinator Visitation, Pollinator Behavior, and Pollen Tube Abundance in Lupinus Perennis

Both the number and the density of flowering plants in a population can be important determinants of pollinator abundance and behavior. We report the joint effects of population size and density on pollinator visitation and pollination success for Lupinus perennis (Fabaceae). Focusing on five pairs of populations, we matched one small population (125-800 flowering plants) with one distinctly larger population (1000-3000 flowering plants). In these pairs, population size did not affect pollinator communities or pollination success. All measures of pollination success increased significantly with density. Only bee behavior (number of flowers probed per inflorescence) exhibited a significant interaction of size and density. Testing whether population sizes smaller than those in the paired populations might affect pollination, we gathered pollen tube samples from 14 unpaired populations (16-215 flowering plants). Combining these data with those from the paired populations revealed a significant decrease in pollination for smaller populations, indicating that effects of population size may be detectable only when populations smaller than a few hundred plants are sampled. We found that effects of density are consistent and much stronger than those of population size. Our results suggest that both size and density of natural populations should be considered in designing restoration and reintroduction programs for this threatened plant

Keeping the golden mantella golden: The effect of dietary carotenoid supplementation and UV provision on the colouration and growth of Mantella aurantiaca

One of the limitations affecting the success of captive breeding programmes for amphibians is a lack of knowledge relating to the diet of wild animals. Carotenoids are known to be an important dietary component for the health and proper development of colouration in many vertebrates, but information relating to amphibians is limited. We investigated the influence of carotenoid supplementation in the Critically Endangered golden mantella Mantella aurantiaca. In a fully factorial design, 60 juvenile M. aurantiaca were provided with two dietary carotenoid treatments, standard and enhanced, and two ultraviolet B (UVB) treatments, no UVB and low-level UVB. There was a significant interaction of the treatments on the skin colouration of the study animals. The provision of both an enhanced carotenoid diet and UVB light resulted in the frogs being more red coloured, however when provided in combination the increase in redness was lower than when the treatments were provided alone. In the second part of the study, 64 juvenile M. aurantiaca were reared on one of two diets containing the same concentration of carotenoids, but different profiles: a ‘red’ diet and a ‘yellow’ diet. These treatments also had a significant effect on colouration, with those receiving the red diet becoming a more intense red colour. Our results demonstrate that the bright colouration of M. aurantiaca is influenced by both the concentration and profile of carotenoids in the diet, in addition to the presence of low-level UVB exposure. None of the treatments had any reported effect on the growth of the study animals, however further work should investigate other physiological responses not investigated here

Physical determinants of the self-replication of protein fibrils

The ability of biological molecules to replicate themselves, achieved with the aid of a complex cellular machinery, is the foundation of life. However, a range of aberrant processes involve the selfreplication of pathological protein structures without any additional factors. A dramatic example is the autocatalytic replication of pathological protein aggregates, including amyloid fibrils and prions, involved in neurodegenerative disorders. Here, we use computer simulations to identify the necessary requirements for the self-replication of fibrillar assemblies of proteins. We establish that a key physical determinant for this process is the affinity of proteins for the surfaces of fibrils. We find that self-replication can only take place in a very narrow regime of inter-protein interactions, implying a high level of sensitivity to system parameters and experimental conditions. We then compare our theoretical predictions with kinetic and biosensor measurements of fibrils formed from the Aβ peptide associated with Alzheimer’s disease. Our results show a quantitative connection between the kinetics of self-replication and the surface coverage of fibrils by monomeric proteins. These findings reveal the fundamental physical requirements for the formation of supra-molecular structures able to replicate themselves, and shed light on mechanisms in play in the proliferation of protein aggregates in nature.We acknowledge support from the Human Frontier Science Program and Emmanuel College (A.Š), Leverhulme Trust and Magdalene College (A.K.B), St. John’s College (T.C.T.M), the Biotechnology and Biological Sciences Research Council (T.P.J.K. and C. M. D.), the Frances and Augustus Newman Foundation (T.P.J.K.), the European Research Council (T.P.J.K., S.L. and D.F), and the Engineering and Physical Sciences Research Council (D.F.).This is the author accepted manuscript. The final version is available from Nature Publishing Group via https://doi.org/10.1038/nphys382

The use of a cap-mounted tri-axial accelerometer for measurement of distance, lap times and stroke rates in swim training

This paper will report some of the findings from a trial which recorded accelerometer data from six elite level swimmers (three female and three male, varying primary event stroke and distance) over the course of a regular 15 week training block. Measurements from a headmounted accelerometer are used to determine when the athlete is swimming, marking of turning points (and therefore distance and lap-time measurements), and is processed by frequency analysis to determine stroke-rate. Comparison with video where available, and with training plans and literature where not, have proven this method to be accurate and reliable for determining these performance metrics. The primary objective of this project was to develop a low-cost, simple and highly usable system for use in swim coaching, feedback from elite coaches has indicated that development of this could be an extremely useful addition to their training regime

Explanatory Style as a Risk Factor for Traumatic Mishaps

Six studies investigated a possible link between hopeless explanatory style—that is, the habitual explanation of bad events with stable and global causes—and risk for traumatic injuries. In samples of college students, dancers, athletes, and trauma patients (total n = 2274), stable and global explanations for bad events correlated with the occurrence of mishaps. The link appeared to be mediated in part by a preference for potentially hazardous settings and activities in response to negative moods associated with hopelessness. Taken together, these findings suggest that catastrophizing individuals may be motivated to escape negative moods by preferring exciting but risky courses of action.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44339/1/10608_2004_Article_363208.pd