Macroeconomic implications of changes in the term premium

Linearized New Keynesian models and empirical no-arbitrage macro-finance models offer little insight regarding the implications of changes in bond term premiums for economic activity. This paper investigates these implications using both a structural model and a reduced-form framework. The authors show that there is no structural relationship running from the term premium to economic activity, but a reduced-form empirical analysis does suggest that a decline in the term premium has typically been associated with stimulus to real economic activity, which contradicts earlier results in the literature.Macroeconomics ; Finance

Macroeconomic implications of changes in the term premium

Linearized New Keynesian models and empirical no-arbitrage macro-finance models offer little insight regarding the implications of changes in bond term premiums for economic activity. We investigate these implications using both a structural model and a reduced-form framework. We show that there is no structural relationship running from the term premium to economic activity, but a reduced-form empirical analysis does suggest that a decline in the term premium has typically been associated with stimulus to real economic activity, which contradicts earlier results in the literature.Interest rates ; Economic forecasting ; Econometric models

Re-Evaluation of the Role of Starch in Gravitropic Sensing

Plant organs grow toward or away from gravity as a way to orient those organs for optimizing growth. Starch has long been thought to be important in sensing the direction of the g-vector in gravitropism, but that hypothesis has also evoked controversy. We have previously shown that starch-deficient mutants of Arabidopsis (TC7) and Nicotiana (NS458) are impaired in their gravitropism. While this suggests that starch is not necessary for reduced gravitropism, it also indicates that the mass of the starch contributes to sensing when present and thus is necessary for full gravitropic sensitivity. The research supported by this grant focused on three related projects, (1) the effect of light on hypocotyl gravitropism in NS458, (2) the effects of root phototropism on measurements of gravitropic sensitivity, and (3) the effects of starch overproduction on sedimentation and gravitropism. Collectively, our results provide additional strong support for the importance of starch in gravitropic sensing. First, by accounting for negative phototropism in roots of two starchless mutants of Arabidopsis we have established that these mutants are much less sensitive to gravity than previously thought. This work also demonstrates the importance of designing experimental protocols that remove the influence of root phototropism on measuring root gravitropism. Second, light apparently promotes gravitropism in starch-deficient Nicotiana hypocotyls by increasing the trace amounts of starch in the plastids, by inducing limited plastid sedimentation and thus by presumably increasing the signal provided by plastid mass. And finally, we show that excess starch in Arabidopsis seedlings has little effect on gravitropic sensitivity implying that the sensing system is already saturated. However, in light-grown stems where this mutation results in starch accumulation and where the wild-type practically lacks starch in the sensing cells, the mutant is much more sensitive than the wild-type again showing that the loss of starch depresses gravity sensing

Cellular polarity and interactions in plant graviperception

Presented are results of studies on the mechanisms of gravitropic sensing in higher and lower plants. Gravitropic roots of the aquatic angiosperm, Limnobium, were found to have sedimented amyloplasts in their elongation zone but not in their rootcap; nuclei were found to sediment in the elongation zone as well. Another study attempted to understand how plastid sedimentation occurs in vertical Ceratodon cells and how this sedimentation is regulated. To determine whether the cytoskeleton restricts plastid sedimentation, the effects of amiprophos-methyl (APM) and cytochalasin (CD) on plastid position were qualified. Results suggest that microtubules restrict the sedimentation of plastids along the length of the cell and that microtubules are load-bearing for all the plastids in the apical cell, demonstrating the importance of the cytoskeleton in maintaining organelle position and cell organization against the force of gravity. Physcomitrella and Funaria were also studied. Results suggest that gravitropism may be relatively common in moss protonemata and reinforce the idea that amyloplast mass functions in gravitropic sensing

A 50-State Survey of Bicycle Crash Reporting Policies

Bicycle crashes result in many injuries and deaths in the United States each year. Bicyclists represented 2.3 percent of the total traffic crash fatalities in 2013, despite the bicycle mode share being less than 1%. Bicycle crash fatality data is collected at the federal level through FARS. However, FARS relies on state-level data that is coded by state analysts. The Model Minimum Uniform Crash Criteria (MMUCC) provides guidance to the states on which elements should be reported in a crash. However, the MMUCC is currently optional, and states are very inconsistent in their bicycle crash reporting policies. Better crash reporting policies would provide more accurate and consistent data on the public health impact of bicycle crashes. A 50-state survey of bicycle crash reporting laws using Westlaw Next was conducted. The survey revealed that very few states legislate bicycle crash reporting. Only six states currently have a statute relating to bicycle crash reporting and only four states have a regulation that requires bicycle crash reporting. Of the states with a statute or regulation, only six of them have at least one law that requires reporting that exceeds what is reported by FARS. To better understand the public health impact of bicycle crash reporting, all states should follow the MMUCC guidelines. A model law should be developed that requires reporting of crashes involving a bicyclist who is injured or killed and requires that reports include specific data in a consistent format. Laws should require reporting of specific precrash data so that infrastructure can be implemented which better protects bicyclists. Each state should adopt the model law or a similar version of it. Because law is not always one-hundred percent enforced, bicycle advocacy groups and public health departments and organizations should provide education on the importance of bicycle crash reporting

The Concept of Photozymes: Short Peptides with Photoredox Catalytic Activity for Nucleophilic Additions to α-Phenyl Styrenes

Conventional photoredox catalytic additions of alcohols to olefins require additives, like thiophenol, to promote back electron transfer. The concept of “photozymes” assumes that forward and backward electron transfer steps in a photoredox catalytic cycle are controllable by substrate binding to photocatalytically active peptides. Accordingly, we synthesized a short tripeptide modified with 1,7-dicyano-perylene-3,4 : 9,10-tetracarboxylic acid bisimide as photoredox catalyst. This peptide undergoes an unconventional photoredox catalytic cycle with the radical anion and dianion of the perylene bisimide-peptide as intermediates. The photoredox catalytic reactions with α-phenyl styrenes as substrates require remarkably low catalyst loadings (0.5 mol%) and give the methoxylation products in high yields. The concept of “photozymes” for photoredox catalysis has significant potential for other photocatalytic reactions, in particular with respect to enantioselective photocatalysis

The Major Veins of Mesomorphic Leaves Revisited: Tests for Conductive Overload in Acer saccharum (Aceraceae) and Quercus rubra (Fagaceae)

Many leaves survive the severing of their major veins in apparently excellent health. According to the classical explanation, the leaf minor veins provide "conductive overload," an excess of parallel conductive paths, rendering the major veins hydraulically dispensable. Whether such an excess of conductive paths exists has important implications for vascular design and for leaf response to vascular damage. We subjected leaves of Acer saccharum and Quercus rubra to cutting treatments that disrupted the major vein system and determined leaf survival, stomatal conductance (g), quantum yield of photosystem II (Phi(PSII)), and leaf hydraulic conductance (K-leaf). For A. saccharum, the cuts led to the death of distal lamina. For Q. rubra, however, the treated leaves typically remained apparently healthy. Despite their appearance, the treated Q. rubra leaves had a strongly reduced K-leaf,K- relative to control leaves, and g and Phi(PSII) were reduced distal to the cuts, respectively, by 75-97% and 48-76%. Gas exchange proximal to the cuts was unaffected, indicating the independence of lamina regions and their local stomata. Analogous results were obtained with excised Q. rubra leaves. These studies demonstrate an indispensable, vital role of the major veins in conducting water throughout the lamina.Organismic and Evolutionary Biolog