3,479 research outputs found
The Outlandish, the Realistic, and the Real: Contextual Manipulation and Agent Role Effects in Trolley Problems
Hypothetical trolley problems are widely used to elicit moral intuitions, which are employed in the development of moral theory and the psychological study of moral judgments. The scenarios used are outlandish, and some philosophers and psychologists have questioned whether the judgments made in such unrealistic and unfamiliar scenarios are a reliable basis for theory-building. We present two experiments that investigate whether differences in moral judgment due to the role of the agent, previously found in a standard trolley scenario, persist when the structure of the problem is transplanted to a more familiar context. Our first experiment compares judgments in hypothetical scenarios; our second experiment operationalizes some of those scenarios in the laboratory, allowing us to observe judgments about decisions that are really being made. In the hypothetical experiment, we found that the role effect reversed in our more familiar context, both in judgments about what the actor ought to do and in judgments about the moral rightness of the action. However, in our laboratory experiment, the effects reversed back or disappeared. Among judgments of what the actor ought to do, we found the same role effect as in the standard hypothetical trolley scenario, but the effect of role on moral judgments disappeared
The dynamics of trade and competition
We present, extend and estimate a model of international trade with firm heterogeneity in the tradition of Melitz (2003) and Melitz and Ottaviano (2005). The model is constructed to yield testable implications for the dynamics of international prices, productivity levels and markups as functions of openness to trade at a sectoral level. The theory lends itself naturally to a difference in differences estimation, with international differences in trade openness at the sector level reflecting international differences in the competitive structure of markets. Predictions are derived for the effects of both domestic and foreign openness on each economy. Using disaggregated data for EU manufacturing over the period 1989-1999 we find evidence that trade openness exerts a competitive effect, with prices and markups falling and productivity rising. Consistent with theory however, these effects diminish and may even revert in the longer term as less competitive economies become attractive havens from which to export from. We provide evidence that this entry into less open economies induces pro-competitive effects overseas in response to domestic trade liberalization.Competition, Globalization, Markups, Openness, Prices, Productivity, Trade
Oil Prices, Profits, and Recessions : An Inquiry Using Terrorism as an Instrumental Variable
Nearly all post-war recessions have been preceded by oil-price shocks, but is this because spikes in the price of petroleum cause economic downturns? Most research has ignored an identification problem : oil prices and the state of the world economy are endogenously determined. This paper uses terrorist incidents as an instrumental variable. In an international panel of industries, we show that after correction for simultaneity bias â though not before â the price of oil has large negative effects upon profitability. Our results seem to lend support to the claim that oil-price spikes can be a source of recessions.
Synthesis of Small Molecule Derivatives of CK-666 as Potential Inhibitors of the Arp2/3 Complex
The Actin-Related Protein (Arp) 2/3 Complex is an actin nucleating factor intrinsically involved in cellular regulation of actin networks during life-essential processes such as motility. Overexpression of the Arp2/3 complex has indicated as a factor allowing the proliferation of certain metastatic cancers. This work describes the synthesis and in vitro biochemical testing of several molecules predicted by computational docking to be inhibitors of Arp2/3 Complex, and therefore of potential interest in clinical applications. The molecules are designed based off of the structure of known Arp2/3 inhibitor CK-666, which was discovered via high-throughput screening. Details of the synthesis of the tryptamine derivatives are discussed, and the bulk actin polymerization assay used to determine potency of the new compounds is discussed
Pruning to Increase Taylor Dispersion in Physarum polycephalum Networks
How do the topology and geometry of a tubular network affect the spread of
particles within fluid flows? We investigate patterns of effective dispersion
in the hierarchical, biological transport network formed by Physarum
polycephalum. We demonstrate that a change in topology - pruning in the
foraging state - causes a large increase in effective dispersion throughout the
network. By comparison, changes in the hierarchy of tube radii result in
smaller and more localized differences. Pruned networks capitalize on Taylor
dispersion to increase the dispersion capability.Comment: 5 pages, 4 figures, 11 pages supplemental materia
A Plate Type Edge-Lift Anchor: Influence of Reinforcing Configurations on Failure Loads
AS3850 Tilt-up Concrete Construction [1] is the current standard for design of lifting anchors and bracing in Australia. However, this standard does not provide a recommendation for calculating the capacity of edge-lifting anchors (normally placed in the edge of thin wall elements) which are commonly used in the precast industry throughout Australia. These anchors may experience a load under tension or combined tension and shear during the lifting process. The American Concrete Institute (ACI)318-08 Building Code Requirements for Structural Concrete [2], the Precast Concrete Institute (PCI) Design Handbook â Precast and Prestressed Concrete [3], and ComitĂ©Euro-International Du BĂ©ton(CEB)Design of Fastenings in Concrete [4] include provisions for general anchorage configurations (such as multiple face lift anchors) rather than what are typically seen in edgelifting anchors. Not only are anchor configurations for edge lifting anchors different from those described in these standards, but the reinforcement around the anchor can vary significantly to those denoted in standards.This paper is an evaluation of pull out test data for edge lift anchors in thin walled elements. Using the formula in the ACI 318-08 [2], developed predominantly for footed anchors, comparisons of the predicted capacity and the test pull out capacity of the edge lift anchors is made. Data is presented on 154 tests; the variables tested include concrete compressive strength at time of testing and the provision and arrangement of reinforcement. In addition to the edge lift anchors, 90 face lift footed anchors were also tested and some of the more relevant data is presented for these tests
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Complications Dawn for Kinetochore Regulation by Aurora
Organisms must faithfully segregate their chromosomes during cell division; mistakes in this process can be costly and even fatal to the organism (1, 2). During mitosis, replicated chromosomes attach to the spindle, a dynamic system of microtubules organized around two poles. Chromosomes attach to the spindle via kinetochores, structures that form on centromeres and bind the ends of microtubules. For accurate segregation, kinetochores on sister chromosomes must attach to microtubules from opposite poles; incorrect attachments lead to missegregation (3). In PNAS, Umbreit et al. (4) expand our understanding of how kinetochoreâmicrotubule interactions can be regulated to correct improper attachments. The authors use in vitro studies to demonstrate that a component of the kinetochore, the Ndc80 complex, can directly influence the dynamics of the microtubules it is bound to and how the complex can be regulated to correct errors in chromosome attachment.
Kinetochores are complicated machines. They can stay attached to microtubule ends as they grow and shrink, regulate the dynamics of microtubules, regulate their own activity, and signal to the remainder of the cell. The outer layer of the kinetochore contains the dumbbell-shaped Ndc80 complex (5): One globular domain [the N-terminal domains of Hec1 (Ndc80 in budding yeast) and Nuf2] binds microtubules (6) and is connected by a long coiled coil to the other globular domain (composed of the C-terminal domains of Spc24/Spc25), which connects to other kinetochore components (7) (Fig. 1A). Hec1 contains a conserved calponin homology domain and an unstructured N-terminal tail: Both regions can bind to microtubules independently, but they must act together to produce high-affinity binding (5âââ8). When sister kinetochores attach...(see full text).Molecular and Cellular Biolog
The Magellanic system X-ray sources
Using archival X-ray data from the second XMM-Newton serendipitous source
catalogue, we present comparative analysis of the overall population of X-ray
sources in the Large and Small Magellanic Clouds. We see a difference between
the characteristics of the brighter sources in the two populations in the X-ray
band. Utilising flux measurements in different energy bands we are able to sort
the X-ray sources based on similarities to other previously identified and
classified objects. In this manner we are able to identify the probable nature
of some of the unknown objects, identifying a number of possible X-ray binaries
and Super Soft Sources.Comment: 4 pages, 2 figures. Poster to appear in proceedings of IAU Symposium
256, The Magellanic System: Stars, Gas, and Galaxies. Keele Univeristy, U
Association between depressive symptoms and pericardial fat in healthy older men and women
Depressive symptoms are associated with increased risk for cardiovascular disease (CVD), and inflammation may contribute to this relationship. Pericardial fat, a highly metabolically active fat depot, is implicated in the pathogenesis of CVD, but its association with depressive symptoms is unclear. This study examined the cross-sectional and longitudinal association between depressive symptoms and pericardial fat over a three-year period. Participants were 543 healthy men and women (mean ageâ=â62.9 years) without history or objective signs of coronary heart disease from the Whitehall II cohort. In men, depressive symptoms were positively associated with pericardial fat at baseline after adjustment for sociodemographics, waist to hip ratio and conventional cardiovascular risk factors. Inflammation, indexed by plasma interleukin 6 concentration, accounted for 17% of this association. Longitudinally, depressive symptoms did not predict pericardial fat three years later in men once baseline levels of pericardial fat were accounted for. No significant associations between depressive symptoms and pericardial fat were found in women. Overall, our findings suggest that greater pericardial fat might be a mechanism by which depressive symptoms are associated with increased risk for CVD in men, and inflammation may also lie on this pathway
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