Increasing Interdependence of Multivariate Distributions

Orderings of interdependence among random variables are useful in many economic contexts, for example, in assessing ex post inequality under uncertainty; in comparing multidimensional inequality; in valuing portfolios of assets or insurance policies; and in assessing systemic risk. We explore five orderings of interdependence for multivariate distributions: greater weak association, the supermodular ordering, the convex-modular ordering, the dispersion ordering, and the concordance ordering. For two dimensions, all five orderings are equivalent, whereas for an arbitrary number of dimensions n > 2, the five orderings are strictly ranked. For the special case of binary random variables, we establish some equivalences among the orderings.dependence ordering; stochastic orders; supermodularity; weak association; concordance JEL Classification Numbers: D63, D81, G11, G22

The Relationship Between Exposure to Lead and Criminal Behavior

In recent years it has been made apparent that exposure to lead is a significant problem for many individuals and families. Lead exposure–whether through the air, water, or by ingestion–has been linked to numerous physical, cognitive, and social problems (Chandramouli, 2009; Nevin, 2007). Furthermore, urban, poor and immigrant populations are at a higher risk for lead exposure (Bakhireva, et al., 2013). And increasingly a connection between lead exposure and criminal behavior has been identified through both correlation studies and experiments. The high cost of exposure to lead is apparent when looking at the effects of lead over a lifetime, and should be avoided if at all possible

Chip-firing on graphs of groups

We define the Laplacian matrix and the Jacobian group of a finite graph of groups. We prove analogues of the matrix tree theorem and the class number formula for the order of the Jacobian of a graph of groups. Given a group $G$ acting on a graph $X$, we define natural pushforward and pullback maps between the Jacobian groups of $X$ and the quotient graph of groups $X/\!/G$. For the case $G=\mathbb{Z}/2\mathbb{Z}$, we also prove a combinatorial formula for the order of the kernel of the pushforward map

Examination of Orthologous Genes (Mrub_2518 and b3728, Mrub_2519 and b3727, Mrub_2520 and b3726, Mrub_2521 and b3725) Responsible for ABC Phosphate Transporters in Two Species \u3cem\u3eM. ruber\u3c/em\u3e and \u3cem\u3eE. coli\u3c/em\u3e

In this project we investigated the biological function of the genes b3725, b3726, b3727, b3728 and Mrub_2518, Mrub_2519, Mrub_2520 and Mrub_2521 (KEGG map number 02010). We predict that these genes encode the components of a Phosphate ABC transporter: Orthologous genes Mrub_2518 (DNA coordinates 2565359..2566438) and b3728 encodes the periplasmic phosphate binding component; Orthologous genes Mrub_2519 (DNA coordinates 2566499..2567485) and b3727, and Mrub_2520 (DNA coordinates 2567496..2568326) and b3726 encode for the two transmembrane proteins; Orthologous genes Mrub_2521 (DNA coordinates 2568338..2569159) and b3725 encode for the ATP binding protein within the cytoplasm. Within the two species, M. ruber and E. coli, the four respective genes are operons and make up the pst system. The four parts of the system work together to transfer a single inorganic phosphate ion from the periplasmic space into the cytoplasm of the cell. This project is part of the Meiothermus ruber genome analysis project, which predicts gene function using the bioinformatics tools collected under the umbrella of the Guiding Education through Novel Investigation –Annotation Collaboration Toolkit (GENI-ACT)

Gaming and Strategic Opacity in Incentive Provision

It is often suggested that incentive schemes under moral hazard can be gamed by an agent with superior knowledge of the environment, and that deliberate lack of transparency about the incentive scheme can reduce gaming. We formally investigate these arguments in a two-task moral hazard model in which the agent is privately informed about which task is less costly for him to work on. We examine two simple classes of incentive scheme that are “opaque” in that they make the agent uncertain ex ante about the values of the incentive coefficients in the linear payment rule. We show that, relative to deterministic menus of linear contracts, these opaque schemes induce more balanced efforts, but they also impose more risk on the agent per unit of aggregate effort induced. We identify settings in which optimally designed opaque schemes not only strictly dominate the best deterministic menu but also completely eliminate the efficiency losses from the agent’s better knowledge of the environment. Opaque schemes are more likely to be preferred to transparent ones when i) efforts on the tasks are highly complementary for the principal; ii) the agent’s privately known preference between the tasks is weak; iii) the agent’s risk aversion is significant; and iv) the errors in measuring performance on the tasks have large correlation or small variance

Selecting the best: the persistent effects of luck

We analyze a model of organizational learning where agents’ performance reflects time-invariant unobservable ability, privately-chosen effort, and noise. Our main result is that, even when performance is almost entirely random, maximizing the probability of identifying the best agent (“selective efficiency”) requires biasing final selection in favor of early winners. Making luck persistent, e.g. through fast-tracks, is thus rationalized by the pursuit of selective efficiency. Agents’ strategic efforts amplify the persistence of luck. Organizational learning also affects the persistence of initial advantages stemming from identity. Identity-dependent biases, e.g. gender specific mentoring, create incentives that make selection both more efficient and more equitable

Embedding generic employability skills in an accounting degree: development and impediments

This paper explores and analyses the views of, and effects on, students of a project that integrated the development of employability skills within the small group classes of two compulsory courses in the first year of an accounting degree at a UK university. The project aimed to build, deliver and evaluate course materials designed to encourage the development of a broad range of employability skills: skills needed for life-long learning and a successful business career. By analysing students' opinions gathered from a series of focus groups spread throughout the year, three prominent skill areas of interest were identified: time management, modelling, and learning to learn. Further analysis highlighted the complex nature of skills development, and brought to light a range of impediments and barriers to both students' development of employability skills and their subject learning. The analysis suggests the need for accounting educators to see skills development as being an essential element of the path to providing a successful accounting education experience

A Study in Methods for Helping the Disabled Reader

The ability to read well constitutes one of the most important skills a person can acquire. Satisfactory adjustment to living in this complex modern world requires effective reading. It is difficult to discover any activity, whether in school, business or daily living that does not require reading. The importance of reading becomes even more obvious when we consider what happens to those who fail to learn to read. They are handicapped in practically all walks of life

Do non-steroidal anti-inflammatory drugs provide a protective effect on developing Barrett’s esophagus and esophageal cancer? A systematic review and meta-analysis

This is a protocol of a systematic review

Oestrogen receptor alpha in pulmonary hypertension

Aims Pulmonary arterial hypertension (PAH) occurs more frequently in women with mutations in bone morphogenetic protein receptor type 2 (BMPR2) and dysfunctional BMPR2 signalling underpinning heritable PAH. We have previously shown that serotonin can uncover a pulmonary hypertensive phenotype in BMPR2+/− mice and that oestrogen can increase serotinergic signalling in human pulmonary arterial smooth muscle cells (hPASMCs). Hence, here we wished to characterize the expression of oestrogen receptors (ERs) in male and female human pulmonary arteries and have examined the influence of oestrogen and serotonin on BMPR2 and ERα expression. Methods and results: By immunohistochemistry, we showed that ERα, ERβ, and G-protein-coupled receptors are expressed in human pulmonary arteries localizing mainly to the smooth muscle layer which also expresses the serotonin transporter (SERT). Protein expression of ERα protein was higher in female PAH patient hPASMCs compared with male and serotonin also increased the expression of ERα. 17β-estradiol induced proliferation of hPASMCs via ERα activation and this engaged mitogen-activated protein kinase and Akt signalling. Female mice over-expressing SERT (SERT+ mice) develop PH and the ERα antagonist MPP attenuated the development of PH in normoxic and hypoxic female SERT+ mice. The therapeutic effects of MPP were accompanied by increased expression of BMPR2 in mouse lung. Conclusion: ERα is highly expressed in female hPASMCs from PAH patients and mediates oestrogen-induced proliferation of hPASMCs via mitogen-activated protein kinase and Akt signalling. Serotonin can increase ERα expression in hPASMCs and antagonism of ERα reverses serotonin-dependent PH in the mouse and increases BMPR2 expression.</p