Population Genetics and Economic Growth

This paper builds an age-structural model of human population genetics in which agents are endowed with a high-dimensional genome that determines their cognitive and physical characteristics. Young adults optimally search for a marriage partner, work for firms, consume goods, save for old age and, if married, decide how many children to have. Applying the fundamental genetic operations, children receive genetic material from their parents. An agent's human capital (productivity) is an aggregate of the received genetic endowment and environmental influences. Thus, the population of agents and the economy co-evolve. The model examines the impact of social and economic institutions on economic performance, including inequality in income and genetic attributes, the transition to an information economy, population bottlenecks, matchmaking, and love. We find that institutional factors significantly impact economic performance by affecting marriage, family size, and the intergenerational transmission of genes.growth; population biology; psychology; fertility; marriage; genetics; evolution

Design and Modeling of a New Biomimetic Soft Robotic Jellyfish Using IPMC-Based Electroactive Polymers

Smart materials and soft robotics have been seen to be particularly well-suited for developing biomimetic devices and are active fields of research. In this study, the design and modeling of a new biomimetic soft robot is described. Initial work was made in the modeling of a biomimetic robot based on the locomotion and kinematics of jellyfish. Modifications were made to the governing equations for jellyfish locomotion that accounted for geometric differences between biology and the robotic design. In particular, the capability of the model to account for the mass and geometry of the robot design has been added for better flexibility in the model setup. A simple geometrically defined model is developed and used to show the feasibility of a proposed biomimetic robot under a prescribed geometric deformation to the robot structure. A more robust mechanics model is then developed which uses linear beam theory is coupled to an equivalent circuit model to simulate actuation of the robot with ionic polymer-metal composite (IPMC) actuators. The mechanics model of the soft robot is compared to that of the geometric model as well as biological jellyfish swimming to highlight its improved efficiency. The design models are characterized against a biological jellyfish model in terms of propulsive efficiency. Using the mechanics model, the locomotive energetics as modeled in literature on biological jellyfish are explored. Locomotive efficiency and cost as a function of swimming cycles are examined for various swimming modes developed, followed by an analysis of the initial transient and steady-state swimming velocities. Applications for fluid pumping or thrust vectoring utilizing the same basic robot design are also proposed. The new design shows a clear advantage over its purely biological counterpart for a soft-robot, with the newly proposed biomimetic swimming mode offering enhanced swimming efficiency and steady-state velocities for a given size and volume exchange

An IPMC-Enabled Bio-Inspired bending/twisting Fin for Underwater Applications

This paper discusses the design, fabrication, and characterization of an ionic polymer–metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a \u27fin\u27) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or \u27activating\u27 the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long× 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s−1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure. These results suggest that such IPMC-enabled fin designs can be used for developing active propeller blades or control surfaces on underwater vehicles

Cost effectiveness analysis of Year 2 of an elementary school-located influenza vaccination program-Results from a randomized controlled trial.

BackgroundSchool-located vaccination against influenza (SLV-I) has the potential to improve current suboptimal influenza immunization coverage for U.S. school-aged children. However, little is known about SLV-I's cost-effectiveness. The objective of this study is to establish the cost-effectiveness of SLV-I based on a two-year community-based randomized controlled trial (Year 1: 2009-2010 vaccination season, an unusual H1N1 pandemic influenza season, and Year 2: 2010-2011, a more typical influenza season).MethodsWe performed a cost-effectiveness analysis on a two-year randomized controlled trial of a Western New York SLV-I program. SLV-I clinics were offered in 21 intervention elementary schools (Year 1 n = 9,027; Year 2 n = 9,145 children) with standard-of-care (no SLV-I) in control schools (Year 1 n = 4,534 (10 schools); Year 2 n = 4,796 children (11 schools)). We estimated the cost-per-vaccinated child, by dividing the incremental cost of the intervention by the incremental effectiveness (i.e., the number of additionally vaccinated students in intervention schools compared to control schools).ResultsIn Years 1 and 2, respectively, the effectiveness measure (proportion of children vaccinated) was 11.2 and 12.0 percentage points higher in intervention (40.7 % and 40.4 %) than control schools. In year 2, the cost-per-vaccinated child excluding vaccine purchase ($59.88 in 2010 US$) consisted of three component costs: (A) the school costs ($8.25); (B) the project coordination costs ($32.33); and (C) the vendor costs excluding vaccine purchase ($16.68), summed through Monte Carlo simulation. Compared to Year 1, the two component costs (A) and (C) decreased, while the component cost (B) increased in Year 2. The cost-per-vaccinated child, excluding vaccine purchase, was$59.73 (Year 1) and $59.88 (Year 2, statistically indistinguishable from Year 1), higher than the published cost of providing influenza vaccination in medical practices ($39.54). However, taking indirect costs (e.g., averted parental costs to visit medical practices) into account, vaccination was less costly in SLV-I ($23.96 in Year 1,$24.07 in Year 2) than in medical practices.ConclusionsOur two-year trial's findings reinforced the evidence to support SLV-I as a potentially favorable system to increase childhood influenza vaccination rates in a cost-efficient way. Increased efficiencies in SLV-I are needed for a sustainable and scalable SLV-I program

Superconductivity in the Chalcogens up to Multimegabar Pressures

Highly sensitive magnetic susceptibility techniques were used to measure the superconducting transition temperatures in S up to 231($\pm$5) GPa. S transforms to a superconductor with T$_c$ of 10 K and has a discontinuity in T_c dependence at 160 GPa corresponding to bco to beta-Po phase transition. Above this pressure T_c in S has a maximum reaching about 17.3(+/-0.5) K at 200 GPa and then slowly decreases with pressure to 15 K at 230 GPa. This trend in the pressure dependence parallels the behavior of the heavier members Se and Te. Superconductivity in Se was also observed from 15 to 25 GPa with T_c changing from 4 to 6 K and above 150 GPa with T_c of 8 K. Similiarities in the T_c dependences for S, Se, and Te, and the implications for oxygen are discussed.Comment: 4 pages, 10 figure