Quantifying the Inefficiency of the US Social Security System

We quantify the inefficiency of the retirement component of the US social security system within a model where agents receive idiosyncratic labor-productivity shocks that are privately observedsocial security, efficient allocations, idiosyncratic shocks

Bioavailability of Organic Pollutants to Aquatic Organisms

Settlement of the Chesapeake Bay region began in earnest in the early 17th century. The native American population and early colonists were impressed by the abundance of fish and shellfish and located their population centers to take advantage of these and other natu!al resources. Introduction of wastes into the bay was coincident with this settlement. As the human population increased, so did the pressure on the ecological system. In the 20th century significant quantities of synthetic chemicals began to be introduced, many of which were toxic and nonbiodegradable [Faust and Hunter 1971]. Today the areas surrounding the bay are experiencing unprecedented development; introduction of toxic organic pollutants has correspondingly increased. Water quality and the abundance of many aquatic organisms have suffered accordingly [O\u27Connor and Huggett 1988].https://scholarworks.wm.edu/vimsbooks/1177/thumbnail.jp

Study of combustion experiments in space

The physical bases and scientific merits were examined of combustion experimentation in a space environment. For a very broad range of fundamental combustion problems, extensive and systematic experimentation at reduced gravitational levels (0 g 1) are viewed as essential to the development of needed observations and related theoretical understanding

Gender Equality and Goal 6: The Critical Connection.

This discussion paper is intended to contribute to the implementation of the High Level Panel on Water (HLPW) Action Plan. It should be read alongside other framing notes commissioned by the Australian Water Partnership.4 The key points of intersection with the High Level Panel on Water Action Plan are shown in Figure 1. This Discussion Paper identifies and explains key areas of action for the High Level Panel on Water and other international development actors and governments. The paper provides a range of case studies, and the implications for improving policy and practice are outlined. This paper focuses primarily on the HLPW Action Plan’s ‘Water Governance’ and ‘Universal Access to Safe Water and Sanitation’ themes

Richmond Crater James River Water Quality Management Program, final report 1984-85 and summary, toxic organics in sediments : a final report to Richmond Regional Planning District

The following report contains detailed results of analyses of sediment grabs and cores from the James and Appomattox rivers and some nearby locations for a spectrum of organic toxics. Some data has been previously reported in interim progress reports, but will be included for completeness. A study of variability of replicate samples taken at a single station (JR4). not included in the proposal, presents possible limitations of interpretation of temporal and station to station results. Finally, a comprehensive summary of toxic organics in the sediments of the James River and certain tributarjes over a two-year period will be presented

Behavioural effects of pheromone-based control system, ExosexTM SPTab, on male Indianmeal moth, Plodia interpunctella

We report on laboratory studies to examine behavioural effects of a new pheromone-based control system for stored product moths, Exosex™ SPTab auto-confusion, on virgin male Plodia interpunctella. The SPTab comprises a compressed electrostatic powder tablet, containing the female sex pheromone (Z,E)-9,12-Tetradecadienyl acetate; designed to be an attractive source to males and disrupt the mate finding ability of several stored moth pest species. Our aims were to examine the effects of SPTab contact on male ability to locate females and to be attractive sources to other males. Observations of behavioural effects were made in a moth flight tunnel. Virgin male P. interpunctella were treated on SPTabs weathered from 1-8 weeks. After treatment, males were either immediately released downwind of calling females in the upwind section of the flight tunnel, or caged individually for 1 to 48 h before release. The ability of treated males to act as false lures for other males was measured by treating males on different age SPTabs as before, caging them and then placing them upwind of untreated males. In all studies males were scored on making source contact. Males treated on the SPTab and immediately released downwind of calling females showed a 96.7% reduction in their ability to contact the females. Males held for 48 h before release still showed a significant reduction in source contact compared to untreated controls. Treated males tested after 3 h, were as attractive as calling females with >75% of flights resulting in source contact. Significant reduction in female source contact was still evident when males were treated on SPTab weathered for 4 weeks. Males treated on SPTabs weathered for up to 8 weeks were significantly attractive to untreated males, and equal to calling females. The results indicate that contact with SPTab significantly reduces the ability of male P. interpunctella to locate females for up to two days. These males could increase the confusion effect by becoming competitive attractive point sources for other males. The Exosex SPTab has novel methods of causing mating disruption. Keywords: Mating disruption, Plodia interpunctella, Exosex SPTab, Sex pheromone, Flight tunnel

Making standards for quantitative real-time pneumococcal PCR.

Quantitative lytA PCR is often performed using in-house standards. We hypothesised equivalence when measuring a standard suspension of Streptococcus pneumoniae by colony-forming-units (CFU) or genome-copies. Median (IQR) ratio of CFU/genome-copies was 0.19 (0.1-1.2). Genome-copies were less variable than CFU, but the discrepancy between the methods highlights challenges with absolute quantification

Twistor theory on a finite graph

We show how the description of a shear-free ray congruence in Minkowski space as an evolving family of semi-conformal mappings can naturally be formulated on a finite graph. For this, we introduce the notion of holomorphic function on a graph. On a regular coloured graph of degree three, we recover the space-time picture. In the spirit of twistor theory, where a light ray is the more fundamental object from which space-time points should be derived, the line graph, whose points are the edges of the original graph, should be considered as the basic object. The Penrose twistor correspondence is discussed in this context