The Safety Net as a Network

The lack of a coherent understanding of what is meant by the American safety net made it difficult to have a meaningful discourse on the current condition. This paper proposes an alternative formulation of the social safety net based in network theory to overcome the shortcomings of the previous literature. The first part of the paper describes this approach, attempting to develop an alternative understanding of the safety net grounded in the actions of anti-poverty actors. Next is a list of propositions for measuring five dimensions of a safety net: the frame, structure, positions, influences, and the context. Three policy implications are derived from this new paradigm. First, shifting the level of analysis to network level allows policy makers to broaden the scope of the modern social safety net. Second, quantifying the interaction among actors reveals interdependency, which in turn redefines the power and influence of each actor within the network. Finally, the modern safety net could demonstrate a core-periphery structure. It calls for a new way of thinking about resource distribution and decision making channels of such unique structure.LBJ School of Public Affair

Cleaning up the catalogue

The London School of Economics wanted to remove cataloguing inconsistencies but the scale of the task was huge, and outsourcing to a specialist bibliographic services company proved only a partial solution. Helen Williams explains why manual and automated processes were needed

Outgroup, alignment and modelling improvements indicate that two TNFSF13-like genes existed in the vertebrate ancestor

Peer reviewedPublisher PD

Phylogenetic analysis accounting for age-dependent death and sampling with applications to epidemics

The reconstruction of phylogenetic trees based on viral genetic sequence data sequentially sampled from an epidemic provides estimates of the past transmission dynamics, by fitting epidemiological models to these trees. To our knowledge, none of the epidemiological models currently used in phylogenetics can account for recovery rates and sampling rates dependent on the time elapsed since transmission. Here we introduce an epidemiological model where infectives leave the epidemic, either by recovery or sampling, after some random time which may follow an arbitrary distribution. We derive an expression for the likelihood of the phylogenetic tree of sampled infectives under our general epidemiological model. The analytic concept developed in this paper will facilitate inference of past epidemiological dynamics and provide an analytical framework for performing very efficient simulations of phylogenetic trees under our model. The main idea of our analytic study is that the non-Markovian epidemiological model giving rise to phylogenetic trees growing vertically as time goes by, can be represented by a Markovian "coalescent point process" growing horizontally by the sequential addition of pairs of coalescence and sampling times. As examples, we discuss two special cases of our general model, namely an application to influenza and an application to HIV. Though phrased in epidemiological terms, our framework can also be used for instance to fit macroevolutionary models to phylogenies of extant and extinct species, accounting for general species lifetime distributions.Comment: 30 pages, 2 figure

Consumers’ Desire for GM Labels: Is the Devil in the Details?

Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,

Social Assistance Programs and Outcomes: Food Assistance in the Context of Welfare Reform

Food assistance programs play an important role in meeting the basic needs of low-income households. We consider the complex interactions among food stamps, labor force participation, and food insecurity status of low-income households under different program designs and economic conditions. The analysis uses data from the Survey of Program Dynamics to jointly estimate the role of participation in the Food Stamp Program (FSP), labor market participation and well-being, measured as food security, through the use of a simultaneous equation model. The results of our research suggest that food insecurity has a positive effect on FSP participation while labor force participation reduces FSP participation. Furthermore, FSP participation is more responsive to changes in the program benefits than to changes in nonlabor income. The linkages among food program participation, labor force participation, and well-being, measured in terms of food insecurity, are complex. The structural approach provides evidence that, among low-income households, program parameters affect FSP participation but no evidence that the food assistance reduces food insecurity.

Dissolution and Mechanical properties of Bioresorbable Glass Fibres for use in Paediatric tracheal stents

Stents provide biological support in body conduits and are useful for counteracting stenosis (constriction) in cardiovascular, gastrointestinal, uretheral and airway passages1. However, the current widespread use of permanent metal stents that remain throughout the lifespan of a patient, threaten restenosis, thrombosis, or physical irritation if not surgically removed. In infants the clinical requirement is for a stent that retains structural integrity for periods of several weeks up to many months in vivo during host tissue restoration2 and from a materials perspective this requires an implant with appropriate mechanical and degradation characteristics. Bioresorbable phosphate glass fibres have shown enormous potential for temporary implants and tissue repair, owing to their mechanical properties and solubility in aqueous media which can be modified by addition of various oxide compounds3,4. Further, when combined with degradable polymers the resulting glass fibre polymer composites (GFRP) become ductile allowing them to be forged into supporting scaffolds with suitable mechanical and dissolution properties. To date however, their use for stenting applications has not been investigated possibly due to major difficulties of processing these compositions into fibre form. In this study, two phosphate glass fibre compositions containing SiO2 (silica) and B2O3 (Boron) were fabricated to test the hypothesis that B2O3 containing phosphate glass fibres present enhanced mechanical and dissolution behaviour for use as a degradable stent

A WILLINGNESS TO PLAY: ANALYSIS OF WATER RESOURCES DEVELOPMENT

Economic analysis shows that the Central Arizona Project will be a poor investment from the point of view of individual farmers. Yet farmers support the Project. In this study of the economics and politics of the CAP, farmers are questioned as to their information, perceptions and motivations. Farmers are willing to play – not necessarily to pay.Resource /Energy Economics and Policy,