Report on Impacts and Costs of the Iowa Low-Income Weatherization Program, 2005

This report summarizes state and utility low-income weatherization program activity for households weatherized to completion during calendar year 2001. The report includes state, utility, and agency summaries of calendar year 2001 spending and impacts by measure, end-use, and fuel.

Report on Impacts and Costs of the Iowa Low-Income Weatherization Program, 2001

This report summarizes state and utility low-income weatherization program activity for households weatherized to completion during calendar year 2001. The report includes state, utility, and agency summaries of calendar year 2001 spending and impacts by measure, end-use, and fuel.

Report on Impacts and Costs of the Iowa Low-Income Weatherization Program, 2002

This report summarizes state and utility low-income weatherization program activity for households weatherized to completion during calendar year 2001. The report includes state, utility, and agency summaries of calendar year 2001 spending and impacts by measure, end-use, and fuel.

Report on Impacts and Costs of the Iowa Low-Income Weatherization Program, 2003

This report summarizes state and utility low-income weatherization program activity for households weatherized to completion during calendar year 2001. The report includes state, utility, and agency summaries of calendar year 2001 spending and impacts by measure, end-use, and fuel.

Report on Impacts and Costs of the Iowa Low-Income Weatherization Program, 2004

This report summarizes state and utility low-income weatherization program activity for households weatherized to completion during calendar year 2001. The report includes state, utility, and agency summaries of calendar year 2001 spending and impacts by measure, end-use, and fuel.

A-1 Monthly Public Assistance Statistical Report Family Investment Program, February 2007

A-1 Monthly Public Assistance Statistical Report Family Investment Program - February 2007

A-1 Monthly Public Assistance Statistical Report Family Investment Program, March 2007

A-1 - Monthly Public Assistance Statistical Report Family Investment Program - March 2007

A-1 Monthly Public Assistance Statistical Report Family Investment Program, April 2007

A-1 - Monthly Public Assistance Statistical Report Family Investment Program - April 2007

A-1 Monthly Public Assistance Statistical Report Family Investment Program, May 2007

A-1 - Monthly Public Assistance Statistical Report Family Investment Program - May 2007

The Growth and Direction of the Biodiesel Industry in the United States, 2007

The biodiesel industry in the United States has realized significant growth over the past decade through large increases in annual production and production capacity and a transition from smaller batch plants to larger-scale continuous producers. The larger, continuous-flow plants provide operating cost advantages over the smaller batch plants through their ability to capture co-products and reuse certain components in the production process. This paper uses a simple capital budgeting model developed by the authors along with production data supplied by industry sources to estimate production costs, return-on-investment levels, and break-even conditions for two common plant sizes (30 and 60 million gallon annual capacities) over a range of biodiesel and feedstock price levels. The analysis shows that the larger plant realizes returns to scale in both labor and capital costs, enabling the larger plant to pay up to $0.015 more per pound for the feedstock to achieve equivalent return levels as the smaller plant under the same conditions. The paper contributes to the growing literature on the biodiesel industry by using the most current conversion rates for the production technology and current price levels to estimate biodiesel production costs and potential plant performance, providing a useful follow-up to previous studies.

Condition, disease and immune defence

Life-history traits and secondary sexual characters often demonstrate condition-dependence, and reproductive success thus ultimately appears to be determined by condition. Here we test the hypothesis that anti-parasite defence is condition-dependent and thus ultimately limits fitness. Animal hosts defend themselves against parasites by an efficient immune system that changes its activity level depending on level of infection. Since immune function is costly, as demonstrated by several field studies, we predicted that large immune defence organs should be maintained when the costs of an elevated immune response were reduced, or when the benefits were increased. Hence, the size of immune defence organs was predicted to increase in response to disease due to increased benefits of investment in immune function, and the; size was predicted to increase in response to high body condition because of reduced costs of investment in immune function. A comparative study of birds demonstrated that the size of the spleen was significantly increased among individuals suffering from parasitic infections and signs of disease as compared to healthy individuals. Furthermore, we found evidence for a positive association between spleen size and body condition. These findings are consistent with the hypothesised cost of immune function and hence a cost of anti-parasite defence.

A-1 Monthly Public Assistance Statistical Report Family Investment Program, June 2007

A-1 - Monthly Public Assistance Statistical Report Family Investment Program - June 2007

A-1 Monthly Public Assistance Statistical Report Family Investment Program, July 2007

A-1 - Monthly Public Assistance Statistical Report Family Investment Program - July 2007

A-1 Monthly Public Assistance Statistical Report Family Investment Program, August 2007

A-1 - Monthly Public Assistance Statistical Report Family Investment Program - August 2007

Beyond Smith's rule: An optimal dynamic index, rule for single machine stochastic scheduling with convex holding costs

Most research on single machine scheduling has assumedthe linearity of job holding costs, which is arguablynot appropriate in some applications. This motivates ourstudy of a model for scheduling $n$ classes of stochasticjobs on a single machine, with the objective of minimizingthe total expected holding cost (discounted or undiscounted). We allow general holding cost rates that are separable,nondecreasing and convex on the number of jobs in eachclass. We formulate the problem as a linear program overa certain greedoid polytope, and establish that it issolved optimally by a dynamic (priority) index rule,whichextends the classical Smith's rule (1956) for the linearcase. Unlike Smith's indices, defined for each class, ournew indices are defined for each extended class, consistingof a class and a number of jobs in that class, and yieldan optimal dynamic index rule: work at each time on a jobwhose current extended class has larger index. We furthershow that the indices possess a decomposition property,as they are computed separately for each class, andinterpret them in economic terms as marginal expected cost rate reductions per unit of expected processing time.We establish the results by deploying a methodology recentlyintroduced by us [J. Niño-Mora (1999). "Restless bandits,partial conservation laws, and indexability. "Forthcomingin Advances in Applied Probability Vol. 33 No. 1, 2001],based on the satisfaction by performance measures of partialconservation laws (PCL) (which extend the generalizedconservation laws of Bertsimas and Niño-Mora (1996)):PCL provide a polyhedral framework for establishing theoptimality of index policies with special structure inscheduling problems under admissible objectives, which weapply to the model of concern.