A linear programming model to optimize diets in environmental policy scenarios.

The objective was to develop a linear programming model to formulate diets for dairy cattle when environmental policies are present and to examine effects of these policies on diet formulation and dairy cattle nitrogen and mineral excretions as well as methane emissions. The model was developed as a minimum cost diet model. Two types of environmental policies were examined: a tax and a constraint on methane emissions. A tax was incorporated to simulate a greenhouse gas emissions tax policy, and prices of carbon credits in the current carbon markets were attributed to the methane production variable. Three independent runs were made, using carbon dioxide equivalent prices of $5, $17, and $250/t. A constraint was incorporated into the model to simulate the second type of environmental policy, reducing methane emissions by predetermined amounts. The linear programming formulation of this second alternative enabled the calculation of marginal costs of reducing methane emissions. Methane emission and manure production by dairy cows were calculated according to published equations, and nitrogen and mineral excretions were calculated by mass conservation laws. Results were compared with respect to the values generated by a base least-cost model. Current prices of the carbon credit market did not appear onerous enough to have a substantive incentive effect in reducing methane emissions and altering diet costs of our hypothetical dairy herd. However, when emissions of methane were assumed to be reduced by 5, 10, and 13.5% from the base model, total diet costs increased by 5, 19.1, and 48.5%, respectively. Either these increased costs would be passed onto the consumer or dairy producers would go out of business. Nitrogen and potassium excretions were increased by 16.5 and 16.7% with a 13.5% reduction in methane emissions from the base model. Imposing methane restrictions would further increase the demand for grains and other human-edible crops, which is not a progressive solution for an industry trying to be sustainable. However, these results might depend on the constraints and inputs used in our model (e.g., feed prices), and more extensive analyses are required before they are used in policy development. The model structure was able to incorporate effects of environmental policies in diet formulation and it can assist dairy producers in meeting limits set by these policies. The model can also assist policy makers examining the effects of policies on the dairy production system.

Comparison of assessment tools to score recovery of function after repair of traumatic lesions of the median nerve.

In this paper the recovery after repair of the median nerve has been used to compare different assessment tools for evaluation of peripheral nerve function: touch (moving 2-point discrimination (2PD); Semmes-Weinstein (SW) monofilament, motor (Medical Research Council (MRC) scale), combined motor and sensory (Dellon modification of the Moberg pick up test; Moberg Recognition test), and pain (visual analogue scale; pinprick-test). The mean (SD) age of our 28 patients was 28 (12) years. The mean (SD) follow-up period was 5 years, 2 months (2 years, 8 months). On the operated side three patients (11%) had a moving 2PD of less than 4 mm. The results of the moving 2PD were compared with those of the SW monofilaments, but with a poor correlation. The MRC score correlated well with opposition movement of the thumb and muscle wasting (p<0.01). We recommend a number of tests to evaluate (the chronological return of) peripheral nerve function.

Incapacitation and just deserts as motives for punishment.

What motivates a person's desire to punish actors who commit intentional, counternormative harms? Two possible answers are a just deserts motive or a desire to incarcerate the actor so that he cannot be a further danger to society. Research participants in two experiments assigned punishments to actors whose offenses were varied with respect to the moral seriousness of the offense and the likelihood that the perpetrator would commit similar future offenses. Respondents increased the punishment as the seriousness of the offense increased, but their sentences were not affected by variations in the likelihood of committing future offenses, suggesting that just deserts was the primary sentencing motive. Only in a case in which a brain tumor was identified as the cause of an actor's violent action, a case that does not fit the standard prototype of a crime intentionally committed, did respondents show a desire to incarcerate the actor in order to prevent future harms rather than assigning a just deserts based punishment.

Functional assessment of sciatic nerve reconstruction: biodegradable poly (DLLA-epsilon-CL) nerve guides versus autologous nerve grafts.

The aim of this study was to compare functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with modified denatured muscle tissue (MDMT), or an autologous nerve graft. We evaluated nerve recovery using walking track analysis (measurement of the sciatic function index [SFI]) and electrostimulation tests. Functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with MDMT was faster when compared with nerve reconstruction using an autologous nerve graft. We conclude that in case of a short nerve gap in the rat, reconstruction can best be carried out using a p(DLLA-epsilon-CL) biodegradable nerve guide filled with MDMT.

Time off work due to scaphoid fractures and other carpal injuries in The Netherlands in the period 1990 to 1993.

This study assessed the epidemiology, treatment, disability and time off work due to carpal injuries in the Netherlands in the period from 1990 to 1993. Most injuries were scaphoid fractures and carpal instabilities were rare. The time off work was considerable (mean, 155 days; median, 105 days; range, 12-1708 days). Patients with non-scaphoid fractures had the shortest time off work, followed by those with scaphoid fractures; patients with carpal instabilities had the longest time off work. Despite the significant time off work, the prognosis for return to work was excellent.