PDRMIP: A Precipitation Driver and Response Model Intercomparison Project, Protocol and preliminary results

As the global temperature increases with changing climate, precipitation rates and patterns are affected through a wide range of physical mechanisms. The globally averaged intensity of extreme precipitation also changes more rapidly than the globally averaged precipitation rate. While some aspects of the regional variation in precipitation predicted by climate models appear robust, there is still a large degree of inter-model differences unaccounted for. Individual drivers of climate change initially alter the energy budget of the atmosphere leading to distinct rapid adjustments involving changes in precipitation. Differences in how these rapid adjustment processes manifest themselves within models are likely to explain a large fraction of the present model spread and needs better quantifications to improve precipitation predictions. Here, we introduce the Precipitation Driver and Response Model Intercomparison Project (PDRMIP), where a set of idealized experiments designed to understand the role of different climate forcing mechanisms were performed by a large set of climate models. PDRMIP focuses on understanding how precipitation changes relating to rapid adjustments and slower responses to climate forcings are represented across models. Initial results show that rapid adjustments account for large regional differences in hydrological sensitivity across multiple drivers. The PDRMIP results are expected to dramatically improve our understanding of the causes of the present diversity in future climate projections.

The efficacy of a new topical treatment for psoriasis: Mirak

BACKGROUND

A new natural product for the treatment of psoriasis has recently become available in many European countries: Mirak. The Mirak Home Care Packs consist of natural spring water, volcanic earth and vitamin E cream. Recently, the efficacy of Mirak has come into question. As this treatment is used by many psoriasis patients in Europe, it is important for dermatologists to be informed about the clinical effects of the therapy.

AIM

To evaluate the efficacy and side effects of the Mirak Home Care Packs.

METHODS

By means of a placebo-controlled left/right comparison, both clinical and histological parameters were evaluated during 6 weeks of treatment.

RESULTS

The reduction in induration was significantly greater in the Mirak-treated lesions than in the lesions treated with a placebo. A reduction in desquamation was found in both treatments; the difference between the treatments was not statistically significant. A decrease in number of proliferative cells in the Mirak-treated lesions was seen, but the difference with placebo-treated lesions was not significant. The other investigated parameters did not change during treatment. No side effects were seen.

CONCLUSIONS

The Mirak Home Care Pack induces a modest therapeutic effect compared to placebo treatment, without significant side effects. Treatment with the Mirak Home Care Packs alone will probably not be able to compete with the already existing treatments for psoriasis.