Pairwise comparisons (PC) method is an efficient technique and hierarchical analysis is a popular means coping with complex decision problems. Based on two proposed theorems, this paper shows that the PC-based hierarchical decision models stem from the weighted average methods (including the arithmetic form and the geometric form). Some issues (including the rank reversal, the criterion for acceptable consistency and the method for deriving priorities, etc) associated with the current PC-based hierarchical models (including the AHP, the multiplicative AHP and the FPR-AHP) are investigated. Another PC-based hierarchical decision model, which is different from the Saaty’s AHP, is introduced for applications by virtue of its desirable traits (such as the rank preservation, the isomorphic correspondence, etc).
A field experiment was conducted to examine the effects of plastic mulching (PM) on the photosynthetic rate, endogenous hormones and root yield of summer sweet potato [I. batatas L. cv. Jishu18 and Ayamuraski (Aya.)]. The results showed that the PM treatments decreased soil bulk density, increased soil porosity and soil available nutrient content, and retained soil water content at a relatively stable level, but no significant difference in soil temperature was observed compared with the control. The leaf chlorophyll content, photosynthetic rate, ribulose 1,5- bisphosphate carboxylase activity, leaf area index, soluble sugar content, and adenosine triphosphate content was higher in the PM treatments compared with the control. In addition, root gibberellic acid, zeatin riboside and abscisic acid content increased under PM treatment. The PM treatment improved the soil micro-environment of sweet potato, resulting in a higher storage root yield and top/root ratio (T/R). According to these results, it is concluded that mulching summer-sown sweet potato is an effective way to increase root yield in northern China, most likely through the modification of the soil micro-environment, photosynthetic capacity and endogenous hormones.
Nigrostriatal neurons expressing RET protein, a receptor protein tyrosine kinase of glial cell line-derived neurotrophic factor (GDNF), were investigated in rats using retrograde neural tracing with horseradish peroxidase (HRP) combined with immunohistochemistry. HRP/RET double-labeled neurons were abundantly distributed in the substantia nigra pars compacta ipsilateral to the caudate-putamen stereotaxically injected with HRP. Almost all the HRP-labeled neurons in nigra exhibited RET-like immunoreactivity, which however constituted more than half of the RET-immunoreactive cells. Our results present morphological evidence that GDNF-RET interaction plays important roles in physiological processes of nigrostriatal neuronal circuits of mammals.