Foraging and bedding sites are key ungulate demands of their habitats. Research however, on the differences between these two types of sites has been neglected. This study deals with the winter foraging and bedding site selection of the Asiatic ibex (Capra sibirica) in the Tianshan Mountains in the Xinjiang Uyghur Autonomous Region, China. A total of twelve line-transects were used to assist research of the Asiatic ibex within five valleys and canyons during December of 2010 and January of 2011. Ninety-five bedding and one hundred foraging sites used by the Asiatic ibex were examined and the effects of fifteen different environmental factors on habitat selection were analyzed and evaluated in this study. In comparison with its bedding sites, the Asiatic ibex in winter showed a greater preference for semi-shady slopes and higher vegetation density in its selection of foraging sites. Regarding its foraging site preferences when compared to its bedding site preferences, this species was less sensitive to deeper and greater snow cover, to a lower hiding cover level, and to greater
distances from the nearest escape structures. Stepwise Discriminant Analysis showed that a group of five environmental factors played a dominant role in bedding and foraging site preferences. These factors were, in the order of their contribution value: vegetation density, hiding cover level, distance from the top of the mountain, and distance from escape structures. Using these five environmental factors alone, the ability to accurately predict bedding and foraging site preferences of the Asiatic ibex reached 93.3 %.
Regulation mechanism of excitation energy transfer between phycobilisomes (PBS) and the photosynthetic reaction centres was studied by the state transition techniques in PBS-thylakoid membrane complexes. DCMU, betaine, and N-ethylmaleimide were applied to search for the details of energy transfer properties based on the steady fluorescence measurement and individual deconvolution spectra at state 2 or state 1. The closure of photosystem (PS) 2 did not influence on fluorescence yields of PS1, i.e., energy could not spill to PS1 from PS2. When the energy transfer pathway from PBS to PS1 was disturbed, the relative fluorescence yield of PS2 was almost the same as that of PS2 in complexes without treatment. If PBSs were fixed by betaine, the state transition process was restrained. Hence PBS may detach from PS2 and become associated to PS1 at state 2. Our results contradict the proposed "spill-over" or "PBS detachment" models and support the mobile "PBS model". and Ye Li ... [et al.].