Micro-autoradiographic determination of the viability of algae inhabiting deep sediment layers     

Norbert Wasmund 《Estuarine, Coastal and Shelf Science》1989,28(6)

Examination of sediment cores taken from shallow coastal regions of the Baltic showed that some algae were still alive at depths beyond the depth of light penetration. Their cells contained chlorophyll and photosynthesis resumed when they were exposed to light. Photosynthesis was detected by simultaneous measurement of oxygen production and ¹⁴C uptake. Autoradiography was used to detect incorporated ¹⁴C. The autoradiographic method was improved by a few modifications.  相似文献   

Modelling diffusion in a heterogeneous rock matrix with a time-domain Lagrangian method and an inversion procedureModélisation de la diffusion dans une matrice rocheuse hétérogène par une méthode lagrangienne dans le domaine des temps et une procédure d'inversion     

Frédérick Delay  Gilles Porel  Paul Sardini 《Comptes Rendus Geoscience》2002,334(13):967-973

A Lagrangian method in time domain is proposed to solve transport by diffusion over large grids such as those extracted from autoradiographs of rock samples. The method is rapid and well suited to simulate out-diffusion experiments in a heterogeneous rock matrix. By coupling with a Gauss–Newton optimiser, it is possible to identify automatically the diffusion coefficients of porous areas in the matrix. This offers a more comprehensive view of a potential transport of contaminants, e.g., after a leak from an underground repository site. To cite this article: F. Delay et al., C. R. Geoscience 334 (2002) 967–973.  相似文献   

Rhythmic swimming of the isopod Exosphaeroma obtusum (Dana)     

A. A. Fincham 《新西兰海洋与淡水研究杂志》2013,47(4):655-662

The tidal swimming rhythm of the New Zealand rocky shore isopod Exosphaeroma obtusum (Dana) is described. Peak swimming was on the ebb tide about 2.5 h after high water; the peak in the dark period was 6–8 times greater in amplitude than the daytime peak. Positive thigmotaxis was shown at all other times. The rhythm period in continuous darkness (free‐running period) was greater than tidal periodicity, and there was a semi‐lunar swimming pattern with peaks at the first and third quarters of the moon. Rheotropic experiments showed that changes in water flow did not initiate the swimming rhythm. The work was compared with the infaunal species Pseudaega punctala and the northern Eurydice pulchra. It was concluded that infaunal species rely more on endogenous control of the swimming rhythm because of their isolation, when buried, from exogenous Zeitgeber.  相似文献