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Barley (Hordeum vulgare L.) plants were grown hydroponically with or without inorganic phosphate (Pi) in the medium. Leaves were analyzed for the intercellular and the intracellular distribution of Pi. Most of the leaf Pi was contained in mesophyll cells; Pi concentrations were low in the xylem sap, the apoplast and in the cells of the epidermis. The(More)
in English There are doubts about the effectiveness of regional policy. Well known are the fruitless attempts of Italy to bridge the gap between the Mezzogiorno and the North, of Germany to bridge the gap between the Neue Länder and the West, and of the European Commission to reduce regional disparities in general. We validate one explanation: agglomeration(More)
The anion contents of young barley leaves and of mesophyll protoplasts from the leaves was compared. Anion loss from the protoplasts during isolation was small. Although only about 60% of the leaf cells were mesophyll cells, phosphate and sulfate contents of the mesophyll cells accounted for almost 90% of the leaf contents. Chloride accumulated in the leaf(More)
In well-watered plants of Welwitschia mirabilis, grown in the glass-house under high irradiance conditions, net CO(2) assimilation was almost exclusively observed during the daytime. The plants exhibited a very low potential for Crassulacean acid metabolism, which usually resulted in reduced rates of net CO(2) loss for several hours during the night. In(More)
Using German district data we estimate the structural parameters of a new economic geography model as developed by Helpman (1998) and Hanson (1998). The advantage of the Helpman-Hanson model is that it incorporates the fact that agglomeration of economic activity increases the prices of local (non-tradable) services, like housing. This model thereby(More)
Three variations of the in vitro neonatal rat spinal cord preparation were used to investigate motor responses to stimulation of the ventrolateral funiculus (VLF). In a partially hemisected spinal cord preparation, stimuli elicited frequency-dependent activity in lumbar ventral roots that outlasted the stimulus train by up to 30 s. In a spinal cord-hindlimb(More)
Based on a new economic geography (NEG) model by Puga (1999), we use the equilibrium wage equation to estimate two key structural model parameters for the NUTS II EU regions. These estimations enable us to come up with an empirically grounded free-ness of trade parameter. In line with NEG theory, the estimation results show that a spatial wage structure(More)
A method is described for isolating epidermal protoplasts from the primary leaves of barley (Hordeum vulgare L.). Epidermal protoplasts are lighter than mesophyll protoplasts because of their smaller ratio of cytoplasm to vacuole, and can be separated from the latter by density-gradient centrifugation after complete digestion of the leaves. We have started(More)
Using experimental information obtained in earlier studies on cellular buffering and SO2 uptake into leaves (Pfanz and Heber, 1986, Plant Physiol. 81, 597-602; Pfanz et al., 1987 a, b, Plant Physiol.), a mathematical model is presented which permits computer analysis of the transport of SO2 from the atmosphere into the mesophyll of leaves and describes the(More)