Zmiany w komórkach mezofilu liści roślin Lycopersicon esculentum Mill. spowodowane zasoleniem

Five-week-old tomato plants (Lycopersicon esculentum) cv. Perkoz grown in pots containing garden soil in a growth chamber were submitted to 50 or 150 mM NaCl for 1 h, 2 and 5 days. Tomato leaf anatomy generally did not change after short time salinity, except 5-day-treatment with 150 mM NaCl, where changed cell shape (shrunk and deformed) simultaneously with increased volume of intercellular spaces (IS) were observed. Although leaf hydration (H) depleted only 1 h after 150 mM NaCl treatment both salt concentrations generated two coexisting populations of saltaffected mesophyll cells: (i) slightly-affected (Sl-A) which showed incipient plasmolysis or slightly changed shapes, and (ii) severely-affected (Sv-A) which showed severe plasmolysis; serious deformation of cell shape or disorganization including cell degeneration. In Sl-A cells salinity changed location and shape of chloroplasts which were: more rounded, with oversized starch grains (SG) (2d) or more flat (5d). Salt-mediated changes were becoming more distinguished and pronounced with length of 150 mM NaCl treatment. The amount of salt-affected cells was changing during the experiment and depended on the salt concentration. In 50 mM-treated plants salt-affected cells appeared 1 h after treatment (~40%) and raised up to 78% on 2nd day, however the population of Sl-A cells dominated. In 150 mM NaCl-treated plants the percentage of affected cells raised during the experiment from 75% to 99%. Firstly Sl-A cells dominated, but on the 5th day the majority was Sv-A. Salt-affected cells were distributed quite evenly in palisade or spongy mesophyll, except 2 d after treatment with 50 mM NaCl, when their number was higher in the palisade mesophyll. Sv-A cells in the spongy mesophyll were located mostly near the bundle while in the palisade mesophyll more irregularly. Different susceptibility of cells to salt stress might be the consequence of an unequal distribution of osmotic stress and subsequent ionic stress or physiological state of cells

Supply-side effects of strong energy price hikes in German industry and transportation

The paper studies the short-term effects of energy price hikes on the supply of industrial goods and transport services including the repercussions on remuneration of input factors. While industry had suffered more strongly from the oil price shock of the late 1970s compared with the one of the early 1970s and the 2004-08 upsurge, evidence is reverse for transportation. Regarding the impact on the income distribution, both sectors share the pattern that in the recent episode rising energy costs were more than compensated by falling unit labor costs while in the 1970s cost structures had been strained by expansive wage policy in addition to the oil price shocks. --Energy prices,supply of goods and services,income distribution

Pricing Capital Under Mandatory Unbundling and Facilities Sharing

The regulation of telecommunications, railroads, and other network industries has been based on mandatory unbundling and facilities sharing - entrants have the option to lease part or all of incumbents' facilities if and when they desire, at rates determined by regulators. This flexibility is of great value to entrants, but because investments are largely irreversible, it is costly to supply by incumbents. However, pricing formulas used by regulators to set lease rates for capital do not compensate incumbents for this flexibility, so that incumbents are effectively forced to subsidized entrants, discouraging further investments. This paper shows how pricing formulas used to set lease rates can be adjusted to account for the transfer of option value from incumbents to entrants, and estimates the average size of the adjustment for land-based local voice telecommunications in the U.S.

C-blox: A Scalable and Consistent TSDF-based Dense Mapping Approach

In many applications, maintaining a consistent dense map of the environment is key to enabling robotic platforms to perform higher level decision making. Several works have addressed the challenge of creating precise dense 3D maps from visual sensors providing depth information. However, during operation over longer missions, reconstructions can easily become inconsistent due to accumulated camera tracking error and delayed loop closure. Without explicitly addressing the problem of map consistency, recovery from such distortions tends to be difficult. We present a novel system for dense 3D mapping which addresses the challenge of building consistent maps while dealing with scalability. Central to our approach is the representation of the environment as a collection of overlapping TSDF subvolumes. These subvolumes are localized through feature-based camera tracking and bundle adjustment. Our main contribution is a pipeline for identifying stable regions in the map, and to fuse the contributing subvolumes. This approach allows us to reduce map growth while still maintaining consistency. We demonstrate the proposed system on a publicly available dataset and simulation engine, and demonstrate the efficacy of the proposed approach for building consistent and scalable maps. Finally we demonstrate our approach running in real-time on-board a lightweight MAV.Comment: 8 pages, 5 figures, conferenc

A standard computable general equilibrium model for South Africa

"The paper reports on the construction and testing of a Standard International Food Policy Research Institute (IFPRI) computable general equilibrium model for South Africa. A 1998 social accounting matrix (SAM) for South Africa is compiled using national accounts information and recently released supply-use tables. By updating to a recent year, and by distinguishing between producers and commodities, this SAM is an improvement on the existing SAM databases for South Africa. Furthermore, this SAM is made consistent with the requirements of IFPRI's standard comparative static computable general equilibrium (CGE) model. This model is then used to simulate the economy-wide impact of a range of hypothetical policy levers, including: increased government spending; the elimination of tariff barriers; and an improvement in total factor productivity. Results indicate that assumptions made regarding the mechanisms of macroeconomic adjustment are important in determining the expected impacts of these policies. Firstly, despite mixed results concerning changes in household income distribution, the impact of expansionary fiscal policy appears to be growth enhancing, with the Keynesian style adjustment mechanism producing the most positive results. Secondly, a complete abolition of import tariffs also appears to generate increases in gross domestic product, with negative and positive consequences for aggregate manufacturing and services respectively. Finally, an increase in total factor productivity is growth enhancing, with the most positive results derived under neoclassical assumptions of the macroeconomic adjustment mechanisms. These simulations are meant to demonstrate the usefulness for economy-wide policy modelling and the paper concludes by highlighting areas of policy analysis that might benefit from more detailed applications with this framework." Author's Abstract.Computable general equilibrium (CGE) ,

Spectral Motion Synchronization in SE(3)

This paper addresses the problem of motion synchronization (or averaging) and describes a simple, closed-form solution based on a spectral decomposition, which does not consider rotation and translation separately but works straight in SE(3), the manifold of rigid motions. Besides its theoretical interest, being the first closed form solution in SE(3), experimental results show that it compares favourably with the state of the art both in terms of precision and speed

Steady-state MreB helices inside bacteria: dynamics without motors

Within individual bacteria, we combine force-dependent polymerization dynamics of individual MreB protofilaments with an elastic model of protofilament bundles buckled into helical configurations. We use variational techniques and stochastic simulations to relate the pitch of the MreB helix, the total abundance of MreB, and the number of protofilaments. By comparing our simulations with mean-field calculations, we find that stochastic fluctuations are significant. We examine the quasi-static evolution of the helical pitch with cell growth, as well as timescales of helix turnover and denovo establishment. We find that while the body of a polarized MreB helix treadmills towards its slow-growing end, the fast-growing tips of laterally associated protofilaments move towards the opposite fast-growing end of the MreB helix. This offers a possible mechanism for targeted polar localization without cytoplasmic motor proteins.Comment: 7 figures, 1 tabl