Search results

Filter

Filetype

Your search for "*" yielded 534623 hits

Optimal control for systems with varying sampling rate

The paper addresses the aspects of control of real time systems with varying sampling rate. An example is given in which a stable continuous system is sampled at two different sampling rates. Two controllers are designed to minimize the same continuous quadratic loss function with the same weights. It is shown that although the design leads to stable controlled closed loop systems, for both discre

Neurogenesis in stroke and epilepsy

Ischemic and epileptic insults promote neurogenesis from neural stem cells located in the dentate subgranular zone and in the subventricular zone lining the lateral ventricles. These findings raise the possibility that the adult brain tries to use its own stem cells to repair itself. New neurons generated by ischemic insults have now been shown to migrate from the subventricular zone and posterior

The cultured neuroretina: development, survival and transplantation

Popular Abstract in Swedish Näthinnan är den del av ögat som tar emot ljussignaler och omvandlar dem till elektriska signaler. Dessa signaler förs sedan vidare via synnerven till hjärnan för att man skall kunna erhålla en synupplevelse. Näthinnan består av flera celltyper och en av dessa är fotoreceptorcellen, som omvandlar ljus till elektriska signaler, den s.k. fototransduktionen. Den del av fotIn the cultured immature rat full-thickness neuroretina, massive apoptosis appears in the GCL within hours after explantation, but in the ONL cell death is low. Microglia cells become activated when the retina is kept in culture and are found in the GCL within 24 hours of culture. Embryonic porcine retina kept in culture can survive and develop according to its intrinsic timetable for at least si

Temperature-dependent changes in the soil bacterial community in limed and unlimed soil

A humus soil with a pH(H2O) of 4.9 was limed to a pH of 7.5 and was incubated together with samples from unlimed and field limed (pH 6.1) soils at 5, 20 and 30degreesC for up to 80 days. The changes in the phospholipid fatty acid (PLFA) pattern were most rapid for the bacterial community of the soil incubated at 30degreesC, while no changes were found in the soil incubated at 5degreesC. The respon

Selected research studies from Scandinavia : dedicated to professor Göran Fagerlund on his 60th anniversary November 11, 1997

The book contains selected articles from research in different areas produced by scientists in Scandinavia. However, many of the articles are based upon professor Göran Fagerlund's original ideas. Titles: 1.Cementitious injection grouts - penetration ability (Alemo, J. & Hansson, P.). 2.A disadvantage of high performance concrete and a simple way to avoid it (Alexanderson, J). 3. Early age t

Critical evaluation of factors affecting chloride initiated reinforcement corrosion in concrete

This licentiate study has been completed as a part of a larger experimental program "Durability of Reinforced Concrete Structures in Marine Environment" carried out in Sweden and Denmark. The aim of this work has been to identify and critically evaluate some major parameters influencing the onset of active reinforcement corrosion in concrete in marine environment. Since the topic is naturally very

Det trovärdiga vittnet

Artikeln diskuterar frågan om vittnets och vittnetsmålets trovärdighet utifrån ett antal nedslag i idéhistorien. Den berör vittnetsmålets epistemologiska, psykologiska och politiska problematik och utnyttjar som röd tråd linjen från Sokrates/Platon och Jesus/lärjungarna.

Concrete slab on the ground and moisture control : verification of some methods to improve the moisture conditions in the foundation

This work deals with different types of repair methods for concrete slab on the ground damaged by moisture. Many of the available methods involve some kind of mechanical ventilation of the foundation. The basic principle for all these systems is the same. By establishing air movement through an air-permeable layer below or above the concrete slab, the flowing air can absorb moisture from surroundi

Theory of inversion of dispersive bi-isotropic slab parameters using TEM pulses

A new method of reconstructing the susceptibility kernels of a linear, causal, time-invariant, homogeneous, and bi-isotropic medium from generic scattering data at normal incidence is presented. This inverse problem is shown to be well posed in the space of continuous functions furnished with the maximum norm, C[0,T]. A numerical example is given.

Combined carbon and nitrogen removal from acetonitrile using algal-bacterial bioreactors

When compared with Chlorella vulgaris, Scenedesmus obliquus and Selenastrum capricornutum, C. sorokiniana presented the highest tolerance to acetonitrile and the highest O-2 production capacity. It also supported the fastest acetonitrile biodegradation when mixed with a suitable acetonitrile-degrading bacterial consortium. Consequently, this microalga was tested in symbiosis with the bacterial cul

Candelaria fruticans found in Southern Africa

The distribution and habitat ecology of Candelaria fruticans Poelt & Oberw. is discussed and a distribution map is provided, The distribution pattern is shared by a few species occurring on both sides of the Atlantic Ocean in mainly the subtropical and tropical zones.

La semiosfera y el domino de la alteridad

Aunque los conocidos modelos de la escuela de Tartu contraponen la Cultura a la Naturaleza, realmente se refieren a la relación entre las culturas, una de las cuales se concibe como si fuera naturaleza. La inspiración para el concepto tardío de Lotman de la semiosfera, sin embargo, deriva de la oposición entre los hechos mentales (esto es, semióticos), que pertenecen al dominio de las ciencias soc

Recognizing Macroeconomic Fluctuations in Value Based Management

Value Based Management (VBM) has become a common tool for evaluating corporate strategies and projects from the perspective of shareholder value maximization, and can be an important input for corporate compensation systems. But traditional VBM frameworks make no systematic effort to distinguish between changes in performance attributable to macroeconomic fluctuations beyond management's control a