Towards an evaluation framework for knowledge management systems

In this paper we develop an evaluation framework for Knowledge Management Systems (KMS). The framework builds on the theoretical foundations underlying organizational Knowledge Management (KM) to identify key KM activities and the KMS capabilities required to support each activity. These capabilities are then used to form a benchmark for evaluating KMS. Organizations selecting KMS can use the framework to identify gaps and overlaps in the extent to which the capabilities provided and utilized by their current KMS portfolio meet the KM needs of the organization. Other applications of the framework are also discussed.

A new organotypic culture method to study the actions of steroid hormones on the nervous system

A new organotypic culture method for growing slices of nervous system tissue, based on the use of hyaluronic acid as a growth supporting milieu, is described. This method allows cultures derived from either fetuses or newborns to grow and develop with markedly reduced amounts of added serum. Organotypic cultures from fetal rat hypothalamus were exposed to 17 beta estradiol and compared to control cultures exposed to the ethanol vehicle. When exposed to estradiol, cultures showed an outgrowth of thick nerve fibers that was accompanied by an elevation in the number of microtubules present in the neuronal processes, an increment in the number of synapses, and an increased morphological differentiation of synaptic terminals. Freeze-fracture analysis of neuronal membranes from estradiol-treated cultures revealed a significant increase in the number of exoendocytotic images and a decrease in the number of intramembranous particles. Estradiol's effects parallel those found in in vivo studies, indicating that hyaluronic acid-based organotypic cultures represent an appropriate model to study hormonal influences on the developing nervous system.     

Effects of molecular rotation in low-energy electron collisions of H3+

Measurements on the energetic structure of the dissociative recombination rate coefficient in the millielectronvolt range are described for H3+ ions produced in the lowest rotational levels by collisional cooling and stored as a fast beam in the magnetic storage ring TSR (Test Storage Ring). The observed resonant structure is consistent with that found previously at the storage ring facility CRYRING in Stockholm, Sweden; theoretical predictions yield good agreement on the overall size of the rate coefficient, but do not reproduce the detailed structure. First studies on the nuclear spin symmetry influencing the lowest level populations show a small effect different from the theoretical predictions. Heating processes in the residual gas and by collisions with energetic electrons, as well as cooling owing to interaction with cold electrons, were observed in long-time storage experiments, using the low-energy dissociative recombination rate coefficient as a probe, and their consistency with the recent cold H3+ measurements is discussed.     

Modified Hyaluronic Acid-Laminin-Hydrogel as Luminal Filler for Clinically Approved Hollow Nerve Guides in a Rat Critical Defect Size Model

Hollow nerve guidance conduits are approved for clinical use for defect lengths of up to 3 cm. This is because also in pre-clinical evaluation they are less effective in the support of nerve regeneration over critical defect lengths. Hydrogel luminal fillers are thought to improve the regeneration outcome by providing an optimized matrix inside bioartificial nerve grafts. We evaluated here a modified hyaluronic acid-laminin-hydrogel (M-HAL) as luminal filler for two clinically approved hollow nerve guides. Collagen-based and chitosan-based nerve guides were filled with M-HAL in two different concentrations and the regeneration outcome comprehensively studied in the acute repair rat sciatic nerve 15 mm critical defect size model. Autologous nerve graft (ANG) repair served as gold-standard control. At 120 days post-surgery, all ANG rats demonstrated electrodiagnostically detectable motor recovery. Both concentrations of the hydrogel luminal filler induced improved regeneration outcome over empty nerve guides. However, neither combination with collagen- nor chitosan-based nerve guides resulted in functional recovery comparable to the ANG repair. In contrast to our previous studies, we demonstrate here that M-HAL slightly improved the overall performance of either empty nerve guide type in the critical defect size model.     

A Delphi study of knowledge management systems: Scope and requirements

We empirically explored the roles and scope of knowledge management systems in organizations. Building on a knowledge-based view of the firm, we hypothesized and empirically tested our belief that more integration is needed between technologies intended to support knowledge and those supporting business operations. Findings from a Delphi study and in-depth interviews illustrated this and led us to suggest a revised approach to developing organizational knowledge management systems.     

Electroencephalography in the evaluation of headache patients: a review

The intention of this paper was to review the literature on the use of EEG in headache evaluation and recommend clinical applications of this technique. The consensus of published findings was that EEG can differentiate migraineurs from controls but that it is not justified for routine diagnosis of headache etiology. We conclude that neuroimaging is a superior technique for detecting underlying structural lesions.     

Brain structure volumes in the mole rat, Spalax ehrenbergi (Spalacidae, Rodentia) in comparison to the rat and subterrestrial insectivores

Natural blindness and a subterranean, digging mode of life demand peculiar adaptations of the central nervous system in the mole rat Spalax ehrenbergi, which are the focus of this quantitative investigation. Volumes of 25 brain structures in Spalax were evaluated allometrically, using the least encephalized mammalian species, the Madagassian hedgehog-like tenrecs (Tenrecinae) as a reference base, and their sizes compared with those of the rat (as a more generalized representative of rodents) and of some subterranean Insectivora. The allometric approach reveals that Spalax has a larger brain than tenrecs and the rat. Within the brain, the neocortex and diencephalon are well developed, an observation also made in other mammalian species with a relatively high encephalization. An unique feature in Spalax is the enlargement of motor structures of the brain, such as the cerebellum (and cerebellar nuclei), and the striatum. Most conspicuous is the large size of the nucleus motorius nervi trigemini, reflecting the importance of masticatory muscles for the special digging technique, which demand an intense use of the teeth for loosening the soil.     

The pineal gland of the mole-rat (Spalax ehrenbergi, Nehring). I. The fine structure of pinealocytes

The ultrastructure of pinealocytes of the mole-rat (Spalax ehrenbergi), a blind subterranean mammal living in complete darkness, was examined and compared with pinealocytes of other mammals. Two different populations of pinealocytes (I and II) were observed. They differed in general aspect. In location and especially in their content of cell organelles involved in synthetic processes. Mitochondria, ribosomes, granular endoplasmic reticulum, lysosomes, lipid inclusions and glycogen granules were present in the perikarya of pinealocytes of both populations. In the pinealocyte of population I some granular vesicles were occasionally observed in the cell body. Their presumed origin from the Golgi apparatus could not be clearly demonstrated. In the perikaryon of this pinealocyte, concentrations of ribosomes and of cisternae of the granular endoplasmic reticulum were constantly observed. These concentrations may indicate an intensive synthetic activity. Pinealocytes of population II were characterized by accumulations of proteinaceous material in some cisternae of the granular endoplasmic reticulum and between the two layers of the nuclear membrane. The origin of these peculiar elements is discussed.     

Parametric model derivation of transfer function for noninvasiveestimation of aortic pressure by radial tonometry

Aortic pressure can be estimated noninvasively by applying a transfer function (TF) to radial tonometry signals. This study compares the performance of prior approaches, based on Fourier transform and inverted aortic-to-radial model, with direct radial-to-aortic autoregressive exogenous (ARX) model. Simultaneous invasive aortic pressure and radial tonometry pressure were recorded during rest in 39 patients in the supine position. Individual radial-aortic TF's were estimated from 20 patients, and the average TF was used to predict aortic pressures in the remaining 19 patients. The direct average TF yielded accurate aortic systolic pressure estimation (error 0.4 +/- 2.9 mmHg) and good reproduction of the aortic pressure waveform (root mean squared error 2.2 +/- 0.9 mmHg). The inverted reverse TF (aortic radial) yielded comparable results, while the Fourier-based TF had worse performance. Individual direct TF provided improved predictive accuracy only for indexes which are based on higher frequency components of the waveform (augmentation index, systolic time period). An ARX average TF can be used to accurately estimate central aortic pressure waveform parameters from noninvasive radial pulse tracings, and its performance is superior to previous techniques.     

Model-free dynamic contrast-enhanced MRI analysis: differentiation between active tumor and necrotic tissue in patients with glioblastoma

Magnetic Resonance Materials in Physics, Biology and Medicine - Treatment response assessment in patients with high-grade gliomas (HGG) is heavily dependent on changes in lesion size on MRI....