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Search Results: 1 - 10 of 687 matches for " Wolfram "
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Eigenvalues of Jacobian Matrices Report on Steps of Metabolic Reprogramming in a Complex Plant-Environment Interaction  [PDF]
Thomas N?gele, Wolfram Weckwerth
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.48A007

Mathematical modeling of biochemical systems aims at improving the knowledge about complex regulatory networks. The experimental high-throughput measurement of levels of biochemical components, like metabolites and proteins, has become an integral part for characterization of biological systems. Yet, strategies of mathematical modeling to functionally integrate resulting data sets is still challenging. In plant biology, regulatory strategies that determine the metabolic output of metabolism as a response to changes in environmental conditions are hardly traceable by intuition. Mathematical modeling has been shown to be a promising approach to address such problems of plant-environment interaction promoting the comprehensive understanding of plant biochemistry and physiology. In this context, we recently published an inversely calculated solution for first-order partial derivatives, i.e. the Jacobian matrix, from experimental high-throughput data of a plant biochemical model system. Here, we present a biomathematical strategy, comprising 1) the inverse calculation of a biochemical Jacobian; 2) the characterization of the associated eigenvalues and 3) the interpretation of the results with respect to biochemical regulation. Deriving the real parts of eigenvalues provides information about the stability of solutions of inverse calculations. We found that shifts of the eigenvalue real part distributions occur together with metabolic shifts induced by short-term and long-term exposure to low temperature. This indicates the suitability of mathematical Jacobian characterization for recognizing perturbations in the metabolic homeostasis of plant metabolism. Together with our previously published results on inverse Jacobian calculation this represents a comprehensive strategy of mathematical modeling for the analysis of complex biochemical systems and plant-environment interactions from the molecular to the ecosystems level.

Dopamine signals for reward value and risk: basic and recent data
Wolfram Schultz
Behavioral and Brain Functions , 2010, DOI: 10.1186/1744-9081-6-24
Abstract: The described experiments used standard behavioral and neurophysiological methods to record the activity of single dopamine neurons in awake monkeys during specific behavioral tasks.Dopamine neurons show phasic activations to external stimuli. The signal reflects reward, physical salience, risk and punishment, in descending order of fractions of responding neurons. Expected reward value is a key decision variable for economic choices. The reward response codes reward value, probability and their summed product, expected value. The neurons code reward value as it differs from prediction, thus fulfilling the basic requirement for a bidirectional prediction error teaching signal postulated by learning theory. This response is scaled in units of standard deviation. By contrast, relatively few dopamine neurons show the phasic activation following punishers and conditioned aversive stimuli, suggesting a lack of relationship of the reward response to general attention and arousal. Large proportions of dopamine neurons are also activated by intense, physically salient stimuli. This response is enhanced when the stimuli are novel; it appears to be distinct from the reward value signal. Dopamine neurons show also unspecific activations to non-rewarding stimuli that are possibly due to generalization by similar stimuli and pseudoconditioning by primary rewards. These activations are shorter than reward responses and are often followed by depression of activity. A separate, slower dopamine signal informs about risk, another important decision variable. The prediction error response occurs only with reward; it is scaled by the risk of predicted reward.Neurophysiological studies reveal phasic dopamine signals that transmit information related predominantly but not exclusively to reward. Although not being entirely homogeneous, the dopamine signal is more restricted and stereotyped than neuronal activity in most other brain structures involved in goal directed behavior.Results fro
Prisiones textuales: Artificio y violencia en la poesía espa?ola del barroco
Olivar , 2004,
Abstract: in search of a new artificial language, góngora tries to retrieve by poetic means a similarity between words and things. thus, in his sonnet ?prisión del nácar era articulado? (1620), in which artifice and violence are correlated, artificiality of the description itself corresponds to artificiality of the beauty that is described. gongorine techniques have here a mimologic function, by which the text seems to make visible and audible a violence that has always been underlying the lyric praise of the mistress. her ?hyper-precious? image ows its outstanding beauty to masculine compelling action. this feature is reworked by other baroque poets such as quevedo
European music therapy and the European Music Therapy Confederation (EMTC) in present and future []
Wolfram, Ilse
GMS Zeitschrift für Medizinische Ausbildung , 2007,
The impact of modern traffic and traditional life on informal traffic rules; The example of Yogyakarta
Wolfram Lorenz
Bijdragen tot de Taal-, Land- en Volkenkunde , 2002,
Virtual Universities for African and Arab Countries
Wolfram LAASER
The Turkish Online Journal of Distance Education , 2006,
Abstract: Internet development in Africa is constrained by poor telephone infrastructure, low international bandwidth and high dials up tariffs levied on internet users. This means in Africa we find actually app. 1% of worldwide internet users whereas population share of world population may be around 13%. Nearly half of the internet users are concentrated in South Africa. Another one percent of world users is located in the Middle East. Therefore it is understandable that Africa and the Arab world are latecomers in developing net based educational systems. However today donor organizations put strong emphasis on creating Virtual Campuses for African States (EC, Word Bank) and Mediterranean countries or plan to incorporate selected African States to other institutional arrangements (Commonwealth of Nations, UNESCO). In what follows we will discuss five of these projects differing in scope, structure and funding namely the Virtual African University, the Avicenna Project, the Virtual Arab University, the Syrian Open University and the proposal for a Virtual University for the Small States. From the analysis of the respective projects some tentative conclusions will be derived.
Book Review - Economics of Distance and Online Learning: Theory, Practice and Research
Wolfram Laaser
International Review of Research in Open and Distance Learning , 2011,
Wolfram LAASER
The Turkish Online Journal of Distance Education , 2011,
Abstract: In the past eLearning has been introduced by many public universities however a concise IT-strategy was not followed during implementation. Different learning platforms were acquired by different departments and no systematic approach was set up to give support for course development, eTutoring or upgrading and archiving of electronic files. Although contemporary learning management systems had some administrative functions incorporated these data were not integrated with the rest of the universities administrative system. The need to work on integrated solutions offering most of the universities services with "one face to the customer" became obvious. The paper will discuss scenarios to explain the services needed and report on the present discussion about reforming organizational structures and adjusting IT infrastructure to create the future eUniversity.
Wolfram LAASER
The Turkish Online Journal of Distance Education , 2008,
Abstract: ABSTRACT According to Gartner a certain hype of e-Learning was followed by a downturn but eLearning will continue to be an important factor in learning scenarios. However the economic viability of e-learning projects will be questioned with more scrutiny than in earlier periods. Therefore it seems to be a good opportunity to see what can be learned from past experience in costing distance learning projects and what aspects are added by current attempts to measure economic efficiency. After reviewing early research about costing distance learning some more recent approaches will be discussed, such as eLearning ROI-calculators and the concept of total cost of ownership. Furthermore some microeconomic effects referring to localization of distance learning courses are outlined. Finally several unsolved issues in costing distance education are summarized.
Review: Somchai Phatharathananunth (2006), Civil Society and Democratization. Social Movements in Northeast Thailand Buchbesprechung: Somchai Phatharathananunth (2006), Civil Society and Democratization. Social Movements in Northeast Thailand
Wolfram Schaffar
Journal of Current Southeast Asian Affairs , 2009,
Abstract: Book Review of Somchai Phatharathananunth (2006), Civil Society and Democratization. Social Movements in Northeast Thailand, Copenhagen: NIAS Press; ISBN 10: 8791114381, 251 pages. Buchbesprechung der Monografie: Somchai Phatharathananunth (2006), Civil Society and Democratization. Social Movements in Northeast Thailand, Copenhagen: NIAS Press; ISBN 10: 8791114381, 251 pages.
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