IV-Controlling und Informationsmanagement im Mittelstand - Ergebnisse einer empirischen Studie

Spitta T, Ellerbrock R, Kuhlmann A. IV-Controlling und Informationsmanagement im Mittelstand - Ergebnisse einer empirischen Studie. WIRTSCHAFTSINFORMATK. 1999;41(6):506-515.IS-controlling hardly takes place in SME's although there is a need for it. This is the result of a survey in Easwestfalia-Lippe/Germany consisting of a questionnaire and explorative interviews. The interviews verified our conjecture from the quantitative analysis that SME's do not manage their information technique adequately. There are shortcomings in the understanding of the DP's role (programming bureau instead of competence center) and a hazardous risk-behavior (high personnel dependencies). Aside the presentation of the results and their interpretation, the paper contains proposals for actions in SME's information resource management and IS-controlling

One-dimensional problems in the stability of thin shells

Within the next decades, an increasing number of human beings will be brought into space to carry out technical and scientific tasks. There, they will be exposed simultaneously to combined stimuli, especially microgravity and radiation. In the endeavour to assess the risks for humans during long-duration space missions, it is necessary to understand already at the cellular level the complex interplay of these parameters. Cellular stress protection responses lead to an increased transcription of several genes via the modulation of transcription factors. The activation of the nuclear factor κB (NF-κB) pathway as a possible anti-apoptotic route represents such an important cellular stress response. It is hypothesized that the activation of NF-κB and the subsequent expression of NF-κB-dependent genes is involved in the cellular response to components of the cosmic radiation. Irradiation of human embryonic kidney cells (HEK/293) with α-particles (2.1 MeV, LET ∼160 keV/μm) was performed at the PTB, Braunschweig, Germany. Using the microbeam facility, cells were exposed to nuclear hits or, for the purpose of comparison, to a diffuse irradiation of the whole cell. After irradiation the following biological endpoints were determined: (i) cell survival (by means of the colony forming ability test), and (ii) quantitative RT-PCR analysis of selected NF-κB target genes (IκBα GADD45β, bcl-2, and bcl-XL). One nuclear α-particle traversal reduces the probability to survive to ∼75%. Exposure to two α-particles per nucleus resulted in an upregulation of the expression of the GADD45β gene. After exposure of HEK cells to five nuclear hits, about 43% of the irradiated cells survived, and the transcriptional response was not significant. Ten nuclear hits activated the IκBα expression, this increased IκBα production might be involved in the termination of the radiation-induced NF-κB activation. Diffuse irradiation increased the transcription of IκBα and GADD45β. Expression of the antiapoptotic genes bcl-2 and bcl-XL remained almost unchanged after α-particle irradiation. These findings suggest a role for GADD45β in the cellular radiation response to low fluences, while IκBα is enrolled at higher fluences

Protective signaling pathways in the cellular radiation response: Nuclear Factor κB (NF-κB) and Nrf2

As a prerequisite for developing appropriate countermeasures to mitigate acute effects and late risks of ionizing radiation exposure, the role of protective pathways in the cellular radiation response needs to be better understood. The Nuclear Factor κB (NF-κB) pathway is generally regarded as protective by upregulating anti-apoptotic genes and is known to be activated by DNA double strand breaks. The transcription factor Nuclear Factor Erythroid 2 Like 2 (Nrf2) is activated in response to oxidative stress and increases the expression of anti-oxidative enzymes. In this work, the production of reactive oxygen species (ROS), the activation of NF-κB and Nrf2 and the expression of selected target genes after ionizing radiation exposure (X-rays, heavy ions) were analyzed in human cell lines