415 research outputs found
Insulin-Like Growth Factor II (IGF-II) Is More Potent Than IGF-I in Stimulating Cortisol Secretion from Cultured Bovine Adrenocortical Cells: Interaction with the IGF-I Receptor and IGF-Binding Proteins
Although the stimulating effect of insulin-like growth factor I (IGF-I) on adrenal steroidogenesis has been well established, the role of IGF-II in the adult adrenal gland remains unknown. We, therefore, investigated the effect of recombinant human IGF-II on cortisol and cAMP synthesis from adult bovine adrenocortical cells. IGF-II, time and dose dependently, stimulated basal cortisol secretion maximally 3-fold. In combination with ACTH, IGF-II (13 nM) synergistically increased cortisol secretion from 1-fold (10(-8) M ACTH) to 28-fold of untreated control levels. In contrast, IGF-I at equimolar concentrations did not show an effect on basal cortisol secretion, and in combination with ACTH elicited a significant weaker stimulatory effect than IGF-II (22-fold increase). The synergistic effect of IGF-II on ACTH-promoted cortisol secretion was paralleled by accumulation of cAMP in the culture medium. Although both IGF receptors are present in adult bovine adrenocortical cells, the effect of IGF-II seems to be mediated through interaction with the IGF-I receptor, as [Arg54,55]IGF-II, which only binds to the IGF-I receptor, was equipotent to native IGF-II, whereas [Leu27]IGF-II, which preferentially binds to the type II IGF receptor, did not show any effect. By Western ligand blotting, four different molecular forms of IGF-binding proteins (IGFBPs) were identified in conditioned medium of bovine adrenocortical cells with apparent molecular masses of 39-44, 34, 29, and 24 kilodaltons. ACTH treatment increased the abundance of all binding proteins, on the average, 2.3-fold, except for the 29-kDa band, which was predominantly induced 6.8-fold. Additionally, [des1-3]IGF-I, a truncated IGF variant that exhibits only minimal binding to IGFBPs, was significant more potent than IGF-I and elicited the same maximum stimulatory effect on cortisol secretion as IGF-II and [des1-6]IGF-II. In conclusion, these results demonstrate that 1) IGF-II stimulates basal as well as ACTH-induced cortisol secretion from bovine adrenocortical cells more potently than IGF-I; 2) this effect is mediated through interaction of IGF-II with the IGF-I receptor; 3) bovine adrenocortical cells synthesize various IGFBPs that are induced differentially by ACTH; and 4) IGFBPs apparently play a modulatory role in IGF-induced stimulation of adrenal steroidogenesis. Therefore, bovine adult adrenocortical cells provide a useful tissue culture model in which the interactions among locally produced IGFs, IGFBPs, and the IGF-I receptor can be evaluated
LEGALIZE IT? -OSP AND PEER-TO-PEER NETWORK LIABILITY FOR ONLINE MUSIC COPYRIGHT INFRINGEMENTS IN THE UNITED STATES AND GERMANY
It may be useful to explain why a comparative approach was chosen. It is easy and comfortable to get caught up in one\u27s own legal system and not look abroad. It is often difficult enough to understand and apply oneâs own laws accurately and the study of a foreign legal system may seem an effort too great. Yet, this reluctance to look beyond the familiar is fatal to legal development and improvement since entirely new ideas are rare in the field of law and the main source of change and new approaches is borrowing from another legal system. If one does not stray beyond the boundaries of the familiar, progress is inhibited just as learning would be without a steady flow of accessible information. This may be illustrated by examples as old as the reception of Roman law in Europe. Therefore, it is important to conduct this study comparatively, especially because the problems concerning the topic, like the Internet, are global and may pose much of the same difficulties for many legal systems. As to the structure of this thesis, a few remarks may be useful. In order to keep the work organized and systematic, the relevant law and its application to the issue will be presented and discussed separately for the legal systems of Germany and the United States. Furthermore, the historical and philosophical background of copyright law in the respective legal systems is included but kept as short as possible, so as to address the real issue inappropriate length. It is, however, necessary to elaborate on historical and philosophical topics to some extent, since both are vital to the understanding of copyright law, the problems arising in conjunction with the Internet and even more so to an insightful comparison of the laws discussed. The final part of this thesis, after the presentation, analysis, and comparison of the laws and the respective problems and solutions to the problems concerning the Internet, will be a conclusion including the author\u27s opinions and suggestions
Future prospects of relic bog dweller Carabus menetriesi in the face of climate change
Der HochmoorlaufkĂ€fer (Carabus menetriesi pacholei) ist eine prioritĂ€re Anhang-Art der FFH-Richtlinie und Art mit hoher Schutzverantwortung Deutschlands. Seine LebensrĂ€ume liegen in noch weitgehend intakten Hoch-, Ăbergangs- und Hochlagen-Quellmooren einschlieĂlich von MoorwĂ€ldern. In einem prognostizierten, wĂ€rmer und trockener werdenden Klima werden einige Vorkommen auĂerhalb der hier vorgelegten KlimahĂŒlle zu liegen kommen und daher fĂŒr die Art voraussichtlich verloren gehen. Das gilt in besonderem MaĂe fĂŒr die endemischen Vorkommen im Voralpengebiet. Andere Vorkommen werden nur zu halten sein, wenn jegliche Anstrengungen unternommen werden, einen naturnahen Wasserhaushalt wiederherzustellen. Die KlimahĂŒlle fĂŒr die Nominatform reicht etwas weiter in den trockenen und auch warmen Bereich, erfordert aber ebenfalls sĂ€mtliche BemĂŒhungen zu ihrem Erhalt. Zu den notwendigen MaĂnahmen gehört unter anderem auch die konsequente Erhaltung naturnaher Moor- und MoorrandwĂ€lder. Eine Theorie zur ErklĂ€rung der disjunkten Verbreitung im Voralpengebiet basierend auf der Vereisungsgeschichte wird prĂ€sentiert, da die KlimaverhĂ€ltnisse allein die Verbreitung nicht erklĂ€ren können.The raised bog large ground beetle (Carabus menetriesi pacholei) is listed as a priority species in Annex II of the EU Habitat Directive, and is a subspecies for which Germany has a very high conservation responsibility. Its habitats are largely intact raised and transitional bogs and high-elevation spring bogs, including bog forests. In the future climate that is predicted to be warmer and drier, some of this speciesâ habitats will likely be lost. This is particularly true for the endemic subspecies living in the pre-Alps. Other sites will only be retained if measures are undertaken to reestablish a semi-natural water regime. Among other necessary management measures is strict conservation of all natural and semi-natural bog forests and bog-edge forests. Although the climate envelope for the nominate subspecies extends farther into a drier and also slightly warmer climate, measures to protect its habitat are also warranted. A theory explaining the limited distribution in the prealpine region based on the Ice Age history is presented, since its distribution cannot be explained by the present climatic conditions alone
Generation of Formal Model Metrics for MOF based Domain Specific Languages
The assessment of quality in a software development process is vital for the quality of the final system. A number of approaches exist, which can be used to determine such quality properties. In a model-driven development process models are the primary artifacts. Novel technologies are needed in order to assess the quality of those artifacts. Often, the Object Constraint Language is used to formulate model metrics and to compute them automatically afterwards. This paper describes an approach for the generation of model metrics expressed as OCL statements based on a set of generic rules. These rules can be applied on any domain specific modeling languages for creating a basic set of metrics which can be tailored for the specific needs of a development process. The paper also briefly describes a prototype of a tool for the generation, computation, and management of these model metrics by using the Software Metrics Meta-model - SMM
Numerical study of the statistical characteristics of the mixing processes in rivers
A detailed analysis of statistical characteristics of the vertical mixing process in a horizontally homogeneous and stationary river flow is given. Stochastic models of Langevin type and random displacement models are developed to calculate the statistical characteristics of the vertical mixing. For validation, Langevin type models and random displacement models conventionally applied in this field are compared. All the methods show a good qualitative agreement. However the random diplacement model with constant coefficients is shown to perform with considerable deviations
Generation of Formal Model Metrics for MOF based Domain Specific Languages
The assessment of quality in a software development process is vital for the quality of the final system. A number of approaches exist, which can be used to determine such quality properties. In a model-driven development process models are the primary artifacts. Novel technologies are needed in order to assess the quality of those artifacts. Often, the Object Constraint Language is used to formulate model metrics and to compute them automatically afterwards. This paper describes an approach for the generation of model metrics expressed as OCL statements based on a set of generic rules. These rules can be applied on any domain specific modeling languages for creating a basic set of metrics which can be tailored for the specific needs of a development process. The paper also briefly describes a prototype of a tool for the generation, computation, and management of these model metrics by using the Software Metrics Meta-model - SMM
Recommended from our members
Structural and Electric Properties of Epitaxial Na0.5Bi0.5TiO3-Based Thin Films
Substantial efforts are dedicated worldwide to use lead-free materials for environmentally friendly processes in electrocaloric cooling. Whereas investigations on bulk materials showed that Na0.5Bi0.5TiO3 (NBT)-based compounds might be suitable for such applications, our aim is to clarify the feasibility of epitaxial NBT-based thin films for more detailed investigations on the correlation between the composition, microstructure, and functional properties. Therefore, NBT-based thin films were grown by pulsed laser deposition on different single crystalline substrates using a thin epitaxial La0.5Sr0.5CoO3 layer as the bottom electrode for subsequent electric measurements. Structural characterization revealed an undisturbed epitaxial growth of NBT on lattice-matching substrates with a columnar microstructure, but high roughness and increasing grain size with larger film thickness. Dielectric measurements indicate a shift of the phase transition to lower temperatures compared to bulk samples as well as a reduced permittivity and increased losses at higher temperatures. Whereas polarization loops taken at â100 °C revealed a distinct ferroelectric behavior, room temperature data showed a significant resistive contribution in these measurements. Leakage current studies confirmed a non-negligible conductivity between the electrodes, thus preventing an indirect characterization of the electrocaloric properties of these films
Measurement Testbed for Radar and Emitter Localization of UAV at 3.75 GHz
This paper presents an experimental measurement platform for the research and
development of unmanned aerial vehicles (UAVs) localization algorithms using
radio emission and reflectivity. We propose a cost-effective, flexible testbed
made from commercial off-the-shelf (COTS) devices to allow academic research
regarding the upcoming integration of UAV surveillance in existing mobile radio
networks in terms of integrated sensing and communication (ISAC). The system
enables nanosecond-level synchronization accuracy and centimeter-level
positioning accuracy for multiple distributed sensor nodes and a mobile
UAV-mounted node. Results from a real-world measurement in a 16 km2 urban area
demonstrate the system's performance with both emitter localization as well as
with the radar setup
- âŠ