Gender differences in digital music distribution methods

This study examines gender differences among Greek Internet users in using digital music distribution methods. First, a Web-based questionnaire was developed and placed on most popular Greek forums. Then, 300 Greek Internet users stated their opinions regarding digital music and the following downloading methods: 1) Http downloading, 2) P2P downloading, 3) Torrent downloading, and 4) Combined iTunes method. The results revealed that P2P programs are the first choice for downloading mp3. The responders were satisfied with the P2P’s easiness of use, the variety of songs and the no need to pay. However, they worried about P2P’s safety. Gender differences were identified in several areas. Music industry managers could consider these findings in their strategies to reach the consumers. Advertising companies could use the results to target differently male or female consumers.     

Effect of Drying Methods on Dyeing Capacity of Dyestuff Plant Materials

This article presents a study of the effect of drying methods on dyeing capacity of widespread European flora dyestuff plant materials. The natural colorants, derived from the selected plant materials, were applied on chemical pulp in order to examine their dyeability. In this work, three different drying methods were examined—the natural, the air-, and the freeze-drying method—in various conditions. The plant materials that were dried naturally show weak dyeing results in comparison with the air- and freeze-dried materials. Freeze drying significantly improved the dyeing capacity of dyestuff plant materials with high initial moisture content. On the other hand, air drying at low temperature and high relative humidity improved the dyeing capacity of plant materials with low initial moisture content.     

The STAR automaton: expediency and optimality properties

We present the STack ARchitecture (STAR) automaton. It is a fixed structure, multiaction, reward-penalty learning automaton, characterized by a star-shaped state transition diagram. Each branch of the star contains D states associated with a particular action. The branches are connected to a central "neutral" state. The most general version of STAR involves probabilistic state transitions in response to reward and/or penalty, but deterministic transitions can also be used. The learning behavior of STAR results from the stack-like operation of the branches; the learning parameter is D. By mathematical analysis, it is shown that STAR with deterministic reward/probabilistic penalty and a sufficiently large D can be rendered /spl epsi/-optimal in every stationary environment. By numerical simulation it is shown that in nonstationary, switching environments, STAR usually outperforms classical variable structure automata such as L/sub R-P/, L/sub R-I/, and L/sub R-/spl epsi/P/.     

The effect of fetal neck position on nuchal translucency measurement

Vascular infections after percutaneous endovascular procedures are rare. We report a case of bacterial arteritis following PTA and stent implantation into an iliac artery. It was complicated by septic embolization, ipsilateral empyema of the knee joint and formation of an infected false aneurysm. Contamination of the stent with Staphylococcus aureus is likely to be the cause. The treatment included resection of the infected arterial segment, removal of the stent, and autologous reconstruction.     

Material balance depletion models for two-phase and vapor-dominated geothermal reservoirs

Material balance calculations, often referred to as “zero-dimensional” or “lumped element” reservoir evaluations, have been used extensively in petroleum and geothermal engineering. This paper presents a Havlena and Odeh-type (J. Petrol. Technol. Aug. 1963) material balance depletion model for two-phase reservoirs incorporating adsorption phenomena. A straight line, formed between groups of thermodynamic and adsorption properties of water and the cumulative production history, provides the initial fluid-in-place and the size of the vapor-dominated “steam cap”. Adsorption phenomena were found by Economides and Miller (Paper SPE 12740, California regional meeting, Soc. Petrol. Engrs, 1984) to be the controlling mechanism in the depletion of vapor-dominated geothermal reservoirs. A material balance for vapor-dominated geothermal reservoirs, demonstrating the importance of adsorption phenomena, is also presented. A straight line provides the initial fluid-in-place.     

Biochemical and biophysical characterization of refolded Drosophila DPP, a homolog of bone morphogenetic proteins 2 and 4

The mature C-terminal signaling domain of the Drosophila Decapentaplegic proprotein (DPP) can be efficiently refolded from chaotrope-solubilized inclusion bodies with the aid of a membrane protein-solubilizing detergent, high concentrations (0.75-2 M) of NaCl, and low temperatures (5-15 degreesC). The disulfide-linked homodimeric product contains N-terminal heparin-binding sites that were utilized as intrinsic affinity tags to obtain a highly enriched preparation in one chromatographic step. A subsequent C4 reverse phase high pressure liquid chromatography step provides high purity, salt-free protein that is amenable to biophysical and structural studies at a yield of approximately 3 mg/liter of bacterial culture. The dimeric protein is correctly folded as determined by electrophoretic, spectroscopic, chemical, and proteolytic analyses. Refolded DPP is also bioactive as shown by induction of chondrogenesis in embryonic chick limb bud cells and by high affinity binding to Noggin, an antagonist of bone morphogenetic protein signaling. In contrast to bone morphogenetic proteins extracted from demineralized bone or overexpressed in cell culture, the refolded Escherichia coli-expressed protein is not glycosylated at a conserved N-linked site and is therefore homogeneous. The C-terminal domain dimer is more hydrophobic and thus less soluble than its unfolded or partially folded forms, necessitating highly solubilizing conditions for recovery after folding in vitro. Hence solubilization of the mature ligand may be one of the principal roles of the large (250-400 amino acids) N-terminal prodomains of transforming growth factor-beta superfamily members, shown to act as intramolecular chaperones in vivo.     

Engineering evaluation of geothermal reservoirs

Reservoir engineering evaluation of geothermal systems attempts to provide answers on the extent of the reserves, their probable longevity and the deliverability and production rate of the reservoir. Economic decisions on the desirability of the exploitation of the particular reservoir hinge on these findings. This paper presents a set of calculational procedure and thinking sequences available to the geothermal reservoir engineer that would aid in an appropriate management decision. An exploitable geothermal system consists of a fluid as well as a heat reservoir. Since much of the heat is stored in the confining rock, reinjection strategies are outlines for the efficient mining of heat.     

Geothermal development in alaska: an engineering and geologic analysis

In spite of the vast geothermal potential within the state of Alaska, the economic feasibility is tenuous. Of the five sites examined in this paper, only Tenakee and Summer Bay have even marginal attractiveness for direct utilization. The geothermal reservoirs located at Copper Valley and Makushin Volcano may be feasible for power generation in the near and intermediate future. To make geothermal development feasible, an increase in the population/industrial base would be required, or a consolidation of the present power users. In general, the economic prospects of geothermal power development in Alaska are not attractive at this time, with the exception of Unalaska Island.