An overview of online charging in 3GPP networks: new ways of utilizing user,network, and service‐related information

Modern charging systems routinely apply the user, network, and service‐related information while performing online charging. Compared, however, to all the information available to and used in managing the network as a whole, the charging systems only use a limited subset. This work is motivated by the challenge to identify which information is used, and how it is used in online charging‐related processes, and also to explore whether it could be utilized ‘better’ or ‘smarter’ to improve future online charging systems functionality. We do not attempt to predict which information will be utilized in such systems and for what purpose, but instead summarize the open issues in view of the emerging trend of exploiting the user, network and service‐related information in service provisioning. We focus on the most recent 3GPP standards and relevant research papers, and propose three key aspects of online charging, with respect to information utilization: (a) signaling aspect, (b) inter‐domain aspect, and (c) service‐ and component‐based aspect. We present a state‐of‐the‐art review by grouping the works found in the literature based on the aspects they are associated with, and compare them based on the proposed comparison criteria. The discussion presented at the end of the paper indicates three common open issues, namely: (1) lack of common charging information specification and structure; (2) lack of mechanisms for information sharing among stakeholders in the service delivery process; and (3) lack of a common framework for sharing information while protecting user privacy. Copyright © 2012 John Wiley & Sons, Ltd.     

Effects of high concentrations of hyaluronan in culture medium on development and survival rates of fresh and frozen-thawed bovine embryos produced in vitro

Hyaluronic acid (HA) is the main glycosaminoglycan present in follicular, oviductal and uterine fluids. The main functions of HA include dynamic processes that are mediated through interaction with extracellular matrix components, regulation of gene expression, cell proliferation and cell differentiation. HA increases the viscosity of solutions and also has several physiological functions, including regulation of water distribution and water-binding capacity. The addition of 6 mg HA ml(-1) to synthetic oviduct fluid (SOF; SOF-HA) culture medium on day 5 (IVF = day 0) significantly (P < 0.001) increased the viscosity of the medium in comparison with SOF culture medium containing BSA (SOF-BSA). On day 8, rate of blastocyst development in SOF-HA culture medium was significantly (P < 0.05) higher than in SOF-BSA culture medium (38.2 versus 29.3%). The number of trophectoderm cells and the total number of cells of expanded blastocysts cultured in the presence of HA were significantly (P < 0.01) higher in comparison with expanded blastocysts cultured in the presence of BSA (88.9 +/- 7.3 versus 67.6 +/- 3.0 and 130.1 +/- 10.9 versus 104.8 +/- 2.5, respectively). After freezing and thawing, the percentage of day 8 embryos that re-expanded and hatched when cultured with SOF-HA was greater than that of embryos cultured with SOF-BSA (11.3 and 10.5% versus 75.5 and 36.8%, respectively). After thawing, the ATP contents of in vivo-derived, SOF-HA and SOF-BSA expanded blastocysts were similar. The embryos cultured with HA showed less ultrastructural deviation and de-differentiation after freezing and thawing than the embryos cultured with BSA. This study demonstrates that HA improves the developmental capacity of bovine embryos under in vitro conditions and is warranted as a supplement for in vitro production of bovine embryos, particularly if they are to be cryopreserved.     

Electrocatalytic effects of Mo–Pt intermetallics singly and with ionic activators. Hydrogen production via electrolysis

The intermetallic phases along the Pt–Mo phase diagram, singly or in combination with specific ionic activators, have been investigated as cathode materials for the production of hydrogen by electrolysis from water KOH solutions in an attempt to decrease energy consumption. The influence of ionic activators (activating compounds) on energy consumption was significant. The intermetallic phases, as cathode materials, were activated by the surface deposition of activating compounds from electrolyte. The influence of these cathode materials on the electrolytic evolution of hydrogen was discussed in the context of transition metals features and their electronic configuration.     

Antibody to keyhole limpet hemocyanin labels retinal horizontal cells in some amphibians, but not in others

The intact rat adrenal gland in short-term (3-h) organ culture may be amenable for the identification of factors involved in regulating adrenal cell apoptosis under defined conditions. In this model, culturing in the absence of trophic support (basal; control) triggered apoptosis in the intact rat adrenal gland; oligonucleosome formation, a measure of apoptosis, was 56.4-fold greater than that of glands snap-frozen at the start of incubation. Angiotensin II (Ang II) (100 nM) enhanced apoptosis by 67% over control. By contrast, adrenocorticotropin (ACTH) (100 nM) attenuated basal apoptosis by 59% and antagonized the enhanced apoptosis induced by Ang II back to the control level. Quartering of the glands enhanced basal oligonucleosome formation 182.2% greater than that of intact glands. Interestingly, quartering of the glands abolished the influences of Ang II and ACTH on apoptotic DNA fragmentation, but did not alter ACTH-induced corticosterone secretion. These data suggest that some level of gross adrenal structural information or compartmentalization, sufficiently disrupted by quartering, is required for the hormonal modulation of adrenal cell survival.     

Comparison of functional MR-venography and EPI-BOLD fMRI at 1.5 T

Functional magnetic resonance imaging (fMRI) of the brain using blood oxygenation level dependent (BOLD) contrast relies on the changes of paramagnetic deoxyhemoglobin concentration, which affects brain parenchyma and draining venous vessels. These changes in deoxyhemoglobin concentration in venous vessels can also be monitored using a high-resolution susceptibility-based MR-venography technique. Four volunteers participated in the study in which functional MR-venograms were compared with conventional echo-planar imaging (EPI)-BOLD-fMRI. In all cases, small venous vessels could be identified close to the areas of activation detected by conventional fMRI. In the venograms, task performance (finger tapping) resulted in a loss of venous vessel contrast compared to the resting state, which is consistent with a local decrease of deoxyhemoglobin concentration. MR-venography allows a direct visualization of the BOLD-effect at high spatial resolution. In combination with conventional fMRI, this technique may help to separate the contribution of brain parenchyma and venous vessels in fMRI studies.