National information networks for the advanced developing countries: a study on their functional organisation

Increasing demand in the advanced developing countries for more information more quickly has called into serious question the traditionally fragmented nature of information services by creating a need for greater inter-institutional cooperation. Libraries and information centres have responded to this need by the formation of networks serving limited geographical areas or various special interests. Unless an inclusive network is established on a national scale, expendi tures, facilities and efforts will be unnecessarily duplicated and interconnection will become increasingly difficult as regional and specialised networks develop without a common approach. The time has come in every advanced developing country to create a national information network which would weld together its separate insulated information resources into a nationwide network. The purpose of this study is to identify common information needs and desires responsible for the present information services in the advanced developing countries, and to design a generalised structure of national information networks based on the common factors identified. This study was carried out by postal questionnaire, personal interview and literature review. The countries investigated are: Brazil, Colombia, Hong Kong, Iran, Iraq, Kenya, Korea, Kuwait, Malaysia, Malta, Mexico, Taiwan, Turkey, Venezuela and Yugoslavia. The data gathered by questionnaire and interview have been arranged in fifteen country reports to be summarised later by crocos-section characteristics, requirements and constraints. By choosing between the alternative network models and configurations, a generalised structure of national information networks based on the common characteristics of the information needs and desires existing in the advanced developing countries has been presented. The investigator has attempted in this study to view a network as an arrangement of different functional units working together to accomplish the purpose of the whole rather than an integrated set of different specialised networks such as those in agriculture, chemistry, economics, education, etc

Crystal structure of a DNA aptamer bound to PvLDH elucidates novel single-stranded DNA structural elements for folding and recognition

Structural elements are key elements for understanding single-stranded nucleic acid folding. Although various RNA structural elements have been documented, structural elements of single-stranded DNA (ssDNA) have rarely been reported. Herein, we determined a crystal structure of PvLDH in complex with a DNA aptamer called pL1. This aptamer folds into a hairpin-bulge contact by adopting three novel structural elements, viz, DNA T-loop-like motif, base-phosphate zipper, and DNA G.G metal ion zipper. Moreover, the pL1: PvLDH complex shows unique properties compared with other protein: nucleic acid complexes. Generally, extensive intermolecular hydrogen bonds occur between unpaired nucleotides and proteins for specific recognitions. Although most protein-interacting nucleotides of pL1 are unpaired nucleotides, pL1 recognizes PvLDH by predominant shape complementarity with many bridging water molecules owing to the combination of three novel structural elements making protein-binding unpaired nucleotides stable. Moreover, the additional set of Plasmodium LDH residues which were shown to form extensive hydrogen bonds with unpaired nucleotides of 2008s does not participate in the recognition of pL1. Superimposition of the pL1: PvLDH complex with hLDH reveals steric clashes between pL1 and hLDH in contrast with no steric clashes between 2008s and hLDH. Therefore, specific protein recognition mode of pL1 is totally different from that of 2008s.1152Ysciescopu

On the Csorgo-Révész increments of finite dimensional Gaussian random fields

In this paper, we establish some limit theorems on the combined Csorgo-Révész increments with moduli of continuity for finite dimensional Gaussian random fields under mild conditions, via estimating upper bounds of large deviation probabilities on suprema of the finite dimensional Gaussian random fields.Csorgo-Révész increment; Gaussian process; random field; modulus of continuity; quasi-increasing; regularly varying function; large deviation probability.

Electrogenic transport and K(+) ion channel expression by the human endolymphatic sac epithelium.

The endolymphatic sac (ES) is a cystic organ that is a part of the inner ear and is connected to the cochlea and vestibule. The ES is thought to be involved in inner ear ion homeostasis and fluid volume regulation for the maintenance of hearing and balance function. Many ion channels, transporters, and exchangers have been identified in the ES luminal epithelium, mainly in animal studies, but there has been no functional study investigating ion transport using human ES tissue. We designed the first functional experiments on electrogenic transport in human ES and investigated the contribution of K(+) channels in the electrogenic transport, which has been rarely identified, even in animal studies, using electrophysiological/pharmacological and molecular biological methods. As a result, we identified functional and molecular evidence for the essential participation of K(+) channels in the electrogenic transport of human ES epithelium. The identified K(+) channels involved in the electrogenic transport were KCNN2, KCNJ14, KCNK2, and KCNK6, and the K(+) transports via those channels are thought to play an important role in the maintenance of the unique ionic milieu of the inner ear fluid

Growth of superconducting MgB2 thin films via postannealing techniques

We report the effect of annealing on the superconductivity of MgB2 thin films as functions of the postannealing temperature in the range from 700 C to 950 C and of the postannealing time in the range from 30 min to 120 min. On annealing at 900 C for 30 min, we obtained the best-quality MgB2 films with a transition temperature of 39 K and a critical current density of ~ 10^7 A/cm^2. Using the scanning electron microscopy, we also investigated the film growth mechanism. The samples annealed at higher temperatures showed the larger grain sizes, well-aligned crystal structures with preferential orientations along the c-axis, and smooth surface morphologies. However, a longer annealing time prevented the alignment of grains and reduced the superconductivity, indicating a strong interfacial reaction between the substrate and the MgB2 film.Comment: 7 pages, 4 figures include