8,154 research outputs found
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-RĂŠvĂŠsz increments of finite dimensional Gaussian random fields
In this paper, we establish some limit theorems on the combined Csorgo-RĂŠvĂŠsz 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-RĂŠvĂŠsz 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
The Singer's Formant and Speaker's Ring Resonance: A Long-Term Average Spectrum Analysis
ObjectivesWe previously showed that a trained tenor's voice has the conventional singer's formant at the region of 3 kHz and another energy peak at 8-9 kHz. Singers in other operatic voice ranges are assumed to have the same peak in their singing and speaking voice. However, to date, no specific measurement of this has been made.MethodsTenors, baritones, sopranos and mezzo sopranos were chosen to participate in this study of the singer's formant and the speaker's ring resonance. Untrained males (n=15) and females (n=15) were included in the control group. Each subject was asked to produce successive /a/ vowel sounds in their singing and speaking voice. For singing, the low pitch was produced in the chest register and the high notes in the head register. We collected the data on the long-term average spectra of the speaking and singing voices of the trained singers and the control groups.ResultsFor the sounds produced from the head register, a significant energy concentration was seen in both 2.2-3.4 kHz and 7.5-8.4 kHz regions (except for the voices of the mezzo sopranos) in the trained singer group when compared to the control groups. Also, the chest register had a significant energy concentration in the 4 trained singer groups at the 2.2-3.1 kHz and 7.8-8.4 kHz. For speaking sound, all trained singers had a significant energy concentration at 2.2-5.3 kHz and sopranos had another energy concentration at 9-10 kHz.ConclusionThe results of this study suggest that opera singers have more energy concentration in the singer's formant/speaker's ring region, in both singing and speaking voices. Furthermore, another region of energy concentration was identified in opera singer's singing sound and in sopranos' speaking sound at 8-9 kHz. The authors believe that these energy concentrations may contribute to the rich voice of trained singers
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