24 research outputs found

    Complementary subicular pathways to the anterior thalamic nuclei and mammillary bodies in the rat and macaque monkey brain

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    The origins of the hippocampal (subicular) projections to the anterior thalamic nuclei and mammillary bodies were compared in rats and macaque monkeys using retrograde tracers. These projections form core components of the Papez circuit, which is vital for normal memory. The study revealed a complex pattern of subicular efferents, consistent with the presence of different, parallel information streams, whose segregation appears more marked in the rat brain. In both species, the cells projecting to the mammillary bodies and anterior thalamic nuclei showed laminar separation but also differed along other hippocampal axes. In the rat, these diencephalic inputs showed complementary topographies in the proximal–distal (columnar) plane, consistent with differential involvement in object-based (proximal subiculum) and context-based (distal subiculum) information. The medial mammillary inputs, which arose along the anterior–posterior extent of the rat subiculum, favoured the central subiculum (septal hippocampus) and the more proximal subiculum (temporal hippocampus). In contrast, anterior thalamic inputs were largely confined to the dorsal (i.e. septal and intermediate) subiculum, where projections to the anteromedial nucleus favoured the proximal subiculum while those to the anteroventral nucleus predominantly arose in the distal subiculum. In the macaque, the corresponding diencephalic inputs were again distinguished by anterior–posterior topographies, as subicular inputs to the medial mammillary bodies predominantly arose from the posterior hippocampus while subicular inputs to the anteromedial thalamic nucleus predominantly arose from the anterior hippocampus. Unlike the rat, there was no clear evidence of proximal–distal separation as all of these medial diencephalic projections preferentially arose from the more distal subiculum

    Linguistic features in children born very preterm at preschool age

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    6noAIM This cross-sectional study focused on the effect of very preterm (VPT) birth on language development by analysing phonological, lexical, grammatical, and pragmatic skills and assessing the role of cognitive and memory skills. METHOD Sixty children (29 males, 31 females) born VPT (<32wks) aged 5 years were compared with 60 children with typical development. The linguistic assessment was performed by administering a battery of Italian tests for the evaluation of language; cognitive and memory skills were assessed by Raven’s coloured progressive matrices and digit span subtest (Wechsler Intelligence Scale for Children [WISC-III]). RESULTS Children born VPT showed delays in lexical (comprehension: z-score difference 1.18; 95% confidence interval [CI] 1.60 to 0.77; naming: 0.88; 95% CI 1.19 to 0.58) and pragmatic skills (comprehension: 0.76; 95% CI 1.02 to 0.49; narrative production: 0.47; 95% CI 0.72 to 0.23). Delays in phonology and grammar were less diffuse, involving productive skills (1.09; 95% CI 1.64 to 0.54; 0.48; 95% CI 0.85 to 0.12, respectively), and were dependent by cognitive and memory skills. Lexical delays were more specific. INTERPRETATION The linguistic profile of children born preterm is characterized by some abilities more impaired than others. This highlights the need of a linguistic assessment at the end of preschool age in order to plan a focused intervention aimed at improving lexical and pragmatic skillsopenopenGuarini, Annalisa; Marini, Andrea; Savini, Silvia; Alessandroni, Rosina; Faldella, Giacomo; Sansavini, AlessandraGuarini, Annalisa; Marini, Andrea; Savini, Silvia; Alessandroni, Rosina; Faldella, Giacomo; Sansavini, Alessandr

    Proximity Discovery, Authentication and Link Establishment Between Mobile Devices in 3GPP LTE

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    The invention enables a device to discover one or more other devices within range for a device-to-device mode of communication. This proximity discovery may trigger a target device, e.g. to start listening to signals from a source device or perform any other action based on the proximity discovery like e.g. charging at a toll gate. A source device that wants to be discovered broadcasts a message including an identifier or a representation of the identifier. This identifier may be an identifier of the target device to be contacted or of the source device or a derivation thereof or a common security association used by a set of peers. The target device compares the broadcast identifier with a known identifier to establish proximity discovery

    Overexpression and topology of the Shigella flexneri O-antigen polymerase (Rfc/Wzy).

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    Lipopolysaccharides (LPS), particularly the O-antigen component, are one of many virulence determinants necessary for Shigella flexneri pathogenesis. O-antigen biosynthesis is determined mostly by genes located in the rfb region of the chromosome. The rfc/wzy gene encodes the O-antigen polymerase, an integral membrane protein, which polymerizes the O-antigen repeat units of the LPS. The wild-type rfc/wzy gene has no detectable ribosome-binding site (RBS) and four rare codons in the translation initiation region (TIR). Site-directed mutagenesis of the rare codons at positions 4, 9 and 23 to those corresponding to more abundant tRNAs and introduction of a RBS allowed detection of the rfc/wzy gene product via a T7 promoter/polymerase expression assay. Complementation studies using the rfc/wzy constructs allowed visualization of a novel LPS with unregulated O-antigen chain length distribution, and a modal chain length could be restored by supplying the gene for the O-antigen chain length regulator (Rol/Wzz) on a low-copy-number plasmid. This suggests that the O-antigen chain length distribution is determined by both Rfc/Wzy and Rol/Wzz proteins. The effect on translation of mutating the rare codons was determined using an Rfc::PhoA fusion protein as a reporter. Alkaline phosphatase enzyme assays showed an approximately twofold increase in expression when three of the rare codons were mutated. Analysis of the Rfc/Wzy amino acid sequence using TM-PREDICT indicated that Rfc/Wzy had 10-13 transmembrane segments. The computer prediction models were tested by genetically fusing C-terminal deletions of Rfc/Wzy to alkaline phosphatase and beta-galactosidase. Rfc::PhoA fusion proteins near the amino-terminal end were detected by Coomassie blue staining and Western blotting using anti-PhoA serum. The enzyme activities of cells with the rfc/wzy fusions and the location of the fusions in rfc/wzy indicated that Rfc/Wzy has 12 transmembrane segments with two large periplasmic domains, and that the amino- and carboxy-termini are located on the cytoplasmic face of the membrane
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