GLORIA

GEOMAR Library Ocean Research Information Access

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Online-Ressource
    Online-Ressource
    Society for Neuroscience ; 2010
    In:  The Journal of Neuroscience Vol. 30, No. 38 ( 2010-09-22), p. 12777-12786
    In: The Journal of Neuroscience, Society for Neuroscience, Vol. 30, No. 38 ( 2010-09-22), p. 12777-12786
    Kurzfassung: Mutations in cyclin-dependent kinase-like 5 ( CDKL5 ), also known as serine/threonine kinase 9 ( STK9 ), have been identified in patients with Rett syndrome (RTT) and X-linked infantile spasm. However, the function of CDKL5 in the brain remains unknown. Here, we report that CDKL5 is a critical regulator of neuronal morphogenesis. We identified a neuron-specific splicing variant of CDKL5 whose expression was markedly induced during postnatal development of the rat brain. Downregulating CDKL5 by RNA interference (RNAi) in cultured cortical neurons inhibited neurite growth and dendritic arborization, whereas overexpressing CDKL5 had opposite effects. Furthermore, knocking down CDKL5 in the rat brain by in utero electroporation resulted in delayed neuronal migration, and severely impaired dendritic arborization. In contrast to its proposed function in the nucleus, we found that CDKL5 regulated dendrite development through a cytoplasmic mechanism. In fibroblasts and in neurons, CDKL5 colocalized and formed a protein complex with Rac1, a critical regulator of actin remodeling and neuronal morphogenesis. Overexpression of Rac1 prevented the inhibition of dendrite growth caused by CDKL5 knockdown, and the growth-promoting effect of ectopically expressed CDKL5 on dendrites was abolished by coexpressing a dominant-negative form of Rac1. Moreover, CDKL5 was required for brain-derived neurotrophic factor (BDNF)-induced activation of Rac1. Together, these results demonstrate a critical role of CDKL5 in neuronal morphogenesis and identify a Rho GTPase signaling pathway which may contribute to CDKL5-related disorders.
    Materialart: Online-Ressource
    ISSN: 0270-6474 , 1529-2401
    Sprache: Englisch
    Verlag: Society for Neuroscience
    Publikationsdatum: 2010
    ZDB Id: 1475274-8
    SSG: 12
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Online-Ressource
    Online-Ressource
    Proceedings of the National Academy of Sciences ; 2023
    In:  Proceedings of the National Academy of Sciences Vol. 120, No. 8 ( 2023-02-21)
    In: Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 120, No. 8 ( 2023-02-21)
    Kurzfassung: Microchromosomes are prevalent in nonmammalian vertebrates [P. D. Waters et al. , Proc. Natl. Acad. Sci. U.S.A. 118 (2021)], but a few of them are missing in bird genome assemblies. Here, we present a new chicken reference genome containing all autosomes, a Z and a W chromosome, with all gaps closed except for the W. We identified ten small microchromosomes (termed dot chromosomes) with distinct sequence and epigenetic features, among which six were newly assembled. Those dot chromosomes exhibit extremely high GC content and a high level of DNA methylation and are enriched for housekeeping genes. The pericentromeric heterochromatin of dot chromosomes is disproportionately large and continues to expand with the proliferation of satellite DNA and testis-expressed genes. Our analyses revealed that the 41-bp CNM repeat frequently forms higher-order repeats (HORs) at the centromeres of acrocentric chromosomes. The centromere core regions where the kinetochore attaches often encompass telomeric sequence (TTAGGG)n, and in a one of the dot chromosomes, the centromere core recruits an endogenous retrovirus (ERV). We further demonstrate that the W chromosome shares some common features with dot chromosomes, having large arrays of hypermethylated tandem repeats. Finally, using the complete chicken chromosome models, we reconstructed a fine picture of chordate karyotype evolution, revealing frequent chromosomal fusions before and after vertebrate whole-genome duplications. Our sequence and epigenetic characterization of chicken chromosomes shed insights into the understanding of vertebrate genome evolution and chromosome biology.
    Materialart: Online-Ressource
    ISSN: 0027-8424 , 1091-6490
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: Proceedings of the National Academy of Sciences
    Publikationsdatum: 2023
    ZDB Id: 209104-5
    ZDB Id: 1461794-8
    SSG: 11
    SSG: 12
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Online-Ressource
    Online-Ressource
    Proceedings of the National Academy of Sciences ; 2013
    In:  Proceedings of the National Academy of Sciences Vol. 110, No. 47 ( 2013-11-19), p. 19131-19136
    In: Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 110, No. 47 ( 2013-11-19), p. 19131-19136
    Kurzfassung: Opitz syndrome (OS) is a genetic neurological disorder. The gene responsible for the X-linked form of OS, Midline-1 ( MID1 ), encodes an E3 ubiquitin ligase that regulates the degradation of the catalytic subunit of protein phosphatase 2A (PP2Ac). However, how Mid1 functions during neural development is largely unknown. In this study, we provide data from in vitro and in vivo experiments suggesting that silencing Mid1 in developing neurons promotes axon growth and branch formation, resulting in a disruption of callosal axon projections in the contralateral cortex. In addition, a similar phenotype of axonal development was observed in the Mid1 knockout mouse. This defect was largely due to the accumulation of PP2Ac in Mid1-depleted cells as further down-regulation of PP2Ac rescued the axonal phenotype. Together, these data demonstrate that Mid1-dependent PP2Ac turnover is important for normal axonal development and that dysregulation of this process may contribute to the underlying cause of OS.
    Materialart: Online-Ressource
    ISSN: 0027-8424 , 1091-6490
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: Proceedings of the National Academy of Sciences
    Publikationsdatum: 2013
    ZDB Id: 209104-5
    ZDB Id: 1461794-8
    SSG: 11
    SSG: 12
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Online-Ressource
    Online-Ressource
    Informa UK Limited ; 2017
    In:  International Journal of Speech-Language Pathology Vol. 19, No. 2 ( 2017-03-04), p. 153-164
    In: International Journal of Speech-Language Pathology, Informa UK Limited, Vol. 19, No. 2 ( 2017-03-04), p. 153-164
    Materialart: Online-Ressource
    ISSN: 1754-9507 , 1754-9515
    Sprache: Englisch
    Verlag: Informa UK Limited
    Publikationsdatum: 2017
    ZDB Id: 2406625-4
    SSG: 7,11
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2015
    In:  The Journal of the Acoustical Society of America Vol. 138, No. 5 ( 2015-11-01), p. 2791-2799
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 138, No. 5 ( 2015-11-01), p. 2791-2799
    Kurzfassung: The present study examined the acoustic features of vowel production in Mandarin-speaking children with cochlear implants (CIs). The subjects included 14 native Mandarin-speaking, prelingually deafened children with CIs (2.9–8.3 yr old) and 60 age-matched, normal-hearing (NH) children (3.1–9.0 years old). Each subject produced a list of monosyllables containing seven Mandarin vowels: [i, a, u, y, ɤ, ʅ, ɿ]. Midpoint F1 and F2 of each vowel token were extracted and normalized to eliminate the effects of different vocal tract sizes. Results showed that the CI children produced significantly longer vowels and less compact vowel categories than the NH children did. The CI children's acoustic vowel space was reduced due to a retracted production of the vowel [i] . The vowel space area showed a strong negative correlation with age at implantation (r = −0.80). The analysis of acoustic distance showed that the CI children produced corner vowels [a, u] similarly to the NH children, but other vowels (e.g., [ʅ, ɿ] ) differently from the NH children, which suggests that CI children generally follow a similar developmental path of vowel acquisition as NH children. These findings highlight the importance of early implantation and have implications in clinical aural habilitation in young children with CIs.
    Materialart: Online-Ressource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2015
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2023
    In:  The Journal of the Acoustical Society of America Vol. 153, No. 3_supplement ( 2023-03-01), p. A340-A340
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 153, No. 3_supplement ( 2023-03-01), p. A340-A340
    Kurzfassung: There are abundant acoustic-phonetic cues in speech signals for listeners to encode talker identity. However, speech signals in the real world are always less optimal due to various adverse listening sources. Vocoded speech is one type of simplified signal that has less spectral and/or temporal information in comparison to normal speech. The purpose of this study is to examine whether and how listeners’ judgment of talker accent is affected by noise and tone vocoding. Twelve Mandarin-accented English speakers with varying degree of accentedness and two native English speakers were recorded reading “The Rainbow Passage.” The recorded speech samples from each talker were segmented into small sections that were randomly selected for noise- or tone-excited vocoder processing into 1, 2, 4, 8, and 16 channels. The vocoded and unprocessed speech samples were randomly presented to a group of normal-hearing, monolingual English listeners for accent rating. The listeners judged the degree of talker accent on a 9-point Likert scale with “1” representing no accent and “9” representing extremely strong accent. The data are still in the process of being collected and analyzed. Results and implications of the present study will be discussed.
    Materialart: Online-Ressource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2023
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2017
    In:  The Journal of the Acoustical Society of America Vol. 142, No. 4_Supplement ( 2017-10-01), p. 2640-2640
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 142, No. 4_Supplement ( 2017-10-01), p. 2640-2640
    Kurzfassung: This study investigated the acoustic features of vowel production in Mandarin-speaking patients with post-stroke spastic dysarthria. The subjects included 31 native Mandarin-speaking patients with post-stroke spastic dysarthria (age: 33–73 years old) and 40 normal adults in a similar age range (age: 22–68 years old). Each subject were recorded producing a list of 28 Mandarin monosyllables that composed of six monophthong vowels (i.e., /a, o, ɣ, i, u, y/) embedded in the /CV/ context. The patients’ speech samples were evaluated by two native Mandarin speakers. The evaluation scores were then used to classify each patient into one of the two categories: mild or moderate-to-severe severity. Midpoint F1 and F2 of each vowel token were extracted and normalized. Results showed no significant differences between the patients and normal speakers on vowel duration. However, the vowel categories in the patients were more scattered and greatly overlapped than in the normal speakers. The magnitude of the vowel dispersion and overlap increased as a function of the severity of the disorder. The deviations of the vowel acoustic features in the patients from the normal speakers may provide guidance for clinical rehabilitation to improve the speech intelligibility of this type of patients.
    Materialart: Online-Ressource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2017
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2023
    In:  The Journal of the Acoustical Society of America Vol. 153, No. 6 ( 2023-06-01), p. 3501-3512
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 153, No. 6 ( 2023-06-01), p. 3501-3512
    Kurzfassung: The purpose of the study was to examine the acoustic features of sibilant fricatives and affricates produced by prelingually deafened Mandarin-speaking children with cochlear implants (CIs) in comparison to their age-matched normal-hearing (NH) peers. The speakers included 21 children with NH aged between 3.25 and 10 years old and 35 children with CIs aged between 3.77 and 15 years old who were assigned into chronological-age-matched and hearing-age-matched subgroups. All speakers were recorded producing Mandarin words containing nine sibilant fricatives and affricates (/s, ɕ, ʂ, ts, tsʰ, tɕ, tɕʰ, tʂ, tʂʰ/) located at the word-initial position. Acoustic analysis was conducted to examine consonant duration, normalized amplitude, rise time, and spectral peak. The results revealed that the CI children, regardless of whether chronological-age-matched or hearing-age-matched, approximated the NH peers in the features of duration, amplitude, and rise time. However, the spectral peaks of the alveolar and alveolopalatal sounds in the CI children were significantly lower than in the NH children. The lower spectral peaks of the alveolar and alveolopalatal sounds resulted in less distinctive place contrast with the retroflex sounds in the CI children than in the NH peers, which might partially account for the lower intelligibility of high-frequency consonants in children with CIs.
    Materialart: Online-Ressource
    ISSN: 0001-4966
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2023
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Online-Ressource
    Online-Ressource
    American Speech Language Hearing Association ; 2021
    In:  Journal of Speech, Language, and Hearing Research Vol. 64, No. 2 ( 2021-02-17), p. 664-682
    In: Journal of Speech, Language, and Hearing Research, American Speech Language Hearing Association, Vol. 64, No. 2 ( 2021-02-17), p. 664-682
    Kurzfassung: The purpose of this study was to characterize the acoustic profile and to evaluate the intelligibility of vowel productions in prelingually deafened, Mandarin-speaking children with cochlear implants (CIs). Method Twenty-five children with CIs and 20 age-matched children with normal hearing (NH) were recorded producing a list of Mandarin disyllabic and trisyllabic words containing 20 Mandarin vowels [a, i, u, y, ɤ, ɿ, ʅ, ai, ei, ia, ie, ye, ua, uo, au, ou, iau, iou, uai, uei] located in the first consonant–vowel syllable. The children with CIs were all prelingually deafened and received unilateral implantation before 7 years of age with an average length of CI use of 4.54 years. In the acoustic analysis, the first two formants (F1 and F2) were extracted at seven equidistant time locations for the tested vowels. The durational and spectral features were compared between the CI and NH groups. In the vowel intelligibility task, the extracted vowel portions in both NH and CI children were presented to six Mandarin-speaking, NH adult listeners for identification. Results The acoustic analysis revealed that the children with CIs deviated from the NH controls in the acoustic features for both single vowels and compound vowels. The acoustic deviations were reflected in longer duration, more scattered vowel categories, smaller vowel space area, and distinct formant trajectories in the children with CIs in comparison to NH controls. The vowel intelligibility results showed that the recognition accuracy of the vowels produced by the children with CIs was significantly lower than that of the NH children. The confusion pattern of vowel recognition in the children with CIs generally followed that in the NH children. Conclusion Our data suggested that the prelingually deafened children with CIs, with a relatively long duration of CI experience, still showed measurable acoustic deviations and lower intelligibility in vowel productions in comparison to the NH children.
    Materialart: Online-Ressource
    ISSN: 1092-4388 , 1558-9102
    Sprache: Englisch
    Verlag: American Speech Language Hearing Association
    Publikationsdatum: 2021
    ZDB Id: 2070420-3
    SSG: 5,2
    SSG: 7,11
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2017
    In:  The Journal of the Acoustical Society of America Vol. 142, No. 4_Supplement ( 2017-10-01), p. 2610-2610
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 142, No. 4_Supplement ( 2017-10-01), p. 2610-2610
    Kurzfassung: The aim of the present study is to evaluate the effects of nonlinear frequency compression (NLFC) on Mandarin speech recognition and sound quality perception. Thirty Chinese-speaking, hearing-impaired adults without hearing-aid experiences participated in the study. They were fitted bilaterally with the Phonak behind-the-ear hearing aids. Each participant was evaluated with the Phoneme Perception Test, Mandarin speech recognition, and sound quality perception at post-fitting 0, 4, and 12 weeks with NLFC-on vs. NLFC-off. The NLFC were active at home. Results show significant differences in detection of phonemes of high-frequency components (such as /sa/) between NLFC on and off. The difference between NLFC on and off was significant for consonant and sentence recognition. Duration of NLFC use had significant effects on the recognition of consonants, vowels, and sentences. Regarding the sound quality perception test, there were significant effects of NLFC conditions (on vs. off), duration of NLFC use, and sound types on the four categories of percepts (i.e., loudness, clarity, naturalness, and overall preference). Therefore, NLFC improves the audibility of high-frequency speech signals and provides better recognition of consonants and sentences and perception of sound quality. The benefit of NLFC on speech recognition and sound quality perception requires certain amount of acclimatization.
    Materialart: Online-Ressource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2017
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...