University of York

About: University of York is a education organization based out in York, York, United Kingdom. It is known for research contribution in the topics: Population & Health care. The organization has 22089 authors who have published 56925 publications receiving 2458285 citations. The organization is also known as: York University & Ebor..

Myogenic regulatory factors and the specification of muscle progenitors in vertebrate embryos.

Abstract: Embryological and genetic studies of mouse, bird, zebrafish, and frog embryos are providing new insights into the regulatory functions of the myogenic regulatory factors, MyoD, Myf5, Myogenin, and MRF4, and the transcriptional and signaling mechanisms that control their expression during the specification and differentiation of muscle progenitors. Myf5 and MyoD genes have genetically redundant, but developmentally distinct regulatory functions in the specification and the differentiation of somite and head muscle progenitor lineages. Myogenin and MRF4 have later functions in muscle differentiation, and Pax and Hox genes coordinate the migration and specification of somite progenitors at sites of hypaxial and limb muscle formation in the embryo body. Transcription enhancers that control Myf5 and MyoD activation in muscle progenitors and maintain their expression during muscle differentiation have been identified by transgenic analysis. In epaxial, hypaxial, limb, and head muscle progenitors, Myf5 is controlled by lineage-specific transcription enhancers, providing evidence that multiple mechanisms control progenitor specification at different sites of myogenesis in the embryo. Developmental signaling ligands and their signal transduction effectors function both interactively and independently to control Myf5 and MyoD activation in muscle progenitor lineages, likely through direct regulation of their transcription enhancers. Future investigations of the signaling and transcriptional mechanisms that control Myf5 and MyoD in the muscle progenitor lineages of different vertebrate embryos can be expected to provide a detailed understanding of the developmental and evolutionary mechanisms for anatomical muscles formation in vertebrates. This knowledge will be a foundation for development of stem cell therapies to repair diseased and damaged muscles.

Is preschool language impairment a risk factor for dyslexia in adolescence

Abstract: The literacy skills of 56 school leavers from the Bishop and Edmundson (1987) cohort of preschoolers with specific language impairment (SLI) were assessed at 15 years. The SLI group performed worse on tests of reading, spelling, and reading comprehension than age-matched controls and the literacy outcomes were particularly poor for those with Performance IQ less than 100. The rate of specific reading retardation in the SLI group had increased between the ages of 8 1/2 and 15 years and there had been a substantial drop in reading accuracy, relative to age. However, over 35% had reading skills within the normal range and those who had had isolated impairments of expressive phonology had a particularly good outcome. Our findings highlight the limitations of discrepancy definitions of dyslexia that do not take account of the changing demands of reading over time. We argue that children's phonological difficulties place them at risk of literacy failure at the outset of reading and that later, impairments of other language skills compromise development to adult levels of fluency.

Spectral equivalences, Bethe ansatz equations, and reality properties in PT-symmetric quantum mechanics.

Abstract: The one-dimensional Schrodinger equation for the potential x6 + αx2 + l(l + 1)/x2 has many interesting properties. For certain values of the parameters l and α the equation is in turn supersymmetric (Witten) and quasi-exactly solvable (Turbiner), and it also appears in Lipatov's approach to high-energy QCD. In this paper we signal some further curious features of these theories, namely novel spectral equivalences with particular second- and third-order differential equations. These relationships are obtained via a recently observed connection between the theories of ordinary differential equations and integrable models. Generalized supersymmetry transformations acting at the quasi-exactly solvable points are also pointed out, and an efficient numerical procedure for the study of these and related problems is described. Finally we generalize slightly and then prove a conjecture due to Bessis, Zinn-Justin, Bender and Boettcher, concerning the reality of the spectra of certain -symmetric quantum mechanical systems.

Crossing the border into borderline personality and borderline schizophrenia. The development of criteria.

Abstract: • Although there is a large psychiatric literature on various "borderline" conditions, there has been no agreement as to the definition of the concept. A review of the literature reviewed two major uses of the term: Borderline Schizophrenia and Borderline Personality. Two item sets were developed to provide diagnostic criteria for the two concepts. High sensitivity and specificity were demonstrated for both item sets using data describing 808 borderline and 808 control patients. These criteria will be used in the forthcoming DSM-III classification for the categories of Borderline Personality Disorder and Schizotypal Personality Disorder.

Semantic processing in the anterior temporal lobes: A meta-analysis of the functional neuroimaging literature

Abstract: The role of the anterior temporal lobes (ATLs) in semantic cognition is not clear from the current literature. Semantic dementia patients show a progressive and a specific semantic impairment, following bilateral atrophy of the ATLs. Neuroimaging studies of healthy participants, however, do not consistently show ATL activation during semantic tasks. Consequently, several influential theories of semantic memory do not ascribe a central role to the ATLs. We conducted a meta-analysis of 164 functional neuroimaging studies of semantic processing to investigate factors that might contribute to the inconsistency in previous results. Four factors influenced the likelihood of finding ATL activation: (1) the use of PET versus fMRI, reflecting the fact that fMRI but not PET is sensitive to distortion artifacts caused by large variations in magnetic susceptibility in the area of the ATL; (2) a field of view (FOV) of more than 15 cm, thereby ensuring whole-brain coverage; (3) the use of a high baseline task to prevent subtraction of otherwise uncontrolled semantic activation; (4) the inclusion of the ATL as an ROI. The type of stimuli or task did not influence the likelihood of ATL activation, consistent with the view that this region underpins an amodal semantic system. Spoken words, written words, and picture stimuli produced overlapping ATL peaks. On average, these were more inferior for picture-based tasks. We suggest that the specific pattern of ATL activation may be influenced by stimulus type due to variations across this region in the degree of connectivity with modality-specific areas in posterior temporal cortex.