128 research outputs found

    Nuclear Schiff moment and soft vibrational modes

    Full text link
    The atomic electric dipole moment (EDM) currently searched by a number of experimental groups requires that both parity and time-reversal invariance be violated. According to current theoretical understanding, the EDM is induced by the nuclear Schiff moment. The enhancement of the Schiff moment by the combination of static quadrupole and octupole deformation was predicted earlier. Here we study a further idea of the possible enhancement in the absence of static deformation but in a nuclear system with soft collective vibrations of two types. Both analytical approximation and numerical solution of the simplified problem confirm the presence of the enhancement. We discuss related aspects of nuclear structure which should be studied beyond mean-field and random phase approximations.Comment: 14 pages, 4 figure

    Influence of Special Needs Education Policy on Access to Secondary School Education By Learners With Hearing Impairments In Nandi County, Kenya

    Get PDF
    This study sought to examine influence of Special Needs Education Policy on access to secondary school education by learners with hearing impairments in Nandi County, Kenya. The study was informed by the Multiple Intelligences theory and the Dewey theory of Progressivism. The findings showed that majority of the respondents were aware of the Special Needs Education Policy Framework of 2009 and believed that the policy was being implemented. Majority of the respondents felt that the implementation of the policy had positively affected learners’ enrolment in schools but recognized that there were still several challenges that were acting as barriers to school access by learners with hearing impairments in Nandi County. Further, the respondents observed that the implementation of the Special Needs Education Policy had led to a slight improvement on transition of learners with hearing impairments from primary to secondary schools in Nandi County. The influence of the Special Needs Education Policy on retention of learners with hearing impairments was deemed to be marginally small in schools in Nandi County. The results also showed that there were cases of learners dropping out of school because of a number of reasons including financial problems, lack of motivation to be in school and cultural factors, among others. In order to improve access to school education by learners with hearing impairments, respondents gave their opinions on how the challenges could be handled including the need to train more teachers to teach learners with hearing impairments, provision of adequate learning materials and the need to fund the special units/schools for the hearing impaired in the county, among others. The study recommends that the Government should set clear guidelines on how the Special Needs Education Policy can be implemented and coordinated. The study also recommends increase of necessary support for the secondary and primary school/units for the hearing impaired in the county so as to improve access to school education by children with hearing impairments. Keywords: special needs policy, hearing impairment, access to educatio

    Penta­carbon­yl{3-[(2S)-1-methyl­pyrrolidin-2-yl]pyridine}tungsten(0)

    Get PDF
    The title compound, [W(C10H14N2)(CO)5], contains five carbonyl ligands and a nicotine ligand in an octa­hedral arrangement around the tungsten atom. The metal atom shows cis angles in the range 87.30 (16)–94.2 (2)°, and trans angles between 175.2 (2) and 178.1 (4)°. The W—CO bond trans to the pyridine N atom [1.987 (6) Å] is noticeably shorter than the others, which range between 2.036 (3) and 2.064 (3) Å, possibly due to the well-known trans effect. The distance between the W atom and the pyridine N atom is 2.278 (4) Å

    Features of mammalian microRNA promoters emerge from polymerase II chromatin immunoprecipitation data

    Get PDF
    Background: MicroRNAs (miRNAs) are short, non-coding RNA regulators of protein coding genes. miRNAs play a very important role in diverse biological processes and various diseases. Many algorithms are able to predict miRNA genes and their targets, but their transcription regulation is still under investigation. It is generally believed that intragenic miRNAs (located in introns or exons of protein coding genes) are co-transcribed with their host genes and most intergenic miRNAs transcribed from their own RNA polymerase II (Pol II) promoter. However, the length of the primary transcripts and promoter organization is currently unknown. Methodology: We performed Pol II chromatin immunoprecipitation (ChIP)-chip using a custom array surrounding regions of known miRNA genes. To identify the true core transcription start sites of the miRNA genes we developed a new tool (CPPP). We showed that miRNA genes can be transcribed from promoters located several kilobases away and that their promoters share the same general features as those of protein coding genes. Finally, we found evidence that as many as 26% of the intragenic miRNAs may be transcribed from their own unique promoters. Conclusion: miRNA promoters have similar features to those of protein coding genes, but miRNA transcript organization is more complex. © 2009 Corcoran et al

    The HLA class II allele DRB1*1501 is over-represented in patients with idiopathic pulmonary fibrosis

    Get PDF
    Background: Idiopathic pulmonary fibrosis (IPF) is a progressive and medically refractory lung disease with a grim prognosis. Although the etiology of IPF remains perplexing, abnormal adaptive immune responses are evident in many afflicted patients. We hypothesized that perturbations of human leukocyte antigen (HLA) allele frequencies, which are often seen among patients with immunologic diseases, may also be present in IPF patients. Methods/Principal Findings: HLA alleles were determined in subpopulations of IPF and normal subjects using molecular typing methods. HLA-DRB1*15 was over-represented in a discovery cohort of 79 Caucasian IPF subjects who had lung transplantations at the University of Pittsburgh (36.7%) compared to normal reference populations. These findings were prospectively replicated in a validation cohort of 196 additional IPF subjects from four other U.S. medical centers that included both ambulatory patients and lung transplantation recipients. High-resolution typing was used to further define specific HLA-DRB1*15 alleles. DRB1*1501 prevalence in IPF subjects was similar among the 143 ambulatory patients and 132 transplant recipients (31.5% and 34.8%, respectively, p = 0.55). The aggregate prevalence of DRB1*1501 in IPF patients was significantly greater than among 285 healthy controls (33.1% vs. 20.0%, respectively, OR 2.0; 95%CI 1.3-2.9, p = 0.0004). IPF patients with DRB1*1501 (n = 91) tended to have decreased diffusing capacities for carbon monoxide (DLCO) compared to the 184 disease subjects who lacked this allele (37.8±1.7% vs. 42.8±1.4%, p = 0.036). Conclusions/Significance: DRB1*1501 is more prevalent among IPF patients than normal subjects, and may be associated with greater impairment of gas exchange. These data are novel evidence that immunogenetic processes can play a role in the susceptibility to and/or manifestations of IPF. Findings here of a disease association at the HLA-DR locus have broad pathogenic implications, illustrate a specific chromosomal area for incremental, targeted genomic study, and may identify a distinct clinical phenotype among patients with this enigmatic, morbid lung disease

    Super-Radiant Dynamics, Doorways, and Resonances in Nuclei and Other Open Mesoscopic Systems

    Full text link
    The phenomenon of super-radiance (Dicke effect, coherent spontaneous radiation by a gas of atoms coupled through the common radiation field) is well known in quantum optics. The review discusses similar physics that emerges in open and marginally stable quantum many-body systems. In the presence of open decay channels, the intrinsic states are coupled through the continuum. At sufficiently strong continuum coupling, the spectrum of resonances undergoes the restructuring with segregation of very broad super-radiant states and trapping of remaining long-lived compound states. The appropriate formalism describing this phenomenon is based on the Feshbach projection method and effective non-Hermitian Hamiltonian. A broader generalization is related to the idea of doorway states connecting quantum states of different structure. The method is explained in detail and the examples of applications are given to nuclear, atomic and particle physics. The interrelation of the collective dynamics through continuum and possible intrinsic many-body chaos is studied, including universal mesoscopic conductance fluctuations. The theory serves as a natural framework for general description of a quantum signal transmission through an open mesoscopic system.Comment: 85 pages, 10 figure

    Activism and Legitimation in Israel's Jurisprudence of Occupation

    Get PDF
    Colonial law need not exclude the colonized in order to subordinate them, and ‘activist’ courts can advance the effect of subordination no less than ‘passive’ courts. As a case study, this article examines the jurisprudential legacy of the Israeli Supreme Court in the context of the prolonged Israeli occupation of Palestine. Applying insights from legal realist, law and society, and critical legal studies scholarship, the article questions the utility of using the activist and passive labels. It illustrates how the Israeli activist court, through multiple legal and discursive moves, has advanced and legitimated the colonization of Palestine; that the court is aware of its role; and that arguments that focus on the court’s informal role do not mitigate this legitimating effect. Unlike other scholars, the article shows that the Israeli court’s role—by extending the power of judicial review to the military’s actions in the occupied areas—is neither novel nor unique or benevolent, as the British colonization of India and the US colonization of Puerto Rico show
    corecore