Dosage compensation in birds

AbstractThe Z and W sex chromosomes of birds have evolved independently from the mammalian X and Y chromosomes [1]. Unlike mammals, female birds are heterogametic (ZW), while males are homogametic (ZZ). Therefore male birds, like female mammals, carry a double dose of sex-linked genes relative to the other sex. Other animals with nonhomologous sex chromosomes possess “dosage compensation” systems to equalize the expression of sex-linked genes. Dosage compensation occurs in animals as diverse as mammals, insects, and nematodes, although the mechanisms involved differ profoundly [2]. In birds, however, it is widely accepted that dosage compensation does not occur [3–5], and the differential expression of Z-linked genes has been suggested to underlie the avian sex-determination mechanism [6]. Here we show equivalent expression of at least six of nine Z chromosome genes in male and female chick embryos by using real-time quantitative PCR [7]. Only the Z-linked ScII gene, whose ortholog in Caenorhabditis elegans plays a crucial role in dosage compensation [8], escapes compensation by this assay. Our results imply that the majority of Z-linked genes in the chicken are dosage compensated

Can the adoption of informal approaches to learning music in school music lessons promote musical progression?

The aim of this research was to explore the impact of the adoption of the Musical Futures approach on the musical progression of students in Musical Futures’ Champion schools. The research took place over three years in three phases with 733 students and 28 music teachers completing questionnaires. Data from the interviews with 39 staff and focus groups of 325 students provided greater insights into the questionnaire responses. Overall, teachers reported that Musical Futures had enhanced the musical progression of their students and increased take up at Key Stage 4. In some cases this had led to changes in the qualifications on offer with an emphasis on those which were vocational rather than academic. This created some tensions in catering for the needs of different groups of students who had a range of different musical skills

The perceptions of non music staff and senior management of the impact of the implementation of the Musical Futures approach on the whole school

This research aimed to provide an account of the impact of the Musical Futures approach on the wider school community in Musical Futures ‘Champion Schools’. Questionnaires were completed by 344 non-music teachers. Interviews were undertaken with members of senior management teams. The majority of staff indicated that Musical Futures had had a positive impact on student motivation, well-being, self-esteem and confidence and had encouraged students to work together. There was less agreement that it had improved student concentration, organisation and students’ attitudes towards learning and academic progression. The interviews provided deeper insights into the issues relating to implementation

What impact does teaching music informally in the classroom have on teachers, and their pedagogy?

The aim of this research was to explore the impact of the adoption of the Musical Futures (MF) approach on secondary school music teachers working in MF Champion schools. The research took place over 3 years in 3 phases with 28 teachers completing questionnaires exploring the impact on their confidence, skills and pedagogy and 30 being interviewed individually. Data from the interviews provided greater insights into the questionnaire responses. Most teachers reported that MF had helped them to become a more effective teacher, more confident in teaching music and had increased their enjoyment. MF changed the nature of teaching and learning with a more student-led approach being adopted. Managing this workshop approach on a daily basis, for some teachers, was exhausting and stressful. Overall, the adoption of the MF approach had a wide range of benefits for teachers but there were issues relating to the logistics of managing small group work

Teachers’ perceptions of the impact on students of the Musical Futures approach

Music education has faced considerable challenges in trying to bridge the gap between music in young people's lives and that taking place in the classroom. The ‘Musical Futures’ (MF) initiative aimed to devise new and imaginative ways of engaging young people, aged 11–19, in music activities through a process of informal learning based on popular music. This research aimed to explore teachers’ perceptions of the impact of adopting the MF approach on students’ learning and attainment. Twenty-eight music teachers completed questionnaires and 30 were interviewed. The majority of music staff agreed that since doing MF, students demonstrated higher levels of attainment, greater enjoyment of and positive attitudes towards music lessons, enhanced musical and performance skills, team working, concentration, confidence, listening skills, musical understanding and independent learning

Orbital Selective Magnetism in the Spin-Ladder Iron Selenides Ba1−x_{1-x}Kx_{x}Fe2_2Se3_3

Here we show that the 2.80(8) {\mu}B/Fe block antiferromagnetic order of BaFe2Se3 transforms into stripe antiferromagnetic order in KFe2Se3 with a decrease in moment to 2.1(1) {\mu}B/Fe. This reduction is larger than expected from the change in electron count from Ba$^{2+}$ to K$^{+}$, and occurs with the loss of the displacements of Fe atoms from ideal positions in the ladders, as found by neutron pair distribution function analysis. Intermediate compositions remain insulating, and magnetic susceptibility measurements show a suppression of magnetic order and probable formation of a spin-glass. Together, these results imply an orbital-dependent selection of magnetic versus bonded behavior, driven by relative bandwidths and fillings.Comment: Final versio

Pupils' perceptions of informal learning in school music lessons

Music education has faced considerable challenges in trying to bridge the gap between music in young people’s lives and that taking place in the classroom. The ‘Musical Futures’ initiative aimed to devise new and imaginative ways of engaging young people, aged 11–19, in music activities through a process of informal learning based initially on popular music. This research aimed to explore pupils’ perceptions of the impact of adopting the Musical Futures approach on students’ learning and attainment. 671 students completed a questionnaire and 171 participated in focus group interviews to establish their perceptions of informal learning. The findings showed that the adoption of the Musical Futures approach enhanced student interest and confidence and increased their musical skills. Students appreciated the control that they had over their learning but some raised issues about working in groups and the level of support that teachers were able to offer

Teachers' and students' music preferences for secondary school music lessons: reasons and implications

This paper is based on the data collected from a longitudinal study of seven maintained, secondary schools in England that have adopted Musical Futures as an approach to teaching music. The research had a particular focus on key stage 3 (11–14). For the purposes of this paper, data gained from 18 music staff and 325 student interview transcriptions were reviewed to answer research questions about the music preferences of teachers and students in the context of school music lessons. The data indicated that when teachers chose music they were particularly conscious of difficulty whereas student choices, when permitted, were based solely on liking. Teachers’ choices were often informed by inclusion and feasibility. The music students enjoyed depended on how it was incorporated into the lesson rather than purely on style. Some implications of how music is categorised and chosen are discussed

Tuning the Charge Density Wave and Superconductivity in CuxTaS2

We report the characterization of layered, 2H-type CuxTaS2, for x between 0 and 0.12. The charge density wave (CDW), at 70 K for TaS2, is destabilized with Cu doping. The sub-1K superconducting transition in undoped 2H-TaS2 jumps quickly to 2.5 K at low x, increases to 4.5 K at the optimal composition Cu0.04TaS2, and then decreases at higher x. The electronic contribution to the specific heat, first increasing and then decreasing as a function of Cu content, is 12 mJ mol-1 K-2 at Cu0.04TaS2. Electron diffraction studies show that the CDW remains present at the optimal superconducting composition, but with both a changed q vector and decreased coherence length. We present an electronic phase diagram for the system.Comment: 7 pages, 9 figures. To be published in Physical Review

Disorder from order among anisotropic next-nearest-neighbor Ising spin chains in SrHo2_2O4_4

We describe why Ising spin chains with competing interactions in $\rm SrHo_2O_4$ segregate into ordered and disordered ensembles at low temperatures ($T$). Using elastic neutron scattering, magnetization, and specific heat measurements, the two distinct spin chains are inferred to have N\'eel ($\uparrow\downarrow\uparrow\downarrow$) and double-N\'eel ($\uparrow\uparrow\downarrow\downarrow$) ground states respectively. Below $T_\mathrm{N}=0.68(2)$~K, the N\'eel chains develop three dimensional (3D) long range order (LRO), which arrests further thermal equilibration of the double-N\'eel chains so they remain in a disordered incommensurate state for $T$ below $T_\mathrm{S}= 0.52(2)$~K. $\rm SrHo_2O_4$ distills an important feature of incommensurate low dimensional magnetism: kinetically trapped topological defects in a quasi$-d-$dimensional spin system can preclude order in $d+1$ dimensions.Comment: 10 pages, 10 figure