Numerical simulations of fluid-structure interactions in single-reed mouthpieces

Most single-reed woodwind instrument models rely on a quasistationary approximation to describe the relationship between the volume flow and. the pressure difference across the reed channel. Semiempirical models based on the quasistationary approximation are very useful in explaining the fundamental characteristics of this family of instruments such as self-sustained oscillations and threshold of blowing pressure. However, they fail at explaining more complex phenomena associated with the fluid-structure interaction during dynamic flow regimes, such as the transient and steady-state behavior of the system as a function. of the mouthpiece geometry. Previous studies have discussed the accuracy of the quasistationary approximation but the amount of literature on the subject is sparse, mainly due to the difficulties involved in the measurement of dynamic flows in channels with an oscillating reed. In this paper, a numerical technique based on the lattice Boltzmann method and a finite difference scheme is proposed in order to investigate the characteristics of fully coupled fluid-structure interaction in single-reed mouthpieces with different channel configurations. Results obtained for a stationary simulation with a static reed agree very well with those predicted by the literature based on the quasistationary approximation. However, simulations carried out for a dynamic regime with dn oscillating reed show that the phenomenon associated with flow detachment and reattachment diverges considerably frorn the theoretical assumptions. Furthermore, in the case of long reed channels, the results obtained for the vena contracta factor are in significant disagreement with those predicted by theory. For short channels, the assumption of constant vena contracta was found to be valid for only 40% of the duty cycle. (c) 2007 Acoustical Society of America.

Association analysis of proopiomelanocortin (POMC) haplotypes in type 1 diabetes in a UK population

Aim

To assess the association of POMC haplotype-tagged single nucleotide polymorphisms (htSNPs) with the development of type 1 diabetes (T1D) in a Caucasian population.

Methods

All exons, intron 1, and approximately 6-kb upstream and 3-kb downstream of the POMC gene were bidirectionally resequenced to identify DNA polymorphisms in 30 individuals. Allele frequencies were determined (60 chromosomes) and efficient htSNPs were selected using the htSNP2 programme. Genotyping was performed in 390 cases, 339 controls and 245 T1D parent-offspring trios, using Taqman, Sequenom and direct-sequencing technologies.

Results

Thirteen polymorphisms (two novel) with a minor allele frequency greater than 1% were identified. Six POMC htSNPs (rs3754863 G>A, ss161151662 A>G, rs3754860 C>T, rs1009388 G>C, rs3769671 A>C, rs1042571 G>A) were identified. Allele and haplotype frequencies were similar between case and control groups (P>0.60 by permutation test), and assessment of allele transmission distortion from informative parents to affected offspring also failed to find any association. Stratification of these analyses for age-at-onset and HLA-DR risk group (DR3/DR4) revealed no significant associations. A haplotype block of 9.86-kb from rs3754863 to rs1042571 was identified, encompassing the POMC gene. Comparison of haplotype frequencies identified the GGCGAG haplotype as protective against T1D in 12.9% of cases vs. 18.3% of controls: ?2=8.18, Pc=0.03 by permutation test.

Conclusion

The POMC SNP haplotype GGCGAG may have a protective effect against T1D in the UK population. However, this finding needs to be replicated, and the cellular and molecular processes influenced by this POMC haplotype determined to fully appreciate its impact.

A single microphone capillary-based system for measuring the complex input impedance of musical wind instruments

Capillary-based systems for measuring the input impedance of musical wind instruments were first developed in the mid-20th century and remain in widespread use today. In this paper, the basic principles and assumptions underpinning the design of such systems are examined. Inexpensive modifications to a capillary-based impedance measurement set-up made possible due to advances in computing and data acquisition technology are discussed. The modified set-up is able to measure both impedance magnitude and impedance phase even though it only contains one microphone. In addition, a method of calibration is described that results in a significant improvement in accuracy when measuring high impedance objects on the modified capillary-based system. The method involves carrying out calibration measurements on two different objects whose impedances are well-known theoretically. The benefits of performing two calibration measurements (as opposed to the one calibration measurement that has been traditionally used) are demonstrated experimentally through input impedance measurements on two test objects and a Boosey and Hawkes oboe. © S. Hirzel Verlag · EAA.

Design, recruitment, logistics, and data management of the GEHA (Genetics of Healthy Ageing) project

In 2004, the integrated European project GEHA (Genetics of Healthy Ageing) was initiated with the aim of identifying genes involved in healthy ageing and longevity. The first step in the project was the recruitment of more than 2500 pairs of siblings aged 90 years or more together with one younger control person from 15 areas in 11 European countries through a coordinated and standardised effort. A biological sample, preferably a blood sample, was collected from each participant, and basic physical and cognitive measures were obtained together with information about health, life style, and family composition. From 2004 to 2008 a total of 2535 families comprising 5319 nonagenarian siblings were identified and included in the project. In addition, 2548 younger control persons aged 50-75 years were recruited. A total of 2249 complete trios with blood samples from at least two old siblings and the younger control were formed and are available for genetic analyses (e.g. linkage studies and genome-wide association studies). Mortality follow-up improves the possibility of identifying families with the most extreme longevity phenotypes. With a mean follow-up time of 3.7 years the number of families with all participating siblings aged 95 years or more has increased by a factor of 5 to 750 families compared to when interviews were conducted. Thus, the GEHA project represents a unique source in the search for genes related to healthy ageing and longevity.

Dark Mission

Composition for bass clarinet and computer

Genome-wide association analysis identifies 13 new risk loci for schizophrenia

Schizophrenia is an idiopathic mental disorder with a heritable component and a substantial public health impact. We conducted a multi-stage genome-wide association study (GWAS) for schizophrenia beginning with a Swedish national sample (5,001 cases and 6,243 controls) followed by meta-analysis with previous schizophrenia GWAS (8,832 cases and 12,067 controls) and finally by replication of SNPs in 168 genomic regions in independent samples (7,413 cases, 19,762 controls and 581 parent-offspring trios). We identified 22 loci associated at genome-wide significance; 13 of these are new, and 1 was previously implicated in bipolar disorder. Examination of candidate genes at these loci suggests the involvement of neuronal calcium signaling. We estimate that 8,300 independent, mostly common SNPs (95% credible interval of 6,300-10,200 SNPs) contribute to risk for schizophrenia and that these collectively account for at least 32% of the variance in liability. Common genetic variation has an important role in the etiology of schizophrenia, and larger studies will allow more detailed understanding of this disorder.

A Hamiltonian approach to simulation of acoustic systems involving nonlinear interactions

Nonlinear interactions take place in most systems that arise in music acoustics, usually as a result of player-instrument coupling. Several time-stepping methods exist for the numerical simulation of such systems. These methods generally involve the discretization of the Newtonian description of the system. However, it is not always possible to prove the stability of the resulting algorithms, especially when dealing with systems where the underlying force is a non-analytic function of the phase space variables. On the other hand, if the discretization is carried out on the Hamiltonian description of the system, it is possible to prove the stability of the derived numerical schemes. This Hamiltonian approach is applied to a series of test models of single or multiple nonlinear collisions and the energetic properties of the derived schemes are discussed. After establishing that the schemes respect the principle of conservation of energy, a nonlinear single-reed model is formulated and coupled to a digital bore, in order to synthesize clarinet-like sounds.

Do Nonagenarians siblings provide mutual support? Insights from the EU GeHA project

Introduction.– Sibling relationships have been described as intimate,
congenial, loyal, apathetic or hostile but little is known about
sibling relationships in very old age.Weasked nonagenarian brothers
and sisters from the EU-funded Genetics of Healthy Ageing
(GeHA) project whether they had felt supported by having a living
sibling to have better coping abilities.
Methods and results.– Nonagenarian siblings were a convenience
sample from four countries from the GeHA study–Italy, Poland,
N Ireland, Finland. All were consented willing participants. Most
male/female dyads demonstrated healthy respect for each other’s
opinion and their sibling relationship fits the “loyal” type, though
with a clear sense of independence.Noneof the eight female/female
nor the one male/male dyad seemed to fit the “intimate” description;
two might be described as “apathetic”, while the other two
seemed to show aspects of family “loyalty”, alongside other traits
perhaps best described as “congenial”. There were apparent different
cultural influences across Europe with siblings in Italy and
Poland more likely to report supportive siblinghood, compared to
sibling pairs/trios in Finland or N Ireland where self-resilience and
independence seemed more common. Polish and Italian nonagenarians
often felt supported by their religious faith and church.
Conclusions.– In general, nonagenarian siblings most often demonstrated
loyal family relationships, which may have helped each
other’s coping and survival mechanisms. However, there was
widespread evidence of tolerance for individual decision-making.
Perhaps rather, these 90-year-olds survive because they are
resilient and independent and don’t need to depend on each other!

Factors influencing success of clinical genome sequencing across a broad spectrum of disorders

To assess factors influencing the success of whole-genome sequencing for mainstream clinical diagnosis, we sequenced 217 individuals from 156 independent cases or families across a broad spectrum of disorders in whom previous screening had identified no pathogenic variants. We quantified the number of candidate variants identified using different strategies for variant calling, filtering, annotation and prioritization. We found that jointly calling variants across samples, filtering against both local and external databases, deploying multiple annotation tools and using familial transmission above biological plausibility contributed to accuracy. Overall, we identified disease-causing variants in 21% of cases, with the proportion increasing to 34% (23/68) for mendelian disorders and 57% (8/14) in family trios. We also discovered 32 potentially clinically actionable variants in 18 genes unrelated to the referral disorder, although only 4 were ultimately considered reportable. Our results demonstrate the value of genome sequencing for routine clinical diagnosis but also highlight many outstanding challenges.

Fictions

Work in three movements for chamber ensemble of flute (d piccolo, alto flute), clarinet (d bass clarinet), violin, cello, piano written for Stony Brook Contemporary Music Players, Stony Brook University NY USA

"No Encores" The Royal Dublin Society Concert Archive Recitals in Retrospect: 1925-50

A large archive of sources for the RDS classical music recitals is extant in the Society’s Library, Ballsbridge, Dublin. The recitals were established in 1886 for the promotion of chamber music and in order to expose Dublin audiences to the works of the great composers. Extant in the collection are minute books; autographed programmes; newspaper cuttings which include previews, reviews and advertisements; correspondences with artists and agents; promotional material; selections of photographs; records of attendance, artists fees and takings; and volumes of printed music.
This paper will document the organisation, management and occurrence of the RDS classical music recitals for the period 1925 to 1950 and will encompass the opening of the current concert hall (The Members’ Hall, 1925), the Society’s bi-centenary celebrations (1931) and the continuance of the recitals within the context of the Second World War (1939- 45). The paper will examine and analyse the following: networks, repertoire and reception.
The RDS music committee established significant links with many performers and UK-based classical music agents. Recitalists include musicians of international renown; Myra Hess, Isolde Menges, Lili Kraus, Joseph Szigeti, Leon Goossens, Sir Hamilton Harty and The Hallé Orchestra, The Catterall Quartet and many local, Dublin-based musicians; Raidió Éireann Orchestra, Dublin String Orchestra, Dublin Philharmonic Orchestra and Culwick Choral Society. The compromises and collaborations in evidence between the music committee, agents and performers resulted in the presentation of varied and well-balanced programmes featuring sonatas, quartets, trios, concerti, overtures, symphonies and songs by composers including Beethoven, Mozart, Haydn and Brahms. Works by contemporary composers including Bax, Dohnanyi, Szymanowski and Suk were also regularly performed, as were works with an Irish influence or flavour. Audiences mainly consisted of members of the Society, music students were encouraged to attend at a reduced rate and reviews were regularly published in the Irish Times, Irish Independent and Irish Press.