2,999 research outputs found
Instrumental trouble: a queer organology of Hugh Daviesâs found instruments
Organology, the study of musical instruments, has traditionally concentrated on the documentation of instruments: their history, roles in culture, and classification. However, as post-modern, feminist, and post-colonial perspectives have questioned some of the assumptions inherent in historiographical, ethnographic, and positivist endeavours because of their part in reproducing hegemonic ideologies, re-thinking organology and thus developing a richer account of musical instruments has become an urgent task. With this regard a queer perspective in organology, in particular informed by Judith Butlerâs theories of âgender trouble,â is crucial in agitating normative beliefs, values, and attitudes that underpin notions of instrumental identity, interaction, and meaning. A queer organology becomes especially significant in the critical engagement with musical instruments like those invented by the British composer, performer, and inventor Hugh Davies (1943-2005), and in particular his entirely found, amplified, new musical instruments. This is because the challenges to traditional instrumental ontologies, the âinstrumental troubleâ that these instruments pose, reveal the boundaries of conventional organological approaches and methodologies, which are unsuitable in capturing their full significance. Deploying Butlerâs concepts of recognition, performativity, and subversion in their study can thus represent an effective strategy in the development of a coherent critique of Daviesâs instruments, but also in offering an opportunity to further the understanding of the fundamental importance that musical instruments play in the articulations of music, as part of what may be called an âinstrumental turn.
Decay of geodesic acoustic modes due to the combined action of phase mixing and Landau damping
Geodesic acoustic modes (GAMs) are oscillations of the electric field whose
importance in tokamak plasmas is due to their role in the regulation of
turbulence. The linear collisionless damping of GAMs is investigated here by
means of analytical theory and numerical simulations with the global
gyrokinetic particle-in-cell code ORB5. The combined effect of the phase mixing
and Landau damping is found to quickly redistribute the GAM energy in
phase-space, due to the synergy of the finite orbit width of the passing ions
and the cascade in wave number given by the phase mixing. When plasma
parameters characteristic of realistic tokamak profiles are considered, the GAM
decay time is found to be an order of magnitude lower than the decay due to the
Landau damping alone, and in some cases of the same order of magnitude of the
characteristic GAM drive time due to the nonlinear interaction with an ITG
mode. In particular, the radial mode structure evolution in time is
investigated here and reproduced quantitatively by means of a dedicated initial
value code and diagnostics.Comment: Submitted to Phys. Plasma
Perspectives on Comparative Federalism
Comparative analysis of why territorial second chambers are not fit to represet territories in the central decision-making process and what alternative forms are being create
Increased levels of RNA oxidation enhance the reversion frequency in aging pro-apoptotic yeast mutants
Despite recent advances in understanding the complexity of RNA processes, regulation of the metabolism of oxidized cellular RNAs and the mechanisms through which oxidized ribonucleotides affect mRNA translation, and consequently cell viability, are not well characterized. We show here that the level of oxidized RNAs is markedly increased in a yeast decapping Kllsm4Î1 mutant, which accumulates mRNAs, ages much faster that the wild type strain and undergoes regulated-cell-death. We also found that in Kllsm4Î1 cells the mutation rate increases during chronological life span indicating that the capacity to han- dle oxidized RNAs in yeast declines with aging. Lowering intracellular ROS levels by antioxidants recovers the wild- type phenotype of mutant cells, including reduced amount of oxidized RNAs and lower mutation rate. Since mRNA oxidation was reported to occur in different neurodegen- erative diseases, decapping-deficient cells may represent a useful tool for deciphering molecular mechanisms of cell response to such conditions, providing new insights into RNA modification-based pathogenesis
Studi storici dedicati a Orazio Cancila
Non accade sempre, e non è neppure necessario, che le raccolte di studi in onore di personalitĂ del mondo degli studi trattino temi relativi o affini a quelli coltivati dalla personalitĂ celebrata. Se, però, accade, si può certamente parlare di una felice circostanza o coincidenza, ma può accadere anche che tale circostanza o coincidenza sia significativa di qualcosa dâaltro. E, ad esempio, può essere significativa del fatto che la personalitĂ destinataria della raccolta si è posta o si è trovata al centro di sviluppi della storiografia contemporanea importanti anche perchĂŠ rispondono a interessi diffusi negli studi e nella cultura del suo tempo. Della raccolta di studi per Orazio Cancila si può dire â credo â che ci si trova senzâaltro in questâultimo caso, e, ciò, anche quando la formulazione letterale dei temi dei singoli contributi alla raccolta non sembra autorizzare una tale constatazione. ... Ă un bel panorama, ed è singolarmente conforme alla serie degli ampii e varii interessi storici di Cancila. (Dall'introduzione di Giuseppe Galasso
Exact equilibrium distributions in statistical quantum field theory with rotation and acceleration: scalar field
We derive a general exact form of the phase space distribution function and
the thermal expectation values of local operators for the free quantum scalar
field at equilibrium with rotation and acceleration in flat space-time without
solving field equations in curvilinear coordinates. After factorizing the
density operator with group theoretical methods, we obtain the exact form of
the phase space distribution function as a formal series in thermal vorticity
through an iterative method and we calculate thermal expectation values by
means of analytic continuation techniques. We separately discuss the cases of
pure rotation and pure acceleration and derive analytic results for the
stress-energy tensor of the massless field. The expressions found agree with
the exact analytic solutions obtained by solving the field equation in suitable
curvilinear coordinates for the two cases at stake and already - or implicitly
- known in literature. In order to extract finite values for the pure
acceleration case we introduce the concept of analytic distillation of a
complex function. For the massless field, the obtained expressions of the
currents are polynomials in the acceleration/temperature ratios which vanish at
, in full accordance with the Unruh effect.Comment: 38 pages, 1 figure. Final proofread version published in JHE
Spin-thermal shear coupling in a relativistic fluid
We show that spin polarization of a fermion in a relativistic fluid at local
thermodynamic equilibrium can be generated by the symmetric derivative of the
four-temperature vector, defined as thermal shear. As a consequence, besides
vorticity, acceleration and temperature gradient, also the shear tensor
contributes to the polarization of particles in a fluid. This contribution to
the spin polarization vector, which is entirely non-dissipative, adds to the
well known term proportional to thermal vorticity and may thus have important
consequences for the solution of the local polarization puzzles observed in
relativistic heavy ion collisions.Comment: 10 pages, 1 figure; version accepted for publication in Physics
Letters
Unexpected Enhancement of Antimicrobial Polymer Activity against Staphylococcus aureus in the Presence of Fetal Bovine Serum
Cationic and amphiphilic polymers are known to exert broad-spectrum antibacterial activity by a putative mechanism of membrane disruption. Typically, nonspecific binding to hydrophobic components of the complex biological milieu, such as globular proteins, is considered a deterrent to the successful application of such polymers. To evaluate the extent to which serum deactivates antibacterial polymethacrylates, we compared their minimum inhibitory concentrations in the presence and absence of fetal bovine serum. Surprisingly, we discovered that the addition of fetal bovine serum (FBS) to the assay media in fact enhances the antimicrobial activity of polymers against Gram-positive bacteria S. aureus, whereas the opposite is the case for Gram-negative E. coli. Here, we present these unexpected trends and develop a hypothesis to potentially explain this unusual phenomenon
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