Another derivation of the geometrical KPZ relations

We give a physicist's derivation of the geometrical (in the spirit of Duplantier-Sheffield) KPZ relations, via heat kernel methods. It gives a covariant way to define neighborhoods of fractals in 2d quantum gravity, and shows that these relations are in the realm of conformal field theory

Seebeck Nanoantennas for Infrared Detection and Energy Harvesting Applications

In this letter we introduce a new type of infrared sensor, based on thermocouple nanoantennas, which enables the energy detection and gathering in the mid-infrared region. The proposed detector combines the Seebeck effect, as a transduction mechanism, with the functionalities of the optical antennas for optical sensing. By using finite-element numerical simulations we evaluate the performance and optical-to-electrical conversion efficiency of the proposed device, unveiling its potential for optical sensing and energy harvesting applications.Comment: 4 pages, 3 figures, Invited paper at EUCAP 201

Hydrodynamics of probabilistic ballistic annihilation

We consider a dilute gas of hard spheres in dimension $d \geq 2$ that upon collision either annihilate with probability $p$ or undergo an elastic scattering with probability $1-p$. For such a system neither mass, momentum, nor kinetic energy are conserved quantities. We establish the hydrodynamic equations from the Boltzmann equation description. Within the Chapman-Enskog scheme, we determine the transport coefficients up to Navier-Stokes order, and give the closed set of equations for the hydrodynamic fields chosen for the above coarse grained description (density, momentum and kinetic temperature). Linear stability analysis is performed, and the conditions of stability for the local fields are discussed.Comment: 19 pages, 3 eps figures include

Glutamatergic synaptic currents of nigral dopaminergic neurons follow a postnatal developmental sequence

International audienceThe spontaneous activity pattern of adult dopaminergic (DA) neurons of the substantia nigra pars compacta (SNc) results from interactions between intrinsic membrane conductances and afferent inputs. In adult SNc DA neurons, low-frequency tonic background activity is generated by intrinsic pacemaker mechanisms, whereas burst generation depends on intact synaptic inputs in particular the glutamatergic ones. Tonic DA release in the striatum during pacemaking is required to maintain motor activity, and burst firing evokes phasic DA release, necessary for cue-dependent learning tasks. However, it is still unknown how the firing properties of SNc DA neurons mature during postnatal development before reaching the adult state. We studied the postnatal developmental profile of spontaneous and evoked AMPA and NMDA (N-Methyl-D-aspartic acid) receptor-mediated excitatory postsynaptic currents (EPSCs) in SNc DA neurons in brain slices from immature (postnatal days P4-P10) and young adult (P30-P50) tyrosine hydroxylase (TH)-green fluorescent protein mice. We found that somato-dendritic fields of SNc DA neurons are already mature at P4-P10. In contrast, spontaneous glutamatergic EPSCs show a developmental sequence. Spontaneous NMDA EPSCs in particular are larger and more frequent in immature SNc DA neurons than in young adult ones and have a bursty pattern. They are mediated by GluN2B and GluN2D subunit-containing NMDA receptors. The latter generate long-lasting, DQP 1105-sensitive, spontaneous EPSCs, which are transiently recorded during this early period. Due to high NMDA activity, immature SNc DA neurons generate large and long lasting NMDA receptor-dependent (APV-sensitive) bursts in response to the stimulation of the subthalamic nucleus. We conclude that the transient high NMDA activity allows calcium influx into the dendrites of developing SNc DA neurons

Rapid Diagnosis of Bacterial Infections Using Technologies Based on Nucleic Acid Detection

Bacterial identification and antibiotic susceptibility testing methods used in clinical microbiology laboratories generally require at least two days. This long delay often forces physicians to treat patients presumptively with broad-spectrum antibiotics. Novel diagnostic tests based on the detection of nucleic acids (DNA or RNA) offer a great potential for the rapid (approximately 1 h) diagnosis of bacterial infections. The present article reviews various aspects of the development and validation of nucleic acid-based assays suitable for the detection and identification of bacteria as well as for the detection of associated antibiotic resistance genes. The potential of these assays for routine use in clinical microbiology laboratories is also discussed