Rate of population of CO(v) in a CS2/O2 flame

The rate of vibrational population of carbon monoxide in a steady CS2/O2 flame has been determined from CO overtone emission. A steady-state analysis indicates that, for a flame, the fifteenth vibrational level has the largest rate of population

How Much Are Machine Assistants Worth? Willingness to Pay for Machine Learning-Based Software Testing

Machine Learning (ML) technologies have become the foundation of a plethora of products and services. While the economic potential of such ML-infused solutions has become irrefutable, there is still uncertainty on pricing. Currently, software testing is one area to benefit from ML services assisting in the creation of test cases; a task both complex and demanding human-like outputs. Yet, little is known on the willingness to pay of users, inhibiting the suppliers\u27 incentive to develop suitable tools. To provide insights into desired features and willingness to pay for such ML-based tools, we perform a choice-based conjoint analysis with 119 participants in Germany. Our results show that a high level of accuracy is particularly important for users, followed by ease of use and integration into existing environments. Thus, we not only guide future developers on which attributes to prioritize but also which characteristics of ML-based services are relevant for future research

A point mutation in the hair cell nicotinic cholinergic receptor prolongs cochlear inhibition and enhances noise protection

The transduction of sound in the auditory periphery, the cochlea, is inhibited by efferent cholinergic neurons projecting from the brainstem and synapsing directly on mechanosensory hair cells. One fundamental question in auditory neuroscience is what role(s) this feedback plays in our ability to hear. In the present study, we have engineered a genetically modified mouse model in which the magnitude and duration of efferent cholinergic effects are increased, and we assess the consequences of this manipulation on cochlear function. We generated the Chrna9L9′T of knockin mice with a threonine for leucine change (L9′T) at position 9′ of the second transmembrane domain of the α9 nicotinic cholinergic subunit, rendering α9-containing receptors that were hypersensitive to acetylcholine and had slower desensitization kinetics. The Chrna9L9′T allele produced a 3-fold prolongation of efferent synaptic currents in vitro. In vivo, Chrna9L9′T mice had baseline elevation of cochlear thresholds and efferent-mediated inhibition of cochlear responses was dramatically enhanced and lengthened: both effects were reversed by strychnine blockade of the α9α10 hair cell nicotinic receptor. Importantly, relative to their wild-type littermates, Chrna9L9′T/L9′T mice showed less permanent hearing loss following exposure to intense noise. Thus, a point mutation designed to alter α9α10 receptor gating has provided an animal model in which not only is efferent inhibition more powerful, but also one in which sound-induced hearing loss can be restrained, indicating the ability of efferent feedback to ameliorate sound trauma.Fil: Taranda, Julian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Tufts University School of Medicine; Estados UnidosFil: Maison, Stéphane F.. Massachusetts Eye and Ear Infirmary; Estados UnidosFil: Ballestero, Jimena Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Katz, Eleonora. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Savino, Jessica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Vetter, Douglas E.. Tufts University School of Medicine; Estados UnidosFil: Boulter, Jim. University of California at Los Angeles; Estados UnidosFil: Liberman, M. Charles. Massachusetts Eye and Ear Infirmary; Estados UnidosFil: Fuchs, Paul A.. The Johns Hopkins University School of Medicine; Estados UnidosFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Farmacología; Argentin

Negative phase time for Scattering at Quantum Wells: A Microwave Analogy Experiment

If a quantum mechanical particle is scattered by a potential well, the wave function of the particle can propagate with negative phase time. Due to the analogy of the Schr\"odinger and the Helmholtz equation this phenomenon is expected to be observable for electromagnetic wave propagation. Experimental data of electromagnetic wells realized by wave guides filled with different dielectrics confirm this conjecture now.Comment: 10 pages, 6 figure

A Bio-Polymer Transistor: Electrical Amplification by Microtubules

Microtubules (MTs) are important cytoskeletal structures, engaged in a number of specific cellular activities, including vesicular traffic, cell cyto-architecture and motility, cell division, and information processing within neuronal processes. MTs have also been implicated in higher neuronal functions, including memory, and the emergence of "consciousness". How MTs handle and process electrical information, however, is heretofore unknown. Here we show new electrodynamic properties of MTs. Isolated, taxol-stabilized microtubules behave as bio-molecular transistors capable of amplifying electrical information. Electrical amplification by MTs can lead to the enhancement of dynamic information, and processivity in neurons can be conceptualized as an "ionic-based" transistor, which may impact among other known functions, neuronal computational capabilities.Comment: This is the final submitted version. The published version should be downloaded from Biophysical Journa

Characterisation of Nav types endogenously expressed in human SH-SY5Y neuroblastoma cells

The human neuroblastoma cell line SH-SY5Y is a potentially useful model for the identification and characterisation of Na(v) modulators, but little is known about the pharmacology of their endogenously expressed Na(v)s. The aim of this study was to determine the expression of endogenous Na(v) α and β subunits in SH-SY5Y cells using PCR and immunohistochemical approaches, and pharmacologically characterise the Na(v) isoforms endogenously expressed in this cell line using electrophysiological and fluorescence approaches. SH-SY5Y human neuroblastoma cells were found to endogenously express several Na(v) isoforms including Na(v)1.2 and Na(v)1.7. Activation of endogenously expressed Na(v)s with veratridine or the scorpion toxin OD1 caused membrane depolarisation and subsequent Ca(2+) influx through voltage-gated L- and N-type calcium channels, allowing Na(v) activation to be detected with membrane potential and fluorescent Ca(2) dyes. μ-Conotoxin TIIIA and ProTxII identified Na(v)1.2 and Na(v)1.7 as the major contributors of this response. The Na(v)1.7-selective scorpion toxin OD1 in combination with veratridine produced a Na(v)1.7-selective response, confirming that endogenously expressed human Na(v)1.7 in SH-SY5Y cells is functional and can be synergistically activated, providing a new assay format for ligand screening.NHMRC Program Grant: 056992

Coherent amplification of classical pion fields during the cooling of droplets of quark plasma

In the framework of the linear sigma model, we study the time evolution of a system of classical $\sigma$ and pion fields coupled to quarks. For this purpose we solve numerically the classical transport equation for relativistic quarks coupled to the nonlinear Klein-Gordon equations for the meson fields. We examine evolution starting from variety of initial conditions corresponding to spherical droplets of hot quark matter, which might mimic the behaviour of a quark plasma produced in high-energy nucleus-nucleus collisions. For large droplets we find a strong amplification of the pion field that oscillates in time. This leads to a coherent production of pions with a particular isospin and so would have similar observable effects to a disoriented chiral condensate which various authors have suggested might be a signal of the chiral phase transition. The mechanism for amplification of the pion field found here does not rely on this phase transition and is better thought of as a "pion laser" which is driven by large oscillations of the $\sigma$ field.Comment: 12 TeX pages + 20 postscript figures, psfig styl

A Point Mutation in the Hair Cell Nicotinic Cholinergic Receptor Prolongs Cochlear Inhibition and Enhances Noise Protection

The transduction of sound in the auditory periphery, the cochlea, is inhibited by efferent cholinergic neurons projecting from the brainstem and synapsing directly on mechanosensory hair cells. One fundamental question in auditory neuroscience is what role(s) this feedback plays in our ability to hear. In the present study, we have engineered a genetically modified mouse model in which the magnitude and duration of efferent cholinergic effects are increased, and we assess the consequences of this manipulation on cochlear function. We generated the Chrna9L9′T line of knockin mice with a threonine for leucine change (L9′T) at position 9′ of the second transmembrane domain of the α9 nicotinic cholinergic subunit, rendering $\alpha$9-containing receptors that were hypersensitive to acetylcholine and had slower desensitization kinetics. The Chrna9L9′T allele produced a 3-fold prolongation of efferent synaptic currents in vitro. In vivo, Chrna9L9′T mice had baseline elevation of cochlear thresholds and efferent-mediated inhibition of cochlear responses was dramatically enhanced and lengthened: both effects were reversed by strychnine blockade of the $\alpha$9$\alpha$10 hair cell nicotinic receptor. Importantly, relative to their wild-type littermates, Chrna9$^{L9′T/L9′T}$ mice showed less permanent hearing loss following exposure to intense noise. Thus, a point mutation designed to alter $\alpha$9$\alpha$10 receptor gating has provided an animal model in which not only is efferent inhibition more powerful, but also one in which sound-induced hearing loss can be restrained, indicating the ability of efferent feedback to ameliorate sound trauma

Negative group delay for Dirac particles traveling through a potential well

The properties of group delay for Dirac particles traveling through a potential well are investigated. A necessary condition is put forward for the group delay to be negative. It is shown that this negative group delay is closely related to its anomalous dependence on the width of the potential well. In order to demonstrate the validity of stationary-phase approach, numerical simulations are made for Gaussian-shaped temporal wave packets. A restriction to the potential-well's width is obtained that is necessary for the wave packet to remain distortionless in the travelling. Numerical comparison shows that the relativistic group delay is larger than its corresponding non-relativistic one.Comment: 10 pages, 5 figure