7,709 research outputs found
Who gets credit for AI-generated art?
The recent sale of an artificial intelligence (AI)-generated portrait for $432,000 at Christie's art auction has raised questions about how credit and responsibility should be allocated to individuals involved and how the anthropomorphic perception of the AI system contributed to the artwork's success. Here, we identify natural heterogeneity in the extent to which different people perceive AI as anthropomorphic. We find that differences in the perception of AI anthropomorphicity are associated with different allocations of responsibility to the AI system and credit to different stakeholders involved in art production. We then show that perceptions of AI anthropomorphicity can be manipulated by changing the language used to talk about AI—as a tool versus agent—with consequences for artists and AI practitioners. Our findings shed light on what is at stake when we anthropomorphize AI systems and offer an empirical lens to reason about how to allocate credit and responsibility to human stakeholders
Short-term modulation of distal tubule fluid nitric oxide in vivo by loop NaCl reabsorption
Short-term modulation of distal tubule fluid nitric oxide in vivo by loop NaCl reabsorption.BackgroundIntrarenal nitric oxide (NO) production and signaling effects are influenced by NaCl loading. To gain further insight into NO mechanisms we determined whether rat distal tubular fluid (DTF) [NO] and collected NO may acutely change when NaCl loop delivery is altered.MethodsAn NO microelectrode was used to measure real-time DTF [NO] and DT-collected NO. With proximal flow blocked (open system), 150mmol/L NaCl, with and without 10−4 mol/L furosemide was perfused with measurement of loop [Cl] reabsorption. Using a closed system, DTF [NO] was also determined using several different loop perfusates.ResultsIn the open system, perfusion with 40 nL/min of 150mmol/L NaCl to which 10−4 mol/L furosemide was added, DT [NO] and DT-collected NO was approximately twice that measured with perfusion of 150mmol/L NaCl alone, while loop Cl reabsorption decreased by half. In the closed system, perfusion at 10 nL/min of 150mmol/L NaCl + furosemide 10−4 mol/L also induced a significant rise in DTF [NO] and collected NO. Perfusion of 10−3 mol/L S-methyl-L-thiocitrulline (SMTC) with 150mmol/L NaCl, induces a significant drop in DT [NO], but without a significant increase in collected NO. Furthermore, with addition of 10−3 mol/L SMTC to the 150mmol/L NaCl + 10−4 furosemide perfusate, the rise in DT [NO] was prevented. Analysis of covariance showed that flow changes within, or between all groups, had no significant additional effect.ConclusionIn both open and closed loop perfusion systems, 10−4 mol/L furosemide inhibition of NaCl transport stimulates net loop NO emission independent of flow; 10−3 mol/L SMTC + 150mmol/L NaCl reduces DT [NO], but not DT-collected NO. Short-term net NO emission from the entire loop, as collected in distal tubule fluid, increases with inhibition of loop NaCl transport
Density-Polarization Functional Theory of the response of a periodic insulating solid to an electric field.
The response of an infinite, periodic, insulating, solid to an
infinitesimally small electric field is investigated in the framework of
Density Functional Theory. We find that the applied perturbing potential is not
a unique functional of the periodic density change~: it depends also on the
change in the macroscopic {\em polarization}. Moreover, the dependence of the
exchange-correlation energy on polarization induces an exchange-correlation
electric field. These effects are exhibited for a model semiconductor. We also
show that the scissor-operator technique is an approximate way of bypassing
this polarization dependence.Comment: 11 pages, 1 Fig
Smooth free involution of and Smith conjecture for imbeddings of in
This paper establishes an equivalence between existence of free involutions
on and existence of involutions on with fixed point set an
imbedded , then a family of counterexamples of the Smith conjecture for
imbeddings of in are given by known result on . In
addition, this paper also shows that every smooth homotopy complex projective
3-space admits no orientation preserving smooth free involution, which answers
an open problem [Pe]. Moreover, the study of existence problem for smooth
orientation preserving involutions on is completed.Comment: 10 pages, final versio
Reflection Symmetry and Quantized Hall Resistivity near Quantum Hall Transition
We present a direct numerical evidence for reflection symmetry of
longitudinal resistivity and quantized Hall resistivity
near the transition between quantum Hall state and insulator, in accord
with the recent experiments. Our results show that a universal scaling behavior
of conductances, and , in the transition regime
decide the reflection symmetry of and quantization of ,
independent of particle-hole symmetry. We also find that in insulating phase
away from the transition region deviates from the quantization and
diverges with .Comment: 3 pages, 4 figures; figure 4 is replace
Second harmonic generation in SiC polytypes
LMTO calculations are presented for the frequency dependent second harmonic
generation (SHG) in the polytypes 2H, 4H, 6H, 15R and 3C of SiC. All
independent tensor components are calculated. The spectral features and the
ratios of the 333 to 311 tensorial components are studied as a function of the
degree of hexagonality. The relationship to the linear optical response and the
underlying band structure are investigated. SHG is suggested to be a sensitive
tool for investigating the near band edge interband excitations.Comment: 12 pages, 10 figure
Operation of a quantum dot in the finite-state machine mode: single-electron dynamic memory
A single electron dynamic memory is designed based on the non-equilibrium
dynamics of charge states in electrostatically-defined metallic quantum dots.
Using the orthodox theory for computing the transfer rates and a master
equation, we model the dynamical response of devices consisting of a charge
sensor coupled to either a single and or a double quantum dot subjected to a
pulsed gate voltage. We show that transition rates between charge states in
metallic quantum dots are characterized by an asymmetry that can be controlled
by the gate voltage. This effect is more pronounced when the switching between
charge states corresponds to a Markovian process involving electron transport
through a chain of several quantum dots. By simulating the dynamics of electron
transport we demonstrate that the quantum box operates as a finite-state
machine that can be addressed by choosing suitable shapes and switching rates
of the gate pulses. We further show that writing times in the ns range and
retention memory times six orders of magnitude longer, in the ms range, can be
achieved on the double quantum dot system using experimentally feasible
parameters thereby demonstrating that the device can operate as a dynamic
single electron memory.Comment: 18 pages, 8 figure
Delocalization of electrons in a Random Magnetic Field
Delocalization problem for a two-dimensional non-interacting electron system
is studied under a random magnetic field. With the presence of a random
magnetic field, the Hall conductance carried by each eigenstate can become
nonzero and quantized in units of . Extended states are characterized by
nonzero Hall conductance, and by studying finite-size scaling of the density of
extended states, an insulator-metal phase transition is revealed. The metallic
phase is found at the center of energy band which is separated from the
localized states at the band tails by critical energies . Both
localization exponent and the critical energy are shown to be dependent
on the strength of random magnetic field.Comment: 9 pages, Revtex, 3 figures available upon reques
Photoelasticity of crystalline and amorphous silica from first principles
Based on density-functional perturbation theory we have computed from first
principles the photoelastic tensor of few crystalline phases of silica at
normal conditions and high pressure (quartz, -cristobalite,
-cristobalite) and of models of amorphous silica (containig up to 162
atoms), obtained by quenching from the melt in combined classical and
Car-Parrinello molecular dynamics simulations. The computational framework has
also been checked on the photoelastic tensor of crystalline silicon and MgO as
prototypes of covalent and ionic systems. The agreement with available
experimental data is good.
A phenomenological model suitable to describe the photoelastic properties of
different silica polymorphs is devised by fitting on the ab-initio data.Comment: ten figure
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