3,117 research outputs found
Generative AI and Copyright: A Dynamic Perspective
The rapid advancement of generative AI is poised to disrupt the creative
industry. Amidst the immense excitement for this new technology, its future
development and applications in the creative industry hinge crucially upon two
copyright issues: 1) the compensation to creators whose content has been used
to train generative AI models (the fair use standard); and 2) the eligibility
of AI-generated content for copyright protection (AI-copyrightability). While
both issues have ignited heated debates among academics and practitioners, most
analysis has focused on their challenges posed to existing copyright doctrines.
In this paper, we aim to better understand the economic implications of these
two regulatory issues and their interactions. By constructing a dynamic model
with endogenous content creation and AI model development, we unravel the
impacts of the fair use standard and AI-copyrightability on AI development, AI
company profit, creators income, and consumer welfare, and how these impacts
are influenced by various economic and operational factors. For example, while
generous fair use (use data for AI training without compensating the creator)
benefits all parties when abundant training data exists, it can hurt creators
and consumers when such data is scarce. Similarly, stronger AI-copyrightability
(AI content enjoys more copyright protection) could hinder AI development and
reduce social welfare. Our analysis also highlights the complex interplay
between these two copyright issues. For instance, when existing training data
is scarce, generous fair use may be preferred only when AI-copyrightability is
weak. Our findings underscore the need for policymakers to embrace a dynamic,
context-specific approach in making regulatory decisions and provide insights
for business leaders navigating the complexities of the global regulatory
environment
Andreev Reflection without Fermi surface alignment in High T-Topological heterostructures
We address the controversy over the proximity effect between topological
materials and high T superconductors. Junctions are produced between
BiSrCaCuO and materials with different Fermi
surfaces (BiTe \& graphite). Both cases reveal tunneling spectra
consistent with Andreev reflection. This is confirmed by magnetic field that
shifts features via the Doppler effect. This is modeled with a single parameter
that accounts for tunneling into a screening supercurrent. Thus the tunneling
involves Cooper pairs crossing the heterostructure, showing the Fermi surface
mis-match does not hinder the ability to form transparent interfaces, which is
accounted for by the extended Brillouin zone and different lattice symmetries
Evolution of a domain conserved in microtubule-associated proteins of eukaryotes
The microtubule network, the major organelle of the eukaryotic cytoskeleton, is involved in cell division and differentiation but also with many other cellular functions. In plants, microtubules seem to be involved in the ordered deposition of cellulose microfibrils by a so far unknown mechanism. Microtubule-associated proteins (MAP) typically contain various domains targeting or binding proteins with different functions to microtubules. Here we have investigated a proposed microtubule-targeting domain, TPX2, first identified in the Kinesin-like protein 2 in Xenopus. A TPX2 containing microtubule binding protein, PttMAP20, has been recently identified in poplar tissues undergoing xylogenesis. Furthermore, the herbicide 2,6-dichlorobenzonitrile (DCB), which is a known inhibitor of cellulose synthesis, was shown to bind specifically to PttMAP20. It is thus possible that PttMAP20 may have a role in coupling cellulose biosynthesis and the microtubular networks in poplar secondary cell walls. In order to get more insight into the occurrence, evolution and potential functions of TPX2-containing proteins we have carried out bioinformatic analysis for all genes so far found to encode TPX2 domains with special reference to poplar PttMAP20 and its putative orthologs in other plants
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Giant Light-Emission Enhancement in Lead Halide Perovskites by Surface Oxygen Passivation.
Surface condition plays an important role in the optical performance of semiconductor materials. As new types of semiconductors, the emerging metal-halide perovskites are promising for next-generation optoelectronic devices. We discover significantly improved light-emission efficiencies in lead halide perovskites due to surface oxygen passivation. The enhancement manifests close to 3 orders of magnitude as the perovskite dimensions decrease to the nanoscale, improving external quantum efficiencies from <0.02% to over 12%. Along with about a 4-fold increase in spontaneous carrier recombination lifetimes, we show that oxygen exposure enhances light emission by reducing the nonradiative recombination channel. Supported by X-ray surface characterization and theoretical modeling, we propose that excess lead atoms on the perovskite surface create deep-level trap states that can be passivated by oxygen adsorption
Isolation of a strong Arabidopsis guard cell promoter and its potential as a research tool
<p>Abstract</p> <p>Background</p> <p>A common limitation in guard cell signaling research is that it is difficult to obtain consistent high expression of transgenes of interest in <it>Arabidopsis </it>guard cells using known guard cell promoters or the constitutive 35S cauliflower mosaic virus promoter. An additional drawback of the 35S promoter is that ectopically expressing a gene throughout the organism could cause pleiotropic effects. To improve available methods for targeted gene expression in guard cells, we isolated strong guard cell promoter candidates based on new guard cell-specific microarray analyses of 23,000 genes that are made available together with this report.</p> <p>Results</p> <p>A promoter, <it>pGC1</it>(At1g22690), drove strong and relatively specific reporter gene expression in guard cells including GUS (beta-glucuronidase) and yellow cameleon YC3.60 (GFP-based calcium FRET reporter). Reporter gene expression was weaker in immature guard cells. The expression of YC3.60 was sufficiently strong to image intracellular Ca<sup>2+ </sup>dynamics in guard cells of intact plants and resolved spontaneous calcium transients in guard cells. The <it>GC1 </it>promoter also mediated strong reporter expression in clustered stomata in the stomatal development mutant <it>too-many-mouths </it>(<it>tmm</it>). Furthermore, the same promoter::reporter constructs also drove guard cell specific reporter expression in tobacco, illustrating the potential of this promoter as a method for high level expression in guard cells. A serial deletion of the promoter defined a guard cell expression promoter region. In addition, anti-sense repression using <it>pGC1 </it>was powerful for reducing specific GFP gene expression in guard cells while expression in leaf epidermal cells was not repressed, demonstrating strong cell-type preferential gene repression.</p> <p>Conclusion</p> <p>The <it>pGC1 </it>promoter described here drives strong reporter expression in guard cells of <it>Arabidopsis </it>and tobacco plants. It provides a potent research tool for targeted guard cell expression or gene silencing. It is also applicable to reduce specific gene expression in guard cells, providing a method for circumvention of limitations arising from genetic redundancy and lethality. These advances could be very useful for manipulating signaling pathways in guard cells and modifying plant performance under stress conditions. In addition, new guard cell and mesophyll cell-specific 23,000 gene microarray data are made publicly available here.</p
A rapid paper-based test for quantifying sickle hemoglobin in blood samples from patients with sickle cell disease
Quantification of sickle hemoglobin (HbS) in patients with sickle cell disease (SCD) undergoing hydroxyurea or chronic transfusion therapy is essential to monitoring the effectiveness of these therapies. The clinical monitoring of %HbS using conventional laboratory methods is limited by high per-test costs and long turnaround times usually associated with these methods. Here we demonstrate a simple, rapid, inexpensive paper-based assay capable of quantifying %HbS in blood samples from patients with SCD. A 20 ?L droplet of whole blood and hemoglobin solubility buffer was deposited on chromatography paper. The relative color intensities of regions of the resulting blood stain, determined by automated image analysis, are used to estimate %HbS. We compared the paper-based assay with hemoglobin electrophoresis (comparison method) using blood samples from 88 subjects. The test shows high correlation (R2 = 0.86) and strong agreement (standard deviation of difference = 7 %HbS) with conventional Hb electrophoresis measurement of %HbS, and closely approximates clinically predicted change in %HbS with transfusion therapy (mean difference 2.6 %HbS, n = 4). The paper-based assay can be completed in less than 35 minutes and has a per-test cost less than $0.25. The assay is accurate across a wide range of HbS levels (10–97%) and hemoglobin concentrations (5.6–12.9 g/dL) and is unaffected by high levels of HbF (up to 80.6%). This study demonstrates the feasibility of the paper-based %HbS assay. The paper-based test could improve clinical care for SCD, particularly in resource-limited settings, by enabling more rapid and less expensive %HbS monitoring
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