2,323 research outputs found
Random Silicon Sampling: Simulating Human Sub-Population Opinion Using a Large Language Model Based on Group-Level Demographic Information
Large language models exhibit societal biases associated with demographic
information, including race, gender, and others. Endowing such language models
with personalities based on demographic data can enable generating opinions
that align with those of humans. Building on this idea, we propose "random
silicon sampling," a method to emulate the opinions of the human population
sub-group. Our study analyzed 1) a language model that generates the survey
responses that correspond with a human group based solely on its demographic
distribution and 2) the applicability of our methodology across various
demographic subgroups and thematic questions. Through random silicon sampling
and using only group-level demographic information, we discovered that language
models can generate response distributions that are remarkably similar to the
actual U.S. public opinion polls. Moreover, we found that the replicability of
language models varies depending on the demographic group and topic of the
question, and this can be attributed to inherent societal biases in the models.
Our findings demonstrate the feasibility of mirroring a group's opinion using
only demographic distribution and elucidate the effect of social biases in
language models on such simulations.Comment: 25 pages, 4 figures, 19 Table
Arp2/3 Complex Regulates Asymmetric Division and Cytokinesis in Mouse Oocytes
Mammalian oocyte meiotic maturation involves oocyte polarization and a unique asymmetric division, but until now, the underlying mechanisms have been poorly understood. Arp2/3 complex has been shown to regulate actin nucleation and is widely involved in a diverse range of processes such as cell locomotion, phagocytosis and the establishment of cell polarity. Whether Arp2/3 complex participates in oocyte polarization and asymmetric division is unknown. The present study investigated the expression and functions of Arp2/3 complex during mouse oocyte meiotic maturation. Immunofluorescent staining showed that the Arp2/3 complex was restricted to the cortex, with a thickened cap above the meiotic apparatus, and that this localization pattern was depended on actin. Disruption of Arp2/3 complex by a newly-found specific inhibitor CK666, as well as by Arpc2 and Arpc3 RNAi, resulted in a range of effects. These included the failure of asymmetric division, spindle migration, and the formation and completion of oocyte cytokinesis. The formation of the actin cap and cortical granule-free domain (CGFD) was also disrupted, which further confirmed the disruption of spindle migration. Our data suggest that the Arp2/3 complex probably regulates oocyte polarization through its effect on spindle migration, asymmetric division and cytokinesis during mouse oocyte meiotic maturation
Anomalous crystalline ordering of particles in a viscoelastic fluid under high shear
Addition of particles to a viscoelastic suspension dramatically alters the
properties of the mixture, particularly when it is sheared or otherwise
processed. Shear-induced stretching of the polymers results in elastic stress
that causes a substantial increase in measured viscosity with increasing shear,
and an attractive interaction between particles, leading to their chaining. At
even higher shear rates, the flow becomes unstable, even in the absence of
particles. This instability makes it very difficult to determine the properties
of a particle suspension. Here we use a fully immersed parallel plate geometry
to measure the high-shear-rate behavior of a suspension of particles in a
viscoelastic fluid. We find an unexpected separation of the particles within
the suspension resulting in the formation of a layer of particles in the center
of the cell. Remarkably, monodisperse particles form a crystalline layer which
dramatically alters the shear instability. By combining measurements of the
velocity field and torque fluctuations, we show that this solid layer disrupts
the flow instability and introduces a new, single-frequency component to the
torque fluctuations that reflects a dominant velocity pattern in the flow.
These results highlight the interplay between particles and a suspending
viscoelastic fluid at very high shear rates.Comment: SI Videos and future data sharing are available at
https://doi.org/10.7910/DVN/K0XZ6
Rotational-State-Dependent Dispersion of Molecules by Pulsed Optical Standing Waves
We report on the rotational-state-dependent, transverse acceleration of CS 2 molecules affected by pulsed optical standing waves. The steep gradient of the standing wave potential imparts far stronger dipole forces on the molecules than propagating pulses do. Moreover, large changes in the transverse velocities (i.e., up to 80 m/s) obtained with the standing waves are well reproduced in numerical simulations using the effective polarizability that depends on the molecular rotational states. Our analysis based on the rotational-state-dependent effective polarizability can therefore serve as a basis for developing a new technique of state selection for both polar and nonpolar molecules.open
Engineering gold nanotubes with controlled length and near-infrared absorption for theranostic applications
Important aspects in engineering gold nanoparticles for theranostic applications include the control of size, optical properties, cytotoxicity, biodistribution, and clearance. In this study, gold nanotubes with controlled length and tunable absorption in the near-infrared (NIR) region have been exploited for applications as photothermal conversion agents and in vivo photoacoustic imaging contrast agents. A length-controlled synthesis has been developed to fabricate gold nanotubes (NTs) with well-defined shape (i.e., inner void and open ends), high crystallinity, and tunable NIR surface plasmon resonance. A coating of poly(sodium 4-styrenesulfonate) (PSS) endows the nanotubes with colloidal stability and low cytotoxicity. The PSS-coated Au NTs have the following characteristics: i) cellular uptake by colorectal cancer cells and macrophage cells, ii) photothermal ablation of cancer cells using single wavelength pulse laser irradiation, iii) excellent in vivo photoacoustic signal generation capability and accumulation at the tumor site, iv) hepatobiliary clearance within 72 h postintravenous injection. These results demonstrate that these PSS-coated Au NTs have the ideal attributes to develop their potential as effective and safe in vivo imaging nanoprobes, photothermal conversion agents, and drug delivery vehicles. To the best of knowledge, this is the first in vitro and in vivo study of gold nanotubes
Transcriptome and QTL mapping analyses of major QTL genes controlling glucosinolate contents in vegetable- and oilseed-type Brassica rapa plants
Glucosinolates (GSLs) are secondary metabolites providing defense against pathogens and herbivores in plants, and anti-carcinogenic activity against human cancer cells. Profiles of GSLs vary greatly among members of genus Brassica. In this study, we found that a reference line of Chinese cabbage (B. rapa ssp. pekinensis), ‘Chiifu’ contains significantly lower amounts of total GSLs than the oilseed-type B. rapa (B. rapa ssp. trilocularis) line ‘LP08’. This study aimed to identify the key regulators of the high accumulation of GSLs in Brassica rapa plants using transcriptomic and linkage mapping approaches. Comparative transcriptome analysis showed that, in total, 8,276 and 9,878 genes were differentially expressed between ‘Chiifu’ and ‘LP08’ under light and dark conditions, respectively. Among 162 B. rapa GSL pathway genes, 79 were related to GSL metabolism under light conditions. We also performed QTL analysis using a single nucleotide polymorphism-based linkage map constructed using 151 F5 individuals derived from a cross between the ‘Chiifu’ and ‘LP08’ inbred lines. Two major QTL peaks were successfully identified on chromosome 3 using high-performance liquid chromatography to obtain GSL profiles from 97 F5 recombinant inbred lines. The MYB-domain transcription factor gene BrMYB28.1 (Bra012961) was found in the highest QTL peak region. The second highest peak was located near the 2-oxoacid-dependent dioxygenase gene BrGSL-OH.1 (Bra022920). This study identified major genes responsible for differing profiles of GSLs between ‘Chiifu’ and ‘LP08’. Thus, our study provides molecular insights into differences in GSL profiles between vegetative- and oilseed-type B. rapa plants
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