50 research outputs found
Pirimicarb: 2-dimethylamino-5,6-dimethylpyrimidin-4-yl dimethylcarbamate
In the title compound, C11H18N4O2 (systematic name: 2-dimethylamino-5,6-dimethylpyrimidin-4-yl N,N-dimethylcarbamate), the pyrimidine ring and dimethylamino group are almost in the same plane, making a dihedral angle of 1.6 (1)°. The dihedral angle between the mean plane of the pyrimidine ring and that of the dimethylcarbamate group is 83.42 (5)°. In the crystal structure, intermolecular C—H⋯O hydrogen bonds contribute to the stabilization of the packing
Distributed estimation of stochastic multiagent systems for cooperative control with a virtual network
This article proposes a distributed estimation algorithm that uses local information about the neighbors through sensing or communication to design an estimation-based cooperative control of the stochastic multiagent system (MAS). The proposed distributed estimation algorithm solely relies on local sensing information rather than exchanging estimated state information from other agents, as is commonly required in conventional distributed estimation methods, reducing communication overhead. Furthermore, the proposed method allows interactions between all agents, including non-neighboring agents, by establishing a virtual fully connected network with the MAS state information independently estimated by each agent. The stability of the proposed distributed estimation algorithm is theoretically verified. Numerical simulations demonstrate the enhanced performance of the estimation-based linear and nonlinear control. In particular, using the virtual fully connected network concept in the MAS with the sensing/communication range, the flock configuration can be tightly controlled within the desired boundary, which cannot be achieved through the conventional flocking methods
Oxycodone-induced dopaminergic and respiratory effects are modulated by deep brain stimulation
Introduction: Opioids are the leading cause of overdose death in the United States, accounting for almost 70,000 deaths in 2020. Deep brain stimulation (DBS) is a promising new treatment for substance use disorders. Here, we hypothesized that VTA DBS would modulate both the dopaminergic and respiratory effect of oxycodone.Methods: Multiple-cyclic square wave voltammetry (M-CSWV) was used to investigate how deep brain stimulation (130 Hz, 0.2 ms, and 0.2 mA) of the rodent ventral segmental area (VTA), which contains abundant dopaminergic neurons, modulates the acute effects of oxycodone administration (2.5 mg/kg, i.v.) on nucleus accumbens core (NAcc) tonic extracellular dopamine levels and respiratory rate in urethane-anesthetized rats (1.5 g/kg, i.p.).Results: I.V. administration of oxycodone resulted in an increase in NAcc tonic dopamine levels (296.9 ± 37.0 nM) compared to baseline (150.7 ± 15.5 nM) and saline administration (152.0 ± 16.1 nM) (296.9 ± 37.0 vs. 150.7 ± 15.5 vs. 152.0 ± 16.1, respectively, p = 0.022, n = 5). This robust oxycodone-induced increase in NAcc dopamine concentration was associated with a sharp reduction in respiratory rate (111.7 ± 2.6 min−1 vs. 67.9 ± 8.3 min−1; pre- vs. post-oxycodone; p < 0.001). Continuous DBS targeted at the VTA (n = 5) reduced baseline dopamine levels, attenuated the oxycodone-induced increase in dopamine levels to (+39.0% vs. +95%), and respiratory depression (121.5 ± 6.7 min−1 vs. 105.2 ± 4.1 min−1; pre- vs. post-oxycodone; p = 0.072).Discussion: Here we demonstrated VTA DBS alleviates oxycodone-induced increases in NAcc dopamine levels and reverses respiratory suppression. These results support the possibility of using neuromodulation technology for treatment of drug addiction
The Seoul National University AGN Monitoring Project. II. BLR Size and Black Hole Mass of Two AGNs
Active galactic nuclei (AGNs) show a correlation between the size of the broad line region and the monochromatic continuum luminosity at 5100 Å, allowing black hole mass estimation based on single-epoch spectra. However, the validity of the correlation is yet to be clearly tested for high-luminosity AGNs. We present the first reverberation mapping results of the Seoul National University AGN Monitoring Project (SAMP), which is designed to focus on luminous AGNs for probing the high end of the size–luminosity relation. We report time lag measurements of two AGNs, namely, 2MASS J10261389+5237510 and SDSS J161911.24+501109.2, using the light curves obtained over an ∼1000 days period with an average cadence of 10 and 20 days, respectively, for photometry and spectroscopy monitoring. Based on a cross-correlation analysis and Hβ line width measurements, we determine the Hβ lag as and days in the observed frame, and black hole mass as and , respectively, for 2MASS J1026 and SDSS J1619
The Seoul National University AGN Monitoring Project. IV. Hα Reverberation Mapping of Six AGNs and the Hα Size–Luminosity Relation
The broad-line region (BLR) size–luminosity relation has paramount importance for estimating the mass of black holes in active galactic nuclei (AGNs). Traditionally, the size of the Hβ BLR is often estimated from the optical continuum luminosity at 5100 Å, while the size of the Hα BLR and its correlation with the luminosity is much less constrained. As a part of the Seoul National University AGN Monitoring Project, which provides 6 yr photometric and spectroscopic monitoring data, we present our measurements of the Hα lags of high-luminosity AGNs. Combined with the measurements for 42 AGNs from the literature, we derive the size–luminosity relations of the Hα BLR against the broad Hα and 5100 Å continuum luminosities. We find the slope of the relations to be 0.61 ± 0.04 and 0.59 ± 0.04, respectively, which are consistent with the Hβ size–luminosity relation. Moreover, we find a linear relation between the 5100 Å continuum luminosity and the broad Hα luminosity across 7 orders of magnitude. Using these results, we propose a new virial mass estimator based on the Hα broad emission line, finding that the previous mass estimates based on scaling relations in the literature are overestimated by up to 0.7 dex at masses lower than 107M⊙
The Seoul National University AGN Monitoring Project IV: H reverberation mapping of 6 AGNs and the H Size-Luminosity Relation
The broad line region (BLR) size-luminosity relation has paramount importance
for estimating the mass of black holes in active galactic nuclei (AGNs).
Traditionally, the size of the H BLR is often estimated from the optical
continuum luminosity at 5100\angstrom{} , while the size of the H BLR
and its correlation with the luminosity is much less constrained. As a part of
the Seoul National University AGN Monitoring Project (SAMP) which provides
six-year photometric and spectroscopic monitoring data, we present our
measurements of the H lags of 6 high-luminosity AGNs. Combined with the
measurements for 42 AGNs from the literature, we derive the size-luminosity
relations of H BLR against broad H and 5100\angstrom{}
continuum luminosities. We find the slope of the relations to be
and , respectively, which are consistent with the \hb{}
size-luminosity relation. Moreover, we find a linear relation between the
5100\angstrom{} continuum luminosity and the broad H luminosity across
7 orders of magnitude. Using these results, we propose a new virial mass
estimator based on the H broad emission line, finding that the previous
mass estimates based on the scaling relations in the literature are
overestimated by up to 0.7 dex at masses lower than ~M.Comment: Accepted for publication in ApJ (Jun. 25th, 2023). 21 pages, 12
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The Seoul National University AGN Monitoring Project. II. BLR Size and Black Hole Mass of Two AGNs
Active galactic nuclei (AGNs) show a correlation between the size of the broad line region and the monochromatic continuum luminosity at 5100 Å, allowing black hole mass estimation based on single-epoch spectra. However, the validity of the correlation is yet to be clearly tested for high-luminosity AGNs. We present the first reverberation mapping results of the Seoul National University AGN Monitoring Project (SAMP), which is designed to focus on luminous AGNs for probing the high end of the size─luminosity relation. We report time lag measurements of two AGNs, namely, 2MASS J10261389+5237510 and SDSS J161911.24+501109.2, using the light curves obtained over a ∼1000 days period with an average cadence of 10 and 20 days, respectively, for photometry and spectroscopy monitoring. Based on a cross-correlation analysis and Hβ line width measurements, we determine the Hβ lag as {41.8}-6.0+4.9 and {52.6}-14.7+17.6 days in the observed frame, and black hole mass as {3.65}-0.57+0.49× {10}7{M}ȯ and {23.02}-6.56+7.81× {10}7{M}ȯ , respectively, for 2MASS J1026 and SDSS J1619.</p
Cetaceans evolution:insights from the genome sequences of common minke whales
Background: Whales have captivated the human imagination for millennia. These incredible cetaceans are the only mammals that have adapted to life in the open oceans and have been a source of human food, fuel and tools around the globe. The transition from land to water has led to various aquatic specializations related to hairless skin and ability to regulate their body temperature in cold water. Results: We present four common minke whale (Balaenoptera acutorostrata) genomes with depth of ×13 ~ ×17 coverage and perform resequencing technology without a reference sequence. Our results indicated the time to the most recent common ancestors of common minke whales to be about 2.3574 (95% HPD, 1.1521 - 3.9212) million years ago. Further, we found that genes associated with epilation and tooth-development showed signatures of positive selection, supporting the morphological uniqueness of whales. Conclusions: This whole-genome sequencing offers a chance to better understand the evolutionary journey of one of the largest mammals on earth
Variability and the size-luminosity relation of the intermediate mass AGN in NGC 4395
We present the variability study of the lowest-luminosity Seyfert 1 galaxy
NGC 4395 based on the photometric monitoring campaigns in 2017 and 2018. Using
22 ground-based and space telescopes, we monitored NGC 4395 with a 5
minute cadence during a period of 10 days and obtained light curves in the UV,
V, J, H, and K/Ks bands as well as the H narrow-band. The RMS
variability is 0.13 mag on \emph{Swift}-UVM2 and V filter light curves,
decreasing down to 0.01 mag on K filter. After correcting for continuum
contribution to the H narrow-band, we measured the time lag of the
H emission line with respect to the V-band continuum as
to min. in 2017 and
to min. in 2018, depending on the assumption on the
continuum variability amplitude in the H narrow-band. We obtained no
reliable measurements for the continuum-to-continuum lag between UV and V bands
and among near-IR bands, due to the large flux uncertainty of UV observations
and the limited time baseline. We determined the AGN monochromatic luminosity
at 5100\AA\ , after subtracting the contribution of the
nuclear star cluster. While the optical luminosity of NGC 4395 is two orders of
magnitude lower than that of other reverberation-mapped AGNs, NGC 4395 follows
the size-luminosity relation, albeit with an offset of 0.48 dex
(2.5) from the previous best-fit relation of Bentz et al. (2013).Comment: Accepted for publication in ApJ (Feb. 23rd, 2020). 18 pages, 10
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