417 research outputs found
The full repertoire of Drosophila gustatory receptors for detecting an aversive compound.
The ability to detect toxic compounds in foods is essential for animal survival. However, the minimal subunit composition of gustatory receptors required for sensing aversive chemicals in Drosophila is unknown. Here we report that three gustatory receptors, GR8a, GR66a and GR98b function together in the detection of L-canavanine, a plant-derived insecticide. Ectopic co-expression of Gr8a and Gr98b in Gr66a-expressing, bitter-sensing gustatory receptor neurons (GRNs) confers responsiveness to L-canavanine. Furthermore, misexpression of all three Grs enables salt- or sweet-sensing GRNs to respond to L-canavanine. Introduction of these Grs in sweet-sensing GRNs switches L-canavanine from an aversive to an attractive compound. Co-expression of GR8a, GR66a and GR98b in Drosophila S2 cells induces an L-canavanine-activated nonselective cation conductance. We conclude that three GRs collaborate to produce a functional L-canavanine receptor. Thus, our results clarify the full set of GRs underlying the detection of a toxic tastant that drives avoidance behaviour in an insect
The association between prescription drugs and colorectal cancer prognosis: a nationwide cohort study using a medication-wide association study
Background With the availability of health insurance claim data, pharmacovigilance for various drugs has been
suggested; however, it is necessary to establish an appropriate analysis method. To detect unintended drug effects
and to generate new hypotheses, we conducted a hypothesis-free study to systematically examine the relationship
between all prescription nonanticancer drugs and the mortality of colorectal cancer patients.
Methods We used the Korean National Health Insurance Service-National Sample Cohort database. A total of
2,618 colorectal cancer patients diagnosed between 2004 and 2015 were divided into drug discovery and drug
validation sets (1:1) through random sampling. Drugs were classified using the Anatomical Therapeutic Chemical
(ATC) classification system: 76 drugs classified as ATC level 2 and 332 drugs classified as ATC level 4 were included
in the analysis. We used a Cox proportional hazard model adjusted for sex, age, colorectal cancer treatment, and
comorbidities. The relationship between all prescription nonanticancer drugs and the mortality of colorectal cancer
patients was analyzed, controlling for multiple comparisons with the false discovery rate.
Results We found that one ATC level-2 drug (drugs that act on the nervous system, including
parasympathomimetics, addictive disorder drugs, and antivertigo drugs) showed a protective effect related to
colorectal cancer prognosis. At the ATC level 4 classification, 4 drugs were significant: two had a protective effect
(anticholinesterases and opioid anesthetics), and the other two had a detrimental effect (magnesium compounds
and Pregnen [4] derivatives).
Conclusions In this hypothesis-free study, we identified four drugs linked to colorectal cancer prognosis. The MWAS
method can be useful in real-world data analysis.
Keywords Colorectal cancer, Medication-wide association study, Pharmacovigilance, Hypothesis free, Agnostic,
Korean populationThis work was supported by the Bisa Research Grant of Keimyung University in 2022 and the National Research Foundation of Korea (2017R1A2B4009233). The funding organizations had no role in the design or conduct of this research
Squeezing Limit of the Josephson Ring Modulator as a Non-Degenerate Parametric Amplifier
Two-mode squeezed vacuum states are a crucial component of quantum
technologies. In the microwave domain, they can be produced by Josephson ring
modulator which acts as a three-wave mixing non-degenerate parametric
amplifier. Here, we solve the master equation of three bosonic modes describing
the Josephson ring modulator with a novel numerical method to compute squeezing
of output fields and gain at low signal power. We show that the third-order
interaction from the three-wave mixing process intrinsically limits squeezing
and reduces gain. Since our results are related to other general cavity-based
three-wave mixing processes, these imply that any non-degenerate parametric
amplifier will have an intrinsic squeezing limit in the output fields.Comment: 6+6 pages, 4 figure
Bound for Gaussian-state Quantum illumination using direct photon measurement
We present bound for quantum illumination with Gaussian state when using
on-off detector or photon number resolving detector, where its performance is
evaluated with signal-to-noise ratio. First, in the case of coincidence
counting, the best performance is given by two-mode squeezed vacuum (TMSV)
state which outperforms coherent state and classically correlated thermal (CCT)
state. However coherent state can beat the TMSV state with increasing signal
mean photon number when using the on-off detector. Second, the performance is
enhanced by taking Fisher information approach of all counting probabilities
including non-detection events. In the Fisher information approach, the TMSV
state still presents the best performance but the CCT state can beat the TMSV
state with increasing signal mean photon number when using the on-off detector.
We also show that displaced squeezed state exhibits the best performance in the
single-mode Gaussian state.Comment: 5 pages, 2 figures, comments welcom
Geomagnetic field influences probabilistic abstract decision-making in humans
To resolve disputes or determine the order of things, people commonly use
binary choices such as tossing a coin, even though it is obscure whether the
empirical probability equals to the theoretical probability. The geomagnetic
field (GMF) is broadly applied as a sensory cue for various movements in many
organisms including humans, although our understanding is limited. Here we
reveal a GMF-modulated probabilistic abstract decision-making in humans and the
underlying mechanism, exploiting the zero-sum binary stone choice of Go game as
a proof-of-principle. The large-scale data analyses of professional Go matches
and in situ stone choice games showed that the empirical probabilities of the
stone selections were remarkably different from the theoretical probability. In
laboratory experiments, experimental probability in the decision-making was
significantly influenced by GMF conditions and specific magnetic resonance
frequency. Time series and stepwise systematic analyses pinpointed the
intentionally uncontrollable decision-making as a primary modulating target.
Notably, the continuum of GMF lines and anisotropic magnetic interplay between
players were crucial to influence the magnetic field resonance-mediated
abstract decision-making. Our findings provide unique insights into the impact
of sensing GMF in decision-makings at tipping points and the quantum mechanical
mechanism for manifesting the gap between theoretical and empirical probability
in 3-dimensional living space.Comment: 32 pages, 5 figures, 4 supplementary figures, 2 supplementary tables,
and separate 15 ancillary file
A Study of Micronucleus Induction with Methyl Formate and 2-Methylbutane in Bone Marrow Cells of Male ICR Mice
Objectives: We investigated the genotoxicity of two chemicals, methyl formate and 2-methylbutane, using male ICR mice bone marrow cells for the screening of micronucleus induction. Although these two chemicals have already been tested numerous times, a micronucleus test has not been conducted and the amounts used have recently been increased.Methods: 7 week male ICR mice were tested at dosages of 250, 500, and 1,000mg/kg for methyl formate and 500, 1,000, and 2,000mg/kg for 2-methlybutane, respectively. After 24 hours of oral administration with the two chemicals, the mice were sacrificed and their bone marrow cells were prepared for smearing slides.Results: As a result of counting the micronucleated polychromatic erythrocyte (MNPCE) of 2,000 polychromatic erythrocytes (PCE), all treated groups expressed no statistically significant increase of MNPCE compared to the negative control group. There were no clinical signs related with the oral exposure of these two chemicals.Conclusion: It was concluded that the two chemicals did not induce micronucleus in the bone marrow cells of ICR mice, and there was no direct proportion with dosage. These results indicate that the two chemicals have no mutagenic potential under each study condition
Gaussian Quantum Illumination via Monotone Metrics
Quantum illumination is to discern the presence or absence of a low
reflectivity target, where the error probability decays exponentially in the
number of copies used. When the target reflectivity is small so that it is hard
to distinguish target presence or absence, the exponential decay constant falls
into a class of objects called monotone metrics. We evaluate monotone metrics
restricted to Gaussian states in terms of first-order moments and covariance
matrix. Under the assumption of a low reflectivity target, we explicitly derive
analytic formulae for decay constant of an arbitrary Gaussian input state.
Especially, in the limit of large background noise and low reflectivity, there
is no need of symplectic diagonalization which usually complicates the
computation of decay constants. First, we show that two-mode squeezed vacuum
(TMSV) states are the optimal probe among pure Gaussian states with fixed
signal mean photon number. Second, as an alternative to preparing TMSV states
with high mean photon number, we show that preparing a TMSV state with low mean
photon number and displacing the signal mode is a more experimentally feasible
setup without degrading the performance that much. Third, we show that it is of
utmost importance to prepare an efficient idler memory to beat coherent states
and provide analytic bounds on the idler memory transmittivity in terms of
signal power, background noise, and idler memory noise. Finally, we identify
the region of physically possible correlations between the signal and idler
modes that can beat coherent states.Comment: 16 pages, 6 figure
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