A
bstract
We show that the cosmological abundance of string axions is much smaller than naive estimates if the Hubble scale of inflation,
H
inf
, is sufficiently low (but can still be much higher ...than the axion masses) and if the inflation lasts sufficiently long. The reason is that the initial misalignment angles of the string axions follow the Bunch-Davies distribution peaked at the potential minima. As a result, the cosmological moduli problem induced by the string axions can be significantly relaxed by low-scale inflation, and astrophysical and cosmological bounds are satisfied over a wide range of the mass without any fine-tuning of the initial misalignment angles. Specifically, the axion with its decay constant
f
ϕ
= 10
16
GeV satisfies the bounds over 10
−18
eV ≲
m
ϕ
≲ 10 TeV for
H
inf
≲ 10 keV-10
6
GeV. We also discuss cases with multiple axions and the QCD axion.
A
bstract
In this paper, we construct the first asymmetric strongly interacting massive particles (SIMP) dark matter (DM) model, where a new vector-like fermion and a new complex scalar both having ...nonzero chemical potentials can be asymmetric DM particles. After the spontaneous breaking of a U(1)
D
dark gauge symmetry, these two particles can have accidental ℤ
4
charges making them stable. By adding one more complex scalar as a mediator between the SIMP DM, the relic density of DM is determined by 3 → 2 and two-loop induced 2 → 2 annihilations in this model. On the other hand, the SIMP DM can maintain kinetic equilibrium with the thermal bath until the DM freeze-out temperature via the new gauge interaction. Interestingly, this model can have a bouncing effect on DM, whereby the DM number density rises after the chemical freeze-out of DM. With this effect, the prediction of the DM self-interacting cross section in this model can be consistent with astrophysical observations, and the ratio of the DM energy density to the baryonic matter energy density can be explained by primordial asymmetries. We also predict the DM-electron elastic scattering cross section that can be used to test this model in future projected experiments.
Concerns have been raised regarding the potential association between proton pump inhibitor (PPI) use and dementia.
This study aimed to examine this association in an Asian population.
Patients ...initiating PPI therapy between January 1, 2000 and December 31, 2003 without a prior history of dementia were identified from Taiwan's National Health Insurance Research Database. The outcome of interest was all-cause dementia. Cox regression models were applied to estimate the hazard ratio (HR) of dementia. The cumulative PPI dosage stratified by quartiles of defined daily doses and adjusted for baseline disease risk score served as the primary variables compared against no PPI use.
We analyzed the data of 15726 participants aged 40 years or older and free of dementia at baseline. PPI users (n = 7863; average follow-up 8.44 years) had a significantly increased risk of dementia over non-PPI users (n = 7863; average follow-up 9.55 years) (adjusted HR aHR 1.22; 95% confidence interval: 1.05-1.42). A significant association was observed between cumulative PPI use and risk of dementia (P for trend = .013). Subgroup analysis showed excess frequency of dementia in PPI users diagnosed with depression (aHR 2.73 1.91-3.89), hyperlipidemia (aHR 1.81 1.38-2.38), ischemic heart disease (aHR 1.55 1.12-2.14), and hypertension (aHR 1.54 1.21-1.95).
An increased risk for dementia was identified among the Asian PPI users. Cumulative PPI use was significantly associated with dementia. Further investigation into the possible biological mechanisms underlying the relationship between dementia and PPI use is warranted.
Autotrophic plants have evolved distinctive mechanisms for maintaining a range of homeostatic states for sugars. The on/off switch of reversible gene expression by sugar starvation/provision ...represents one of the major mechanisms by which sugar levels are maintained, but the details remain unclear. α-Amylase (αAmy) is the key enzyme for hydrolyzing starch into sugars for plant growth, and it is induced by sugar starvation and repressed by sugar provision. αAmy can also be induced by various other stresses, but the physiological significance is unclear. Here, we reveal that the on/off switch of αAmy expression is regulated by 2 MYB transcription factors competing for the same promoter element. MYBS1 promotes αAmy expression under sugar starvation, whereas MYBS2 represses it. Sugar starvation promotes nuclear import of MYBS1 and nuclear export of MYBS2, whereas sugar provision has the opposite effects. Phosphorylation of MYBS2 at distinct serine residues plays important roles in regulating its sugar-dependent nucleocytoplasmic shuttling and maintenance in cytoplasm by 14-3-3 proteins. Moreover, dehydration, heat, and osmotic stress repress MYBS2 expression, thereby inducing αAmy3. Importantly, activation of αAmy3 and suppression of MYBS2 enhances plant growth, stress tolerance, and total grain weight per plant in rice. Our findings reveal insights into a unique regulatory mechanism for an on/off switch of reversible gene expression in maintaining sugar homeostatic states, which tightly regulates plant growth and development, and also highlight MYBS2 and αAmy3 as potential targets for crop improvement.
A
bstract
In this paper, we construct for the first time a two-component strongly interacting massive particles (SIMP) dark matter (DM) model, where a complex scalar and a vector-like fermion play ...the role of the SIMP DM candidates. These two particles are stable due to an accidental ℤ
4
symmetry after the breaking of a U(1)
D
gauge symmetry. By introducing one extra complex scalar as a mediator between the SIMP particles, this model can have 3 → 2 processes that determine the DM relic density. On the other hand, the SIMP DM particles can maintain kinetic equilibrium with the thermal bath until the DM freeze-out temperature via the U(1)
D
gauge couplings. Most importantly, we find an unavoidable two-loop induced 2 → 2 process tightly connecting to the 3 → 2 process that would redistribute the SIMP DM number densities after the chemical freeze-out of DM. Moreover, this redistribution would significantly modify the predictions of the self-interacting cross section of DM compared with other SIMP models. It is crucial to include the two-loop induced 2 → 2 annihilations to obtain the correct DM phenomenology.
Abstract Hidden monopole is a plausible dark matter candidate due to its stability, but its direct experimental search is extremely difficult due to feeble interactions with the standard model ...particles in the minimal form. Then, we introduce an axion, a, connecting the hidden monopole and the standard model particles and examine the current limits and future prospects of direct dark matter searches and beam-dump experiments. We find two parameter regions around m a = O $$ \mathcal{O} $$ (10) MeV, f a = O $$ \mathcal{O} $$ (105) GeV and m a = O $$ \mathcal{O} $$ (100) MeV, f a = O $$ \mathcal{O} $$ (104) GeV where monopole dark matter and the axion are respectively within the reach of the future experiments such as PICO-500 and SHiP. We also note that the hidden photons mainly produced by the axion decay contribute to dark radiation with ∆N eff ≃ 0.6 which can relax the H 0 tension.
Recently, the MiniBooNE experiment at Fermilab has updated the results with increased data and reported an excess of 560.6 ± 119.6 electronlike events (4.7σ) in the neutrino operation mode. In this ...paper, we propose a scenario to account for the excess where a Dirac-type sterile neutrino, produced by a charged kaon decay through the neutrino mixing, decays into a leptophilic axionlike particle (ℓ ALP) and a muon neutrino. The electron-positron pairs produced from the ℓ ALP decays can be interpreted as electronlike events provided that their opening angle is sufficiently small. In our framework, we consider the ℓ ALP with a mass ma = 20 MeV and an inverse decay constant ce/fa = 10−2 GeV−1, allowed by the astrophysical and experimental constraints. Then, after integrating the predicted angular or visible energy spectra of the ℓ ALP to obtain the total excess event number, we find that our scenario with sterile neutrino masses within 150 MeV ≲ mN ≲ 380 MeV (150 MeV ≲ mN ≲ 180 MeV) and neutrino mixing parameters between 10 −10 ≲ |Uμ4|2 ≲ 10−8 (3 × 10−7 ≲ |Uμ4|2 ≲ 8 × 10−7) can explain the MiniBooNE data.
In a previous study, photonic-based molecularly imprinted polymers (MIPs) were fabricated using atrazine (ATZ) and its metabolites, desethylatrazine (DEA) and desisopropylatrazine (DIA), as templates ...in separate matrices. For the purposes of monitoring the abovementioned molecules in natural waters, the effect of natural waters—featuring ionic strength and natural organic matter (NOM) on atrazine MIP—were studied in this work, and the photonic MIP was implemented for monitoring the target molecules in natural water samples collected from land in nearby farms in northeast of Columbia MO. Non-imprinted polymers (NIP) were also fabricated and applied in the experiments as a control test. In presence of NaCl, CaCl2, and NOM, MIPs presented lower responses by 26%, higher responses by 23%, and higher responses by 35%, respectively. NIPs response in terms of an increase or decrease was consistent with those of MIPs, but only for a lower percentage. MIPs response in natural waters—which were characterized for their physicochemical characteristics such as conductivity, total organic carbon content, etc.—provided a good approximation of the real concentrations obtained from the LCMS instrument; in general, they showed a good concordance, although large discrepancies occurred for some samples, which can be related to reproducibility issues in the manufacturing process or the presence of unknown interfering compounds in the real samples.
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