The QCD Lagrangian contains a CP violating gluon density term with a physical coefficient θ¯. The upper bound on the electric dipole moment of neutron requires the value of θ¯ to be extremely small. ...The tiny θ¯ is commonly known as the strong CP problem. In order to solve this puzzle, we construct a θ¯-characterized mirror symmetry between a pair of twin dark sectors with respective discrete symmetries. By taking a proper phase rotation of dark fields, we can perfectly remove the parameter θ¯ from the full Lagrangian. In our scenario, the discrete symmetry breaking, which are responsible for the mass generation of dark colored fermions and dark matter fermions, can be allowed near the TeV scale. This means different phenomena from the popular axion models with high scale Peccei-Quinn global symmetry breaking.
A TeV-scale Higgs doublet can acquire a tiny vacuum expectation value via its small mixing with the standard model Higgs doublet. This new Higgs doublet then can offer a testable Dirac neutrino mass ...generation through its sizable Yukawa couplings with several right-handed neutrinos and the standard model lepton doublets. We show the small mixing between the two Higgs doublets can be naturally induced by a seesaw mechanism after an additional symmetry is spontaneously broken. In association with the second Higgs doublet decays, this seesaw mechanism can also accommodate a leptogenesis mechanism to generate the baryon asymmetry in the universe.
A TeV-scale Higgs doublet with a small mixing to the standard model Higgs doublet can have the sizable Yukawa couplings to several right-handed neutrinos and the standard model lepton doublets. This ...provides a testable Dirac neutrino mass generation. We further consider a seesaw mechanism involving a U(1)B−L gauge symmetry, which predicts the existence of two right-handed neutrinos and a stable Dirac fermionic dark matter, to simultaneously explain the small mixing between the two Higgs doublets and the generation of the cosmic baryon asymmetry.
Identification of grain shape determining genes can facilitate breeding of rice cultivars with optimal grain shape and appearance quality. Here, we identify GS9 (Grain Shape Gene on Chromosome 9) ...gene by map-based cloning. The gs9 null mutant has slender grains, while overexpression GS9 results in round grains. GS9 encodes a protein without known conserved functional domain. It regulates grain shape by altering cell division. The interaction of GS9 and ovate family proteins OsOFP14 and OsOFP8 is modulated by OsGSK2 kinase, a key regulator of the brassinosteroids signaling pathway. Genetic interaction analysis reveals that GS9 functions independently from other previously identified grain size genes. Introducing the gs9 allele into elite rice cultivars significantly improves grain shape and appearance quality. It suggests potential application of gs9, alone or in combination with other grain size determining genes, in breeding of rice varieties with optimized grain shape.
It is firmly believed that a signal of neutrinoless double beta decay can confirm the Majorana nature of neutrinos. However, we remind another possibility that a Majorana neutrino mass induced after ...some neutrinoless double beta decay processes can be accidentally cancelled by another Majorana neutrino mass induced before any neutrinoless double beta decay processes. This cancellation can simultaneously allow an observable neutrinoless double beta decay and a vanishing Majorana neutrino mass. In consequence, a future discovery of neutrinoless double beta decay cannot fully rule out the possibility of Dirac neutrinos. For demonstration, we simply show a realistic model with observable neutrinoless double beta decay and purely Dirac neutrinos.
To evaluate the effectiveness of web-based mobile health interventions on paediatric patients and their parents in the day surgery context, where the primary outcome was children's pre-operative ...anxiety and secondary outcomes were postoperative pain and parents' anxiety and satisfaction with entire course of the day surgery.
A systematic review and meta-analysis of randomized controlled trials.
CENTRAL, CINAHL, Scopus, Ovid MEDLINE, and Web of Science were systematically searched without time limits (up to December 2018).
Studies were appraised using the Cochrane risk of bias tool. A random effect meta-analysis of children's pre-operative anxiety was performed.
Eight studies with a total of 722 patients were included in the analysis. The effectiveness of web-based mobile health interventions, including age-appropriate videos, web-based game apps, and educational preparation games made for the hospital environment, was examined in pre-operative settings. A meta-analysis (N = 560 children) based on six studies found a statistically significant reduction in pre-operative anxiety measured by the Modified Yale Pre-operative Anxiety Scale with a moderate effect size. Three studies reported parental satisfaction.
Web-based mobile health interventions can reduce children's pre-operative anxiety and increase parental satisfaction. Web-based mobile health interventions could be considered as non-pharmacological distraction tools for children in nursing. There is not enough evidence regarding the effectiveness of reducing children's postoperative pain and parental anxiety using similar interventions.
Web-based mobile health interventions reduce children´s pre-operative anxiety and could therefore be considered as non-pharmacological distraction tools for children in nursing.
During the Coronavirus Disease 2019 (COVID-19) pandemic, frontline nurses face enormous mental health challenges. Epidemiological data on the mental health statuses of frontline nurses are still ...limited. The aim of this study was to examine mental health (burnout, anxiety, depression, and fear) and their associated factors among frontline nurses who were caring for COVID-19 patients in Wuhan, China.
A large-scale cross-sectional, descriptive, correlational study design was used. A total of 2,014 eligible frontline nurses from two hospitals in Wuhan, China, participated in the study. Besides sociodemographic and background data, a set of valid and reliable instruments were used to measure outcomes of burnout, anxiety, depression, fear, skin lesion, self-efficacy, resilience, and social support via the online survey in February 2020.
On average, the participants had a moderate level of burnout and a high level of fear. About half of the nurses reported moderate and high work burnout, as shown in emotional exhaustion (n = 1,218, 60.5%), depersonalization (n = 853, 42.3%), and personal accomplishment (n = 1,219, 60.6%). The findings showed that 288 (14.3%), 217 (10.7%), and 1,837 (91.2%) nurses reported moderate and high levels of anxiety, depression, and fear, respectively. The majority of the nurses (n = 1,910, 94.8%) had one or more skin lesions, and 1,950 (96.8%) nurses expressed their frontline work willingness. Mental health outcomes were statistically positively correlated with skin lesion and negatively correlated with self-efficacy, resilience, social support, and frontline work willingness.
The frontline nurses experienced a variety of mental health challenges, especially burnout and fear, which warrant attention and support from policymakers. Future interventions at the national and organisational levels are needed to improve mental health during this pandemic by preventing and managing skin lesions, building self-efficacy and resilience, providing sufficient social support, and ensuring frontline work willingness.
In the inverse seesaw scenario, several fermion singlets have a small Majorana mass term. We show such Majorana masses can be suppressed by some heavy fermion and/or Higgs singlets after a global ...symmetry is spontaneously broken. These interactions can also accommodate a leptogenesis mechanism to explain the cosmic baryon asymmetry if there are two or more heavy fermion and/or Higgs singlets.
The active twin variants during {10–12} twinning of magnesium alloys were dependent on the strain path (i.e., compression perpendicular to the
c-axis or tension parallel to the
c-axis), and their ...section mechanism was governed by the Schmid law. The activation of specific twin variants depending on the strain path induced a significant difference in twinning characteristics, such as twin morphology, volume fraction of twins with strain, and twin texture, and consequently gave rise to a totally different effect on the deformation. The differences in the deformation characteristics (flow stress and strain hardening) between both strain paths are explained in relation to activation stresses for twinning and slips, activities of twinning and slips in the deformation, the Hall–Petch effect by twinning-induced grain size change, and twinning-induced change in activities of slips.
A
bstract
We demonstrate a common origin for high-scale leptogenesis and three-loop neutrino mass generation. Specifically we extend the standard model by two real singlet scalars, two singly charged ...scalars carrying different quantum numbers under certain global symmetry and two or more singlet fermions with Majorana masses. This global symmetry is only allowed to be softly or spontaneously broken. Our model also respects an exactly conserved
Z
2
discrete symmetry. Through the real scalar decays and then the charged scalar decays, we can obtain a lepton asymmetry stored in the standard model leptons. This lepton asymmetry can be partially converted to a baryon asymmetry by the sphaleron processes. The interactions for this leptogenesis can also result in a three-loop diagram to generate the neutrino masses. The lightest singlet fermion can keep stable to serve as a dark matter particle.
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