Dark matter for excess of AMS-02 positrons and antiprotons

We propose a dark matter explanation to simultaneously account for the excess of antiproton-to-proton and positron power spectra observed in the AMS-02 experiment while having the right dark matter relic abundance and satisfying the current direct search bounds. We extend the Higgs triplet model with a hidden gauge symmetry of $SU(2)_X$ that is broken to $Z_3$ by a quadruplet scalar field, rendering the associated gauge bosons stable weakly-interacting massive particle dark matter candidates. By coupling the complex Higgs triplet and the $SU(2)_X$ quadruplet, the dark matter candidates can annihilate into triplet Higgs bosons each of which in turn decays into lepton or gauge boson final states. Such a mechanism gives rise to correct excess of positrons and antiprotons with an appropriate choice of the triplet vacuum expectation value. Besides, the model provides a link between neutrino mass and dark matter phenomenology.Comment: 12 pages, 3 figures, references and comments added, version to appear in Phys. Lett.

Rare BB and KK decays in a scotogenic model

A scotogenic model can radiatively generate the observed neutrino mass, provide a dark matter candidate, and lead to rare lepton flavor-violating processes. We aim to extend the model to establish a potential connection to the quark flavor-related processes within the framework of scotogenesis, enhancing the unexpectedly large branching ratio (BR) of $B^+\to K^+ \nu \bar\nu$, observed by Belle II Collaboration. Meanwhile, the model can address tensions between some experimental measurements and standard model (SM) predictions in flavor physics, such as the muon $g-2$ excess and the higher BR of $B_s \to \mu^- \mu^+$. We introduce in the model the following dark particles: a neutral singlet Dirac-type lepton ($N$); two inert Higgs doublets ($\eta_{1,2}$), with one of which carrying a lepton number; a charged singlet dark scalar $(\chi^+)$, and a singlet vector-like up-type dark quark ($T$). The first two entities are responsible for the radiative neutrino mass, and $\chi^+$ couples to right-handed quarks and leptons and can resolve the tensions existing in muon $g-2$ and $B_s\to \mu^- \mu^+$. Furthermore, the BR of $B^+ \to K^+ \nu \bar\nu$ can be enhanced up to a factor of 2 compared to the SM prediction through the mediations of the dark $T$ and the charged scalars. In addition, we also study the impacts on the $K\to \pi \nu \bar\nu$ decays.Comment: 34 pages, 6 figures, references added, text revise

La adquisición del tiempo-aspecto en español en L3 para los aprendices taiwaneses

The purpose of this study was to investigate the inter-language development of the Spanish past tense by Taiwanese learners who learned Spanish as a second foreign language. The analysis of this study was based on the Lexical Aspect Hypothesis, which focuses on the inherent lexical aspect of verbs. We came to the following conclusions. (1) Taiwanese learners, whose first language was Mandarin Chinese, demonstrated more accurate uses of the Spanish preterite than the imperfect in written texts at their early stages of development. The acquisition of the lexical aspects of verbs in the preterite in terms of lexical aspect demonstrated the following order: achievement + accomplishment, activity and finally stative, whereas the acquisition of the imperfect showed the opposite sequence. (2) In the majority of the cases, the Taiwanese learners of Spanish demonstrated a similar pattern of acquisition of the Spanish past tense in terms of lexical aspect as that of English-speaking learner of Spanish. This paper will end with discussions on pedagogical implications of the findings and we hope this study will shed light on the current research on the second language acquisition of the Spanish tense/aspect.Este trabajo tiene como fin investigar el desarrollo de los tiempos pasados en la interlengua de los aprendices taiwaneses que aprenden español como segunda lengua extranjera. El análisis se basa en la Hipótesis de Aspecto Léxico que se centra en la importancia del aspecto léxico de los verbos. Llegamos a las siguientes conclusiones: (1) los aprendices taiwaneses de español cuya lengua materna es chino-mandarín manejan el pretérito mejor que el imperfecto en la producción escrita de los niveles iniciales de aprendizaje, el desarrollo de adquisición del pretérito indefinido es de acuerdo al siguiente orden: estado, actividad y realización+logro, mientras que para la adquisición del imperfecto los estudiantes siguen un orden contrario. (2) En la mayoría de los casos los aprendices taiwaneses de español siguen el mismo patrón de aprendizaje que los aprendices cuya lengua materna es el inglés en la adquisición del aspecto temporal. Por último, hacemos sugerencias pedagógicas correspondientes a las conclusiones deducidas para mejorar el resultado de aprendizaje. Con esto, esperamos que esta investigación represente una contribución al estudio relacionado con la adquisición del tiempo-aspecto en español

The Severity of Fatty Liver Disease Relating to Metabolic Abnormalities Independently Predicts Coronary Calcification

Background. Nonalcoholic fatty liver disease (NAFLD) is one of the metabolic disorders presented in liver. The relationship between severity of NAFLD and coronary atherosclerotic burden remains largely unknown. Methods and Materials. We analyzed subjects undergoing coronary calcium score evaluation by computed tomography (MDCT) and fatty liver assessment using abdominal ultrasonography. Framingham risk score (FRS) and metabolic risk score (MRS) were obtained in all subjects. A graded, semiquantitative score was established to quantify the severity of NAFLD. Multivariate logistic regression analysis was used to depict the association between NAFLD and calcium score. Results. Of all, 342 participants (female: 22.5%, mean age: 48.7 ± 7.0 years) met the sufficient information rendering detailed analysis. The severity of NAFLD was positively associated with MRS (X2 = 6.12, trend P < 0.001) and FRS (X2 = 5.88, trend P < 0.001). After multivariable adjustment for clinical variables and life styles, the existence of moderate to severe NAFLD was independently associated with abnormal calcium score (P < 0.05). Conclusion. The severity of NAFLD correlated well with metabolic abnormality and was independently predict coronary calcification beyond clinical factors. Our data suggests that NAFLD based on ultrasonogram could positively reflect the burden of coronary calcification

Comparison of the Prevalence of Metabolic Syndrome Between the Criteria for Taiwanese and Japanese and the Projected Probability of Stroke in Elderly Hypertensive Taiwanese

SummaryBackgroundThe cutoff of abdominal circumference for metabolic syndrome (MS) defined by the Bureau of Health Promotion (BHP) of Taiwan for Taiwanese (men, 90cm; women, 80cm) and by the International Diabetes Federation (IDF) for Japanese (men, 85cm; women, 90cm) differs. This study aimed to examine the impact of this difference on the prevalence of MS and the impact of an MS diagnosis on the projected risk of stroke in hypertensive Taiwanese.MethodsMS was examined in a sample of 3,472 hypertensive patients (aged 55–80 years; 1,709 women) across Taiwan. The 10-year probability of stroke estimated from the Framingham equation was compared between MS and non-MS patients.ResultsThe prevalence of MS using the BHP criteria was 59.2% using the BHP criteria (95% confidence interval, CI, 57.6–60.8%; men, 52.5%; women, 66.1%) and 48.9% by the IDF criteria (95% CI, 47.2–50.5%; men, 61.3%; women, 36.1%). Both criteria showed that, compared with non-MS, MS has higher predicted 10-year probability of stroke (BHP, 0.153 ± 0.115 vs. 0.133 ± 0.105; IDF, 0.159 ± 0.109 vs. 0.132 ± 0.112; both p < 0.001) because of the difference in women (BHP, 0.143 ± 0.124 vs. 0.102 ± 0.091; IDF, 0.147 ± 0.121 vs. 0.118 ± 0.110; both p < 0.001) rather than men (BHP, p = 0.21; IDF, p = 0.29).ConclusionBoth criteria demonstrate that MS is highly prevalent in elderly hypertensive patients in Taiwan. Additionally in women, but not men, the predicted probability of stroke is higher in MS than in non-MS patients. The diagnosis of MS is potentially useful for identifying elderly hypertensive females with an elevated risk of stroke in Taiwan

Hafnium oxide-based ferroelectric thin-film transistor with a-InGaZnO channel fabricated at temperatures \u3c= 350°C

HfO2-based ferroelectric materials integrated with oxide-based thin-film transistors have been considered as potential candidates for back-end-of-line compatible ferroelectric field-effect transistors, which can be vertically stacked on silicon CMOS circuits to realize high-density neural network applications. However, the formation of ferroelectric orthorhombic phase in HfO2-based materials usually requires an annealing temperature of 400°C or higher. In this work, ferroelectric thin-film transistors (Fe-TFTs) were developed by monolithically integrating HfZrO2 (HZO) ferroelectric capacitors with amorphous indium-gallium-zinc oxide (a-IGZO) TFTs at a maximum processing temperature of 350°C on a glass substrate. A butterfly-shaped C-V curve was clearly observed in the low-temperature annealed metal-HZO-metal capacitor, indicating the formation of ferroelectricity in the HZO layer, as shown in Fig. 1. The positive and negative coercive voltages were 3 V and -2.4 V, respectively. The dielectric constant was 20.65. The field-effect mobility, threshold voltage, subthreshold swing and on/off current ratio of the a-IGZO TFT extracted from the transfer characteristics shown in Fig. 2 were 6.15 cm2V-1s-1, 1.5 V, 0.1 V/dec and 4.3´107, respectively. Fig. 3 shows the transfer hysteresis curves of the low-temperature Fe-TFTs in a metal-ferroelectric-metal-insulator-semiconductor configuration. The Fe-TFTs exhibited large hysteresis memory windows of 2.8 V and 3.8 V when the area ratios between ferroelectric capacitors and gate insulators (AFE / ADE) were 1/8 and 1/12, respectively. The result shows a great potential for back-end-of-line compatible memory applications. Please click Download on the upper right corner to see the full abstract