Top Quark Rare Decays via Loop-Induced FCNC Interactions in Extended Mirror Fermion Model

Flavor changing neutral current (FCNC) interactions for a top quark $t$ decays into $Xq$ with $X$ represents a neutral gauge or Higgs boson, and $q$ a up- or charm-quark are highly suppressed in the Standard Model (SM) due to the Glashow-Iliopoulos-Miami mechanism. Whilst current limits on the branching ratios of these processes have been established at the order of $10^{-4}$ from the Large Hadron Collider experiments, SM predictions are at least nine orders of magnitude below. In this work, we study some of these FCNC processes in the context of an extended mirror fermion model, originally proposed to implement the electroweak scale seesaw mechanism for non-sterile right-handed neutrinos. We show that one can probe the process $t \to Zc$ for a wide range of parameter space with branching ratios varying from $10^{-6}$ to $10^{-8}$, comparable with various new physics models including the general two Higgs doublet model with or without flavor violations at tree level, minimal supersymmetric standard model with or without $R$-parity, and extra dimension model.Comment: 30 pages, 8 figures, 2 tables and 1 appendix. Version to appear in NP

A Study on Factors Affecting the Abstention of Drug Abuse in Private Rehabilitation Institutes in Taiwan — Operation Dawn Taiwan as an Example

The purpose of this study is to understand problems of the abstention of drug abuse in Taiwan. Comparing the model of Operation Dawn Taiwan with that of the government’s official rehabilitation institutes, this paper aims to identify advantages and disadvantages of the model in private institutes. The opinions of all inmates and tutors in Operation Dawn Taiwan, the biggest private rehabilitation institute in Taiwan, were collected via questionnaires. This study’s findings show that factors of relapse for a drug abuser after leaving rehabilitation institutes include: 1) the enticement from drug fellows; 2) incapability to resist the allure of drugs; 3) unemployment or hindrances to job-finding; 4) psychological depression; and 5) his/her desire for drugs. Inmates and tutors hold the same opinion on all models of the abstention of drug abuse. Specific suggestions of the abstention of drug abuse in Taiwan will also be discussed in this paper. Finally, inmates consider that career planning has significant positive correlations with abstention

In vivo sub-femtoliter resolution photoacoustic microscopy with higher frame rates

Microscopy based on non-fluorescent absorption dye staining is widely used in various fields of biomedicine for 400 years. Unlike its fluorescent counterpart, non-fluorescent absorption microscopy lacks proper methodologies to realize its in vivo applications with a sub-femtoliter 3D resolution. Regardless of the most advanced high-resolution photoacoustic microscopy, sub-femtoliter spatial resolution is still unattainable, and the imaging speed is relatively slow. In this paper, based on the two-photon photoacoustic mechanism, we demonstrated a in vivo label free laser-scanning photoacoustic imaging modality featuring high frame rates and sub-femtoliter 3D resolution simultaneously, which stands as a perfect solution to 3D high resolution non-fluorescent absorption microscopy. Furthermore, we first demonstrated in vivo label-free two-photon acoustic microscopy on the observation of non-fluorescent melanin distribution within mouse skin

The Arabidopsis Malectin-Like/LRR-RLK IOS1 is Critical for BAK1-Dependent and BAK1-Independent Pattern-Triggered Immunity

Plasma membrane-localized pattern recognition receptors (PRRs) such as FLAGELLIN SENSING2 (FLS2), EF-TU RECEPTOR (EFR) and CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) recognize microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). A reverse genetics approach on genes responsive to the priming agent beta-aminobutyric acid (BABA) revealed IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) as a critical PTI player. Arabidopsis thaliana ios1 mutants were hyper-susceptible to Pseudomonas syringae bacteria. Accordingly, ios1 mutants showed defective PTI responses, notably delayed up-regulation of the PTI-marker gene FLG22-INDUCED RECEPTOR-LIKE KINASE1 (FRK1), reduced callose deposition and mitogen-activated protein kinase activation upon MAMP treatment. Moreover, Arabidopsis lines over-expressing IOS1 were more resistant to bacteria and showed a primed PTI response. In vitro pull-down, bimolecular fluorescence complementation, co-immunoprecipitation, and mass spectrometry analyses supported the existence of complexes between the membrane-localized IOS1 and BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1)-dependent PRRs FLS2 and EFR, as well as with the BAK1-independent PRR CERK1. IOS1 also associated with BAK1 in a ligand-independent manner, and positively regulated FLS2-BAK1 complex formation upon MAMP treatment. In addition, IOS1 was critical for chitin-mediated PTI. Finally, ios1 mutants were defective in BABA-induced resistance and priming. This work reveals IOS1 as a novel regulatory protein of FLS2-, EFR- and CERK1-mediated signaling pathways that primes PTI activation

SIFTING FOR SAPPHIRES IN THE TRANSIENT SKY: THE SEARCH FOR TIDAL DISRUPTION EVENTS IN THE OPTICAL TIME DOMAIN

Tidal disruption events (TDEs) refer to the scenario where a star passes within the tidal disruption sphere of a supermassive black hole (SMBH) and becomes torn apart by tidal stresses. In the classical picture, a thermal flare is expected once the bound stellar debris circularize to form an accretion disk that feeds onto the black hole. This flare of radiation provides a unique window to study the demographics of black holes within distant and quiescent galaxies that cannot be probed by other means. In addition, TDEs serve as a powerful probe of the accretion process, where the mass fallback rate can be super-Eddington for \Mbh{} $<$ a few $\times$ 10$^7$ \Msun{}. In recent years, ground-based wide-field optical surveys have successfully detected about a dozen of TDEs. Yet our knowledge of these events is still limited due to their low occurrence rate ($\approx$ 10$^{-4}$--10$^{-5}$ gal$^{-1}$ yr$^{-1}$). In the first part of this thesis, we present results from a systematic selection of TDEs in the Intermediate Palomar Transient Factory (iPTF). Our selection targets typical optically-selected TDEs: blue transients ($g-r$ $<$ 0 mag) residing in the center of resolved red galaxies that are absent of previous nuclear activity. Our photometric selection has led to discoveries of two TDEs in $\sim$4 months, iPTF16axa and iPTF16fnl, in 2016. With the most stringent criteria, we significantly reduced the contamination rate from SN Ia and AGN from 200:1 to 4.5:1. We derived a TDE rate of 1.7$^{+2.9}_{-1.3}$ $\times$ 10$^{-4}$ gal$^{-1}$ yr$^{-1}$ and forecast a discovery rate of 32$^{+41}_{-25}$ TDEs per year for ZTF. The second part of this thesis features a detailed analysis of the photometric and spectroscopic observations on iPTF16axa. We compared iPTF16axa with 11 other TDEs in the literature with well-sampled optical light curves. We concluded that most of these TDE candidates have peak luminosities confined between log(L [erg s$^{-1}$]) = 43.4--44.4, with constant temperatures of a few $\times$ 10$^4$ K during their power-law declines, implying blackbody radii on the order of ten times the tidal disruption radius, that decrease monotonically with time. For TDE candidates with hydrogen and helium emission, the high helium-to-hydrogen ratios suggest that the emission arises from high-density gas, where nebular arguments break down. In the last part of this thesis, I present statistical analyses on the Zwicky Transient Facility (ZTF) data and comments on the TDE rate from the first few months of the survey. Finally, I close this chapter with an analysis on the optical spectra of the first ZTF TDE -- AT2018zr

THE ANALYSIS OF ANGULAR MOMENTUM OF SIDE-VOLLEY SOCCER SHOTS PERFORMED AT THREE BALL-HEIGHT

The purpose of this study was to examine side-volley soccer shots performed at three ballheight. Five amateur, right leg dominant, male soccer players (height = 173 ±2.86 cm; weight = 68 ±6.04 kg; age = 20.5 ±0.5 yrs) participated in this study. Two electrically synchronized highspeed video cameras (Redlake) were used to sample the kicking motion at 250 Hz. By the three-dimensional cinematographic technical analysis, the kicking leg was modeled as a threelink kinetic chain composed of thigh, shank, and foot, from which angular velocities and angular momentum were computed. Significantly greater ball velocity and foot velocity were achieved in kicking lower ball-height, with a shorter leg-swing time. The foot moment of inertia exhibited a high value in side-volley shot performed at the lower ball-height. These results indicated that the side-volley soccer shots performed at the lower ball-height would made higher value of foot angular momentum, and benefited ball velocity

Pengembangan Suplemen Pembelajaran Fisika Gelombang Elektromagnetik Cahaya Sebagai Partikel Memanfaatkan Virtual Laboratorium

This research has been done to make a supplement for physics learning about light electromagnetic wave as a particle using virtual laboratory. The population of this research was the second year science-students at SMA Muhammadiyah 1 Metro. This development is begun by needs analysis, then identification of resource which is the background of this developmental research. The next step is, identifying the product specification then developing products which contained a tutorial book for teacher and a work sheet for student (LKS). The material and design expert test result is that those products were approved. The external test resulted by users show that the LKS was attractive, very easy to use, and useful. It also was effective to be used as a learning resource because 80% of students reached the passing grade.Telah dilakukan penelitian untuk mengembangkan suplemen pembelajaran fisika gelombang elektromagnetik cahaya sebagai partikel dengan memanfaatkan virtual laboratorium. Populasi penelitian pengembangan ini adalah siswa kelas XI IPA di SMA Muhammadiyah 1 Metro. Pengembangan ini diawali dengan analisis kebutuhan, kemudian identifikasi sumber daya yang melatar belakangi pengembangan. Langkah selanjutnya identifikasi spesifikasi produk yang dilanjutkan dengan mengembangkan produk berupa LKS untuk siswa dan buku panduan untuk guru. Hasil uji internal oleh ahli materi dan ahli desain menyatakan produk yang dikembangkan layak digunakan sebagai media pembelajaran. Hasil uji eksternal oleh pengguna menunjukkan kualitas media pembelajaran menarik, sangat mudah digunakan, dan bermanfaat serta efektif digunakan sebagai media pembelajaran dengan presentase hasil belajar sebesar 80% siswa telah memenuhi KKM