Anomalous response in the vicinity of spontaneous symmetry breaking

We propose a mechanism to induce negative AC permittivity in the vicinity of a ferroelectric phase transition involved with spontaneous symmetry breaking. This mechanism makes use of responses at low frequency, yielding a high gain and a large phase delay, when the system jumps over the free-energy barrier with the aid of external fields. We illustrate the mechanism by analytically studying spin models with the Glauber-typed dynamics under periodic perturbations. Then, we show that the scenario is supported by numerical simulations of mean-field as well as two-dimensional spin systems.Comment: 6 pages, 5 figure

The Effect of Transparency Policies on Shadow Economy: Measurement and Evidence from Korea

This paper provides a new and simple methodology to examine the relative size of the shadow economy to the official one using the quantity theory of money identity. We measure the shadow economy size in Korea annually. The Korean government has implemented various transparency policy measures to identify the tax source in commercial transactions. We find significant evidence that credit card encouragement and the cash payment receipt system have a negative effect on the shadow economy size

Valuation of Credit Derivatives with Multiple Time Scales in the Intensity Model

We propose approximate solutions for pricing zero-coupon defaultable bonds, credit default swap rates, and bond options based on the averaging principle of stochastic differential equations. We consider the intensity-based defaultable bond, where the volatility of the default intensity is driven by multiple time scales. Small corrections are computed using regular and singular perturbations to the intensity of default. The effectiveness of these corrections is tested on the bond price and yield curve by investigating the behavior of the time scales with respect to the relevant parameters

Penerapan Bermain Messy Play dalam Meningkatkan Kemampuan Motorik Halus Anak Tk Kelompok A

Salah satu aspek kemampuan yang penting untuk dikembangkan pada anak usia dini adalahkemampuan motorik halus anak. Kemampuan motorik halus membantu anak untukmemperoleh kemandiriannya, membantu mendapatkan penerimaan sosial, dan dapatmenimbulkan rasa percaya diri pada anak. Kemampuan motorik halus dapat ditingkatkan melaluibermain messy play. Messy Play merupakan jenis permainan yang merangsang sensor motorikhalus dan kasar.Permainan ini dilakukan anak baik di alam terbuka maupun di dalam ruangandan membuat tubuh anak menjadi kotor, sehingga dikatakan dengan bermain messy play.Selaintubuh anak aktif, anak juga akan belajar mengkoordinasikan panca inderanya melalui sentuhan,bau, rasa, pendengaran, dan penglihatan. Tujuan dalam penelitian ini yaitu (1)mendeskripsikanpenerapan bermain messy play dalam meningkatkan kemampuan motorik halus anak KelompokA, (2) Mendeskripsikan hasil penerapan bermain messy play dalam meningkatkan kemampuanmotorik halus anak Kelompok A. Sedangkan luaran yang ditargetkan dalam penelitian ini adalahtersedianya perangkat pembelajaran dengan penerapan bermain Messy Play untukmeningkatkan kemampuan motorik halus pada anak TK kelompok A. Metode yang digunakandalam penelitian ini adalah metode penelitian tindakan kelas (PTK) yang dilakukan melalui 4tahapan dalam setiap siklusnya. Adapun tahapan tersebut adalah: (1) perencanaan, (2)pelaksanaan, (3) observasi, dan (4) refleksi. Penelitian ini dilaksanakan di TK Aisyiyah BustanulAthfal Kalibader dengan 2 siklus. Siklus I dilakukan empat kali pertemuan, jika dalam siklus Ibelum berhasil, maka dilakukan siklus II dengan tiga kali pertemuan. Teknik pengumpulan datamenggunakan observasi, lembar asesmen, wawancara dan dokumentasi. Hasil penerapanbermain messy play dapat meningkatkan kemampuan motorik halus anak kelompok A di TKAisyiyah Kalibader. Hal ini dibuktikan adanya peningkatan pada nilai ketuntasan di siklus I dansiklus II. Pada siklus I ketuntasan nilai keseluruhan kelompok A adalah 65%, dan pada siklus IIketuntasan nilai keseluruhan kelompok A adalah 88,1%. Hal ini membuktikan adanya peningkatankemampuan motorik halus anak kelompok A setelah dilakukan penerapan bermain messy play

Signaling Events During Induction of Plasminogen Activator Inhibitor-1 Expression by Sphingosylphosphorylcholine in Cultured Human Dermal Fibroblasts

Sphingosylphosphorylcholine (SPC) is a bioactive sphingolipid metabolite that can enhance wound healing. In a search for effectors downstream of SPC in the wound-healing process, we found that the expression of the gene for plasminogen activator inhibitor-1 (PAI-1) was significantly affected. ELISA and western blot analyses showed that SPC markedly induced PAI-1 production in human dermal fibroblasts cultured in vitro. Inhibition by pre-treatment with pertussis toxin (PTx), but not by tyrphostin A47 (a receptor tyrosine kinase inhibitor), indicated that PTx-sensitive G proteins were involved in SPC-induced PAI-1 expression. SPC elicited a rapid and transient increase in intracellular calcium levels ([Ca2+]i), measured using laser scanning confocal microscopy, which was partly mediated through PTx-sensitive G proteins. Pre-treatment with thapsigargin, but not with EGTA, abolished SPC-induced PAI-1 expression, indicating the importance of Ca2+ release from internal stores. Phorbol-12-myristate-13-acetate (PMA) induced the expression of PAI-1, and pre-treatment with Ro 31-8220 (a PKC inhibitor) markedly suppressed SPC-induced PAI-1 expression. SPC-induced PAI-1 expression was also significantly suppressed by PD98059 (a specific MAPK kinase 1/2 inhibitor). Consistent with this result, SPC stimulated the phosphorylation of p42/44 extracellular signal-regulated kinase (ERK). Together, these results suggest that SPC induces PAI-1 production through a G protein-coupled calcium increase and downstream kinase signaling events in cultured human dermal fibroblasts

Pulmonary Metastases of Alveolar Soft-Part Sarcoma: CT Findings in Three Patients

Alveolar soft-part sarcoma is a rare soft tissue sarcoma of young adults with unknown histogenesis, and the organ most frequently involved in metastasis is the lung. We report the CT findings of three patients of pulmonary metastases of alveolar soft-part sarcoma, which manifested as clearly enhanced pulmonary nodules or masses. On enhanced scans, some of the masses were seen to contain dilated and tortuous intratumoral vessels

Forward-looking ultrasound wearable scanner system for estimation of urinary bladder volume

Accurate measurement of bladder volume is an important tool for evaluating bladder function. In this study, we propose a wearable bladder scanner system that can continuously measure bladder volume in daily life for urinary patients who need urodynamic studies. The system consisted of a 2-D array, which included integrated forward-looking piezoelectric transducers with thin substrates. This study aims to estimate the volume of the bladder using a small number of piezoelectric transducers. A least-squares method was implemented to optimize an ellipsoid in a quadratic surface equation for bladder volume estimation. Ex-vivo experiments of a pig bladder were conducted to validate the proposed system. This work presents the potential of the approach for wearable bladder monitoring, which has similar measurement accuracy compared to the commercial bladder imaging system. The wearable bladder scanner can be improved further as electronic voiding diaries by adding a few more features to the current function. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.1