Korean Child-Rearing Practices in the United States: An Ethnographic Study on Korean Immigrants in the Cultural Transition

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TT‾T\overline{T} Deformation of N=(1,1)\mathcal{N}=(1,1) Off-Shell Supersymmetry and Partially Broken Supersymmetry

We construct the superaction for the $T\overline{T}$ deformation of 2D free $\mathcal{N}=(1,1)$ supersymmetric model with a deformed superfield. We show that the $\mathcal{N}=(1,1)$ off-shell is deformed under the $T\overline{T}$ deformation, which is reflected by the deformed superfield. We interpret this superaction as an effective action of the Goldstone superfield for the partial spontaneous breaking of $\mathcal{N}=(2,2)$ supersymmetry to $\mathcal{N}=(1,1)$. We demonstrate that the unbroken and broken supersymmetry of the effective superaction corresponds to the off-shell $\mathcal{N}=(1,1)$ supersymmetry and the off-shell fermi global non-linear symmetry in the $T\overline{T}$-deformed theory, respectively. We show that this effective superaction can be obtained by the non-linear realization of the partially broken global supersymmetry (PBGS) from the coset superspace. Furthermore, we reproduce the superaction by the constrained superfield method accompanied by a field redefinition.Comment: 33 pages; v2: reference adde

An Empirical Analysis of Repurchase Behavior in Mobile Commerce According to Different Mobile Channels

Smartphone-based m-commerce enables customers to purchase products in different channels. In the complicated mobile shopping channels, retaining existing customers becomes important. In light of these developments, this study focuses on crucial factors of repurchase behavior of consumers based on the recency, frequency, and monetary value (RFM) model and analyzes how their effects differ among mobile channels and the online channel. The mobile channels are divided into three channels: mobile application ( app ), mobile browser, and mobile shopping portal channels. Real purchase data for three million orders from online shopping sites is used for our empirical analysis. The results show that all RFM variables significantly affect repurchase behavior. Our findings imply that mobile app users are more likely to repurchase than users in other channels. It is also found that the frequency variable is more important for mobile channel users, while the recency variable is more important for online channel users

A Survey on the Impact of Operation Volume on Rectal Cancer Management

The rectal cancer management can be influenced by the surgeon's practice and the hospital. This study was to evaluate the differences according to the surgeon's operative volume and the level of the hospital. Questionnaires were sent out to the members of the 'Korean Society of Coloproctology', and the responses were evaluated according to the surgeon's operation volume, the surgeon's age, and the level of the hospital. Sixty responses were received during the three months' period (from August to October 2004). Thirty three respondents (55%) operated more than 50 cases of rectal cancer per year (high-volume surgeons), and 37 respondents (61%) worked at university hospitals or tertiary care facilities (high-level hospitals). The preoperative evaluation with endorectal ultrasonography (ERUS) was significantly different according to the surgeon's operation volume and the level of the hospital, whereas magnetic resonance imaging and positron emission tomography (PET) was significantly different only for the surgeon's operation volume. The preoperative radiation therapy was significantly different according to the surgeon's operation volume, the surgeon's age, and the level of the hospital. However, there was no significant difference found on the operative procedures or postoperative surveillance. The preoperative loco-regional evaluation and the preoperative radiation therapy could be considered as the factors that influence the volume-outcome relationship in rectal cancer treatment

A New p53 Target Gene, RKIP, Is Essential for DNA Damage-Induced Cellular Senescence and Suppression of ERK Activation

Abstractp53, a strong tumor suppressor protein, is known to be involved in cellular senescence, particularly premature cellular senescence. Oncogenic stresses, such as Ras activation, can initiate p53-mediated senescence, whereas activation of the Ras-mitogen-activated protein kinase (MAPK) pathway can promote cell proliferation. These conflicting facts imply that there is a regulatory mechanism for balancing p53 and Ras-MAPK signaling. To address this, we evaluated the effects of p53 on the extracellular signal-regulated kinase (ERK) activation and found that p53 could suppress ERK activation through de novo synthesis. Through several molecular biologic analyses, we found that RKIP, an inhibitor of Raf kinase, is responsible for p53-mediated ERK suppression and senescence. Overexpression of RKIP can induce cellular senescence in several types of cell lines, including p53-deficient cells, whereas the elimination of RKIP by siRNA or forced expression of ERK blocks p53-mediated cellular senescence. These results suggested that RKIP is an essential protein for cellular senescence. Moreover, modification of the p53 serine 46 residue was critical for RKIP induction and ERK suppression as well as cellular senescence. These results indicated that RKIP is a novel p53 target gene that is responsible for p53-mediated cellular senescence and tumor suppressor protein expression

Real-time measurement of the three-axis contact force distribution using a flexible capacitive polymer tactile sensor

In this paper, we report real-time measurement results of various contact forces exerted on a new flexible capacitive three-axis tactile sensor array based on polydimethylsiloxane (PDMS). A unit sensor consists of two thick PDMS layers with embedded copper electrodes, a spacer layer, an insulation layer and a bump layer. There are four capacitors in a unit sensor to decompose a contact force into its normal and shear components. They are separated by a wall-type spacer to improve the mechanical response time. Four capacitors are arranged in a square form. The whole sensor is an 8 _ 8 array of unit sensors and each unit sensor responds to forces in all three axes. Measurement results show that the full-scale range of detectable force is around 0–20 mN (250 kPa) for all three axes. The estimated sensitivities of a unit sensor with the current setup are 1.3, 1.2 and 1.2%/mN for the x- , y- and z -axes, respectively. A simple mechanical model has been established to calculate each axial force component from the measured capacitance value. Normal and shear force distribution images are captured from the fabricated sensor using a real-time measurement system. The mechanical response time of a unit sensor has been estimated to be less than 160 ms. The flexibility of the sensor has also been demonstrated by operating the sensor on a curved surface of 4 mm radius of curvature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90798/1/0960-1317_21_3_035010.pd