We show that in generic leptoquark (LQ) extensions of the standard model lepton and baryon numbers are broken at the level of renormalizable operators. In particular, this may cause fast proton decay unless the leptoquarks are heavy enough. We derive stringent bounds for the 1st generation LQ masses and couplings from the proton stability constraints. Leptoquark models [1, 2] remain an attracti...

Model Introduction With the advancement of image-guided radiation therapy (RT), SRS, SBRT and HDR brachytherapy, there is increasing interest in the use of large dose fractions to irradiate human cancer. The dose prescription has been guided by clinical experience accumulated from conventional RT (2Gy fractions) and low-dose-rate (LDR) brachytherapy using the classic LQ model. However, concerns...

We develop a higher-order generalization of the LQ decomposition and show that this decomposition plays an important role in likelihood-based estimation and testing for separable, or Kronecker structured, covariance models, such as the multilinear normal model. This role is analogous to that of the LQ decomposition in likelihood inference for the multivariate normal model. Additionally, this hi...

We investigated the applicability of the repairable-conditionally repairable (RCR) model and the multi-target (MT) model to dose conversion in high-dose-per-fraction radiotherapy in comparison with the linear-quadratic (LQ) model. Cell survival data of V79 and EMT6 single cells receiving single doses of 2-12 Gy or 2 or 3 fractions of 4 or 5 Gy each, and that of V79 spheroids receiving single do...

The linear-quadratic (LQ) model is widely used to model the effect of total dose and dose per fraction in conventionally fractionated radiotherapy. Much of the data used to generate the model are obtained in vitro at doses well below those used in radiosurgery. Clinically, the LQ model often underestimates tumor control observed at radiosurgical doses. The underlying mechanisms implied by the L...

BACKGROUND The most frequently used method to quantitatively describe the response to ionizing irradiation in terms of clonogenic survival is the linear-quadratic (LQ) model. In the LQ model, the logarithm of the surviving fraction is regressed linearly on the radiation dose by means of a second-degree polynomial. The ratio of the estimated parameters for the linear and quadratic term, respecti...

Introduction: The aim of this study was to evaluation radiobiological modeling parameters on tumor control probability (TCP) for prostate cancer in three different models. These parameters included α⁄β ratios and cell surviving fraction at 2 Gy (SF2). Materials and Methods: The Poisson, equivalent uniform dose (EUD) and linear quadratic (LQ) models was used as...

We introduce a maximum Lq-likelihood estimation (MLqE) of mixture models using our proposed expectation maximization (EM) algorithm, namely the EM algorithm with Lq-likelihood (EM-Lq). Properties of the MLqE obtained from the proposed EMLq are studied through simulated mixture model data. Compared with the maximum likelihood estimation (MLE) which is obtained from the EM algorithm, the MLqE pro...

We perform an analysis of the quark angular momentum in a light-cone representation by taking into account the effect due to the Melosh-Wigner rotation and find that there is a relativistic correction factor connecting the quark orbital angular momentum with the quark model spin distribution: Lq(x) = < ML(x) >∆qQM(x). The quark orbital angular momentum Lq(x) and the quark helicity distribution ...

Given a dictionary of Mn initial estimates of the unknown true regression function, we aim to construct linearly aggregated estimators that target the best performance among all the linear combinations under a sparse q-norm (0 ≤ q ≤ 1) constraint on the linear coefficients. Besides identifying the optimal rates of aggregation for these lq-aggregation problems, our multi-directional (or adaptive...