3,465,042 research outputs found
Toward the classification of the realistic free fermionic models
The realistic free fermionic models have had remarkable success in providing
plausible explanations for various properties of the Standard Model which
include the natural appearance of three generations, the explanation of the
heavy top quark mass and the qualitative structure of the fermion mass spectrum
in general, the stability of the proton and more. These intriguing achievements
makes evident the need to understand the general space of these models. While
the number of possibilities is large, general patterns can be extracted. In
this paper I present a detailed discussion on the construction of the realistic
free fermionic models with the aim of providing some insight into the basic
structures and building blocks that enter the construction. The role of free
phases in the determination of the phenomenology of the models is discussed in
detail. I discuss the connection between the free phases and mirror symmetry in
(2,2) models and the corresponding symmetries in the case of the (2,0) models.
The importance of the free phases in determining the effective low energy
phenomenology is illustrated in several examples. The classification of the
models in terms of boundary condition selection rules, real world-sheet fermion
pairings, exotic matter states and the hidden sector is discussed.Comment: 43 pages. Standard Late
Vortex line representation for flows of ideal and viscous fluids
It is shown that the Euler hydrodynamics for vortical flows of an ideal fluid
coincides with the equations of motion of a charged {\it compressible} fluid
moving due to a self-consistent electromagnetic field. Transition to the
Lagrangian description in a new hydrodynamics is equivalent for the original
Euler equations to the mixed Lagrangian-Eulerian description - the vortex line
representation (VLR). Due to compressibility of a "new" fluid the collapse of
vortex lines can happen as the result of breaking (or overturning) of vortex
lines. It is found that the Navier-Stokes equation in the vortex line
representation can be reduced to the equation of the diffusive type for the
Cauchy invariant with the diffusion tensor given by the metric of the VLR
The influence of toxicity constraints in models of chemotherapeutic protocol escalation
The prospect of exploiting mathematical and computational models to gain insight into the influence of scheduling on cancer chemotherapeutic effectiveness is increasingly being considered. However, the question of whether such models are robust to the inclusion of additional tumour biology is relatively unexplored. In this paper, we consider a common strategy for improving protocol scheduling that has foundations in mathematical modelling, namely the concept of dose densification, whereby rest phases between drug administrations are reduced. To maintain a manageable scope in our studies, we focus on a single cell cycle phase-specific agent with uncomplicated pharmacokinetics, as motivated by 5-Fluorouracil-based adjuvant treatments of liver micrometastases. In particular, we explore predictions of the effectiveness of dose densification and other escalations of the protocol scheduling when the influence of toxicity constraints, cell cycle phase specificity and the evolution of drug resistance are all represented within the modelling. For our specific focus, we observe that the cell cycle and toxicity should not simply be neglected in modelling studies. Our explorations also reveal the prediction that dose densification is often, but not universally, effective. Furthermore, adjustments in the duration of drug administrations are predicted to be important, especially when dose densification in isolation does not yield improvements in protocol outcomes
Evaluation of Rice Cultivars for Resistance to \u3ci\u3eCnaphalocrocis medinalis\u3c/i\u3e Guenée (Lepidoptera: Pyralidae)
Greenhouse screening of 17,914 accessions of rice, Oryza sativa L., from 62 countries identified 115 accessions from 10 countries having resistant or moderately resistant reactions to Cnaphalocrocis medinalis GuenĂ©e. Of 264 wild rices (Oryza spp.) screened, 10 (3.7%) were resistant. Several breeding lines having âPtb33â and âW1263â as donor parents were moderately resistant. All of the resistant accessions are from regions where C. medinalis is an important pest, except for one accession from Italy, which is beyond the range of C. medinalis distribution
Anticommutativity Equation in Topological Quantum Mechanics
We consider topological quantum mechanics as an example of topological field
theory and show that its special properties lead to numerous interesting
relations for topological corellators in this theory. We prove that the
generating function for thus corellators satisfies the
anticommutativity equation . We show that the
commutativity equation could be considered as a special case of the
anticommutativity equation.Comment: 6 pages, no figures, Late
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