RNA in human sperm

We have yet to develop a fundamental understanding of the molecular complexities of human spermatozoa.This encompasses the unique packaging and structure of the sperm genome along with their paternally derived RNAs in preparation for their delivery to the egg.The diversity of these transcripts is vast,including several anti-sense mol- ecules resembling known regulatory micro-RNAs.The field is still grasping with its delivery to the oocyte at fertiliza- tion and possible significance.It remains tempting to analogize them to maternally-derived transcripts active in early embryo patterning.Irrespective of their role in the embryo,their use as a means to assess male factor infertility is promising.

Characterization of nucleohistone and nucleoprotamine components in the mature human sperm nucleus

Aim： To simultaneously determine the localization of histones and protamines within human sperm nuclei. Methods： Immunofluorescence of the core histones and protamines and fluorescence in situ hybridization of the telomere region of chromosome 16 was assessed in decondensed human sperm nuclei. Results： Immunofluorescent localization of histones, protamine 1 （PRM1） and protamine 2 （PRM2） along with fluorescence in situ hybridization localization of chromosome 16 telomeric sequences revealed a discrete distribution in sperm nuclei. Histones localized to the posterior ring region （i.e. the sperm nuclear annulus）, whereas PRM1 and PRM2 appeared to be dispersed throughout the entire nucleus. Conclusion： The co-localization of the human core sperm histones with the telomeric regions of chromosome 16 is consistent with the reorganization of specific non-protamine regions into a less compacted state.

人类精子RNA的重要性

我们对人类精子分子组成复杂性的理解仍处于初步阶段。这包括随时准备与卵细胞结合的精子基因组及其RNA具有独特的包装和结构。两者凸现了我们对遗传学因素如何有助于一个健康的孩子的出生理解不足。最近从人类精液中分离出的RNA可被用来显示转录的男性配子的轮廓。完全可以预期,具有正常生育能力的精子基因指纹特征能被鉴定,由此轮廓产生的背离能被检测。

A Generalized Numerical Approach for Modeling Multiphase Flow and Transport in Fractured Porous Media

A physically based numerical approach is presented for modeling multiphase flow and transport processes in fractured rock.In particular,a general framework model is discussed for dealing with fracture-matrix interactions,which is applicable to both continuum and discrete fracture conceptualization.The numerical modeling approach is based on a general multiple-continuum concept,suitable for modeling any types of fractured reservoirs,including double-,triple-,and other multiplecontinuum conceptual models.In addition,a new,physically correct numerical scheme is discussed to calculate multiphase flow between fractures and the matrix,using continuity of capillary pressure at the fracture-matrix interface.The proposed general modeling methodology is verified in special cases using analytical solutions and laboratory experimental data,and demonstrated for its application in modeling flow through fractured vuggy reservoirs.

Boundary Conditions for Limited Area Models Based on the Shallow Water Equations

A new set of boundary conditions has been derived by rigorousmethods for the shallow water equations in a limited domain.The aim of this article is to present these boundary conditions and to report on numerical simulations which have been performed using these boundary conditions.The new boundary conditions which are mildly dissipative let the waves move freely inside and outside the domain.The problems considered include a one-dimensional shallow water system with two layers of fluids and a two-dimensional inviscid shallow water system in a rectangle.

Balanced Truncation Based on Generalized Multiscale Finite Element Method for the Parameter-Dependent Elliptic Problem

In this paper,we combine the generalized multiscale finite element method(GMsFEM)with the balanced truncation(BT)method to address a parameterdependent elliptic problem.Basically,in progress of a model reduction we try to obtain accurate solutions with less computational resources.It is realized via a spectral decomposition from the dominant eigenvalues,that is used for an enrichment of multiscale basis functions in the GMsFEM.The multiscale bases computations are localized to specified coarse neighborhoods,and follow an offline-online process in which eigenvalue problems are used to capture the underlying system behaviors.In the BT on reduced scales,we present a local-global strategy where it requires the observability and controllability of solutions to a set of Lyapunov equations.As the Lyapunov equations need expensive computations,the efficiency of our combined approach is shown to be readily flexible with respect to the online space and an reduced dimension.Numerical experiments are provided to validate the robustness of our approach for the parameter-dependent elliptic model.

Colocated Finite Volume Schemes for Fluid Flows

Our aim in this article is to improve the understanding of the colocated finite volume schemes for the incompressible Navier-Stokes equations.When all the variables are colocated,that means here when the velocities and the pressure are computed at the same place(at the centers of the control volumes),these unknowns must be properly coupled.Consequently,the choice of the time discretization and the method used to interpolate the fluxes at the edges of the control volumes are essentials.In the first and second parts of this article,two different time discretization schemes are considered with a colocated space discretization and we explain how the unknowns can be correctly coupled.Numerical simulations are presented in the last part of the article.This paper is not a comparison between staggered grid schemes and colocated schemes(for this,see,e.g.,[15,22]).We plan,in the future,to use a colocated space discretization and the multilevel method of[4]initially applied to the two dimensional Burgers problem,in order to solve the incompressible Navier-Stokes equations.One advantage of colocated schemes is that all variables share the same location,hence,the possibility to use hierarchical space discretizations more easily when multilevel methods are used.For this reason,we think that it is important to study this family of schemes.

Multiscale Modeling and Simulations of Flows in Naturally Fractured Karst Reservoirs

Modeling and numerical simulations of fractured,vuggy,porus media is a challenging problem which occurs frequently in reservoir engineering.The problem is especially relevant in flow simulations of karst reservoirs where vugs and caves are embedded in a porous rock and are connected via fracture networks at multiple scales.In this paper we propose a unified approach to this problem by using the StokesBrinkman equations at the fine scale.These equations are capable of representing porous media such as rock as well as free flow regions(fractures,vugs,caves)in a single system of equations.We then consider upscaling these equations to a coarser scale.The cell problems,needed to compute coarse-scale permeability of Representative Element of Volume(REV)are discussed.A mixed finite element method is then used to solve the Stokes-Brinkman equation at the fine scale for a number of flow problems,representative for different types of vuggy reservoirs.Upscaling is also performed by numerical solutions of Stokes-Brinkman cell problems in selected REVs.Both isolated vugs in porous matrix as well as vugs connected by fracture networks are analyzed by comparing fine-scale and coarse-scale flow fields.Several different types of fracture networks,representative of short-and long-range fractures are studied numerically.It is also shown that the Stokes-Brinkman equations can naturally be used to model additional physical effects pertaining to vugular media such as partial fracture with fill-in by some material and/or fluids with suspended solid particles.

Solving Delay Differential Equations through RBF Collocation

A general and easy-to-code numerical method based on radial basis functions(RBFs)collocation is proposed for the solution of delay differential equations(DDEs).It relies on the interpolation properties of infinitely smooth RBFs,which allow for a large accuracy over a scattered and relatively small discretization support.Hardy’s multiquadric is chosen as RBF and combined with the Residual Subsampling Algorithm of Driscoll and Heryudono for support adaptivity.The performance of the method is very satisfactory,as demonstrated over a cross-section of benchmark DDEs,and by comparison with existing general-purpose and specialized numerical schemes for DDEs.

Time Discrete Approximation of Weak Solutions to Stochastic Equations of Geophysical Fluid Dynamics and Applications(Dedicated to Haim Brézis on the occasion of his 70th birthday)

As a first step towards the numerical analysis of the stochastic primitive equations of the atmosphere and the oceans, the time discretization of these equations by an implicit Euler scheme is studied. From the deterministic point of view, the 3D primitive equations are studied in their full form on a general domain and with physically realistic boundary conditions. From the probabilistic viewpoint, this paper deals with a wide class of nonlinear, state dependent, white noise forcings which may be interpreted in either the Itor the Stratonovich sense. The proof of convergence of the Euler scheme,which is carried out within an abstract framework, covers the equations for the oceans, the atmosphere, the coupled oceanic-atmospheric system as well as other related geophysical equations. The authors obtain the existence of solutions which are weak in both the PDE and probabilistic sense, a result which is new by itself to the best of our knowledge.

ＲＥＧＵＬＡＲＩＴＹ ＲＥＳＵＬＴＳ ＦＯＲ ＬＩＮＥＡＲＥＬＬＩＰＴＩＣ ＰＲＯＢＬＥＭＳ ＲＥＬＡＴＥＤＴＯ ＴＨＥ ＰＲＩＭＩＴＩＶＥ ＥＱＵＡＴＩＯＮＳ

The authors study the regularity of soutions of the GFD-Stokes problem and of some second order linear elliptic partial differential equations related to the PrimitiveEquations of the ocean .The present work generallizes the regularity results in[18] by taking into consideraion the non- homogeneous boundary conditions and teh dependence of solutions on the thickness of the domain occupied by the ocean and its varying bottom topography. These regularity results are important tools in the study of the PEs(see e.g.[6]), and they seem also to possess their own interest.

Finite Volume Multilevel Approximation of the Shallow Water Equations

The authors consider a simple transport equation in one-dimensional space and the linearized shallow water equations in two-dimensional space, and describe and implement a multilevel finite-volume discretization in the context of the utilization of the incremental unknowns. The numerical stability of the method is proved in both cases.

Mathematical Analysis of the Jin-Neelin Model of El Niño-Southern-Oscillation

The Jin-Neelin model for the El Nio–Southern Oscillation(ENSO for short) is considered for which the authors establish existence and uniqueness of global solutions in time over an unbounded channel domain. The result is proved for initial data and forcing that are sufficiently small. The smallness conditions involve in particular key physical parameters of the model such as those that control the travel time of the equatorial waves and the strength of feedback due to vertical-shear currents and upwelling; central mechanisms in ENSO dynamics.From the mathematical view point, the system appears as the coupling of a linear shallow water system and a nonlinear heat equation. Because of the very different nature of the two components of the system, the authors find it convenient to prove the existence of solution by semi-discretization in time and utilization of a fractional step scheme. The main idea consists of handling the coupling between the oceanic and temperature components by dividing the time interval into small sub-intervals of length k and on each sub-interval to solve successively the oceanic component, using the temperature T calculated on the previous sub-interval, to then solve the sea-surface temperature(SST for short) equation on the current sub-interval. The passage to the limit as k tends to zero is ensured via a priori estimates derived under the aforementioned smallness conditions.

The 2D Euler–Boussinesq Equations in Planar Polygonal Domains with Yudovich’s Type Data

We address the well-posedness of the 2D(Euler)–Boussinesq equations with zero viscosity and positive diffusivity in the polygonal-like domains with Yudovich’s type data,which gives a positive answer to part of the questions raised in Lai(Arch Ration Mech Anal 199(3):739–760,2011).Our analysis on the the polygonallike domains essentially relies on the recent elliptic regularity results for such domains proved in Bardos et al.(J Math Anal Appl 407(1):69–89,2013)and Di Plinio(SIAM J Math Anal 47(1):159–178,2015).

Numerical Resolution Near t=0 of Nonlinear Evolution Equations in the Presence of Corner Singularities in Space Dimension 1

The incompatibilities between the initial and boundary data will cause singularities at the time-space corners,which in turn adversely affect the accuracy of the numerical schemes used to compute the solutions.We study the corner singularity issue for nonlinear evolution equations in 1D,and propose two remedy procedures that effectively recover much of the accuracy of the numerical scheme in use.Applications of the remedy procedures to the 1D viscous Burgers equation,and to the 1D nonlinear reaction-diffusion equation are presented.The remedy procedures are applicable to other nonlinear diffusion equations as well.