Numerical Simulation of Effects of Cloud Top Temperatures and Generating Cells on Secondary Ice Production in Stratiform Clouds with a Detailed Microphysical Model

This paper outlines a one-dimensional,heightdependent bin model with detailed microphysical processes in which ice splinters are produced by a riming process.The model is then applied to simulate the shift of particle size distribution effected by the secondary ice production process within clouds with different generating cells and cloud top temperatures.The result of model simulations reveals the general effects of cloud updrafts on increasing ice particle concentration by extending the residence time of ice particles in clouds and providing sufficiently large supercooled water droplets.The rimesplintering mechanism is more effective in clouds with lower ice seeding rates than those with higher rates.Evolutions of hydrometeor size distribution triggered by the rime-splintering mechanism indicate that the interaction between large ice particles and supercooled water drops adds a "second maximum" to the primary ice spectra.

F-Actin Visualization in Generative and Sperm Cells of Living Pollen of Rice Using a GFP-Mouse Talin Fusion Protein

Green fluorescent protein (GFP) fused to the F-actin binding domain of mouse talin labels the actin cytoskeleton in the living generative and sperm cells of a third generation transgenic rice (Oryza sativa L.) plant, A005-G-T-1-2. Observations were made on pollen at four major developmental stages, viz. I. uni-nucleate microspore stage; II. early bi-cellular pollen stage; III. late bi-cellular pollen stage; and IV. tri-cellular pollen stage. At each of these developmental stages vegetative nucleus, generative nucleus/ cell, and sperm cells were seen undergoing continuous and coordinated motion and migration. These movements seemed to be influenced by associated microfilament networks existing in the pollen. Based on these observations we propose that it is the interaction between the microfilament networks (usually one existing in the central cytoplasm and another in the cortex) that controls the dynamic movement of the vegetative nucleus, generative nucleus/cell and sperm cells. Furthermore, we have also observed that there is an array of microfilaments (oriented mostly parallel to the long axis of the cell) existing in the generative and sperm cells. As far as we are aware, this is the first report showing the existence of microfilaments in living generative and sperm cells of rice pollen. The implication and significance of the existence of microfilaments in generative and sperm cells in rendering self-propelled motion of these cells in relation to their passage and movement in the pollen tube and embryo sac for fertilization were discussed.

Probing Lectin Receptors on the Plasma Membrane of Isolated Viable Generative Cells in Angiosperms by Means of Single Cell Manipulation

Fluorescein isothiocyanate (FITC) conjugated concanavalin agglutinin (Con A), wheat germ agglutinin (WGA) and soybean agglutinin (SBA) were used as probes to localize their specific receptors on the plasma membrane of generative cells (GCs) isolated from Vicia faba L., Iris tectorium Maxim. and Hippeastrum vittatum Herb. It is a further investigation on possible distributive dynamic of lectin receptors during the developmental process from generative cells to sperm cells. In the present study, all the three lectin receptors were found on the surface of generative cells of V faba and I. tectorium. However, on generative cells of H vittatum only Con A and WGA, but not SBA receptors were observed. The same lectin receptors on the generative cells from different species showed various distribution patterns. The distribution of various lectin receptors on the same generative cells also showed different characteristics. Lectin receptors were totally absent on some generative cells of all three investigated species. Polar distribution of lectin receptors was observed on tailed generative cells. The findings offer important clues to investigate sperm cell function and possible sperm dimorphism of surface glycoprotein.

Two Modes of Cytoklnesis in the Generative Cells of Amaryllis

The cytokinesis process of generative cells in Amaryllis vitiata Ait. wasexamined with electron microscopy. Investigation of 14 pollen tubes showed that 70percent of the generative cells were divided by a cell plate, while the other, 30 percentshowed a cleavage furrow which occurred at the position where a cell plate should takeplace. The cell plate appeared at First as a subunit in late anaphase, which was assembledin the midzone of the phragmoplast and coalesced as one large continued unit in telophase.On the other hand, just in anaphase, as two identical chromosome masses were segregatedfrom each other, the plasma membrane of the generative cell were furrowing inside fromthe tWo sides in the interzonal region. In some instances, the cell was almost divided intotwo parts by the constriction furrow. The occurrence of cleavage seemed to be associatedwith the re-establishment of the nuclear envelope and the disorder of microtubular arrays,as well as the unusual behavior of the chromosomes.

Analysis of handoff in distributed mobile communications system based on remote antenna unit selection

A remote antenna unit （RAU） selection model is presented, and two kinds of handoffs, intra-cell handoff （HO） and inter-cell HO, are defined in distributed mobile communications systems （DAS）. After that, an inter-cell HO model is proposed, in which the average power of the active set （AS） is used to predict the position of the mobile station （MS）. The total power of the AS and the handoff set （HOS） are utilized to determine whether an inter-cell HO is necessary. Furthermore, the relationship between HO parameters and performance metrics is studied in detail based on RAU selection. Simulation results show that both the intra-cell HO and the inter-cell HO can achieve oerfect performance by aoprooriate settings of HO parameters.

Fluorescent vital staining of plant sexual cell nuclei with DNA-specific fluorochromes and its application in gametoplast fusion

DNA-binding fluorochromes are often used for vital staining of plant cell nuclei. However, it is not always sure whether the cells after staining still remain in living state. We chose several criteria to estimate the validity of real vital staining for sexual cell nuclei. These were: the cytoplasmic streaming in pollen tubes whose nuclei were stained, the simultaneous visualization of fluo-rochromatic reaction and nucleus staining in isolated generative cells, and the capability of isolated, prestained generative or sperm cells to fuse with other protoplasts. The results confirmed that 4',6-diamidino-2-phenylindole (DAPI), Hoechst 33258 and mithramycin could be used as real vital stains, though their efficiency varied from case to case; among them DAPI showed best effect. The fluorescent vital staining technique offered a useful means fori-dentification and selection of heterokaryons in gametoplast manipulation studies.

Stochastic response analysis of noisy system with non-negative real-power restoring force by generalized cell mapping method

The stochastic response of a noisy system with non-negative restoring force is investigated. The generalized cell mapping （GCM） method compute the transient and stationary probability density functions （PDFs） real-power is used to Combined with the global properties of the noise-free system, the evolutionary process of the tran- sient PDFs is revealed. The results show that stochastic P-bifurcation occurs when the system parameter varies in the response analysis and the stationary PDF evolves from bimodal to unimodal along the unstable manifold during the bifurcation.

Causal association rule mining methods based on fuzzy state description

Aiming at the research that using more new knowledge to develope knowledge system with dynamic accordance, and under the background of using Fuzzy language field and Fuzzy language values structure as description framework, the generalized cell Automation that can synthetically process fuzzy indeterminacy and random indeterminacy and generalized inductive logic causal model is brought forward. On this basis, a kind of the new method that can discover causal association rules is provded. According to the causal information of standard sample space and commonly sample space, through constructing its state （abnormality） relation matrix, causal association rules can be gained by using inductive reasoning mechanism. The estimate of this algorithm complexity is given,and its validiw is proved through case.

Stationary response of colored noise excited vibro-impact system

The generalized cell mapping(GCM) method is used to obtain the stationary response of a single-degree-of-freedom.Vibro-impact system under a colored noise excitation. In order to show the advantage of the GCM method, the stochastic averaging method is also presented. Both of the two methods are tested through concrete examples and verified by the direct numerical simulation. It is shown that the GCM method can well predict the stationary response of this noise-perturbed system no matter whether the noise is wide-band or narrow-band, while the stochastic averaging method is valid only for the wide-band noise.

Thermoviscoelastic Analysis of Stress in Composite Structures Micro-to-Structural Approach

Manufacturing of composite materials is usually accompanied with residual stresses.These stresses should be evaluated and assessed.To this end,a micromechanical model for periodic material whose temperature dependent constituents behave as thermorheologically complex materials(TCM)has been developed.This model,referred as the high fidelity generalized method of cells(HFGMC),takes into account the detailed interaction between the fiber and resin,their volume ratios,the fibers distribution and their waviness.This model is linked,in conjunction with a special UMAT subroutine,to the ABAQUS finite element code for prediction of the response of thermoviscoelastic composite structures during cool down process.The present investigation shows the effect of the cool down rate on the residual stress developed in the composite cylindrical structures.

Stochastic bifurcations in the SD (smooth and discontinuous) oscillator under bounded noise excitation

Stochastic bifurcations of the SD （smooth and discontinuous） oscillator with additive and/or multiplicative bounded noises are studied by the generalized cell mapping method using digraph analysis algorithm. From the global viewpoint, stochastic bifur- cation can be described as a sudden change in shape and size of a random attractor as the system parameter valies. The evolu- tionary process of stochastic bifurcation in the SD oscillator is shown in detail. Meanwhile, we show the phenomenon that un- der stochastic excitation the shape and size of random attractor and random saddle change along with the direction of unstable manifold. A plane stochastic bifurcation diagram is included.