Evolutionary Boundary Research Articles

Formulation and Spectral Reduction of the Dynamical Model of a Circulating Fluidized Bed Combustor

The distributed dynamic model of a circulating fluidized bed combustor in isothermal operation is developed and proposed, consisting of four 1–D evolutionary partial differential equations and relevant boundary and initial conditions. The continuum model is then approximated by a finite–difference method to provide a "reference" solution. Then, proper orthogonal decomposition with Galerkin projection is introduced to derive a reduced order model. The POD modes are then tested in the low-order reconstruction of space profiles of the state variables at different times, during the transient and at steady-state. POD–based models prove to be effective, being able to reproduce steady–state with four basis functions. Quantitative accuracy even during the early transient stage is achieved with as little as 24 modes.

A transferrin-like homolog in amphioxus Branchiostoma belcheri: Identification, expression and functional characterization

Previous studies have shown the universal presence of transferrin (Tf) in both invertebrates and vertebrates, but little information is available regarding Tf in amphioxus, a protochordate on the evolutionary boundary between invertebrates and vertebrates. Here we isolated a Tf-like homolog from Branchiostoma belcheri, which encodes a deduced protein, BbTfl, of 1256 amino acids containing a N-terminal signal peptide, a conserved transferrin domain in its N-terminal lobe, with a putative iron-binding site consisting of Asp63 and Try188 and another transferrin domain in its C-terminal lobe with an long intervening sequence of 305 amino acids. Phylogenetic analysis shows BbTfl is grouped together with all the invertebrate Tfs and located at the base of melanotransferrins and other Tfs. Quantitative PCR analysis reveals that exposure to Escherichia coli and Vibrio anguillarum causes a significant increase in BbTfl expression mainly in the gut within 12-24h, suggesting that BbTfl is a positive acute phase reactant involved in the immune defense of B. belcheri. The recombinant N-terminal lobe, BbTflN, is able to bind iron and to inhibit E. coli and Staphylococcus aureus growth. Moreover, the antibacterial activity of BbTflN markedly decreases in the presence of excess iron. All these results provide a direct empirical evidence establishing a definitive link between binding to iron and bacterial growth-inhibiting activity. It is also shown that BbTfl is expressed in a tissue-specific manner, with the most abundant expression in the hepatic caecum, hind-gut and ovary, supporting the idea that the digestive system including the hepatic caecum of amphioxus is the primary tissue involved in acute phase response.

Embryos—the evolutionary boundary of kingdoms of organisms

Bioevolution is still a main puzzle and attracts many scientists to research on it. Here I present that organisms have two important properties, definite structure and self-reproduction. Based on the number and connection of the structural units, organisms can be divided into three groups, unicellular, particellular and polycellular organisms. It can be called polycellular evolution that organisms evolve from unicellular, particellular to polycellular. Also it can be called diploid evolution that organisms evolve from haplobes to diplobes, two groups based on the reproductive differences. Some concepts like spore, zygote and embryos are redefined in the paper. Moreover, I present that embryos are the most important boundary of bioevolution and organisms can be divided into two evolutionary phases, the lower and the higher. The lower organisms, Kindgom Microbia (kingd. nov.), are inembryonate, which include Acytophyla (phyl. nov.), bacteria, protozoa, fungi and inembryonate algae. The higher organisms are embryonate and have two branches, Kingdom Plantae and Kingdom Animalia. Plantae are sessile and, autotrophic or sporogenic, which include higher plants and Nudembryophyta (phyl. nov.). Animalia are heterotrophic and, motile or gametogenic, which include all multicellular animals. The new system, which reflects the two important phases of bioevolution and two branches of higher organisms, can really correct the problem of different kingdoms in different researches or by different researchers.

Pattern nesting on irregular-shaped stock using Genetic Algorithms

Pattern nesting aims to position 2-D shapes on a sheet so as to achieve maximum usage of a stock, or equivalently to minimise wastage. There are different methods used on computer to lay out the positions of the shapes on the stock, such as linear programming and heuristic method . A recent approach attempts to use Genetic Algorithms (GAs) to solve the problem of pattern nesting. The successful development of using GAs to nest 2-D shapes on regular-shaped stock has proved the feasibility of using GAs to solve pattern nesting problem. This work presents a new method of solving the pattern nesting problem on irregular-shaped stock using GAs, known as the evolutionary boundary nesting algorithm. This approach further generalises the scope of the pattern nesting problem by allowing nesting on stocks of any shapes and sizes. This implies that the nesting algorithm can be used universally in any industry, such as the garment, shipbuilding and aerospace industry. Basically, the shapes are nested sequentially in the stock and the evolutionary boundary nesting algorithm uses GAs to find the best position to nest each shape along the boundary of the stock.

The joys of HexNAc. The synthesis and function of N- and O-glycan branches.

This review covers discoveries made over the past 30-35 years that were important to our understanding of the synthetic pathway required for initiation of the antennae or branches on complex N-glycans and O-glycans. The review deals primarily with the author's contributions but the relevant work of other laboratories is also discussed. The focus of the review is almost entirely on the glycosyltransferases involved in the process. The following topics are discussed. (1) The localization of the synthesis of complex N-glycan antennae to the Golgi apparatus. (2) The "evolutionary boundary" at the stage in N-glycan processing where there is a change from oligomannose to complex N-glycans; this switch correlates with the appearance of multicellular organisms. (3) The discovery of the three enzymes which play a key role in this switch, N-acetylglucosaminyltransferases I and II and mannosidase II. (4) The "yellow brick road" which leads from oligomannose to highly branched complex N-glycans with emphasis on the enzymes involved in the process and the factors which control the routes of synthesis. (5) A short discussion of the characteristics of the enzymes involved and of the genes that encode them. (6) The role of complex N-glycans in mammalian and Caenorhabditis elegans development. (7) The crystal structure of N-acetylglucosaminyltransferase I. (8) The discovery of the enzymes which synthesize O-glycan cores 1, 2, 3 and 4 and their elongation.

FROM BOUNDARY VALUE PROBLEMS TO DIFFERENCE EQUATIONS: A METHOD OF INVESTIGATION OF CHAOTIC VIBRATIONS

Among evolutionary boundary value problems for partial differential equations, there is a wide class of problems reducible to difference, differential-difference and other relevant equations. Of especial promise for investigation are problems that reduce to difference equations with continuous argument. Such problems, even in their simplest form, may exhibit solutions with extremely complicated long-time behavior to the extent of possessing evolutions that are indistinguishable from random ones when time is large. It is owing to the reduction to a difference equation followed by the employment of the properties of the one-dimensional map associated with the difference equation, that, it is in many cases possible to establish mathematical mechanisms for one or other type of dynamical behavior of solutions. The paper presents the overall picture in the study of boundary value problems reducible to difference equations (on which the authors have a direct bearing over the last ten years) and demonstrates with several simplest examples the potentialities that such a reduction opens up.

Physical Mapping of the Evolutionary Boundary between Human Chromosomes 21 and 22 on Mouse Chromosome 10

Adjacent regions of mouse Chromosome 10 (MMU10) show conserved synteny with human chromosome 22 (HSA22) and the telomeric region of HSA21. Physical mapping on MMU10 using YAC fragmentation and PAC contig analyses demonstrates that Prmt2 has a position consistent with its human homolog, HRMT1L1, being telomeric to S100B on HSA21. This result establishes Prmt2 as the new proximal boundary of the region of conserved synteny between MMU10 and HSA21 and predicts that it is the most telomeric gene known on HSA21. Physical mapping refines the positions and order of HSA22 homologs Mmp11, Mif, and Ddt, demonstrates the orientation of S100b on the mouse chromosome, and localizes the junction of conserved synteny between HSA21 and HSA22 on MMU10. Comparative mapping in this region is important for defining gene structure and dosage imbalance in Down syndrome (DS), for developing animal models of DS, and for understanding processes of chromosome evolution.

Periodic behaviour for the evolutionary dam problem and related free boundary problems Evolutionary dam problem

The time dependent dam problem describing the seepage of a compressible or incompressible fluid in a porous dam is studied. We prove existence of solutions in a suitable weak sense, and uniqueness for rectangular dams. Existence or periodic solutions is established and questions ofstability and periodic behavior for large time are studied.