Wood, bark and stem anatomy of New World species of Gnetum

Quantitative and qualitative data are presented for 11 collections of six species. The wide range of character states for the species is presented in the form of a key to emphasize their potential systematic correlations. Distinctive among these are phcllem characteristics. Fibre-tracheids are newly reported for lianoid Gnetum species. Cells previously thought to be like companion cells in secondary phloem are shown to be uniseriate rays, counterparts to uniseriate xylem rays. Laticifers are abundant in most of the species, and are newly described for secondary tissues of Gnetum. Presence of tyloses in laticifers of two species is apparently a new report for vascular plants. Tori are present in two New World Gnetum species, adding to the report in African species. Perforation plates are simple except near or in primary xylem, where they are simple or foraminate. Torus presence and foraminate perforation plate presence are features more reminiscent of Ephedra and other gymnosperms than of angiosperms. The bark of Gnetum is also very similar to that of Ephedra.     

Basic strategies for valid cytometry using image analysis

The present review provides a starting point for setting up an image analysis system for quantitative densitometry and absorbance or fluorescence measurements in cell preparations, tissue sections or gels. Guidelines for instrumental settings that are essential for the valid application of image analysis in cytophotometry and cytofluorometry are described. The general principles of the working mechanism of CCD cameras in combination with general methods to improve the behaviour of the cameras are presented. Optimization of illumination of microscopical and macroscopical objects receives special attention because of its importance for valid cytometry. Sources of errors in quantitative measurements are listed and step-by-step charts for tuning the CCD camera, frame grabber and illumination for the optimal use of the systems are described. Suggestions are given for improvement of image arithmetics in difficult imaging situations, such as low fluorescence signals and high absorbance signals. This revised version was published online in November 2006 with corrections to the Cover Date.     

Bacteriophage and Bacteria in a Flow Reactor

The Levin-Stewart model of bacteriophage predation of bacteria in a chemostat is modified for a flow reactor in which bacteria are motile, phage diffuse, and advection brings fresh nutrient and removes medium, cells and phage. A fixed latent period for phage results in a system of delayed reaction-diffusion equations with non-local nonlinearities. Basic reproductive numbers are obtained for bacteria and for phage which predict survival of each in the bio-reactor. These are expressed in terms of physical and biological parameters. Persistence and extinction results are obtained for both bacteria and phage. Numerical simulations are in general agreement with those for the chemostat model.     

Hydrogen bonding in DNA base complexes.

Experimental intermolecular frequencies in the DNA base complexes 1-methylthymine (1-MT) and cytosine monohydrate (CMH) are analyzed in terms of simple analytic interatomic potentials. Calculations with two different values for the constants of the nonbonded interactions are considered, and the hydrogen bond potentials are determined for each of these models. The observed frequencies in 1-MT are reasonably well described, although corresponding potentials are very different in the two models. The observed frequencies in CMH are less well described, although corresponding hydrogen bond potentials are similar in the two models. Hydration interactions are found to be important in CMH and the role of the water molecule is discussed. Possible reasons for the shortcomings of this simple analysis are considered.     

Process technology for production and recovery of heterologous proteins with Pichia pastoris

Developments in process techniques for production and recovery of heterologous proteins with Pichia pastoris are presented. Limitations for the standard techniques are described, and alternative techniques that solve the limitations problems are reviewed together with the methods that resulted in higher productivity of the P. pastoris processes. The main limitations are proteolysis of the secreted products and cell death in the high cell density bioreactor cultures. As a consequence, both low productivity and lower quality of the feedstock for downstream processing are achieved in processes hampered with these problems. Methods for exploring proteolysis and cell death are also presented. Solving the problems makes the conditions for downstream processing superior for the P. pastoris expression systems compared to other systems, which either need complex media or rely on intracellular production. These improved conditions allow for interfacing of cultivation with downstream processing in an integrated fashion.     

A general approach to the concept of varietal ability for synthetic varieties

Summary Genetic effects for varietal value are defined at the level of the population of k-parent synthetic varieties. A simple expression for the total variance among synthetics arises directly from these definitions. A general expression for the covariance among related synthetics is given. Genetic effects are also defined in a completely general way so as to allow for any system of testing and used to derive an expression for the genetic advance in recurrent selection for varietal value. Covariances between relatives evaluated in the system of testing and in varietal combination are introduced, allowing a direct expression of the genetic advance in varietal development when parents are selected either individually or in groups. Some general implications for plant breeding are outlined.Dedicated to Professor F.W. Schnell on the occasion of his 65th birthday     

Strategies for computer modeling

Modeling is a ubiquitous and often misunderstood enterprise in which data from diverse disciplines are analyzed by techniques from other diverse disciplines in an attempt to confirm or falsify a set of hypotheses about the real world. Guidelines are offered for designing models to match the goals of modeling biological systems. Techniques for the construction and interpretation of models are discussed. The requirements for credibility of models are detailed, and tests are suggested for their validation.     

Cell surface proteins and malignant transformation

Many of the altered properties of malignant cells are thought to involve alterations in cell surface functions. In order to understand these alterations it is necessary to know more about the molecular structure of the surface. Methods for analyzing surface proteins are discussed and their application to normal and transformed tissue culture cells are reviewed. A number of surface proteins are observed to be altered by transformation. Most of the alterations are reductions in amounts of particular species, although a few proteins do increase. Evidence concerning the reasons for these alterations and the possible functions of some of the molecules is reviewed. Working hypotheses arising from these data are presented and prospects for understanding the physiological changes in terms of molecular effects are discussed. Particular emphasis is placed on the idea that surface molecules are associated in specific-non-covalent complexes which are important for their functions.     

Economics and success factors of flexible manufacturing systems: The conventional explanation revisited

This article analyzes costs and relative benefits of several hundred flexible manufacturing systems (FMSs) in the world. The analyses are based on the computerized data bases, which make it easy to correlate different cost and benefit indicators with each other and to look for regular patterns and tendencies in the applications. Both investment cost distributions and the system complexity distributions are analyzed. The relative benefits and advantages and their relationships are shown. Finally, technical and economic explanations for successful implementation strategies are given. The results show that there are two classes of economically successful systems. The small-scale and technically compact systems are usually used in small-batch production for the replacement of semimanual production. The main benefits are increased capacity and productivity as well as quality improvements. The large-scale and technically complex systems are used in large-volume production for the replacement of fixed automation and transfer lines. The benefits are mainly due to the increased potential for flexibility and capital savings.     

Phycobiliproteins as a commodity: trends in applied research,patents and commercialization

Phycobiliproteins are a group of colored proteins commonly present in cyanobacteria and red algae possessing a spectrum of applications. They are extensively commercialized for fluorescent applications in clinical and immunological analysis. They are also used as a colorant, and their therapeutic value has also been categorically demonstrated. However, a comprehensive knowledge and technological base for augmenting their commercial utilities is lacking. Hence, this work is focused towards this objective by means of analyzing global patents and commercial activities with application oriented research. Strategic mining of patents was performed from global patent databases resulting in the identification of 297 patents on phycobiliproteins. The majority of the patents are from USA, Japan and Europe. Patents are grouped into fluorescent applications, general applications and production aspects of phycobiliproteins and the features of each group are discussed. Commercial and applied research activities are compared in parallel. It revealed that US patents are mostly related to fluorescent applications while Japanese are on the production, purification and application for therapeutic and diagnostic purposes. Fluorescent applications are well represented in research, patents and commercial sectors. Biomedical properties documented in research and patents are not ventured commercially. Several novel applications are reported only in patents. The paper further pinpoints the plethora of techniques used for cell breakage and for extraction and purification of phycobiliproteins. The analysis identifies the lacuna and suggests means for improvements in the application and production of phycobiliproteins.     

Meiotic chromosomes of green frogs (Rana esculenta complex) of the Ukraine territory

In this work meiotic chromosomes of R. ridibunda, R. lessonae and their hybrid form R. esculenta of the Ukraine territory are described for the first time. These chromosomes are connected in diakinesis more often by two chiasma, rarely by one or three chiasma in 13 bivalents. Bivalents with one chiasma in R. ridibunda are typical only for large bivalents, in R. lessonae only for small ones. Three chiasma in parental species are typical only for small bivalents. In the hybrid form R. esculenta chromosomes with two, one and three chiasma are typical both for large bivalents, and for small ones. In the hybrid form (R. esculenta) chiasma frequency noticeably decreases, comparatively with parental species that, possibly, specifies the aberration of normal meiosis realization. The chiasma frequencies of the hybrid form of the eastern and the southern parts of Ukraine are almost the same, but the types of chromosomes are different in such regions. In the eastern region chromosomes of the hybrid form are represented by two or one chiasma, in the southern region by two, one or three chiasma.     

Fibronectin and integrin alpha 5 play requisite roles in cardiac morphogenesis

Fibronectin and its major receptor, integrin α5β1 are required for embryogenesis. These mutants have similar phenotypes, although, defects in integrin α5-deficient mice are milder. In this paper, we examined heart development in those mutants, in which the heart is formed, and discovered that both fibronectin and integrin α5 were required for cardiac morphogenesis, and in particular, for the formation of the cardiac outflow tract. We found that Isl1⁺ precursors are specified and migrate into the heart in fibronectin- or integrin α5-mutant embryos, however, the hearts in these mutants are of aberrant shape, and the cardiac outflow tracts are short and malformed. We show that these defects are likely due to the requirement for cell adhesion to fibronectin for proliferation of myocardial progenitors and for Fgf8 signaling in the pharyngeal region.     

基因型错误对数量性状精细定位的哈迪-温伯格不平衡指数的效应

使用紧密相邻的标记位点且与标记基因频率无关的哈迪-温伯格不平衡(HWD)指数被用来对数量性状位点(QTL)进行精细定位.本文讨论了当存在基因型错误时HWD指数的性质.文章指出,当存在基因型错误时,对于在群体的标记基因频率已知的情形使用的两个HWD指数尽管受基因型错误的影响但仍然有效;而仅仅极端样本的标记基因频率已知的情形下使用的两个HWD指数同时与基因型错误和标记基因频率有关.计算机模拟表明,仅仅极端样本的标记基因频率已知的情形下使用的两个HWD指数在精细定位时会产生偏差,不适宜作精细定位.     

One-sided Tests for Comparing Treatment Effects for Qualitative Data

Various one-sided tests for the comparison of differential treatment effects in two independent groups are developed for qualitative data. This is done for matched and for independent samples, in the case of identical and of different initial distributions. Tests for various kinds of treatment effects are considered. In each case the two observed contingency tables are collapsed into two independent fourfold tables. It is described in which way to select the appropriate procedure for practical problems, and most methods are illustrated in detail by means of a numerical example from clinical psychology.     

Application of Reflectance Spectroscopy for Analysis of Higher Plant Pigments

Nondestructive techniques developed by the authors for assessment of chlorophylls, carotenoids, and anthocyanins in higher plant leaves and fruits are presented. The spectral features of leaf reflectance in the visible and near infrared regions are briefly considered. For pigment analysis only reflectance values at several specific wavelengths are required. The chlorophyll (Chl) content over a wide range of its changes can be assessed during leaf ontogeny using reflectance near 700 nm and, in the absence of anthocyanins, at 550 nm. The approaches used for elimination of Chl interference in the analysis of carotenoids (reflectance at 520 nm) and anthocyanins (at 550 nm) are described. The suitability of reflectance spectroscopy for estimates of carotenoid/chlorophyll ratios during leaf senescence and fruit ripening is demonstrated. The algorithms developed for pigment analysis are presented, and the conditions of their applicability are considered. Further perspectives for the application of reflectance spectroscopy including remote sensing for estimation of plant pigment content and physiological states are discussed.     

Linear regression analysis of censored medical costs

This paper deals with the problem of linear regression for medical cost data when some study subjects are not followed for the full duration of interest so that their total costs are unknown. Standard survival analysis techniques are ill-suited to this type of censoring. The familiar normal equations for the least-squares estimation are modified in several ways to properly account for the incompleteness of the data. The resulting estimators are shown to be consistent and asymptotically normal with easily estimated variance-covariance matrices. The proposed methodology can be used when the cost database contains only the total costs for those with complete follow-up. More efficient estimators are available when the cost data are recorded in multiple time intervals. A study on the medical cost for ovarian cancer is presented.     

Methods for prevention of mass development of the cyanobacterium Microcystis aeruginosa Kutz emend. Elenk. in aquatic ecosystems

Methods for prevention of mass development of the cyanobacterium Microcystis aeruginosa Kutz emend. Elenk. in continental water bodies and industrial water supply systems are reviewed. The physicochemical, chemical, and biological methods for prevention of M. aeruginosa development in water bodies and water supply systems are considered; examples of successful inhibition of M. aeruginosa growth in laboratory experiments are demonstrated. The scientific problems are outlined that are to be solved for perfecting techniques for prevention of M. aeruginosa mass development in open water bodies and in closed water supply systems.     

Liposomes as drug carriers.

The use of liposomes as drug carrying vehicles are summarized. Introduction of smaller doses, increased permeability, reduced toxicological and allergic effects and altered immunological responses are the advantages of the method. Experimental techniques for the preparation of drug containing liposomes and for their deliveries are surveyed. Proposed mechanisms for the incorporation of liposomes in cells are discussed. Examples for $\text{in vivo}$ applications and for functional liposomes capable of “homing-in” to given targets are presented.