Micro Indirect Hemagglutination Test for Cytomegalovirus

In an effort to obtain the flexibility and ease of performance of a rapid, serological test for detection of cytomegalovirus antibody, the indirect hemagglutination (IHA) technique was investigated by using a microserological system. Antigens were prepared from tissue cultures of infected human fibroblasts. The specificity of the cytomegalovirus antibody response detected by the IHA test correlated well with the standard neutralization test. The IHA method was more sensitive than the complement fixation test in detecting antibody in congenitally infected newborns. There appeared to be some heterologous antibody response with Herpesvirus hominis or varicella virus infections. The IHA test pattern was found to be very stable with excellent persistence of agglutination.     

Is <Emphasis Type="Italic">Campanula glomerata</Emphasis> Threatened by Competition of Expanding Grasses?

In East Germany, a high percentage of species-rich, semi-natural dry grasslands has been converted into species-poor communities dominated either by Poa angustifolia or Festuca rupicola. The disappearance of low-intensity types of agricultural land-use such as mowing and grazing has been the cause for the decline of many grassland species, as lack of biomass extraction leads to a new situation in competition. Here we evaluate the performance of the rare forb Campanula glomerata in competition with P. angustifolia and F. rupicola using a replacement design experiment. C. glomerata responded to the presence of these grass species in contrasting ways: whereas the presence of P. angustifolia had a negative effect on C. glomerata biomass and fitness, the presence of F. rupicola affected the forb in a positive way. The results of an additional sowing experiment revealed that the germination and establishment rates of C. glomerata decrease in accordance with increasing density of P. angustifolia. Thus the response of this rare forb varies among neighbour species.     

Biostatistical assessment of mutagenicity studies by including the positive control

Statistical analysis plays a fundamental part in the evaluation of mutagenicity experiments. However, a statistically significant or non-significant test result without incorporating the biological relevance cannot be a valid scientific criterion for concluding a positive or negative effect of the underlying compound (Hauschke et al., 1997). The classification of an experiment as being negative or positive should be based also on the magnitude of the responses in the positive control. We address the problem of determining the maximum safe dose by incorporating a biologically meaningful threshold value, which is expressed as a fraction of the difference between positive and vehicle control.     

Experimental and structural investigations of anemochorous dispersal

The present paper describes the anemochorous dispersal of representative diaspores of Asteraceae, Dipsacaceae, and Poaceae from xerothermic grassland communities of Central and Northeastern Germany. For eleven species, potential dispersal distance was determined by fall velocity experiments as well as by taking into account the diaspore flight angle under the influence of an artificially-produced, regularly, and horizontally blowing air stream. The latter is a new and comparatively simple method enabling the implementation of mathematical formulas which describe the potential flight capacity of a diaspore for different wind speeds and exposition heights. Surface structures, shown by a scanning electron microscope, were consulted for the interpretation of results.Of the species considered, the best fliers are the diaspores of Asteraceae and Melica ciliata (Poaceae) characterized by a plumous pappus or a hairy lemma. The wing-like attachments of the diaspores of the other investigated Poaceae and Dipsacaceae are clearly less efficient for wind dispersal.The fall rates of the investigated species agree to a great extent with literature data. But a critical comparison of both methods employed shows that fall velocity as a measure of horizontal diaspore flight capacity is only suitable for low wind force < 2 m s^-1. With increasing wind force, the dispersal distance of a flying diaspore does not rise in a linear, but rather in an approximately quadratic manner. Thus, in nature, conditions of higher wind forces may be very important for the reachable dispersal distances of well-flying diaspores. This could be of particular significance for nature conservation concepts concerning the vulnerability of species towards isolation within fragmented landscapes.     

Rubella Virus: Continuous and Concurrent Production of Complement-fixing Antigen and Infectious Virus in Suspension Cultures

Rubella complement-fixing (CF) antigen and infectious virus were produced continuously and concurrently for as long as 63 days in suspension cultures of BHK-21 cells prepared from uncloned monolayer stock cultures. CF titers ranged from 1:4 to 1:32, and the peak infectivity titer was greater than 8.0 (TCID(50) log(10)) per ml. Suspension cultures could be recultivated after prolonged storage in liquid nitrogen. The resulting monolayer or suspension cultures also produced CF antigen. Suspension cultures provide an effective system for the long-term continuous and concurrent production of rubella virus diagnostic reagents.     

A biochemical characterization of feline MHC products: Unusually high expression of class 11 antigens on peripheral blood lymphocytes

The polymorphism of feline MHC antigens was examined using biochemical methods. The following observations were made: (1) feline class I and II antigens are polymorphic. Their biochemical features were established using rabbit and mouse reagents directed against human MHC products; they resemble those observed for other mammalian species; (2) the expression of class II antigens in unstimulated cat peripheral blood lymphocytes (PBLs) appears to be unusually high. Cat PBLs express far more class II than class I antigens, whereas in human Epstein-Barr virus-transformed lines, which are known to express relatively large amounts of class II antigens, the situation is reversed.Abbreviations used in this paper EBV Epstein-Barr virus - FLA feline lymphocyte antigen - MHC major histocompatibility complex - MLC mixed lymphocyte culture - MLR mixed lymphocyte reaction - PBL peripheral blood lymphocyte - RT room temperature - TX-114 Triton X-114 - 1-D IEF one-dimensional isoclectric focusing - 2-D SDS-PAGE twodimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis     

Extensive clonality of the endemic Calamagrostis pseudopurpurea Gerstl. ex O.R. Heine in central Germany revealed by RAPD markers

Calamagrostis pseudopurpurea is one of only a few endemic species in Germany and is confined to the catchment area of the River Mulde in the states of Saxony and Saxony-Anhalt. We studied the genetic structure and seed viability across its entire distribution area. Patterns of random amplified polymorphic DNA (RAPD) variation were analysed using 183 individuals from 43 stands in order to assess the overall genetic structure and the extent of clonality. In addition, four related Calamagrostis species ( C. canescens , C. epigejos , C. phragmitoides and C. villosa ) were included in our study to consider the probable phylogenetic origin of C. pseudopurpurea . We detected two clearly different RAPD phenotypes of C. pseudopurpurea , each distributed along the river banks of two spatially isolated stream courses. Both phenotypes are present downstream of the confluence. Our results indicate that C. pseudopurpurea originates from two distinct periods of hybridisation between the same parental taxa, and that clonal propagation is most likely the main reproduction method. In line with its hybrid origin, embryos of sampled C. pseudopurpurea caryopses were found to be mostly degraded or unviable over several years. Calamagrostis pseudopurpurea is genetically closer to C. canescens and C. phragmitoides than it is to other studied species, but C. canescens and C. phragmitoides have not been proven to be direct parental taxa of C. pseudopurpurea . Calamagrostis pseudopurpurea should therefore still be treated as a separate species that needs special attention from a conservation point of view.     

Non-woody life-form contribution to vascular plant species richness in a tropical American forest

We provide total vascular plant species counts for three 1-ha plots in deciduous, semi-deciduous and evergreen forests in central Bolivia. Species richness ranged from 297 species and 22,360 individuals/ha in the dry deciduous forest to 382 species and 31,670 individuals/ha in the evergreen forest. Orchidaceae, Pteridophyta and Leguminosae were among the most species-rich major plant groups in each plot, and Peperomia (Piperaceae), Pleurothallis (Orchidaceae) and Tillandsia (Bromeliaceae), all epiphytes, were the most species-rich genera. This dominance of a few but very diverse and/or widespread taxa contrasted with the low compositional similarity between plots. In a neotropical context, these Central Bolivian forest plots are similar in total species richness to other dry deciduous and humid montane forests, but less rich than most Amazonian forests. Nevertheless, lianas, terrestrial herbs and especially epiphytes proved to be of equal or higher species richness than most other neotropical forest inventories from which data are available. We therefore highlight the importance of non-woody life-forms (especially epiphytes and terrestrial herbs) in Andean foothill forest ecosystems in terms of species richness and numbers of individuals, representing in some cases nearly 50% of the species and more than 75% of the individuals. These figures stress the need for an increased inventory effort on non-woody plant groups in order to accurately direct conservation actions. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Bioclimatic regions influence genetic structure of four Jordanian Stipa species

Strong environmental gradients can affect the genetic structure of plant populations, but little is known as to whether closely related species respond similarly or idiosyncratically to ecogeographic variation. We analysed the extent to which gradients in temperature and rainfall shape the genetic structure of four Stipa species in four bioclimatic regions in Jordan. Genetic diversity, differentiation and structure of Stipa species were investigated using amplified fragment length polymorphism (AFLP) molecular markers. For each of the four study species, we sampled 120 individuals from ten populations situated in distinct bioclimatic regions and assessed the degree of genetic diversity and genetic differentiation within and among populations. The widespread ruderals Stipa capensis and S. parviflora had higher genetic diversity than the geographically restricted semi‐desert species S. arabica and S. lagascae. In three of the four species, genetic diversity strongly decreased with precipitation, while genetic diversity increased with temperature in S. capensis. Most genetic diversity resided among populations in the semi‐desert species (Φ_ST = 0.572/0.595 in S. arabica/lagascae) but within populations in the ruderal species (Φ_ST = 0.355/0.387 S. capensis/parviflora). Principal coordinate analysis ( PCoA) and STRUCTURE analysis showed that Stipa populations of all species clustered ecogeographically. A genome scan revealed that divergent selection at particular AFLP loci contributed to genetic differentiation. Irrespective of their different life histories, Stipa species responded similarly to the bioclimatic gradient in Jordan. We conclude that, in addition to predominant random processes, steep climatic gradients might shape the genetic structure of plant populations.