Species abundance patterns of plants in Swedish semi-natural pastures

This investigation is based on a species inventory m semi-natural pastures, remnants of an "old" traditional landscape, in Sweden The aim was to examine relationships between species richness and pasture area, neighbour pasture area, distance to nearest pasture, pasture heterogeneity and fertilization Species occurrences were also investigated individually for the same parameters Pasture area, neighbour pasture area and distance to nearest pasture were not found to influence species richness Habitat heterogeneity and indications that pastures had been influenced by fertilization were however associated with both species richness and species occurrences Heterogeneity had only positive effects whereas the effects of fertilization were only negative Species regional abundance pattern tended to be bimodal, as predicted by the core-satellite hypothesis No correlation between abundance and plant height, or seed size was found, as would have been expected if competitive dominance effects determined species regional abundance There was a close to significant tendency that pasture area was positively associated with occurrences of species with features favouring a high seed dispersal capacity We suggest that the previous history of pasture distribution and management may be of vital importance for present day species abundance pattern, even though this remains obscure in the recent landscape     

Fractional factorial design optimization of the separation of pilocarpine and its degradation products by capillary electrophoresis

The separation of pilocarpine and its degradation products by micellar electrokinetic capillary chromatography (MECC) has been optimized by using fractional factorial design of the experiments. Critical parameters were identified in a screening design, and an optimization design was used to optimize the separation. The optimal separation method was based on a borate buffer with sodium dodecyl sulfate (SDS). It is concluded that by using fractional factorial design it is possible to improve the separation of pilocarpine, it trans epimer, isopilocarpine and their hydrolysis products, pilocarpic acid and isopilocarpic acid.     

Ultrastructure of the endometrial blood vessels during implantation of the rat blastocyst

The ultrastructure of the blood vessels of the endometrium was analysed during implantation of the blastocyst in rats, at the time of appearance of the Pontamine Blue Reaction. Vessels from implantation sites and from interimplantation sites were compared. In vessels from implantation sites the endothelial cells showed fenestrations covered by diaphragms. In addition, small interruptions (gaps) between the endothelial cells were observed. These features were present in vessels larger than 5 micrometers in diameter and more than 100 micrometers away from the uterine epithelium, both in the mesometrial and antimesometrial wall of the endometrium. Vessels from interimplantation sites displayed neither fenestrations nor interruptions. The endothelial cells of the implantation sites displayed morphological signs of metabolic activation. These consisted of increased numbers of polyribosomes, well developed Golgi complexes and prominent nucleoli. The fenestrations and gaps in the vessel wall were interpreted as constituting the morphological basis for the increase in vascular permeability and the consequent edema which characterize the Pontamine Blue Reaction.     

Geographical Patterns of Four Polymorphisms in ZOARCES VIVIPARUS as Evidence of Selection

Two unlinked polymorphisms of a marine teleost, one in hemoglobin and one in esterase, show parallel clines through Danish waters, while two unlinked phosphoglucosemutase polymorphisms maintain constant gene frequencies. It is argued that the clinal and the constant polymorphisms cannot be accounted for simultaneously by random genetic drift of selectively neutral genes. It is therefore concluded that selection is responsible for at least one of the two classes of geographical patterns, be it the clinal, the constant, or both.     

Afternoon plasma cortisol in depressed patients: A measure of diagnosis or severity?

Plasma cortisol concentration was measured at 20 min intervals from 3 p.m. (1500 hrs) to 6 p.m. (1800 hrs) in 26 hospitalized patients classified according to the Newcastle Index as endogenously depressed (n = 16) or non-endogenously depressed (n = 10). When examined in depressed state, before treatment, maximum, mean and range of plasma cortisol concentration in this time interval was significantly higher in the endogenously depressed patients than in the non-endogenously depressed patients (p less than 0.01-0.02). The diagnostic identification of endogenous depression on the basis of these cortisol concentration measurements was at least as good as that reported by others using post-dexamethasone cortisol levels. The plasma cortisol levels (maximum, mean) and fluctuations (range) correlated significantly with the degree of depression (Hamilton Depression Scale), and differences in severity of depression could explain most of the differences in cortisol levels between the two diagnostic groups. Nine patients were reexamined after 3-12 months in a non-depressed state, and all unipolar endogenously depressed patients (n = 6) then had clearly reduced cortisol levels and fluctuations.     

Phenological variation in fruit characteristics in vertebrate-dispersed plants

Summary We investigated inter-specific variation in fruit characteristics — fruit size, seed number per fruit, seed weight, nutritional content, fruit persistence, and fruit synchronization — in relation to flowering and fruiting phenology in 34 species of fleshy fruited plants. Except for aspects of fruit synchrony and persistence, the results in general were inconsistent with previous suggestions about adaptive variation in phenologically related fruit traits. The main results were as follows: (1) Late flowering, late fruiting, lengthy development time from flower to fruit, and highly persistent fruits constitute a complex of correlated characteristics among the species. (2) Synchronization of fruiting within individuals increased from early ripening fruits to late ripening fruits. Fruiting synchrony was more pronounced in species with a small crop size than in species with a large fruit crop, whereas synchrony was not significantly related to flowering synchronization, nor to life form. (3) Nitrogen and carbohydrate content of fruit pulp did not vary in relation to phenology, whereas lipid content decreased from early to late ripening fruits. (4) No seasonal trends were found for variation in seed size or seed number per fruit. (5) Interactions with flowering phenology and developmental constraints are important in phenological fruiting patterns. Temporal variation in start of fruiting was partly (36%) explained by variation in flowering time. Seed weight variation explained 17% of variation in development time from flower to fruit. (6) Despite constraints from flowering and seed development, some adaptive adjustment in fruiting phenology is likely to be allowed for among the investigated species. Such an adaptive variation in fruiting phenology was suggested by intra-generic comparisons of Prunus and Vaccinium species.     

Occurrence and distribution of dictyostelid cellular slime molds in Norway

The distribution of eleven dictyostelid cellular slime molds found in Norway was studied. They were divided into four groups according to their dominance. In decreasing order the groups were: (1) two varieties of Dictyostelium mucoroides , (2) D. aureostipes and Polysphondylium violaceum , (3) D. fasciculatum, D. minutum, P. pallidum and Dictyostelium sp. 1, and (4) Dictyostelium sp. 2 and 3 and Acytostelium lep–tosomum. Differences in distribution related to altitudes and latitudes, climates and dominant tree species were observed for some species.