Altitudinal and environmental variation in lifespan in the Copper butterfly Lycaena tityrus

1.  Variation in longevity within and between natural populations is widespread, and understanding the relative importance of environmental and genetic factors as well as their interactions in mediating such variation is crucial in longevity research.
2.  In this study lifespan of adult copper butterflies was examined in relation to altitude, temperature (20 and 27 °C), sex and adult feeding.
3.  As expected, longevity increased with decreasing temperature, and sucrose-fed butterflies had longer lifespans compared to water-fed and finally non-fed individuals. The impact of feeding, especially of having access to water or not, was larger at the higher compared to the lower temperature.
4.  Regarding altitudinal patterns, increased lifespan in high-altitude populations was largely restricted to beneficial feeding conditions, while under carbohydrate deprivation low-altitude animals lived longer, suggesting that low-altitude butterflies do better under food stress.
5.  Differences in longevity between sexes were small at 20 °C, while females lived substantially longer than males at the higher temperature. Consequently, females may be less susceptible to high temperature stress than males. Further, males suffered more from food stress than females, suggesting that females are generally more stress resistant than males.
6.  Using a full factorial design, this study demonstrates that variation in longevity is caused by several factors, and additionally by substantial interactive effects. Consequently, patterns of variation in longevity are complex, and one needs to be cautious when neglecting this source of variation, by focussing on individual factors only.     

Gradients in dry grassland and heath vegetation on rock outcrops in eastern Germany — An analysis of a large phytosociological data set

The following study presents a statistical analysis of 595 relevés gathered during a survey of isolated grasslands and dwarf shrub heaths in the region of Halle, eastern Germany. Relevés were classified with UPGMA clustering based on a Bray-Curtis distance matrix; the resulting classification was compared with a previously published phytosociological classification. Most of the 14 target communities were supported by both approaches, but in the case of communities on heavily disturbed sites cluster analysis corresponded to units on higher phytosociological levels (alliances). DCA ordinations clearly revealed that nutrient and moisture availability controlled the community differentiation. Both factors were, however, highly correlated with the distance to the outcrop edge. Thus the outcrop size also influenced differentiation of communities, making larger outcrops richer in xerophytic and endangered species. This appears to be largely due to edge effects since the relationships diminished sharply when we controlled for progressively increasing distances from the edge in partial ordinations. Thus, microtopography of outcrops was the most important factor for community differentiation. It is therefore suggested that future research and conservation management should concentrate on the consequences of nutrient influx and changing land use on larger outcrops.     

CD55 deposited on synovial collagen fibers protects from immune complex-mediated arthritis

IntroductionCD55, a glycosylphosphatidylinositol-anchored, complement-regulating protein (decay-accelerating factor), is expressed by fibroblast-like synoviocytes (FLS) with high local abundance in the intimal lining layer. We here explored the basis and consequences of this uncommon presence.MethodsSynovial tissue, primary FLS cultures, and three-dimensional FLS micromasses were analyzed. CD55 expression was assessed by quantitative polymerase chain reaction (PCR), in situ hybridization, flow cytometry, and immunohistochemistry. Reticular fibers were visualized by Gomori staining and colocalization of CD55 with extracellular matrix (ECM) proteins by confocal microscopy. Membrane-bound CD55 was released from synovial tissue with phospholipase C. Functional consequences of CD55 expression were studied in the K/BxN serum transfer model of arthritis using mice that in addition to CD55 also lack FcγRIIB (CD32), increasing susceptibility for immune complex-mediated pathology.ResultsAbundant CD55 expression seen in FLS of the intimal lining layer was associated with linearly oriented reticular fibers and was resistant to phospholipase C treatment. Expression of CD55 colocalized with collagen type I and III as well as with complement C3. A comparable distribution of CD55 was established in three-dimensional micromasses after ≥3 weeks of culture together with the ECM. CD55 deficiency did not enhance K/BxN serum-induced arthritis, but further exaggerated disease activity in Fcgr2b^−/− mice.ConclusionsCD55 is produced by FLS and deposited on the local collagen fiber meshwork, where it protects the synovial tissue against immune complex-mediated arthritis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0518-4) contains supplementary material, which is available to authorized users.     

Preparative scale enantioseparation of 1-cyclohexyl-1-phenylethyl hydroperoxide and 1,2,3,4-tetrahydro-1-naphthyl hydroperoxide on a modified cellulose stationary phase

The analytical and preparative scale optical resolution of 1-cyclohexyl-1-phenylethyl hydroperoxide and 1,2,3,4-tetrahydro-1-napthyl hydroperoxide has been achieved by chiral HPLC on a cellulose tris(3,5-dimethylphenyl carbamate) stationary phase coated on silica gel. The method has been used to obtain several hundred milligrams of highly enriched enantiomers (%ee >98) which were characterized by [α]_D and circular dichroism spectra, respectively. Configurational assignments were achieved for 1,2,3,4-tetrahydro-1-naphthyl hydroperoxide enantiomers. © 1995 Wiley-Liss, Inc.     

Intra-seasonal decline of clutch size in Lesser Snow Geese

Summary Different mechanisms proposed to explain the intra-seasonal decline in clutch size of Lesser Snow Geese (Anser caerulescens caerulescens) were tested at the La Perouse Bay colony, Manitoba, Canada. Ovary examination of females collected after laying revealed that the actual number of eggs produced per female decreased over the laying period. This finding eliminates nest-parasitism, partial clutch predation and renesting attempts as sufficient explanations for seasonal clutch size decline. Follicular atresia induced by reserve depletion was also rejected since its occurrence was similar among early and late nesters. The decline in clutch size was observed within age-classes, and therefore age effects on clutch size and laying date per se do not account for the observed relationship. Clutch size and laying date were respectively positively and negatively correlated with the amount of nutrient reserves in females at the onset of laying, and also covaried within individuals observed breeding in several seasons. Laying date repeatability was estimated at 0.22. It is postulated that the seasonal decline in clutch size results mainly from a positive feed-back of female's nutrient reserves on the hormones controlling ovary development. Hatching synchrony or shortness of the breeding season may be the ultimate factors responsible for the intra-seasonal clutch size decline in Lesser Snow Geese.     

Adventitious root formation in cuttings of loblolly pine (Pinus taeda L .): developmental sequence and effects of maturation

 Adventitious root formation in cuttings from fascicular shoots in loblolly pine (Pinus taeda L.) consists of four more or less discontinuous stages: (1) proliferation of cells at the base of the cutting, (2) differentiation of wound vascular tissue and periderm, (3) dedifferentiation of a zone near the wound cambium and wound phloem to form a root initial, and (4) formation of a root meristem. Anatomical changes during adventitious root initiation are described in cuttings from donors of different types and ages. Cuttings from seedlings and 3- to 7-year-old hedged stock plants rooted better than cuttings from 3-year-old tree form donors. It is concluded that the loss of rooting capacity in loblolly pine can be arrested by shearing loblolly pine stock plants to low hedges. The process of root initiation, however, was similar in cuttings from all sources and is apparently not the cause for the rapid decline of rooting potential with increasing age of the donor plant. Received: 3 June 1997 / Accepted: 15 August 1997