Sub-cortical Coleoptera in dead pines and spruces: is primeval species composition maintained in managed forests?

The sub-cortical beetle fauna of dead Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) trunks was compared in primeval forests and managed forests in central Finland. The numbers of both individuals and species were higher in the managed forest in spite of the smaller trunk surface area examined. The proportion of rare species was higher in the primeval forest. Although most species occurred both in primeval and managed forests, there were striking differences in the abundance relations: there was only one species (Pytho depressus) in common among the ten most abundant species. The proportion of bark beetles (Scolytidae) was more than 50% in the managed forests, and less than 5% in the primeval forests. The number of species per site was associated with observation date, occurrence of snails and trunk position (standing or lying) in the primeval forest, and with trunk diameter in the managed forests. The occurrence of rare beetle species in dead conifer trunks was related to man's effects on the forest. Although many sub-cortical species can live in managed forests, the fauna differs drastically from that of primeval forests.     

Do female leaf beetles Galerucella nymphaeae choose their mates and does it matter?

The role of active female choice in sexual selection is frequently difficult to ascertain, and this is particularly the case for many insect species. Also, it is uncertain whether choosing between males would affect offspring viability. We designed an experiment to investigate the presence of female choice in a Coleoptera species (Galerucella nymphaeae). We also estimated whether mate choice would have any effect on offspring performance. Females were first placed with two males in a test arena to see which of the males copulated with the virgin female, and how quickly. Subsequently the loser male was offered a new virgin female to test for any change in latency time until mating. The two-male tests indicated that males with wider upper prothoraxes were more likely to mate with the female, and the latency time until mating was shorter when the winner male had relatively long wings. When the loser males were placed singly with females the latency time was not correlated with male size, and was the same as when two males were used. These results suggest that male-male competition is the most likely cause of sexual selection on size, and if females have any preferences they are not very strong. The seemingly passive female strategy may be sufficient to ensure that females mate with the most vigorous males, since in the field several males usually compete for access to each female. Finally, the benefits of female choosiness were estimated to be low and non-significant. The eggs of the winner males were no more likely to hatch, offspring survival into adulthood was no greater among descendants of winner males, and the offspring did not differ in adult size. Received: 3 March 1997 / Accepted: 13 October 1997     

Mass spectrometric analysis reveals changes in phospholipid, neutral sphingolipid and sulfatide molecular species in progressive epilepsy with mental retardation, EPMR, brain: a case study

Progressive epilepsy with mental retardation, EPMR, belongs to a group of inherited neurodegenerative disorders, the neuronal ceroid lipofuscinoses. The CLN8 gene that underlies EPMR encodes a novel transmembrane protein that localizes to the endoplasmic reticulum (ER) and ER-Golgi intermediate compartment. Recently, CLN8 was linked to a large eukaryotic protein family of TLC (TRAM, Lag1, CLN8) domain homologues with postulated functions in lipid synthesis, transport or sensing. By using liquid chromatography/mass spectrometry we analysed molecular species of major phosholipid and simple sphingolipid classes from cerebral samples of two EPMR patients representing a progressive and advanced state of the disease. The progressive state brain showed reduced levels of ceramide, galactosyl- and lactosylceramide and sulfatide as well as a decrease in long fatty acyl chain containing molecular species within these classes. Among glycerophospholipid classes, an increase in species containing polyunsaturated acyl chains was detected especially in phosphatidylserines and phosphatidylethanolamines. By contrast, saturated and monounsaturated species were overrepresented among phosphatidylserine, phosphatidylethanolamine and phosphatidylinositol classes in the advanced state sample. The observed changes in brain sphingo- and phospholipid molecular profiles may result in altered membrane stability, lipid peroxidation, vesicular trafficking or neurotransmission and thus may contribute to the progression of the molecular pathogenesis of EPMR.     

Effects of mobile phone radiation on X-ray-induced tumorigenesis in mice.

The increased use of mobile phones has raised the question of possible health effects of such devices, particularly the risk of cancer. It seems unlikely that the low-level radiofrequency (RF) radiation emitted by them would damage DNA directly, but its ability to act as a tumor promoter is less well characterized. In the current study, we evaluated the effect of low-level RF radiation on the development of cancer initiated in mice by ionizing radiation. Two hundred female CBA/S mice were randomized into four equal groups at the age of 3 to 5 weeks. The mice in all groups except the cage-control group were exposed to ionizing radiation at the beginning of the study and then to RF radiation for 1.5 h per day, 5 days a week for 78 weeks. One group was exposed to continuous NMT (Nordic Mobile Telephones)-type frequency-modulated RF radiation at a frequency of 902.5 MHz and a nominal average specific absorption rate (SAR) of 1.5 W/kg. Another group was exposed to pulsed GSM (Global System for Mobile)-type RF radiation (carrier-wave frequency 902.4 MHz, pulse frequency 217 Hz) at a nominal average SAR of 0.35 W/kg. The control animals were sham-exposed. Body weight, clinical signs, and food and water consumption were recorded regularly. Hematological examinations and histopathological analyses of all lesions and major tissues were performed on all animals. The RF-radiation exposures did not increase the incidence of any neoplastic lesion significantly. We conclude that the results do not provide evidence for cancer promotion by RF radiation emitted by mobile phones.     

A bovine dander allergen, comparative modeling, and similarities and differences in folding with related proteins

The most important allergenic protein in cow dander and urine is Bos d 2. It is proposed to belong to the family of lipocalins, which are proteins capable of binding small hydrophobic molecules. The allergenic properties of Bos d 2 indicate an interaction between the accessible regions of the native protein and IgE. In this work, a three-dimensional model was created for Bos d 2 by comparative modeling, and features characteristic of outlier lipocalins were observed. The protruding regions of the surface were characterized and used in predicting the possible B-cell epitopes. There is a pocket inside the core and its size is appropriate for small molecules. The model shows a hydrophilic amino acid side chain of glutamic acid 115 on the inner surface of the hole and a phenylalanine as the “gatekeeper” instead of tyrosine, which is common in experimentally modeled lipocalins.     

Tumorigenicity and H-2 expression of papillomavirus-transformed mouse cell lines

Summary Tumorigenicity in immunocompetent syngeneic mice and H-2 class I antigen expression of BPV1-transformed mouse cell lines had no correlation. H-2 expression was examined using monoclonal anti-(H-2K^b) and anti-(H-2D^b) antibodies in immunofluorescence staining for flow cytometry analysis and by determining the sensitivity of the cells to cytolysis by allostimulated spleen cells. Nontumorigenic cell lines were as resistant as tumorigenic cell lines to natural killer activity. The results indicate that in our model defence by natural killer cells is not a decisive factor. The results also show that instead of or in addition to H-2 class I antigens other factors (e. g. the presence or absence of virus-specific antigens) are important in determining the tumorigenicity of BPV1-transformed cell lines.     

Overwintering survival in relation to body mass in a field population of the wolf spider (Hygrolycosa rubrofasciata)

Body size is often considered to be an important trait affecting individual fitness. In arthropods, females commonly benefit from larger size directly through increased fecundity (Roff, 1992), and males through increased mating success (Andersson, 1994). It has also been suggested that larger individuals may in general have a better survival than smaller individuals (Calder, 1983; Peters, 1983). From this suggestion it may be predicted that during stressful environmental conditions larger individuals should do better than smaller individuals.