Effects of seed-irradiation on meiosis in M1 plants of Lactuca and related plants

Meiosis was studied in control and seed-irradiated materials of Lactuca sativa, cultivars Tom, Cos and Webbs, L. serriola from the wild, and Cichorium intybus. In meiosis of the M₁ plants from irradiated seed, observations of univalent and multivalent formation, bridge formation at Anaphase I and II, micronucleus formation and persistence, and pollen fertility, were carried out, and compared with controls. Quantitative estimations of bridge formation were made in L. sativa Tom and Cos and in L. serriola, at anaphase I only. It was found that the frequency of anaphase I bridges and reduction of pollen fertility in the M₁ and also M₂ generation, were different for each variety or species; these could be sequenced radiation-resistant to sensitive in the order Tom, Cos and L. serriola.     

Low degree of ubiquitination of histone 2A in the dipteran Chironomus tentans

A polyclonal antibody to ubiquitin has been prepared and shown to react with both ubiquitin and ubiquitinated histone 2A (uH2A). Applying this antibody in Western blotting experiments, we have observed that the salivary glands of Chironomus tentans contain an unusually low amount of uH2A (1% of histone 2A), while the amount of free ubiquitin is as abundant as in other animal cells, e.g. HeLa cells. The same low content of uH2A was also found in diploid epidermal cells of Chironomus origin suggesting that the low amount is not a characteristic of the polytene state of chromatin in salivary gland cells but rather a property of C. tentans as a species. The significance of the low degree of ubiquitination is discussed in relation to the information available on the organization of Chironomus chromatin into unusually large chromomeric entities.     

The increased population of the Wild Boar (Sus scrofa L.) in Europe

In this paper the recent population changes of the Wild Boar in different European countries is analysed through the study of hunting statistics. A simultaneous increase in numbers is observed throughout the whole area during the period 1965–1975. From 1975 onwards the population stabilizes itself apart from in peripheral areas like Finland. Potentially favourable factors which play a part in this process are discussed and certain reproductive and dispersive characteristics which favour its invasive behaviour are discussed.     

Determination of dialkyl phosphates in human hair for the biomonitoring of exposure to organophosphate pesticides

A new, simple, fast and sensitive method that enables the measurement of four dialkyl phosphates (DAPs) in human head hair is presented in the current study. The dialkyl phosphates, dimethyl phosphate (DMP), diethyl phosphate (DEP), diethyl thiophosphate (DETP) and diethyl dithiophosphate (DEDTP) are non-selective metabolites of the organophosphate pesticides (OPs). The extraction of DAPs from hair matrix was achieved by one step methanolic extraction. Head hair samples from general population and population occupationally exposed to OPs were analysed using gas chromatography–mass spectrometry (GC–MS) after derivatization with pentafluorobenzylbromide. The recovery of the target compounds was estimated at 84.3% for DMP, 116.1% for DEP, 109.0% for DETP and 91.5% for DEDTP. The limit of quantitation (LOQ) and detection (LOD) was 20 and 6 pg/mg for DMP, 10 and 5 pg/mg for DEP and DETP and 5 and 3 pg/mg for DEDTP, respectively. With-run and between-run precision as well as accuracy was estimated. The percentage of positive hair samples for DMP, DEP, DETP and DEDTP for the group of general population was 63.0%, 96.3%, 66.7%, and 70.4% respectively. The samples from the group with occupational exposure were positive for all dialkyl phosphates analysed. The median concentrations for DMP were 165.0 and 181.7 pg/mg, for DEP were 51.2 and 812.9 pg/mg, for DETP were 54.0 and 660.1 pg/mg, and for DEDTP were 40.0 and 60.6 pg/mg for the general population group and the group with occupational exposure respectively. Significant differences in the levels of the total dialkyl phosphates amongst exposed and not exposed groups were observed (p < 0.001). More specifically, the total ethyl phosphate (DEPs) and DAPs median concentrations were 119.5 and 301.5 pg/mg for the general population group and 1498.8 and 1694.4 pg/mg for the group with occupational exposure.     

The diet of coastal breeding hooded crows corvus corone comix

Three methods of analysis were used to determine the diet of territorial hooded crows at Lough Hyne Marine Reserve, Co Cork, Ireland The regular collection of prey Items from these sites at Lough Hyne was integrated with pellet and stomach analysis to determine diet Intertidal organisms occurred in over 80% of pellets and 43% of stomachs and occupied over 77% of the total wet weight of foods identified in pellets All prey items recovered from drop sites originated from the intertidal habitat, involved either large-sized species or larger individuals of smaller-sized species, and were only dropped during October to February Twenty-five intertidal species were identified but only a few of these species contributed to the bulk of the diet Hooded crows were shown to consume a wide range of intertidal species throughout the year, though the species composition in the diet was seasonally influenced Depletion and weight loss of intertidal molluscs through the winter was shown to have a minimal effect on selection suggesting that prey switching was driven by the birds nutritional requirements     

Intragroup serotyping of meningococci

The method for obtaining antisera to meningococci of different serotypes are described and the scheme for the preparation of serotyping is presented, as well as the method for the preparation of the determinate fraction of serotype 2. Antisera to typing antigens 1, 2, 2-7, 2-10, 4, 5, 6, 8 (1) have been obtained, their specificity tested in parallel experiments with American and French typing sera. When typing meningococci, the use of antisera to purified protein antigen 2 is recommended.