Field Studies on the African Fruit Bat Epomophorus wahlbergi (Sundevall), with Special Reference to Male Calling

Social interactions, site attachment and group cohesion were studied in a free-living colony of Epomophorus fruit bats. Daily activities in an undisturbed colony were recorded. Special attention was paid to the peculiar calling behaviour of courting ♂♂ during the night. Structure and repetition rate of their sounds were analyzed in the laboratory. A special mode of acoustic interaction was found and related to the observed spacing out of calling ♂♂ By following feeding animals in the field and by analysis of their faeces we found that besides fruits they eat special leaves which afford steroidal sapogenins.     

Targeted On‐line SPE‐LC‐MS/MS Assay for the Quantitation of 12 Apolipoproteins from Human Blood

Laborious sample pretreatment of biological samples represents the most limiting factor for the translation of targeted proteomics assays from research to clinical routine. An optimized method for the simultaneous quantitation of 12 major apolipoproteins (apos) combining on‐line SPE and fast LC‐MS/MS analysis in 6.5 min total run time was developed, reducing the manual sample pretreatment time of 3 μL serum or plasma by 60%. Within‐run and between‐day imprecisions below 10 and 15% (n = 10) and high recovery rates (94–131%) were obtained applying the high‐throughput setup. High‐quality porcine trypsin was used, which outperformed cost‐effective bovine trypsin regarding digestion efficiency. Comparisons with immunoassays and another LC‐MS/MS assay demonstrated good correlation (Pearson's R: 0.81–0.98). Further, requirements on sample quality concerning sampling, processing, and long‐term storage up to 1 year were investigated revealing significant influences of the applied sampling material and coagulant on quantitation results. Apo profiles of 1339 subjects of the LIFE‐Adult‐Study were associated with lifestyle and physiological parameters as well as establish parameters of lipid metabolism (e.g., triglycerides, cholesterol). Besides gender effects, most significant impact was seen regarding lipid‐lowering medication. In conclusion, this novel highly standardized, high‐throughput targeted proteomics assay utilizes a fast, simultaneous analysis of 12 apos from least sample amounts.     

Density-dependent shift from facilitation to competition in a dwarf <Emphasis Type="Italic">Avicennia germinans</Emphasis> forest

The global effort to rehabilitate and restore destroyed mangrove forests is unable to keep up with the high mangrove deforestation rates, which exceed the average pace of global deforestation. Although facilitation theory presents new possibilities for the restoration of heavily degraded mangrove sites, knowledge of tree–tree interactions in stressed mangrove forest ecosystems is too limited to utilize facilitation appropriately. The aim was to determine the mode of local interaction among stressed mangrove trees by investigating the effect of clustering on tree size and crown morphology under contrasting stand densities. The study was conducted in a dwarf Avicennia germinans forest in Northern Brazil, in which tree growth is limited by infrequent inundation and high pore-water salinity. Autoregressive regression, Voronoi tessellation and spatial point pattern statistics were used to address the spatial processes underlying tree interaction. Under low stand density (1.2 trees m^?2) dwarf trees which grew in clustered cohorts of A. germinans had a less stunted crown morphology revealing the dominance of a positive neighborhood influence among plants. In contrast, dwarf trees in the denser forest stand (2.7 trees m^?2) were interacting competitively as indicated by the more negative effect of neighbors on crown morphology and size. The shift from facilitative to competitive interactions is an important feature of mangrove forest regeneration under harsh environmental conditions. If mangrove trees are unable to regenerate naturally on severely degraded sites, intraspecific facilitation could be used to assist regeneration by planting seedlings in clusters and not evenly spaced.     

Identification of a Gene (GPR30) with Homology to the G-Protein-Coupled Receptor Superfamily Associated with Estrogen Receptor Expression in Breast Cancer

Using the technique of differential cDNA library screening, a cDNA clone was isolated from an estrogen receptor (ER)-positive breast carcinoma cell line (MCF7) cDNA library based upon the overexpression of this gene compared to an ER-negative cell line (MDA-MB-231). Sequence analysis of this clone determined that it shared significant homology to G-protein-coupled receptors. This receptor, GPCR-Br, was abundantly expressed in the ER-positive breast carcinoma cell lines MCF7, T-47D, and MDA-MB-361. Expression was absent or minimal in the ER-negative breast carcinoma cell lines BT-20, MDA-MB-231, and HBL-100. GPCR-Br was ubiquitously expressed in human tissues examined but was most abundant in placenta. GPCR-Br expression was examined in 11 primary breast carcinomas. GPCR-Br was detected in all 4 ER-positive tumors and only 1 of 7 ER-negative tumors. Based upon PCR analysis in hybrid cell lines, the gene for GPCR-Br (HGMW-approved symbol GPR30) was mapped to chromosome 7p22. The pattern of expression of GPCR-Br indicates that this receptor may be involved in physiologic responses specific to hormonally responsive tissues.     

Reproductive Behaviour in Zonocerus elegans (Orthoptera: Pyrgomorphidae) with Special Reference to Nuptial Gift Guarding

Egglaying aggregations, mate fidelity and male and female mate choice and mating behaviour of the African pyrgomorphid grasshopper Zonocerus elegans are described from the field. Several hundred males and females were individually marked at oviposition sites. Pairs remained stable over days, during egglaying and presumably also over the weeks prior to egglaying. In addition to long-term consorting with a female, males may try to obtain inseminations by “footpad”–tactics at oviposition sites. It is suggested that prolonged consorting and repeated copulations increase the female's reproductive output as well as the male's share in it. Our data and the literature indicate that males are involved not only in rival competition but also in a “battle of the sexes” which females are likely to win. The intra– and intersexual “war on two fronts” results behaviourally in elaborate mating tactics and anatomically in highly developed internal female genitalia and male copulatory organs (well known taxonomic characters). This applies not only to grasshoppers but also to other insects and arthropods.     

Localization of beta-glycerophosphatase and Mg++-activated adenosine triphosphatase in a moss haustorium,and the relation of these enzymes to the cell wall labyrinth

Summary Acid phosphatase and ATPase were localized in the bryophyte haustorium and in the surrounding paternal tissue of the gametophyte. Only cells with wall labyrinths are the sites of intense enzyme activity.The reaction products of both enzymes were found to occur in cell organelles, the plasma membrane and particularly in wall inclusions that are supposedly proteinaceous in nature.The intensity of the reaction is proportional to the state of differentiation of the labyrinth. The highest enzyme activity was encountered in the epidermal cells which are furnished with the most elaborate wall labyrinths. Somewhat lower was the activity in the other labyrinth cells with filiform ingrowths.These findings stress the role of the epidermis as an absorptive epithelium, and also show clearly that the enzyme activity associated with the plasma surface is in no reciprocal ratio to the degree of amplification of the surface area.