Effects of stress on human mating preferences: stressed individuals prefer dissimilar mates

Although humans usually prefer mates that resemble themselves, mating preferences can vary with context. Stress has been shown to alter mating preferences in animals, but the effects of stress on human mating preferences are unknown. Here, we investigated whether stress alters men''s preference for self-resembling mates. Participants first underwent a cold-pressor test (stress induction) or a control procedure. Then, participants viewed either neutral pictures or pictures of erotic female nudes whose facial characteristics were computer-modified to resemble either the participant or another participant, or were not modified, while startle eyeblink responses were elicited by noise probes. Erotic pictures were rated as being pleasant, and reduced startle magnitude compared with neutral pictures. In the control group, startle magnitude was smaller during foreground presentation of photographs of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to self-resembling mates. In the stress group, startle magnitude was larger during foreground presentation of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to dissimilar mates. Our findings show that stress affects human mating preferences: unstressed individuals showed the expected preference for similar mates, but stressed individuals seem to prefer dissimilar mates.     

Oxidative enzymes in the urinary apparatus of several marine fishes

Summary The distribution and activities of several oxidative enzymes in the urinary apparatus of seven marine fish species (hagfish, lesser spotted dogfish, electric ray, herring, marine catfish, cod, sea-horse) have been studied. Species were selected from three main taxonomic groups: Cyclostomata, Elasmobranchii and Teleostei. Distinctly positive enzyme reactions were found in the tubular elements of the kidney and the collecting duct-archinephric duct system, with the exception of the generally weak staining intensities for NADP-liked malate dehydrogenase. In the proximal tubule segment the second, more distal part (PII) reacted, in general, very strongly when compared with the first proximal part (PI). If present, the distal tubule in teleosts showed only weak reactions, while this segment in elasmobranchs exhibited moderate to strong enzyme activities. In the epithelial cells of the collecting tubule-collecting duct system stronger reactions were confined to the glomerular teleost species, the corresponding part of the elasmobranch kidney showing weak staining intensities. In the urinary duct system distinctly positive enzyme reactions were only to be found in the archinephric duct of the teleost species, except forPlotosus. The ureters of the elasmobranchs exhibited weak enzyme activities throughout.The enzyme patterns of the various types of urinary tubules and ducts are compared with observations from several morphological and physiological studies. The histochemical findings are discussed in relation to corresponding investigations of fresh water fishes and problems arising from phylogenetic divergence of marine fish groups.     

Analysis of the community structure of abyssal kinetoplastids revealed similar communities at larger spatial scales

Knowledge of the spatial scales of diversity is necessary to evaluate the mechanisms driving biodiversity and biogeography in the vast but poorly understood deep sea. The community structure of kinetoplastids, an important group of microbial eukaryotes belonging to the Euglenozoa, from all abyssal plains of the South Atlantic and two areas of the eastern Mediterranean was studied using partial small subunit ribosomal DNA gene clone libraries. A total of 1364 clones from 10 different regions were retrieved. The analysis revealed statistically not distinguishable communities from both the South-East Atlantic (Angola and Guinea Basin) and the South-West Atlantic (Angola and Brazil Basin) at spatial scales of 1000–3000 km, whereas all other communities were significantly differentiated from one another. It seems likely that multiple processes operate at the same time to shape communities of deep-sea kinetoplastids. Nevertheless, constant and homogenous environmental conditions over large spatial scales at abyssal depths, together with high dispersal capabilities of microbial eukaryotes, maintain best the results of statistically indistinguishable communities at larger spatial scales.     

Solid-Supported Oligonucleotide Systems for Special Biomedical Applications

Abstract

The use of composite beads consisting of a 6 μm polystyrene core with 30 nm surface-bound silica particles to routine automatic oligodeoxynucleotide (ODN) synthesis is described.     

False Memory ≠ False Memory: DRM Errors Are Unrelated to the Misinformation Effect

The DRM method has proved to be a popular and powerful, if controversial, way to study ‘false memories’. One reason for the controversy is that the extent to which the DRM effect generalises to other kinds of memory error has been neither satisfactorily established nor subject to much empirical attention. In the present paper we contribute data to this ongoing debate. One hundred and twenty participants took part in a standard misinformation effect experiment, in which they watched some CCTV footage, were exposed to misleading post-event information about events depicted in the footage, and then completed free recall and recognition tests. Participants also completed a DRM test as an ostensibly unrelated filler task. Despite obtaining robust misinformation and DRM effects, there were no correlations between a broad range of misinformation and DRM effect measures (mean r  = −.01). This was not due to reliability issues with our measures or a lack of power. Thus DRM ‘false memories’ and misinformation effect ‘false memories’ do not appear to be equivalent.     

Biotechnological production of unnatural L-amino acids from D,L-5-monosubstituted hydantions. I. Derivatives of L-phenylalanine

Summary Resting cells of a mutant ofArthrobacter sp. (DSM 3747) were used for the bioconversion of D,L-5-benzylhydantoin and related compounds to the corresponding L-amino acids. After optimization of the reaction conditions in shake flask experiments, bioconversions were performed in a preparative scale in a 2-l-bioreactor under nitrogen atmosphere. Specific productivities of 0.4 (p-NO₂-L-phenylalanine) up to 3.9 mM amino acid x g cell dry mass^–1 x h^–1 (p-Cl-L-phenylalanine) were obtained. D,L-5-p-COOH-Benzylhydantoin, D,L-5-phenylhydantoin and D,L-5-p-OH-phenylhydantoin were not accepted as substrates.     

Unfixed Material Embedded in A Methacrylate Resin (Technovit 7100) For Immunofluorescent Staining

Wheat grains were embedded with or without fixation in Technovit 7100 or in paraffin. This enabled us to produce 4 μm sections for imnwnofluorescent staining to see whether serum of patients with baker's asthma contained IgG antibodies against wheat grains. Embedding without fixation in Technovit 7100 appeared to be suitable for unmunofluorescent staining and gave superior results to protocols requiring fixation.