Selecting films for sex research: Gender differences in erotic film preference

The official published version can be obtained from the link below.The aim of this study was to explore gender differences in sexual responsiveness to erotic films that had been selected for their differential appeal for men and women. A secondary objective was to identify variables that influence sexual arousal and explore whether these variables differ for men and women. Fifteen men (M age = 26 yrs) and 17 women (M age = 24 yrs) were presented with 20 film clips depicting heterosexual interactions, half of which were female- and the other half male-selected, and were asked to rate the clips on a number of dimensions. Overall, men found the film clips more sexually arousing than did the women. Gender differences in arousal were negligible for female-selected clips but substantial for male-selected clips. Furthermore, men and women experienced higher levels of sexual arousal to clips selected for individuals of their own gender. Cluster regression analyses, explaining 77% of the variance for male and 65% for female participants, revealed that men's sexual arousal was dependent upon the attractiveness of the female actor, feeling interested, and both imagining oneself as a participant and watching as an observer. For women, with all variables entered, only imagining oneself as a participant contributed to sexual arousal ratings. The findings suggest that how films are selected in sex research is an important variable in predicting levels of sexual arousal reported by men and women

Individual epidermal growth factor receptor autophosphorylation sites do not stringently define association motifs for several SH2-containing proteins

To determine whether individual autophosphorylation sites in the epidermal growth factor (EGF) receptor define specific interaction sites for the in vivo association of signal transduction proteins that contain src homology 2 (SH2) domains, the capacity of wild-type and mutant EGF receptors to associate with several SH2 domain-containing proteins has been assayed. Mutants included receptors with single autophosphorylation site mutations at each of five autophosphorylation sites and receptors in which multiple autophosphorylation sites were removed by point mutation or deletion of carboxyl-terminal residues. Receptor association, as measured by coimmunoprecipitation, has been determined for phospholipase C-gamma 1, the ras GTPase-activating protein, the p85 subunit of phosphatidylinositol 3-kinase, and the src homology and collagen protein. In contrast to data obtained with single autophosphorylation site mutants of other receptor tyrosine kinases, none of the EGF receptor single site mutants was dramatically impaired in its capacity to associate with any of these SH2-containing proteins. However, association was completely abrogated when all five autophosphorylation sites were mutated or removed by deletion. These results indicate that individual autophosphorylation sites in the EGF receptor are not stringently required for the recognition and association of different SH2-containing substrates. Thus, EGF receptor autophosphorylation sites seem to be flexible and/or compensatory in their capacity to mediate association with these four SH2-containing substrates

Texture Segregation By Visual Cortex: Perceptual Grouping, Attention, and Learning

A neural model is proposed of how laminar interactions in the visual cortex may learn and recognize object texture and form boundaries. The model brings together five interacting processes: region-based texture classification, contour-based boundary grouping, surface filling-in, spatial attention, and object attention. The model shows how form boundaries can determine regions in which surface filling-in occurs; how surface filling-in interacts with spatial attention to generate a form-fitting distribution of spatial attention, or attentional shroud; how the strongest shroud can inhibit weaker shrouds; and how the winning shroud regulates learning of texture categories, and thus the allocation of object attention. The model can discriminate abutted textures with blurred boundaries and is sensitive to texture boundary attributes like discontinuities in orientation and texture flow curvature as well as to relative orientations of texture elements. The model quantitatively fits a large set of human psychophysical data on orientation-based textures. Object boundar output of the model is compared to computer vision algorithms using a set of human segmented photographic images. The model classifies textures and suppresses noise using a multiple scale oriented filterbank and a distributed Adaptive Resonance Theory (dART) classifier. The matched signal between the bottom-up texture inputs and top-down learned texture categories is utilized by oriented competitive and cooperative grouping processes to generate texture boundaries that control surface filling-in and spatial attention. Topdown modulatory attentional feedback from boundary and surface representations to early filtering stages results in enhanced texture boundaries and more efficient learning of texture within attended surface regions. Surface-based attention also provides a self-supervising training signal for learning new textures. Importance of the surface-based attentional feedback in texture learning and classification is tested using a set of textured images from the Brodatz micro-texture album. Benchmark studies vary from 95.1% to 98.6% with attention, and from 90.6% to 93.2% without attention.Air Force Office of Scientific Research (F49620-01-1-0397, F49620-01-1-0423); National Science Foundation (SBE-0354378); Office of Naval Research (N00014-01-1-0624

Visualization of Epidermal Growth Factor Receptors in Human Epidermis

The localization of epidermal growth factor (EGF) receptors in normal human epidermis was examined with two independent experimental methods. The distribution of EGF receptor sites was studied using light microscopic autoradiography with [125I]EGF and direct immunocytochemical techniques with EGF receptor antibodies and protein A-colloidal gold complexes. Direct visualization by autoradiography indicated that the concentration of EGF receptors was greatest in the lower epidermal layers. Ultrastructural morphometric analysis of protein A-gold complexes showed that EGF receptors were primarily associated with the plasma membranes although intranuclear and cytoplasmic localization was also evident. This postembedment immunolocalization method also confirmed the relative differences in the number of EGF receptors found in individual epidermal layers (basalis > spinosum > granulosum corneum layers). This inverse relationship between numbers of EGF receptors and the degree of epidermal differentiation and/or keratinization may suggest a physiologic role for EGF in these processes in human epidermis

Region-wide temporal and spatial variation in Caribbean reef architecture: is coral cover the whole story?

The architectural complexity of coral reefs is largely generated by reef-building corals, yet the effects of current regional-scale declines in coral cover on reef complexity are poorly understood. In particular, both the extent to which declines in coral cover lead to declines in complexity and the length of time it takes for reefs to collapse following coral mortality are unknown. Here we assess the extent of temporal and spatial covariation between coral cover and reef architectural complexity using a Caribbean-wide dataset of temporally replicated estimates spanning four decades. Both coral cover and architectural complexity have declined rapidly over time, with little evidence of a time-lag. However, annual rates of change in coral cover and complexity do not covary, and levels of complexity vary greatly among reefs with similar coral cover. These findings suggest that the stressors influencing Caribbean reefs are sufficiently severe and widespread to produce similar regional-scale declines in coral cover and reef complexity, even though reef architectural complexity is not a direct function of coral cover at local scales. Given that architectural complexity is not a simple function of coral cover, it is important that conservation monitoring and restoration give due consideration to both architecture and coral cover. This will help ensure that the ecosystem services supported by architectural complexity, such as nutrient recycling, dissipation of wave energy, fish production and diversity, are maintained and enhanced

Simple and effective exercise design for assessing in vivo mitochondrial function in clinical applications using (31)P magnetic resonance spectroscopy.

The growing recognition of diseases associated with dysfunction of mitochondria poses an urgent need for simple measures of mitochondrial function. Assessment of the kinetics of replenishment of the phosphocreatine pool after exercise using (31)P magnetic resonance spectroscopy can provide an in vivo measure of mitochondrial function; however, the wider application of this technique appears limited by complex or expensive MR-compatible exercise equipment and protocols not easily tolerated by frail participants or those with reduced mental capacity. Here we describe a novel in-scanner exercise method which is patient-focused, inexpensive, remarkably simple and highly portable. The device exploits an MR-compatible high-density material (BaSO4) to form a weight which is attached directly to the ankle, and a one-minute dynamic knee extension protocol produced highly reproducible measurements of post-exercise PCr recovery kinetics in both healthy subjects and patients. As sophisticated exercise equipment is unnecessary for this measurement, our extremely simple design provides an effective and easy-to-implement apparatus that is readily translatable across sites. Its design, being tailored to the needs of the patient, makes it particularly well suited to clinical applications, and we argue the potential of this method for investigating in vivo mitochondrial function in new cohorts of growing clinical interest.We are grateful to all the participants. This work was funded by the Clinical Research Infrastructure Grant. We thank the National Institute for Health Research (NIHR) Cambridge BioResource and S. Nutland, for facilitating the recruitment of the 24 BioResource volunteers. We thank the NIHR Cambridge Biomedical Research Centre for funding the BioResource and we also acknowledge research grants from Addenbrooke's Charitable Trust and the British Society for Pediatric Endocrinology and Diabetes. D.B.S. is supported by the Wellcome Trust [091551] and the U.K. National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre. A.S. and the Siemens MAGNETOM 3T Verio scanner are funded by the NIHR via an award to the Cambridge NIHR/Wellcome Trust Clinical Research Facility. A.T. and D.B.D. are supported by the U.K. NIHR Cambridge Biomedical Research Centre. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.This is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/srep19057