Sexual Attraction to Others: A Comparison of Two Models of Alloerotic Responding in Men

The penile response profiles of homosexual and heterosexual pedophiles, hebephiles, and teleiophiles to laboratory stimuli depicting male and female children and adults may be conceptualized as a series of overlapping stimulus generalization gradients. This study used such profile data to compare two models of alloerotic responding (sexual responding to other people) in men. The first model was based on the notion that men respond to a potential sexual object as a compound stimulus made up of an age component and a gender component. The second model was based on the notion that men respond to a potential sexual object as a gestalt, which they evaluate in terms of global similarity to other potential sexual objects. The analytic strategy was to compare the accuracy of these models in predicting a man’s penile response to each of his less arousing (nonpreferred) stimulus categories from his response to his most arousing (preferred) stimulus category. Both models based their predictions on the degree of dissimilarity between the preferred stimulus category and a given nonpreferred stimulus category, but each model used its own measure of dissimilarity. According to the first model (“summation model”), penile response should vary inversely as the sum of stimulus differences on separate dimensions of age and gender. According to the second model (“bipolar model”), penile response should vary inversely as the distance between stimulus categories on a single, bipolar dimension of morphological similarity—a dimension on which children are located near the middle, and adult men and women are located at opposite ends. The subjects were 2,278 male patients referred to a specialty clinic for phallometric assessment of their erotic preferences. Comparisons of goodness of fit to the observed data favored the unidimensional bipolar model

The Evolution of X-ray Clusters of Galaxies

Considerable progress has been made over the last decade in the study of the evolutionary trends of the population of galaxy clusters in the Universe. In this review we focus on observations in the X-ray band. X-ray surveys with the ROSAT satellite, supplemented by follow-up studies with ASCA and Beppo-SAX, have allowed an assessment of the evolution of the space density of clusters out to z~1, and the evolution of the physical properties of the intra-cluster medium out to z~0.5. With the advent of Chandra and Newton-XMM, and their unprecedented sensitivity and angular resolution, these studies have been extended beyond redshift unity and have revealed the complexity of the thermodynamical structure of clusters. The properties of the intra-cluster gas are significantly affected by non-gravitational processes including star formation and Active Galactic Nucleus (AGN) activity. Convincing evidence has emerged for modest evolution of both the bulk of the X-ray cluster population and their thermodynamical properties since redshift unity. Such an observational scenario is consistent with hierarchical models of structure formation in a flat low density universe with Omega_m=0.3 and sigma_8=0.7-0.8 for the normalization of the power spectrum. Basic methodologies for construction of X-ray-selected cluster samples are reviewed and implications of cluster evolution for cosmological models are discussed.Comment: 40 pages, 15 figures. Full resolution figures can be downloaded from http://www.eso.org/~prosati/ARAA

Changes in microphytobenthos fluorescence over a tidal cycle: implications for sampling designs

Intertidal microphytobenthos (MPB) are important primary producers and provide food for herbivores in soft sediments and on rocky shores. Methods of measuring MPB biomass that do not depend on the time of collection relative to the time of day or tidal conditions are important in any studies that need to compare temporal or spatial variation, effects of abiotic factors or activity of grazers. Pulse amplitude modulated (PAM) fluorometry is often used to estimate biomass of MPB because it is a rapid, non-destructive method, but it is not known how measures of fluorescence are altered by changing conditions during a period of low tide. We investigated this experimentally using in situ changes in minimal fluorescence (F) on a rocky shore and on an estuarine mudflat around Sydney (Australia), during low tides. On rocky shores, the time when samples are taken during low tide had little direct influence on measures of fluorescence as long as the substratum is dry. Wetness from wave-splash, seepage from rock pools, run-off, rainfall, etc., had large consequences for any comparisons. On soft sediments, fluorescence was decreased if the sediment dried out, as happens during low-spring tides on particularly hot and dry days. Surface water affected the response of PAM and therefore measurements used to estimate MPB, emphasising the need for care to ensure that representative sampling is done during low tide

The Eyes Have It: Sex and Sexual Orientation Differences in Pupil Dilation Patterns

Recent research suggests profound sex and sexual orientation differences in sexual response. These results, however, are based on measures of genital arousal, which have potential limitations such as volunteer bias and differential measures for the sexes. The present study introduces a measure less affected by these limitations. We assessed the pupil dilation of 325 men and women of various sexual orientations to male and female erotic stimuli. Results supported hypotheses. In general, self-reported sexual orientation corresponded with pupil dilation to men and women. Among men, substantial dilation to both sexes was most common in bisexual-identified men. In contrast, among women, substantial dilation to both sexes was most common in heterosexual-identified women. Possible reasons for these differences are discussed. Because the measure of pupil dilation is less invasive than previous measures of sexual response, it allows for studying diverse age and cultural populations, usually not included in sexuality research

On the number of signals in multivariate time series

We assume a second-order source separation model where the observed multivariate time series is a linear mixture of latent, temporally uncorrelated time series with some components pure white noise. To avoid the modelling of noise, we extract the non-noise latent components using some standard method, allowing the modelling of the extracted univariate time series individually. An important question is the determination of which of the latent components are of interest in modelling and which can be considered as noise. Bootstrap-based methods have recently been used in determining the latent dimension in various methods of unsupervised and supervised dimension reduction and we propose a set of similar estimation strategies for second-order stationary time series. Simulation studies and a sound wave example are used to show the method's effectiveness

Location of the CD8 T Cell Epitope within the Antigenic Precursor Determines Immunogenicity and Protection against the Toxoplasma gondii Parasite

CD8 T cells protect the host from disease caused by intracellular pathogens, such as the Toxoplasma gondii (T. gondii) protozoan parasite. Despite the complexity of the T. gondii proteome, CD8 T cell responses are restricted to only a small number of peptide epitopes derived from a limited set of antigenic precursors. This phenomenon is known as immunodominance and is key to effective vaccine design. However, the mechanisms that determine the immunogenicity and immunodominance hierarchy of parasite antigens are not well understood.Here, using genetically modified parasites, we show that parasite burden is controlled by the immunodominant GRA6-specific CD8 T cell response but not by responses to the subdominant GRA4- and ROP7-derived epitopes. Remarkably, optimal processing and immunodominance were determined by the location of the peptide epitope at the C-terminus of the GRA6 antigenic precursor. In contrast, immunodominance could not be explained by the peptide affinity for the MHC I molecule or the frequency of T cell precursors in the naive animals. Our results reveal the molecular requirements for optimal presentation of an intracellular parasite antigen and for eliciting protective CD8 T cells. © 2013 Feliu et al

DRhoGEF2 Regulates Cellular Tension and Cell Pulsations in the Amnioserosa during Drosophila Dorsal Closure

Coordination of apical constriction in epithelial sheets is a fundamental process during embryogenesis. Here, we show that DRhoGEF2 is a key regulator of apical pulsation and constriction of amnioserosal cells during Drosophila dorsal closure. Amnioserosal cells mutant for DRhoGEF2 exhibit a consistent decrease in amnioserosa pulsations whereas overexpression of DRhoGEF2 in this tissue leads to an increase in the contraction time of pulsations. We probed the physical properties of the amnioserosa to show that the average tension in DRhoGEF2 mutant cells is lower than wild-type and that overexpression of DRhoGEF2 results in a tissue that is more solid-like than wild-type. We also observe that in the DRhoGEF2 overexpressing cells there is a dramatic increase of apical actomyosin coalescence that can contribute to the generation of more contractile forces, leading to amnioserosal cells with smaller apical surface than wild-type. Conversely, in DRhoGEF2 mutants, the apical actomyosin coalescence is impaired. These results identify DRhoGEF2 as an upstream regulator of the actomyosin contractile machinery that drives amnioserosa cells pulsations and apical constriction

Brazilian obstetrician-gynecologists and abortion: a survey of knowledge, opinions and practices

BACKGROUND: Abortion laws are extremely restrictive in Brazil. The knowledge, opinions of abortion laws, and abortion practices of obstetrician-gynecologists can have a significant impact on women's access to safe abortion. METHODS: We conducted a mail-in survey with a 10% random sample of obstetrician-gynecologists affiliated with the Brazilian Federation of Obstetricians and Gynecologists. We documented participants' experiences performing abortion under a range of legal and illegal circumstances, and asked about which abortion techniques they had experience with. We used chi-square tests and crude logistic regression models to determine which sociodemographic, knowledge-related, or practice-related variables were associated with physician opinion. RESULTS: Of the 1,500 questionnaires that we mailed out, we received responses from 572 (38%). Less than half (48%) of the respondents reported accurate knowledge about abortion law and 77% thought that the law should be more liberal. One-third of respondents reported having previous experience performing an abortion, and very few of these physicians reported having experience with manual vacuum aspiration (MVA) or with misoprostol with either mifepristone or methotrexate. Physicians that favored liberalization of the law were more likely to have correct knowledge about abortion law, and to be in favor of public funding for abortion services. CONCLUSION: Brazilian obstetrician-gynecologists need more information on abortion laws and on safe, effective abortion procedures