A literature review of studies into the prevalence and frequency of men's pornography use

This review aims to provide information on the prevalence and frequency of adult males' pornography use. It appears, the majority (> 80%) of adult men have accessed pornography at some point, and in the past year (40–70%). Around half of younger men (25 or under) are weekly consumers. Pornography use tapers-off with age. Relatively few (<10%) younger men have accessed violent pornography in the past year. The Internet is the primary method of access. Pornography use is associated with masturbation; use during partnered sex is less common. Differences in consumption rates between heterosexual and gay and bisexual men are discussed

An experimental investigation into pornography's effect on men's perceptions of the likelihood of women engaging in porn-like sex

This experimental study investigates whether exposure to pornography affects men's perceptions of the likelihood of women engaging in, and enjoying, "porn-like" sex. Participants (N = 418) were either exposed to nonpornographic control videos or pornographic videos in which a male taxi driver has sex with a female passenger. Participants' perceptions of the likelihood of women engaging in various sexual practices commonly depicted in pornography (e.g., unprotected sex with a stranger and rough sex) were then assessed across 2 vignettes. In the first vignette, a male taxi driver propositions a female passenger. In the second, a male boss propositions a female employee. The study was administered online to maximize ecological validity. No effect was found for experimental exposure. However, an effect was detected for past exposure. Men who had viewed taxi-themed pornography in the past 6 months rated the female taxi vignette character as being more likely to engage in porn-like sex with a male taxi driver. Similarly, those who had viewed workplace-themed pornography in the past 6 months judged the female workplace vignette character as being more likely to engage in porn-like sex with a male boss. The implications of these findings for theoretical models of sexual media socialization are discussed

Equilibrium clumped-isotope effects in doubly substituted isotopologues of ethane

We combine path-integral Monte Carlo methods with a new intramolecular potential energy surface to quantify the equilibrium enrichment of doubly substituted ethane isotopologues due to clumped-isotope effects. Ethane represents the simplest molecule to simultaneously exhibit 13C–13C, 13C–D, and D–D clumped-isotope effects, and the analysis of corresponding signatures may provide useful geochemical and biogeochemical proxies of formation temperatures or reaction pathways. Utilizing path-integral statistical mechanics, we predict equilibrium fractionation factors that fully incorporate nuclear quantum effects, such as anharmonicity and rotational-vibrational coupling which are typically neglected by the widely used Urey model. The magnitude of the calculated fractionation factors for the doubly substituted ethane isotopologues indicates that isotopic clumping can be observed if rare-isotope substitutions are separated by up to three chemical bonds, but the diminishing strength of these effects suggests that enrichment at further separations will be negligible. The Urey model systematically underestimates enrichment due to 13C–D and D–D clumped-isotope effects in ethane, leading to small relative errors in the apparent equilibrium temperature, ranging from 5 K at 273.15 K to 30 K at 873.15 K. We additionally note that the rotameric dependence of isotopologue enrichment must be carefully considered when using the Urey model, whereas the path-integral calculations automatically account for such effects due to configurational sampling. These findings are of direct relevance to future clumped-isotope studies of ethane, as well as studies of 13C–13C, 13C–D, and D–D clumped-isotope effects in other hydrocarbons

Syndromic treatment of gonococcal and chlamydial infections in women seeking primary care for the genital discharge syndrome: decision-making.

The syndromic treatment of gonococcal and chlamydial infections in women seeking primary care in clinics where resources are scarce, as recommended by WHO and implemented in many developing countries, necessitates a balance to be struck between overtreatment and undertreatment. The present paper identifies factors that are relevant to the selection of specific strategies for syndromic treatment in the above circumstances. Among them are the general aspects of decision-making and caveats concerning the rational decision-making approach. The positive and negative implications are outlined of providing or withholding treatment following a specific algorithm with a given accuracy to detect infection, i.e. sensitivity, specificity and predictive values. Other decision-making considerations that are identified are related to implementation and include the stability of risk factors with regard to time, space and the implementer, acceptability by stakeholders, and environmental constraints. There is a need to consider empirically developed treatment algorithms as a basis for policy discourse, to be evaluated together with the evidence, alternatives and arguments by the stakeholders

Semantic Approach in Image Change Detection

International audienceChange detection is a main issue in various domains, and especially for remote sensing purposes. Indeed, plethora of geospatial images are available and can be used to update geographical databases. In this paper, we propose a classification-based method to detect changes between a database and a more recent image. It is based both on an efficient training point selection and a hierarchical decision process. This allows to take into account the intrinsic heterogeneity of the objects and themes composing a database while limiting false detection rates. The reliability of the designed framework method is first assessed on simulated data, and then successfully applied on very high resolution satellite images and two land-cover databases

A weakly stable algorithm for general Toeplitz systems

We show that a fast algorithm for the QR factorization of a Toeplitz or Hankel matrix A is weakly stable in the sense that R^T.R is close to A^T.A. Thus, when the algorithm is used to solve the semi-normal equations R^T.Rx = A^Tb, we obtain a weakly stable method for the solution of a nonsingular Toeplitz or Hankel linear system Ax = b. The algorithm also applies to the solution of the full-rank Toeplitz or Hankel least squares problem.Comment: 17 pages. An old Technical Report with postscript added. For further details, see http://wwwmaths.anu.edu.au/~brent/pub/pub143.htm

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Atlas construction and image analysis using statistical cardiac models

International audienceThis paper presents a brief overview of current trends in the construction of population and multi-modal heart atlases in our group and their application to atlas-based cardiac image analysis. The technical challenges around the construction of these atlases are organized around two main axes: groupwise image registration of anatomical, motion and fiber images and construction of statistical shape models. Application-wise, this paper focuses on the extraction of atlas-based biomarkers for the detection of local shape or motion abnormalities, addressing several cardiac applications where the extracted information is used to study and grade different pathologies. The paper is concluded with a discussion about the role of statistical atlases in the integration of multiple information sources and the potential this can bring to in-silico simulations

Optimization of the Strength-Fracture Toughness Relation in Particulate-Reinforced Aluminum Composites via Control of the Matrix Microstructure

The article of record as published may be found at http://dx.doi.org/10.1007/s11661-998-0119-9The evolution of the microstructure and mechanical properties of a 17.5 vol. pct SiC particulatereinforced aluminum alloy 6092-matrix composite has been studied as a function of postfabrication processing and heat treatment. It is demonstrated that, by the control of particulate distribution, matrix grain, and substructure and of the matrix precipitate state, the strength-toughness combination in the composite can be optimized over a wide range of properties, without resorting to unstable, underaged (UA) matrix microstructures, which are usually deemed necessary to produce a higher fracture toughness than that displayed in the peak-aged condition. Further, it is demonstrated that, following an appropriate combination of thermomechanical processing and unconventional heat treatment, the composite may possess better stiffness, strength, and fracture toughness than a similar unreinforced alloy. In the high- and low-strength matrix microstructural conditions, the matrix grain and substructure were found to play a substantial role in determining fracture properties. However, in the intermediate- strength regime, properties appeared to be optimizable by the utilization of heat treatments only. These observations are rationalized on the basis of current understanding of the grain size dependence of fracture toughness and the detailed microstructural features resulting from thermomechanical treatments.United States Army Research OfficeArmy Research LabratoryUnited States Air Force Office of Scientific ResearchWright Materials LabratoryDWA Composite