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Sexual assault continues to plague college campuses despite years of targeted intervention. Recent prevention efforts have focused on the role of bystanders in reducing rates. However, limited work has explored actual intervention behaviors as opposed to intentions to intervene or reasons why individuals might choose not to help. College students (N = 1219; aged 19-62; 66% women) completed an online survey assessing experiences as a bystander witnessing a sexual assault, willingness to intervene, helping behavior, and associated beliefs and attitudes (rape myth attitudes, perceived peer norms, perceived self-efficacy). Fifteen percent witnessed a recent situation that they believed involved sexual assault, and most students (69%) intervened. Lower rape myth endorsement, greater self-efficacy regarding intervening, and greater perceived norms that peers would intervene on behalf of a peer predicted willingness to intervene. A personal history of sexual assault and knowing of another's assault increased the odds of perceiving an assault was underway. Knowing the victim increased the odds of intervening for all groups except men. Reports were compared among students who identified as men, women, heterosexuals, and sexual minorities. This research advances our understanding of how common it is to witness sexual assault, who is willing to intervene, and cognitive-affective barriers to intervention among college students. Specific recommendations for practitioners and educators are provided.

The Tokamak Fusion Test Reactor (TFTR) is a large tokamak which has performed experiments with 50:50 deuterium-tritium fuelled plasmas. Since 1993, TFTR has produced about 1090 D-T plasmas using about 100 grams of tritium and producing about 1.6 GJ of D-T fusion energy. These plasmas have significant populations of 3.5 MeV alphas (the charged D-T fusion product). TFTR research has focused on alpha particle confinement, alpha driven modes, and alpha heating studies. Maximum D-T fusion power production has aided these studies, requiring simultaneously operation at high input heating power and large energy confinement time (to produce the highest temperature and density), while maintaining low impurity content. The principal limitation to the TFTR fusion power production was the disruptive stability limit. Secondary limitations were the confinement time, and limiter power handling capability. © 1997 IOP Publishing Ltd.

Experiments in the Tokamak Fusion Test Reactor (TFTR) [Phys. Plasmas 2, 2176 (1995)] have explored several novel regimes of improved tokamak confinement in deuterium–tritium (D–T) plasmas, including plasmas with reduced or reversed magnetic shear in the core and high-current plasmas with increased shear in the outer region (high [formula omitted]). New techniques have also been developed to enhance the confinement in these regimes by modifying the plasma-limiter interaction through in situ deposition of lithium. In reversed-shear plasmas, transitions to enhanced confinement have been observed at plasma currents up to 2.2 MA [formula omitted] accompanied by the formation of internal transport barriers, where large radial gradients develop in the temperature and density profiles. Experiments have been performed to elucidate the mechanism of the barrier formation and its relationship with the magnetic configuration and with the heating characteristics. The increased stability of high-current, high-[formula omitted] plasmas produced by rapid expansion of the minor cross section, coupled with improvement in the confinement by lithium deposition has enabled the achievement of high fusion power, up to 8.7 MW, with D–T neutral beam heating. The physics of fusion alpha-particle confinement has been investigated in these regimes, including the interactions of the alphas with endogenous plasma instabilities and externally applied waves in the ion cyclotron range of frequencies. In D–T plasmas with [formula omitted] and weak magnetic shear in the central region, a toroidal Alfvén eigenmode instability driven purely by the alpha particles has been observed for the first time. The interactions of energetic ions with ion Bernstein waves produced by mode conversion from fast waves in mixed-species plasmas have been studied as a possible mechanism for transferring the energy of the alphas to fuel ions. © 1997, American Institute of Physics. All rights reserved.

Sexual assault continues to plague college campuses despite years of targeted intervention. Recent prevention efforts have focused on the role of bystanders in reducing rates. However, limited work has explored actual intervention behaviors as opposed to intentions to intervene or reasons why individuals might choose not to help. College students (N = 1219; aged 19–62; 66% women) completed an online survey assessing experiences as a bystander witnessing a sexual assault, willingness to intervene, helping behavior, and associated beliefs and attitudes (rape myth attitudes, perceived peer norms, perceived self-efficacy). Fifteen percent witnessed a recent situation that they believed involved sexual assault, and most students (69%) intervened. Lower rape myth endorsement, greater self-efficacy regarding intervening, and greater perceived norms that peers would intervene on behalf of a peer predicted willingness to intervene. A personal history of sexual assault and knowing of another's assault increased the odds of perceiving an assault was underway. Knowing the victim increased the odds of intervening for all groups except men. Reports were compared among students who identified as men, women, heterosexuals, and sexual minorities. This research advances our understanding of how common it is to witness sexual assault, who is willing to intervene, and cognitive–affective barriers to intervention among college students. Specific recommendations for practitioners and educators are provided. [ABSTRACT FROM AUTHOR]

The article discusses the existence of different species of humans in the past, including Neanderthals, who are now extinct. Scientists have discovered that our ancestors had children with Neanderthals, and Neanderthal DNA can be found in many people today. However, it was unclear what the children of humans and Neanderthals would look like. By studying hybrid animals, such as mice, scientists have determined that human-Neanderthal hybrids would likely have large heads and faces that resemble humans more than Neanderthals. This information can help identify human fossils that may be hybrids. The article emphasizes that having Neanderthal DNA is a normal part of our ancestry and that we all have a little bit of DNA from another human species. [Extracted from the article]

Background: Yield is used as a marker of HIV programme performance, but is increasing yield a valid indicator of success? Understanding the influence of HIV testing delivery and individual testing [...]

Here, we present evidence, in the context of OMEGA cryogenic target implosions, that laser imprint, known to be capable of degrading laser-direct-drive target performance, plays a major role in generating fuel–ablator mix. OMEGA cryogenic target implosions show a performance boundary correlated with acceleration-phase shell stability; for sufficiently low adiabats (where the adiabat is the ratio of the pressure to the Fermi pressure) and high in-flight aspect ratios (IFAR's), the neutron-weighted shell areal density and neutron yield relative to the clean simulated values sharply decline. Direct evidence of Rayleigh–Taylor fuel–ablator mixing was previously obtained using a Si Heα backlighter driven by an ∼20-ps short pulse generated by OMEGA EP. The shadow cast by the shell shortly prior to stagnation, as diagnosed using backlit radiographs, shows a softening near the limb, which is evidence of an ablator–fuel mix region for a low-adiabat implosion (α ∼ 1.9, IFAR = 14) but not for a moderate adiabat implosion (α ∼ 2.5, IFAR = 10). We find good agreement between experimental and synthetic radiographs in simulations that model laser imprint and account for uncertainty in the initial ablator thickness. We further explore the role of other mechanisms such as classical instability growth at the fuel–ablator interface, species concentration diffusion, and long-wavelength drive and target asymmetries. [ABSTRACT FROM AUTHOR]

Time dependent changes in 13.5 nm extreme ultraviolet (EUV) reflectivity of Ru mirrors due to variations in surface composition were investigated. The surface properties of Ru films were analyzed in situ by means of X-ray photoelectron spectroscopy (XPS), and further verified by Auger electron spectroscopy (AES). Moreover, the impact on EUV reflectivity (EUVR) with time was examined in situ via continuous and/or discrete EUV exposures. The rapid decrease in EUVR was observed in the presence of photoelectrons (PEs) from Ru mirror of the EUV setup, whereas no significant variation was recorded by screening out additional PEs. Detailed XPS and AES analyses suggest that carbon deposition via dissociation of residual hydrocarbons plays a dominant role in the presence of additional PEs, and thus reduces the reflectivity rapidly. Using EUV photoelectron spectroscopy, systematic reduction of the secondary electron yield from the Ru mirror surface was observed in consecutive scans, and therefore supports the formation of carbonaceous Ru surface in the presence of additional PEs. [ABSTRACT FROM AUTHOR]