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Aim Methods Results Conclusion Many trials have demonstrated the efficacy of specific therapy modalities for individuals with attenuated psychosis symptoms (APS). Less is known regarding mechanisms behind positive outcomes, including the role of nonspecific therapeutic factors. This study explored working alliance (WA) in a clinic serving individuals with APS to see how WA changed across the course of treatment and its relation to APS.Session level APS and WA data was available for 12 individuals of diverse racial and gender identity, (M = 48 sessions each). Multilevel models with random intercepts tested change in WA and APS over time, and cross‐sectional and prospective relations.WA increased and APS decreased over time. Cross sectionally, WA and APS were inversely related. Prospective relations were non‐significant.When symptoms increase, therapists for individuals with APS should be attentive to potential disruptions in WA, though strong WA may be a cross‐sectional protective factor. [ABSTRACT FROM AUTHOR]

The article focuses on cross-platform materials and methods in performance studies which meet digital humanities and digital media studies. It mentions genealogical foundations in various classical and Enlightenment philosophies and intellectual power with imperialism, genocide, mass enslavement, and settler colonialism in the U.S. It also mentions critical imaginations by digital technological affordances with notions as virtual realities.

This paper takes up the economic logics of 'community-based' scholarly research and archival collection, and proposes a system of accounting for 'collaborative' labour across different locations within subcultural scenes, and 'the labour of being studied' within an academic-cultural milieu that increasingly camouflages free affective labour as collaboration and research-co-creation. Here, we consider the ways that a 2.0 academic economy thrives off the 'sharing' values of communality that were once the hallmark of counter-institutional subcultural scenes and we suggest that by introducing accounting measures as part of a research praxis, we can study the material conditions that constitute the relations of research production. [ABSTRACT FROM AUTHOR]

The article reviews the exhibition "Rare & Raw: Queer history then and Now" at the Leslie-Lohman Museum of Gay and Lesbian History located in New York City on February 15, 2013.

A precise knowledge of the temperature and number of hot electrons generated in the interaction of short-pulse high-intensity lasers with solids is crucial for harnessing the energy of a laser pulse in applications such as laser-driven ion acceleration or fast ignition. Nevertheless, present scaling laws tend to overestimate the hot electron temperature when compared to experiment and simulations. We present a novel approach that is based on a weighted average of the kinetic energy of an ensemble of electrons. We find that the scaling of electron energy with laser intensity can be derived from a general Lorentz invariant electron distribution ansatz that does not rely on a specific model of energy absorption. The scaling derived is in perfect agreement with simulation results and clearly follows the trend seen in recent experiments, especially at high laser intensities where other scalings fail to describe the simulations accurately. [ABSTRACT FROM AUTHOR]

The article examines the expression of Canadian nationalism in Dayna McLeod's cabaret production "Tales of the Canadian Beaver" and in the entertainment production "Made in Canada," staged as the closing ceremony for the 2010 Olympic and Paralympic Winter Games in Vancouver, British Columbia. It contends that "Made in Canada" highlighted white supremacist masculinity, decorative femininity and the symbolisms of the Royal Canadian Mounted Police, the beaver and male hockey players. McLeod delivers potent messages in her satire on women's bodies.

The article analyzes developments related to feminist cultural research in Canada, as discussed in various conferences and other events during the period from October 2009 to July 2010. It also offers insights on articles published within the issue, including articles on feminist critique, feminist scholarship, feminist studies, political activism, and feminist reading practices. It states that post-feminism is reaching its peak in Canada, with increasing attacks on feminism in the media and declining support for women's studies programs.

Relativistic electrons are efficiently generated when multiterawatt lasers focused to ultrahigh intensities >=1019 W/cm2 illuminate the surface of dense plasma targets. A theoretical study finds that during typical picosecond pulse widths, significant amounts of Dreicer produced runaway electrons can build up due to the high axial electric field driving the neutralizing return current. An important consequence is that there will be a conversion of plasma current to runaway electron current, which is maximized at some optimum value of the beam-to-plasma density ratio Nb=nb/ne, depending on the plasma collisionality. At collisionalities representative of solid target experiments, complete conversion to runaway electrons can only take place over a certain range of Nb values. At higher collisionalities and pulse widths, applicable to the fast ignition concept for inertial confinement fusion, it was found that conversion to runaways has a peak at ∼90% around Nb∼0.06. Significant lessening of target material heating by Joule current dissipation is also possible, since part of the beam energy loss is transferred through the electric field directly to the formation of energetic runaways. Implications for beam transport inhibition by the electric field are also discussed. [ABSTRACT FROM AUTHOR]

The article relates the author's perspective on what constitutes a good critical writing in the study of English language. She argues that a good critical writing begins with a thesis paragraph systematically followed by a series of well-organized paragraphs elaborating a main idea that is reliably found in topic sentence somewhere close to the beginning of the paragraph. She points that good writing should have little rambling and almost no ranting of ideas.

Excitation energies, line strengths, oscillator strengths, and transition probabilities are calculated for 4d–14f, 4d–15p, 4d–15f, and 4d–16p hole–particle states in Pd-like ions with nuclear charges Z ranging from 49 to 100. Relativistic many-body perturbation theory (MBPT), including the Breit interaction, is used to evaluate retarded E1 matrix elements in length and velocity forms. The calculations start from a [Kr] 4d10 closed-shell Dirac–Hartree–Fock (DHF) potential and include second- and third-order Coulomb corrections and second-order Breit–Coulomb corrections. First-order perturbation theory is used to obtain intermediate-coupling coefficients and second-order MBPT is used to determine matrix elements. Contributions from negative-energy states are included in the second-order electric-dipole matrix elements. The resulting transition energies, line strengths, and transition rates are compared with experimental values and with other recent calculations. Trends of oscillator strengths as functions of nuclear charge Z are shown graphically for all transitions from the 4d–14f, 4d–15p, 4d–15f, and 4d–16p states to the ground state. PACS Nos.: 31.15.Ar, 31.15.Md, 32.70.Cs, 32.30.Rj, 31.25.Jf [ABSTRACT FROM AUTHOR]

The generation of high energy protons from the interaction of a short laser pulse with a dense plasma, accompanied by a preformed low density plasma, has been studied by particle-in-cell simulations. The proton acceleration toward the laser direction in the preformed plasma is characterized by a time-dependent model and the peak proton energy is given. The effect of electron recirculation on the rear side sheath acceleration is discussed and it is found that the peak proton energy increases in inverse proportion to the target thickness. These results shed light on the peak proton energy dependence on laser intensity, laser pulse length, and target thickness. Finally the optimal parameters of the laser pulse for large ion peak energy and conversion efficiency are discussed. [ABSTRACT FROM AUTHOR]

Recent experiments on the interaction of intense, ultrafast pulses with large van der Waals bonded clusters have shown that these clusters can explode with sufficient kinetic energy to drive nuclear fusion. Irradiating deuterium clusters with a 35 fs laser pulse, it is found that the fusion neutron yield is strongly dependent on such factors as cluster size, laser focal geometry, and deuterium gas jet parameters. Neutron yield is shown to be limited by laser propagation effects as the pulse traverses the gas plume. From the experiments it is possible to get a detailed understanding of how the laser deposits its energy and heats the deuterium cluster plasma. The experiments are compared with simulations. [ABSTRACT FROM AUTHOR]

The article discusses the performance of optimism in dancing. It indicates that cruel optimism is a relation of attachment to compromised conditions of possibility whose realisation is discovered either to be impossible or too possible. The proximity to the scene of desire or attrition is the cruel aspect of the attachments in cruel optimism.

Laser-accelerated beams of Mega-electron volt protons have been produced at the Los Alamos Trident laser facility and used for high-resolution point-projection proton radiography of Au grids. The effective proton source size affords an inherent resolution of 2-3 µm in the object plane. The proton beam is characterized by ion time-of-flight Faraday cup measurements and nuclear particle track detectors. Laser-driven proton radiography appears promising as a valuable research tool for probing plasmas or modest density objects. [ABSTRACT FROM AUTHOR]

A response from the author of the article which discusses the electron injection into the laser wave and injection into the plasma that are both time-dependent processes is presented.

A mechanism that has gained great attention in the field of laser-ion acceleration due to remarkable properties of the accelerated beam is laser acceleration of protons from the rear surface of solid targets. It is shown that these protons are capable of transporting structure information from the rear surface of the target into the detector, which can be used to measure essential properties of the flow like an upper limit of the lateral beam emittance and the source area of the laser accelerated protons for a particular energy. In this Letter the essential mechanism responsible for the generation of images of surface structures by laser-accelerated protons is addressed and used to explain the experiment is described in the Letter. [ABSTRACT FROM AUTHOR]

The dynamics of bulk heating and ionization is investigated both in simulations and theory, which determines the crucial plasma parameters such as plasma temperature and density in ultra-short relativistic laser-solid target interactions. During laser-plasma interactions, the solid density plasma absorbs a fraction of laser energy and converts it into kinetic energy of electrons. A portion of the electrons with relativistic kinetic energy goes through the solid density plasma and transfers energy into the bulk electrons, which results in bulk electron heating. The bulk electron heating is finally translated into the processes of bulk collisional ionization inside the solid target. A simple model based on the Ohmic heating mechanism indicates that the local and temporal profile of bulk return current is essential to determine the temporal evolution of bulk electron temperature. A series of particle-in-cell simulations showing the local heating model is robust in the cases of target with a preplasma and without a preplasma. Predicting the bulk electron heating is then benefit for understanding the collisional ionization dynamics inside the solid targets. The connection of the heating and ionization inside the solid target is further studied using Thomas-Fermi model. [ABSTRACT FROM AUTHOR]

The laser-driven acceleration of protons from thin foils irradiated by hollow high-intensity laser beams in the regime of target normal sheath acceleration (TNSA) is reported for the first time. The use of hollow beams aims at reducing the initial emission solid angle of the TNSA source, due to a flattening of the electron sheath at the target rear side. The experiments were conducted at the PHELIX laser facility at the GSI Helmholtzzentrum für Schwerionenforschung GmbH with laser intensities in the range from 1018 Wcm-2 to 1020W cm-2 We observed an average reduction of the half opening angle by (3.07 ±.42)° or (13.2±2.0)% when the targets have a thickness between 12 μ and 14 μm. In addition, the highest proton energies were achieved with the hollow laser beam in comparison to the typical Gaussian focal spot. [ABSTRACT FROM AUTHOR]

The recent advancements in the field of laser-driven particle acceleration have made Laser-driven Ion Beam Therapy (L-IBT) an attractive alternative to the conventional particle therapy facilities. To bring this emerging technology to clinical application, we introduce the broad energy assorted depth dose deposition model which makes efficient use of the large energy spread and high dose-per-pulse of Laser Accelerated Protons (LAP) and is capable of delivering homogeneous doses to tumors. Furthermore, as a key component of L-IBT solution, we present a compact iso-centric gantry design with 360° rotation capability and an integrated shot-to-shot energy selection system for efficient transport of LAP with large energy spread to the patient. We show that gantry size could be reduced by a factor of 2-3 compared to conventional gantry systems by utilizing pulsed air-core magnets. [ABSTRACT FROM AUTHOR]

We report the development of a multipurpose differential x-ray calorimeter with a broad energy bandwidth. The absorber architecture is combined with a Bayesian unfolding algorithm to unfold high energy x-ray spectra generated in high-intensity laser–matter interactions. Particularly, we show how to extract absolute energy spectra and how our unfolding algorithm can reconstruct features not included in the initial guess. The performance of the calorimeter is evaluated via Monte Carlo generated data. The method accuracy to reconstruct electron temperatures from bremsstrahlung is shown to be 5% for electron temperatures from 1 to 50 MeV. We study bremsstrahlung generated in solid target interaction showing an electron temperature of 0.56 ± 0.04 MeV for a 700 μm Ti titanium target and 0.53 ± 0.03 MeV for a 50 μm target. We investigate bremsstrahlung from a target irradiated by laser-wakefield accelerated electrons showing an endpoint energy of 551 ± 5 MeV, inverse Compton generated x rays with a peak energy of 1.1 MeV, and calibrated radioactive sources. The total energy range covered by all these sources ranges from 10 keV to 551 MeV. [ABSTRACT FROM AUTHOR]

We investigate the dynamics of hot refluxing electrons in the interaction of an ultra-short relativistic laser pulse with a thin foil target via particle-in-cell (PIC) simulations, which is governed by the multidimensional spatiotemporal evolution of a self-generated sheath field. The comparison of time-integrated energy spectra of refluxing and escaping electrons indicates the refluxing efficiency is higher than 95% in average for each bounce. The characteristics of wide transverse spatial distribution and energy-resolved angular distribution caused by the refluxing electrons show a direct correlation with the angular-dependent photon yield of bremsstrahlung emission, as verified by the hybrid simulations of coupling the PIC results with Monte Carlo particle transport code. We further clarify the energy dissipation mechanisms of refluxing electrons through the recirculation in the thin target under the electron-refluxing dominated regime and conclude that the self-generated sheath field plays a dominant role over the competing processes, such as the radiation loss, collisional stopping, and anomalous inhibition via the resistive field. The lifetime of recirculation is calculated to be a few hundred femtoseconds, that is, one order of magnitude shorter than the timescale of collisional dissipation, while it is one order of magnitude longer than the laser pulse duration. The results could provide useful insights to understand the hot electron transport and stopping, secondary radiation generation, and ion acceleration in the high energy density plasmas. [ABSTRACT FROM AUTHOR]

Electron transport in femtosecond laser-irradiated solid targets is investigated by means of one-dimensional particle-in-cell simulations that include a model of collisional ionization, binary collisions and field ionization, while treating ions as individual particles. In particular, heat and particle fluxes in conductor and insulator targets are compared at the onset of relativistic laser intensities, i.e., at I=1017 W/cm2. Simulations show that fast electrons generate a longitudinal electric field of the order 1011 V/m in the bulk material that acts to inhibit heat flux in insulators, while the electric fields observed in metals are weaker and electrons penetrate deeper into the target. The bulk heat transport is found to be similar in both materials and mainly Spitzer-like, with a noticeable contribution by fast electrons. [ABSTRACT FROM AUTHOR]

Results from particle-in-cell simulations of the three-dimensional regime of proton acceleration in the interaction of laser radiation with a thin spherical target are presented. It is shown that the density of accelerated protons can be several times higher than that in conventional accelerators. The focusing of fast protons created in the interaction of laser radiation with a spherical target is demonstrated. The focal spot of fast protons is localized near the center of the sphere. The conversion efficiency of laser energy into fast ion energy attains 5%. The acceleration mechanism is analyzed and the electron and proton energy spectra are obtained. © 2001 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

An explanation for the energetic ions observed in the PetaWatt experiments is presented. In solid target experiments with focused intensities exceeding 10[sup 20] W/cm[sup 2], high-energy electron generation, hard bremsstrahlung, and energetic protons have been observed on the backside of the target. In this report, an attempt is made to explain the physical process present that will explain the presence of these energetic protons, as well as explain the number, energy, and angular spread of the protons observed in experiment. In particular, we hypothesize that hot electrons produced on the front of the target are sent through to the back off the target, where they ionize the hydrogen layer there. These ions are then accelerated by the hot electron cloud, to tens of MeV energies in distances of order tens of μm, whereupon they end up being detected in the radiographic and spectrographic detectors. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Focuses on hard x-ray production from high intensity laser solid interactions. Use of the Petawatt laser system at the Lawrence Livermore Laboratory in California to determine the potential of the laser driven sources; Accomplishment of absolutely calibrated spectra extending to 20 MeV and high resolution radiographs.

We reconstruct spectra of secondary X-rays from a tunable 250–350 MeV laser wakefield electron accelerator from single-shot X-ray depth-energy measurements in a compact (7.5 × 7.5 × 15 cm), modular X-ray calorimeter made of alternating layers of absorbing materials and imaging plates. X-rays range from few-keV betatron to few-MeV inverse Compton to > 100 MeV bremsstrahlung emission, and are characterized both individually and in mixtures. Geant4 simulations of energy deposition of single-energy X-rays in the stack generate an energy-vs-depth response matrix for a given stack configuration. An iterative reconstruction algorithm based on analytic models of betatron, inverse Compton and bremsstrahlung photon energy distributions then unfolds X-ray spectra, typically within a minute. We discuss uncertainties, limitations and extensions of both measurement and reconstruction methods. [ABSTRACT FROM AUTHOR]

We present structure and equation of state (EOS) measurements of biaxially orientated polyethylene terephthalate (PET, (C 10 H 8 O 4) n , also called mylar) shock-compressed to ( 155 ± 20 ) GPa and ( 6000 ± 1000 ) K using in situ X-ray diffraction, Doppler velocimetry, and optical pyrometry. Comparing to density functional theory molecular dynamics (DFT-MD) simulations, we find a highly correlated liquid at conditions differing from predictions by some equations of state tables, which underlines the influence of complex chemical interactions in this regime. EOS calculations from ab initio DFT-MD simulations and shock Hugoniot measurements of density, pressure and temperature confirm the discrepancy to these tables and present an experimentally benchmarked correction to the description of PET as an exemplary material to represent the mixture of light elements at planetary interior conditions. [ABSTRACT FROM AUTHOR]

We report on experimental investigations of proton acceleration from solid foils irradiated with PW-class laser-pulses, where highest proton cut-off energies were achieved for temporal pulse parameters that varied significantly from those of an ideally Fourier transform limited (FTL) pulse. Controlled spectral phase modulation of the driver laser by means of an acousto-optic programmable dispersive filter enabled us to manipulate the temporal shape of the last picoseconds around the main pulse and to study the effect on proton acceleration from thin foil targets. The results show that applying positive third order dispersion values to short pulses is favourable for proton acceleration and can lead to maximum energies of 70 MeV in target normal direction at 18 J laser energy for thin plastic foils, significantly enhancing the maximum energy compared to ideally compressed FTL pulses. The paper further proves the robustness and applicability of this enhancement effect for the use of different target materials and thicknesses as well as laser energy and temporal intensity contrast settings. We demonstrate that application relevant proton beam quality was reliably achieved over many months of operation with appropriate control of spectral phase and temporal contrast conditions using a state-of-the-art high-repetition rate PW laser system. [ABSTRACT FROM AUTHOR]

Small angle x-ray scattering (SAXS) is a well established technique to detect nanometer scale structures in matter. In a typical setup, this diagnostic uses a detector with a direct line of sight to the scattering target. However, in the harsh environment of high intensity laser interaction, intense secondary radiation and high-energy particles are generated. Such a setup would therefore suffer a significant increase of noise due to this background, which could eventually prevent such measurements. In this paper, we present a novel tool consisting of a mosaic graphite crystal that works as a mirror for the SAXS signal and allows us to position the detector behind appropriate shielding. This paper studies the performance of this mirror both by experiment at the European XFEL (X-Ray Free-Electron Laser Facility) laboratory and by simulations. [ABSTRACT FROM AUTHOR]