687 research outputs found
Dynamics of Nanometer-Scale Foil Targets Irradiated with Relativistically Intense Laser Pulses
In this letter we report on an experimental study of high harmonic radiation
generated in nanometer-scale foil targets irradiated under normal incidence.
The experiments constitute the first unambiguous observation of odd-numbered
relativistic harmonics generated by the component of the
Lorentz force verifying a long predicted property of solid target harmonics.
Simultaneously the observed harmonic spectra allow in-situ extraction of the
target density in an experimental scenario which is of utmost interest for
applications such as ion acceleration by the radiation pressure of an
ultraintense laser.Comment: 5 pages, 4 figure
Enhanced Proton Acceleration by an Ultrashort Laser Interaction with Structured Dynamic Plasma Targets
We experimentally demonstrate a notably enhanced acceleration of protons to
high energy by relatively modest ultrashort laser pulses and structured
dynamical plasma targets. Realized by special deposition of snow targets on
sapphire substrates and using carefully planned pre-pulses, high proton yield
emitted in a narrow solid angle with energy above 21MeV were detected from a
5TW laser. Our simulations predict that using the proposed scheme protons can
be accelerated to energies above 150MeV by 100TW laser systems.Comment: Submitted to Physical Review Letter
Have Another Round on Me: Missouri Court Awards Workers\u27 Compensation Benefits to Intoxicated Employees
This Note examines the broadened application of Missouri’s workers’ compensation statute under Smith v. District II A & B, in which the Missouri Court of Appeals awarded workers’ compensation benefits to a worker injured when he drove from a work function while intoxicated. By awarding workers’ compensation benefits to cover illegal conduct such as illegally driving while intoxicated, Missouri courts are violating legislative intent, violating the historical purpose of workers’ compensation, and potentially hurting the society the legislature sought to unburden when it created a compensation scheme for injured workers
Have Another Round on Me: Missouri Court Awards Workers\u27 Compensation Benefits to Intoxicated Employees
This Note examines the broadened application of Missouri’s workers’ compensation statute under Smith v. District II A & B, in which the Missouri Court of Appeals awarded workers’ compensation benefits to a worker injured when he drove from a work function while intoxicated. By awarding workers’ compensation benefits to cover illegal conduct such as illegally driving while intoxicated, Missouri courts are violating legislative intent, violating the historical purpose of workers’ compensation, and potentially hurting the society the legislature sought to unburden when it created a compensation scheme for injured workers
Acquisition of pneumococci specific effector and regulatory Cd4+ T cells localising within human upper respiratory-tract mucosal lymphoid tissue
The upper respiratory tract mucosa is the location for commensal Streptococcus (S.) pneumoniae colonization and therefore represents a major site of contact between host and bacteria. The CD4(+) T cell response to pneumococcus is increasingly recognised as an important mediator of immunity that protects against invasive disease, with data suggesting a critical role for Th17 cells in mucosal clearance. By assessing CD4 T cell proliferative responses we demonstrate age-related sequestration of Th1 and Th17 CD4(+) T cells reactive to pneumococcal protein antigens within mucosal lymphoid tissue. CD25(hi) T cell depletion and utilisation of pneumococcal specific MHCII tetramers revealed the presence of antigen specific Tregs that utilised CTLA-4 and PDL-1 surface molecules to suppress these responses. The balance between mucosal effector and regulatory CD4(+) T cell immunity is likely to be critical to pneumococcal commensalism and the prevention of unwanted pathology associated with carriage. However, if dysregulated, such responses may render the host more susceptible to invasive pneumococcal infection and adversely affect the successful implementation of both polysaccharide-conjugate and novel protein-based pneumococcal vaccines
Asbestos Litigation in Madison County, Illinois: The Challenge Ahead
Why is Madison County attracting so many claims and so much attention? What makes the lawsuit industry different there compared to other jurisdictions? We do not think the county’s reputation is the fault of jurors. In many cases, jurors are simply making judgments based on the evidence they are permitted to hear and the instructions they are given. As the St. Louis Post-Dispatch has said: “It’s a little hard to blame Madison County juries, since [cases] rarely come to trial. They’re normally settled. Instead, we wonder about the judges.” Similar concerns have been raised with respect to the Madison County Circuit Court’s handling of serious personal injury cases, such as asbestos-exposure suits. We understand that the judges in Madison County work hard, and we believe they mean well. They may view their role as helping to facilitate the resolution of claims on behalf of legitimately injured plaintiffs. For example, they may believe it is appropriate to handle asbestos cases from around the United States because asbestos litigation is national in scope. Nevertheless, it seems that the drive for efficiency is being promoted over basic fairness. It also appears that procedures adopted by the court to manage its large docket have simply invited the filing of more claims. In this Article, we will touch on some of the issues. We will then focus on asbestos litigation in Madison County, and suggest ways the asbestos litigation environment in the county should be improved and made fairer
Social capital of venture capitalists and start-up funding
How does the social capital of venture capitalists (VCs) affect the funding of start-ups? By building on the rich social capital literature, we hypothesize a positive effect of VCs' social capital, derived from past syndication, on the amount of money that start-ups receive. Specifically, we argue that both structural and relational aspects of VCs' social networks provide VCs with superior access to information about current investment objects and opportunities to leverage them in the future, increasing their willingness to invest in these firms. Our empirical results, derived from a novel dataset containing more than 1,500 first funding rounds in the Internet and IT sector, strongly confirm our hypotheses. We discuss the implications of our findings for theories of venture capital and entrepreneurship, showing that the role and effect of VCs' social capital on start-up firms may be more complex than previously argued in the literature
First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength
We present the first observation of Self-Amplified Spontaneous Emission
(SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109
nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and
the radiation characteristics, such as dependency on bunch charge, angular
distribution, spectral width and intensity fluctuations all corroborate the
existing models for SASE FELs.Comment: 6 pages including 6 figures; e-mail: [email protected]
Nontunneling high-order harmonics from ultra-intense laser-driven tightly bound systems
High-order harmonic emission is investigated by numerical solution of the weakly relativistic, two-dimensional Schrödinger equation for the case of ultra-intense laser-driven tightly bound systems (for example, multiply charged ions such as O7+ exposed to laser fields of the order of 1018 W cm-2 at 248 nm). In contrast to their usual substantial decrease, the low-order harmonics having an energy less than the ionization potential exhibit a high efficiency (i.e. intense) plateau with a well defined cutoff. The shape of this plateau is found to depend on the shape of the binding potential. A classical “surfing” mechanism for the generation of these harmonics is proposed that does not involve tunneling and that nevertheless explains the observed cutoff. Thus we call them “nontunneling harmonics.” The significance of relativistic effects for these harmonics is investigated and found to be small, despite the high laser intensity, because of the absence of tunneling
The main concerns of European anaesthesiology postgraduate trainees: A European survey
This is the first study intended to identify the European anaesthesiology trainees' main concerns, to initiate a process of improvement of the training in anaesthesiology by the European Society of Anaesthesiology (ESA). The authors developed an electronic survey which addressed seven different concerns: autonomy transition, technical skills, exchange programs, residency costs, residency workload, employment prospects and educational contents/preparation for the European Diploma in Anaesthesiology and Intensive Care (EDAIC). The survey was disseminated by email to all anaesthesiology trainees registered in ESA and all European National Societies were asked to distribute the survey to their graduating trainees. 665 trainees initiated the survey with a completion rate of 54.6%. The trainees' main concerns were in descending order: educational contents, residency costs, employment prospects, residency workload, exchange programs, technical skills and autonomy transition. This report analyzes the three main concerns in more detail. 68% of respondents were unaware of the existence of the ESA e-learning platform. Other means to improve the preparation for the EDAIC such as a multiple-choice questions book should be developed. The main reason for not becoming an ESA Trainee member was the associated cost and 68% of respondents gave up activities or opportunities during their residency due to economic constraints; 56% of respondents considered emigrating for economic reasons and 28% elected Northern/Central Europe. The results of the present survey may provide additional background information for the development of specific improvements in strategies for training in anaesthesiology. (c) 2018 Elsevier Ltd. All rights reserved
- …
