76 research outputs found

    Eternity, Boredom, and One’s Part-Whole-Reality Conception

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    Bernard Williams famously argued that eternal life is undesirable for a human because it would inevitably grow intolerably boring. I will argue against Williams and those who share his view. To make my case, I will provide an account of what staves off boredom in our current, earthly-mortal lives, and then I will draw on this account while advancing reasons for thinking that eternal life is desirable, given certain conditions. Though my response to Williams will partly overlap with some prior responses to Williams, especially the one offered by J. M. Fischer, my response will also be distinctive in some important ways. For instance, it will be distinctive in that it will discuss the role that one’s part-whole-reality conception plays in fending off boredom, where by “one’s part-whole-reality conception” I mean “one’s conception of his or her place in the whole of reality.

    RF Measurements of the 1.6 cell Lead Niobium Photoinjector in HoBiCat

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    The development of a simple and robust SRF photoinjector capable of delivering 1 mA average current in c.w. operation continues to advance with the horizontal RF testing of the 1.6 cell Pb Nb hybrid photoinjector. This injector utilizes a sputtered lead coating on a removable Nb cathode plug as the photoelectron source and has recently been tested in the horizontal test cryostat facility, HoBiCaT, at Helmholtz Zentrum Berlin. In this paper we will report on the status of these RF measurements and compare the performance to previous vertical RF tests performed at Jefferson Laboratory. We will also provide a summary of the cavity tuning range and microphonics measurements now that it has been installed into a helium vessel equipped with a Saclay style tuner

    Critical behavior of thermopower and conductivity at the metal-insulator transition in high-mobility Si-MOSFET's

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    This letter reports thermopower and conductivity measurements through the metal-insulator transition for 2-dimensional electron gases in high mobility Si-MOSFET's. At low temperatures both thermopower and conductivity show critical behavior as a function of electron density which is very similar to that expected for an Anderson transition. In particular, when approaching the critical density from the metallic side the diffusion thermopower appears to diverge and the conductivity vanishes. On the insulating side the thermopower shows an upturn with decreasing temperature.Comment: 4 pages with 3 figure

    Results from Beam Commissioning of an SRF Plug Gun Cavity Photoinjector

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    Superconducting rf photo electron injectors SRF photoinjectors hold the promise to deliver high brightness, high average current electron beams for future light sources or other applications demanding continuous wave operation of an electron injector. This paper discusses results from beam commissioning of a hybrid SRF photoinjector based on a Pb coated plug and a Nb rf gun cavity for beam energies up to 2.5MeV at Helmholtz Zentrum Berlin HZB . Emittance measurements and transverse phase space characterization with solenoid scan and slitmask methods will be presente

    Surface passivation of crystalline silicon by Cat-CVD amorphous and nanocrystalline thin silicon films

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    In this work, we study the electronic surface passivation of crystalline silicon with intrinsic thin silicon films deposited by Catalytic CVD. The contactless method used to determine the effective surface recombination velocity was the quasi-steady-state photoconductance technique. Hydrogenated amorphous and nanocrystalline silicon films were evaluated as passivating layers on n- and p-type float zone silicon wafers. The best results were obtained with amorphous silicon films, which allowed effective surface recombination velocities as low as 60 and 130 cms -1 on p- and n-type silicon, respectively. To our knowledge, these are the best results ever reported with intrinsic amorphous silicon films deposited by Catalytic CVD. The passivating properties of nanocrystalline silicon films strongly depended on the deposition conditions, especially on the filament temperature. Samples grown at lower filament temperatures (1600 °C) allowed effective surface recombination velocities of 450 and 600 cms -1 on n- and p-type silicon

    Current recommendations on the selection of measures for well-being

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    Measures of well-being have proliferated over the past decades. Very little guidance has been available as to which measures to use in what contexts. This paper provides a series of recommendations, based on the present state of knowledge and the existing measures available, of what measures might be preferred in which contexts. The recommendations came out of an interdisciplinary workshop on the measurement of well-being. The recommendations are shaped around the number of items that can be included in a survey, and also based on the differing potential contexts and purposes of data collection such as, for example, government surveys, or multi-use cohort studies, or studies specifically about psychological well-being. The recommendations are not intended to be definitive, but to stimulate discussion and refinement, and to provide guidance to those relatively new to the study of well-being

    RESULTS FROM BEAM COMMISSIONG OF AN SRF PLUG-GUN CAVITY PHOTOINJECTOR

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    Abstract Superconducting rf photo-electron injectors (SRF photoinjectors) hold the promise to deliver high brightness, high average current electron beams for future light sources or other applications demanding continuous wave operation of an electron injector. This paper discusses results from beam commissioning of a hybrid SRF photoinjector based on a Pb coated plug and a Nb rf gun cavity for beam energies up to 2.5 MeV at Helmholtz-Zentrum Berlin (HZB). Emittance measurements and transverse phase space characterization with solenoid-scan and slitmask methods will be presented. MOTIVATIO

    Lineages, Sub-Lineages and Variants of Enterovirus 68 in Recent Outbreaks

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    Enterovirus 68 (EV68) was first isolated in 1962. Very few cases of EV68 infection were described over the ensuing 40 years. However, in the past few years, an increase in severe respiratory tract infections associated with EV68 has been reported. We identified two clusters of EV68 infection in South London, UK, one each in the autumn/winters of 2009 and 2010. Sequence comparison showed significant homology of the UK strains with those from other countries including the Netherlands, Japan and the Philippines, which reported EV68 outbreaks between 2008 and 2010. Phylogenetic analysis of all available VP1 sequences indicated the presence of two modern EV68 lineages. The 2010 UK strains belonged to lineage 2. Lineage 1 could be further divided into two sub-lineages: some Japanese and Dutch strains collected between 2004 and 2010 form a distinct sub-lineages (sub-lineage 1.1), whereas other strains from the UK, Japan, Netherlands and Philippines collected between 2008 and 2010 represent sub-lineage 1.2. The UK 2009 strains together with several Dutch and Japanese strains from 2009/2010 represents one variant (1.2.1), whereas those from the Philippines a second variant (1.2.2). Based on specific deletions and substitutions, we suggest rules for the assignment of lineages and sub-lineages. Molecular epidemiological analysis indicates rapid recent evolution of EV68 and this may explain the recent findings of a global resurgence of EV68. Continuous global monitoring of the clinical and molecular epidemiology of EV68 is recommended

    BRAFΔβ3αC^{Δβ3-αC} in-frame deletion mutants differ in their dimerization propensity, HSP90 dependence, and druggability

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    In-frame BRAF exon 12 deletions are increasingly identified in various tumor types. The resultant BRAFΔβ3αC^{Δβ3-αC} oncoproteins usually lack five amino acids in the β3-αC helix linker and sometimes contain de novo insertions. The dimerization status of BRAFΔβ3αC^{Δβ3-αC} oncoproteins, their precise pathomechanism, and their direct druggability by RAF inhibitors (RAFi) has been under debate. Here, we functionally characterize BRAFΔLNVTAP>F^{ΔLNVTAP>F} and two novel mutants, BRAFdelinsFS^{delinsFS} and BRAFΔLNVT>F^{ΔLNVT>F}, and compare them with other BRAFΔβ3αC^{Δβ3-αC} oncoproteins. We show that BRAFΔβ3αC^{Δβ3-αC} oncoproteins not only form stable homodimers and large multiprotein complexes but also require dimerization. Nevertheless, details matter as aromatic amino acids at the deletion junction of some BRAFΔβ3αC^{Δβ3-αC} oncoproteins, e.g., BRAFΔLNVTAP>F^{ΔLNVTAP>F}, increase their stability and dimerization propensity while conferring resistance to monomer-favoring RAFi such as dabrafenib or HSP 90/CDC37 inhibition. In contrast, dimer-favoring inhibitors such as naporafenib inhibit all BRAFΔβ3αC^{Δβ3-αC} mutants in cell lines and patient-derived organoids, suggesting that tumors driven by such oncoproteins are vulnerable to these compounds
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