1,083 research outputs found
Machine-learning prediction of tumor antigen immunogenicity in the selection of therapeutic epitopes
Current tumor neoantigen calling algorithms primarily rely on epitope/major histocompatibility complex (MHC) binding affinity predictions to rank and select for potential epitope targets. These algorithms do not predict for epitope immunogenicity using approaches modeled from tumor-specific antigen data. Here, we describe peptide-intrinsic biochemical features associated with neoantigen and minor histocompatibility mismatch antigen immunogenicity and present a gradient boosting algorithm for predicting tumor antigen immunogenicity. This algorithm was validated in two murine tumor models and demonstrated the capacity to select for therapeutically active antigens. Immune correlates of neoantigen immunogenicity were studied in a pan-cancer data set from The Cancer Genome Atlas and demonstrated an association between expression of immunogenic neoantigens and immunity in colon and lung adenocarcinomas. Lastly, we present evidence for expression of an out-of-frame neoantigen that was capable of driving antitumor cytotoxic T-cell responses. With the growing clinical importance of tumor vaccine therapies, our approach may allow for better selection of therapeutically relevant tumor-specific antigens, including nonclas-sic out-of-frame antigens capable of driving antitumor immunity
An evolutionarily-unique heterodimeric voltage-gated cation channel found in aphids
We describe the identification in aphids of a unique heterodimeric voltage-gated sodium channel which has an atypical ion selectivity filter and, unusually for insect channels, is highly insensitive to tetrodotoxin. We demonstrate that this channel has most likely arisen by adaptation (gene fission or duplication) of an invertebrate ancestral mono(hetero)meric channel. This is the only identifiable voltage-gated sodium channel homologue in the aphid genome(s), and the channel’s novel selectivity filter motif (DENS instead of the usual DEKA found in other eukaryotes) may result in a loss of sodium selectivity, as indicated experimentally in mutagenised Drosophila channels
Uncertainties of the CJK 5 Flavour LO Parton Distributions in the Real Photon
Radiatively generated, LO quark (u,d,s,c,b) and gluon densities in the real,
unpolarized photon, calculated in the CJK model being an improved realization
of the CJKL approach, have been recently presented. The results were obtained
through a global fit to the experimental F2^gamma data. In this paper we
present, obtained for the very first time in the photon case, an estimate of
the uncertainties of the CJK parton distributions due to the experimental
errors. The analysis is based on the Hessian method which was recently applied
in the proton parton structure analysis. Sets of test parametrizations are
given for the CJK model. They allow for calculation of its best fit parton
distributions along with F2^gamma and for computation of uncertainties of any
physical value depending on the real photon parton densities. We test the
applicability of the approach by comparing uncertainties of example
cross-sections calculated in the Hessian and Lagrange methods. Moreover, we
present a detailed analysis of the chi^2 of the CJK fit and its relation to the
data. We show that large chi^2/DOF of the fit is due to only a few of the
experimental measurements. By excluding them chi^2/DOF approx 1 can be
obtained.Comment: 28 pages, 8 eps figures, 2 Latex figures; FORTRAN programs available
at http://www.fuw.edu.pl/~pjank/param.html; table 10, figure 10 and section 6
correcte
The Frequency Dependence of Critical-velocity Behavior in Oscillatory Flow of Superfluid Helium-4 Through a 2-micrometer by 2-micrometer Aperture in a Thin Foil
The critical-velocity behavior of oscillatory superfluid Helium-4 flow
through a 2-micrometer by 2-micrometer aperture in a 0.1-micrometer-thick foil
has been studied from 0.36 K to 2.10 K at frequencies from less than 50 Hz up
to above 1880 Hz. The pressure remained less than 0.5 bar. In early runs during
which the frequency remained below 400 Hz, the critical velocity was a
nearly-linearly decreasing function of increasing temperature throughout the
region of temperature studied. In runs at the lowest frequencies, isolated 2 Pi
phase slips could be observed at the onset of dissipation. In runs with
frequencies higher than 400 Hz, downward curvature was observed in the decrease
of critical velocity with increasing temperature. In addition, above 500 Hz an
alteration in supercritical behavior was seen at the lower temperatures,
involving the appearance of large energy-loss events. These irregular events
typically lasted a few tens of half-cycles of oscillation and could involve
hundreds of times more energy loss than would have occurred in a single
complete 2 Pi phase slip at maximum flow. The temperatures at which this
altered behavior was observed rose with frequency, from ~ 0.6 K and below, at
500 Hz, to ~ 1.0 K and below, at 1880 Hz.Comment: 35 pages, 13 figures, prequel to cond-mat/050203
Guidebook for the sixteenth annual field conference of the Tri-State Geological Society / Illinois State Geological Survey guidebook series, vol. 2
Cover title."Illinois, Iowa, Wisconsin - 1933"--Cover."October 11 and 12, 1952."Includes bibliographical references (l. 9)
Modeling of Photoionized Plasmas
In this paper I review the motivation and current status of modeling of
plasmas exposed to strong radiation fields, as it applies to the study of
cosmic X-ray sources. This includes some of the astrophysical issues which can
be addressed, the ingredients for the models, the current computational tools,
the limitations imposed by currently available atomic data, and the validity of
some of the standard assumptions. I will also discuss ideas for the future:
challenges associated with future missions, opportunities presented by improved
computers, and goals for atomic data collection.Comment: 17 pages, 8 figures, to appear in the proceedings of Xray2010,
Utrecht, the Netherlands, March 15-17 201
Paying for treatments? Influences on negotiating clinical need and decision-making for dental implant treatment
Background
The aim of this study is to examine how clinicians and patients negotiate clinical need and treatment decisions within a context of finite resources. Dental implant treatment is an effective treatment for missing teeth, but is only available via the NHS in some specific clinical circumstances. The majority of people who receive this treatment therefore pay privately, often at substantial cost to themselves. People are used to paying towards dental treatment costs. However, dental implant treatment is much more expensive than existing treatments – such as removable dentures. We know very little about how dentists make decisions about whether to offer such treatments, or what patients consider when deciding whether or not to pay for them.
Methods/Design
Mixed methods will be employed to provide insight and understanding into how clinical need is determined, and what influences people's decision making processes when deciding whether or not to pursue a dental implant treatment. Phase 1 will use a structured scoping questionnaire with all the General dental practitioners (GDPs) in three Primary Care Trust areas (n = 300) to provide base-line data about existing practice in relation to dental implant treatment, and to provide data to develop a systematic sampling procedure for Phase 2. Phases 2 (GDPs) and 3 (patients) use qualitative focused one to one interviews with a sample of these practitioners (up to 30) and their patients (up to 60) to examine their views and experiences of decision making in relation to dental implant treatment. Purposive sampling for phases 2 and 3 will be carried out to ensure participants represent a range of socio-economic circumstances, and choices made.
Discussion
Most dental implant treatment is conducted in primary care. Very little information was available prior to this study about the quantity and type of treatment carried out privately. It became apparent during phase 2 that ISOD treatment was an unusual treatment in primary care. We thus extended our sample criteria for Phase 3 to include people who had had other implant supported restorations, although not single tooth replacements
Ion-beam-induced reconstruction of amorphous GaN
Wurtzite GaN can be rendered amorphous by high-dose heavy-ion bombardment. We show here that relatively low-dose reirradiation of such amorphous GaN (a-GaN) with MeV light ions can significantly change some of the physical properties of a-GaN. In particular, light-ion reirradiation of a-GaN results in (i) an increase in material density, (ii) the suppression of complete decomposition during postimplantation annealing, (iii) a significant increase in the values of hardness and Young's modulus, and (iv) an apparent decrease in the absorption of visible light. Transmission electronmicroscopy shows that a-GaN remains completely amorphous after light-ion reirradiation. Therefore, we attribute the above effects of light-ion reirradiation to an ion-beam-induced atomic-level reconstruction of the amorphous phase. Results indicate that electronic energy loss of light ions is responsible for the changes in the mechanical properties and for the suppression of thermally induced decomposition of a-GaN. However, the changes in the density of a-GaN appear to be controlled by the nuclear energy loss of light ions
Grain Destruction in Interstellar Shocks
Interstellar shock waves can erode and destroy grains present in the shocked
gas, primarily as the result of sputtering and grain-grain collisions.
Uncertainties in current estimates of sputtering yields are reviewed. Results
are presented for the simple case of sputtering of fast grains being stopped in
cold gas. An upper limit is derived for sputtering of refractory grains in
C-type MHD shocks: shock speeds v_s \gtrsim 50 \kms are required for return
of more than 30\% of the silicate to the gas phase. Sputtering can also be
important for removing molecular ice mantles from grains in two-fluid MHD shock
waves in molecular gas. Recent estimates of refractory grain lifetimes against
destruction in shock waves are summarized, and the implications of these short
lifetimes are discussed.Comment: To appear in Shocks in Astrophysics, ed. T.J. Millar. Talk given at
conference Shocks in Astrophysics, Manchester, Jan. 1995. 13 pages with 6
figures: uuencoded compressed postscript. Also available as POPe-633 on
http://astro.princeton.edu/~library/prep.htm
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