3,359 research outputs found

    Underlap counterdoping as an efficient means to suppress lateral leakage in the electron\u2013hole bilayer tunnel FET

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    The electron\u2013hole bilayer tunnel (EHBTFET)\uf0a0has been proposed as a density of states (DOS) switch capable of achieving a subthreshold slope lower than 60mV/decade at room temperature; however, one of the main challenges is the control of the lateral band-to-band tunneling (BTBT) leakage in the OFF state. In this work, we show that by using oppositely doped underlap regions; the unwanted penetration of the wavefunction into the underlap region at low gate biases is prevented; thereby drastically reducing the lateral BTBT leakage without any penalty on the ON current. The method is verified using a full-quantum 2D Schr\uf6dinger\u2013Poisson solver under the effective mass approximation. For a channel thickness of 10 nm, an In0.53Ga0.47As EHBTFET with counterdoping can exhibit an ON-current up to 20 mA mm and an average subthreshold swing (SS) of about 30 mV/dec. Compared to previous lateral leakage suppression solutions, the proposed method can be fabricated using template-assisted selective epitaxy

    Anomalous behavior of pion production in high energy particle collisions

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    A shape of invariant differential cross section for charged hadron production as function of transverse momentum measured in various collider experiments is analyzed. Contrary to the behavior of produced charged kaons, protons and antiprotons, the pion spectra require an anomalously high contribution of an exponential term to describe the shape.Comment: 4 pages, 6 figure

    An experimental evaluation of software redundancy as a strategy for improving reliability

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    The strategy of using multiple versions of independently developed software as a means to tolerate residual software design faults is suggested by the success of hardware redundancy for tolerating hardware failures. Although, as generally accepted, the independence of hardware failures resulting from physical wearout can lead to substantial increases in reliability for redundant hardware structures, a similar conclusion is not immediate for software. The degree to which design faults are manifested as independent failures determines the effectiveness of redundancy as a method for improving software reliability. Interest in multi-version software centers on whether it provides an adequate measure of increased reliability to warrant its use in critical applications. The effectiveness of multi-version software is studied by comparing estimates of the failure probabilities of these systems with the failure probabilities of single versions. The estimates are obtained under a model of dependent failures and compared with estimates obtained when failures are assumed to be independent. The experimental results are based on twenty versions of an aerospace application developed and certified by sixty programmers from four universities. Descriptions of the application, development and certification processes, and operational evaluation are given together with an analysis of the twenty versions

    Impact of Lumacaftor/Ivacaftor on Pulmonary Exacerbation Rates in Members with Cystic Fibrosis in a Medicaid Population

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    This poster gives an overview of pulmonary exacerbation rates pre- and post-initiation of Lumacaftor/Ivacaftor (LUM/IVA) in Massachusetts\u27 Medicaid program. Pulmonary disease is one of the leading causes of morbidity and mortality among patients with cystic fibrosis. LUM/IVA has been effective in improving pulmonary outcomes in two observational studies, but before this study, there had been no published data evaluating real-world outcomes for Medicaid patients receiving this therapy. This poster on the impact of a drug for patients with cystic fibrosis was shared during the 2018 Academy of Managed Care Pharmacy Managed Care & Specialty Pharmacy Annual Meeting and awarded a gold ribbon. The poster abstracts were evaluated on relevance, originality, quality, bias and clarity. Only 20 percent of submitted abstracts were honored with awards

    k cl co transport plays an important role in normal and β thalassemic erythropoiesis

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    Background and Objectives Cell volume changes are hallmarks of both cell maturation and apoptosis, and are paralleled by modulation of membrane ion transport pathways. We evaluated the possible role of K-Cl co-transport (KCC) in both normal and β-thalassemic erythropoiesis in vitro . Design and Methods We studied the effects of the KCC inhibitor, DIOA, on cell proliferation and differentiation, on expression of KCC mRNA and polypeptides, and on expression of cell cycle and apoptosis genes in in vitro liquid-cultures of CD34+ cells from normal and β-thalassemic subjects. Results β-thalassemic erythroid precursors showed increased abundance of KCC1-3 mRNA and of KCC polypeptides in late erythropoiesis. DIOA markedly modified the composition of normal erythroid precursors, promoting differentiation and arrest at the polychromatic erythroblast stage and resulting in a precursor distribution profile similar to that of untreated β-thalassemic cells. DIOA up-regulated cyclin-D mRNA levels in late erythropoiesis in both cell models, paralleling changes in the percentage of S-phase-cells. Caspase-3 activity in late erythropoiesis declined to similar degrees in both cell models. DIOA did not modify caspase-3 or -8 mRNA levels. Interpretation and Conclusions Ineffective erythropoiesis of in vitro cultured β-thalassemic cells is likely related to impaired cell maturation. KCC activity appears to contribute to erythroid cell growth during late erythropoiesis

    Geometric invariant theory of syzygies, with applications to moduli spaces

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    We define syzygy points of projective schemes, and introduce a program of studying their GIT stability. Then we describe two cases where we have managed to make some progress in this program, that of polarized K3 surfaces of odd genus, and of genus six canonical curves. Applications of our results include effectivity statements for divisor classes on the moduli space of odd genus K3 surfaces, and a new construction in the Hassett-Keel program for the moduli space of genus six curves.Comment: v1: 23 pages, submitted to the Proceedings of the Abel Symposium 2017, v2: final version, corrects a sign error and resulting divisor class calculations on the moduli space of K3 surfaces in Section 5, other minor changes, In: Christophersen J., Ranestad K. (eds) Geometry of Moduli. Abelsymposium 2017. Abel Symposia, vol 14. Springer, Cha

    Observation of confined current ribbon in JET plasmas

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    we report the identification of a localised current structure inside the JET plasma. It is a field aligned closed helical ribbon, carrying current in the same direction as the background current profile (co-current), rotating toroidally with the ion velocity (co-rotating). It appears to be located at a flat spot in the plasma pressure profile, at the top of the pedestal. The structure appears spontaneously in low density, high rotation plasmas, and can last up to 1.4 s, a time comparable to a local resistive time. It considerably delays the appearance of the first ELM.Comment: 10 pages, 6 figure

    Who I Am: The Meaning of Early Adolescents’ Most Valued Activities and Relationships, and Implications for Self-Concept Research

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    Self-concept research in early adolescence typically measures young people’s self-perceptions of competence in specific, adult-defined domains. However, studies have rarely explored young people’s own views of valued self-concept factors and their meanings. For two major self domains, the active and the social self, this mixed-methods study identified factors valued most by 526 young people from socioeconomically diverse backgrounds in Ireland (10-12 years), and explored the meanings associated with these in a stratified subsample (n = 99). Findings indicate that self-concept scales for early adolescence omit active and social self factors and meanings valued by young people, raising questions about content validity of scales in these domains. Findings also suggest scales may under-represent girls’ active and social selves; focus too much on some school-based competencies; and, in omitting intrinsically salient self domains and meanings, may focus more on contingent (extrinsic) rather than true (intrinsic) self-esteem

    On Embeddability of Buses in Point Sets

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    Set membership of points in the plane can be visualized by connecting corresponding points via graphical features, like paths, trees, polygons, ellipses. In this paper we study the \emph{bus embeddability problem} (BEP): given a set of colored points we ask whether there exists a planar realization with one horizontal straight-line segment per color, called bus, such that all points with the same color are connected with vertical line segments to their bus. We present an ILP and an FPT algorithm for the general problem. For restricted versions of this problem, such as when the relative order of buses is predefined, or when a bus must be placed above all its points, we provide efficient algorithms. We show that another restricted version of the problem can be solved using 2-stack pushall sorting. On the negative side we prove the NP-completeness of a special case of BEP.Comment: 19 pages, 9 figures, conference version at GD 201

    The Young and Bright Type Ia Supernova ASASSN-14lp: Discovery, Early-Time Observations, First-Light Time, Distance to NGC 4666, and Progenitor Constraints

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    On 2014 Dec. 9.61, the All-Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin") discovered ASASSN-14lp just 2\sim2 days after first light using a global array of 14-cm diameter telescopes. ASASSN-14lp went on to become a bright supernova (V=11.94V = 11.94 mag), second only to SN 2014J for the year. We present prediscovery photometry (with a detection less than a day after first light) and ultraviolet through near-infrared photometric and spectroscopic data covering the rise and fall of ASASSN-14lp for more than 100 days. We find that ASASSN-14lp had a broad light curve (Δm15(B)=0.80±0.05\Delta m_{15}(B) = 0.80 \pm 0.05), a BB-band maximum at 2457015.82±0.032457015.82 \pm 0.03, a rise time of 16.940.10+0.1116.94^{+ 0.11 }_{- 0.10 } days, and moderate host--galaxy extinction (E(BV)host=0.33±0.06E(B-V)_{\textrm{host}} = 0.33 \pm 0.06). Using ASASSN-14lp we derive a distance modulus for NGC 4666 of μ=30.8±0.2\mu = 30.8 \pm 0.2 corresponding to a distance of 14.7±1.514.7 \pm 1.5 Mpc. However, adding ASASSN-14lp to the calibrating sample of Type Ia supernovae still requires an independent distance to the host galaxy. Finally, using our early-time photometric and spectroscopic observations, we rule out red giant secondaries and, assuming a favorable viewing angle and explosion time, any non-degenerate companion larger than 0.34Rsun0.34 R_{\textrm{sun}}.Comment: 12 pages, 9 figures, 4 tables. Accepted to ApJ. Photometric data presented in this submission are included as an ancillary file. For a brief video explaining this paper, see https://www.youtube.com/watch?v=1bOV-Cqs-a
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