78 research outputs found
Arbitrage, Clientele Effects, and the Term Structure of Interest Rates
This paper derives a new and intuitive estimation procedure for the term structure under potential tax arbitrage. No a priori assumptions regarding the equality of the prices and present values of bonds are made. The data are employed to determine whether this equality holds, and an appropriate estimator is thereby endogenously derived. The suggested estimator is based on the optimizing behavior of an investor in a market with frictions, and emerges directly from the solution of the dual of the no-arbitrage optimization problem. In addition, the proposed estimator benefits from being both theoretically sound and straightforward to apply
Completeness and Ambiguity of Schema Cover
Given a schema and a set of concepts, representative of entities in the domain of discourse, schema cover deïŹnes correspondences between concepts and parts of the schema. Schema cover aims at interpreting the schema in terms of concepts and thus, vastly simplifying the task of schema integration. In this work we investigate two properties of schema cover, namely completeness and ambiguity. The former measures the part of a schema that can be covered by a set of concepts and the latter examines the amount of overlap between concepts in a cover. To study the tradeoffs between completeness and ambiguity we deïŹne a cover model to which previous frameworks are special cases. We analyze the theoretical complexity of variations of the cover problem, some aim at maximizing completeness while others aim at minimizing ambiguity. We show that variants of the schema cover problem are hard problems in general and formulate an exhaustive search solution using integer linear programming. We then provide a thorough empirical analysis, using both real-world and simulated data sets, showing empirically that the integer linear programming solution scales well for large schemata. We also show that some instantiations of the general schema cover problem are more effective than others
Propulsion in a viscoelastic fluid
Flagella beating in complex fluids are significantly influenced by
viscoelastic stresses. Relevant examples include the ciliary transport of
respiratory airway mucus and the motion of spermatozoa in the mucus-filled
female reproductive tract. We consider the simplest model of such propulsion
and transport in a complex fluid, a waving sheet of small amplitude free to
move in a polymeric fluid with a single relaxation time. We show that, compared
to self-propulsion in a Newtonian fluid occurring at a velocity U_N, the sheet
swims (or transports fluid) with velocity U / U_N = [1+De^2 (eta_s)/(eta)
]/[1+De^2], where eta_s is the viscosity of the Newtonian solvent, eta is the
zero-shear-rate viscosity of the polymeric fluid, and De is the Deborah number
for the wave motion, product of the wave frequency by the fluid relaxation
time. Similar expressions are derived for the rate of work of the sheet and the
mechanical efficiency of the motion. These results are shown to be independent
of the particular nonlinear constitutive equations chosen for the fluid, and
are valid for both waves of tangential and normal motion. The generalization to
more than one relaxation time is also provided. In stark contrast with the
Newtonian case, these calculations suggest that transport and locomotion in a
non-Newtonian fluid can be conveniently tuned without having to modify the
waving gait of the sheet but instead by passively modulating the material
properties of the liquid.Comment: 21 pages, 1 figur
Entangled Stories: The Red Jews in Premodern Yiddish and German Apocalyptic Lore
âFar, far away from our areas, somewhere beyond the Mountains of Darkness, on the other side of the Sambatyon RiverâŠthere lives a nation known as the Red Jews.â The Red Jews are best known from classic Yiddish writing, most notably from Mendele's Kitser masoes Binyomin hashlishi (The Brief Travels of Benjamin the Third). This novel, first published in 1878, represents the initial appearance of the Red Jews in modern Yiddish literature. This comical travelogue describes the adventures of Benjamin, who sets off in search of the legendary Red Jews. But who are these Red Jews or, in Yiddish, di royte yidelekh? The term denotes the Ten Lost Tribes of Israel, the ten tribes that in biblical times had composed the Northern Kingdom of Israel until they were exiled by the Assyrians in the eighth century BCE. Over time, the myth of their return emerged, and they were said to live in an uncharted location beyond the mysterious Sambatyon River, where they would remain until the Messiah's arrival at the end of time, when they would rejoin the rest of the Jewish people.
This article is part of a broader study of the Red Jews in Jewish popular culture from the Middle Ages through modernity. It is partially based on a chapter from my book, Umstrittene Erlöser: Politik, Ideologie und jĂŒdisch-christlicher Messianismus in Deutschland, 1500â1600 (Göttingen: Vandenhoeck & Ruprecht, 2011). Several postdoctoral fellowships have generously supported my research on the Red Jews: a Dr. Meyer-Struckmann-Fellowship of the German Academic Foundation, a Harry Starr Fellowship in Judaica/Alan M. Stroock Fellowship for Advanced Research in Judaica at Harvard University, a research fellowship from the Heinrich Hertz-Foundation, and a YIVO Dina Abramowicz Emerging Scholar Fellowship. I thank the organizers of and participants in the colloquia and conferences where I have presented this material in various forms as well as the editors and anonymous reviewers of AJS Review for their valuable comments and suggestions. I am especially grateful to Jeremy Dauber and Elisheva Carlebach of the Institute for Israel and Jewish Studies at Columbia University, where I was a Visiting Scholar in the fall of 2009, for their generous encouragement to write this article. Sue Oren considerably improved my English. The style employed for Romanization of Yiddish follows YIVO's transliteration standards. Unless otherwise noted, translations from the Yiddish, Hebrew, German, and Latin are my own. Quotations from the Bible follow the JPS translation, and those from the Babylonian Talmud are according to the Hebrew-English edition of the Soncino Talmud by Isidore Epstein
Association between B-cell depletion and attack risk in neuromyelitis optica spectrum disorder: An exploratory analysis from N-MOmentum, a double-blind, randomised, placebo-controlled, multicentre phase 2/3 trial
BACKGROUND: Inebilizumab is an anti-CD19 antibody approved for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in adults with aquaporin-4 autoantibodies. The relationship between B-cell, plasma-cell (PC), and immunoglobulin depletion with longitudinal reductions in NMOSD activity after inebilizumab treatment was characterised post hoc in an exploratory analysis from the N-MOmentum study (NCT02200770). METHODS: Peripheral blood CD20+ B cells, PC gene signature, and immunoglobulin levels were assessed throughout N-MOmentum (follow-up =2.5 years); correlations with clinical metrics and magnetic resonance imaging (MRI) lesion activity were assessed. FINDINGS: Inebilizumab induced durable B-cell and PC depletion within 1 week versus placebo. Although no association was observed between B-cell counts at time of attack and NMOSD activity, depth of B-cell depletion after the first dosing period correlated with clinical outcomes. All participants receiving inebilizumab demonstrated a robust long-term therapeutic response, and participants with =4 cells/”L after the first 6-month dosing interval had persistently deeper B-cell depletion, lower annualised attack rates (estimated rate [95% CI]: 0.034 [0.024â0.04] vs 0.086 [0.056â0.12]; p = 0.045), fewer new/enlarging T2 MRI lesions (0.49 [0.43â0.56] vs 1.36 [1.12â1.61]; p < 0.0001), and a trend towards decreased Expanded Disability Status Scale worsening (0.076 [0.06â0.10] vs 0.14 [0.10â0.18]; p = 0.093). Antibodies to inebilizumab, although present in a proportion of treated participants, did not alter outcomes. INTERPRETATION: This analysis suggests that compared with placebo, inebilizumab can provide specific, rapid, and durable depletion of B cells in participants with NMOSD. Although deep and persistent CD20+ B-cell depletion correlates with long-term clinical stability, early, deep B-cell depletion correlates with improved disease activity metrics in the first 2 years
Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease
We identified rare coding variants associated with Alzheimerâs disease (AD) in a 3-stage case-control study of 85,133 subjects. In stage 1, 34,174 samples were genotyped using a whole-exome microarray. In stage 2, we tested associated variants (P<1Ă10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, an additional 14,997 samples were used to test the most significant stage 2 associations (P<5Ă10-8) using imputed genotypes. We observed 3 novel genome-wide significant (GWS) AD associated non-synonymous variants; a protective variant in PLCG2 (rs72824905/p.P522R, P=5.38Ă10-10, OR=0.68, MAFcases=0.0059, MAFcontrols=0.0093), a risk variant in ABI3 (rs616338/p.S209F, P=4.56Ă10-10, OR=1.43, MAFcases=0.011, MAFcontrols=0.008), and a novel GWS variant in TREM2 (rs143332484/p.R62H, P=1.55Ă10-14, OR=1.67, MAFcases=0.0143, MAFcontrols=0.0089), a known AD susceptibility gene. These protein-coding changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified AD risk genes. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to AD development
Management of recurrent hepatitis C after liver transplantation: a concise review
Recurrent hepatitis C infection and subsequent graft failure are increasingly recognized problems after orthotopic liver transplantation. Although many prospective therapeutic, controlled trials in primary hepatitis C disease have been reported, large-scale studies are yet to be performed in patients with posttransplant recurrent hepatitis C after liver transplantation. In this review, we summarize the current literature on the therapeutic approaches for recurrent hepatitis C and discuss the results of published studies on therapy with ribavirin or interferon (IFN) alone and on combination therapy with IFN plus ribavirin. Further, we discuss results of prophylactic approaches to the problem of recurrent hepatitis C after transplant. Finally, we discuss additional aspects of anti-hepatitis C virus therapy after liver transplantation
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