68 research outputs found
Bohm-Like Trees for Rewriting
No full textKlop, J.W. [Promotor]Raamsdonk, F. [Copromotor]Vrijer, R.C. de [Copromotor
Variability in calling signals of the planthopper Javesella pellucida (F) (Homoptera: Delphacidae) in relation to temperature, and consequences for species rec
No full textConditional linearization
No full textAbstractA non-leftlinear term rewriting system lacking the Church-Rosser property can sometimes be shown to satisfy the unique normal form property by shifting attention to an associated conditional term rewriting system that is leftlinear. We call this the method of conditional linearization. In the present paper the method is described in a general setting and some applications are discussed. In particular we present a simple proof of the unique normal form property for Combinatory Logic extended with ‘Parallel Conditional’, that is, with constants C,T and F (conditional, true, false) and extra reduction rules CTxy → x, CFxy → y and Czxx → x. A special feature of this application is that it involves the use of negative conditions
Fetal hypertension and abnormal Doppler velocimetry in an ovine model of intrauterine growth restriction
No full textOur objective was to test the hypothesis that systemic blood pressure (BP) is increased above normal in intrauterine growth restricted (IUGR) fetal lambs with elevated umbilical artery (UmA) Doppler indices. Five pregnant ewes were exposed to hyperthermic conditions for 80 days beginning at 40 days' gestation (dGA) to induce IUGR. They were then placed in ambient conditions with 6 additional ewes that served as controls. Doppler indices were calculated from UmA Doppler flow velocity waveforms. At 128 dGA, fetal catheters were placed for measurement of umbilical blood flow (UBF) by an ethyl alcohol steady-state diffusion technique and for aortic BP measurements. At 132 dGA, fetal mean systemic BP and blood flow were determined. At necropsy the placental and fetal weights were recorded. UBF was normalized for fetal weight. Linear regression, F tests and t tests were performed as appropriate. P <. 05 was considered significant. Compared with control pregnancies, the IUGR pregnancies showed: (1) reduced fetal and placental weights, (2) elevated systemic BP, (3) reduced UBF, (4) elevated UmA and aortic Doppler velocimetry indices, (5) increased resistance per 100 g placenta, and (6) decreased UmA oxygenation and increased lactic academia. The UmA Doppler index of resistance (systolic/diastolic ratio) correlated strongly with calculated resistance (R 2 = 0.7). Doppler indices also correlated with systemic BP (R 2 = 0.5). Ovine IUGR fetuses with high UmA Doppler indices have elevated systemic BPs. UmA Doppler indices of resistance correlate well with (1) fetal systemic BPs and (2) resistance as calculated by pressure/flow. This whole animal study shows that IUGR fetuses are hypertensive and that increased UmA Doppler resistance indices are consistent with a fetal-placental hypertensive state
Monetary transmission and bank lending in the Netherlands
No full textThis paper investigates the role of bank lending in the monetary transmission process in the Netherlands. We observe significant differences between the responses of corporate and household lending following a monetary shock. We also find that banks hold a buffer stock of securities which they use to offset monetary shocks. The main implication of our study is that a bank lending channel is not likely to be an important transmission mechanism of monetary policy.
Zijn we echt zo veel vrijer dan de generaties voor ons?
No full textItem does not contain fulltextS. Knepper De vrijheidsillusie Amsterdam:Uitgeverij Boom ,2018 978902440763
Equivalence of call-by-name and call-by-need for lambda-calculi with letrec
No full textWe develop a proof method to show that in a (deterministic) lambda calculus with letrec and equipped with contextual equivalence the call-by-name and the call-by-need evaluation are equivalent, and also that the unrestricted copy-operation is correct. Given a let-binding x = t, the copy-operation replaces an occurrence of the variable x by the expression t, regardless of the form of t. This gives an answer to unresolved problems in several papers, it adds a strong method to the tool set for reasoning about contextual equivalence in higher-order calculi with letrec, and it enables a class of transformations that can be used as optimizations. The method can be used in different kind of lambda calculi with cyclic sharing. Probably it can also be used in non-deterministic lambda calculi if the variable x is "deterministic", i.e., has no interference with non-deterministic executions. The main technical idea is to use a restricted variant of the infinitary lambda-calculus, whose objects are the expressions that are unrolled w.r.t. let, to define the infinite developments as a reduction calculus on the infinite trees and showing a standardization theorem
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