OBJECTIVE In order to determine the mechanism by which nitric oxide (NO) inhibits prolactin release, we investigated the participation of cGMP-dependent cAMP-phosphodiesterases (PDEs) and protein kinase G (PKG) in this effect of NO. METHODS Anterior pituitary glands of male rats were incubated with inhibitors of PDE and PKG with or without sodium nitroprusside (NP). Prolactin release, and cAM...

We study the problem of efficient identification of particular classes of ptime languages, called uniform. We require the learner to identify each language of such a class by constantly guessing, after a small number of examples, the same index for it. We present three identification paradigms based on different kind of examples: identification on informant (positive and negative information), ...

We prove that no online algorithm (even randomized, against an oblivious adversary) is better than 1/2competitive for welfare maximization with coverage valuations, unless NP = RP . Since the Greedy algorithm is known to be 1/2-competitive for monotone submodular valuations, of which coverage is a special case, this proves that Greedy provides the optimal competitive ratio. On the other hand, w...

Let G = (V, E) be a graph and p be a positive integer. A subset S ⊆ V is called a p-dominating set if each vertex not in S has at least p neighbors in S. The p-domination number γp(G) is the size of a smallest p-dominating set of G. The p-reinforcement number rp(G) is the smallest number of edges whose addition to G results in a graph G ′ with γp(G ′) < γp(G). In this paper, we give an original...

We present results from multi-epoch spectral analysis of XMM-Newton and Chandra observations of the mini broad absorption line (BAL) quasar PG 1115+080. This is one of the few X-ray detected mini-BAL quasars to date that is bright enough in the X-ray band, mostly due to large gravitationallensing magnifications, to allow in-depth spectral analysis. The present XMM-Newton observations of PG 1115...

We show that if NP , co−RP then the existence of efficient indistinguishability obfuscation (iO) implies the existence of one-way functions. Thus, if we live in “Pessiland”, where NP problems are hard on the average but one-way functions do not exist, or even in “Heuristica”, where NP problems are hard in the worst case but easy on average, then iO is impossible. Our result makes it redundant t...

Restored prairies are expected to improve soil physical properties, yet little is known about the extent of change to soil properties and how rapidly these changes take place. The objective of this study was to compare effects of prairie restoration on computed tomography (CT)-measured pore parameters. Undisturbed soil cores (76 mm diam. by 76 mm long) from native prairie (NP), restored prairie...

This report documents the results of two follow-up workshops on the International Handbook of Labour Market Policy and Evaluation. The aim of these workshops was the exchange of experience among academics and practitioners in the evaluation of labour market policies. The Handbook project as well as the two workshops were supported from the beginning by DG V of the European Commission through th...

Impagliazzo and Levin showed a reduction from average-case hardness of any NP-search problem under any polynomialtime samplable distribution to that of another NP-search problem under the uniform distribution in [12]. Their target was the hardness of positive instances occurring with probability 1/poly(n) under the distributions. In this paper, we focus on hardness of a larger fraction of insta...

In this paper we study the consequences of the existence of sparse hard sets for diierent complexity classes under certain types of deterministic, randomized and nondeterministic reductions. We show that if an NP-complete set is bounded-truth-table reducible to a set that conjunctively reduces to a sparse set then P = NP. Relatedly, we show that if an NP-complete set is bounded-truth-table redu...