The European Solar Radiation Atlas: a valuable digital tool

International audienceThe new CD-ROM based European Solar Radiation Atlas (ESRA) is now available. It is published by Les Presses de l'Ecole des Mines de Paris on behalf of the European Commission. This atlas, in 2 volumes, is an instrument dedicated to providing knowledge and aiding exploitation of the solar resources across a wide sweep of Europe, from the Urals to the Azores and from Northern Africa to Polar Circle. It is a powerful tool for architects, engineers, meteorologists, agronomists, local authorities, and tourism professionals, as well as for researchers and students. The input data are based on the period 1981-1990

Cheat Sensitive Quantum Bit Commitment

We define cheat sensitive cryptographic protocols between mistrustful parties as protocols which guarantee that, if either cheats, the other has some nonzero probability of detecting the cheating. We give an example of an unconditionally secure cheat sensitive non-relativistic bit commitment protocol which uses quantum information to implement a task which is classically impossible; we also describe a simple relativistic protocol.Comment: Final version: a slightly shortened version of this will appear in PRL. Minor corrections from last versio

The effects of antiretroviral treatment on liver function enzymes among HIV-infected out patients attending the Central Hospital of Yaounde, Cameroon

The emergence of liver diseases as one of the major causes of death in people infected with HIV has paralleled the introduction of more effective antiretroviral therapies. This study was carried out with the aim of determining the effects of antiretroviral treatment on liver enzymes (SGOT and SGPT) in patients placed on antiretroviral therapy. A prospective cross-sectional 3 years study was carried out among patients confirmed to be HIV positive and who were to be placed on antiretroviral drugs at the HIV/AIDS out patient clinic of the Yaoundé Central Hospital, . Cameroon. Levels of transaminases of patients were measured in four phases using the International Federation of Clinical Chemistry (IFCC) protocol. Of the 150 patients who participated in the study, 54.0 %( 81/150) presented with transaminitis at the final phase of the study with respect to aspartate aminotransferase (AST), 77.78% (63/81) of whose AST levels only increased after initiation of highly active antiretroviral therapy (HAART). 22.67% (34/150) presented with transaminitis with respect to alanine aminotransferase (ALT). At the final phase, 70.58% of whose ALT levels only increased after HAART initiation. Increase in blood transaminase levels was statistically independent on age group and the drug combinations. Increase in AST levels was associated with an increase in ALT levels upon treatment (r = 0.58). There was a significant positive linear relationship between duration of treatment and concentration of transaminases over the years (r= 0.9). We therefore concluded that highly active antiretroviral therapy (HAART) is associated with low level hepatotoxicity at therapy initiation, regardless of drug class or combination.Keywords: Antiretroviral treatment, Liver function enzymes, Hepatotoxicity, Highly active antiretroviral therap

The Ithaca Interpretation of Quantum Mechanics

I list several strong requirements for what I would consider a sensible interpretation of quantum mechanics and I discuss two simple theorems. One, as far as I know, is new; the other was only noted a few years ago. Both have important implications for such a sensible interpretation. My talk will not clear everything up; indeed, you may conclude that it has not cleared anything up. But I hope it will provide a different perspective from which to view some old and vexing puzzles (or, if you believe nothing needs to be cleared up, some ancient verities.)Comment: 21 pages, plain TEX. Notes for a lecture given at the Golden Jubilee Workshop on Foundations of Quantum Theory, Tata Institute, Bombay, September 9-12, 199

Comparative cyclic voltammetry and surface analysis of passive films grown on stainless steel 316 in concrete pore model solutions

The study of passive layers grown on AISI 316 stainless steel in two model solutions, saturated Ca(OH)2 and cement extract (CE) solution, show that each solution simulates the concrete pore environment in a different way. A more resistant passive layer is formed in CE solution due to its distinctive composition, homogeneity, thickness and porosity. The CE-exposed sample withstood several hours of cathodic polarization before the characteristic cyclic voltammetry peaks of the non-passivated AISI 316 reappeared. This is in contrast to the saturated Ca(OH)2-exposed sample, which showed the characteristic CV peaks after several minutes of cathodic polarization. XPS spectra of the passive layer formed in saturated Ca(OH)2 indicate that the amount of Ca is as much as 10 times larger than that in the passive-layer formed in the CE solution. Films formed in CE solution contained Si and S, which are part of the cement mixture composition. Topographical dissimilarities in the passive films are also found in the AFM and optical microscopy images. The passive layer formed in CE solution is homogeneous and covers the metal surface completely. The film formed in saturated Ca(OH)2 is rough, crystalline, and nonhomogeneous. The differences in the composition and electrochemical behavior of passive layers formed on AISI 316 in saturated Ca(OH)2 solution or CE model solution suggest that CE solutions are superior for simulating concrete pore environments and that CE solutions create a more resistive passive film. In addition, passive films formed without polarization were superior to films formed on AISI 316 under anodic polarization

Garbled Circuit Lookup Tables with Logarithmic Number of Ciphertexts

Garbled Circuit (GC) is a basic technique for practical secure computation. GC handles Boolean circuits; it consumes significant network bandwidth to transmit encoded gate truth tables, each of which scales with the computational security parameter $\kappa$. GC optimizations that reduce bandwidth consumption are valuable. It is natural to consider a generalization of Boolean two-input one-output gates (represented by $4$-row one-column lookup tables, LUTs) to arbitrary $N$-row $m$-column LUTs. Known techniques for this do not scale, with naive size-$O(Nm\kappa)$ garbled LUT being the most practical approach in many scenarios. Our novel garbling scheme -- logrow -- implements GC LUTs while sending only a logarithmic in $N$ number of ciphertexts! Specifically, let $n = \lceil \log_2 N \rceil$. We allow the GC parties to evaluate a LUT for $(n-1)\kappa + nm\kappa + Nm$ bits of communication. logrow is compatible with modern GC advances, e.g. half gates and free XOR. Our work improves state-of-the-art GC handling of several interesting applications, such as privacy-preserving machine learning, floating-point arithmetic, and DFA evaluation

Entanglement Swapping Chains for General Pure States

We consider entanglement swapping schemes with general (rather than maximally) entangled bipartite states of arbitary dimension shared pairwise between three or more parties in a chain. The intermediate parties perform generalised Bell measurements with the result that the two end parties end up sharing a entangled state which can be converted into maximally entangled states. We obtain an expression for the average amount of maximal entanglement concentrated in such a scheme and show that in a certain reasonably broad class of cases this scheme is provably optimal and that, in these cases, the amount of entanglement concentrated between the two ends is equal to that which could be concentrated from the weakest link in the chain.Comment: 18 pages, 5 figure