Nitrous oxide (N2 O) is a potent, globally important, greenhouse gas, predominantly released from agricultural soils during nitrogen (N) cycling. Arbuscular mycorrhizal fungi (AMF) form a mutualistic symbiosis with two-thirds of land plants, providing phosphorus and/or N in exchange for carbon. As AMF acquire N, it was hypothesized that AMF hyphae may reduce N2 O production. AMF hyphae were eit...

In 1937, Wilson and Umbreit1 reported that H2 inhibited N2 fixation in red clover plants and when this inhibition proved to be competitive, it implied that N2 and H2 were bound at the same site on the enzyme. The enzyme also binds CO2 and N20' competitively with N2. The first evidence that any compound other than N2 bound at the N2-fixing site could be reduced was supplied when Mozen and Burris...

This paper is a report on the highlights of aeroacoustics research and development in Europe in 1999, compiled from information provided to the Aeroacoustics Specialists Committee (ASC) of the Confederation of European Aerospace Societies (CEAS). CEAS presently comprises the national Aerospace Societies of France (AAAF), Germany (DGLR), Italy (AIDAA), The Netherlands (NVvL), Spain (AIAE), Swede...

In this paper we demonstrate how broadband cavity enhanced absorption spectroscopy (CEAS) with supercontinuum (SC) radiation in the near-infrared spectral range can be used as a sensitive, multiplexed, and simple tool to probe gas-phase species in high-temperature environments. Near-infrared SC radiation is generated by pumping a standard single-mode fiber with a picosecond fiber laser. Standar...

We report IR active N2 stretching frequencies in isolated and size selected cobalt cluster nitrogen adsorbate complexes, [Con(N2)1](+) as recorded by virtue of InfraRed Photon Dissociation (IRPD) spectroscopy. The observed frequencies of the [Con(N2)1](+) complexes (n = 8-17) are significantly redshifted (2180 to 2290 cm(-1)) with respect to the IR inactive vibrations of free N2 (2359 cm(-1)). ...

The crossing number cr(G) of a graph G is the minimum number of crossings in a nondegenerate planar drawing of G. The rectilinear crossing number cr(G) of G is the minimum number of crossings in a rectilinear nondegenerate planar drawing (with edges as straight line segments) of G. Zarankiewicz proved in 1952 that cr(Kn1,n2) ≤ Z(n1, n2) := ⌊ n1 2 ⌋ ⌊ n1−1 2 ⌋ ⌊ n2 2 ⌋ ⌊ n2−1 2 ⌋ . We define an ...

The transmission of Buruli ulcer (BU), caused by Mycobacterium ulcerans (MU), remains puzzling although a number of hypothesis including through bites of infected aquatic insects have been proposed. We report the results of experiments using ICR mice that give credence to our hypothesis that Acanthamoeba species may play a role in BU transmission. We cocultured MU N2 and MU 1615 which expresses...

ion : règle (comb-K). M est de la forme fun z → C où C est soit une variable différente de z, soit un opérateur, soit un setm, soit un getm. Dans ce cas, [M ] vaut K C. On cherche à montrer que fun z → C ≃ (fun x → fun y → x)C. Or on a : (fun x → fun y → x)C / s → fun y → C / s (on suppose ici que C n’est pas la variable y pour éviter les considérations sur l’alpha-conversion lors de l’applicat...

The effects of different modified atmospheres (air: atm1; 100% CO2: atm2; 100% N2: atm3; 50% CO2/50% N2: atm4) on the textural and sensory characteristics of the ready-to-serve pizza at 7 ̊C ± 1 ̊C were investigated. The values of hardness, gumminess and chewiness were found to be increased during the storage period while cohesiveness and springiness exhibited a decreasing trend. Overall, the 100...

The maximum of the linking number between two lattice polygons of lengths n1, n2 (with n1 ≤ n2) is proven to be of the order of n1(n2) 1 3 . This result is generalized to smooth links of unit thickness. The result also implies that the writhe of a lattice knot K of length n is at most 26 n4/3/π. In the second half of the paper examples are given to show that linking numbers of order n1(n2) 1 3 ...