Biphenyls are unique phytoalexins de novo synthesized in plants in response to pathogen attack. These compounds are found in Maloideae, a subfamily of the Rosaceae. The anti-microbial activities of biphenyls have been reported in a number of studies and they appear to represent an important defense strategy against pathogens common in the Maloideae, such as species in Malus, Pyrus, Sorbus, and ...

S-RNase-based gametophytic self-incompatibility evolved once before the split of the Asteridae and Rosidae. In Prunus (tribe Amygdaloideae of Rosaceae), the self-incompatibility S-pollen is a single F-box gene that presents the expected evolutionary signatures. In Malus and Pyrus (subtribe Pyrinae of Rosaceae), however, clusters of F-box genes (called SFBBs) have been described that are express...

The antioxidant efficiency of dry extracts from inflorescences and/or leaves of seven Sorbus species was studied using four in vitro tests of SET (single electron transfer) and HAT-type (hydrogen atom transfer) mechanisms. The 70% methanol extracts and its diethyl ether, ethyl acetate, n-butanol and water fractions were tested in parallel with the phenolic standards, e.g., caffeic acid, quercet...

amorphous silicate sample showing the typical fractal aggregate texture. CHARACTERIZATION OF AMORPHOUS SILICATE AND ORGANIC BEARING MIXTURES IN ANTICIPATION OF THE OSIRIS-REx ARRIVAL AT BENNU. K. L. Donaldson Hanna, L. P. Keller, D. L. Schrader, T. J. McCoy, N. E. Bowles, N. M. Johnson, J. A. Nuth, G. D. Cody, H. C. Connolly Jr., L. F. Lim and D. S. Lauretta, University of Oxford (Kerri.Donalds...

The classical matrix groups are of fundamental importance in many parts of geometry and algebra. Some of them, like Sp.n/, are most conceptually defined as groups of quaternionic matrices. But, the quaternions not being commutative, we must reconsider some aspects of linear algebra. In particular, it is not clear how to define the determinant of a quaternionic matrix. Over the years, many peopl...

COVERAGE: Lecture Notes 6 and 7; Problem Sets 3 and 4; Rowan-Robinson, Chapters 4 and 5; Weinberg, Chapters 4 and 5. One of the problems on the quiz will be taken verbatim (or at least almost verbatim) from either the homework assignments, or from the starred problems from this set of Review Problems. The starred problems are the ones that I recommend that you review most carefully: Problems 1,...

The classical matrix groups are of fundamental impor­ tance in many parts of geometry and algebra. Some of them, like Sp(n), are most conceptually defined as groups of quaternionic matrices. But, the quaternions not being commutative, we must reconsider some as­ pects of linear algebra. In particular, it is not clear how to define the determinant of a quaternionic matrix. Over the years, many p...

In order to find new sources of natural antioxidants, the antioxidant potential of 70% methanolic extracts from the inflorescences and leaves of 16 species from the genus Sorbus s.s. was evaluated using two complementary in vitro test systems: the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging assay and the AAPH [2,2¢-azobis-(2-amidinopropane)dihydrochloride]-induced linoleic acid (LA)...

Mountain ash (Sorbus decora and S. americana) is used by the Cree Nation of the James Bay region of Quebec (Eeyou Istchee) as traditional medicine. Its potential as an antidiabetic medicine is thought to vary across its geographical range, yet little is known about the factors that affect its antioxidant capacity. Here, we examined metabolite gene expression in relation to antioxidant activity,...

Caspar Clark 1,*, Riccardo Bassiri 2,*, Iain W. Martin 3, Ashot Markosyan 2, Peter G. Murray 3, Des Gibson 4, Sheila Rowan 3 and Martin M. Fejer 2 1 Helia Photonics Ltd., Livingston EH54 7EJ, UK 2 E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA; [email protected] (A.M.); [email protected] (M.M.F.) 3 Scottish Universities Physics Alliance, School of Physics and Astronom...