Antifungal effects of sisal leaf juice on Lasiodiplodia theobromae, the causal agent of mulberry root rot

This study was carried out to evaluate the antifungal activities of leaf juices (fresh juice, fermented juice, boiled juice and sterile juice) of nine sisal varieties on Lasiodiplodia theobromae, the causal agent of mulberry root rot. Results show that all the leaf juices could inhibit the mycelial growth in different degrees (the inhibitory rates ranged from 63.3 to 100%), due to different varieties and treatments. Among the nine varieties, the inhibition effects of hybrid 76416 and Agave americana were the best with absolute inhibition of all the leaf juice treatments against the mycelial growth, followed by Agave Amaniensis, Agave virdis, Agave angustifolia and Hybrid 11648. The inhibitory effect of some fresh juices would be cut down after being fermented, boiled and sterilized. The treated mycelia of L.theobromae were malformed, enlarged, broken and plasma leaked when observed under the microscope. Most of the leaf juices could inhibit the conidial germination absolutely, except A.amaniensis, H.11648 and A. angustifolia. The average germination rate of A. amaniensis, H.11648 and A. angustifolia was 72.4, 16.6 and 13%, respectively. The control efficiency of the fresh juice of H. 11648 against mulberry root rot in the field reached 73.1%.Key words: Sisal, leaf juice, anti-fungi, anti-fungal activities, mulberry root rot, Lasiodiplodia theobromae

Antioxidant Properties of Polysaccharide from the Brown Seaweed Sargassum graminifolium (Turn.), and Its Effects on Calcium Oxalate Crystallization

We investigated the effects of polysaccharides from the brown seaweed Sargassum graminifolium (Turn.) (SGP) on calcium oxalate crystallization, and determined its antioxidant activities. To examine the effects of SGP on calcium oxalate crystallization, we monitored nucleation and aggregation of calcium oxalate monohydrate crystals, using trisodium citrate as a positive control. We assessed antioxidant activities of SGP by determining its reducing power, its ability to scavenge superoxide radicals, and its activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The nucleation inhibition ratio of trisodium citrate and SGP was 58.5 and 69.2%, respectively, and crystal aggregation was inhibited by 71.4 and 76.8%, respectively. Increasing concentrations of SGP resulted in increased scavenging of superoxide anions and DPPH radicals (IC50 = 1.9 and 0.6 mg/mL, respectively). These results suggest that SGP could be a candidate for treating urinary stones because of its ability to inhibit calcium oxalate crystallization and its antioxidant properties

Vertices with the Second Neighborhood Property in Eulerian Digraphs

The Second Neighborhood Conjecture states that every simple digraph has a vertex whose second out-neighborhood is at least as large as its first out-neighborhood, i.e. a vertex with the Second Neighborhood Property. A cycle intersection graph of an even graph is a new graph whose vertices are the cycles in a cycle decomposition of the original graph and whose edges represent vertex intersections of the cycles. By using a digraph variant of this concept, we prove that Eulerian digraphs which admit a simple dicycle intersection graph have not only adhere to the Second Neighborhood Conjecture, but have a vertex of minimum outdegree that has the Second Neighborhood Property.Comment: fixed an error in an earlier version and made structural change

Nonlinear Floquet dynamics of spinor condensates in an optical cavity: Cavity-amplified parametric resonance

We investigate Floquet dynamics of a cavity-spinor Bose-Einstein condensate coupling system via periodic modulation of the cavity pump laser. Parametric resonances are predicted and we show that due to cavity feedback-induced nonlinearity the spin oscillation can be amplified to all orders of resonance, thus facilitating its detection. Real-time observation on Floquet dynamics via cavity output is also discussed