Evaluation of neem seed powder for Fusarium wilt and Meloidogyne control on tomato

Fusarium wilt and root-knot are important diseases of tomato. The use of chemical is becoming less appealing because of the health implications. Also, the chemicals required are often not within the reach of farmers in most of the developing part of the world. This research is aimed at finding an alternative mode of control. Tomato variety Roma VF inoculated with Meloidogyne and Fusarium were treated with 2 g/kg soil neem seed powder in the screenhouse and 2 Mg ha ^{? 1} in the field. An untreated and Furadan treated plot in the field served as control. Neem seed powder significantly reduced the disease severity of Fusarium and root-knot in both screenhouse and field. Results suggest the possible use of neem seed powder for control of the root-knot nematodes - Fusarium wilt disease complex.     

Testing statistical significance scores of sequence comparison methods with structure similarity

Background  

In the past years the Smith-Waterman sequence comparison algorithm has gained popularity due to improved implementations and rapidly increasing computing power. However, the quality and sensitivity of a database search is not only determined by the algorithm but also by the statistical significance testing for an alignment. The e-value is the most commonly used statistical validation method for sequence database searching. The CluSTr database and the Protein World database have been created using an alternative statistical significance test: a Z-score based on Monte-Carlo statistics. Several papers have described the superiority of the Z-score as compared to the e-value, using simulated data. We were interested if this could be validated when applied to existing, evolutionary related protein sequences.     

Identifying dynamical modules from genetic regulatory systems: applications to the segment polarity network

Background  

It is widely accepted that genetic regulatory systems are 'modular', in that the whole system is made up of smaller 'subsystems' corresponding to specific biological functions. Most attempts to identify modules in genetic regulatory systems have relied on the topology of the underlying network. However, it is the temporal activity (dynamics) of genes and proteins that corresponds to biological functions, and hence it is dynamics that we focus on here for identifying subsystems.     

Survival pathways triggered by peroxynitrite in cells belonging to the monocyte/macrophage lineage

Peroxynitrite, a highly reactive nitrogen species, promotes in U937 cells (a promonocytic cell line) a mitochondrial permeability transition (MPT)-dependent necrosis. An initial event triggered by peroxynitrite (i.e., inhibition of complex III of the mitochondrial respiratory chain) is responsible for the time-dependent formation of H(2)O(2), essential for the occurrence of cell death. Otherwise non-toxic concentrations of peroxynitrite nevertheless commit cells to MPT-dependent necrosis, which is however prevented by a cytoprotective signaling driven by arachidonic acid (AA) released by the cytosolic PLA(2) isoform. Interestingly, the mechanism whereby delayed formation of H(2)O(2) promotes toxicity in cells exposed to intrinsically toxic concentrations of peroxynitrite is independent of the accumulation of additional damage. Cell death is in fact mediated by inhibition of the AA-dependent cytoprotective signaling. Exogenous AA, however, prevented toxicity also under these conditions. An additional point to be made is that the major findings obtained using U937 cells were reproduced in different cell types belonging to the monocyte/macrophage lineage. Hence, within the context of the inflammatory response, monocytes and macrophages may cope with peroxynitrite by using AA, a signaling molecule largely available at the inflammatory sites.     

A Medium for the Isolation of Staphylococci from Foodstuffs

S ummary . A liquid medium for the isolation of staphylococci from foodstuffs, containing lithium chloride, potassium tellurite and glycine as inhibitors of contaminants other than cocci, is described. Micrococci are inhibited in the cultures by anaerobic conditions produced by agar seals. With this medium staphylococci are easily isolated even when their numbers in foodstuffs are low.