Synthesis and insecticidal activity of lipophilic amides. Part 5: Influence on activity of varying the substituent on nitrogen

Isomerisation or shortening of the 2-methylpropyl group in (2-methylpropyl)-6-phenylhexa-2, 4-dienamide lowers insecticidal activity, as does methylation at nitrogen. Methylation at each carbon atom in turn, and, within limits, in combination, gives compounds with substantial, sometimes increased, activity. Cyclic and olefinic equivalents of the effective alkyl substituents are mostly less active.     

The Effects of Fertilization and Water Management on Growth and Production of Nile Tilapia in Deep Ponds During the Dry Season

Abstract— Fertilization guidelines developed for shallow ponds (1 m) with controlled depths were tested in deeper (2.5 m) ponds to determine effectiveness of these guidelines for culture of Nile tilapia Oreochromis niloticus . Twelve ponds of 2.5-m depth were used in four treatments: (A) weekly fertilization with water addition; (B) weekly fertilization without water addition; (C) one early fertilization without water addition; and (D) fertilization frequency dependent on nutrient concentrations, without water addition. Sex-reversed Nile tilapia were stocked at 2 fish/m² with an initial weight of 15 g, and harvested after 234 d. Depth of water declined from 2.4 m to 1.6 m over the experiment in ponds without water addition. Fish growth rate was significantly higher in treatments A and B (0.86 g/d), than in other treatments, as was yield (3,830 kg/ha). Treatment C was lowest in growth (0.086 g/d) and yield (168 kg/ha), with treatment D intermediate. Fish growth rates and yields were strongly correlated to manure input ( R² = 0.89 and 0.94, respectively), and residuals were not correlated to any physical or chemical variables. Growth and yield in these deep ponds were somewhat lower than those in previous experiments for shallow ponds with regular water inputs. However, stagnant ponds did not accumulate nutrients and metabolites at rates higher than ponds with controlled water depths.     

Molekulare Muster der bakteriellen Besiedlung von Möhren aus ökologischer und konventioneller Erzeugung

In order to assess the effects of different cropping systems on the bacterial flora, we stored 34 batches of carrots of defined origin for extended periods at 5°C and high relative humidity and characterised the pattern of the bacterial flora by using DNA-based fingerprint methods. Four of these batches were spoiled by fungi. Of these, two were from a field experiment where organically grown carrots received additional organic nitrogen. Other effects of the cropping method (organic vs. conventional) were not observed. The “fingerprint methods” SSCP and ARDRA detect differences in the ribosomal RNA. Using them, we found differences in the composition of the bacterial flora of carrots of different origin, and detected shifts of this flora during storage. No clear correlations with the cropping method were found. T-RFLP (a method based on the ARDRA principle) showed differences in the bacterial flora of visibly spoiled carrots.     

Antibiofilm Activity of the Brown Alga Halidrys siliquosa against Clinically Relevant Human Pathogens

The marine brown alga Halidrys siliquosa is known to produce compounds with antifouling activity against several marine bacteria. The aim of this study was to evaluate the antimicrobial and antibiofilm activity of organic extracts obtained from the marine brown alga H. siliquosa against a focused panel of clinically relevant human pathogens commonly associated with biofilm-related infections. The partially fractionated methanolic extract obtained from H. siliquosa collected along the shores of Co. Donegal; Ireland; displayed antimicrobial activity against bacteria of the genus Staphylococcus; Streptococcus; Enterococcus; Pseudomonas; Stenotrophomonas; and Chromobacterium with MIC and MBC values ranging from 0.0391 to 5 mg/mL. Biofilms of S. aureus MRSA were found to be susceptible to the algal methanolic extract with MBEC values ranging from 1.25 mg/mL to 5 mg/mL respectively. Confocal laser scanning microscopy using LIVE/DEAD staining confirmed the antimicrobial nature of the antibiofilm activity observed using the MBEC assay. A bioassay-guided fractionation method was developed yielding 10 active fractions from which to perform purification and structural elucidation of clinically-relevant antibiofilm compounds.     

Pro‐inflammatory caspase‐1 activation during the immune response in cells from rainbow trout Oncorhynchus mykiss (Walbaum 1792) challenged with pathogen‐associated molecular patterns

In response to pathogens, the higher vertebrate innate immune system activates pro‐inflammatory caspase‐1 which is responsible for the processing and secretion of several important cytokines involved in the host's defence against infection. To date, caspase‐1 has been described in few teleost fish, and its activity has been demonstrated through substrate cleavage and inhibition by pharmacological agents. In this study, the detection of the active form of caspase‐1 during the immune response in salmonid fish is described, where two antibodies were produced. These antibodies differentially recognize the structural epitopes of the inactive pro‐caspase‐1 and the processed active form of the caspase. Firstly, caspase‐1 activation was demonstrated in vitro by ELISA, Western blotting and immunocytochemistry in rainbow trout macrophages exposed to different pathogen‐associated molecular patterns plus the pathogen Aeromonas hydrophila. This activity was clearly abrogated by a caspase inhibitor and seems to be unrelated to IL‐1β secretion. Caspase‐1 activation was then validated in vivo in gill cells from fish challenged with Aeromonas salmonicida. These results represent the first demonstration of caspase‐1 activation in salmonids, and the first evidence of the putative regulatory role which this protease plays in inflammatory response in this fish group, as described for some other teleosts and mammals.     

Regime dynamics of hydrochemical and toxicological parameters of the Irtysh River in Kazakhstan

Since the Irtysh River flows through the important economic,ecological and social territories of China,Kazakhstan and Russia,the water quality issues growingly draw the attention of the water authorities from these countries.Therefore,a detailed study of the hydrochemical regime and toxicological indicators in Kazakhstan was carried out for understanding the regime dynamics of water quality and its affect factors.The combined assessment of maximum permissible concentration(MPC)of chemical components and biotesting method were proposed and performed for the study area.The results clearly showed that the concentrations of single chemical component at different locations are mostly under MPC standard in a basin scale.However,the watershed surface runoff and tributary stream flow from mining industry areas had high concentration of heavy metals and had significant impact on the water quality near Ust-Kamenogorsk.Furthermore,even the stream water generally meet MPC standard,the results of biotesting method show the toxicity level of water sample is lethal for the test objects of phytoplankton and Daphnia.The survival rates of most water samples are lower than 46.7%.Hereby,this study strongly suggests using combined water assessment methods to evaluate the water quality.