Egg-limited functional response of Uscana lariophaga, egg parasitoid of bruchid beetle pests in stored cowpea

The functional response of the egg parasitoid Uscana lariophaga Steffan (Hymenoptera: Trichogrammatidae) to eggs of its host Callosobruchus maculatus Fab. (Coleoptera: Bruchidae) was investigated in storage containers filled with a cowpea (Vigna unguiculata Walp.) seed mass. Foraging time was limited to 4 or 24 h. These indirect experiments were supplemented by direct observations of the parasitoid's handling time, egg-laying capacity and initial egg load. The foraging process of U. lariophaga can be divided into two distinct stages: the process leading to detection of host clusters and, after arrival within a host cluster, the response of the parasitoid to the host density within the cluster. The chance that a cluster is found by U. lariophaga appeared independent of the number of host eggs per cluster, but was influenced by the available foraging time. Within a host cluster, U. lariophaga demonstrated a Holling II type functional response. Parasitoids were strongly arrested in host clusters, leading to high levels of parasitism. Direct observations proved that handling time was not a limiting factor, but that U. lariophaga's initial egg load and egg maturation rate limited the plateau level of her functional response. As such, direct observations were essential for a correct interpretation of the mechanisms underlying the shape of the functional response.     

OntologyWidget – a reusable,embeddable widget for easily locating ontology terms

Background  

Biomedical ontologies are being widely used to annotate biological data in a computer-accessible, consistent and well-defined manner. However, due to their size and complexity, annotating data with appropriate terms from an ontology is often challenging for experts and non-experts alike, because there exist few tools that allow one to quickly find relevant ontology terms to easily populate a web form.     

Molecular docking analysis of glycogen phosphorylase with inhibitors from Cissampelos pareira Linn.

Cissampelos pareira Linn. is a climbing herb known in Indian traditional medicine as laghupatha. It belongs to the Menispermaceae family. The enzyme glycogen phosphorylase (GP) is a promising target for the treatment of type-2 diabetes (T2DM). A variety of natural product inhibitors with both pharmaceutical and nutraceutical potential have been reported in the search for powerful, selective and drug-like GP inhibitors that could lead to hypoglycemic medicines. Therefore, it is of interest to document the molecular docking analysis data of glycogen phosphorylase with compounds from Cissampelos pareira Linn. We report the optimal binding features of 4 compounds namely Trans-N-feruloyltyramine, Coclaurine, Magnoflorine, and Curine with the target protein for further consideration in the context of T2DM.     

The relation between gaze aversion and cortisol reactivity in middle childhood

The present study sought to investigate the relation between ethological observations of children's gaze aversion during a psychosocial stress task and their cortisol reactivity to the task, and how this relation might be moderated by how stressful the children perceived the stress task to be.     

Membrane protein-ligand interactions in Escherichia coli vesicles and living cells monitored via a biosynthetically incorporated tryptophan analogue.

This paper presents a deceptively straightforward experimental approach to monitoring membrane protein-ligand interactions in vesicles and in living Escherichia coli cells. This is achieved via the biosynthetic incorporation of 7-azatryptophan, a tryptophan analogue with a red-shifted absorption spectrum, allowing collection of the emission signal of the target protein in a high tryptophan background via red-edge excitation. The approach is demonstrated for the mannitol permease of E. coli (EII(mtl)), an integral membrane protein of 637 amino acids, including four tryptophans, and single-tryptophan mutants of EII(mtl). By using a tryptophan auxotroph, a high level of 7-azatryptophan incorporation in EII(mtl) was achieved. The change in emission signal of the purified enzyme upon mannitol binding (-28%) was 4-fold larger than with EII(mtl) containing tryptophan, demonstrating the known higher sensitivity of this analogue for changes in the microenvironment [Schlesinger, R. (1968) J. Biol. Chem. 243, 3877-3883]. Changes in emission signal could also be monitored (-5%) when the enzyme was situated in vesicles, although it constituted only 10-15% of the total cytoplasmic membrane fraction. Of the five single-tryptophan mutants, the emission signal of the mutant with 7-azatryptophan at position 198 was the most sensitive for mannitol binding. Changes in emission signal not only were observed in vesicles (-18%) but also could be monitored in viable cells (-5%). The fact that only modest expression levels and no protein purification are needed makes this a useful approach for the characterization of numerous protein systems under in vitro and in vivo conditions.     

Environmental manipulation for edible insect procurement: a historical perspective

Throughout history humans have manipulated their natural environment for an increased predictability and availability of plant and animal resources. Research on prehistoric diets increasingly includes small game, but edible insects receive minimal attention. Using the anthropological and archaeological literature we show and hypothesize about the existence of such environmental manipulations related to the procurement of edible insects. As examples we use eggs of aquatic Hemiptera in Mexico which are semi-cultivated by water management and by providing egg laying sites; palm weevil larvae in the Amazon Basin, tropical Africa, and New Guinea of which the collection is facilitated by manipulating host tree distribution and abundance and which are semi-cultivated by deliberately cutting palm trees at a chosen time at a chosen location; and arboreal, foliage consuming caterpillars in sub-Saharan Africa for which the collection is facilitated by manipulating host tree distribution and abundance, shifting cultivation, fire regimes, host tree preservation, and manually introducing caterpillars to a designated area. These manipulations improve insect exploitation by increasing their predictability and availability, and most likely have an ancient origin.     

MTT assay based inhibition analysis of A2780 cells proliferation using Mollugo nudicaulis Lam. extract with CXCR4 and HER2 expression

It is of interest to document the inhibition of A2780 cell proliferation using Mollugo nudicaulis Lam.(M.nudicaulis) extract by MTT assay and by monitoring the CXCR4 and HER2 expression through RT-PCR analysis. Results shown that the n-hexane extract of M.nudicaulis have anticancer activity IC₅₀ values of 32.46±0.92 µg/mL on A2780 cell lines. It is further found that the CXCR4 and HER2 mRNA and protein expression were significantly reduced in M.nudicaulis treated A2780 cell lines. Thus, the n-hexane extract of M.nudicaulis is a natural source of bioactive compounds as potential anticancer agents.     

Accumulation of a 50-kDa protein during leaf senescence of alstroemeria cut flowering stems

Leaf senescence of alstroemeria cut flowering stems in the dark was accompanied by a decrease in the soluble protein and chlorophyll content. Two-dimensional (2D) electrophoresis revealed that a polypeptide with an apparent molecular mass of 50 (± 2) kDa and isoelectric point of 5.0 (± 0.1) accumulated during the senescence process. Treatments which delayed leaf senescence (light and gibberellic acid) diminished the accumulation of this polypeptide. This polypeptide was purified and one of the peptides, resulting from digestion with trypsin, was sequenced. The se quence shows a high degree of homology to that of 3-isopropylmalate dehydrogenase. This enzyme plays a role in the biosynthesis of leucine. Possibly, leucine plays a role in carbon partitioning between sources and sinks in this plant.