Environmental heterogeneity influences life-form richness and species composition but not species richness of aquatic macrophytes in tropical coastal rivers

1. The coastal rivers of the São Paulo State in SE Brazil have different lengths and seawater influence. We evaluated whether: (1) environmental heterogeneity (EH) is associated with the species and life-form richness of aquatic macrophytes; and (2) EH and geographical distance influence species composition in these coastal rivers.
2. We recorded the macrophyte species and life form occurrence and collected explanatory variables characterising the water, sediment, and river channel at 100 sampling sites over 8 rivers. We applied a principal component analysis to the explanatory variables and calculated the rivers' EH using the range of principal component 1 scores. We also determined the position of each river mouth along the coastline to measure the distance between the rivers. We used quasi-Poisson generalised linear models to evaluate the effects of EH on richness of species and life forms. To determine the effect of EH and geographical distance (Euclidean distance matrices) on the variation in species composition (Jaccard dissimilarity matrix) among the rivers, we applied multiple regressions on distance matrices.
3. The most heterogeneous river had heterogeneity score about five times greater than the least heterogeneous river. Sediment salinity, river width, total phosphorus concentration of water and distance from river mouth were the most important variables contributing to the rivers' EH. We found that EH did not explain variation in species richness; however, it had a significant positive relationship with life-form richness. The effect of EH was greater than that of the geographical distance on the variation in species composition among the rivers. The pairs of rivers with the most similar EH were the most similar in species composition, but not all of them were geographically close.
4. We conclude that EH influences life-form richness but does not influence species richness of aquatic macrophytes in the coastal rivers we studied; however, EH does influence species composition regardless of geographical distance among rivers.

     

Phenomic and genomic approaches to studying the inhibition of multiresistant Salmonella enterica by microcin J25

In livestock production, antibiotics are used to promote animal growth, control infections and thereby increase profitability. This practice has led to the emergence of multiresistant bacteria such as Salmonella, of which some serovars are disseminated in the environment. The objective of this study is to evaluate microcin J25 as an inhibitor of Salmonella enterica serovars of various origins including human, livestock and food. Among the 116 isolates tested, 37 (31.8%) were found resistant to at least one antibiotic, and 28 were multiresistant with 19 expressing the penta-resistant phenotype ACSSuT. Microcin J25 inhibited all isolates, with minimal inhibitory concentration values ranging from 0.06 μg/ml (28.4 nM) to 400 μg/ml (189 μM). Interestingly, no cross-resistance was found between microcin J25 and antibiotics. Multiple sequence alignments of genes encoding for the different proteins involved in the recognition and transport of microcin J25 showed that only ferric-hydroxamate uptake is an essential determinant for susceptibility of S. enterica to microcin J25. Examination of Salmonella strains exposed to microcin J25 by transmission electronic microscopy showed for the first-time involvement of a pore formation mechanism. Microcin J25 was a strong inhibitor of several multiresistant isolates of Salmonella and may have a great potential as an alternative to antibiotics.     

SUCLG1 mutations and mitochondrial encephalomyopathy: a case study and review of the literature

Molecular Biology Reports - The mitochondrial encephalomyopathies represent a clinically heterogeneous group of neurodegenerative disorders. The clinical phenotype of patients could be explained by...     

Parasitoids of the ladybird beetles (Coleoptera: Coccinellidae) in Iran: an update

Summary

Over the past few decades, many records of the parasitoids parasitizing Coccinellidae have been reported from Iran. Some of them, presented in hard to access conference proceedings, theses, older books and journal articles, were then inaccurately quoted in other papers. Furthermore, some other records were subsequently considered misidentifications and the corrected identity of the parasitoids was proposed in later published papers. Due to the accumulation of that misleading information, we decided to gather and critically evaluate all available Iranian data on the parasitoids of Coccinellidae. To the review presented here we also added new data on the parasitism of Coccinella septempunctata L. by a braconid Dinocampus coccinellae (Schrank) in the Lorestan province and on the parasitism of Hyperaspis pseudopustulata Mulsant by an encyrtid Homalotylus flaminius (Dalman) in the Kermanshah province. Hyperaspis pseudopustulata is a new host for H. flaminius, and is also a species new to the fauna of Iran. Altogether, our review revealed one species of dipteran and 16 species of hymenopteran parasitoids associated with Coccinellidae in Iran. The identity of some of those species, however, seems uncertain and should be re-examined.     

Mating frequency of female false codling moth,Thaumatotibia leucotreta (Lepidoptera: Tortricidae): trade-off between fecundity and longevity

Journal of Insect Behavior - Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a polyphagous insect pest native to sub-Saharan Africa. The larvae burrow into the fruit and...     

Comparing iDNA from mosquitoes and flies to survey mammals in a semi-controlled Neotropical area

Ingested-derived DNA (iDNA) from insects represents a powerful tool for assessing vertebrate diversity because insects are easy to sample, have a diverse diet and are widely distributed. Because of these advantages, the use of iDNA for detecting mammals has gained increasing attention. Here we aimed to compare the effectiveness of mosquitoes and flies to detect mammals with a small sampling effort in a semi-controlled area, a zoo that houses native and non-native species. We compared mosquitoes and flies regarding the number of mammal species detected, the amount of mammal sequence reads recovered, and the flight distance range for detecting mammals. We also verified if the combination of two mini-barcodes (12SrRNA and 16SrRNA) would perform better than either mini-barcode alone to inform local mammal biodiversity from iDNA. To capture mosquitoes and flies, we distributed insect traps in eight sampling points during 5 days. We identified 43 Operational Taxonomic Units from 10 orders, from the iDNA of 17 mosquitoes and 46 flies. There was no difference in the number of species recovered per individual insect between mosquitoes and flies, but the number of flies captured was higher, resulting in more mammal species recovered by flies. Eight species were recorded exclusively by mosquitoes and 20 by flies, suggesting that using both samplers would allow a more comprehensive screening of the biodiversity. The maximum distance recorded was 337 m for flies and 289 m for mosquitoes, but the average range distance did not differ between insect groups. Our assay proved to be efficient for mammal detection, considering the high number of species detected with a reduced sampling effort.     

Chemiluminescent and bioluminescent assays as innovative prospects for mycotoxin determination in food and feed.

Mycotoxin contamination of food and feedstuffs is among the top priorities for human and animal safety. The currently used techniques for mycotoxin determination, either chromatography or ELISA, are unsuitable for routine in-field assessment. There is an urgent need for other accurate, simple and cost-effective techniques that can be used as a screening tool for a rapid estimation of mycotoxin contamination in commodity lots. This paper reviews the literature on the use of chemiluminescence (CL) and bioluminescence (BL) assays for direct or indirect mycotoxin assessment. The chemiluminescence immunoassays, adenosine triphosphate (ATP) bioluminescence and bioassays are reviewed and their advantages and limitations discussed. These techniques used in food testing and the pharmaceutical industry offer promise as rapid techniques for mycotoxin determination. Chemiluminescence and bioluminescence bioassays are the most innovative alternatives to the conventional techniques used for mycotoxin determination in food and feed.     

Synthesis and biological evaluation of some nitrogen containing steroidal heterocycles

epi-Androsterone 1 was converted into its hydrazone derivative through the reaction with hydrazine hydrate 80%. Hydrazonoandrostane derivative 2b reacted with hydrazonoyl halides in the presence of K₂CO₃ forming the corresponding hydrazopyridazinoandrostane derivatives 6a–d. The 3β-acetyl-17-hydrazonoandrostane derivative 2b reacted with a halogen reagent, benzoyl chloride, to form the non-cyclic 16-benzoylated hydrazone 9.On the other hand, compound 2b produced the corresponding pyridazinoandrostane derivatives 11 and 12 via its reaction with phenacyl bromide and chloroacetone respectively. Reaction of the hydrazono derivative 2b with benzaldehyde in the presence of acetic acid drops led to the formation of the benzylidenehydrazonoandrostane derivative 13. The product 14, phosphinom-ethylenehydrazonoandrostane was obtained by the reaction of the derivative 13 with trisdimethylaminophosphine in the presence of dry benzene. The reaction of compound 2b with phenyl isothiocyanate followed by boiling in chloroacetic acid or thioglycolic acid produced the pyrazoloandrostane derivatives 17 and 18 respectively. The biological activity of compounds 6a, 6d, 11, 12, and 15 was evaluated as inhibitor of growth in a human liver carcinoma cell line and doxorubicine was used for comparison. Compounds 15 and 12 showed a higher potency than the other tested compounds.