Onion thrips, Thrips tabaci Lindeman, 1889 (Thysanoptera: Thripidae) has three distinctive reproductive modes: arrhenotokous, thelytokous and deuterotokous. This experiment was focused on the arrhenotokous leek-(L1) and tobacco-associated (T) T. tabaci lineages. These two lineages are distinctively varied genetically and in host adaptations. L1 and T lineages perform better on leek and tobacco plants, respectively. Fighting occurs between males when they compete for food, mating, and oviposition sites. The aim of this research was to examine the fighting behaviour and characterize the fighting elements of males in L1 and T lineages. The experiment was performed in the laboratory by using a Euromex VC.3036 video camera and each experiment was recorded for a duration of 10 minutes. Transparent PCR tube caps formed the arena to observe the fighting interactions in both lineages. A total of 40 video recordings have been observed and each recording had a different arena. The fighting performance was observed at 2, 5, 8, 10, 12 days old specimens in four replications. This result has shown L1 lineage had better fighting performance and a more aggressive fighting ability than T lineage. Antennal bouts, jumping, flipping, stabbing and pitching are the most commonly observed fighting elements.
Authors:Carlo Pazzini, Parviz Ahmad-Nejad and Beniam Ghebremedhin
Nowadays, multidrug-resistant bacteria are considered as an increasing serious threat to public health worldwide. Global and local surveillance data are helpful in the application of the most efficient antimicrobial agent in bacterial infections. In the current study, we aimed to analyze the activity of the previously cleared agent ceftolozane/tazobactam (C/T) in African and European multidrug-resistant Gram-negative bacteria. Susceptibility testing was performed on 147 extended-spectrum β-lactamase (107 Escherichia coli and 40 Klebsiella pneumoniae) and 103 carbapenemase-producing Gram-negative bacteria using Etest according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoints. Among the extended-spectrum β-lactamase producing isolates, 91 Escherichia coli isolates (85%) and 23 Klebsiella pneumoniae isolates (57.5%) were susceptible towards C/T whereas out of the 103 carbapenemase-producing isolates 102 (99.0%) were C/T-resistant. C/T should be included in susceptibility testing to fairly administer this antimicrobial agent in infections caused by multidrug-resistant bacteria. It may be considered as a therapy option for infections caused by extended-spectrum β-lactamase-producing bacteria once susceptibility to this antimicrobial combination has been confirmed.
Authors:Carlos Florindo, Cinthia Alves Barroco, Inês Silvestre, Vera Damião, João Paulo Gomes, Barbara Spellerberg, Ilda Santos-Sanches and Maria José Borrego
Genetic lineages of Streptococcus agalactiae , such as genotype III ST17, have been considered highly virulent because of their association with the development of meningitis in neonates. This may be due to their intrinsic
Liver cells of the twenty-one day old rat embryo are isolated by a modified method and autophagy is studied in them by electron microscopic morphology and morphometry. Immediately after isolation or 2.5 h incubation in nutrient-free medium, embryonic hepatocytes contain high amount of glycogen and only very few autophagic vacuoles. In contrast, all glycogen is lost and 15% of the cytoplasmic volume is occupied by late autophagic vacuoles in hepatocytes after 18 h in the same medium. Presence of 3- methyladenine in the latter case inhibits both the loss of glycogen and the appearance of autophagic vac- uoles while enlarging the multivesicular body compartment. Our findings reveal major differences between isolated embryonic and adult hepatocytes concerning autophagy. Several types of autophagic vacuoles are described in the cell types of the erythropoietic cell lineage. This means that autophagy is an integral part of erythropoiesis not only in bone marrow, but also in embryonic liver that is investigat- ed here for the first time from this point of view. The presence of unclosed isolation membranes and the predominance of early autophagic vacuoles in reticulocytes indicates that the molecular machinery of segregation is still active in this functionally and structurally highly reduced cell type.
This is being hypothesised that the heterospory to begin with, might have originated within one specific sporangium thereafter separate male and female sporangia would have evolved in due course of time. This new category of a sporangium, is hereby named as “heterosporangium”, conceived to have been the cradle sporangium for the origin of heterospory. Such a sporangium may have possessed three types of spores, viz. microspores, megaspores and morphologically distinct spores possessing resemblances with spores of past lineages/fossils. Such a classical structure has been exemplified by a fundamental discovery of “intrasporangial heterospory” in 1968. This appears that this evolutionary phase could have followed the path of sequential evolution of isosporangium-anisosporangium-heterosporangium and finally, leading to “intersporangial heterospory” in the form of independent microsporangium and megasporangium. The independent sex differentiated sporangia must have had evolved by selective degeneration of spore mother cells in a differentiating young heterosporangium. In other words, a microsporangium should have evolved by the degeneration of megaspore mother cells and megasporangium by early degeneration of microspore mother cells. This selective degeneration must have been operative on account of some genetic mechanism as suggested by Bell in 1996 and later, demonstrated by our observations on epigenetic mechanisms suspecting mainly abrupt hypomethylation of DNA, to be responsible event as indicated in heterosporangia of Isoetes pantii Goswami et Arya. This paper exclusively establishes heterosporangium as a structure of rare evolutionary importance genetically inherent within the genome of the species observed consistently for more than five decades. Recent decline of such plants of I. × pantii does not lower down importance of heterosporangium because its physical presence can never be denied. The future of a species or an organ depends on operative modes of natural selection.
Plant community diversity is a major research focus in community ecology. The relationship between diversity patterns and different diversity indices is important for developing and improving biodiversity protection. In order to fully understand multi-dimensional diversity patterns of the subalpine meadow on Heyeping peak of Luya Mountain, we used a systematic sampling method and set 150 1 m × 1 m plots in June of 2018. Based on an analysis of the subalpine meadow community on Heyeping peak, we measured multiple diversity indices, carried out a correlation analysis between diversity and environmental factors, and compared correlations among different diversity indices. The goal was to clarify the ecological mechanisms and variation among various diversity indices and environmental factors. The main results were as follows: (1) The species diversity distribution was uniform, the taxonomic level was narrow, functional differences were small, and different pedigree structures were present in each plot. (2) A stable correlation between pedigree diversity index (PD) and species diversity index indicated niche conservativism; the net relatedness index (NRI) of community lineage structure was significantly correlated with the nearest species taxon index (NTI), species richness, and evenness index, indicating that plant community composition in the study area is mainly affected by habitat filtration. (3) The average taxonomic distinctness index (Λ+) and the average taxonomic distinctness index (Λ+) had a stable correlation; only the functional richness index (FRic) and Patrick species richness index were closely related. (4) Among the selected environmental factors, only the forest line had a stable correlation with species diversity index and PD and showed a negative correlation change, indicating an “edge effect” distribution of species diversity in the study area. In summary, the forest line was the key factor affecting the distribution of species diversity in the study area and the species relationships within the community. This work was supported by the National Natural Science Foundation of China (31400358).