scholarly journals Differential Hormetic Response of Fenoxaprop-p-Ethyl Resistant and Susceptible Phalaris minor Populations: a Potential Factor in Resistance Evolution

2019 ◽  
Vol 37 ◽  
Author(s):  
N. FAROOQ ◽  
T. ABBAS ◽  
A. TANVEER ◽  
M.M. JAVAID ◽  
H.H. ALI ◽  
...  

ABSTRACT: Resistance evolution in weeds against all major herbicide groups demand investigations to identify various factors responsible for resistance development. Herbicide hormesis has not yet been included in the list of factors promoting the evolution of resistance. Studies were conducted to evaluate the degree of hormesis in fenoxaprop-p-ethyl susceptible and resistant Phalaris minor to provide a first indication of whether hormesis is a potential factor in the development of resistance. In the first experiment, a wide range of doses up to 160% of the recommended field rate was used to identify potential hormetic doses for resistant and susceptible P. minor populations. Doses below 40% have been designated as potential hormetic doses. In the second experiment, ten different doses of fenoxaprop below 40% (0, 2, 4, 8, 12, 16, 20, 24, 28 and 32% of the recommended rate) were sprayed at the 4-5 leaf stage of both resistant and susceptible P. minor populations. At fifteen days after spraying, dose range of 2-12% and 2-20% caused a significant increase (up to 22% and 24%) in growth traits of susceptible and resistant populations, respectively. At maturity, dose range of 2-12% for susceptible and 2-24% for resistant populations caused a significant increase (up to 20% and 57%) in growth and seed production potential (13% and 17%), respectively. The upper limit of the hormetic dose range (16 to 24%) for the resistant population was inhibitory for the susceptible populations. These results indicate that fenoxaprop hormesis could play a vital role in the evolution of fenoxaprop resistance in P. minor.

2021 ◽  
Vol 54 (2) ◽  
pp. 1-42
Author(s):  
Abdullah Qasem ◽  
Paria Shirani ◽  
Mourad Debbabi ◽  
Lingyu Wang ◽  
Bernard Lebel ◽  
...  

In the era of the internet of things (IoT), software-enabled inter-connected devices are of paramount importance. The embedded systems are very frequently used in both security and privacy-sensitive applications. However, the underlying software (a.k.a. firmware) very often suffers from a wide range of security vulnerabilities, mainly due to their outdated systems or reusing existing vulnerable libraries; which is evident by the surprising rise in the number of attacks against embedded systems. Therefore, to protect those embedded systems, detecting the presence of vulnerabilities in the large pool of embedded devices and their firmware plays a vital role. To this end, there exist several approaches to identify and trigger potential vulnerabilities within deployed embedded systems firmware. In this survey, we provide a comprehensive review of the state-of-the-art proposals, which detect vulnerabilities in embedded systems and firmware images by employing various analysis techniques, including static analysis, dynamic analysis, symbolic execution, and hybrid approaches. Furthermore, we perform both quantitative and qualitative comparisons among the surveyed approaches. Moreover, we devise taxonomies based on the applications of those approaches, the features used in the literature, and the type of the analysis. Finally, we identify the unresolved challenges and discuss possible future directions in this field of research.


Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 680
Author(s):  
Thuy T. P. Mai ◽  
Craig M. Hardner ◽  
Mobashwer M. Alam ◽  
Robert J. Henry ◽  
Bruce L. Topp

Macadamia is a recently domesticated Australian native nut crop, and a large proportion of its wild germplasm is unexploited. Aiming to explore the existing diversity, 247 wild accessions from four species and inter-specific hybrids were phenotyped. A wide range of variation was found in growth and nut traits. Broad-sense heritability of traits were moderate (0.43–0.64), which suggested that both genetic and environmental factors are equally important for the variability of the traits. Correlations among the growth traits were significantly positive (0.49–0.76). There were significant positive correlations among the nut traits except for kernel recovery. The association between kernel recovery and shell thickness was highly significant and negative. Principal component analysis of the traits separated representative species groups. Accessions from Macadamia integrifolia Maiden and Betche, M. tetraphylla L.A.S. Johnson, and admixtures were clustered into one group and those of M. ternifolia F. Muell were separated into another group. In both M. integrifolia and M. tetraphylla groups, variation within site was greater than across sites, which suggested that the conservation strategies should concentrate on increased sampling within sites to capture wide genetic diversity. This study provides a background on the utilisation of wild germplasm as a genetic resource to be used in breeding programs and the direction for gene pool conservation.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 717
Author(s):  
Rita Abou Nader ◽  
Rawan Mackieh ◽  
Rim Wehbe ◽  
Dany El El Obeid ◽  
Jean Marc Sabatier ◽  
...  

Honeybees are one of the most marvelous and economically beneficial insects. As pollinators, they play a vital role in every aspect of the ecosystem. Beehive products have been used for thousands of years in many cultures for the treatment of various diseases. Their healing properties have been documented in many religious texts like the Noble Quran and the Holy Bible. Honey, bee venom, propolis, pollen and royal jelly all demonstrated a richness in their bioactive compounds which make them effective against a variety of bacterial strains. Furthermore, many studies showed that honey and bee venom work as powerful antibacterial agents against a wide range of bacteria including life-threatening bacteria. Several reports documented the biological activities of honeybee products but none of them emphasized on the antibacterial activity of all beehive products. Therefore, this review aims to highlight the antibacterial activity of honey, bee venom, propolis, pollen and royal jelly, that are produced by honeybees.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chaojian Chen ◽  
Manjesh Kumar Singh ◽  
Katrin Wunderlich ◽  
Sean Harvey ◽  
Colette J. Whitfield ◽  
...  

AbstractThe creation of synthetic polymer nanoobjects with well-defined hierarchical structures is important for a wide range of applications such as nanomaterial synthesis, catalysis, and therapeutics. Inspired by the programmability and precise three-dimensional architectures of biomolecules, here we demonstrate the strategy of fabricating controlled hierarchical structures through self-assembly of folded synthetic polymers. Linear poly(2-hydroxyethyl methacrylate) of different lengths are folded into cyclic polymers and their self-assembly into hierarchical structures is elucidated by various experimental techniques and molecular dynamics simulations. Based on their structural similarity, macrocyclic brush polymers with amphiphilic block side chains are synthesized, which can self-assemble into wormlike and higher-ordered structures. Our work points out the vital role of polymer folding in macromolecular self-assembly and establishes a versatile approach for constructing biomimetic hierarchical assemblies.


2021 ◽  
Vol 9 (5) ◽  
pp. 899
Author(s):  
Anthony Torres-Ruesta ◽  
Rhonda Sin-Ling Chee ◽  
Lisa F.P. Ng

Alphaviruses are mosquito-borne pathogens distributed worldwide in tropical and temperate areas causing a wide range of symptoms ranging from inflammatory arthritis-like manifestations to the induction of encephalitis in humans. Historically, large outbreaks in susceptible populations have been recorded followed by the development of protective long-lasting antibody responses suggesting a potential advantageous role for a vaccine. Although the current understanding of alphavirus antibody-mediated immunity has been mainly gathered in natural and experimental settings of chikungunya virus (CHIKV) infection, little is known about the humoral responses triggered by other emerging alphaviruses. This knowledge is needed to improve serology-based diagnostic tests and the development of highly effective cross-protective vaccines. Here, we review the role of antibody-mediated immunity upon arthritogenic and neurotropic alphavirus infections, and the current research efforts for the development of vaccines as a tool to control future alphavirus outbreaks.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Tao Yue ◽  
Da Zhao ◽  
Duc T. T. Phan ◽  
Xiaolin Wang ◽  
Joshua Jonghyun Park ◽  
...  

AbstractThe vascular network of the circulatory system plays a vital role in maintaining homeostasis in the human body. In this paper, a novel modular microfluidic system with a vertical two-layered configuration is developed to generate large-scale perfused microvascular networks in vitro. The two-layer polydimethylsiloxane (PDMS) configuration allows the tissue chambers and medium channels not only to be designed and fabricated independently but also to be aligned and bonded accordingly. This method can produce a modular microfluidic system that has high flexibility and scalability to design an integrated platform with multiple perfused vascularized tissues with high densities. The medium channel was designed with a rhombic shape and fabricated to be semiclosed to form a capillary burst valve in the vertical direction, serving as the interface between the medium channels and tissue chambers. Angiogenesis and anastomosis at the vertical interface were successfully achieved by using different combinations of tissue chambers and medium channels. Various large-scale microvascular networks were generated and quantified in terms of vessel length and density. Minimal leakage of the perfused 70-kDa FITC-dextran confirmed the lumenization of the microvascular networks and the formation of tight vertical interconnections between the microvascular networks and medium channels in different structural layers. This platform enables the culturing of interconnected, large-scale perfused vascularized tissue networks with high density and scalability for a wide range of multiorgan-on-a-chip applications, including basic biological studies and drug screening.


Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 82
Author(s):  
Liping Liu ◽  
Hanne Ingmer ◽  
Martin Vestergaard

Resveratrol has been extensively studied due to its potential health benefits in multiple diseases, for example, cancer, obesity and cardiovascular diseases. Besides these properties, resveratrol displays inhibitory activity against a wide range of bacterial species; however, the cellular effects of resveratrol in bacteria remain incompletely understood, especially in the human pathogen, Staphylococcus aureus. In this study, we aimed to identify intrinsic resistance genes that aid S. aureus in tolerating the activity of resveratrol. We screened the Nebraska Transposon Mutant Library, consisting of 1920 mutants with inactivation of non-essential genes in S. aureus JE2, for increased susceptibly to resveratrol. On agar plates containing 0.5× the minimum inhibitory concentration (MIC), 17 transposon mutants failed to grow. Of these, four mutants showed a two-fold reduction in MIC, being the clpP protease mutant and three mutants with deficiencies in the electron transport chain (menD, hemB, aroC). The remaining 13 mutants did not show a reduction in MIC, but were confirmed by spot-assays to have increased susceptibility to resveratrol. Several genes were associated with DNA damage repair (recJ, xerC and xseA). Treatment of S. aureus JE2 with sub-inhibitory concentrations of resveratrol did not affect the expression of recJ, xerC and xseA, but increased expression of the SOS–stress response genes lexA and recA, suggesting that resveratrol interferes with DNA integrity in S. aureus. Expression of error-prone DNA polymerases are part of the SOS–stress response and we could show that sub-inhibitory concentrations of resveratrol increased overall mutation frequency as measured by formation of rifampicin resistant mutants. Our data show that DNA repair systems are important determinants aiding S. aureus to overcome the inhibitory activity of resveratrol. Activation of the SOS response by resveratrol could potentially facilitate the development of resistance towards conventional antibiotics in S. aureus.


2012 ◽  
Vol 52 (3) ◽  
pp. 308-313 ◽  
Author(s):  
Ilias Travlos

Evaluation of Herbicide-Resistance Status on Populations of Littleseed Canarygrass (Phalaris MinorRetz.) from Southern Greece and Suggestions for their Effective ControlIn 2010, a survey was conducted in the wheat fields of a typical cereal-producing region of Greece to establish the frequency and distribution of herbicide-resistant littleseed canarygrass (Phalaris minorRetz.). In total, 73 canarygrass accessions were collected and screened in a field experiment with several herbicides commonly used to control this weed. Most of the weed populations were classed as resistant (or developing resistance) to the acetyl-CoA varboxylase (ACCase)-inhibiting herbicide diclofop, while resistance to clodinafop was markedly lower. The results of the pot experiments showed that some of the canary populations were found to have a very high level of diclofop resistance (resistance index up to 12.4), while cross resistance with other herbicides was also common. The levels of resistance and cross resistance patterns among populations varied along with the different amounts and times of selection pressure. Such variation indicated either more than one mechanism of resistance or different resistance mutations in these weed populations. The population which had the highest diclofop resistance level, showed resistance to all aryloxyphenoxypropinate (APP) herbicides applied and non-ACCase inhibitors. Alternative ACCase-inhibiting herbicides, such as pinoxaden remain effective on the majority of the tested canarygrass populations, while the acetolactate synthase (ALS)-inhibiting herbicide mesosulfuron + iodosulfuron could also provide some solutions. Consequently, there is an opportunity to effectively control canarygrass by selecting from a wide range of herbicides. It is the integration of agronomic practices with herbicide application, which helps in effective management ofP. minorand particularly its resistant populations.


Author(s):  
Emdormi Rymbai ◽  

Plants are an important source of natural products and they play a vital role in the field of medicinal chemistry and pharmaceutical science. Traditional medicines have been practiced and used for thousands of years, mostly in Asian countries, where plants are the main sources of medicine. Houttuynia cordata, a herb that belongs to the family Saururaceae, has a wide range of pharmacological activities and is used traditionally in conditions like anisolobis sores, heatstroke, lung carbuncles, malaria, scrotal abscess, tonsillitis, salammoniac poison and has also been widely accepted to possess anti-cancer, anti-oxidant, anti-hypertension, anti-inflammatory, anti-mutagenic, antibacterial, anti-viral and anti-purulent activity. Moreover, it is one of the herbs that was recognized during pandemic outbreaks, such as Severe Acute Respiratory Syndrome Coronavirus (SARS CoV) in China, virulent Newcastle Disease Virus (VNDV) in Java (Indonesia) and Newcastle (England). In this review, we briefly discuss the role of H. cordata as an anti-viral agent and the possibility of developing a dosage form against Coronavirus disease-19 (COVID-19).


Author(s):  
S. B. Lysko ◽  
M. V. Zadorozhnaya ◽  
O. A. Suntsova

The modern market of drugs off ers a wide range of disinfectants. However, the constant use of the same drugs contributes to the development of resistance in the microfl ora and reduces the quality of activities. In this regard to develop eff ective measures to combat and prevent infectious diseases, it is necessary to periodically monitor the activity of disinfectants used in the enterprise. The purpose of the researches was to study the bactericidal eff ect of disinfectants on the microfl ora of poultry enterprises. The researches have been carried out at the Siberian Scientifi c and Research Institute of Poultry Farming – a branch of the Federal State Budgetary Scientifi c Institution “Omsk Agrarian Scientifi c Center”. The activity of 8 disinfectants to 37 test cultures isolated from poultry farms of diff erent productivity trends and species of poultry (chickens, turkeys, quails) has been tested. It has been found as a result of the conducted research that the most expressed bactericidal eff ect on gram-positive and gram-negative microorganisms were complex disinfectants, which included glutaraldehyde in combination with quaternary ammonium compounds. Thus, 1 % solutions of Gludesive and Viroshield provided the death of all test cultures, Dinovis Ultra and TN-4+ – 92 and 84 % of cultures. The disinfecting activity of Mirosan drug and formalin was most expressed for gram-positive microfl ora, among gram-negative microfl ora resistance was registered in 25–75 % and 25–50 % of cultures, respectively. Drugs EcoSide Advansa and Ecocide C have showed the lowest activity to all investigated microorganisms. The largest number of resistant cultures to the tested disinfectants have been registered in the bacteria of the genus Citrobacter spp. and Pseudomonas aeruginosa, while simultaneously noted resistance to 4–6 drugs.


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