62 research outputs found
Evaluation of the coat protein of the Tombusviridae as HR elicitor in Nicotiana section
Plants are able to recognize and respond to virus infection with a hypersensitive response, a plant defense response that triggers a cell death pathway and limits the viral infection to the infected leaf. We have previously shown that the coat protein of Tomato bushy stunt virus (TBSV) and Tobacco necrosis virus strain DH (TNV-D[superscript H]) trigger HR in several species of Nicotiana, including Nicotiana langsdorffii. To identify structural features in the coat protein recognized by the host, we tested the capacity of eight coat proteins of the Tombusviridae to trigger a HR in N. langsdorffii. These eight coat proteins represented six genera of the Tombusviridae. We found that the coat proteins of TBSV, Cucumber Necrosis Virus, Cymbidium ringspot virus, Red Clover necrotic mosaic virus and TNV-D[superscript H] triggered HR, whereas the coat proteins of Turnip crinkle virus, Maize chlorotic mottle virus and Panicum mosaic virus did not. A comparison of the amino acid sequences of all eight coat proteins revealed that only two amino acids (Asp155 and Arg161) were conserved amongst the coat proteins that triggered HR and distinguished them from the coat proteins that did not trigger HR. Computer modeling of the coat protein structure allowed for placement of these two amino acids within the three dimensional structure of the coat protein and suggested how mutations might affect the overall structure. Site directed mutagenesis of these two amino acids in the TNV-D[superscript H] coat protein abolished HR, demonstrating that they have an essential role in recognition and elicitation of plant defenses against this virus
Study on Adaptive Harmonic Extraction Approaches in Active Power Filter Applications
Active power filter (APF) has now become a mature technology for harmonic and reactive power compensations in two-wire (single phase), three-wire (three phase without neutral), and four-wire (three phase with neutral) ac power networks with nonlinear loads. This paper presents a study on three different adaptive algorithms for active power filtering applications. These algorithms are adaptive linear combiner (ADALINE), least mean square adaptive notch filter (ANF-LMS), and recursive least square adaptive notch filter (ANF-RLS). In this paper, these approaches are employed for extracting load harmonic currents. The important issues associated with adaptive methods are accuracy and prediction speed. These issues will be addressed in the paper. Simulations using MATLAB/Simulink are presented to clarify the algorithms
Antibacterial effects of medicinal plant extracts against Lactococcus garvieae, the etiological agent of rainbow trout lactococcosis
Eight medicinal plants were assessed for antimicrobial activity against Lactococcus garvieae isolate obtained from diseased Oncorhynchus mykiss collected from rainbow trout fish farms in Iran. Lactococcus garvieae is among the major pathogens of a large number of fish species cultured in fresh and marine recirculating and net pen production systems. The antibacterial activity of the medicinal plants against L. garvieae was evaluated using disc diffusion, well diffusion and minimum inhibitory concentration. Results showed that the extracts and essential oils had a relatively high antibacterial activity against L. garvieae. Of the plants studied, the most active extracts were those from the methanol extract of Peganum harmala, the essential oil of Satureja bachtiarica, the ethanol extract of Juglans regia and Trachyspermum copticum with minimum inhibitory concentration (MIC) of 105, 126, 510 and 453 ÎĽg/ml, respectively. Conversly, some of the extracts such as Quercus branti Lindley and Glycyrrhiza glabra L. had lower activity against L. garvieae with MIC values of 978 and 920 ÎĽg/ml respectively. Plant extracts as natural and environment- friendly compounds can be an important source of antibacterial agents against L. garvieae. They may be used for disinfection of instruments and rainbow trout raceways or treatment of the fish
Evaluation of SARS-CoV-2 Specific Antibodies in Recovered Patients by Different ELISA Kits
Background: The coronavirus disease 2019 (COVID-19) was first reported in December 2019 in Wuhan, Hubei Province of China. As long as the 27th of December 2021, approximately 280 million people have been infected with coronavirus, resulting in more than 5,418,421 deaths worldwide. Since the beginning of the COVID-19 pandemic, different methods were introduced for diagnosing coronavirus-infected patients and evaluating the immune response, following the vaccination.Objective: The current study aimed to compare the level of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) specific IgG in a group of patients who recovered from COVID-19, measured by three different enzyme-linked immunosorbent assay (ELISA) kits.Methods: This cross-sectional study was conducted on sera from patients who recovered from a real-time reverse transcriptase-polymerase chain reaction (RT-PCR)-confirmed COVID-19 in Birjand, South Khorasan, Iran. SARS-CoV-2 anti-nucleocapsid (N) and spike (S) protein IgG levels were measured using commercial ELISA kits. Comparison between groups was made using one-way ANOVA and Tukey post hoc tests.Results: The mean titer of anti-N IgG was significantly higher for the PishtazTeb Diagnostics kit than the Ideal Tashkhis Atieh kit (p<0.05). There was no correlation between the titer of anti-N IgG (PishtazTeb Diagnostics and Ideal Tashkhis Atieh) and anti-S IgG (Chemobind Company) antibodies.Conclusion: This study indicates that the domestic ELISA kits have variable but acceptable sensitivity for detecting SARS-CoV-2 specific IgG antibodies
Does real estate transparency matter for foreign real estate investments?
The purpose of this paper is to examine the impact of real estate transparency (RET) on foreign real estate investments (FREI). Most of the previous studies have argued that the free flow of information and the fair and consistent application of local property laws could attract greater amounts of FREI. Using observations from 32 countries covering 2004, 2006, 2008 and 2010 and applying fixed-effect and the generalized method of moments (GMM) techniques, our empirical results reveal that RET is not a major determinant of FREI. However, we find that the effect of RET on FREI is dependent on its interaction with the level of income implying that the higher the level of income in the host country, the higher the effect of RET on FREI. Finally, the results show that foreign direct investment (FDI) in other sector, market size and property prices are important determinants of FREI
Effects of the aromatase inhibitor Letrozole on serum immunoglobulin and lysozyme levels in immunized rainbow trout (Oncorhynchus mykiss Walbaum) females
Letrozole is a synthetic aromatase inhibitor and interfere in the committed step in the synthesis of endogenous estrogens from androgens. Also estrogens regulate the immune system in teleost. Changes of 17- β- esrtradiol (E2), serum immunoglobulin and lysozyme levels were measured using a method based on the ability of lysozyme to lyse the bacterium Micrococcus lysodeikticus, enzyme-linked immunosorbent assay (ELISA) and ELISA respectively. Twelve broodstocks were injected weekly with 2.5 mg kg-1 letrozole (an endocrine disrupter component) two months before spawning season and vaccinated intraperitoneally (i.p) with a bacterin (inactivated L. garviae) one month before spawning. Twelve broodstocks for vaccination and twelve female rainbow trout as control group were also immiunised (i.p) with the bacterin and injected (i.p) with PBS, respectively. In the group received 2.5 mg AI kg-1 per week, serum E2 levels were significantly lower than that of other groups. Total immunoglobulin level and lysozyme activity were significantly higher in the parents received 2.5 mg kg-1 per week and were immunized with 10-9 cells ml-1 Lactococcus garvieae compared to the group which immunized with L. garvieae and the control (non- immunized). The present study, suggests that aromatase inhibitors such as letrozole may be a potential tool to regulate the synthesis of E2, is involved in the hormone- immune system interaction in rainbow trout
Persistence of immunity to hepatitis B vaccine as infants, 17 years earlier
Background: In Iran since 1992, hepatitis B vaccination was a part of the national vaccination program. Hepatitis B vaccination is effective in the epidemiology of hepatitis B. The aim of this study was to evaluate the long – term persistence of immunity.
Methods: This cross-sectional analytical study was conducted on children and adolescents aged between 6-18 years in Birjand, who received a three – dose hepatitis B vaccination in accordance with the national immunization program. No students were infected with hepatitis B. Antibody titer higher than10 IU/L was considered positive.
Results: A total of 530 patients (307 boys and 223 girls) were recruited for the study of which 44% had positive antibody titer (≥10 IU / L). The geometric concentration mean (GMCs) of antibody in subjects was 64.9±34.2, HBS antibody titer was positive in 40.4% of the boys and 59.6% of the girls. A significant difference in antibody titers was observed in terms of gender and according to the time elapsed since the last vaccination. Antibody titer in children older than 13 years had passed since their last vaccination and was significantly less than those children younger than thirteen years old had passed since their vaccination logistic regression analysis showed that the only predictive factor of anti-HBS low titer (<10 IU/L) is elapsed time of vaccination.
Conclusions: Based on results of this study, hepatitis B vaccine has created a good level of protection in 44% of the adolescents after 17 years
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