13 research outputs found

    Enzyme activities in brown forest soils after introduction of Bacillus thuringiensis-based bioinsecticides

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    Much attention in the complex of forest pest control methods nowadays is devoted to the application of biological preparations, especially to bacterial formulations produced on the base of Bacillus thuringiensis (BT) that in addition to their high biological effectiveness against injurious insects are safe for man, homoiоtherms, beneficial insects and fish. As is known only 20-40% of sprayed preparation influences directly on pests while its 60-80% by different ways eventually penetrates into the soil. Taking into account also the fact that usage norm of commercial bacterial preparations makes up to 1-3 kg ha^-1^ and that preparation powder contains 45-100 billion viable spores g^-1^ it becomes evident that as a result of spraying huge quantity of bacterial stimulants introduces into the forest soils. In this connection a goal was set to determine the impact of some separately applied domestic insecticides of BT species (BT кб-1, BT кб-2, BT(SAR)-49, BT(SAR)-54, BT(SAR)-86, BT subsp. thuringiensis) introduced into the brown forest soils after spraying on soil enzymatic activity (invertase, urease) defining its fertility. Studies were conducted in 2010 under laboratory conditions. The results obtained indicate that in soils sprayed and non-sprayed by bioinsecticides the activities of invertase and urease undergo to changes from May to August. Maximal activities in soils were registered in June (25.641mg C~6~H~12~O~6~ g^-1^ for invertase and 12.254 mg NH~3~ g^-1^ for urease) and minimal – in May (20.643 mg C~6~H~12~O~6~ g^-1^ for invertase) and in August (9.297 mg NH~3~ g^-1^ for urease) at the average for all variants. By statistical analysis of study results it has been established that there aren’t any significant differences between indices of enzyme activities in sprayed and non-sprayed by biopesticides soils. Study results have led us to the assumption that tested insecticides don’t influence adversely on enzyme activities of brown forest soils and can be widely used in the field of plant protection

    Evaluation of the Effectiveness of Foot-and-Mouth Disease Vaccination of Animals in the Buffer Zone of the Republic of Armenia in 2016–2020

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    BACKGROUND: Foot-and-mouth disease (FMD) is a high impact viral disease of livestock for which vaccines are extensively used for limiting the spread of infection. Armenia shares a border with both Turkey and Iran where FMD is endemic, making vaccination an important component of Armenia\u27s control strategy. Additionally, Armenian veterinary services utilize both passive and active monitoring for prevention control. METHODS: We sought to determine the immune status of animals vaccinated against FMD and to evaluate the effectiveness of our vaccination policy in Armenia. This was conducted in three regions including Shirak, Armavir, and Ararat Region which are located in the buffer zones that border Turkey and Iran. Through active monitoring in 2020, we studied blood serum samples from cattle and sheep using an enzyme immunoassay to determine the level of immune animals in these regions following the use of a polyvalent inactivated vaccine containing FMDV serotypes A, O, and Asia-1 that are relevant for this region. ELISA titers were assessed at 28, 90, and 180 days after vaccination in cattle of three age groups at the time of initial vaccination: 4-6 months, 6-18 months and ≥ 24 months of age with sheep of all ages. RESULTS: The 3 age groups of cattle had similarly high levels of immunity with over 90% of the cattle showing a ≥ 50% protective titer 28 days after the first vaccination. By day 90, titers in cattle from the initial 4-18-month age groups dropped below 58% across the 3 serotypes and at or below 80% for the oldest cattle ≥ 24 months. Re-vaccination of cattle at 120 days did improve protective titers but never reached the level of immunity of the first vaccination. Sheep showed a similar rapid drop to less than 50% having a ≥ 50% protective titer at 90 days emphasizing the need for continual revaccination. CONCLUSIONS: The results of this study have important implications for the current FMD vaccine policy in Armenia and improves our understanding of the rapid loss of protective titers over short periods. Since small ruminants are only vaccinated once per year and vaccination titers drop rapidly by 90 days suggests that they are vulnerable to FMD and that vaccination protocols need to be updated. Cattle should continue to be vaccinated every 3-6 months depending on their age to maintain a protective level of antibodies to protect them from FMD. More studies are needed to understand the possible role of small ruminants in the epidemiology of FMD and to evaluate revaccination at shorter intervals. These results show the concerns of rapid loss of protection to both cattle and small ruminants following 1 or more doses of commercial vaccines and that additional vaccines need to be evaluated in both groups to know how often they must be vaccinated to provide full protection. The addition of challenge studies should also be considered to better understand the level of protection as measured by serology and how it relates to protection from challenge. These results should be considered by anyone using these vaccines in cattle and sheep at longer than 3 month intervals

    How well are international students prepared academically and socially for the American higher education?

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    The purpose of the study was to determine the needs and issues of international students in the United States colleges and universities. The researcher attempted to learn what kind of services and activities educational advisors working at educational advising/information centers organized for prospective international students that would introduce them academic and social life in the United States. The participants in the study included a sample of 300 educational advisors promoting American higher education at 125 ECA/A/S/A affiliated educational advising/ information centers in Europe and CIS.Significant findings were found for international students' academic and social preparedness for the education in the United States.Thesis (M.A.)Department of Educational Studie

    Biochemical and mutagenic analysis of a G protein-coupled receptor: Photocrosslinking of the tridecapeptide alpha-Factor into Ste2p of Saccharomyces cerevisiae reveals contact points between the peptide and its receptor binding site

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    Mating of Saccharomyces cerevisiae is initiated by binding of a peptide pheromone, alpha-factor, to its cognate G protein-coupled receptor (Ste2p). Analogs of alpha-factor (WHWLQLKPGQPMY) containing the photoactivatable group p-benzoyl-L-phenylalanine (Bpa) and biotin as a tag were synthesized using solid-phase methodologies. Bpa was inserted at positions one, three, five, eight, and thirteen of alpha-factor to obtain a set of cross-linkable analogs spanning the pheromone. The biological activity and binding affinities of all analogs for Ste2p were determined. Two of the analogs tested, [Bpa1]alpha-factor and [Bpa5]alpha-factor, showed three- to four-fold lower affinity compared to alpha-factor, whereas [Bpa3]alpha-factor and [Bpa13]alpha-factor had seven- to twelve-fold lower affinities, respectively. [Bpa8]alpha-factor competed poorly with [3H]alpha-factor for Ste2p. All of the analogs tested except [Bpa8]alpha-factor were alpha-factor agonists. Cross-linking studies demonstrated that [Bpa1]alpha-factor, [Bpa3]alpha-factor, [Bpa5]alpha-factor and [Bpa13]alpha-factor cross-linked to Ste2p; the biotin tag on the pheromone was detected by a NeutrAvidin-HRP conjugate on Western blots. Digestion of receptors crosslinked to [Bpax]alpha-factor (x = 1, 3, 13) with chemical and enzymatic reagents suggested that the N-terminus of the pheromone interacts with a binding domain consisting of residues from the extracellular ends of TM5 (transmembrane 5), TM6, and TM7 and portions of EL2 (extracellular loop 2) and EL3 close to these TMs and that there is a direct interaction between the position 13 side chain and a region of Ste2p (F55-R58) at the extracellular end of TM1. Site-directed mutagenesis results correlated with the crosslinking studies. The results have been incorporated into a model for alpha-factor bound to its receptor

    The Serological Response in Cattle following Administration of a Heterologous Sheep Pox Virus Strain Vaccine for Protection from Lumpy Skin Disease; Current Situation in Armenia

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    Lumpy skin disease (LSD) is a highly infectious viral disease of cattle caused by LSD virus (LSDV), which was first reported in Armenia in late 2015. It was identified in pasture-raised cattle near the border with Iran. Currently, vaccination plays a key role in preventing further incursion of disease in high-risk areas. The purpose of this work was to assess the quality of vaccination currently used in Armenia by determining the immune response of the heterologous dry culture sheep pox virus-based vaccine against LSD in cattle. Seroprevalence and seroconversion testing was carried out using an ELISA to detect specific antibodies against LSD before and 30 days after vaccination in three adjacent regions of Armenia (Ararat, Armavir, Gegharkunik). Ixodes ticks were also examined for the presence of LSDV via real-time PCR. We found that the heterologous vaccine used in Armenia creates a high level of population immunity of 86.09% (83.83–87.97%) and no adverse side effects were observed in cattle. Of the 6 types of Ixodes ticks identified and tested, we found no evidence of LSDV circulating in these vectors. These results suggest that regular serological monitoring via ELISA and heterologous vaccination should continue in areas of Armenia at high risk for incursion of LSD to reduce the spread of this highly infectious transboundary disease

    The Serological Response in Cattle following Administration of a Heterologous Sheep Pox Virus Strain Vaccine for Protection from Lumpy Skin Disease; Current Situation in Armenia

    No full text
    Lumpy skin disease (LSD) is a highly infectious viral disease of cattle caused by LSD virus (LSDV), which was first reported in Armenia in late 2015. It was identified in pasture-raised cattle near the border with Iran. Currently, vaccination plays a key role in preventing further incursion of disease in high-risk areas. The purpose of this work was to assess the quality of vaccination currently used in Armenia by determining the immune response of the heterologous dry culture sheep pox virus-based vaccine against LSD in cattle. Seroprevalence and seroconversion testing was carried out using an ELISA to detect specific antibodies against LSD before and 30 days after vaccination in three adjacent regions of Armenia (Ararat, Armavir, Gegharkunik). Ixodes ticks were also examined for the presence of LSDV via real-time PCR. We found that the heterologous vaccine used in Armenia creates a high level of population immunity of 86.09% (83.83–87.97%) and no adverse side effects were observed in cattle. Of the 6 types of Ixodes ticks identified and tested, we found no evidence of LSDV circulating in these vectors. These results suggest that regular serological monitoring via ELISA and heterologous vaccination should continue in areas of Armenia at high risk for incursion of LSD to reduce the spread of this highly infectious transboundary disease

    Evaluation of the effectiveness of foot-and-mouth disease vaccination of animals in the buffer zone of the Republic of Armenia in 2016–2020

    No full text
    Abstract Background Foot-and-mouth disease (FMD) is a high impact viral disease of livestock for which vaccines are extensively used for limiting the spread of infection. Armenia shares a border with both Turkey and Iran where FMD is endemic, making vaccination an important component of Armenia’s control strategy. Additionally, Armenian veterinary services utilize both passive and active monitoring for prevention control. Methods We sought to determine the immune status of animals vaccinated against FMD and to evaluate the effectiveness of our vaccination policy in Armenia. This was conducted in three regions including Shirak, Armavir, and Ararat Region which are located in the buffer zones that border Turkey and Iran. Through active monitoring in 2020, we studied blood serum samples from cattle and sheep using an enzyme immunoassay to determine the level of immune animals in these regions following the use of a polyvalent inactivated vaccine containing FMDV serotypes A, O, and Asia-1 that are relevant for this region. ELISA titers were assessed at 28, 90, and 180 days after vaccination in cattle of three age groups at the time of initial vaccination: 4–6 months, 6–18 months and ≥ 24 months of age with sheep of all ages. Results The 3 age groups of cattle had similarly high levels of immunity with over 90% of the cattle showing a ≥ 50% protective titer 28 days after the first vaccination. By day 90, titers in cattle from the initial 4–18-month age groups dropped below 58% across the 3 serotypes and at or below 80% for the oldest cattle ≥ 24 months. Re-vaccination of cattle at 120 days did improve protective titers but never reached the level of immunity of the first vaccination. Sheep showed a similar rapid drop to less than 50% having a ≥ 50% protective titer at 90 days emphasizing the need for continual revaccination. Conclusions The results of this study have important implications for the current FMD vaccine policy in Armenia and improves our understanding of the rapid loss of protective titers over short periods. Since small ruminants are only vaccinated once per year and vaccination titers drop rapidly by 90 days suggests that they are vulnerable to FMD and that vaccination protocols need to be updated. Cattle should continue to be vaccinated every 3–6 months depending on their age to maintain a protective level of antibodies to protect them from FMD. More studies are needed to understand the possible role of small ruminants in the epidemiology of FMD and to evaluate revaccination at shorter intervals. These results show the concerns of rapid loss of protection to both cattle and small ruminants following 1 or more doses of commercial vaccines and that additional vaccines need to be evaluated in both groups to know how often they must be vaccinated to provide full protection. The addition of challenge studies should also be considered to better understand the level of protection as measured by serology and how it relates to protection from challenge. These results should be considered by anyone using these vaccines in cattle and sheep at longer than 3 month intervals
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