625 research outputs found
Study of potential activity of clove oil 10 % emulsifiable concentrate formulation on Two-spotted spider Mite Tetranychus urticae Koch (Acari: Tetranychidae)
Clove oil is reported to have a great range of biological activities against many species of pests; termites, cockroaches, aphids, weevils and moths, and many different usages such as perfume and food flavoring agent. This study aimed to determine the acaricidal activity of clove oil emulsifiable concentrate new formulation against two-spotted spider mites Tetranychus urticae. Clove oil was formulated as 10 % emulsifiable concentrate (EC). The new formula passed successfully all physical and chemical tests reported for emulsifiable concentrates. It was then tested biologically on the individuals of two-spotted spider mite T. urticae Koch (Acari: Tetranychidae) on two host plants beans and squash under laboratory conditions. In both cases, there were a direct relationship between the increase in the concentration of the formulation and the percentage of inhibition on the individuals of the two-spotted spider mite, after 72 hours of treatment, at concentrations of 20, 40, and 80 mg/ml the new formulation showed 10.30, 44.8, and 75 percent inhibition, respectively in case of beans, while squash at the same concentrations and for the same period of treatment showed 33.3, 40.7, and 51.9 percent inhibition, but the effect in case of beans was greater than that in case of squash as its EC50 value was lower than that in case of squash. In the case of the former, it was 39.81 mg/ml, whereas in the case of the latter, it was 79.43 mg/ml. Therefore, the new clove oil formulation can be used to combat the two-spotted spider mite
Proteomic analysis of Glossina pallidipes salivary gland hypertrophy virus virions for immune intervention in tsetse fly colonies
Many species of tsetse flies (Diptera: Glossinidae) can be infected by a virus that causes salivary gland hypertrophy (SGH). The viruses isolated from Glossina pallidipes (GpSGHV) and Musca somestica (MdSGHV) have recently been sequenced. Tsetse flies with SGH have a reduced fecundity and fertility which cause a serious problem for mass rearing in the frame of sterile insect technique (SIT) programs to control and eradicate tsetse populations in the wild. A potential intervention strategy to mitigate viral infections in fly colonies is neutralizing of the GpSGHV infection with specific antibodies against virion proteins. Two major GpSGHV virion proteins of about 130 kDa and 50 kDa, respectively, were identified by Western analysis using polyclonal rabbit antibody raised against whole GpSHGV virions. The proteome of GpSGHV, containing the antigens responsible for the immune-response, was investigated by liquid chromatography tandem mass spectrometry (LC-MS/MS) and 61 virion proteins were identified by comparison with the genome sequence. Specific antibodies were produced in rabbits against seven candidate proteins including the ORF10 / C-terminal fragment, ORF47 and ORF96 as well as proteins involved in peroral infectivity PIF-1 (ORF102), PIF-2 (ORF53), PIF-3 (ORF76) and P74 (ORF1). Antiserum against ORF10 specifically reacted to the 130 kDa protein in a Western blot analysis and to the envelope of GpSGHV using immunogold-EM. This result suggests that immune intervention of viral infections in colonies of G. pallidipes is a realistic optio
Variability and inheritance of okra leaf- shape of cotton cv. Sudac-k in different genetic backgrounds
Okra leaf- shape is an important trait in cotton. Sudac-k is the only cotton variety with okra leaf type in the Sudan. The objectives of the study were to analyze the inheritance of the okra leaf of Sudac-k and its expression in different genetic backgrounds. The experiment was carried out for two seasons (2004/05 and 2005/06) and one off-season in 2006 at Gezira Research Farm of the Agricultural Research Corporation (ARC), Wad Medani, Sudan. The plant material consisted of Sudac-k and nine different varieties; B-pima, Barakat-90, G.S, Maryoud, Shambat-B, Acala-M, Acala-H, Barac (67) B and Albar (57)12. Eighteen reciprocal F1s were produced between Sudac-k and respective cultivars. In the second season, F2 ҆s, backcrosses and F3 plants were (Sudac-k X Albar (57)12). At maturity, individual plants were visually scored according to the leaf-shape into okra and normal leaf shape. Okra leaf morphology, lobe length, width and angle were measured in fully expanded 5- lobed leaf. It was observed that the okra leaf of Sudac-k had deep sinuses and narrow lobes while in F1 ҆ s, the sinuses were shorter and the lobes were broader. The okra leaf started at seedling stage with three lobes at the 3rd to 4th node and reached a maximum of 5 lobes at node 6 to 8 in Sudac-k, F1 plants and their progenies. Chi-square test for the segregation of leaf type in F2 indicated no significant differences among all F1 ҆ s between Sudac-k and the varieties in the distribution of okra and normal which followed the ratio of 1:2:1. This indicates that the okra leaf trait is conditioned by a single partially dominant gene. Significant differences were observed among the F1 hybrids for the expression of leaf lobing depth, lobe width and angle, indicating the effect of the genetic background on the expression of these parameters. The information will be useful in designing strategy for breeding of cotton varieties with suitable size of okra leaf to maximize its utilization in integrated insect pest management
The Antiviral Drug Valacyclovir Successfully Suppresses Salivary Gland Hypertrophy Virus (SGHV) in Laboratory Colonies of Glossina pallidipes
Many species of tsetse flies are infected with a virus that causes salivary gland hypertrophy (SGH) symptoms associated with a reduced fecundity and fertility. A high prevalence of SGH has been correlated with the collapse of two laboratory colonies of Glossina pallidipes and colony maintenance problems in a mass rearing facility in Ethiopia. Mass-production of G. pallidipes is crucial for programs of tsetse control including the sterile insect technique (SIT), and therefore requires a management strategy for this virus. Based on the homology of DNA polymerase between salivary gland hypertrophy virus and herpes viruses at the amino acid level, two antiviral drugs, valacyclovir and acyclovir, classically used against herpes viruses were selected and tested for their toxicity on tsetse flies and their impact on virus replication. While long term per os administration of acyclovir resulted in a significant reduction of productivity of the colonies, no negative effect was observed in colonies fed with valacyclovir-treated blood. Furthermore, treatment of a tsetse colony with valacyclovir for 83 weeks resulted in a significant reduction of viral loads and consequently suppression of SGH symptoms. The combination of initial selection of SGHV-negative flies by non-destructive PCR, a clean feeding system, and valacyclovir treatment resulted in a colony that was free of SGH syndromes in 33 weeks. This is the first report of the use of a drug to control a viral infection in an insect and of the demonstration that valacyclovir can be used to suppress SGH in colonies of G. pallidipes
Effect of heat and mass transfer and rotation on peristaltic flow through a porous medium with compliant walls
Purpose: The purpose of this paper is to investigate the peristaltic flow of an incompressible Newtonian fluid in a channel with compliant walls. The effects of rotation and heat and mass transfer are also taken into account. The governing equations of two dimensional fluid have been simplified under long wavelength and low Reynolds number approximation. An exact solutions is presented for the stream function, temperature, concentration field, velocity and heat transfer coefficient. Design/methodology/approach: The effect of the concentration distribution, heat and mass transfer and rotation on the wave frame are analyzed theoretically and computed numerically. Numerical results are given and illustrated graphically in each case considered. Comparison was made with the results obtained in the presence and absence of rotation and heat and mass transfer. Findings: The results indicate that the effect of the permeability and rotation are very pronounced in the phenomena. Originality/value: The objective of the present analysis is to analyze the effects of rotation, heat and mass transfer and compliant walls on the peristaltic flow of a viscous fluid
Tsetse Salivary Gland Hypertrophy Virus: Hope or Hindrance for Tsetse Control?
Many species of tsetse flies (Diptera: Glossinidae) are infected with a virus that causes salivary gland hypertrophy (SGH), and flies with SGH symptoms have a reduced fecundity and fertility. The prevalence of SGH in wild tsetse populations is usually very low (0.2%–5%), but higher prevalence rates (15.2%) have been observed occasionally. The successful eradication of a Glossina austeni population from Unguja Island (Zanzibar) using an area-wide integrated pest management approach with a sterile insect technique (SIT) component (1994–1997) encouraged several African countries, including Ethiopia, to incorporate the SIT in their national tsetse control programs. A large facility to produce tsetse flies for SIT application in Ethiopia was inaugurated in 2007. To support this project, a Glossina pallidipes colony originating from Ethiopia was successfully established in 1996, but later up to 85% of adult flies displayed symptoms of SGH. As a result, the colony declined and became extinct by 2002. The difficulties experienced with the rearing of G. pallidipes, epitomized by the collapse of the G. pallidipes colony originating from Ethiopia, prompted the urgent need to develop management strategies for the salivary gland hypertrophy virus (SGHV) for this species. As a first step to identify suitable management strategies, the virus isolated from G. pallidipes (GpSGHV) was recently sequenced and research was initiated on virus transmission and pathology. Different approaches to prevent virus replication and its horizontal transmission during blood feeding have been proposed. These include the use of antiviral drugs such as acyclovir and valacyclovir added to the blood for feeding or the use of antibodies against SGHV virion proteins. In addition, preliminary attempts to silence the expression of an essential viral protein using RNA interference will be discussed
PHYTOPHENOLICS COMPOSITION, HYPOLIPIDEMIC, HYPOGLYCEMIC AND ANTIOXIDATIVE EFFECTS OF THE LEAVES OF FORTUNELLA JAPONICA (THUNB.) SWINGLE
Objective: Fortunella japonica (Thunb.) Swingle is an evergreen shrub, its whole fruit, including the peel, is eaten. There have been few detailed phytophenolics composition reports on this genus and the hypoglycemic and hypolipidemic effects of the plant were not evaluated. Methods: Structures of the isolated compounds were elucidated by spectral analysis. Serum glucose level, activities of liver enzymes, total protein content, serum lipid profiles, antioxidant parameters and some glycolytic and gluconeogenic enzymes in streptozotocin (STZ)-induced diabetic rats were determined. The evaluation also carried out through determination of liver disorder biomarkers and histopathological examination of liver, kidney and pancreas. Results: Six phytophenolics were isolated, for the first time from the genus Fortunella as well as a sterol compound. Treatment with the ethanolic extract of F. japonica leaves effectively meliorated antioxidant markers and glycolytic enzymes. The histopathological analyzes also confirmed the experimental findings.Conclusion: The results show that the ethanolic extract has hypoglycemic, hypotriglyceridemic and antioxidant effects in STZ-induced diabetic rats, suggesting that this extract supplementation can be useful in preventing diabetic complications associated with hyperlipidemia and oxidative stress.Â
Magnetic Field and Gravity Effects on Peristaltic Transport of a Jeffrey Fluid in an Asymmetric Channel
In this paper, the peristaltic flow of a Jeffrey fluid in an asymmetric channel has been investigated. Mathematical modeling is carried out by utilizing long wavelength and low Reynolds number assumptions. Closed form expressions for the pressure gradient, pressure rise, stream function, axial velocity, and shear stress on the channel walls have been computed numerically. Effects of the Hartmann number, the ratio of relaxation to retardation times, time-mean flow, the phase angle and the gravity field on the pressure gradient, pressure rise, streamline, axial velocity, and shear stress are discussed in detail and shown graphically. The results indicate that the effect of Hartmann number, ratio of relaxation to retardation times, time-mean flow, phase angle, and gravity field are very pronounced in the peristaltic transport phenomena. Comparison was made with the results obtained in the presence and absence of magnetic field and gravity field
Effects of Rotation and Gravity Field on Surface Waves in Fibre-Reinforced Thermoelastic Media under Four Theories
Estimation is done to investigate the gravitational and rotational parameters effects on surface waves in fibre-reinforced thermoelastic media. The theory of generalized surface waves has been firstly developed and then it has been employed to investigate particular cases of waves, namely, Stoneley waves, Rayleigh waves, and Love waves. The analytical expressions for surface waves velocity and attenuation coefficient are obtained in the physical domain by using the harmonic vibrations and four thermoelastic theories. The wave velocity equations have been obtained in different cases. The numerical results are given for equation of coupled thermoelastic theory (C-T), Lord-Shulman theory (L-S), Green-Lindsay theory (G-L), and the linearized (G-N) theory of type II. Comparison was made with the results obtained in the presence and absence of gravity, rotation, and parameters for fibre-reinforced of the material media. The results obtained are displayed by graphs to clear the phenomena physical meaning. The results indicate that the effect of gravity, rotation, relaxation times, and parameters of fibre-reinforced of the material medium is very pronounced
ESTIMATE OF SOME GENETIC PARAMETERS FOR SOME VEGETATIVE AND YIELDING TRAITS IN COMPLETE DIALLEL CROSSES AMONG FIVE INBRED LINES OF CUCUMBER
This experiment was implemented in the experimental farm of (Misr hytech seed co. Giza, Egypt) during winter growing seasons 2014 and 2015 to evaluate the inheritance of some cucumber vegetative and yielding traits using a complete diallel cross among five inbred lines. The results showed that the mean square of genotypes, parental inbred lines, crosses and parent vs crosses were significant for the studied traits. The hybrids P2xP4 and P2xP5 exhibited a useful heterosis relative to Mp and Bp for the fruit yield per plant and number of leaves per plant. The mean square of general and specific combining ability was significant for the studied traits. The higher GCA/SCA ratio than the unity of the studied traits indicating to the greatest role of the additive gene action in the expression of these traits. The inbred lines P1 and P 2 exhibited significant positive i g ˆ effects in the traits of number of fruit per plant and fruit yield per plant, so these inbred lines could be act as a good combiner for developing high yielding genotypes. The F1 hybrids P1xP3, P2xP4, P2xP5 and P4xP5 as well as the reciprocal hybrids P4xP1, P4xP2, P4xP3 and P5xP3 recorded a significant positive ij S ^ effect but the reciprocal hybrids recorded a significant rij effect. The results revealed to more than one hybrid distinct in some traits that could be utilized in the greenhouse cucumber cultivation and the future breeding programs
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