Planning in the Agricultural Extension System for its systematic and moderate development in order to achieve food security requires the identification, explanation and presentation of solutions compatible with the internal and external environment of this system. Therefore, the goal of this study was to identify, explain and provide solutions to improve the performance of the extension system to achieve food security. The statistical population of the study was 130 policy makers and experts on agricultural extension and development in the country who were counted. In order to examine the importance and applicability of each of the solutions mentioned by the experts, the results of their views by the experts of Jihad Agricultural Centers in Kohgiluyeh and Boyer Ahmad province was examined. To conduct the research, the desired solutions were identified, studied and refined in three rounds through Delphi method. Then, using the technique and method of content analysis, it was classified into two main categories of macro and local solutions. Macro-solutions fall into three categories: structural, infrastructural, and cultural, and local solutions fall into four sub-categories: structural, infrastructural, research, and cultural. Finally, Nvivio software was used to provide a comprehensive model of strategies to improve the performance of the extension system to achieve food security. Findings from the software showed that human resources training in the field of food security, attention to the tangible and intangible needs of users, transparency of the functional areas of the extension system to move in the direction of food security, knowledge promotion and well-being. Providing training in line with global standards of food security is one of the most obvious ways to improve agricultural extension & education to achieve food security.

BACKGROUND: Causing site direct mutation can be one of the efficient methods to evaluate the characteristics and properties of various genes. Brucellosis is the most common zoonotic infectious disease that would cause great economic losses. Thus, recognition of pathogenic and immunogenic factors in the genus Brucella can lead to control this health problem.OBJECTIVES: Considering the importance of site direct mutation in identification of genome structure and numerous ways to achieve this goal, Overlap Extension PCR is introduced as an improved technique for the removal and replacement of the gene target.METHODS: For this study, with two-step PCR using specific primers, upstream and downstream fragments from target gene and antibiotic resistance cassette from plasmid pET28a (+), were reproduced and were connected to each other. The resulting fragment was cloned in specific position of pBluescriptIISK(-) plasmid by the restriction enzymes. Then, the construction was transferred into the genome of Brucella abortus by electroporation method.RESULTS: Fusion PCR product was obtained without any change in the nucleotide sequence and then it was cloned into pBluescriptIISK (-) plasmid, finally the construction was replaced and the target gene was deleted.CONCLUSIONS: The results of this study show that the Overlap Extension PCR is an optimized and modified technique to create mutations in the bacterial genome structure and can easily be used in the family Brucella.

The main purpose of this study was to investigate factors influencing job performance of extension experts from Yazd province, Iran. All the extension experts in Yazd province were included in the study (N=120) of whom 67 were selected through Proportional Stratified random sampling method (n=67). The study was a descriptive-correlation, survey research one. A questionnaire was designed and employed to gather the required data. The reliability and validity of the Job Performance Index was determined. Cronbach's alpha computed to measure the reliability of the 32 items of job performance was 0.97. The instrument was presented to the Department of Agricultural Extension and Education, University Faculty members of Tehran to be tested for content above validity. The findings revealed that the job performance of extension experts was average level. Also the findings revealed significant correlations between job performance and job satisfaction, job motivation, attitude, and job ability, the rate of use of information resources and communication channels, degree of communication with media, participatory cooperation with organization management. Also the results of the multiple regression revealed that 48.6% of job performance variance in the experts, performance was determined by the three variables of: "job motivation", "participatory contacts with organization management" and "job performance ability".

The purpose of this study was to compare the technique of taking cephalometric radiographs in Natural Head Position (NHP) with slightly changing of the head in the direction of flexion and extension (In the amount of 5 degrees.) 40 Cephalometric head films of 20 cases, all of whom were dental students, were utilized in this study.The cephalograms were divided into two groups. At first lateral cephalometric radiographs in NHP were taken from all of the cases, then another radiograph was taken in extended head position (the head changed 5 degrees upward from NHP position) from cases of group one, and in flexion head position (the head changed 5 degrees downward from NHP position) from cases of the second group. In this study 24 landmarks and 36 variable were evaluated.All radiographs were twice and data captured with a digitizer and computer. Evaluation of the results, which are shown in table I, revealed that 9 of the variable among 36 showed significant differences compared to NHP position, and two of the variable was common between the two groups. However, 27 of the measurments didn't show any significant differences. Considering the fact that one fourth of the landmark measurments which were evaluated in this study showed significant differences during slight extension or flexion of head, taking of lateral cephalometric headfilms in NHP is recommended specially when they are to be used in serial studies or ar taken for research purpose.However, because other 27 measurment (which comprise three fourth of all the measurments) showed no significant changes, we concluded that lateral cephlograms which are not taken in NHP may be used for diagnostic and treatment planning purpose.

This causal-research study was conducted with the general purpose of factors affecting the performance of learners participating in the horticulture-vegetable and summer cultivation training course in urban agriculture. The statistical population of this study is the total number of learners participating in urban agriculture training courses held by the General Department of Municipal Education of Tehran Region 2 in 2019 (N = 80). In this study, census method was used. Data were collected using a questionnaire. The apparent and content validity of the questionnaire was confirmed by a group of experts and the estimation of the reliability of the questionnaire was provided by calculating the sequential alpha (α = 0. 97). Data analysis was performed using SPSS25 and AMOS23 software. According to the findings, the reaction with an average of 7. 77 and the attitude of learners towards the horticulture-vegetable and summer cultivation training course in urban agriculture with an average of 7. 02 =, is considered desirable. The level of knowledge of the learners participating in this course before the course with an average of 5. 18 at the average level and after participating in the course with an average of 8. 86 was very high. Path analysis findings using AMOS23 software also showed that the variable of agricultural work experience of learners (β = 0. 99) has the greatest impact on their performance. Then the variables of learners 'reaction to the course (β = 0. 85), age of learners (β = 0. 83), knowledge (β = 0. 63) and students' attitude towards the course (β = 0. 62) They have the greatest impact on their performance. Meanwhile, the variables of learners' participation history in classes and extension training courses related to urban agriculture (β = 0. 42) and their level of education (β = 0. 39) Also affect the performance of learners participating in the training course of horticulture-vegetable growing and summer urban agriculture, respectively. Therefore, since urban agriculture is one of the components of sustainable urban development, citing the findings of this study can pay more attention to the training of learners in supporting decisions to achieve sustainable development by policy makers, planners and relevant managers. Be exploited.

This study examined the major effective factors on sustainability and continuity of private extension services from the perspective of public sector experts in Qazvin and Zanjan province based on the Structural Equation Modeling. The population of this study comprised public sector experts who worked in Agricultural Extension Services Centers in Qazvin and Zanjan provinces (N=241). The study sample consisted of 148 public sector experts selected through stratified random sampling. A questionnaire was utilized for data collection. Validity was confirmed by face validity, convergent validity, and content validity and reliability was calculated using Composite Reliability and Cronbach's alpha coefficient. Data was analyzed using Smart-PLS software based on Partial Least Squares approach. The findings showed that the infrastructure, education & extension, and economic factors had the most positive and significant effect on the sustainability and continuity of private extension activities from the perspective of public sector experts in Qazvin and Zanjan province, respectively. Due to the impact of the infrastructure factor, the organization of private extension network by the Agricultural Jihad Organization at first and the implementation of supportive policies to set up consulting start-ups such as information, education and culture to accept the culture of private promotion in the region, and accept A portion of the private promotion fee is offered.

Draft tube of Francis type hydraulic turbine usually consists of: cone, elbow and diffuser. On the contrary, in some power stations an extra pipe should be added to the draft tube at the bottom of cone because of installation limitation. In this paper, this special case has been numerically studied. To this end CFD analysis was applied to simulate all parts of hydraulic turbine. A homogeneous multiphase model with Rayleigh-Plesset cavitation model was applied for presence of cavitation. The results reveal that the additional tube causes pressure drop and severe cavitation at the trailing edge of runner blades. Also, results showed that the efficiency reduces in comparison with original hill-diagram of model test in which this extension was not considered. With the removal of the extension tube, the efficiency increased significantly. The comparison of pressure recovery factors along draft tube, and theoretical investigation showed that the height of the draft tube is an important parameter and addition of an extra pipe will cause reduction in draft tube performance and increases the probability of occurrence of cavitation under the runner.