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 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.

Introduction As one of the largest ports in southern Iran, MahshahrPort faces the risk of seawater intrusion from Mahshahr estuary. Mahshahr and Mousa estuary form an 86 kilometerwaterway. Midday mixed tide is dominant throughout this waterway. Moving towards the vertex of the estuary, this dominance of the midday tidebecomes much more evident. Considering an average depth of 38. 4 m, midday tidal wave of M2 with an approximate wavelength of 860 km can be reinforced in this waterway. Grounding of boats and otherammunitions in the basin of Mahshahr port (betweenMajidiyeh garrison and the Persian Gulf) was one of the most important issues during the Imposed War. Mahshahrestuary is the only possible way to access the Persian Gulf fromImam Khomeini port and Majidiyehnaval garrison. From a military perspective, Mahshahrestuary has a special feature that can be considered as a strategic factor and used in various types of active and passive defense. In spite of the shallowness of its internal parts, it is considered to be a safe haven for small vesselsin times of crisis and air attacks. Sometimes, it is critical to use these estuaries and their navigable waterways as the main route for transportation of military weapons, medical aid, and rescue services. Crisis managers and urban planners need an appropriate plan based on risk map of the study areato reduce the risk of tidal process. However, zoning tidal process and mapping its risk are not enough by their own: a useful system needs toidentify sensitive and vulnerable pointsto increase the efficiency of tide risk zoning. Materials & Methods Seeking to reduce the risk of tidal process, the present study determinesmaximum level of development in areas covered during high tides usingHecgeoras software. In order to achieve the goals, hydrographic data of the substrate was used along with information and statistics received from high accuracy hydrometric stations. This zonesurrounds an area of around 944 hectares. Field visits indicate thatduring tidal process, soil conditions in the study area hampers sending emergency aids using land routes. Considering the conditions and structures inMahshahr estuary and the tide zone in the study area, investigating geology of the study area seems necessary. Results & Discussion Considering the soil conditions in the study area, the highest level of soil flooding was observed during high tide. This increasessoil adhesion, affects water intrusion, and hampers sending aids. Critical areas in danger of water intrusion from the estuary (such as Mahshahr gas reservoirs and Majidieh military garrison) were identified in the present study. Moreover, results were investigated and land visits were performed to present accurate and reliable results. Land visits were carried out during 2016-2017 winter and 2017 summer in order to achieve better and more accurate results based on the climatic changes. Investigating the recorded level of water in the study area shows up to 3-metervariation in the water level of Mahshahr estuary. Necessary decisions regardingthe use of different types of vessels, and passive/active defenses can be made in accordance with water level fluctuations and specified times for each water level. During local visits performed for quantitative analysis of results, soil type and its role in passive defense were also discussed. Conclusion Field studies and observations in the study area indicated that 1) dominant soil type of the region is a highly adhesive type with a high clay content; 2) during tide time, soil flooding results in increased adhesion of soil and practically hampers movements of ammunition; 3) In summer and winter, water level changes repeatedly and thus, necessary measures shall be considered for military programs in accordance with the time in which water fluctuations occur. Although the depth of water in the study area is significant, it should be noted that Mahshahr estuary finally reaches an urban area, and thus can be used for military actions. In fact, mapping tide zone is a very effective method for reducing the risk of tidal process in coastal areas.

This article studies the stages in which Leibniz's thoughts had been shaped about extension and place, and their interrelation. It shows how Leibniz considers "kraft-virtus-vis" to be the base of all things and extension, by rejecting any substance for extension. By going out of the Cartesian and Kantian dualism, he suggests a spiritual base for worldly entities. Leibniz assumes extension, matter, and place as phenomenal levels and derivative realities, and therefore, considers the world to be infinite on both sides (from within and from without). Hence, he rejects atom and void. He considers the base of things as metaphysical points called, "monads", which have life and understanding, and have a comprehension of their environment.In this way he also explains the nature of connection.

Agent specialization is the core concept and process of extension specialization. In this context, specialized agent is specializing in a single subject matter area. These specialized agents are highly proficient in their subject area, better servicing to clientele, while reducing workload and frustration of general extension. The main purpose of this study was to investigate and determine the viewpoints of extension experts toward extension specialization in Iran. Casual-correlation research was employed in the study. The population of the research included all extension experts employed in units of Jehad Keshavarzi ministry at staff level (n=136). The census (enumeration) method was employed to gather data questionnaires and according to the purpose of the study. From a review of literature and related to research objective, a questionnaire consisting of seven separate questions was developed. Validity of the questionnaires was confirmed after assessment by some extension experts and professors. Coronbach Alpha coefficient was employed to determine the questionnaire's reliability and its value was found within the range of 0.74-0.82, which was favorable. Data analysis was accomplished using SPSS. WIN software. Appropriate statistics was applied to expound the results. Results show that the overall attitude of extension experts toward extension specialization is quite positive. There were significant relationships observed between attitudes of extension experts toward extension specialization and their job as well a their organizational and personal characteristics (organizational unit, subject matter of specialization, work span of interest, engagement or non-engagement in a second job, filed of study, years in service, provision of extension papers, participating in educational courses, job satisfaction and in-service education). Also, extension experts attached ranks to some important progressive factors as well as to the implications of extension specialization in Iran.

The main objective of present paper was to study the validity of agricultural extension indices for ranking Iranian provinces in terms of extension and education activities. The study was carried out in two phases. In phase one through review of literature, 137 extension-education indices were identified. The indices were classified in seven fields as following: 1) Indices of extension workers, 2) infrastructural indices of agricultural extension, 3) indices of extension-education activities, 4) organization and management indices of agricultural extension, 5) indices of mass education, 6) indices of extension communication and 7) indices of extension credits. The indices were validated by 180 extension experts of six provinces which randomly were selected. For data analysis the mode, mean, standard deviation and coefficient of variation were estimated. In second phase, data collected for 133 indices, through Deputy of extension and Operation System, affiliated to the Ministry of Agricultural Jihad and by using principal component techniques composite indices of each of the fields was calculated. The results revealed that except four indices, the rest of. 133 indices were appropriate for agricultural and extension planning and evaluation purposes. The calculated composite index also showed that Hamadan province was ranked in first position and Qazvin province in the last position in this aspect.

In the new approaches to agricultural extension, extension workers play a major role in transferring knowledge and technologies from research stations to farmers. This role is highlighted when it comes to participatory extension approach which is to empower farmers through building their capacities. In such an approach, extension workers play different roles out of which facilitation is highly important. Keeping this in view, the main objective of this research was to analyze participation areas of state and local extension workers in extension activities of the national extension system of the country. This was a correlational-descriptive study conducted through survey method. The population of the study consisted of about 7000 state extension workers and 7100 local extension workers out of which 140 and 120 samples were selected by using Cochran Formula. Multi-stage sampling technique including both simple and cluster random techniques were applied in the study. Panel of experts' judgment. The reliability of the tool of the study was proved by Cronbach Alpha as it was above 0.75 for main scales of the questionnaire. The results of factor analysis indicated that four factors viz., individual and group education of farmers, context analysis and provision of educational opportunities, distribution of agricultural inputs and production as well as distribution of extension-education materials accounted for 64 per cent of variation of state extension workers. With respect to local extension workers, four factors namely: context analysis, provision and expansion of educational opportunities; distribution of farming and form related inputs; mutual relationship with research centers and executive offices and close contact with progressive farmers accounted for 70 percent of variation in the respondents' pattern of participation in extension activities.

The purpose of this study was to assess the feasibility of privatization of agricultural extension service in Iran, as perceived by extension specialists in Ministries Of Agriculture and Jahad Sazandegy and faculty members of agricultural extension.The sample was 160 extension specialists and faculty members. This consists of 40 extension specialists in Ministry of Agriculture, 40 extension specialists in Ministry Of Jahad Sazandegy and 40 faculty members of extension in several universities in Iran. The research design included a survey research, and a questionnaire was developed. The data was collected by interviewing sample population and was analyzed by using regression analysis and spearman ranking methods.The results of the study show that 51 respondents (42.5%) indicated that the public extension service was not successful in delivering goods and services to farmers. The three factors "weak linkages between research and extension, weak program planning, and problem of limited numbers of manpower", was found out to be the main reasons for inefficiency and ineffectiveness of extension service in Iran.The majority of respondents (62 respondents, 51.6%) stated that private sector can improve the current public system of extension in Iran, but they also indicated that private firms can not substitute for public extension.The results of the study show that majority of respondents (52.5%) disagreed with using only public resources for extension service in Iran.The perception of respondents was that the commodity - based and farmer - controlled approach can be the most usefull approaches for extension service in Iran. The majority of respondents stated that the mixed public and private entities can deliver goods and services effectively to the farmers.