Cerebellar pilocytic Astrocytoma is a benign tumor, acounts for 80% of all cerebellar Astrocytoma, and has a relatively good prognosis. This tumor usually presents with Ataxia and in the case of hydrocephaly with raised intracranial pressure signs such as headeach, and vomiting. Treatment of this tumor is complete resection and if hydrocephally is present V.P. shunt should be inserted. In the case of recurrence or tumor seeding radiotherapy is recommended. Seeding of cerbellar Astrocytoma has been reported rarerly. Spontaneous regression of chiasmatic pilocytic Astrocytoma associated with neurofibromatosis type I has been reported but Spontaneous regression of cerebellar Astrocytic tumor without neurofibromatosis has been reported very rarely in the literature. In this report a young patient with seeding of cerebellar Astrocytoma in the lumbosacral region with severe neurological deficit who has recovered spontaneously without any treatment is presented. This case is intresting for both seeding and spontaneous regression of tumor.

This study was conducted during two years (2007-2009) in Shawoor Agricultural Research Station on a siltyclay soil. Experiment conducted in split plots in a Randomized Complete Blocks Design in three replications.Main plots were planting methods including centrifugal broadcaster (P1), centrifugal broadcaster+furrower (P2), seed drill (P3), seed drill+furrower (P4), three lines bed drilling (P5) and four lines bed drilling (P6).Subplots were included seed rates of 120, 160, 200 and 240 kg.ha-1. The results showed that P2 method with 14.91 litter.ha-1 and P3 method with 5.02 litter.ha-1 had the highest and lowest fuel consumption respectively. P3 method with 1.462 h.ha-1 and P5 method with 0.620 h.ha-1 required maximum and minimum total operation time respectively. P2 method with 0.684 ha.h-1 had minimum field capacity. Field capacity of P5 and P6 with averagely 1.67 ha.h-1 was maximum. Field capacity of all drilling methods (P3, P4, P5 and P6) was significantly more than that of broadcasting methods (P1 and P2). The highest seed spacing uniformity (87.2%) was belonged to P6 method and the lowest value (54.7%) was for P1 method. By using drilling methods of P3 and P5 (or P6) instead of P1 method total cost was reduced 41% and 29% respectively. The results of variance analysis of data showed that the difference between planting methods in case of wheat grain yield and yield components was not significant. However, the seed rate had significant effect on some yield components. Suggestion for cropping of wheat Chamran variety in silty-clay soil in Khuzestan province, used P5, P6 and P3 methods are recommended respectively with seed rate of 120 - 160 kg.ha-1.

Changing rice cultivation system from puddle transplanting to direct seeding greatly reduces labor and crop production costs. A field experiment was conducted at Rice Research Institute of Iran-Rasht in 2018 as split plot based on a randomized complete block design to evaluate the effect of seeding date and planting method on growth and grain yield of Hashemi cultivar in direct seeding method. Main plots included seeding date (May 1, 8, 15, 22, 29 and June5 and 12) and sub plots were planting methods (broadcast seeding, row seeding and hill seeding). Moreover, transplanting plots were included to the experiment as control treatment. Analysis of variance showed that seeding date had significant effects on paddy yield but planting method and their interaction had no significant effect on paddy yield. Maximum paddy yield were recorded at the dates of 1 and 15 May (4414 and 4325 kg ha-1, respectively). Paddy yield was significantly reduced when seeding date delayed, as grain yield reduce by 41%, 43%, and 70% at the seeding dates of 22 and 29 May, and 5 June compared to the seeding date of 1 May. There was no significant difference in paddy yield between direct seeding (4295±215 kg ha-1) and transplanting (4414±184 kg ha-1) production systems. Moreover, seeding date and planting method had no significant effect on weed biomass. In general, result revealed that optimum paddy yield in direct seeding was recorded at the seeding date of 1 and15 May.

In this study, cloud formation and its seeding efficiency at room temperature have been envestigated by different particles such as ambient aerosols, salt, and smoke induced by burning match. In the first step, the effect of ambient aerosol concentration on the time of clearing cloud was considered. Since the aerosols concentration is almost constant during the day, there for it is accepted as base point for comparison of not-seeded and seeded condition for cloud formation and precipitation. The effect of aerosols concentration variation in different days also was considered. In the second step, the effect of salt and smoke injected as seeding nuclei to the chamber on the cloud clearing time was studied. The salt solution density was used with 20, 30 and 40 g/lit. The time of cloud clearing by the salt nuclei is less than ambient aerosols. The results showed, the more salt solution density, the less cloud clearing time. In most experiments with increasing smoke concentration the precipitation increased too and extraordinary amounts of smoke concentration rarely caused cloud to be overseed. The experimental results on nucleation efficiency showed that hygroscopic and giant salt particles are more efficient than smaller smoke particles but with respect to higher concentrations of smoke it is observed that the cloud has precipitated in shorter time by smoke nuclei. In fact, if it would be possible to make the experiments under the quantity control coditions, the cloud could be cleaned with salt nuclei in the shorter time.

Determination of affected area by seeding agents, the so-called target area, is an essential requirement for evaluation of cloud seeding projects. The most conservative and credible estimates of seeding effects were obtained from control matches drawn from outside the operational target within 2 hours of the time that each unit was seeded initially (DeFelice et al., 2014). A coupled modeling system consisting of the mesoscale WRF model and the Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT), provides capability to simulate the transportation and dispersion of seeding materials and to characterize target area on the map. This study is devoted to sensitivity analysis of simulated dispersion patterns to several parameters including different configuration based on physical parameterizations used in WRF model, horizontal and temporal resolution of WRF and spatial resolution of HYSPLIT, to determine the most probable dispersion patterns. Since temperature and wind parameters are the most important parameters in cloud seeding operations, they are measured instantaneously at 1-second intervals at the flight height of the airplane during each flight and therefore, they are very valuable data to assess the performance of the WRF model in simulating these fields. Hence, at first the WRF model outputs such as temperature and wind are validated by data measured by the airplane. Results indicate that there is an acceptable agreement between field data and WRF outputs that are going to be used as input data for dispersion model. In this study, eight configurations of the WRF model based on different physical parameterization schemes are used for 34 flights in cloud seeding project in 2015 and HYSPLIT model is run by these types of input data and resulting target area are compared on the map. Then, HYSPLIT model is run for four selected seeding operations according to three temporal and two horizontal resolutions of input data in addition to three spatial resolutions of HYSPLIT model and the transport of seeding plumes is characterized on the geographical map. The results indicate that dispersion model is sensitive to all mentioned parameters. Also, in most cases, dispersion model results at the flight height of cloud seeding aircraft are significantly influenced by the input data provided by the WRF model. In addition, the dispersion model results are less sensitive to other parameters. Furthermore, when the spatial resolution of the HYSPLIT model is close to the horizontal resolution of the input meteorological data provided by the WRF model, affected area of seeding agents is more integrated and therefore there is a greater degree of certainty in determining the target area.

This study examined suitable mechanized methods to seed rice in dry-bed conditions using dried seeds and determined the most suitable varieties for each method. The experimental design was strip-plots in a randomized complete block design with two factors (seeding methods and rice varieties) and three replications. The testing took place during 2003-2004 at the Shavour Agricultural Research Station in Khuzestan province. The rice varieties were Anboury, Champa and Danial (horizontal factors) and the seeding methods were use of grain drill (Barzagar Hamadan), row planter (hill drop planter) and centrifugal broadcaster (vertical factors). The rice varieties were evaluated based on total yield, yield components and other agronomic characteristics. Seeding machines were evaluated and compared based on field capacity, fuel consumption, inter-row and intra-row seed spacing uniformity and seed germination. The analysis of variance for the two years showed that the grain yield was significantly affected by year, variety and their interaction. The average yield of the second year was significantly greater than that of the first year. A maximum yield of 7246 kg/h and minimum yield of 5667 kg/h were recorded for Danial (LD183) and Champa, respectively. There was no significant difference between the average yields of the different seeding methods in both years. Seeding methods also had no significant effect on the agronomic characteristics of the rice varieties except for the number of panicles per m2. In this case, the grain drill with 329 and row planter with 289 panicles per m2 had the highest and lowest values, respectively. The evaluation of the seeding machines showed that there was a significant difference between the machines for all operational parameters. The centrifugal broadcaster had greater field capacity, low fuel consumption and better seed germination. In case of inter-row and intra-row seed spacing uniformity, the row planter had 68.8% inter-row uniformity and 89.7% intra-row uniformity, giving it the best seeding uniformity of the tested machines. Results indicate that the use of a row planter for dry seeding of rice is recommended because it used a less seed (20-25 kg/h) and had better seeding uniformity. However, considering farm conditions and available facilities, the centrifugal broadcaster and grain drill can be used for dry rice and direct seeding, respectively.

Introduction: Cloud seeding is one of the most known aspects of weather modification in most regions of world, that according to the World Meteorological Organization among all weather modification applications, most of operational projects were focused on the increase in rain. Determination of the area under effect of seeding materials, known as the target area during measuring its efficiency is one of the most challenges in applying the cloud seeding method. In the current method of determining the target area, in measuring the cloud seeding project in Iran, the seeding materials from shooting place is transferred in GIS environment for two hours using wind speed and direction output of WRF mode in wind direction. Considering the complexities and lack of present sureness in determination methods of target area, in this paper it was attempted to provide a new method in order to determine the target area using the martial distribution model.