The range of soil water content where plant growth is least limited by water potential, soil aeration or mechanical resistance is called least limiting water range (LLWR). This study evaluated the values of LLWR determined according to the procedures proposed by da Silva et al. with those calculated on the basis of sunflower plant (Helianthus annuus L) response (LLWRP). In both methods LLWR is taken as the difference between the two soil moisture limits designated as upper (θ UL) and lower (θ LL). In the first method, the two limits are determined basically from the soil moisture and soil resistance characteristic curves, almost overlooking the plant type and its particular needs or behaviors. In the second method, as proposed in this research, the two limits are determined based on the stomatal response in a sandy clay loam soil packed into PVC tubes (called pots hereafter) with 30 cm diameter and 70 cm height at three compaction levels (soil bulk density equal to 1. 75, 1. 55 and 1. 35 Mg. m-3) designated as D1, D2 and D3. Each pot was planted with three pre-soaked sunflower seeds and pots were kept under optimum condition until onset of the flowering stage. At this time two successive drying cycles were imposed and soil moisture and midday stomatal conductance were routinely measured. LLWRP were computed on the basis of relationship between soil matric suction and stomatal conductance. Results showed that on the basis of stomatal conductance behavior water uptake began at the soil matric suctions of 44, 16, 60 and continued up to 17394, 31614, 39983 cm in D1, D2 and D3 treatments, respectively. Appreciable differences were observed between LLWR and LLWRP particularly when the lower limit moisture suction (equivalent to θ UL for LLWR) was set at 330 cm (LLWR330). LLWR330 values of 0. 148, 0. 147 and 0. 080 cm3cm-3 were obtained for D1, D2, D3 treatments, respectively, which were 51, 49 and 63 percent lower than the corresponding LLWRP values. This differences imply that the two moisture limits (θ UL and θ LL) proposed by da Silva et al. may not be applied indiscriminately for all plants and thus need to be modified according to plant needs or responses.

Scarcity of irrigation water and reduction of its quality are the most important reasons in reducing the growth and yield of agricultural products in arid and semi-arid regions. Optimization of the water use and proper management of saline water is a way to increase water use efficiency. In this research, sugar beet production function was obtained based on the amount and salinity of irrigation water. Then, the needed equations for determining the optimum irrigation water depth when the price of sugar beet is variable and dependant on its quality (sugar content rate) is determined. For salinity of 0 ds/m and based on current prices of water and crop, optimum amounts of water were 1. 87, 1. 77 and 1. 52 m to obtain the maximum yield and maximum profit under limited land and limited water conditions, respectively. The amount of water saving under water limiting conditions were 18. 7 %, respectively, and the cultivation area increased by 20%, respectively.

Plant growth and yield are influenced by many production parameters such as the amount of irrigation water, fertilization, plant density, etc. Due to the limitation of resources and agricultural inputs, increased production costs, food demand, population growth, and environmental problems, the development of scheduling approaches to use production parameters is necessary. In this study, firstly, crop yield and net benefit responses to variation of production parameters and secondly, economic-mathematical analysis of production parameters such as irrigation water were reviewed. Presented analyses in this study were categorized into four cases including 1) constant or variable crop price, 2) single, two, or multiple variables production functions, 3) limited land area and water or not limited, and 4) variable water price. The economic-mathematical analysis presented about deficit irrigation in this study was extended to determine the optimum value of other production parameters such as fertilizer rate, plant density, seed density, corm planting intensity, etc.

Water, oxygen, temperature, and mechanical resistance are the soil physical factors that can directly influence plant growth. Under favorable temperature not only sufficient water is available for the plant at the last limiting water range (LLWR), but also the other two factors are not limiting for the root activity. In order to study the corn single cross (Zea mays L.) response to the soil water content with reference to LLWR, a greenhouse experiment was conducted. Topsoil with clay loam texture was passed through 4.76-mm sieve, and transferred into PVC cylinders (diameter 15.2 cm and height 50 cm). The soil columns were compacted to achieve two levels of bulk densities (1.25 and 1.6 g cm-3). With three soil moisture levels (the LLWR range, less than its lower limit and greater than its upper limit), two compactions and three replications, 18 soil columns were prepared. Three corn seeds were planted in each column. After seedling emergence and thinning them to one plant per PVC pot, soil water treatments were applied at 5-leaves growth stage. Plant traits including plant height, leaf area, leaf relative water content and stomatal conductance were measured. The difference in these traits between the three soil water levels were significant (p<0.01). Increase in bulk density decreased LLWR (v/v) from 18% at 1.25 g cm-3 to 6% at 1.6 g cm-3. Mean values comparisons of the plant traits at both bulk densities showed that the soil water range defined by LLWR led to the highest values of the traits. Therefore, the thresholds values corresponding to air-filled porosity of 10%, permanent wilting point of 1.5 MPa suction and mechanical resistance of 2 MPa (as defined in the LLWR concept) were verified for the corn growth in the examined soil.

Purpose: To compare the anatomical and functional results of deep vitrectomy with and without ILM peeling for full thickness macular hole.Materials & Methods: 37 eyes of 37 patients with full thickness macular hole (FTMH), confirmed by clinical examination and optical coherence tomography (OCT), enrolled in this clinical trial. Based on the stage of FTMH (stage 2, 3, 4) as described by Gass and the techniques of surgery (with or without ILM peeling) the patients were randomized into two different groups. All patients underwent preoperative Act and at least one OCT image was obtained during the postoperative follow up.After obtaining informed consent, deep vitrectomy and 20% SF6 injection was performed. The patients were unaware of their allocation status. Patients data & surgical outcome were collected and statistically analyzed. Anatomical success was defined as hole closure at postoperative OCT and functional success was referred to any improvement in visual acuity. Macular hole index (MHI) was defined as a ratio of the greatest height to the base diameter of the hole on cross-sectional OCT images.Results: 37 eyes of 37 patients (15 men & 22 women) were enrolled. The mean age of the patients was 56.4±21.94 years and FTMH were traumatic in 13 cases (35%) and Idiopathic in 24 (65%) cases. Twenty cases underwent deep vitrectomy with ILM peeling (ILM group) and the remaining cases underwent vitrectomy without ILM peeling (no ILM group).The mean preoperative 10gMAR visual acuity was 1.38±1 in the ILM group and 1.22±0.13 in the no ILM group, these improved to 0.95±1 and 0.77±0.31 postoperatively in the ILM and no ILM group, respectively (P=0.871). The overall anatomical success rate was 64%. The hole was closed in 70% of ILM peeling and 47% in the no ILM group (Chi-square test, P=0.15). In anatomically successful cases the mean of postoperative VA was significantly improved (P=0.001).In traumatic subgroup, ILM peeling seems did not affect the anatomical (P=0.2) and visual Success rates (P=0.5). There was no significant differences in hole closure rates between the traumatic and idiopathic FTMH (P=0.968). Visual acuity significantly improved after operation In MHI ³ 0.5 group compared with the MHk 0.5 group. The stage of the hole did not affect the anatomical success rate (P=0.52) or visual acuity improvement (P=0.741). Macular hole index ³ 0.5 had a prognostic value for postoperative visual acuity improvement. The hole duration was not related to anatomical success rate but there is an inverse relation between duration of the symptoms and improvement in VA.Conclusion: Deep vitrectomy and SF6 injection was a safe & effective surgical technique for full thickness macular hole and peeling of the ILM seems did not affect the anatomical or functional success rates. The hole duration, stage and origin of the hole (traumatic or idiopathic) does not related to the anatomical success or visual acuity improvement. MHI  ³ 0.5 seems to be a prognostic factor for postoperative visual improvement but not for closure rate.

Introduction Soil salinity has a negative effect on physical, chemical and biological properties of soil. Salinity also affects the relationships between soil and plants, which in turn has a significant effect on plant growth. One of the solutions used to reduce the effects of salinity and improve the physical properties of the soil is application of organic and chemical conditioners. Organic matter as well as calcium improve the structure and physical condition of the soil. Conditioners in saline soils include soluble calcium salts such as gypsum (CaSO4. 2H2O), calcium chloride (CaCl2. 2H2O) and phosphogypsum (phosphorous gypsum), and acids such as sulfuric acid, sulfur, pyrite, Aluminum sulfate and sulfur lime (calcium polysulfide). Strategies aimed at evaluating and ameliorating the structural quality of soils should be developed to ensure the sustainable use of lands. The least limiting water range (LLWR) attempts to incorporate crop-limiting values of soil strength, aeration, and water supply to plant roots into one effective parameter (on the basis of soil water content). The LLWR can be a useful indicator of soil quality and soil physical constraints on crop production. Therefore, the objective of this research was to study the effects of organic and inorganic conditioners on some structural and hydraulic indices of saline sodic soils. Material and Methods In this study, the effect of two types of organic and chemical conditioners and the simultaneous application of them on modifying the physical properties of 5 saline soils around the lake of Urmia were investigated. Treatments included algae, salfit and algae+salfit. The soil samples were transferred to culture boxes (40 × 40 × 40) according to the bulk density of the sampling site. The soil samples were wetted and dried several times. Conditioners treatments including application of calcium and organic compounds. After reaching the field capacity, wheat seeds were sown and irrigated with water (electrical conductivity 0. 28 dS/m and pH= 7. 78). It should be noted that irrigation was done at intervals of 8 days. Two months after the beginning the experiment, irrigation was stopped and soil moisture was allowed to reach a permanent wilting point. At this stage, undisturbed soil samples were prepared from the treated soil of each box and the mean weight‐, diameter of dry (MWDdry) and wet (MWDwet) aggregates were measured. Then the values of least limiting water range in two suctions of 330 and 100 cm and water integral capacity of samples were measured. Results and Discussion According to the initial analysis, all soils used were saline and the amount of calcium carbonate was high in two soils (number 3 and 5). Soil organic carbon content was also low. The results of salfit analysis also showed that the dissolved calcium and sulfur content were 8 and 3. 9%, respectively. The results showed that soil 1 had the highest amount of MWDwet and soil 5 had the lowest amount of MWDwet. The highest and lowest aggregate stability values were obtained in soils 3 and 5, respectively, where soil 5 was very saline soil. The studied soils differed in terms of soil water relations. The highest amount of LLWR330 was found in soil 5, while the lowest amount of LLWR100 and IWC parameters was also obtained in same soil. The results of this study showed that salfit treatment caused the highest increase in aggregate stability (74. 9%) LLWR330 (14. 5%) and integral water capacity (26. 2%) compared to the control and the highest mean weight‐, diameter of aggregates in both wet and dry conditions was obtained in salfit-algae treatment (52. 4% and 40. 4% increase, respectively). The results of correlation analysis among the measured parameters showed that the highest correlation was found between aggregate stability and MWDwet. Among the measured parameters, aggregate stability had the highest correlation with other parameters and the correlation of this parameter with LLWR330, LLWR100, IWC and MWDwet were 0. 36, 55, 75 and 88 %, respectively. Soil water integral capacity also had a significant correlation (p < 0. 01) with LLWR330 (0. 84) and MWDwet (0. 7). Conclusion The effect of initial soil properties on studied parameters was significant and the use of conditioners improved studied parameters, and use of conditioners increased indices structural and hydraulic of saline soils. In general, the results of this study showed the positive effect of conditioners on physical properties of the studied soils, in which salfit and salfit-algae have a better effect on studied parameter, and they could be useful to improve soil physical condition. It seems that the application of different rates of conditioners as well as their interaction with each other should be considered according to the basic properties of the soil.

Several voting systems are utilized to allocate both political and non-political positions across countries worldwide. Plurality voting and approval voting are among the most widely implemented electoral systems. Established statistical methods are employedto ensure the accuracy of vote counting and the validation of election results. Two fundamental approaches that significantly enhance the likelihood of identifying errors in election outcomes are Risk-limiting audit (RLA) and Bayesian audit (BA). These audit methods assess the security of elections using statistical tools, based on the random selection of castvotes and their interpretation as evidence supporting or contradicting the reported results. In this paper, we first examine the advantages of a specific form of approval voting, referred to as score voting, and then describe two types of risk-limiting audits to evaluate the accuracy of vote counting and the results. The proposed auditing method for score voting is adapted from the Ballot-polling risk-limiting audits to verify outcomes (BRAVO). Simulation results confirm the effectiveness and accuracy of our approach.