The prevalent aphid pests of almond are Brachycaudus amygdalinus Schout. (Hom.: Aphididae) and B. helichrysi Kalt. In Chahar-Mahal va Bakhtiari province. SEASONAL VARIABILITY of B. amygdalinus and B. helichrysi was studied in Shahre-Kord during 2003 and 2004. Aphid stages were counted in 100 sample unites, (twigs with 5 centimeter lengths), in 10 trees. The results showed that gynoparous of the two species were observed on almond trees in mid October in Shahr-e kord. Overwintering eggs were produced by viviparous females and laid on twigs near the developmental and flowering buds. The eggs of these two species were in diapause stage in winter. The fundatrices, which were produced from overwintered eggs, were apeterous with robust appearance. Many numbers of fertilized overwintered eggs died during winter so that 4.1% and 0.4% of two species remained to establish colonies on almond trees in 2003 and 2004, respectively. The viviparous forms produced from fundatrices and developed rapidly in April and May and reached to a high density of 116 B. helichrysi on 5 centimeter twigs. B. helichrysi developed at lower temperature and produced higher population density in Shahr-e kord. B. amygdalinus migrated to Polygonum persicaria L., P. aviculare L., P. patulum M. B. and P. aridum but B. helichrysi had many foliage hosts in summer.

In recent years, the concentration of suspended particles in the atmosphere of Tehran has been increasing. Therefore, we see more polluted days in this city. This situation has had economic, health, welfare, social and negative effects. In this study, we want to investigate the SEASONAL changes in particle concentration, chemical composition and aerodynamic distribution in Tehran. Atmospheric matter sampling was performed in four seasons in 2020 to 2021. Sampling was performed by Andersen Cascade Impactor 8 stages. Also, in each period of sampling process, samples were prepared to study the physical and chemical properties by SEM method. The particle surfaces with magnifications of 5000x, 10000x, 20000x and 50000x were studied. The EDS method was used to study the chemical composition of particulate matters. The results show that the north and northwest of the region are affected by the prevailing wind and a large volume of particulate matter produced by fixed and moving pollutants move to these areas. The highest and lowest concentrations of total PM collected in Azadi square and Hakimiyeh were 162.11±16.5 µg/m3 and 139.21±12.22 µg/m3, respectively. Also, the distribution of particulate matter in the western and southern regions of the region was more towards coarse particles, while the distribution of particles in the eastern and northern regions was more towards smaller particles. Due to the geomorphological characteristics of the region, the production of particulate matter should be controlled and monitored by moving and fixed sources, to reduce the destructive effect of particles on the health of people living in the region.

Introduction: Air pollution, due to its harmful effects especially on human health, is one of the major problems of industrial cities and metropolises, including Tehran. Therefore, recognizing the atmospheric conditions that lead to the accumulation of the pollutants can help decision-maker organizations. Materials and methods: In this study, based on the intensity and persistency of the air pollution in the period of 1389-1397 and according to the season of its occurrence, 47 air pollution incidents in Tehran were identified and studied from synoptic perspective. Spatial (T-Mode) principal component analysis was applied to 500-hpa geopotential height data of these events to classify the synoptic patterns which make the city prone to intensification of pollution in different seasons. Results: The results indicate three different synoptic patterns leading to an increase in the potential of pollution of Tehran. In these patterns, the main pollutant is the airborne particulate matter (PM2. 5 and PM10). Accordingly, the first pattern with percentage frequency of 62% occurs in the fall and winter. In this pattern, the presence of Siberian high pressure, along with the mid-tropospheric ridge is obvious. Two other patterns are active in the late spring and summer (related to Indian monsoon in the southeast of Iran) and spring and autumn (related to dynamic low-pressure in Iraq and the west of Iran), respectively. Conclusion: Classifying of the data of polluted days during recent eight years for Tehran results in three synoptic patterns related to different seasons. This information can help better managing of urban activities.

Backgrownd: Studies in regions with SEASONAL climatic variations have revealed a correlation between human natural conception and birth rates. Holidays and other cultural activities probably have influence on conception, but the ambient temperature and emotional influences on the female hormones related to fertility may play an important part in the SEASONAL variation in conception. Objectives: The aim of study was to determine the relationship between the success rate of Assisted Reproductive Technique (ART) treatment cycles and temperature in different seasons. Materials and Methods: A retrospective study on all individuals undergoing assisted ART at our institution was performed during June 2000 to June 2001. The study population represented 258 IVF-ET cycles and 821 ICSI treatment cycles. Different variables were analyzed using X2 test.Results: In IVF treatment cycles, conception was more common from early spring (March to June).This decreased from spring, with the minimum in fall, 22% and 14%, respectably. A significant SEASONAL VARIABILITY in the number of eggs, embryo transferred and sperm motility was not demonstrated (p>0.05), but sperm count was significantly higher in spring than any other season (72+4 x106 and 52+7x106, respectively).Conclusion: The SEASONAL changes should be taken into account together with other factors when evaluating infertility data.

The aim of this research was to quantify the SEASONAL variations in rainfall interception (I) by individual ash trees (Fraxinus rotundifolia Mill.) during growing season (GS), and non-growing season (NGS) in Chitgar forest park located in the semiarid climate zone of Iran, near Tehran. From September 2012 to September 2013, gross rainfall (GR) and TF were collected through 6 and 12 rain-gauges, respectively, in an open area and under the tree crown. Rainfall interception was calculated as the difference between GR and TF. Fifty rainfall events were recorded and the cumulative GR was measured 156.0 mm. Over the study period, GS, NGS and I ranged 19.4%, 23.0%, and 16.2%, respectively. Significant positive correlations were observed between I and GR over the study period (r2= 0.780), GS (r2= 0.743), and NGS (r2= 0.903) (p<0.01). During the measurement period, GS, and NGS, the percentage of the relative interceptions (I: GR) % were estimated to be 46.6%, 49.3%, and 41.6%, respectively. T-test suggested that there were significant differences between the (I: GR) % values within GS and NGS (p<0.01). It is important to select species trees with lower I values for plantation, since they increase the higher amounts of net rainfall (NR) in semiarid and arid regions where water availability is a limiting factor for plantations growth. Transpiration as well as litter interception of selected trees should be also considered.

The Karnafully is one of the most important rivers due to its profound influence on water chemistry and sediment characteristics. The present study intended to assess the quality of water and sediment from intertidal zone of this river in respect to the pollution index. SEASONAL water and sediment samples were collected during four seasons (Monsoon, post-monsoon, winter, and pre-monsoon) of 2014. The result indicates that these investigated parameters ranged as water temperature (21.7-36oC), pH (8.0-8.7), salinity (2.4-8.8‰), total suspended solid (0.08-0.8 g/L), dissolve oxygen (0.00-4.52 mg/L), soil temperature (21.3-33oC), pH (5.0-6.8), sand (4.13-44.10%), silt (39.93-75.89%), clay (11.98-21.19%), soil organic matter (4.33-6.21%), organic carbon (2.5-3.6%), nitrite-nitrogen (0.69-3.97 mg/L), and phosphate-phosphorus (0.23-3.44 mg/L). Multivariate statistical analyses like post-hoc LSD test, Cluster Analysis (CA), and Principal Component analysis (PCA) brought out the spatial and temporal changing pattern of water chemistry and sediment characteristics with the effect of uprising pollution. CA ascertained the compatibility among different parameters and categorized the monitoring sites into highly and moderately polluted areas. Moreover, PCA brought out five primary components and highlighted the three dormant factors, enormously regulating the river water chemistry such as municipal waste, carbon based nitrogenous compound, and local geomorphological weathering process. This investigation provided an outline on deterioration of water and sediment quality by high anthropogenic impact and suggests national policy maker to take some initiatives for retaining the quality water and sediment properties.