فهرست مطالب سمیه بیات

The increasing population of the large cities has led to developing new constructions in areas around cities to create settlements for the overflow of the population.Such changes in the natural land cover not only disturb the heat balance, but also have negative effects on the landscape, energy efficiency, health and quality of human life. Therefore, it is important for urban planners and managers to be aware of the changes in land cover and land use, especially in metropolitan areas, during long-term periods of time, in order to evaluate and predict the problems caused by these changes. Multi-temporal remote sensing data are one the powerful tools fordetecting land use/cover changes due to the increasing urban growth and then, for updating the three dimensional city models.

In this paper, the impact of Mehr Pardis housing construction is investigated on the land use/cover changes. The proposed land use/ cover change detection strategy in this paper is a post-classification method based on performing object based image analysis procedure. For this reason, Landsat satellite images have been used in 17 years’ time interval, between 2002 and 2019. After performing initial image processing and image segmentation, the three object classes of residential buildings, vegetation, and soil were identified by the object based image analysis procedure. Then, post-classification change detection performed on the generated object based classification maps of both 2002 and 2019 epochs. For change detection in this research, while comparing and contrasting the classes of recognized objects in the classification maps, the results of revealing the changes in the environment, including determining the amount of increase in constructions, changes in the area of soil and vegetation It is obtained.

The produced change map and statistical analysis of the post-classification change detection results reveals that the soil object class is decreased for about 17% and built up areas are increased for about 184% in the 17 years’ time interval. Agricultural fields in this study area are mostly destructed due to the developments in constructing built up areas. The increasing amount of about 104% in vegetation covers relates to the trees and grasslands in new constructed built up areas. To evaluate the obtained results of changes detection in this research, the evaluation of classification maps was used. In this regard, the values of the overall accuracy and Kappa coefficient of the land cover/use classification map in 2002 were 98.41% and 0.86, respectively, and for 2019, 97.01% and 0.87, respectively. Using the capabilities of the object-based analysis method in this research, along with the 15-meter spatial accuracy of the Landsat images, made the classification maps have an acceptable accuracy.

Due to the fact that construction is associated with changing the ecosystem, the construction of housing units in Mehr Pardis has led to the destruction of the mountain environment in some areas and the loss of vegetation in other areas. It is illustrated in the produced land use/ cover change map between 2002 and 2019 that the constructions are rapidly increased in Pardis area and this causes the serious impacts on the environment.

The presence of toxicogenic fungi and the production of ochratoxin in flour are dangerous to human health. Therefore, identification of these fungi by molecular and precise methods is essential. The aim of this study was molecular identification of fungal species and investigation of ochratoxin A contamination in flours used in bakeries in Hamadan

In this descriptive-analytical study, 60 flour samples were collected from bakeries in Hamadan. At first, fungi were identified using phenotypic methods such as slide culture. Then, the genus and species of fungi were confirmed by PCR and sequencing of PCR products. ELISA method was used to detect ochratoxin A. Data were analyzed with GraphPad software version 6.

Of the 60 samples, 28 flour samples (46.66%) were free of fungal contamination and 32 flour samples (53.33%) were over fungal contamination (104 colonies/gr). Aspergillus and penicillium were the most abundant in samples. The prevalence of fungi in flour of Lavash bread, Sangak Bread, Barbari bread, Taftoon bread (Handmade), Taftoon bread (Machinal made), Stokbrood bread and Loaf bread were 50%, 46%, 35%, 31%, 26%, 18% and 11%, respectively. However, the highest levels of ochratoxin A were reported in flour of Lavash bread (3.98 ppb) and the lowest in Loaf bread (0.66 ppb). There was also a significant relationship between the fungal species and the amount of ochratoxin A production in flour of beards.

While phenotypic and genotypic methods did not show the same sensitivity, the presence of ochratoxin in the studied flours indicated the necessity of modification in wheat storage and bakery flours.

Soil contamination with heavy metals is one of the most serious problems in the agricultural environments. Due to excessive injudicious and unregulated use of agrochemicals such as pesticides, bactericides and fungicides, which contain Cu as an active component, contamination of agricultural soils with Cu is often occurred. In many plant species, excess copper (Cu) toxicity is an important disorder that limits uptake and accumulation of mineral nutrients. The root system of crops in contact with the roots of neighbor plants (crop or weed) has different characteristics in terms of heavy metals adsorption compared to the pure stand of crops. The position of the roots of heavy metal accumulator weeds may affect the absorption of such metals by adjacent crops in infected conditions. The heavy metal accumulator weeds by reducing or evacuating metals from the rhizosphere of the adjacent plants, cause the plants to be immune to the toxicity of metals. Biomass reduction is a dominant effect of copper toxicity in plants. Application of high copper doses (50 and 75 µM) in nutrient solution, decreased the dry weight of common bean plants in comparison with control. Contamination of soil can affect ecological interactions between plants such as the weed-crop competition. Positive plant-plant interactions are expected to be especially beneficial under high abiotic stresses and therefore, the facilitation effects could be enhanced by increasing stress intensity. Weeds possess the ability to accumulate heavy metal and nutrients, in comparison with crops. The role of nurse plants in facilitating plant community has been applied in severe conditions. Metal hyper-accumulator plants have a positive effect on co-occurring species in met al-rich soils. Redroot pigweed (Amaranthus retroflexus L.) is a serious weed, which affects common bean production. Amaranthus retroflexus and Amaranthus spinosus are known as metal accumulators. We hypothesized that in contaminated fields, the effects of heavy metals on crop growth may be modified by the presence of a metal accumulator weed such as redroot pigweed.

To investigate copper uptake and accumulation of mineral nutrients by common bean in association with redroot pigweed under excessive copper conditions, a factorial experiment based on a completely randomized design with four replications was carried out in a research greenhouse of Bu-Ali Sina University in 2016. Experimental factors were three Cu doses of 1 (control), 25 and 50µM CuSO4 and five replacement intercropping ratios of bean (B) and redroot pigweed (P) (1B: 0P, 0.75B: 0.25P, 0.5B: 0.5P, 0.25B: 0.75P, 0B:1P). The experiment was carried out in a hydroponic condition. 15 days after seedling establishment, the seedlings of both plants were transferred to the hydroponic conditions with a Hoagland solution, and Cu doses were applied in the Hoagland solution. 30 days after growing the plants in above condition, biomass dry weight and concentration of Cu, K, P and Mg in the leaves and roots of both plants as well as copper translocation factor were determined.

The results showed that under three doses of copper, the highest concentration of copper in bean was obtained in sole crops, and with increasing replacement intercropping ratios of pigweed, the copper concentration was decreased in bean. In pigweed, the highest concentration of copper was observed in 0.75B: 0.25P proportion. At 1µM CuSO4, potassium concentration in the roots and the leaves of bean in 0.25B: 0.75P proportion, was decreased by 7 percentage in comparison with that of the sole crops, and at 25 µM CuSO4, by 10 percentage and at 50 µM CuSO4, by 15 percentage were increased compared to the sole crops, respectively. At 25 µM CuSO4, phosphorus and magnesium concentration in the roots of bean in 0.25B: 0.75P proportion was increased by 17 and 18 percentage, and at 50 µM CuSO4, by 21 and 26 percentage, respectively in comparison with the sole crops, respectively. Association of pigweed to the bean, decreased Cu pollution in bean plants, which could be related to the balance of nutrient elements uptake by bean under excessive copper conditions. Under excessive copper conditions, the higher copper uptake by pigweed, improved the growth of bean.

The results of this study showed the facilitative effects of pigweed plant in decreasing the Cu toxicity stress effects to the bean and indicated that pigweed could be as a potential Cu accumulator to improve bean plant growth under the Cu stress. Here we showed that the presence of some heavy met al accumulator plants such as pigweed in common bean farms, might be a useful practice in contaminated soils. In addition, these facilitation effects of such weeds, emphasize ecological management of weeds rather than weed eradication.

Green toad (Bufotes variabilis) is the most successful species of the Bufonidae family distributed throughout Iran due to its high ecological tolerance.  In this study, the populations of this species in the northern and southern regions of Khuzestan province were studied with emphasis on microclimate differences and sea level elevation. The results showed that: sex ratio in Northern Province was in favor of females and in south in favor of males.  Results of multivariate analysis of variance confirmed the existence of sexual dimorphy in the species populations of both regions .Demographic separation between the northern and southern populations of both sexes was confirmed.Female populations were completely separated at Shush and Shavour stations, and at Shadegan and Khorramshahr stations, respectively.In the male population, Hamidieh and Shadegan stations had the least similarity and Shavour, Shadegan and Khorramshahr stations were the most similar. The number of chromosomes was 2n=22 in both regions and no polyploidy was observed.

Progress in nano-science and nanotechnology in the past decade has provided many opportunities to study the biological effects of nanoparticles, in particular their anti-bacterial effects. The aim of this study was to evaluate the antimicrobial properties of silver nanoparticles for the removal of Klebsiella pneumoniae isolated from industrial effluents.
In this experimental study, after sampling polluted industries, coliform and total coliform measurements of fecal industrial wastewater microbiology were performed by standard methods. The antimicrobial activity of silver nanoparticles on the bacteria (Klebsiella pneumoniae isolates and standard) was evaluated with the agar dilution method and broth dilution. One milliliter suspension containing bacteria at 1.5 × 108 CFU/mL was added to each sample followed by incubation at 37°C for 24 hours. After the mentioned period, the optical density at a wavelength of 600 nm was used to measure the concentration of bacteria. Next, 100 mL of each dilution was transferred to solid medium followed by incubation. The results were analyzed with SPSS 22 software.
Fecal and total coliform bacteria pollution of textile wastewater was approved, and Klebsiella pneumoniae (textile industry pollution index) were isolated. With increasing concentration, the antibacterial activity of silver nanoparticles increased while the number of colonies decreased. Although none of the concentrations were able to eliminate the bacteria, a non-significant decrease in the number of bacteria was observed.
The results of the study showed that the type of bacteria and concentrations of silver nanoparticles antimicrobial properties of silver nanoparticles are risk factors. Although the concentrations used were effective against bacteria yet they did not lead to complete elimination of bacteria Therefore potential impact of nanoparticles for use requires further research and economic factors and other factors should be considered in their application.

The effect of anti-transpiration substances on dry matter remobilization of maize cv. SC 500 under water stress, a split plot experiment in randomized complete block design with three replications was conducted in Hamedan during 2009 growing season. Three irrigation treatments including irrigation after 60, 90 and 120 mm evaporation and anti-transpiration substances including 0.5 mM salicylic acid (SA), 50 ppm paclobutrazol (PBZ) and control were considered as main- and sub-plots, respectively. The anti-transpiration substances were sprayed on plants at 6 and 8 leaf stages. Results showed that SA under irrigation after 90 mm evaporation increased 20.15% and 34.59% and under 120 mm evaporation increased 23.55% and 37.95% of the remobilization of dry matter from stem and leaf, respectively, compared with control treatment. PBZ treatment also increased 13.33% and 16.51% of the remobilization of dry matter from stem and 27.73% and 29.96% from leaf under 90 and 120 mm evaporation, respectively, compared with control. Furthermore, dry matter translocation efficiency and contribution significantly increased under both 90 and 120 mm evaporation than the control, but under 60 mm evaporation, SA treatment decreased and PBZ treatment increased the rate, efficiency and contribution of the remobilization of dry matter from stem, leaf and spathe. SA increased 15.84%, 20.82% and 29.74% of the grain yield under 60, 90 and 120 mm evaporation compared with control, respectively, but the highest grain yield (10267.36 kg.ha-1) was achieved by SA under the 60 mm evaporation. In contrast, PBZ under the 60 mm evaporation decreased and under the 90 and 120 mm evaporation increased grain yield (17.52% and 21.65%, respectively), compared to control. Therefore, the application of salicylic acid and paclobutrazol anti-transpiration substances are recommended for alleviating effects of water stress in maize plants.

In order to investigate the effect of growth regulators to mitigate impact of water stress on yield and yield components of maize, an experiment was carried out in research farm of Bu-Ali Sina university of Hamedan in field season 2009. The experiment al design was a split plot in completely randomized block design with three replications. The main factor included three irrigation intervals (7, 11 and 15 days interval) as the main plot and antitranspiration substances (salicylic acid (SA) and paclobutrazol (PBZ)) as the sub-plot. The results showed that the interaction between SA andwater regimes (7, 11 and 15 days interval) significantly increased grain yield by 13.69, 17.24, 22.93 percentage, the mean of seed weight by 10.24, 13.63, 16.79 percentage and biological yield by 13.36, 16.24, 18.84 percentage compared to untreated plants, respectively. The number of grains per row and the number of grains per ear significantly increased under SA treatment compared to untreated plants. The interaction between PBZ and 7 days interval significantly decreased grain yield and the mean of seed weight by 8.61, 8.65 percentage compared to untreated plants, respectively. The interaction between PBZ and 11 days interval significantly increased grain yield and the mean of seed weight by 14.92, 9.41 percentage compared to untreated plants, respectively. The interaction between PBZ and 15 days interval significantly increased grain yield and the mean of seed weight by 17.81, 12.96 percentage compared to untreated plant, respectively. The present investigation suggests that exogenous application of SA and PBZ may help reduce the adverse effects of drought in maize.

Growth and yield of maize is seriously restricted by water deficit. Salicylic acid (SA) and Paclobutrazol)PBZ) induces biotic and abiotic stress tolerance in crops. In order to evaluate effect of antitranspiration substances and water stress on growth, yield and yield components of maize (Zea mays L.) an experiment was conducted in 2009, Hamedan, Iran. The experiment was laid out in randomized complete block design with split plot arrangement. The plants were sprayed with the salicylic acid (0.5 mM) and paclobutrazol (50 ppm). The results showed that vegetative growth indices such as total dry weight, leaf area index and crop growth rate, was considerably affected by application of SA and PBZ under different irrigation regimes. Interaction between SA and 100, 70 and 40% of full irrigation significantly increased grain yield by15.85, 20.81, 29.74 percentage, weight of 1000 seeds by 11.40, 15.77, 20.17 percentage and biological yield by 15.41, 19.38, 23.19 percentage compared to untreated plants, respectively. Grain yield and 1000-grain weight significantly decreased under PBZ treatment by 8.60, 8.64 percentage compared to untreated plants under non-water stress. Grain yield and weight of 1000 seed displayed a significant increase in response to rate of the PBZ compared to untreated plants under low and high water stress. Exogenous SA application was advantageous under three irrigation levels, but exogenous PBZ application was advantageous only under stress conditions.

Sodium lactate has been regarded as an antimicrobial substance for the preservation of food. The antimicrobial effect of sodium lactate at 0, 2.5 and 4.5% concentrations combined with heat treatment at different temperatures on the survival of Salmonella Typhimurium RTCC 1370 inoculated in to lean ground beef was studied. Samples were subjected to heating by immersion in a water bath stabilized at 60, 65,70 and 75oC. Statistical analysis were performed by randomized design and Duncan`s Multiple Range Test. The results indicated that heating temperature had significant effect on the thermal reduction time (D value) of Salmonella typhimurium in ground lean meat (P<0.05). The effect of Sodium Lactate was not significant (P>0.05). Interaction of heating and Sodium Lactate was only significant at 70 and 75oC (P<0.05). The results of this study indicated that antimicrobial effect of sodium lactate on Salmonella typhimurium in ground lean meat is significant only when temprature is over70 oC.