زینب خلیلی

Natural disturbances caused by the canopy gap an important role in forest dynamics. Analyzing the dynamics of the canopy gap provides an accurate understanding of the process of forest stands dynamics as well as natural disturbances that play an important role in the future management of the forest ecosystem. The present study examines the dynamics of the canopy gap in the Arab Dagh forestry in Golestan province.

The identification and preparation of the gaps map was done by the basic object classification method. The classification of the basic object can be done in three general stages, which include segmentation, classification and evaluation of classification accuracy.In the next step, the 1345 canopy gap in 2011 and the 1058 canopy gap in 2019 were extracted from the method that had the best performance compared to other methods of preparing gap maps. The characteristics of the gaps were obtained at each time period. Also, with the intersection of these two maps, the dynamics of the gaps was analyzed by calculating the characteristics Gap formation rate, Gap closure rate, Gap expansion rate, Gap reduction rate, and Gap number increase rate.

The results of the canopy gap dynamics during the 9 years showed that the number and density of the canopy gap decreased. But the average area canopy gap and the share of the area of the canopy gap in the total area increased.In both periods, 65% of the canopy gap have an area of less than 150 m2, and a large canopy gap (larger than 300 m2) covered the lowest frequency and share of the total area of the canopy gap. The highest rate of changes in the canopy gap source was related to the Gap expansion rate (1.09% per year). The Gap closure rate is almost equal to the Gap reduction rate. The lowest rate of changes in the light is the Gap formation rate (0.77% per year). The logarithmic Gap number increase rate (GNIR) was negative (-2.6) that in all canopy gap classes, the number of closed canopy gaps per year is more than It is the number of new canopy gap that is created.

With the passage of 9 years, the density of gaps and the number of gaps have decreased and the total surface of gaps has increased. This increase in the total level of gap can be attributed to the increase in the Gap expansion during the period. Because the Gap expansion rate is higher than the Gap formation rate, the Gap closure rate and Gap reduction rate.In both periods of time, the most abundant size was related to small holes. which indicates the predominance of small lights in the studied area. which shows the predominance of small gaps in the studied area, small gaps make up most of the dynamics of gaps and close faster than big gaps.Keywords: Gap, UAV, dynamic indicators, coniferous forestry, remote sensingps.

Forest canopy gaps play an important role in forest dynamics. Unmanned aerial vehicle (UAV) data provide demonstrated capacity to systematically and accurately detect and map canopy gaps and have been considered as an alternative way to describe the forest stands. This study aims to extract canopy gaps using UAV data and compare the performance of different canopy gap extraction methods in a part of the replanted forest in the Arab Dagh Region, Golestan Province, Iran.

After the acquisition of UAV images and initial preprocessing, the digital terrain model (DTM), digital surface model (DSM), Canopy height model (CHM), and orthophoto mosaic were produced. CHM classification performs to extract forest gaps by different methods of height thresholding on CHM, CHM slope thresholding, and object-based classification. For performance evaluation of used methods and accuracy assessment of the canopy gap maps, the central position and boundary of some gaps were measured by DGPS. Finally, the point and polygon base accuracy of delineated gaps were assessed for each of the methods..

The results of the point accuracy assessment showed that the canopy gap map obtained by object-based classification method with applying the support vector machine (SVM) algorithm with 99% overall accuracy and 0.98 kappa coefficient had the best performance compared to other algorithms and methods. About area accuracy assessment, the best match between delineated gaps and ground truth polygons was achieved by using 3 m height thresholding.

The results showed that with aerial images of the UAV and its outputs, as well as the use of automated methods, the map of the canopy gap can be accurately extracted. Of course, the degree of accuracy depends on several factors such as the type of drone and cameras used, flight parameters and so on. Given the results, it is hoped that this approach will gradually be used as a cheap and accurate method in forest surveying.

Due to the importance of the forest park, it is necessary to evaluate the nature of tourism and identify potential areas for nature tourism in them. In this research, Saman Ghoori Ghale basin, located in the northwest of Paveh city with an area of ​​2498/46 was selected to evaluate the potential of nature tourism based on the principles of land management and GIS. After conducting basic studies and preparing thematic maps of the area (slope, direction, altitude, vegetation and soil), digitization, analysis and summarizing and superimposing the layers in GIS environment, finally an environmental map of the area was produced. The results showed that according to this model, almost all areas can be used for nature tourism. SWOT model was used to develop nature tourism in the region. Using field studies, a list of strengths, weaknesses, opportunities and threats of the region was prepared within the dimensions of nature tourism development. The results showed that 27 strengths and opportunities can be identified as advantages and 31 weaknesses and threats as limitations and bottlenecks for the development of nature tourism in the study area. In order to determine the priorities of these factors, 335 questionnaire were distributed among tourists and officers. These results indicate that the threshold of vulnerability in the region in terms of nature development is very high and needs to be reviewed and appropriate policies to address the limitations and use of comparative advantages. Appropriate features were provided.

This research was conducted to compare the water quality of the major rivers of Azna city in Lorestan province. For this purpose information on the chemical parameters of the 4 rivers of Kamandan, Marbareh, Darehtakht and ChamZaman was prepared in the April of years 2001, 2006, 2012, 2016 and 2017. For compare the water quality of these rivers for drinking, farming and determining the water type, Shouler, Wilcox and Piper charts were drawn. Samples are within the range of WHO and ISIRI. Calcium has the highest amount of cation and The highest amount of anion is bicarbonate. The amount of SAR increased in rivers from years 2012 to 2016; Altogether, the Kamanan River in year 2017 has been of the best quality for farming and drinking. The quality of rivers in the city is good and in different years the important quality elements of rivers are in the standard of Iran and the world. The results of the Piper diagram show that the water type of the studied stations is calcium-bicarbonate and magnesium-bicarbonate. According to Schuler and Wilcox Diagrams, it can be concluded that overall the rivers have good quality for drinking and are suitable and slightly saline for agriculture.

Melatonin is a hormone secreted from the pineal gland and plays an important role in regulating the brain functions. This hormone with antioxidant activity supports the body against internal and external damaging factors. Melatonin reduces the production of free radicals by preserving mitochondrial homeostasis, and contributes to ATP synthesis in mitochondria. Reduction of melatonin by aging is one of the hypotheses suggested to be implicated in increase of the incidence of neurological disorders. Various factors play a role in the regulation and production of the melatonin. This hormone can act as a neuroprotective agent for some neurological disorders, such as Alzheimer's disease, Parkinson's disease, depression, and migraine. According to the positive effects on the nervous system, non-toxic properties following long-term application, and the absence of side effects, melatonin can be a suitable compound for treatment of some neurological disease.

  Breast cancer is one of the leading causes of cancer death in women. Variations in the BRCA1, BRCA2, CDH1, STK11 and TP53 genes increase the risk of developing breast cancer. In addition to specific genetic changes, environmental factors may influence an individual’s risk of developing breast cancer. Lead is one of the most dangerous chemicals in the air as well as many products, such as cosmetics. Therefore, this study aimed to evaluate BRCA1 gene mutations in 9 rats receiving different doses of lead in the lipstick, compared to the control group.   In this case-control study, 12 female Wistar rats with mean weight of 250 g were randomly divided into 4 groups of control (1) and the rats receiving low (2), average (3) and high doses (4) of lead in lipstick according to the measurements by the American  Food and Drug Administration. Groups 2, 3, and 4 received lead acetate in their drinking water for 2 months on a daily basis. Afterward, DNA from blood samples was extracted and the BRCA1 gene was amplified using polymerase chain reaction (PCR) method. All PCR products were sequenced to investigate the genomic changes. Ethics code: IR.UMZ.REC.1397.48 The results of the sequencing showed no nucleotide changes in the BRCA1 sequences in the experimental and control groups.

According to the results, none of the doses of lead in lipstick change the BRCA1 gene. There may have been changes in other parts of the gene that have not been investigated in this study. Moreover, it is also possible that the same amounts of lead in the long run cause changes in the gene sequence.

In this study the appropriate areas for tourism and ecotourism plans were identified Using GIS and the system analysis model. No class1 mass ecotourism existed in the study area. Twenty nine percent of the area has capability for class2 intensive ecotourism 38% for class1 extensive ecotourism and 33% for extensive ecotourism. Due to the fact that for the management and deployment of any facilities the views and needs of tourists also should be considered in addition to the natural potentials of the region, were considered. Therefore, the method of assessing the socio - economic Clawson to assess needs and recreational demands were used. In this study, a comprehensive questionnaire was used to collect information. Recreational demand assessment results showed that most people choose to walk places that are closer to water sources and its access is easy. In order to access to the so, water and road map was prepared. Therefore these factors as positive information layer was overlaid with maps can be obtained ecotourism and ecotourism map can be obtained final. These results show that the factor of water resources through access to physical factors have the greatest impact on the assessment process in the tourist suitability evaluation.