Search

BackgroundNanoparticles have wide range of application while there are some reports regarding their probable effects on male reproductive system and spermatozoa.ObjectiveThe aim of this study was to evaluate the effect of different doses of silver nanoparticles (AgNPs) (70nm) on acrosome of rat spermatozoa and number of spermatogenic cells.Materials and methodsIn this experimental study, in experimental group, 32 male wistar rats (8 rats/group) received oral feeding AgNPs every 12 hr in one spermatogenesis period (48 days) by means of gavages in 25, 50 , 100 and 200 mg/kg concentration (experimental groups 1-4, respectively). The control group (8 rats) was treated on schedule with distilled water. Spermatozoa were stained by triple staining protocol for acrosome reaction. Histological evaluation on testis sections was performed using tissue processing and hematoxylin-eosin (H&E) staining.ResultsThere was significant difference between the control group and the experimental group 1 for acrosome reaction (11.00±0.00 and 24.25±3.68, respectively, p=0.01). There was only significant reduction in spermatogonia cells in experimental group 4. Experimental groups 2, 3 and 4 showed a significant reduction in the number of primary spermatocytes and spermatids as well as spermatozoa. But there were no significant differences between different groups for Sertoli cell number and seminiferous tubule diameter.ConclusionIt seems that Ag NPs have acute and significant effects on spermatogenesis and number of spermatogenic cells and also on acrosome reaction in sperm cells. More experimental investigations are necessary to elucidate better conclusion regarding the safety of nanoparticles on male reproduction system.

Background and Objectives: Natural disturbances caused by canopy gaps play a crucial role in forest dynamic processes and help preserve biodiversity, influence nutrient cycles, and maintain the complex structure of the forests. Analyzing the characteristics of canopy gaps is necessary to improve our understanding of temporal and spatial changes in the forest canopy and plays an important role in the future management of forest ecosystems. This study was conducted to analyze the canopy gap dynamics in plantation coniferous forests in Golestan province over a period of nine years using remote sensing data. Materials and Methods: UAV images were taken and processed in a part of plantation conifer masses of Arab Dagh in 2019. In addition, aerial digital camera images taken in 2013 from the Army's Geographical Organization were received and processed. In the first step, the identification and preparation of the canopy gaps map was done using the object-based classification method. To evaluate the correctness and accuracy of the maps, the centers and boundaries of several canopy gaps were taken using a differential global positioning device, and some were prepared on the orthomosaic image and CHM. In the second step, 1345 lights were extracted from the classified map of aerial digital camera images, and 1058 canopy gaps were extracted from the classified map of the UAV, which had the highest accuracy, and the characteristics of the canopy gaps were obtained at each time point. In the third step, by crossing the classified maps of aerial digital camera and drone images, which had the highest accuracy. The dynamics of the gaps were analyzed by calculating the characteristics of gap formation rate, gap closure rate, gap expansion rate, gap reduction rate, and gap number increase rate. Finally, to statistically analyze the data, first, their normality was checked using the Kolmogorov-Smirnov test in SAS 9.4 statistical software and then the paired t-test was used to compare the averages. Results: The results of the canopy gap dynamics during the 9 years showed that the number and density of the canopy gap decreased. However, the average area canopy gap and the share of the area of the canopy gap in the total area increased significantly. In both periods, 65% of the canopy gap had 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) and in all canopy gap classes, the number of closed canopy gaps per year is more than it is the number of new canopy gaps that are created. Conclusion: 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 significantly. This increase in the total level of the 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 closures rate, and the gap reduction rate. In both periods, 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. [ABSTRACT FROM AUTHOR]

Increased CO2 levels caused by human activities (e.g., fossil fuel consumption and deforestation) has become a major concern for climate change and caused environmental problems. Afforestation/reforestation can help mitigate CO2 emission in the atmosphere by sequestering atmospheric carbon (C) in tree biomass. Herein, the above- and below-ground C sequestration of two pioneer tree species, including Acer velutinum Bioss and Alnus glutinosa L plantation stands of 25 (A25) and 35 (A35) years old were studied. The mean annual growth of diameter at breast height (cm/year) was significantly higher in A35 than A25, while the mean growth of height (m/year) was significantly higher in A25. The total and mean annual growth of the tree biomass and C storage (root and trunk) was significantly higher in A35. The amount of soil C sequestration in A35 was also significantly higher than in A25. The above-ground C sequestration and the annual average of C sequestration of the trees were positively correlated with soil moisture, pH, nitrogen, and phosphorus. Our study illustrates the benefits of considering stand age in the growth and developmental patterns of forest ecosystems in estimating terrestrial C stocks. [ABSTRACT FROM AUTHOR]

Phytoremediation is an effective and affordable approach to extract or remove lead from contaminated soil. An understanding of the physiological responses of different species subjected to heavy metal contamination is necessary before considering their use for environmental clean-up. The objective of this study was to assess the effect of lead (Pb) on growth and nutrient uptake in three forest species native to Iran: Cappadocian maple (Acer cappadocicum), European ash (Fraxinus excelsior) and Oriental aborvitae (Platycladus orientalis). The capability of lead uptake in different organs was studied in oneyear- old potted seedlings grown in contaminated soils with Pb concentration ranging from 100 to 500 mg kg-1 for six months in a nursery. Several phytoextraction parameters such as translocation factor (TF), tolerance index (TI) and bioconcentration factor (BCF) were assessed to investigate the phytoremediation potential of these species. Increasing Pb application in the soil caused a gradual decrease in dry weight of leaf and shoot of all species, while the dry weight of root remains unaffected. However, such inhibition was less marked in the conifer (P. orientalis) compared to the two broad-leaf species. Phosphorus uptake of all species slightly declined in contaminated soils. Contrastingly, Pb application did not hinder nitrogen and potassium uptake in seedlings. Atomic absorption thermo electron analysis of Pb-treated plants showed an increasing Pb accumulation in all plant compartments, although the result was more evident in the tissues of P. orientalis. This species also showed the highest values for TF, TI and BCF, indicating this conifer species as a potential candidate for phytoremediation of lead-polluted soils in Iran. [ABSTRACT FROM AUTHOR]

Zagros forests are one of the vegetative regions which have been located in the west of Iran. The investigation of sustainable forest management in Zagros is one of the key issues which make us to consider the challenges concerned with the protection of forest resources and socioeconomic problems of local people. Demand for criteria evaluation and indicators for sustainable forest management from local to national level to conduct administrative affairs have been increased. The aim of the present study is to evaluate 7 criteria and 65 sustainable indicators which have been utilized in the Near East. Accordingly, a questionnaire, with its reliability confirmed by experts, was distributed among involved participants. The results indicated that the Cronbach’s alpha coefficient for the questionnaire was 0/729. Then, using DEMATEL model, the sustainability criteria were prioritized and the significant correlation among them determined. Likert scale was also utilized to rank all the indicators, and in terms of their relative weight they were compared with. The result indicated that the most significant criteria were legal, political, and institutional frameworks, and protective functions of forest criterion were the most influential factor. By analyzing the experts’ attitudes, reliance on natural regeneration indicator with the relative weight of 31/15% was the most significant criteria in the region. The existence of number of seed provenance with the relative weight of 9/17% was the least significant role. At the end, 27 verifiers, 25 threshold values, and the most significant indicators in this research were determined. [ABSTRACT FROM AUTHOR]

This study was conducted on Pilambara- Talesh area in the Guilan province (Nort of Iran). The present research have been carried out on suitable volume table for forest Plantations with Pinus taeda L. in Pilambara area which 220 trees were selected and felled from different diameter and height classes. Using different volume equations, suitable volume table were prepared based on diameter and diameter-height. The results in this study show that minimum RMSE was relevant to two variable volume models that measured about 0.0332. Moreover, the minimum amount of estimated error relevant to two variable volume table was -2/7% while this amount for one variable volume table measured about -8.01%. [ABSTRACT FROM AUTHOR]

Background: Cancer-related anemia (CRA) negatively influences cancer patients' survival, disease progression, treatment efficacy, and quality of life (QOL). Current treatments such as iron therapy, red cell transfusion, and erythropoietin-stimulating agents (ESAs) may cause severe adverse effects. Therefore, the development of long-lasting and curative therapies is urgently required., Objective: In this study, a cell and gene therapy strategy was developed for in vivo delivery of EPO cDNA by way of genetic engineering of human Wharton's jelly mesenchymal stem cells (hWJMSCs) to produce and secrete human EPO protein for extended periods after transplantation into the mice model of CRA., Methods: To evaluate CRA's treatment in cancer-free and cancerous conditions, first, a recombinant breast cancer cell line 4T1 which expressed herpes simplex virus type 1 thymidine kinase (HSV1-TK) by a lentiviral vector encoding HSV1-TK was developed and injected into mice. After three weeks, all mice developed metastatic breast cancer associated with acute anemia. Then, ganciclovir (GCV) was administered for ten days in half of the mice to clear cancer cells. Meanwhile, another lentiviral vector encoding EPO to transduce hWJMSCs was developed. Following implantation of rhWJMSCs-EPO in the second group of mice, peripheral blood samples were collected once a week for ten weeks from both groups., Results: Analysis of peripheral blood samples showed that plasma EPO, hemoglobin (Hb), and hematocrit (Hct) concentrations significantly increased and remained at therapeutic for >10 weeks in both treatment groups., Conclusion: Data indicated that rhWJMSCs-EPO increased the circulating level of EPO, Hb, and Hct in both mouse subject groups and improved the anemia of cancer in both cancer-free and cancerous mice., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)