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Showing 9 results for Sem

Manijeh Pakravan,
Volume 3, Issue 2 (9-2016)
Abstract

The pollen grains of 34 populations, representing 16 species of Consolida (DC.) Gray, have been examined by LM and SEM. The polar axis (P), equatorial diameter (E), P/E ratio and exine patterns were measured. The pollen grains were found out to be 3-zonocolpate, euprolate to subprolate. The shortest polar axis to belong to C. tehranica (Boiss.) Rech.f. and the longest to belong to C. trigonelloides (Boiss.) Munz (28.15-37.3 µm); the shortest equatorial axis to belong to C. stocksiana (Boiss.) Nevski. and the longest to C. orientalis Schrödinger (17.5-25.2 µm). Based on exine ornamentation observed under SEM, two types of pollen grains were recognized. Type I, exine distinctly thickened at poles with broad colpi and stronglymicro-echinate sculpturing, and type II, with exine obtuse at poles, narrow colpi and weekly micro-echinate sculpturing. Pictures of all species and characteristics of pollen grain structure were presented. Our results showed that pollen shape and sculpturing were diagnostic characters for distinguishing the species. Although they did not suffice enough to resolve taxonomic conflicts in the genus, our results confirmed embed of Aconitella in Consolida due to the occurrence of Aconitella species in two pollen groups.

                                                                                                                                                             


Behnaz Alijanpour, Masoud Sheidai,
Volume 4, Issue 2 (9-2017)
Abstract

The cosmopolitan genus salvia L. (Lamiaceae) consists of nearly 1000 species distributed throughout the Old and New Worlds. America and South- West of Asia are the two most important distribution centers. Of the 70 species reported in the flora Iranica area nearly 56 species belong to Iran. This investigation deals with the morphology of Salvia. The morphological studies were performed on 36 populations of 11 species which grow in Central Alborz Mo-untains. In this analysis 42 quality and quantity characters were used. The results of this analysis have been used for the preparation of the identification key. Clustering, cladistics and PCA ordination reveals the relationships of the species in this genus.
Maryam Abbasi, Nader Shabanipour,
Volume 5, Issue 4 (3-2019)
Abstract

In this study, the morphology and organization of the retina of Caspian kutum and fish response to ambient light as retinomotor reaction was investigated. The Rutilus frisii subsp. kutum is an anadromous fish and important native fish specimen of Caspian Sea. The specimens were obtained from Shahid Ansari Teleost Reproduction and Culture center (Guilan province, Iran). For light and dark adaptation fish were left in dark and light at least 30 minute prior to death. The eye retina were dissected out and processed for histological and SEM studies. The eye retina of Caspian kutum like most vertebrates, was composed of ten layers. Two types of photoreceptor cells including rod and short single cone were identified. Sagittal and transverse retinal sections did not show any particular patterns of cone arrangement. The retinomotor response observed in adapted retina to light and dark conditions revealed that Caspian kutum strongly reacts to changing light conditions. A remarkable pigment index indicated kutum relied mostly on rod rather than cone vision. The movement of pigment granules and slight change of cone myoid showed that the fish could recognize colors.


Fatemeh Rabizadeh, Hassan Zare-Maivan, Shahrokh Kazempour,
Volume 6, Issue 2 (8-2019)
Abstract

Astragalus semnanensis Bornm. & Rech. belongs to sect. Semnanensis, of thorny astragali and A. fridae, of non-thorny astragali, belongs to sect. Incani are the only endemic gypsophyllic species in western Semnan. The morphological and systematical studies available on these two species are scarce. Nor have the anatomical, distribution and adaptive capabilities in relation to soil and elevation of these species been investigated yet. Therefore, this study is aimed to comparatively investigate these features. The effect of soil and elevation on the anatomy, morphology and micro-morphology of the leaves of both species, as well as associated plant species, were analyzed using RDA and CCA analytical methods, Canoco 4.5 software. Comparison of RDA analysis of both species indicated that gypsum had the highest effect on the abundance of both species, while elevation had a strongly positive correlation with A. fridae and a negative correlation with A. semnanensis. Both species adsorb gypsum on their epidermis and part of the gypsum absorbed is accumulated in leaf parenchyma cells as calcium sulfate crystals. Adaptability of leaf surface is in the form of long and dense hairs which, in A. semnanensis, are longer and basifixed and, in A. fridae, thicker and medifixed. Increase in soil Ec and Na, K and Mg content and content of CaCO3 reduce both species abundances. Species such as Acantholimon cymosum and Prunus lycioides were found to be associated with A. semnanensis and species such as Moltkia gypsaceae and Euphorbia gypsicola with A. fridae.
 


Hernán Cucho, Yolvi López, Carina Caldeira, Anthony Valverde, César Ordóñez, Carles Soler,
Volume 6, Issue 3 (10-2019)
Abstract

Sperm morphometry is a part of the semen analysis based on CASA technology and has shown a big role in the prediction of male fertility. This analysis implies the use of stain techniques, although it has been shown that staining can make dramatic changes in the cell morphometry in different species. The aim of the present work was to evaluate the differences in sperm morphometry in Alpaca, introduced by the use of different stain techniques. Single ejaculates from five adult alpacas were used. Samples were recovered by deferent duct deviation surgery technique. Three stain techniques (i.e. Hemacolor, Harri’s Henatoxylin and Diff-Quik) were evaluated. Morphometric analysis was done using ISAS® v1 CASA-Morph system, at 100x bright field objective magnification and a digital video camera with a final resolution of 0.08 µm/pixel. Almost 200 randomly selected cells were automatically analysed per sample and stain technique, considering several sperm-head and midpiece parameters regarding size and shape. Almost all of the parameters showed different levels of difference among the employed techniques. In general, the largest cell heads were the ones stained with Harri’s Hematoxylin and the smallest ones were the ones stained with Diff-Quik. The discriminant parameters used to differentiate between animals better were the head width, area and acrosome percentage. In conclusion, like in other species, alpaca sperm morphometry results were found to be sensitive to the applied stain technique. This implies the necessity of referring clearly the stain technique used in each case to perform comparisons between different works on the same species. None of the employed techniques was superior to the others. In addition, the method used to obtain the samples showed its usefulness and simplicity for repeated samplings.
 
 
 


Zeinab Ghaedi, Reyhaneh Saberipirouz, Elham Ebrahimi, Sahar Badri, Faraham Ahmadzadeh,
Volume 7, Issue 2 (7-2020)
Abstract

There are different methods to investigate the effects of climatic fluctuations on the biota, two of which, molecular phylogeography and SDM, are the most useful tools to trace the past climate induced modifications on species’ geographic distributions. In this study, seven samples were collected from the species distribution range in Iran for the purpose of measuring the genetic variation within the Iranian spiny-tailed lizards, using cytochrome b. SDM was carried out by 41 presence points and bioclimatic variables for the present and future climatic conditions (by the year 2050), employing the statistical package ‘sdm’ in order to implement the ensemble model. The results of genetic analyses revealed that the specimens from Bastak in Hormozgan Province are distinguishable from all other specimens. Haplotype diversity was calculated as 0.8. The haplotype network illustrated that the central haplotype is located in the central Iranian Plateau. Moreover, the ensemble model predicted that, while the suitable habitats of this species were found to be in the south of Iran and the Iranian Central Plateau in the present climatic conditions, there will be a decrease in the extent of these patches and Baluchistan will be added as a suitable habitat in 2050. Generally, both genetic studies and modeling predictions suggested that the western and southern specimens (Bastak in Hormozgan) were divided according to the separation of their habitats. In addition, based on modeling scenarios in the future, the optimal habitat for the species is located in the central haplotype area.
 
 
Elham Ebrahimi, Faraham Ahmadzadeh,
Volume 9, Issue 1 (3-2022)
Abstract

Climate change is currently considered a serious threat for many species and recognized as one of the most important factors in the global biodiversity loss. Among animal groups, amphibians are known to be among the most sensitive groups of vertebrates to climate change due to their inability to travel long distances, and mountain habitat species are more exposed to climate change pressures than other species. Therefore, in this study, the current distribution potential of five species of amphibians living in the Zagros Mountains was assesed and their response to climate change in 2070 was predicted. To do so, a group approach for modeling the distribution of species (SDMs) was utilized to estimate the risks of losing the desired habitat potential in the event of climate change. Also, to estimate the desired habitat area in the context of climate change, calculations related to habitat area changes for each species were performed. Predictions showed that two out of five species studied, i.e., Azarbaijan Mountain Newt (Neurergus crocatus) and Yellow Spotted Newt (Neurergus derjugini) negatively reaction to climate change and their distribution range was predicted to be decreased and contracted. Habitat displacement behavior in the face of new changes is predictable for two species, i.e., Lorestan Toad (Bufotes luristanicus) and Fire Salamander (Salamandra infraimmaculata semenovi). Considering the speed of climate change in the Zagros Mountains, the present study is a step towards identifying the dynamics of habitat changes affecting amphibians of Zasgros region to cope with the impacts of climate change.

 
Asghar Zamani,
Volume 9, Issue 3 (12-2022)
Abstract

The seed micromorphological characters of 15 taxa of Iranian Pyrus comprising 22 individuals were examined by Scanning Electron Microscopy (SEM) and Digital Microscopy (DM) for the first time in this survey. For the assessment of probable ecological effects, several individuals of some widespread species were studied. After collecting several samples of each wild taxa of Pyrus from different localities in a ten-year period, the specimens were identified by means of the examination of type specimens and different Floras. After the examination of the seeds surface, qualitative (e.g., shape and ornamentation of seeds including areolate, foveate, reticulate, colliculate, striate and undulate types) and quantitative characters (e.g., size of seeds, size of surface cells and thickness of cell walls) were assessed. Statistical analyses were performed on the data using SPSS software. According to these observations, seed morphological characters showed to have a considerable variation even among the different individuals of the same species, verifying complexity of the genus as revealed by the different approaches which were previously reported. However, some descriptive characters of seeds such as shape, size, surface ornamentation type, cell size and cell wall thickness are presented for the first time for the genus.

 
Mostafa Hosseinpour, Mohammad Mohammadi, Gholam Reza Ghezelbash,
Volume 10, Issue 3 (12-2023)
Abstract

Biological cementation is a new process in which urea hydrolysis bacteria or free urease enzyme decompose urea and increases the pH of the environment and chemical interactions in the presence of calcium ions to form calcite. Nowadays, nano-calcite is widely used in engineering, such as increasing the strength of soil and concrete, as well as in medicine, such as drug delivery and cancer treatment. This study aimed to investigate the laboratory conditions for producing nano-calcite particles with appropriate quality, size and purity by Sporosarcina pasteurii enzyme extract for use in medical and engineering studies. This investigation aimed to make calcite by S. pasteurii enzyme extract and optimize influential factors in calcite production. For this purpose, the bacterium S. pasteurii was cultured in nutrient broth containing urea and nickel, and upon reaching the appropriate time, the cells were separated and washed. Then, their enzyme extract was prepared by sonication, and calcite precipitation was studied in different amounts of urea, calcium chloride, enzyme and temperature. The quality of produced calcite crystals and their ratio compared to other crystals were investigated by XRD and SEM analyses. According to the results of XRD analysis, it was found that in 0.5 M urea and 0.25 M calcium chloride, the highest amount of calcite is produced with 96%, and the least side products are produced. Examining the particle size histogram in the sample containing 0.5 M urea and 0.25 M calcium chloride revealed that the range of particles were between 50 and 100 nm. The nature and type of crystals were studied by electron microscopy, and EDX analysis showed the presence of calcium, oxygen, and carbon. According to the results, it was found that by the increase of the concentrations of urea and calcium, the range of particle size became larger. Also, the percentage of calcite produced in low urea and calcium chloride concentrations is higher than those in high concentrations.


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