Conversion of communal grazing land into arable land and its impacts on soil properties and vegetation cover     

Hiwet Gebremedhin  Girmay Gebresamual  Nigussie Abadi  Kassa Teka  Shimbahri Mesfin 《Arid Land Research and Management》2018,32(2):236-252

With rapid population growth and absence of agricultural intensification, smallholders need more land to grow crops. This resulted in communal grazing land conversion to cultivated land. This study, therefore, aimed at exploring the magnitude of communal grazing land conversion and its influence on soil properties and vegetation cover change. Ecological time line approach was used to measure the magnitude of change. Plants and soil samples were taken from open grazing land, seasonal grazing land, 6 years old cultivated land, 16 years old cultivated land and 20 years old cultivated land. Moreover, 95 respondents were selected to assess their perception on the subject. Data were analyzed using statistical analysis system software. Results showed that grazing land declined by 41.88%, while cultivated land increased by 56.80% in the years between 1992 and 2012. Plant attributes showed significant (P?P?相似文献   

Description of Soil Evolution in Southern Mashhad City Using Jenny's and Johnson and Watson-Stegner's Conceptual Models     

Alireza KARIMI  Isa ESFANDIARPOUR BORUJENI  Mohamad GHASEMZADEH GANJEHIE 《土壤圈》2018,28(4):656-665

Conceptual models are suitable for describing internal relationships of complex systems, including soil. We used conceptual models, the Jenny's and Johnson and Watson-Stegner's models to understand the formation and evolution of soil. We studied 20 pedons in granitic hilly lands, loessial piedmont, and piedmont plain in southern Mashhad, northeast Iran. These soils were characterized by high levels of gypsum, especially in the granitic saprolites, which suggested the importance of the wind in shaping the soil structure. Jenny's model is a developmental and equilibrium model, which only describes the state of the soil formation factors and considers that each bioclimatic zone has a specific climax soil. It focuses on the genesis of the surface soil and is not suitable for buried soils and paleosols. Johnson and Watson-Stegner's model describes soil as a product of progressive and regressive processes due to horizonation or haploidization. Progressive processes during the last interglacial cycle created a well-developed paleosol with an argillic horizon in all landforms, except the piedmont plain. Developmental soil up-building by aeolian addition led to gypsum enrichment of the granitic saprolite. Erosion decreased soil thickness and exposed the argillic horizon. The Last Glacial Maximum led to greater deposition of loess, covering the paleosol. Humidity was higher during the early Holocene than today, leading to the development of a Bk horizon. This horizon was preserved in the stable surfaces of granitic hilly land and in the loessial piedmont, but buried on the piedmont plain via the deposition of alluvial sediments. Jenny's model could be used for current soil formation factors, whereas Johnson and Watson-Stegner's model required morphological characteristics of pedons for interpretation.  相似文献   

Effect of interaction between salinity and nanoparticles (Fe2O3 and ZnO) on physiological parameters of Zea mays L.     

Alireza Fathi  Morteza Zahedi 《Journal of plant nutrition》2017,40(19):2745-2755

A pot experiment was conducted to evaluate the effects of zinc oxide (ZnO) and iron oxide (Fe₂O₃) nanoparticles on the growth of two maize cultivars under the saline condition. Salt stress induced decreases of shoot, root dry weight, leaf area and leaf gas exchange of S.C. 704 more than Bulk. The increase of salinity level, chlorophyll a, b and total chlorophyll content and iron (Fe) and zinc (Zn) concentrations under all spray treatments declined. Application of ZnO and Fe₂O₃ significantly enhanced the root growth (17%), net carbon dioxide (CO₂), assimilation rate (8%) and sub-stomatal CO₂ concentration (5%) of maize compared to control. Nanoparticles of Fe₂O₃ and ZnO caused an increase in leaf Fe (22%) and Zn (11%) concentrations, respectively, compared with normal forms. According to the results, although the alleviation effects of Zn and Fe have been demonstrated under stress conditions, nanoparticles were more effective than normal forms, which may be due to their shape, size, distribution and characteristics.  相似文献   

Use of IR thermography in screening wheat (Triticum aestivum L.) cultivars for salt tolerance     

Alireza Esmaeili  Hojat Ahmadi  Alireza Abbasi 《Archives of Agronomy and Soil Science》2017,63(2):161-170

Thermography is proposed to be an alternative non-destructive and rapid technique for the study and diagnosing of salt tolerance in plants. In a pot experiment, 30 cultivars of wheat (Triticum aestivum L.) were evaluated in terms of their leaf temperature and shoot growth and their ion distribution responses to NaCl salinity at two concentration levels: the control with electrical conductivity (EC) of 1 dS m^?1 and salinity treatment with EC of 16 dS m^?1 (150 mM). A completely randomized block design with factorial treatments was employed with three replications. The results indicated that thermography may accurately reflect the physiological status of salt-stressed wheat plants. The salt stress-based increase in leaf temperature of wheat cultivars grown at 150 mM NaCl reached 1.34°C compared to the control. According to the results obtained, it appears that thermography has the capability of discerning differences of salinity tolerance between the cultivars. Three salt-tolerant wheat cultivars, namely Roshan, Kharchia and Sholeh, had higher mean shoot dry matter (0.039 g plant^?1) and higher mean ratio of leaf K⁺/Na⁺ (14.06) and showed lower increase in the mean leaf temperature (0.37°C) by thermography compared to the control. This was while nine salt-sensitive cultivars, namely Kavir, Ghods, Atrak, Parsi, Bahar, Pishtaz, Falat, Gaspard and Tajan, had lower mean plant dry matter production (0.027 g plant^?1), lower mean ratio of K⁺/Na⁺ (9.49) and higher mean increases in leaf temperature (1.24°C).  相似文献   

Characterization of supported lipid bilayers incorporating the phosphoinositides phosphatidylinositol 4,5-biphosphate and phosphoinositol-3,4,5-triphosphate by complementary techniques     

Baumann MK  Amstad E  Mashaghi A  Textor M  Reimhult E 《Biointerphases》2010,5(4):114-119

Phosphoinositides are involved in a large number of processes in cells and it is very demanding to study individual protein-lipid interactions in vivo due to their rapid turnover and involvement in simultaneous events. Supported lipid bilayers (SLBs) containing controlled amounts of phosphoinositides provide a defined model system where important specific recognition events involving phosphoinositides can be systematically investigated using surface sensitive analytical techniques. The authors have demonstrated the formation and characterized the assembly kinetics of SLBs incorporating phosphatidylinositol 4,5-biphosphate (PIP(2); 1, 5, and 10 wt?%) and phosphoinositol-3,4,5-triphosphate (1 wt?%) using the quartz crystal microbalance with dissipation monitoring and fluorescence recovery after photobleaching. An increased fraction of phosphoinositides led to a higher barrier to liposome fusion, but full fluidity for the phosphatidylcholine lipids in the formed SLB. Significantly, the majority of phosphoinositides were shown to be immobile. X-ray photoelectron spectroscopy was used for the first time to verify that the PIP(2) fraction of lipids in the SLB scales linearly with the amount mixed in from stock solutions.  相似文献   

Improvement in wild endangered Persian sturgeon,Acipenser persicus (Borodin, 1897) semen cryopreservation by 2‐hydroxypropyl‐beta‐cyclodextrin (HβCD)          下载免费PDF全文

Ruhollah Rahimi  Hamid Farahmand  Alireza Mirvaghefi  Gholamreza Rafiee  Amirreza Abed Elmdoust 《Aquaculture Research》2015,46(10):2452-2456

In this study, cryopreservation feasibility of Persian sturgeon (Acipenser persicus) and the effect of different doses of 2‐hydroxypropyl‐beta‐cyclodextrin on thawed spermatozoa quality (motility duration and motility percentage) were investigated. For freezing, semen of seven male individuals was pooled in equal volumes and diluted with 4°C [Tris‐HCl (100 mM), pH = 8, DMSO 10%] extenders containing 0, 5, 10, 15 mM of HβCD in a ratio of 1:1(semen/extenders). Then semen was filled into 0.5‐mL straws, and was frozen with vapour of liquid nitrogen at 4‐cm above surface of liquid nitrogen. After 3 min, straws were plunged in to liquid nitrogen. Thawing was performed at 40°C water baths for 15 s. Motility duration of the 10 mM HβCD treated spermatozoa at days 14 (228.98 ± 16.39) and 56 (199.66 ±21.78) were longer than other treatments. In day 56, the motility percentage in treatment with 10 mM was significantly higher (16.14 ± 2.54) (P < 0.05) compared with 5 mM treatment (8.75 ± 2.47) (P < 0.05). Therefore, it is recommended that 10 mM of HβCD can be used as an additive cryoprotectant for increasing cryopreserved spermatozoa quality in this species.  相似文献   

Expression of Two Basic mRNA Biomarkers in Peripheral Blood of Patients with Non-Small Cell Lung Cancer Detected by Real-Time RT-PCR,Individually and Simultaneously     

Shirin Karimi  Abdolreza Mohamadnia  Seyed Alireza Nadji  Reza Yadegarazari  Adnan Khosravi  Naghmeh Bahrami  Massoud Saidijam 《Iranian Biomedical Journal》2015,19(1):17-22

Introduction: Although extensive research has been conducted on lung cancer markers, a singular clinically applicable marker has not been found yet. The objective of this study was to evaluate the sensitivity and the specificity of carcinoembryonic antigen (CEA) mRNA and lung-specific X protein (LUNX) mRNA biomarkers in peripheral blood to detect lung cancer individually and simultaneously. Methods: Thirty patients affected by lung cancer and 30 healthy individuals were studied in this research. Three vials of cDNA were made from each sample after taking peripheral blood samples and extracting total RNA. Each sample was examined by the real-time RT-PCR technique. The result from each vial was then compared with the sensitivity of overall marker. Results: The CEA mRNA was positive in 24 out of 30 lung cancer patients. Hence, its sensitivity was determined at 80%, differing significantly from that observed in healthy individuals, where 11 positive cases were seen. The overall sensitivity of this marker was significantly associated with positivity in vials 2 and 3 but not in vial 1. The LUNX mRNA was positive in 21 out of 30 patients, indicating 70% sensitivity. This finding significantly differed from that in healthy individuals. The overall sensitivity of this marker was significantly associated with positivity in vials 1 and 3, but not in vial 2. In 93.3% of the patients, at least one positive marker was observed. Conclusion: The mentioned mRNA could be suggested as sensitive and specific markers in peripheral blood for primary diagnosis of lung cancer.Key Words: Lung neoplasms, RNA, Carcinoembryonic antigen, Sensitivity and specificity  相似文献   

Protective Effect of Vitamin E against Diabetes-Induced Oxidized LDL and Aorta Cell Wall Proliferation in Rat     

Alireza Shirpoor  Leila Norouzi  Samira Nemati  Mohammad Hasan Khadem Ansari 《Iranian Biomedical Journal》2015,19(2):117-123

Background:

Hyperlipidemia and oxidized-low-density lipoproteins (Ox-LDL) are important independent cardiovascular risk factors that have been shown to stimulate vascular smooth muscle cell (VSMC) proliferation. The purpose of the present study was to investigate the effect of vitamin E on Ox-LDL, lipid profile, C-reactive protein (CRP), and VSMC proliferation of rat aorta.

Methods:

Male Wistar rats (n = 32) were divided into four groups namely: sham (SH), control (C), non-treated diabetic, and vitamin E-treated diabetic (VETD) groups. Ox-LDL, lipid profile, CRP and VSMC proliferation of aorta were measured after 42 days.

Results:

The results revealed that along with a significant increase in VSMC proliferation, the amount of CRP, Ox-LDL, and lipid profiles in diabetic rats. VSMC proliferation was significantly ameliorated, and elevated CRP, Ox-LDL, and lipid profiles were also restored to those of shams in VETD.

Conclusions:

These findings strongly support the idea that diabetes induces Ox-LDL-mediated oxidative stress and VSMC proliferation in aorta of rat and imply that vitamin E has a strong protective effect as an antioxidant. Key Words: Ox-LDL, Vitamin E, Diabetes, VSMC proliferation  相似文献   

Effect of dietary chitosan on growth performance,hematological parameters,intestinal histology and stress resistance of Caspian kutum (<Emphasis Type="Italic">Rutilus frisii kutum</Emphasis> Kamenskii, 1901) fingerlings     

Masume Kamali Najafabad  Mohammad Reza Imanpoor  Vahid Taghizadeh  Alireza Alishahi 《Fish physiology and biochemistry》2016,42(4):1063-1071

This study was conducted to investigate the effects of dietary chitosan on growth performance, hematological parameters, intestinal histology, stress resistance and body composition in the Caspian kutum (Rutilus frisii kutum, Kamenskii, 1901) fingerlings. Fish (1.7 ± 0.15 g) were fed diets containing chitosan at different levels (0, 0.25, 0.5, 1 and 2 g kg^?1 diet) for a period of 60 days. Results showed that the feed conversion ratio significantly decreased in fish fed diet containing 1 g kg^?1 of chitosan compared to the other groups (P < 0.05), but there were no significant differences between treatments in terms of specific growth rate and condition factor (P > 0.05). Leukocyte increased in fish fed diet containing 2 g kg^?1 of chitosan compared to the other groups (P < 0.05). Lymphocytes, eosinophils and neutrophils did not significantly change among dietary treatments (P > 0.05). Also, the chitosan supplementation did not affect the whole-fish body composition (P > 0.05). Light microscopy demonstrated that the intestinal villus length increased in fish fed diet containing 1 g kg^?1 of chitosan compared to control group (P < 0.05). While 11 and 13 ‰ salinity and 30 °C thermal stress had no effect, 1 g kg^?1 of chitosan (P < 0.05) showed highest survival rate (70 %) in 34 °C thermal stress. The results showed that chitosan in the diet of the Caspian kutum fingerlings could improve feed conversion ratio, the nonspecific defense mechanisms and resistance to some of the environmental stresses.  相似文献   

Siberian sturgeon (Acipenser baerii) larvae fed Artemia nauplii enriched with poly‐β‐hydroxybutyrate (PHB): effect on growth performance,body composition,digestive enzymes,gut microbial community,gut histology and stress tests          下载免费PDF全文

Ebrahim Hossein Najdegerami  Kartik Baruah  Alireza Shiri  Anamaria Rekecki  Wim Van den Broeck  Patrick Sorgeloos  Nico Boon  Peter Bossier  Peter De Schryver 《Aquaculture Research》2015,46(4):801-812

The effects of feeding Artemia nauplii enriched with or without poly‐β‐hydroxybutyrate (PHB) and/or highly unsaturated fatty acids (HUFA) on Siberian sturgeon (Acipenser baerii) larvae were investigated. Feeding larvae with PHB‐enriched nauplii (PHB, PHB + HUFA) decreased the growth performance of the larvae. PHB affected the body composition by increasing the lipid content of the whole body and decreasing total saturated, monoenoic, n3, n6 and decosahexanoeic acid (DHA) in the larvae, indicating that the PHB addition affected lipid metabolism. A high activity of pepsin was observed in the digestive extracts of PHB treatments (PHB, PHB + HUFA), while PHB suppressed amylase activity in the intestine of the larvae. Based on molecular analysis, PHB changed the microbial community in the distal intestine of the larvae. The highest counts of goblet cells were observed in the HUFA‐containing treatments (HUFA, PHB + HUFA), indicating that HUFA addition may improve the mucosal barrier defence system. The overall quality of the larvae was evaluated by exposing them to different salinities and ammonia stress levels. PHB decreased survival rates in these challenges. Our results show that optimal PHB doses for bio‐encapsulation into Artemia remain to be determined for further application at the earliest larval stages of sturgeon.  相似文献