Comparison of five distance sampling methods for estimating quantitative characteristics of Zagros Forests

Distance sampling methods are extensively used for forests management of Zagros region of Iran. In the present study, estimation of quantitative characteristics of sampling methods, including individual, nearest neighbor, second nearest neighbor, compound and joint point, were studied and compared. The individual sampling method was examined, using the estimators of Morisita, Byth & Ripley and Cottam et al. and the nearest neighbor method was assessed, using the estimators of Byth & Ripley and two predictors of Cottam & Curtis1 and Cottam & Curtis2. Location of total trees and shrubs of a 53 hectare forest stand at Ardal city of Chaharmahal and Bakhtiari Province was recorded. Having the actual trees density and canopy cover percentage, as well as their estimated values, the bias of each replication was obtained. Difference between the bias and the actual values (for bias test) by one-sample t-test method and analysis of variance by Games Howell test, were studied. The results showed that the differences between the distance sampling methods in respect to mean trees density per hectare were significant, except for the nearest neighbor method, using the Cottam & Curtis1 estimator, which was not significant, whereas in respect to mean canopy cover percentage, the differences were significant, except for the second-nearest neighbor and the combined methods. According to the results of this study, it is suggested to use the Cottam & Curtis1 method for estimating the density and to use the compound sampling and the second nearest neighbor methods for estimating the canopy cover percentage

Estimation of fruit production of Cornelian cherry (Cornus mas L.) and Hazelnut (Corylus avellana L.) in Arasbaran forests

Importance of Non-Wood Forest Products (NWFPs) in providing food, medicine, hygienic and industrial materials has caused to harvesting of more amount of them annually. These products are entered in the local, national, and international markets and therefore, the local people gain high income through selling them. Therefore, identifying and measuring of NWFPs is one of research priorities in Iran. This study was carried out to collect necessary data for estimation the amount of produced fruit of two important species in Arasbaran forests: Cornelian cherry (Cornus mas) and Hazelnut (Corylus avellana) for economic studies. Transect sampling was used to estimate the annual products of the fruits. A number of trees were selected in systematic random manner. Characteristics such as weight of fruit, crown height, crown diameter and, the number of sprout at each tree were measured to investigate on correlation between these characteristics and the relations among them. In the next step, suitable model was fitted in order to estimate the amount of fruit production. PROC CORR and GLM of SAS 9.1 software were used for statistical analysis. Finally, the fruit amounts of cornelian cherry and hazelnut were estimated as 914 kg and 395 kg per hectare, respectively

Curcumin in Liver Diseases: A Systematic Review of the Cellular Mechanisms of Oxidative Stress and Clinical Perspective

Oxidative stress has been considered a key causing factor of liver damage induced by a variety of agents, including alcohol, drugs, viral infections, environmental pollutants and dietary components, which in turn results in progression of liver injury, non-alcoholic steatohepatitis, non-alcoholic liver disease, liver fibrosis and cirrhosis. During the past 30 years and even after the major progress in the liver disease management, millions of people worldwide still suffer from an acute or chronic liver condition. Curcumin is one of the most commonly used indigenous molecules endowed by various shielding functionalities that protects the liver. The aim of the present study is to comprehensively review pharmacological effects and molecular mechanisms, as well as clinical evidence, of curcumin as a lead compound in the prevention and treatment of oxidative associated liver diseases. For this purpose, electronic databases including “Scopus,” “PubMed,” “Science Direct” and “Cochrane library” were extensively searched with the keywords “curcumin or curcuminoids” and “hepatoprotective or hepatotoxicity or liver” along with “oxidative or oxidant.” Results showed that curcumin exerts remarkable protective and therapeutic effects of oxidative associated liver diseases through various cellular and molecular mechanisms. Those mechanisms include suppressing the proinflammatory cytokines, lipid perodixation products, PI3K/Akt and hepatic stellate cells activation, as well as ameliorating cellular responses to oxidative stress such as the expression of Nrf2, SOD, CAT, GSH, GPx and GR. Taking together, curcumin itself acts as a free radical scavenger over the activity of different kinds of ROS via its phenolic, β-diketone and methoxy group. Further clinical studies are still needed in order to recognize the structure-activity relationships and molecular mechanisms of curcumin in oxidative associated liver diseases