1. IntroductionDefining and measuring drought is a difficult concept. Perhaps the most general definition of drought refers to "a specific period of abnormal rainfall in a specific area", in other words, a drought occurs when a significant water shortage is widespread in time and space. But there has long been disagreement over the details. Disputes about the concept of drought and the uncertainty of measuring its characteristics can be an obstacle to research and planning related to drought. This shows that the qualitative and quantitative analysis of drought is a challenging issue. Although several studies have been conducted in connection with the evaluation of drought indices around the world, the somewhat forgotten point in past studies is that drought indices sometimes do not provide the same results in estimating and quantifying the severity of drought. Using the estimates obtained from multiple indicators as input for other similar studies, evaluating and managing the vulnerability and risk caused by this hazard, which is of great interest, and using its results in planning and even allocating budget and insurance coverage, doubles the importance of the issue. Therefore, the present research, focusing on meteorological drought indicators as a basic drought monitoring indicator that requires limited variables (rainfall, and in some cases temperature) but is effective in other types of drought, tries to provide a general presentation (introduction, calculation details, required data) of the main meteorological drought indicators, to address the difference in estimation and quantification of the drought index.2. MethodologyTo evaluate the severity of drought for the period of 1979-2021, precipitation and temperature were used as their main variables on a daily and monthly scale according to the input of the indicators. The studied indicators were carried out in the selected year 2016-2017 when different regions of Iran were affected by drought and wet. It should be noted that the beginning of the annual period is considered from September. After developing the database, the drought indicators studied in the research were used to calculate the severity of the drought on an annual scale. Meteorological drought indices were classified into two categories of drought indices. In the last step, the drought hazard index was calculated, which expresses the severity of the drought event and is used as the first step to calculate the vulnerability and drought hazard index.3. Results and DiscussionThe 12-month SPI drought intensity values are lower than the results of RAI, DI, and ZSI indices, which is a significant point that is considered one of the disadvantages of this index. The estimation results of the ZSI index are almost equal to the RAI index, and the results of the CZI index are almost the same as the 12-month SPI index. The results of the EDI index showed that although this index can show the severity to some extent, it underestimates the severity of the annual drought events. In addition, this index has not exactly corresponded to the actual conditions caused by the drought. But this index is used to identify the length of the period and the start and end of the drought. which is a great advantage for this index. The spatial distribution of the RDI index estimate shows that half of Iran’s area had normal conditions in the year under review. In terms of space pattern, it is similar to the CZI index. The estimation of the SPEI index, similar to SPI and EDI indices, has not estimated the end of extreme conditions (very severe drought and wets).Among the indicators, the coverage percentage of drought severity in the ZSI, CZI, and RAI indices are almost closer to each other. While the intensity of the EDI index is different from other indices. According to the amount of internal standard deviation, it seems that RAI, DI, and ZSI indices had a more appropriate estimation of drought conditions. In addition to the mentioned cases, the comparison between the intensities of the investigated indicators also showed that the differences in normal conditions, droughts, and wets weak are greater and as the intensity increases, this difference decreases. The results of the drought hazard index resulting from the drought indices have had significant differences from each other.4. ConclusionAccording to the obtained results, it can be said that although the results of the three indices RAI, DI, and ZSI are closer to each other, the drought indices used (RAI, DI, SPI, PNPI, ZSI, CZI, EDI, RDI, SPEI) in the selected year, the drought intensities have been estimated differently. The difference in drought intensities was more in normal conditions, wet, and weak droughts. The standard deviation of the ranges of negative intensities of the index (drought) is more than that of drought conditions. Calculating the severity of drought hazard (DHI) using the intensity results obtained from the indicators showed a significant and sometimes extreme difference in this estimate. Estimation of drought intensity is used in other important studies such as calculating vulnerability, loss, and risk caused by drought. These differences and as a result the difference in results can affect environmental planning and management and economic considerations such as budget allocation and insurance coverage. Therefore, it is very important to check the accuracy of drought intensities estimation using indicators. Although there have been studies aimed at achieving a suitable index, an index that is approved and accepted in the diverse geographical-climatic area of the Country has not been introduced, which shows the need for a more comprehensive study in this field.

The world is embroiled in a pandemic of a new coronavirus at the end of 2019 and early in 2020, with such a large scale that it has severely involved the political, economic, and social systems in most countries around the world. The scale of the crisis is so widespread that many experts believe that the post-corona world will be substantially different from the pre-corona world. In the face of this massive epidemic, how people perceive risk and how to risk is communicated, plays a central role in deciding and choosing people's behavior. Fighting with this emerging phenomenon requires mobilizing all the possibilities of society and helping all people in the field of empathy and altruism. In this article, we briefly review aspects of the important concept of risk perception and communication in this pervasive crisis.

Background: The Connective Tissue Growth Factor (CTGF) gene encoding an extracellular matrix (ECM)-associated protein and as a member of the CCN family of proteins plays a major role in fibrosis, inflammation and connective tissue remodeling in a variety of diseases including cancer. The CCN proteins are multifunctional and are involved in cell proliferation, adhesion and cell development during pathogenesis. The purpose of our study was to determine the expression level of CTGF mRNA in patients with colorectal cancer (CRC). Methods: paraffin embedded tissues from 122 patients with colorectal cancer and their matched normal colon tissues and 20 paraffin embedded normal tissues blocks from normal individual were collected from Taleghani and Shohada hospital in Tehran. The fold change of CTGF expression was analyzed by quantitative real time PCR method, using REST and Prism softwares. Also, LinReg PCR software was also used for the efficiency of primers. Results: We found that expression of CTGF gene in tumor tissue was significantly higher than in adjacent normal tissue (P<0. 0001, RQ>2). A Significant increase was also observed in the expression of this gene in right-sided colon cancer than left side. Conclusion: The findings indicated that the expression pattern of CTGF gene is significantly altered in the development of cancer from normal tissue. Thus, according to major role of CTGF gene in fibrosis, inflammation and connective tissue remodeling, it may be effective in various diseases process including cancer.

Iris contour is relevant to a number of clinical situations including primary angle-closure (pupillary block and plateau iris) and pigment dispersion syndrome. Since iris contour is known to be affected by various phenomena such as prevention of blinking, exercise and accomodation, a method is needed to quantify the shape of the iris and allow comparison among individuals or under different conditions (e.g. before and after accommodation).

In this paper, a novel risk-based, two-objective (technical and economical) optimal reactive power dispatch method in a wind-integrated power system is proposed which is more consistent with operational criteria.  The technical objective includes the minimization of the new voltage instability risk index. The economical objective includes cost minimization of reactive power generation and active power loss. The proposed voltage instability risk employs a hybrid possibilistic (Delphi-Fuzzy)-probabilistic approach that takes into consideration the operator’s experience, the wind speed and demand forecast uncertainties when quantifying the risk index. The decision variables are the reactive power resources of the system. To solve the problem, the modified multi-objective particle swarm optimization algorithm with sine and cosine acceleration coefficients is utilized. The method is implemented on the modified IEEE 30-bus system. The proposed method is compared with those in the previously published literature, and the results confirm that the proposed risk index is better at estimating the voltage instability risk of the system, especially in cases with severe impact and low probability. In addition, according to the simulation results compared to typical security-based planning, the proposed risk-based planning may increase the security and economy of the system due to better utilization of system resources.

In the past two decades caries risk prediction has been and important subject for investigators. Caries risk assessment is an effective method for the prediction of future caries. By CRA the high-risk groups are determined. Then the prevention programs in relation to high-risk groups, be perform. This article is the results of a research project which has been performed by the author in Tehran. 218 primary school children (7 years old) have participated in this study. They have been examined for caries risk factors in three stages: 1- By a questionnaire for personal and socio demographic information. 2- Bite wing radiography to diagnosis the incipient proximal caries. 3- Dental examination of the student. Results of the research showed 34 person (15.6%) were high-risk, 63 person were low-risk and 121 person (55.5%) were moderate risk. Some of the caries risk factor have been also evaluated.