O impacto dos distúrbios monetários na inflação e nos ciclos de negócios na economia iraniana

In this paper, we have investigated the effect of monetary disorders on inflation and business cycles in Iran’s economy during the period 1973 to 2012. Monetary disorders are defined by two indexes of monetary policy uncertainty and shock to liquidity growth. In the first step, the causal relationship of monetary policy uncertainty on real GDP fluctuations, employment fluctuations and inflation are estimated using Granger causality test. To this purpose, to follow Haghighat and Mohammad Gholipour Tapeh (2014), the conditional variance of liquidity growth extracted from models of GARCH family was applied as a substitute for monetary policy uncertainty. In the second stage, the reaction of economic growth, employment growth and inflation to the shock to liquidity growth are estimated using impulse response function technique derived from VAR model. The results indicate the existence of one-way Granger causality relation of monetary policy uncertainty in all three variables of real GDP fluctuations, employment fluctuations and inflation. Also, based on the results, impulse response function reduces the shock to liquidity growth as much as a standard deviation, real GDP growth and employment after a period and increases inflation. Accordingly, the hypothesis of the effect of monetary disorders on business cycles in Iran’s economy in the period of this research cannot be rejected.JEL classification: E23, E31, E32, E52En este documento, hemos investigado el efecto de los trastornos monetarios en la inflación y los ciclos económicos en la economía de Irán durante el período de 1973 a 2012. Los trastornos monetarios se definen por dos índices de incertidumbre de la política monetaria y el impacto del crecimiento de la liquidez. En el primer paso, la relación causal de la incertidumbre de la política monetaria sobre las fluctuaciones del PIB real, las fluctuaciones del empleo y la inflación se estiman mediante la prueba de causalidad de Granger. Para este propósito, siguiendo a Haghighat y Mohammad Gholipour Tapeh (2014), se aplicó la varianza condicional del crecimiento de la liquidez extraída de los modelos de la familia GARCH como sustituto de la incertidumbre de la política monetaria. En la segunda etapa, la reacción del crecimiento económico, el crecimiento del empleo y la inflación al impacto del crecimiento de la liquidez se estiman utilizando la técnica de función de respuesta al impulso derivada del modelo VAR. Los resultados indican la existencia de una relación de causalidad de Granger unidireccional de la incertidumbre de la política monetaria en las tres variables de fluctuaciones del PIB real, fluctuaciones del empleo e inflación. Además, en función de los resultados, la función de respuesta al impulso reduce el impacto del crecimiento de la liquidez tanto como una desviación estándar, el crecimiento del PIB real y el empleo después de un período y aumenta la inflación. En consecuencia, la hipótesis del efecto de los trastornos monetarios en los ciclos económicos de la economía de Irán en el período de esta investigación no puede ser rechazada.Clasificación JEL: E23, E31, E32, E52Neste artigo, investigamos o efeito dos distúrbios monetários sobre a inflação e os ciclos econômicos na economia do Irã durante o período de 1973 a 2012. Os distúrbios monetários são definidos por dois índices de incerteza da política monetária e por choque no crescimento da liquidez. No primeiro passo, a relação causal entre a incerteza da política monetária sobre as flutuações do PIB real, as flutuações do emprego e a inflação é estimada usando o teste de causalidade de Granger. Para este propósito, para seguir Haghighat e Mohammad Gholipour Tapeh (2014), a variância condicional do crescimento de liquidez extraída de modelos da família GARCH foi aplicada como um substituto para a incerteza da política monetária. No segundo estágio, a reação do crescimento econômico, crescimento do emprego e inflação ao choque para o crescimento da liquidez são estimados usando a técnica de função de resposta impulsiva derivada do modelo VAR. Os resultados indicam a existência de uma relação de causalidade de Granger unidirecional da incerteza da política monetária em todas as três variáveis de flutuações reais do PIB, flutuações do emprego e inflação. Além disso, com base nos resultados, a função de resposta ao impulso reduz o choque para o crescimento da liquidez, tanto quanto um desvio padrão, crescimento do PIB real e emprego após um período e aumenta a inflação. Consequentemente, a hipótese do efeito dos distúrbios monetários nos ciclos de negócios na economia do Irã no período desta pesquisa não pode ser rejeitada.Classificação JEL: E23, E31, E32, E5

Scrutinizing relationships between submarine groundwater discharge and upstream areas using thermal remote sensing: A case study in the northern Persian gulf

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. Nutrient input through submarine groundwater discharge (SGD) often plays a significant role in primary productivity and nutrient cycling in the coastal areas. Understanding relationships between SGD and topo-hydrological and geo-environmental characteristics of upstream zones is essential for sustainable development in these areas. However, these important relationships have not yet been completely explored using data-mining approaches, especially in arid and semi-arid coastal lands. Here, Landsat 8 thermal sensor data were used to identify potential sites of SGD at a regional scale. Relationships between the remotely-sensed sea surface temperature (SST) patterns and geoenvironmental variables of upland watersheds were analyzed using logistic regression model for the first time. The accuracy of the predictions was evaluated using the area under the receiver operating characteristic curve (AUC-ROC) metric. A highly accurate model, with the AUC-ROC of 96.6%, was generated. Moreover, the results indicated that the percentage of karstic lithological formation and topographic wetness index were key variables influencing SGD phenomenon and spatial distribution in the northern coastal areas of the Persian Gulf. The adopted methodology and applied metrics can be transferred to other coastal regions as a rapid assessment procedure for SGD site detection. Moreover, the results can help planners and decision-makers to develop efficient environmental management strategies and the design of comprehensive sustainable development policies

Molecular identification of bacterial and fungal pathogens in certain disease-free shrimp

At present, the aquaculture industry to provide proper instructions in the field of health management, including production of Specific Pathogen Free shrimp (SPF), require sensitive and reliable methods for the detection and identification of pathogenic microorganisms. Molecular methods which used in the detection of microorganisms have a high discriminatory power in the taxonomy and in relation to libraries in the world. On the other hand, the accurate identification of microorganisms, providing the genetic data bank of shrimp pathogens and maintenance of these strains is the step to promote further research on the mechanisms of pathogenesis of pathogens, diagnosis, treatment, prevention of disease, identify indigenous production kits, diagnosis re emerging and emerging diseases and their origin. Therefore, in this project, by using ribotyping technique, native isolated pathogenic bacteria and fungi were identified and recorded in the gene bank database center. During sampling of shrimp and water of Specific Pathogen Free shrimp center, 40 bacterial strains were isolated, which 8 of them had the most frequency and identification based on 16S rDNA sequencing was performed. Bacteria identified are: Vibrio nigripulchritudo strain IS013(GenBank:KP843725), Vibrio brasiliensis strain IS014 (GenBank:KR186076), Vibrio rotiferianus strain IS015 (GenBank:KR186077), Vibrio azureus strain IS012 (GenBank:KJ018724.1), Vibrio owensii strain IS016 (GenBank:KR186078), Agarivorans gilvus strain IS017 (GenBank:KR186079), Vibrio brasiliensis IS018 (GenBank:KR186080) and Vibrio alginolyticus strain IS019 (GenBank:1817854), which were recorded in The World Bank genes. In this study fungal isolates were not detected

How fast do gully headcuts retreat?

© 2016 Elsevier B.V. Gully erosion has important on and off site effects. Therefore, several studies have been conducted over the past decades to quantify gully headcut retreat (GHR) in different environments. Although these led to important site-specific and regional insights, the overall importance of this erosion process or the factors that control it at a global scale remain poorly understood. This study aims to bridge this gap by reviewing research on GHR and conducting a meta-analysis of measured GHR rates worldwide. Through an extensive literature review, GHR rates for 933 individual and actively retreating gullies have been compiled from more than 70 study areas worldwide (comprising a total measuring period of >19 600 years). Each GHR rate was measured through repeated field surveys and/or analyses of aerial photographs over a period of at least one year (maximum: 97 years, median: 17 years). The data show a very large variability, both in terms of gully dimensions (cross-sectional areas ranging between 0.11 and 816 m2 with a median of 4 m2) and volumetric GHR rates (ranging between 0.002 and 47 430 m3 year- 1 with a median of 2.2 m3 year- 1). Linear GHR rates vary between 0.01 and 135 m year- 1 (median: 0.89 m year- 1), while areal GHR rates vary between 0.01 and 3628 m2 year- 1 (median: 3.12 m2 year- 1). An empirical relationship allows estimating volumetric retreat rates from areal retreat rates with acceptable uncertainties. By means of statistical analyses for a subset of 724 gullies with a known contributing area, we explored the factors most relevant in explaining the observed 7 orders of magnitudes of variation in volumetric GHR rates. Results show that measured GHR rates are significantly correlated to the runoff contributing area of the gully (r2 = 0.15) and the rainy day normal (RDN; i.e. the long-term average annual rainfall depth divided by the average number of rainy days; r2 = 0.47). Other factors (e.g. land use or soil type) showed no significant correlation with the observed GHR rates. This may be attributed to the uncertainties associated with accurately quantifying these factors. In addition, available time series data demonstrate that GHR rates are subject to very large year-to-year variations. As a result, average GHR rates measured over short (100%) uncertainties. We integrated our findings into a weighted regression model that simulates the volumetric retreat rate of a gully headcut as a function of upstream drainage area and RDN. When weighing each GHR observation proportional to its measuring period, this model explains 68% of the observed variance in GHR rates at a global scale. For 76% of the monitored gullies, the simulated GHR values deviate less than one order of magnitude from their corresponding observed value. Our model clearly indicates that GHR rates are very sensitive to rainfall intensity. Since these intensities are expected to increase in most areas as a result of climate change, our results suggest that gully erosion worldwide will become more intense and widespread in the following decades. Finally, we discuss research topics that will help to address these challenges