Search

We present 58-year-old man on long-term statin therapy with history of ischemic heart disease and percutaneous coronary intervention. Statin-associated tendon rupture is an uncommon clinical presentation that happened in our case. We review the literature to find the reliable substitute of statin in such high-risk patients for atherosclerotic cardiovascular disease.

Iran is a semi-arid and arid country which always faces a water shortage crisis. Thus, the water resources in Iran should be studied by accurate methods such as stable isotope techniques. In precipitation sampling stations across Iran, the δ18O (ranges from -16.3 to -0.3 ‰, -4.9 ‰ average), δ2H (-114 to -13 ‰, -24.2 ‰ average) and d-excess (-2.1 to -22.7, 16.5 ‰ average) values are higher compared to δ18O (ranges from -10.9 to -3.1 ‰, -6.7 ‰ average), δ2H (-71 to -6 ‰, -37.4 ‰ average) and d-excess (1.0 to -21.6 ‰, 14.9 ‰ average) values in groundwater stations. Stable isotope distribution maps in precipitation and groundwater were also developed for Iran. The stepwise technique was used to study the role of parameters influencing stable isotopes in Iran precipitation. Results show the dominant role of temperature, elevation and latitude as well as 'cP and MedT' air masses mixture on stable isotope values in precipitation. Furthermore, the contribution percentage of each air mass which influences Iran in groundwater resources recharge was studied using 'Simmr' package in R programming language. Finally, the accuracy of the developed stable isotope distribution maps was validated.

In this article, we report a 34-year-old man who presented with a buccal progressive ulcerated lesion which through histopathologic and IHC findings diagnosed as Peripheral T-cell lymphoma.

Consider primary bone lymphoma as an important differential diagnosis of osteomyelitis.In patients who are unresponsive to antibiotics and core needle biopsy result is incoherent with clinical symptoms, consider open biopsy for accurate diagnosis., Consider primary bone lymphoma as an important differential diagnosis of osteomyelitis. In patients who are unresponsive to antibiotics and core needle biopsy result is incoherent with clinical symptoms, consider open biopsy for accurate diagnosis.

This study examines the multiple dust storms that hit the eastern Mediterranean and Greece during March 2018, emphasizing on the atmospheric dynamics for their generation, the source regions, the dust-induced radiative forcing and the impacts on PM concentrations in Athens. In March 2018, several dust storms facilitated by increased cyclonicity in the western Europe/Mediterranean and by the Sharav cyclogenesis along the north African coast resulted in abnormal-high columnar aerosol loading and PM concentrations over Greece. The dusty days were associated with intense winds (>15 - 20 ms−1) from southwestern directions, triggered by cyclonic circulations over the central/eastern Mediterranean and troughs over Italy and the north African coast. Statistical analysis of the backward air-mass trajectories shows that the highest PM10 concentrations are related to dust sources in Libya, while Ceilometer profiles indicate thick dust plumes with highest intensity between the surface and 3 km over Athens. The monthly-averaged hourly PM10 concentrations at several stations in the Athens basin ranged from 37 μgm−3 to 53 μgm−3, while nine days exhibited PM10 daily-means above 50 μgm−3, characterized as dusty days. The PM10 concentrations in Athens maximized on 25–26 March (∼500 μgm−3 at hourly basis), while the PM2.5 constitutes 38%–59% of PM10, indicating a dominance of coarse particles. Aerosol radiative forcing (ARF) estimates via the synergy of OPAC and SBDART models at three AERONET stations in Greece revealed significant impact of dust on radiation budget, with large (∼−40 W m−2 to −50 W m−2) decrease in surface solar radiation and an overall cooling effect at the top of atmosphere (∼−5 to −30 W m−2). The atmospheric heating via the dust-aerosol absorption results in heating rates of ∼0.5 K day−1.

This study examines the atmospheric dynamics that facilitated frequent and intense dust storms over the eastern Mediterranean in March 2018 via the synergy of satellite observations, ground-based measurements and reanalysis. The negative NAO phase in March 2018 caused cold weather conditions over the central/west Europe and strengthened the temperature gradient between cold European and warm North-African air at all levels from the surface up to 300 hPa. Large negative mean sea-level pressure (MSLP) anomalies over the western Mediterranean and south Europe strengthened the sea-level pressure and geopotential-height gradients across the Mediterranean, resulting in intensification of the westerlies over the west/central Mediterranean and the development of the Sharav cyclones along the north African coast. In addition, enhanced south/southwesterlies dominated over the eastern Mediterranean, associated with cyclonic conditions and intense dust storms on several days in March 2018. These meteorological conditions resulted in an increase of ~0.3–0.4 in AOD (~100%) and ~200 μg m−3 in surface dust concentration over parts of the eastern Mediterranean, compared to the mean March climatology. The vertical aerosol profiles over the eastern Mediterranean show a large increase in the mean extinction coefficient (~200 Mm−1) due to dust loading at altitudes between ~1 and 4 km. The dust radiative impact caused a significant decrease (~−10 Wm−2) in the incoming solar radiation under clear skies and in the latent and sensible energy fluxes over the eastern Mediterranean in March 2018, thus modulating the radiation/energy budget.

International audience; This study examines the atmospheric circulation patterns that are associated with contrasting wind regimes, desert dust outflows and accumulation of dust over the Arabian Sea in the summer season. The examined period is 11-16 July 2016, when several dust plumes of various intensity and from different sources (Arabian Peninsula, Somalia and Iran), affected the Arabian Sea. During summer, south Asia is under the influence of the southwest monsoon, with main characteristics being the thermal low-pressure system centered over northwest India/Pakistan with secondary lows over south Iran and southeast Arabian Peninsula, and the Arabian ridge combined with the Indian trough in the mid troposphere. Apart from the dominant southwest monsoon flow over the Arabian Sea, strong local winds are developed over the desert areas, such as the northwest Shamal along the east Arabian Peninsula and northern Levar in southeast Iran. These wind regimes initiate several dust outbreaks, while their convergence over the Arabian Sea results in accumulation of large amounts of dust aerosols (AOD > 2.0), as observed by satellite (MODIS, MISR, CALIPSO) observations and reanalysis (MERRA-2). The dust-accumulation area (central/north part of the Arabian Sea) is characterized by weak winds, while the position of the Inter-Tropical Discontinuity (ITD) plays an important role in merging the contrasting dust plumes. The vertical profiles of the monsoon, Shamal and Levar winds are especially important for the dust accumulation, since the low-altitude dust plumes come from the southeastern Arabian Peninsula and Somalia, while those above 3000 m from northern directions (Iran, Pakistan).

Paying attention to human activities in terms of land grazing infrastructure, crops, forest products and carbon impact, the so-called ecological impact (EF) is one of the most important economic issues in the world. In the present study, data from global databases were used. The ability of the penalized regression approach (PR including Ridge, Lasso and Elastic Net) and artificial neural network (ANN) to predict EF indices in the G-20 over the past two decades (1999–2018) was depicted and compared. For this purpose, 10-fold cross-validation was used to assess predictive performance and to specify a penalty parameter for PR models. Based on the results, a slight improvement in prediction performance was observed over linear regression. Using the Elastic Net model, more global macro indices were selected than Lasso. Although Lasso included only some indicators, it still had better predictive performance among PR models. Although the findings using PR methods were only slightly better than linear regression, their interest in selecting a subset of controllable indicators by shrinking the coefficients and creating a parsimonious model was apparent. As a result, penalized regression methods would be preferred, using feature selectivity and interpretive considerations rather than predictive performance alone. On the other hand, neural network-based models with higher values of coefficients of determination (R2) and values lower of RMSE than PR and OLS had significant performance and showed that they are more accurate in predicting EF. The results showed that the ANN network could provide considerable and appropriate predictions for EF indicators in the G-20 countries. predictions

Iran is a semi-arid and arid country which always faces a water shortage crisis. Thus, the water resources in Iran should be studied by accurate methods such as stable isotope techniques. In precipitation sampling stations across Iran, the

Paying attention to human activities in terms of land grazing infrastructure, crops, forest products, and carbon impact, the so-called ecological impact (EF) is one of the most important economic issues in the world. For the present study, global database data were used. The ability of the penalized regression (RR) approaches (including Ridge, Lasso and Elastic Net) and artificial neural network (ANN) to predict EF indices in the G-20 countries over the past two decades (1999–2018) was illustrated and compared. For this purpose, 10-fold cross-validation was used to evaluate the predictive performance and determine the penalty parameter for PR models. According to the results, the predictive performance compared to linear regression improved somewhat using the penalized methods. Using the elastic net model, more global macro indices were selected than Lasso. Although Lasso selected only a few indicators, it had better predictive performance among PR ns models. In addition to relative improvement in the predictive performance of PR methods, their interest in selecting a subset of indicators by shrinking coefficients and creating a parsimonious model was evident and significant. As a result, PR methods would be preferred, using variable selection and interpretive considerations to predictive performance alone. On the other hand, ANN models with higher determination coefficients (R2) and lower RMSE values performed significantly better than PR and OLS and showed that they were more accurate in predicting EF. Therefore, ANN could provide considerable and appropriate predictions for EF indicators in the G-20 countries.

Dust storm phenomenon is one of the main features over the Sistan plain, eastern Iran. To examine of dust storm structure in the Sistan area, an experiment was conducted by forth-generation regional climate model in an area between 20°–48°N and 42°–78°E during the cold period of 2000 and 2002 years with two horizontal resolutions (20 and 80 km) in 6-h time step. Validation of satellite data and NCEP/NCAR re-analysis were used to stimulate model outputs. In order to have information pertaining to the dust storms, model is coupled with chemical scheme of the atmosphere, showing dust emission based on various factors. There is a systematic underestimation of dust emission especially over Sistan plain when compared with analyzed data in 80 km. However vectors and streamlines show the same direction in both resolutions but they are show better and near the fact in 20 km horizontal grid spacing compared with NCEP/NCAR re-analysis results, while 20 km will be shown the complex-terrain conditions in studied region. An additional experiment was showed that by using different resolutions and running model to calculate the dust storm factors over the Sistan plain, in 20 km resolution all land surface coverage and functions are better than 80 km resolution and this feature affected on the model outputs. This item led to obtain a clear insight regarding to dust storms when it is indicated in wind velocity cross section and sea level pressure while they are influenced by the Sistan situation.

Objectives: Indices are extensively used for ranking various units of a chemical process industry on the basis of the hazards they pose of risk a fire, explosion and toxicity release. Methods: This type of ranking enables the professionals to identify the more hazardous units from the less hazardous ones so that greater attention can be paid to the former. The key process subunits in the Iso-max unit were identified based on parameters such as process pressure, temperature and material value. In next step, the main parameters affecting the FETI were identified and estimated, and the Mond FETI index was calculated for each subunit. In addition, the criteria offset measures for each case were identified and their influences were studied. Results: The results showed that the process route’s potential hazardous characteristics, such as major incidents, were associated with one or more of the following dangerous phenomena: thermal radiation, blast (pressure wave) and ejection of fragments, release of toxic materials and chemical concentration in the air. Intake amount assessments and the corresponding risk of exposure were also produced. By using statistical incident data of the risks of fire, explosion and toxicity, exposure risks can be estimated more realistically as probabilities. This approach is capable of comparing alternative processes to select the one which is inherently safest. Conclusion: Using this method, the exposure risks in a process can be identified sooner, and proper risk management decisions can be made early in the process development or predesign stages.

An exceptional southerly Foehn in the Alborz Mountains in northern Iran is investigated by using a combination of observations, reanalysis, and simulation data. A synoptic analysis is used as well as a high-resolution numerical modeling to clarify the Foehn event at different scales. The event resulted in an extensive and high-intensity fire in the Gilan and Mazandaran forests in northern Iran. The results indicate that a mechanically driven Foehn occurred in the Alborz Mountains during December 16–18, 2005. On the synoptic scale, the Foehn event occurred due to the presence of high pressure over the interior regions of Iran and lee cyclone over the southern Caspian Sea, with a strong south–north pressure gradient across the Alborz Mountains. In the mesoscale, the results suggest that mountain waves generated over the northern slopes of the Alborz Mountains are the primary source of the localized southerly wind maximum around the lee side of Alborz. A numerical simulation reveals that strong meridional surface pressure differences along with southerly flow, which is blocked upstream of the Alborz Mountains, result in higher nonlinearity and create large-amplitude vertically propagating mountain waves over the Alborz Mountains. The study also indicates that the wave-breaking region on the lee side with a critical level ranging from 600 to 400 hPa is responsible for reflecting the mountain wave energy back to the ground and for creating severe downslope wind (Garmij) in leeward side of Alborz Mountains. The Foehn event first appeared early on December 16, due to a wave-breaking at 550 hPa in western part of the Alborz Mountains.

Dust storms are considered natural hazards that seriously affect atmospheric conditions, ecosystems and human health. A key requirement for investigating the dust life cycle is the analysis of the meteorological (synoptic and dynamic) processes that control dust emission, uplift and transport. The present work focuses on examining the synoptic and dynamic meteorological conditions associated with dust-storms in the Sistan region, southeastern Iran during the summer season (June–September) of the years 2001–2012. The dust-storm days (total number of 356) are related to visibility records below 1 km at Zabol meteorological station, located near to the dust source. RegCM4 model simulations indicate that the intense northern Levar wind, the high surface heating and the valley-like characteristics of the region strongly affect the meteorological dynamics and the formation of a low-level jet that are strongly linked with dust exposures. The intra-annual evolution of the dust storms does not seem to be significantly associated with El-Nino Southern Oscillation, despite the fact that most of the dust-storms are related to positive values of Oceanic Nino Index. National Center for Environmental Prediction/National Center for Atmospheric Research reanalysis suggests that the dust storms are associated with low sea-level pressure conditions over the whole south Asia, while at 700 hPa level a trough of low geopotential heights over India along with a ridge over Arabia and central Iran is the common scenario. A significant finding is that the dust storms over Sistan are found to be associated with a pronounced increase of the anticyclone over the Caspian Sea, enhancing the west-to-east pressure gradient and, therefore, the blowing of Levar. Infrared Difference Dust Index values highlight the intensity of the Sistan dust storms, while the SPRINTARS model simulates the dust loading and concentration reasonably well, since the dust storms are usually associated with peaks in model simulations.

During the period from 12 to 15 April, 2009 nearly the entire Iran, apart from the southern border, experienced an advective cooling event. While winter freezing concerns are typical, the nature of this freezing event was unusual with respect to its date of occurrence and accompanying synoptic meteorological situation. To analyze the freezing event, the relevant meteorological data at multiple levels of the atmosphere were examined from the NCEP/NCAR reanalysis dataset. The results showed that a polar vortex was responsible for the freezing event over the country extending southward extraordinarily in such a way that its ridge influenced most parts of Iran. This was recognized as an abnormal extension of a polar vortex in the recent years. The sea-level pressure fields indicated that a ridge of large-scale anticyclone centered over Black Sea extended southward and prevailed over most parts of Iran. This resulted in the formation of a severe cold air advection from high latitudes (Polar region) over Iran. During the study period, moisture pumping was observed from the Arabian Sea and Persian Gulf. The winds at 1000 hPa level blew with a magnitude of 10 m s−1 toward south in the region of convergence (between −2 × 10−6 s−1 and −12 × 10−6 s−1). The vertical profiles of temperature and humidity also indicated that the ICE structural icing occurred at multiple levels of the atmosphere, i.e, from 800 hPa through 400 hPa levels. In addition to the carburetor (or induction), icing occurred between 900 and 700 hPa levels in the selected radiosonde stations during the study period. In addition, the HYSPLIT backward trajectory model outputs were in quite good agreement with the observed synoptic features.

The relationship between daily large-scale atmospheric circulation types (CTs) and wintertime daily precipitation over Iran during the period 1965–2000 is investigated. Twelve atmospheric CTs identified in a previous study, which applied the K-means clustering technique to the rotated principal components (RPCs) of the 500 hPa geopotential height fields, are also considered in this study. The leading spatial modes of daily precipitation variability over Iran are extracted by a PC analysis, with Varimax rotation, applied to the APHRODITE (Asian Precipitation-Highly Resolved Observational Data Integration Towards Evaluation of the Water Resources) gridded precipitation dataset; six Iranian sub-regions with independent precipitation variability are identified. The relationships between the CTs and the daily precipitation are investigated by computing: (1) the spatial patterns of the performance index (PI) for each CT and (2) the cross tabulations between the frequencies of occurrence of the CTs and the RPC scores of the daily precipitation, associated with each of the six sub-regions. Results suggest that two particular CTs affect the precipitation occurrence over most of the country, while the remaining ten provide more regional or negligible contributions to precipitation. The more (less) influencing CTs in each precipitation sub-region are then identified and a characterization of the main large-scale atmospheric features governing the winter precipitation fields is provided.

The relationships between large-scale atmospheric circulation types and seasonal regimes of daily precipitation over Iran are assessed using daily precipitation from a high-resolution gridded dataset provided by the Asian Precipitation-Highly Resolved Observational Data Integration Towards the Evaluation of Water Resources (APHRODITE) Project. Regional spatial modes of daily precipitation variability were identified by S-mode Principal Component Analysis (PCA) with Varimax rotation, applied to the subset of days when at least 10% of all grid-points over Iran received precipitation ≥ 5 mm. The study refers to the period 1961–2004 and is carried out for each season (excluding summer) separately. To characterize the dynamical features associated with each regional precipitation regime (PR), composites of daily atmospheric fields are computed by only averaging days with rotated PCA scores ≥ 1.5 (strong positive phase). In autumn and winter, Iran is divided into five PRs, while four PRs are identified in spring. Results suggest that the spatial distribution of precipitation over Iran is largely governed by the geographical position of both the mid-tropospheric trough over the Middle East and the Arabian anticyclone. In fact, in almost all PRs, the trough, as a pre-conditioning factor, leads to regional-scale ascending motions, whereas the Arabian anticyclone induces low-tropospheric moisture transports from southern water bodies into the cyclonic systems near Iran, triggering rain-generating conditions. Copyright © 2011 Royal Meteorological Society

Iran anticyclone is one of the main features of the summer circulation over the Middle East in the middle and upper troposphere. To examine the effect of the Zagros Mountains on the formation and maintenance of the Iran anticyclone, an experiment was conducted by Regional Climate Model (RegCM4) in an area between 22°–44°N and 35°–70°E with a 40 km horizontal grid spacing. The NCEP/NCAR re-analysis data set were used to provide the initial and lateral boundary conditions in a control run and in a simulation run by removing the Zagros Mountains. The result reveals that the Zagros Mountains have an important effect on the formation and maintenance of the low-level cyclonic circulation and mid-level anticyclonic circulation in summer. Examining the diabatic heating shows that the elimination of the Zagros Mountains causes a significant change in the heating values and its spatial distributions over the study area. Comparing the diabatic heating terms, the vertical advection term has the main contribution to the total heating. In the absence of the Zagros Mountains, the vertical advection and the mid-troposphere anticyclonic circulation are apparently weak and, therefore, the Iran subtropical anticyclone vanishes over the west of Iran. The study indicates that the Zagros Mountains as an elevated heat source have the main impact in the formation of a thermally driven circulation over the Middle East.