Vulnerability of the Drinking Water Resources of the Nabataeans of Petra – Jordan

This article deals with pollution/toxicology in an archaeological frame. Although the Nabataeans had created a highly sophisticated water supply system, the water sources feeding the system can, according to recent evaluations, be considered as highly vulnerable to human activities within the catchment area of these resources or even to sabotage actions. The natural water quality of the sources, even after recent urban and agricultural development, is still suitable for drinking purposes and there are no signs in these waters of components, which may cause chronic of acute poisoning. The recharge, flow and discharge analyses show that only a few weeks are required for the recharge water of the close vicinity (10-20km) to reach the spring discharge sites. The extended Nabateans civilization ended abruptly within two years 106-108 A.D. The Romans surrounded the Nabataean city and conquered its outskirts. They most probably could not enter the near-Petra area to control the springs of Wadi Musa; supplying Petra. But, it seems that the catchment areas of these springs were known to them as they were to the Nabataeans. Could the Roman have misused the vulnerability of these water sources? Had the high vulnerability of the spring waters of Petra and Wadi Musa been the weak point leading to the end of the Nabataean civilization? These questions are discussed in the article, recognizing the necessity of further analysis and evaluation of the whole water supply system for evidence of eventual poisoning of the supply water

Value of venous color flow duplex scan as initial screening test for geriatric inpatients with clinically suspected pulmonary embolism

Raghid Kreidy1, Elias Stephan2, Pascale Salameh3, Mirna Waked4 1Department of Vascular Surgery, Saint George Hospital, University Medical Center, University of Balamand, Beirut, Lebanon; 2Department of Geriatrics, Saint George Hospital, University Medical Center, University of Balamand, Beirut, Lebanon; 3Laboratory of Clinical and Epidemiological Research, Faculty of Pharmacy, Lebanese University, 4Department of Pulmonary Medicine, Saint George Hospital, University Medical Center, University of Balamand, Beirut, Lebanon Aim: The contribution of lower extremity venous duplex scan to the diagnostic strategy for pulmonary embolism has been demonstrated by many authors. However, the positive diagnostic value of this noninvasive test in clinically suspected pulmonary embolism is not very high (10%–18%). Since thromboembolic risks increase considerably in hospitalized patients with advanced age, this study aims to determine the importance of lower extremity venous color flow duplex scan in this particular subgroup of patients with clinically suspected pulmonary embolism. The effects of clinical presentation and risk factors on the results of duplex scan have been also studied. Methods: Between July 2007 and January 2010, 95 consecutive Lebanese geriatric ($60 years of age) inpatients with clinically suspected pulmonary embolism assessed in an academic tertiary-care center for complete lower extremity venous color flow duplex scan were retrospectively reviewed. Age varied between 60 and 96 years (mean, 79.9 years). Forty patients were males and 55 females. Absence of compressibility was the most important criteria for detecting acute venous thrombosis. Results: Out of 95 patients, 33 patients (34.7%) were diagnosed with recent deep venous thrombosis of lower extremities (14 proximal and 19 distal) using complete venous ultrasound. Nine of these 33 patients (27.2%) had a history of venous thromboembolism and eleven (33.3%) presented with edema of lower extremities. A total of 28 patients (84.8%) with positive duplex scan had associated risk factors for venous thromboembolism. Conclusion: Lower extremity venous color flow duplex scan appears to be a reasonable initial screening test in the diagnostic algorithm of pulmonary embolism in geriatric inpatients with clinically suspected pulmonary embolism. This is particularly true in patients with a history of venous thromboembolism, in patients with a clinical presentation suggesting venous thrombosis, in uremic patients and in patients with altered general and mental status who are not candidates for chest computed tomography. Keywords: venous thrombosis, lower extremities, geriatri

The effects of ex-situ oil shale mining on groundwater resources in Siwaqa area, southern Jordan, using DRASTIC index and hydrochemical water assessment

Energy resources in addition to water resources are the most limited resources in Jordan, being one of the fourth poorest countries in water resources, and limitation of surface water resources put huge pressure on groundwater which is the main resource there. High expenses and the increasing prices of oil over all worlds increase the feasibility to mining the oil shale that exists in southern Jordan area, Siwaqa. This study took place to clarify the possible effects of mining and energy production activities on the water resources in that area. Groundwater vulnerability mapping was done for many areas all over the country, including this part. The initiative of this work is to determine the vulnerability under the conditions of removing the bedrock of the oil shale which is described as a con ning layer. Results that are obtained by this work conclude that the oil shale area becomes highly vulnerable to the human activities because of the existing geological structures while it is small and medium vulnerable in the elds in which there are no geological structures. In addition to the structural features and adding the possibility of the oil shale mining from the outcropped areas which will decrease the depth to water table and hence will affect the vulnerability values. Efectos en las fuentes de agua subterránea de la minería ex situ de esquistos bituminosos, en el área de Siwaqa, al sur de Jordania, a través del índice DRASTIC y la evaluación hidroquímica del agua ResumenLas fuentes de energía y agua son las más limitadas en Jordania, uno de los cuatro países más pobres en recursos hídricos; además, las limitadas fuentes super ciales hacen de las aguas subterráneas las más importantes. Las ganancias y el precio del petróleo, por su parte, incrementan la viabilidad de la minería de esquistos bituminosos en el sur de Jordania, en la región de Siwaqa. Este estudio se realiza con el  n de establecer los posibles efectos de las actividades de producción de energía y minería en las fuentes hídricas de la zona. Se elaboró un mapa de vulnerabilidad para las fuentes de agua subterránea en varias regiones del país, incluida el área de estudio. La iniciativa de este trabajo es determinar la vulnerabilidad si se remueve el lecho rocoso del esquisto bituminoso, que funciona como una capa de con namiento. Los resultados obtenidos evidencian que el esquisto bituminoso se torna bastante vulnerable a las actividades humanas debido a la presencia de estructuras geológicas, mientras que su vulnerabilidad es media o baja en aquellos lugares donde no hay estructuras geológicas. Además de los rasgos estructurales, existe la posibilidad de que la minería del esquisto bituminoso en las áreas de a oramiento podría descender hasta la capa freática y allí afectar los valores de vulnerabilidad

Sources of Salinization of Groundwater in the Lower Yarmouk Gorge, East of the River Jordan

In the Lower Yarmouk Gorge the chemical composition of regional, fresh to brackish, mostly thermal groundwater reveals a zonation in respect to salinization and geochemical evolution, which is seemingly controlled by the Lower Yarmouk fault (LYF) but does not strictly follow the morphological Yarmouk Gorge. South of LYF, the artesian Mukeihbeh well field region produces in its central segment groundwaters, an almost pure basaltic-rock type with a low contribution (<0.3 vol-%) of Tertiary brine, hosted in deep Cretaceous and Jurassic formations. Further distal, the contribution of limestone water increases, originating from the Ajloun Mountains in the South. North of the LYF, the Mezar wells, the springs of Hammat Gader and Ain Himma produce dominantly limestone water, which contains 0.14-3 vol-% of the Tertiary brine, and hence possesses variable salinity. The total dissolved equivalents, TDE, of solutes gained by water/rock interaction (WRI) and mixing with brine, TDEWRI+brine, amount to 10-70% of total salinity in the region comprising the Mukheibeh field, Ain Himma and Mezar 3 well; 55-70% in the springs of Hammat Gader; and 80-90% in wells Mezar 1 and 2. The type of salinization indicates that the Lower Yarmouk fault seemingly acts as the divide between the Ajloun and the Golan Heights-dominated groundwaters

Atrial Fibrillation in the Arab World: A Bibliometric Analysis of Research Activity from 2004 to 2019

Background: Atrial fibrillation (AF) is in an increasing pattern worldwide, especially in the Arab world. Objective: The aim of this article is to assess AF research activity in the Arab countries over the past 16 years, taking into consideration the population size, gross domestic product (GDP) and disability-adjusted life years (DALY). Methods: Atrial fibrillation related research articles published from Arab countries between 2004 and 2019 were collected from the MEDLINE database and are cited online on PubMed. Medical Subject Heading (MeSH) terms related to the subject, the origin and the date of publication were used to search for the published articles. Results: The number of AF related publications in the Arab world over the past 16 years was only 283 (0.73%) out of a total of 38,983 publications worldwide. Saudi Arabia ranked first in terms of number of AF related publications, followed by Egypt. Lebanon is the country with the highest number of publications per USD billion GDP, while Egypt and Saudi Arabia have the highest number of publications per 1% DALYs. According to the population size, Qatar and Bahrain produced the highest number of publications per million persons (PPMP). A strong and positive correlation was found between the number of publications and the GDP. The population size and the percentage of DALY showed positive yet weak correlation. Conclusion: A slight increase in AF related publications is observed. Nonetheless, AF research activity in the Arab world is still insufficient

Atrial Fibrillation in the Arab World: A Bibliometric Analysis of Research Activity from 2004 to 2019

Background: Atrial fibrillation (AF) is in an increasing pattern worldwide, especially in the Arab world. Objective: The aim of this article is to assess AF research activity in the Arab countries over the past 16 years, taking into consideration the population size, gross domestic product (GDP) and disability-adjusted life years (DALY). Methods: Atrial fibrillation related research articles published from Arab countries between 2004 and 2019 were collected from the MEDLINE database and are cited online on PubMed. Medical Subject Heading (MeSH) terms related to the subject, the origin and the date of publication were used to search for the published articles. Results: The number of AF related publications in the Arab world over the past 16 years was only 283 (0.73%) out of a total of 38,983 publications worldwide. Saudi Arabia ranked first in terms of number of AF related publications, followed by Egypt. Lebanon is the country with the highest number of publications per USD billion GDP, while Egypt and Saudi Arabia have the highest number of publications per 1% DALYs. According to the population size, Qatar and Bahrain produced the highest number of publications per million persons (PPMP). A strong and positive correlation was found between the number of publications and the GDP. The population size and the percentage of DALY showed positive yet weak correlation. Conclusion: A slight increase in AF related publications is observed. Nonetheless, AF research activity in the Arab world is still insufficient

Phase Stability of Hexagonal/cubic Boron Nitride Nanocomposites

Boron nitride (BN) is an exceptional material and among its polymorphs, two-dimensional (2D) hexagonal and three-dimensional (3D) cubic BN (h-BN and c-BN) phases are most common. The phase stability regimes of these BN phases are still under debate and phase transformations of h-BN/c-BN remain a topic of interest. Here, we investigate the phase stability of 2D/3D h-BN/c-BN nanocomposites and show that the co-existence of two phases can lead to strong non-linear optical properties and low thermal conductivity at room temperature. Furthermore, spark-plasma sintering of the nanocomposite shows complete phase transformation to 2D h-BN with improved crystalline quality, where 3D c-BN grain sizes governs the nucleation and growth kinetics. Our demonstration might be insightful in phase engineering of BN polymorphs based nanocomposites with desirable properties for optoelectronics and thermal energy management applications.Comment: 29 pages, 5 figure

Carboxylic ester hydrolases from hyperthermophiles

Carboxylic ester hydrolyzing enzymes constitute a large group of enzymes that are able to catalyze the hydrolysis, synthesis or transesterification of an ester bond. They can be found in all three domains of life, including the group of hyperthermophilic bacteria and archaea. Esterases from the latter group often exhibit a high intrinsic stability, which makes them of interest them for various biotechnological applications. In this review, we aim to give an overview of all characterized carboxylic ester hydrolases from hyperthermophilic microorganisms and provide details on their substrate specificity, kinetics, optimal catalytic conditions, and stability. Approaches for the discovery of new carboxylic ester hydrolases are described. Special attention is given to the currently characterized hyperthermophilic enzymes with respect to their biochemical properties, 3D structure, and classification