47 research outputs found

    A Young Man with Multiple Pulmonary Cysts

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    Several diseases cause cystic or cyst-like parenchymal lung abnormalities including adult pulmonary Langerhan's cell histiocytosis (PLCH), lymphangioleiomyomatosis (LAM), emphysema, end-stage interstitial lung disease, and cystic bronchiectasis. Many of these diseases can now be diagnosed with high accuracy by the use of high-resolution computerized tomography (HRCT). In fact, HRCT of chest has proved a major breakthrough in the diagnosis of these diseases. We are presenting a young man with a cystic lung disease in which, the HRCT findings were virtually diagnostic of that disease. The clinical and HRCT findings of this disease along with its differential diagnosis are discussed in this paper

    Environmental contamination in mangrove crustaceans inhabiting Qatari waters

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    The increasing level of pollutants in the marine environment is a major concern in all countries, in particular where the main diet is seafood. The major goal of this project was to assess the level of pollution and their effects in three local species, namely blue crab (Portunus pelagicus), barnacle (Balanus amphitrite), and shrimp (Palaemon khori). Samples were collected from intertidal and subtidal zones at Al-Khor Bay.The levels of pollutants such as poly chlorinated biphenyls (PCBs), heavy metals, and methylmercury in tissues and water samples were determined by Gas Chromatography (GC) , Cold vapor atomic fluorescence spectrometer (CVAFS), and inductively coupled plasma optical emission spectrometry (ICP-OES).The results show that the concentrations of the contaminants were very low in the water (mostly below detection limits), but PCB congeners (2,2,3,5-Tetrachlorobiphenyl and 2,2,4,5,5-Pentachlorobiphenyl) in shrimp and crab tissues was at the detectable levels. Methylmercury was measured (1 ppb approximately) in all three species' tissues. The order of heavy metal concentrations in the tissues was Zn>Al>As>Mn>Cd>Mn>Ni>Cu>Mo>V>Pb>Co for barnacles; Zn>Al>Ni>Mo>Mn>As for blue crab, and Zn>Fe>Ni>Mn>Cr>As>Cd>Pb>Co>V for shrimp. The data presented in this study reports the first ever estimated baseline of contaminants both in the marine environment (water) and in animal tissues from this particular study area of Qatar.qscienc

    Baseline monitoring gastropods in the intertidal zone of Qatar - target species and bioindicators for hyper-thermic and hyper-saline Conditions

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    The Arabian Gulf is subjected to some of the most intense sea water temperatures and salinity levels in the world. In an attempt to understand the distribution and species composition of gastropod assemblages which live in these hyper-thermic and hyper-saline conditions a rapid assessment survey was undertaken along the intertidal zone of Qatar. The research revealed an obvious geographical temperature/salinity gradient between sites on the southeast and southwest coastlines. Water temperatures of 34°C and salinities ranging from 39.9 to 56.8ppt were recorded in-situ. There was detectable change in gastropod assemblage composition in accordance with this gradient. The abundance and diversity of live species decreased as temperature and salinity rose while high densities of dead species were recorded at sites where extremes of temperatures and salinities were documented. Ceritidiopsila conica was the dominant species at sites which experienced the most extreme conditions and has value as a recognized bio-indicator of high temperature/salinity environments within the region

    Decline in oyster populations in traditional fishing grounds; is habitat damage by static fishing gear a contributory factor in ecosystem degradation?

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    The territorial waters of Qatar once supported dense assemblages of the pearl oyster Pinctada radiata. The oysters settled on a patchy network of limestone platforms (hairãt) and provided a suite of ecosystem services to the surrounding marine environment. Commercially important fish species are associated with hairãt and as a result, industrial fishing with traps focused on these areas. This study has shown that heavily-fished areas are presently in a state which can be considered non-favorable to conservation while areas closed to fishing are recovering. It is probable that an increase in fishing activity using traditional Gargoor traps and grapple retrieval are responsible for the current ecological status of the hairãt. The intensity in trap fishing appears to be having a detrimental effect on species such as corals, sea grasses and oysters. The decline in the standing stock of oysters is dramatic with an estimated reduction ratio of 580:1 between 2002 and 2016. As fishing damage appears to be a significant contributor to these losses, measures such as spatial protection of productive shallow offshore habitats and restriction on fishing effort are urgently required to address the decline. Strategic oyster stock enhancement through the re-seeding of selected areas could boost the recovery of damaged hairãt as P. radiata ecosystem services return.Qatar National Research Foundation, National Priorities Research programme project NPRP-6-1680-4-02

    Prevalence of microplastics in the marine waters of Qatar

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    The issue of plastic pollution in the marine environment is of increasing global concern. As plastics typically have an intrinsic durability, water insolubility and slow degradation rates, debris has now become both ubiquitous and persistent in the marine environment. Overtime, plastic ultimately result in the generation of microplastics via photolytic, thermal and biological degradation processes. Although the potential threat of microplastics on marine ecosystems is well recognized, there is no baseline data available for the Arabian Gulf. The Environmental Science Center of Qatar University has now documented the first evidence for the prevalence of microplastics within the Arabian Gulf, specifically in the marine waters of Qatar Exclusive Economic Zone (EEZ). Qatar has an arid climate and is situated midway along the western coast of the semi-enclosed Arabian Gulf. Qatar's coastline is particularly susceptible to marine debris due to the county's rapid urbanization and economic development. Surface seawater samples were collected from 12 stations during May 2015 research cruise of the RV Janan. An optimized and validated protocol was developed for the extraction of microplastics from plankton-rich samples without loss of microplastics present. Plankton present in seawater samples may readily mask the identification of microplastics and lead to an underestimation of the quantity of microplastics present. The protocol involved sample digestion using solutions of 1M NaOH, 10M NaOH, and 16M HNO3 in conjunction at different temperatures. Twenty mL of each solution was spiked with known quantities of reference polymer pellets, of varying diameters (63 μm to 4.70 mm) and used to digest the plankton biomass. The use of 1M NaOH proved to be a more efficient digestion treatment than 10M NaOH and 16M HNO3 solutions. Although 10M NaOH, and 16M HNO3 have been proven effective to mineralize plankton biomass, these solutions also resulted in some structural damage and discoloration of reference polymers with a low pH tolerance: polyvinyl alcohol, polyvinyl chloride, polystyrene, polyethylene, and nylon. After extraction, the microplastics were characterized using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. In total 30 microplastics were isolated from the mineralized samples, with an average concentration of 0.71 particles m− 3 (range 0–3 particles m− 3). Nine out of 30 were identified as polypropylene, with the majority either granular, sizes ranging from 125 μm to 1.82 mm, or fibrous, sizes from 150 μm to 15.98 mm. Microplastics were more prevalent in areas where nearby anthropogenic activities, including oil-rig installations and shipping operations, are present.qscienc

    Endobronchial Tuberculosis Simulating Lung Cancer and Healing without Bronchial Stenosis

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    Endobroncheal tuberculosis is defined as tuberculous infection of the tracheobronchial tree with microbial and histopathological evidence. The disease is usually mistaken for other lung diseases including lung cancer. Bronchial stenosis is a common complication of this type of tuberculosis despite the use of effective anti-tuberculous chemotherapy. We are presenting a case of endobronchial tuberculosis that simulated lung cancer and healed without residual bronchial stenosis

    Marine collection in Qatar - basis for biodiversity management

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    Biological Collections, which deal directly with identifying and documenting biodiversity, have a major role in assisting biodiversity management. They form the basis for research, documenting flora and fauna and creating repositories of biological information. Without taxonomic research the biological collections would be merely a collection of curious objects, of limited value to our understanding of the natural world. The Environmental Scientific Centre of Qatar University has created a Marine Collection to house the species collected in the region. The species are being identified by taxonomists and deposited in the Marine Collection with a Collection Number and accompanied by descriptive characteristics. The Specify Software Project, a database platform for museum and herbarium research data, is being used concomitantly for registration of each species. The collection includes marine animals from coastal and offshore waters of Qatar, such as invertebrates (poriferas, cnidarians, crustaceans, gastropods, molluscs, echinoderms and others) and vertebrate specimens (urochordata, cephalochordate, Condrictyes, Osteicties and Reptiles). A total of 4830 specimens was collected and are being deposited in the Collection, as well as subsequent samples from new projects, including species for articles in preparation which are currently listed as a new occurrence in Qatar such as; Coeloplana (Benthoplan) meteoris,Branchyostoma arabia, Paranchystus pictodontaeamong several other species. Furthermore the collection houses a new systematic ofPortunus segnis, and the biodiversity of benthic organisms from offshore oyster beds and crabs from the mangrove ecosystem. It is well recognized for any impending assessment of biodiversity indices a baseline of existing data is required and the marine collection at the ESC will be a crucial tool in any future research or environmental monitoring programs that might be undertaken in not only Qatar but the Arabian Gulf.qscienc

    Mangrove carbon stocks and biomass partitioning in an extreme environment

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    Global inventories that show mangrove forests have rich carbon stores currently lack data from arid areas where carbon stocks may be functionally impoverished relative to humid regions. We quantified total carbon stocks (C) of three arid Avicennia marina stands in Qatar and report an aboveground biomass allometric equation and the first below ground biomass allometric equation in the region. The allometric relationships indicate that below ground mangrove C stocks in arid locations are more important than previously reported. Comparison of previously published and our locally developed allometric equations show that A. marina in Qatar allocate comparatively more biomass to below ground components than the same species in tropical humid settings, which is consistent with plant adaptations to living in stressed conditions. Total C stocks were 45.70 ± 3.70 Mg C ha−1, of which tree and soil C stocks to 50 cm depth represented 10.18 ± 0.82 Mg C ha−1 and 35.52 ± 2.88 Mg ha−1 respectively. Soil C stocks to 1 m depth were 50.17 ± 6.27 Mg C ha−1. Overall, mangroves sustain relatively small C stocks in the arid, hypersaline environment of Qatar, which may be due to both relatively low tree productivity and growth, as well as limited rainfall-driven transport of terrigenous sediment inputs. By providing further estimates of mangrove carbon at their climatic extremes, these results can contribute to a better quantification of global mangrove carbon, reduce uncertainty in below ground tree C estimates from arid mangroves and have implications for mangrove carbon stocks in the face of climate change.Qatar National Research Fund, National Priorities Research Program (NPRP) [grant number 7–1302 – 1–24
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