Experimental Investigations into CO₂ Injection Associated Fracture Behaviour in Shale Caprocks

Leakage of CO2 through fractures is a risk for the secure storage of CO2. Fracture closure, stress state and fracture geometry will control CO2 leakage rates in storage reservoirs where the seal has been compromised by fractures. This study investigates an acid induced fracture closure remediation technique using a series of laboratory acid injection experiments in shale caprocks. The test aims to reduce the permeability of fractures through induced fracture closure in order to demonstrate the technique as a remedial measure to reduce leakage. In the tests viscous acid is injected through a range of fractured shale caprock samples under confining stress. Preliminary tests on a single sample of shale caprock show that a significant reduction in fracture permeability is achieved using acid injection across a range of confining stresses. CT scans of the fracture show the fracture closure, and appear to suggest that dissolution of asperities on the fracture face may promote fracture closure. Ongoing work will involve testing the technique in a wide range of caprock samples with different mineralogy, artificial fracture surfaces and with gaseous CO2 and CO2 rich brines included in the injected fluids to determine any reduction in the effectiveness of the remediation technique, more extensive analysis of the CT imagery will also be carried out

Association between waterpipe smoking and obesity: Population-based study in Qatar

Introduction: Over the past decade obesity prevalence has been increasing rapidly in the Gulf region (GR) including Qatar, becoming one of the major health issues in the region. Concomitantly, waterpipe (WP) smoking is increasing worldwide especially in the GR, and although the effect of cigarette smoking on body weight is well-established, studies indicating an association between WP smoking and obesity are scarce. Thus, we explored the association between WP smoking and obesity in comparison with cigarette smokers and healthy population in Qatar. Methods: We performed a cross-sectional study using data from Qatar Biobank and analyzed anthropometric measurements among 879 adults (aged 18–65 years) that included WP smokers, cigarette smokers, dual smokers and never smokers. Body composition was measured using bioelectrical impedance analysis and reported as lean mass, fat mass, and body fat percentage. Results: Overall, 12% (n=108) were WP smokers, 22% (n=196) were cigarette smokers, 9% (n=77) smoked both WP and cigarettes and 57% (n=498) were never smokers. Age, sex, history of diabetes, and hypertension, in addition to nationality were considered as confounding factors. Our analysis revealed that WP smokers had a significantly higher BMI (kg/m2) and fat mass when compared with cigarette smokers (p<0.05). Moreover, compared to cigarette smoking, WP smoking had a higher significant effect on BMI (β=3.8, SE=0.38; and β=5.5, SE=0.46; respectively), and fat mass (β=5.1, SE=0.79; and β=9.0, SE=0.97; respectively). However, WP users were similar to never-smokers in terms of body fat percent. Conclusions: Our data indicate that compared to never smokers, daily WP users have higher BMI and fat mass, and are likely to be obese.This work is supported by the College of Medicine and Health Cluster of Qatar University. The funder had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.Scopu

Novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of Xanthomonas fuscans subsp. aurantifolii

Background: Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C. Results: We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein. Conclusion: We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientIfico e Tecnologico (CNPq)Coordenacao para Aperfeicoamento de Pessoal de Ensino Superior (CAPES)Fundo de Defesa da Citricultura (FUNDECITRUS

Effects of Treated Municipal Wastewater and Sea Water Irrigation on Soil and Plant Characteristics

The increasing need for water in the arid areas of the world has resulted in the emergence of wastewater application for agriculture and landscape. Using treated wastewater in agricultural irrigation can provide more adequate supply of high quality water for human consumption, but their heavy metal applications effect must be regulated to ensure no physiological problems for both the plant and its consumer. The objective of the present research was to study the effects of treated wastewater on soil chemical properties and plant growth characteristics as well as accumulation of heavy metals in plant tissues. This research was conducted at Qatar university greenhouse in the growing season of 2007. Treated wastewater was obtained from Abu Nakhala pond in Doha City, Qatar. The soil was a mixture of sand and clay with ratio of (1:1). Two crop plants were used in this study; grain sorghum ( Sorghum bicolor L.) and Sunflower ( Helianthus annuus L). Plants were irrigated with four different mixtures of wastewater and sea water (1:0, 1:1, 3:1, and 0:1) in addition to potable water as a control. The accumulation of salts and heavy metals in the soil as well as concentration of the nutrients and heavy metal accumulation in the plant tissues were determined at the end of the experiment. Cr, Mn and Zn showed significant differences between soil irrigated with portable tap water and other irrigation treatments. On the other hand, Al, Fe, Ni, Co, Cu, As, Cd and Pb did not show significant differences among the irrigation water treatments. Sorghum soils have significantly less concentration of Co, Cu and As compared to that of Sunflower soils. Sorghum was found to accumulate significantly higher concentration of Mn and Zn (72.47 and 92.00 mg/L, respectively) than that of Sunflower. On the other hand, Sunflower has significantly higher concentration of Cr compared to that of Sorghum

Diabetic papillopathy with macular edema treated with intravitreal bevacizumab

A 46-year-old diabetic male presented with acute painless visual loss in his left eye (OS). Visual acuity was 6/36 OS with an unremarkable anterior segment examination (OU). Posterior segment showed a swollen left optic disc with large diffuse macular edema and moderate nonproliferative diabetic retinopathy (NPDR). The right eye fundus showed only mild NPDR. Optical coherence tomography and fundus fluorescein angiography were performed which revealed left macular edema and a hyperfluorescent left optic disc. Computerized tomography scan orbit and brain was normal. The patient received an intravitreal bevacizumab injection OS followed by focal laser photocoagulation 1 month later. His optic disc swelling and the macular edema subsided rapidly after the injection and his visual acuity improved to 6/6 with disc pallor

A comparison of the Ranging behaviour and habitat use of the Ethiopian hedgehog (Paraechinus aethiopicus) in Qatar with hedgehog taxa from temperate environments

We investigated seasonal changes in the ecology and behaviour of the Ethiopian hedgehog (Paraechinus aethiopicus) in Qatar, particularly in respect to differences in behaviour between hedgehogs living in arid environments and hedgehogs in temperate mesic environments. These comparisons will allow us to explore behavioural adaptations to different environments across hedgehog taxa. We radio-tracked 30 hedgehogs in Qatar over two years, and measured home range size, habitat preference, travel speed, activity and body mass. Whilst we found no difference in body mass between males and females, male home range size was over twice as large as that for females. Unlike hedgehogs in Europe, males maintained large home ranges during the non-breeding season. This behaviour may be sustained by the low cost of maintaining a large home range; males travelled less far per hour during the non-breeding season. Habitat use was non-random; arid areas with human influence, including rubbish dumping sites, was the most selected habitat type compared with its availability. Dense scrub and/or trees was the most selected habitat for nesting. This study gives us greater understanding as to how hedgehog taxa are adapted to their environment and therefore how they may be conserved, for example, the recent increase of “lower” level human activities, including irrigated farms and food waste, in harsh arid environments may have influenced the space use by Ethiopian hedgehogs

A comparison of the Ranging behaviour and habitat use of the Ethiopian hedgehog (Paraechinus aethiopicus) in Qatar with hedgehog taxa from temperate environments

We investigated seasonal changes in the ecology and behaviour of the Ethiopian hedgehog (Paraechinus aethiopicus) in Qatar, particularly in respect to differences in behaviour between hedgehogs living in arid environments and hedgehogs in temperate mesic environments. These comparisons will allow us to explore behavioural adaptations to different environments across hedgehog taxa. We radio-tracked 30 hedgehogs in Qatar over two years, and measured home range size, habitat preference, travel speed, activity and body mass. Whilst we found no difference in body mass between males and females, male home range size was over twice as large as that for females. Unlike hedgehogs in Europe, males maintained large home ranges during the non-breeding season. This behaviour may be sustained by the low cost of maintaining a large home range; males travelled less far per hour during the non-breeding season. Habitat use was non-random; arid areas with human influence, including rubbish dumping sites, was the most selected habitat type compared with its availability. Dense scrub and/or trees was the most selected habitat for nesting. This study gives us greater understanding as to how hedgehog taxa are adapted to their environment and therefore how they may be conserved, for example, the recent increase of “lower” level human activities, including irrigated farms and food waste, in harsh arid environments may have influenced the space use by Ethiopian hedgehogs