Assessment of heavy metals in roadside dust along the Abu Dhabi–Al Ain National Highway, UAE

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. Concentrations of key heavy metals (Pb, Zn, Cd, Ni, Cr, Mn, As, and Hg) have been investigated in roadside dust collected from Abu Dhabi–Al Ain National Highway in UAE. The heavy metals contents were analyzed by atomic absorption spectrometer. Heavy metal levels varied widely from 227.9 to 2765, 19 to 1540, 37.4 to 398.6, 20.1 to 123, 0.3 to 0.7, 0.1 to 0.9, 0.1 to 0.7, and 0.1 to 0.5 mg/kg for Mn, Cr, Zn, Pb, Cd, Hg, Ni, and As, respectively. The spatial distribution pattern showed that different sources of roadway metal emissions dominate at specific locations. Peaks in heavy metal concentrations were frequently observed in locations with high traffic volume, road intersections and junctions, gas and bus stations. Decreased levels of heavy metals were measured in locations with low traffic loadings and in close proximity to farm and forest areas. In addition to traffic-related heavy metals, emissions from fossil fuel and industries remain of significance. Natural sources, through regular dust storms, are important contributors to the observed metal levels. Enrichment factor indicated that As and Ni were entirely originated from crustal sources. Cd, Zn, Pb, and Mn were moderately enriched and are probably derived from mixed sources (traffic flows, gas stations, construction and agricultural activities, among others). Road dust was significantly enriched in Cr and Hg indicating their dominant anthropogenic origin. The average geo-accumulation index values suggested that road dust are uncontaminated with Mn, Ni, and As, uncontaminated to moderately contaminated with Zn and Pb, and moderately contaminated with Cr, Cd, and Hg. The contamination factors indicated very highly contaminated road dust with Cr and Hg, considerably contaminated with Cd, and moderately contaminated with Mn, Zn, and Pb. Results of ecological risk assessment revealed that all heavy metals in road dust pose low risk to local ecosystems, except for Cd and Hg, which constitute potentially considerable risk and high risk, respectively

Baseline marine investigation and impact of fish farming on the marine environment in Jebel Ali, Dubai, United Arab Emirates

© 2020 Scattered seashells were observed on the seabed with no marine corals. The baseline studies indicate that biodiversity decreased from the northeast to southwest direction. The dominant groups of phytoplankton were diatoms followed by dinoflagellates, with insignificant vertical variations in species composition and population due to shallow water. The benthic diversity over the majority of the study area was relatively low compared with other nearshore areas in the region. All subtidal habitats showed evidence of disturbance to varying degrees, with no fish species recorded at these locations. The soft sediment habitat was found to cover much of the area footprint, and faunal diversity was very low. Fish diversity and abundance were equally poor with only a few demersal species recorded. No evidence of coral colonization was recorded although the presence of a low-profile, encrusting species was recorded in close proximity, to the east of the study area. Mangrove, coral, and seagrass were absent in the study area and its immediate vicinity. Modelling of waste plume suggested that the harbor water is fairly well-mixed, and the dispersion of ammonia attenuates with distance

Re-architecting datacenter networks and stacks for low latency and high performance

© 2017 ACM. Modern datacenter networks provide very high capacity via redundant Clos topologies and low switch latency, but transport protocols rarely deliver matching performance. We present NDP, a novel datacenter transport architecture that achieves near-optimal completion times for short transfers and high flow throughput in a wide range of scenarios, including incast. NDP switch buffers are very shallow and when they fill the switches trim packets to headers and priority forward the headers. This gives receivers a full view of instantaneous demand from all senders, and is the basis for our novel, high-performance, multipath-aware transport protocol that can deal gracefully with massive incast events and prioritize traffic from different senders on RTT timescales. We implemented NDP in Linux hosts with DPDK, in a software switch, in a NetFPGA-based hardware switch, and in P4. We evaluate NDP's performance in our implementations and in large-scale simulations, simultaneously demonstrating support for very low-latency and high throughput.This work was partly funded by the SSICLOPS H2020 project (644866)

Long-term trends in ambient fine particulate matter from 1980 to 2016 in United Arab Emirates

© 2019, Springer Nature Switzerland AG. This paper presents the most comprehensive datasets of ambient fine particulate matter (PM 2.5 ) for the UAE from 1980 to 2016. The long-term distributions of PM 2.5 showed the annual average PM 2.5 concentrations constantly exceeded the EPA and WHO guidelines. They varied from 77 to 49 μg/m 3 with an overall average of 61.25 μg/m 3 . While the inter-annual variability in PM 2.5 concentrations showed relatively a cyclic pattern, with successive ups and downs, it broadly exhibited an increasing trend, particularly, over the last 14 years. PM 2.5 concentrations displayed a strong seasonal pattern, with greatest values observed during warm summer season, a period of high demand of electricity and dust events. The lowest values found in autumn are attributable to reduced demand of energy. Decreased atmospheric temperatures and high relative humidity coinciding with this period are likely to reduce the secondary formation of PM 2.5 . The spatial changes in PM 2.5 concentrations exhibited gradual downward trends to the north and northeast directions. Airborne PM 2.5 is prevalent in the southern and western regions, where the majority of oil and gas fields are located. PM 2.5 /PM 10 ratio indicated that ambient aerosols are principally associated with anthropogenic sources. Peaks in PM 2.5 /CO ratio were frequently observed during June, July, and August, although few were concurrent with March. This indicates that secondary formation plays an important role in PM 2.5 levels measured in these months, especially as the photochemical activities become relatively strong in these periods. The lowest PM 2.5 /CO ratios were found during September, October, and November (autumn) suggesting a considerable contribution of primary combustion emissions, especially vehicular emissions, to PM 2.5 concentration. PM 2.5 concentrations are positively correlated with sulfate levels. In addition to sea and dust aerosols, sulfate concentration in the coastal region is also related to fossil fuel burning from power plants, oil and gas fields, and oil industries. The population-weighted average of PM 2.5 in UAE was 63.9 μg/m 3 , which is more than three times greater than the global population-weighted mean of 20 μg/m 3

Seasonal impact to air qualities in industrial areas of the arabian gulf region

© 2018 Korean Society of Environmental Engineers. Air quality conditions and pollution status have been evaluated in the industrial area between Sharjah and Ajman border in UAE. Daily concentrations of O3, CO, NO2, SO2, PM2.5, PM10, Total Volatile Organic Compounds (TVOC) and Total Suspended Particulate (TSP) have been monitored from Sept. 2015 to April 2016. The monthly average concentrations of O3, CO, NO2, SO2, TVOC were within the UAE ambient air quality standards during the survey period. However, PM10 and TSP levels exceeded the recommended limits in Sept. 2015, Oct. 2015 and March 2016. Temporal variations in air quality parameters showed highest levels in March 2016 for PM2.5, PM10, NO2, TVOC and TSP, whereas O3, SO2 and CO showed relatively low values in this month. PM2.5 levels in ambient air were above the EPA guideline of 35 μg/m³ in all months. PM2.5 was the critical ambient air pollutant with Index for Pollutant (Ip) values varying from 103-209, indicating Air Quality Index categories of unhealthy for sensitive groups (62.5%) to unhealthy (25%) to very unhealthy (12.5%). The Ip average values of PM2.5 decreased from Sept. 2015 to reach lowest value in Dec. 2015 before increasing gradually, peaking in March 2016. These results suggest the potential health risks associated with PM2.5 is low in winter, where the prevailing meteorological conditions of lower temperatures, higher humidity, higher wind speed reduced particulate matter. The results revealed the industrial area is impacted by anthropogenic and natural sources of particulate matter

Rak tarczycy po terapii jodem radioaktywnym z powodu nadczynności tarczycy — opis serii przypadków i przegląd piśmiennictwa

Introduction: To assess the rate of thyroid cancer and mortality rate in a cohort of patients who received RAI131 treatment for hyperthyroidism and to report the index cases’ characteristics and management Material and methods: A cohort of 264 patients who received RAI131 treatment for different causes of thyrotoxicosis were followed up over a period of 18 years (1996–2014) by physical exam, radiological evaluation and serial thyroid function tests. Results: During the follow up period, three cases of thyroid cancer were identified. The prevalence of thyroid cancer was 1.136% of cases who received RAI131. The relative risk was 378.79 (95% CI: 76.8 < RR < 1868.23). The P value was < 0.0000004 and the SMR is 1.99/1000. Conclusions: The prevalence of thyroid cancer was 1.136% in the cohort of patients treated with RAI131. Despite the fact that no direct cause-effect relationship between RAI and thyroid cancer could be established, these cases highlights the importance of life-long surveillance of patients who receive RAI131.Wstęp: Badanie przeprowadzono w celu oceny częstości występowania raka tarczycy i odsetka zgonów w kohorcie chorych poddanych terapii RAI131 z powodu nadczynności tarczycy oraz przedstawienia charakterystyki tych chorych i stosowanego u nich leczenia. Materiał i metody: U kohorty 264 chorych poddanych terapii RAI131 z uwagi na tyreotoksykozę o różnej etiologii przez ponad 18 lat (1996–2014) prowadzono obserwację obejmującą badanie przedmiotowe, ocenę radiologiczną i serię badań czynności tarczycy. Wyniki: W okresie obserwacji wykryto 3 przypadki raka tarczycy. Częstość występowania raka tarczycy w grupie chorych poddanych terapii RAI131 wynosiła 1,136%. Ryzyko względne wynosiło 378,79 (95% CI: 76,8 < RR < 1868,23). Wartości p i SMR wynosiły odpowiednio < 0,0000004 i 1,99/1000. Wnioski: Częstość występowania raka tarczycy w kohorcie chorych poddanych terapii RAI131 wynosiła 1,136%. Mimo że nie wykazano bezpośredniego związku przyczynowo-skutkowego między RAI a rakiem tarczycy, opisane przypadki zwracają uwagę na znaczenie bezterminowej obserwacji chorych poddanych terapii RAI131

Low latency via redundancy

Low latency is critical for interactive networked applications. But while we know how to scale systems to increase capacity, reducing latency --- especially the tail of the latency distribution --- can be much more difficult. In this paper, we argue that the use of redundancy is an effective way to convert extra capacity into reduced latency. By initiating redundant operations across diverse resources and using the first result which completes, redundancy improves a system's latency even under exceptional conditions. We study the tradeoff with added system utilization, characterizing the situations in which replicating all tasks reduces mean latency. We then demonstrate empirically that replicating all operations can result in significant mean and tail latency reduction in real-world systems including DNS queries, database servers, and packet forwarding within networks

Perception and intentions to quit among waterpipe smokers in Qatar: a cross-sectional survey

Objective: To evaluate the perceptions and attitudes of waterpipe (shisha) smokers in Qatar regarding the health risks associated with addiction and to determine their intentions to quit. Methods: A cross-sectional survey was conducted among 181 self-reported waterpipe smokers. Participants were approached in public places as well as in shisha cafes in Qatar. The questionnaire included items related to perception, attitude and intention to quit. Both descriptive and inferential statistics were performed for data analyses, with P ≤ 0.05 considered statistically significant. Results: About 44% of the respondents believed that waterpipe smoking was safer than cigarette smoking, and more than 70% would not mind if their children became involved in waterpipe smoking. More than half of the current smokers wanted to quit smoking shisha at some point, and 17% identified health concerns as the main motivating factor for their intention to quit. Conclusion: A large proportion of shisha smokers viewed shisha as a safer alternative to cigarettes, yet they admitted to intending to quit. These findings underscore the need to design educational interventions and awareness campaigns as well as impose stringent laws on waterpipe smoking in public places in Qatar.Undergraduate Research Experience Program (UREP) grant (UREP 13-063-3-016) from the Qatar National Research Fund (a member of the Qatar Foundation)

Evaluation of the gulf of aqaba coastal water, Jordan

© 2020 by the authors. (1) Background: The Gulf of Aqaba (GoA) supports unique and diverse marine ecosystems. It is one of the highest anthropogenically impacted coasts in the Middle East region, where rapid human activities are likely to degrade these naturally diverse but stressed ecosystems. (2) Methods: Various water quality parameters were measured to assess the current status and conditions of GoA seawater including pH, total dissolved solids (TDS), total alkalinity (TA), Cl-, NO3-, SO42-, PO43-, NH4+, Ca2+, Mg2+, Na+, K+, Sr, Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn. (3) Results: The pH values indicated basic coastal waters. The elevated levels of TDS with an average of about 42 g/L indicated highly saline conditions. Relatively low levels of inorganic nutrients were observed consistent with the prevalence of oligotrophic conditions in GoA seawater. The concentrations of Ca2+, Mg2+, Na+, K+, Sr, Cl-, and SO42- in surface layer varied spatially from about 423-487, 2246-2356, 9542-12,647, 513-713, 9.2-10.4, 22,173-25,992, and 317-407 mg/L, respectively. The average levels of Cd, Co, Cr, Cu, Fe, Mn, Pb and Zn ranged from 0.51, 0.38, 1.44, 1.29, 0.88, 0.38, and 6.05 μg/L, respectively. (4) Conclusions: The prevailing saline conditions of high temperatures, high evaporation rates, the water stratification and intense dust storms are major contributing factors to the observed seawater chemistry. The surface distribution of water quality variables showed spatial variations with no specific patterns, except for metal contents which exhibited southward increasing trends, closed to the industrial complex. The vast majority of these quality parameters showed relatively higher values compared to those of other regions