70 research outputs found

    Spatial and temporal variations in trace metal concentrations in sediments, pore water of the Forth estuary, and their potential impact on water quality

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    The concentrations of trace metals: cadmium, copper, nickel, lead and mercury, in addition to aluminium, iron and manganese were determined in the sediments and pore water (except aluminium) of the Forth estuary. Organic matter (as loss on ignition), total organic carbon (TOe), total organic nitrogen (TON), particle size and redox potential were also determined in the sediments. In addition, chloride, sulphate, conductivity, alkalinity, pH, dissolved organic carbon, phosphate and nitrate were determined in the sediments pore water. Trace metals in the pore water were determined using a modified preconcentration technique and measurements were carried out by graphite furnace. Mercury was measured using the p.s.a mercury specific fluorescence detector. organic matter (TOC & TON) in the sediments were measured using CHNS/O analyzer. Samples were collected at seasonal intervals for a period of 18 months on board the survey vessel "Forth Ranger". Six stations were selected to represent upper, middle and lower estuary. Sediment cores collected at each station were subjected to centrifugation under nitrogen gas atmosphere to separate the pore water after being sectioned at 2.5 cm intervals for a depth of 10 centimetres. Concentrations of trace metals in the Forth estuary varied from station to station and from one season to another. Mean concentrations for sediments were as follows (mg\kg): lead, 56.9; cadmium, 0.22; copper, 38.9; nickel, 33.7 and mercury, 1.86. For pore water, the mean concentraxxi tions (Jlg\l) were as follows: lead, 3.14; cadmium, 1.86; copper, 31.9; nickel, 24.7 and mercury, 0.075. Measurements of sulphates, nitrates, phosphate, conductivity and dissolved organic carbon were used to examine the processes controlling their distributions in the pore water. The results indicated that the distributions of nutrients (phosphate and nitrate) in the upper 10 cm seemed to be controlled by macro-infaunal irrigation activities and their values varied according to the overlying water conditions. The distributions of trace metals in the sediments were found to be controlled by particle size and organic matter both spatially and temporally. Vertical distribution of trace metals in the pore water were found to be controlled by redox potential variations especially for iron and manganese. Concentrations of trace metals (Pb, Hg, Ni, Cd and CU) in the pore water were found to be higher than that in the overlying water. Enrichment factors were limited to 10-50 fold increase. Lead and mercury were 10 fold higher while 50 fold higher were found for nickel, copper and cadmium. Benthic flux calculations showed a significant flux of trace metals both in the summer and winter. However, flux of copper, nickel and lead tended to increase in the summer. Spatially, the lower estuary showed a higher flux of trace metals than the upper and middle reaches of the estuary

    Decentralized Formation Selection Mechanisms Inspired by Foraging Bottlenose Dolphins

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    Presented at the Mathematical Theory of Networks and Systems, Blacksburg, VA, July 2008

    A High-Resolution Earth Observations and Machine Learning-Based Approach to Forecast Waterborne Disease Risk in Post-Disaster Settings

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    Responding to infrastructural damage in the aftermath of natural disasters at a national, regional, and local level poses a significant challenge. Damage to road networks, clean water supply, and sanitation infrastructures, as well as social amenities like schools and hospitals, exacerbates the circumstances. As safe water sources are destroyed or mixed with contaminated water during a disaster, the risk of a waterborne disease outbreak is elevated in those disaster-affected locations. A country such as Haiti, where a large quantity of the population is deprived of safe water and basic sanitation facilities, would suffer more in post-disaster scenarios. Early warning of waterborne diseases like cholera would be of great help for humanitarian aid, and the management of disease outbreak perspectives. The challenging task in disease forecasting is to identify the suitable variables that would better predict a potential outbreak. In this study, we developed five (5) models including a machine learning approach, to identify and determine the impact of the environmental and social variables that play a significant role in post-disaster cholera outbreaks. We implemented the model setup with cholera outbreak data in Haiti after the landfall of Hurricane Matthew in October 2016. Our results demonstrate that adding high-resolution data in combination with appropriate social and environmental variables is helpful for better cholera forecasting in a post-disaster scenario. In addition, using a machine learning approach in combination with existing statistical or mechanistic models provides important insights into the selection of variables and identification of cholera risk hotspots, which can address the shortcomings of existing approaches

    The Reconstruction of General Election with “Noken” System on the President and Vice President Election in Indonesia

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    The diversity of values ​​that live in the community has entered into the electoral system in Indonesia. Direct election systems, in Papua - Indonesia, precisely in some customary areas, the community uses the “noken” system in elections. This research is a normative and empirical research to determine and examine the legal substance aspect and legal structure to the organizer of General Election in Indonesia. The results shows that the implementation of Noken system in the general elections in Papua Province use two systems in the general election, namely Big Man system and hanging or noken system. The Big Man system is done by means of all voting submitted to the chieftain while noken system the community comes alone to the polling staton, see and put ballot to the party pocket that had previously been agreed. Both systems are just according to their will in accordance with the beliefs and customs of people in the mountainous region of Papua. Noken system in the Big Man system and hanging system or binding system by the customary law represents accommodation in consensus and agreement, based on indigenous values ​​and local wisdom in indigenous cultures in the mountainous regions of Papua. This consensus process is interpreted as a democracy of indigenous peoples. Keywords: General Election, Election System, Indigenous Peoples, Noke

    One-Pot Synthesis of 5,6-Dihydro-4H-1,2-Oxazines by Cyclization of Ketoximes with Derivatives of Allylbenzene

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    A new series of 5,6-dihydro-4H-1,2-oxazines were synthesized via hetero Diels-Alder reaction of  α-nitrosolefins with derivatives of allylbenzene. α-Nitrosoolefins were generated from ketoximes by the action of chloramine-T and triethylamine

    DNA Fingerprints of Two Tilapia Fish Species of Euphrates River at Governorate ofAl-Muthanna Using RAPD Markers

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    During the last decade, tilapia species (Cichlidae: Teleostei) becamemembers of Iraqi fish fauna. They characterized with morphological similarity amonggenera and species. That makes species differentiation not easily. Molecular methodsfollowed to differentiate between redbelly tilapia Coptodon zillii (Gervais, 1848) andblue tilapia Oreochromis aureus (Steindachner, 1864) of the Euphrates River sectorat Al-Samawah city. RAPD-PCR method used to create the genetic fingerprints of twotilapia fish species. Seven decamer primers (OPA08, OPA10, OPA13, OPA17,OPA19, OPB08 and OPC02) used to amplify DNA fragments using PCR-RAPDtechnique. Forty-four bands scored after electrophoresis on 2% agarose gel alongwith molecular marker fragmented to each 100 base pair. The molecular weight ofbands was calculated using PhotoCapt-MW software. The volume of bands rangedfrom C. zillii 168 bp to 2227 bp while they ranged from 62 bp to 2154 bp in O.aureus. The results achieve the RAPD fingerprints of two tilapia species in EuphratesRiver at for genetic Al-Samawa city and draw the genetic tree with the same speciesfrom Shatt A-Arab River in Basrah city. The study concluded that there is the closestrelatedness among tilapia populations from Euphrates and Shatt Al-Arab Rivers. Theresults proved that RAPD markers were efficient to generate DNA fingerprints oftilapia fish species. Furthermore, the utilizing of the RAPD markers can differentiatethe two studied species. The present study may be the first genetic study on thesetilapia fish species. Moreover, this would be the baseline studies in the future. Inaddition, this study would be valuable for conservation program and documentationof identities of tilapia fish species in Iraqi inland water

    Development of microextraction methods for the determination of sulfamethoxazole in water and biological samples: modelling, optimization and verification by central composite design

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    This study aimed to preconcentration of sulfamethoxazole (SMX) in water and biological samples. Ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) and ultrasound-assisted dispersive solid-phase microextraction (UA-DSPME) methods paired with spectrophotometry were applied to extraction and preconcentration of SMX. ZnFe2O4 nanoparticles were prepared as adsorbent in UA-DSPME method by hydrothermal method. The scanning electron microscopy (SEM) technique showed that the adsorbent had symmetrical, bullet-shaped particles with uniform size. The results of the X-ray diffraction (XRD) showed the successful synthesis of the ZnFe2O4 nanoparticles. Effective parameters in extraction, including ultrasonication time, disperser solvent volume, adsorbent amount, extraction solvent volume, eluent volume, and pH were investigated and optimized. The practical and optimal conditions of the process were determined by the central composite design (CCD). The optimal conditions were 0.024 g of adsorbent, 535 µL of disperser solvent volume, 7.5 min of ultrasonication time, 235 µL of eluent volume, pH of 5, and 185 µL of extraction solvent volume. Linear ranges and detection limits were 20–1,200 μg L−1 and 6 μg L−1 for UA-DSPME and 10–800 μg L−1 and 3 μg L−1 for UA-DLLME. Relative standard deviation (RSD) of less than 4% were obtained for UA-DSPME and UA-DLLME methods. The reusability showed that the ZnFe2O4 adsorbent could extract SMX up to five cycles of adsorption/desorption without significant reduction in its efficiency. Also, interference studies showed that the presence of different cations and anions did not significantly interfere in the extraction of SMX. The outcomes of real-time samples analysis showed that the extraction of SMX for both methods was in the range of 92.44%–99.12%. The results showed the developed methods are simple, sensitive, and suitable for SMX preconcentration in environmental water and biological samples

    Identification and characterization of antibacterial compound(s) of cockroaches (Periplaneta americana)

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    Infectious diseases remain a significant threat to human health, contributing to more than 17 million deaths, annually. With the worsening trends of drug resistance, there is a need for newer and more powerful antimicrobial agents. We hypothesized that animals living in polluted environments are potential source of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of microbes, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances. Here, we characterized antibacterial properties in extracts of various body organs of cockroaches (Periplaneta americana) and showed potent antibacterial activity in crude brain extract against methicillin-resistant Staphylococcus aureus and neuropathogenic E. coli K1. The size-exclusion spin columns revealed that the active compound(s) are less than 10 kDa in molecular mass. Using cytotoxicity assays, it was observed that pre-treatment of bacteria with lysates inhibited bacteria-mediated host cell cytotoxicity. Using spectra obtained with LC-MS on Agilent 1290 infinity liquid chromatograph, coupled with an Agilent 6460 triple quadruple mass spectrometer, tissues lysates were analyzed. Among hundreds of compounds, only a few homologous compounds were identified that contained isoquinoline group, chromene derivatives, thiazine groups, imidazoles, pyrrole containing analogs, sulfonamides, furanones, flavanones, and known to possess broad-spectrum antimicrobial properties, and possess anti-inflammatory, anti-tumour, and analgesic properties. Further identification, characterization and functional studies using individual compounds can act as a breakthrough in developing novel therapeutics against various pathogens including superbugs
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