428 research outputs found

    Utilization of aquatic plants: a method to enhance the productivity of water in seasonal tanks in the Anuradhapura District

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    Heavy infestations of aquatic plants in a water body cause considerable economic and ecological losses. Many seasonal tanks in the Anuradhapura District suffer from this problem and cannot be neglected in water resource development and management schemes. This study was focused on the uses of aquatic plants and the problems caused by huge manifestations of aquatic plants in the selected seasonal tanks in the Anuradhapura District. The study was conducted in four seasonal tanks viz., Galkulama, Thirappane Maradankadawala and Thibbatuwewa in the Anuradhapura District. Information on the utilization of aquatic plants, exploitation level and harmful effects were gathered by using a structured questionnaire to interview people who were residing close to the study sites. The attitudes of the public towards the aquatic plants i.e., conservation of aquatic plants, the potential uses of native plants and harmful effects of invasive aquatic plants were collected. Twelve species were identified as economically important aquatic plants through the questionnaire survey. Among the 50 respondents, 92 % utilized aquatic plants for food, 58 % utilized flowers for offerings and decorations, 52 % utilized aquatic plants for medicinal purposes, 42 % utilized them as ornamental plants, 30 % used them as bio-fertilizers and 28 % utilized them for weaving. The edible aquatic plants consumed by the rural community in the Anuradhapura District are Ipomoea aquatica (72 %), Alternanthera sessilis (66 %), Nelumbo nucifera (64 %), Nymphaea pubescens (60 %) and Aponogeton spp. (52 %). Some edible aquatic plants, namely Neptunia oleracea, Ottelia alismoides and Ceratopteris thalictriodes, which are present in the Anuradhapura District, are not consumed, although these are consumed in many other countries. N. nucifera is the most commonly used flower for offerings in the temples and for decorations. In addition, N. pubescens, Nymphaea nouchali are also used for flowers. Bacopa monnieri, N. nucifera, Acanthus illicifolia, N. nouchali and Aponogeton spp. have been recorded as medicinally important plants. Though there are many ornamentally important aquatic plants, only N. pubescens, N. nouchali, B. monnieri, Nymphoides hydrophylla are used. Salvinia molesta and Eichhornia crassipes are the two aquatic plants commonly used as bio fertilizers. With reference to the questionnaire survey, there were seven major problems that were discovered to exist due to heavy infestations of aquatic weeds in the water bodies viz., sedimentation and unsuitability for domestic use, interference with navigation, effects on fisheries, blocking irrigation canals and evapotranspiration. The most problematic plants in the Anuradhapura District include E. crassipes, N. nucifera, S. molesta, Pistia stratiotes and Ceratophyllum demersum. Economically important aquatic plants available in the shallow water bodies of the Anuradhapura District, are marginally utilized, when compared with the utilization of aquatic plants in the global scenario. There appears to be a lack of a well organized action plan to cope with this situation. The public suffer a lot from the problems created by the heavy mass of aquatic plants, which covered the village tanks. The public are, however, willing to get organized and to engage in a participatory approach to restore their water bodies. There is a need for research and development of management strategies for the sustainable utilization of these valuable resources. Awareness programs should be conducted to promote sustainable utilization of aquatic plants. Creating awareness among the people about the nutritional and economic benefits of these natural resources will be useful for Sri Lanka, as a developing nation.Length: pp.23-32Aquatic plantsTanks

    Interworking between WLAN and 3G Cellular Networks: An IMS Based Architecture

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    In this paper, a novel architecture for interworking of the Wireless Local Area Network (WLAN) and the Third Generation (3G) mobile cellular network is presented. This architecture is a hybrid model with additional controls compared with the existing architectures and the use of IP Multimedia Subsystem (IMS), as an arbitrator for coupling and real-time session management. Furthermore, a new networking entity called a mobility manager has been introduced within the IMS for seamless management of vertical handoffs. Efficient strategies for IP address distribution and bypassing high traffic loads form the cellular core network are other benefits of this architecture

    Wireless VPNs: An evaluation of QoS metrics and measures

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    Impact of Destination Attributes on Tourists Destination Selection: With Special Reference to Cultural Triangle of Sri Lanka

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    Sri Lanka is one of the fastest-growing tourist destinations in the world. Amongst tourists’attractions, “Cultural Triangle”, a region of the cultural heritage of the country has becomethe highest income generating destination. However, when compared with the othertourists’ destinations of the country, the number of tourists visiting the cultural triangle islow. As the literature reveals, the attributes of the destination matter in destinationselection by the international tourists. Thus, considering the importance of this region asthe top income contributor but not in terms of the number of tourists' visits, this studyproblematizes the impacts of destination attributes on tourist`s destination selection.Accordingly, the objective of this study is to identify the destination attributes and theirrelationship with the tourists’ destination selection decisions. Data was collected throughquestionnaires from a sample of 222 foreign tourists who visited the cultural triangleduring 2019 through a selected travel agent. Results of the multiple regression analysisrevealed that attributes of Amenities, Destination Attractions, Accessibility, AncillaryServices, and Destination Environment as having a moderate positive relationship whilst,the service quality weak positive relationship with Tourist’s Destination selection.Destination attraction was identified as the most influential factor of all attributes. Thefindings of this study can be used by policymakers in developing destinations for tourists’attractions in the country

    The Floodwater Depth Estimation Tool (FwDET v2.0) for improved remote sensing analysis of coastal flooding

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    Remote sensing analysis is routinely used to map flooding extent either retrospectively or in near-real time. For flood emergency response, remote-sensing-based flood mapping is highly valuable as it can offer continued observational information about the flood extent over large geographical domains. Information about the floodwater depth across the inundated domain is important for damage assessment, rescue, and prioritizing of relief resource allocation, but cannot be readily estimated from remote sensing analysis. The Floodwater Depth Estimation Tool (FwDET) was developed to augment remote sensing analysis by calculating water depth based solely on an inundation map with an associated digital elevation model (DEM). The tool was shown to be accurate and was used in flood response activations by the Global Flood Partnership. Here we present a new version of the tool, FwDET v2.0, which enables water depth estimation for coastal flooding. FwDET v2.0 features a new flood boundary identification scheme which accounts for the lack of confinement of coastal flood domains at the shoreline. A new algorithm is used to calculate the local floodwater elevation for each cell, which improves the tool\u27s runtime by a factor of 15 and alleviates inaccurate local boundary assignment across permanent water bodies. FwDET v2.0 is evaluated against physically based hydrodynamic simulations in both riverine and coastal case studies. The results show good correspondence, with an average difference of 0.18 and 0.31 m for the coastal (using a 1 m DEM) and riverine (using a 10 m DEM) case studies, respectively. A FwDET v2.0 application of using remote-sensing-derived flood maps is presented for three case studies. These case studies showcase FwDET v2.0 ability to efficiently provide a synoptic assessment of floodwater. Limitations include challenges in obtaining high-resolution DEMs and increases in uncertainty when applied for highly fragmented flood inundation domains

    Blockchain and SDN Architecture for Spectrum Management in Cellular Networks

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    Whereas 4G LTE networks have brought about an increase in data rates of mobile networks, they are unable to meet the capacity demands of future networks. Specifically, the centralized nature of the evolved packet core (EPC) makes the network non-scalable to match the exponential increase in number of wireless devices in addition to the complexities of diverse service requirements. The SDN concept has recently attracted a lot of research interest as a viable proposition for bringing about programmability and ease of network management while also offering flexibility for innovative network designs. However, current SDN implementations are not adapted to support business agreements that foster interoperability among mobile network operators (MNOs). This paper is an extended version of our earlier work and we intend to present a unified SDN and blockchain architecture with enhanced spectrum management features for enabling seamless user roaming capabilities between MNOs. Our simulation results show that users can experience no disruption in service with very minimal delay as they traverse between operators

    Low temperature gas sensing properties of Graphene Oxide/SnO2 nanowires composite for H-2

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    In this work Graphene Oxide (GO) and SnO2 nanowires (NWs) composite sensing performance were studied. Single crystal SnO2 NWs were directly grown by thermal evaporation method and GO was successfully synthesized using modified Hummers method. RF magnetron sputtered Pt particles were used as a catalyst for the growth of SnO2 NWs. Drop cast technique was used to deposited GO on top of the SnO2 NWs. FE-SEM (LEO 1525) was used to investigate the morphology of SnO2 NWs and GO. Fabricated sensors were tested towards various concentration of H-2 at different working temperatures. This GO/SnO2 hybrid sensors show a reversible response to H-2 at low operating temperature. (C) 2016 The Authors. Published by Elsevier Ltd

    A holistic approach to dissecting SPARC family protein complexity reveals FSTL-1 as an inhibitor of pancreatic cancer cell growth.

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    SPARC is a matricellular protein that is involved in both pancreatic cancer and diabetes. It belongs to a wider family of proteins that share structural and functional similarities. Relatively little is known about this extended family, but evidence of regulatory interactions suggests the importance of a holistic approach to their study. We show that Hevin, SPOCKs, and SMOCs are strongly expressed within islets, ducts, and blood vessels, suggesting important roles for these proteins in the normal pancreas, while FSTL-1 expression is localised to the stromal compartment reminiscent of SPARC. In direct contrast to SPARC, however, FSTL-1 expression is reduced in pancreatic cancer. Consistent with this, FSTL-1 inhibited pancreatic cancer cell proliferation. The complexity of SPARC family proteins is further revealed by the detection of multiple cell-type specific isoforms that arise due to a combination of post-translational modification and alternative splicing. Identification of splice variants lacking a signal peptide suggests the existence of novel intracellular isoforms. This study underlines the importance of addressing the complexity of the SPARC family and provides a new framework to explain their controversial and contradictory effects. We also demonstrate for the first time that FSTL-1 suppresses pancreatic cancer cell growth

    Evaluation of salt content and effectiveness of excessive salt reduction methods in selected commercially available dried fish types in Sri Lanka

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    High salt intake elevates the risk of non-communicable diseases such as high blood pressure, cardiovascular diseases and stroke worldwide. Sri Lanka has recorded in 2010 as the country with highest average fish & fish products consumption in South Asia. In the current study, salt in ten types of commonly available dried fish namely; sprats, prawns, smoothbelly sardinella, queen fish, cat fish, sail fish, shark, skipjack tuna, Bombay duck and trenched sardinella was analyzed and determined salt reduction methods with minimal protein loss. Four salt reduction methods were tested; Method 1: washed with water at Room Temperature (RT) for five times; Method 2: washed with water for five times at RT and kept in hot water for 5min; Method 3: washed with water for five times at RT and boiled for 5min; Method 4: washed with water for five times at RT and kept in coconut water for 5min. Using Volhard method, sodium chloride was analyzed while protein was determined using Kjeldahl method. All four methods showed significant reduction of salt level in tested dried fish (p < 0.05). Among the tested salt reduction methods, Method 3 showed the highest salt reduction for all types of dried fish except smoothbelly sardinella and cat fish.The highest salt mean value of 28.8% was recorded in queen fish and the lowest mean value of 12.8% was recorded in smoothbelly sardinella. The highest protein loss was recorded in Method 3. To reduce considerable amount of salt, the easiest and fairly effective method is method 1 except for prawns and Shark. Although higher salt reduction showed in method 2 and 3, they are not recommended due to high protein loss, high energy expenditure and reduction of freshness of dried fish. Method 4 can be applied for all dried fish types because it is economical and reduces considerable amount of salt, removes less amount of protein comparatively. The results revealed that all tested dried fish except smoothbelly sardinella contain significantly high amount of salt (p < 0.05) than the standard value specified (12%) by the Sri Lanka Standards Institution (SLSI).Keywords: Dried fish, protein loss, salt-intake, salt reduction, non-communicable disease
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