Landslide and Subsidence Potential due to the Progressive Development of Cave Network in Ella-Wellawaya Area, Sri Lanka

Carbonate rocks are highly soluble. Sinkholes are formed by both the failure of solution cavities andthe rapid removal of fines from solution cavities in carbonate and metacarbonate rocks. Sri Lankanlandmass is composed of Proterozoic high-grade metamorphic rocks such as gneiss andmetacarbonates like marble. Large caves in Sri Lanka form in both marble and gneiss. A few landsubsidence events have occurred recently in Ella-Wellawaya area, which is a hilly terrain. In addition,some cases of groundwater table lowering, which has caused drying of dug wells have also beenrecorded within the area, apparently related to a major development project presently under way in thearea.The main objective of this paper is to draw the immediate attention of local researchers andauthorities whom are working on mitigation and management of disasters, groundwater and climatechange, showing the importance of carrying out detail studies on potential landslides and landsubsidence of Ella-Wellawaya area for avoiding and minimising loss of humans and properties.Preliminary surveys on some land subsidence cases and speleological studies including geology,hydrogeology and morphological mapping of the underground caves in the area have been activelycarried out. According to the results, it is shown that the subsidence is likely to be correlated with thecollapsing of cavities and weathered zones in metacarbonates, and disturbances to the groundwatertable. Field explorations done during the last two years have discovered several large undergroundcaves in the area some more than 100 m across. Most of the cave roofs have been thinned by thebreakdown of bedrock along weak zones such as joints. Since the process of collapse, trigged byweathering is continuing and patches and lenses of carbonate rocks observed in the caves are stillbeing dissolved, the expansion of the cave spaces is unending. Some of the chambers of these cavesare aligned parallel to the steep slopes in the Ella-Wellawaya area and some acted as undergroundwater conduits and storages during the rainy seasons. The Ella-Wellawaya area has been undergone achange in vegetation cover since the colonial period and hence the area is more prone to soil erosionwhich exposes the near surface natural cavities to the underground caves. Present human exposuresand interactions within the susceptible slopes have brought lives and properties under threat. Hencefuture land subsidence and landslide occurrences are highly predictable with the recent conditions inthe area and hence threat to human life and properties is high. The tourism industry, unique to the areacould particularly be affected. Hence such hazardous should properly be identified and demarcatedand the erosion triggered by present vegetation changes must properly be addressed.Keywords: Metacarbonate rocks, Subsidence, Ella-Wellawaya, Cave network, Erosio

Systematic Review of Medicine-Related Problems in Adult Patients with Atrial Fibrillation on Direct Oral Anticoagulants

New oral anticoagulant agents continue to emerge on the market and their safety requires assessment to provide evidence of their suitability for clinical use. There-fore, we searched standard databases to summarize the English language literature on medicine-related problems (MRPs) of direct oral anticoagulants DOACs (dabigtran, rivaroxban, apixban, and edoxban) in the treatment of adults with atri-al fibrillation. Electronic databases including Medline, Embase, International Pharmaceutical Abstract (IPA), Scopus, CINAHL, the Web of Science and Cochrane were searched from 2008 through 2016 for original articles. Studies pub-lished in English reporting MRPs of DOACs in adult patients with AF were in-cluded. Seventeen studies were identified using standardized protocols, and two reviewers serially abstracted data from each article. Most articles were inconclusive on major safety end points including major bleeding. Data on major safety end points were combined with efficacy. Most studies inconsistently reported adverse drug reactions and not adverse events or medication error, and no definitions were consistent across studies. Some harmful drug effects were not assessed in studies and may have been overlooked. Little evidence is provided on MRPs of DOACs in patients with AF and, therefore, further studies are needed to establish the safety of DOACs in real-life clinical practice

Qualitative and quantitative assessment of plastic debris in the coastal eco system of Matara District, Sri Lanka

The current study was conducted to assess the types and amounts of plastic waste accumulated in the marine beaches and mangrove forest in Matara district, Southern Sri Lanka. Monitoring was conducted during October - November 2019 selecting five beach sites. The type and quantity of plastics accumulation in the sites were monitored in weekly intervals. The role played by local communities (Fisherman, villagers, hoteliers, NGOs and local authorities) to control the plastic accumulation in the marine environment was also evaluated through face to face semi structured interviews. Findings revealed that coastal plastic has become a barrier in maintaining both the aesthetic and environmental health of the coastline. This in turn impacted the local communities who relied on tourism and fishing. The study showed that most of the accumulated plastics on coastlines were polyolefins, polystyrene and other “float plastics”. Plastic debris have migrated through waterways from inland to the ocean. Local community actions such as beach cleaning and burning of plastic wastes have provided only temporary solutions. Therefore, more progressive measures are needed to be conducted to give sustainable solutions to coastal plastics. This could be achieved through education programs for all stakeholders involved in the plastic’s journey in the marine environment. Complementary solutions would be the provision of alternatives by devising technological solutions to divert plastic from the environment

Surface-Structured Bacterial Cellulose with Guided Assembly-Based Biolithography (GAB)

A powerful replica molding methodology to transfer on-demand functional topographies to the surface of bacterial cellulose nanofiber textures is presented. With this method, termed guided assembly-based biolithography (GAB), a surface-structured polydimethylsiloxane (PDMS) mold is introduced at the gas-liquid interface of an Acetobacter xylinum culture. Upon bacterial fermentation, the generated bacterial cellulose nanofibers are assembled in a three-dimensional network reproducing the geometric shape imposed by the mold. Additionally, GAB yields directional alignment of individual nanofibers and memory of the transferred geometrical features upon dehydration and rehydration of the substrates. Scanning electron and atomic force microscopy are used to establish the good fidelity of this facile and affordable method. Interaction of surface-structured bacterial cellulose substrates with human fibroblasts and keratinocytes illustrates the efficient control of cellular activities which are fundamental in skin wound healing and tissue regeneration. The deployment of surface-structured bacterial cellulose substrates in model animals as skin wound dressing or body implant further proves the high durability and low inflammatory response to the material over a period of 21 days, demonstrating beneficial effects of surface structure on skin regeneration

Surface-Structured Bacterial Cellulose with Guided Assembly-Based Biolithography (GAB)

A powerful replica molding methodology to transfer on-demand functional topographies to the surface of bacterial cellulose nanofiber textures is presented. With this method, termed guided assembly-based biolithography (GAB), a surface-structured polydimethylsiloxane (PDMS) mold is introduced at the gas–liquid interface of an <i>Acetobacter xylinum</i> culture. Upon bacterial fermentation, the generated bacterial cellulose nanofibers are assembled in a three-dimensional network reproducing the geometric shape imposed by the mold. Additionally, GAB yields directional alignment of individual nanofibers and memory of the transferred geometrical features upon dehydration and rehydration of the substrates. Scanning electron and atomic force microscopy are used to establish the good fidelity of this facile and affordable method. Interaction of surface-structured bacterial cellulose substrates with human fibroblasts and keratinocytes illustrates the efficient control of cellular activities which are fundamental in skin wound healing and tissue regeneration. The deployment of surface-structured bacterial cellulose substrates in model animals as skin wound dressing or body implant further proves the high durability and low inflammatory response to the material over a period of 21 days, demonstrating beneficial effects of surface structure on skin regeneration

Surface-Structured Bacterial Cellulose with Guided Assembly-Based Biolithography (GAB)

A powerful replica molding methodology to transfer on-demand functional topographies to the surface of bacterial cellulose nanofiber textures is presented. With this method, termed guided assembly-based biolithography (GAB), a surface-structured polydimethylsiloxane (PDMS) mold is introduced at the gas–liquid interface of an <i>Acetobacter xylinum</i> culture. Upon bacterial fermentation, the generated bacterial cellulose nanofibers are assembled in a three-dimensional network reproducing the geometric shape imposed by the mold. Additionally, GAB yields directional alignment of individual nanofibers and memory of the transferred geometrical features upon dehydration and rehydration of the substrates. Scanning electron and atomic force microscopy are used to establish the good fidelity of this facile and affordable method. Interaction of surface-structured bacterial cellulose substrates with human fibroblasts and keratinocytes illustrates the efficient control of cellular activities which are fundamental in skin wound healing and tissue regeneration. The deployment of surface-structured bacterial cellulose substrates in model animals as skin wound dressing or body implant further proves the high durability and low inflammatory response to the material over a period of 21 days, demonstrating beneficial effects of surface structure on skin regeneration