A Comprehensive Model for Anaerobic Degradation in Bio-Reactor Landfills

A new generation of sustainable landfill was designed and constructed in the City of Calgary, Canada to achieve sustainable municipal solid waste (MSW) management. This sustainable landfill called “biocell” involves sequential operation of a landfill cell to produce methane gas during the first stage of anaerobic degradation and in-situ composting within the cell footprint. Once methane recovery is minimal, the second stage aerobic degradation initiated by injecting air through methane recovery system and finally landfill is mined for resource and space recovery in the third stage. The resources that can be recovered include compost like material and recyclables such as plastics, metal, and glass. Non-recovered waste but with high energy content can be used as refuse derived fuel. The practice of this approach will no longer require the need to allocate valuable land for new landfills on an on-going basis. There is leachate re-circulation and environmental monitoring to enhance biodegradation in the biocell. The biocell eliminate problems of ground/surface water contamination, landfill gas emission and the need for new land to use for waste disposal. However, currently there is limited knowledge on landfill mining and in order to estimate the best time to initiate landfill mining a comprehensive mathematical model was developed. The model developed solves the mass and energy balance of waste decay, which computes the rate of gas generation, change of gas and gas flux through the system. This study focuses on anaerobic phase of biodegradation of biomass and the degradation of the biomass was assumed to follow first order kinetics. The decomposing bio mass is represented as cellulose for energy balance computation, which is a major constitution of the MSW. The degradation of bio mass due to micro-organisms generates methane, carbon dioxide and water as the final products and the reaction is exothermic. In this model using the decay of waste computed from mass balance and cellulose as equivalent chemical representing the waste a relationship between the mass degraded with time was established. The heat released due to anaerobic decay is computed and hence computes the increase in biocell temperature. Then selecting the representative decay constant for the computed biocell temperature, the decomposition of waste was computed for the next time step. The above computation is continued in order to obtain the landfill settlement, temperature and the movement of landfill gas and leachate

Fate of Zinc Oxide Nanoparticles Coated onto Macronutrient Fertilizers in an Alkaline Calcareous Soil

Citation: Milani, N., Hettiarachchi, G. M., Kirby, J. K., Beak, D. G., Stacey, S. P., & McLaughlin, M. J. (2015). Fate of Zinc Oxide Nanoparticles Coated onto Macronutrient Fertilizers in an Alkaline Calcareous Soil. Plos One, 10(5), 16. doi:10.1371/journal.pone.0126275Zinc oxide (ZnO) nanoparticles may provide a more soluble and plant available source of Zn in Zn fertilizers due to their greater reactivity compared to equivalent micron-or millimetresized (bulk) particles. However, the effect of soil on solubility, spatial distribution and speciation of ZnO nanoparticles has not yet been investigated. In this study, we examined the diffusion and solid phase speciation of Zn in an alkaline calcareous soil following application of nanoparticulate and bulk ZnO coated fertilizer products (monoammonium phosphate (MAP) and urea) using laboratory-based x-ray techniques and synchrotron-based mu-x-ray fluorescence (mu-XRF) mapping and absorption fine structure spectroscopy (mu-XAFS). Mapping of the soil-fertilizer reaction zones revealed that most of the applied Zn for all treatments remained on the coated fertilizer granule or close to the point of application after five weeks of incubation in soil. Zinc precipitated mainly as scholzite (CaZn2(PO4)(2)center dot 2H(2)O) and zinc ammonium phosphate (Zn(NH4)PO4) species at the surface of MAP granules. These reactions reduced dissolution and diffusion of Zn from the MAP granules. Although Zn remained as zincite (ZnO) at the surface of urea granules, limited diffusion of Zn from ZnO-coated urea granules was also observed for both bulk and nanoparticulate ZnO treatments. This might be due to either the high pH of urea granules, which reduced solubility of Zn, or aggregation (due to high ionic strength) of released ZnO nanoparticles around the granule/point of application. The relative proportion of Zn(OH)(2) and ZnCO3 species increased for all Zn treatments with increasing distance from coated MAP and urea granules in the calcareous soil. When coated on macronutrient fertilizers, Zn from ZnO nanoparticles (without surface modifiers) was not more mobile or diffusible compared to bulk forms of ZnO. The results also suggest that risk associated with the presence of ZnO NPs in calcareous soils would be the same as bulk sources of ZnO

Santalum album L. (Indian sandalwood) oil content variation of Welimada region, Sri Lanka

Indian sandalwood (Santalum album) has a cultural and economic attraction mainly because of its fragrant oil, known as Santalol, produced in the heartwood. Due to its woody, sweet aroma and fixative properties, Santalol is widely employed in the fragrance industry; in highly priced perfumes and for incenses. The increasing demand and price therefore, have produced a very high market interest.Welimada-Badulla region of Sri Lanka is accepted as the best geographical location for best growth of sandalwood trees with higher oil yields. However, according to the literature, sandalwood oil quantity varies within the same area even for the same size of trees. The present study was therefore initiated to identify the oil quantity variation in Welimada region due to diameter at breast height (dbh) and height of the tree, as well as the percentage of heartwood available.Samples from four different locations of Welimada area were collected for the present study. Core samples were extracted from the selected trees. Oil from each tree was extracted by hydro- distillation method. The dbh, height and the sapwood heartwood percentages were measured for the sample trees. The variations of oil content were then tested with dbh, height and heartwood percentage. Twenty three trees were used for the present study and the oil content of them varied from 0.05% to 4.28%. According to the results, the oil quantity did not significantly vary with diameter at breast height and percentage of heartwood but showed a negative correlation with height. Therefore, it can be concluded that sandalwood oil quantity does not vary with dbh and heartwood percentage. However more samples need to be analyzed to test the relationship between oil content and height of sandalwood trees.

Review on Photomicrography based Full Blood Count (FBC) Testing and Recent Advancements

With advancements in related sub-fields, research on photomicrography in life science is emerging and this is a review on its application towards human full blood count testing which is a primary test in medical practices. For a prolonged period of time, analysis of blood samples is the basis for bio medical observations of living creatures. Cell size, shape, constituents, count, ratios are few of the features identified using DIP based analysis and these features provide an overview of the state of human body which is important in identifying present medical conditions and indicating possible future complications. In addition, functionality of the immune system is observed using results of blood tests. In FBC tests, identification of different blood cell types and counting the number of cells of each type is required to obtain results. Literature discuss various techniques and methods and this article presents an insightful review on human blood cell morphology, photomicrography, digital image processing of photomicrographs, feature extraction and classification, and recent advances. Integration of emerging technologies such as microfluidics, micro-electromechanical systems, and artificial intelligence based image processing algorithms and classifiers with cell sensing have enabled exploration of novel research directions in blood testing applications.

Child Labour Utilization in the Tourism Industry: A Case Study from Ampara District in Sri Lanka

The tourism industry is considered as one of the world's fastest growing economic activities and the largest employer of manpower which generates millions of employment opportunities. Since tourism is a labour intensive industry there is an escalating demand for labour in different sectors of tourism. This demand becomes a critical issue due to reasons such as the scarcity of the trained and skilled human resource, lower salaries and wages and unwillingness among many people to pursue tourism-related employment. As a remedy to this critical issue, child labour has been used frequently. They have been employed in both formal and informal sectors of the tourism industry.  This situation is more common in the Sri Lanka tourism industry, especially in remote tourism regions.  The main objective of this research was to study the nature of child labour in the tourism industry of the Ampara district of Eastern Tourism region of Sri Lanka. After a preliminary survey, Ulla, Panama North and Panama West GNDs of the Ampara district of Eastern tourism region were selected as the study area. Applying judgment and purposive sampling techniques, 56 child workers and 19 accommodation establishments were selected as the sample. Both quantitative and qualitative methods such as questionnaire surveys, observations, interviews, group discussions and case studies were employed to collect data. The data was analyzed applying both qualitative and quantitative analytical methods. The overall findings of the study are discussed under several subheadings including the socioeconomic and family background of child workers, the existing nature and types of child labour, reasons for selecting of employment linked to tourism, places of work, salaries and wages, the nature of expenditure and problems faced by child workers. The overall findings of this study revealed that child workers have been employed in formal and informal sectors of the tourism industry. All the child labours are in the age range between 15 to 17 years. The most common form of utilizing child labour in the study area is as sellers. Economic burdens at home are the major reasons which draw the children to these jobs. Engaging in different activities, they are able to earn an income ranging from Rs. 3,000 to 15,000 and they have spent this income on different purposes. Since there are many problems related to child labour utilization active policies and plans are timely and significant to alleviate these problems.  KEYWORDS: Tourism Industry, Child Labour, Labour utilizatio

Prior exposure of graphic editing, video editing and animation software among new medical entrants at Faculty of Medicine, University of Kelaniya

Introduction: The use of graphic related educational materials is common in modern medicaleducation.Objectives: This study assesses the familiarity of graphic editing software (GES), video editingsoftware (VES) and animation software (AS) among new medical entrants.Methods: Moodle based self-administered questionnaire was given to new medical students who joinedthe Faculty of Medicine, University of Kelaniya in 2017.Results: There were 155 students in the batch where 66 (43%) were males. Thirty-nine percent (n=60)had used GES before entering to the faculty, among them 20% used GES at least once a month and55% reported to have at least an average skill level. Twenty-one percent (n=32) had used VES, amongthem 20% used it at least once and 24 % reported to have at least an average skill level. Ten percent(n=15) had used AS, among them 13% used it at least once and 11% reported to have at least an averageskill level. Students had used GES more than VES (P<0.01) and AS (P<0.01), and VES more than AS(P=0.01) before entering to the faculty.Conclusions: The majority of students had not used GES, VES and AS before entering to the facultyand it would be beneficial to teach this software to medical students. Self-assessment of skill level canunderestimate or overestimate the actual skill level of the student and can be identified as a limitationof the study

Comparison of the Early Childhood Oral Health Impact Scale (ECOHIS-4D) and Child Health Utility Index (CHU-9D) in children with oral diseases

First published: 09 October 2023. OnlinePublOBJECTIVE: Accurate assessment of child oral health is important for guiding economic evaluations and informing healthcare decision-making. Early Childhood Oral Health Impact Scale (ECOHIS-4D) is a preference-based instrument that measures the oral health-related quality of life of young children. The aim of this study was to compare the utility scores of ECOHIS-4D and Child Health Utility Index (CHU-9D), against an oral health indicator to evaluate which utility score corresponds better with the oral health indicator. METHOD: The ECOHIS-4D and CHU-9D were applied to 314 parent/child dyads from preschools in a primary healthcare setting in Perth, Western Australia. Four parameters were used to assess which instrument corresponds better with the oral health indicator (decayed, missing and filled teeth score-dmft score): (i) discrimination, the ability to discriminate between different clinical severity groups, (ii) external responsiveness, how much the utility values relate to the changes in dmft scores, (iii) correlation, the association between the two instruments and the related dimensions and (iv) differences in the utility values across the two instruments. RESULTS: Most participants (81%) were 2-6 years old, and nearly 50% had a dmft score <3. ECOHIS-4D demonstrated a superior ability to differentiate between dmft severity groups and respond to changes in dmft scores. A significant weak correlation was observed between dmft and ECOHIS-4D (-0.26, 95%, CI -0.36 to -0.15) compared to a non-significant very poor correlation between dmft and CHU-9D (0.01, 95% CI -0.12 to 0.10). The utility scores of the two instruments had relatively good agreement towards good health and weak agreement towards poor health. CONCLUSIONS: ECOHIS-4D, the oral health-specific instrument, is more sensitive in assessing children's oral health-related quality of life than the generic CHU-9D. Thus, ECOHIS-4D is more appropriate for utility estimates in economic evaluations of oral health-related interventions and resource allocation decision-making.Sucharitha R. Weerasuriya, Ruvini M. Hettiarachchi, Sanjeewa Kularatna, Alexia Rohde, Peter Arrow, Lisa Jamieson, Utsana Tonmukayakul, Sameera Senanayak

A key role for peroxynitrite-mediated inhibition of cardiac ERG (Kv11.1) K+ channels in carbon monoxide–induced proarrhythmic early afterdepolarizations

Exposure to carbon monoxide (CO) causes early afterdepolarization arrhythmias. Previous studies in rats indicated arrhythmias arose due to augmentation of the late Na+ current. The purpose of the present study was to examine the basis of CO-induced arrhythmias in guinea pig myocytes in which action potentials more closely resemble those of human myocytes. Whole-cell current- and voltage-clamp recordings were made from isolated guinea pig myocytes and also from HEK293 cells expressing wild-type or a C723S mutant form of Kv11.1 (ERG). We also monitored formation of peroxynitrite (ONOO-) in HEK293 cells fluorimetrically. CO, applied as the CO releasing molecule, CORM-2, prolonged action potentials and induced early after-depolarizations (EADs) in guinea pig myocytes. In HEK293 cells CO inhibited wild-type but not C723S mutant Kv11.1 K+ currents. Inhibition was prevented by an antioxidant, mitochondrial inhibitors or inhibition of nitric oxide formation. CO also raised ONOO- levels, an effect reversed by the ONOO- scavenger, FeTPPS which also prevented CO inhibition of Kv11.1 currents, and abolished the effects of CO on Kv11.1 tail currents and action potentials in guinea pig myocytes. Our data suggest that CO induces arrhythmias in guinea pig cardiac myocytes via ONOO--mediated inhibition of Kv11.1 K+ channel

Cancer and thrombosis: Managing the risks and approaches to thromboprophylaxis

Patients with cancer are at increased risk of venous thromboembolism (VTE) compared with patients without cancer. This results from both the prothrombotic effects of the cancer itself and iatrogenic factors, such as chemotherapy, radiotherapy, indwelling central venous devices and surgery, that further increase the risk of VTE. Although cancer-associated thrombosis remains an important cause of morbidity and mortality, it is often underdiagnosed and undertreated. However, evidence is accumulating to support the use of low-molecular-weight heparins (LMWHs) in the secondary prevention of VTE in patients with cancer. Not only have LMWHs been shown to be at least as effective as coumarin derivatives in this setting, but they have a lower incidence of complications, including bleeding, and are not associated with the practical problems of warfarin therapy. Furthermore, a growing number of studies indicate that LMWHs may improve survival among patients with cancer due to a possible antitumor effect. Current evidence suggests that LMWHs should increasingly be considered for the long-term management of VTE in patients with cancer