Development of a low cost method for breeding paracheirodon innesi (Neon Tetra) in captivity.

The Tetras are one of the most popular groups of fishes that are kept in modern aquaria. The neon tetra, Paracheirodon innesi, is one of the most popular tetras in the world and they are the second highest fish imported to the U.S both in numbers of individuals and total value, second only to the Guppy, Poecillia reticulate. The production of neon tetra in Sri Lanka is inadequate to fulfill the demand in export market since efforts of aquarists in breeding them has failed in most instances. Commercial breeding is done successfully in other countries but breeding in small scale has also reported not successful. Water pH is recognized as the main factor affecting on neon tetra breeding and artificially acidified fresh water is recommended. Pairs of brood fish have routinely spawned in acidified, soft water at 25 0 C (pH, 5.5—6.5, adjusted with phosphoric acid; total alkalinity, 3.2 mg 1-1 and total hardness, 6.0 mg I-I , as CaC03). Water was also conditioned with humic acids (0.04%). Water acidification is not a cost effective method for Sri Lanka and this study attempted to find an alternative low cost method to breed neon tetra in captivity. Twenty one glass aquarium tanks were settled inside the hatchery and rain water, river water and well water were used separately for the experiment. Temperature and the pH of water in each tank were recorded daily using a pH meter (EcoScan pH 5). Four sides of the tanks were covered with black polythene papers to control the light further. Brooders were introduced to the tanks (pair per tank) and after 24 hours the tanks were observed for the eggs. Brooders were removed from the tanks and 2 ppm methylene blue was added. Fry were started to feed with paramecium culture and fry were transferred to cement tanks after 10 days. Collected data were analyzed with Pearson Chi-Squire Test using Minitab 14 statistical package. The pH of rain water, river water and well water during the period of study were 6.2± 0.05, 8.0±0.04 and 7.5±0.05 respectively. Spawning and hatching were only observed in tanks filled with rain water. After the tetras were transferred to the cement tank, there was a 5% of reduction of the population. The results of the study has shown that the rain water has a significant effect (P<0.05) on the breeding of neon tetra. The reported rearing pH of the neon tetra is 6.9 — 7.4 and the breeding pH of the neon tetra is 5.5 — 6.5. The tropical rain forests in South American countries where neon tetra originated also have low pH level, low light condition and moderate temperature. These findings are directly compatible with the recent findings about the neon tetra breeding. Breeding of neon tetra with rain water is possible in aquarium condition. Use of rain water is a low cost method to breed neon tetra rather than using expensive chemicals

Superheating Field in Superconductors with Nanostructured Surfaces

We report calculations of a dc superheating field Hsh in superconductors with nanostructured surfaces. Numerical simulations of the Ginzburg-Landau (GL) equations were performed for a superconductor with an inhomogeneous impurity concentration, a thin superconducting layer on top of another superconductor, and superconductor-insulator-superconductor (S-I-S) multilayers.The superheating field was calculated taking into account the instability of the Meissner state with a nonzero wavelength along the surface, which is essential for realistic values of the GL parameter κ. Simulations were done for the materials parameters of Nb and Nb3Sn at different values of κ and the mean free paths. We show that the impurity concentration profile at the surface and thicknesses of S-I-S multilayers can be optimized to enhance Hsh above the bulk superheating fields of both Nb and Nb3Sn. For example, a S-I-S structure with 90 nm thick Nb3Sn layer on Nb can boost the superheating field up to ≈ 500 mT, while protecting the SRF cavity from dendritic thermomagnetic avalanches caused by local penetration of vortices

In vitro investigation of anti-inflammatory activity and evaluation of phytochemical profile of Syzygium caryophyllatum

This study examined the anti-inflammatory potential of an aquous root extract of Syzygium caryophyllatum (Family: Myrtaceae) and reference drug Declofenac sodium, invitro using heat induced egg albumin denaturation bio assay technique. The concentrations of the root extract used were 781.25, 1562.5, 3125, 6250 and 12500 μg/mL. While diclofenac sodum were 78.12, 156.25, 312.5, 625, 1250 and 2500 μg/mL. Both the extract (r2 = 0.97; P<0.05) and Diclofenac sodium (r2 = 0.87; P<0.05) displayed marked and concentration dependent inhibition of heat-induced protein denaturation with IC50 value of 6.229 *103 μ g/ml and ~1.704*108 μg/mL respectively. Phytochemical analysis of the extract revealed the presence of the flavanoids, phenols, tanins, alkaloids, saponins and amino acids. It is concluded that the aquous root extract of Sri Lankan grown Syzygium caryophyllatum possess marked in vitro antiinflammatory activity which is mediated possibly by flavanoids, tanins and alkaloids. This is a novel finding. Further the results scientifically justify the use of roots of Syzygium caryophyllatum in Sri Lankan traditional medicine to treat inflammation

A Study on the Exposure to E-Learning during COVID-19: Special Reference to Management Undergraduates of Non-State Universities

Education is a goal of every human being in this modern era. The remarkable growth in information technology and the internet over the past few years has propelled the need for the application of e-learning among the educational sectors. Due to the recent outbreak of the COVID-19 pandemic, Sri Lankan educational institutes were forced to transform to e-learning. Hence, it is essential to have a strong awareness on the engagement of students in this e-learning. The purpose of this study is to examine the level of exposure to e-learning with special reference to the management undergraduates of non-state universities in Sri Lanka. This study is a quantitative research study and&nbsp;is based on a deductive research approach. For data collection, researchers used a questionnaire based on a convenience sampling process. A sample of 332 students was considered from a total population of 2500 students including 3rd and 4th year management undergraduates from two non-state universities. The collected data were analysed using one sample t-test analysis and descriptive analysis using the Statistical Package for Service Solutions. The researchers used one sample t-test to predict the students' level of exposure to e-learning based on the mean value of e-learning. The results show that students had a high level of exposure to e-learning with a value of 3.92. In addition, it revealed that system quality, instructors’ quality, digital readiness and learners’ attitude are highly influential towards the students’ level of exposure to e-learning. Furthermore, descriptive analysis revealed that the average GPA achieved by undergraduates utilising e-learning is higher than by traditional learning with an average score of 3.35. The findings of this study can serve as a guideline for higher educational institutions in developing appropriate initiatives to uplift the e-learning exposure. The main limitation of the study was that only management undergraduates were taken into consideration. As a result, future researchers should focus their efforts on different faculty studies separately to explore the level of e-learning exposure in each one of them. Keywords: COVID-19, E-Learning, Exposure, GPA, Undergraduate

Nonlinear Dynamics and Dissipation of a Curvilinear Vortex Driven by a Strong Time-Dependent Meissner Current

We report numerical simulations of large-amplitude oscillations of a trapped vortex line under a strong ac magnetic field $H(t)=H\sin\omega t$ parallel to the surface. The power dissipated by an oscillating vortex segment driven by the surface ac Meissner currents was calculated by taking into account the nonlinear vortex line tension, vortex mass and a nonlinear Larkin-Ovchinnikov (LO) viscous drag coefficient $\eta(v)$. We show that the LO decrease of $\eta(v)$ with the vortex velocity $v$ can radically change the field dependence of the surface resistance $R_i(H)$ caused by trapped vortices. At low frequencies $R_i(H)$ exhibits a conventional increases with $H$, but as $\omega$ increases, the surface resistance becomes a nonmonotonic function of $H$ which decreases with $H$ at higher fields. The effects of frequency, pin spacing and the mean free path $l_i$ on the field dependence of $R_{i}(H)$ were calculated. It is shown that, as the surface gets dirtier and $l_i$ decreases, the anomalous drop of $R_{i}(H)$ with $H$ shifts to lower fields which can be much smaller than the lower critical magnetic field. Our numerical simulations also show that the LO decrease of $\eta(v)$ with $v$ can cause a vortex bending instability at high field amplitudes and frequencies, giving rise to the formation of dynamic kinks along the vortex. Measurements of $R_i(H)$ caused by sparse vortices trapped perpendicular to the surface can offer opportunities to investigate an extreme nonlinear dynamics of vortices driven by strong current densities up to the depairing limit at low temperatures. The behavior of $R_i(H)$ which can be tuned by varying the rf frequency or concentration of nonmagnetic impurities is not masked by strong heating effects characteristic of dc or pulse transport measurements

Numerical investigations on the influencing factors of rapid fire spread of flammable cladding in a high-rise building

This paper investigates aluminium composite panels (ACPs) to understand the fire behaviour of combustible cladding systems under different fire scenarios. A fire dynamics simulator (FDS) is used to develop the numerical model of full-scale fire tests of combustible cladding systems using the procedures of the British BS 8414.1 standards. The results obtained from the FDS models are verified with test data. Seven test scenarios are investigated with four distinct parameters, i.e., cavity barrier, air-cavity gap, panel mounting (with and without joining gaps between the panels), and material combustibility qualities. A critical air-cavity gap (50–100 mm) is established at which maximum fire spread is noticed. Furthermore, variations in the cavity barrier, panel mounting, and material combustibility significantly impact the rapid fire spread of ACP cladding systems and the internal failure criterion. The results from the present study can serve as a basis for future research on the full-scale fire-test development of combustible ACPs

Fire behaviour of insulation panels commonly used in high-rise buildings

The energy efficiency of buildings drives the replacement of traditional construction materials with lightweight insulating materials. However, energy-efficient but combustible insulation might contribute to the building’s fire load. Therefore, it is necessary to analyse the reaction-to-fire properties of various insulating materials to provide a better understanding of designing a fire-safe structure. In this study, reaction-to-fire tests were carried out to assess the fire behaviour of lightweight polystyrene insulating panels commonly employed in high-rise buildings. The flammability characteristics of expanded polystyrene (EPS) and extruded polystyrene (XPS) were determined using a cone calorimeter under two distinct external irradiance regimes, 35 kW/m2 and 50 kW/m2, to approximate small to medium fire exposure situations. To investigate the effect of a fire-rated (FR) foil layer on a sandwich panel, three distinct test configurations were used: (i) sample without FR layer (standard sample), (ii) sample with FR layer (FR foil), and (iii) damaged layer (foil and vent) for EPS. Except for the smoke toxicity index (STI), the overall fire performance of EPS is superior to that of XPS. The findings of this study are useful in analysing fire performance and fire safety design for lightweight insulation panels

Development of an Innovative Mobile Phone-Based Newborn Care Training Application

Mobile infrastructure in low - and middle-income countries (LMIC) has shown immense potential to reach the unreachable. Healthcare providers (HCP) are one such group who are at the frontline of the fight against infant mortality in LMICs. Mortality among newborn infants (birth to 28 days) now accounts for around 45% of all under 5-years child mortality. Birth asphyxia is one of the three leading causes of newborn death; neonatal resuscitation training, among health care providers, reduces mortality from birth asphyxia. We have developed a mobile phone-based training app, called mobile Helping Babies Survive (mHBS), to support the training of health care providers on neonatal resuscitation. mHBS is integrated with the District Health Information System (DHIS2) platform, which is used in over 60 countries around the world. The mHBS/DHIS2 training app is a part of an application suite which includes another DHIS2-linked data collection app, mHBS tracker. The mHBS training application has the potential to scale-up integration with other neonatal training apps. Ultimately, the mHBS training suite will provide new insights into healthcare worker education along with the necessary tools for effective care of newborn babies

EFFECT OF GRAZING ON SOME PHYSIOLOGICAL PROPERTIES IN INTEGRATED FARMING SOILS.

The objective of this study was to investigate the effect of grazing on somesoil properties; bulk density (BD), true density, porosity, moisture content(Me) and pH. The effect of long term grazing (&gt;20 yrs) was examined in acoconut - pasture - cattle integrated farming system in Kamburupitiya area.Short term grazing effect was compared with an adjoining coconut plantationpermitting 18 buffaloes to graze for 6 months. Another adjoining ungrazedcoconut farm soil was considered as control. Soil samples were taken fromthe topsoil using a core sampler (v = 98.21 em"). Four replicate samples weretaken three times with 30 days interval and analyzed in triplicates. Data werestatistically analyzed using SAS.Soils collected from the long term integrated farming site had a significantlyhigher (p &lt; 0.05) average pH (5.58) than that of non-integrated sites (4.65).Reduction of acidity may be due to the improvement of soil nutrients viadung, urine and accumulation of litter. It was observed that the soil inintegrated sites were comparatively dark in color. BD of integrated soil(1.15g/cm3) was significantly lower than that of non-integeated soil (21.26%)due to the better ground cover by dominant prostate type herbages comparedto ungrazed soils where erect type herbages were prominent. Soil porosityalso improved due to integration (47.76%) with that of non-integrated soil(43.76%). There was no significant difference observed under the effect ofshort term grazing. A considerable time period may be required to change toimproved soil properties.It is concluded that long term crop-livestock integration could improve thesoil physiochemical properties

EFFECT OF BUFFALO GRAZING ON PLANT SPECIES DIVERSITY IN A COCONUT-PASTURE-CATTLE INTEGRATED SYSTEM

The effects of long and short-term buffalo grazing on plant species diversityunder coconut were examined. 18 Murrah and Surthi pure and crossbredbuffaloes were allowed to graze 3 hours a month for 6 months (short termgrazing). Herbage from an adjoining coconut plantation was taken as thecontrol. Quadrate sampling was adopted to analyze herbage up to specieslevel and four random samples were taken at each event.The Shannon diversity Index (H), species richness and evenness werecalculated for each treatment.Results showed that the diversity index and evenness in the undisturbedhabitat (ungrazed coconut plantation) were 2.176 and 0.6679 respectively andwere much higher than highly disturbed habitat (grazed plantation) where thesame values were 0.4.747 and 0.2160. The short term grazing effect showedan intermediate results. In the ungrazed site there were greater number ofplant species and more equitable the individuals in the community weredistributed. Long term grazed coconut plantation had only 9 species and over80% of the individuals belong to one species; Carpet grass (Axonopus affinis)the most common species in a grazing land. Grazing pressure was favorableto dominate prostate type plants. It was shown that grazing pressure whethershort term or long term changed the abundance of plant species.It is concluded that different levels of disturbance have different effects onplant species diversity