3,911 research outputs found
Isolation and Characterization of Plant growth-promoting Endophyticdiazotrophic Bacteria from Sri Lankan Rice Cultivars and Rapid Screening for their effect on Plant Growth Promotion
The present study was conducted to isolate and identify endophyticdiazotrophic bacteria in two Sri Lankan rice (Oryza Sativa L.) varieties; Suwandel and Bg 358 and to evaluate their potential to promote rice plant growth. A total of 15 putative endophyticdiazotrophic bacterial isolates were obtained from shoots and roots of Suwandel and Bg 358 rice varieties out of which 7 isolates were selected based on their ability to produce IAA and phosphate solubilization. According to the morphological characters and biochemical tests, these bacteria were identified belong to genera Bacillus (IN003, IN006, and IN007), Klebsiella (IN008 and IN018), Pantoea (IN009), and Enterobacter (IN015). All selected bacterial isolates produced IAA (7.1µmgl-1 to 30.9 µ mgl-1) in the tryptophan supplemented medium. Five out of seven bacterial isolates (IN006, IN007, IN008, IN015, and IN018) were able to solubilize inorganic phosphate on Pikovskaya\u27s agar medium. Rice seeds (Suwandel variety) treated with these endophyticdiazotrophic bacteria with plant growth-promoting ability showed significantly enhanced shoot length, root length, shoot fresh weight, shoot dry weight and root fresh weight compared to the uninoculated control. Plant inoculation experiment indicated that Enterobacter sp. (IN015) was most effective in rice plant growth promotion among seven bacterial isolates tested. These results strongly suggest that endophyticdiazotrophic bacteria characterized in this study could be successfully used to promote rice plant growth
AN ASSESSMENT OF BIODIVERSITY IN THE REKAWA, USSANGODA AND KALAMETIYA INLAND COASTAL ECOSYSTEMS IN SOUTHERN SRI LANKA
The survey was carried out to document the status of inland biodiversity in the Rekawa,Ussangoda and Kalametiya area along the Southern coastal zone of Sri Lanka. Thesurvey extended from October 2002 - March 2003 (6 months). A reconnaissance surveyof the inland areas was conducted, prior to the regular field sampling, in order to selectrepresentative sampling sites within the Ruk area. Eight sites were selected for regularfield sampling at fortnightly intervals, and the plants and animals of the area weresurveyed in a scientific manner, using appropriate sampling techniques.The survey area harbours a variety of natural and man-made vegetationlhabitat types,including both terrestrial and wetland systems. A total of 287 plant species belonging to222 genera under 94 families were documented from the above inland vegetationlhabitattypes of the Ruk area. Several sub types of Mangroves, based mainly on floristics, couldbe found in the RUK area. These include the Lumnitzera dominated stands (Rekawa),Ceriops dominated stands (Rekawa), Avicennia dominated stands (Rekawa), Mixedstands (Rekawa, Kahanda), Excoecaria dominated stands (between Lunawa andKalametiya) and Sonneratia dominated stands (Kalametiya, Malpeththawa). It isinteresting to note that some mangrove stands are represented by only a single species.A total of 328 species of vertebrates were recorded from the RUK area, of which 14species (4%) are endemic, while 27 species (8%) are nationally threatened. Thevertebrates include 52 species of fish, 17 species of amphibians, 49 species of reptiles,184 species of birds, and 26 species of mammals. The invertebrates include 72 species ofcolorful butterflies, 25 spec.es of terrestrial molluscs an": 9 species of aquatic molluscs.Three beach stretches that are important turtle nesting sites, eleven birding hotspots andthree bird roosting sites were identified within the RUK area.The study area has been identified for major development initiatives, under the SouthernDevelopment Programme of the Government of Sri Lanka. Therefore, the relevantconservation agencies should take steps to ensure that, biodiversity conservation concernsare adequately addressed in specific developmental activities planned for the area.
Diffusion and viscosity in a supercooled polydisperse system
We have carried out extensive molecular dynamics simulations of a supercooled
polydisperse Lennard-Jones liquid with large variations in temperature at a
fixed pressure. The particles in the system are considered to be polydisperse
both in size and mass. The temperature dependence of the dynamical properties
such as the viscosity () and the self-diffusion coefficients () of
different size particles is studied. Both viscosity and diffusion coefficients
show super-Arrhenius temperature dependence and fit well to the well-known
Vogel-Fulcher-Tammann (VFT) equation. Within the temperature range
investigated, the value of the Angell's fragility parameter (D )
classifies the present system into a strongly fragile liquid. The critical
temperature for diffusion () increases with the size of the
particles. The critical temperature for viscosity () is larger than
that for the diffusion and a sizeable deviations appear for the smaller size
particles implying a decoupling of translational diffusion from viscosity in
deeply supercooled liquid. Indeed, the diffusion shows markedly non-Stokesian
behavior at low temperatures where a highly nonlinear dependence on size is
observed. An inspection of the trajectories of the particles shows that at low
temperatures the motions of both the smallest and largest size particles are
discontinuous (jump-type). However, the crossover from continuous Brownian to
large length hopping motion takes place at shorter time scales for the smaller
size particles.Comment: Revtex4, 7 pages, 8 figure
Development of a Real-Time, Secure and Reliable Automobile Service Center
Lack of ambition will prevent you from moving forward in life, as much like a car without petrol. The majority of people on earth isobsessed with automobiles. We have provided you with a web application for Real time automobile service that functions effectively on all the platforms. Occasionally, automobiles and other motorized vehicles require maintenance. They must be maintained clean, just as humans practice proper hygiene. They run on dirty streets and in polluted environment. They are subjected to loads that harm them since they travel on uneven roads with obstacles. Therefore, it is necessary to maintain automobiles and other motorized vehicles on a regular basis. This project aims to keep service centers running smoothly in terms of things like vehicle maintenance, customer quotation generation, vehicle servicing, spare parts sales, customer information, and customer feedback. The system is efficient at generating reports that will make service center routine maintenance easy.Additionally, it can handle car repairs, insurance, payments, delivery, etc. This project will be very helpful to customers who want to fix or repair their cars. As a result, we develop a software that is both compatible and unique
FitFlame – Health and Fitness Coaching Application to Mitigate the Issues in the Current Applications
Online fitness coaches help people achieve a healthy lifestyle by offering customized solutions. The demand for professional coaching is expected to grow in the coming years. Nevertheless, no applications in the market address the problems in the coaching process. Today, coaches and clients had to use many third-party apps. The reason for this is that no single fitness coaching app offers communication and exercise-tracking features. Even though some apps meet some of these requirements, they are out of reach for most people's budgets. This paper aims to suggest a robust and full-fledged app to mitigate those issues. FitFlame is the name of the proposed app. Both coaches and clients can benefit from this app. Also, FitFlame is a fitness coaching system available on mobile and the web. It helps clients locate and contact coaches, subscribe to coaching plans, and track their progress. It does away with third-party programs and gives users a better experience
Normalization factors for magnetic relaxation of small particle systems in non-zero magnetic field
We critically discuss relaxation experiments in magnetic systems that can be
characterized in terms of an energy barrier distribution, showing that proper
normalization of the relaxation data is needed whenever curves corresponding to
different temperatures are to be compared. We show how these normalization
factors can be obtained from experimental data by using the
scaling method without making any assumptions about the nature of the energy
barrier distribution. The validity of the procedure is tested using a
ferrofluid of Fe_3O_4 particles.Comment: 5 pages, 6 eps figures added in April 22, to be published in Phys.
Rev. B 55 (1 April 1997
Kinetic Heterogeneities in a Highly Supercooled Liquid
We study a highly supercooled two-dimensional fluid mixture via molecular
dynamics simulation. We follow bond breakage events among particle pairs, which
occur on the scale of the relaxation time . Large scale
heterogeneities analogous to the critical fluctuations in Ising systems are
found in the spatial distribution of bonds which are broken in a time interval
with a width of order . The structure factor of the broken
bond density is well approximated by the Ornstein-Zernike form. The correlation
length is of order at the lowest temperature studied,
being the particle size. The weakly bonded regions thus identified evolve in
time with strong spatial correlations.Comment: 3 pages, 6 figure
Antifungal activity of secondary metabolites present in Psidium guajava leaves against dermatophytes
Dermatophytes are a group of fungi that commonly cause skin diseases in animals and humans. Psidium guajava is a fruit tree with high medicinal value commonly used to cure various skin ailments. Methanol leaf extract of Psidium guajava was used to screen for the antifungal activity against five species of dermatophytes; Epidermophyton floccosum, Trichophyton rubrum, T. mentagrophytes, Microsporum gypseum and M. canis. The antifungal activity of the extract was tested using the agar well diffusion method from which the methanol crude extract revealed the highest antifungal activity exhibiting 22.5 mm against E. floccosum. Preliminary analysis of secondary metabolites was performed for the methanol crude extract which revealed the presence of many bio-active compounds including saponins, steroids and alkaloids. It was then subjected to fractionation and hexane, chloroform, ethyl acetate and aqueous fractions were obtained. Ethyl acetate fraction exhibited the highest antifungal activity against the test organisms recording 27.13 mm against M. canis. The secondary metabolites present in this chosen fraction were separated using thin layer chromatography (TLC) followed by the detection under UV light (365 nm and 254 nm). Contact bioautography was performed against the tested dermatophyte species using the detected spots from UV to determine the growth inhibitory activities. The secondary metabolites that were separated by TLC were identified using specific spray reagents which revealed the presence of alkaloids, steroids and flavonoids. Thus, P. guajava possesses different types of secondary metabolites which are effective antifungal compounds against dermatophytes.Key words: dermatophytes, Psidium guajava, secondary metabolites, antifungal activit
Dynamical heterogeneities in a supercooled Lennard-Jones liquid
We present the results of a large scale molecular dynamics computer
simulation study in which we investigate whether a supercooled Lennard-Jones
liquid exhibits dynamical heterogeneities. We evaluate the non-Gaussian
parameter for the self part of the van Hove correlation function and use it to
identify ``mobile'' particles. We find that these particles form clusters whose
size grows with decreasing temperature. We also find that the relaxation time
of the mobile particles is significantly shorter than that of the bulk, and
that this difference increases with decreasing temperature.Comment: 8 pages of RevTex, 4 ps figure
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