Publications by authors named "Priyadarshani N"

Ethnic tribals in northeast India have been growing and maintaining local chili landraces for ages. These chilies are known for their characteristic pungency and immense therapeutic properties. Capsaicin, a significant chili metabolite, is recognized as a natural drug for pain relief, diabetic neuropathy, psoriasis, arthritis, etc.

View Article and Find Full Text PDF

Long-term soundscape recordings are useful for a variety of applications, most notably in bioacoustics. However, the processing of such data is currently limited by the ability to efficiently and reliably detect the target sounds, which are often sparse and overshadowed by environmental noise. This paper proposes a sound detector based on changepoint theory applied to a wavelet representation of the sound.

View Article and Find Full Text PDF

To explore the influence of a biologically inspired second and outer coordination sphere on Rh-bis(diphosphine) CO2 hydrogenation catalysts, a series of five complexes were prepared by varying the substituents on the pendant amine in the P(Et)2CH2NRCH2P(Et)2 ligands (PEtNRPEt), where R consists of methyl ester modified amino acids, including three neutral (glycine methyl ester (GlyOMe), leucine methyl ester (LeuOMe), and phenylalanine methyl ester (PheOMe)), one acidic (aspartic acid dimethyl ester (AspOMe)) and one basic (histidine methyl ester (MeHisOMe)) amino acid esters. The turnover frequencies (TOFs) for CO2 hydrogenation for each of these complexes were compared to those of the non-amino acid containing [Rh(depp)2]+ (depp) and [Rh(PEtNMePEt)2]+ (NMe) complexes. Each complex is catalytically active for CO2 hydrogenation to formate under mild conditions in THF.

View Article and Find Full Text PDF

Autonomous recording units are now routinely used to monitor birdsong, starting to supplement and potentially replace human listening methods. However, to date there has been very little systematic comparison of human and machine detection ability. We present an experiment based on broadcast calls of nocturnal New Zealand birds in an area of natural forest.

View Article and Find Full Text PDF

The use of automatic acoustic recorders is becoming a principal method to survey birds in their natural habitats, as it is relatively noninvasive while still being informative. As with any other sound, birdsong degrades in amplitude, frequency, and temporal structure as it propagates to the recorder through the environment. Knowing how different birdsongs attenuate under different conditions is useful to, for example, develop protocols for deploying acoustic recorders and improve automated detection methods, an essential part of the research field that is becoming known as ecoacoustics.

View Article and Find Full Text PDF

Aim: To ascertain if the factors associated with depression differ among ethnic groups in community-dwelling older people in Kandy District, Sri Lanka.

Methods: A cross-sectional survey was carried out of people aged ≥60 years living in a single divisional secretariat of Kandy District. The participants were asked about ethnicity (Sinhalese, Tamil and Muslim), sociodemographic characteristics and depression status by face-to-face interviews with a structured questionnaire.

View Article and Find Full Text PDF

Automatic recording of birdsong is becoming the preferred way to monitor and quantify bird populations worldwide. Programmable recorders allow recordings to be obtained at all times of day and year for extended periods of time. Consequently, there is a critical need for robust automated birdsong recognition.

View Article and Find Full Text PDF

Building on our recent report of an active H production catalyst [Ni(P N)] (Prop = phenylpropionic acid, peptide (R10) = WIpPRWTGPR-NH, p = D-proline and PN = 1-aza-3,6-diphosphacycloheptane) that contains structured β-hairpin peptides, here we investigate how H production is effected by: (1) the length of the hairpin (eight or ten residues) and (2) limiting the flexibility between the peptide and the core complex by altering the length of the linker: phenylpropionic acid (three carbons) or benzoic acid (one carbon). Reduction of the peptide chain length from ten to eight residues increases or maintains the catalytic current for H production for all complexes, suggesting a non-productive steric interaction at longer peptide lengths. While the structure of the hairpin appears largely intact for the complexes, NMR data are consistent with differences in dynamic behavior which may contribute to the observed differences in catalytic activity.

View Article and Find Full Text PDF

Inspired by nature's ability to regulate catalysis using physiological stimuli, azobenzene was incorporated into Rh(bis)diphosphine CO2 hydrogenation catalysts to photoinitiate structural changes to modulate the resulting catalytic activity. The rhodium bound diphosphine ligands (P(Ph2)-CH2-N(R)-CH2-P(Ph2)) contain the terminal amine of a non-natural amino acid, with the R-group being either β-alanine (β-Ala) or γ-aminobutyric acid (GABA). For both β-Ala and GABA containing complexes, the carboxylic acids of the amino acids were coupled to the amines of diaminoazobenzene, creating a complex consisting of a rhodium bound to a photo-responsive tetradentate ligand.

View Article and Find Full Text PDF

Background: In Sri Lanka, one of the major challenges in rabies control is to manage the dog population and subsequently to protect people, especially young children, from dog bites.

Methods: In 2009, an educational-entertainment campaign called 'Rabies Edutainment 4 Kids' was introduced in the school curricula in rural Sri Lanka to improve practices on rabies prevention and pet care among school children, and to evaluate its effectiveness through pre- and post-tests.

Results: The level of rabies knowledge, attitude and practice among the pupils was dependent on their responses to a survey, and scores were significantly improved both among the study and control groups after the intervention.

View Article and Find Full Text PDF

Polyisobutylene (PIB)-bound ruthenium bipyridine [Ru(PIB-bpy)] metal complexes were prepared from PIB ligands formed by alkylation of 4,4'-dimethylbipyridine with polyisobutylene bromide. The product Ru(PIB-bpy)Cl complexes with at least one PIB ligand per bipyridine unit function as soluble recyclable photoredox catalysts in free radical polymerization of acrylate monomers under visible light irradiation at 25 °C with ethyl 2-bromoisobutyrate as the initiator in the presence of diisopropylethylamine. The polyacrylate products contained only about 1 ppm Ru contamination.

View Article and Find Full Text PDF

Religious leaders in Sri Lanka may have a high potential of contributing to HIV/AIDS prevention among the general public because of their social status. In order to assess their current HIV/AIDS-related knowledge and attitude and the possibility of becoming community advocates of HIV/AIDS prevention, we conducted a questionnaire survey among Buddhist, Hindu, Muslim and Christian leaders in Sri Lanka in 2009. There were limited correct responses about HIV/AIDS-related knowledge and attitudes toward people living with HIV/AIDS (PLHIV), and information regarding condoms, HIV testing and counselling were poorly understood.

View Article and Find Full Text PDF

The studies described here show that a relatively low molecular weight, narrow polydispersity polyethylene (PE) wax (Polywax) can serve as a nontoxic and nonvolatile alternative to alkane solvents in monophasic catalytic organic reactions where catalysts and products are separated under biphasic conditions. In this application, a polymer that is a solid at room temperature substitutes for a conventional alkane solvent at ca. 80 °C.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_session2ah5fb2j7jrmq82q3uskqtqtjminod8f): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once