Pub Date : 2023-10-12DOI: 10.4038/jnsfsr.v51i3.11213
R. Jabeen, A. Zaka
In real life, the distribution of the errors during any life testing of products or process does not meet the assumption of normality. Statistical process control (SPC) is defined as the use of statistical techniques to control a process or production method. SPC tools and procedures can help to monitor process behavior, discover problems in internal systems, and find solutions for production issues. To identify and remove the variation in different reliability processes and to monitor the reliability of machines where the number of errors follows skewed distributions, we develop control charts to keep the process in control. For such situations, we have modified the existing control charts such as Shewhart control chart, exponentially weighted moving average (EWMA), hybrid exponentially weighted moving average (HEWMA) and extended exponentially weighted moving average (EEWMA) control charts. The current study introduced classical estimator based modified control charts for phase-II monitoring by assuming that the errors occur during the process follow skewed distribution called Beta Lehmann 2 Power function distribution (BL2PFD). The proposal for these control charts is based on the percentile estimator. We have compared all these control charts using Monte Carlo simulation studies and real-life applications to compare the proposed control charts. This study shows that an EEWMA control chart based on PE performs better than Shewhart, EWMA and HEWMA control charts, when the underlying distribution of the errors in process monitoring follows BL2PFD. These findings can be useful for researchers and practitioners in dealing with production errors and optimizing the output.
{"title":"Error detection through modified phase II process monitoring under different classical estimators","authors":"R. Jabeen, A. Zaka","doi":"10.4038/jnsfsr.v51i3.11213","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11213","url":null,"abstract":"In real life, the distribution of the errors during any life testing of products or process does not meet the assumption of normality. Statistical process control (SPC) is defined as the use of statistical techniques to control a process or production method. SPC tools and procedures can help to monitor process behavior, discover problems in internal systems, and find solutions for production issues. To identify and remove the variation in different reliability processes and to monitor the reliability of machines where the number of errors follows skewed distributions, we develop control charts to keep the process in control. For such situations, we have modified the existing control charts such as Shewhart control chart, exponentially weighted moving average (EWMA), hybrid exponentially weighted moving average (HEWMA) and extended exponentially weighted moving average (EEWMA) control charts. The current study introduced classical estimator based modified control charts for phase-II monitoring by assuming that the errors occur during the process follow skewed distribution called Beta Lehmann 2 Power function distribution (BL2PFD). The proposal for these control charts is based on the percentile estimator. We have compared all these control charts using Monte Carlo simulation studies and real-life applications to compare the proposed control charts. This study shows that an EEWMA control chart based on PE performs better than Shewhart, EWMA and HEWMA control charts, when the underlying distribution of the errors in process monitoring follows BL2PFD. These findings can be useful for researchers and practitioners in dealing with production errors and optimizing the output.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-12DOI: 10.4038/jnsfsr.v51i3.11886
Ajit Abeysekara
The modern science museum is not merely a collection of historical artefacts and exhibits from the natural world depicting physical, chemical and biological phenomena. It is also a science center, which creates a space for learning about and understanding science mainly through interactive exhibits. Working with interactive exhibits can play an important role in the educational process of young people interested in science. It can provide an opportunity to actively engage in making observations, analyze information and draw conclusions, in an enjoyable setting. The incorporation of these ideas in science education is reflected in the commonly used phrases, “learning science by doing science” and “science is fun”.
At a time when developing an educational system relevant for Sri Lanka in the 21st century is being discussed at various levels of policy making, undue importance is given sometimes to changing syllabi and course contents. In keeping with world-wide trends, a more important aspect of reforms should be to shift the focus from curriculum-based teacher directed education, to one that is curiosity driven, student centred active learning, particularly in the early years. In catalyzing this shift, the access to modern science museums can play a major role. It will be difficult for a school to provide children with the experience they can have in a science centre functioning within a science museum. In addition to exhibits, the museum will provide for an information system including a library and also other resources such as an auditorium for public lectures, films and demonstrations. The learning experience in a science museum is often a social experience, shared by family, friends and other visitors to the museum.
Thus, science museums will also serve to spread scientific knowledge and the culture of science among the general population which will help in creating an informed population, better able to take rational decisions on issues facing society.
{"title":"The value of a modern science museum","authors":"Ajit Abeysekara","doi":"10.4038/jnsfsr.v51i3.11886","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11886","url":null,"abstract":"The modern science museum is not merely a collection of historical artefacts and exhibits from the natural world depicting physical, chemical and biological phenomena. It is also a science center, which creates a space for learning about and understanding science mainly through interactive exhibits. Working with interactive exhibits can play an important role in the educational process of young people interested in science. It can provide an opportunity to actively engage in making observations, analyze information and draw conclusions, in an enjoyable setting. The incorporation of these ideas in science education is reflected in the commonly used phrases, “learning science by doing science” and “science is fun”. 
 
 At a time when developing an educational system relevant for Sri Lanka in the 21st century is being discussed at various levels of policy making, undue importance is given sometimes to changing syllabi and course contents. In keeping with world-wide trends, a more important aspect of reforms should be to shift the focus from curriculum-based teacher directed education, to one that is curiosity driven, student centred active learning, particularly in the early years. In catalyzing this shift, the access to modern science museums can play a major role. It will be difficult for a school to provide children with the experience they can have in a science centre functioning within a science museum. In addition to exhibits, the museum will provide for an information system including a library and also other resources such as an auditorium for public lectures, films and demonstrations. The learning experience in a science museum is often a social experience, shared by family, friends and other visitors to the museum.
 
 Thus, science museums will also serve to spread scientific knowledge and the culture of science among the general population which will help in creating an informed population, better able to take rational decisions on issues facing society.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-12DOI: 10.4038/jnsfsr.v51i3.11221
I.F. Shakoor, G.K. Pamunuwa, D.N. Karunaratne
Topical skin application of curcumin is challenging due to the low solubility and poor stability, including fast photodegradation, of this bioactive compound. Therefore, curcumin encapsulated alginate (CU-Al) nanoparticles were prepared by the ionic gelation method followed by freeze drying to determine the efficacy of alginate in facilitating curcumin release. Evaluation of the release of curcumin from the encapsulate in the presence of artificial sweat (pH 4.7) and skin (pH 5.5), about which the literature is meagre, was carried out after particle size characterization. CU-Al nanoparticles were in the nano-range (186.8 nm), assimilated a negative zeta-potential value (-15.4 ± 8.13 mV), and displayed a high encapsulation efficiency (94.55 ± 0.53%). The release of encapsulated curcumin at pH 5.5 (max. 64%) and at pH 4.7 (max. 27%) were significantly different. In pH 5.5 and pH 4.7, the release profiles of encapsulated curcumin fitted best with the Weibull (followed an anomalous transport mechanism) and Gompertz (followed a super case II transport mechanism) models respectively, displaying sigmoidal release patterns. Diffusion and polymer relaxation/swelling based release at pH 5.5 and rapid polymer relaxation/erosion based release at pH 4.7 have governed the encapsulated curcumin release. The results indicated that CU-Al nanoparticles may be utilized to facilitate controlled and prolonged release of curcumin in both skin and artificial sweat, thereby functioning as a promising novel delivery vehicle for curcumin. However, skin deposition or penetration may be required for yielding a satisfactory topical administration of curcumin during sweating.
{"title":"pH-dependent release properties of curcumin encapsulated alginate nanoparticles in skin and artificial sweat","authors":"I.F. Shakoor, G.K. Pamunuwa, D.N. Karunaratne","doi":"10.4038/jnsfsr.v51i3.11221","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11221","url":null,"abstract":"Topical skin application of curcumin is challenging due to the low solubility and poor stability, including fast photodegradation, of this bioactive compound. Therefore, curcumin encapsulated alginate (CU-Al) nanoparticles were prepared by the ionic gelation method followed by freeze drying to determine the efficacy of alginate in facilitating curcumin release. Evaluation of the release of curcumin from the encapsulate in the presence of artificial sweat (pH 4.7) and skin (pH 5.5), about which the literature is meagre, was carried out after particle size characterization. CU-Al nanoparticles were in the nano-range (186.8 nm), assimilated a negative zeta-potential value (-15.4 ± 8.13 mV), and displayed a high encapsulation efficiency (94.55 ± 0.53%). The release of encapsulated curcumin at pH 5.5 (max. 64%) and at pH 4.7 (max. 27%) were significantly different. In pH 5.5 and pH 4.7, the release profiles of encapsulated curcumin fitted best with the Weibull (followed an anomalous transport mechanism) and Gompertz (followed a super case II transport mechanism) models respectively, displaying sigmoidal release patterns. Diffusion and polymer relaxation/swelling based release at pH 5.5 and rapid polymer relaxation/erosion based release at pH 4.7 have governed the encapsulated curcumin release. The results indicated that CU-Al nanoparticles may be utilized to facilitate controlled and prolonged release of curcumin in both skin and artificial sweat, thereby functioning as a promising novel delivery vehicle for curcumin. However, skin deposition or penetration may be required for yielding a satisfactory topical administration of curcumin during sweating.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":"310 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-12DOI: 10.4038/jnsfsr.v51i3.11097
A.C. Bandara, C.L. Abayasekara, A.M. Karunaratne, G.J. Panagoda
Probiotics are live microorganisms which confer health benefits to the host when administered in adequate amounts. Endophytes, which live in plant tissues between the plant cells, can act as potential probiotic bacteria. The leaves of Murraya koenigii L. is a common cuisine and herbal ingredient used in indigenous medicine. The main objective of the current study was to assess probiotic characteristics of isolated bacterial endophytes of M. koenigii leaves. Young and mature leaves of M. koenigii were collected from sites in the wet and dry zones of Sri Lanka. The endophytes were isolated using three techniques: placing leaf segments, leaf macerations and preparation of pour plates on three different media viz., nutrient agar, Luria-Bertani (LB), and De Man, Rogosa and Sharpe agar (MRS). They were identified from morphological characteristics and preliminary biochemical tests. Probiotic characterization of the isolates was carried out by using a series of standard tests including resistance to low pH, tolerance of bile salts, antimicrobial activity (Escherichia coli and Pseudomonas aeruginosa), antibiotic resistance (Gentamycine), anti-haemolytic activity, and non-DNase activity. Ten endophytic bacteria (two bacilli, eight cocci including two Gram positive cocci, and eight Gram negative cocci and bacilli) were isolated from the young and mature leaf samples collected. While probiotic characterization tests were positive, four isolates showed antibiotic susceptibility. These results indicate the possibility that M. koenigii leaves possess bacterial endophytes with probiotic potential.
{"title":"Probiotic&nbsp;potential&nbsp;of&nbsp;bacterial&nbsp;endophytes&nbsp;isolated&nbsp;from&nbsp;leaves&nbsp;of&nbsp;<em style=\"mso-bidi-font-style: normal;\">Murraya</em><em style=\"mso-bidi-font-style: normal;\">&nbsp;</em><em style=\"mso-bidi-font-style: normal;\">koenigii</em><em style=\"mso-bidi-font-style: normal;\">&nbsp;</em>L.","authors":"A.C. Bandara, C.L. Abayasekara, A.M. Karunaratne, G.J. Panagoda","doi":"10.4038/jnsfsr.v51i3.11097","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11097","url":null,"abstract":"Probiotics are live microorganisms which confer health benefits to the host when administered in adequate amounts. Endophytes, which live in plant tissues between the plant cells, can act as potential probiotic bacteria. The leaves of Murraya koenigii L. is a common cuisine and herbal ingredient used in indigenous medicine. The main objective of the current study was to assess probiotic characteristics of isolated bacterial endophytes of M. koenigii leaves. Young and mature leaves of M. koenigii were collected from sites in the wet and dry zones of Sri Lanka. The endophytes were isolated using three techniques: placing leaf segments, leaf macerations and preparation of pour plates on three different media viz., nutrient agar, Luria-Bertani (LB), and De Man, Rogosa and Sharpe agar (MRS). They were identified from morphological characteristics and preliminary biochemical tests. Probiotic characterization of the isolates was carried out by using a series of standard tests including resistance to low pH, tolerance of bile salts, antimicrobial activity (Escherichia coli and Pseudomonas aeruginosa), antibiotic resistance (Gentamycine), anti-haemolytic activity, and non-DNase activity. Ten endophytic bacteria (two bacilli, eight cocci including two Gram positive cocci, and eight Gram negative cocci and bacilli) were isolated from the young and mature leaf samples collected. While probiotic characterization tests were positive, four isolates showed antibiotic susceptibility. These results indicate the possibility that M. koenigii leaves possess bacterial endophytes with probiotic potential.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-12DOI: 10.4038/jnsfsr.v51i3.11193
K.A.S. Kodikara, T. Hoessein, P.M.C.S. De Silva, P. Ranasinghe, H.P.P.S. Somasiri, S.K. Madarasinghe, D.U.V. Gunathilake, D. Ranawaka, M. Danaee, J. Andrieu, F. Dahdouh-Guebas
Heavy metal pollution has become a serious threat to coastal aquatic ecosystems. Therefore, this study, aimed to assess the spatial distribution of five selected heavy metals/metalloids, arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), and mercury (Hg), in surface sediment samples collected from the Kalametiya Lagoon in southern Sri Lanka. Sixteen (16) areas of the lagoon were sampled. The sediment samples were analysed for heavy metal content by using ICP-MS while the water samples were measured for salinity and pH. A questionnaire survey was conducted to investigate the possible sources of heavy metal pollution in the Lagoon. Water pH and salinity showed significant variations across the lagoon. The overall mean value of pH and salinity were 6.68 ± 0.17 and 2.9 ± 2.2 PSU, respectively. The spatial distribution of the heavy metals was not monotonous and showed a high spatial variation. The kernel density maps of the measured heavy metals demarcated several spatially different patches in the lagoon. The mean levels of As, Cd, Cr, Hg, and Pb were lower than the threshold effect level (TEL) although it was higher for Hg in the North inlet. Nevertheless, it was still lower than the potential effect level (PEL). Industrial sewage, river suspended sediments, and agrochemicals such as fertilizers and pesticides were identified as the possible sources for heavy metal loads. Accumulation of toxic heavy metals can be minimized by by-passing the freshwater inflow to the lagoon.
{"title":"Spatial distribution of heavy metals in surface sediments of the Kalametiya Lagoon in southern Sri Lanka: Insights into the pollution status and socio-economic interactions&nbsp;","authors":"K.A.S. Kodikara, T. Hoessein, P.M.C.S. De Silva, P. Ranasinghe, H.P.P.S. Somasiri, S.K. Madarasinghe, D.U.V. Gunathilake, D. Ranawaka, M. Danaee, J. Andrieu, F. Dahdouh-Guebas","doi":"10.4038/jnsfsr.v51i3.11193","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11193","url":null,"abstract":"Heavy metal pollution has become a serious threat to coastal aquatic ecosystems. Therefore, this study, aimed to assess the spatial distribution of five selected heavy metals/metalloids, arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), and mercury (Hg), in surface sediment samples collected from the Kalametiya Lagoon in southern Sri Lanka. Sixteen (16) areas of the lagoon were sampled. The sediment samples were analysed for heavy metal content by using ICP-MS while the water samples were measured for salinity and pH. A questionnaire survey was conducted to investigate the possible sources of heavy metal pollution in the Lagoon. Water pH and salinity showed significant variations across the lagoon. The overall mean value of pH and salinity were 6.68 ± 0.17 and 2.9 ± 2.2 PSU, respectively. The spatial distribution of the heavy metals was not monotonous and showed a high spatial variation. The kernel density maps of the measured heavy metals demarcated several spatially different patches in the lagoon. The mean levels of As, Cd, Cr, Hg, and Pb were lower than the threshold effect level (TEL) although it was higher for Hg in the North inlet. Nevertheless, it was still lower than the potential effect level (PEL). Industrial sewage, river suspended sediments, and agrochemicals such as fertilizers and pesticides were identified as the possible sources for heavy metal loads. Accumulation of toxic heavy metals can be minimized by by-passing the freshwater inflow to the lagoon.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-12DOI: 10.4038/jnsfsr.v51i3.11203
A. Gunarathne, H.D.R.V.L. Harasgama, T. Wijewickrama, A. Attanayake, R.N. Attanayake, R.M.C.S. Ratnayake
Sri Lanka, a biodiversity hotspot in Asia, records 30 Hedyotis species of which 25 species and a variety are endemic. Among these 25 species, seven Hedyotis species were categorized as critically endangered (CR), and 13 as endangered (EN). During our field survey in 2014, an extremely attractive plant belonging to the genus Hedyotis was discovered from Mount Thotupola, Sri Lanka. The plant was tentatively identified as H. quinquinervia. For accurate species identification, morphological characters were compared with voucher specimens, and identification keys were also used. In addition, DNA barcoding using the sequence of the internal transcribed spacer region of the nuclear ribosomal DNA (rDNA-ITS) region was performed, followed by molecular phylogenetic analysis. A simple method to remove a thick cuticle layer on the leaves was employed to obtain a sufficient amount of DNA suitable for Polymerase Chain Reaction. A comparison with its protologue and type specimen along with molecular phylogenetic analysis confirmed that the unidentified plant was H. quinquinervia Thwaites. The National Red List of Sri Lanka (2020) had revised H. quinquinervia as a CR species upon the rediscovery confirmed after the lapse of a century. Habitat characteristics, ex situ and in situ conservation measures for H. quinquinervia, and general conservation strategies applicable to threatened heterostylous plants are also discussed.
{"title":"Rediscovery, identity, and conservation strategies of a critically endangered endemic plant, <em>Hedyotis quinquinervia</em> Thwaites (Rubiaceae) in Sri Lanka","authors":"A. Gunarathne, H.D.R.V.L. Harasgama, T. Wijewickrama, A. Attanayake, R.N. Attanayake, R.M.C.S. Ratnayake","doi":"10.4038/jnsfsr.v51i3.11203","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11203","url":null,"abstract":"Sri Lanka, a biodiversity hotspot in Asia, records 30 Hedyotis species of which 25 species and a variety are endemic. Among these 25 species, seven Hedyotis species were categorized as critically endangered (CR), and 13 as endangered (EN). During our field survey in 2014, an extremely attractive plant belonging to the genus Hedyotis was discovered from Mount Thotupola, Sri Lanka. The plant was tentatively identified as H. quinquinervia. For accurate species identification, morphological characters were compared with voucher specimens, and identification keys were also used. In addition, DNA barcoding using the sequence of the internal transcribed spacer region of the nuclear ribosomal DNA (rDNA-ITS) region was performed, followed by molecular phylogenetic analysis. A simple method to remove a thick cuticle layer on the leaves was employed to obtain a sufficient amount of DNA suitable for Polymerase Chain Reaction. A comparison with its protologue and type specimen along with molecular phylogenetic analysis confirmed that the unidentified plant was H. quinquinervia Thwaites. The National Red List of Sri Lanka (2020) had revised H. quinquinervia as a CR species upon the rediscovery confirmed after the lapse of a century. Habitat characteristics, ex situ and in situ conservation measures for H. quinquinervia, and general conservation strategies applicable to threatened heterostylous plants are also discussed.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-12DOI: 10.4038/jnsfsr.v51i3.11068
K. Yakandawala, A. Bandara, D. Yakandawala, R. Abeynayake
Shrubs are popularly incorporated to establish green infrastructure in urban spaces. We argue that the functions provided by shrubs could be further enhanced by giving due consideration to their leaf morphological characters. Therefore, our objective was to recognise how the different morphological characters of leaves, listed as contributing to determining the plant texture in literature, would collectively contribute to recognizing textural groups of plants, and further, to define each of these groups into either coarse, medium, or fine textural categories using ornamental shrubs. We investigated the quantitative and qualitative leaf morphology of 30 tropical ornamental shrubs in the Peradeniya area. According to our analysis, leaf area, petiole length, and internodal distance have significantly contributed to the separation of shrubs into three textural groups; fine, medium and coarse, and were considered as preliminary characters that determine the texture. Leaf hair related characters viz., hair densities on upper and lower surfaces, and the length of hairs on both surfaces, together with qualitative morphological characters, viz., leaf margins, leaf arrangement, and prominent venation were identified as secondary characters that contributed to defining textural groups. Shrubs with coarse texture possess significantly larger leaves, longer petioles and internodal distances compared to fine textured group. Our recommendation is to consider plant textural groups as a criterion in the selection of plants for planting designs during the establishment of green infrastructure in urban spaces, enabling the obtaining of benefits beyond aesthetics, which include other functional, health and environmental benefits, to improve the quality of life of city dwellers under the context of limited urban green spaces.
{"title":"Beyond aesthetics: Integration of textural groups of tropical ornamental shrubs into urban planting designs","authors":"K. Yakandawala, A. Bandara, D. Yakandawala, R. Abeynayake","doi":"10.4038/jnsfsr.v51i3.11068","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11068","url":null,"abstract":"Shrubs are popularly incorporated to establish green infrastructure in urban spaces. We argue that the functions provided by shrubs could be further enhanced by giving due consideration to their leaf morphological characters. Therefore, our objective was to recognise how the different morphological characters of leaves, listed as contributing to determining the plant texture in literature, would collectively contribute to recognizing textural groups of plants, and further, to define each of these groups into either coarse, medium, or fine textural categories using ornamental shrubs. We investigated the quantitative and qualitative leaf morphology of 30 tropical ornamental shrubs in the Peradeniya area. According to our analysis, leaf area, petiole length, and internodal distance have significantly contributed to the separation of shrubs into three textural groups; fine, medium and coarse, and were considered as preliminary characters that determine the texture. Leaf hair related characters viz., hair densities on upper and lower surfaces, and the length of hairs on both surfaces, together with qualitative morphological characters, viz., leaf margins, leaf arrangement, and prominent venation were identified as secondary characters that contributed to defining textural groups. Shrubs with coarse texture possess significantly larger leaves, longer petioles and internodal distances compared to fine textured group. Our recommendation is to consider plant textural groups as a criterion in the selection of plants for planting designs during the establishment of green infrastructure in urban spaces, enabling the obtaining of benefits beyond aesthetics, which include other functional, health and environmental benefits, to improve the quality of life of city dwellers under the context of limited urban green spaces.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-04DOI: 10.4038/jnsfsr.v51i2.11747
R. Seneviratne
Ethical conduct of research involving humans has gained relevance and importance over the years with the expansion of research beyond boundaries of traditional medical and clinical research into a multiplicity of disciplines with human participation. Human research is regarded as research conducted on or with or about people, or their tissues or cells or data obtained from them. Historically, it is stated that the Greek Philosopher Aristotle (384-322 BCE) was probably the first to discuss principles of ethics ‘by studying and offering criteria to assess human behaviour’. It is believed that he taught a course of ethics at the Lyceum during his mature years which was based on the many treatises he wrote on the subject. Increased attention to ethics in human research started after the Second World War following the judgment of the International Military Tribunal which also included 10 principles of permissible medical experiments which have since then been referred to as the Nuremburg Code (1949). Later discussions by the World Medical Assembly of the Code led to the adoption of the Helsinki Declaration (1964) which has been revised many times since then. The Council for International Organizations of Medical Sciences (CIOMS) which in association with the World Health Organizations (WHO) undertook its work on ethics in biomedical research in late 1970s. It has published an updated version with a wider scope of coverage titled ‘International Ethical Guidelines for Health-Related Research Involving Humans’ (2016). Close cooperation with World Medical Assembly has ensured that the guidelines are closely aligned to the Helsinki Declaration. Traditionally, ethics has received much attention both in clinical practice and in health research. Faculties of Medicine were the first to establish ethics review boards and ethics review committees in Sri Lanka to undertake review of research proposals with human participation for ethical aspects and issues and granting approval. The primary aim is to safeguard the interests and right of participants of research and prevent their exploitation. There is no doubt about the value of health research and the benefits it has brought and will continue to bring to ensure health, wellbeing, safety and quality of life of people. Most research on human participants is simple, observational, descriptive and non-invasive and the ethical issues though may be minimal, still needs explicit attention and review by an ethics review board before approval. The more complex research where human participants are subject to ‘experimentation’ or ‘interventions’ has many ethical issues that need to assessed by recognized ethics review committees with experience and capability to do so. If a new drug, a new vaccine, medicinal product, device, or equipment not already in use by people is to be tested on humans before being granted approval for use in day-to-day life by the appropriate authority, the researcher should adopt recommended p
{"title":"Ethics of research","authors":"R. Seneviratne","doi":"10.4038/jnsfsr.v51i2.11747","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i2.11747","url":null,"abstract":"\u0000Ethical conduct of research involving humans has gained relevance and importance over the years with the expansion of research beyond boundaries of traditional medical and clinical research into a multiplicity of disciplines with human participation. Human research is regarded as research conducted on or with or about people, or their tissues or cells or data obtained from them.\u0000Historically, it is stated that the Greek Philosopher Aristotle (384-322 BCE) was probably the first to discuss principles of ethics ‘by studying and offering criteria to assess human behaviour’. It is believed that he taught a course of ethics at the Lyceum during his mature years which was based on the many treatises he wrote on the subject. Increased attention to ethics in human research started after the Second World War following the judgment of the International Military Tribunal which also included 10 principles of permissible medical experiments which have since then been referred to as the Nuremburg Code (1949). Later discussions by the World Medical Assembly of the Code led to the adoption of the Helsinki Declaration (1964) which has been revised many times since then.\u0000The Council for International Organizations of Medical Sciences (CIOMS) which in association with the World Health Organizations (WHO) undertook its work on ethics in biomedical research in late 1970s. It has published an updated version with a wider scope of coverage titled ‘International Ethical Guidelines for Health-Related Research Involving Humans’ (2016). Close cooperation with World Medical Assembly has ensured that the guidelines are closely aligned to the Helsinki Declaration. \u0000 Traditionally, ethics has received much attention both in clinical practice and in health research. Faculties of Medicine were the first to establish ethics review boards and ethics review committees in Sri Lanka to undertake review of research proposals with human participation for ethical aspects and issues and granting approval. The primary aim is to safeguard the interests and right of participants of research and prevent their exploitation. There is no doubt about the value of health research and the benefits it has brought and will continue to bring to ensure health, wellbeing, safety and quality of life of people. Most research on human participants is simple, observational, descriptive and non-invasive and the ethical issues though may be minimal, still needs explicit attention and review by an ethics review board before approval. The more complex research where human participants are subject to ‘experimentation’ or ‘interventions’ has many ethical issues that need to assessed by recognized ethics review committees with experience and capability to do so. If a new drug, a new vaccine, medicinal product, device, or equipment not already in use by people is to be tested on humans before being granted approval for use in day-to-day life by the appropriate authority, the researcher should adopt recommended p","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42005365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-30DOI: 10.4038/jnsfsr.v51i2.11080
V. Anusooya, S. Ponmalar, M. Manikandan, S. Gobalakrishnan
As a result of the development of advanced semiconductor-based optical switching devices and their commercialization, concepts and technologies in all-optical signal processing have evolved significantly in the past few years. In order to realize logical operations in photonic computing, universal gates are needed. In this research, the simple and compact all-optical NAND gate was designed using SOA and simulated at a high data rate of 10Gbps to 40 Gbps. The performance of the proposed NAND gate is shown by the numerical analysis for various input combinations and SOA. By changing wavelengths, injection currents, confinement factors, as well as optical components such as sources, amplifiers, and filters, a numerical analysis is performed. Unique results were obtained at a 10 Gbps data rate for NRZ-L user-defined bit sequences. This kind of all-optical NAND gate will be the perfect alternative in the field of optical computing to realize a high-speed optical communication network. An extinction ratio of 11.48 dB is achieved at a high-speed data rate of 10 Gbps to 40Gbps. The output spectrum of the designed NAND logic is also received for a wide input spectrum and the system responds selectively for the input wavelength at 1548.3 nm which is the probe signal wavelength.
{"title":"Simulation and Numerical Analysis of SOA Based All Optical NAND Gate for High Data Rate Communication","authors":"V. Anusooya, S. Ponmalar, M. Manikandan, S. Gobalakrishnan","doi":"10.4038/jnsfsr.v51i2.11080","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i2.11080","url":null,"abstract":"As a result of the development of advanced semiconductor-based optical switching devices and their commercialization, concepts and technologies in all-optical signal processing have evolved significantly in the past few years. In order to realize logical operations in photonic computing, universal gates are needed. In this research, the simple and compact all-optical NAND gate was designed using SOA and simulated at a high data rate of 10Gbps to 40 Gbps. The performance of the proposed NAND gate is shown by the numerical analysis for various input combinations and SOA. By changing wavelengths, injection currents, confinement factors, as well as optical components such as sources, amplifiers, and filters, a numerical analysis is performed. Unique results were obtained at a 10 Gbps data rate for NRZ-L user-defined bit sequences. This kind of all-optical NAND gate will be the perfect alternative in the field of optical computing to realize a high-speed optical communication network. An extinction ratio of 11.48 dB is achieved at a high-speed data rate of 10 Gbps to 40Gbps. The output spectrum of the designed NAND logic is also received for a wide input spectrum and the system responds selectively for the input wavelength at 1548.3 nm which is the probe signal wavelength.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47903157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-30DOI: 10.4038/jnsfsr.v51i2.11217
W.M.S. Kurera, N. Adikaram, D. Yakandawala, S.S.N. Maharachchikumbura, Jayasinghe, K. Samarakoon
Most of the commercial banana cultivars in Sri Lanka are susceptible to anthracnose disease. Colletotrichum musae has been known as the causal agent of banana anthracnose for decades and the pathogen has been identified using morphological characteristics. Molecular analyses based on multigene phylogenetics are now standard protocols to identify Colletotrichum species. The present study was aimed at identifying Colletotrichum species causing banana anthracnose by molecular and phenotypic characterization. Thirty-seven isolates were obtained from ripened bananas showing anthracnose symptoms, collected from different locations in the Central Province of Sri Lanka. Of them, 36 were preliminarily identified as Colletotrichum based on conidial morphology. The remaining isolate did not sporulate during the entire study period. Ten isolates taken for molecular studies consisted of eight with orange/white arial mycelia and orange conidial masses, one with a white to greyish colony and blackish clusters of ascomata, and one with a white to faint pink colour colony. DNA extracted from each isolate was subjected to multi-gene DNA sequence analysis using ITS, TUB, GAPDH and GS loci. Based on phylogenetic analyses, eight isolates were identified as Colletotrichum musae, and the other two as C. plurivorum and C. siamense. The vegetative morphology of C. plurivorum differed considerably from C. musae and C. siamense. Slight differences in colony morphology were observed among the C. musae isolates. Freshly harvested healthy bananas were artificially inoculated with isolates of C. musae or C. plurivorum and produced typical anthracnose lesions within a week. The Colletotrichum siamense isolate failed to develop anthracnose symptoms. This is the first report of C. plurivorum causing banana anthracnose.
{"title":"Molecular and phenotypic characterization of Colletotrichum plurivorum and Colletotrichum musae causing banana anthracnose disease in the Central Province of Sri Lanka","authors":"W.M.S. Kurera, N. Adikaram, D. Yakandawala, S.S.N. Maharachchikumbura, Jayasinghe, K. Samarakoon","doi":"10.4038/jnsfsr.v51i2.11217","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i2.11217","url":null,"abstract":"\u0000Most of the commercial banana cultivars in Sri Lanka are susceptible to anthracnose disease. Colletotrichum musae has been known as the causal agent of banana anthracnose for decades and the pathogen has been identified using morphological characteristics. Molecular analyses based on multigene phylogenetics are now standard protocols to identify Colletotrichum species. The present study was aimed at identifying Colletotrichum species causing banana anthracnose by molecular and phenotypic characterization. Thirty-seven isolates were obtained from ripened bananas showing anthracnose symptoms, collected from different locations in the Central Province of Sri Lanka. Of them, 36 were preliminarily identified as Colletotrichum based on conidial morphology. The remaining isolate did not sporulate during the entire study period. Ten isolates taken for molecular studies consisted of eight with orange/white arial mycelia and orange conidial masses, one with a white to greyish colony and blackish clusters of ascomata, and one with a white to faint pink colour colony. DNA extracted from each isolate was subjected to multi-gene DNA sequence analysis using ITS, TUB, GAPDH and GS loci. Based on phylogenetic analyses, eight isolates were identified as Colletotrichum musae, and the other two as C. plurivorum and C. siamense. The vegetative morphology of C. plurivorum differed considerably from C. musae and C. siamense. Slight differences in colony morphology were observed among the C. musae isolates. Freshly harvested healthy bananas were artificially inoculated with isolates of C. musae or C. plurivorum and produced typical anthracnose lesions within a week. The Colletotrichum siamense isolate failed to develop anthracnose symptoms. This is the first report of C. plurivorum causing banana anthracnose.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42663917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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