Pub Date : 2023-10-12DOI: 10.4038/jnsfsr.v51i3.11201
C. Wijesiriwardana, P. Wimalaratne, T. Abeysinghe, S. Shalika, N. Ahmed, M. Mufarrij
Over the last few decades, the software industry investigated security best practices to guide software developers in producing less vulnerable software products. As a result, security engineering has emerged as an integral part of the software development lifecycle. With the increase in the number of security vulnerabilities discovered, the software industry encountered challenges finding software security experts. Despite the availability of static code analysis tools to detect security vulnerabilities, they are underused due to several reasons such as inadequate usability and the lack of integration support. For example, such tools are deficient in providing enough information, produce faulty warning messages, and miscommunicate with developers. As a solution, this work presents a conceptual framework and a proof-of-concept visualization tool, Secure CodeCity, as an extension to the CodeCity metaphor, to facilitate security analytics. Secure CodeCity extends the CodeCity metaphor into three different granularity levels in 3-dimensional space, facilitating the vulnerability analysis in different granularities. Thus, software practitioners can use Secure CodeCity to obtain useful security-related information such as "What is the most vulnerable class/method in a particular software project?". A between-subjects design-based user study was conducted with 23 subjects using a set of security-related tasks with two benchmark open-source Apache projects. The evaluation results show that Secure CodeCity surpasses the state-of-the-art security analysis tools in terms of correctness, usability, and time efficiency.
{"title":"Secure CodeCity: 3-dimensional visualization of software security facets","authors":"C. Wijesiriwardana, P. Wimalaratne, T. Abeysinghe, S. Shalika, N. Ahmed, M. Mufarrij","doi":"10.4038/jnsfsr.v51i3.11201","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11201","url":null,"abstract":"Over the last few decades, the software industry investigated security best practices to guide software developers in producing less vulnerable software products. As a result, security engineering has emerged as an integral part of the software development lifecycle. With the increase in the number of security vulnerabilities discovered, the software industry encountered challenges finding software security experts. Despite the availability of static code analysis tools to detect security vulnerabilities, they are underused due to several reasons such as inadequate usability and the lack of integration support. For example, such tools are deficient in providing enough information, produce faulty warning messages, and miscommunicate with developers. As a solution, this work presents a conceptual framework and a proof-of-concept visualization tool, Secure CodeCity, as an extension to the CodeCity metaphor, to facilitate security analytics. Secure CodeCity extends the CodeCity metaphor into three different granularity levels in 3-dimensional space, facilitating the vulnerability analysis in different granularities. Thus, software practitioners can use Secure CodeCity to obtain useful security-related information such as \"What is the most vulnerable class/method in a particular software project?\". A between-subjects design-based user study was conducted with 23 subjects using a set of security-related tasks with two benchmark open-source Apache projects. The evaluation results show that Secure CodeCity surpasses the state-of-the-art security analysis tools in terms of correctness, usability, and time efficiency.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057568","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.v51i3.11367
L.D.B. Suriyagoda, N.A.S.A. Neththasinghe, E.D.C.T. Chandrasekara, E.M.S. Ekanayake, D.M.S.B. Dissanayaka, M. Ariyarathne, B. Marambe
Rice (Oryza sativa L.) is the staple food in Sri Lanka and phosphorus (P) and potassium (K) are major nutrients for the rice plant. However, the variation of P and K contents (mg kg−1) in rice soils and rice grains as affected by agro-climatic zones (ACZs), water source used (i.e., major irrigation, minor irrigation and rain-fed) and cropping systems adopted (i.e., fallow, vegetable, perennials, other field crops) by Sri Lankan farmers are not well elucidated, and are thus investigated in the present study. A total of 200 rice soil and 230 rice grain samples across the country were collected from farmer fields, representing different ACZs, water sources used, and cropping systems adopted using a stratified random sampling approach. The total and available P and K contents in rice soil, and the P and K contents in rice grains were determined. The plant-available P contents in soil were similar among ACZs, water sources, and rice-based cropping systems. Exchangeable K content was higher in rice fields where vegetables were cultivated in the previous season. Grain P and K contents were similar among the water sources used and rice-based cropping systems. Grain P content was the lowest in the Low country Wet zone. Soil available-P and total-P contents (r = 0.29, p < 0.0001), and grain P and K contents were positively correlated (r = 0.51, p < 0.0001). The knowledge generated in the present study is important in P and K nutrient management in rice cultivation in the country.
水稻(Oryza sativa L.)是斯里兰卡的主食，磷(P)和钾(K)是水稻的主要营养成分。然而，水稻土壤和稻谷中磷和钾含量(mg kg−1)的变化受农业气气带(ACZs)、使用的水源(即主要灌溉、次要灌溉和雨养)和采用的种植制度(即休耕、蔬菜、多年生作物和其他大田作物)的影响并没有得到很好的阐明，因此在本研究中进行了调查。采用分层随机抽样方法，从全国各地的农民田间收集了200个水稻土壤和230个水稻颗粒样本，代表了不同的acz、使用的水源和采用的种植制度。测定了水稻土全磷、速效磷、速效钾含量和水稻籽粒磷、钾含量。土壤中植物速效磷含量在acz、水源和稻作制度中相似。前一季种植蔬菜的稻田交换态钾含量较高。不同水源与稻作方式的粮食磷、钾含量基本一致。低乡湿区籽粒磷含量最低。土壤有效磷和全磷含量(r = 0.29, p <0.0001)，籽粒磷、钾含量呈正相关(r = 0.51, P <0.0001)。本研究所获得的知识对我国水稻种植中磷、钾养分管理具有重要意义。
{"title":"Distribution of phosphorus and potassium in selected rice cultivated soils and their accumulation in rice grains under farmer-managed field conditions in Sri Lanka","authors":"L.D.B. Suriyagoda, N.A.S.A. Neththasinghe, E.D.C.T. Chandrasekara, E.M.S. Ekanayake, D.M.S.B. Dissanayaka, M. Ariyarathne, B. Marambe","doi":"10.4038/jnsfsr.v51i3.11367","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11367","url":null,"abstract":"Rice (Oryza sativa L.) is the staple food in Sri Lanka and phosphorus (P) and potassium (K) are major nutrients for the rice plant. However, the variation of P and K contents (mg kg−1) in rice soils and rice grains as affected by agro-climatic zones (ACZs), water source used (i.e., major irrigation, minor irrigation and rain-fed) and cropping systems adopted (i.e., fallow, vegetable, perennials, other field crops) by Sri Lankan farmers are not well elucidated, and are thus investigated in the present study. A total of 200 rice soil and 230 rice grain samples across the country were collected from farmer fields, representing different ACZs, water sources used, and cropping systems adopted using a stratified random sampling approach. The total and available P and K contents in rice soil, and the P and K contents in rice grains were determined. The plant-available P contents in soil were similar among ACZs, water sources, and rice-based cropping systems. Exchangeable K content was higher in rice fields where vegetables were cultivated in the previous season. Grain P and K contents were similar among the water sources used and rice-based cropping systems. Grain P content was the lowest in the Low country Wet zone. Soil available-P and total-P contents (r = 0.29, p < 0.0001), and grain P and K contents were positively correlated (r = 0.51, p < 0.0001). The knowledge generated in the present study is important in P and K nutrient management in rice cultivation in the country.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057716","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.v51i3.11380
T.R. Vishnu, K.S. Kumar, S.K.H. Ahammad, G.N.S. Kumar, N. Umakanth, M.C. Rao, S. Krishna
Pre-monsoon showers occur before the beginning of the rainy season. From the months of March to May, they take place, and can be anything from little drizzles to powerful thunderstorms. March, April and May are known as the pre-monsoon season (PRMS). The precipitation patterns recorded in PRMS are critical because they have an impact on a wide range of crop-related operations across the country. During PRMS, the maximum temperature (TMAX), minimum temperature (TMIN), soil moisture, relative humidity, latent heat, convective available potential energy (CAPE), and total precipitable water (TPW) were analysed at Kakinada region. These variables were collected using daily ERA5 reanalysis data for the PRMS from 1981 to 2021. Studying the convection-related characteristics over the Kakinada station during the PRMS was our goal. During the study period, the five years with the highest PRMS rainfall were 1990, 1995, 2008, 2010 and 2016 and the five years with the lowest rainfall were 1990, 1995, 2008, 2010 and 2016. In the months leading up to the monsoon, the Kakinada station experiences CAPE values between 1000 and 6000 J/kg, while TPW values are between 25 and 60 mm. The PRMS values for CAPE and TPW both show that the prerequisites for moderate to severe convection activity have been fulfilled. TPW, soil moisture, relative humidity, and CAPE parameters during PRMS were well estimated using the ARMA and ARIMA models.
{"title":"Variations of Pre-monsoon season related atmospheric parameters over Kakinada region","authors":"T.R. Vishnu, K.S. Kumar, S.K.H. Ahammad, G.N.S. Kumar, N. Umakanth, M.C. Rao, S. Krishna","doi":"10.4038/jnsfsr.v51i3.11380","DOIUrl":"https://doi.org/10.4038/jnsfsr.v51i3.11380","url":null,"abstract":"Pre-monsoon showers occur before the beginning of the rainy season. From the months of March to May, they take place, and can be anything from little drizzles to powerful thunderstorms. March, April and May are known as the pre-monsoon season (PRMS). The precipitation patterns recorded in PRMS are critical because they have an impact on a wide range of crop-related operations across the country. During PRMS, the maximum temperature (TMAX), minimum temperature (TMIN), soil moisture, relative humidity, latent heat, convective available potential energy (CAPE), and total precipitable water (TPW) were analysed at Kakinada region. These variables were collected using daily ERA5 reanalysis data for the PRMS from 1981 to 2021. Studying the convection-related characteristics over the Kakinada station during the PRMS was our goal. During the study period, the five years with the highest PRMS rainfall were 1990, 1995, 2008, 2010 and 2016 and the five years with the lowest rainfall were 1990, 1995, 2008, 2010 and 2016. In the months leading up to the monsoon, the Kakinada station experiences CAPE values between 1000 and 6000 J/kg, while TPW values are between 25 and 60 mm. The PRMS values for CAPE and TPW both show that the prerequisites for moderate to severe convection activity have been fulfilled. TPW, soil moisture, relative humidity, and CAPE parameters during PRMS were well estimated using the ARMA and ARIMA models.","PeriodicalId":17429,"journal":{"name":"Journal of the National Science Foundation of Sri Lanka","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057717","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.v51i3.11213
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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：