243 research outputs found

    The Implication of Landscape Composition, Landscape Configuration, and Climatic Factors on the Variation of Pavo cristatus (Indian Peafowl) Density in the Southern Province of Sri Lanka

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    Indian peafowl (Pavo cristatus) which was predominantly found in the arid regions of the country, have been observed venturing into the wetter zones in recent times, raising significant concerns on potential threats to crops in the Southern Province. In the present study landscape composition, landscape configuration and climatic variables were recognized as potential contributing factors to the variation of Indian peafowl density and were investigated in croplands of the Southern Province of Sri Lanka, which encompasses the wet, dry and intermediate zones, characterized by diverse landscapes and unique ecological features. The density of Indian peafowl was determined using fixed-width strip-transect surveys conducted between September 2023 to February 2024 in 25 sampling plots (4×4 km). Sentinel-2 L2A satellite images of the study area acquired from Landviewer were classified into six land use and land cover (LULC) classes using Maximum Likelihood (ML) classification in ArcMap 10.8. Landscape composition factors including percentages of forest cover, natural vegetation cover, crop cover, built-up areas, and patch diversity were assessed, alongside landscape configuration factors such as forest patch density, largest patch index for forest cover, and forest patch cohesion for each sampling plot to examine their influence on peafowl density. The associations of the Indian peafowl density with landscape composition and configuration data obtained from the ML classification and climatic data acquired from Chelsa V2.1 were assessed using Generalized Linear Mixed Models (glmmTMB package in R). Among the landscape composition factors examined, the percentage croplands related positively (GLMM: β±SE=0.066±0.01, p=0.001), while the percentage built-up areas showed a negative relationship with the peafowl density (GLMM: β±SE=-0.111±0.01, p=0.018). From the landscape configuration attributes tested, forest patch density showed a significant positive relationship with peafowl density (GLMM: β±SE=7.111±2.83, p=0.012). A significant negative relationship was found between annual average precipitation and peafowl density (GLMM: β±SE=-0.003±0.01, p=0.006). The landscape changes in the Southern Province, particularly the reduction in forest patch density and the increase in built-up areas, appear to be key drivers influencing shifts in peafowl populations towards wet zone areas. The findings of this study suggest the relevance of land-use planning and management in controlling peafowl populations for mitigating conflicts between peafowl and humans. Keywords: Indian peafowl, Landscape composition, Landscape configuration, Climate, Southern provinc

    IDENTIFYING AND MAPPING SALT-AFFECTED LANDS IN HAMBANTOTA DISTRICT, SRI LANKA: AN INTEGRATED GIS AND REMOTE SENSING APPROACH

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    Since available lands in Sri Lanka is decreasing every year mainly due to degradation oflands, it is very important to restore these lands for useful agricultural production. In thisregard, identification of salt-affected lands and differentiates into salinity levels wouldhelp to take necessary actions to restore these lands.An extensive soil survey was conducted throughout the Hambantota district in order to10 0 to to KA•••••.•.identify the salt-affected lands in the district The sampling was done at different depths(i.e. O-lOcm, IO-20cm, 20-30cm, 30-4Ocm and 40-50cm) by using a manual soil auger.The distance between sampling sites was approximately 3km. The exact position ofsampling points in latitude and longitl!c!~ ~ identified by GP~ (Global PositioningSystea), A total number of 100 points and 400 samples were collected. Topographicmaps of survey of Sri Lanka used in the study were Timbolketiya (82), Kataragama(83),Yala(l4), Hambantota(88) and Tissamaharama(89) of scale 1:50,000. Digital thematicmaps of same map sheets and Scale of I :25000 digital maps were also been used.The samples were taken to the laboratory of the Department of Crop Science, Faculty ofAgriallture, University of Ruhuna, where EC and pH measurements were taken using theEC meter and the pH meter. AIl the locational data taken using GPS system, entered intoa database. EC and pH data also been entered to the database. Using ArcView software, apoint map was generated using all the locational data including EC and pH values asattribstes. By applying interpolating techniques, salinity maps were produced.

    Synthesis, Characterization, and Biological Studies of a Piperidinyl Appended Dipicolylamine Ligand and Its Rhenium Tricarbonyl Complex as Potential Therapeutic Agents for Human Breast Cancer

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    © 2016 Amali Subasinghe et al. A novel ligand bearing a central piperidinyl sulfonamide group, N(SO2pip)dpa, and its corresponding Re tricarbonyl complex, [Re(CO)3(N(SO2pip)dpa)]+, have been synthesized in good yield. The methylene CH2 signal seen as a singlet (4.54 ppm) in a 1H NMR spectrum of the ligand in DMSO-d6 appears as two doublets (5.39, 5.01 ppm) in a spectrum of the [Re(CO)3(N(SO2pip)dpa)]+ complex and confirms the presence of magnetically nonequivalent protons upon coordination to Re. Structural results revealed that the Re-N bond lengths fall within the normal range establishing coordination of ligand to metal. The presence of intraligand π→π and n→π transitions is indicated by the absorption peaks around 200-250 nm in UV-visible spectra. Absorption peaks in UV-visible spectra around 300 nm for metal complexes were identified as MLCT transitions. The S-N stretch observed as a strong peak at 923 cm-1 for N(SO2pip)dpa appeared at a shorter frequency, at 830 cm-1 in an FTIR spectrum of the [Re(CO)3(N(SO2pip)dpa)]+. The intense fluorescence displayed by the N(SO2pip)dpa ligand has quenched upon coordination to Re. Relatively low IC50 values given by human breast cancer cells, MCF-7, (N(SO2pip)dpa = 139 μM, [Re(CO)3(N(SO2pip)dpa)]+ = 360 μM) indicate that N(SO2pip)dpa and [Re(CO)3(N(SO2pip)dpa)]+ are promising novel compounds that can be further investigated on their usage as potential anticancer agents

    Cost-Efficient Light-Weight YOLO V5_s for Whole Fetus Detection in Early-Stage Ultrasound Scans

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    Routine medical Ultrasound (US) scans are recommended for expectant mothers to monitor the health and growth of the fetus. However, expectant mothers in rural areas of developing and underdeveloped countries face difficulties in receiving timely scans due to a lack of expertise and facilities. Consequently, maternal and fetal deaths occur at higher rates in these countries, especially in the first trimester. Novel concepts such as Virtual Doctors, Hospital to Home, self- scans and the Internet of Medical Things (IoMT) may address the aforementioned problem effectively. Therefore, computational-efficient algorithms which support low-end smart devices should be introduced to assist expectant mothers in rural areas to provide comfortable and timely fetal scans. In light of the above, this paper discusses computationally efficient YOLO V5_s for fetal detection in first-trimester ultrasound images using a highly diverse dataset including abnormal and multiple pregnancies. The implemented model was compared with five benchmark detection models, namely, ResNet-50 and MobileNet-based faster R-CNN, YOLO-n, YOLO-m and YOLO-l. YOLO was comparatively better than faster R-CNN. Even though YOLO-n is the most computationally inexpensive model, its mAP is 0.709, which is comparatively low, hence cannot be applied to the clinical set-up. YOLO-l model has the best performance with F-1 score and mAP of 0.978 and 0.751, respectively. However, YOLO-s has also achieved a F-1 score of 0.979 with a mAP 0.734. Therefore, a subjective test was conducted to verify using YOLO-s in the clinical set-up with five experts in the field with more than five years of experience. The subjective analysis test, assessed through Fleiss Kappa, suggests substantial agreement beyond chance (κ = 0.69), while the Intraclass Correlation Coefficient (ICC) indicates modest reliability (ICC = 0.7). The findings endorse the application of YOLO-s for real-time detection of whole fetuses in the first trimester with reduced computational complexity with further validation

    EFFECT OF DIAMETER ON VOLUME MEASUREMENTS OF Pinus caribaea (MORELET).

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    is the most important parameter in commercial forestry especially at themature stage. Among those methods, the most common way is to useSmalian's, Huber's and Newton's formulae. In order to use these threeformulae the stem should be divided into sections and volume of each sectionshould be determined separately. Huber's formula is the easiest one to usebecause it needs only one diameter measurement of the log. Smalian'sformula needs two diameter measurements while Newton's formula needsthree. Log length is required for all three formulae. Due to the low number ofmeasurements Huber's formula is more popular among the foresters.However, Smalian's and Huber's formulae can introduce errors because theyuse fewer measurements compared to the Newton's formula. Therefore thepresent study was conducted to identify the variation of the error withincreasing diameter of trees when Huber's and Smalian' s formulae are used.Newton's formula was considered as the one that provides precise values involume estimation.Present study was conducted in the 26 year old Pinus caribaea plantation inYagirala Forest Reserve situated in the low country wet zone of Sri Lanka. Inorder to represent the whole area of the forest, stratified random samplingmethod was used and one O.OSha sample plot was laid in each stratum (i.e.,valley, slope and ridge).Each tree of the plot was divided into twelve 1m long sections using aranging staff. Bottom, mid and top diameter of the each section wasmeasured using the Spiegal relascope. Other than above measurements,diameter at the breast height and height of the tree were measured using thediameter tape and the Blume Leiss Altimeter respectively.In order to find out whether the diameter at breast height affected on volumecalculations using above formulae, trees were grouped into two centimeterdiameter classes. At each diameter class, volumes estimated using Huber'sformula were tested separately for different section lengths using one wayANa vA. Results indicated that at 95% probability level diameter does not have a significant influence in volume measurements for Huber's formula upto twelve meter stem length.First part of this study was conducted to identify the effect of Huber's andSmalian's formula in volume calculations without considering the diameterdifferences of trees in the forest and results proved that Huber's formulaproduced least errors when compared with Smalian's formula. However, inthis instance the maximum stem length that can be measured using Huber'sformula became 6m. According to both tests, it can be concluded thatHuber's formula can be use effectively up to 6m stem length in volumecalculations with out considering the diameter range of trees

    Construction of a growth model to predict the individual stem volume of Tectona grandis L.f. (Teak) in Sri Lanka

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    Stem volume is one of the most important variables in commercial forestry since all the managementdecisions are taken on the volume production of trees. Also volume is the most difficult variable tomeasure and therefore it has to be predicted using a reliable method. Therefore, a growth model wasnewly constructed in this study to predict the individual stem volume of teak (Tectona grandis L.f.)planted as even-aged rnonocultures in Svi Lanka.In order to construct the model, data were collected from 11 plantations in dry zone (Anuradhapura,Harnbatota and Puttlam Forest Divsions) and intermediate zone (Kurunegala Forest Division). Theselected plantations vary in age from 27 to 44 years. Stratified random sampling was used to collectthe data with 0.02 ha circular sample plots. It was decided to use the Newton's formula for volumecalculations and for this reason, the standing tree stems were divided into 3-5 sections and enddiameters, mid diameter and length of each section were measured. The final section was assumedas a cone. The stem volume was then calculated by adding all the section volumes together. Inaddition to that, breast height diameter, total height and crown height were also measured. Usingthose data. tree volume, basal area and top height were calculated which were necessary for theanalysis.A theoretical model was developed to predict the individual tree volume using the relationship of treevolume with form factor, basal area and total height. Three site factors and four transformationswhich are biologically accepted were used to enhance the quality of the models. When tested for thesite differences using top height/age index, five classes were identified from the 1 J plantations. At thefirst stage of analysis, the data of ench site class were fitted separately to the basic model structures.As J result, eight cornmon models v-e-e i :1c'1tified for all five site classes with R2 over 91.0 and goodstandard residua' d.stributions. However, the regression parameters were different for different siteclasses evei (or the same model structure.In order to eliminate the difficulty of using different parameter sets for different site classes, datacollected from all plantations were fooled anc' fitted at the second stage to tile selected eight modelsand new parameter sets were estimated. Then the normal residuals were calculated separately forfiv , site classes using those models and tested using one way ANaYA. Only one model indicated thenon-significant residuals for all site types, i.e., V1/2= 0.5730 (basal area * total height')1/2+ 0.0235 [1/(top height / age)]. That model indicated negligible bias (-0.002) and very high modelling efficiency(0.91). When validated with the reserved data which were 110tused for model building, it indicated agood distribution of normal residuals. Finally it was conc!uded that the selected model proved itsability of predicting the unbiased volume of individual teak stems of all site classes in Sri Lanka andtherefore it is recommended to LIse in the field.(Financial support from the University of Sri Jayewardenepura is acknowledged.)

    COMPARISON OF TOP HEIGHT AND DOMINANT HEIGHT WITH TREE VARIABLES AT THE EVEN AGED Pinus caribaea (MORELET) PLANTATION AT YAGIRALA

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    Top height and dominant heights are 'Confusedlyinterpret in many countries. The mainaim of this study was find the similarity of above two terms and to build some models topredict them.The study was carried out in Yagirala 25 year old even aged Pinus caribaea plantation.Top height and dominant heights were compared with other tree variables. Stratifiedrandom sampling without replacement was used to select the sampling unit. Circular plotsof 0,05 hectare with slope correction and boundary adjustment were used to obtain therequired tree measurementsDiameter at breast height, total height, lower and upper crownheight were measured andbasal area and crown depth were calculated. Top height and dominant height were alsoestimated.Results indicated that there is a significant difference between top and dominant heights.Also two separate equations to predict these two heights were developed. According to theresults initially ten equations were selected. Five equations described the relationshipbetween top and total height while the other five described the relationship betweendominant height and total height. Finally the best two equations were selected usingcoefficient of variation values and the distributions of standard residuals.

    RELATIONSHIP BETWEEN STEM BIOMASS WITH HEIGHT AND DIAMETER OF Pinus caribaea IN THE YAGIRALA FOREST RESERVE

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    The biomass is an important measurement in commercial forestry maintained to producepulp, paper, chips, fuel wood products etc. The estimation of biomass of the tree is not aneasy task and a few studies were carried out so far on this problem.The present study was conducted in 25 years old pine plantation in Yagirala ForestReserve, situated in low country wet zone. According to the geographical differences ofthe plantation, stratified random sampling was carried out and two 0.05 ha circular plotswere established in each stratum. Altogether 6 plots were used for the data collection.The diameter at the breast height (dbh) and total height were measured for all the trees inthese plots.Biomass of the tree was estimated by extracting core samples at the breast height and midheight of the tree. The density of the core samples was estimated using oven dry weightand green volume of the core samples. When tested, there was no significant differenceof density along the stem. Therefore stem biomass was estimated using the density atbreast height. Also there was no significant density difference between three sites.The regression analysis was used with pooled data to find out the relationship betweenthe stem biomass with the tree diameter and height. Using variables of stem volume (W),total height (h), diameter at breast height (d) and their transformations, several modelswere developed. The best model was selected by testing for the R2 value, standardresidual distribution, modelling efficiency and bias. The best relationship for the stembiomass, total height and diameter at breast height was given by the following equation,which has R2 value of90.3.logW = -0.917 + 2.081ogd + O.0195h

    IN· VITRO PROPAGATION OF BLACK PEPPER (Piper nigrum)

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    Black pepper (Piper nigrum) is an important spice crop among minor export crops. Inconventional vegetative propagation systems of black pepper, cuttings and seeds havebeen used. But these methods provide limited quantities of planting materials, and alsospread certain pests and diseases. These problems can be overcome by adopting apropagation method through tissue culture techniquesAll experiments were set up according to completely randomized design. The beststerilization was obtained in 0.1 % HgCb solution for 10 minutes immersion prior todissection of the final explants. Bud length was maximized (4.6 ±..0.84) after 8 weeks inWP medium supplemented with 2 mgll BA and I mgll Kn. The highest survival rate (78%) was observed, when surface sterilized in leaf sections of third leaf with 0.1 % HgCI2in 10 minutes followed by dipping in 90 % alcohol solution. MS medium supplementedwith 0 mgll Kn and I mgll 2,4- D was the most suitable medium for callus formation ofpepper leaf culture.According to the experiment results, 0.1 % HgCI2 with 10 minutes was best treatment forsurface sterilization of buds. For multiplication of pepper buds, 2 mgll BA and I mg/I Kncombination was superior to other treatments. When surface sterilized in leaf sections ofthird leaf with 0.1 %HgCI2 in 10 minutes and dipped in 90 %alcohol solution was bestfor pepper leaf culture and MS medium supplemented with 0 mg/I Kn and I mg/I 2,4- Dwas superior treatment for callus formation.

    In vitro shoot tip culture of Red Sandalwood (Pterocarpus santalinus L.)

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    Red Sandalwood (Pterocarpus santalinus L.) is an endangered woody plant species of familyLeguminosae with high medicinal value. According to some assessments (Arunakumara et 01. =005)trees of this species are available in Southern parts of Sri Lanka. Ilowever seed propagation of redsandalwood has some constraints like low germination of seeds, dormancy of seeds. fungal growthinside the seed coat, scarcity of plants, seasonal fruit bearing habit of trees (Kumarasinghe et al ,2003). Therefore in vitro shoot tip culture can be applied as an alternative propagation technique forconservation and multiplication of Red sandalwood plants in Sri Lanka.Shoot tips were excised from field grown and plant house grown plants. Experiments were carriedout to identify proper surface steril ization procedures for explants and to identify proper establ ishmentmedia for sterilized explants. NaOCI (10.15.20%) with different exposure times (10. 15.20 minutes)were tested and Murashige and Skoog (MS) and Mccown woody plant (WPM)) media were used asestablishment media with and without activated charcoal (1 g/I). Completely Randomized Design (CRD)with twenty replicates was applied for the study.Results revealed that, usage of 10% NaOCI for 20 minutes exposure time showed highest survivalpercentage (100%) for shoot tips detected from plantlets grown in the plant house where contaminationwere controlled up to zero level. Promotion of auxiliary buds within two weeks after culture initiationand appearance of new leaves within a month were observed in survived cultures. For explantsdetected from field grown plants 10% NaOCI for 15 minutes exposure time showed 70% survivalwhere promotion of auxiliary buds within two weeks time and appearance of new leaves within amonth was observed. Among the two media tested both MS medium and WPM medium were wellsuited for culture establishment of plant house derived explants where 1.0 gr1 activated charcoal wasincorporated or not as an absorbent. However MS medium with 1.0 gl' activated charcoal was thebest medium for explants from field grown plants. Of well established explants, 10% showedadventitious root formation in MS charcoal free medium. Immature stem cuttings showed best growthperformances where semi hard wood stem cuttings showed enlargement of stem diameter and callusformation at cut ends.Further studies are needed to identify proper shoot proliferation and rooting media for establishedshoot tips of red sandalwood. Finally there is a need to identify a suitable 
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