Investigation of the agricultural resources in Sri Lanka

The author has identified the following significant results. Several in-house capabilities were developed. The facilities to prepare color composites of excellent quality were developed, using bulk B/W 70 mm transparencies or 1:1,000,000 positive transparencies. These color composites were studied through optical devices on light tables. A zoom transfer scope was also added, enabling direct transfer of LANDSAT composite data on to base maps

A Variable Stiffness Robotic Probe for Soft Tissue Palpation

During abdominal palpation diagnosis, a medical practitioner would change the stiffness of their fingers in order to improve the detection of hard nodules or abnormalities in soft tissue to maximize the haptic information gain via tendons. Our recent experiments using a controllable stiffness robotic probe representing a human finger also confirmed that such stiffness control in the finger can enhance the accuracy of detecting hard nodules in soft tissue. However, the limited range of stiffness achieved by the antagonistic springs variable stiffness joint subject to size constraints made it unsuitable for a wide range of physical examination scenarios spanning from breast to abdominal examination. In this letter, we present a new robotic probe based on a variable lever mechanism able to achieve stiffness ranging from 0.64 to 1.06 N ⋅m/rad that extends the maximum stiffness by around 16 times and the stiffness range by 33 times. This letter presents the mechanical model of the novel probe, the finite element simulation as well as experimental characterization of the stiffness response for lever actuation

Newly Discovered Bright z~9-10 Galaxies and Improved Constraints on Their Prevalence Using the Full CANDELS Area

We report the results of an expanded search for z~9-10 candidates over the ~883 arcmin^2 CANDELS+ERS fields. This study adds 147 arcmin^2 to the search area we consider over the CANDELS COSMOS, UDS, and EGS fields, while expanding our selection to include sources with bluer J_{125}-H_{160} colors than our previous J_{125}-H_{160}>0.5 mag selection. In searching for new z~9-10 candidates, we make full use of all available HST, Spitzer/IRAC, and ground-based imaging data. As a result of our expanded search and use of broader color criteria, 3 new candidate z~9-10 galaxies are identified. We also find again the z=8.683 source previously confirmed by Zitrin+2015. This brings our sample of probable z~9-11 galaxy candidates over the CANDELS+ERS fields to 19 sources in total, equivalent to 1 candidate per 47 arcmin^2 (1 per 10 WFC3/IR fields). To be comprehensive, we also discuss 28 mostly lower likelihood z~9-10 candidates, including some sources that seem to be reliably at z>8 using the HST+IRAC data alone, but which the ground-based data show are much more likely at z<4. One case example is a bright z~9.4 candidate COS910-8 which seems instead to be at z~2. Based on this expanded sample, we obtain a more robust LF at z~9 and improved constraints on the volume density of bright z~9 and z~10 galaxies. Our improved z~9-10 results again reinforce previous findings for strong evolution in the UV LF at z>8, with a factor of ~10 evolution seen in the luminosity density from z~10 to z~8.Comment: 22 pages, 12 figures, 6 tables, accepted for publication in the Astrophysical Journa

Investigation of different methods to minimize cracking in masonry walls

Masonry is widely used as a construction material for load bearing structures or as infill walls in reinforced concrete skeleton frame structures. Cracking is one of the most common problems in masonry walls. It would be better to take relevant precautions at the construction stage rather than carrying out rectification work after cracks are formed. Laboratory tests were carried out to investigate the effectiveness of five methods that can be used as remedial measures to prevent cracking near the wall openings. Test wall panels would represent the load bearing brick masonry walls with openings. Five different types of wall panels were constructed in this study, namely, walls with normal lintel above the opening, normal lintel above the opening and walls reinforced with hexagonal wire mesh, normal lintel above the opening and walls reinforced with hexagonal plastic mesh, continuous lintel above the opening and both the continuous lintel above the opening with a continuous beam just below the opening. Loads at which cracks propagate were compared. From the test results it was found that many cracks propagated on walls with normal lintels at low load levels. When walls were reinforced with hexagonal wire mesh or plastic mesh, walls could withstand higher loads before cracking. However, from the results it could be clearly seen that walls having both the continuous lintels above the opening and continuous beams below the openings were the most effective method to control cracking in masonry walls compared to all four other remedial measures considered in this study

Comparative single dose pharmacokinetics and metabolism of racemic primaquine and its enantiomers in human volunteers

Primaquine (PQ) is a racemic drug used in treatment of malaria for six decades. Recent studies suggest that the two enantiomers of PQ are differentially metabolized in animals, and this results in different pharmacological and toxicological profiles. The current study characterizes the pharmacokinetic (PK) properties, metabolism and tolerability of the individual enantiomers of PQ in healthy human volunteers with normal glucose-6-phosphate dehydrogenase (G6PD) activity. Two cohorts (at two dose levels), each with 18 subjects, participated in three study arms in a crossover fashion: a single dose of the (−)-R enantiomer (RPQ), a single dose of the (+)-S enantiomer (SPQ), and a single dose of racemic PQ (RSPQ). PQ and its key metabolites carboxyprimaquine (cPQ) and PQ-N-carbamoyl glucuronide (PQ-N-CG) were analyzed. Clear differences were observed in PK and metabolism of the two enantiomers. Relative PQ exposure was higher with SPQ as compared to RPQ. PQ maximum plasma concentration (Cmax) and area under the plasma concentration-time curve were higher for SPQ, while the apparent volume of distribution and total body clearance were higher for RPQ. Metabolism of the two enantiomers showed dramatic differences: plasma PQ-N-CG was derived solely from SPQ, while RPQ was much more efficiently converted to cPQ than was SPQ. Cmax of cPQ and PQ-N-CG were 10 and 2 times higher, respectively, than the parent drugs. The study demonstrates that the PK properties of PQ enantiomers show clear differences, and metabolism is highly enantioselective. Such differences in metabolism suggest potentially distinct toxicity profiles in multi-dose regimens, especially in G6PD-deficient subjects

Control Space Reduction and Real-Time Accurate Modeling of Continuum Manipulators Using Ritz and Ritz-Galerkin Methods

To address the challenges with real-time accurate modeling of multi-segment continuum manipulators in the presence of significant external and body loads, we introduce a novel series solution for variable-curvature Cosserat rod static and Lagrangian dynamic method. By combining a modified Lagrange polynomial series solution, based on experimental observations, with Ritz and Ritz-Galerkin methods, the infinite modeling state space of a continuum manipulator is minimized to geometrical position of a handful of physical points (in our case two). As a result, a unified easy to implement vector formalism is proposed for the nonlinear impedance and configuration control. We showed that by considering the mechanical effects of highly elastic axial deformation, the model accuracy is increased up to 6%. The proposed model predicts experimental results with 6-8% (4-6 [mm]) mean error for the Ritz-Galerkin method in static cases and 16-20% (12-14 [mm]) mean error for the Ritz method in dynamic cases, in planar and general 3D motions. Comparing to five different models in the literature, our approximate solution is shown to be more accurate with the smallest possible number of modeling states and suitable for real-time modeling, observation and control applications

A database optimization model with quantitative benchmark

Query optimization and indexing have an immense impact on database optimization. This has been considered in many different perspectives which provide several different solutions in each case. The purpose of this paper is to primarily provide a comprehensive review and discussion of the core problems through the research on query optimization technology and indexing, based on a number of optimization techniques commonly used in the general approach of a query. A new database optimization model is designed and experiments show that this model can significantly reduce the amount of query execution time to improve the optimization efficiency. Regardless of research on the database optimization model, significant work has been done to comparatively evaluate three scenarios; non-optimized query, optimized query without following any optimization standard, and optimized query via proposed optimization model using the same experimental methodology. Further, this paper describes a benchmark that was developed specifically for the purpose of measuring the quantitative evaluations of the proposed database optimization model

A case series of spotted fever rickettsiosis with neurological manifestations in Sri Lanka

SummaryBackgroundSpotted fever group (SFG) rickettsial infections are increasingly detected in Sri Lanka. We describe 17 patients with SFG who developed neurological manifestations.MethodsThe cases were studied prospectively from 2008 at the Teaching Hospital, Peradeniya. An immunofluorescent antibody assay (IFA) was used to confirm the diagnosis.ResultsAll had an IFA IgG titer ranging from 1/64 to 1/4096 and a positive IFA IgM titer against Rickettsia conorii antigen; in 10 (59%) cases the IgG titers were ≥1/256 (definitive cases). The median age of the patients was 62 years (range 26–82 years); 10 were male and seven female. The median duration of fever was 12 days (range 4–35 days). Neurological manifestations on admission were drowsiness or confusion in 14 (82%) and a semi-comatose state in three (18%). Rigidity of the limbs occurred in 14 (82%), bradykinesia and resting tremors in 12 (71%), which persisted after defervescence, neck stiffness in seven (42%), weakness of the limbs in five (29%), deafness in two (12%), and stupor in three (18%). Electroencephalograms in three (18%) showed generalized slow waves. Cerebrospinal fluid examination showed a cellular reaction, predominantly lymphocytes, in three cases. Two patients died (fatality rate 12%).ConclusionWe have documented for the first time the neurological features of SFG rickettsioses in the Central Province, Sri Lanka. These were predominantly extrapyramidal features in patients of older age

Enantioselective interactions of anti-infective 8-aminoquinoline therapeutics with human monoamine oxidases a and b

8-Aminoquinolines (8-AQs) are an important class of anti-infective therapeutics. The monoamine oxidases (MAOs) play a key role in metabolism of 8-AQs. A major role for MAO-A in metabolism of primaquine (PQ), the prototypical 8-AQ antimalarial, has been demonstrated. These investigations were further extended to characterize the enantioselective interactions of PQ and NPC1161 (8-[(4-amino-1-methylbutyl) amino]-5-[3, 4-dichlorophenoxy]-6-methoxy-4-methylquinoline) with human MAO-A and-B. NPC1161B, the (R)-(−) enantiomer with outstanding potential for malaria radical cure, treatment of visceral leishmaniasis and pneumocystis pneumonia infections is poised for clinical development. PQ showed moderate inhibition of human MAO-A and-B. Racemic PQ and (R)-(−)-PQ both showed marginally greater (1.2-and 1.6-fold, respectively) inhibition of MAO-A as compared to MAO-B. However, (S)-(+)-PQ showed a reverse selectivity with greater inhibition of MAO-B than MAO-A. Racemic NPC1161 was a strong inhibitor of MAOs with 3.7-fold selectivity against MAO-B compared to MAO-A. The (S)-(+) enantiomer (NPC1161A) was a better inhibitor of MAO-A and-B compared to the (R)-(−) enantiomer (NPC1161B), with more than 10-fold selectivity for inhibition of MAO-B over MAO-A. The enantioselective interaction of NPC1161 and strong binding of NPC1161A with MAO-B was further confirmed by enzyme-inhibitor binding and computational docking analyses. Differential interactions of PQ and NPC1161 enantiomers with human MAOs may contribute to the enantioselective pharmacodynamics and toxicity of anti-infective 8-AQs therapeutics

Developing a Cost-Efficient Employee and Project Management System for Small-Scale Software Development Startups

Startups are a vital and significant part of the software development landscape. They are the first to implement and embrace new technologies and changes in existing technologies. Even though the vast majority of startups are minor in scale, they represent a significant market share. They develop innovative products within a limited time frame with less capital. Their need to work within a limited time frame guides most startups to embrace the agile methodology. These companies also work with proprietary data and procedures essential to maintain competitiveness with other companies in the market. Employee management systems can reduce the workload on human resource management, and project management systems can increase the efficiency of software development. Both these systems are essential tools for a startup. Even though many tools provide these functionalities in the market, they were not developed specifically for startups. This research aims to create a single service optimized for a small employee base that can provide both of these functionalities in the most cost-efficient and secure way