A 1.5 to 3 Mb microdeletion of chromosome 22q11. 2 with loss of multiple genes including histone cell cycle regulator (HIRA) causes 22q11. 2 deletion syndrome (22q11. 2 DS), a common disorder with variable manifestations including congenital malformations affecting the heart, palate and kidneys in association with neurodevelopmental, psychiatric, endocrine and autoimmune abnormalities. The aim of this study was to develop a TaqMan based dosage analysis PCR (TaqMan qPCR) for use as a rapid, cost-effective test for clinically suspected patients fulfilling previously described criteria for molecular diagnosis of 22q11. 2 DS in a lower middle-income country where the cost of testing limits its use in routine clinical practice. Nineteen patients were recruited with informed consent following ethical approval from the Ethics Review Committee (ERC), Lady Ridgway hospital, Colombo. Dosage analysis of extracted DNA was performed using a TaqMan qPCR assay by amplifying regions within the target (HIRA) and control [Testin LIM domain protein (TES)] genes of a suspected patient (P) and unaffected person (N). For detection of a deletion, the normalized values (HIRA/TES dosage) of a patient were compared with normalized values of an unaffected person. A ratio of P: N of 0.5 confirmed presence of a deletion while a ratio of 1.0 refuted this. Seven of 19 (37%) cases were confirmed to have a HIRA deletion, confirming the diagnosis of 22q11. 2 DS, with these results being in complete agreement with those of fluorescence in-situ hybridization (FISH),(performed in 9/19 (47.3%) of recruited cases) and whole exome sequencing (WES)(all 19 …

Tropical forests have declined in extent considerably owing to large scale deforestation for providing land for multiple uses, and this has reduced their collective capacity to provide many important ecological functions. In the present study, conducted in the tropical island of Sri Lanka, we focus on remnant patches of two common and co-occurring vegetation types in the dry zone, Dry Mixed Evergreen Forest and Scrub Forest, to test (a) whether small remnant forest patches facilitate microclimate buffering and, if so, (b) whether the two forest types differ in terms of their potential to buffer the microclimate, and (c) whether the extent of canopy cover influences the microclimate buffering capacity. Co-occurring Grasslands were used as reference habitats. We used multiple temperature, relative humidity and vapour pressure deficit related metrics, and showed that Dry mixed Evergreen Forest and Scrub Forest had …

Abstract Background: Williams Beuren Syndrome (WBS) is a well-recognized and common genetic cause of congenital heart defects, developmental delay, hypercalcemia, and characteristic facial features. It is caused by a 1.5-1.8 Mb heterozygous deletion of chromosome 7q11. 23 with loss of around 28 coding genes. The aim of this study was to develop a low-cost, semi-quantitative PCR (sqPCR) method to detect the chromosome 7q11. 23 deletion. Methods: Twenty-four suspected WBS cases were recruited following ethical clearance and informed consent. Blood was obtained, DNA extracted and spectrophotometrically quantified using standard methods. To detect the deletion by dosage analysis, a target region within a gene located in the WBS commonly deleted region of 7q11. 23 was amplified together with a control region in a duplex sqPCR assay. The control region was telomeric to the WBS commonly …

Raman spectroscopy is an ideal technique for gemstones identification due to its nondestructive nature, rapid detection, no sample preparation, and ability to analyze interior compositions. Notwithstanding the benefits, most routine gemstone analysis requires complementary techniques to verify the accuracy due to difficulties in matching Raman spectra against a known database, while ensuring high sensitivity, specificity, and accuracy. This work presents a technique where computational methods are used to accurately identify gemstones for routine operations. The acquired Raman spectroscopic data is preprocessed using baseline subtraction and signal smoothing for optimal signal extraction and then cross correlated with a verified database of spectra. The correlation coefficient results are then clustered using a K-means algorithm to distinguish the gemstone families. The locally sourced unknown gemstone was found to belong to the quartz family with a sensitivity of 100%, specificity of 98% and accuracy of 98%. A second technique was also introduced by considering both cross correlation and overlap between the area under the curves of matched spectra. Both methods converged on the same conclusion and was backed up by three common cluster validation indices thereby assuring the validity of the identification. The technique was further validated to be used with other gemstone families such as beryl, diamond, and corundum.

ABSTRACT:

Inter-population disparities in a species have been shown to occur as an adaptation to different thermal regimes in the environment. We investigated the thermal sensitivities of the tropical toad Duttaphrynus melanostictus (Asia Common Toad) from two populations at different altitudes: Nuwara-Eliya – 1870 m, and Polonnaruwa – 25 m, above mean sea level. The two locations were separated by what may be considered a short direct distance – 110 km. Thermal sensitivity trials were conducted at six temperatures between 12 and 39 °C. Assessments were made using the performance indicators jump distance, jump force, contact time on the test plate following stimulus to jump, and righting time after being overturned. Optimum performance is taken to be the greatest jump distance and jump force, the least contact time on the test plate, and the least righting time. The populations at the two altitudes had markedly different thermal sensitivities – toads in the cool area (Nuwara-Eliya) performed at an optimal level under low temperatures, whereas the toads in the warm area (Polonnaruwa) performed optimally under high temperatures. The finding that the thermal optima (i.e., the temperatures at which the optimal performance for the four performance indicators was recorded) of the toads in Polonnaruwa were below the mean maximum ambient temperature at this location suggests that these toads would be more susceptible to global warming than those in Nuwara-Eliya whose thermal optima were above the mean maximum ambient temperature in that location. This was consistent with the narrower thermal safety margin (i.e., difference between the mean optimum temperature and mean ambient temperature) of toads in Polonnaruwa, compared to those in Nuwara-Eliya. Importantly, these findings demonstrate that, although thermal sensitivity is considered a conservative trait, differentiation does occur even over a small spatial scale presumably because it offers an adaptive advantage to the population concerned.

ABSTRACT:

Chronic kidney disease (CKD) of unknown etiology is recognized as a major public health challenge and a leading cause of morbidity and mortality in the dry zone in Sri Lanka. CKD is asymptomatic and are diagnosed only in late stages. Evidence points to strong correlation between progression of CKD and kidney fibrosis. Several biochemical markers of renal fibrosis have been associated with progression of CKD. However, no marker is able to predict CKD consistently and accurately before being detected with traditional clinical tests (serum creatinine, and cystatin C, urine albumin or protein, and ultrasound scanning).
In this paper, we hypothesize that fibrosis in the kidney, and therefore the severity of the disease, is reflected in the frequency spectrum of the scattered ultrasound from the kidney. We present a design of a simple ultrasound system, and a set of clinical and laboratory studies to identify spectral characteristics of the scattered ultrasound wave from the kidney that correlates with CKD. We believe that spectral parameters identified in these studies can be used to detect and stratify CKD at an earlier stage than what is possible with current markers of CKD.

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Chlorophyll content of a water sample is used as an indirect estimate for the nutrient level of the sample. Optical spectroscopic techniques are widely used to estimate chlorophyll contents of water samples. However, in a complex environment such an urban lake, there are many other pollutant constituent exists. Hence it is difficult to determine the pollutant level only by investigating the chlorophyll signatures. A study is carried out by collecting water samples from different spatial location of Beira Lake, Colombo (29º 52’N, 77º 53’E, 0.0001 m above mean sea level) and fluorescence spectrum excited at 405 nm and absorption spectrum were obtained for each samples. Despite spectral signatures of chlorophyll, spectral signatures of different polluted constituents were observed in both fluorescence and absorption spectra of the every sample. Obtained data set was compressed using singular value decomposition and used first two components which carry 62% of information. It was found that the samples got into four clusters with cophenetic correlation coefficient of 0.76 when the compressed data set was clustered using K-means algorithm. Water samples from the locations near Gangarama Simamalakaya, near Sri Uttarananda Mawatha and near floating market shows highest polluted level. It is evident that in the absorption spectra also 775 nm peak were found which characteristics an infestation of green photosynthetic bacteria due to stagnation. Water quality of Beira Lake near Lake House clustered into two polluted levels. And highest absorption intensity and lowest fluorescence intensities of polluted constituents show in the upper part of the …

ABSTRACT:

We describe the development of a novel versatile optical platform for active and passive remote sensing of environmental parameters. Applications include assessment of vegetation status and water quality. The system is also adapted for ecological studies, such as identification of flying insects including agricultural pests. The system is based on two mid-size amateur astronomy telescopes, continuous-wave diode lasers at different wavelengths ranging from violet to the near infrared, and detector facilities including quadrant photodiodes, two-dimensional and line scan charge-coupled device cameras, and a compact digital spectrometer. Application examples include remote Ramanlaser-induced fluorescence monitoring of water quality at 120 m distance, and insect identification at kilometer ranges using the recorded wing beat frequency and its spectrum of overtones. Because of the low cost this developmental …

ABSTRACT:

Comparison of material usage and cost of two types of cross-flow steam condensers is reported in this study which can be used for water desalination in conjunction with a parabolic trough solar energy concentrator plant. Traditional shell and tube condensers (where steam flows inside the tubes) and surface condensers (where steam flows in the shell and cooling water flows in the tubes) are considered in this study. It has been found that the energy production from the PTC of dimensions 4.5 m× 4.8 m with an aperture area of 21.6 m2 was 19.4 kW. It has been calculated that the distilled water production capacity of the solar energy harnessing system per day is 55.6 l, assuming solar irradiance to be 0.9 kW m-2 and the efficiency of solar energy harnessing system as 50% if the sun is available for four hours. The cooling water input temperature was assumed to be 30 C. The minimum length required for a SS 304 tube of Ø 9.5 mm was 7.16 m for the traditional condenser and 1.30 m for the surface condenser. The efficiency of the traditional condenser reduced due to the formation of a condensed water layer on the surface of the tube, as it acts as a thermal barrier. However, in the surface condenser, efficiency was enhanced due to easy condensation while increasing the system pressure. Further, efficiency is enhanced due to density separation of wet vapour by changing the flow direction near the wet sump. Fabrication cost and maintenance cost are also found to be less in the surface condenser. As such, it can be concluded that use of surface condenser is the most cost effective method, which uses a smaller amount of material making the …