DESIGNING A WATER QUALITY INDEX FOR KESBEWA LAKE

Water Quality Index (WQI) is a raung reflecting the composite influence on overall quality of anumber of individual quality parameters in a selected water body. The objective of this researchproject is to establish a comprehensive Water Quality Index (WQI) for the Kesbewa Lake byusing physical, chemical and microbiological water quality parameters, to identify the pollutionlevels. These results could be USI.;~( to maintain the quality of water, and conserve flora andfauna, and also to advise the individuals, organizations and funding bodies associated with thelake.The Water Quality Index is defined as, WQI =I WiQi where, WQI = Water Quality Index, anumber between 0 - 100, Qi == Quality ofthe ith parameter, Wi = The weighting factor of the ilbparameter, a number between 1 an 1'), such that, I Wi = 1 for n number of parameters, Wi = Xi IY, Xi = Points given by reference material data for ilb parameter, Y = The total points for nnumber of parameters.The raw analytical results for each parameter, having different units of measurements, aretransformed into unit less Qwalues by using the respective function of quality value of eachparameter in the Q-value graphs. These Q- value graphs are plotted with respect to the eachmeasured parameter value and their relative Q-values assigned by a points system.Based on the World Health Organization (WHO) guidelines, points system for the Q-values for aparameter is assigned and Central Environment Authority (CEA) standards were used, where theWHO guidelines are not available. The highest Q-value 100 is assigned for the best value of aparticular parameter that falls within the above guideline values. Separate ratings for Qualityvalues were given for drinking and bathing, irrigation water, and for fish and aquatic life. Thesethree Quality values were averaged to one value, which gives the Q-value for the measuredvalue of that particular parameter ill the Q-value graph. By using the functions of these graphs,the Q-value (Qi) for any measured value of ith parameter can be obtained.The weighting factor, (Wi) was determined by considering a large number of reference materialdata obtained from different water quality indices, in which the relative contribution of aparameter for the overall water quality has been weighted in different manner, according to thedifferent point of views of scientists. The Q-value (Qi) is then multiplied by the weighting factor(Wi) and resulted values of all n number of parameters are summed to yield the total value of theWQI.Twenty samples were collected from ten different locations of the lake over a period of eightmonths. According to the analyzed results, the prepared WQI for the Kesbewa lake gets ageneral ratings of 49.74, which falls, in the region of Bad in the water quality index. Incomparing the average values of measured parameters with WHO and Sri Lankan Standards, itcan be concluded that the water of Kesbewa Lake is relatively polluted and water quality shouldbe improved for aquatic life, irrigation and drinking and bathing purposes

2-Stroke Engine Options for Automotive Use::A Fundamental Comparison of Different Potential Scavenging Arrangements for Medium-Duty Truck Applications

The work presented here seeks to compare different means of providing scavenging systems for an automotive 2-stroke engine. It follows on from previous work solely investigating uniflow scavenging systems, and aims to provide context for the results discovered there as well as to assess the benefits of a new scavenging system: the reverse-uniflow sleeve-valve. For the study the general performance of the engine was taken to be suitable to power a medium-duty truck, and all of the concepts discussed here were compared in terms of indicated fuel consumption for the same cylinder swept volume using a one-dimensional engine simulation package. In order to investigate the sleeve-valve designs layout drawings and analysis of the Rolls-Royce Crecy-type sleeve had to be undertaken. A new methodology for optimization was developed and the analysis process also took into account work done by the charging system, this being assumed to be a combination of supercharger and turbocharger to permit some exhaust waste heat recovery. As a result of this work it was found that the opposed-piston configuration provides the best attributes since it allows maximum expansion and minimum heat transfer. It gave net specific fuel consumption results which were 9.6% lower than the loop-scavenged engine (which was marginally the worst of the configurations investigated). The other uniflow systems were next, with the reverse sleeve valve being the most promising (3.4% better than the loop-scavenged engine). Furthermore, although the general performance of the loop-scavenged configuration was closer to the other designs than was initially expected, it was found to be compromised by its requirement to have intake and exhaust ports at the same height in the cylinder, thus lengthening the gas exchange events for any given angle-area and consequently reducing the effective (or trapped) compression and expansion ratios. This was despite the use of a charge trapping valve to provide asymmetric port timing and minimize charge short-circuiting, the adoption of which was felt to be a factor in its better-than-expected performance. Finally, the reverse-loop-scavenged poppet-valve type was found to be so compromised by breathing and valve train kinematics that it was not taken to a full optimization. For the opposed-piston engine, once the port timing obtained by the optimizer had been established, a supplementary study was conducted looking at the effect of relative phasing of the crankshafts on performance and economy. This was found to have a small effect on fuel consumption for a significant change in compression ratio, suggesting that, if available, variable crankshaft phasing could be a very important control actuator for gasoline compression ignition in such an engine. Importantly, it was found that existing experiential guidelines for port angle-area specification for loop-scavenged, piston-ported engines using crankcase compression could also be applied to all of the other scavenging types, this having been done here in order to provide a starting point for the work. This important result has not been demonstrated before for such a wide range of architectures. The optimizer employed then allowed further improvements to be made over the starting point. The paper therefore presents a fundamental comparison of scavenging systems using a new approach, providing insights and information which have not been shown before.</p

Zooplankton Assemblage in Hambanota Port and Adjacent Coastal Waters of Sri Lanka

Present study was to investigate zooplankton assemblage in Hambantota port andadjacent coastal waters in Sri Lanka. Samples were collected from the port before thecommencement of commercial operations in order to have baseline information onzooplankton assemblage that can be used in the future to study any community change.Species composition, abundance, spatial distribution and diversity of zooplankton wereinvestigated over a period of six months from January 2011 to June 2011. Monthlysamples were collected from both inner-harbor and outer-harbor. Physico-chemicalparameters such as temperature, pH, salinity, density, conductivity, nitrate,orthophosphate, DO, BOD5 and Ch a were also measured. Zooplankton diversity, speciesrichness and evenness were calculated using Shannon-Weiner diversity index (Hˊ ),Simpson‟s index (D) and Pielou‟s evenness (E). A total of 72 zooplankton types wereidentified throughout the research project mainly Calanus sp., Paracalanus sp.,Sapphirina sp., Acartia tranteri, Barnacle nauplii, Crustacean cypris larvae, Oikopleurasp., Tunicate larvae, Brachionus calyciflorus calyciflorus, Brachionus forficula, Fishlarvae, Discorbis sp., Actinula larvae and Sagitta sp.. Copepod nauplii dominated thezooplankton. According to percentage occurrences arthropods (71%), protozoans (10%)and ichthyoplankton (9%) were abundant in the inner harbor. In the outer harbor alsoarthropods (66%), ichthyoplankton (11%) and protozoans (7%) were recorded in highernumbers. Highest species diversity (Hˊ =2.685), highest species richness (S=39) andhighest evenness (E=0.856) were recorded from outer harbor locations (HFHB1 andHPM). Several species such as Ceratium furca, Chaetoceros sp., Thalassiosira sp.,Rhizosolenia sp. and Protoperidinium sp. known to form harmful algal blooms were alsoobserved in this study.Key words: Zooplankton assemblage, Hambantota port, Ballast water, Invasive AlienSpecies (IAS

mGluR5 Regulates Glutamate-Dependent Development of the Mouse Somatosensory Cortex

We have previously reported that mGluR5 signaling via PLC-β1 regulates the development of whisker patterns within S1 (barrel) cortex of mice (Hannan et al., 2001). However, whether these defects arise from the loss of postsynaptic mGluR5 signaling, and whether the level of mGluR5 is important for barrel formation, was not examined. Furthermore, whether mGluR5 regulates other developmental processes that occur before or after barrel development is not known. We now show that mGluR5 is present postsynaptically at thalamocortical synapses during barrel formation. In addition, Mglur5(+/−) mice exhibit normal TCA patch formation but reduced cellular segregation in layer 4, indicating a dose-dependent role for mGluR5 in the regulation of pattern formation. Furthermore Mglur5(−/−) and Mglur5(+/−) mice display normal cortical arealization, layer formation, and size of PMBSF indicating the defects within S1 do not result from general abnormalities of cortical mapping during earlier stages of development. At P21 layer 4 neurons from Mglur5(−/−) and Mglur5(+/−) mice show a significant reduction in spine density but normal dendritic complexity compared with Mglur5(+/+) mice indicating a role in synaptogenesis during cortical development. Finally, mGluR5 regulates pattern formation throughout the trigeminal system of mice as the representation of the AS whiskers in the PrV, VpM, and S1 cortex was disrupted in Mglur5(−/−) mice. Together these data indicate a key role for mGluR5 at both early and late stages of neuronal development in the trigeminal system of mice

DigitalAir^™ Camless FVVA System - Part 2, Gasoline Engine Performance Opportunities

The paper describes a completely new approach to fully variable valve actuation (FVVA), which allows almost unlimited continuously variable control of intake and exhaust valve opening and closing events, and duration without the use of a camshaft. DigitalAir replaces conventional poppet valves with horizontally actuated valves located directly above the combustion deck of the cylinder head, which open and close a number of slots connecting the cylinder with the intake and exhaust ports, Figure 1. The stroke of the valves to provide the full flow area is approximately 25% of the stroke of the equivalent poppet valve, thus allowing direct electrical actuation with very low power consumption. This design arrangement also avoids the risk of poppet valve to piston collision, or the need for cut-outs in the piston crown, since the valves do not open into the cylinder. The paper will present analytical and experimental data which confirms that the proposed FVVA system can meet the basic performance requirements of modern GDI engines with respect to breathing characteristics across the speed range, throttleless operation at and above idle, opening and closing event optimization, cylinder deactivation, control of residual gas fraction / scavenging and exhaust thermal management. Analytical results were developed using GT-POWER Cycle Simulation and CONVERGE computational fluid dynamics (CFD). Cycle simulation was used to study the system level performance, such as full load capability and transient response, and in particular to quantify the fuel consumption benefits of throttleless operation. CFD was used to better understand the opportunities for in-cylinder charge motion - tumble, swirl and turbulence. JP SCOPE Inc. has been running experimental engines with DigitalAir for several years and has successfully completed performance and durability tests. The mechanical and thermal design of the cylinder head, and the design of the actuator will be covered in Part 1 of this paper [1].</p

The molecular characterisation of Escherichia coli K1 isolated from neonatal nasogastric feeding tubes

Background: The most common cause of Gram-negative bacterial neonatal meningitis is E. coli K1. It has a mortality rate of 10–15%, and neurological sequelae in 30– 50% of cases. Infections can be attributable to nosocomial sources, however the pre-colonisation of enteral feeding tubes has not been considered as a specific risk factor. Methods: Thirty E. coli strains, which had been isolated in an earlier study, from the residual lumen liquid and biofilms of neonatal nasogastric feeding tubes were genotyped using pulsed-field gel electrophoresis, and 7-loci multilocus sequence typing. Potential pathogenicity and biofilm associated traits were determined using specific PCR probes, genome analysis, and in vitro tissue culture assays. Results: The E. coli strains clustered into five pulsotypes, which were genotyped as sequence types (ST) 95, 73, 127, 394 and 2076 (Achman scheme). The extra-intestinal pathogenic E. coli (ExPEC) phylogenetic group B2 ST95 serotype O1:K1:NM strains had been isolated over a 2 week period from 11 neonates who were on different feeding regimes. The E. coli K1 ST95 strains encoded for various virulence traits associated with neonatal meningitis and extracellular matrix formation. These strains attached and invaded intestinal, and both human and rat brain cell lines, and persisted for 48 h in U937 macrophages. E. coli STs 73, 394 and 2076 also persisted in macrophages and invaded Caco-2 and human brain cells, but only ST394 invaded rat brain cells. E. coli ST127 was notable as it did not invade any cell lines. Conclusions: Routes by which E. coli K1 can be disseminated within a neonatal intensive care unit are uncertain, however the colonisation of neonatal enteral feeding tubes may be one reservoir source which could constitute a serious health risk to neonates following ingestion

2-Stroke Engine Options for Automotive Use::A Fundamental Comparison of Different Potential Scavenging Arrangements for Medium-Duty Truck Applications

The work presented here seeks to compare different means of providing scavenging systems for an automotive 2-stroke engine. It follows on from previous work solely investigating uniflow scavenging systems, and aims to provide context for the results discovered there as well as to assess the benefits of a new scavenging system: the reverse-uniflow sleeve-valve. For the study the general performance of the engine was taken to be suitable to power a medium-duty truck, and all of the concepts discussed here were compared in terms of indicated fuel consumption for the same cylinder swept volume using a one-dimensional engine simulation package. In order to investigate the sleeve-valve designs layout drawings and analysis of the Rolls-Royce Crecy-type sleeve had to be undertaken. A new methodology for optimization was developed and the analysis process also took into account work done by the charging system, this being assumed to be a combination of supercharger and turbocharger to permit some exhaust waste heat recovery. As a result of this work it was found that the opposed-piston configuration provides the best attributes since it allows maximum expansion and minimum heat transfer. It gave net specific fuel consumption results which were 9.6% lower than the loop-scavenged engine (which was marginally the worst of the configurations investigated). The other uniflow systems were next, with the reverse sleeve valve being the most promising (3.4% better than the loop-scavenged engine). Furthermore, although the general performance of the loop-scavenged configuration was closer to the other designs than was initially expected, it was found to be compromised by its requirement to have intake and exhaust ports at the same height in the cylinder, thus lengthening the gas exchange events for any given angle-area and consequently reducing the effective (or trapped) compression and expansion ratios. This was despite the use of a charge trapping valve to provide asymmetric port timing and minimize charge short-circuiting, the adoption of which was felt to be a factor in its better-than-expected performance. Finally, the reverse-loop-scavenged poppet-valve type was found to be so compromised by breathing and valve train kinematics that it was not taken to a full optimization. For the opposed-piston engine, once the port timing obtained by the optimizer had been established, a supplementary study was conducted looking at the effect of relative phasing of the crankshafts on performance and economy. This was found to have a small effect on fuel consumption for a significant change in compression ratio, suggesting that, if available, variable crankshaft phasing could be a very important control actuator for gasoline compression ignition in such an engine. Importantly, it was found that existing experiential guidelines for port angle-area specification for loop-scavenged, piston-ported engines using crankcase compression could also be applied to all of the other scavenging types, this having been done here in order to provide a starting point for the work. This important result has not been demonstrated before for such a wide range of architectures. The optimizer employed then allowed further improvements to be made over the starting point. The paper therefore presents a fundamental comparison of scavenging systems using a new approach, providing insights and information which have not been shown before.</p

Characterizing the pathotype of neonatal meningitis causing <i>Escherichia coli</i> (NMEC)

Background Neonatal meningitis-causing Escherichia coli (NMEC) is the predominant Gram-negative bacterial pathogen associated with meningitis in newborn infants. High levels of heterogeneity and diversity have been observed in the repertoire of virulence traits and other characteristics among strains of NMEC making it difficult to define the NMEC pathotype. The objective of the present study was to identify genotypic and phenotypic characteristics of NMEC that can be used to distinguish them from commensal E. coli. Methods A total of 53 isolates of NMEC obtained from neonates with meningitis and 48 isolates of fecal E. coli obtained from healthy individuals (HFEC) were comparatively evaluated using five phenotypic (serotyping, serum bactericidal assay, biofilm assay, antimicorbial susceptibility testing, and in vitro cell invasion assay) and three genotypic (phylogrouping, virulence genotyping, and pulsed-field gel electrophoresis) methods. Results A majority (67.92 %) of NMEC belonged to B2 phylogenetic group whereas 59 % of HFEC belonged to groups A and D. Serotyping revealed that the most common O and H types present in NMEC tested were O1 (15 %), O8 (11.3 %), O18 (13.2 %), and H7 (25.3 %). In contrast, none of the HFEC tested belonged to O1 or O18 serogroups. The most common serogroup identified in HFEC was O8 (6.25 %). The virulence genotyping reflected that more than 70 % of NMEC carried kpsII, K1, neuC, iucC, sitA, and vat genes with only less than 27 % of HFEC possessing these genes. All NMEC and 79 % of HFEC tested were able to invade human cerebral microvascular endothelial cells. No statistically significant difference was observed in the serum resistance phenotype between NMEC and HFEC. The NMEC strains demonstrated a greater ability to form biofilms in Luria Bertani broth medium than did HFEC (79.2 % vs 39.9 %). Conclusion The results of our study demonstrated that virulence genotyping and phylogrouping may assist in defining the potential NMEC pathotype

Child with Deletion 9p Syndrome Presenting with Craniofacial Dysmorphism, Developmental Delay, and Multiple Congenital Malformations

A 4-month-old Sri Lankan male child case with a de novo terminal deletion in the p22 → pter region of chromosome 9 is described. The child presented with craniofacial dysmorphism, developmental delay, and congenital malformations in agreement with the consensus phenotype. A distinctive feature observed in this child was complete collapse of the left lung due to malformation of lung tissue. Cytogenetic studies confirmed terminal deletion of the short arm of chromosome 9 distal to band p22 [46,XY,del(9)(p22 → pter)]. This is the first reported case of a de novo deletion 9p syndrome associated with pulmonary hypoplasia. This finding contributes to the widening of the spectrum of phenotypic features associated with deletion 9p syndrome

Convergence of hippocampal pathophysiology in <i>Syngap^+/- </i>and <i>Fmr1</i>^<i>-/y</i>mice

Previous studies have hypothesized that diverse genetic causes of intellectual disability (ID) and autism spectrum disorders (ASDs) converge on common cellular pathways. Testing this hypothesis requires detailed phenotypic analyses of animal models with genetic mutations that accurately reflect those seen in the human condition (i.e., have structural validity) and which produce phenotypes that mirror ID/ASDs (i.e., have face validity). We show that SynGAP haploinsufficiency, which causes ID with co-occurring ASD in humans, mimics and occludes the synaptic pathophysiology associated with deletion of the Fmr1 gene. Syngap[superscript +/−] and Fmr1[superscript −/y] mice show increases in basal protein synthesis and metabotropic glutamate receptor (mGluR)-dependent long-term depression that, unlike in their wild-type controls, is independent of new protein synthesis. Basal levels of phosphorylated ERK1/2 are also elevated in Syngap[superscript +/−] hippocampal slices. Super-resolution microscopy reveals that Syngap[superscript +/−] and Fmr1[superscript −/y] mice show nanoscale alterations in dendritic spine morphology that predict an increase in biochemical compartmentalization. Finally, increased basal protein synthesis is rescued by negative regulators of the mGlu subtype 5 receptor and the Ras–ERK1/2 pathway, indicating that therapeutic interventions for fragile X syndrome may benefit patients with SYNGAP1 haploinsufficiency