Comparative performance of two extractants in colorimetric determination of soil organic matter in paddy soil

Commonly used soil organic carbon (SOC) determination methods are expensive, time consuming, require equipment and skilled personnel making them impractical to use at field level. Therefore, a laboratory analytical study was carried out to identify a suitable extractant for SOC extraction as part of an ongoing effort to develop a low cost quick method for determining soil organic matter (SOM) at field level. For this purpose, 38 soil samples were collected from different Agro Ecological Zone (AEZ) to represent typical rice based cropping pattern covering a sufficient range in texture, soil organic matter, pH, and type of management. Two extractants e.g. NaOH-Pyrophosphate + HCl and NaOH-EDTA were used to extract organic carbon from soil and two wavelength e.g. 300 and 400 nm were used to measure the absorbance of organic carbon in spectrophotometer. Soil organic carbon measurements by CNS analyzer were used as reference measurement to compare the extracting efficiency of SOC by the selected extractants. Both the extract and wavelength showed different degrees of error in OC measurement. The error sum square of NaOH-Pyrophosphate + HCl and NaOH-EDTA measured at 300 nm wavelength were 15.21 and 13.35 whereas at 400 nm it was 227.37 and 19.95, respectively. Consequently, the average error percentages at 300 nm were -33 and -8 while at 400 nm it was - 187 and -16. Based on the error sum square and error percentage, NaOH-Pyrophosphate + HCl performed better than the NaOH-EDTA, and 400 nm wavelength came out better than the 300 nm wavelength. In addition, both the extracts produced coloured solutions which were easily visible or detectable by naked eye and the colour intensity increased with the increase in SOC content. Variations in colour among the soils depending on organic matter content indicate that it would be possible to develop a new low cost method for SOM determination at field level by using NaOH-Pyrophosphate + HCl as the extractant. Further research is warranted to confirm this finding

Observation on some of the environmental parameters and feed quality of selected golda (Macrobrachium rosenbergii) farms in Bangladesh

A study was conducted to ascertain the existing farm water, effluent and feed quality of selected giant freshwater prawn farms from major prawn farming areas (Bagerhat Sadar, Noakhali Sadar and Mymensingh) of Bangladesh during July to November 2005. Water quality parameters such as the mean values of dissolved oxygen, alkalinity, nitrite-nitrogen, phosphate-phosphorus and ammoniacal nitrogen did not show any significantly differences among the farming areas. Whereas significant differences (p < 0.05) were observed in the mean values of temperature, secchi disc visibility, pH and chlorophyll a. However, all the water quality parameters in the farming areas were within the suitable range for prawn culture. There was no significant variation in nutrients concentration of discharged effluent among the prawn farming areas. All of the nutrients measured in effluent water were within the acceptable range and did not seem to pose a direct threat to the recipient environment. The analysed crude protein contents of commercial CP, Quality and Saudi-Bangla prawn feeds were 31.84%, 27.21% and 28.97%, respectively, whereas all analysed farm made feeds were less than 25%. The other nutrients of prawn feeds varied largely with the source of feeds and ingredients used to prepare feed. The annual yield of prawn varied from 320.4 to 512.6 kg/ha (mean 412.3 kg/ha) depending on the management system

Integrated cage-cum-pond culture systems with high valued climbing perch (Anabas testudineus) in cages and low-valued carps in open ponds

An on-farm trial was conducted over 150 days to determine appropriate stocking ratio, growth and production of climbing perch (Anabas testudineus) in cages and carps in open water of ponds in eighteen farmers' ponds from Haluaghat Upazila at Mymensingh district of Bangladesh. One or two 1 m super(3) cage was suspended in each of 12 earthen ponds and other 6 ponds served as control without cages. Climbing perch of 2-3 g in size were stocked in cages while fingerlings of silver carp (Hypophthalmicthys molitrix), catla (Catla catla), rohu (Labeo rohita), mirgal (Cirhinus cirrhosus), rajputi (Puntius sarana) and common carp (Cyprinus carpio) were stocked at 1 fish/m super(2) with a species ratio of 5:4:4:4:2:1 in open water of all ponds to give cage to open-pond fish ratios of 1:1 (T sub(1:1)) and 2:1 (T sub(2:1)) and 0:1 (T sub(0:1)) as three treatments with six replicates each. Survival of climbing perch was higher in T sub(1:1) (61.67%) than that of T sub(2:1) (29.5%) and was significantly different (p>0.05) between the treatments. Stocking of small size climbing perch fry increased the mortality rate in cages. The net yields of Thai koi were 0.13±0.01 (t/ha) and 0.10±0.01 (t/ha) in treatments T sub(1:1) and T sub(2:1), respectively and both were significantly different (p>0.05). Survival of-open-pond carps was high, ranging from 50 to 91.67% with significantly lower in T sub(0:1) than that of T sub(1:1) and T sub(2:1) treatment. Net and gross yield of each carp species were significantly higher in the T sub(1:1) and T sub(2:1) treatment than that in T sub(0:1) treatment. Net revenues were positive but low in all treatments. Therefore, bigger size climbing perch with lower stocking ratio (T sub(1:1)) is suitable for integrated cage-pond culture of climbing perch and carps. However, more on-farm trials in different ecosystem with scientific interventions are necessary to develop the technology for further dissemination among the rural farmers

Quantum particle filter: a multiple mode method for low delay abrupt pedestrian motion tracking

Pedestrian tracking is a key building block in many emerging technologies, and there are many applications that require a very accurate and reliable pedestrian tracking. Two problems, namely the abrupt changes in motion and the delay in the tracking process are addressed in the reported work. The approach seeks to simulate the uncertainty of the position of electrons around the nucleus by propagating particles in areas where the person is more likely to be, depending on the person's possible motions and taking into account various sources of uncertainty. A novel feature of the presented approach is that it can track abrupt motions accurately with a low delay. The robustness of this approach for abrupt motion situations is demonstrated

Size-dependent permittivity and intrinsic optical anisotropy of nanometric gold thin films: A density functional theory study

Physical properties of materials are known to be different from the bulk at the nanometer scale. In this context, the dependence of optical properties of nanometric gold thin films with respect to film thickness is studied using density functional theory (DFT). We find that the in-plane plasma frequency of the gold thin film decreases with decreasing thickness and that the optical permittivity tensor is highly anisotropic as well as thickness dependent. Quantitative knowledge of planar metal film permittivity's thickness dependence can improve the accuracy and reliability of the designs of plasmonic devices and electromagnetic metamaterials. The strong anisotropy observed may become an alternative method of realizing indefinite media. © 2013 Optical Society of America

Tensile Properties of Glass Fiber Reinforced Polyamide 6-Polypropylene Composites

In this research study, glass fiber (GF) reinforced polyamide 6 (PA6)-polypropylene blends were prepared using injection molding machine. Test specimens of five different compositions such as, 70%PA6+30%PP, 65%PA6+30%PP+5%GF, 60%PA6+30%PP+10%GF, 55%PA6+30%PP+15%GF and 50%PA6+30%PP+20%GF were prepared successfully. The effects of glass fiber content on the tensile properties of the composites were investigated. Test results reveal that yield strength, elastic modulus, tensile strength and tensile elongation are influenced by glass fiber content. Results show that yield strength is low for 70%PA6+30%PP pure polymer blend whereas 50%PA6+30%PP+20%GF composite shows high yield strength. Test results also show that elastic modulus is low for 70%PA6+30%PP, it increases with the increase in fiber content and elastic modulus is remarkably high for 50%PA6+30%PP+20%GF composite. On the other hand, tensile strength is low for 70%PA6+30%PP blend and tensile strength of GF reinforced composite increases steadily with the increase in glass fiber content. In addition, the tensile elongation of 70%PA6+30%PP pure blend is very high, whereas the composite shows reduced tensile elongation with the increase in fiber content and particularly, 50%PA6+30%PP+20%GF composite shows notably low tensile elongation

Use of In Vivo-Induced Antigen Technology (IVIAT) to Identify Genes Uniquely Expressed During Human Infection with Vibrio Cholerae

In vivo-induced antigen technology is a method to identify proteins expressed by pathogenic bacteria during human infection. Sera from 10 patients convalescing from cholera infection in Bangladesh were pooled, adsorbed against in vitro-grown El Tor Vibrio cholerae O1, and used to probe a genomic expression library in Escherichia coli constructed from El Tor V. cholerae O1 strain N16961. We identified 38 positive clones in the screen, encoding pili (PilA and TcpA), cell membrane proteins (PilQ, MshO, MshP, and CapK), methyl-accepting chemotaxis proteins, chemotaxis and motility proteins (CheA and CheR), a quorum-sensing protein (LuxP), and four hypothetical proteins. Analysis of immune responses to purified PilA and TcpA in individual patients demonstrated that the majority seroconverted to these proteins, confirming results with pooled sera. These results suggest that PilA and its outer membrane secretin, PilQ, are expressed during human infection and may be involved in colonization of the gastrointestinal tract. These results also demonstrate substantial immune responses to TcpA in patients infected with El Tor V. cholerae O1. In vivo-induced antigen technology provides a simple method for identifying microbial proteins expressed during human infection, but not during in vitro growth

A randomised pilot equivalence trial to evaluate diamagnetically enhanced transdermal delivery of key ground substance components in comparison to an established transdermal non-steroidal anti-inflammatory formulation in males with prior knee injury

Objective This pilot study assessed the efficacy of a knee guard device, which used magnetophoresis to transdermally deliver Glucosamine, Chondroitin and Hyaluronic Acid in a cohort of individuals with prior knee injury. The aim was to determine if the change in physical function and pain with the knee guard device was equivalent to the change produced by an established topical NSAID formulation containing diclofenac sodium 1%. Methods A randomized, controlled, equivalence trial evaluated outcomes following treatment with the knee guard device or NSAID formulation. The study recruited 114 male participants (aged 40–55 years). Participants were randomly allocated to wear the knee guard device or to use a NSAID gel daily for two weeks. The primary outcomes were the knee injury osteoarthritis function score (KOOS-F) and an aggregated function score (AFS). The lower extremity functional scale (LEFS), pain numerical rating scale (PNRS), global rating of change (GROC) and other KOOS scores were also evaluated. Results Multiple linear regression analyses indicated that there were no significant differences between the interventions for changes in the primary outcomes of AFS and KOOS_F. The 95% confidence interval (-2.89 to 5.15) of the estimated treatment difference for KOOS-F was within the lower (-5.61) and upper (5.61) bounds of the 7% equivalence margin for that measure, The mean value for the AFS was within, but the 95% CI (-3.11 to 7.37) exceeded the 7% equivalence margin (-2.97 to 2.97) for that measure. There was a significant difference in PNRS, which favored the knee guard device. Conclusion The knee guard device demonstrated equivalence for the KOOS-F measure but not the AFS measure of function over the two week trial period when compared to a widely available NSAID gel that has been shown to be superior to placebo. The knee guard produced a greater reduction in pain report (p = 0.002) than the NSAID gel. Users of the knee guard device experienced more skin irritation than participants using the NSAID gel. Further research is required to fully evaluate the therapeutic potential of this innovative treatment approach