•Congener specific analysis of 24 most toxic and abundant PCNs in sediment and biota.•Femtogram IDLs and low to sub pg/g MDLs in sediment and biota.•Average accuracy of 100% (precision of 12% RSD) ...for 34 spiked fish samples.•Average accuracy of 104% (precision of 12% RSD) for 28 spiked sediment samples.
An isotope dilution congener-specific method for the determination of the most abundant and most toxic polychlorinated naphthalenes (PCNs) was developed using gas chromatography with high resolution mass spectrometry (GC-HRMS). The method was used to determine the concentration of 24 target congeners and total PCN concentrations in fish and sediment samples. Tissue samples were extracted using pressurized liquid extraction (PLE) and sediment samples were extracted using Soxhlet extraction. Sample extracts were cleaned up using either a manual two-stage open column procedure or an automated FMS Power Prep System with multi-analyte and multi-sample capability using a three-column cleanup procedure. Sediment extracts were cleaned up with a dual open column cleanup technique involving the use of both a multi-layered silica (silver nitrate/acid/base/neutral silica) column followed by column containing carbon-activated silica. Fish tissue extracts were cleaned up on the automated system involving the use of a high capacity ABN (acid/base/neutral column), carbon celite column, and a basic alumina column. The method is capable of producing instrument detection limits (IDLs) between 0.06 and 0.13pg for each PCN (on column), with method detection limits (MDLs) for the fish extracts ranging from 1.3 to 3.4pg/g (wet weight) and 0.46 to 1.2pg/g (dry weight) for sediments. The average accuracy of 34 spiked fish samples analysed over a period of several months was 100% with a precision (%RSD) of 12%. Similarly, the average accuracy for 28 spiked sediment samples was 104% with a precision (%RSD) of 12%. The application of the method to environmental samples was demonstrated through the analysis of sediment and fish samples obtained from Lake Ontario, Canada. The method is used both for the determination of 24 PCNs and to perform non-targeted screening for the remaining 51 PCN congeners, which are included in the total PCN quantification result. It is currently one of the most comprehensive and accurate congener-specific methods available and was developed from the existing techniques used for the determination of polychlorinated dioxins and furans to produce high quality data with only minor modifications in the clean-up procedure. It can therefore be readily adopted by other laboratories performing dioxin and POP analyses.
Peptide YY (PYY) is a 36 amino-acid peptide secreted from ileal L cells following meals. The cleaved subpeptide PYY3-36 is biologically active and may constitute the majority of circulating PYY-like ...immunoreactivity. The peptide family that includes PYY, pancreatic peptide and neuropeptide Y is noted for its orexigenic effect following intracerebroventricular administration.
To investigate the effects of peripheral (intraperitoneal and chronic subcutaneous) infusions of PYY3-36 on food intake, body weight and glycemic indices.
Food intake was measured in normal mice and in several rodent models of obesity and type II diabetes. In marked contrast to the reported central orexigenic effects, in the present study, PYY3-36 acutely inhibited food intake by up to 45%, with an ED(50) of 12.5 microg/kg in fasted female NIH/Swiss mice. A 4-week infusion reduced weight gain in female ob/ob mice, without affecting the cumulative food intake. In diet-induced obese male mice, PYY3-36 infusion reduced cumulative food intake, weight gain and epididymal fat weight (as a fraction of carcass) with similar ED(50)'s (466, 297 and 201 microg/kg/day, respectively) and prevented a diet-induced increase in HbA1c. Infusion at 100 microg/kg/day for 8 weeks in male fa/fa rats reduced the weight gain (288+/-11 vs 326+/-12 g in saline-infused controls; P<0.05), similar to effects in a pair-fed group. In female ob/ob and db/db mice, there was no acute effect of PYY3-36 on plasma glucose concentrations. In male diabetic fatty Zucker rats, PYY3-36 infused for 4 weeks reduced HbA1c and fructosamine (ED(50)'s 30 and 44 microg/kg/day).
Peripheral PYY3-36 administration reduced the food intake, body weight gain and glycemic indices in diverse rodent models of metabolic disease of both sexes. These findings justify further exploration of the potential physiologic and therapeutic roles of PYY3-36.
Above Ground Biomass (AGB) is a vital factor in the forest ecosystem, closely linked to the carbon cycle and global climate change. Synthetic Aperture Radar (SAR) remote sensing is a potent tool for ...AGB quantification, due to its ability to penetrate vegetation canopies and its reliability for all-weather forest mapping and monitoring. The study used HH/HV dual-polarization SAR data from EOS-04 (C) and ALOS-2 PALSAR-2 (L) satellites to estimate AGB. Multiple linear regression-based statistics model was developed for AGB prediction by considering the best suited frequency and polarisation data for different forest density classes in the study area. The results revealed a strong correlation between AGB and HV backscatter from both the frequencies. The combined HV backscatter from both the sensors showed improvement in the goodness-of-fit (R
2
> 0.5) with reduced error for all the forest density classes. The model estimated AGB was validated with the ground estimated AGB over 80 number of forest inventory plots (0.1 ha), and the overall root-mean-squared error corresponding to the estimated AGB was 32.02 Mg/ha. The model predicted versus ground estimated AGB showed a high correlation upto AGB density of 120 Mg/ha, beyond which underestimation was observed due to saturation of SAR backscatter at higher AGB density values. The AGB in the study ranged from about 10 to 200 Mg/ha. From the results, it was observed that the use of multi-frequency SAR data can be helpful in reducing error with consideration of forest categorisation in the AGB prediction model.
Yarn traversing with counter rotating blades is a well-established method of traversing the yarn, employed on several commercial winding machines. This method is mainly suitable for shorter traverse ...strokes and does not have positive control on yarn during traversing (especially at traverse extremes) as compared to other traversing systems. Moreover, yarn may be subjected to greater abrasion with traversing elements. This may lead to deficiencies such as lack of precision in yarn lay during package build-up that may be reflected in terms of poor package appearance. In this study, the blade profile of the existing yarn traversing mechanism employed on an assembly precision winder has been modified. Three modified blade profiles have been developed with the intention of improving control over yarn during traversing as well as at yarn transfer at traverse extremes from one blade to the other. Packages were built successfully with modified blade profiles. This paper summarizes developmental work of improving profiles of the original design of counter rotating blades to achieve the aforementioned intentions.
Wire Arc Additive Manufacturing (WAAM) is a revolutionary process under the category of Direct Energy Deposition (DED) method in the field of Additive Manufacturing (AM). The research is being done ...exponentially since 2011 which is integrating into the advancement of production specifically for fourth Industrial Revolution (Industry 4.0). The deposition of filler metals in layers over the substrate is done mainly through Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW), and Plasma Arc Welding (PAW) which are leading heat input sources to fabricate the product with improved strength of material than from other DED's. Although defects are similar as of welding defects. In this paper, concepts and processes for WAAM have been studied thoroughly and a critical review is done on important and defining parameters of good quality WAAM manufactured products. It also focuses on the recent advancements in tuning the mechanical and microstructural properties of WAAM fabricated parts and the financial aspects of WAAM for the production of cost-effective fabricated materials.
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•The present work focusses on wire-arc additive manufacturing (WAAM) and highlights the key points and merits of it.•It also emphasis the developments in WAAM, especially on alloys and composite.•The effect of process parameters related to heat generation, material flow is explored.•Microstructural, mechanical characterization and defects associated with WAAM are the key highlights of the present work.
To determine the effect of two physiologically important temperatures on growth and chemotaxis in Campylobacter jejuni. Growth curves of Camp. jejuni were compared at 37°C and 42°C. Chemotaxis was ...compared at 37°C and 42°C by the disc and capillary assays. Student's t-test was applied to the results of the capillary assay to assess the significance in the difference between chemotaxis at the two temperatures. Both, the growth rate and chemotactic ability of the isolate, were found to be greater at 37°C. Quorum sensing (related to population density), a regulation mechanism of virulence in micro-organisms, has been reported in Campylobacter. Chemotaxis is also a known virulence factor of Campylobacter. Both, growth (in terms of population density) and chemotaxis, being greater at 37°C than at 42°C, suggests that the physiological temperature of humans (37°C) might be more favourable for the expression of virulence in Campylobacter than that of birds (42°C). It is as yet not known why Campylobacter causes disease in humans but is avirulent in birds. This study suggests that the human body temperature is optimum for growth and chemotaxis in Campylobacter. There is scope for the study of temperature regulation of other virulence determinants of Campylobacter.
Purpose To report the incidence of endophthalmitis following intravitreal injection using a standardized injection procedure. Design Two randomized clinical trials. Methods Nonpreserved intravitreal ...triamcinolone acetonide in prefilled syringes (Allergan, Inc, Irvine, California, USA) was injected intravitreally in the Diabetic Retinopathy Clinical Research Network (DRCR net) and the Standard Care vs COrticosteroid for REtinal Vein Occlusion (SCORE) clinical trials. The standardized injection procedure did not include the use of topical antibiotics during the days prior to the injection. Results As of December 31, 2006, 1,378 intravitreal injections (538 eyes) have been administered in the Diabetic Retinopathy Clinical Research Network Diabetic Macular Edema trial and 631 injections (301 eyes) in Standard Care vs COrticosteroid for REtinal Vein Occlusion. There was one case of endophthalmitis in the 2,009 injections to date (0.05%, 95% confidence interval 0.001% to 0.277%). Conclusion A low rate of endophthalmitis is achievable using a standardized procedure for intravitreal injection without prescribing antibiotic prophylaxis on the days prior to the injection.
In all 312 actinomycete strains were isolated from water and soil samples from different regions. All these isolates were purified and screened for their antifungal activity against pathogenic fungi. ...Out of these, 22% of the isolates exhibited activity against fungi. One promising strain, Streptomyces albidoflavus PU 23 with strong antifungal activity against pathogenic fungi was selected for further studies. Antibiotic was extracted and purified from the isolate. Aspergillus spp. was most sensitive to the antibiotic followed by other molds and yeasts. The antibiotic was stable at different temperatures and pH tested and there was no significant loss of the antifungal activity after treatment with various detergents and enzymes. Synergistic effect was observed when the antibiotic was used in combination with hamycin. The antibiotic was fairly stable for a period of 12 months at 4 degree C. The mode of action of the antibiotic seems to be by binding to the ergosterol present in the fungal cell membrane resulting in the leakage of intracellular material and eventually death of the cell. The structure of the antibiotic was determined by elemental analysis and by ultraviolet (UV), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) and liquid chromatography mass spectra (LCMS). The antibiotic was found to be a straight chain polyhydroxy, polyether, non-proteinic compound with a single double bond, indicating a nonpolyene antifungal antibiotic.
An evaluation of spatial and temporal trends in fish lipid content may provide insight into trends of lipophilic contaminant levels, fish population health, and nutritional benefits to fish ...consumers. Currently, little is known about lipid content in fishes of the Great Lakes, where commercial and recreational fisheries are important. We examined 35+ years of muscle lipid content data for ten Great Lakes fishes from Canadian waters and found lipid content to have significantly (p < 0.05) declined in 2/6 species in Lake Superior, 3/8 species in Lake Huron, 1/8 species in Lake Erie, and 5/10 species in Lake Ontario. Lake Erie showed the least number of declining trends and most increasing trends (2/8 populations, p < 0.1). For most species, recent (2000–2008) muscle lipid values for Lakes Erie and Ontario are significantly higher compared with Lakes Superior and Huron. These observed trends may be linked to a number of environmental changes within the Great Lakes, and the mechanism(s) of decline are likely to be complex.
A coupled metal transport and speciation model (TRANSPEC) has been developed for surface aquatic systems that explicitly considers the influence of metal speciation on fate. The TRANSPEC, which is ...general to most metal and surface aquatic systems, is constructed by sequentially coupling the speciation/complexation module (in this application MINEQL+) with the fugacity/aquivalence approach for the fate calculations. This model formulation increases the mechanistic detail, predictive power, and fidelity to reality of current fugacity‐aquivalence fate models for metals by estimating aqueous speciation and complexation, rather than relying on empirically derived partition coefficients. A pseudo‐steady state version of TRANSPEC was used to simulate Zn dynamics in Ross Lake (Flin Flon, MB, Canada) that received elevated metal and organic matter inputs for over 50 years. Field studies revealed that ZnS forms soluble ZnL, Zn2+, and ZnSO40 increasing pore water concentrations when surficial sediments turn oxic during fall. The model results for three seasonal scenarios suggest that Zn remobilization is driven by resuspension of insoluble ZnS and the contribution of diffusion is negligible, even during fall when ZnS dissolves to increase the concentration of soluble species under oxic conditions in the sediments. The low diffusive flux is due to the binding of Zn to colloidal dissolved organic matter (DOM) for which sediment‐water diffusion is relatively slow, a result that was obtained as a result of considering metal speciation in the fate calculations.
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![Effects of PYY[3-36] in rod...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0307-0565/small "Effects of PYY[3-36] in rodent models of diabetes and obesity")
