Effect of phage on survival of Salmonella enteritidis during manufacture and storage of cheddar cheese made from raw and pasteurized milk.

The ability of Salmonella Enteritidis to survive in the presence of phage, SJ2, during manufacture, ripening, and storage of Cheddar cheese produced from raw and pasteurized milk was investigated. Raw milk and pasteurized milk were inoculated to contain 10(4) CFU/ml of a luminescent strain of Salmonella Enteritidis (lux) and 10(8) PFU/ml SJ2 phage. The milks were processed into Cheddar cheese following standard procedures. Cheese samples were examined for Salmonella Enteritidis (lux), lactic acid bacteria, molds and yeasts, coliforms, and total counts, while moisture, fat, salt, and pH values were also measured. Salmonella Enteritidis (lux) was enumerated in duplicate samples by surface plating on MacConkey novobiocin agar. Bioluminescent colonies of Salmonella Enteritidis were identified in the NightOwl molecular imager. Samples were taken over a period of 99 days. Counts of Salmonella Enteritidis (lux) decreased by 1 to 2 log cycles in raw and pasteurized milk cheeses made from milk containing phage. In cheeses made from milks to which phage was not added, there was an increase in Salmonella counts of about 1 log cycle. Lower counts of Salmonella Enteritidis (lux) were observed after 24 h in pasteurized milk cheese containing phage compared to Salmonella counts in raw milk cheese with phage. Salmonella Enteritidis (lux) survived in raw milk and pasteurized milk cheese without phage, reaching a final concentration of 10(3) CFU/g after 99 days of storage at 8 degrees C. Salmonella did not survive in pasteurized milk cheese after 89 days in the presence of phage. However, Salmonella counts of approximately 50 CFU/g were observed in raw milk cheese containing phage even after 99 days of storage. In conclusion, this study demonstrates that the addition of phage may be a useful adjunct to reduce the ability of Salmonella to survive in Cheddar cheese made from both raw and pasteurized milk.     

Micro-Structural and Thermoelectric Characterization of Zinc-Doped In0.6Se0.4 Crystal Grown by Direct Vapour Transport Method

Semiconductors - Crystal of zinc-doped In0.6Se0.4 was successfully grown by direct vapour transport (DVT) method. Grown In0.6Se0.4:Zn crystal has been characterized by energy dispersive X-ray...     

Recapitulation on latent heat hybrid buildings

In the existent paper, the performance of thermal storage hybrid buildings exploiting the latent heat of phase change materials (PCMs) for thermal refrigeration and heating of the contemporary period has been investigated. The conventional buildings consume a large amount of electricity, primarily for the heating and cooling applications. Electricity generation primarily relies on coal-based thermal power plants. The emissions from these establishments pose a serious threat to the environment. Moreover, conventional heating/cooling units rely on exorbitant energy cost. The usage of any kind of thermal storage system is an efficacious way of stockpiling thermal energy and utilizing it when needed. This paper gives a comprehensive overview of the available thermal storage units incorporating PCMs. The various segments of the buildings, viz, ceiling, window, wall, and floor have been analyzed in details. The results are quite promising in terms of load reduction and overall energy saving. Indoor surface temperature reduction of up to 7^oC has been achieved. The energy saving of up to 40% can be realized by employing PCM. A comprehensive list of the PCMs is also tried to build up for end users according to their temperature requirement.     

In vitro assessment of antimicrobial efficacy of the D-tagatose and lactobacilli-based synbiotic preparations against the pathogenic Escherichia coli and Salmonella typhimurium

The study aimed to investigate the utilisation of prebiotic D-tagatose by probiotic lactobacilli (L. rhamnosus GG, L. casei, L. acidophilus and L. fermentum) and enteric pathogens (E. coli and S. typhimurium) to determine synbiotic potential of D-tagatose and lactobacilli combination. The antimicrobial efficacy of the synbiotic preparations (D-tagatose with lactobacillus) was assessed against selected pathogens in co-culture assays. Evidently, D-tagatose supported growth of selected lactobacilli, especially the L. rhamnosus GG and L. casei, but not the enteric pathogens. The tested synbiotic preparations completely inhibited growth of both the pathogens, even in the presence of D-glucose in co-cultures. The well-diffusion assay demonstrated the presence of antimicrobial activity as recorded by drop of culture pH. The study substantiated that D-tagatose could be an effective prebiotic component for formulation of potential synbiotic combinations with L. rhamnosus GG or L. casei that can be used as an alternative to antibiotics against enteric pathogens.     

Cloning of human Stat5B. Reconstitution of interleukin-2-induced Stat5A and Stat5B DNA binding activity in COS-7 cells

We have isolated a second human Stat5 cDNA, Stat5B, and demonstrated that the genes encoding both Stat5A and Stat5B are located at chromosome 17q11.2. Both genes were constitutively transcribed in peripheral blood lymphocytes. By using specific antisera, we demonstrated that both Stat5A and Stat5B are activated by interleukin-2 (IL-2) in peripheral blood lymphocytes, natural killer-like YT leukemia cells, and human T cell lymphotropic virus type I-transformed MT-2 T cells. In COS-7 cells, which constitutively express the Janus family tyrosine kinase Jak1, reconstitution of IL-2-induced Stat5A and Stat5B DNA binding activities was dependent on the coexpression of Jak3 along with the IL-2 receptor beta chain and the common cytokine receptor gamma-chain. This IL-2-induced Stat5 activation was dependent on the presence of either of two tyrosines (Tyr-392 or Tyr-510) in the IL-2 receptor beta chain, indicating that either of these two tyrosines can serve as a docking site. Moreover, we demonstrated that human Stat5 activation is also dependent on Tyr-694 in Stat5A and Tyr-699 in Stat5B, indicating that these tyrosines are required for dimerization. The COS-7 reconstitution system described herein provides a valuable assay for further elucidation of the IL-2-activated JAK-STAT pathway.     

A model study of cavity growth in superplasticity using single premachined holes

Experiments were conducted on a superplastic copper alloy to investigate the growth of single holes machined in the gage length prior to testing. Specimens were deformed in tension in the three regions of flow associated with superplastic materials. Within each flow region, three distinct stages of hole growth were identified. Initially, in stage 1, the hole simultaneously increases in length along the tensile axis but decreases in the dimension measured perpendicular to the tensile axis (“transverse contraction”). Subsequently, in stage 2, the hole grows both along and perpendicular to the tensile axis (“transverse growth”). Finally, in stage 3, a crack nucleates on either side of the hole and propagates to cause failure (“crack propagation”). It is shown that the transitions between the different stages of growth is dependent upon the initiation and development of macroscopic necking adjacent to the hole.     

Attitude Control of Space Platform Based Tethered Satellite System

Using an order N Lagrangian formulation, the paper studies attitude control of a rigid platform supporting a flexible tether connected to a rigid satellite. The system, in an arbitrary orbit, is free to undergo three-dimensional motion in both rigid and flexible degrees of freedom. As can be expected, the governing equations of motion, in general, are highly nonlinear, nonautonomous, and coupled, and are amenable only to numerical integration. The control is achieved through time dependent offset of the tether attachment point, as determined through the Liapunov method, thus providing regulated amount of tether tension induced damping moment. Results suggest that the controller is quite successful in stabilizing the platform about its nominal equilibrium position in a few orbits, even in the presence of relatively large disturbances. Furthermore, extensive parametric study suggests that the controller is quite versatile in imparting any desired orientation to the platform. This would enable the system to undertake diverse missions aimed at communications, launch and retrieval of spacecraft, monitoring the Earth's environment, planetary and galactic observations, etc.     

Comparative behaviour of yeast strains for ethanolic fermentation of culled apple juice

The culled apple juice contained (% w/v): nitrogen, 0.036; total sugars, 11.6 and was of pH 3.9. Saccharomyces cerevisiae NCIM 3284, Pichia kluyeri and Candida krusei produced more ethanol from culled apple juice at its optimum initial pH 4.5, whereas S. cerevisiae NCIM 3316 did so at pH 5.0. An increase in sugar concentration of apple juice from natural 11.6% to 20% exhibited enhanced ethanol production and improved fermentation efficiency of both the S. cerevisiae strains, whereas P. kluyveri and C. krusei produced high ethanol at 11.6% and 16.0% sugar levels, respectively. Urea was stimulatory for ethanol production as well as fermentation efficiency of the yeast strains under study.