1,929 research outputs found
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Encapsulation of Bifidobacterium longum in alginate-dairy matrices and survival in simulated gastrointestinal conditions, refrigeration, cow milk and goat milk
The aim of this study was to microencapsulate Bifidobacterium longum subsp. infantis CCUG 52486 using the extrusion method in a variety of matrices, namely sodium alginate (SA), sodium alginate-cow milk (SACM), sodium alginate-goat milk (SAGM) and sodium alginate-casein hydrolysate (SACH), and to evaluate the survival of free and encapsulated bacterial cells under different conditions. The encapsulation yield, size and surface morphology of the microcapsules were evaluated. The survival of microencapsulated bacterial cells and free bacterial cells were evaluated under simulated gastrointestinal conditions as well as in refrigeration, cow milk and goat milk during storage at 4 oC for 28 days. The average size of SACM capsules and SAGM capsules was 2.8±0.3 mm and 3.1±0.2 mm respectively. Goat milk and cow milk based matrices resulted in dense microcapsules which led to better performances in simulated gastrointestinal conditions than SA and SACH microcapsules. The bacterial cells encapsulated in SAGM showed the highest survival rate in cow milk (7.61 log cfu g-1) and goat milk (8.10 log cfu g-1) after the storage of 28 d. The cells encapsulated in SA and SACH and the free cells performed poorly under the simulated gastrointestinal conditions and in all different storage conditions. This study showed that SACM and SAGM are suitable to encapsulate B. longum subsp. infantis CCUG 52486 using the extrusion technique and more specifically, SAGM has a potential to be used as a new encapsulation material for encapsulating probiotic bacteria, resulting milk and goat milk-based products with higher probiotic cell concentrations during refrigerated storage
Self lensing effects for compact stars and their mass-radius relation
During the last couple of years astronomers and astrophysicists have been
debating on the fact whether the so called `strange stars' - stars made up of
strange quark matter, have been discovered with the candidates like SAX
J1808.4-3658, 4U 1728-34, RX J1856.5-3754, etc. The main contention has been
the estimation of radius of the star for an assumed mass of ~ 1.4 M_sun and to
see whether the point overlaps with the graphs for the neutron star equation of
state or whether it goes to the region of stars made of strange matter equation
of state. Using the well established formulae from general relativity for the
gravitational redshift and the `lensing effect' due to bending of photon
trajectories, we, in this letter, relate the parameters M and R with the
observable parameters, the redshift z and the radiation radius R_\infty, thus
constraining both M and R for specific ranges, without any other arbitrariness.
With the required inputs from observations, one ought to incorporate the
effects of self lensing of the compact stars which has been otherwise ignored
in all of the estimations done so far. Nonetheless, these effect of self
lensing makes a marked difference and constraints on the M-R relation.Comment: 7 pages, 1 figure, accepted for publication in Mod. Phys. Lett.
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Encapsulation in an alginateâgoatsâ milkâinulin matrix improves survival of probiotic Bifidobacterium in simulated gastrointestinal conditions and goatsâ milk yoghurt
In this work, a new encapsulating matrix, alginateâgoatsâ milkâinulin, was used to encapsulate Bifidobacterium animalis subsp. lactis BBâ12. The addition of inulin resulted in capsules with a compact structure, and a higher probiotic cell count under simulated gastrointestinal conditions and in probiotic goatsâ milk yoghurt during refrigerated storage. Encapsulation of the probiotic bacteria led to slower postâacidification yoghurts. The results of this study showed that the alginateâgoatsâ milkâinulin matrix has potential to be used as a new encapsulation material to encapsulate probiotics for use in goatsâ milkâbased probiotic fermented dairy products, avoiding the crossâcontamination caused by using capsules based on cowsâ milk
Use of natural plant extracts as a novel microbiological quality indicator in raw milk: An alternative for resazurin dye reduction method
In the present study, we propose a novel field-scale analytical tool for rapid screening of microbiological quality in raw milk using aqueous extracts of plant materials, i.e. flowers (e.g. Hibiscus rosa-sinensis L. and Clitoria ternatea), taproots (e.g. Beta vulgaris) and pricklypears (e.g. Opuntia dillenii). For each plant extract, the colour changes in raw milk were evaluated between 4.5 and 6.5 pH against the resazurin dye as a control. The plant anthocyanin content in each extract was analyzed by the differential pH method using a spectrophotometer. The Hibiscus rosa-sinensis flower extract was opted to further test since it had a pH-sensitive colour change (6.5; maroon to 6.2; light-pink) compared to other plant extracts, which did not indicate a noticeable colour variation with pH. Anthocyanin content of the Hibiscus extract was 0.59 g/mL. The novel method showed high linearity (R-2 = 0.95), 100% accuracy and greater repeatability with an intermediate level of precision. The limit of quantification and detection was 0.46 and 0.15 g/mL, respectively. In conclusion, we demonstrated the potential in using water extract of Hibiscus rosa-sinensis L. flowers as an alternative to the resazurin dye reduction method for rapid and accurate microbiological quality control for raw milk procurement in remote areas
Extraction of manganese from Ferro-manganese slag
In the present investigation an attempt has been made to recover manganese from ferro-manganese slag of ferro-alloy plant. Roasting and leaching are the techniques used to recover- manganese. Roasting has been carried out by mixing the slag with CaO and CaCO3, at 1200Cfor 2 hours. The leaching of the roasted mass has been carried out in
ferric chloride solution alone, as well as in presence of sucrose in ferric chloride solution. The optimum condit-ions have been established by varying the parameters like concentration of leaching agent, percent solids, particle size of the slag, temperature and time of leaching. It is possible to recover 87% of manganese from the ferro-manganese slag of 200# at a temperature of 80°C, 2 hours of leaching time and 5% solids in 0. 154 M ferric chloride solution. It has been found that the presence of sucrose in ferric chloride solution enhances the rate & recovery)recovery of manganese from slag
A prospective study indicating that fractional excretion of sodium is a good marker for fluid loss
Background: Pre-renal failure, a reversible form of acute renal failure (ARF), accounts for 60-70% of all cases of ARF. To study the factors affecting fractional excretion of sodium (FENa) in patients with pre-renal failure.Methods: The study involved patients with pre-renal failure, admitted in a multi-speciality hospital in south India for a period of two years. The demographic and clinical data were collected using a standard pro forma. The correlation between FENa and factors such as age, diabetes mellitus, fluid loss, fever, urine output and creatinine of pre-renal failure were statistically evaluated.Results: The prospective study involved 24 patients diagnosed as pre-renal failure with a mean age of 52.75±18.78. The subjects included 14 males and 10 females, with a median FENa of 0.55 (0.10-0.90). A moderate negative correlation was observed between FENa and fluid loss in pre-renal failure patients (r -0.646, P=0.0007).Conclusions: The level of FENa may assist in estimating fluid loss in patients with pre-renal failure
Forage Potential of Summer Annual Grain Legumes in the Southern Great Plains
Winter wheat (Triticum aestivum L.) and perennial warm-season grasses are the primary forage resources for grazing yearling stocker cattle (Bos taurus) in the US Southern Great Plains (SGP). However, low nutritive value of perennial grasses during mid to late summer limits high rates of growth by stocker cattle. In response, there has been a continued search for plant materials with the potential to provide forage high in crude protein (CP) and digestibility during August through September. A broad range of under-utilized legume species that are grown as grain crops in Africa, India, and South and Central America may have some capacity to serve as high quality pasture or harvested forage in the SGP. However, any crop selection must account for limitations related to unpredictable summer rainfall amounts and patterns, and the frequent occurrence of prolonged drought. Further, any selection should not create water deficits for following winter wheat, the primary forage and grain crop in the region. This article summarizes a small subset of the broad range of underutilized grain legumes (pulses) which exist worldwide and soybean [Glycine max (L.) Merr.] that may have capacity to serve as high quality forage for late-summer grazing. Bringing these crops into forageâstocker production systems could improve the overall system effectiveness, in addition to providing other ecosystem services (e.g., ground cover, grain crops)
Reissner Nordstr\"{o}m Background Metric in Dynamical Co-ordinates: Exceptional Behaviour of Hadamard States
We cast the Reissner Nordstrom solution in a particular co-ordinate system
which shows dynamical evolution from initial data. The initial data for the
case is regular. This procedure enables us to treat the metric as a
collapse to a singularity. It also implies that one may assume Wald axioms to
be valid globally in the Cauchy development, especially when Hadamard states
are chosen. We can thus compare the semiclassical behaviour with spherical dust
case, looking upon the metric as well as state specific information as
evolution from initial data. We first recover the divergence on the Cauchy
horizon obtained earlier. We point out that the semiclassical domain extends
right upto the Cauchy horizon. This is different from the spherical dust case
where the quantum gravity domain sets in before. We also find that the
backreaction is not negligible near the central singularity, unlike the dust
case. Apart from these differences, the Reissner Nordstrom solution has a
similarity with dust in that it is stable over a considerable period of time.
The features appearing dust collapse mentioned above were suggested to be
generally applicable within spherical symmetry. Reissner Nordstrom background
(along with the quantum state) generated from initial data, is shown not to
reproduce them
Modeling Groundwater Levels on the Calera Aquifer Region in Central Mexico Using ModFlow
A conceptual model for the Calera Aquifer has been created to represent the aquifer system beneath the Calera Aquifer Region (CAR) in the State of Zacatecas, Mexico. The CAR area was uniformly partitioned into a 500 X 500 m grid generating a high resolution model that represented the natural boundaries of the aquifer. A computer model was calibrated and validated to verify output from the model corresponding to situations that matched the historical aquifer performance. Predicted groundwater levels were compared with measured data collected from nine observation wells between 1954 and 2004 to evaluate model performance. The main objective of this study was to develop and evaluate a groundwater modeling system using ModFlow-2000 for the CAR. Performance statistics indicated that the model performed well in simulating historic groundwater levels in the central part of the CAR where irrigated agriculture was concentrated. Results evaluation yielded average coefficients of determination of 0.81 and 0.67 and root mean square error values lower than 25.1 m and 25.9 m for the calibration and validation processes, respectively. These results are indicative of a good agreement between predicted and observed groundwater levels. However, further improvements in the conceptual model may be needed to improve predictions in other parts of the CAR for evaluating alternative groundwater management strategies
New Samarium and Neodymium based admixed ferromagnets with near zero net magnetization and tunable exchange bias field
Rare earth based intermetallics, SmScGe and NdScGe, are shown to exhibit near
zero net magnetization with substitutions of 6 to 9 atomic percent of Nd and 25
atomic percent of Gd, respectively. The notion of magnetic compensation in them
is also elucidated by the crossover of zero magnetization axis at low magnetic
fields (less than 103 Oe) and field-induced reversal in the orientation of the
magnetic moments of the dissimilar rare earth ions at higher magnetic fields.
These magnetically ordered materials with no net magnetization and appreciable
conduction electron polarization display an attribute of an exchange bias
field, which can be tuned. The attractively high magnetic ordering temperatures
of about 270 K, underscore the importance of these materials for potential
applications in spintronics.Comment: 6 page text + 5 figure
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