Intestinal barrier function and cow's milk sensitization in guinea pigs fed milk or fermented milk

BACKGROUND: The respective effect of milk and fermented milks on intestinal barrier capacity and on sensitization to beta-lactoglobulin was studied using a guinea pig model of cow's milk allergy. METHODS: Guinea pigs were fed a control diet or the same diet supplemented with milk, fermented milk (Streptococcus thermophilus and Bifidobacterium breve), or dehydrated fermented milk. Intestinal barrier capacity to macromolecules was assessed in an Ussing chamber, and sensitization to cow's milk proteins was measured by systemic anti-beta-lactoglobulin immunoglobulin G1 titers and by intestinal anaphylaxis, the latter assessed by the beta-lactoglobulin-induced increase in short-circuit current of jejunal fragments (deltaIsc(beta-LG)). RESULTS: The electrical resistance of jejunum was similar in the four groups (approximately 80 omega/cm2) suggesting the same paracellular permeability. The transport of 14C-beta-lactoglobulin from mucosa to serosa was significantly decreased in the animals fed dehydrated fermented milk (403+/-131 ng / hr x cm2) compared with that in control animals or animals fed milk (767+/-250 ng / hr x cm2 and 749+/-475 ng / hr x cm2, respectively; p < 0.05). Milk fermentation did not modify native beta-lactoglobulin concentration but anti-beta-lactoglobulin immunoglobulin G1 titers were higher in fermented milk and dehydrated fermented milk (log10 titer = 2.86 and 2.79, respectively) than in guinea pigs fed milk (log10 titer = 2.5; p < 0.007). However, beta-lactoglobulin-induced intestinal anaphylaxis remained the same in the three groups (deltaIsc(beta-LG), 9.6+/-4.1 microA/cm2, 8.5+/-4.3 microA/cm2, and 8.5+/-3.4 microA/cm2 in milk-fed, fermented milk-fed, and dehydrated fermented milk-fed guinea pigs, respectively). CONCLUSIONS: The intestinal barrier capacity to milk proteins seems to be reinforced by dehydrated fermented milk, but milk and fermented milks are equally efficient in inducing cow's milk allergy in guinea pigs.     

Performance analysis of satellite link using Gaussian mixture model under rain

The evolution of communication systems to the next generation, for example, B5G and 6G, demands an ultrareliable performance regardless of weather conditions. Such ultrareliable system design will require that the effects of adverse weather events on the communication system have to be computed more accurately so that physical layer compensation should be optimally and dynamically adaptive to such events. The performance of satellite links is severely affected by dynamic rain attenuation, and thus, accurate and reliable modeling of performance parameters is essential for dynamic fade countermeasures, especially above 10 GHz. In this work, we model the energy per bit to noise spectral density ratio ( $E_b/N_0$) using Gaussian mixture (GM) model during rainy events. The developed mathematical expression is used to accurately model the average $E_b/N_0$, bit error rate (BER), outage probability, and ergodic channel capacity of the link. The average BER, upper bound on BER, and average ergodic capacity of an M-ary phase shift keying scheme (MPSK) using the GM model of $E_b/N_0$ are derived to evaluate the performance of the link under such weather impairments. We then show the numerical results and analysis using the GM model of the measured $E_b/N_0$ data obtained with the AMoS-7 satellite at a site located in Israel.     

Concerning the relationship between clear‐sky,global and direct‐beam,solar spectra

Clear‐sky direct‐beam and normal global solar spectra were measured with a spectroradiometer with and without a collimating tube. The ratio of the two spectra was found to be well approximated by a simple two‐parameter formula suggested by Rayleigh scattering. Copyright © 2002 John Wiley & Sons, Ltd.     

Particulate multi‐phase polymeric nanocomposites

The present research focuses on a model system of a blend of two immiscible polymers containing an inorganic nanofiller, exploring the effect of various melt processing procedures on structuring and on the resulting properties. Binary polypropylene/alumina and ternary polypropylene/nylon/alumina composites were produced by batch compounding under various processing conditions and compositions. Several types of polypropylene and alumina grades were examined. The alumina nanoparticles vary primarily in their mean particle size (13, 50, 500 nm). The morphology of the nanocomposites produced and their thermal, and rheological properties were studied. It was found that under certain processing conditions the nanoparticles significantly affect the morphology of the polypropylene/nylon polymer blend causing compatibilization. Also, the alumina nanoparticles affect the melt viscosity of the polypropylene/nylon blends, whereas their effect on either polypropylene or nylon melts was found insignificant. POLYM. COMPOS., 27:425–430, 2006. © 2006 Society of Plastics Engineers     

Mode I interlaminar fracture toughness of Nylon 66 nanofibrilmat interleaved carbon/epoxy laminates

Carbon/epoxy laminates interleaved with laboratory scale electrospun Nylon 66 nanofibrilmat and spunbonded nonwoven mats were investigated. The effect of the nanoscale fibers on the fracture toughness of the composite under pure Mode I loading was evaluated. It was shown that the nanofibrilmat is responsible for a major interlaminar fracture toughness improvement, as high as 255–322%, compared to a noninterleaved carbon/epoxy reference laminate. We further studied the improvement mechanism of the electrospun nanofibrilmat compared to a commercial spunbonded nonwoven Nylon 66 mat. A combination of two interlayer fracture mechanisms responsible for the toughness improvement is suggested: the first is related to the high energy dissipated by bridged thermoplastic nanofibers and the second is attributed to the generation of a plastic zone near the crack tip. The interlaminar fracture mechanisms of both electrospun nanofibrilmat and the nonwoven mat interleaving was analyzed and discussed. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers