Early-Life Development of the Bifidobacterial Community in the Infant Gut

The establishment of the gut microbiota poses implications for short and long-term health. Bifidobacterium is an important taxon in early life, being one of the most abundant genera in the infant intestinal microbiota and carrying out key functions for maintaining host-homeostasis. Recent metagenomic studies have shown that different factors, such as gestational age, delivery mode, or feeding habits, affect the gut microbiota establishment at high phylogenetic levels. However, their impact on the specific bifidobacterial populations is not yet well understood. Here we studied the impact of these factors on the different Bifidobacterium species and subspecies at both the quantitative and qualitative levels. Fecal samples were taken from 85 neonates at 2, 10, 30, 90 days of life, and the relative proportions of the different bifidobacterial populations were assessed by 16S rRNA–23S rRNA internal transcribed spacer (ITS) region sequencing. Absolute levels of the main species were determined by q-PCR. Our results showed that the bifidobacterial population establishment is affected by gestational age, delivery mode, and infant feeding, as it is evidenced by qualitative and quantitative changes. These data underline the need for understanding the impact of perinatal factors on the gut microbiota also at low taxonomic levels, especially in the case of relevant microbial populations such as Bifidobacterium. The data obtained provide indications for the selection of the species best suited for the development of bifidobacteria-based products for different groups of neonates and will help to develop rational strategies for favoring a healthy early microbiota development when this process is challenged.     

Determination of heavy metals and volatile aromatic compounds in used engine oils and sludges

Assessment of contaminant releases during utilization of used oils is essential for the determination of environmental acceptability. These paper reports the results of the study examining a toxic metal leachability from used engine oil and sludge samples employing leaching test (TCLP). The leaching test indicated that lead in oil samples exceeded 5-ppm concentration level what qualified them as a toxic waste. The samples of contaminated sludge were found to contain high concentration of total lead, barium and chromium, but the leaching test showed concentration below regulatory limit. The total content of benzene, ethylbenzene, toluene, and xylenes (BETX), and naphthalene in used oil and sludge samples was also determined and was found not to be a significant factor to contamination.     

Activity of gold towards methylamine electrooxidation

The kinetics of methylamine oxidation at a gold electrode in contact with an alkaline electrolyte solution was studied. The adsorptive behaviour of substrate molecules was determined by changes in the differential capacitance of the double layer at the electrode/solution interface. The electrooxidation of methylamine occurs only in the potential range of gold oxide layer formation. The general reaction pathways of methylamine oxidation on the gold electrode is proposed.     

On reactive routing protocols in ZigBee wireless sensor networks

ZigBee is the primary standard solution for wireless sensor networks, implementing the Ad hoc On‐Demand Distance Vector (AODV) protocol in the network layer and supported by the standard IEEE 802.15.4. This study is focused on mesh topologies and the critical problems encountered when AODV is executed in conjunction with the Carrier Sense Multiple Access with Collision Avoidance protocol. These problems are mainly related to the packet overhead required to carry out route creation. To perform preliminary experiments to be able to implement AODV in a real network, a new metric is proposed herein. This metric uses fuzzy logic to help in the decision‐making process. The objective of the fuzzy routine is to determine, during the route‐discovery process, the best node to forward request/reply packets, with the aim of reducing packet overhead and energy consumption. Moreover, minor changes are also added to the discovery procedure of AODV to improve the performance of the route‐creation process. This intelligent version of AODV has provided promising experimental results, greatly reducing the number of packets required, with the consequent energy saving while selecting the best nodes to be part of the routes.     

CHARACTERIZATION OF EVA-BASED ADHESIVES CONTAINING DIFFERENT AMOUNTS OF ROSIN ESTER OR POLYTERPENE TACKIFIER

Different amounts (50-170 php--parts per hundred parts of EVA, 33-63 wt%) of two tackifiers (hydrogenated rosin ester, polyterpene resin) were added to an ethylene vinyl acetate (EVA) copolymer containing 28 wt% vinyl acetate. The EVA and the tackifier were characterized using infrared (IR) spectroscopy, DSC measurements, and stress-controlled plate-plate rheology. The properties and compatibility of the EVA-tackifier mixtures were studied using DSC, DMTA, and stress-controlled plate-plate rheology. Immediate adhesion was measured as a quantification of tack, and the T-peel strength of roughened styrene-butadiene rubber/EVA-tackifier adhesive joints was also obtained. The increase in the amount of tackifier noticeably changed the crystallinity of polyethylene blocks in the EVA, and the temperature at the cross-over between the curves of the storage and loss moduli as a function of the temperature was displaced to a lower value. Whereas the hydrogenated rosin ester was compatible with the amorphous ethylene vinyl acetate copolymer regions of the EVA (Tg value increased) reducing its crystallinity, the polyterpene resin was compatible with the polyethylene blocks of the EVA (T g value was not modified), increasing its crystallinity. Immediate adhesion of the EVA-tackifier mixtures was improved by adding both hydrogenated rosin ester and polyterpene tackifiers. On the other hand, there was an optimum tackifier content at which the maximum T-peel strength value was obtained.     

Chia seeds as a source of natural lipid antioxidants

Chia (Salvia sp) seeds were investigated as a source of natural lipid antioxidants. Methanolic and aqueous extracts of defatted chia seeds possessed potent antioxidant activity. Analysis of 2 batches of chia-seed oils demonstrated marked difference in the fatty acid composition of the oils. In both batches, the oils had high concentrations of polyunsaturated fatty acids. The major antioxidant activity in the nonhydrolyzed extract was caused by flavonol glycosides, chlorogenic acid (7.1 × 10⁻⁴ mol/kg of seed) and caffeic acid (6.6 × 10⁻³ m/kg). Major antioxidants of the hydrolyzed extracts were flavonol aglycones/kaempferol (1.1 × 10⁻³ m/kg), quercetin (2.0 × 10⁻⁴ m/kg) and myricetin (3.1 × 10⁻³ m/kg); and caffeic acid (1.35 × 10⁻² m/kg). Two methods were used to measure antioxidant activities. Both were based on measuring bleaching ofβ-carotene in the coupled oxidation ofβ-carotene and linoleic acid in the presence of added antioxidants.     

Asphalts as inhibitors of radical polymerization

The results of investigations concerning the effect of asphalts on radical polymerization of a monomer for model systems composed of styrene and two petroleum asphalts originated from two different crude oils: low sulphur nonparaffinic crude oil and medium sulphur paraffinic crude oil. Based on determination of styrene conversion in the radical polymerization process in the presence of asphalts, it was found that both asphalts act as inhibitors of this reaction. The inhibiting effect of asphalts is weakened by using higher temperatures and prolongation of polymerization time or application of greater initiator rates. On the basis of the analysis of group and elementary chemical composition of both asphalts as well as electron paramagnetic resonance, it was found that the inhibiting effect to radical polymerization is caused mainly by the presence of structures which are stable free radicals in character. The probability of inhibiting effect by sulphur compounds present in asphalts is also discussed.     

Effect of natural antioxidants in virgin olive oil on oxidative stability of refined,bleached, and deodorized olive oil

The factors influencing the oxidative stability of different commercial olive oils were evaluated. Comparisons were made of (i) the oxidative stability of commercial olive oils with that of a refined, bleached, and deodorized (RBD) olive oil, and (ii) the antioxidant activity of a mixture of phenolic compounds extracted from virgin olive oil with that of pure compounds andα-tocopherol added to RBD olive oil. The progress of oxidation at 60°C was followed by measuring both the formation (peroxide value, PV) and the decomposition (hexanal and volatiles) of hydroperoxides. The trends in antioxidant activity were different according to whether PV or hexanal were measured. Although the virgin olive oils contained higher levels of phenolic compounds than did the refined and RBD oils, their oxidative stability was significantly decreased by their high initial PV. Phenolic compounds extracted from virgin olive oils increased the oxidative stability of RBD olive oil. On the basis of PV, the phenol extract had the best antioxidant activity at 50 ppm, as gallic acid equivalents, but on the basis of hexanal formation, better antioxidant activity was observed at 100 and 200 ppm.α-Tocopherol behaved as a prooxidant at high concentrations (>250 ppm) on the basis of PV, but was more effective than the other antioxidants in inhibiting hexanal formation in RBD olive oil.o-Diphenols (caffeic acid) and, to a lesser extent, substitutedo-diphenols (ferulic and vanillic acids), showed better antioxidant activity than monophenols (p- ando-coumaric), based on both PV and hexanal formation. This study emphasizes the need to measure at least two oxidation parameters to better evaluate antioxidants and the oxidative stability of olive oils. The antioxidant effectiveness of phenolic compounds in virgin olive oils can be significantly diminished in oils if their initial PV are too high.     

Reciprocal Tree-Like Fractal Structures

Sometimes the complex structures of nature inspire human constructions. Gothic construction has shown that forces can cross space along intricate paths that may even be arbitrary if correctly dimensioned. In some way, ribbed structures are like trees where the branches conduct forces instead of sap; they operate as branches and trunks descending by fractal ways. Here we discuss reciprocal tree-like fractal structures and the difficulty in their design and erection and solutions for constructive details, as well as the possible analytical questions and automatic generation by means of proper software. The results are shown in the design of the Natural Interpretation Centre in Melilla where we have proposed two connected trees like shown at figures included below.