miRNA Expression Profiling in Subcutaneous Adipose Tissue of Monozygotic Twins Discordant for HIV Infection: Validation of Differentially Expressed miRNA and Bioinformatic Analysis

Combined AntiRetroviral Treatments (cARTs) used for HIV infection may result in varied metabolic complications, which in some cases, may be related to patient genetic factors, particularly microRNAs. The use of monozygotic twins, differing only for HIV infection, presents a unique and powerful model for the controlled analysis of potential alterations of miRNAs regulation consequent to cART treatment. Profiling of 2578 mature miRNA in the subcutaneous (SC) adipose tissue and plasma of monozygotic twins was investigated by the GeneChip^® miRNA 4.1 array. Real-time PCR and ddPCR experiments were performed in order to validate differentially expressed miRNAs. Target genes of deregulated miRNAs were predicted by the miRDB database (prediction score > 70) and enrichment analysis was carried out with g:Profiler. Processes in SC adipose tissue most greatly affected by miRNA up-regulation included (i) macromolecular metabolic processes, (ii) regulation of neurogenesis, and (iii) protein phosphorylation. Furthermore, KEGG analysis revealed miRNA up-regulation involvement in (i) insulin signaling pathways, (ii) neurotrophin signaling pathways, and (iii) pancreatic cancer. By contrast, miRNA up-regulation in plasma was involved in (i) melanoma, (ii) p53 signaling pathways, and (iii) focal adhesion. Our findings suggest a mechanism that may increase the predisposition of HIV⁺ patients to insulin resistance and cancer.     

Sugar and dietary fibre composition influence, by different hormonal response, the satiating capacity of a fruit-based and a β-glucan-enriched beverage

In this study the satiating capacity of three beverages containing 3 g barley β-glucan, or 2.5 g dietary fibre (DF) from fruit, or without DF (control) was evaluated. Fourteen healthy volunteers were randomized to have isocaloric breakfasts including one of the beverages in different occasions. Appetite ratings over 3 h post-breakfast and energy intakes at ad libitum lunch, blood glucose, insulin, ghrelin, PYY, GLP-1, GIP, and PP concentrations, and 24 h food intake, were assessed. The bevaerages containing DF increased fullness and satiety over 3 h post-breakfast, but only the β-glucan-enriched vs. the control significantly reduced energy intakes by 18% at lunch and 40% over the rest of the day. Blood ghrelin and PP responses were differently modulated by beverages. The fruit-based and the β-glucan-enriched beverage suppressed by 8.9% and 8.1% ghrelin response over the 3 h and the first hour post-breakfast, respectively, while only the latter increased PP response by 34.6%, compared to the control. A sucrose-sweetened beverage providing 3 g barley β-glucans can control food intake by modulating PP response and it can even reduce 24 h energy intake. Ghrelin suppression by fruit dietary fibre and mixed sugars was not sufficient to significantly reduce food intake compared to the control.     

Pd/Ce0.6Zr0.4O2/Al2O3 as advanced materials for three-way catalysts: Part 1. Catalyst characterisation, thermal stability and catalytic activity in the reduction of NO by CO

Pd-loaded Ce_0.6Zr_0.4O₂ solid solutions supported on Al₂O₃ are investigated as catalysts for the reduction of NO by CO. The attention is focused on the role of the Ce_0.6Zr_0.4O₂ and of the Pd dispersion on the catalytic activity. The system shows a very high activity below 500 K, which is almost independent on the Pd dispersion. The high activity is attributed to a promoting effect of the Ce_0.6Zr_0.4O₂ on the NO conversion. Investigation of the influence of high temperature treatments disclosed a thermal stabilisation of both Ce_0.6Zr_0.4O₂ and Al₂O₃ in the Ce_0.6Zr_0.4O₂/Al₂O₃ system.     

Nutrient balance of shifting cultivation by burning or mulching in the Eastern Amazon – evidence for subsoil nutrient accumulation

For over a hundred years shifting cultivation with slash-and-burn land preparation has been the predominant type of land use by smallholders in the Bragantina region of the Brazilian Eastern Amazon. This study contrasts the nutrient balance of slash-and-burn agriculture with a fire-free cultivation. Therefore, one half of a 3.5-year-old (28.7 t DM ha^–1) and a 7-year-old woody fallow vegetation (46.5 t DM ha^–1) was burnt and the other half mulched, leaving the biomass as a surface residue. Subsequently, a sequence of maize, beans and cassava was cropped for 1.5 year. Burning the 3.5- and 7-year-old fallow removed 97 and 94% of the C, 98 and 96% of the N, 90 and 63% of the P-stocks, and between 45 and 70% of the cations K, Mg and Ca of the aboveground biomass by volatilization or ash-particle transfer. These losses were avoided with the slash-and-mulch land preparation. Mulching did not increase the losses of nutrients by leaching, despite the high amount of rapidly decomposing surface mulch. Also the length of preceding fallow had no significant influence on leaching losses. At a depth of 3 m, leached nutrients were quantitatively negligible in both treatments. Comparing the nutrient fluxes at soil depths of 0.9 m, 1.8 m and 3 m, the amounts of all mobile nutrients, and also of chloride and sodium were markedly reduced during percolation and must have been retained. It is likely that nutrient retention in the subsoil layer is only temporary, emphasizing the need for a rapid re-establishment of the naturally deep-rooting secondary vegetation after abandonment of sites to enable uptake of these nutrients. The overall nutrient balance was highly negative for slash-and-burn. 291 and 403 kg N ha^–1, 21 and 18 kg P ha^–1, and 70 and 132 kg K ha^–1 were removed from the burnt plots with a preceding fallow of 3.5 and 7 years, respectively. A reduced fallow period (3.5 years), which is a common trend in the region, resulted in a higher mean annual rate of nutrient loss averaged over the duration of the cycle than a fallow period of 7 years. Eliminating the burning losses by mulching brought the agricultural system back to an equilibrated or even slightly positive nutrient balance, even after a reduced fallow period. Thus, slash-and-mulch is a viable alternative to maintain agricultural productivity and ecosystem functioning.     

Effects of Sedentarism and Treadmill Training in Mechanical Properties of Muscles of Ovariectomized Rats with High-Fat Diet

The aim of this study is to evaluate the ability of physical training in the maintenance of muscle strength in rats with HFD （high-fat diet） after OVX （ovariectomy）. Eighty Wistar rats are at eight weeks of age and weight 200 g which divided into 8 groups （n = 10） and treated for 12 weeks： GA： OVX ＋ ND （normal diet）, GB： OVX ＋ ND ＋ training, GC： sham ＋ ND, GD： sham ＋ ND ＋ training, GE： OVX ＋ HFD, GF： OVX ＋ HFD ＋ training, GG： sham ＋ HFD and GH： sham ＋ HFD ＋ training. HFD consists of standard ration for rats with addition of 30% lipids. In training groups, physical training five training/week was conducted on a treadmill with adaptation period of three weeks up to 18 m/s for one hour, training were performed for 12 weeks. The sedentary animals remained in individual box. To analyze the effects of training and diet, tensile strength tests of the gastrocnemius muscles were conducted： the speed of 0.1 mm/min. Analysis of variance was performed to compare groups. The mean （SD） obtained for the maximum load （N） were： GA 57.77 （6.89）, GB 62.74 （5.07）, GC 49.45 （6.06）, GD 59.42 （5.26） and GE 55.58 （4.72）, GF 62.50 （4.56）, GG 58.35 （4.54） and GH 56.67 （5.87）, respectively. There were no differences for maximum load between surgeries （p = 0.004） and between treatments （p = 0.000）. Differences were found also for the relationship surgery diet treatment （p = 0.007）. For the variable stiffness （N/mm）, there were not statistically significant differences： GA 5.03 （0.72）, GB 5.08 （1.09）, GC 5.17 （0.53）, GD 5.35 （0.80）, GE 5.52 （1.20）, GF 5.36 （1.07）, GG 4.83 （1.03） and GH 5.40 （0.73）. For the toughness （N/mm）, there were differences between treatments （p = 0.010） and the ratio diet treatment （p = 0.024）： GA 455.00 （107.21）, GB 541.96 （126.80）, GC 394.97 （84.67）, GD 566.90 （157.07）; GE 424.63 （113.03）, GF 478.07 （106.03）; GG 517.44 （98.65?     

Exploitation of the Antibacterial Properties of Photoactivated Curcumin as ‘Green’ Tool for Food Preservation

In the search for non-chemical and green methods to counteract the bacterial contamination of foods, the use of natural substances with antimicrobial properties and light irradiation at proper light waves has been extensively investigated. In particular, the combination of both techniques, called photodynamic inactivation (PDI), is based on the fact that some natural substances act as photosensitizers, i.e., produce bioactive effects under irradiation. Notably, curcumin is a potent natural antibacterial and effective photosensitizer that is able to induce photodynamic activation in the visible light range (specifically for blue light). Some practical applications have been investigated with particular reference to food preservation from bacterial contaminants.     

L'Épaisseur d'un décimètre carré 1

Résumé:

Le présent article illustre les difficultés qui peuvent surgir lorsque la distinction entre les notions mathématiques et leurs modèles issus du monde physique n'est pas bien comprise. Les exemples fournis touchent divers ordres d'enseignement, notamment celui de la formation des enseignantes et des enseignants pour le primaire.