Efficacy evaluation of the molasses supplementation in normal and depleted rats diet

Molasses, a sugar cane by-product, has been consumed in Brazil since colonial times. The efficacy of molasses added to the diet of normal and depleted laboratory animals on growth and hemoglobin was tested. Forty weaning males rats, of 21 days of age, were divided into four groups of ten animals: Control (casein diet with 10.14% protein); Molasses (casein diet with 10.14% protein and 12.50% molasses); Depleted Control and Depleted Molasses, the later two submitted to protein depletion for the first 7 days of the trial. Animals were weighed at weaning (initial weight) and at the end of the experiment (final weight) and were fed the experimental rations and water ad libitum for 28 days (normal animals) and 21 days (depleted animals). Consumption was registered in order to calculate the Food Efficiency Ratio. At the end, animals fasted for 10 hours, killed and blood was collected by cardiac puncture to determine hemoglobin levels. Weight gain in all groups did not show statistically significant differences. Molasses fed animals presented a small, but not significant increase in hemoglobin levels, compared to the control groups. Considering the possible deleterious effects of a high sugar diet, that can originate furfural during food processing, it is necessary to conduct more studies to evaluate the utilization of these products for human consumption.     

A survey of optimal structural design under dynamic constraints

Recent published research on structural optimization subject to dynamic constraints is reviewed, and suggestions for further work are offered. Both methods for handling constraints on natural frequencies and methods for treating the more difficult constraints on quantities directly related to the dynamic response are discussed. Computational aspects are emphasized throughout.     

Membrane phospholipids and sterols in microfiltered milk fat globules

Native milk fat globules of various mean diameters, ranging from d₄₃ = 2.3 µm to 8.0 µm, were obtained using microfiltration of raw whole milk. After milk fat globule washing, the milk fat globule membrane (MFGM) was separated by manual churning. After total lipid extraction and separation of polar lipids, their phospholipid (PL) and sterol composition was measured using thin‐layer chromatography, methyl ester analyses by gas chromatography, and gas chromatography coupled to mass spectrometry. The main PL species were phosphatidylethanolamine, phosphatidylcholine and sphingomyelin. The respective fatty acid composition of each PL species was measured. Many different minor bioactive sterols were detected in the MFGM, e.g. lanosterol, lathosterol, desmosterol, stigmasterol and β‐sitosterol. No significant differences in the PL and sterol profile were found between MFGM extracted from small and large milk fat globule fractions.     

NOx storage capacity,SO2 resistance and regeneration of Pt/(Ba)/CeZr model catalysts for NOx-trap system

NOx storage capacity, sulphur resistance and regeneration of 1wt%Pt/Ce_0.7Zr_0.3O₂ (Pt/CeZr) and 1wt%Pt/10wt%BaO/Ce_0.7Zr_0.3O₂ (Pt/Ba/CeZr) catalysts were studied and compared to a 1wt%Pt/10wt%BaO/Al₂O₃ (Pt/Ba/Al) model catalyst submitted to the same treatments. Pt/Ba/CeZr presents the best NOx storage capacity at 400 °C in accordance with basicity measurements by CO₂ TPD and Pt/CeZr shows the better performance at 200 °C mainly due to a low sensitivity to CO₂ at this temperature. For all samples, sulphating induces a detrimental effect on NOx storage capacity but regeneration at 550 °C under rich conditions generally leads to the total recovery of catalytic performance. However, the nearly complete sulphur elimination is only observed on Pt/CeZr. Moreover, an oxidizing treatment at 800 °C leads to partial sulphates elimination on the Pt/CeZr catalyst whereas a stabilization of sulphates on Ba containing species is observed.     

How modality specific is the iambic–trochaic law? Evidence from vision.

The iambic–trochaic law has been proposed to account for the grouping of auditory stimuli: Sequences of sounds that differ only in duration are grouped as iambs (i.e., the most prominent element marks the end of a sequence of sounds), and sequences that differ only in pitch or intensity are grouped as trochees (i.e., the most prominent element marks the beginning of a sequence). In 3 experiments, comprising a familiarization and a test phase, we investigated whether a similar grouping principle is also present in the visual modality. During familiarization, sequences of visual stimuli were repeatedly presented to participants, who were asked to memorize their order of presentation. In the test phase, participants were better at remembering fragments of the familiarization sequences that were consistent with the iambic–trochaic law. Thus, they were better at remembering fragments that had the element with longer duration in final position (iambs) and fragments that had the element with either higher temporal frequency or higher intensity in initial position (trochees), as compared with fragments that were inconsistent with the iambic–trochaic law or that never occurred during familiarization. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Impact of support oxide and Ba loading on the NOx storage properties of Pt/Ba/support catalysts: CO2 and H2O effects

A series of 1 wt.%Pt/_xBa/Support (Support = Al₂O₃, SiO₂, Al₂O₃-5.5 wt.%SiO₂ and Ce_0.7Zr_0.3O₂, x = 5–30 wt.% BaO) catalysts was investigated regarding the influence of the support oxide on Ba properties for the rapid NO_x trapping (100 s). Catalysts were treated at 700 °C under wet oxidizing atmosphere. The nature of the support oxide and the Ba loading influenced the Pt–Ba proximity, the Ba dispersion and then the surface basicity of the catalysts estimated by CO₂-TPD. At high temperature (400 °C) in the absence of CO₂ and H₂O, the NO_x storage capacity increased with the catalyst basicity: Pt/20Ba/Si < Pt/20Ba/Al5.5Si < Pt/10Ba/Al < Pt/5Ba/CeZr < Pt/30Ba/Al5.5Si < Pt/20Ba/Al < Pt/10BaCeZr. Addition of CO₂ decreased catalyst performances. The inhibiting effect of CO₂ on the NO_x uptake increased generally with both the catalyst basicity and the storage temperature. Water negatively affected the NO_x storage capacity, this effect being higher on alumina containing catalysts than on ceria–zirconia samples. When both CO₂ and H₂O were present in the inlet gas, a cumulative effect was observed at low temperatures (200 °C and 300 °C) whereas mainly CO₂ was responsible for the loss of NO_x storage capacity at 400 °C. Finally, under realistic conditions (H₂O and CO₂) the Pt/20Ba/Al5.5Si catalyst showed the best performances for the rapid NO_x uptake in the 200–400 °C temperature range. It resulted mainly from: (i) enhanced dispersions of platinum and barium on the alumina–silica support, (ii) a high Pt–Ba proximity and (iii) a low basicity of the catalyst which limits the CO₂ competition for the storage sites.     

Determination of five tetracyclines and their epimers by LC-MS/MS based on a liquid-liquid extraction with low temperature partitioning

An LC-MS/MS method is presented for screening five tetracyclines and their epimers in a broad range of food products. The scope of matrices includes meat-, fish-, seafood-based products, various dairy ingredients, infant formulae and fats. The method principle is based on a liquid–liquid extraction with aqueous ethylenediaminetetraacetic acid (EDTA) and acetonitrile followed by a freezing step to promote phase separation at low temperature. After defatting with hexane, sample extracts were evaporated and reconstituted before injection onto the LC-MS/MS system. The addition of oxalic acid in the aqueous mobile phase was mandatory to maintain good peak shape and sensitivity over the run. The screening is based upon a double preparation of each sample, one ‘as such’ and a second one with the analytes spiked in the sample, in order to mitigate the risk of false negative response. The method was validated according to the European Community Reference Laboratories Residues Guidelines. A total of 93 samples were included in the validation by two independent laboratories giving both false-negative and false-positive rates at 0% for all compounds. Over the last two years, 2600 samples were analysed routinely and only one chicken sample was found above the regulatory limit.     

Cross-country sailplane flight as a dynamic optimization problem

A minimum?time, thermal?to?thermal sailplane trajectory optimization problem is formulated as a non?linear optimal control problem. Numerical solutions are obtained using a gradiaent projection algorithm which incorporates conjugate directions of search. Further insight into the nature of the solutions and the computational process is ontained through an analysis of the linearized sailplane dynamics and the necessary conditions for optimality. Numerical results are presented for two sailplane types and various values of thermal strength and distance between thermals. An additional problem is formulated and solved for the case of bounded control rate.     

Use of diet containing yeast protein (Saccharomyces cerevisiae): effects upon pregnancy, lactation and development in rats

The nutritive value of manioc flour (Manihot esculenta) enriched with yeast protein (Saccharomyces cerevisiae) added to a food mixture most frequently consumed by low-income populations was assessed in female Wistar rats (n = 30; 100-120 days old). Animals were divided into three groups, mated and had free access to diets and water. Diets were as follows: beans, rice, yeast-enriched manioc flour (BRYMF17); beans, rice, manioc flour (BRMF13); casein (17% protein) (CAS17). Body weight gains and food consumption were recorded during pregnancy and lactation. At the parturition, the number of pups per litter was recorded and offspring were uniformly distributed (7 pups per litter). Weight gains were determined until weaning (21 days). At weaning two youngs were selected from each litter and individually housed. Weight gains, food consumption and the length of the tail were measured until rats were 70 days old. Rats had their liver and brain removed for protein determination and wet and relative weights. Liver samples were histologically examined. Blood hemoglobin, hematocrit and proteins, as well as the Food Efficiency Ratio (FER), were determined. ANOVA and Tukey's test were used. The experimental diet had not significant effect on pregnant and lactating dams. Values for the investigated parameters were higher in experimental youngs than in their controls and lower than in the standard group. This yeast protein-enriched manioc flour proved to be valid in terms of dietary supplementation.