1,779 research outputs found

    Dietary fibre and cell-wall polysaccharides in chaenomeles fruits

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    In this paper, research on dietary fibre and cell-wall polysaccharides in chaenomeles fruits is reported and summarised. The dietary fibre in fruits of 12 genotypes of Japanese quince (Chaenomeles japonica) and 1 genotype of flowering quince (C. speciosa) was prepared using two different methods: the Alcohol Insoluble Solid (AIS) method; and the AOAC method for total as well as for soluble and insoluble fibre. The two methods resulted in significantly different estimates, however, no interaction was found between the methods and the genotypes studied. For content of total dietary fibre, three main groups were distinguished, one containing a low amount of fibre (3 genotypes, 28–30 g/100 g dry matter); one containing a moderate amount of fibre (9 genotypes, 30–36 g/100 g dry matter) and an isolated genotype (C. speciosa) that contained a high amount of fibre (38 g/100 g dry matter). The amount and the nature of monomeric sugars in the constituent polysaccharides of the fibre were determined after total hydrolysis of the AIS and the TDF (Total Dietary Fibre). The fibre contained mostly pectic and cellulosic polysaccharides. A sequential extraction scheme allowed the separation of the cell-wall material into its major components (cellulose, pectins and hemicelluloses). The AIS was composed of 30 g pectins, 8 g hemicelluloses and 60 g cellulosic residue/100 g AIS. In 100 g entire dry fruit (800 g entire fresh fruit) there were 11 g pectins, 3 g hemicelluloses and 18 g cellulosic residue. Pectins were mostly located in the flesh of the fruit. Pectins were more efficiently extracted with hot dilute acid than with other extraction media. Pectins had a high degree of methylation (DM) and a low degree of acetylation (DAc). No difference was found in the quantity of polysaccharides extracted from two Japanese quince genotypes, or in the composition of these constituent polysaccharides. The physico-chemical properties of pectins extracted from two genotypes of Japanese quince were studied. On average, the fruits contained 11 g pectins/100 g dry fruit corresponding to 1.4 g pectins/100 g fresh fruit. Pectins were sequentially extracted, and the cells from the flesh of the fruits were observed with a confocal laser scan microscope. Although the dilute acid conditions were the most efficient for extraction of pectins, pectins extracted by water or potassium oxalate had higher (> 600 ml/g) intrinsic viscosities than pectins extracted by dilute acid (< 400 ml/g). Anionic exchange chromatography was performed on the acid-extracted pectins. The pectins were composed of four populations, the first being mainly composed of arabinans, the second of homogalacturonans and the third of rhamnogalacturonans. The composition of the fourth population differed depending on the genotype studied

    On the geometric nature of characteristic classes of surface bundles

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    Each Morita--Mumford--Miller (MMM) class e_n assigns to each genus g >= 2 surface bundle S_g -> E^{2n+2} -> M^{2n} an integer e_n^#(E -> M) := in Z. We prove that when n is odd the number e_n^#(E -> M) depends only on the diffeomorphism type of E, not on g, M, or the map E -> M. More generally, we prove that e_n^#(E -> M) depends only on the cobordism class of E. Recent work of Hatcher implies that this stronger statement is false when n is even. If E -> M is a holomorphic fibering of complex manifolds, we show that for every n the number e_n^#(E -> M) only depends on the complex cobordism type of E. We give a general procedure to construct manifolds fibering as surface bundles in multiple ways, providing infinitely many examples to which our theorems apply. As an application of our results we give a new proof of the rational case of a recent theorem of Giansiracusa--Tillmann that the odd MMM classes e_{2i-1} vanish for any surface bundle which bounds a handlebody bundle. We show how the MMM classes can be seen as obstructions to low-genus fiberings. Finally, we discuss a number of open questions that arise from this work.Comment: 26 pages. v2: added examples to final section; v3: improved main theorem for complex fiberings; v4: final version, to appear in Journal of Topolog

    Spatial Point Pattern Analysis of the Unidentified Aerial Phenomena in France

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    We model the unidentified aerial phenomena observed in France during the last 60 years as a spatial point pattern. We use some public information such as population density, rate of moisture or presence of airports to model the intensity of the unidentified aerial phenomena. Spatial exploratory data analysis is a first approach to appreciate the link between the intensity of the unidentified aerial phenomena and the covariates. We then fit an inhomogeneous spatial Poisson process model with covariates. We find that the significant variables are the population density, the presence of the factories with a nuclear risk and contaminated land, and the rate of moisture. The analysis of the residuals shows that some parts of France (the Belgian border, the tip of Britany, some parts in the SouthEast , the Picardie and Haute-Normandie regions, the Loiret and Corr eze departments) present a high value of local intensity which are not explained by our model

    The Oil Shale Transformation in the Presence of an Acidic BEA Zeolite under Microwave Irradiation

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    The transformation of an oil shale sample from the Autun Basin in the Massif Central, France, was studied using two different heating strategies: microwave irradiation and conventional heating. Microwave heating was performed using a single-mode cavity operating at a frequency of 2.45 GHz under an inert atmosphere. Heating of the sample generated liquid products of similar composition using either microwave or conventional heating. The yields of liquid products were similar in the two cases, while the overall energy requirements were much lower using microwave irradiation. The influence of water vapor on the oil shale decomposition was also studied under microwave energy. In order to simulate conversion of the organic fraction of the oil shale in the presence of an acidic zeolite catalyst, the oil shale sample was mixed with 5 wt % BEA zeolite and heated under microwave irradiation. It was found that the liquid products yield decreased along with an increase in the amount of coke produced. Gaseous and liquid products recovered showed a tendency for the production of lighter components in the presence of zeolite. The aromatic character of the oils was more important when microwaves were used, especially in the presence of zeolite

    Adverse Effects of Cholinesterase Inhibitors in Dementia, According to the Pharmacovigilance Databases of the United-States and Canada.

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    This survey analyzes two national pharmacovigilance databases in order to determine the major adverse reactions observed with the use of cholinesterase inhibitors in dementia. We conducted a statistical analysis of the Food and Drug Administration Adverse Event Reporting System (FAERS) and the Canada Vigilance Adverse Reaction Database (CVARD) concerning the side effects of cholinesterase inhibitors. The statistics calculated for each adverse event were the frequency and the reporting odds ratios (ROR). A total of 9877 and 2247 reports were extracted from the FAERS and CVARD databases, respectively. A disproportionately higher frequency of reports of death as an adverse event for rivastigmine, compared to the other acetylcholinesterase inhibiting drugs, was observed in both the FAERS (ROR = 3.42; CI95% = 2.94-3.98; P&lt;0.0001) and CVARD (ROR = 3.67; CI95% = 1.92-7.00; P = 0.001) databases. While cholinesterase inhibitors remain to be an important therapeutic tool against Alzheimer's disease, the disproportionate prevalence of fatal outcomes with rivastigmine compared with alternatives should be taken into consideration

    Multiple Rabi Splittings under Ultra-Strong Vibrational Coupling

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    From the high vibrational dipolar strength offered by molecular liquids, we demonstrate that a molecular vibration can be ultra-strongly coupled to multiple IR cavity modes, with Rabi splittings reaching 24%24\% of the vibration frequencies. As a proof of the ultra-strong coupling regime, our experimental data unambiguously reveal the contributions to the polaritonic dynamics coming from the anti-resonant terms in the interaction energy and from the dipolar self-energy of the molecular vibrations themselves. In particular, we measure the opening of a genuine vibrational polaritonic bandgap of ca. 6060 meV. We also demonstrate that the multimode splitting effect defines a whole vibrational ladder of heavy polaritonic states perfectly resolved. These findings reveal the broad possibilities in the vibrational ultra-strong coupling regime which impact both the optical and the molecular properties of such coupled systems, in particular in the context of mode-selective chemistry.Comment: 10 pages, 9 figure

    About predictions in spatial autoregressive models

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    We address the problem of prediction in the spatial autoregressive SAR model for areal data which is classically used in spatial econometrics. With the Kriging theory, prediction using Best Linear Unbiased Predictors is at the heart of the geostatistical literature. From the methodological point of view, we explore the limits of the extension of BLUP formulas in the context of the spatial autoregressive SAR models for out-of-sample prediction simultaneously at several sites. We propose a more tractable \almost best" alternative and clarify the relationship between the BLUP and a proper EM-algorithm predictor. From an empirical perspective, we present data-based simulations to compare the efficiency of the classical formulas with the best and almost best predictions
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