Implementing collection of sets with trie: a stepping stone for performances ?

Main operations of the Set Collection Abstract Data Type are insertion, research and deletion. A well known option to implement these operations is to use hashtable. Although hashtable does not admit good time complexities in the worst case, the practical time complexities are efficient. Another option is to use the data structure known as the trie. The trie is useful for two main reasons. Firstly, with such a data structure, mentionned operations admit very good theoretical time complexities. Secondly a trie can be seen as a compact representation of a collection of sets since some parts of them are merged together. Aim of this article is to evaluate performances of the trie data structure. The Java language proposes an abstract class corresponding to the Set Collection A.D.T. operations. We propose in this article three different implementations of this abstract class. All of them are variations of the way to manage the sons of nodes. Theoretical complexities are then evaluated. After that, comparison with performances of hashtable are made in different contexts depending of the collection density, the set size and the ground set size. Finally we analyze our results and conclude in which cases the trie structure outperforms others structures

Analysis of Short Food Supply Chain Governances: Innovative Collective Platforms Supplying Local Produce

This paper addresses the issue of governance diversity of innovative semi wholesale SFSC such as multi stake-holder platforms acting as middlemen between local producers and buyers (individual and collective ones) wishing to procure local products. We apply the new institutional economics approach with special attention to ownership rights allocation (Hansmann, 1988), collective decision-making (Pozzobon and Zylbersztajn, 2013) and associated transaction costs (Williamson, 1991; Menard, 2004; Chaddad, 2012). Those concepts were already used in analysis of various agri-businesses, cooperatives and their vertical relations in supply chains but little has been done in terms of SFSC. We rely on this framework to provide a comparative analysis of their governance structures based on a detailed description of the “horizontal” relations among stake-holders and “vertical” relations between the platforms and their suppliers and customers

Matrix-Matching as an Improvement Strategy for the Detection of Pesticide Residues

More than 90% of the pesticides residues in apples are located in the peel. We developed a gas chromatography/ion trap tandem mass spectrometry method for investigating all detectable residues in the peel of 3 apple varieties. Sample preparation is based on the use of the Quick Easy Cheap Effective Rugged and Safe method on the whole fruit, the flesh, and the peel. Pesticide residues were quantified with solvent‐matched and matrix‐matched standards, by spiking apple sample extracts. Matrix effects dependent on the type of extract (fruit, flesh, or peel) and the apple variety were detected. The best data processing methods involved normalizing matrix effect rates by matrix‐matched internal/external calibration. Boscalid, captan, chlorpyrifos, fludioxonil, and pyraclostrobin were the most frequently detected pesticides. However, their concentrations in the whole fruit were below European maximum residue levels. Despite negative matrix effects, the residues in peel were detected at concentrations up to 10 times higher than those in whole fruits. Consequently, other pesticide residues present at concentrations below the limit of quantification in the whole fruit were detected in the peel

Recovery of hydroxycinnamic acids from renewable resources by adsorption on zeolites

The aim of the study is to examine the adsorption capacity of hydroxycinnamic compounds (ferulic acid, p-coumaric acid, cinnamic acid) on zeolite adsorbents (FAU- and *BEA-type structure) versus Amberlite resin XAD16. The pH and contact time effects on adsorption were evaluated. The adsorption capacity was dependent on pH and higher at pH less than pKa1. The kinetic adsorption is faster onto FAU and *BEA zeolites than onto XAD16 resin. Maximum adsorption capacities were calculated for the target compounds for pH=3.5 by using the Langmuir isotherm model. They reached higher values for zeolites than for XAD16 and are respectively of 139, 122 and 109 mg g-1 for ferulic, p-coumaric and cinnamic acids. Values around 30 mg g-1 were observed for XAD16. Desorption ratios are close to 100 % for *BEA zeolite and XAD16 resin in the presence of ethanol 96 %. The use of regenerated zeolites leads to a loss of adsorption capacities of 30 % for the cinnamic acid and 20 % for the two other acids. It was concluded that *BEA zeolites are particularly interesting adsorbants to isolate the hydroxycinnamic compounds from vegetal extracts

Evaluation and prevention of the negative matrix effect of terpenoids on pesticides in apples quantification by gas chromatography–tandem mass spectrometry

The sample matrix can enhance the gas chromatography signal of pesticide residues relative to that obtained with the same concentration of pesticide in solvent. This paper is related to negative matrix effects observed in coupled gas chromatography-mass spectrometry ion trap (GC/MS2) quantification of pesticides in concentrated extracts of apple peel prepared by the Quick Easy Cheap Effective Rugged and Safe (QuEChERS) method. It is focused on the pesticides most frequently used on the apple varieties studied, throughout the crop cycle, right up to harvest, to combat pests and diseases and to improve fruit storage properties. Extracts from the fleshy receptacle (flesh), the epiderm (peel) and fruit of three apple varieties were studied by high-performance thin-layer chromatography hyphenated with UV–vis light detection (HPTLC/UV visible). The peel extracts had high concentrations of triterpenic acids (oleanolic and ursolic acids), reaching 25mgkg−1, whereas these compounds were not detected in the flesh extracts (<0.05mgkg−1). A significant relationship has been found between the levels of these molecules and negative matrix effects in GC/MS2. The differences in the behavior of pesticides with respect to matrix effects can be accounted for by the physicochemical characteristics of the molecules (lone pairs, labile hydrogen, conjugation). The HPTLC/UV visible method developed here for the characterization of QuEChERS extracts acts as a complementary clean-up method, aimed to decrease the negative matrix effects of such extracts

Thermo-mechano-chemical extraction of hydroxycinnamic acids from industrial hemp by-products using a twin-screw extruder

This work aims at developing a continuous intensified green process to extract high-value added molecules from industrial hemp by-products. Hemp hurds and hemp dust were studied as potential sources for the production of two hydroxycinnamic acids (HCA): ferulic (FA) and p-coumaric acids (p-CA). Prior to pilot scale extraction, FA and p-CA analytical contents were evaluated to 0.3 and 3.5g/kg dry matter (DM) for hemp hurds and 0.1 and 0.8g/kg DM for hemp dust as potentials of reference. The continuous pilot scale extraction was then carried out using twin-screw extrusion. Mild conditions were developed: 50°C, alkaline aqueous or hydroalcoholic solvent (less than 0.5M NaOH) and low liquid to solid ratios. The mechanical effect helps the diffusion of the solvent, promotes the hydrolysis of the ester and ether bonds and favors the extraction of HCA in a short time. Yields in p-CA and FA reached 50% and 33% of the free and bound contents for hemp hurds. For hemp dust, all of p-CA was extracted whereas 60% of FA was recovered. The solid residue may be submitted to a second extraction stage with a polar solvent in order to increase HCA recovery. Extraction by extrusion could be seen as an alternative green processing technique as it is responsible for a reduction of extraction time and energy and a decrease in solvent and reagent consumptions

Physicochemical characterization and study of molar mass of industrial gelatins by AsFlFFF-UV/MALS and chemometric approach

Industrial gelatins have different physicochemical properties that mainly depend of the raw materials origin and the extraction conditions. These properties are closely related to the molar mass distribution of these gelatins. Several methods exist to characterize molar mass distribution of polymer, including the Asymmetrical Flow Field Flow Fractionation method. The goal of this study is to analyze the relationship between physicochemical properties and the gelatins molar mass distribution obtained by Asymmetrical Flow Field Flow Fractionation. In this study, 49 gelatins samples extracted from pig skin are characterized in terms of gel strength and viscosity and their molar mass distribution are analyzed by Asymmetrical Flow Field Flow Fractionation coupled to an Ultraviolet and Multi Angle Light Scattering detector. This analytical method is an interesting tool for studying, simultaneously, the primary chains and the high-molar-mass fraction corresponding to the polymer chains. Correlation analysis between molar mass distribution data from the different fractions highlights the importance of high molar mass polymer chains to explain the gel strength and viscosity of gelatins. These results are confirmed by an additional chemometric approach based on the UV absorbance of gelatin fractograms to predict gel strength (r2Cal = 0.85) and viscosity (r2Cal = 0.79)

Spatial distribution of PAH concentrations and stable isotope signatures (δ13C, δ15N) in mosses from three European areas – Characterization by multivariate analysis

Polycyclic aromatic hydrocarbon (PAH) concentrations and N, C stable isotope signatures were determined in mosses Hypnum cupressiforme Hedw. from 61 sites of 3 European regions: Île-de-France (France); Navarra (Spain); the Swiss Plateau and Basel area (Switzerland). Total PAH concentrations of 100-700 ng g-1, as well as δ13C values of -32 to -29‰ and δ15N values of -11 to -3‰ were measured. Pearson correlation tests revealed opposite trends between high molecular weight PAH (4-6 aromatic rings) content and δ13C values. Partial Least Square regressions explained the very significant correlations (r > 0.91, p < 0.001) between high molecular weight PAH concentrations by local urban land use (<10 km) and environmental factors such as elevation and pluviometry. Finally, specific correlations between heavy metal and PAH concentrations were attributed to industrial emissions in Switzerland and road traffic emissions in Spain

ESPEN Guideline on Clinical Nutrition and Hydration in Geriatrics

Background: Malnutrition and dehydration are widespread in older people, and obesity is an increasing problem. In clinical practice, it is often unclear which strategies are suitable and effective in counteracting these key health threats. Aim: To provide evidence-based recommendations for clinical nutrition and hydration in older persons in order to prevent and/or treat malnutrition and dehydration. Further, to address whether weight-reducing interventions are appropriate for overweight or obese older persons. Methods: This guideline was developed according to the standard operating procedure for ESPEN guidelines and consensus papers. A systematic literature search for systematic reviews and primary studies was performed based on 33 clinical questions in PICO format. Existing evidence was graded according to the SIGN grading system. Recommendations were developed and agreed in a multistage consensus process. Results: We provide eighty-two evidence-based recommendations for nutritional care in older persons, covering four main topics: Basic questions and general principles, recommendations for older persons with malnutrition or at risk of malnutrition, recommendations for older patients with specific diseases, and recommendations to prevent, identify and treat dehydration. Overall, we recommend that all older persons shall routinely be screened for malnutrition in order to identify an existing risk early. Oral nutrition can be supported by nursing interventions, education, nutritional counselling, food modification and oral nutritional supplements. Enteral nutrition should be initiated if oral, and parenteral if enteral nutrition is insufficient or impossible and the general prognosis is altogether favorable. Dietary restrictions should generally be avoided, and weight-reducing diets shall only be considered in obese older persons with weight-related health problems and combined with physical exercise. All older persons should be considered to be at risk of low-intake dehydration and encouraged to consume adequate amounts of drinks. Generally, interventions shall be individualized, comprehensive and part of a multimodal and multidisciplinary team approach. Conclusion: A range of effective interventions is available to support adequate nutrition and hydration in older persons in order to maintain or improve nutritional status and improve clinical course and quality of life. These interventions should be implemented in clinical practice and routinely used

The Physiological Mechanisms of Effect of Vitamins and Amino Acids on Tendon and Muscle Healing: A Systematic Review

© 2018 Human Kinetics, Inc.To evaluate the current literature via systematic review to ascertain whether amino acids/vitamins provide any influence on musculotendinous healing and if so, by which physiological mechanisms. Methods: EBSCO, PubMed, ScienceDirect, Embase Classic/Embase, and MEDLINE were searched using terms including "vitamins," "amino acids," "healing," "muscle," and "tendon." The primary search had 479 citations, of which 466 were excluded predominantly due to nonrandomized design. Randomized human and animal studies investigating all supplement types/forms of administration were included. Critical appraisal of internal validity was assessed using the Cochrane risk of Bias Tool or the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias Tool for human and animal studies, respectively. Two reviewers performed duel data extraction. Results: Twelve studies met criteria for inclusion: eight examined tendon healing and four examined muscle healing. All studies used animal models, except two human trials using a combined integrator. Narrative synthesis was performed via content analysis of demonstrated statistically significant effects and thematic analysis of proposed physiological mechanisms of intervention. Vitamin C/taurine demonstrated indirect effects on tendon healing through antioxidant activity. Vitamin A/glycine showed direct effects on extracellular matrix tissue synthesis. Vitamin E shows an antiproliferative influence on collagen deposition. Leucine directly influences signaling pathways to promote muscle protein synthesis. Discussion: Preliminary evidence exists, demonstrating that vitamins and amino acids may facilitate multilevel changes in musculotendinous healing; however, recommendations on clinical utility should be made with caution. All animal studies and one human study showed high risk of bias with moderate interobserver agreement (k = 0.46). Currently, there is limited evidence to support the use of vitamins and amino acids for musculotendinous injury. Both high-quality animal experimentation of the proposed mechanisms confirming the physiological influence of supplementation and human studies evaluating effects on tissue morphology and biochemistry are required before practical application.Peer reviewe