Optimization of the HS-SPME-GC/MS technique for determining volatile compounds in red wines made from Isabel grapes (Vitis labrusca)

Abstract Brazilian wine production is characterized by Vitis labrusca grape varieties, especially the economically important Isabel cultivar, with over 80% of its production destined for table wine production. The objective of this study was to optimize and validate the conditions for extracting volatile compounds from wine with the solid-phase microextraction technique, using the response surface method. Based on the response surface analysis, it can be concluded that the central point values maximize the process of extracting volatile compounds from wine, i.e., an equilibrium time of 15 minutes, an extraction time of 35 minutes, and an extraction temperature of 30 °C. Esters were the most numerous compounds found under these extraction conditions, indicating that wines made from Isabel cultivar grapes are characterized by compounds that confer a fruity aroma; this finding corroborates the scientific literature.

Development of a rapid method for the determination of antibiotic residues in honey using UPLC-ESI-MS/MS

Abstract An accurate, reliable and fast multianalyte/multiclass ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was developed and validated for the simultaneous analysis of 23 pharmaceuticals, belonging to different classes amphenicols, sulfonamides, tetracyclines, in honey samples. The method developed consists of ultrasonic extraction followed by UPLC–ESI–MS/MS with electrospray ionization in both positive mode and negative mode. The influence of the extraction solvents and mobile phase composition on the sensitivity of the method, and the optimum conditions for sample weight and extraction temperature in terms of analyte recovery were extensively studied. The identification of antibiotics is fulfilled by simultaneous use of chromatographic separation using an Acquity BEH C18 (100 mm x 2.1 mm, 1.7 µm) analytical column with a gradient elution of mobile phases and tandem mass spectrometry with an electrospray ionization. Finally, the method developed was applied to the determination of target analytes in honey samples obtained from the local markets and several beekeepers in Muğla, Turkey. Ultrasonic-extraction of pharmaceuticals from honey samples is a well-established technique by UPLC–ESI–MS/MS, the uniqueness of this study lies in the simultaneous determination of a remarkable number of compounds belonging to 23 drug at the sub-nanogram per kilogram level.

Optimization of the HS-SPME-GC/MS technique for the analysis of volatile compounds in caprine Coalho cheese using response surface methodology

Abstract Caprine Coalho cheese presents great potential for a typical protected designation of origin, considering that this traditional Brazilian cheese presents a slightly salty and acid flavor, combined with a unique texture. This study optimized the HS-SPME-GC-MS methodology for volatile analysis of Coalho cheese, which can be used as a tool to help in the identification of the distinctive aroma profile of this cheese. The conditions of equilibrium time, extraction temperature and time were optimized using the statistical tool factorial experimental design 23, and applying the desirability function. After the evaluation, it was concluded that the optimum extraction conditions comprised equilibrium and extraction time of 20 and 40 minutes, respectively; and ideal extraction temperature of 45 °C. The optimum extraction of volatile compounds in goat Coalho cheese captured 32 volatile compounds: 5 alcohols, 5 esters, 3 ketones, 6 acids, 3 aldehydes, 3 terpenes, and 7 hydrocarbons.

Modeling Energy Futures Returns With Markov Regime Switching Model

Financial time series have a tendency of abruptly changing their behavior and maintain this behavior for several consecutive periods, and commodity futures returns are not an exception. This quality proposes that nonlinear models, as opposed to linear models, can more accurately describe returns and volatility. Markov regime switching models are able to match this behavior and have become a popular way to model financial time series. This study uses Markov regime switching model to describe the behavior of energy futures returns on a commodity level, because studies show that commodity futures are a heterogeneous asset class. The purpose of this thesis is twofold. First, determine how many regimes characterize individual energy commodities’ returns in different return frequencies. Second, study the characteristics of these regimes. We extent the previous studies on the subject in two ways: We allow for the possibility that the number of regimes may exceed two, as well as conduct the research on individual commodities rather than on commodity indices or subgroups of these indices. We use daily, weekly and monthly time series of Brent crude oil, WTI crude oil, natural gas, heating oil and gasoil futures returns over 1994–2014, where available, to carry out the study. We apply the likelihood ratio test to determine the sufficient number of regimes for each commodity and data frequency. Then the time series are modeled with Markov regime switching model to obtain the return distribution characteristics of each regime, as well as the transition probabilities of moving between regimes. The results for the number of regimes suggest that daily energy futures return series consist of three to six regimes, whereas weekly and monthly returns for all energy commodities display only two regimes. When the number of regimes exceeds two, there is a tendency for the time series of energy commodities to form groups of regimes. These groups are usually quite persistent as a whole because probability of a regime switch inside the group is high. However, individual regimes in these groups are not persistent and the process oscillates between these regimes frequently. Regimes that are not part of any group are generally persistent, but show low ergodic probability, i.e. rarely prevail in the market. This study also suggests that energy futures return series characterized with two regimes do not necessarily display persistent bull and bear regimes. In fact, for the majority of time series, bearish regime is considerably less persistent. Rahoituksen aikasarjoilla on taipumus arvaamattomasti muuttaa käyttäytymistään ja jatkaa tätä uutta käyttäytymistä useiden periodien ajan, eivätkä hyödykefutuurien tuotot tee tähän poikkeusta. Tämän ominaisuuden johdosta lineaaristen mallien sijasta epälineaariset mallit pystyvät tarkemmin kuvailemaan esimerkiksi tuottojen jakauman parametreja. Markov regiiminvaihtomallit pystyvät vangitsemaan tämän ominaisuuden ja siksi niistä on tullut suosittuja rahoituksen aikasarjojen mallintamisessa. Tämä tutkimus käyttää Markov regiiminvaihtomallia kuvaamaan yksittäisten energiafutuurien tuottojen käyttäytymistä, sillä tutkimukset osoittavat hyödykefutuurien olevan hyvin heterogeeninen omaisuusluokka. Tutkimuksen tarkoitus on selvittää, kuinka monta regiimiä tarvitaan kuvaamaan energiafutuurien tuottoja eri tuottofrekvensseillä ja mitkä ovat näiden regiimien ominaisuudet. Aiempaa tutkimusta aiheesta laajennetaan määrittämällä regiimien lukumäärä tilastotieteellisen testauksen menetelmin sekä tutkimalla energiafutuureja yksittäin; ei indeksi- tai alaindeksitasolla. Tutkimuksessa käytetään päivä-, viikko- ja kuukausiaikasarjoja Brent-raakaöljyn, WTI-raakaöljyn, maakaasun, lämmitysöljyn ja polttoöljyn tuotoista aikaväliltä 1994–2014, siltä osin kuin aineistoa on saatavilla. Likelihood ratio -testin avulla estimoidaan kaikille aikasarjoille regiimien määrä,jonka jälkeen Markov regiiminvaihtomallia hyödyntäen määritetään yksittäisten regiimientuottojakaumien ominaisuudet sekä regiimien välinen transitiomatriisi. Tulokset regiimien lukumäärän osalta osoittavat, että energiafutuurien päiväkohtaisten tuottojen aikasarjoissa regiimien lukumäärä vaihtelee kolmen ja kuuden välillä. Viikko- ja kuukausituottojen kohdalla kaikkien energiafutuurien prosesseissa regiimien lukumäärä on kaksi. Kun regiimejä on enemmän kuin kaksi, on prosessilla taipumus muodostaa regiimeistä koostuvia ryhmiä. Prosessi pysyy ryhmän sisällä yleensä pitkään, koska todennäköisyys siirtyä ryhmään kuuluvien regiimien välillä on suuri. Yksittäiset regiimit ryhmän sisällä eivät kuitenkaan ole kovin pysyviä. Näin ollen prosessi vaihtelee ryhmän sisäisten regiimien välillä tiuhaan. Regiimit, jotka eivät kuulu ryhmään, ovat yleensä pysyviä, mutta prosessi ajautuu niihin vain harvoin, sillä todennäköisyys siirtyä muista regiimeistä niihin on pieni. Tutkimuksen tulokset osoittavat myös, että prosesseissa, joita ohjaa kaksi regiimiä, nämä regiimit eivät välttämättä ole pysyvät bull- ja bear-markkinatilanteet. Tulokset osoittavat sen sijaan, että bear-markkinatilanne on energiafutuureissa selvästi vähemmän pysyvä.

Sequence-characterized amplified region (SCAR) technique used for variety discrimination in vinca (Catharanthus roseus (L.) G.Don)

Sequence-Characterized Amplified Region (SCAR) appears as a useful technique for genetic purity testing and variety discrimination, applicable to species in which some other techniques have failed. In particular, this technique is very attractive with species in which RAPD results were not consistent. The RAPD polymorphic bands were cloned, sequenced and from the sequence information, primers pairs for normal PCR were developed. Since the probability of obtaining successful SCAR primers from RAPD polymorphic bands was about 50%, a larger number of RAPD polymorphic bands are needed to develop sufficient SCAR primers for varietal discrimination in vinca. In addition, the efficiency of the SCAR technique is strongly affected by the quality of DNA extracted from seeds. The SCAR banding patterns obtained from vinca seed were consistent and repeatable making the results reliable for genetic purity testing and variety discrimination. The SCAR technique is simple, fast, relatively inexpensive and allows the use of DNA extracted from dry seeds, which is very important in a seed-quality evaluating program

Sensibility of the PCR technique in the detection of Stenocarpella sp. associated with maize seeds

Maize seeds, infected by Stenocarpella species, are important sources of inoculum for the introduction and dissemination of stalk and ear rot and macrospore leaf spot diseases. The use of healthy seeds is an important strategy for the preventive control of these diseases. However, one of the difficulties in the health quality control programs for maize seeds is the availability of a reliable and quick method for detecting these fungi during routine seed analyses. Therefore, the objective of the present study was to investigate the possibility of using the PCR technique as an alternative method for accurately detecting these pathogens in maize seed samples. Maize seeds were kept in contact with S. maydis colonie developed in PDA media containing mannitol at -1.4 MPa for 72 h. The seed samples used in this study were prepared with infected seeds at incidences of 100, 20, 10, 2, 1 and zero %.The primers used were able to detect S. maydis fungi in association with seeds with a maximum of 2% , however those primers were not able to differentiate between the two species.

Value-based selling of the column connection solution as part of project sales

The objective of this study was to find out how third party influencers can facilitate value-based selling in a network and how suppliers should aim to impact on these third party influencers to facilitate value-based selling. The study considers construction industry, selling the column connection solution and third party influencers. Third party influencers examined in this study were structural designers. The study also aims to find out structural designers’ value drivers and the differences between the market areas that this study related to. The theoretical part of the study focuses on two separate areas. The first part of the theory focuses on a value-based selling concept: what it is, what it requires and what are the main barriers for value-based selling. The second part of the theory examines value creation in networks. The present knowledge over value creation in networks and different network actors are presented. Project marketing is also discussed briefly because this study’s topic, which is highly related to project business. The results reveal structural designers’ value drivers considering the usage of the column connection solution and present ways how suppliers should aim to impact structural designers to facilitate value-based selling. The main result of the study indicates that third party influencers can have a positive impact on facilitating value-based selling. Structural designers are communicating more or less with all the salient actors in different project phases and they can act as sponsors to support the sales of Peikko’s column connection solution and promote solution to other actors involved to the project. This requires that structural designers can understand the actual benefits of how the solution can improve their and their customers’ business.

Lignoselluloosapohjaisten väkevähappohydrolysaattien kromatografinen fraktiointi

Väkevän hapon katalysoiman hydrolyysin avulla lignoselluloosasta on mahdollista valmistaa arvokkaita sokereita. Katalyyttinä toimiva happo voidaan käyttää uudelleen hydrolyysissä, jos se saadaan erotettua sokereista ilman neutralointia. Tämän kandidaatintyön tavoitteena oli selvittää, soveltuuko happoretardaatiotekniikka väkevähappohydrolysaatin fraktiointiin. Työssä verrattiin happoretardaatiotekniikkaa elektrolyyttiekskluusiotekniikkaan. Työn kirjallisuusosassa käsiteltiin happoretardaation ja elektrolyyttiekskluusion teoriaa. Lisäksi esiteltiin elektrolyyttiekskluusioon ja happoretardaatioon liittyviä tutkimuksia. Työn kokeellisessa osassa suoritettiin panoskromatografiakokeita käyttäen syöttöliuoksena rikkihappoa, etikkahappoa, glukoosia ja ksyloosia sisältävää synteettistä liuosta. Erotusmateriaaleina käytettiin neljää eri anionin- ja yhtä kationinvaihtohartsia. Kokeiden perusteella tutkittiin anioninvaihtohartsin tyypin ja kolonnin latauksen vaikutusta happoretardaatiotekniikalla saavutettavaan erotustulokseen sekä verrattiin elektrolyyttiekskluusiota happoretardaatioon. Työn tulosten perusteella rikkihappo laimeni happoretardaatiotekniikalla jopa 20-kertaisesti kromatografiakolonniin syötettyyn liuokseen verrattuna, riippumatta kolonnin latauksesta ja anioninvaihtohartsista. Rikkihapon laimenemisen vuoksi happoretardaatio ei soveltunut lignoselluloosapohjaisten väkevähappohydrolysaattien fraktiointiin. Elektrolyyttiekskluusiotekniikalla rikkihapon laimeneminen oli merkittävästi vähäisempää, minkä vuoksi elektrolyyttiekskluusion todettiin soveltuvan happoretardaatiota paremmin lignoselluloosapohjaisten väkevähappohydrolysaattien fraktiointiin.

Revue de l'immigration : organe technique et pratique pour l'étude du statut et des conditions d'emploi des étrangers en France

1931/07 (N38).

17/5/20, procès du général Fournier, le général Legrand défenseur technique [procès de la reddition de Maubeuge] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59323