Development and chemical characterization of flour obtained from the external mesocarp of "pequizeiro" fruit

The objective of this work was to develop a recommendation for the chemical peeling of pequi fruit and characterize the flour obtained from the external mesocarp of "Pequizeiro", pequi tree (Caryocar brasiliense Camb.). The technology applied to obtain the external mesocarp pequi flour included the epicarp removal with NaOH solution. The Response Surface Method was used to optimize the chemical peeling process by applying the Central Composite Rotatable Design, with eleven trials including three replicates at the central point, varying the NaOH aqueous solution concentration and fruit immersion time. The mass loss was evaluated through the analysis of variance and using bi and three dimensional graphs. The chemical characteristics of the external mesocarp pequi flour evaluated were: moisture content, ashes, proteins, lipids, total carbohydrates, dietary fiber, and some minerals. The best combination for an efficient removal of the fruit peel with the lowest mass loss was reached with 7.05 minutes of immersion in a 5.08 g.L-1 NaOH aqueous solution. This study indicated that the external mesocarp pequi flour is a food source rich in dietary fiber, carbohydrates, ashes, magnesium, calcium, manganese, and copper, but it is poor in lipids, zinc, and iron.

Effect of process variables on the osmotic dehydration of star-fruit slices

The objective of this work was to study the effect of blanching and the influence of temperature, solution concentration, and the initial fruit:solution ratio on the osmotic dehydration of star-fruit slices. For blanching, different concentrations of citric and ascorbic acids were studied. The samples immersed in 0.75% citric acid presented little variation in color in relation to the fresh star-fruit. Osmotic dehydration was carried out in an incubator with orbital shaking, controlled temperature, and constant shaking at 120 rpm. The influence of process variables was studied in trials defined by a complete 23 central composite design. In general, water loss and solids gain were positively influenced by temperature and by solution concentration. Nevertheless, lower temperatures reduced water loss throughout the osmotic dehydration process. An increase in the amount of dehydrating solution (initial fruit:solution ratio) slightly influenced the evaluated responses. The process carried out at 50 ºC with a solution concentration of 50% resulted in a product with lower solids gain and greater water loss. Under these conditions, blanching minimized the effect of the osmotic treatment on star-fruit browning, and therefore the blanched fruits showed little variation in color in relation to the fresh fruit.

Spectral characteristics of bacteriorhodopsin water solution

The object of the study is bacteriorhodopsin. This light-sensitive protein have been selected as perspective substance for optical and optoelectronic applications. Bacteriorhodopsin carries out pumping protons through the cell membrane. Biomolecule converts light into an electric signal when sandwiched between electrodes. These properties were utilized in this research to implement photosensors on the basis of BR layers. These properties were utilized in this research to the bR water solution. According to the absorption spectra and using Kramers – Kronig relation the extinction coefficient has been calculated, as well as the related change of the refractive index value.

Viability of barley seeds by the tetrazolium test

The tetrazolium test is used to control seed quality of various plant species since it allows a rapid evaluation of viability. Freshly harvested barley seeds show dormancy that can make the germination test ineffective for an immediate evaluation. Therefore, the development of more efficient methods, such as the tetrazolium test, is necessary. The objective of this research work was to study various procedures for performing the tetrazolium test on barley seeds. Five lots of cv. BRS 195 barley seeds were used and subjected to the following treatments: two different methods of seed preconditioning (direct immersion in H2O and between sheets of moistened paper towels); two types of preparation for staining (longitudinal cross-section of the seed through the embryo with immersion of one half in a 2,3,5 triphenyl tetrazolium chloride solution or placing both halves on top of filter paper moistened with the tetrazolium salt solution); two methods of staining (on top of filter paper and direct immersion in the tetrazolium salt solution). Three concentrations of the tetrazolium salt solution (0.1%, 0.5%, and 1.0%) were used. It was concluded that the tetrazolium test on barley seeds may be accomplished with preconditioning by direct immersion in H2O and staining by immersing in a 0.1% or 0.5% concentration of tetrazolium salt solution or staining on top of filter paper moistened with such solution at a 1.0% concentration.

Regional variations of deformation mechanisms in the Lorrain Quartzite near Whitefish Falls, Ontario, Canada /

The quartzite microfabric found in the Lorrain Formation was studied across the La Cloche syncline, along a regional north-south transect along highway 6, near Whitefish Falls, Ontario. The complete stratigraphic sequence across the syncline is preserved, and is present on each fold limb. The lithostratigraphic units with the smallest grains size and lowest mica content are located close to the core of the fold, while coarser grained mica and feldspar rich units are situated at the northern and southern most extent of the transect. Deformation mechanisms vary with lithology and with position across the fold. Pressure solution appears to be the dominant deformation mechanism in the feldspathic, micaceous and ferruginous units. In the finer grained, mica poor white medium grained and cherty sandstone units, grain boundary migration (GBM) characteristics show dominance over those of pressure solution and show high amounts of fracturing which cut migrated boundaries and therefore post date GBM. All samples across the fold display a preferred orientation of quartz c-axes. The senses of asymmetry of fabrics are found to be similar across the syncline, with the exception of the ferruginous sandstone unit. Formation of these similar fabrics synmietries can not be the result of strain related to first order folding. The mica content appears to be related to the percentage of quartz lost due to pressure solution as a result of strain; the more mica present, the less quartz was lost. Calculations based on the shape of initial grains suggest that conservatively 30% of the quartz volume has been dissolved out of the Lorrain quartzite, and potentially migrated hundreds of meters to other members of the Huronian Supergroup as there was no meso or macroscopic evidence observed in outcrop.

Social neuroendocrinology of competition

The relationship between testosterone concentrations and aggressive behaviour in studies of people has produced very inconsistent findings. However, one consistent fmding that has emerged is that competitive and aggressive interactions potentiate testosterone release in both human and non-human species. It has been argued that socially-induced alterations in testosterone concentrations may function to influence ongoing and/or future social behaviour. Nonetheless, few studies have empirically tested this hypothesis. The current series of experiments was designed to address the extent to which competitioninduced fluctuations in testosterone concentrations were associated with ongoing and/or subsequent social behaviour. In Study 1, men (n = 38) provided saliva samples prior to, and at the conclusion of, the Point Subtraction Aggression Paradigm (PSAP). Although baseline testosterone concentrations were not related to aggressive behaviour, there was a positive correlation between change in testosterone and aggressive behaviour such that men who were most aggressive on the PSAP demonstrated the largest increase in testosterone concentrations. Furthermore, a rise in testosterone during the PSAP predicted willingness to choose a subsequent competitive task. In Study 2, men and women provided saliva samples prior to and after competing against a same-sex opponent on the Number Tracing Task (NTT). The outcome of the competition was rigged such that half of the individuals won most of the races, while the other half lost most of the races, thus experimentally creating a winner and loser in the laboratory. Following the competitive interaction, men and women played the PSAP with their same-sex partner. Results indicated that men selected the aggressive response (but not reward or protection responses), more frequently than women. For men assigned to the loss condition, an increase in testosterone concentrations in response to the NTT predicted subsequent aggressive behaviour. For men assigned to the win condition, an increase in testosterone concentrations in response to the NTT predicted subsequent aggressive behaviour, but only among those men who scored high on trait dominance. Change in testosterone and trait dominance did not predict aggressive behaviour in women. In Study 3, men provided saliva samples prior to, during, and at the end of the PSAP. They were randomly assigned to one of four experimental conditions that differed in the extent to which they were provoked and whether they received reward for behaving aggressively (i.e., stealing points). Results indicated that baseline testosterone concentrations did not correlate with aggression in any of the experimental conditions. Consistent with Study 1, there was a positive correlation between change in testosterone and aggressive behaviour among men who were provoked, but did not receive reward for aggression (i.e., reactive condition). Men who were provoked but did not receive reward for aggression enjoyed the task the most and were more likely to choose the competitive versus non-competitive task relative to men assigned to the other experimental conditions. Also, individual differences in aggressive behaviour among these men were positively correlated with the extent to which they enjoyed the task. Together, these studies indicate that testosterone dynamics within the context of competition influence subsequent competitive and aggressive behaviours in humans and that testosterone may be a marker of the intrinsically rewarding nature of costly aggressive behaviour.

Article - "Canadian Lass in 170 Beats Male Competitors in Cup Race", 1956

An article covering the win of Dorothy Rungeling in the Canadian Governor-General Cup race. She was the only female competitor against ten males. She has won two out of the last three years.

‘Designer Vaginas': The Representation of Female Genitals on Canadian Cosmetic Surgeons' Websites

This thesis critically examines the online marketing tactics of 10 (English language) Canadian cosmetic surgery clinics’ websites that offer Female Genital Cosmetic Surgery (FGCS), specifically, labiaplasty (labial reduction) and vaginoplasty (vaginal tightening). Drawing on a qualitative Multimodal Critical Discourse Analysis (MCDA) and a feminist-informed social constructionist framework (Lazar, 2007), I examine how FGCS discourses reiterate and reinforce heteronormative sexual scripts for women, and impose restrictive models of femininity through the pathologization of genital diversity and the appropriation of postfeminist and neoliberal discourses of individual choice and empowerment. I explore feminist analyses of the links between FGCS and contemporary Western women’s postfeminist subjectivity, and the reconfiguration of women’s sexual agency, to better understand what these contemporary shifts may mean for women’s sexual anxiety and expression. My analysis highlights several discourses that organize the online marketing material of Canadian FGCS websites, including: the pathologization of genital diversity; restrictive models of femininity; heteronormative sexual scripts; neoliberal and post-feminist rhetorics of individual choice and empowerment; and psychological and sexual transformation. Overall, these discourses undermine acceptance of women’s genital diversity, legitimize the FGCS industry and frame FGCS as the only viable solution to alleviate women’s genital and sexual distress despite the lack of evidence regarding the long-term benefits and risks of these procedures, and the recommendations against FGCS by professional medical organizations.

Cooperative VS. Non-cooperative Truels: Little Agreement, but Does that Matter?

It is well-known that non-cooperative and cooperative game theory may yield different solutions to games. These differences are particularly dramatic in the case of truels, or three-person duels, in which the players may fire sequentially or simultaneously, and the games may be one-round or n-round. Thus, it is never a Nash equilibrium for all players to hold their fire in any of these games, whereas in simultaneous one-round and n-round truels such cooperation, wherein everybody survives, is in both the a -core and ß -core. On the other hand, both cores may be empty, indicating a lack of stability, when the unique Nash equilibrium is one survivor. Conditions under which each approach seems most applicable are discussed. Although it might be desirable to subsume the two approaches within a unified framework, such unification seems unlikely since the two approaches are grounded in fundamentally different notions of stability.

Towards the nanomechanical actuation and controlled assembly of nanomaterials using charge-transfer reactions in electroactive self-assembled monolayers

Les microcantileviers fonctionnalisés offrent une plateforme idéale pour la nano- et micro-mécanique et pour le développement de (bio-) capteurs tres sensible. Le principe d’opération consiste dans des évènements physicochimiques qui se passent du côté fonctionnalisé du microcantilevier induisant une différence de stress de surface entre les deux côtés du cantilevier qui cause une déflexion verticale du levier. Par contre, les facteurs et les phénomènes interfacials qui régissent la nature et l'intensité du stress de surface sont encore méconnus. Pour éclaircir ce phénomène, la première partie de cette thèse porte sur l'étude des réactions de microcantileviers qui sont recouverts d'or et fonctionnalisés par une monocouche auto-assemblée (MAA) électroactive. La formation d'une MAA de ferrocènylundécanethiol (FcC11SH) à la surface d'or d'un microcantilevier est le modèle utilisé pour mieux comprendre le stress de surface induit par l’électrochimie. Les résultats obtenus démontrent qu'une transformation rédox de la MAA de FcC11SH crée un stress de surface qui résulte dans une déflexion verticale du microcantilevier. Dépendamment de la flexibilité du microcantilevier, cette déflexion peut varier de quelques nanomètres à quelques micromètres. L’oxydation de cette MAA de FcC11SH dans un environnement d'ions perchlorate génère un changement de stress de surface compressive. Les résultats indiquent que la déflexion du microcantilevier est due à une tension latérale provenant d'une réorientation et d'une expansion moléculaire lors du transfért de charge et de pairage d’anions. Pour vérifier cette hypothèse, les mêmes expériences ont été répéteés avec des microcantileviers qui ont été couverts d'une MAA mixte, où les groupements électroactifs de ferrocène sont isolés par des alkylthiols inactifs. Lorsqu’un potentiel est appliqué, un courant est détecté mais le microcantilevier ne signale aucune déflexion. Ces résultats confirment que la déflexion du microcantilevier est due à une pression latérale provenant du ferrocènium qui se réorganise et qui crée une pression sur ses pairs avoisinants plutôt que du couplage d’anions. L’amplitude de la déflexion verticale du microcantilevier dépend de la structure moléculaire de la MAA et du le type d’anion utilisés lors de la réaction électrochimique. Dans la prochaine partie de la thèse, l’électrochimie et la spectroscopie de résonance de plasmon en surface ont été combinées pour arriver à une description de l’adsorption et de l’agrégation des n-alkyl sulfates à l’interface FcC11SAu/électrolyte. À toutes les concentrations de solution, les molécules d'agent tensio-actif sont empilées perpendiculairement à la surface d'électrode sous forme de monocouche condensé entrecroisé. Cependant, la densité du film spécifiquement adsorbé s'est avérée être affectée par l'état d'organisation des agents tensio-actifs en solution. À faible concentration, où les molécules d'agent tensio-actif sont présentes en tant que monomères solvatés, les monomères peuvent facilement s'adapter à l’évolution de la concentration en surface du ferrocènium lors du balayage du potential. Cependant, lorsque les molécules sont présentes en solution en tant que micelles une densité plus faible d'agent tensio-actif a été trouvée en raison de l'incapacité de répondre effectivement à la surface de ferrocenium générée dynamiquement.

Mesure de la concentration en métaux traces dans la solution de sol par microlysimétrie

La présente étude porte sur l’évaluation d’une méthode d’acquisition de la solution de sol présente à l’interface sol-racine, dans la rhizosphère. Cette interface constitue le lieu privilégié de prise en charge par les plantes des contaminants, tels que les métaux traces. Comme les plantes acquièrent ces éléments à partir de la phase liquide, la solution de sol de la rhizosphère est une composante clé pour déterminer la fraction de métaux traces biodisponibles. La microlysimétrie est la méthode in situ la plus appropriée pour aborder les difficultés liées à l’échelle microscopique de la rhizosphère. Ainsi, dans les études sur la biodisponibilité des métaux traces au niveau de la rhizosphère, les microlysimètres (Rhizon©) gagnent en popularité sans, toutefois, avoir fait l’objet d’études exhaustives. L’objectif de cette étude est donc d’évaluer la capacité de ces microlysimètres à préserver l’intégrité chimique de la solution, tout en optimisant leur utilisation. Pour ce faire, les microlysimètres ont été soumis à une série d’expériences en présence de solutions et de sols, où la quantité de solution prélevée et le comportement des métaux traces (Cd, Cu, Ni, Pb, Zn) ont été étudiés. Les résultats montrent que les microlysimètres fonctionnent de façon optimale lorsque le contenu en eau du sol est au-dessus de la capacité au champ et lorsqu’il y a peu de matière organique et d’argile. Les sols sableux ayant un faible contenu en C organique reproduisent mieux le volume prélevé et la solution sous la capacité au champ peut être récoltée. L’utilisation des microlysimètres dans ces sols est donc optimale. Dans les essais en solution, les microlysimètres ont atteint un équilibre avec la solution après 10 h de prélèvement. En respectant ce délai et les conditions optimales préalablement établies (pH acide et COD élevé), les microlysimètres préservent la composition chimique de la solution. Dans les essais en sol, cet équilibre n’a pas été atteint après dix jours et huit prélèvements. Le contenu en matière organique et l’activité microbienne semblent responsables de la modification des concentrations en métaux au cours de ces prélèvements, notamment, dans l’horizon FH où les microlysimètres performent très mal. En revanche, dans l’horizon B, les concentrations tendent à se stabiliser vers la fin de la série de prélèvements en se rapprochant des valeurs de référence. Bien que des valeurs plus élevées s’observent pour les microlysimètres, leurs concentrations en métaux sont comparables à celles des méthodes de référence (extrait à l’eau, lysimètres de terrain avec et sans tension). En somme, les microlysimètres se comportent généralement mieux dans l’horizon B. Même si leur utilisation est plus optimale dans un sol sableux, cet horizon est privilégié pour de futures études sur le terrain avec les microlysimètres.

Solution de C. Hyltén-Cavallius pour un problème de P. Turán concernant des polynômes

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Le rapport Displaced Persons and Their Resettlement in the United States et le début des politiques d’accueil aux États-Unis

RÉSUMÉ : Avec le dénouement de la Deuxième Guerre mondiale, le problème des réfugiés en Europe devient un enjeu international. Plusieurs millions de personnes, que l’on nomme les Displaced Persons (DP), sont sans refuge et doivent recevoir une aide immédiate pour survivre. Même si la majorité de ces gens retourneront dans leurs pays d’origine, il reste encore des centaines de milliers de réfugiés en 1948. La seule solution concrète pour régler cette problématique est l’émigration des réfugiés dans des pays prêts à les accepter. Les Américains jouent un rôle crucial en acceptant 415 000 DP entre 1948 et 1952 grâce au Displaced Persons Act de 1948 et ses amendements en 1950 et 1951. Après d’âpres discussions entre les restrictionnistes et ceux qui défendent la libéralisation des lois d’immigration, naîtra le Displaced Persons Act (DP Act) signé avec beaucoup de réticence, le 25 juin 1948, par le président Harry S. Truman. Cette loi qui prévoit la venue de 202 000 DP en deux ans, contient des mesures jugées discriminatoires à l'endroit de certaines ethnies. Afin d'améliorer le DP Act, le Congrès effectue des recherches sur la situation des réfugiés toujours dans les camps en 1949 tout en étudiant l’impact de la venue des DP aux États-Unis entre 1948 et 1950. Cette étude est soumise sous forme de rapport, le Displaced Persons and Their Resettlement in the United States, le 20 janvier 1950. Ce mémoire propose une analyse minutieuse du rapport et de son contexte politique afin de démontrer le rôle important de cette étude dans le processus décisionnel du Congrès américain visant à accueillir un plus grand nombre de DP tout en posant les bases pour une politique d’accueil en matière de refugiés.

Systematic construction of models for the exchange hole of density functional theory.

Dans ce travail, nous étendons le nombre de conditions physiques actuellement con- nues du trou d’échange exact avec la dérivation de l’expansion de quatrième ordre du trou d’échange sphérique moyenne exacte. Nous comparons les expansions de deux- ième et de quatrième ordre avec le trou d’échange exact pour des systèmes atomiques et moléculaires. Nous avons constaté que, en général, l’expansion du quatrième ordre reproduit plus fidèlement le trou d’échange exact pour les petites valeurs de la distance interélectronique. Nous démontrons que les ensembles de base de type gaussiennes ont une influence significative sur les termes de cette nouvelle condition, en étudiant com- ment les oscillations causées par ces ensembles de bases affectent son premier terme. Aussi, nous proposons quatre modèles de trous d’échange analytiques auxquels nous imposons toutes les conditions actuellement connues du trou d’échange exact et la nou- velle présentée dans ce travail. Nous évaluons la performance des modèles en calculant des énergies d’échange et ses contributions à des énergies d’atomisation. On constate que les oscillations causeés par les bases de type gaussiennes peuvent compromettre la précision et la solution des modèles.

Influence of the buffer environment on the Relative Biological Effectiveness of carbon ion radiation, investigated by Scanning Force Microscopy and gel electrophoresis

This work focuses on the analysis of the influence of environment on the relative biological effectiveness (RBE) of carbon ions on molecular level. Due to the high relevance of RBE for medical applications, such as tumor therapy, and radiation protection in space, DNA damages have been investigated in order to understand the biological efficiency of heavy ion radiation. The contribution of this study to the radiobiology research consists in the analysis of plasmid DNA damages induced by carbon ion radiation in biochemical buffer environments, as well as in the calculation of the RBE of carbon ions on DNA level by mean of scanning force microscopy (SFM). In order to study the DNA damages, besides the common electrophoresis method, a new approach has been developed by using SFM. The latter method allows direct visualisation and measurement of individual DNA fragments with an accuracy of several nanometres. In addition, comparison of the results obtained by SFM and agarose gel electrophoresis methods has been performed in the present study. Sparsely ionising radiation, such as X-rays, and densely ionising radiation, such as carbon ions, have been used to irradiate plasmid DNA in trishydroxymethylaminomethane (Tris buffer) and 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES buffer) environments. These buffer environments exhibit different scavenging capacities for hydroxyl radical (HO0), which is produced by ionisation of water and plays the major role in the indirect DNA damage processes. Fragment distributions have been measured by SFM over a large length range, and as expected, a significantly higher degree of DNA damages was observed for increasing dose. Also a higher amount of double-strand breaks (DSBs) was observed after irradiation with carbon ions compared to X-ray irradiation. The results obtained from SFM measurements show that both types of radiation induce multiple fragmentation of the plasmid DNA in the dose range from D = 250 Gy to D = 1500 Gy. Using Tris environments at two different concentrations, a decrease of the relative biological effectiveness with the rise of Tris concentration was observed. This demonstrates the radioprotective behavior of the Tris buffer solution. In contrast, a lower scavenging capacity for all other free radicals and ions, produced by the ionisation of water, was registered in the case of HEPES buffer compared to Tris solution. This is reflected in the higher RBE values deduced from SFM and gel electrophoresis measurements after irradiation of the plasmid DNA in 20 mM HEPES environment compared to 92 mM Tris solution. These results show that HEPES and Tris environments play a major role on preventing the indirect DNA damages induced by ionising radiation and on the relative biological effectiveness of heavy ion radiation. In general, the RBE calculated from the SFM measurements presents higher values compared to gel electrophoresis data, for plasmids irradiated in all environments. Using a large set of data, obtained from the SFM measurements, it was possible to calculate the survive rate over a larger range, from 88% to 98%, while for gel electrophoresis measurements the survive rates have been calculated only for values between 96% and 99%. While the gel electrophoresis measurements provide information only about the percentage of plasmids DNA that suffered a single DSB, SFM can count the small plasmid fragments produced by multiple DSBs induced in a single plasmid. Consequently, SFM generates more detailed information regarding the amount of the induced DSBs compared to gel electrophoresis, and therefore, RBE can be calculated with more accuracy. Thus, SFM has been proven to be a more precise method to characterize on molecular level the DNA damage induced by ionizing radiations.