The Law and Regulation of ICO (Initial Coin Offering) Abstract This diploma thesis deals with legal analysis of ICO (Initial Coin Offering) and legal analysis of tokens that are issued within an ICO. The thesis aims to find out whether and to what extent an ICO is subjected to initial public offering law and whether the tokens can be characterized as things, securities, dematerialized securities, and electronic money. In the first part of the thesis, I define the basic concepts and terms. Definitions and terms are supplemented by the technical and economic background of each respective institute. The first part also briefly summarizes the historical development of ICO, which shaped it into its present form. The second part of the thesis deals with the legal categorization of tokens. Firstly conceptual features of the thing in the legal sense, dematerialized security, security, and electronic money are established. Subsequently, it is examined whether the tokens can fall within these conceptual features or not. In the chapter regarding securities, it is pointed out that different understanding of securities in public and private law may have some negative consequences. The analysis of the contractual relationship between the issuer and the investor is also addressed in the second part. In the third part, ICO...

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper investigates the feasibility of using commercial satellite constellations to relay telemetry data from flight test vehicles as part of a Global Test Range. The use of a commercial satellite constellation would provide an augmented capability to the test range, providing near real-time data to the data reduction site and test range control at reasonable cost. This includes an analysis of current and proposed commercial communication satellite constellations to determine if any of them would fulfill the needs of a telemetry test range. Preliminary assessment of the communication link between a flight vehicle and the satellite constellations is performed.

Thesis advisor: Vyacheslav Fos / In the first essay, I examine the role of cross-listings in the digital token marketplace ecosystem. Using a unique set of publicly available and hand-collected data from 3,625 tokens traded in 108 marketplaces, I find significant increases in price and trading activity around the date of a token’s first cross-listing. Tokens earn a 49% raw cumulative return in the two weeks around the cross-listing date. Global token-trading volume is almost 50 times higher after cross-listing. Using the uniquely heterogeneous characteristics of token marketplaces, I am able to identify specific value-creation channels. I provide the first evidence supporting value creation through network externalities proposed by recent token-valuation models. Consistent with equity cross-listing theory, I find higher returns for cross-listings that reduce market segmentation and improve information production. In the second essay, we analyze a dataset of 4,003 executed and planned ICOs, which raised a total of $12 billion in capital, nearly all since January 2017. We find evidence of significant ICO underpricing, with average returns of 179% from the ICO price to the first day’s opening market price, over a holding period that averages just 16 days. After trading begins, tokens continue to appreciate in price, generating average buy-and-hold abnormal returns of 48% in the first 30 trading days. We also study the determinants of ICO underpricing and relate cryptocurrency prices to Twitter followers and activity. In the third essay, I examine reputation building by activist hedge funds and document two new findings with regard to hostile activism. First, there is evidence of a permanent reputation effect to hostile activism. Activist hedge funds that have engaged in hostile tactics, receive on average a 3% higher CAR [-10,+10] on their subsequent non-hostile campaigns, compared to hedge funds that have never engaged in hostile tactics. This abnormal return is positively correlated with the level of hostile reputation of the campaigning hedge fund. Second, I find that activist hedge funds with more hostile reputation modify their non-hostile activism style to engage “hostile-like” targets and pursue “hostile-like” objectives, but withhold the use of hostile tactics. These findings imply that hedge funds are able to build reputation using their past engagement tactics and that market participants value such reputation as evidenced by the higher announcement return observed in their targets. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Carroll School of Management. / Discipline: Finance.

Initial Coin Offerings (ICOs) came into worldwide attention in 2018, when over $11.6 billion flowed through them. The CME Group launched Bitcoin futures contracts in December 2017, giving large funds their first regulated exposure to digital assets. As digital assets move towards the mainstream of finance, institutional investors have followed. This study comparatively analyzes Hedge Fund investment in digital assets against that of other institutional investment firm types (Private Equity and Venture Capital) by analyzing their crypto holdings and rebuilding an equally weighted portfolio for each fund. Under these conditions, the study succeeds in finding significant differences between hedge fund results in the sample and those of private equity/venture capital firms. Specifically, this study shows through the composite portfolios built that digital asset investments made by hedge funds generate a much higher return than that of private equity and venture capital firms. Average hedge fund investments have much higher trading volumes and market capitalizations than those made by private equity and venture capital firms, suggesting that PE and VC firms are taking higher risks by investing in new and little-known crypto projects. The results of this study signal that the hedge fund business model is much better suited for the high-risk, high-volatility cryptocurrency market than strategies employed by venture capital and private equity firms.

Made available in DSpace on 2015-04-14T13:34:53Z (GMT). No. of bitstreams: 1 422772.pdf: 853974 bytes, checksum: 30f273a08c5bcc95899b572a9f7d1933 (MD5) Previous issue date: 2010-03-05 / Introdu??o: Ao longo da hist?ria o homem busca entender os mecanismos envolvidos no desenvolvimento dos Transtornos Mentais. O principal objetivo do presente trabalho foi investigar o papel do ?cido Valpr?ico na preven??o do preju?zo cognitivo em ratos Wistar submetidos ao estresse neonatal, induzido por separa??o materna, combinado ao tratamento com Anfetamina na idade adulta. Metodologia: Os animais foram subdivididos em estressados e n?o estressados do primeiro ao d?cimo quarto dia de vida. Foram utilizados apenas animais machos para prevenir vi?s com rela??o a altera??es hormonais em f?meas. Na idade adulta foram tratados com Anfetamina (D-AMPH) 2mg/kg e ?cido Valpr?ico (VAL, 400mg/kg/dia). Foram subdivididos em oito sub-grupos cada um contendo entre 10 a 13 animais por grupo. Um grupo recebeu solu??o Salina, outro recebeu D-AMPH e Salina, outro recebeu D-AMPH e ?cido Valpr?ico e outro grupo ?cido Valpr?ico e Salina, por um per?odo de sete dias. Duas horas ap?s a administra??o da ?ltima inje??o de anfetamina foram realizados os testes comportamentais, os quais foram repetidos oito dias mais tarde, no sentido de verificar se os efeitos cognitivos induzidos pelo tratamento cr?nico com anfetamina seriam persistentes mesmo ap?s a interrup??o do tratamento. Resultados: O experimento I (realizado 2 horas ap?s a administra??o da ?ltima inje??o), ambos os grupos n?o separado (NS) e separado (S) de animais que receberam D-AMPH na idade adulta demonstraram no n?mero de cruzamentos e n?mero de explora??es verticais quando comparados com o grupo NS que recebeu Salina na idade adulta. O VAL levou ? redu??o do n?mero de cruzamentos e explora??es verticais quando comparados aqueles grupos de animais NS e S que receberam D-AMPH. 7 No experimento II (realizado sete dias ap?s a ?ltima inje??o), n?o encontramos diferen?as estatisticamente significativas entre os grupos experimentais quanto aos par?metros analisados. A administra??o de D-AMPH produziu preju?zos cognitivos severos, que foram mais pronunciados nos animais submetidos ? priva??o materna, sugerindo que eventos adversos no in?cio da vida podem aumentar a vulnerabilidade a um pat?geno ambiental mais tardiamente. Al?m disso, nossos resultados indicaram que o VAL atenuou o preju?zo cognitivo induzido pela D-AMPH, mas n?o foi efetivo quando os animais foram expostos ? priva??o materna e ? D-AMPH. Conclus?es Nosso trabalho vem ao encontro dos trabalhos anteriores refor?ando o papel dos estabilizantes do humor como ?cido Valpr?ico no mecanismo de neuroprote??o dos transtornos do humor como o transtorno bipolar.

Denna uppsats ämnar att undersöka de kommunikativa processer för blockedjeteknologi startups som ska lansera en så kallad “initial coin offering” och således mynta sin egna kryptovaluta, såsom till exempel bitcoin. Vi avser att undersöka det strategiska kommunikation processerna detta involverar. Från ena perspektivet är ett decentraliserat blockkedjesystem högt värderat på grund av det faktum att det jämställer samtliga medverkande och på så vis skapar en “perfekt demokrati”, å andra sidan argumenterar många att centralisering behövs för att bibehålla tillit. Tillit till organisationer skapas genom vetandet att det finns konsekvenser till dess handlingar som kan införas av högre auktoriteter ifall dessa handlingar faller utanför ramarna av vad som anses accepterat (De Fillipe & Wright, 2015). Utan en högre auktoritet som kan implementera detta blir tillit svårare att upprätthålla. Dock verkar blockkedjeteknologi motbevisa detta koncept. Hur är det möjligt för organisationer utan någon reglering från centrala myndigheter att skapa legitimitet och tillit för att på så sätt kunna få investeringar? Resultaten vi fann ställdes i jämförelse sig till våra tre legitimitets teorier som var kognitiv legitimitet, moral legitimitet och pragmatisk legitimitet, samt centrala teman och nyckelord. Att etablera en levande närvaro på sociala medier som till exempel Twitter, LinkedIn och framför allt Telegram grupper var mycket relevant. I telegram grupper sågs en grupp med många aktiva medlemmar och snabb svarsfrekvens från organisationen som mycket betydelsefullt, samt att ha botar som städar upp irrelevant material utan att deltagarna upplever detta som automatiserat och genuint. Att delta på event och etablera relationer med andra individer inom området och även närliggande områden som till exempel banksektorn var centralt, målet med detta var i många fall att kunna få betydelsefulla individer i sin styrelse av rådgivare vilket ökar legitimiteten. Att kunna ställa organisationens implementering av decentraliserad blockkedjeteknologi i jämförelse med den nuvarande centraliserade lösningen var essentiellt för att locka investerare som var villiga att riskera kapital för en ny modernare lösning.

Les Interfaces Cerveau Ordinateur Actives (ICOs) permettent à une personne d'exercer un contrôle direct et volontaire sur un système informatique par interprétation de son activité cérébrale : certains signaux du cerveau sont capturés afin que le système reconnaisse des actions imaginées spécifiques (mouvements, images, concepts). Les ICOs actives et leurs utilisateurs doivent être entrainés. Cet entraînement rend les signaux plus aisés à reconnaître par le système.Cependant, à l'heure actuelle les ICO servent principalement dans un contexte médical pour aider les personnes en situation de handicap (moteur, ou empêchant complètement la communication avec le monde extérieur) et se trouvent rarement en dehors de laboratoires spécialisés.Les ICO ont de nombreuses limitations :• La variabilité dans les signaux: les signaux sont différents d'une personne à l'autre voire même chez un même individu à des moments différents.• Des sessions d'entraînement longues et répétitives: entre dix minutes et deux mois, sont ennuyantes et désengagent les utilisateurs du processus d'apprentissage.• Un feedback limité: les systèmes actuels proposent un feedback unimodal élémentaire qui est inadapté pour les nombreux utilisateurs. la communication est unidirectionnelle dans le sens où le système donne des instructions que l'utilisateur doit exécuter.L'objectif de cette thèse est de proposer des solutions aux problèmes sus décrits afin d'obtenir une architecture consistante qui rendra les ICO plus compatibles avec les applications d'IHM. L'idée principale est l'implantation du co-apprentissage dans la boucle ICO et l'exploration de la manière dont les utilisateurs et le système peuvent mutuellement se donner du feedback dans le but de l'amélioration de l'utilisabilité des ICO.Cette thèse se structure autour de trois innovations portant sur la boucle ICO :• Une architecture générale basée sur les principes des ICO asynchrones et sur l'entraînement incrémental combinés avec une séparation aveugle des sources et un classifieur à distance minimum. Nous évaluerons l'architecture sur une tache de pilotage de drone au long d'un mois et concluons qu'elle est en adéquation avec les besoins d'une utilisation quotidienne ludique.• Une modalité de visualisation plus intuitive pour les résultats de classification ainsi que pour les caractéristiques de distance sur la base d'une projection en coordonnées de Wachspress pour un nombre arbitraire de classes. Nous combinons la visualisation avec un feedback direct des utilisateurs leur permettant d'interactivement changer la marge de classification, le type de distance où encore de trier et de gérer les signaux d'entraînement en temps réel. Nous évaluons cette contribution sur un jeu de tir simple et découvrons qu'il y a une bonne synergie entre la modalité de visualisation et le feedback direct des utilisateurs et qu'une telle combinaison est bien plus agréable à utiliser qu'un entraînement d'ICO standard.• Enfin, nous développons une ICO fonctionnelle à base d'imagerie conceptuelle à l'aide de notre architecture ainsi que de nos systèmes de visualisation et de feedback, ce qui permet une interaction plus agréable au travers de l'imagination de catégories sémantiques et de concepts. Nous démontrons que ce type d'ICO détecte plus aisément les catégories sémantiques éloignées plutôt que les catégories sémantiques proches. Pour terminer, nous créons un nouveau protocole d'entraînement implicite pour les ICO à base d'Imagerie Conceptuelle basé sur l'amorçage sémantique et conceptuel, ce qui permet d'intégrer l'entraînement dans le scénario et l'environnement d'une jeu vidéo sans que l'utilisateur n'en soit conscient. Notre protocole mène à une meilleure immersion et à meilleur sentiment de flot vis à vis du jeu. / Active Brain Computer Interfaces (BCIs) allow people to exert direct voluntary control over a computer system: their brain signals are captured and the system recognizes specific imagined actions (movements, images, concepts). Active BCIs and their users must undergo training. This makes the signals easier to recognize by the system. This acquisition can take from 10 minutes up to 2 months. BCIs can thus be applied to many control and interaction scenarios of our everyday lives, especially in relation to entertainment (Wolpaw et al., 2002).BCIs are mostly used by disabled people in a medical setting and seldom leave the lab. First of all, high-grade equipment is expensive and non-portable. Although there are commercial ventures proposing BCI acquisition equipment to the general public, the quality is still insufficient to build accurate and robust BCIs.BCIs also suffer from numerous limitations:• Variability of the signals: signals different across people or within the same individual at different times.• Long and repetitive training sessions: between 10 minutes up to several months, disengage and bore users.• Limited feedback: simple unimodal feedback ill adapted for many users. Feedback is unidirectional and the user just has to follow instructions.All these issues limit the adoption of BCI, the lack of widespread commercial success and the use of BCI from human computer interaction applications.The objective of the thesis is to propose solutions to the above problems so as to obtain a consistent architecture that will allow BCIs to be better suitable to Human-Computer Interaction (HCI) applications. The idea is to implement co-learning in the BCI loop and to explore how users and system can give feedback to each other in order to improve BCI usability.This thesis is structured around three innovations surrounding the BCI loop:• A general architecture based on asynchronous BCI principles and on incremental training combined with an unsupervised blind-source separation filter and a minimum distance classifier. This architecture allows producing BCIs with minimal training session. We evaluate the architecture on a drone piloting task over a month and find that it is suitable for use in daily recreational applications.• A more intuitive visualization modality for classification outcomes and distance features using Wachspress coordinate projection for an arbitrary number of classes. We combine the visualization with direct feedback mechanism where users can interactively change the classification margin, change the types of features as well as edit the training trials in real-time. We evaluate our contribution on a simple shooter game and find there is a good synergy between our visualization modality and direct user feedback and that the combination is much more enjoyable to users than a standard BCI training.• Finally we develop an operational Conceptual Imagery BCI based on our architecture, visualization and feedback system that allow for more natural interactions through the imagination of sematic categories and concepts. We show that this type of BCI is more effective at detecting distinct semantic categories rather than close ones. Then, we build on this conceptual BCI to propose a smart home control system for healthy and disabled users. Finally we invent a new seamless training protocol for Conceptual Imagery that uses conceptual and semantic priming in order to integrate the training in the narrative and environment of the game without the realization of the user. Our technique leads to better flow and immersion of users in the game. We believe this training protocol can be extended to many tasks outside of games or even of Conceptual Imagery.

?rea de Concentra??o: Qu?mica Anal?tica. / Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-06T16:39:24Z No. of bitstreams: 2 catia_da_cruz_santos.pdf: 3231163 bytes, checksum: 02f6b9329a3b1f0bfb3aba6cc16a3ef7 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-07T11:55:17Z (GMT) No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) catia_da_cruz_santos.pdf: 3231163 bytes, checksum: 02f6b9329a3b1f0bfb3aba6cc16a3ef7 (MD5) / Made available in DSpace on 2016-01-07T11:55:17Z (GMT). No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) catia_da_cruz_santos.pdf: 3231163 bytes, checksum: 02f6b9329a3b1f0bfb3aba6cc16a3ef7 (MD5) Previous issue date: 2014 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Neste trabalho foi investigada a eletropolimeriza??o do ?cido 4-aminobenz?ico (4-ABA), visando sua aplica??o como plataforma funcionalizada para imobiliza??o de biomol?culas, para o desenvolvimento de sensores biol?gicos. Foi utilizado o mon?mero 4-ABA, e por meio deste a eletrogera??o foi conduzida sobre a superf?cie do eletrodo de grafite (EG), utilizando-se as t?cnicas de voltametria c?clica (VC) e cronoamperometria (CA), onde nesta, foi investigado o tempo de eletrodeposi??o. Associado a este estudo, foi investigado a imobiliza??o de pequenos fragmentos de DNA (oligonucleot?deos), observando a atua??o da plataforma funcionalizada na resposta do biossensor em rela??o ? detec??o dos oligonucleot?deos, bem como avalia??o do reconhecimento do evento de hibridiza??o, com o alvo complementar. Para a VC, os EG foram modificados com 100 ciclos consecutivos de potencial, em velocidade de varredura de 50 mV/s, na faixa de potencial de +0,00 a +1,20 V, enquanto que na CA, os EG foram modificados nos potenciais de +0,95 V; +1,05 V e +1,15 V, onde tempo de polimeriza??o foi investigado em 4800 segundos e 2400 segundos. Observou-se que dentre os tr?s potenciais pr?-estabelecidos, o que apresentou maior eletroatividade, foi no eletrodo modificado ? +1,05 V, seguido dos potenciais de +1,15 V e +0,95 V, respectivamente. Para o filme formado em +0,95 V, h? um ligeiro aumento da corrente na atividade do par redox, sendo tamb?m observado que um maior deslocamento de potencial e corrente, ocorreu para o eletrodo modificado em +1,05 V seguido do potencial +1,15 V. A atividade eletroqu?mica dos filmes polim?ricos ? praticamente da mesma magnitude quando a eletropolimeriza??o por CA, ocorre a 4800 segundos e 2400 segundos. O eletrodo que apresentou as melhores respostas para imobiliza??o e detec??o das bases p?ricas, guanina e adenina, foi o eletrodo modificado por VC, seguido do eletrodo modificado no potencial de +1,05 V, uma vez que mostrou-se maiores amplitudes nos valores de corrente de pico an?dica (Ipa) dentre os potenciais constantes. Os filmes formados a 2400 segundos apresentam menor sensibilidade para a imobiliza??o e detec??o da guanina, biomarcador. Medidas de espectroscopia de imped?ncia eletroqu?mica (EIE) mostraram maior resist?ncia ? transfer?ncia de carga (Rtc) para o eletrodo modificado no potencial +1,05 V, seguido do eletrodo modificado por VC. Imagens de microscopia eletr?nica de varredura (MEV) mostraram que em todos os casos n?o h? total recobrimento da superf?cie do EG. Para o poli(4-ABA) eletropolimerizado por VC, as imagens de MEV mostraram morfologia completamente distinta, pois se observa uma maior cobertura da superf?cie do grafite, quando comparado aos filmes polim?ricos formados por CA. ? n?tido que para os filmes formados a 4800 segundos, h? maior presen?a de material depositada para a plataforma desenvolvida em +1,05 V. A plataforma Poli(4-ABA)/EG mostrou-se eficiente e sens?vel para a imobiliza??o do oligonucleot?deo (poliGA), bem como a detec??o do evento de hibridiza??o com o oligonucleot?deo complementar (poliCT). A ssDNA apresentou melhor afinidade pelo azul de metileno (AM) devido aos pares de bases da guanina presentes na sonda, comparada a dsDNA, onde a forma??o do h?brido diminui o acesso de intercala??o do azul de metileno (AM) ?s bases guanina, enquanto que a resposta eletroqu?mica do brometo de et?dio (BE) foi melhor observada na dsDNA. Estudos da imobiliza??o do pept?deo DD K, com o alvo espec?fico (fosfolip?deo POPC), e o alvo n?o espec?fico (fosfolip?deo POPC + colesterol), mostraram-se bastante promissores. A imobiliza??o do pept?deo sobre o poli(4-ABA) n?o gerou grandes altera??es no perfil dos espectros de EIE. Foi poss?vel observar uma semelhan?a entre os diagramas de Bode para as medidas da sonda e da sonda + alvo espec?fico devido ? forte intera??o existente entre pept?deo/LUVs sem colesterol. Contudo, para o eletrodo contendo a sonda + alvo n?o espec?fico (LUVs com colesterol), o espectro foi alterado. Tais resultados indicam promissora aplica??o da plataforma desenvolvida no reconhecimento de alvos biol?gicos, bem como o desenvolvimento de biossensores. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2014. / ABSTRACT The electropolymerization of 4-aminobenzoic acid (4-ABA) on graphite electrodes (GE) was investigated for the development of electrochemically functionalized platforms applied in the immobilization of biomolecules. The electrogeneration of 4-ABA was carried out in perchloric acid solutions using cyclic voltammetry (CV) and chronoamperometry (CA) techniques. In the case of CV studies, the GEs were modified by applying 100 consecutive potential cycles, while in the case of CA studies the electrodes were modified at different potentials (E/V vs. Ag/AgCl): +0.95, +1.05 and +1.15. The modified GEs were characterized using CV and electrochemical impedance spectroscopy (EIS) techniques in HClO4 solutions in the presence and absence of the ferricyanide/ferrocyanide redox couple (redox probe). Scanning electron microscopy (SEM) was used for morphological characterization. In case of CA, the best electrochemical activities for the electropolymerization reaction were verified at +1.05 V > +1.15 V > +0.95 V. The poly(4-ABA) platforms were investigated for the immobilization and direct detection of purine bases (adenine and guanine), where the higher values of the anodic peak current (Ip,a) were observed for the transducers electroformed using CV. For immobilization of oligonucleotides poly(GA) and recognition of hybridization event with the complementary target poly(CT), methylene blue (MB) and ethidium bromide (EB) were used as indicator and intercalator, respectively. MB was reduced at ?0.26 V resulting in the cathodic peak current (Ip,c) for the ssDNA, while in the case of EB the oxidation was observed at +0.58 V thus resulting in the higher values of Ip,a for the dsDNA. The platforms were also evaluated for immobilization of the DD K peptide, whose antibacterial activity and biological recognition were verified using the complementary (phospholipid 1- palmitoyl - 2 - oleoyl phosphatidylcholine - POPC) and non-complementary (phospholipid POPC + cholesterol) targets. The recognition mechanism was monitored using impedance measurements, where it was verified a good interaction of the peptide DD K with the POPC mimetic membrane. In addition, the interaction was affected by the presence of cholesterol, thus revealing that the use of poly(4-ABA) platforms is very promising for the development of biosensors.

Made available in DSpace on 2014-12-17T14:13:39Z (GMT). No. of bitstreams: 1 RandRM_TESE.pdf: 1297937 bytes, checksum: 0f7a6a1fba885f473c658ba94147cfc3 (MD5) Previous issue date: 2011-06-20 / Introdu??o: Os horm?nios estrog?nicos possuem importante papel na defesa contra as esp?cies reativas do oxig?nio, fato que se evidencia na maior incid?ncia de doen?as cardiovasculares e neurodegenerativas ap?s a menopausa. O exerc?cio f?sico melhora as defesas antioxidantes, contudo em altas cargas e em baixas concentra??es de estr?geno possui efeito aditivo ao dano oxidativo. O ?cido α-lip?ico possui uma ampla gama de a??o antioxidante e poderia contribuir para diminui??o do dano nestas condi??es. Objetivo: O objetivo deste estudo ? caracterizar a a??o do ?cido α-lip?ico sobre a adapta??o antioxidante e fun??es reprodutivas de ratas submetidas a nata??o moderada. Material e m?todos: Os animais foram submetidos a nata??o di?ria (1 hora) e sacrificados ap?s 30, 60 e 90 dias. Os animais foram divididos em controles sedent?rios e exercitados; suplementados (?cido α-lip?ico 100mg/Kg/dia) sedent?rios e exercitados e animais ovariectomizados e suplementados com ?cido lip?ico. Avaliou-se diariamente o ciclo estral e os seguintes marcadores de estresse oxidativos foram mensurados em f?gado e sangue: atividade enzim?tica da SOD, GPx e CAT, al?m do SRAT e GSH. Resultados: O protocolo de exerc?cio aumentou a dura??o do ciclo estral no grupo controle exercitado, sobretudo na fase diestral. Neste mesmo grupo, houve diminui??o da lipoperoxida??o com melhora da atividade antioxidante da SOD e GPx. O grupo exercitado e suplementado n?o apresentou altera??o na dura??o do ciclo estral e manteve os benef?cios sobre o sistema antioxidante antes observado nos animais exercitados. A suplementa??o antioxidante juntamente com a nata??o em per?odos superiores a 30 dias, diminuiu o processo de adapta??o antioxidante quando comparado aos animais somente exercitados. Nos animais ovariectomizados, o exerc?cio e a suplementa??o com ?cido lip?ico n?o promoveu adapta??o antioxidante ao contr?rio dos demais grupos. Conclus?o: O aumento na dura??o do ciclo estral e a melhora nos marcadores de estresse oxidativo seriam uma resposta adaptativa frente ao exerc?cio moderado. O ?cido lip?ico impediu a altera??o no ciclo induzida pelo exerc?cio, mas preservou a melhoria no sistema antioxidante. A deple??o estrog?nica provocada pela ovariectomia eleva o potencial de dano oxidativo gerado pelo exerc?cio. A a??o antioxidante do LA na presen?a de estr?geno diminuiu excessivamente o dano oxidativo, comprometendo a adapta??o antioxidante a nata??o. Nos animais ovariectomizados, contudo, o AL promoveu adapta??o antioxidante ao exerc?cio

Made available in DSpace on 2014-12-17T14:16:36Z (GMT). No. of bitstreams: 1 CandidaMSM_DISSERT.pdf: 2674854 bytes, checksum: 35ec01e6e19e4129b6100e813363df78 (MD5) Previous issue date: 2014-03-25 / Universidade Federal do Rio Grande do Norte / Retinoic acid (RA) and hydroquinone (HQ) assets are widely used in pharmaceutical and cosmetic formulations, for having depigmenting properties and are largely produced in drugstores. To assist in the development of formulations containing the active RA and HQ National Forms of Brazilian Pharmacopoeia (2005 and 2012 ) proposes formulations with different excipients such as cetyl alcohol (AC), cetostearyl alcohol (ACT), methylparaben (MTP), propyl paraben ( PPB), glycerin (GLY), dipropylene glycol (DPG), imidazolidinil urea ( IMD ), cyclomethicone (CCM ), butylated hydroxytoluene (BHT), octyl stearate (ETO), EDTA, decil oleate (ODC) and hydroxipropymethyl celullose (HPMC). One of the difficulties found in most cosmetic formulations is the large number of incompatibilities between the components of the formulations, so the aim this study was to evaluate thermal stability and interactions between these active pharmaceutical ingredients and excipients. The depigmenting agents were analyzed by DSC and TG and excipients were analyzed by TG. The dynamic thermogravimetric curves were obtained on a SHIMADZU thermobalance, model DTG-60, using an alumina crucible, at the heating rate of 10?C min-1, in the temperature range of 25-900 ?C, under an atmosphere of nitrogen at 50 mL min-1. The DSC curves were obtained using Shimadzu calorimeter, model DSC-60, using aluminum crucible, at the heating rate of 10?C min-1, in the temperature range of 25-400?C. The thermogravimetric and calorimetric curves were analyzed using TASYS software SHIMADZU. In this study no were found interactions between AR and the following excipients: MTP, PPB, IMD, ODC, EDTA, CCM, ETO, HPMC. However, were found interactions with the following excipients: AC, ACT, BHT, GLI and DPG. For HQ were found interactions with IMD and DPG. Interactions remained even changing proportions of the mixtures and the ternary. Thus, the studies conducted with excipients of National Formulary from 2005 and 2012 showed that these new excipients do not interact by thermogravimetry with the active pharmaceutical ingredients of this study / A Termogravimetria (TG) e a Calorimetria Explorat?ria Diferencial (DSC) s?o t?cnicas usadas em estudos farmac?uticos para a caracteriza??o de f?rmacos, determina??o da pureza, compatibilidade de formula??es, identifica??o de polimorfismo, avalia??o da estabilidade, decomposi??o t?rmica de f?rmacos e formula??es farmac?uticas. A Hidroquinona (HQ) e produtos contendo HQ t?m sido largamente utilizados como agentes despigmentantes para o clareamento da pele. Os retin?ides, que tamb?m exibem propriedades despigmentantes, s?o compostos que apresentam em sua estrutura o n?cleo b?sico da vitamina A. O ?cido retin?ico (AR) ? um exemplo de despigmentante dessa classe e ? muito utilizado em formula??o cosm?ticas. Para auxiliar no desenvolvimento de formula??es contendo os ativos AR e HQ o Formul?rio Nacional da ANVISA (2005 e 2012) prop?e formula??es com diferentes excipientes como: ?lcool cet?lico, ?lcool cetoestear?lico, parabenos (metil e propil), glicerina, dipropilenoglicol, imidazolidinilur?ia, ciclometicona, BHT, estearato de octila, EDTA, oleato de decila, hidroxipropimetilcelulose. Os agentes despigmentantes e excipientes foram analisados por TG e DSC. As curvas din?micas foram obtidas atrav?s de uma termobalan?a SHIMADZU, modelo DTG-60, usando cadinho de alumina, em uma raz?o de aquecimento de 10 ?C min-1 no intervalo de temperatura 25-900 ?C sob a atmosfera de nitrog?nio com fluxo de 50 mL min-1. As massas das amostras foram aproximadamente 10 ? 0,05 mg. As curvas DSC foram obtidas usando o calor?metro SHIMADZU, modelo DSC-60, em cadinho de alum?nio sob raz?o de aquecimento de 10 ?C min-1, em uma temperatura de 25-400 ?C. As curvas termogravim?tricas e calorim?tricas foram analisadas usando o software TASYS da SHIMADZU. Neste estudo n?o foram encontradas intera??es entre AR e os seguintes excipientes: MTP, PPB, IMD, ODC, EDTA, CCM, ETO, HPMC. No entanto, foram encontradas intera??es com os seguintes excipientes: AC, ACT, BHT, GLI e DPG. Para a HQ foram encontradas intera??es com a IMD e DPG. As intera??es permanecem mesmo alterando as propor??es das misturas, bem como nas tern?rias. Desta forma, os estudos realizados com os excipientes do formul?rio nacional de 2012 da ANVISA mostram que esses novos excipientes n?o interagem por termogravimetria com os ativos deste estudo