Développement d’une matrice prébiotique pour l’encapsulation des probiotiques bactériocinogènes, destinée à l’alimentation animale - de la physicochimie à la biopharmacie

L’antibiorésistance est un problème de santé publique majeur, causé principalement par l’usage abusif d’antibiotiques dans les élevages. Les probiotiques sont une alternative potentielle aux antibiotiques. Cependant, acheminer ces microorganismes vivants et fonctionnels jusqu’au côlon est un grand défi, à cause du pH et des sels biliaires à affronter lors du passage gastro-intestinal. L’objectif de ce travail était de développer une matrice prébiotique capable de maintenir la survie et l’activité des probiotiques pendant le transit gastro-intestinal et de permettre leur libération dans le côlon. Pour atteindre cet objectif, cinq types de matrices sphériques (A, AI5, AI10, AI15, AI20) à base d’inuline (0 %, 5 %, 10 %, 15 % et 20 %) et d’alginate (2 %) ont été préparés par la méthode d’extrusion/gélification ionotropique. Trois souches probiotiques ont été utilisées au cours du développement des billes : Pediococcus acidilactici UL5 (UL5), Lactobacillus reuteri (LR) et Lactobacillus salivarius (LS). Dans un premier temps, toutes les formulations ont été caractérisées d’un point de vue physicochimique et microbiologique. Ces analyses ont permis de révéler une distribution homogène de l’inuline et de l’alginate au sein des matrices et ont démontré que la viabilité et la capacité antimicrobienne des souches utilisées n’étaient pas affectées par l’encapsulation. À la lumière de ces résultats, trois formulations A, AI5 et AI20 ont été sélectionnées pour la suite de l’étude. Dans un deuxième temps, la mucoadhésion et le comportement des billes A, AI5 et AI20 ont été étudiés dans les parties supérieures du tractus gastro-intestinal. Ces études ont démontré que la présence de l’inuline améliore les propriétés mucoadhésives des billes. Elles ont également établi que seule la formulation AI5 résiste jusqu’à la fin de la digestion. Ce comportement est expliqué en partie par l’interaction alginate-inuline décelée par spectroscopie infrarouge à transformée de Fourier (FTIR). Cette interaction était stable pour les billes AI5 au pH 6,8 mais instable pour la formulation AI20. Enfin, le comportement et la dynamique bactérienne de la formulation AI5 dans les milieux coliques fermenté et non fermenté ont été étudiés. Cette étude a révélé que les billes AI5 se dégradent et libèrent la totalité des bactéries après environ 4 heures d’incubation dans le milieu fermenté. Cette dégradation est due aux enzymes très abondantes dans ce milieu. En conclusion, la formulation AI5 s’est avérée être un très bon véhicule pour protéger les bactéries dans les parties supérieures du tube digestif et favoriser leur libération dans le côlon. Elle pourrait donc, être utilisée pour une application en alimentation animale.

Os romances de Lygia Fagundes Telles : uma tessitura narrativa na senda do humano

Tese de doutoramento, Estudos de Literatura e de Cultura (Estudos Brasileiros), Universidade de Lisboa, Faculdade de Letras, 2015

Hybrid authentication systems: towards robust user authentication on wireless and mobile devices using biometric technologies

Adequate user authentication is a persistent problem, particularly with mobile devices, which tend to be highly personal and at the fringes of an organisation's influence. Yet these devices are being used increasingly in various business settings, where they pose a risk to security and privacy, not only from sensitive information they may contain, but also from the means they typically offer to access such information over wireless networks. User authentication is the first line of defence for a mobile device that falls into the hands of an unauthorised user. However, motivating users to enable simple password mechanisms and periodically update their authentication information is difficult at best. This paper examines some of the issues relating to the use of biometrics as a viable method of authentication on mobile wireless devices. It is also a critical analysis of some of the techniques currently employed and where appropriate, suggests novel hybrid ways in which they could be improved or modified. Both biometric technology and wireless setting based constraints that determine the feasibility and the performance of the authentication feature are specified. Some well known biometric technologies are briefly reviewed and their feasibility for wireless and mobile use is reviewed. Furthermore, a number of quantitative and qualitative parameters for evaluation are also presented. Biometric technologies are continuously advancing toward commercial implementation in wireless devices. When carefully designed and implemented, the advantage of biometric authentication arises mainly from increased convenience and coexistent improved security.

A Educação em Direitos Humanos através da discussão e ação sociopolítica sobre controvérsias sociocientíficas e socioambientais

A sociedade atual, marcada por dilemas morais e políticos suscitados pelo crescimento científico e tecnológico, só será verdadeiramente democrática quando as decisões sobre as opções científicas e tecnológicas deixarem de ser entendidas como responsabilidade exclusiva de especialistas, de governos nacionais ou instâncias internacionais. A ignorância e o medo da ciência e da tecnologia podem escravizar os cidadãos na servidão do século XXI, tornando-os estranhos na sua própria sociedade e completamente dependentes da opinião de especialistas (Prewitt, 1983). Torna-se vital a passagem progressiva do conceito de cidadão passivo, governado por uma elite iluminada, para um conceito de cidadão ativo predisposto e apto a participar em processos de decisão sobre as opções de desenvolvimento que lhe são apresentadas. É neste contexto que surge o projeto “We Act”, focado na capacitação de professores e alunos para a realização de ações coletivas sobre controvérsias sociocientíficas e socioambientais (Reis, 2014a,b). Perante a gravidade das problemáticas que afetam o mundo atual, considera-se que não basta envolver os alunos na identificação e na discussão destas questões, tornando-se indispensável capacitá-los para ações coletivas fundamentadas que possam contribuir para a resolução desses problemas. Esta capacitação passa pelo desenvolvimento de competências de cidadania ativa e de consciência e eficácia políticas. Torna-se necessário que tanto professores como alunos (independentemente da sua idade) se sintam com o direito e a capacidade (o poder) de intervenção social. Com este projeto, pretende-se contrariar práticas de educação em ciência que promovem a conformidade relativamente ao conhecimento autorizado e ao discurso científico e encorajam os alunos a procurarem a aprovação de uma autoridade legitimada para validar as suas ações, em vez de os implicarem em discurso e ação críticos e democráticos (Désautels e Larochelle, 2003; Roth e Lee, 2002). Para tal, o projeto “We Act” baseia-se nos pilares da investigação, da discussão e da ação.

Human Computer Interaction using gestures for mobile devices and serious games: A review

The Human-Computer Interaction (HCI) with interfaces is an active challenge field in the industry over the past decades and has opened the way to communicate with the means of verbal, hand and body gestures using the latest technologies for a variety of different applications in areas such as video games, training and simulation. However, accurate recognition of gestures is still a challenge. In this paper, we review the basic principles and current methodologies used for collecting the raw gesture data from the user for recognize actions the users perform and the technologies currently used for gesture-HCI in games enterprise. In addition, we present a set of projects from various applications in games industry that are using gestural interaction.

Using Mobile Learning Games for Delivery Purposes in Humanities

Games and applications with gamified elements have been used in teaching and learning widely. Gamified applications attract the interest of students and teachers because they assist them to achieve their cognitive and pedagogical purposes. This paper describes a study that explores the use of a gamified learning application designed to introduce students at key stages 3 and 4 (ages 14-15) to ancient Greek Philosophy. The study involves 3 tests and 3 different groups of students and aimed to explore if the application improves students' knowledge and understanding and to compare different styles of subject delivering. This paper presents and discusses in details the results of the first test.

SAR determination and influence of the human head in the radiation of a mobile antenna for two different frequencies

The big proliferation of mobile communication systems has caused an increased concern about the interaction between the human body and the antennas of mobile handsets. In order to study the problem, a multiband antenna was designed, fabricated and measured to operate over two frequency sub bands 900 and 1800 MHz. After that, we simulated the same antenna, but now, in the presence of a human head model to analyze the head's influence. First, the influence of the human head on the radiation efficiency of the antenna has been investigated as a function of the distance between the head and the antenna and with the inclination of the antenna. Furthermore, the relative amount of the electromagnetic power absorbed in the head has been obtained.

Influence of the Human Head in the Radiation of a Mobile Antenna

The big proliferation of mobile communication systems has caused an increased concern about the interaction between the human body and the antennas of mobile handsets. In order to study the problem, a multiband antenna was designed, fabricated and measured to operate over two frequency sub bands 900 and 1800 MHz. After that, we simulated the same antenna, but now, in the presence of a human head model to analyze the head's influence. First, the influence of the human head on the radiation efficiency of the antenna has been investigated as a function of the distance between the head and the antenna and with the inclination of the antenna. Furthermore, the relative amount of the electromagnetic power absorbed in the head has been obtained. In this study the electromagnetic analysis has been performed via FDTD (Finite Difference Time Domain).

Mobile Banking: fatores determinantes na adesão

Dissertação apresentada à Escola Superior de Comunicação Social para obtenção de grau de mestre em Publicidade e Marketing.

Low Profile Multi-Band Antenna for Mobile Communications

In this paper, the design of low profile antennas by using Electromagnetic Band Gap (EBG) structures is introduced. Taking advantage of the fact that they can behave as Perfect Magnetic Conductor (PMC), it is shown that these structures exhibit dual band in-phase reflection at WLAN (Wireless Local Area Network) bands, the 2.4 GHz and 5.2 GHz bands. These structures are applied to PIFA (Planar Inverted-F Antenna) and the results show that it is possible to obtain low profile PIFA's.

Mobile application to provide personalized sightseeing tours

Tourist recommendation systems have been growing over the last years, mainly because of the use of mobile devices to get user context. This work discuss some of the most relevant systems on the field and presents PSiS Mobile, which is a mobile recommendation and planning application designed to support a tourist during his vacations. It provides recommendations about points of interest to visit based on tourist preferences and on user and sight context. Also, it suggests a visit planning which can be dynamically adapted based on current user and sight context. This tool works like a journey dairy since it records the tourist moves and tasks to help him remember how the trip was like. To conclude, some field experiences will be presented.

Projecto de conceito e estrutura de uma aplicação mobile para a marca NIVEA

Trabalho de projecto apresentado à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Publicidade e Marketing.