Remineralização preventiva primária do esmalte através do sistema CPP-ACP

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

Tratamento de lesões white spot pelo sistema fosfato de cálcio caseína-fosfopeptideo amorfo (CPP-ACP): prevenção secundária

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

La activación de conocimientos previos (ACP): Una estrategia de comprensión lectora

El objetivo de este artículo es presentar un estudio sobre la activación de conocimientos previos como una de las estrategias que los docentes utilizan para trabajar la comprensión lectora con alumnos de segundo y tercero de Educación Primaria. Los datos que se analizan han sido recogidos mediante observaciones realizadas, durante dos cursos, en diversas aulas de la geografía española. Como resultado del análisis, se ofrece una panorámica de las maneras de activar conocimientos previos y cómo se distribuyen en función del tipo de texto y de la finalidad de la lectura.

New particle formation and growth at a remote, sub-tropical coastal location

A month-long intensive measurement campaign was conducted in March/April 2007 at Agnes Water, a remote coastal site just south of the Great Barrier Reef on the east coast of Australia. Particle and ion size distributions were continuously measured during the campaign. Coastal nucleation events were observed in clean, marine air masses coming from the south-east on 65% of the days. The events usually began at ~10:00 local time and lasted for 1-4 hrs. They were characterised by the appearance of a nucleation mode with a peak diameter of ~10 nm. The freshly nucleated particles grew within 1-4 hrs up to sizes of 20-50 nm. The events occurred when solar intensity was high (~1000 W m-2) and RH was low (~60%). Interestingly, the events were not related to tide height. The volatile and hygroscopic properties of freshly nucleated particles (17-22.5 nm), simultaneously measured with a volatility-hygroscopicity-tandem differential mobility analyser (VH-TDMA), were used to infer chemical composition. The majority of the volume of these particles was attributed to internally mixed sulphate and organic components. After ruling out coagulation as a source of significant particle growth, we conclude that the condensation of sulphate and/or organic vapours was most likely responsible for driving particle growth during the nucleation events. We cannot make any direct conclusions regarding the chemical species that participated in the initial particle nucleation. However, we suggest that nucleation may have resulted from the photo-oxidation products of unknown sulphur or organic vapours emitted from the waters of Hervey Bay, or from the formation of DMS-derived sulphate clusters over the open ocean that were activated to observable particles by condensable vapours emitted from the nutrient rich waters around Fraser Island or Hervey Bay. Furthermore, a unique and particularly strong nucleation event was observed during northerly wind. The event began early one morning (08:00) and lasted almost the entire day resulting in the production of a large number of ~80 nm particles (average modal concentration during the event was 3200 cm-3). The Great Barrier Reef was the most likely source of precursor vapours responsible for this event.

Love at first sight : Sanja Pahoki

I am a landscape architect, a non-photographer, and in reviewing this exhibition, it seems that in a critical discourse on photography the nature of the view and its relation to the observer (presumably the camera) is inevitably a key focus of creative inquiry, in an epistemological sense. In conducting such a review, of 'self-portraits' by 'female photographers' in relation to 'the landscape', one cannot help but ask what priority this critique should allocate to each of these conceptual agendas, quite apart from the simple formal quality of the individual pieces themselves. Analytically, each could form the axes of a matrix that might allow for a number of quite different permutations and therefore differently conclusive commentaries on the others: the view vs landscape; the view vs sexuality; the self-portrait vs the landscape picture. All of these would be productive in their own right and each is alluded to in the works themselves and in the narrative of the catalogue. Considering this range of possible permutations, this show is certainly rich and this richness sits well with the relative formal saturation of the images themselves.

Measuring episodic memory: A novel approach with an indefinite number of alternative forms

Both clinical practice and clinical research settings can require successive administrations of a memory test, particularly when following the trajectory of suspected memory decline in older adults. However, relatively few verbal episodic memory tests have alternative forms. We set out to create a broad based memory test to allow for the use of an essentially unlimited number of alternative forms. Four tasks for inclusion in such a test were developed. These tasks varied the requirement for recall as opposed to recognition, the need to form an association between unrelated words, and the need to discriminate the most recent list from earlier lists, all of which proved useful. A total of 115 participants completed the battery of tests and were used to show that the test could differentiate between older and younger adults; a sub-sample of 73 participants completed alternative forms of the tests to determine test-retest reliability and the amount of learning to learn.

The role of sulphates and organic vapours in growth of newly formed particles in a eucalypt forest

The influence of biogenic particle formation on climate is a well recognised phenomenon. To understand the mechanisms underlying the biogenic particle formation, determining the chemical composition of the new particles and therefore the species that drive the particle production is of utmost importance. Due to the very small amount of mass involved, indirect approaches are frequently used to infer the composition. We present here the results of such an indirect approach by simultaneously measuring volatile and hygroscopic properties of newly formed particles in a forest environment. It is shown that the particles are composed of both sulphates and organics, with the amount of sulphate component strongly depending on the available gas-phase sulphuric acid, and the organic components having the same volatility and hygroscopicity as photooxidation products of a monoterpene such as α-pinene. Our findings agree with a two-step process through nucleation and cluster formation followed by simultaneous growth by condensation of sulphates and organics that take the particles to climatically relevant sizes.