A model of cellular dosimetry for macroscopic tumors in radiopharmaceutical therapy.

PURPOSE: In the radiopharmaceutical therapy approach to the fight against cancer, in particular when it comes to translating laboratory results to the clinical setting, modeling has served as an invaluable tool for guidance and for understanding the processes operating at the cellular level and how these relate to macroscopic observables. Tumor control probability (TCP) is the dosimetric end point quantity of choice which relates to experimental and clinical data: it requires knowledge of individual cellular absorbed doses since it depends on the assessment of the treatment's ability to kill each and every cell. Macroscopic tumors, seen in both clinical and experimental studies, contain too many cells to be modeled individually in Monte Carlo simulation; yet, in particular for low ratios of decays to cells, a cell-based model that does not smooth away statistical considerations associated with low activity is a necessity. The authors present here an adaptation of the simple sphere-based model from which cellular level dosimetry for macroscopic tumors and their end point quantities, such as TCP, may be extrapolated more reliably. METHODS: Ten homogenous spheres representing tumors of different sizes were constructed in GEANT4. The radionuclide 131I was randomly allowed to decay for each model size and for seven different ratios of number of decays to number of cells, N(r): 1000, 500, 200, 100, 50, 20, and 10 decays per cell. The deposited energy was collected in radial bins and divided by the bin mass to obtain the average bin absorbed dose. To simulate a cellular model, the number of cells present in each bin was calculated and an absorbed dose attributed to each cell equal to the bin average absorbed dose with a randomly determined adjustment based on a Gaussian probability distribution with a width equal to the statistical uncertainty consistent with the ratio of decays to cells, i.e., equal to Nr-1/2. From dose volume histograms the surviving fraction of cells, equivalent uniform dose (EUD), and TCP for the different scenarios were calculated. Comparably sized spherical models containing individual spherical cells (15 microm diameter) in hexagonal lattices were constructed, and Monte Carlo simulations were executed for all the same previous scenarios. The dosimetric quantities were calculated and compared to the adjusted simple sphere model results. The model was then applied to the Bortezomib-induced enzyme-targeted radiotherapy (BETR) strategy of targeting Epstein-Barr virus (EBV)-expressing cancers. RESULTS: The TCP values were comparable to within 2% between the adjusted simple sphere and full cellular models. Additionally, models were generated for a nonuniform distribution of activity, and results were compared between the adjusted spherical and cellular models with similar comparability. The TCP values from the experimental macroscopic tumor results were consistent with the experimental observations for BETR-treated 1 g EBV-expressing lymphoma tumors in mice. CONCLUSIONS: The adjusted spherical model presented here provides more accurate TCP values than simple spheres, on par with full cellular Monte Carlo simulations while maintaining the simplicity of the simple sphere model. This model provides a basis for complementing and understanding laboratory and clinical results pertaining to radiopharmaceutical therapy.

Abordagem da amamentação nos primeiros anos do ensino fundamental

Para analisar os currículos e os livros escolares adotados nos primeiros cinco anos do Ensino Fundamental na disciplina de Ciências quanto à presença ou não de termos relacionados à prática da amamentação, realizamos um estudo descritivo analisando o currículo e 16 manuais de 25 escolas públicas de três municípios do interior paulista, de setembro/2010 a fevereiro/2011. Definimos previamente alguns conceitos considerados imprescindíveis para ensinar e explicar à criança noções de amamentação. Verificamos que nenhum bloco temático do currículo aborda explicitamente a temática amamentação. Nove dos 16 conteúdos definidos estavam presentes em oito dos 16 livros. Da análise emergiu a categoria apoio e ajuda da família. Três obras utilizavam ilustrações associadas à alimentação artificial. No programa e nos manuais escolares existem diversas oportunidades de incluir este tema. Aconselha-se a integração dos conteúdos em todos os manuais de Ciências dos primeiros anos do ensino fundamental.

Social use of alcohol among adolescent offenders: a fundamental approach toward human needs

This study examined some basic health care approaches toward human needs, with a particular focus on nursing. We aimed to incorporate these approaches into the discussion of the mental health of adolescent offenders who consume alcohol. We discuss specific needs of the delinquent group, critique policies that prioritize coercion of adolescent offenders, and the role that nurses could play in the sphere of juvenile delinquency.

Perfil do formador – um atributo fundamental na melhoria da qualidade do ensino Um estudo de caso

O presente trabalho que tem como tema O perfil do formador/professor um atributo na melhoria da qualidade do ensino é um estudo de caso realizado na escola Secundária Manuel Lopes. Pretendemos com este trabalho saber se existe um perfil adequado para o formador/professor do ensino Secundário. Este trabalho está estruturado em três capítulos. Apresentamos na introdução os objectivos do trabalho, a metodologia utilizada, a justificação do tema, e as dificuldades que encontramos no desenrolar do mesmo. Foram abordados os conceitos relevantes para a compreensão do tema em estudo. Apresentamos ainda um breve historial da escola bem como as características da zona onde está inserida. Apresentamos os dados que foram recolhidos e de seguida fizemos a respectiva análise, que nos permitiu formular as nossas conclusões, onde retomamos alguns pontos centrais da nossa investigação, numa análise suscita do perfil do formador/professor um atributo fundamental da melhoria da qualidade do ensino, e procuramos apresentar algumas recomendações visando a melhoria da mesma.

A diagram of public spaces within urban landscape as a strategy for sustainable urban planning in Chinese cities

Destruction of historical urban fabric in many Chinese cities and towns, without the possibility of its recovery as an urban asset, leads us to consider alternative strategies and criteria for formulating new urban projects, using creative urban planning instruments and strategies to provide a sense of place and identity to the urban landscape. The challenge is to set up an urban structure that constitutes a spatial reference system, a structure consisting of a set of urban landmarks that construct a system of related public spaces, endowed with collective significance and identity. Such a network could include a wide variety of urban typologies and natural elements. An important result of this strategy would be the recovery of the social and cultural values attached to the natural landscape in Chinese civilization. Hangzhou city will be analyzed as a case study

Microscopic and macroscopic polarization within a combined quantum mechanics and molecular mechanics model

A polarizable quantum mechanics and molecular mechanics model has been extended to account for the difference between the macroscopic electric field and the actual electric field felt by the solute molecule. This enables the calculation of effective microscopic properties which can be related to macroscopic susceptibilities directly comparable with experimental results. By seperating the discrete local field into two distinct contribution we define two different microscopic properties, the so-called solute and effective properties. The solute properties account for the pure solvent effects, i.e., effects even when the macroscopic electric field is zero, and the effective properties account for both the pure solvent effects and the effect from the induced dipoles in the solvent due to the macroscopic electric field. We present results for the linear and nonlinear polarizabilities of water and acetonitrile both in the gas phase and in the liquid phase. For all the properties we find that the pure solvent effect increases the properties whereas the induced electric field decreases the properties. Furthermore, we present results for the refractive index, third-harmonic generation (THG), and electric field induced second-harmonic generation (EFISH) for liquid water and acetonitrile. We find in general good agreement between the calculated and experimental results for the refractive index and the THG susceptibility. For the EFISH susceptibility, however, the difference between experiment and theory is larger since the orientational effect arising from the static electric field is not accurately described

Cartographier les géomorphosites : objectifs, publics et propositions méthodologiques

Related to the raise of the awareness of the importance of the Earth heritage, geomorphosites receive increasing attention from the scientific community. Assessment methods, classification and conservation strategies have been developed to safeguard the geomorphological heritage for present and future generations. On the other hand, Earth heritage offers opportunities to develop educational and recreational programs as well as tourism projects. Various interpretive supports and local development projects have been engendered in the past few years to promote geoheritage.¦Be it for the assessment, conservation or promotion of geomorphosites, maps are valuable from many standpoints. They can provide fundamental data for detailed geomorphosite description, serve as visual communication tools helping to guide the selection process in defining protection priority or supporting Earth heritage promotion and interpretàtion.¦This study reviews the main achievements and the objectives yet to be accomplished in the field of geomorphosite mapping and proposes a general framework for the mapping of geomorphosites that takes into account the different aims and publics. The main focus is on mapping geomorphosites for non-specialists in the field of Earth heritage promotion (Geotourism). In this context, maps are often employed to show itineraries or points of interest. Like a scheme or a diagram, a map can also be used as a method for visualising geoscientific information. This function is particularly important since some processes, which contributed to the formation of a geomorphosite or a geomorphological landscape are no longer or not always clearly visible in the landscape. In this case, maps become interpretive media that serve popularisation purposes.¦Mapping for non-specialists holds the challenging task to ensure the information transfer between the cartographer and the user. We therefore focus on both the implementation of the map by the cartographer (which information? which visualisation?) and the interpretation of the map by the user (effectiveness of the knowledge transfer). The research is based on empirical studies carried out in the Maderan valley (Canton of Uri) and in classes of the Cantons of Uri and Tessin that aim to gain knowledge about the familiarity and interests of non- specialists for geoheritage as well as about their map reading skills. The final objective is to formulate methodological proposals for geomorphosite mapping for interpretive purpose.

Usando um Jogo Digital na Sala de Aula do Ensino Fundamental: Visão dos Professores

A digital game was created as a resource for cognitive learning and afterwards it was used in primary schools in order to survey its active users. The methods used to recollect data were observation, in-depth interviews and focus groups. The main target of this study is to collect points of view of different primary school teachers. Conclusions show us how the group of study members perceive the use of digital games in the classroom.

An analysis of the currently available calibrations inStromgren photometry by using open clusters

In recent years, several authors have revised the calibrations used to compute physical parameters (tex2html_wrap_inline498, tex2html_wrap_inline500, log g, [Fe/H]) from intrinsic colours in the tex2html_wrap_inline504 photometric system. For reddened stars, these intrinsic colours can be computed through the standard relations among colour indices for each of the regions defined by Strömgren (1966) on the HR diagram. We present a discussion of the coherence of these calibrations for main-sequence stars. Stars from open clusters are used to carry out this analysis. Assuming that individual reddening values and distances should be similar for all the members of a given open cluster, systematic differences among the calibrations used in each of the photometric regions might arise when comparing mean reddening values and distances for the members of each region. To classify the stars into Strömgren's regions we extended the algorithm presented by Figueras et al. (1991) to a wider range of spectral types and luminosity classes. The observational ZAMS are compared with the theoretical ZAMS from stellar evolutionary models, in the range tex2html_wrap_inline506 K. The discrepancies are also discussed.

Period-Luminosity-Colour distribution and classification of Galactic oxygen-rich LPVs I. Luminosity calibrations

The absolute K magnitudes and kinematic parameters of about 350 oxygen-rich Long-Period Variable stars are calibrated, by means of an up-to-date maximum-likelihood method, using HIPPARCOS parallaxes and proper motions together with radial velocities and, as additional data, periods and V-K colour indices. Four groups, differing by their kinematics and mean magnitudes, are found. For each of them, we also obtain the distributions of magnitude, period and de-reddened colour of the base population, as well as de-biased period-luminosity-colour relations and their two-dimensional projections. The SRa semiregulars do not seem to constitute a separate class of LPVs. The SRb appear to belong to two populations of different ages. In a PL diagram, they constitute two evolutionary sequences towards the Mira stage. The Miras of the disk appear to pulsate on a lower-order mode. The slopes of their de-biased PL and PC relations are found to be very different from the ones of the Oxygen Miras of the LMC. This suggests that a significant number of so-called Miras of the LMC are misclassified. This also suggests that the Miras of the LMC do not constitute a homogeneous group, but include a significant proportion of metal-deficient stars, suggesting a relatively smooth star formation history. As a consequence, one may not trivially transpose the LMC period-luminosity relation from one galaxy to the other.

Popularização da taxonomia de solo: vocabulário mínimo e aspectos sócio-econômicos no contexto do ensino fundamental, em São Miguel, Esperança (PB)

Este estudo objetivou construir uma proposta pedagógica com alunos de nível fundamental na comunidade de São Miguel, Esperança (PB). Procurou-se despertar o interesse dos estudantes para a importância do solo em suas vidas, bem como adequar a terminologia usada na pedologia à linguagem cotidiana dos alunos. Seguiu-se como método a abordagem paulofreireana na qual se considera que o contexto da escola extrapola o da sala de aula, devendo envolver o máximo de pessoas da comunidade. Assim, procurou-se levantar informações quanto à renda familiar, moradia, número de irmãos e irmãs, atividade principal do responsável pela família, etc. Deste levantamento, extraiu-se, também, o vocabulário mínimo, com palavras e expressões geradoras que sintetizam o universo de conhecimento em São Miguel. Os resultados denotaram a dureza do cotidiano e uma educação repressiva diante da indomabilidade dos filhos. Observou-se que elementos pedagógicos presentes no vocabulário mínimo podem facilitar a popularização do saber pedológico no ensino fundamental. O vocabulário mínimo promoveu uma melhor comunicação durante as aulas entre educadores e educandos, bem como permitiu a construção de conceitos para as ordens de solos mais representativas da região: Neossolos e Argissolos. A construção de monólitos de solos constituiu importante recurso auxiliar nas aulas expositivas e dialógicas, despertando nas crianças maior interesse para o tema solo e meio ambiente.

New insights on the crystalline forms in binary systems of n-alkanes: Characterization of the solid ordered phases in the phase diagram tricosane + pentacosane

X-ray diffraction analyses of the pure components n-tricosane and n-pentacosane and of their binary mixed samples have enabled us to characterize the crystalline phases observed at low temperature. On the contrary to what was announced in literature on the structural behavior of mixed samples in odd-odd binary systems with D n = 2, the three domains are not all orthorhombic. This work has enabled us to show that two of the domains are, in fact, monoclinic, (Aa, Z = 4) and the other one is orthorhombic (Pca21, Z = 4). The conclusions drawn in this work can be easily transposed to other binary systems of n-alkanes.

Anomalous crossover between thermal and shot noise in macroscopic diffusive conductors

We predict the existence of an anomalous crossover between thermal and shot noise in macroscopic diffusive conductors. We first show that, besides thermal noise, these systems may also exhibit shot noise due to fluctuations of the total number of carriers in the system. Then we show that at increasing currents the crossover between the two noise behaviors is anomalous, in the sense that the low-frequency current spectral density displays a region with a superlinear dependence on the current up to a cubic law. The anomaly is due to the nontrivial coupling in the presence of the long-range Coulomb interaction among the three time scales relevant to the phenomenon, namely, diffusion, transit, and dielectric relaxation time.

Semiclassical theory of shot noise in ballistic n+in+ semiconductor structures: relevance of Pauli and long range Coulomb interactions

We work out a semiclassical theory of shot noise in ballistic n+-i-n+ semiconductor structures aiming at studying two fundamental physical correlations coming from Pauli exclusion principle and long-range Coulomb interaction. The theory provides a unifying scheme which, in addition to the current-voltage characteristics, describes the suppression of shot noise due to Pauli and Coulomb correlations in the whole range of system parameters and applied bias. The whole scenario is summarized by a phase diagram in the plane of two dimensionless variables related to the sample length and contact chemical potential. Here different regions of physical interest can be identified where only Coulomb or only Pauli correlations are active, or where both are present with different relevance. The predictions of the theory are proven to be fully corroborated by Monte Carlo simulations.