Motion clouds: model-based stimulus synthesis of natural-like random textures for the study of motion perception

Choosing an appropriate set of stimuli is essential to characterize the response of a sensory system to a particular functional dimension, such as the eye movement following the motion of a visual scene. Here, we describe a framework to generate random texture movies with controlled information content, i.e., Motion Clouds. These stimuli are defined using a generative model that is based on controlled experimental parametrization. We show that Motion Clouds correspond to dense mixing of localized moving gratings with random positions. Their global envelope is similar to natural-like stimulation with an approximate full-field translation corresponding to a retinal slip. We describe the construction of these stimuli mathematically and propose an open-source Python-based implementation. Examples of the use of this framework are shown. We also propose extensions to other modalities such as color vision, touch, and audition

Social media and nurse education: an integrative reviewof the literature

Introduction. The exponential advance of social media has touched all areas of society, no exception for the professional and personal lives of healthcare people. The issue to be considered is not whether or not social media are being used, but how they are used. The line between proper and improper use, and even abuse, of social media is a subtle one. Thus, the key issue is to be aware of the tool that is being used and this should be supported with suitable training for healthcare professionals and, at an even earlier stage, for students at healthcare training institutions during their studies. Objective. To describe, through an integrative review of the literature, the use of social media by teachers and students during teaching activity and practical training courses. Materials and methods. An integrative review of the literature was conducted in October 2014. The literature search was performed by consulting the main biomedical databases: PubMed, CINAHL and Embase. Results. The literature search brought up a total of 854 citations. 804 abstracts were excluded as they were not relevant. Of the remaining 50, 31 were excluded for not meeting the general criteria and, hence, only 19 articles were included. Two aspects emerged from the works selected: the use and potential of social media in nursing education and the ethical and professional implications of their use. Conclusions. The analysis of the literature reveals two areas for further investigation: evaluating the level of moral awareness in nursing education with regards to the use of Web 2.0 communication tools and implementing teaching methods to promote the construction and development of moral reasoning in professionals

Postmodern String Theory: Stochastic Formulation

In this paper we study the dynamics of a statistical ensemble of strings, building on a recently proposed gauge theory of the string geodesic field. We show that this stochastic approach is equivalent to the Carath\'eodory formulation of the Nambu-Goto action, supplemented by an averaging procedure over the family of classical string world-sheets which are solutions of the equation of motion. In this new framework, the string geodesic field is reinterpreted as the Gibbs current density associated with the string statistical ensemble. Next, we show that the classical field equations derived from the string gauge action, can be obtained as the semi-classical limit of the string functional wave equation. For closed strings, the wave equation itself is completely analogous to the Wheeler-DeWitt equation used in quantum cosmology. Thus, in the string case, the wave function has support on the space of all possible spatial loop configurations. Finally, we show that the string distribution induces a multi-phase, or {\it cellular} structure on the spacetime manifold characterized by domains with a purely Riemannian geometry separated by domain walls over which there exists a predominantly Weyl geometry.Comment: 24pages, ReVTe

Communication with the public in the health-care system: a descriptive study of the use of social media in Local Health Authorities and public hospitals in Italy

Introduction. In 2010 the Italian Ministry of Health set out recommendations for the use of social technology and Web 2.0, inviting organisations within the Italian national health service (Servizio Sanitario Nazionale, SSN) to equip themselves with instruments. Objectives. 1. to ascertain how many local health authorities (Aziende Sanitarie Locali, ASL) and public hospitals have a presence on the most widely used social media websites in Italy: Facebook, Twitter and YouTube; 2. to find out how well the Facebook, Twitter and YouTube pages of ASLs and public hospitals are known among the general population; 3. to find out how ASLs and public hospitals engage with the general public on social media sites. Materials and methods. The websites of all ASLs and public hospitals across the country were visited to look for the icons of the social media sites under examination. The data considered were publicly available upon access. Results. A total of 245 websites were analysed. 7.34% ASLs and hospitals had social media accounts. 8 organisations had an account on all three of the social media sites considered in the study. Conclusions. The results show a low presence of ASLs and hospitals on social media. Other studies are needed in this field

Approche variationnelle pour la déconvolution rapide de données 3D en microscopie biphotonique

National audienceBetter understanding of biological processes requires new, improved, high resolution imagery techniques. The present work concerns the restoration of data acquired with two-photon microscopy in biological tissue, in-vivo in particular. Two main challenges to tackle are: the large dimensionality of the acquired data and the incomplete knowledge of the impulse response of the system. We propose here an experimental setting to estimate it based on the observation of fluorescent micro-beads. The non-blind formulation of the related inverse problem of image restoration is then solved by minimizing a penalized criterion using an efficient convex optimization strategy based on the Majoration-Minimization approach. The effectiveness of the proposed approach is not only shown on simulated data but also on real data.Les technologies d'imagerie permettant d'obtenir des images à l'échelle cellulaire sont devenues incontournables pour mieux comprendre les processus biologiques. Nous nous intéressons ici à l'imagerie biphotonique et plus particulièrement, à la reconstruction des images acquises par un tel système dans un contexte in-vivo. Deux difficultés majeures sont : les gros volumes de données que représentent les acquisitions et la mauvaise connaissance de la réponse impulsionnelle de l'instrument. Nous proposons dans ce travail d'estimer cette dernière à l'aide d'un montage expérimental basé sur l'observation de micro-billes fluorescentes. Le problème inverse de restauration d'image est ensuite résolu dans un cadre non aveugle, en le formulant sous la forme d'un critère pénalisé minimisé à l'aide d'une méthode d'optimisation convexe efficace fondée sur la technique de Majoration-Minimisation. L'efficacité de l'approche proposée est démontrée sur données simulées et réelles

Development of broad-spectrum human monoclonal antibodies for rabies post-exposure prophylaxis

Currently available rabies post-exposure prophylaxis (PEP) for use in humans includes equine or human rabies immunoglobulins (RIG). The replacement of RIG with an equally or more potent and safer product is strongly encouraged due to the high costs and limited availability of existing RIG. In this study, we identified two broadly neutralizing human monoclonal antibodies that represent a valid and affordable alternative to RIG in rabies PEP. Memory B cells from four selected vaccinated donors were immortalized and monoclonal antibodies were tested for neutralizing activity and epitope specificity. Two antibodies, identified as RVC20 and RVC58 (binding to antigenic site I and III, respectively), were selected for their potency and broad-spectrum reactivity. In vitro, RVC20 and RVC58 were able to neutralize all 35 rabies virus (RABV) and 25 non-RABV lyssaviruses. They showed higher potency and breath compared to antibodies under clinical development (namely CR57, CR4098, and RAB1) and commercially available human RIG. In vivo, the RVC20-RVC58 cocktail protected Syrian hamsters from a lethal RABV challenge and did not affect the endogenous hamster post-vaccination antibody response

Modelagem matemática-computacional do método híbrido FUCOM-RAFSI: apoio à decisão na ordenação de navios escoltas para a Marinha do Brasil

O Brasil possui uma das maiores extensões de litoral e de plataforma continental do mundo, estendendo-se por aproximadamente por 350 milhas náuticas (563,27 quilômetros), uma área vasta que demanda vigilância constante. Para operar eficientemente nessa região, é planejado que a Marinha do Brasil (MB) tenha uma frota de no mínimo 18 navios de escolta. Atualmente, porém, sua frota está reduzida a apenas oito navios, muitos dos quais próximos ao fim de sua vida útil. Com isso, a MB precisa repor e substituir esses navios para não comprometer ainda mais sua capacidade mínima de combate. As opções incluem "compras de oportunidade" de novas embarcações por meio de uma seleção criteriosa do modelo de navio a ser obtido. Diante desse desafio, a pesquisa propôs um método híbrido multicritério para ordenar e selecionar os navios de escolta disponíveis em outros países que melhor atendam às funções esperadas pela MB. A proposta incluiu uma pesquisa do tipo descritiva, qualitativa-quantitativa mista, com questionário semiestruturada para validação de dados, uma revisão abrangente dos métodos Full Consistency Method (FUCOM) e Ranking of Alternatives through Functional Mapping of Criterion Sub-intervals Into a Single Interval (RAFSI), buscando combinar seus pontos fortes: o FUCOM para gerar pesos com poucas comparações entre critérios e com grande consistência dos resultados e o RAFSI para ordenar as alternativas, preservando estabilidade contra inversões de ordem, indicando os navios Thaondi Revel, Bergamini e Forbin como alternativas não dominadas dentro do contexto da decisão. Para facilitar o uso e a acessibilidade do método, foi realizada a modelagem-matemática computacional do método FUCOM-RAFSI, que apresenta os resultados de forma numérica e gráfica, aprimorando a compreensão da análise, além de ser testado quanto à estabilidade e robustez, incluindo testes de reversão de ordem, com inserção e remoção de alternativas, mantendo a consistência da ordenação inicial. Com a aplicação desse método, espera-se oferecer apoio decisório à MB, beneficiando a sociedade ao contribuir para a segurança e defesa nacional

An Anti-HIV-1 V3 Loop Antibody Fully Protects Cross-Clade and Elicits T-Cell Immunity in Macaques Mucosally Challenged with an R5 Clade C SHIV

Neutralizing antibodies have been shown to protect macaques against SHIV challenge. However, genetically diverse HIV-1 clades have evolved, and a key question left unanswered is whether neutralizing antibodies can confer cross-clade protection in vivo. The novel human monoclonal antibody HGN194 was isolated from an individual infected with an HIV-1 clade AG recombinant circulating recombinant form (CRF). HGN194 targets an epitope in the third hypervariable loop (V3) of HIV-1 gp120 and neutralizes a range of relatively neutralization-sensitive and resistant viruses. We evaluated the potential of HGN194 to protect infant rhesus monkeys against a SHIV encoding a primary CCR5-tropic HIV-1 clade C envelope. After high-dose mucosal challenge, all untreated controls became highly viremic while all HGN194-treated animals (50 mg/kg) were completely protected. When HGN194 was given at 1 mg/kg, one out of two monkeys remained aviremic, whereas the other had delayed, lower peak viremia. Interestingly, all protected monkeys given high-dose HGN194 developed Gag-specific proliferative responses of both CD4+ and CD8+ T cells. To test whether generation of the latter involved cryptic infection, we ablated CD8+ cells after HGN194 clearance. No viremia was detected in any protected monkeys, thus ruling out virus reservoirs. Thus, induction of CD8 T-cell immunity may have resulted from transient “Hit and Run” infection or cross priming via Ag-Ab-mediated cross-presentation. Together, our data identified the HGN194 epitope as protective and provide proof-of-concept that this anti-V3 loop mAb can prevent infection with sterilizing immunity after challenge with virus of a different clade, implying that V3 is a potential vaccine target

Global and regional brain metabolic scaling and its functional consequences

Background: Information processing in the brain requires large amounts of metabolic energy, the spatial distribution of which is highly heterogeneous reflecting complex activity patterns in the mammalian brain. Results: Here, it is found based on empirical data that, despite this heterogeneity, the volume-specific cerebral glucose metabolic rate of many different brain structures scales with brain volume with almost the same exponent around -0.15. The exception is white matter, the metabolism of which seems to scale with a standard specific exponent -1/4. The scaling exponents for the total oxygen and glucose consumptions in the brain in relation to its volume are identical and equal to $0.86\pm 0.03$, which is significantly larger than the exponents 3/4 and 2/3 suggested for whole body basal metabolism on body mass. Conclusions: These findings show explicitly that in mammals (i) volume-specific scaling exponents of the cerebral energy expenditure in different brain parts are approximately constant (except brain stem structures), and (ii) the total cerebral metabolic exponent against brain volume is greater than the much-cited Kleiber's 3/4 exponent. The neurophysiological factors that might account for the regional uniformity of the exponents and for the excessive scaling of the total brain metabolism are discussed, along with the relationship between brain metabolic scaling and computation.Comment: Brain metabolism scales with its mass well above 3/4 exponen