Electromagnetism in terms of quantum measurements

We consider the question whether electromagnetism can be derived from quantum physics of measurements. It turns out that this is possible, both for quantum and classical electromagnetism, if we use more recent innovations such as smearing of observables and simultaneous measurability. In this way we justify the use of von Neumann-type measurement models for physical processes. We apply operational quantum measurement theory to gain insight in fundamental aspects of quantum physics. Interactions of von Neumann type make the Heisenberg evolution of observables describable using explicit operator deformations. In this way one can obtain quantized electromagnetism as a measurement of a system by another. The relevant deformations (Rieffel deformations) have a mathematically well-defined "classical" limit which is indeed classical electromagnetism for our choice of interaction

Cell sorting in a Petri dish controlled by computer vision.

Fluorescence-activated cell sorting (FACS) applying flow cytometry to separate cells on a molecular basis is a widespread method. We demonstrate that both fluorescent and unlabeled live cells in a Petri dish observed with a microscope can be automatically recognized by computer vision and picked up by a computer-controlled micropipette. This method can be routinely applied as a FACS down to the single cell level with a very high selectivity. Sorting resolution, i.e., the minimum distance between two cells from which one could be selectively removed was 50-70 micrometers. Survival rate with a low number of 3T3 mouse fibroblasts and NE-4C neuroectodermal mouse stem cells was 66 +/- 12% and 88 +/- 16%, respectively. Purity of sorted cultures and rate of survival using NE-4C/NE-GFP-4C co-cultures were 95 +/- 2% and 62 +/- 7%, respectively. Hydrodynamic simulations confirmed the experimental sorting efficiency and a cell damage risk similar to that of normal FACS

Stretching the Rules: Monocentric Chromosomes with Multiple Centromere Domains

The centromere is a functional chromosome domain that is essential for faithful chromosome segregation during cell division and that can be reliably identified by the presence of the centromere-specific histone H3 variant CenH3. In monocentric chromosomes, the centromere is characterized by a single CenH3-containing region within a morphologically distinct primary constriction. This region usually spans up to a few Mbp composed mainly of centromere-specific satellite DNA common to all chromosomes of a given species. In holocentric chromosomes, there is no primary constriction; the centromere is composed of many CenH3 loci distributed along the entire length of a chromosome. Using correlative fluorescence light microscopy and high-resolution electron microscopy, we show that pea (Pisum sativum) chromosomes exhibit remarkably long primary constrictions that contain 3-5 explicit CenH3-containing regions, a novelty in centromere organization. In addition, we estimate that the size of the chromosome segment delimited by two outermost domains varies between 69 Mbp and 107 Mbp, several factors larger than any known centromere length. These domains are almost entirely composed of repetitive DNA sequences belonging to 13 distinct families of satellite DNA and one family of centromeric retrotransposons, all of which are unevenly distributed among pea chromosomes. We present the centromeres of Pisum as novel ``meta-polycentric'' functional domains. Our results demonstrate that the organization and DNA composition of functional centromere domains can be far more complex than previously thought, do not require single repetitive elements, and do not require single centromere domains in order to segregate properly. Based on these findings, we propose Pisum as a useful model for investigation of centromere architecture and the still poorly understood role of repetitive DNA in centromere evolution, determination, and function

Privatização dos serviços de extensão rural: uma discussão (des)necessária?

The article analyzes and discusses the privatization of the rural extension services according to international literature. To start with, the subject is set in the horizon of the debate of the so called State Reform, which determined the agenda for the development since the 1980’s. Next, we show how the subject has been treated so far having the economic theory as background and we examine experiments of privatization at international level. The analysis of such experiments reveals that the early agenda for the privatization took for granted that the rural extension services − which were a responsibility of the State − would be held completely by the private sectors. However, a series of obstacles appeared and arguments for models of privatization in which the State has a main role spread over. Therefore, the exam of international experiments of privatization led to the conclusion that they followed different orientations. One set of experiments was oriented by the notion of the “Minimum State†while the other had for reference the State as a supporter for private action. The privatization is a current and relevant process and, therefore, the discussion about it is considered necessary.Rural extension, privatization, State reform, rural development., Agribusiness, Q16.,

A HISTÓRICA CONCEPÇÃO DE DESENVOLVIMENTO FRENTE ÀS IDENTIDADES REGIONAIS: O CASO DO RINCÃO DOS MENDES NO MUNICÍPIO DE ROSÁRIO DO SUL/RS

O presente artigo propõe uma reflexão sobre o enfoque convencional de desenvolvimento da região denominada de Metade Sul do Rio Grande do Sul, tomando como referência uma comunidade situada na APA do Ibirapuitã, no município de Rosário do Sul. As abordagens atuais, apoiadas em indicadores como PIB per capta, Valor Adicionado Fiscal e geração de postos de trabalho, consideram a região como pouco desenvolvida. Entre as estratégias utilizadas para reversão desse quadro destacam-se a expansão das modernas lavouras empresarias de arroz e soja e o fomento aos empreendimentos no ramo florestal. Assim, a pergunta central desse artigo é sobre a capacidade dessas estratégias em promover verdadeiramente o “desenvolvimento” da metade sul do RS. O estudo destaca os possíveis impactos das estratégias convencionais de desenvolvimento na complexa situação sócio-ambiental da região e sugere a necessidade de aprofundar os conhecimentos sobre as especificidades locais, considerando os princípios de sustentabilidade.------------------------------------------------This paper proposes a reflection about the troubles with actual development approach used in the southern half region in the Rio Grande do Sul state. The case study use as reference a community located in the APA do Rio Ibirapuitã at Rosário do Sul County. The actual approaches using GDP per capita, Value Added Tax and job generation, consider the region as poorly developed. Among the strategies used to reversal of this framework the increase of rice and soybean crop production and forest crop are used. Thus, the central question of this article is these strategies in fact to support the "development" of the southern half of the RS. The study highlights the potential impact of conventional development strategies in the complex socio-environmental region situation and suggests more investigation to recognize specific location situation, considering the principles of sustainability.Desenvolvimento, Metade sul do RS, Identidade Territorial, Development, southern half of the RS, International Development,

Should Research Ethics Encourage the Production of Cost-Effective Interventions?

This project considers whether and how research ethics can contribute to the provision of cost-effective medical interventions. Clinical research ethics represents an underexplored context for the promotion of cost-effectiveness. In particular, although scholars have recently argued that research on less-expensive, less-effective interventions can be ethical, there has been little or no discussion of whether ethical considerations justify curtailing research on more expensive, more effective interventions. Yet considering cost-effectiveness at the research stage can help ensure that scarce resources such as tissue samples or limited subject popula- tions are employed where they do the most good; can support parallel efforts by providers and insurers to promote cost-effectiveness; and can ensure that research has social value and benefits subjects. I discuss and rebut potential objections to the consideration of cost-effectiveness in research, including the difficulty of predicting effectiveness and cost at the research stage, concerns about limitations in cost-effectiveness analysis, and worries about overly limiting researchers’ freedom. I then consider the advantages and disadvantages of having certain participants in the research enterprise, including IRBs, advisory committees, sponsors, investigators, and subjects, consider cost-effectiveness. The project concludes by qualifiedly endorsing the consideration of cost-effectiveness at the research stage. While incorporating cost-effectiveness considerations into the ethical evaluation of human subjects research will not on its own ensure that the health care system realizes cost-effectiveness goals, doing so nonetheless represents an important part of a broader effort to control rising medical costs

Uso de SMS na educação de jovens e adultos.

O artigo relata o desenvolvimento de uma proposta de uso da ferramenta de SMS em práticas pedagógicas na educação de jovens e adultos (EJA), em uma escola municipal de ensino fundamental, em Campinas, SP. O estudo baseou-se nos princípios do "Design Thinking", uma metodologia de desenvolvimento de projetos centrados nas necessidades dos usuários. Inicialmente, realizou-se um diagnóstico de utilização do telefone celular junto aos estudantes de EJA, com vistas à identificação do seu perfil, dos seus hábitos e de suas necessidades de interação social no ambiente escolar. Com base no conhecimento dos hábitos e das necessidades desses alunos, procurou-se investigar "o que poderia ser feito para melhorar a integração do aluno de EJA na comunidade escolar". Como resultado de pesquisa obteve-se uma proposta de uso de SMS na educação de jovens e adultos (EJA), em apoio a atividades pedagógicas, com o intuito de contribuir para promover uma maior aproximação e integração entre o aluno,o professor e a escola

Warm stellar matter with deconfinement: application to compact stars

We investigate the properties of mixed stars formed by hadronic and quark matter in $\beta$-equilibrium described by appropriate equations of state (EOS) in the framework of relativistic mean-field theory. We use the non- linear Walecka model for the hadron matter and the MIT Bag and the Nambu-Jona-Lasinio models for the quark matter. The phase transition to a deconfined quark phase is investigated. In particular, we study the dependence of the onset of a mixed phase and a pure quark phase on the hyperon couplings, quark model and properties of the hadronic model. We calculate the strangeness fraction with baryonic density for the different EOS. With the NJL model the strangeness content in the mixed phase decreases. The calculations were performed for T=0 and for finite temperatures in order to describe neutron and proto-neutron stars. The star properties are discussed. Both the Bag model and the NJL model predict a mixed phase in the interior of the star. Maximum allowed masses for proto-neutron stars are larger for the NJL model ($\sim 1.9$ M$_{\bigodot}$) than for the Bag model ($\sim 1.6$ M$_{\bigodot}$).Comment: RevTeX,14 figures, accepted to publication in Physical Review

Do red deer stags (Cervus elaphus) use roar fundamental frequency (F0) to assess rivals?

It is well established that in humans, male voices are disproportionately lower pitched than female voices, and recent studies suggest that this dimorphism in fundamental frequency (F0) results from both intrasexual (male competition) and intersexual (female mate choice) selection for lower pitched voices in men. However, comparative investigations indicate that sexual dimorphism in F0 is not universal in terrestrial mammals. In the highly polygynous and sexually dimorphic Scottish red deer Cervus elaphus scoticus, more successful males give sexually-selected calls (roars) with higher minimum F0s, suggesting that high, rather than low F0s advertise quality in this subspecies. While playback experiments demonstrated that oestrous females prefer higher pitched roars, the potential role of roar F0 in male competition remains untested. Here we examined the response of rutting red deer stags to playbacks of re-synthesized male roars with different median F0s. Our results show that stags’ responses (latencies and durations of attention, vocal and approach responses) were not affected by the F0 of the roar. This suggests that intrasexual selection is unlikely to strongly influence the evolution of roar F0 in Scottish red deer stags, and illustrates how the F0 of terrestrial mammal vocal sexual signals may be subject to different selection pressures across species. Further investigations on species characterized by different F0 profiles are needed to provide a comparative background for evolutionary interpretations of sex differences in mammalian vocalizations

Macroscopic transport by synthetic molecular machines

Nature uses molecular motors and machines in virtually every significant biological process, but demonstrating that simpler artificial structures operating through the same gross mechanisms can be interfaced with—and perform physical tasks in—the macroscopic world represents a significant hurdle for molecular nanotechnology. Here we describe a wholly synthetic molecular system that converts an external energy source (light) into biased brownian motion to transport a macroscopic cargo and do measurable work. The millimetre-scale directional transport of a liquid on a surface is achieved by using the biased brownian motion of stimuli-responsive rotaxanes (‘molecular shuttles’) to expose or conceal fluoroalkane residues and thereby modify surface tension. The collective operation of a monolayer of the molecular shuttles is sufficient to power the movement of a microlitre droplet of diiodomethane up a twelve-degree incline.