413 research outputs found

    Hadronic Atoms and Effective Interactions

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    We examine the problem of hadronic atom energy shifts using the technique of effective interactions and demonstrate equivalence with the conventional quantum mechanical approach.Comment: 22 page latex file with 2 figure

    Preclinical PET and MR Evaluation of 89Zr- and 68Ga-Labeled Nanodiamonds in Mice over Different Time Scales

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    Nanodiamonds (NDs) have high potential as a drug carrier and in combination with nitrogen vacancies (NV centers) for highly sensitive MR-imaging after hyperpolarization. However, little remains known about their physiological properties in vivo. PET imaging allows further evaluation due to its quantitative properties and high sensitivity. Thus, we aimed to create a preclinical platform for PET and MR evaluation of surface-modified NDs by radiolabeling with both short- and long-lived radiotracers. Serum albumin coated NDs, functionalized with PEG groups and the chelator deferoxamine, were labeled either with zirconium-89 or gallium-68. Their biodistribution was assessed in two different mouse strains. PET scans were performed at various time points up to 7 d after i.v. injection. Anatomical correlation was provided by additional MRI in a subset of animals. PET results were validated by ex vivo quantification of the excised organs using a gamma counter. Radiolabeled NDs accumulated rapidly in the liver and spleen with a slight increase over time, while rapid washout from the blood pool was observed. Significant differences between the investigated radionuclides were only observed for the spleen (1 h). In summary, we successfully created a preclinical PET and MR imaging platform for the evaluation of the biodistribution of NDs over different time scales

    Fusion of Color Doppler and Magnetic Resonance Images of the Heart

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    This study was designed to establish and analyze color Doppler and magnetic resonance fusion images of the heart, an approach for simultaneous testing of cardiac pathological alterations, performance, and hemodynamics. Ten volunteers were tested in this study. The echocardiographic images were produced by Philips IE33 system and the magnetic resonance images were generated from Philips 3.0-T system. The fusion application was implemented on MATLAB platform utilizing image processing technology. The fusion image was generated from the following steps: (1) color Doppler blood flow segmentation, (2) image registration of color Doppler and magnetic resonance imaging, and (3) image fusion of different image types. The fusion images of color Doppler blood flow and magnetic resonance images were implemented by MATLAB programming in our laboratory. Images and videos were displayed and saved as AVI and JPG. The present study shows that the method we have developed can be used to fuse color flow Doppler and magnetic resonance images of the heart. We believe that the method has the potential to: fill in information missing from the ultrasound or MRI alone, show structures outside the field of view of the ultrasound through MR imaging, and obtain complementary information through the fusion of the two imaging methods (structure from MRI and function from ultrasound)

    Finite-size effect on two-particle production in continuous and discrete spectrum

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    The formalism allowing one to account for the effect of a finite space-time extent of particle production region is given. Its applications to the lifetime measurement of hadronic atoms produced by a high-energy beam in a thin target, as well as to the femtoscopy techniques widely used to measure space-time characteristics of the production processes, are discussed. Particularly, it is found that the neglect of the finite-size effect on the pionium lifetime measurement in the experiment DIRAC at CERN could lead to the lifetime overestimation comparable with the 10% statistical error. The theoretical systematic errors arising in the calculation of the finite-size effect due to the neglect of non-equal emission times in the pair center-of-mass system, the space-time coherence and the residual charge are shown to be negligible.Comment: LaTeX, 77 pages including 5 tables and 18 figures. Somewhat extended version to be published in Phys. El. Part. At. Nuc

    Descrição dos dados da pesquisa geoespacial: a experiência da Embrapa.

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    Sob as premissas do acesso aberto, o atual contexto de produção da ciência vem expressando valor ao compartilhamento e abertura dos dados de pesquisa. No Brasil, o Decreto Lei n. 6.666/08, que instituiu a Infraestrutura Nacional de Dados Espaciais (Inde), estabelece-se como um exemplo bem sucedido de iniciativa para a abertura de dados espaciais, tendo influenciado a Embrapa a promover a abertura de seus dados espaciais gerados no âmbito de suas pesquisas. Para a disponibilização do dado de pesquisa, é preciso considerar as questões associadas à representação do dado, ou precisamente, a descrição dos metadados como elemento crucial para que o dado possa disponibilizado. Diante disso, o objetivo deste trabalho é apresentar a experiência da Embrapa em estruturar o processo da organização e representação dos dados espaciais, contextualizando-os sob as considerações da Ciência da Informação e Geociências.Suplemento. Trabalhos apresentados na 8a Conferência Luso Brasileira sobre Acesso Aberto - ConfOA. Na publicação: Davi Oliveira Custódio, Bibiana Teixeira Almeida, Margareth Simões, Gustavo Bayma-Silva

    Corporate Social Responsibility/Sustainability Reporting Among the Fortune Global 250: Greenwashing or Green Supply Chain?

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    The sustainability reporting efforts of MNCs who are members of the Fortune Global 250 (FG250) was investigated. The focus was on sustainability reporting by MNCs of supply chain impacts. The reporting of FG250 MNCs was examined to determine if greenwashing was occurring or whether MNCs had committed to operating a green supply chain. A mixed methodology was used consisting of quantitative analysis of twenty-five MNC CSR/sustainability reports which were randomly selected from the FG250 listing. Qualitative analysis using content analysis was also conducted on the reports. Both methodologies concentrated on the sustainability reporting of the selected MNCs in regard to their supply chain. Findings were mixed as there were great variations among the MNCs in their level of sustainability reporting about their supply chains. Some MNCs did not report on the activities of their supply chain at all (20%), the majority of the MNCs reported on their supply chain impacts at the value and goal level (48%), while the rest reported at the management approach level (32%). A majority of the sampled MNCs could be accused of greenwashing due to the lack of detailed quantitative information provided by the MNCs on the environmental impacts of their supply chai

    Contrast-enhanced whole-heart coronary MRA at 3.0T for the evaluation of cardiac venous anatomy

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    This study was designed to evaluate the value of contrast-enhanced whole-heart coronary MRA (CMRA) at 3.0T in depicting the cardiac venous anatomy. In cardiac resynchronization therapy (CRT), left ventricular (LV) pacing is achieved by positioning the LV lead in one of the tributaries of the coronary sinus (CS). Pre-implantation knowledge of the venous anatomy may help determine whether transvenous LV lead placement for CRT is feasible. Images of 51 subjects undergoing contrast-enhanced whole-heart CMRA at 3.0T were retrospectively analyzed. Data acquisition was performed using electrocardiography-triggered, navigator-gated, inversion-recovery prepared, segmented gradient-echo sequence. A 32-element cardiac coil was used for data acquisition. The visibility of the cardiac veins was graded visually using a 4-point scale (1: poor–4: excellent). The paired Student t test was used to evaluate differences in diameters of the ostium of the CS in anteroposterior and superoinferior direction. The cardiac veins were finally evaluated in 48 subjects with three anatomic variations. The diameter of the CS ostium in the superoinferior direction (1.13 ± 0.26 cm) was larger than in the anteroposterior direction (0.82 ± 0.19 cm) (P < 0.05). The mean visibility score of CS, posterior interventricular vein, posterior vein of the left ventricle, left marginal vein, and anterior interventricular vein was 4.0 ± 0.0, 3.4 ± 0.5, 3.4 ± 0.5, 3.0 ± 0.8, and 3.3 ± 0.5, respectively. In conclusion, contrast-enhanced whole-heart CMRA at 3.0T can depict the normal and variant cardiac venous anatomy

    Halloween, Organization, and the Ethics of Uncanny Celebration

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    This article examines the relationship between organizational ethics, the uncanny, and the annual celebration of Halloween. We begin by exploring the traditional and contemporary organizational function of Halloween as ‘tension-management ritual’ (Etzioni, Sociol Theory 18(1):44–59, 2000) through which collective fears, anxieties, and fantasies are played out and given material expression. Combining the uncanny with the folkloric concept of ostension, we then examine an incident in which UK supermarket retailers made national news headlines for selling offensive Halloween costumes depicting ‘escaped mental patients’. Rather than treating this incident as a problem of moral hygiene—in which products are removed, apologies made, and lessons learned—we consider the value of Halloween as a unique and disruptive ethical encounter with the uncanny Other. Looking beyond its commercial appeal and controversy, we reflect on the creative, generous, and disruptive potential of Halloween as both tension-management ritual and unique organizational space of hospitality through which to receive and embrace alterity and so discover the homely within the unheimlich
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