3,719 research outputs found

    Multiploidy occurrence in tomato calli from anther culture

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    Anther culture has long been used for the production of fully homozygous lines in order to produce, mainly, doubled haploid plants, which are of great interest in plant breeding. For tomato, a recalcitrant species for androgenesis production protocols have not been standardized. It is known that the genotype, anther size, the developmental stage of the microspore, and the medium composition are some factors that can influence the calli production. The present study aimed to adapt flow cytometry methodology to verify the microsporogenesis phases of anthers in order to assess the anther responsiveness of different tomato genotypes in an androgenesis-induction culture medium and to analyze the DNA ploidy level of calli produced by flow cytometry. Anthers from flower buds of length 1.0 to 5.9 mm, corresponding to the size range as analyzed by flow cytometry and cytogenetic methods, were inoculated into Murashige and Skoog (MS) basal medium containing the growth regulators 6-(y,ydimethylallylamino) purine and indole-3-acetic acid. The obtained calli were subsequently analyzed by flow cytometry to determine the DNA ploidy level. Surprisingly, despite no pretreatment with microtubule-depolymerizing agents, five classes of multiploid calli were observed, as follows: class I (2C-4C-8C-16C), class II (2C-4C-8C-16C-32C), class III (4C-8C), class IV (4C-8C-16C) and class V (8C-16C- 32C). Multiploid calli were identified in short-term (two month) culturing, suggesting that the variable culture duration did not directly influence the occurrence of endoreduplication. In this work, this type of somaclonal variation has been reported for the first time in tomato anther culture, and their possible origin has been discussed.Key words: Callogenesis, flow cytometry, polyploidy, Solanum lycopersicum, somaclonal variation

    Field Theory for a Deuteron Quantum Liquid

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    Based on general symmetry principles we study an effective Lagrangian for a neutral system of condensed spin-1 deuteron nuclei and electrons, at greater-than-atomic but less-than-nuclear densities. We expect such matter to be present in thin layers within certain low-mass brown dwarfs. It may also be produced in future shock-wave-compression experiments as an effective fuel for laser induced nuclear fusion. We find a background solution of the effective theory describing a net spin zero condensate of deuterons with their spins aligned and anti-aligned in a certain spontaneously emerged preferred direction. The spectrum of low energy collective excitations contains two spin waves with linear dispersions -- like in antiferromagnets -- as well as gapped longitudinal and transverse modes related to the Meissner effect -- like in superconductors. We show that counting of the Nambu-Goldstone modes of spontaneously broken internal and space-time symmetries obeys, in a nontrivial way, the rules of the Goldstone theorem for Lorentz non-invariant systems. We discuss thermodynamic properties of the condensate, and its potential manifestation in the low-mass brown dwarfs.Comment: 19 LaTeX pages; v2: 2 refs added, JHEP versio

    Geo-environmental mapping using physiographic analysis: constraints on the evaluation of land instability and groundwater pollution hazards in the Metropolitan District of Campinas, Brazil

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    Geo-environmental terrain assessments and territorial zoning are useful tools for the formulation and implementation of environmental management instruments (including policy-making, planning, and enforcement of statutory regulations). They usually involve a set of procedures and techniques for delimitation, characterisation and classification of terrain units. However, terrain assessments and zoning exercises are often costly and time-consuming, particularly when encompassing large areas, which in many cases prevent local agencies in developing countries from properly benefiting from such assessments. In the present paper, a low-cost technique based on the analysis of texture of satellite imagery was used for delimitation of terrain units. The delimited units were further analysed in two test areas situated in Southeast Brazil to provide estimates of land instability and the vulnerability of groundwater to pollution hazards. The implementation incorporated procedures for inferring the influences and potential implications of tectonic fractures and other discontinuities on ground behaviour and local groundwater flow. Terrain attributes such as degree of fracturing, bedrock lithology and weathered materials were explored as indicators of ground properties. The paper also discusses constraints on- and limitations of- the approaches taken

    Rede de cuidado em saúde mental: visão dos coordenadores da estratégia saúde da família

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    RESUMO Objetivo Objetivou-se analisar a visão de coordenadores da Estratégia Saúde da Família (ESF) sobre a conformação da rede de saúde mental no município de Pelotas/RS. Método Estudo descritivo e exploratório, com abordagem qualitativa, realizado com seis coordenadores de ESF no ano de 2012. Para a coleta dos dados, foi utilizada a entrevista semiestruturada, e os resultados foram avaliados por análise temática. Resultados A rede construída pelos coordenadores é composta por poucos serviços formais e focada no Centro de Atenção Psicossocial (CAPS), e a rede informal é descrita com maiores pontos de cuidado. As trocas de corresponsabilidade no cuidado em rede ocorrem de forma frágil, sem o diálogo necessário. Conclusão Os coordenadores demonstram pouco conhecimento da rede formal de cuidado e uma atenção focada nos serviços da ESF e no CAPS. Reconhecem a importância de haver políticas públicas que valorizem e ampliem os espaços informais de cuidado no território

    Evaluation of the impact of strain correction on the orientation of cardiac diffusion tensors with in vivo and ex vivo porcine hearts

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    Purpose To evaluate the importance of strain-correcting stimulated echo acquisition mode echo-planar imaging cardiac diffusion tensor imaging. Methods Healthy pigs (n = 11) were successfully scanned with a 3D cine displacement-encoded imaging with stimulated echoes and a monopolar-stimulated echo-planar imaging diffusion tensor imaging sequence at 3 T during diastasis, peak systole, and strain sweet spots in a midventricular short-axis slice. The same diffusion tensor imaging sequence was repeated ex vivo after arresting the hearts in either a relaxed (KCl-induced) or contracted (BaCl2-induced) state. The displacement-encoded imaging with stimulated echoes data were used to strain-correct the in vivo cardiac diffusion tensor imaging in diastole and systole. The orientation of the primary (helix angles) and secondary (E2A) diffusion eigenvectors was compared with and without strain correction and to the strain-free ex vivo data. Results Strain correction reduces systolic E2A significantly when compared without strain correction and ex vivo (median absolute E2A = 34.3° versus E2A = 57.1° (P = 0.01), E2A = 60.5° (P = 0.006), respectively). The systolic distribution of E2A without strain correction is closer to the contracted ex vivo distribution than with strain correction, root mean square deviation of 0.027 versus 0.038. Conclusions The current strain-correction model amplifies the contribution of microscopic strain to diffusion resulting in an overcorrection of E2A. Results show that a new model that considers cellular rearrangement is required

    Detection and Quantification of Leptospira interrogans in Hamster and Rat Kidney Samples: Immunofluorescent Imprints versus Real-time PCR

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    A major limitation in the clinical management and experimental research of leptospirosis is the poor performance of the available methods for the direct detection of leptospires. In this study, we compared real-time PCR (qPCR), targeting the lipL32 gene, with the immunofluorescent imprint method (IM) for the detection and quantification of leptospires in kidney samples from the rat and hamster experimental models of leptospirosis. Using a virulent strain of Leptospira interrogans serovar Copenhageni, a chronic infection was established in the rat model, which were euthanized 28 days post-infection, while the hamster model simulated an acute infection and the hamsters were euthanized eight days after inoculation. Leptospires in the kidney samples were detected using culture isolation, qPCR and the IM, and quantified using qPCR and the IM. In both the acute and chronic infection models, the correlation between quantification by qPCR and the IM was found to be positive and statistically significant (P<0.05). Therefore, this study demonstrates that the IM is a viable alternative for not only the detection but also the quantification of leptospires, particularly when the use of qPCR is not feasible

    Multicenter study of the natural history and therapeutic responses of patients with chikungunya, focusing on acute and chronic musculoskeletal manifestations - a study protocol from the clinical and applied research in Chikungunya (REPLICK network)

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    BACKGROUND: Chikungunya is associated with high morbidity and the natural history of symptomatic infection has been divided into three phases (acute, post-acute, and chronic) according to the duration of musculoskeletal symptoms. Although this classification has been designed to help guide therapeutic decisions, it does not encompass the complexity of the clinical expression of the disease and does not assist in the evaluation of the prognosis of severity nor chronic disease. Thus, the current challenge is to identify and diagnose musculoskeletal disorders and to provide the optimal treatment in order to prevent perpetuation or progression to a potentially destructive disease course. METHODS: The study is the first product of the Clinical and Applied Research Network in Chikungunya (REPLICK). This is a prospective, outpatient department-based, multicenter cohort study in Brazil. Four work packages were defined: i. Clinical research; ii) Translational Science - comprising immunology and virology streams; iii) Epidemiology and Economics; iv) Therapeutic Response and clinical trials design. Scheduled appointments on days 21 (D21) ± 7 after enrollment, D90 ± 15, D120 ± 30, D180 ± 30; D360 ± 30; D720 ± 60, and D1080 ± 60 days. On these visits a panel of blood tests are collected in addition to the clinical report forms to obtain data on socio-demographic, medical history, physical examination and questionnaires devoted to the evaluation of musculoskeletal manifestations and overall health are performed. Participants are asked to consent for their specimens to be maintained in a biobank. Aliquots of blood, serum, saliva, PAXgene, and when clinically indicated to be examined, synovial fluid, are stored at -80° C. The study protocol was submitted and approved to the National IRB and local IRB at each study site. DISCUSSION: Standardized and harmonized patient cohorts are needed to provide better estimates of chronic arthralgia development, the clinical spectra of acute and chronic disease and investigation of associated risk factors. This study is the largest evaluation of the long-term sequelae of individuals infected with CHIKV in the Brazilian population focusing on musculoskeletal manifestations, mental health, quality of life, and chronic pain. This information will both define disease burden and costs associated with CHIKV infection, and better inform therapeutic guidelines

    Identifying metabolites by integrating metabolome databases with mass spectrometry cheminformatics.

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    Novel metabolites distinct from canonical pathways can be identified through the integration of three cheminformatics tools: BinVestigate, which queries the BinBase gas chromatography-mass spectrometry (GC-MS) metabolome database to match unknowns with biological metadata across over 110,000 samples; MS-DIAL 2.0, a software tool for chromatographic deconvolution of high-resolution GC-MS or liquid chromatography-mass spectrometry (LC-MS); and MS-FINDER 2.0, a structure-elucidation program that uses a combination of 14 metabolome databases in addition to an enzyme promiscuity library. We showcase our workflow by annotating N-methyl-uridine monophosphate (UMP), lysomonogalactosyl-monopalmitin, N-methylalanine, and two propofol derivatives
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