142 research outputs found

    Inclusive Breakup Theory of Three-Body Halos

    Full text link
    We present a recently developed theory for the inclusive breakup of three-fragment projectiles within a four-body spectator model \cite{CarPLB2017}, for the treatment of the elastic and inclusive non-elastic break up reactions involving weakly bound three-cluster nuclei in A(a,b)XA\,(a,b)\,X / a=x1+x2+ba = x_1 + x_2 + b collisions. The four-body theory is an extension of the three-body approaches developed in the 80's by Ichimura, Autern and Vincent (IAV) \cite{IAV1985}, Udagawa and Tamura (UT) \cite{UT1981} and Hussein and McVoy (HM) \cite{HM1985}. We expect that experimentalists shall be encouraged to search for more information about the x1+x2x_{1} + x_{2} system in the elastic breakup cross section and that also further developments and extensions of the surrogate method will be pursued, based on the inclusive non-elastic breakup part of the bb spectrum.Comment: 8 pages, 3 figures, Contribution to the Proceedings of Fusion17: "International Conference on Heavy-Ion Collisions at Near-Barrier Energies", 20-24 February 2017 Hobart, Tasmania, Australi

    Transition Temperature for Weakly Interacting Homogeneous Bose Gases

    Get PDF
    We apply the nonperturbative optimized linear δ expansion method to the O(N) scalar field model in three dimensions to determine the transition temperature of a dilute homogeneous Bose gas. Our results show that the shift of the transition temperature ΔTc/Tc of the interacting model, compared with the ideal-gas transition temperature, really behaves as γan1/3 where a is the s-wave scattering length and n is the number density. For N=2 our calculations yield the value γ=3.059

    Beneficial Effects of Long-Term Administration of an Oral Formulation of Angiotensin-(1–7) in Infarcted Rats

    Get PDF
    In this study was evaluated the chronic cardiac effects of a formulation developed by including angiotensin(Ang)-(1–7) in hydroxypropyl β-cyclodextrin (HPβCD), in infarcted rats. Myocardial infarction (MI) was induced by left coronary artery occlusion. HPβCD/Ang-(1–7) was administered for 60 days (76 μg/Kg/once a day/gavage) starting immediately before infarction. Echocardiography was utilized to evaluate usual cardiac parameters, and radial strain method was used to analyze the velocity and displacement of myocardial fibers at initial time and 15, 30, and 50 days after surgery. Real-time PCR was utilized to evaluate the fibrotic signaling involved in the remodeling process. Once-a-day oral HPβCD/Ang-(1–7) administration improved the cardiac function and reduced the deleterious effects induced by MI on TGF-β and collagen type I expression, as well as on the velocity and displacement of myocardial fibers. These findings confirm cardioprotective effects of Ang-(1–7) and indicate HPβCD/Ang-(1–7) as a feasible formulation for long-term oral administration of this heptapeptide

    Oral Angiotensin-(1–7) prevented obesity and hepatic inflammation by inhibition of resistin/TLR4/MAPK/NF-κB in rats fed with high-fat diet

    Get PDF
    AbstractObesity is characterized by a pro-inflammatory state commonly associated with type 2 diabetes and fat-liver disease. In the last few years, different studies pointed out the role of Angiotensin (Ang)-(1–7) in the metabolic regulation. The aim of the present study was to evaluate the effect of oral-administration of Ang-(1–7) in metabolism and inflammatory state of high-fat feed rats. Twenty-four male Sprague Dawley rats were randomized into three groups: High Fat Diet (HFD); Standard Diet (ST); High Fat Diet+Angiotensin-(1–7) [HFD+Ang-(1–7)]. Glycemic profile was evaluated by glucose tolerance and insulin sensitivity tests, plasmatic glucose and insulin. Cholesterol, HDL and triglycerides analyses presented lipidic profile. RT-PCR evaluated mRNA expression to ACE, ACE2, resistin, TLR4, IL-6, TNF-α and NF-κB genes. The main results showed that oral Ang-(1–7) decreased body weight and abdominal fat-mass. In addition, HFD+Ang-(1–7) treated rats presented enhanced glucose tolerance, insulin-sensitivity and decreased plasma-insulin levels, as well as a significant decrease in circulating lipid levels. These alterations were accompanied by a marked decreased expression of resistin, TLR4, ACE and increased ACE2 expression in liver. Furthermore, Ang-(1–7) decreases phosphorylation of MAPK and increases NF-κB expression. These alterations diminished expression of interleukin-6 and TNF-α, ameliorate inflammatory state in liver. In summary, the present study showed that oral-treatment with Ang-(1–7) in high-fat feed rats improved metabolism down-regulating resistin/TLR4/NF-κB-pathway

    Inoculation with the endophytic bacterium Herbaspirillum seropedicae promotes growth, nutrient uptake and photosynthetic efficiency in rice

    Get PDF
    Main conclusion: Higher vacuolar proton pump activity may increase plant energy and nutrient use efficiency and provide the nexus between plant inoculation with Herbaspirillum seropedicae and growth promotion. Abstract: Global change and growing human population are exhausting arable land and resources, including water and fertilizers. We present inoculation with the endophytic plant-growth promoting bacterium (PGPB) Herbaspirillum seropedicae as a strategy for promoting growth, nutrient uptake and photosynthetic efficiency in rice (Oryza sativa L.). Because plant nutrient acquisition is coordinated with photosynthesis and the plant carbon status, we hypothesize that inoculation with H. seropedicae will stimulate proton (H+) pumps, increasing plant growth nutrient uptake and photosynthetic efficiency at low nutrient levels. Plants were inoculated and grown in pots with sterile soil for 90 days. Herbaspirillum seropedicae endophytic colonization was successful and, as hypothesized, inoculation (1) stimulated root vacuolar H+ pumps (vacuolar H+-ATPase and vacuolar H+-PPase), and (2) increased plant growth, nutrient contents and photosynthetic efficiency. The results showed that inoculation with the endophytic bacterium H. seropedicae can promote plant growth, nutrient uptake and photosynthetic efficiency, which will likely result in a more efficient use of resources (nutrients and water) and higher production of nutrient-rich food at reduced economic and environmental costs.info:eu-repo/semantics/publishedVersio

    Higher Order Evaluation of the Critical Temperature for Interacting Homogeneous Dilute Bose Gases

    Get PDF
    We use the nonperturbative linear \delta expansion method to evaluate analytically the coefficients c_1 and c_2^{\prime \prime} which appear in the expansion for the transition temperature for a dilute, homogeneous, three dimensional Bose gas given by T_c= T_0 \{1 + c_1 a n^{1/3} + [ c_2^{\prime} \ln(a n^{1/3}) +c_2^{\prime \prime} ] a^2 n^{2/3} + {\cal O} (a^3 n)\}, where T_0 is the result for an ideal gas, a is the s-wave scattering length and n is the number density. In a previous work the same method has been used to evaluate c_1 to order-\delta^2 with the result c_1= 3.06. Here, we push the calculation to the next two orders obtaining c_1=2.45 at order-\delta^3 and c_1=1.48 at order-\delta^4. Analysing the topology of the graphs involved we discuss how our results relate to other nonperturbative analytical methods such as the self-consistent resummation and the 1/N approximations. At the same orders we obtain c_2^{\prime\prime}=101.4, c_2^{\prime \prime}=98.2 and c_2^{\prime \prime}=82.9. Our analytical results seem to support the recent Monte Carlo estimates c_1=1.32 \pm 0.02 and c_2^{\prime \prime}= 75.7 \pm 0.4.Comment: 29 pages, 3 eps figures. Minor changes, one reference added. Version in press Physical Review A (2002

    Hidrostática: Teoria x Prática Experimental, História em quadrinhos: manual utilizável de Hidrostática para o ensino/aprendizagem em Física

    Get PDF
    As atividades experimentais quando inseridas na grade curricular da escola, sejam elas feitas na sala de aula ou no laboratório são estratégias que podem contribuir para o aprendizado do ensino de Física. Muitos autores têm pesquisado e discutido as atividades experimentais no ensino no Brasil. O produto educacional que pretende-se desenvolver com este projeto caracteriza-se como um conjunto de processos, a saber: avaliação inicial do conteúdo de Hidrostática com aplicação de um questionário objetivo do tema, averiguando os conhecimentos prévios dos alunos sobre o assunto; apresentação dos conceitos de Hidrostática ilustradas em histórias em quadrinhos; desenvolvimento dos experimentos, estes relacionados ao cotidiano e finalizando com uma feira expositiva dos experimentos. No planejamento dessas atividades experimentais busca-se contemplar experimentos simples que sejam ao mesmo tempo cativantes, que estejam relacionados ao cotidiano dos alunos e desenvolvidos com materiais de baixo custo. As atividades experimentais aplicadas permitem ao aluno fazer conexões entre o experimento e seus conhecimentos prévios estudados na abordagem conceitual para que de fato ocorra aprendizagem significativa, confirmando a fundamentação teórica desse trabalho. Os Parâmetros Curriculares Nacionais do Ensino Médio (PCN’s) afirmam que: “É indispensável que a experimentação esteja sempre presente ao longo de todo o processo de desenvolvimento das competências em Física, privilegiando-se o fazer, manusear, operar, agir, em diferentes formas e níveis”. Para Moreira (2009), a teoria do pesquisador Vygotsky propõe que o desenvolvimento cognitivo se dá por meio da interação social, em que, no mínimo, duas pessoas estão envolvidas ativamente trocando experiência e ideias, gerando novas experiências e conhecimento. A proposta desse trabalho é justamente envolver os alunos nos experimentos sob a perspectiva vygotskiana
    corecore