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Nitrogen (N) metabolism during embryogenesis may be fundamental in the embryogenic response. We used different explants of Medicago arborea L. subsp. arborea seedlings: cotyledons, petioles and leaves, which form calluses with different embryogenic responses. The endogenous contents of total nitrogen, nitrate, nitrite and ammonia and nitrate reductase activity were determined in embryogenic and non-embryogenic calluses induced from the different explants. The endogenous total N content decreased in the calluses as the culture time progressed, this decrease being more pronounced in the more embryogenic calluses obtained from petioles with the H8 and F0 media. Inorganic N decreased during embryogenesis, coinciding with an increase in organic N. Thus, N metabolism somehow seems to be essential in embryogenesis. The N detected in calluses, at the start of culture, was mainly metabolised to nitrite. This metabolism was very pronounced; especially in embryogenic calluses obtained from cotyledons and petioles. That is, the metabolism of N seemed to be more marked in the calluses in which embryogenesis was greater. The nitrite content decreased in all the calluses, the contents being lower, especially in the last months of culture, in the more embryogenic calluses obtained from petioles. In many calluses, ammonia levels did not follow any general pattern. Neither was it possible to detect changes in ammonia levels between the embryogenic and non-embryogenic calluses. Regarding nitrate reductase activity, no clear differences between embryogenic and non-embryogenic calluses were found. [ABSTRACT FROM AUTHOR]

The regulator of angiogenesis most extensively studied is VEGF. VEGF mRNA in plasma from patients with colorectal cancer was analyzed as a possible surrogate marker of tumor angiogenesis. VEGF mRNA was measured by quantitative PCR in plasma, tumors and circulating tumor cells from colorectal cancer patients. Circulating VEGF protein was analyzed by ELISA. Microvessel density was determined. Levels of VEGF mRNA and protein in plasma were higher in patients than in controls. VEGF mRNA was overexpressed in tumors with respect to normal tissues. Levels of VEGF protein were associated with VEGF mRNA in plasma, but no associations with tumor samples were found. A trend to statistical significance was shown between high VEGF mRNA and vascular invasion. MVD was not related to VEGF mRNA in plasma. Thus, VEGF mRNA could be a marker similar to VEGF protein in plasma. [ABSTRACT FROM AUTHOR]

This paper presents a parallel algorithm to solve a structured linear system with a symmetric-Toeplitz matrix. Our main result concerns the use of a combination of shared and distributed memory programming tools to obtain a multilevel algorithm that exploits the actual different hierarchical levels of memory and computational units present in parallel architectures. This gives, as a result, a so-called parallel hybrid algorithm that is able to exploit each of these different configurations. Our approach has been done not only by means of combining standard implementation tools like OpenMP and MPI, but performing the appropriate mathematical derivation that allows this derivation. The experimental results over different representations of available parallel hardware configurations show the usefulness of our proposal. [ABSTRACT FROM AUTHOR]

Scientific investigation of flamenco is quite young but it has already demonstrated the vainness of a neoromantic approach to this kind of this primary ethnic music style. The present article treats it as an element of other, comparable European popular musical cultures within the dynamics of contemporary reanimation and hybridization of passionate music. It demonstrates the historical, cultural, and ideological influences in flamenco music as well as its contribution to different kinds of nationalism in music from the nineteenth century until today. It discusses the cultural and artistic value of flamenco within the process of Spain's national unification and the origin of a peculiar collective identity able to combine the feelings of traditional and modern life. As a result of this ambiguity, flamenco tends either toward fossilizing classicism or eclectic hybridization as a part of world music. It should be demonstrated that dialectics between music and society can be explained from the point of view of a critical social constructionism as a process of mutual influence of ideological and mentality factors. Due to this hypothesis and in view of the socializing function of popular music styles it is intended to revalue the rarely used concept of mentality in sociological analysis in order to explain the tenacity of certain traditional and ideological concepts in the collective consciousness of post-modern society.. [ABSTRACT FROM AUTHOR]

Primary brain lymphoma is a rare variant of extranodal non-Hodgkin's B-cell lymphoma. In >90% of cases, this is diffuse large B-cell lymphoma with CD20 expression and is confined to the brain, meninges, spinal cord, and eyes. It accounts for fewer than 7% of primary brain tumors. Its incidence has been rising in recent years in immunocompetent patients in their fifth and sixth decades. The rate of relapse after initial therapy based on high-dose methotrexate and/or total brain irradiation is high. There is no consensus for treating relapse, which ranges from retreatment with high doses of methotrexate, polychemotherapy, high doses of chemotherapy backed up by autologous stem-cell transplant to intrathecal chemotherapy, with widely differing results. Given the lack of consensus and poor results, new therapy options have appeared, including immunotherapy with rituximab. At a systemic level, alongside chemotherapy, its results are very modest and limited due to the low concentration it reaches in cerebrospinal fluid (CSF). However, its intrathecal and intraventricular use, though only isolated cases have been reported, has provided promising results. [ABSTRACT FROM AUTHOR]

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