A Novel Role of Cdk9/CyclinT2 complexes in skeletal muscle and Rhabdomyosarcoma cells

Cyclin dependent kinase 9 (Cdk9) is a member of the cyclin dependent kinase family. The regulatory units of Cdk9 are the T family Cyclins (T1, T2) and Cyclin K1. Cyclin T2 has two forms termed CycT2a and CycT2b that arise by an alternative splicing of the primary transcript. Previous studies underscored a crucial role for Cdk9 in association of Cyclin T2 during skeletal myogenesis. Upon induction of muscle differentiation, MyoD recruits Cdk9/CycT2 on musclespecific gene promoter sequences. This complex is able to phosphorylate the C-terminal domain of RNA polymerase II, enhancing Myod function and promoting myogenic differentiation. Rhabdomyosarcoma (RMS), one of the most common childhood solid tumor, arises from muscle precursor cells and fails to complete both the differentiation program both the irreversibly cell cycle exit, resulting in uncontrolled proliferation and incomplete myogenesis. In RMS, Cdk9 fails to phosphorylate MyoD and the ability of MyoD to arrest cell proliferation and to activate the myogenic program is repressed. The result of this study confirmed the involvement of Cdk9/ CyclinT2 complexes during the myogenesis. Both isoforms of Cyclin T2 are able to activate the myogenic program at different stages of differentiation but CycT2b have a predominant role of in particular during the latest stages. Moreover we demonstred that EZH2 is probably responsible to inhibition of Cdk9 in RMS cells and her overexpression contribuite to inhibition of myogenesis

Adoption of an IMF Programme and Debt Rescheduling. An Empirical Analysis

The existence of an empirical relationship between the adoption of an IMF programme and the concession of a debt rescheduling by commercial creditors is tested using a bivariate probit model. If countries who have arrangements with the IMF are more likely than others to obtain a rescheduling of their external debt we could conclude that the adoption of an IMF programme could work as a sort of signal of a country’s “good willingness”, which is thus rewarded with the debt relief. The results confirm the existence of a significant effect of the adoption of an IMF programme on the subsequent concession of a debt rescheduling by creditors.IMF Conditionality, Debt Rescheduling, Bivariate probit

Adoption of an IMF Programme and Debt Rescheduling. An Empirical Analysis

The existence of an empirical relationship between the adoption of an IMF programme and the concession of a debt rescheduling by commercial and official creditors is tested using a bivariate probit model. If countries who have arrangements with the IMF are more likely than others to obtain a rescheduling of their external debt we could conclude that the adoption of an IMF programme could work as a sort of signal of a country’s “good willingness”, which is thus rewarded with the debt relief. The results confirm the existence of a significant effect of the adoption of an IMF programme on the subsequent concession of a debt rescheduling by creditors.IMF Conditionality ; Debt Rescheduling ; Bivariate probit

The historical dimension as a guide-tool identification and reading wine landscape character of Mendoza, Argentina

The wine landscape of the province of Mendoza is characterized by an integrating heterogeneity and active, own agricultural production activity dynamism. This is considered as a cultural heritage and a provincial collective redress. This has elements that clarify its nature, understood as the formal manifestation of identity, but others contribute to the trivialization of it. In this context, the research carried out, raised the reflection on how the historical dimension to identify and take a reading of the character of the landscape wine. The historical dimension allows detecting the elements of the character of the landscape and those which are trivializing in a dynamic landscape framework and heterogeneity. In response, resulting from the framework of cultural conservation, it was proposed that the historical dimension of landscape can be used as a guide - tool for analysis.Fil: Manzini Marchesi, Lorena Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin

p-Buchsbaum rank 2 bundles on the projective space

It has been proved by various authors that a normalized, 1-Buchsbaum rank 2 vector bundle on P3 is a nullcorrelation bundle, while a normalized, 2-Buchsbaum rank 2 vector bundle on P3 is an instanton bundle of charge 2. We find that the same is not true for 3-Buchsbaum rank 2 vector bundles on P3, and propose a conjecture regarding the classification of such objects.Comment: Corrected previous result

Role of enhancer of zeste homolog 2 polycomb protein and its significance in tumor progression and cell differentiation

Epigenetics is a branch of genetics that focuses on the heritable changes of DNA or associated proteins, other than DNA sequence variations, which carry information content during cell division [1,2]. These heritable changes are ascribed to chromatin, which constitutes the ultrastructure of DNA and whose modifications affect the genetic material functionality. Differences in chromatin structure have been associated to transcription regulation [3-5] and chromosome stability [6,7], affecting both gene’s information, expression and heritability. Noteworthy, these epigenetic modifications are involved in both transcriptional activation and repression, indicating their widespread role as modulators of gene expression in numerous biological processes [8,9]. Chromatin is subjected to numerous modifications roughly classified in two groups: DNA and histone post-translational modifications (histone-PTMs). DNA methylation is the most studied epigenetic modification of DNA and corresponds to the covalent addition of a methyl (CH3) group to the nucleotide cytosine within CG dinucleotides or CNG trinucleotides where N can be C, A, G or T. Usually, DNA methylation induces decreased protein-DNA binding of transcription factors and leads to the repression of gene expression [10]. DNA “methylable” sequences are not uniform across the human genome but restricted in CpG rich DNA regions termed CpG islands (CGI). CGI are localized at repetitive sequences, heavy methylated, to prevent the reactivation of endoparasitic sequences such as transposons, and at gene promoter sequences, which are normally refractory to methylation in normal somatic cells [8,11].</br

Is two better than one? Effects on growth of Bank-Fund interaction

We estimate the impact on economic growth of the joint participation in both IMF and WB programs. More specifically, using panel data for 128 developing countries over the period 1982-2005, and employing 2SLS to control for the possible endogeneity of participation in an IMF/WB program, we find that even if the WB and the IMF do not boost growth when they operate by themselves, the interaction term between these two organization is positive and significant at conventional levels. However, when we restrict the sample to low and lower middle income countries only (for which Bank-Fund cooperation is more “formalized”) the coefficient of the interaction term is not significant. Thus, so far, a trade-off emerges between a greater precision in the definition of Bank-Fund cooperation and the reliability of the estimates due to an insufficient number of observations.