30,424 research outputs found
Silver in Peru: Present status and future challenge
Silver production in Peru was 118 Moz in 2013, which was 3rd ranked in the world. Silver production mines which were ranked from 1st to 5th in Peru in 2013 were Antamina(16.7 Moz), Uchuchacua(12 Moz), Pallancata(7.6 Moz), AnimĂłn(7 Moz), and Arcata(5.4 Moz). Total reported silver resources in Peru is about 7,012 Moz, and resources from the belts of Miocene epithermal deposits and the belts of Miocene skarn, replacement and vein deposits are 4,812 Moz, which corresponds to 69% of total resources. There are 14 ongoing projects which will be developed to the production stage from 2014 to 2019. Through these projects, silver production in Peru is expected to be 148 Moz in 2017
Expression of the MOZ-TIF2 oncoprotein in mice represses senescence
The MOZ-TIF2 translocation, which fuses monocytic leukemia zinc finger protein (MOZ) histone acetyltransferase (HAT) with the nuclear co-activator TIF2, is associated with the development of acute myeloid leukemia. We recently found that in the absence of MOZ HAT activity, p16INK4a transcriptional levels are significantly increased, triggering an early entrance into replicative senescence. Because oncogenic fusion proteins must bypass cellular safeguard mechanisms, such as senescence and apoptosis, to induce leukemia, we hypothesized that this repressive activity of MOZ over p16INK4a transcription could be preserved, or even reinforced, in MOZ leukemogenic fusion proteins, such as MOZ-TIF2. We describe here that, indeed, MOZ-TIF2 silences expression of the CDKN2A locus (p16INK4a and p19ARF), inhibits the triggering of senescence and enhances proliferation, providing conditions favorable to the development of leukemia. Furthermore, we describe that abolishing the MOZ HAT activity of the fusion protein leads to a significant increase in expression of the CDKN2A locus and the number of hematopoietic progenitors undergoing senescence. Finally, we report that inhibition of senescence by MOZ-TIF2 is associated with increased apoptosis, suggesting a role for the fusion protein in p53 apoptosis-versus-senescence balance. Our results underscore the importance of the HAT activity of MOZ, preserved in the fusion protein, for repression of the CDKN2A locus transcription and the subsequent block of senescence, a necessary step for the survival of leukemic cells.Work in our laboratory is supported by the Leukemia and Lymphoma
Research Foundation (LLR), Cancer Research UK
(CRUK), and the Biotechnology and Biological Sciences
Research Council (BBSRC)
Gold in Peru: Present status and future challenge
Total reported gold resources in Peru is about 192 Moz. Gold production in Peru was 4.9 Moz in 2013, which was ranked first in Latin America and sixth in the world. Historic cumulative gold production in Peru is 118 Moz, and production from main gold belts including Miocene epithermal belt, Carboniferous-Permian orogenic gold belt and Upper Cretaceous intrusion-related gold belt corresponds to 84%. Most of production areas are located in Northern part of Peru, which corresponds to 63.5% of the total domestic production. Annual production onces in Yanacocha mine and Alto Chicama were 1 Moz and 0.606 Moz in 2013, which were ranked first and second in Peru, respectively. Gold production in Peru is expected to be 6.5 Moz in 2017. To accomplish the expected production, ongoing 14 projects should be developed to the production stage in three years
Inclusiones fluĂdas e isĂłtopos de Pb y Sr en Chipmo y Poracota, regiĂłn minera de Orcopampa, PerĂș. Implicaciones para la exploraciĂłn
Chipmo y Poracota forman parte de los depĂłsitos epitermales miocĂ©nicos de oro y plata de los Andes centrales en el sur del PerĂș, entre los 3900 y 4900 metros sobre nivel del mar. Figura 1. PolĂticamente pertenecen a las provincias de Castilla y Condesuyos en la regiĂłn de Arequipa y actualmente representan la mayor producciĂłn subterranea de oro del PerĂș. La producciĂłn total, a finales del 2009 fue de 2.1 Moz Au â 2.0 Moz Chipmo y 0.1 Moz Poracotaâ, cuentan con reservas del orden de 0.7 Moz Au y recursos estimados superan los 1.0 Moz Au. Chipmo es el deposito mas importante de la regiĂłn de Orcopampa, en los Ășltimos 15 años importantes publicaciones se han venido desarrollando: Swanson, 1998; Noble, 1999; Caddey and Sabastizagal, 1999; Mayta, 1999, Salazar et al., 2009 y Salazar 2008 y en Poracota cabe destacar a Bradford, 1999; Miranda Vidal, 2006 y Sarmiento, 2008
Exchange Market Pressure in African Lusophone Countries
This paper explores the credibility of exchange rate arrangements for the five African Portuguese-speaking (PALOP) countries. Our working hypothesis is that credibility necessarily implies low mean exchange market pressure (EMP), low EMP conditional volatility and low-severity EMP crises. In addition, economic fundamentals must account for EMP dynamics. We also seek evidence of a risk-return relationship for mean EMP and of âbad newsâ (negative shocks) having a greater impact on EMP volatility than âgood newsâ (positive shocks). Using our econometric models, we are able to rank PALOP countriesâ conditional volatility in ordinal terms. Our main conclusion is that countries with currency pegs, such as Guinea-Bissau (GB) and Cape Verde (CV), clearly have lower volatility when compared to those with managed floats and are therefore more credible. Moreover, EMP crises episodes under pegs are much less severe. We find that economic fundamentals correctly account for mean EMP in all countries and that the risk-return relationship is much more favourable for investors under currency pegs, as the increase in volatility is lower for the same rate of return. The exception to this finding is Mozambique (MOZ), which apparently has a risk-return profile akin to that enjoyed by countries with pegs. A plausible reason is that MOZ has the only managed float in our sample implementing monetary and exchange rate policy within the confines of an IMF framework, which establishes floors for international reserves and ceilings for the central bankâs net domestic assets. This intuition needs to be tested, however. EMP conditional volatility is generally driven by changes in domestic credit (lowers it) and foreign reserve changes (raises it). The first effect is more pronounced under currency pegs, but also under MOZâs managed float. âBad newsâ increases volatility more that âgood newsâ only in the case of CVâs currency peg, which we take to be another sign of its credibility. A few striking cross-country comparisons also emerge in our analysis. Among countries with managed floats, we find that Angola (ANG) has the most severe EMP crises whilst MOZ has the least severe. SĂŁo TomĂ© & PrincĂpe (STP), meanwhile, lies between these two extremes but its EMP crises behaviour is clearly much closer to that of MOZ. STPâs credibility may also be improving since its volatility has declined as of 2002 and its level is now much closer to that of MOZ, whose managed float has lowest volatility of such arrangements.
A Long-term Survivor after Congenital Acute Myeloid Leukemia with t(8 ; 16)(p11 ; p13)
The treatment of patients with congenital leukemia is difficult and often results in a poor prognosis. We present here the case of a female child with congenital acute myeloid leukemia (AML) with t(8 ; 16) (p11 ; p13) who received chemotherapy and survived for more than 10 years without relapse. A novel MOZ-CBP chimera was found in her diagnostic sample. Although adult AML patients with MOZ-CBP have mainly been reported as having therapy-related AML and showed poor prognoses, the present case supports the idea that AML with MOZ-CBP in the pediatric population might show better prognoses
MOZ-mediated repression of p16(INK) (4) (a) is critical for the self-renewal of neural and hematopoietic stem cells
Although inhibition of p16(INK4a) expression is critical to preserve the proliferative capacity of stem cells, the molecular mechanisms responsible for silencing p16(INK4a) expression remain poorly characterized. Here, we show that the histone acetyltransferase (HAT) monocytic leukemia zinc finger protein (MOZ) controls the proliferation of both hematopoietic and neural stem cells by modulating the transcriptional repression of p16(INK4a) . In the absence of the HAT activity of MOZ, expression of p16(INK4a) is upregulated in progenitor and stem cells, inducing an early entrance into replicative senescence. Genetic deletion of p16(INK4a) reverses the proliferative defect in both Moz(HAT) (-) (/) (-) hematopoietic and neural progenitors. Our results suggest a critical requirement for MOZ HAT activity to silence p16(INK4a) expression and to protect stem cells from early entrance into replicative senescence
Reemergence of Oropouche Fever, Northern Brazil
Oropouche fever has reemerged in Parauapebas and Porto de Moz municipalities, ParĂĄ State, Brazil. Serologic analysis (immunoglobulin MâELISA) and virus isolation confirmed Oropouche virus (OROV) in both municipalities. Nucleotide sequencing of 2 OROV isolates from each location indicated genotypes I (Parauapebas) and II (Porto de Moz) in Brazil
Metriorhynchidae (Crocodylomorpha: Thalattosuchia) del jurĂĄsico superiorâcretĂĄcico inferior de la Cuenca Neuquina (Argentina), con comentarios sobre los moldes naturales del encĂ©falo
Los Metriorhynchidae fueron los Ășnicos Crocodylomorpha con un estilo de vida marino pelĂĄgico. Relacionado con este estilo de vida, su peculiar plan corporal permite diferenciarlos claramente de los demĂĄs Crocodylomorpha. El registro fĂłsil de los metriorrĂnquidos titoniensesâberriasienses de la FormaciĂłn Vaca Muerta (Cuenca Neuquina, Argentina) es excepcional, tanto en tĂ©rminos cuantitativos como cualitativos. Su diversidad taxonĂłmica estĂĄ compuesta por cuatro taxones: Cricosaurus araucanensis, Cricosaurus lithographicus, Dakosaurus andiniensis y Purranisaurus potens. Este registro fĂłsil tambiĂ©n se caracteriza por la preservaciĂłn tridimensional de los materiales y por la preservaciĂłn de numerosos moldes naturales de las cavidades del crĂĄneo. En este trabajo se presenta una descripciĂłn de los moldes naturales del encĂ©falo de Cricosaurus araucanensis junto con una sĂntesis de los avances en el conocimiento realizados, en los Ășltimos años, sobre estos cuatro taxones argentinos. La calidad de la informaciĂłn que aporta los moldes naturales, sumado a la cantidad de moldes recuperados, hacen del registro patagĂłnico una pieza clave para la exploraciĂłn y reconstrucciĂłn de la anatomĂa blanda de estos crocodilomorfos, y para la comprensiĂłn de los cambios fisiolĂłgicos que acompañaron los cambios estructurales del esqueleto. La comprensiĂłn de estos cambios permitirĂĄ delimitar las innovaciones evolutivas claves que le permitieron a los metriorrĂnquidos la conquista, sin paralelo entre los arcosaurios, del medio pelĂĄgico.Metriorhynchidae was the only Crocodylomorpha with a pelagic marine lifestyle. Related to this lifestyle, its peculiar body plan al- lows clearly differentiate them from others Crocodylomorpha. The fossil record of metriorhynchids from TithonianâBerriasian levels of the Vaca Muerta Formation (NeuqueÌn Basin, Argentina) is outstanding, in terms of quantitative and qualitative record. Its taxonomical diversity is composed by four taxa: Cricosaurus araucanensis, Cricosaurus lithographicus, Dakosaurus andiniensis, and Purranisaurus potens. This fossil record is also characterized by the tridimensional preservation of the materials and by the preservation of numerous natural endocasts of the skull cavities. Here, I made a description of the natural endocasts of the brain of Cricosaurus araucanensis together with a synthesis of the advances in the knowledge of these four taxa that were performed during the last years. The information that provides the endocasts, to- gether with the quantity of endocasts, make of the Patagonian fossil record of metriorhynchids a key to the exploration and reconstruction of soft anatomy of these crocodylomorphs, and for the understanding of the physiological changes that accompanied the structural changes of the skeleton. Understanding these changes will allow defining the key innovations that allowed to the metriorhynchids conquer the pelagic environment, unparalleled among archosaurs.Fil: Herrera, Laura Yanina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. DivisiĂłn PaleontologĂa Vertebrados; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
Histone H3 lysine 9 acetylation obstructs ATM activation and promotes ionizing radiation sensitivity in normal stem cells
Dynamic spatiotemporal modification of chromatin around DNA damage is vital for efficient DNA repair. Normal stem cells exhibit an attenuated DNA damage response (DDR), inefficient DNA repair, and high radiosensitivity. The impact of unique chromatin characteristics of stem cells in DDR regulation is not yet recognized. We demonstrate that murine embryonic stem cells (ES) display constitutively elevated acetylation of histone H3 lysine 9 (H3K9ac) and low H3K9 tri-methylation (H3K9me3). DNA damage-induced local deacetylation of H3K9 was abrogated in ES along with the subsequent H3K9me3. Depletion of H3K9ac in ES by suppression of monocytic leukemia zinc finger protein (MOZ) acetyltransferase improved ATM activation, DNA repair, diminished irradiation-induced apoptosis, and enhanced clonogenic survival. Simultaneous suppression of the H3K9 methyltransferase Suv39h1 abrogated the radioprotective effect of MOZ inhibition, suggesting that high H3K9ac promoted by MOZ in ES cells obstructs local upregulation of H3K9me3 and contributes to muted DDR and increased radiosensitivity
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