Methane emission from tropical savanna <i>Trachypogon sp.</i> grasses

International audienceMethane flux measurements from the soil-grass system were made during the wet season in unperturbed plots and plots where standing dry and green Trachypogon sp. grasses were clipped to just above the soil surface. Results support the surprising discovery that vegetation emits methane. The dry/green mixture of grasses produce methane at a rate of ~10 ng m?2 s?1, which extrapolated to the global savanna would produce an annual emission of ~5 Tg, much lower than the production recently suggested in the literature. On the other hand, during the wet season savanna soil consume CH4 at a rate of ~4.7 ng m?2 s?1, producing a global sink of ~1.3 Tg yr?1. Therefore, the tropical savanna soil-grass system would make a modest contribution to the global budget of methane

Utilização da luz ultravioleta (UV-C) na proteção de maçãs fuji da podridão por Penicillium expansum.

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Optical Sky Brightness at Cerro Tololo Inter-American Observatory from 1992 to 2006

We present optical UBVRI sky brightness measures from 1992 through 2006. The data are based on CCD imagery obtained with the CTIO 0.9-m, 1.3-m, and 1.5-m telescopes. The B- and V-band data are in reasonable agreement with measurements previously made at Mauna Kea, though on the basis of a small number of images per year there are discrepancies for the years 1992 through 1994. Our CCD-based data are not significantly different than values obtained at Cerro Paranal. We find that the yearly averages of V-band sky brightness are best correlated with the 10.7-cm solar flux taken 5 days prior to the sky brightness measures. This implies an average speed of 350 km/sec for the solar wind. While we can measure an enhancement of the night sky levels over La Serena 10 degrees above the horizon, at elevation angles above 45 degrees we find no evidence that the night sky brightness at Cerro Tololo is affected by artificial light of nearby towns and cities.Comment: 24 pages, 5 figures, to be published in the June, 2007, issue of the Publications of the Astron. Society of the Pacifi

New insights in the global cycle of acetonitrile: release from the ocean and acetonitrile: release from the ocean and Venezuela

International audienceCUsing the proton transfer reaction mass spectrometry (PTR-MS) technique, acetonitrile was measured during the wet season in a Venezuelan woodland savanna. The site was located downwind of the Caribbean Sea and no biomass burning events were observed in the region. High boundary layer concentrations of 211 ±36 pmol/mol (median, ± standard deviation) were observed during daytime in the well mixed boundary layer, which is about 60 pmol/mol above background concentrations recently measured over the Mediterranean Sea and the Pacific Ocean. Most likely acetonitrile is released from the warm waters of the Caribbean Sea thereby enhancing mixing ratios over Venezuela. Acetonitrile concentrations will probably still be much higher in biomass burning plumes, however, the general suitability of acetonitrile as a biomass burning marker should be treated with care. During nights, acetonitrile dropped to levels typically around 120 pmol/mol, which is consistent with a dry deposition velocity of ~0.14 cm/s when a nocturnal boundary layer height of 100 m is assumed

Projeto-piloto de promoção comercial de frutas da produção integrada: fundamentos e resultados.

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Laparoscopic radical nephrectomy of angiomyolipoma with renal vein involvement

Indexación: Web of Science; Scielo.Objetivo: Se presenta el caso clínico de un Angiomiolipoma renal con extensión a vena renal, patología de muy baja frecuencia. Caso clínico: Mujer de 36 años, quien consulta por dolor en flanco izquierdo. En una tomografía computada se encuentra una lesión tumoral extensa del riñón izquierdo compatible con un Angiomiolipoma renal infiltrante e invasión tumoral de la vena renal. Se realiza nefrectomía laparoscópica, con extirpación de trombo tumoral. El tiempo operatorio fue de 127 min y el sangrado estimado de 20 ml. No hubo complicaciones intra ni postoperatorias. La paciente se encuentra actualmente asintomática luego de 12 meses de seguimiento. La histología mostró un Angiomiolipoma renal con invasión del riñón y un tumor sólido en el lumen de la vena renal. Conclusión: La invasión de vena renal por un Angiomiolipoma es extremadamente raro. Su resolución laparoscópica es posible, con sólo una comunicación previa en la literatura.Background: Angiomyolipomas associated with tuberous sclerosis may invade the renal vein and generate intramural thrombi. Case report: We report a 36-years-old woman, consulting for left flank pain. CT scan showed a large tumor in the left kidney consistent with the diagnosis of infiltrating renal angiomyolipoma with tumor invasion of the vein. Laparoscopic nephrectomy was performed, with removal of tumor thrombus. The operative time was 127 minutes and estimated bleeding 20 ml. There were no intraoperative or postoperative complications. The patient is currently asymptomatic after 12 months of follow up. The pathological study of the surgical piece showed a renal angiomyolipoma with invasion of the kidney and a solid tumor in the lumen of the renal vein.http://ref.scielo.org/7pqpx

The Caveolin-1 Connection to Cell Death and Survival

Nunez, S (Nunez, S.)[ 1,4 ] 1. Fac Med, CEMC, Lab Comunicac Celulares, Santiago, Chile. 4. Univ Talca, Fac Hlth Sci, Talca, ChileCaveolins are a family of membrane proteins required for the formation of small plasma membrane invaginations called caveolae that are implicated in cellular trafficking processes. In addition to this structural role, these scaffolding proteins modulate numerous intracellular signaling pathways; often via direct interaction with specific binding partners. Caveolin-1 is particularly well-studied in this respect and has been attributed a large variety of functions. Thus, Caveolin-1 also represents the best-characterized isoform of this family with respect to its participation in cancer. Rather strikingly, available evidence indicates that Caveolin-1 belongs to a select group of proteins that function, depending on the cellular settings, both as tumor suppressor and promoter of cellular traits commonly associated with enhanced malignant behavior, such as metastasis and multi-drug resistance. The mechanisms underlying such ambiguity in Caveolin-1 function constitute an area of great interest. Here, we will focus on discussing how Caveolin-1 modulates cell death and survival pathways and how this may contribute to a better understanding of the ambiguous role this protein plays in cancer

First Detection of Mycobacterium ulcerans DNA in Environmental Samples from South America

The occurrences of many environmentally-persistent and zoonotic infections are driven by ecosystem changes, which in turn are underpinned by land-use modifications that alter the governance of pathogen, biodiversity and human interactions. Our current understanding of these ecological changes on disease emergence however remains limited. Buruli ulcer is an emerging human skin disease caused by the mycobacterium, Mycobacterium ulcerans, for which the exact route of infection remains unclear. It can have a devastating impact on its human host, causing extensive necrosis of the skin and underlying tissue, often leading to permanent disability. The mycobacterium is associated with tropical aquatic environments and incidences of the disease are significantly higher on floodplains and where there is an increase of human aquatic activities. Although the disease has been previously diagnosed in South America, until now the presence of M. ulcerans DNA in the wild has only been identified in Australia where there have been significant outbreaks and in western and central regions of Africa where the disease is persistent. Here for the first time, we have identified the presence of the aetiological agent's DNA in environmental samples from South America. The DNA was positively identified using Real-time Polymerase Chain Reaction (PCR) on 163 environmental samples, taken from 23 freshwater bodies in French Guiana (Southern America), using primers for both IS2404 and for the ketoreductase-B domain of the M. ulcerans mycolactone polyketide synthase genes (KR). Five samples out of 163 were positive for both primers from three different water bodies. A further nine sites had low levels of IS2404 close to a standard CT of 35 and could potentially harbour M. ulcerans. The majority of our positive samples (8/14) came from filtered water. These results also reveal the Sinnamary River as a potential source of infection to humans. © 2014 Morris et al