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1.
J Struct Biol ; 192(2): 179-87, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26431895

RESUMEN

In early 2011 FEI Company launched the "Falcon", its first commercial direct electron detector product intended for application in 3-D electron microscopy in the life sciences. In this paper we discuss the principle of direct electron detection and its implementation in Falcon cameras. We describe the signal formation in the sensor and its impact on the detection quantum efficiency (DQE) of the sensor. Insights into the signal formation led us to improved camera designs. Three significant improvements are discussed. (1) Back thinning of the sensor. This is implemented in the second-generation Falcon (Falcon 2), where the sensor thickness is reduced to 50 µm, and in the latest generation Falcon 3 detector with further back-thinning down to 30 µm. (2) The introduction of electron counting, a signal processing technology implemented in Falcon 3. (3) Dose fractionation mode, which allows the user to access intermediate results during the illumination of the sample.


Asunto(s)
Microscopía por Crioelectrón/métodos , Imagenología Tridimensional/métodos , Electrones
2.
mBio ; 11(4)2020 08 18.
Artículo en Inglés | MEDLINE | ID: mdl-32817104

RESUMEN

The environmental surveys following the 2010 Deepwater Horizon (DWH) spill identified a variety of hydrocarbon-degrading microorganisms, and laboratory studies with field-collected water samples then demonstrated faster-than-expected hydrocarbon biodegradation rates at 5°C. Knowledge about microbial community composition, diversity, and functional metabolic capabilities aids in understanding and predicting petroleum biodegradation by microbial communities in situ and is therefore an important component of the petroleum spill response decision-making process. This study investigates the taxonomic composition of microbial communities in six different global basins where petroleum and gas activities occur. Shallow-water communities were strikingly similar across basins, while deep-water communities tended to show subclusters by basin, with communities from the epipelagic, mesopelagic, and bathypelagic zones sometimes appearing within the same cluster. Microbial taxa that were enriched in the water column in the Gulf of Mexico following the DWH spill were found across marine basins. Several hydrocarbon-degrading genera (e.g., Actinobacteria, Pseudomonas, and Rhodobacteriacea) were common across all basins. Other genera such as Pseudoalteromonas and Oleibacter were highly enriched in specific basins.IMPORTANCE Marine microbial communities are a vital component of global carbon cycling, and numerous studies have shown that populations of petroleum-degrading bacteria are ubiquitous in the oceans. Few studies have attempted to distinguish all of the taxa that might contribute to petroleum biodegradation (including, e.g., heterotrophic and nondesignated microbes that respond positively to petroleum and microbes that grow on petroleum as the sole carbon source). This study quantifies the subpopulations of microorganisms that are expected to be involved in petroleum hydrocarbon biodegradation, which is important information during the decision-making process in the event of a petroleum spill accident.


Asunto(s)
Bacterias/clasificación , Variación Genética , Microbiota , Agua de Mar/microbiología , Biodegradación Ambiental , Petróleo/metabolismo , Filogenia
3.
Mar Pollut Bull ; 47(1-6): 265-72, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12787630

RESUMEN

UNESCO is one of the specialized agencies under the United Nations charged with the advancement and improvement of education, social and natural sciences, culture and communication. This global mandate translates into programmes in the field tailored to the member states' specific requirements that build on the full breadth of expertise available in UNESCO. Environmental awareness building is an integral component of many of UNESCO's programmes. This paper describes how UNESCO addresses the need for awareness building in a variety of settings under different programmes and sectors. A first example is taken from the work of the education sector, which aims at introducing innovative learning methods and curricula that change or cultivate the perspective of people of all ages on sustainable development. The second example is taken from the Man and Biosphere Programme. The Biosphere Reserve concept has had a long history within UNESCO and is increasingly applied to protected areas in the coastal zone. Notable examples are Ranong Biosphere Reserve in Thailand, Can Gio Biosphere Reserve in Vietnam and the Island of Palawan in the Philippines. The concept is currently experiencing a revival as more and more countries realize the importance of striking a balance between human development and strict conservation. Many people know about UNESCO through the so-called World Heritage Sites. These are sites that are recognized by the world community as particular monuments, either natural or cultural, that warrant preservation for the whole of mankind. In the Asia-Pacific region, there are quite a number of coastal and marine sites that have been designated as natural world heritage sites, e.g. Halong Bay in Vietnam, the Komodo marine national park, Indonesia, the Great Barrier Reef in Australia, East-Rennell Island in the Solomon Islands, and Tubbataha Reef in the Philippines. The need for a cross-sectoral approach is evident under the so-called Coastal Zone and Small Islands endeavour, which aims at assisting Member States towards environmentally sound, socially equitable and culturally appropriate development in coastal regions and in small islands. Four examples of current pilot projects (Surin Island, Thailand, Jakarta Bay, Indonesia, Upolo Island, Samoa and Ulugan Bay, the Philippines) are highlighted. Each setting and each audience requires a different strategy. UNESCO's strength is to learn from all these experiences and make such new insights universally available and to put novel concepts into practice.


Asunto(s)
Conservación de los Recursos Naturales , Opinión Pública , Naciones Unidas , Animales , Asia , Características Culturales , Ambiente , Humanos , Servicios de Información , Islas del Pacífico
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