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Registros recuperados: 584 | |
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Moyano,Hugo I.. |
Se describe la historia de los descubrimientos briozoológicos hechos en la Antártica durante el siglo que va entre la publicación de los resultados de la Expedición Antártica Belga (1904) y la realización de la 13ª conferencia de la International Bryozoology Association habida en Concepción, Chile, en enero de 2004 (Moyano et al. 2003). Los países participantes en los descubrimientos incluyen a Bélgica, Francia, Alemania, Australia, Suecia, Rusia, UK, USA, Nueva Zelanda, España, China, Italia, Argentina y Chile lo que se ha traducido en la descripción de 6 familias nuevas 41 géneros nuevos y no menos de 315 especies nuevas. Sin embargo, como algunas de las especies nuevas son subantárticas, y otras tanto antárticas como subantárticas el número real de... |
Tipo: Journal article |
Palavras-chave: Historia de la ciencia; Antártica; Bryozoa. |
Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382005000100014 |
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Buckingham,Michael J; Giddens,Eric M. |
The sound from a propeller-driven aircraft is largely generated by the propeller itself. Its acoustic signature consists of a series of harmonics, the lowest of which, the fundamental, is typically in the region of 100 Hz, with the higher harmonics appearing at multiples of the fundamental. Experiments have recently been conducted off the coast of southern California, using several different types of single-engine, light aircraft, which show that the first 10 or so propeller harmonics are detectable not in the atmosphere, in the water column and also on sensors buried to a depth of about 1 m in the seabed. The Doppler-shifted comb of frequencies produced by an aircraft propeller is the basis of a recently developed technique for making point measurements... |
Tipo: Journal article |
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Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000200013 |
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Victoriano,Pedro F; Coronado,Tanía M; Ortiz,Juan Carlos. |
The gemís Diplolaemus Bell, 1843 is a common squamate component of the Patagonian región of South América. Considerable taxonomic confusión exists within this gemís, particularly about the status of Chilean-Andean populations and the actual distribution of D. leopardinas (Werner, 1898). In an attempt to clarify the taxonomic status and distribution of Diplolaemus species, we performed a principal component analysis (PCA) and discriminant function analysis (DFA) using both standard morphometric and meristic data. Multivariate summaries of morphometric data show that most species are poorly discriminated, with the exception of D. darwinii. In contrast, a PCA analyses performed on the meristic data clearly distinguish three discrete groups: 1. D. darwinii, 2.... |
Tipo: Journal article |
Palavras-chave: Species limits; Taxonomy; Patagonia; Polychrotidae. |
Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382010000100006 |
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Brown,Robert A. |
The University of Washington PBL model is a nonlinear similarity model (with organized large eddies in an equilibrium mean flow) suitable for km-scale to General Circulation Model or Climate numerical models. The theory and verification for this solution are now well established. Researchers who work with winds in the boundary layer with scales from point to 20-km regimes must be aware of this horizontal inhomogenuity in the PBL flow to avoid significant errors. Since the OLE contribute advectively to the mean flow there can be 10-20% (or more) increase in surface winds and fluxes over K-theory models. The model is described and several applications have been made |
Tipo: Journal article |
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Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000200010 |
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Kenneth W,Bruland. |
This presentation is a review of the chemistries of redox sensitive elements within suboxic regions of extreme oxygen minimum zones. Suboxic regions are defined as extreme oxygen minimum zones with dissolved oxygen < 10 µmol kg-1 (and likely <5 µmol kg-1), and with clear evidence of nitrate reduction, but not sulfate reduction. These are regions with nitrate deficits > 10 µmol kg-1 or N* values of _10 µmol kg-1. Suboxic regions predictably occur in the tropical and subtropical eastern Pacific and the Arabian Sea. These suboxic zones are important in the global biogeochemistry of nitrogen and act as an important sink for fixed nitrogen. Minor and trace element redox couples such as iodate/iodide and leachable particulate Mn/dissolved Mn undergo... |
Tipo: Journal article |
Palavras-chave: Nitrate; Iodine; Manganese; Iron. |
Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382006000300003 |
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Gusso,Aníbal; Ducati,Jorge Ricardo; Cotlier,Carlos G; Lopez,Diego A. G. |
A search is made for indicators of the presence of phytoplankton, using satellite images of the Pacific (Central Chile) and Atlantic (South Brazil). AVHRR/NOAA-16 and -17 visible (1 and 2) and thermal (4 and 5) channels were used to perform a detection test, respectively, the Suspended Particulate Matter (SPM) and the Sea Surface Temperature (SST). In Brazilian waters, a positive correlation is found between SST and SPM's reflectance. This is interpreted as due to phytoplankton being more abundant in colder waters, where nutrients availability are higher because CO2 dissolution rates, thus being a favorable environment for phytoplankton contents, which when mixed with SPM, tends to reduce the total water reflectance, since organic matter causes absorption... |
Tipo: Journal article |
Palavras-chave: Phytoplankton biomass; Remote sensing; AVHRR/NOAA. |
Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000200046 |
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Yoo,Hong-Rhyong; Ryu,Joo-Hyung; Bae,Il-Hwan; Ahn,Yu- Hwan. |
The southern tidal flat of Kanghwa Island with an area of approximately 90 km² is one of the biggest flats on the western coast of Korea. Remote sensing has been identified as potential tool to provide synoptic information of the intertidal environments. To estimate quantitatively the morphological changes in a tidal flat, it is necessary to measure both the amount of sedimentation or erosion and the sediment facies involved. Thus, the objectives of this study are : (i) to generate an intertidal digital elevation model (DEM) using the waterline method around 1989; (ii) to quantitatively estimate the morphological changes from the generated DEM for the years 1989 and the extracted waterlines for the year 2002; (iii) to discriminate the surface sedimentary... |
Tipo: Journal article |
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Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000300049 |
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Espinosa,Mara I; Bertin,Angéline; Gómez,John; Mejía,Florencio; Guerra,Martha; Baez,Lina; Gouin,Nicolas; Patiño,Edgar. |
The American crocodile, Crocodylus acutus, has experienced important population declines worldwide due to human persecution, overexploitation and habitat loss. C. acutus remains critically endangered in some countries such as Colombia where the lack of detailed surveys on its ecology and distribution constitutes a major barrier to the development of effective conservation strategies. We conducted a three-year capture-recapture study to investigate the demographic status of C. acutus and to identify environmental variables likely to in uence its distribution in Portete Bay (Colombia). We estimated the crocodile population to be relatively small (< 140 animals), to include very few adults, and to demonstrate a very strong de cit in females in the juvenile... |
Tipo: Journal article |
Palavras-chave: Capture-recapture; Crocodile; Environmental variables; Mangrove. |
Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382012000200006 |
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Dewitte,B; Ganachaud,A; Dejoan,M.-A; Grimini,P; duPenhoat,Y. |
An intermediate ocean-atmosphere coupled model of the tropical Pacific is used to investigate the sensitivity of the seasonal forecasts to the configuration of the oceanic vertical structure. The models consist in a three baroclinic mode tropical Pacific Ocean model and a Gill (1980)'s tropical atmosphere. The predictive skill of the model using a simple nudging method for the initialization is first presented from 1970 and compared to the results of other prediction system of similar complexity, which emphasizes the modulation of the skill on decadal timescales. It is then demonstrated that the skill is critically dependant on the energy distribution on the baroclinic mode, higher-order mode contributions being favored at some period and not at others.... |
Tipo: Journal article |
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Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000200027 |
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Manise,Nicolas; Neyt,Xavier; Acheroy,Marc. |
The scatterometer on-board ERS-2, earth-observation satellite developed by the European Space Agency, is an active real aperture radar instrument designed to measure the backscatter coefficient 0 from the earth. Its main utility is to measure physical parameters such as wind speeds and directions over the sea surface. Due to malfunctions of the on-board gyroscopes and even though a new attitude and orbit control system is used, the yaw-orientation of the spacecraft still exhibits random variations from the nominal attitude. This unpredictable attitude requires re-developing the calibration chain of the scatterometer instrument. Distributed targets, such as the rain forest, are used to perform a relative calibration while transponders situated at known... |
Tipo: Journal article |
Palavras-chave: Scatterometer; Calibration; Transponder. |
Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000300011 |
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Elgueta,Mario; Cerda,Miguel. |
RESUMEN Se describe una nueva especie de Macrodontini de Chile: Acalodegma vidali n. sp. Se ubica en el género Acalodegma, decisión que involucra un sentido ampliado a aquel conjunto de caracteres establecidos originalmente para el género. La nueva entidad específica tiene hasta el momento una distribución exclusiva en la Cordillera de los Andes alrededor de los 27º 36' S y 69º 20' O, área que corresponde a un ambiente de tipo prepuneño; dada esta distribución es altamente probable que se presente en similares ambientes del noroeste de Argentina. A fin de entender esta repartición en un contexto biogeográfico, se entregan antecedentes biológicos generales y de distribución geográfica para las especies de Prioninae reportadas para Chile |
Tipo: Journal article |
Palavras-chave: Prioninae; Macrodontini; Acalodegma; Distribución; Hábitat; Chile; Argentina. |
Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382002000100003 |
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Worcester,Peter F.; Cornuelle,Bruce D.; Dushaw,Brian D.; Dzieciuch,Matthew A.; Howe,Bruce M.; Menemenlis,Dimitris; Mercer,James A.; Munk,Walter H.; Spindel,Robert C.; Stammer,Detlef; Zarnetske,Michael. |
Tipo: Journal article |
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Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000300047 |
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Registros recuperados: 584 | |
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