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1

eNANOS Grid Resource Broker  

Microsoft Academic Search

Grid computing has been presented as a way to share geographically and organizationally distributed resources and to perform successfully distributed computation. For achieve this goals a software layer is necessary to interact with grid environments. Therefore, not only a middleware and its services are needed, it is necessary to offer resource management services to hide the underlying complexity of the

Ivan Rodero; Julita Corbalán; Rosa M. Badia; Jesús Labarta

2005-01-01

2

Effects of engineered nano-titanium dioxide on pore surface properties and phosphorus adsorption of sediment: its environmental implications.  

PubMed

Understanding the environmental safety and human health implications of engineered nanoparticles (ENPs) is of worldwide importance. As an important ENPs, engineered nano-TiO(2) (Enano-TiO(2)) may have been substantially deposited in aquatic sediments because of its widely uses. Sediment pore surface properties would be thus significantly influenced due to the large surface area of Enano-TiO(2). In this study, Enano-TiO(2) was found to greatly impact on sediment pore surface properties. The attachment of Enano-TiO(2) particles to sediment surfaces enhanced markedly BET specific surface area and t-Plot external specific surface area, and thereby increased sediment phosphorus (P) adsorption maximum (S(max)). Contrarily, the fill of Enano-TiO(2) particles into the micropores of sediments could significantly reduce t-Plot micropore specific surface area, and cause slight decrease in sediment P binding energy (K). Clearly, P sorbed in sediment would be easily released because of the decreasing P binding energy of the sediment with elevated Enano-TiO(2). Enano-TiO(2) would thus cause aggravated endogenous pollution in water if such sediment was re-suspended on disturbance. The results obtained in this study contribute to our increasing knowledge of how to regulate physicochemical behavior of pollutants in sediments under the influences of Enano-TiO(2) and/or similar ENPs. PMID:21794978

Luo, Zhuanxi; Wang, Zhenhong; Wei, Qunshan; Yan, Changzhou; Liu, Feng

2011-07-05

3

Volcanic Hazard Map as a Tool of City Planning: Experiences at Galeras Volcano and the county of Pasto, Colombia  

Microsoft Academic Search

Large populated areas located near active volcanoes emphasize the importance to take effective actions towards risk reduction. A volcanic hazard map is believed to be the first step in order to inform government officials, private institutions and community about the danger that poses a particular volcano. The hazard map is a tool that must be used to evaluate risk and

M. L. Calvache

2001-01-01

4

ANÁLISE DE CRESCIMENTO DO CAPIM-ELEFANTE 'NAPIER' ADUBADO E IRRIGADO1 Growth analysis of 'Napier' elephant grass fertilized and irrigated  

Microsoft Academic Search

The growth indexes were evaluated: relative to growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), leaf area index (LAI) and the luminous interception of the 'Napier' elephant grass after graze. The work consisted of two experiments for the study of four manuring treatments of N and K, in kg\\/ha (T1: 100 kg of N and 80 kg

Alex Carvalho Andrade; Dilermando Miranda da Fonseca; Rogério dos Santos Lopes; Nascimento Júnior; Paulo Roberto Cecon; Domingos Sávio Queiroz; Dalton Henrique Pereira; Sidnei Tavares Reis

5

CARACTERÍSTICAS MORFOGÊNICAS E ESTRUTURAIS DO CAPIM-ELEFANTE 'NAPIER' ADUBADO E IRRIGADO1 Morphogenetic and structural characteristics of 'Napier' elephant grass fertilized and irrigated  

Microsoft Academic Search

The objective of this study was evaluate the leaf appearance, extension and senescence rates in 'Napier' elephant grass after uniformized graze. The study consisted of two experiments, for the evaluate the effect of four manuring treatments (T1: 100 kg of N and 80 kg of K, T2: 200 kg of N and 160 kg of K, T3: 300 kg of

Alex Carvalho Andrade; Dilermando Miranda da Fonseca; Rogério dos Santos Lopes; Domício do Nascimento Júnior; Paulo Roberto Cecon; Domingos Sávio Queiroz; Dalton Henrique Pereira; Sidnei Tavares Reis

6

Determinación de la excreción total de alantoína en suero de leche por Cromatografía Líquida de Alta Eficiencia (HPLC) en vacas Holstein alimentadas con pasto Kikuyo (Pennisetum clandestinum )  

Microsoft Academic Search

A B S T R A C T Title: Determination of allantoin excre- tion by High Performance Liquid Chromatography (HPLC) in milk serum from Holstein cows fed kikuyu grass (Pennisetum clandestinum). An experiment was carried out to deter- mine allantoin excretion in late lactation dairy cows, using tree multiparous (four lactations or more) Holstein cows, fed exclusively on kikuyu grass

Luis C. Arreaza; Hugo R. Jiménez; Dora E. Sánchez; Leonardo Sánchez

7

Dinámica poblacional y fenología del salivazo de los pastos Zulia carbonaria (Lallemand) (Homoptera: Cercopidae) en el valle geográfico del río Cauca, Colombia  

Microsoft Academic Search

We studied the population fluctuation of nymphs, adults, eggs and natural enemies of the spittlebug Zulia carbonaria(Lallemand) (Homoptera: Cercopidae) associated with Brachiaria dictyoneura pastures of the Cauca River Valley, Colombia. Our objective was to describe spittlebug phenology under seasonal conditions of bimodal precipitation (March-May and September-November). Weekly, over two years, populations of spittlebugs and certain natural enemies were quantified using

Ulises Castro; Anuar Morales; Daniel C. Peck

2005-01-01

8

PRIMEROS REGISTROS DE LA ORCA PIGMEA Feresa attenuata (Cetacea, Delphinidae) Y DEL CACHALOTE ENANO Kogia simus (Cetacea, Physeteridae) EN ECUADOR CONTINENTAL FIRST RECORD OF PYGMY KILLER WHALE Feresa attenuata (Cetacea, Delphinidae) AND DWARF SPERM WHALE Kogia simus (Cetacea, Physeteridae) ON THE ECUADOREAN CONTINENTAL COAST  

Microsoft Academic Search

A young specimen of pygmy killer whale (Feresa attenuata), 91 cm long, stranded in San Pedro, Province of Guayas (80°44'W, 01050'S) in 27 April 1992. The animal was frozen and examined after. 20 days. External measurements and photographs of the specimen are presented.

Fernando Félix; Ben Haase; Jorge Samaniego

9

Influencia de la fecha de siembra y distancia entre surcos sobre el establecimiento de asociaciones de desmanthus y el pasto klein Influence of row-spacing and planting date on the establishment of bundleflower-kleingrass mixtures  

Microsoft Academic Search

Understanding factors that affect the establishment of pastures is important to the management of persistent grass-legume mixtures. The objective of this study was to evaluate kleingrass (Panicum coloratum L.)-bundeflower (Desmanthus sp.) associations during the establishment year in terms of plant density and yield. The study was carried out at Brazos County, TX. (near College Station). Plots were drilled at a

Eduardo A. González Valenzuela; Mark A. Hussey

10

COMPOSICIÓN QUÍMICA del PASTO AGUJA (brachiaria humidìcola) SOMETIDA A PASTOREO EN UNA FINCA DEL MUNICIPIO GUANARE ESTADO PORTUGUESA Chemical composition of Brachiaria humidicola grazed into a farm in Guanare, Portuguesa state, Venezuela  

Microsoft Academic Search

In order to evaluate the chemical composition of Brachiaria humidicola in a farm of Guanare, Portuguesa state, eight samples were taken monthly by means of metallic frame (0.5 x 0.5), and dried off at 60 ºC during 48 h, for dry matter estimation. Each sample was divided in two components: (PI) the plant as a whole, (H) just leaves. Proximal

Adelis Arias; Helber Hernández

2002-01-01

11

Biochemical characterization of the eelgrass Zostera marina at its southern distribution limit in the North Pacific [Caracterizacio??n bioqui??mica del pasto marino Zostera marina en el li??mite sur de su distribucio??n en el Paci??fico Norte  

USGS Publications Warehouse

The eelgrass Zostera marina L. is distributed along the Baja California Peninsula (Mexico) where it is exposed to a wide range of irradiances and temperatures that could promote changes in its biochemical composition. Consequently, the objective of this study was to characterize the variations in the levels of chlorophyll, carbohydrates, proteins, fiber, ash and calories in the shoots of Z. marina from the north (San Quintin) and south (Ojo de Liebre and San Ignacio lagoons) of the peninsula. Temperature in the southern lagoons was 5-6??C higher than in the northern lagoon; likewise, in situ irradiance was two-fold greater in the south than in the north. As a result of the lower irradiance levels, the concentration of chlorophyll in the shoots of Z. marina was twice as high (1.7 mg gWW-1) in the northern lagoon than in the southern ones (0.8 mg gWW-1). Similar to chlorophyll levels, the concentration of soluble carbohydrates in the shoots was greater in the northern lagoon than in the southern ones, suggesting that the high levels of chlorophyll are enough to compensate for the low irradiance levels and to maintain a positive carbon balance at San Quintin. On the other hand, the levels of proteins in the shoots from the north of the peninsula were slightly lower than those from the southern populations. In general, these results suggest that the different environmental conditions to which Z. marina is exposed along the peninsula impact its biochemical composition.

Cabello-Pasini, A.; Muniz-Salazar, R.; Ward, D. H.

2004-01-01

12

Use of digital multispectral videography to assess seagrass distribution in San Quinti??n Bay, Baja California, Mexico [Uso de videografi??a multiespectral digital para evaluar la distributio??n del pasto marino en Bahi??a San Quinti??n, Baja California, Me??xico  

USGS Publications Warehouse

Apparent threats to the spatial distribution of seagrass in San Quinti??n Bay prompted us to make a detailed assessment of habitats in the bay. Six coastal habitats and three seagrass subclasses were delineated using airborne digital multispectral videography (DMSV), Eelgrass, Zostera marina, was the predominant seagrass and covered 40% (1949 ha) of the areal extent of the bay in 1999. Eelgrass grew over a wide range of tidal depths from about -3.0 in mean lower low water (MLLW) to about 1.0 m MLLW, but greatest spatial extent occurred in intertidal areas -0.6 m to 1.0 m MLLW. Exposed-continuous (i.e., high density) eelgrass was the most abundant habitat in the bay. Widgeongrass, Ruppia maritima, was the only other seagrass present and covered 3% (136 ha) of the areal extent of the entire bay. Widgeongrass grew in single species stands in the upper intertidal (??? 0.4 MLLW) and intermixed with eelgrass at lower tidal depths. Overall accuracy of the six habitat classes and three subclasses in the DMSV map was relatively high at 84%. Our detailed map of San Quintin Bay can be used in future change detection analyses to monitor the health of seagrasses in the bay.

Ward, D. H.; Tibbitts, T. L.; Morton, A.; Carrera-Gonzalez, E.; Kempka, R.

2004-01-01

13

Limits on Common Pasture Use in an Agro-Pastoral Community: The Case of Toqra, Peru.  

National Technical Information Service (NTIS)

One of the major issues concerning development activities among groups of traditional livestock producers is that of common pastures and the overgrazing that is often associated with this type of land tenure. Worries about competitive behavior among pasto...

K. A. Jamtgaard L. Jimenez-Zamalloa

1984-01-01

14

Dominant Language Transfer in Spanish Heritage Speakers and Second Language Learners in the Interpretation of Definite Articles  

ERIC Educational Resources Information Center

|This study investigates dominant language transfer (from English) in adult Spanish second language (L2) learners and Spanish heritage speakers. We focus on contrasting properties of English and Spanish definite articles with respect to generic reference ("Elephants have ivory tusks" vs. "Los elefantes tienen colmillos de marfil") and inalienable…

Montrul, Silvina; Ionin, Tania

2012-01-01

15

Precipitation as the main driver of Neoglacial fluctuations of Gualas glacier, Northern Patagonian Icefield  

NASA Astrophysics Data System (ADS)

Glaciers are frequently used as indicators of climate change. However, the link between past glacier fluctuations and climate variability is still highly debated. Here, we investigate the mid- to late-Holocene fluctuations of Gualas Glacier, one of the northernmost outlet glaciers of the Northern Patagonian Icefield, using a multi-proxy sedimentological and geochemical analysis of a 15 m long fjord sediment core from Golfo Elefantes, Chile, and historical documents from early Spanish explorers. Our results show that the core can be sub-divided into three main lithological units that were deposited under very different hydrodynamic conditions. Between 5400 and 4180 cal yr BP and after 750 cal yr BP, sedimentation in Golfo Elefantes was characterized by the rapid deposition of fine silt, most likely transported by fluvio-glacial processes. By contrast, the sediment deposited between 4130 and 850 cal yr BP is composed of poorly sorted sand that is free of shells. This interval is particularly marked by high magnetic susceptibility values and Zr concentrations, and likely reflects a major advance of Gualas glacier towards Golfo Elefantes during the Neoglaciation. Several thin silt layers observed in the upper part of the core are interpreted as secondary fluctuations of Gualas glacier during the Little Ice Age, in agreement with historical and dendrochronological data. Our interpretation of the Golfo Elefantes glaciomarine sediment record in terms of fluctuations of Gualas glacier is in excellent agreement with the glacier chronology proposed for the Southern Patagonian Icefield, which is based on terrestrial (moraine) deposits. By comparing our results with independent proxy records of precipitation and sea surface temperature, we suggest that the fluctuations of Gualas glacier during the last 5400 yr were mainly driven by changes in precipitation in the North Patagonian Andes.

Bertrand, S.; Hughen, K. A.; Lamy, F.; Stuut, J.-B. W.; Torrejón, F.; Lange, C. B.

2012-03-01

16

Precipitation as the main driver of Neoglacial fluctuations of Gualas glacier, Northern Patagonian Icefield  

NASA Astrophysics Data System (ADS)

Glaciers are frequently used as indicators of climate change. However, the link between past glacier fluctuations and climate variability is still highly debated. Here, we investigate the mid- to late-Holocene fluctuations of Gualas Glacier, one of the northernmost outlet glaciers of the Northern Patagonian Icefield, using a multi-proxy sedimentological and geochemical analysis of a 15 m long fjord sediment core from Golfo Elefantes, Chile, and historical documents from early Spanish explorers. Our results show that the core can be sub-divided in three main lithological units that were deposited under very different hydrodynamic conditions. Between 5400 and 4180 cal yr BP and after 750 cal yr BP, sedimentation in Golfo Elefantes was characterized by the rapid deposition of fine silt, most likely transported by fluvio-glacial processes. By contrast, the sediment deposited between 4130 and 850 cal yr BP is composed of poorly sorted sand that is free of shells. This interval is particularly marked by high magnetic susceptibility values and Zr concentrations, and likely reflects a major advance of Gualas glacier towards Golfo Elefantes during the Neoglaciation. Several thin silt layers observed in the upper part of the core are interpreted as secondary fluctuations of Gualas glacier during the Little Ice Age, in agreement with historical and dendrochronological data. Our interpretation of the Golfo Elefantes glaciomarine sediment record in terms of fluctuations of Gualas glacier is in excellent agreement with the glacier chronology proposed for the Southern Patagonian Icefield, which is based on terrestrial (moraine) deposits. By comparing our results with independent proxy records of precipitation and sea surface temperature, we demonstrate that the fluctuations of Gualas glacier during the last 5400 yr were mainly driven by changes in precipitation in the Andes.

Bertrand, S.; Hughen, K. A.; Lamy, F.; Stuut, J.-B. W.; Torrejón, F.; Lange, C. B.

2011-09-01

17

Contiuous gas monitoring at the volcano Galeras, Colombia  

Microsoft Academic Search

(1) Federal Institute for Geosciences and Natural Resources, Hannover, Germany (e.faber@bgr.de), (2) Instituto de Investigación en Geocientifica, Mineroambiental y Nuclear - INGEOMINAS, San Juan de Pasto, Colombia (3) Instituto de Investigación en Geocientifica, Mineroambiental y Nuclear - INGEOMINAS, Manizales, Colombia A gas monitoring system has been installed on the volcano Galeras in Colombia as part of a multi-parameter station. Gases

E. Faber; C. Morán; J. Poggenburg; G. Garzón; M. Teschner; F. H. Weinlich

2003-01-01

18

Effects of acid suppression and bismuth medications on the performance of diagnostic tests for Helicobacter pylori infection  

Microsoft Academic Search

OBJECTIVE: This study was designed to investigate whether acid suppression and bismuth medications interfere with the performance of diagnostic tests for Helicobacter pylori (H. pylori) infection.METHODS: Sixty patients with previous diagnoses of atrophic gastritis and H. pylori infection made in gastric biopsies taken at Hospital Departmental, Pasto, Colombia, were enrolled in the study. 13C breath urea test (UBT) and stool

Luis E. Bravo; J. Luis Realpe; Cristina Campo; Robertino Mera; Pelayo Correa

1999-01-01

19

Quaternary tectonic movements in the Argentine Puna, 24° to 27° s latitude  

Microsoft Academic Search

The Puna of NW Argentina, one of the highest plateaus in the world, is the southern continuation of the Andean Altiplano geomorphic province of Peru and Bolivia. The region is not seismically active and reports of neotectonic movements are scarce. However, the areas of Salar de los Pastos Grandes, Salar del Hombre Muerto and Sierra Calalaste clearly have experienced Quaternary

M. R. Strecker; R. Alonso; F. Rivelli; R. Mon

1985-01-01

20

TERAPIA PERIODONTAL BÁSICA EN PACIENTES DE BAJOS RECURSOS CON PERIODONTITIS CRÓNICA  

Microsoft Academic Search

Objetive: To compare clinical and microbiologic changes over microflora subgingival in low income patients with chronic periodontitis who received treatment with hand instrumentation with or without ultrasound therapy. Method. An experimental study was designed, a total of 19 voluntarie patients with chronic periodontitis from Universidad Cooperativa de Colombia - Pasto Dentistry School Clinical Center were included at it. Results: After

Virginia Cerón Souza; Ana Cristina Mafla-Chamorro; Claudia Elena Moncayo-Jurado

2008-01-01

21

The first hominin of Europe.  

PubMed

The earliest hominin occupation of Europe is one of the most debated topics in palaeoanthropology. However, the purportedly oldest of the Early Pleistocene sites in Eurasia lack precise age control and contain stone tools rather than human fossil remains. Here we report the discovery of a human mandible associated with an assemblage of Mode 1 lithic tools and faunal remains bearing traces of hominin processing, in stratigraphic level TE9 at the site of the Sima del Elefante, Atapuerca, Spain. Level TE9 has been dated to the Early Pleistocene (approximately 1.2-1.1 Myr), based on a combination of palaeomagnetism, cosmogenic nuclides and biostratigraphy. The Sima del Elefante site thus emerges as the oldest, most accurately dated record of human occupation in Europe, to our knowledge. The study of the human mandible suggests that the first settlement of Western Europe could be related to an early demographic expansion out of Africa. The new evidence, with previous findings in other Atapuerca sites (level TD6 from Gran Dolina), also suggests that a speciation event occurred in this extreme area of the Eurasian continent during the Early Pleistocene, initiating the hominin lineage represented by the TE9 and TD6 hominins. PMID:18368116

Carbonell, Eudald; Bermúdez de Castro, José M; Parés, Josep M; Pérez-González, Alfredo; Cuenca-Bescós, Gloria; Ollé, Andreu; Mosquera, Marina; Huguet, Rosa; van der Made, Jan; Rosas, Antonio; Sala, Robert; Vallverdú, Josep; García, Nuria; Granger, Darryl E; Martinón-Torres, María; Rodríguez, Xosé P; Stock, Greg M; Vergès, Josep M; Allué, Ethel; Burjachs, Francesc; Cáceres, Isabel; Canals, Antoni; Benito, Alfonso; Díez, Carlos; Lozano, Marina; Mateos, Ana; Navazo, Marta; Rodríguez, Jesús; Rosell, Jordi; Arsuaga, Juan L

2008-03-27

22

Effects of Boron on Proton Transport and Membrane Properties of Sunflower (Helianthus annuus L.) Cell Microsomes.  

PubMed

Boron deficiency and toxicity inhibit ATP-dependent H+ pumping and vanadate-sensitive ATPase activity in sunflower roots and cell suspensions. The effects of boron on H+ pumping and on passive H+ conductance, as well as on fluorescence anisotropy in KI-washed microsomes isolated from sunflower (Helianthus annuus L. cv Enano) cell suspensions, have been investigated. Boron deficiency reduced the total and vanadate-sensitive ATPase activities as well as the vanadate-sensitive ATP-dependent H+ pumping without affecting the amount of antigenic ATPase protein as measured by immunoblotting with an Arabidopsis thaliana plasma membrane anti-H+-ATPase polyclonal antibody. Kinetic studies revealed that boron deficiency reduced Vmax of vanadate-sensitive ATPase activity with little change in the apparent Km for Mg2+-ATP. Proton leakage was greater in microsomal vesicles isolated from cells grown without boron and incubated in reaction medium without added boron, and this effect was reversed by addition of boron to the reaction medium. Fluorescence anisotropy indicated that diphenyl hexatriene and 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene probes were immobilized to a greater extent in microsomes from cells grown without boron than in those from cells grown with 100 [mu]M H3BO3. The apparent decrease of membrane fluidity in microsomes from cells grown without boron was reversed by the addition of boron to the reaction medium. Taken together these data suggest that inhibition of H+ gradient formation in microsomes from sunflower cells grown in the absence of boron could be due to the combined effects of reduced H+-ATPase activity and increased passive conductance across the membrane, possibly resulting from increased membrane rigidity. PMID:12231978

Ferrol, N.; Belver, A.; Roldan, M.; Rodriguez-Rosales, M. P.; Donaire, J. P.

1993-11-01

23

The oldest human fossil in Europe, from Orce (Spain).  

PubMed

The Orce region has one of the best late Pliocene and early Pleistocene continental paleobiological records of Europe. It is situated in the northeastern sector of the intramontane Guadix-Baza Basin (Granada, Andalusia, southern Spain). Here we describe a new fossil hominin tooth from the site of Barranco León, dated between 1.02 and 1.73 Ma (millions of years ago) by Electron Spin Resonance (ESR), which, in combination with paleomagnetic and biochronologic data, is estimated to be close to 1.4 Ma. While the range of dates obtained from these various methods overlaps with those published for the Sima del Elefante hominin locality (1.2 Ma), the overwhelming majority of evidence points to an older age. Thus, at the moment, the Barranco León hominin is the oldest from Western Europe. PMID:23481345

Toro-Moyano, Isidro; Martínez-Navarro, Bienvenido; Agustí, Jordi; Souday, Caroline; Bermúdez de Castro, José María; Martinón-Torres, María; Fajardo, Beatriz; Duval, Mathieu; Falguères, Christophe; Oms, Oriol; Parés, Josep Maria; Anadón, Pere; Julià, Ramón; García-Aguilar, José Manuel; Moigne, Anne-Marie; Espigares, María Patrocinio; Ros-Montoya, Sergio; Palmqvist, Paul

2013-03-05

24

Quaternary tectonic movements in the Argentine Puna, 24/sup 0/ to 27/sup 0/ s latitude  

SciTech Connect

The Puna of NW Argentina, one of the highest plateaus in the world, is the southern continuation of the Andean Altiplano geomorphic province of Peru and Bolivia. The region is not seismically active and reports of neotectonic movements are scarce. However, the areas of Salar de los Pastos Grandes, Salar del Hombre Muerto and Sierra Calalaste clearly have experienced Quaternary tectonic movements. At Salar de los Pastos Grandes, early Pleistocene lake sediments are offset by reverse faulting. At Salar del Hombre Muerto, Quaternary pyroclastic and debris-flow deposits are unconformable over sediments 5.86 m.y. old that were folded during the Pliocene-Pleistocene Diaguita deformation. Within the Quaternary sediments two separate deformational phases with reverse faulting and shallow thrusting are recognized. The timing of movement is well defined since the deformed strata are covered by a basalt flow 0.75 m.y. old. The flow in turn is affected by normal faulting. Similar normal faults associated with basalt flows were found at Sierra Calalaste. These observations are in accord with pronounced extensional movements and basaltic volcanism at the Calama-Olacapato-Toro Lineament (0.2 m.y. old flows) and might document the Quaternary transition from a compressive to an extensional tectonic regime in the southern Puna.

Strecker, M.R.; Alonso, R.; Rivelli, F.; Mon, R.

1985-01-01

25

Seasonal plankton variability in Chilean Patagonia fjords: Carbon flow through the pelagic food web of Aysen Fjord and plankton dynamics in the Moraleda Channel basin  

NASA Astrophysics Data System (ADS)

Two research cruises ( CIMAR 13 Fiordos) were conducted in the N-S oriented macrobasin of the Moraleda Channel (42-47°S), which includes the E-W oriented Puyuhuapi Channel and Aysen Fjord, during two contrasting productive seasons: austral winter (27 July-7 August 2007) and spring (2-12 November 2007). These campaigns set out to assess the spatio-temporal variability, defined by the local topography along Moraleda Channel, in the biological, physical, and chemical oceanographic characteristics of different microbasins and to quantify the carbon budget of the pelagic trophic webs of Aysen Fjord. Seasonal carbon fluxes and fjord-system functioning vary widely in our study area. In terms of spatial topography, two constriction sills (Meninea and Elefantes) define three microbasins along Moraleda Channel, herein the (1) north (Guafo-Meninea), (2) central (Meninea-Elefantes), and (3) south (Elefantes-San Rafael Lagoon) microbasins. In winter, nutrient concentrations were high (i.e. nitrate range: 21-14 ?M) and primary production was low (153-310 mgC m -2 d -1), suggesting that reduced light radiation depressed the plankton dynamics throughout Moraleda Channel. In spring, primary production followed a conspicuous N-S gradient, which was the highest (5167 mgC m -2 d -1) in the north microbasin and the lowest (742 mgC m -2 d -1) in the south microbasin. The seasonal pattern of the semi-enclosed Puyuhuapi Channel and Aysen Fjord, however, revealed no significant differences in primary production (˜800 mgC m -2 d -1), and vertical fluxes of particulate organic carbon were nearly twice as high in spring as in winter (266 vs. 168 mgC m -2 d -1). At the time-series station (St. 79), the lithogenic fraction dominated the total sedimented matter (seston). The role of euphausiids in the biological carbon pump of the Patagonian fjords was evident, given the predominance of zooplankton fecal material, mostly euphausiid fecal strings (46% of all fecal material), among the recognizable particles contributing to the particulate organic carbon flux. The topographic constriction sills partially modulated the exchange of oceanic waters (Subantarctic Surface Water) with freshwater river discharges along the Moraleda Channel. This exchange affects salinity and nutrient availability and, thus, the plankton structure. The north microbasin was dominated by a seasonal alternation of the classical (spring) and microbial (winter) food webs. However, in the south microbasin, productivity was low and the system was dominated year-round by large inputs of glacier-derived, silt-rich freshwater carrying predominantly small-sized diatoms ( Skeletonema spp) and bacteria. When superimposed upon this scenario, highly variable (seasonal) solar radiation and photoperiods could exacerbate north-south differences along Moraleda Channel.

González, H. E.; Castro, L.; Daneri, G.; Iriarte, J. L.; Silva, N.; Vargas, C. A.; Giesecke, R.; Sánchez, N.

2011-03-01

26

[Sierra of the Atapuerca, thinking about the evolution].  

PubMed

Homo sapiens walks to the future in a uncertain way. The fosil evidences from the lithosphere can help us to get into know the social and cultural evolution of all the species that have precede us and even our own. Atapuerca, with more than 1.2 MA old of fossilized history from the Pleistocene to the Holocene is throwing a scientific message through the study of all its archaeological sites. There are thousands of animal and human fossils in Trinchera del Ferrocarril, Cueva de Gran Dolina, Sima del Elefante and Galeria that yield information on the cultural cannibalism practices by Homo antecessor 900,000 years ago, and the hunting and gathering that Homo heidelbergensis developed 400,000 years ago. Finally in the Sima de los Huesos, with a similar chronology than at the H. heidelbergensis sites from the Trinchera del Ferrocarril, we find the first intentional accumulation of hominid bodies. These contributions are significant to the knowledge of the biological and cultural human evolution and permits to deepen it empirically. We hope that understanding the message we will be able to improve our species through the socialization of the scientific knowledge. PMID:18069605

Carbonell, Eudald

2007-01-01

27

Management of pest mole crickets in Florida and Puerto Rico with a nematode and parasitic wasp  

SciTech Connect

Non-indigenous invasive mole crickets, Scapteriscus vicinus Scudder (Orthoptera: Gryllotalpidae) in Florida and S. didactylus (Latreille) (the 'changa') in Puerto Rico, are being managed with an entomopathogenic nematode, Steinernema scapterisci (Nguyen and Smart) (Rhabditida: Steinernematidae), and a parasitic wasp, Larra bicolor L. (Hymenoptera: Sphecidae). Pest mole cricket populations have declined by 95% in north central Florida since these specialist natural enemies were released and established in the 1980s. Commercial production of the nematode was initiated, nearly 70 billion were applied in 34 Florida counties, and their establishment, spread, and impact on mole crickets were monitored. The infected mole crickets dispersed the nematode rapidly, so that within 6 months these parasites were present in most of the insects trapped in experimental pastures. Three years later, mole cricket populations were reduced to acceptable levels and the bahiagrass had recovered. The nematode was released for the first time in Puerto Rico during 2001 and has persisted; the wasp was introduced in the late 1930s. The geographical distribution of the wasp is being expanded in Florida and Puerto Rico by planting plots of Spermacoce verticillata (L.), a wildflower indigenous to Puerto Rico and widely distributed in southern Florida. Pastures, sod farms, golf courses, landscapes, and vegetable farms in Florida and Puerto Rico are benefiting from biological control of invasive mole crickets. (author) [Spanish] Los grillotopos invasores no indigenas, Scapteriscus vicinus (Orthoptera: Gryllotalpidae) en el estado de Florida y S. didactylus ('changa') en Puerto Rico, estan siendo manejados por el nematodo entomopathogeno, Steinernema scapterisci (Rhabditida: Steinernematidae) y la avispa parasitica, Larra bicolor (Hymenoptera: Sphecidae). Las poblaciones de los grillotopo plagas han declinado un 95% en el norte central de la Florida desde que estos enemigos naturales especialistas fueron liberados y establecidos en los 80s. Consecuentemente, la produccion comercial del nematodo fue iniciada, casi 70 billones fueron aplicados en 34 condados de la Florida, y se realizo un monitoreo para evaluar su establecimiento, dispersion e impacto sobre los grillotopos. Los gillotopos infectados dispersaron los nematodos rapidamente, tanto que despues de 6 meses estos parasitos estaban presentes en la mayoria de los insectos atrapados en los pastos experimentales. Tres anos despues, las poblaciones de los grillotopos fueron reducidas a niveles aceptables y los campos de pasto 'bahia' se recuperaron. El nematodo fue liberado para la primera vez en Puerto Rico durante del 2001 y ha persistido; la avispa fue introducida al final de los 30s. La distribucion geografica de la avispa se esta extendiendo en la Florida y Puerto Rico por medio de la siembra de parcelas de Spermacoce verticillata, una flor silvestre indigena a Puerto Rico y distribuida ampliamente en el sur de la Florida. Los campos de pasto, las operaciones comerciales de cesped, los campos de golf, los paisajes y las fincas de hortalizas en la Florida y Puerto Rico se estan beneficiando del control biologico de los grillotopos invasores. (author)

Leppla, N.C.; Frank, J.H. [University of Florida, Institute of Food and Agricultural Sciences, Department of Entomology and Nematology, P.O. Box 110630, Gainesville, FL 32611-0630 (United States); Adjei, M.B. [University of Florida, Range Cattle Research and Education Center, 3401 Experiment Station, Ona, FL 33865-9706 (United States); Vicente, N.E. [University of Puerto Rico, Agricultural Experiment Station, P.O. Box 9030, Mayaguez, PR 00681-9030 (Puerto Rico)

2007-03-15

28

A sulfur isotopic study of the San Cristobal tungsten-base metal mine, Peru  

NASA Astrophysics Data System (ADS)

The San Cristobal tungsten-base metal deposit differs from other quartz-wolframite vein deposits in that it has a major period of base metal mineralization consisting of pyrite, chalcopyrite, sphalerite, and galena. Homogenization temperatures of primary and pseudosecondary inclusions were measured in augelite (260 400°C), quartz (230 350°C) and sphalerite (180 220°C). The ?34S values of H2S in solution in equilibrium with the vein minerals range from 1.6 to 9.0 permil increasing through the paragenesis. The relatively heavy ? ^{34} {text{S}}_{{text{H}}_{text{2}} {text{S}}} values suggest a nonmagmatic source for the sulfur. Evaporitic sulfates are a likely source of heavy sulfur and sedimentary anhydrite is known to occur near the San Cristobal region. In contrast to San Cristobal are three similar quartz-wolframite vein deposits, Pasto Bueno, Panasqueira, and Tungsten Queen. They each have an average ?34S value for sulfides of about 0 permil, suggesting a sulfur of magmatic origin. At San Cristobal an influx of sedimentary sulfur could not only account for the distinctive isotopic signature of the sulfides but also for the presence of the base metal mineralization.

Campbell, A. R.

1987-01-01

29

Contiuous gas monitoring at the volcano Galeras, Colombia  

NASA Astrophysics Data System (ADS)

(1) Federal Institute for Geosciences and Natural Resources, Hannover, Germany (e.faber@bgr.de), (2) Instituto de Investigación en Geocientifica, Mineroambiental y Nuclear - INGEOMINAS, San Juan de Pasto, Colombia (3) Instituto de Investigación en Geocientifica, Mineroambiental y Nuclear - INGEOMINAS, Manizales, Colombia A gas monitoring system has been installed on the volcano Galeras in Colombia as part of a multi-parameter station. Gases are extracted from the fumarolic vapour through a short pipe. After the water has been condensed the gas passes over sensors for carbon dioxide, sulphur dioxide and radon. Other parameters measured are temperature of the fumarolic vapour, fumarolic pressure, temperature of the ambient air and the ambient atmospheric pressure. The signals of the sensors are digitised in the electronics. The digital data are transmitted every 6 seconds by a telemetry system to the observatory down in the city of Pasto via a repeater station at the rim of the Galeras. The system at the volcano is powered by batteries connected to solar panels. Data are stored in the observatory, they are plotted and compared with all the other information of the multi-parameter station. Although the various compounds of the gas system are well preserved for the very aggressive environment close to the fumarole some problems still remain: Sulphur often plugs the pipe to the sensors and requires maintenance more often than desired. As the volcano is most of the time in clouds the installed solar power system (about 400 Watts maximum power) does not enable to run the system at the fumarole (consumption about 15 Watts) continuously during all nights. Despite these still existing problems some results have been obtained encouraging us to continue the operation of the system, to further develop the technical quality and to increase the number of fumaroles included into a growing monitoring network. In March 2000 seismic activity in the crater increased accompanied by a small eruption. Several hours before the eruption occurred the usually high CO2-concentration of the fumarolic gas was no longer constant as before but started to oscillate. It continued to oscillate until the seismic events started. Then the CO2-concentration as well as the radon counts decreased and the pressure of the fumarolic vapour increased. Some hours later the seismic activity ceased and the CO2 and radon readings increased again. From other observations it is suggested that meteorological parameters like wind direction and wind speed at the volcano do influence the pressure and flow regime in the conduits of the fumarole. The observations made so far are important to improve the understanding of processes within the volcano. However, more “events” have to be waited for during the coming years before processes in the volcano can be modelled.

Faber, E.; Morán, C.; Poggenburg, J.; Garzón, G.; Teschner, M.; Weinlich, F. H.

2003-04-01

30

The Cerro Aguas Calientes caldera, NW Argentina: an example of a tectonically controlled, polygenetic, collapse caldera, and its regional significance  

NASA Astrophysics Data System (ADS)

Polygenetic, silicic collapse calderas such as Cerro Galán, Pastos Grandes, La Pacana, Vilama, Negra Muerta, Farallón Negro, Cerro Guacha, among others are common in the central Andes. Here we describe in detail the Cerro Aguas Calientes caldera in NW Argentina, which comprises two caldera-forming episodes occurred at 17.15 Ma and 10.3 Ma, respectively. We analyse the significance of its structural setting, composition, size and the subsidence style of both caldera episodes. Our results reveal that the caldera eruptions had a tectonic trigger. In both cases, an homogeneous dacitic crystal-rich (>60 vol. % of crystals) reservoir of batholitic size became unstable due to the effect of increasing regional transpression, favouring local dilation throughout minor strike slip faults from which ring faults nucleated and permitted caldera collapse. Both episodes are similar in shape, location and products of the resulting calderas. The 17.15 Ma caldera has an elliptical shape (17 × 14 km) and is elongated in a N30° trend; both intracaldera and extracaldera ignimbrites covered an area of around 620 km2 with a minimum volume estimate of 138 km3 (DRE). The 10.3 Ma episode generated another elliptical caldera (19 ×14 km), with the same orientation as the previous one, from which intracaldera and outflow ignimbrites covered a total area of about 1,700 km2, representing a minimum eruption volume of 341 km3 (DRE). In this work we discuss the significance of the Cerro Aguas Calientes caldera in comparison with other well known examples from the central Andes in terms of tectonic setting, eruption mechanisms, and volumes of related ignimbrites. We suggest that our kinematic model is a common volcano-tectonic scenario during the Cenozoic in the Puna and Altiplano, which may be applied to explain the origin of other large calderas in the same region.

Petrinovic, Ivan A.; Martí, Joan; Aguirre-Diaz, Gerardo J.; Guzmán, Silvina R.; Geyer, Adelina; Grosse, Pablo; Salado Paz, Natalia

2010-05-01

31

The Asteroid 1998 QE2  

NASA Astrophysics Data System (ADS)

This big asteroid was at 5.8 millions of kilometers from the Earth on May 31 (2013) and it has a diameter of 2.7 km. The radar images obtained by JPL showed that the period of rotation around its axis is close to five hours. Hills. K (2013) reported that the period is of 5.281 +/- 0.002 hours. On June 4 the team of Goldstone-Arecibo found a period of 4.75 +/- 0.01 hours. We also contributed with the light and phase curves to estimate the period by means of the telescope (with red filter). The radar imagery (JPL and Arecibo) revealed that 1998 QE2 has a moon, and we captured a mutual event (eclipse). From our Observatory, located in Pasto-Colombia, we captured several pictures, videos and astrometry data during several days. Our data was published by the Minor Planet Center (MPC) and also appears at the web page of NEODyS. The pictures of the asteroid were captured with the following equipment: CGE PRO 1400 CELESTRON (f/11 Schmidt-Cassegrain Telescope) and STL-1001 SBIG camera. We obtained the light curve of the body. Astrometry was carried out, and we calculated the orbital elements. We obtained the following orbital parameters: eccentricity = 0.5692181, semi-major axis = 2.41104631 A.U, orbital inclination = 12.82771 deg, longitude of the ascending node = 250.16876 deg, argument of perihelion = 345.61328 deg, mean motion = 0.26326658 deg/d, perihelion distance = 1.03863508 A.U, aphelion distance = 3.78345755 A.U. The asteroid has an orbital period of 3.74 years The parameters were calculated based on 191 observations (2013 May: 17-24) with mean residual = 0.162 arcseconds. A video of the asteroid from our Observatory was published on the main page of the “SPACEWEATHER” web: http://www.spaceweather.com/archive.php?view=1&day=21&month=05&year=2013 Note: The autors would like to thank to: Dr. Alessondra Springmann (Arecibo Observatory), Dr. Petr Pravec (Czech Republic), Dr. Lance Benner (JPL), Dr. Carl Hergenrother (Target Asteroids Team), and Dr. Dolores Hill (Target Asteroids Team) for their special suggestions.

Vodniza, Alberto Q.; Pereira, M. R.; Arecibo Observatory Team; JPL Target Asteroids Team

2013-10-01

32

Knowledge Sharing and Collaboration in Volcanic Risk Mitigation at Galeras Volcano, Colombia: A Participative Workshop to Reduce Volcanic Risk  

NASA Astrophysics Data System (ADS)

Galeras has been in nearly constant activity during modern historic times (roughly the past 500 years). Approximately 10,000 people live within an area designated as the highest-hazard and nearly 400,000 people are within areas of potential harmful effects. A wide variety of stakeholders are affected by the hazards, including: farmers, indigenous villagers, and people in urban environments. Hazards assessment and volcano monitoring are the responsibility of the Colombian Geological Survey (INGEOMINAS), whereas decisions regarding mitigation and response procedures are the responsibility of various governmental offices and the national emergency system (SNPAD). According to the current plan, when the risk level rises to a high level the people in the highest risk zone are required to evacuate. The volcano currently is in a very active, but fluctuating, condition and a future large eruption in a medium time frame (years to decades) is possible. There is a growing level of discomfort among many of the affected groups, including indigenous communities, farmers, and urban dwellers, related to the risk assessment. The general opinion prior to July 2009 was quite polarized as the decision makers saw the people of the region as poorly prepared to understand this hazard, whereas the population felt that their views were not being heard. The result was that the people in the hazardous areas decided not to evacuate, even during the current period of explosive activity. To resolve this situation the University of Nariño (Colombia) and the State University of New York at Buffalo organized a workshop named "Knowledge, Sharing and Collaboration in Volcanic Risk Mitigation at Galeras Volcano, Colombia" that was held in Pasto (Colombia), between 6 and 11 July, 2009. The general objective of this workshop was to analyze the existing hazard maps and safety plans for Galeras and form a bridge connecting scientists, decision makers, and other stake holders to promote a better understanding of the hazards presented by Galeras and the measures needed for mutual understanding and protection of people and property in the potentially threatened areas. Progress towards developing trust was achieved by requiring all the parties, including technicians, scientists, administrators and even farmers and indigenous people to listen to each others’ perceptions thought the entire week of the workshop. On the final day of the meeting a roundtable dialogue between the conflicting parts was moderated by social scientists. This intercourse identified, in a consensual manner, points of agreement to serve as starting positions for finding solutions to the areas of conflict. Irresolvable points were also identified during this roundtable discussion. The workshop showed that by sharing information within the framework of a full and frank communication, accepting (or at least listening to) each others’ arguments and trying to understand different points of view and served as a framework for an ongoing process of dialogue focused on resolving conflicts between the various stakeholder groups, even though they had previously reached the point of radicalized positions and statements.

Sheridan, M. F.; Cordoba, G. A.

2009-12-01

33

Macroscale and Microscale Organic Experiments, 3rd Edition (by Kenneth L. Williamson)  

NASA Astrophysics Data System (ADS)

The third edition of Williamson's Macroscale and Microscale Organic Experiments is welcome. Williamson's lab texts trace their lineage back not only through earlier editions, but, via a multi-edition conventional-scale text (Fieser and Williamson), to Louis Fieser's 1935 lab text. All these books are characterized by well-honed, reliable experiments and innovations such as the use of high-boiling solvents to accelerate reactions and an interesting sequence of transformations based on derivatives of 1,2-diphenylethane. Another connective thread, familiar to many, is the construction and use of simple homemade devices for a variety of laboratory purposes. Williamson himself is a pioneer in the change from macroscale chemistry in the student lab to the microscale approach. His text is written to use a set of glassware designed by him. At San Francisco State University we have used this glassware since the appearance of his first microscale book. Other instructors prefer microscale glassware with ground glass joints, but we find Williamson's kit to be entirely adequate for the undergraduate lab. Moreover, it is the least expensive type available, does not break easily, and is unattractive to graduate research students, hence does not "disappear". Other innovations appearing in earlier editions include sharp attention (all of Chapter 2) to safety, and the integration of waste disposal methods into the lab experiments themselves. By having students convert waste products into less harmful and less bulky materials in the lab, the enormous costs of disposal can be reduced without postlab treatment, a step not permitted except by a licensed waste-treatment facility. Williamson is also the first or one of the first to place computational chemistry into an introductory organic lab text. In this new edition, (optional) molecular mechanics calculations remain the workhorse method. These are now used in conjunction with 20 experiments, and are supplemented in some cases by suggested semiempirical computations. Other new texts, for example that by Pavia et al. (3rd ed., 1999), take computation even further. New features in the third edition include reduction of the macroscale experimental quantities to amounts compatible with 14/20 standard-taper glassware. Additionally, there are some useful and characteristically clever equipment adaptations for microfiltration and gas phase IR spectra, a few new or updated experiments, replacement of all IR spectra by Fourier transform spectra, and routine use of 250-MHz 1H NMR spectra. Two-dimensional NMR spectroscopy is briefly discussed but not further encountered. One new feature which looks promising is called "Surfing the Web". Pertinent Web site addresses dot the book, but it would be useful if these were indexed as a group. The brief but up-to-date chapter on searching the literature includes addresses and some advice on accessing commercial databases. Regarding the lab course itself, two useful addresses are http://ull.chemistry.uakron.edu/organic_lab/ and Williamson's own site (under construction as I write), http://www.mtholyoke.edu/courses/kwilliam/microscale.shtml, where pictures of techniques and other support information will interest teachers and students alike. Williamson has always been responsive to users of his texts, and will probably be quick to incorporate new information and improved techniques at this site. There are a few areas where improvement can still be made. The chapter on IR spectroscopy, although revised, does not contain an extensive, conventional table of characteristic group frequencies. All our instructors supplement the text with standard tables. We also find the section on organic qualitative analysis to be limited and mildly difficult to use. Students must do a lot of page turning, back and forth, to find some of the tests and recipes needed. At SFSU more than half of our second-semester lab is given over to organic qual, and no single lab text except that of Pasto, Johnson, and Miller seems adequate for this purpose. These cautions aside,

Keeffe, Reviewed By James

1999-11-01

34

Ground-water in the Teresina-Campo Maior area, Piaui, Brazil  

USGS Publications Warehouse

The Teresina-Campo Maior area lies in a presently developing farming and grazing region near the margin of drought-prone northeast Brazil where irrigated farming offers the best potential for economic development. The area comprises 9,700 square kilometers largely of catinga-covered tabular uplands which are drained by the perennial Rio Parnatba. The climate is hot and humid most of the year but with distinct wet and dry seasons. Temperature extremes range from 20?C to 39?C and the annum rainfall averages 1,200 millimeters. The area's ground-water reservoir is contained chiefly in sandstone aquifers of six westward-dipping sedimentary rock formations, all part of the Maranhao sedimentary basin. The youngest of these formations, namely the Piaut (Pennsylvarian), Poti (Mississippian), Longa (Upper Devonian), and Cabecas (Middle Devoniar), contain the principal aquifers. Precipitation is the primary source of recharge to these aquifers and is more than sufficient to replenish current withdrawals from wells. Underlying the principal aquifers are the untapped Pimenteiras and Serra Grande Formations (both Lower Devonian) which in areas adjacent to the report area are moderately good to excellent water producers. These aquifers are recharged principally by lateral inflow from the east. Water also occurs in the alluvial deposits (Quaternary) underlying the flood plain of the Rio Parnatba but recurrent and uncontrolled flooding at present (1966) precludes their development. Of little economic importance, because they lie above the zone of saturation, are the thin erosional remnants of the Pastos Bons (Upper Triassic), Matuca, and Pedra de Fogo (both Permian) Formations. There are in the report area about 200 drilled wells most of which are pumped with power-driven engines. The wells range from 40 to 500 meters deep but most do not exceed 150 meters, and practically all are completed open hole. Yields range from 500 liters per day for 6-inch-diameter domestic wells to 240,000 liters per hour for 10-inch high-capacity municipal wells. Although there are many more dug wells than drilled wells, dug wells account for less than 1 percent of the current (1966) draft. The current annual withdrawal from the principal aquifers is approximately 5 million cubic meters of which almost half is used for municipal supply and the rest for rural household and irrigation uses. Additional water for public supply is available from aquifers now being pumped, and larger yields probably could be obtained from rural wells designed to take full advantage of the aquifer. Analyses of 28 samples show that the chemical quality of the water is well below the accepted limits of mineral concentration for most uses. Water from the Longa Formation averages 842 milligrams per liter in total dissolved solids and is more mineralized than that in the Piaul and Port Formations which contain water averaging less than 300 milligrams per liter. The water in the Piaui and Poti aquifers is the most suitable in the area for irrigation and has SAR values of C1-S1 and C2-S1. The quantities of water currently being used for irrigation are relatively small (600,000 cubic meters annually) but will increase substantially when intensive irrigation becomes a reality. Divisio de Hydrogeologia da Superintendancia do Desenvolvimento do Nordeste estimates that about 2,500 million cubic meters of water per year would be needed to irrigate about 250,000 hectares in the Teresina-Campo Maior area (about 25 percent of the total area). This goal, however, is not likely to be realized as the water requirement is five times the estimated natural recharge to the aquifers of the area. Most of the water-bearing formations in the report area have barely been tapped and can be developed a great deal more. In fact, the current annual withdrawal from the principal aquifers is less than 0.0025 percent of a conservative estimate of annual replenishment from rainfall. Additionally, only the

Rodis, Harry G.; Suszczynski, Edison F.

1972-01-01