973 resultados para Southwest Iberian margin
Resumo:
The primary goal of this project was to launch a pilot population study in the spring-fed wetland area southwest of Montana Tech to establish baseline data on density, distribution, abundance, and diversity of amphibians in the area. The current confirmed species at the select site is the Columbia spotted frog (Rana luteiventris). Based on preliminary habitat assessment and existing literature, other species possibilities included the long-toed salamander (Ambrystoma macrodactylum) boreal chorus frog (Pseudacris maculata), the Rocky Mountain tailed frog (Ascaphus montanus), and the leopard frog (Rana pipiens), (Werner et al. 2004) though the latter species is considered unlikely based on the specie’s declining status (Werner 2003; Werner et al. 2004). The project’s secondary goal was to collect basic habitat and environmental data: vegetation, precipitation, temperature. The third goal was to explore correlations between species prevalence and environmental data to expand the scientific understanding of population dynamics in the field of amphibian studies (see: Ferner, 2007; Dodd, 2010).
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The purpose of this study was to investigate the accuracy of diagnosing interproximal subgingival caries at crown margins. A total of 32 subgingival interproximal crown margin areas were examined by 10 clinicians (n = 320) using conventional diagnostic methods on extracted, crowned teeth mounted in a specially designed cast. Crown margins were located 1.5 mm below the level of the artificial gingiva. Clinical and radiographic diagnoses were compared to the histopathologic findings for each site. Both visual-tactile and radiographic evaluations revealed a weak diagnostic accuracy for interproximal subgingival crown margin caries.
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Bathurst Harbour in World Heritage southwest Tasmania, Australia, is one of the world’s most pristine estuarine systems. At present there is a lack of data on pollution impacts or long-term natural variability in the harbor. A ca. 350-year-old 210Pb-dated sediment core was analysed for trace metals to track pollution impacts from local and long-range sources. Lead and antimony increased from AD 1870 onwards, which likely reflects remote (i.e. mainland Australian and global) atmospheric pollution sources. Variability in the concentrations of copper and zinc closely followed the history of mining activities in western Tasmania, which began in the AD 1880s. Tin was generally low throughout the core, except for a large peak in AD 1989 ± 0.5 years, which may be a consequence of input from a local small-scale alluvial tin mine. Changes in diatom assemblages were also investigated. The diatom flora was composed mostly of planktonic freshwater and benthic brackish-marine species, consistent with stratified estuarine conditions. Since mining began, however, an overall decrease in the proportion of planktonic to benthic taxa occurred, with the exception of two distinct peaks in the twentieth century that coincided with periods of high rainfall. Despite the region’s remoteness, trace metal analyses revealed evidence of atmospheric pollution from Tasmanian and possibly longer-range mining activities. This, together with recent low rainfall, appears to have contributed to altering the diatom assemblages in one of the most pristine temperate estuaries in the world.
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Economic comparisons of income on highly erodible land (HEL) in Adams County were made utilizing five years of grazing data collected from a 13- paddock intensive-rotational grazing system and a four-paddock rotational-grazing system and four years of data collected from an 18-paddock intensive-rotational grazing system, all at the Adams County CRP Research and Demonstration Farm near Corning. Net income from the average grazing weight-gain of Angus-sired calves nursing crossbred cows was compared to the net income from grazing yearling steers, to the net income of eight NRCS-recommended crop rotations, and to the Conservation Reserve Program (CRP) option. Results of these comparisons show the 13-paddock intensive rotational grazing system with cow-calf pairs to be the most profitable alternative, with a net return of $19.86 per acre per year. The second most profitable alternative is the CRP option, with a net return of $13.09 per acre, and the third most profitable option is the fourpaddock rotation with cows and calves with a net return of $12.53 per acre. An 18-paddock system returned a net income of $2.47 per acre per year with cows and calves in 1993, but lost an average of $107.69 per acre each year in 1994 and 1995 with yearling steers. Each year, the steers were purchased high and sold low, contributing to the large loss per acre. The following recommended crop rotations all show net losses on these 9-14 % slope, Adair-Shelby Complex soils (ApD3): continuous corn; corn-soybean rotation; corn-soybean rotation with a farm program deficiency payment; corn-corn-corn-oats-meadow-meadow rotation with grass headlands; continuous corn to “T” with grass headlands and buffer strips; continuous corn to “T” with grass headlands, buffer strips, and a deficiency payment; corn-corn-oats-meadow rotation to “T”; and corn-soybeans-oats-meadow-meadow-meadow-meadow rotation to “T”. Per-acre yield assumptions of 90 bushels for corn, 30 bushels for soybeans, 45 bushels for oats, and four tons for alfalfa were used, with per-bushel prices of $2.40 on corn, $5.50 on soybeans, and $1.50 on oats. Alfalfa hay was priced at $40.00 per ton and grass hay at $33.33 per ton. The calf weight-gain in the cow/ calf systems was valued at $.90 per pound. All crop expenses except land costs were calculated from ISU publication Fm 1712, “Estimated Costs of Crop Production in Iowa - 1995.” Land costs were determined by using an opportunity cost and actual property tax figures for the land at the grazing site. In preparation for the end of the CRP beginning in 1996, further economic comparisons will be made after additional grazing seasons and data collection. This project is an interagency cooperative effort sponsored by the Southern Iowa Forage and Livestock Committee which has special permission from the USDA Farm Service Agency (FSA) to use CRP land for research and demonstration.
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In the forearc of the Andean active margin in southwest Ecuador, the El Oro metamorphic complex exhibits a well exposed tilted forearc section partially migmatized. We used Raman spectroscopy on carbonaceous matter (RSCM) thermometry and pseudosections coupled with mineralogical and textural studies to constrain the pressure–temperature (P–T) evolution of the El Oro metamorphic complex during Triassic times. Our results show that anatexis of the continental crust occurred by white-mica and biotite dehydration melting along a 10 km thick crustal domain (from 4.5 to 8 kbar) with increasing temperature from 650 to 700 °C. In the biotite dehydration melting zone, temperature was buffered at 750–820 °C in a 5 km thick layer. The estimated average thermal gradient during peak metamorphism is of 30 °C/km within the migmatitic domain can be partitioned into two apparent gradients parts. The upper part from surface to 7 km depth records a 40–45 °C/km gradient. The lower part records a quasi-adiabatic geotherm with a 10 °C/km gradient consistent with an isothermal melting zone. Migmatites U–Th–Pb geochronology yielded zircon and monazite ages of 229.3 ± 2.1 Ma and 224.5 ± 2.3 Ma, respectively. This thermal event generated S-type magmatism (the Marcabeli granitoid) and was immediately followed by underplating of the high-pressure low-temperature (HP-LT) Arenillas–Panupalí unit at 225.8 ± 1.8 Ma. The association of high-temperature low-pressure (HT-LP) migmatites with HP-LT unit constitutes a new example of a paired metamorphic belt along the South American margin. We propose that in addition to crustal thinning, underplating of the Piedras gabbroic unit before 230 Ma provided the heat source necessary to foster crustal anatexis. Furthermore, its MORB signature shows that the asthenosphere was involved as the source of the heat anomaly. S-type felsic magmatism is widespread during this time and suggests that a large-scale thermal anomaly affected a large part of the South American margin during the late Triassic. We propose that crustal anatexis is related to an anomaly that arose during subduction of the Panthalassa ocean under the South American margin. Slab verticalization or slab break-off can be invoked as the origin of the upwelling of the asthenosphere.
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PURPOSE: To determine whether a 3-mm isotropic target margin adequately covers the prostate and seminal vesicles (SVs) during administration of an intensity-modulated radiation therapy (IMRT) treatment fraction, assuming that daily image-guided setup is performed just before each fraction. MATERIALS AND METHODS: In-room computed tomographic (CT) scans were acquired immediately before and after a daily treatment fraction in 46 patients with prostate cancer. An eight-field IMRT plan was designed using the pre-fraction CT with a 3-mm margin and subsequently recalculated on the post-fraction CT. For convenience of comparison, dose plans were scaled to full course of treatment (75.6 Gy). Dose coverage was assessed on the post-treatment CT image set. RESULTS: During one treatment fraction (21.4+/-5.5 min), there were reductions in the volumes of the prostate and SVs receiving the prescribed dose (median reduction 0.1% and 1.0%, respectively, p<0.001) and in the minimum dose to 0.1 cm(3) of their volumes (median reduction 0.5 and 1.5 Gy, p<0.001). Of the 46 patients, three patients' prostates and eight patients' SVs did not maintain dose coverage above 70 Gy. Rectal filling correlated with decreased percentage-volume of SV receiving 75.6, 70, and 60 Gy (p<0.02). CONCLUSIONS: The 3-mm intrafractional margin was adequate for prostate dose coverage. However, a significant subset of patients lost SV dose coverage. The rectal volume change significantly affected SV dose coverage. For advanced-stage prostate cancers, we recommend to use larger margins or improve organ immobilization (such as with a rectal balloon) to ensure SV coverage.
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OBJECTIVE: The primary objective of this trial was to evaluate the response rate for trimetrexate in conjunction with 5-FU and leucovorin (LV) (= TFL) in the treatment of advanced gastric cancer in a phase II, cooperative group setting. METHODS: Patients with locally advanced, unresectable, or metastatic adenocarcinoma of the stomach received trimetrexate 110 mg/m IV over 60 minutes day 1, followed by 5-FU 500 mg/m IV bolus and LV 200 mg/m IV over 60 minutes day 2, followed by oral LV 15 mg every 6 hours x 7 doses, all weekly for 6 weeks followed by 2 weeks of rest, continued until progression. RESULTS: Characteristics for 37 eligible patients: median age 63 (range: 23-83); male/female: 69% of 31%; performance status 0/1/2 15/20/1. The confirmed response rate was 19%, and median overall survival was 6 months. Two patients died as a result of therapy, 1 because of infection without significant neutropenia, and 1 due to perforation of a responding gastric lesion. Seventy-two percent experienced grades 3 and 4 toxicity, most commonly diarrhea, fatigue, and lymphopenia. CONCLUSIONS: This regimen achieves response rates comparable to other 5-FU-based regimens, when used in treatment of incurable gastric cancer. Toxicity appears manageable.
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Regional climate simulations are conducted using the Polar fifth-generation Pennsylvania State University (PSU)-NCAR Mesoscale Model (MM5) with a 60-km horizontal resolution domain over North America to explore the summer climate of the Last Glacial Maximum (LGM: 21 000 calendar years ago), when much of the continent was covered by the Laurentide Ice Sheet (LIS). Output from a tailored NCAR Community Climate Model version 3 (CCM3) simulation of the LGM climate is used to provide the initial and lateral boundary conditions for Polar MM5. LGM boundary conditions include continental ice sheets, appropriate orbital forcing, reduced CO2 concentration, paleovegetation, modified sea surface temperatures, and lowered sea level. The simulated LGM summer climate is characterized by a pronounced low-level thermal gradient along the southern margin of the LIS resulting from the juxtaposition of the cold ice sheet and adjacent warm ice-free land surface. This sharp thermal gradient anchors the midtropospheric jet stream and facilitates the development of synoptic cyclones that track over the ice sheet, some of which produce copious liquid precipitation along and south of the LIS terminus. Precipitation on the southern margin is orographically enhanced as moist southerly low-level flow (resembling a contemporary, Great Plains low-level jet configuration) in advance of the cyclone is drawn up the ice sheet slope. Composites of wet and dry periods on the LIS southern margin illustrate two distinctly different atmospheric flow regimes. Given the episodic nature of the summer rain events, it may be possible to reconcile the model depiction of wet conditions on the LIS southern margin during the LGM summer with the widely accepted interpretation of aridity across the Great Plains based on geological proxy evidence.
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Two Proterozoic terranes with different metamorphic histories are distinguished from geological mapping in southwestern Wedel Jarlsberg Land: a northern greenschist facies terrane and a southern amphibolite facies terrane which has been overprinted by greenschist facies metamorphism. To better characterize the tectonothermal history of these terranes we have obtained new Ar-40/Ar-39 mineral dates from this area. A muscovite separate from the northern terrane yielded a Caledonian plateau age of 432 +/- 7 Ma. The southern terrane yielded significantly older Ar-40/Ar-39 ages with three muscovite plateau dates of 584 +/- 14 Ma, 575 +/- 15 Ma, and 459 +/- 9 Ma, a 484 +/- 5 Ma biotite plateau date, and a 616 +/- 17 Ma hornblende plateau date. The oldest thermochronological dates are over 300 Ma younger than the age of amphibolite facies metamorphism and therefore probably do not represent uplift-related cooling. Instead, the Vendian dates correlate well with a regionally widespread magmatic and metamorphic/thermal resetting event recognized within Caledonian complexes of northwestern Spitsbergen and Nordaustlandet. The apparent Ordovician dates are interpreted to represent partial resetting, suggesting that late Caledonian greenschist facies overprinting of the southern terrane was of variable intensity.
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Assuming a channelized drainage system in steady state, we investigate the influence of enhanced surface melting on the water pressure in subglacial channels, compared to that of changes in conduit geometry, ice rheology and catchment variations. The analysis is carried out for a specific part of the western Greenland ice-sheet margin between 66 degrees N and 66 degrees 30' N using new high-resolution digital elevation models of the subglacial topography and the ice-sheet surface, based on an airborne ice-penetrating radar survey in 2003 and satellite repeat-track interferometric synthetic aperture radar analysis of European Remote-sensing Satellite 1 and 2 (ERS-1/-2) imagery, respectively. The water pressure is calculated up-glacier along a likely subglacial channel at distances of 1, 5 and 9 km from the outlet at the ice margin, using a modified version of Rothlisberger's equation. Our results show that for the margin of the western Greenland ice sheet, the water pressure in subglacial channels is not sensitive to realistic variations in catchment size and mean surface water input compared to small changes in conduit geometry and ice rheology.
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During November 2010–February 2011, we used camera traps to estimate the population density of Eurasian lynx Lynx lynx in Ciglikara Nature Reserve, Turkey, an isolated population in southwest Asia. Lynx density was calculated through spatial capture—recapture models. In a sampling eff ort of 1093 camera trap days, we identifi ed 15 independent individuals and estimated a density of 4.20 independent lynx per 100 km2, an unreported high density for this species. Camera trap results also indicated that the lynx is likely to be preying on brown hare Lepus europaeus, which accounted for 63% of the non-target species pictured. As lagomorph populations tend to fl uctuate, the high lynx density recorded in Ciglikara may be temporary and may decline with prey fl uctuation. Therefore we recommend to survey other protected areas in southwestern Turkey where lynx is known or assumed to exist, and continuously monitor the lynx populations with reliable methods in order to understand the populations structure and dynamics, defi ne sensible measures and management plans to conserve this important species.