Search Results
Results 251 - 300 of 514
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Poirier André - - 2005
Higher osmium concentrations and lower 187Os/188Os ratios in sediments from urban areas have been linked to anthropogenic osmium sources. Automobile catalytic converters that use platinum group metals (PGM) are a potential source for this Os pollution. We present the first direct Os concentrations and isotopic measurements of catalytic converters for ...
Sudaryanto Y - - 2006
Cassava is one of the most important commodities in Indonesia, an agricultural country. Cassava is one of the primary foods in our country and usually used for traditional food, cake, etc. Cassava peel is an agricultural waste from the food and starch processing industries. In this study, this solid waste ...
Braune Birgit M - - 2005
Adult long-tailed ducks (Clangula hyemalis) were collected from nine locations across their breeding grounds in northern Canada and measurements of stable isotopes of carbon (delta(13)C), nitrogen (delta(15)N) and sulfur (delta(34)S) in bone collagen were used to investigate if relative use of freshwater habitats such as the Great Lakes (with expected ...
Robison Bruce H - - 2005
An unresolved issue in ocean science is the discrepancy between the food requirements of the animals living on the deep sea floor and their food supply, as measured by sediment traps. A 10-year time-series study of the water column off Monterey Bay, California, revealed that the discarded mucus feeding structures ...
Petzke Klaus J - - 2005
The stable nitrogen (15N) and carbon (13C) isotopic composition of tissues reflects the isotopic pattern of food sources. We investigated whether the isotopic composition of human hair can be used as a biomarker to predict the dietary intake of animal-derived food. Hair samples were collected from subjects during a 1987-1988 ...
Yamashita Koichi - - 2005
BACKGROUND: Prefilled disposable oxygen humidifiers are considered to prevent nosocomial pneumonia in hospital wards. However, their usefulness in intensive care units (ICUs) has not yet been established. In this study, we evaluated and compared contamination in prefilled disposable oxygen humidifiers and that in reusable oxygen humidifiers. METHODS: Six oxygen outlets ...
Perga M E - - 2005
Isotope turnover in muscle of ectotherms depends primarily on growth rather than on metabolic replacement. Ectotherms, such as fish, have a discontinuous pattern of growth over the year, so the isotopic signature of muscle (delta13C and delta15N) may only reflect food consumed during periods of growth. In contrast, the liver ...
Vaddi Haranath K - - 2005
PURPOSE: Physicochemical characterization and in vitro human skin diffusion studies of branched-chain ester and carbonate prodrugs of naltrexone (NTX) were compared and contrasted with straight-chain ester and carbonate NTX prodrugs. METHODS: Human skin permeation rates, thermal parameters, solubilities in mineral oil and buffer, and stabilities in buffer and plasma were ...
Taylor Geoff D - - 2005
A study was conducted to characterise the composition of nitrogen in urban stormwater in Melbourne, Australia, during baseflows and storm events, and to compare the results with international data. Nitrogen in Melbourne stormwater was predominantly dissolved (approximately 80%), with ammonia the least-abundant form (approximately 11%). Concentrations of nitrogen species did ...
Abouchami W - - 2005
The two parallel chains of Hawaiian volcanoes ('Loa' and 'Kea') are known to have statistically different but overlapping radiogenic isotope characteristics. This has been explained by a model of a concentrically zoned mantle plume, where the Kea chain preferentially samples a more peripheral portion of the plume. Using high-precision lead ...
Hollingsworth Robert G - - 2005
Ozone (O3) fumigation is a potential quarantine treatment alternative for controlling stored-product pests and surface insect pests on fresh agricultural commodities. We explored the effects of temperature, treatment time, controlled atmospheres, and vacuum in combination with O3 to control two important pests of ornamental crops: western flower thrips, Frankliniella occidentalis ...
Ometto Jean Pierre H B - - 2005
In this paper, we review some critical issues regarding carbon cycling in Amazonia, as revealed by several studies conducted in the Large Scale Biosphere Atmosphere Experiment in Amazonia (LBA). We evaluate both the contribution of this magnificent biome for the global net primary productivity/net ecosystem exchange (NPP/NEE) and the feedbacks ...
Chaler R - - 2005
The Ocean Anoxic Event 1 (OAE-1) in central sites of the Basque-Cantabrian Basin exhibits very reducing depositional conditions of sedimentation. These sedimentation events have left a distinct mixture of hydrocarbons that are represented by C22-C30 n-alkanes with a predominance of the even-carbon-number homologues, high relative proportions of squalane and C16-C24 ...
García Ruano José L - - 2005
The reduction of delta-ketosulfoxides constitutes the first evidence of the efficiency of the sulfinyl group to control the stereoselectivity of 1,5-asymmetric induction processes. The use of DIBAL/Yb(OTf)3 or L-Selectride as the reducing agents provides delta-hydroxysulfoxides with the opposite configuration at the hydroxylic carbon in a highly stereoselective way.
Mbande, Sekiwe; Zoology Department, ...
A number of studies have used stable carbon isotopes to analyse aspects of the food web structure in South African estuaries but none has compared mangrove and non-mangrove estuarine food webs. This study compares the primary carbon sources utilised by the ichthyofauna in the Mngazana (with extensive mangroves) and Mngazi ...
Schurr Mark R - - 2005
Earlier weaning has often been suggested as a cause for population growth after the evolution of food production. However, evidence for weaning-time reduction is largely circumstantial. Collagen stable nitrogen- and carbon-isotope ratios from juvenile and adult burials from four sites in eastern North America were measured to estimate weaning onsets ...
Deng Wei - - 2005
Besides affecting the xylanases production, different nitrogen sources present in the media also caused changes in the xylanosomal subunit composition of Streptomyces olivaceoviridis E-86. Four xylanosome fractions, purified from the culture supernatant of S. olivaceoviridis E-86 grown on different nitrogen sources, exhibited high specificity towards different xylans and were composed ...
Hasek B E - - 2005
Biochemical composition of ovary, embryo, and hepatopancreas tissues in wild populations of Armases cinereum and Sesarma nr. reticulatum were monitored during the reproductive season. Total lipid, carbon, nitrogen, C:N ratio, and water concentration of the ovary, hepatopancreas and embryos were quantified over the course of ovarian maturation. Ovary nitrogen concentration ...
Long John F - - 2005
In this study, we tested the hypothesis that the presence of iron in carbon particulates enhances ultrastructural perturbation in human monocyte-derived macrophages (MDMs) after phagocytosis. We used 1-microm synthetic carbon-based particulates, designed to simulate environmental particulates of mass median aerodynamic diameter < or = 2.5 microm (PM2.5). Cultures of human ...
Basile-Doelsch Isabelle - - 2005
Silicon is the second most abundant element on Earth. It is an important nutrient for phytoplankton and is readily absorbed by terrestrial vegetation; it also assists the removal of carbon dioxide from the atmosphere through the weathering of silicates. But the continental cycle of silicon is not well known, and ...
Peters Charles R - - 2005
A small minority of Africa's wild plant foods are C4. These are primarily the seeds of some of the C4 grasses, the rootstocks and stem/leaf bases of some of the C4 sedges (especially papyrus), and the leaves of some of the C4 herbaceous dicots (forbs). These wild food plants are ...
Sponheimer Matt - - 2005
Stable carbon isotope analyses have shown that South African australopiths did not have exclusively frugivorous diets, but also consumed significant quantities of C4 foods such as grasses, sedges, or animals that ate these foods. Yet, these studies have had significant limitations. For example, hominin sample sizes were relatively small, leading ...
Widory David - - 2005
Nitrate (NO3) is one of the world's major pollutants of drinking water resources. Although recent European Directives have reduced input from intensive agriculture, NO3 levels in groundwater are approaching the drinking water limit of 50 mg L(-1) almost everywhere. Determining the sources of groundwater contamination is an important first step ...
Hu W F - - 2005
Accumulation of poly hydroxyalkanoate (PHA) from excess activated sludge (EAS) was monitored and controlled via the oxidation-reduction potential (ORP) adjusting process. The ORP was adjusted and controlled by only regulating the gas-flow rate pumped into the cultural broth in which sodium acetate (C2) and propionate (C3) were used as carbon ...
Shim S - - 2005
The aim of this study was to quantify and characterize the dissolved organic carbon (DOC) of paddy fields and crop fields in Tottori, Japan. Dissolved organic carbon (DOC) and ultraviolet (UV) absorbance was measured for the filtrated water of each samples. DOC concentration and SUVA (specific UV absorbance) of biodegradation ...
Cherel Yves - - 2005
Using measurements of naturally occurring stable isotopes to reconstruct diets or source of feeding requires quantifying isotopic discrimination factors or the relationships between isotope ratios in food and in consumer tissues. Diet-tissue discrimination factors of carbon ((13)C/(12)C, or delta (13)C) and nitrogen ((15)N/(14)N, or delta (15)N) isotopes in whole blood ...
Langford Nigel J - - 2005
Carbon dioxide is a physiologically important gas, produced by the body as a result of cellular metabolism. It is widely used in the food industry in the carbonation of beverages, in fire extinguishers as an 'inerting' agent and in the chemical industry. Its main mode of action is as an ...
Gao Shan - - 2004
Foundering of mafic lower continental crust into underlying convecting mantle has been proposed as one means to explain the unusually evolved chemical composition of Earth's continental crust, yet direct evidence of this process has been scarce. Here we report that Late Jurassic high-magnesium andesites, dacites and adakites (siliceous lavas with ...
Ikehata Keisuke - - 2004
Optimum culture conditions for the batch production of extracellular peroxidase by Coprinus cinereus UAMH 4103 and Coprinus sp. UAMH 10067 were explored using 2 statistical experimental designs, including 2-level, 7-factor fractional factorial design and 2-factor central composite design. Of the 7 factors examined in the screening study, the concentrations of ...
Hanan Barry B - - 2004
The origin of the isotopic signature of Indian mid-ocean ridge basalts has remained enigmatic, because the geochemical composition of these basalts is consistent either with pollution from recycled, ancient altered oceanic crust and sediments, or with ancient continental crust or lithosphere. The radiogenic isotopic signature may therefore be the result ...
Bonnefille R - - 2004
Plio-Pleistocene global climate change is believed to have had an important influence on local habitats and early human evolution in Africa. Responses of hominin lineages to climate change have been difficult to test, however, because this procedure requires well documented evidence for connections between global climate and hominin environment. Through ...
Xie Huixiang - - 2004
Photodecarboxylation (often stoichiometrically expressed as RCOOH + (1/2)O2 --> ROH + CO2) has long been postulated to be principally responsible for generating CO2 from photooxidation of dissolved organic matter (DOM). In this study, the quantitative relationships were investigated among O2 consumption, CO2 production, and variation of carboxyl content resulting from ...
Chang Moo Been - - 2004
Oxides of nitrogen (NOx) [nitrogen oxide (NO) + nitrogen dioxide (NO2)] and sulfur dioxide (SO2) are removed individually in traditional air pollution control technologies. This study proposes a combined plasma scrubbing (CPS) system for simultaneous removal of SO2 and NOx. CPS consists of a dielectric barrier discharge (DBD) and wet ...
Simpson Myrna J - - 2004
Several recent reports suggest that black carbon (BC), which broadly encompasses charcoal, soot, and other forms of pyrogenic carbon, may constitute a significant proportion of the refractory carbon in soil and sedimentary organic matter. BC is a sink for biospheric and atmospheric carbon dioxide, and is intimately tied to the ...
Dickhut Rebecca M - - 2004
To test the potential for using stable isotope fractionation to examine the atmospheric transport of semivolatile organic compounds (SOCs), we conducted simplified distillation experiments in the laboratory and a tracer-release experiment using mixtures of stable isotope-labeled (D and 13C) and unlabeled SOCs. Perdeuterated phenanthrene and alpha-hexachlorocyclohexane were transported more slowly ...
Freeman C - - 2004
Peatlands represent a vast store of global carbon. Observations of rapidly rising dissolved organic carbon concentrations in rivers draining peatlands have created concerns that those stores are beginning to destabilize. Three main factors have been put forward as potential causal mechanisms, but it appears that two alternatives--warming and increased river ...
Thornley J H M - - 2004
Climate change is predicted to shorten the fire interval in boreal forests. Many studies have recorded positive effects of fire on forest growth over a few decades, but few have modeled the long-term effects of the loss of carbon and nitrogen to the atmosphere. We used a process-based, dynamic, forest ...
Yavich Alex A - - 2004
The major purpose of this study was to develop a simple procedure to describe the kinetics of biodegradation of natural organic matter (NOM) in drinking water and to use this procedure to evaluate changes in the concentration of biodegradable organic matter during ozonation and biotreatment. The proposed approach quantitatively describes ...
Sowunmi, Akindayo O; Department ...
Influence of inorganic N<sub>2</sub> forms on pond food organisms was investigated. Seven identified plankton taxa comprising four phytoplankton: Desmidiaceae (desmids), Bacillariophyceae (diatoms), Cyanophyceae (blue-green algae) and Chlorophyceae (green algae) and three zooplankton: Protozoa, Cladocera and Rotifera fluctuated in response to nutrient inputs. All recorded significant F-value across treatments. With exception ...
Chadwick V. Tillberg
Workers of Paraponera clavata, a common Neotropical ant, collect both nectar and insect prey. Previous reports show that nectar accounts for up to 90 percent of the ants' food loads, while calculations suggest that nectar contributes only 10 percent of colonies' energy supply. We assessed the trophic source of carbon ...
Thom Corinna - - 2004
The hawkmoth Manduca sexta (Lepidoptera: Sphingidae), an experimentally favorable Lepidopteran that is highly sensitive to carbon dioxide (CO2), feeds on the nectar of a range of flowering plants, such as Datura wrightii (Solanaceae). Newly opened Datura flowers give off dramatically elevated levels of CO2 and offer ample nectar. Thus, floral ...
Zimnoch Miroslaw - - 2004
This article presents the results of measurements of the isotopic composition and concentration of atmospheric carbon dioxide, performed on air samples from Kraków (Southern Poland) in different seasons of the year. A simple isotope mass balance model has been applied to determine the contributions of different sources of CO2 to ...
Nagashima Kazuhide - - 2004
Primitive chondritic meteorites contain material (presolar grains), at the level of a few parts per million, that predates the formation of our Solar System. Astronomical observations and the chemical composition of the Sun both suggest that silicates must have been the dominant solids in the protoplanetary disk from which the ...
Matthews Blake - - 2004
Individual variation in the diet of consumers is common in many ecological systems and has important implications for the study of population dynamics, animal behavior, and evolutionary or ecological interactions. Ecologists frequently quantify the niche of a population by intensive analyses of gut contents and feeding behaviors of consumers. Inter-individual ...
Huang W J - - 2004
Bromate (BrO3-) and assimilable organic carbon (AOC) removal by activated carbon after ozonation is a subject of concern, since BrO3- and AOC are commonly found in the ozonation of bromide-containing and organic-rich waters. In batch ozonation experiment of this study, the major ozonation by-products were bromate, bromform, aldehydes, and AOC, ...
Tripathi G - - 2004
An epigeic (surface dweller) earthworm species Eisenia fetida and an anecic (deep burrower) earthworm species Lampito mauritii have been tested for decomposition of kitchen waste plus cow dung. Chemical analyses of worm-worked substrates by both species showed g/kg increases in nitrogen, phosphorus and potassium and decreases in C/N and C/P ...
Virtue Mark A - - 2004
OBJECTIVE: Subjects with decreased erythrocyte survival have an unusually low GHb percentage. The goal of this study was to determine whether hyperglycemia, as reflected by GHb percentage, is associated with decreased erythrocyte survival. RESEARCH DESIGN AND METHODS: Erythrocyte survival was quantitated in 23 subjects with type 2 diabetes, and these ...
Alster Tina S - - 2004
BACKGROUND: Upper eyelid dermatochalasis is typically treated with excisional blepharoplasty. The role of the CO2 laser previously had been confined to that of a vaporizing, incisional, or hemostatic tool. Over the past several years, however, ablative CO2 laser skin resurfacing has been popularized as an adjunctive treatment to blepharoplasty to ...
Froneman, PW; Department of ...
Stable isotope (&delta;13C) composition of the food web in the temperate Kariega estuary in summer and winter was analysed to determine the trophic relationships between 19 taxa. There was no seasonality in the stable isotope ratios of the dominant producers and consumers in the estuary. Two distinct zooplankton assemblages were ...
Raczek Barbara - - 2004
The results of dynamic measurements of carbon dioxide (CO2, in %) in exhaled air during speech are presented. Fourteen stuttering persons and 14 persons with fluent speech took part in a test that involved independent speaking and echo-assisted speaking (delayed auditory feedback). A statistical comparative analysis of average levels of ...
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