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Bozelli, Reinaldo Luiz
Bauxite processing in Porto Trombetas, Brazil, generated a fine particulate effluent that was dumped into Lake Batata over a ten-year period, leading to high suspended solids, reduced water transparency and increased turbidity in parts of the lake. The influence of bauxite tailings on cladoceran feeding was studied by measuring carbon ...
Schulze E - - 1998
Naturally produced methane shows different delta 13C-values with respect to its origin, e.g., geological or biological. Methane-production of ruminants is considered to be the dominant source from the animal kingdom. Isotopic values of rumen methane--given in literature--range between -80/1000 and -50/1000 and are related to feed composition and also sampling ...
Okamoto M - - 1998
A full-automated hyperbaric environmental control system (HECS) for nitrox saturation diving HABITAT has been examined since 1994. HECS was planned to be located inside HABITAT and operated automatically by supplying electricity and cooling water. To realize this, a regenerative-type carbon dioxide removal method and AC 100 V electric powered blower ...
Boag B - - 1998
We report the first isotopic study of an animal host-parasite system. Parasitic, intestinal nematodes, Graphidium strigosum and Passalurus ambiguus, were 15N-enriched relative to their host, the European rabbit Oryctolagus cuniculus, while parasitic cestodes, Cittataenia denticulata and Mosgovoyia pectinata, were 15N-depleted, suggesting different trophic relationships. Host embryos were more similar in ...
Ambrose S H - - 1997
Proportions of marine vs. terrestrial resources in prehistoric human diets in the southern Mariana Islands (Guam, Rota, Saipan), Micronesia, have been estimated by analysis of stable isotope ratios of carbon and nitrogen in bone collagen and of carbon in apatite. The isotopic composition of marine and terrestrial food resources from ...
Manabe K K Department of Psychology, University of Maryland, College Park MD 20742, - - 1997
Budgerigars were trained to make a specific call using a real-time automated call recognition system and food reward. Calls produced by the bird were followed by food only if they were similar enough to a template call. The selective reinforcement of a particular call type increased the similarity of the ...
Bidigare R R - - 1997
The carbon isotopic fractionation accompanying formation of biomass by alkenone-producing algae in natural marine environments varies systematically with the concentration of dissolved phosphate. Specifically, if the fractionation is expressed by epsilon p approximately delta e - delta p, where delta e and delta p are the delta 13C values for ...
Raj A B - - 1997
1. Carcase and meat quality were evaluated under commercial conditions in 400 broilers either killed with a mixture of 30% carbon dioxide and 60% argon in air or stunned with a 50 Hz AC with clipped sine wave. 2. Compared with electrical stunning, killing broilers with the gas mixture eliminated ...
Mohan R - - 1997
We used rebreathing with prior hyperventilation to measure ventilatory responses to CO2 at iso-oxic PO2's of 100, 80, 60 and 40 mmHg in seven subjects. The mean sub-threshold ventilation (S.E.) of 7.60 (1.31) L min-1 did not vary with iso-oxic PO2. The mean peripheral-chemoreflex threshold of 41 (0.6)) mmHg PCO2 ...
Cabana G - - 1996
Recent studies have shown the utility of delta(15)N to model trophic structure and contaminant bioaccumulation in aquatic food webs. However, cross-system comparisons in delta(15)N can be complicated by differences in delta(15)N at the base of the food chain. Such baseline variation in delta(15)N is difficult to resolve using plankton because ...
Raj A B - - 1996
The reactions of turkeys to the presence of either 90 per cent argon in air (anoxia), 72 per cent carbon dioxide in air or a mixture of 30 per cent carbon dioxide and 60 per cent argon in air with 3 per cent residual oxygen were tested. The majority of ...
Collins L S - - 1996
Oceanographic changes caused by the emerging Central American isthmus, which completely severed connections between the Caribbean Sea and tropical Pacific Ocean about 3.5 million years ago, began to stimulate evolution of Caribbean reef corals and benthic foraminifera in the Late Miocene. At that time, first appearances of benthic foraminifera increased, ...
Yoshinaga J - - 1996
The carbon and nitrogen stable isotopic composition of the scalp hair and diet of Gidra-speaking people in four villages in Papua New Guinea is presented. The isotopic composition of hair was measured, while that of the diet was estimated from food consumption survey data and the measured isotopic composition and ...
Relakis K - - 1996
This study was undertaken to assess the effect of CO2 laser vaporization, 5-fluorouracil 5% (5-FU) topical application and Interferon alpha-2a (IFA alpha-2a) in the treatment of C.A. or F.C. of the male genital tract. From March 1986 to September 1991, 1372 men, sexual partners of women with F.C. or C.A. ...
Frost C - - 1995
BACKGROUND: Observational and short term intervention studies have reported that smokers of low tar cigarettes inhale more deeply (that is, compensate) than those who smoke high tar cigarettes. To quantify this effect a long term randomised trial was conducted on the effects of switching to low tar cigarettes. METHODS: The ...
Bowring S A - - 1995
The Archean crust contains direct geochemical information of the Earth's early planetary differentiation. A major outstanding question in the Earth sciences is whether the volume of continental crust today represents nearly all that formed over Earth's history or whether its rates of creation and destruction have been approximately balanced since ...
Ishibe T - - 1995
Inhaled nitric oxide (NO) is used for the treatment of pulmonary hypertension as a selective pulmonary vasodilator. However, NO is oxidized rapidly to the more toxic nitrogen dioxide (NO2). Elimination of NO2 from inspired gas is essential for safe clinical use NO. We therefore investigated the efficacy of soda lime ...
Raj A B - - 1995
The efficacy for the euthanasia of day-old chicks of mixtures of carbon dioxide and air, or carbon dioxide and argon containing 1, 2 or 5 per cent residual oxygen, or argon containing 1 or 2 per cent residual oxygen was tested in three experiments. The time to the onset of ...
Weisler M I - - 1995
The prehistoric settlement of the Pacific Ocean has intrigued scholars and stimulated anthropological debate for the past two centuries. Colonized over a few millennia during the mid to late Holocene, the islands of the Pacific--displaying a wide diversity of geological and biotic variability--provided the stage for endless "natural experiments" in ...
Maurette M - - 1995
"Interplanetary Dust Particles" with sizes approximately 10 micrometers collected in the stratosphere (IDPs), as well as much larger "giant" micrometeorites retrieved from Antarctic ice melt water (AMMs), are mostly composed of unequilibrated assemblages of minerals, thus being related to primitive unequilibrated meteorites. Two independent evaluations of the mass flux of ...
Mitchell C A - - 1994
Long-duration future habitation of space involving great distances from Earth and/or large crew sizes (eg, lunar outpost, Mars base) will require a controlled ecological life-support system (CELSS) to simultaneously revitalize atmosphere (liberate oxygen and fix carbon dioxide), purify water (via transpiration), and generate human food (for a vegetarian diet). Photosynthetic ...
Chesler M M Department of Physiology, New York University Medical Center, NY - - 1994
The extracellular pH of the brain is subject to shifts during neural activity. To understand these pH changes, it is necessary to measure [H+], [HCO3-], [CO3(2-)] and [CO2]. In principle, this can be accomplished using CO3(2-) and pH-sensitive microelectrodes; however, interference from HCO3- and Cl-, and physiological changes in [HCO3-], ...
Hedge A - - 1994
The effect of alternative smoking policies, which prohibited or restricted smoking, on indoor air quality was studied in 27 air-conditioned office buildings. Carbon monoxide, carbon dioxide, respirable particulates, formaldehyde, ultraviolet particulate matter (u.v.PM), nicotine, air temperature, relative humidity and illumination were measured at eight sample sites in each building. Smoking ...
Shelef M - - 1994
In 1970, before the implementation of strict controls on emissions in motor vehicle exhaust gas (MVEG), the annual USA incidence of fatal accidents by carbon monoxide in the MVEG was approximately 800 and that of suicides approximately 2000 (somewhat less than 10% of total suicides). In 1987, there were approximately ...
Kumagai H - - 1994
The biosynthesis of antitumor antibiotic cytogenin, 3-hydroxymethyl-6-methoxy-8-hydroxy-isocoumarin, was studied by feeding 14C- or 13C-labeled compounds to culture of the producing organism, Streptoverticillium eurocidicum MI43-37F11. 14C-Acetate and 14C-methionine were efficiently incorporated into cytogenin as precursors. 13C NMR studies proved that the carbon skeleton of cytogenin is derived from pentaketide intermediate due ...
Havens K E - - 1994
An in-situ experiment was performed to quantify the impacts of copper sulfate on plankton structure and carbon dynamics. Plankton were exposed to 140 microg litre(-1) copper in quadruplicate mesocosms. Community structure was monitored for 14 days by microscopical counts and compared with untreated controls. Carbon dynamics were assessed by tracer ...
Simpkins C O - - 1994
The effect of the stress-induced, cysteine-rich protein, metallothionein I (MT), on oxygen consumption by rat liver mitochondria was studied. Using a Clark-type oxygen electrode we found that electron transport from succinate to oxygen was enhanced by MT whereas ADP-initiated oxygen consumption was inhibited by MT. The MT effect was concentration ...
Murphy C E CE - - 1993
The transport and cycling of tritium in the environment can be understood in terms of the role of hydrogen in the environment. Physical and chemical isotopic effects, while present in some transport mechanisms and chemical reactions, are not important factors in environmental tritium dynamics. In addition, because of the role ...
Lal D - - 1993
We present calculations of rates of production of several nuclides in the Martian atmosphere and in the regolith due to nuclear interactions of cosmic ray and radiogenic particles and consider their implications to the evolutionary history of Mars. Nuclides selected are those which, considering their chemical properties, may be useful ...
Auer D E - - 1993
Total plasma carbon dioxide (TCO2) concentrations were measured in Standardbred horses to determine criteria to discriminate between normal horses and horses with excessive TCO2 concentrations on raceday. TCO2 concentrations from stabled horses were distributed normally with a mean of 30.2 mmol/L and a standard deviation of 1.2 (n = 192) ...
Kronberg S L - - 1993
Leafy spurge (Euphorbia esula) is an introduced forb that is invading western rangelands. Goats (Capra hircus) readily graze the plant, but cattle (Bos tarus) generally and sheep (Ovis aries) locally appear to develop conditioned flavor aversions to leafy spurge. They either avoid the plant entirely or graze it reluctantly. We ...
Kasting J F - - 1993
Ideas about atmospheric composition and climate on the early Earth have evolved considerably over the last 30 years, but many uncertainties still remain. It is generally agreed that the atmosphere contained little or no free oxygen initially and that oxygen concentrations increased markedly near 2.0 billion years ago, but the ...
Herman D C - - 1993
An environmental actinomycetes, capable of utilizing p-nitrophenol as its sole carbon and nitrogen source, was starved for an 8-week period and showed no reduction in its ability to biodegrade p-nitrophenol. Microscopic examination revealed that starvation of the bacterium resulted in the fragmentation of filaments into individual cells.
Lydersen T T Fircrest School, Seattle, Washington - - 1992
Three rats pressed a lever for food on differential-reinforcement-of-low-rate (DRL) schedules ranging from 16 s to 96 s. During DRL performance, a response to a second lever turned off chamber illumination and produced a timeout period during which food could not be obtained. During timeout periods, a response to the ...
Larsen C S - - 1992
Measurement of carbon and nitrogen stable isotope ratios (delta 13C and delta 15N) in samples of human bone collagen (n = 93) from a temporal series of four prehistoric (early preagricultural, late preagricultural, early agricultural, late agricultural) and two historic (early contact, late contact) periods from the Georgia Bight, a ...
Allen H - - 1992
Carbon monoxide poisoning is a well recognized, but uncommon hazard of sport and inshore diving, which occurs either as a result of a faulty air compressor or from air contamination by the exhaust of nearby petrol engines. The incidence of carbon monoxide poisoning may be under-reported as it may mimic ...
Liu Z - - 1992
Carbon monoxide (CO) was employed to assess the role of ferrous hemoproteins in the vasodilation and biotransformation of glyceryl trinitrate (GTN) in rabbit aortic strips. These tissues were contracted submaximally with phenylephrine, exposed to CO for 5 min, and then incubated with 0.5 microM [1,3(14) C]GTN in the presence of ...
Atanasov P - - 1992
Amperometric biosensors for the determination of beta-D-glucose have been constructed. They were based on a porous matrix of carbon blacks--'Ketjenblack' (KB) and 'Shawinigan black' (SB) wet-proofed with polytetrafluorethylene. Glucose-sensitive elements were prepared by subsequent adsorptional immobilization of 1,1'-dimethylferrocene (DMFc) and nickel-ocene (Nc) on 'Shawinigan black' or tetracyanoquinodimethane (TCNQ) on 'Ketjenblack' ...
Kaiserman M J - - 1992
Thirty-one Canadian brands of fine-cut tobaccos for roll-your-own cigarettes (RYOs) were evaluated under standard conditions using mandated tube and filter combinations. Results indicate no evidence of a significant difference in the amounts of tar, nicotine, and carbon monoxide produced by the 31 brands. In addition, the data emphasize that it ...
Kline D L - - 1991
Field studies were conducted to determine the responses of mosquitoes associated with irrigated riceland in Arkansas to 1-octen-3-ol (octenol), carbon dioxide (CO2) and combinations of both. Octenol was released at 4.1 (wick in) and 41.1 (wick out) mg/h and CO2 at 200, 500 and 1,000 ml/min. Octenol alone did not ...
Stone J - - 1991
A suite of morphologically distinctive silicon carbide (SiC) grains from the Orgueil and Murchison carbonaceous chondrite meteorites contains Si and C of highly anomalous isotopic composition. All of the SiC grains in this suite are characterized by a distinctive platy morphology and roughly developed hexagonal crystal forms that allow them ...
Turnlund J R - - 1991
A number of minerals contained in foods are essential nutrients for humans, animals, and/or plants. While most vitamins are very well absorbed, most essential minerals are not. Usual absorption of minerals ranges from less than 1% to over 90%. The bioavailability of dietary minerals must be considered when determining whether ...
Dutkiewicz T - - 1991
For each environmental poison the index of harmfulness was calculated on the basis of quantitative evaluation of the following properties: emission of the substance to the environment (Fi), toxicity (F2), the population exposed (F3), exposure (F4), persistence of the substance in the environment (F5), secondary substances and mixtures (F6), bioaccumulation ...
Jasper J P - - 1990
Analyses of gases trapped in continental ice sheets have shown that the concentration of CO2 in the Earth's early atmosphere increased from 180 to 280 p.p.m. during the most recent glacial-interglacial transition. This change must have been driven by an increase in the concentration of CO2 dissolved in the mixed ...
Kennedy B V - - 1990
The isotopic compositions of animal tissues, minerals, and fluids reflect those of ingested food and water and inhaled gases. This relationship is illustrated by a review of data pertaining to five light elements of biological interest (carbon, nitrogen, hydrogen, oxygen, and sulphur). Processes affecting the isotopic composition of inorganic compounds ...
Skogerboe K J - - 1990
This instrumental method for total urinary nitrogen (TUN) is based on the principle of gas-phase chemiluminescence. Results correlate well with measurements of TUN by the Kjeldahl method, which has long provided the means to calculate nitrogen balances for nutritional management. In recent years, because of speed and convenience of measurement, ...
Schneider D A - - 1990
VO2max and the ventilatory threshold (Tvent) were measured during cycle ergometry (CE) and treadmill running (TR) in a group of 10 highly trained male triathletes. Tvent was indicated as the VO2 at which the ventilatory equivalent for oxygen increased without a marked rise in the ventilatory equivalent for carbon dioxide. ...
Shahkhalili Y - - 1990
The extent to which tea, cocoa and carob (foods rich in polyphenols) influence fecal nitrogen (N) excretion was investigated in rats. The studies took into account the methylxanthine contents of tea and cocoa as well as the poor digestibility of cocoa nitrogen. Balance measurements indicated that all three food sources ...
Grupe G - - 1990
Feeding habits of free-ranging martens (Martes martes and Martes foina) are evaluated by means of trace element and stable carbon isotope analyses of their skeletons. This investigation was carried out as an inter-disciplinary project of both wildlife biology and physical anthropology. As a result, data are obtained on the feeding ...
Doull J L - - 1990
Actinorhodin production in Streptomyces coelicolor A3(2) was relatively insensitive to the carbon source concentration but was elicited by nitrogen or phosphate depletion, or by a decline in the growth rate. In starch-glutamate media with nitrogen limitation, increasing the nitrogen supply delayed the onset of antibiotic synthesis and, at concentrations above ...
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