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PubMed1988

The relationship between hydrogen and sulphate ions in precipitation-A numerical analysis of rain and snowfall chemistry.

Acidic rain has been identified as potentially harmful to the aquatic and terrestrial components of the ecosystem. Sulphate measured in rain and snow has been used as a surrogate indicator of acidic deposition. If sulphur dioxide controls are the means to limit acidic deposition, then the association between sulphate and hydrogen ion concentrations in precipitation is an important factor in establishing such limits. Selected data on rain and snowfall chemistry from the National Atmospheric Deposition Program (NADP), the Electric Power Research Institute's SURE, the utility industries' UAPSP, and the Department of Energy's MAP3S were reviewed. Numerical analyses were performed to assess the relationship between hydrogen and sulphate ion concentrations. The strength of the association between hydrogen and sulphate ions varied from site to site. In the Midwestern and Eastern regions, the Pearson correlation coefficient was over 0.50 while in the Central and Upper Midwestern parts of the United States, the correlation coefficients were less than 0.25. Regardless of the strength of the association between hydrogen and sulphate ions, all but one of the NADP/NTN sites used in our analysis exhibited at least 30% of the anions (sulphate, nitrate, and chloride) associated with cations other than hydrogen. For sites where the strength of the association was weak, between 65% and 98% of the anions appeared to be associated with cations other than hydrogen. Because a large percentage of the anions (i.e. sulphate, nitrate, and chloride) appear to be associated with cations other than hydrogen even at those sites where the association between hydrogen and sulphate ions was strong, the complex chemistry controlling the acidity in precipitation may make it difficult to predict the impact of a reduction in sulphate concentration.

Journal Article↗
PubMed1988

The abstinence syndrome in diazepam-dependent cats is precipitated by Ro 15-1788 and Ro 15-4513 but not by the benzodiazepine receptor antagonist ZK 93426.

Diazepam-dependent cats were challenged with different benzodiazepine recognition site ligands 24 h after the last dose of chronic treatment with diazepam (7 mg/kg, i.p. at 08.00 and 20.00 h, for 21 consecutive days). The benzodiazepine derivatives Ro 15-4513 (a partial inverse agonist) and Ro 15-1788 (a pure antagonist), precipitated an abstinence syndrome within minutes after i.p. administration. Abstinence signs included tremors, increased muscle tone, irritability, fear, pupillary dilation and vocalizations. On the contrary, the beta-carboline derivatives ZK 93426 (an antagonist) and FG 7142 (a partial inverse agonist) failed to precipitate abstinence signs in diazepam-dependent cats when given at doses that prevented the acute effects of diazepam. Our results demonstrate that the ability to induce withdrawal signs in diazepam-dependent cats strongly depends on the benzodiazepine structure of the challenge drug since beta-carboline antagonist and partial inverse agonists lack this property.

Animals↗
PubMed1992

Centrally administered aminoglycoside antibiotics antagonize naloxone-precipitated withdrawal in mice acutely dependent on morphine.

The effects of i.c.v. administration of several aminoglycoside antibiotics on naloxone-precipitated morphine withdrawal symptoms were evaluated in mice acutely dependent on morphine. Neomycin (10-40 micrograms/mouse), gentamicin (40-160 micrograms/mouse) and kanamycin (80-320 micrograms/mouse) produced a dose-dependent reduction of the number of precipitated jumps, forepaw tremors and head shakes. The order of potency of the aminoglycoside antibiotics on all withdrawal symptoms was neomycin > gentamicin > kanamycin, which is the same order that these drugs show as N-type calcium channel blockers. The capacity of several drugs that decrease neuronal calcium availability (such as lanthanum and L-type calcium channel blockers) to antagonize opiate withdrawal is well known. In the light of these findings, our results suggest that the mechanism of aminoglycoside-induced inhibition of morphine abstinence may be related to the capacity of these antibiotics to block N-type calcium channels, and to decrease neuronal calcium availability.

Animals↗
PubMed1993

Inhibitory effect of nitric oxide (NO) synthase inhibitors on naloxone-precipitated withdrawal syndrome in morphine-dependent mice.

The effect of intraperitoneally administered nitric oxide (NO) synthase inhibitors has been examined on the naloxone-precipitated withdrawal syndrome in morphine-dependent mice. L-NAME (30-200 mg/kg) and L-NOARG (7.5-50 mg/kg) induced a significant decrease of naloxone-precipitated withdrawal jumping and diarrhoea. However, L-NMMA (3.5-100 mg/kg), considered as a less potent NO synthase inhibitor, did not significantly affect the withdrawal signs in mice. Although a specificity of NO synthase inhibitors is not fully established, these results indicate that inhibition of NO synthesis in the central nervous system and periphery may significantly affect the morphine withdrawal phenomena. Accordingly, this study suggests an involvement of NO in morphine withdrawal syndrome.

Amino Acid Oxidoreductases↗
PubMed1990

Slide precipitation: a simple method to type Actinobacillus (Haemophilus) pleuropneumoniae.

Soluble thermostable antigens prepared from Actinobacillus pleuropneumoniae, as commonly applied in the ring precipitation test, were used in rapid slide tests. This method was easier to perform than the ring precipitation test and showed the same specificity. This specificity was higher than that obtained in slide agglutination tests using whole bacterial cells.

Actinobacillus↗
PubMed1982

Risk of bilirubin acid precipitation in preterm infants with respiratory distress syndrome: considerations of blood/brain bilirubin transfer equilibrium.

Twenty-six preterm infants with respiratory distress syndrome (RDS), were examined daily during the first 6 days of life. Twenty-six equally preterm but clinically well infants served as controls. In the RDS infants, plasma albumin concentration was low, hyperbilirubinemia was prolonged, plasma pH was decreased during the first two days, and the concentration of reserve albumin for binding of monoacetyldiaminodiphenylsulfone (MADDS), a deputy ligand for bilirubin, was decreased on the second throughout the sixth day, when compared with the controls. These factors concur in increasing the likelihood of bilirubin acid precipitation in RDS above the increased risk present in preterm infants. The plasma of the preterm controls was supersaturated with respect to crystalline bilirubin acid by an average factor 5 (index of plasma bilirubin toxicity = 0.7) on the first day of life, peaking at a factor 10 (index 1.0) on the third and fourth days while these factors were 10 and 20 (index 1.0 and 1.3), respectively, in the RDS infants. Two of the latter surpassed a level of 60 times supersaturation (index 1.8) where acute precipitation of amorphous bilirubin acid becomes possible.

Bilirubin↗
PubMed1994

Relationship of air temperature, relative humidity, precipitation, photoperiod, wind speed and solar radiation with serum insulin-like growth factor I (IGF-I) concentration in Angus beef cattle.

Eight paternal half-sib Angus calves born in late April and early May, 1988 were used to investigate the potential relationship of serum IGF-I concentration with photoperiod and various weather variables including minimum, maximum and average air temperatures, relative humidity, precipitation, wind speed and solar radiation. To determine IGF-I concentration, blood samples were obtained at birth and then weekly until the calves reached 1 mo of age and bi-weekly thereafter. Blood sampling continued until the calves reached puberty as determined by progesterone and testosterone assays. Photoperiod and each weather variable were averaged over the 3 d prior to and including the day of blood sampling (4-d average). Data were divided into two periods: (1) birth through the end of the postweaning period and (2) postweaning period only. Serum IGF-I concentrations were analyzed using a model which included the fixed effects of sex and sample number, the random effect of calf nested within sex and the fixed interaction of sex x sample number, in addition to covariates for weight, photoperiod and weather variables. From birth through the end of the postweaning test, none of the weather variables or photoperiod had significant effects on serum IGF-I concentrations when each was fitted separately. For the postweaning period only, cubic regression coefficients for minimum and average temperatures were .0962 +/- .0325 ng/ml/degrees C3 and .0976 +/- .0272 ng/ml/degrees C3, respectively (P < .01). The quadratic regression coefficient for relative humidity during the postweaning period was -.2991 +/- .1142 ng/ml/%2 (P < .05). The quartic regression coefficient for wind speed during the postweaning period was -36.435 +/- 13.00 ng/ml/(km/hr)4 (P < .01). Maximum temperature, precipitation, solar radiation and photoperiod did not have significant effects on postweaning serum IGF-I concentrations. Based on these data, we conclude that temperature, humidity and wind speed were contributing factors to variation in serum IGF-I concentrations in postweaned beef calves.

Aging↗
PubMed1995

The severity of naloxone-precipitated opiate withdrawal is attenuated by felbamate, a possible glycine antagonist.

Recent studies indicate that an N-methyl-D-aspartate (NMDA) receptor system in the rostral medulla is involved in opiate withdrawal. Although NMDA antagonists attenuate naloxone-precipitated opiate withdrawal, they can cause phencyclidine (PCP)like effects that contraindicate clinical use. Because NMDA channels contain sites for the glutamate coagonist, glycine, we assessed the effects of glycinergic agents on naloxone-precipitated opiate withdrawal in rats. The putative antagonist, felbamate (100, 300 mg/kg), attenuated overall withdrawal severity in a dose-related manner and reduced occurrences of chews, teeth chatters, and penile grooming. The partial agonist, D-cycloserine (3, 10 mg/kg), attenuated withdrawal severity, but not in a dose-related manner. Conversely, the low dose of the partial agonist, (+/-)-HA-966 (3, 10 mg/kg), heightened the occurrences of some withdrawal signs. These results support a role for glycine in opiate withdrawal and suggest that these agents, which do not cause PCPlike effects, may be potential treatment for agents for opiate detoxification.

Animals↗
PubMed1996

The effect of gamma-hydroxybutyric acid on naloxone-precipitated opiate withdrawal.

Because gamma-hydroxybutyric acid (GHB), a GABA metabolite, attenuated spontaneous opiate withdrawal in a prior study, we studied GHB's effect on naloxone-precipitated opiate withdrawal. Eight opiate-dependent inpatients were stabilized on the opioid levorphanol, 18 mg daily. After an initial acclimatization challenge, subjects underwent three double-blind challenges on consecutive days. Pretreatment in a balanced randomization was with either placebo, GHB, 15 mg/kg, or GHB, 30 mg/kg, followed an hour later by intravenous naloxone, 0.4 mg/70 kg. GHB produced no significant attenuation of multiple withdrawal measures except for hot-cold feelings. GHB pretreatment slightly accelerated respiration prior to naloxone. Differences with prior studies may be due to (1) timing of GHB administration (giving postwithdrawal in prior studies), (2) direct reversal of GHB's anti-withdrawal effects by naloxone, or (3) differences between naloxone-precipitated and spontaneous opiate withdrawal.

Adult↗
PubMed1996

Neurosteroids and the naloxone-precipitated withdrawal syndrome in morphine-dependent mice.

The effects of some neurosteroids on behavioral and hormonal markers of the naloxone-precipitated withdrawal syndrome in morphine-dependent mice were examined. 5 alpha-Pregnane-3, 20-dione inhibited dose-dependently the jumping behavior and the number of forepaw tremors, at a dose of 5 mg/kg it attenuated body weight loss; deoxycorticosterone acetate inhibited dose-dependently the jumping behavior and body weight loss, whereas dehydroepiandrosterone in a dose of 1 mg/kg prevented body weight loss, and in a dose of 20 mg/kg forepaw tremor. The other steroids tested had no significant effect on the morphine withdrawal syndrome. None of the neurosteroids influenced the increased plasma corticosterone level in the naloxone-precipitated morphine withdrawal syndrome. The above results indicate that 5 alpha-pregnane-3, 20-dione, deoxycorticosterone acetate and dehydroepiandrosterone, but not other neurosteroids tested, alleviate some signs of the morphine abstinence syndrome in mice.

5-alpha-Dihydroprogesterone↗
PubMed2006

Signal enhancement of surface plasmon resonance immunoassay using enzyme precipitation-functionalized gold nanoparticles: a femto molar level measurement of anti-glutamic acid decarboxylase antibody.

Colloidal gold nanoparticles (AuNPs) and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation of 3,3'-diaminobenzidine (DAB) in the presence of H2O2 were used to enhance the signal obtained from the surface plasmon resonance (SPR) biosensor. The AuNPs were synthesized and functionalized with HS-OEG3-COOH by self assembling technique. Thereafter, the HS-OEG3-COOH functionalized nanoparticles were covalently conjugated with horseradish peroxidase (HRP) and anti IgG antibody to form an enzyme-immunogold complex. Characterizations were performed by several methods: UV-vis absorption, DLS, HR-TEM and FT-IR. The Au-anti IgG-HRP complex has been applied in enhancement of SPR immunoassay using a sensor chip constructed by 1:9 molar ratio of HS-OEG6-COOH and HS-OEG3-OH for detection of anti-GAD antibody. As a result, AuNPs showed their enhancement as being consistent with other previous studies while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the SPR detection. The limit of detection was found as low as 0.03 ng/ml of anti-GAD antibody (or 200 fM) which is much higher than that of previous reports. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays.

Antibodies↗
PubMed2006

An inventory of N(2)O emissions from agriculture in China using precipitation-rectified emission factor and background emission.

Fertilized agricultural soils are a major anthropogenic source of atmospheric N(2)O. A credible national inventory of agricultural N(2)O emission would benefit its global strength estimate. We compiled a worldwide database of N(2)O emissions from fertilized fields that were consecutively measured for more than or close to one year. Both nitrogen input (N) and precipitation (P) were found to be largely responsible for temporal and spatial variabilities in annual N(2)O fluxes (N(2)O-N). Thus, we established an empirical model (N(2)O-N=1.49 P+0.0186 P.N), in which both emission factor and background emission for N(2)O were rectified by precipitation. In this model, annual N(2)O emission consists of a background emission of 1.49 P and a fertilizer-induced emission of 0.0186 P.N. We used this model to develop a spatial inventory at the 10x10km scale of direct N(2)O emissions from agriculture in China. N(2)O emissions from rice paddies were separately quantified using a cropping-specific emission factor. Annual fertilizer-induced N(2)O emissions amounted to 198.89GgN(2)O-N in 1997, consisting of 18.50GgN(2)O-N from rice paddies and 180.39GgN(2)O-N from fertilized uplands. Annual background emissions and total emissions of N(2)O from agriculture were estimated to be 92.78GgN(2)O-N and 291.67GgN(2)O-N, respectively. The annual direct N(2)O emission accounted for 0.92% of the applied N with an uncertainty of 29%. The highest N(2)O fluxes occurred in East China as compared with the least fluxes in West China.

Agriculture↗
PubMed2006

Precipitation of Zn(II), Cu(II) and Pb(II) at bench-scale using biogenic hydrogen sulfide from the utilization of volatile fatty acids.

Biological production of hydrogen sulfide (H(2)S) using sulfate-reducing bacteria (SRB) has important potential within environmental biotechnology. The aim of this work was to study the possibility of using SRB for the treatment of an acid mine drainage (AMD) at bench-scale. This process involved three stages: the optimization of H(2)S production through the utilization of total volatile fatty acids (TVFAs) by SRB, the establishment of a biofilm reactor for sulfide production, and the precipitation of metals by using the biologically produced H(2)S. The substrates used for TVFAs production consisted of papaya, apple and banana. The H(2)S produced from the degradation of TVFAs was utilized for the precipitation of a metal-contaminated effluent collected from Bolivar mine (Oruro, Bolivia). The maximum concentration of H(2)S obtained was approximately 16mM. Removal efficiencies of ca. 100% for copper, above 94% for zinc, and above 92% for lead were achieved.

Bacteria↗
PubMed2004

Chitosan as a macroaffinity ligand purification of chitinases by affinity precipitation and aqueous two-phase extractions.

(1) Chitosan was found to be a suitable macroaffinity ligand for affinity precipitation of chitinase from Neurospora crassa, cabbage and puffballs. (2) The activity recoveries of 85, 82 and 90% with concomitant fold purifications in terms of specific activities were 27, 15 and 30 with N. crassa, cabbage and puffballs and were obtained with affinity precipitation. These results were obtained with clarified extracts/homogenates as the starting materials. (3) The incorporation of chitosan in poly(ethylene glycol) (PEG)-salt aqueous two-phase system allowed purification of chitinases from these sources directly from unclarified extracts/homogenates. (4) The 96% (w/v) chitosan (of initially introduced into the aqueous two-phase system) partitioned into PEG-phase and this enhanced the partitioning of chitinases into PEG-phase. The chitosan, free as well as bound to chitinases, could be separated from PEG-phase by increasing the pH to 7. (5) By the process of desorption with 2.0 M MgCl2, 86, 80 and 88% activity recoveries (% expressed in terms of total units of enzyme activities in the crude extract) were obtained in the case of N. crassa, cabbage and puffballs, respectively. The corresponding fold purifications in terms of specific activities were 34, 20 and 38. (6) The purified preparations gave single bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the estimated molecular masses agreed with the reported values in the literature.

Chitinases↗
PubMed2005

Nonlinear regression and ARIMA models for precipitation chemistry in East Central Florida from 1978 to 1997.

Continuous monitoring of precipitation in East Central Florida has occurred since 1978 at a sampling site located on the University of Central Florida (UCF) campus. Monthly volume-weighted average (VWA) concentration for several major analytes that are present in precipitation samples was calculated from samples collected daily. Monthly VWA concentration and wet deposition of H(+), NH(4)(+), Ca(2+), Mg(2+), NO(3)(-), Cl(-) and SO(4)(2-) were evaluated by a nonlinear regression (NLR) model that considered 10-year data (from 1978 to 1987) and 20-year data (from 1978 to 1997). Little change in the NLR parameter estimates was indicated among the 10-year and 20-year evaluations except for general decreases in the predicted trends from the 10-year to the 20-year fits. Box-Jenkins autoregressive integrated moving average (ARIMA) models with linear trend were considered as an alternative to the NLR models for these data. The NLR and ARIMA model forecasts for 1998 were compared to the actual 1998 data. For monthly VWA concentration values, the two models gave similar results. For the wet deposition values, the ARIMA models performed considerably better.

Acid Rain↗
PubMed2006

Environmental monitoring of fluoride emissions using precipitation, dust, plant and soil samples.

A pollution gradient was observed in precipitation, plants and soils sampled at different locations around a fluoride producing chemical plant in Germany. In all samples the influence of emissions was discernible up to a distance of 500 m from the plant. However, fluoride concentrations in plant bioindicators (leaves of birch and black berry) and in bulk precipitation showed a more pronounced relationship with the distance from the source than fluoride concentrations in soil. Vegetables sampled in the vicinity of the plant also had elevated concentrations of fluoride, but only the consumption of larger quantities of this material would lead to exceedances of recommended daily F-intake. The present study did not indicate the existence of low phytotoxicity thresholds for fluoride in the plant species used in the study. Even at very high fluoride concentrations in leaf tissue (963 ppm) plants did not show injury due to HF. Dust sampling downwind of the chemical plant confirmed that particulate fluoride was of minor importance in the study area.

Air Pollutants↗
PubMed2006

Exogenously administered D-serine failed to potentiate the ability of MK-801 to antagonize electrically precipitated seizures in nonhandled control and stressed mice.

NMDA receptor hypofunction (NRH) has been implicated in the pathophysiology of schizophrenia because of the ability of phencyclidine (PCP), a noncompetitive NMDA receptor antagonist, to precipitate a schizophreniform psychosis. The possible role that NRH plays in the pathophysiology of schizophrenia stimulated characterization of behaviors elicited by PCP and its analogues. For example, MK-801 (dizocilpine), a noncompetitive NMDA receptor antagonist that binds with higher affinity to the same hydrophobic channel domain as PCP, raises the threshold voltage required for the electrical precipitation of tonic hindlimb extension in mice. This ability of MK-801 is significantly reduced following stress. We showed that an exogenously administered glycine prodrug (i.e., milacemide) was able to potentiate MK-801's antiseizure efficacy in unstressed mice and restore MK-801's antiseizure efficacy in stressed animals. d-Serine may serve as an endogenous agonist for the obligatory glycine co-agonist site on the NMDA receptor complex. Orally administered d-serine has been studied clinically as an adjuvant therapeutic intervention in schizophrenia. Thus, we were surprised at its inability to potentiate MK-801's antiseizure efficacy in either control or stressed animals. These data do not support the development of d-serine as a viable therapeutic intervention for schizophrenia and, possibly, other disorders.

Animals↗
PubMed2005

Is low mood an adaptation? Evidence for subtypes with symptoms that match precipitants.

BACKGROUND: Although severe depression is dysfunctional, the capacity to experience normal low mood may be useful in certain fitness-threatening situations. Moreover, if specific kinds of situations recurred often enough in the course of evolution, natural selection may have shaped partially differentiated subtypes of low mood that are parallel to the subtypes of anxiety that protect against different kinds of danger. To test this hypothesis, we examined how symptoms of low mood differ depending upon the precipitating situation, and whether these differences match expectations of symptoms useful in each kind of situation. METHOD: 337 subjects who experienced a period of low mood within the last year wrote accounts describing perceived causes of their low mood and they filled out the CES-D depression inventory. Seven symptom scales were derived from analysis of CES-D data. Independent judges blindly coded the accounts into one of six precipitant categories. RESULTS: Different untoward situations were associated with different symptoms that were predicted to be useful in those situations. Social losses (death of a loved one, romantic breakups, and social isolation) were associated with greater crying and arousal. Failure to reach a goal, stress, and winter seasons were associated with more fatigue and pessimism. DISCUSSION: These results suggest that natural selection shaped not only a generic state of low mood but also partially differentiated subtypes shaped to cope with specific situations that were associated with fitness losses among our ancestors.

Adaptation, Psychological↗