The kinetics of phosphate removal in small alkaline lakes by natural and artificial processes     

Donald Haumann  Thomas D. Waite 《Water, air, and soil pollution》1978,10(3):291-313

Two small lakes in Southeast Florida were observed to have intermittently high P concentrations as a result of surface runoff from fertilized drainage areas. Simulation of this phenomenon was effected through direct fertilization of a lake with high phosphate fertilizer (0 - 46 - 0), and phosphate levels were monitored with time. Removal rates were observed to adhere closely to two consecutive first-order reactions. The components of the total rate of removal were identified as hydraulic flushing (HF), primary productivity (PP) and physicochemical processes (PCP). Of the P applied, PCP were found to remove 79.7 to 97.6% during the first stage (phase 1) of each experiment, however the highest per diem removal by natural processes was 11.1%. Adsorption and subsequent nucleation on calcite were thought to be the predominant mechanisms governing orthophosphate concentrations in the water column. The second phase of phosphate removal was accounted for primarily through HF and PP. Decreasing high levels of P in the water column by precipitation with Al was found to have a high per diem efficiency (40.8%). This effectively reduced the high potential yield of macrophyte biomass experienced with natural phosphate limiting mechanisms.  相似文献   

Rosewood polyphenols alter phenoloxidase activity from the mantle of the marine bivalve mollusc, Modiolus demissus dillwyn     

J. Herbert Waite 《Pesticide biochemistry and physiology》1976,6(3):239-242

Phenoloxidase from the mantle of the marine bivalve Modiolus demissus Dillwyn slowly catalyzes the oxidation of the rosewood ingredient obtusastyrene (K_m 0.13 mM, V_max 0.30 mM/min/mg). However, in the presence of another rosewood ingredient, obtusaquinone, the oxidation rate is increased to a limiting maximal velocity of 11 mM obtusastyrene/min/mg, without a concommitant change in the K_m. The oxidation products of either the slow reaction or the obtusaquinone-enhanced reaction inhibit the catechol dehydrogenase function of phenoloxidase. The phenoloxidase-modifying properties of obtusaquinone and obtusastyrene may be related to the inhibition of shell formation in wood-boring bivalve larvae settling on rosewood.  相似文献   

Development and Evaluation of an ELISA for the Quantitation of Anti‐Lagenidium giganteum forma caninum Antibodies in Dogs     

J.N. Hartfield  A.M. Grooters  K.J. Waite 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(5):1479-1484

Background

Lagenidium giganteum forma caninum infection causes severe cutaneous and disseminated disease in dogs. Currently, diagnosis requires culture and rRNA gene sequencing.

Objective

To develop and evaluate an ELISA for quantitation of anti‐L. giganteum f. caninum IgG in canine serum.

Animals

Sera were evaluated from 22 dogs infected with L. giganteum f. caninum, 12 dogs infected with Paralagenidium karlingii, 18 dogs infected with Pythium insidiosum, 26 dogs with nonoomycotic fungal infections or other cutaneous or systemic diseases, and 10 healthy dogs.

Methods

Antigen was prepared from a soluble mycelial extract of L. giganteum f. caninum. Optimal antigen and antibody concentrations were determined by checkerboard titration. Results were expressed as percent positivity (PP) relative to a strongly positive control serum.

Results

Medians and ranges for PP for each group were: L. giganteum f. caninum (73.9%, 27.9–108.9%), P. karlingii (55.0%, 21.0–90.6%), P. insidiosum (31.3%, 15.8–87.5%), nonoomycotic fungal infection or other cutaneous or systemic diseases (19.2%, 3.2–61.0%), and healthy dogs (9.9%, 7.6–24.6%). Using a PP cutoff value of 40%, sensitivity and specificity (with 95% CI) of the ELISA for detecting L. giganteum f. caninum infection in clinically affected dogs were 90.9% (72.2–97.5%) and 73.2% (60.4–83.0%), respectively. Specificity in dogs infected with P. karlingii was 41.7% (19.3–68.1%) and with P. insidiosum was 66.7% (43.8–83.7%).

Conclusions and Clinical Importance

Quantitation of anti‐L. giganteum f. caninum antibodies for detection of this infection in dogs has moderately high sensitivity but poor specificity, the latter because of substantial cross‐reactivity with anti‐P. karlingii and anti‐P. insidiosum antibodies.  相似文献   

Modelling long-term effects of IGRs on honey bee colonies     

Thompson HM  Wilkins S  Battersby AH  Waite RJ  Wilkinson D 《Pest management science》2007,63(11):1081-1084

Systems have been developed to monitor the direct effects of insect growth regulator (IGR) pesticide exposure on honey bee development, but there has been little work on the longer-term impact of exposure on the colony. A honey bee population model provided the opportunity to investigate the effects of short-term mortality of brood and of sublethal changes in behaviour of the surviving adults on honey bee populations. The model showed that brood mortality alone has limited effect on colony size. There were two mechanisms that could have greater influence on productivity. Precocious foraging in affected adult bees, and hence early loss of brood-rearing (nurse) capabilities, had a much larger effect than expected. Increasing mortality rates by 30% to simulate sublethal effects on lifespan, rather than reduced brood-rearing capability, gave a significantly smaller effect. In order to simulate an effect with the 'shortened lifespan' mechanism as large as that with the 'premature ageing' mechanism, the mortality rate of affected adults had to be increased by 500%. A significant finding from the model is that application of IGRs in spring and early summer could have substantial effects on colony size and viability. Sublethal effects such as precocious foraging can have worse effects than massive brood mortality, as it severely reduces the ability to rear the next generation of nurse bees.  相似文献   

The kinetics of bacterial degradation of the aquatic weed ‘Hydrilla’ sp.     

Thomas D. Waite  Charles Kurucz 《Water, air, and soil pollution》1977,7(1):33-43

Degradation rates of the rooted hydrophyte Hydrilla sp. by a gram-negative non-motile rod shaped bacterium were determined. A first order model was conceived, which included the effects of nitrate nitrogen on the rate constants. The rate constants varied between 0.0239 day^?1 and 0.0907 day^?1 for nitrate nitrogen values of 0.48 mg l^?1 to 5.38 mg l^?1 A strong inverse relationship between degradation rate and nitrate levels within the range of 0.5 to 6.0 mg l^?1 NO₃-N was observed. The resultant model was able to predict plant degradation rates quite accurately as a function of nitrate levels.  相似文献   

Planetary evolution: atmospheres and ionospheres of the outer planets and their satellites     

Waite JH 《Science (New York, N.Y.)》1987,236(4802):729-730

  相似文献   

Polyphenolic Substance of Mytilus edulis: Novel Adhesive Containing L-Dopa and Hydroxyproline     

Waite JH  Tanzer ML 《Science (New York, N.Y.)》1981,212(4498):1038-1040

The fouling marine mussel Mytilus edulis attaches itself to various substrates by spinning byssal threads, the adhesive discs of which are rich in the amino acid 3,4-dihydroxyphenylalanine (dopa). An acid-soluble protein was extracted and purified from the phenol gland located in the byssus-secreting foot of the animal. This protein is highly basic and contains large amounts of lysine, dopa, and 3- and 4-hydroxyproline. The composition of this protein and its sticky tendencies in vitro strongly suggest that it contributes to byssal adhesion.  相似文献   

The process of tholin formation in Titan's upper atmosphere     

Waite JH  Young DT  Cravens TE  Coates AJ  Crary FJ  Magee B  Westlake J 《Science (New York, N.Y.)》2007,316(5826):870-875

Titan's lower atmosphere has long been known to harbor organic aerosols (tholins) presumed to have been formed from simple molecules, such as methane and nitrogen (CH4 and N2). Up to now, it has been assumed that tholins were formed at altitudes of several hundred kilometers by processes as yet unobserved. Using measurements from a combination of mass/charge and energy/charge spectrometers on the Cassini spacecraft, we have obtained evidence for tholin formation at high altitudes (approximately 1000 kilometers) in Titan's atmosphere. The observed chemical mix strongly implies a series of chemical reactions and physical processes that lead from simple molecules (CH4 and N2) to larger, more complex molecules (80 to 350 daltons) to negatively charged massive molecules (approximately 8000 daltons), which we identify as tholins. That the process involves massive negatively charged molecules and aerosols is completely unexpected.  相似文献   

Production of Oocytes of Nile Tilapia (Oreochromis niloticus) for In Vitro Fertilization via Hormonal Treatments     

DAA Oliveira  CG Aleixo  SA Prado  RK Luz  NLAF Sarmento  EA Teixeira  MR Luz  EM Turra 《Reproduction in domestic animals》2013,48(6):1049-1055

Only a few studies have described hormonal treatments for induction of synchronicity and gamete collection in Nile tilapia (Oreochromis niloticus), both important for assortative matings in breeding programmes and essential for polyploidy technologies. In this study, we compared the effectiveness of carp pituitary extract (CPE), Nile tilapia pituitary extract (TPE), human chorionic gonadotropin (hCG) and gonadotropin‐releasing hormone (GnRH) protocols on the induction of spawning and egg production in Nile tilapia. Among the hormonal treatments analysed, only hCG was effective for producing viable gametes for in vitro fertilization. To verify the viability of this hormonal treatment, hCG was tested using different doses (1000, 2000, 3000, 4000 and 5000 IU/kg) in a large number of females (208 animals) from two Nile tilapia lines. The results indicated that hCG doses between 1000 and 5000 IU/kg could be used to induce final oocyte maturation in Nile tilapia with collection of stripped oocytes. This is the first study to report differential reproductive responses to hormonal treatment between tilapia lines: line 1 was more efficient at producing eggs and post‐hatching larvae after hCG induction than line 2. In conclusion, we demonstrated that the hCG protocol may be applied on a large scale to induce final oocyte maturation in Nile tilapia. The development of a protocol for in vitro fertilization in Nile tilapia may aid in breeding programmes and biotechnological assays for the development of genetically modified lines of Nile tilapia.  相似文献   

Cassini finds an oxygen-carbon dioxide atmosphere at Saturn's icy moon Rhea     

Teolis BD  Jones GH  Miles PF  Tokar RL  Magee BA  Waite JH  Roussos E  Young DT  Crary FJ  Coates AJ  Johnson RE  Tseng WL  Baragiola RA 《Science (New York, N.Y.)》2010,330(6012):1813-1815

The flyby measurements of the Cassini spacecraft at Saturn's moon Rhea reveal a tenuous oxygen (O(2))-carbon dioxide (CO(2)) atmosphere. The atmosphere appears to be sustained by chemical decomposition of the surface water ice under irradiation from Saturn's magnetospheric plasma. This in situ detection of an oxidizing atmosphere is consistent with remote observations of other icy bodies, such as Jupiter's moons Europa and Ganymede, and suggestive of a reservoir of radiolytic O(2) locked within Rhea's ice. The presence of CO(2) suggests radiolysis reactions between surface oxidants and organics or sputtering and/or outgassing of CO(2) endogenic to Rhea's ice. Observations of outflowing positive and negative ions give evidence for pickup ionization as a major atmospheric loss mechanism.  相似文献