Volatilization of 1,3-Dichloropropene under Different Application Methods

Atmospheric emission of volatilepesticides can be a significant source of airpollution. A field study was conducted to reduce1,3-dichloropropene (1,3-D) emission by applying thechemical via subsurface drip irrigation with a reduceddosage (4.7 g m^-2 or 47 kg ha^-1). Comparisons were made between ashallow drip application with the plot covered with apolyethylene film, a deep drip application and aconventional shank injection (at 11.2 g m^-2) withthe plots left as bare soil surface. For eachtreatment, seven replicated active flux chambers wereused continuously to measure 1,3-D loss until nomeasurable emission was found. Results indicated thattotal 1,3-D emission loss was over 90% for the shankinjection, and 66 and 57% for the shallow and deepdrip plots, respectively. The emission loss wasextremely high for shank injection since about 80%were lost from the bed furrows where the slantedshanks left uncompacted fractures. On mass basis, theshank plot lost 10.4 g m^-2, whereas the shallow-and deep-drip plots lost 3.1 and 2.7 g m^-2,respectively. Applying 1,3-D using subsurface dripirrigation with reduced dosage has a great potentialfor emission reduction.     

Fluorometric determination of benzylideneacetone in fragrance products by liquid chromatography with post-column derivatization

A method is described for the liquid chromatographic (LC)-fluorometric determination of benzylideneacetone in fragrance products. Benzylideneacetone is first separated from other fragrance ingredients by LC and then reacted post-column with a methanolic solution of isonicotinic acid hydrazide and aluminum nitrate. The reactants are maintained at 65 degrees C for about 1.5 min to quantitatively form the fluorescent isonicotinoyl hydrazone derivative of benzylideneacetone. The aluminum ion forms a complex with the hydrazone to enhance the fluorescence of the derivative. The amount of benzylideneacetone is determined by measuring the intensity of the fluorescence emitted by the hydrazone derivative and comparing that value with those obtained for derivatized standards. Recovery studies were conducted by spiking commercial fragrances with benzylideneacetone at concentrations of 0.01, 0.05, and 0.1% (w/v). Recoveries ranged from 98 to 104% with a mean recovery of 100.2% and a standard deviation of 2.4%.     

Determination of cinnamyl anthranilate in perfume, cologne, and toilet water by liquid chromatography with fluorescence detection

A liquid chromatographic method with fluorescence detection was developed for the determination of cinnamyl anthranilate in perfumes and other fragrance compositions. The method was evaluated by conducting recovery studies of 10 different commercial fragrance compositions to which cinnamyl anthranilate had been added at levels of 0.1, 0.5, and 1.0 mg/mL. Recoveries ranged from 91 to 103% with a mean of 97% and a standard deviation of +/- 3.3%.     

Comparative fine mapping of fruit quality QTLs on chromosome 4 introgressions derived from two wild tomato species

Despite their unsuitability for agricultural production, the wild relatives of crop species represent a largely untapped resource of novel QTLs potentially useful for crop plant improvement. In this regard, previous introgression studies, involving several different wild tomato species, have shown that the long arm of chromosome 4 contains QTLs for many horticulturally important traits including soluble solids content, fruit shape, lycopene content and biochemical composition. However, these earlier studies were unable to determine how many genes control these traits and whether genes affecting the same character from different wild species are allelic or not. In an effort to shed light on these issues,we have constructed a series of lines containing small, overlapping introgressions for portions of the long arm of chromosome 4 from L. peruvianum and L. hirsutum and tested these lines in replicated field trials. The results provide evidence for multiple, non-allelic loci controlling soluble solids and fruit weight. They also show that the loci controlling some traits (e.g. fruit shape, fruit weight, epidermal reticulation) co-localize to the same portions of chromosome 4, a result that maybe attributed to pleiotropy and/or gene dense areas with lower than average recombination. The implications of these finding for molecular breeding and utilization of exotic germplasm are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Maternofetal inflammation induced for 2 wk in late gestation reduced birth weight and impaired neonatal growth and skeletal muscle glucose metabolism in lambs

Intrauterine stress impairs growth and metabolism in the fetus and offspring. We recently found that sustained maternofetal inflammation resulted in intrauterine growth-restricted (MI-IUGR) fetuses with asymmetric body composition, impaired muscle glucose metabolism, and β-cell dysfunction near term. These fetuses also exhibited heightened inflammatory tone, which we postulated was a fetal programming mechanism for the IUGR phenotype. Thus, the objective of this study was to determine whether poor growth and metabolism persisted in MI-IUGR lambs after birth. Polypay ewes received serial lipopolysaccharide or saline injections in the first 2 wk of the third trimester of pregnancy to produce MI-IUGR (n = 13) and control (n = 12) lambs, respectively. Lambs were catheterized at 25 d of age. β-Cell function was assessed at 29 d, hindlimb glucose metabolism at 30 d, and daily blood parameters from day 26 to 31. Glucose metabolism was also assessed in flexor digitorum superficialis (FDS) muscle isolated at necropsy on day 31. Asymmetric body composition persisted in MI-IUGR neonates, as these lambs were lighter (P < 0.05) than controls at birth and 31 d, but body and cannon bone lengths did not differ at either age. FDS muscles from MI-IUGR lambs were smaller (P < 0.05) and exhibited reduced (P < 0.05) glucose oxidation and Akt phosphorylation but similar glucose uptake compared with controls when incubated in basal or insulin-spiked media. Similarly, hindlimb glucose oxidation was reduced (P < 0.05) in MI-IUGR lambs under basal and hyperinsulinemic conditions, but hindlimb glucose utilization did not differ from controls. Circulating urea nitrogen and cholesterol were reduced (P < 0.05), and triglycerides, high-density lipoprotein cholesterol, and glucose-to-insulin ratios were increased (P < 0.05) in MI-IUGR lambs. Glucose and insulin concentrations did not differ between groups during basal or hyperglycemic conditions. Although circulating monocyte and granulocyte concentrations were greater (P < 0.05) in MI-IUGR lambs, plasma tumor necrosis factor α (TNFα) was reduced (P < 0.05). FDS muscle contained greater (P < 0.05) TNF receptor 1 (TNFR1) and IκBα protein content. These findings indicate that maternofetal inflammation in late pregnancy results in fetal programming that impairs growth capacity, muscle glucose oxidation, and lipid homeostasis in offspring. Inflammatory indicators measured in this study appear to reflect heightened cytokine sensitivity in muscle and compensatory systemic responses to it.     

Spectroscopic observation of dual catalytic sites during oxidation of CO on a Au/TiO₂ catalyst

The prevailing view of CO oxidation on gold-titanium oxide (Au/TiO(2)) catalysts is that the reaction occurs on metal sites at the Au/TiO(2) interface. We observed dual catalytic sites at the perimeter of 3-nanometer Au particles supported on TiO(2) during CO oxidation. Infrared-kinetic measurements indicate that O-O bond scission is activated by the formation of a CO-O(2) complex at dual Ti-Au sites at the Au/TiO(2) interface. Density functional theory calculations, which provide the activation barriers for the formation and bond scission of the CO-O(2) complex, confirm this model as well as the measured apparent activation energy of 0.16 electron volt. The observation of sequential delivery and reaction of CO first from TiO(2) sites and then from Au sites indicates that catalytic activity occurs at the perimeter of Au nanoparticles.     

Ventral fixation of chronic atlanto-occipital luxation in a dog

A 4·5-year-old male Australian Kelpie was presented for evaluation of ambulatory tetraparesis and neck pain of five weeks duration. Atlanto-occipital luxation was diagnosed by computed tomography. The joint was unstable following closed reduction, and a ventral surgical approach to the cranial cervical spine and occiput permitted manual reduction and stabilisation of the atlanto-occipital joint. The thickened joint capsule and articular cartilage were removed to promote AO arthrodesis. Eight cortical screws, inserted into the occipital condyles and C1, were embedded in polymethylmethacrylate to stabilise the atlanto-occipital articulation. The dog recovered uneventfully after it was placed in a neck brace and rested for six weeks. Neurologic examination at six weeks was normal and the dog returned to normal farm work 12 weeks after surgery.     

Degradation kinetics and mechanism of antibiotic ceftiofur in recycled water derived from a beef farm

Ceftiofur is a third-generation cephalosporin antibiotic that has been widely used to treat bacterial infections in concentrated animal feeding operations (CAFOs). Land application of CAFO waste may lead to the loading of ceftiofur residues and its metabolites to the environment. To understand the potential contamination of the antibiotic in the environment, the degradation kinetics and mechanisms of ceftiofur in solutions blended with and without the recycled water derived from a beef farm were investigated. The transformation of ceftiofur in aqueous solutions in the presence of the CAFO recycled water was the combined process of hydrolysis and biodegradation. The total degradation rates of ceftiofur at 15 °C, 25 °C, 35 °C, and 45 °C varied from 0.4-2.8×10(-3), 1.4-4.4×10(-3), 6.3-11×10(-3), and 11-17×10(-3) h(-1), respectively, in aqueous solutions blended with 1 to 5% CAFO recycled water. Hydrolysis of ceftiofur increased with incubation temperature from 15 to 45 °C. The biodegradation rates of ceftiofur were also temperature-dependent and increased with the application amounts of the recycled CAFO water. Cef-aldehyde and desfuroylceftiofur (DFC) were identified as the main biodegradation and hydrolysis products, respectively. This result suggests that the primary biodegradation mechanism of ceftiofur was the cleavage of the β-lactam ring, while hydrolytic cleavage occurred at the thioester bond. Unlike DFC and ceftiofur, cef-aldehyde does not contain a β-lactam ring and has less antimicrobial activity, indicating that the biodegradation of ceftiofur in animal wastewater may mitigate the potentially adverse impact of the antibiotic to the environment.     

Seroprevalence of psittacine beak and feather disease in wild psittacine birds in New South Wales

SUMMARY A haemagglutination inhibition assay was used to detect antibody to psittacine beak and feather disease virus in sera from wild sulphur crested cockatoos (Cacatua galerita), galahs (Eolophus roseicapillus), short-billed corellas (Cacatua sanguinea), eastern long-billed corellas (Cacatua tenuirostris) and other psittacine birds in New South Wales. The seroprevalence of psittacine beak and feather disease ranged from 41% to 94% in different flocks, indicating infection with the virus is widespread in wild populations.     

Depletion of intramuscularly and subcutaneously injected procaine penicillin G from tissues and plasma of yearling beef steers.

Withdrawal periods required when doses of 24,000 IU and 66,000 IU of procaine penicillin G/kg body weight were administered to yearling beef steers by intramuscular injection daily for five consecutive days were investigated. These dosages are in excess of product label recommendations, but are in the range of procaine penicillin G dosages that have been administered for the treatment of some feedlot bacterial diseases. The approved dose in Canada is 7,500 IU/kg body weight intramuscularly, once daily, with a withdrawal period of five days. Based on the tissue residue data from this study, the appropriate withdrawal period is ten days for the 24,000 IU/kg body weight dose and 21 days for the 66,000 IU/kg body weight dose when administered intramuscularly to yearling beef steers. In a related study, 18 yearling beef steers received 66,000 IU of procaine penicillin G/kg body weight administered by subcutaneous injection, an extra-label treatment in terms of both dose and route of administration, typical of current practice in some circumstances. Deposits of the drug were visible at subcutaneous injection sites up to ten days after injection, with more inflammation and hemorrhage observed than for intramuscular injections of the same dose. These results suggest that procaine penicillin G should not be administered subcutaneously at high doses; and therefore a withdrawal period was not established for subcutaneous injection.