Review of equations to predict methane emissions in dairy cows from milk fatty acid profiles and their application to commercial dairy farms.

Greenhouse gas emission from the activities of all productive sectors is currently a topic of foremost importance. The major contributors in the livestock sector are ruminants, especially dairy cows. This study aimed to evaluate and compare 21 equations for predicting enteric methane emissions (EME) developed on the basis of milk traits and fatty acid profiles, which were selected from 46 retrieved through a literature review. We compiled a reference database of the detailed fatty acid profiles, determined by GC, of 992 lactating cows from 85 herds under 4 different dairy management systems. The cows were classified according to DIM, parity order, and dairy system. This database was the basis on which we estimated EME using the selected equations. The EME traits estimated were methane yield (20.63 ± 2.26 g/kg DMI, 7 equations), methane intensity (16.05 ± 2.76 g/kg of corrected milk, 4 equations), and daily methane production (385.4 ± 68.2 g/d, 10 equations). Methane production was also indirectly calculated by multiplying the daily corrected milk yield by the methane intensity (416.6 ± 134.7 g/d, 4 equations). We also tested for the effects of DIM, parity, and dairy system (as a correction factor) on the estimates. In general, we observed little consistency among the EME estimates obtained from the different equations, with exception of those obtained from meta-analyses of a range of data from different research centers. We found all the EME predictions to be highly affected by the sources of variation included in the statistical model: DIM significantly affected the results of 19 of the 21 equations, and parity order influenced the results of 13. Different patterns were observed for different equations with only some of them in accordance with expectations based on the cow's physiology. Finally, the best predictions of daily methane production were obtained when a measure of milk yield was included in the equation or when the estimate was indirectly calculated from daily milk yield and methane intensity.

Predictors of severity of absenteeism in children with anxiety-based school refusal.

Examined possible relations among sociodemographic, clinical, and familial variables and level of school absenteeism in children with anxiety-based school refusal. These children exhibit a great deal of variability in the severity of school refusal, with some youngsters missing only an occasional day of school, whereas other exhibit pervasive school absenteeism. Participants were 76 children referred for treatment of anxiety-based school refusal. Children and a parent completed a structured clinical interview (Schedule for Affective Disorders and Schizophrenia for School-Age Children) and self-report measures that assess children's levels of fear (Fear Survey Schedule for Children-Revised), trait and somatic anxiety (Modified State-Trait Anxiety Inventory for Children), and depressive symptomatology (Children's Depression Inventory), as well as family environment characteristics (Family Environment Scale). Regression analyses revealed that older age, lower levels of fear, and less active families were primary predictors of greater levels of school absenteeism.

Brodimoprim: effects of subminimal inhibitory concentrations on virulence traits of respiratory and urinary tract pathogens, and on plasmid transfer and stability.

The effects of brodimoprim, a new trimethoprim analogue, on several virulence traits of respiratory and urinary tract pathogens exposed to sub-lethal levels of the drug was studied. Adherence to tracheal epithelial cells was inhibited by brodimoprim in Klebsiella pneumoniae (41-67% reduction), Moraxella catarrhalis (87-90%) and Haemophilus influenzae (0-53%), while in Streptococcus pneumoniae binding was unaffected. With buccal epithelial cells the comparison between treated and control bacteria indicated statistically significant reduction in adherence with both S.pneumoniae and H.influenzae, (P < 0.015). With M.catarrhalis and Streptococcus pyogenes only marginal changes were detected (P > 0.05). Exoenzyme and capsule production were assessed in at least three isolates of diverse respiratory pathogens grown in the presence of sub-lethal levels of the new agent. The drug affected protease and beta-hemolysin (alpha-toxin) production in both oxacillin-susceptible and -resistant S.aureus. On the contrary, synthesis of lipase, DNase, coagulase, and beta-lactamase (S.aureus), pneumolysin (S.pneumoniae), streptolysin S, DNase, and protease (S.pyogenes), capsule (K.pneumoniae, H.influenzae and S.pneumoniae), and beta-lactamase (K.pneumoniae, H.influenzae and M.catarrhalis) were not inhibited by subminimal inhibitory concentrations (sub-MICs) of the drug. Finally, motility was blocked in urinary pathogens E.coli, P.mirabilis and P.aeruginosa, while in this latter microorganism pigment production was also affected. High molecular weight low-copy F'lac, and low molecular weight high-copy pHSG298 plasmids were eliminated from E.coli treated with sub-MIC concentrations of brodimoprim. The incidence and cured cells ranged from 9% for F'lac to 23% for pHSG298. F'lac transfer was also inhibited by the drug. When conjugation was carried out with bacteria exposed to brodimoprim (5XMIC), a reduction (50%) in the number of recombinants was noted in comparison to the control. The fact that brodimoprim interferes with the expression of some virulence traits, in particular with adherence, at sub-MIC levels may assist the drug in eradicating respiratory pathogens from the epithelial lining, thus diminishing the probability of reinfection.

Method development strategy for the analysis of anionic solutes by capillary electrophoresis.

A systematic approach to the development of methodology for the analysis of anionic solutes by capillary electrophoresis (CE) has been implemented. The strategy allows a rapid optimization of the experimental conditions and is based on the following steps: 1) A near optimum pH is chosen by inspection of the effective mobility versus pH curves of the sample components. The optimum pH lies in a region where the differences in the mobilities of all solutes are maximal. 2) An electrolyte system is selected by comparing the effective mobility of the electrolyte with the effective mobility of the primary components of the studied mixture. The appropriate electrolyte has a mobility as similar as possible to the mobility of the major components of the sample. 3) An initial experiment is run with the selected electrolyte system adjusted to the chosen pH and input values for other instrumental variables and electrolyte characteristics. 4) Depending on the degree of resolution obtained in the initial run, two important variables, the applied voltage and the electrolyte concentration, are then tuned in the proper direction, favoring the achievement of the highest resolution at the lowest possible analysis time. The proposed method development strategy was validated experimentally with a mixture of short-chained carboxylic acids and inorganic anions.

In vitro activity of metronidazole alone and in combination with clotrimazole against clinical isolates of Trichomonas vaginalis.

Trichomonas vaginalis vaginitis is generally treated with oral metronidazole. Widespread use of this drug has led, however, to selection of resistant strains. Topical therapy seems appropriate whenever systemic high dosage schedule cannot be adopted in order to overcome resistance. This study was designed to assess the activity of metronidazole alone and in combination with clotrimazole, an imidazole derivative for topical use, against T. vaginalis. Tests were performed employing the antitrichomonas activity of a fixed ratio of metronidazole with clotrimazole (5:1) which has been recently suggested for topical therapy and the checkerboard technique. All tests were carried out under aerobic conditions to maximize T. vaginalis resistance traits. Minimum inhibitory concentrations (MICs) of metronidazole for the 12 strains studied were in the range reported in the literature (0.5-32 micrograms/ml). The interaction of metronidazole with clotrimazole as assessed by the checkerboard technique gave an indifferent outcome with all the strains assayed (FIC = 1-2). The fixed concentration of drugs, however, produced synergism (FIC = 0.5) in 5 of 12 isolates. Spontaneous resistant strains were not selected from T. vaginalis exposed to sub-lethal levels of the drugs or by culturing a large inoculum in the presence of 1, 2, 4 and 8 times the MICs of metronidazole alone or in combination with clotrimazole. These results confirm and extend previous reports highlighting the good in vitro efficacy of the association of metronidazole plus clotrimazole against T. vaginalis.

Inhibition of F'lac transfer by various antibacterial drugs in Escherichia coli.

Several antimicrobial agents including mitomycin C and molecules belonging to the 4-quinolone, aminoglycoside and beta-lactam groups inhibited plasmid transfer to a varying extent, in actively growing Escherichia coli. In contrast, the same antibiotics did not prevent effective conjugation in nongrowing bacteria with the exception of mitomycin C. These results indicate that the drugs inhibit plasmid transfer by interfering with bacterial host functions rather than by recognizing a specific plasmid-mediated target. Several drugs are therefore capable, in principle, of reducing the spread of plasmid-mediated antibiotic resistance.

A case study of Beckwith-Wiedemann syndrome associated with hepatoblastoma.

Though the development of neoplasia is frequent with Beckwith-Wiedemann Syndrome its association with hepatoblastoma is extremely rare. Such a case in a fifteen month old child was studied in terms of its clinico-pathological features.