39 research outputs found
Establishing the spread of bluetongue virus at the end of the 2006 epidemic in Belgium
Vlaamse hulpverleningstrajecten in de bijzondere jeugdzorg in een internationale context
Mathematics anxiety: An intergenerational approach
This study investigated mathematics anxiety from an intergenerational perspective, by investigating data on 172 primary school children and both their biological parents. This family dataset (n = 516) allowed us to not only replicate previous findings per generation, but, importantly, to explore intergenerational correlations. We found a significant negative association between sixth graders’ arithmetical performance and their mathematics anxiety. Gender differences occurred in each generation: females were more anxious than males about mathematics. Interestingly, these gender differences were not found in actual arithmetical performance. Analyses of our intergenerational data revealed that children’s mathematics anxiety was significantly associated with their mothers’ mathematics anxiety and both their mothers’ and fathers’ educational level. Regression analyses revealed that the significance level of mothers’ mathematics anxiety became borderline when considering mathematics anxiety and educational level of both parents simultaneously. Interestingly, mathematics anxiety as well as educational level of both biological parents was associated, suggesting that mathematics anxiety results from a complex entanglement of nature and nurture. Current intergenerational data suggest a complex familial basis of mathematics anxiety and indicate that the investigation of parental levels of education and mathematics anxiety contributes to the understanding of individual differences in children’s arithmetic performance
Vlaamse hulpverleningstrajecten in de bijzondere jeugdzorg in een internationale context
A duplex real-time RT-PCR for the detection of bluetongue virus in bovine semen.
<p>The control measures prescribed by the World Organization for Animal Health (OIE) for international trade in extended semen implicate repeated free testing of the donor's blood for bluetongue virus (BTV). The aim of this study was to validate a real-time RT-PCR for the direct testing of semen for artificial insemination (AI). The amplification of the BTV target was combined with an internal control target in duplex format. Optimal RNA recovery and efficient removal of PCR inhibitors was established using Trizol-based RNA extraction. The total assay was highly repeatable, the preliminary analysis of the specificity was 100% (95% CI: 92-100%) and the limit of detection was -0.36 log(10)TCID(50) ml(-1) (95% CI: -0.53 to -0.18 log(10)TCID(50) ml(-1)) in BTV-8 spiked extended semen. The protocol was evaluated using 89 extended semen samples from 19 bulls showing typical clinical signs of a natural BTV-8 infection. Forty-eight samples were positive, 30 were doubtful and 11 were negative. Infectious BTV-8 was isolated. Based on varying real-time RT-PCR results of additional straws from cut-off samples it is highly recommended to analyse at least five straws per semen batch before declaring semen free of BTV. In conclusion, the partially validated assay presented has the potential to be used for the control of semen for international trade through direct testing of the semen.</p></p
Viral RNA load in semen from bluetongue serotype 8-infected rams: Relationship with sperm quality
<p>This study investigated if viral RNA was detectable in the semen of rams clinically infected with bluetongue virus serotype 8 (BTV-8) by RT-qPCR, and to what extent the amount detected may be predictive of sperm quality. Semen samples were collected on six occasions from 93 BTV-8 infected rams involved in two longitudinal (n=12 and 27, respectively) and one cross-sectional (n=54) field study. Semen quality was assessed in terms of mass motility, concentration of spermatozoa, percentage of living and dead spermatozoa as well as cytological features. An overall semen quality score (SQS) was established. Depending upon the studied population, BTV RNA was detected in 75-100% of semen samples at initial testing 25-57 days post-observation (DPO) of clinical signs, and was detectable up to 116 DPO in a proportion of rams undergoing repeated sampling. Semen quality variables were significantly altered following natural BTV-8 infection and correlated with the amount of BTV RNA present. The SQS did not return to normal when virus was no longer detectable, suggesting that clearance of BTV precedes full recovery of sperm quality. In conclusion, viral RNA may be transiently recovered from the semen of BTV-8 affected rams and may serve as an indicator in predicting ram breeding potential following natural infection.</p></p
Effect of pooling and multiplexing on the detection of bluetongue virus RNA by real-time RT-PCR.
<p>Real-time RT-PCR (RT-qPCR) was used routinely for laboratory diagnosis during the 2006/2007 bluetongue virus (BTV) serotype 8 epidemic. In the present study the impact of pooling and multiplexing strategies on RT-qPCR are assessed. To avoid any bias in the pooling experiments, 121 BTV-8 positive blood samples with a low to high viral load were selected and pooled individually with nine negative blood samples. Analyses of the individually and pooled samples indicated an overall mean difference of 4.32 Ct-values. The most pronounced differences were observed in samples with the lowest viral load of which 70% could no longer be detected after pooling. The pooling strategy is therefore not suitable for BTV detection at the individual level since animals infected recently may be missed. An alternative approach to reduce costs and workload is to apply a multiplexing strategy in which the viral RNA and internal beta-actin control RNA are detected in a single reaction. Parallel analysis (singleplex versus multiplex) of a 10-fold dilution series and 546 field samples proved that the sensitivity of the BTV RT-qPCR was not affected whereas the beta-actin reaction was reduced only slightly. Without the use of an internal control, 0.6% of 1985 field samples is at risk of being diagnosed incorrectly as negative.</p></p
Alfentanil-induced miosis clearance as a liver CYP3A4 and 3A5 activity measure in healthy volunteers: improvement of experimental conditions.
The aims of this study were to demonstrate the correlation between alfentanil-induced miosis evaluation and alfentanil pharmacokinetics (PK) as a CYP3A4 and 3A5 activity probe in volunteers and to explain the variability in pupilar response and in alfentanil PK. In ambient light, the miosis kinetic parameters were significantly correlated with PK (CLs: r = 0.9, P = .00; AUCs: r = 0.8, P = .01). In dark, a similar correlation was observed between miosis and alfentanil clearances (r = 0.85, P = .03). In 6 volunteers, the sigmoid E(max) model was applicable (average E(max) = 2.5 +/- 0.7 mm, gamma = 2.5 +/- 1.6 and EC(50) = 76.8 +/- 22.3 ng/mL), and in 3, the simple E(max) model was applicable (average E(max) = 2.8 +/- 0.3 mm and EC(50) = 19.9 +/- 8.5 ng/mL). There was a large interindividual variability in PK parameters (coefficient of variation = 19.7%-31.2%). Free drug fraction concentrations were negatively correlated with plasma alpha(1)-AGP (r = -0.9, P = .04) and albumin levels (r = -0.94, P = .02). Alfentanil-induced miosis clearance as a noninvasive CYP3A4 and 3A5 activity measure can be done in both ambient and dark conditions. Drug free fraction may be responsible for large intersubject variability in alfentanil PK
Molecular-structure of and Restricted Internal-rotation About the Tin Tin Bond in [clsn(ch2ch2ch2)2nch3]2 and Solution Isomerism and Isomerizations in [ch3sn(ch2ch2ch2)2nch3]2, 2 Compounds With 5-coordinate Tin Centers Bound To Each Other
info:eu-repo/semantics/publishe