2,835 research outputs found
Development and evaluation of an enterovirus D68 real-time reverse transcriptase PCR assay
We have developed and evaluated a real-time reverse transcriptase PCR (RT-PCR) assay for the detection of human enterovirus D68 (EV-D68) in clinical specimens. This assay was developed in response to the unprecedented 2014 nationwide EV-D68 outbreak in the United States associated with severe respiratory illness. As part of our evaluation of the outbreak, we sequenced and published the genome sequence of the EV-D68 virus circulating in St. Louis, MO. This sequence, along with other GenBank sequences from past EV-D68 occurrences, was used to computationally select a region of EV-D68 appropriate for targeting in a strain-specific RT-PCR assay. The RT-PCR assay amplifies a segment of the VP1 gene, with an analytic limit of detection of 4 copies per reaction, and it was more sensitive than commercially available assays that detect enteroviruses and rhinoviruses without distinguishing between the two, including three multiplex respiratory panels approved for clinical use by the FDA. The assay did not detect any other enteroviruses or rhinoviruses tested and did detect divergent strains of EV-D68, including the first EV-D68 strain (Fermon) identified in California in 1962. This assay should be useful for identifying and studying current and future outbreaks of EV-D68 viruses
The Application of Risk–Needs Programming in a Juvenile Diversion Program
As “gatekeepers” into the juvenile justice system, diversion programs are positioned to prevent future delinquency. Although research on the effectiveness of diversion is mixed, the risk–needs–responsivity (RNR) model may explain how diversion programming that matches youth to services based on their risk and needs may reduce reoffending. Most RNR research has included juveniles at the deeper end of the system, fewer studies have examined RNR with early system–involved youth. The current study explored the application of risk and needs matching in a juvenile diversion program by gender and race/ethnicity. Furthermore, we estimated a survival function to estimate risk and needs alignment on time to recidivism. Although there were no gender differences in the application of RNR, some racial/ethnic differences did emerge. Findings provide support for assessing diversion youth with the Youth Level of Service/Case Management Inventory (YLS/CMI) and applying the RNR framework to early system–involved youth assessed as low to moderate risk
Gas injection into second mode instability on a 7 degree cone at Mach 7
The influence of injection gas type on second mode instabilities is researched on a 7 degree half-angle cone at Mach 7. The wind tunnel model of 594.5 mm length with a sharp nosetip is fitted with a porous aluminium patch that spans 60 degree in azimuth and 25 mm in axial length. Four different gases are injected into the boundary layer flow, namely nitrogen, carbon dioxide, helium and argon. Three different tunnel test conditions with different unit Reynolds numbers provide a variety of amplification levels of the second mode instability at the injection location. Frequency data is obtained using PCB sensors and the density boundary layer thickness is inferred from high speed z-type schlieren images. Early analysis of initial data shows a drop in second mode frequency and second mode power behind the injector. If transition is not caused the effect weakens further downstream. Higher blowing ratios caused a stronger decrease in frequency and also reduced the power in the frequency band more. Larger blowing ratios are required at lower unit Reynolds numbers to achieve the same effect. The observed boundary layer thickness, as inferred from schlieren images, followed comparable dynamics. A larger blowing ratio of the same coolant gas lead to more thickening, while Helium had a significantly stronger total effect than carbon dioxide. Preliminary results suggest that helium injection at a moderate rate causes the second mode peak to be disproportionally damped and its bandpower to be significantly reduced. A strongly simplified analytical model suggest that the mechanical increase in boundary layer thickness alone may not be sufficient to explain all observed outcomes
The effect of individual radiographers on rates of attendance to breast screening: A 7-year retrospective study
AIM: To establish whether individual radiographers had significantly different rescreening rates whilst controlling for other known confounding factors.
MATERIALS AND METHODS: Women aged 50e69 years were identified from a state-wide screening database at their first screening attendance during the study period (2007e2013). The radiographer performing this index screen and potential confounding factors were recorded and subsequent screening behaviour was assessed. Clients with abnormal screens and those known to have died during the time period were excluded. A univariate analysis of the data from 160,028 women was assessed using the chi-square test to compare those women who attended their next mammography with non-re-attenders. Logistic regression was used to calculate the likelihood of “re-attendance success” across a range of variables. The probability of re-attendance for 11 randomly selected radiographers was determined from the logistic regression model, whilst controlling for other variables.
RESULTS: Comparison of non-re-attenders (nÂĽ49,698) with 110,330 (69%) women attending the next round of screening revealed significant differences, including radiographer (Wald statisticsÂĽ1188, p\u3c0.000) even when all other known factors were controlled.
CONCLUSION: This large, population-level study demonstrates that individual radiographer factors appear to influence a women’s decision to return for their next screening round. Further research is required to identify reasons for differing rescre
Casimir Force between a Dielectric Sphere and a Wall: A Model for Amplification of Vacuum Fluctuations
The interaction between a polarizable particle and a reflecting wall is
examined. A macroscopic approach is adopted in which the averaged force is
computed from the Maxwell stress tensor. The particular case of a perfectly
reflecting wall and a sphere with a dielectric function given by the Drude
model is examined in detail. It is found that the force can be expressed as the
sum of a monotonically decaying function of position and of an oscillatory
piece. At large separations, the oscillatory piece is the dominant
contribution, and is much larger than the Casimir-Polder interaction that
arises in the limit that the sphere is a perfect conductor. It is argued that
this enhancement of the force can be interpreted in terms of the frequency
spectrum of vacuum fluctuations. In the limit of a perfectly conducting sphere,
there are cancellations between different parts of the spectrum which no longer
occur as completely in the case of a sphere with frequency dependent
polarizability. Estimates of the magnitude of the oscillatory component of the
force suggest that it may be large enough to be observable.Comment: 18pp, LaTex, 7 figures, uses epsf. Several minor errors corrected,
additional comments added in the final two sections, and references update
Application of a urine and hair validated LC-MS/MS method to determine the effect of hair colour on the incorporation of 25B-NBOMe, 25C-NBOMe and 25I-NBOMe into hair in the rat.
NBOMes are a group of new psychoactive substances derived from phenethylamines. Recreational abuse is thought to have begun in 2010 and they are commonly associated with the “club drug” scene. They are administered in liquid form or as blotters due to their high potency.
An LC-MS/MS method was validated using SWGTOX parameters for the detection of 25B-, 25C- and 25I-NBOMe using 25B-NBOMe-D3 as internal standard for urine and hair. Calibration graphs with R2 values >0.99 were observed for urine and hair for concentrations ranging from 0.1 -100 ng/mL and 0.025-2.5 ng/mg respectively. Urine LODs ranged from 5-25 pg/mL and had an LOQ of 50 pg/mL. Hair LOD and LOQs ranged from 3-5 pg/mg and 6.25-12.5 pg/mg respectively. Intra and inter-day precision was <20% and accuracy was within ± 20% for both matrices. The method was shown to be selective for both exogenous and endogenous compounds. No matrix effects were observed for either matrix. LLE recovery ranged from 90-103% for urine samples and SPE recovery ranged from 80-107% for hair samples.
Long-Evans rats (n=55) were administered 25B-, 25C- or 25I-NBOMe at doses ranging from 30-300 µg/kg over a period of 10 days. Rats were shaved prior to their first dose and re-shaved after the 10-day period. Hair was separated by colour (black: n=55 and white: n=55) and analysed using the validated LC-MS/MS method to assess the impact hair colour has on the incorporation of these drugs.
All drugs were successfully detected in black hair. 25B-NBOMe from rats receiving the highest dose and 25C-NBOMe from rats receiving the medium and high doses were quantified in white hair. 25I-NBOMe was detected but fell below the limit of quantification. A dose-dependent concentration increase was observed in the black hair. All pooled urine samples tested positive for their expected NBOMes
Contribution of a Real Depth Distance Stereoacuity Test to Clinical Management
Measurement of Stereopsis forms an important part of the clinical assessment of patients with disorders of ocular motility. The introduction of a real depth distance stereoacuity test (FD2) was evaluated in clinical practice and to what extent the introduction affected clinical management. Seventy-three patients under evaluation before and following the introduction of the test were included. Combined thresholds were measured at near using the Frisby and TNO test and at distance using the FD2. Fifty healthy controls were included. Forty-five patients demonstrated Stereopsis using the FD2 and 23 of these had a change in their management based in part on their responses using the FD2. Patients with evidence of Stereopsis using the FD2 were significantly more likely to have change in their management than expected from the whole sample (P = .02). The introduction of a real depth distance stereoacuity test into clinical practice contributed to a change in management when used in conjunction with other tests. The usefulness of the FD2 is limited by its range at 6 m. Use at closer distances necessitates the calculation of binocular threshold from the combined and monocular threshold
How Valid Are Measures of Children’s Self-Concept/ Self-Esteem? Factors and Content Validity in Three Widely Used Scales
Children’s self-esteem/self-concept, a core psychological construct, has been measured in an overwhelming number of studies, and the widespread use of such measures should indicate they have well-established content validity, internal consistency and factor structures. This study, sampling a demographically representative cohort in late childhood/early adolescence in Dublin, Ireland (total n = 651), examined three major self-esteem/self-concept scales designed for late childhood/early adolescence: Piers-Harris Self-Concept Scale for Children 2 (Piers et al. 2002), Self-Description Questionnaire I (Marsh 1992) and Self-Perception Profile for Children (Harter 1985). It also examined findings in light of the salient self factors identified by participants in a linked mixed-methods study. The factor structure of Piers-Harris Self-Concept Scale was not replicated. The Self-Description Questionnaire I and Self-Perception Profile for Children were replicated only in part although in similar ways. In all three scales, a global/ appearance self evaluation factor accounted for the largest variance in factor analyses. Sport/athletic ability, school ability, school enjoyment, maths and reading ability/enjoyment, behaviour, peer popularity, and parent factors were also identified but did not always reflect existing scale structures. Notably, the factors extracted, or items present in these scales, often did not reflect young people’s priorities, such as friendship over popularity, the importance of family and extended family members, and the significance of incremental personal mastery in activities rather than assessing oneself as comparatively good at preferred activities. The findings raise questions about how self-esteem/self-concept scales are used and interpreted in research with children and young people
A case of persistent human pegivirus infection in two separate pregnancies of a woman
Human pegivirus (HPgV) is best known for persistent, presumably non-pathogenic, infection and a propensity to co-infect with human immunodeficiency virus or hepatitis C virus. However, unique attributes, such as the increased risk of malignancy or immune modulation, have been recently recognized for HPgV. We have identified a unique case of a woman with high levels HPgV infection in two pregnancies, which occurred 4 years apart and without evidence of human immunodeficiency virus or hepatitis C virus infection. The second pregnancy was complicated by congenital heart disease. A high level of HPgV infection was detected in the maternal blood from different trimesters by RT-PCR and identified as HPgV type 1 genotype 2 in both pregnancies. In the second pregnancy, the decidua and intervillous tissue of the placenta were positive for HPgV by PCR but not the chorion or cord blood (from both pregnancies), suggesting no vertical transmission despite high levels of viremia. The HPgV genome sequence was remarkably conserved over the 4 years. Using VirScan, sera antibodies for HPgV were detected in the first trimester of both pregnancies. We observed the same anti-HPgV antibodies against the non-structural NS5 protein in both pregnancies, suggesting a similar non-E2 protein humoral immune response over time. To the best of our knowledge, this is the first report of persistent HPgV infection involving placental tissues with no clear indication of vertical transmission. Our results reveal a more elaborate viral-host interaction than previously reported, expand our knowledge about tropism, and opens avenues for exploring the replication sites of this virus
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