220 research outputs found
The level of embryonation influences detection of Ostertagia ostertagi eggs by semi-quantitative PCR
BACKGROUND: The Internal Transcribed Spacer 2 (ITS2) is a candidate diagnostic marker of the pathogenic cattle nematode Ostertagia ostertagi. The aims of this study were: (i) to document and quantify how the development of O. ostertagi eggs affects ITS2 copies under different storage conditions, and (ii) to suggest optimal storage conditions for faecal samples in a diagnostic pipeline that involves detection and semi-quantification by real-time semi-quantitative polymerase chain reaction (qPCR). FINDINGS: Eggs of Ostertagia ostertagi were obtained from fresh faeces and stored at 4 °C or 25 °C under aerobic or anaerobic (vacuum packing) conditions. Development was monitored by microscopy for up to 336 h, and the ITS2 copies were determined by qPCR from a fixed number of parasites. Under aerobic conditions at 25 °C, embryonation and a significant increase of ITS2 copies (P < 0.0001) were observed after 12 h. At 4 °C, embryonation occurred after 168 h with a trend towards increased ITS2 copies. Anaerobic conditions inhibited egg development at both temperatures and no significant increase in ITS2 copies was noticed (P = 0.90). ITS2 copies were analysed for each parasite stage: first-stage larvae (L1) exhibited significantly higher copy numbers (20,353 ± 1,950) than unembryonated eggs (568 ± 168; P < 0.0001) with lower coefficient of variation (33 vs 266 %). CONCLUSIONS: Aerobic storage of O. ostertagi eggs at 25 °C led to a significant increase in ITS2 copies after 12 h due to embryonation and subsequent hatching. In contrast, anaerobic storage (vacuum packing) at 25 °C completely inhibited egg development and any undesirable semi-quantification bias for up to 336 h. Hence, vacuum packing is an optimal storage strategy prior to molecular diagnostic analyses. Alternatively, aerobic storage at 4 °C for up to 72 h can be used. Due to high copy numbers and lower genetic variation, the L1 stage may be considered for diagnostics and further molecular research. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1657-4) contains supplementary material, which is available to authorized users
Streamlining screening of emotional function in Veterans with traumatic brain injury
ObjectivesThis study examined how depression, anxiety, and sleep items from the Neurobehavioral Symptom Inventory (NSI) predict results from longer inventories.MethodThis was a retrospective review from 484, predominantly male (96.1%) Veterans, mean age 29.7 years, who underwent brief neuropsychological screening during a comprehensive, multidisciplinary evaluation for mild traumatic brain injury (TBI). Participants completed the NSI, insomnia severity index (ISI), and hospital anxiety and depression scale (HADS).Results: Overall,97.1% who endorsed “severe”/“very severe” anxiety on the NSI had significant anxiety on the HADS; 85% reporting “severe”/“very severe” depression on the NSI, had significant depression on the HADS; and 97.7% reporting “severe”/“very severe” sleep problems on the NSI, had significant sleep difficulties on the ISI.ConclusionClose correspondence between “severe”/“very severe” symptoms on the NSI and lengthier checklists suggests additional checklists may be eliminated and individuals can be referred for mental health treatment. NSI reports of “mild”/“moderate” require further screening.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144598/1/jclp22595_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144598/2/jclp22595.pd
Photoassociation inside an optical dipole trap: absolute rate coefficients and Franck-Condon factors
We present quantitative measurements of the photoassociation of cesium
molecules inside a far-detuned optical dipole trap. A model of the trap
depletion dynamics is derived which allows to extract absolute photoassociation
rate coefficients for the initial single-photon photoassociation step from
measured trap-loss spectra. The sensitivity of this approach is demonstrated by
measuring the Franck-Condon modulation of the weak photoassociation transitions
into the low vibrational levels of the outer well of the 0g- state that
correlates to the 6s+6p3/2 asymptote. The measurements are compared to
theoretical predictions. In a magneto-optical trap these transitions have
previously only been observed indirectly through ionization of ground state
molecules
Parties, promiscuity and politicisation: business-political networks in Poland
Research on post-communist political economy has begun to focus on the interface between business and politics. It is widely agreed that informal networks rather than business associations dominate this interface, but there has been very little systematic research in this area. The literature tends to assume that a politicised economy entails business-political networks that are structured by parties. Theoretically, this article distinguishes politicisation from party politicisation and argues that the two are unlikely to be found together in a post-communist context. Empirically, elite survey data and qualitative interviews are used to explore networks of businesspeople and politicians in Poland. Substantial evidence is found against the popular idea that Polish politicians have business clienteles clearly separated from each other according to party loyalties. Instead, it is argued that these politicians and businesspeople are promiscuous. Since there seems to be little that is unusual about the Polish case, this conclusion has theoretical, methodological, substantive and policy implications for other post-communist countries
Aerodynamics of aero-engine installation
This paper describes current progress in the development of methods to assess aero-engine airframe installation effects. The aerodynamic characteristics of isolated intakes, a typical transonic transport aircraft as well as a combination of a through-flow nacelle and aircraft configuration have been evaluated. The validation task for an isolated engine nacelle is carried out with concern for the accuracy in the assessment of intake performance descriptors such as mass flow capture ratio and drag rise Mach number. The necessary mesh and modelling requirements to simulate the nacelle aerodynamics are determined. Furthermore, the validation of the numerical model for the aircraft is performed as an extension of work that has been carried out under previous drag prediction research programmes. The validation of the aircraft model has been extended to include the geometry with through flow nacelles. Finally, the assessment of the mutual impact of the through flow nacelle and aircraft aerodynamics was performed. The drag and lift coefficient breakdown has been presented in order to identify the component sources of the drag associated with the engine installation. The paper concludes with an assessment of installation drag for through-flow nacelles and the determination of aerodynamic interference between the nacelle and the aircraft
Saturation in heteronuclear photoassociation of 6Li7Li
We report heteronuclear photoassociation spectroscopy in a mixture of
magneto-optically trapped 6Li and 7Li. Hyperfine resolved spectra of the
vibrational level v=83 of the singlet state have been taken up to intensities
of 1000 W/cm^2. Saturation of the photoassociation rate has been observed for
two hyperfine transitions, which can be shown to be due to saturation of the
rate coefficient near the unitarity limit. Saturation intensities on the order
of 40 W/cm^2 can be determined.Comment: 5 pages, 3 figures, to appear in Phys. Rev. A (Rapid Communication
High-precision calculations of van der Waals coefficients for heteronuclear alkali-metal dimers
Van der Waals coefficients for the heteronuclear alkali-metal dimers of Li,
Na, K, Rb, Cs, and Fr are calculated using relativistic ab initio methods
augmented by high-precision experimental data. We argue that the uncertainties
in the coefficients are unlikely to exceed about 1%.Comment: 11 pages, 2 figs, graphicx.st
High-precision determination of transition amplitudes of principal transitions in Cs from van der Waals coefficient C_6
A method for determination of atomic dipole matrix elements of principal
transitions from the value of dispersion coefficient C_6 of molecular
potentials correlating to two ground-state atoms is proposed. The method is
illustrated on atomic Cs using C_6 deduced from high-resolution Feshbach
spectroscopy. The following reduced matrix elements are determined < 6S_{1/2}
|| D || 6P_{1/2} > =4.5028(60) |e| a0 and
=6.3373(84) |e| a0 (a0= 0.529177 \times 10^{-8} cm.) These matrix elements are
consistent with the results of the most accurate direct lifetime measurements
and have a similar uncertainty. It is argued that the uncertainty can be
considerably reduced as the coefficient C_6 is constrained further.Comment: 4 pages; 3 fig
Quantum computation with trapped polar molecules
We propose a novel physical realization of a quantum computer. The qubits are
electric dipole moments of ultracold diatomic molecules, oriented along or
against an external electric field. Individual molecules are held in a 1-D trap
array, with an electric field gradient allowing spectroscopic addressing of
each site. Bits are coupled via the electric dipole-dipole interaction. Using
technologies similar to those already demonstrated, this design can plausibly
lead to a quantum computer with qubits, which can perform CNOT gates in the anticipated decoherence time of s.Comment: 4 pages, RevTeX 4, 2 figures. Edited for length and converted to
RevTeX, but no substantial changes from earlier pdf versio
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