The effect of Rift Valley fever virus Clone 13 vaccine on semen quality in rams

Rift Valley fever (RVF) is an arthropod-borne viral disease of importance in livestock and humans. Epidemics occur periodically in domestic ruminants. People in contact with infected livestock may develop disease that varies from mild flu-like symptoms to fatal viraemia. Livestock vaccination may assist in disease control. Rift Valley fever virus (RVFV) Clone 13 is a relatively new vaccine against RVF, derived from an avirulent natural mutant strain of RVFV, and has been shown to confer protective immunity against experimental infection with RVFV. The hypothesis tested in the current trial was that rams vaccinated with RVFV Clone 13 vaccine would not experience a reduction in semen quality (measured by evaluating the percentage progressively motile and percentage morphologically normal spermatozoa in successive ejaculates) relative to unvaccinated control animals. Ram lambs were screened for antibodies to RVFV using a serum neutralisation test. Animals without detectable antibodies (n = 23) were randomly allocated to either a test group (n = 12) or a control group (n = 11). Animals in the test group were vaccinated with RVFV Clone 13 vaccine. Daily rectal temperature measurements and weekly semen and blood samples were taken from all animals. Seven animals were eliminated from the statistical analysis because of potential confounding factors. Logistic regression analysis was performed on data gathered from the remaining animals to determine whether an association existed between animal group, rectal temperature and semen quality parameters. No correlation existed between the treatment group and values obtained for the semen quality parameters measured. There was no statistically significant post-vaccination decline in the percentage of live morphologically normal spermatozoa, or the percentage of progressively motile spermatozoa, either when assessed amongst all animals or when assessed within individual groups. A repeat study with a larger sample size and a more comprehensive pre-screening process may be indicated to avoid the inclusion of unsuitable animals

High frequency detection of Toxoplasma gondii DNA in human neonatal tissue from Libya

Background: Toxoplasma gondii is a parasite that causes significant disease in humans. Toxoplasmosis is normally asymptomatic, unless associated with congenital transmission, or in immunocompromised people. Congenital transmission generally occurs at low frequencies. In this study, we use PCR to investigate possible congenital transmission of T. gondii during pregnancy in a cohort of mothers from Libya. Methods: Two hundred and seventy two pregnant women (producing 276 neonates) were recruited to obtain umbilical cord tissue from their neonates at birth. DNA was extracted from umbilical cord tissue and tested for T. gondii DNA using two specific PCR protocols based on the sag 1 and sag 3 genes. Results: Toxoplasma gondii DNA was detected in the umbilical cord DNA from 27 of the 276 neonates giving a prevalence of 9.9% (95% CI: 6.8-13.9%). Compared with more commonly reported rates of congenital transmission of 0.1% of live births, this is high. There was no association of infection with unsuccessful pregnancy. Conclusions: This study shows a high frequency presence of T. gondii DNA associated with neonatal tissue at birth in this cohort of 276 neonates from Libya. Although PCR cannot detect living parasites, there is the possibility that this indicates a higher than usual frequency of congenital transmission

The timing of strike-slip shear along the Ranong and Khlong Marui faults, Thailand

The timing of shear along many important strike-slip faults in Southeast Asia, such as the Ailao Shan-Red River, Mae Ping and Three Pagodas faults, is poorly understood. We present 40Ar/39Ar, U-Pb SHRIMP and microstructural data from the Ranong and Khlong Marui faults of Thailand to show that they experienced a major period of ductile dextral shear during the middle Eocene (48–40 Ma, centered on 44 Ma) which followed two phases of dextral shear along the Ranong Fault, before the Late Cretaceous (>81 Ma) and between the late Paleocene and early Eocene (59–49 Ma). Many of the sheared rocks were part of a pre-kinematic crystalline basement complex, which partially melted and was intruded by Late Cretaceous (81–71 Ma) and early Eocene (48 Ma) tin-bearing granites. Middle Eocene dextral shear at temperatures of ~300–500°C formed extensive mylonite belts through these rocks and was synchronous with granitoid vein emplacement. Dextral shear along the Ranong and Khlong Marui faults occurred at the same time as sinistral shear along the Mae Ping and Three Pagodas faults of northern Thailand, a result of India-Burma coupling in advance of India-Asia collision. In the late Eocene (<37 Ma) the Ranong and Khlong Marui faults were reactivated as curved sinistral branches of the Mae Ping and Three Pagodas faults, which were accommodating lateral extrusion during India-Asia collision and Himalayan orogenesis

Recovering simulated planet and disk signals using SCALES aperture masking

The Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy (SCALES) instrument is a lenslet-based integral field spectrograph that will operate at 2 to 5 microns, imaging and characterizing colder (and thus older) planets than current high-contrast instruments. Its spatial resolution for distant science targets and/or close-in disks and companions could be improved via interferometric techniques such as sparse aperture masking. We introduce a nascent Python package, NRM-artist, that we use to design several SCALES masks to be non-redundant and to have uniform coverage in Fourier space. We generate high-fidelity mock SCALES data using the scalessim package for SCALES' low spectral resolution modes across its 2 to 5 micron bandpass. We include realistic noise from astrophysical and instrument sources, including Keck adaptive optics and Poisson noise. We inject planet and disk signals into the mock datasets and subsequently recover them to test the performance of SCALES sparse aperture masking and to determine the sensitivity of various mask designs to different science signals

Simulating medium-spectral-resolution exoplanet characterization with SCALES angular/reference differential imaging

SCALES (Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy) is a 2 - 5 micron high-contrast lenslet-based integral field spectrograph (IFS) designed to characterize exoplanets and their atmospheres. The SCALES medium-spectral-resolution mode uses a lenslet subarray with a 0.34 x 0.36 arcsecond field of view which allows for exoplanet characterization at increased spectral resolution. We explore the sensitivity limitations of this mode by simulating planet detections in the presence of realistic noise sources. We use the SCALES simulator scalessim to generate high-fidelity mock observations of planets that include speckle noise from their host stars, as well as other atmospheric and instrumental noise effects. We employ both angular and reference differential imaging as methods of disentangling speckle noise from the injected planet signals. These simulations allow us to assess the feasibility of speckle deconvolution for SCALES medium resolution data, and to test whether one approach outperforms another based on planet angular separations and contrasts

Mediating Memories. The Ethics of Post-9/11 Spectatorship

Contains fulltext : M_317855.pdf (publisher's version ) (Open Access)2 november 201119 p

Mononuclear tantalum (V) pentalene complexes: synthesis of [Ta n8-C8H4(1,4-SiiPr3)2 X3] (X = CH3, Cl, I) and the X-ray crystal structures of [Ta n8-C8H4(1,4-SiiPr3)2 (CH3)3], [Ta n8-C8H4(1,4-SiiPr3)2 (CH3)2Cl], [Ta n8-C8H4(1,4-SiiPr3)2 (CH3)Cl2] and [Ta n8-C8H4(1,4-SiiPr3)2 I3]

The reaction between [TaMe3Cl2] and the potassium salt of the silylated pentalene dianion [K2{C8H 4(1,4-SiiPr3)2}] gives the ¿8-pentalene complex [Ta{¿8-C8H 4(1,4-SiiPr3)2}(CH3) 3]. The reaction between [TaMe3Cl2] and the potassium salt of the silylated pentalene dianion [K2{C 8H4(1,4-SiiPr3)2}] gives the ¿8-pentalene complex [Ta{¿8-C 8H4(1,4-SiiPr3)2}(CH 3)3] (1). Sequential protonolysis of 1 with [Et 3NH]Cl affords [Ta{¿8-C8H 4(1,4-SiiPr3)2}(CH3) 2Cl] (2), [Ta{¿8-C8H4(1,4- SiiPr3)2}(CH3)Cl2] (3) and [Ta{¿8-C8H4(1,4-SiiPr 3)2}Cl3] (4). An alternative and cleaner route to 4 involves treatment of 1 with BCl3; in an analogous fashion, the reaction of 1 with BI3 gives [Ta{¿8-C 8H4(1,4-SiiPr3)2}I 3] (5). The X-ray crystal structures of 1, 2, 3 and 5 are reported

Angiotensin II-induced fluid phase endocytosis in human cerebromicrovascular endothelial cells is regulated by the inositol-phosphate signaling pathway

NRC publication: Ye

Focusing Mutations into the P. fluorescens Esterase Binding Site Increases Enantioselectivity More Effectively than Distant Mutations

SummaryRational design of enzymes with improved properties, such as enantioselectivity, usually focuses mutations within the substrate binding site. On the other hand, directed evolution of enzymes usually targets the entire protein and discovers beneficial mutations far from the substrate binding site. In this paper, we propose an explanation for this discrepancy and show that a combined approach—random mutagenesis within the substrate binding site—is better. To increase the enantioselectivity (E) of a Pseudomonas fluorescens esterase (PFE) toward methyl 3-bromo-2-methylpropionate, we focused mutagenesis into the substrate binding site at Trp28, Val121, Phe198, and Val225. Five of the catalytically active mutants (13%) showed better enantioselectivity than wild-type PFE. The increases in enantioselectivity were higher (up to 5-fold, reaching E = 61) than with mutants identified by random mutagenesis of the entire enzyme

Monitoring and repair of isolated trackbed defects on a ballasted railway

Ballasted railway track suffers from a gradual loss of vertical geometry (level) as a result of settlements caused by trafficking and differences in support conditions. However, certain trackbed defects giving rise to a particularly rapid and severe loss of geometry are often localised, and possibly associated with zones of inadequate or variable support stiffness. Conventional line-tamping (usually by machine) may not be effective for these isolated trackbed defects. This paper demonstrates, with reference to three particular defect sites on a ballasted railway in the UK, the benefits in terms of both effectiveness and longevity of a more targeted repair strategy at such locations. First, track-based instrumentation was used to assess the nature and extent of the defect and to identify differential support stiffness conditions, which might also need to be addressed. The data were then used to inform repair strategy; for example, deflections measured during train passage were used to specify the thickness of shims placed between the rail pad and the sleeper. Finally, the track-based instrumentation was used to monitor the effectiveness and longevity of the repair, providing evidence that adequate support conditions had been restored. At the three defect sites investigated, the localised repairs are shown to be more effective and longer-lived than conventional line-tamping