Deformed wing virus prevalence and load in honeybees in South Africa

Deformed wing virus (DWV) is an emerging honeybee pathogen that has appeared across the globe in the past 40 years. When transmitted by the parasitic varroa mite, it has been associated with the collapse of millions of colonies throughout the Northern Hemisphere. However, despite the presence of the mite in the Southern Hemisphere, infested colonies survive. This study investigated the prevalence of DWV genotypes A, B and C along with their viral loads in South Africa and compared the fndings with recent data from Brazil, the UK and the USA. We found that DWV-B was the most prevalent genotype throughout South Africa, although the total DWV viral load was signifcantly lower (2.8E+07) than found in the Northern Hemisphere (2.8E+07 vs. 2.7E+10, p > 0.00001) and not signifcantly diferent to that found in Brazil (5E+06, p = 0.13). The diferences in viral load can be explained by the mite resistance in Brazil and South Africa, since mite-infested cells containing high viral loads are removed by the bees, thus lowering the colony’s viral burden. This behaviour is much less developed in the vast majority of honeybees in the Northern Hemisphere

Equine piroplasmosis status in the UK: an assessment of laboratory diagnostic submissions and techniques

Equine piroplasmosis (EP) has historically been of minor concern to UK equine practitioners, primarily due to a lack of competent tick vectors. However, increased detection of EP tick vector species in the UK has been reported recently. EP screening is not currently required for equine importation, and when combined with recent relaxations in movement regulations, there is an increased risk regarding disease incursion and establishment into the UK. This study evaluated the prevalence of EP by both serology and PCR among 1242 UK equine samples submitted for EP screening between February and December 2016 to the Animal and Plant Health Agency and the Animal Health Trust. Where information was available, 81.5 per cent of submissions were for the purpose of UK export testing, and less than 0.1 per cent for UK importation. Serological prevalence of EP was 8.0 per cent, and parasite DNA was found in 0.8 per cent of samples. A subsequent analysis of PCR sensitivity in archived clinical samples indicated that the proportion of PCR-positive animals is likely to be considerably higher. The authors conclude that the current threat imposed by UK carrier horses is not adequately monitored and further measures are required to improve national biosecurity and prevent endemic disease

Pressure Support in Galaxy Disks: Impact on Rotation Curves and Dark Matter Density Profiles

Rotation curves constrain a galaxy's underlying mass density profile, under the assumption that the observed rotation produces a centripetal force that exactly balances the inward force of gravity. However, most rotation curves are measured using emission lines from gas, which can experience additional forces due to pressure. In realistic galaxy disks, the gas pressure declines with radius, providing additional radial support to the disk. The measured tangential rotation speed will therefore tend to lag the true circular velocity of a test particle. The gas pressure is dominated by turbulence, and we evaluate its likely amplitude from recent estimates of the gas velocity dispersion and surface density. We show that where the amplitude of the rotation curve is comparable to the characteristic velocities of the interstellar turbulence, pressure support may lead to underestimates of the mass density of the underlying dark matter halo and the inner slope of its density profile. These effects may be significant for galaxies with rotation speeds <75km/s, but are unlikely to be significant in higher mass galaxies. We find that pressure support can be sustained over long timescales, because any reduction in support due to the conversion of gas into stars is compensated for by an inward flow of gas. However, we point to many uncertainties in assessing the importance of pressure support in galaxies. Thus, while pressure support may alleviate possible tensions between rotation curve observations and LambdaCDM on kiloparsec scales, it should not be viewed as a definitive solution at this time.Comment: Accepted to the Astrophysical Journal; 18 pages including 5 pages of figure

The RMS Survey: Mid-Infrared Observations of Candidate Massive YSOs in the Southern Hemisphere

Abridged abstract: The Red MSX Source (RMS) survey is an ongoing effort to return a large, well-selected sample of massive young stellar objects (MYSOs) within our Galaxy. A series of ground-based follow-up observations are being undertaken in order to remove contaminant objects from our list of 2000 candidates, and to begin characterising these MYSOs. As a part of these follow-up observations, high resolution (~1") mid-IR imaging aids the identification of contaminant objects which are resolved (UCHII regions, PN) as opposed to those which are unresolved (YSOs, evolved stars) as well as identifying YSOs near UCHII regions and other multiple sources. We present 10.4 micron imaging observations for 346 candidate MYSOs in the RMS survey in the Southern Hemisphere, primarily outside the region covered by the GLIMPSE Spitzer Legacy Survey. These were obtained using TIMMI2 on the ESO 3.6m telescope in La Silla, Chile. Our photometric accuracy is of order 0.05Jy, and our astrometric accuracy is 0.8", which is an improvement over the nominal 2" accuracy of the MSX PSC.Comment: 9 page paper accepted to A&A. Online data for table 2 and figure 1 will be available in the published online version of this paper via A&A. The paper contains 7 figures and 3 table

A randomised controlled trial of cognitive behavioural treatment for obsessive compulsive disorder in children and adolescents

Cognitive behaviour therapy (CBT) for young people with obsessive compulsive disorder (OCD) has become the treatment of first choice. However, the literature is largely based on studies emphasising exposure and response prevention. In this study, we report on a randomised controlled trial of CBT for young people carried out in typical outpatient clinic conditions which focused on cognitions. A randomised controlled trial compares 10 sessions of manualised cognitive behavioural treatment with a 12-week waiting list for adolescents and children with OCD. Assessors were blind to treatment allocation. 21 consecutive patients with OCD aged between 9 and 18 years were recruited. The group who received treatment improved more than a comparison group who waited for 3 months. The second group was treated subsequently using the same protocol and made similar gains. In conclusion, CBT can be delivered effectively to young people with OCD in typical outpatient settings

Telomere lengths in human oocytes, cleavage stage embryos and blastocysts

Telomeres are repeated sequences that protect the ends of chromosomes and harbour DNA-repair proteins. Telomeres shorten during each cell division in the absence of telomerase. When telomere length becomes critically short, cell senescence occurs. Telomere length therefore reflects both cellular ageing and capacity for division. We have measured telomere length in human germinal vesicle (GV) oocytes and pre-implantation embryos, by quantitative fluorescence in-situ hybridisation (Q-FISH), providing baseline data towards our hypothesis that telomere length is a marker of embryo quality. The numbers of fluorescent foci suggest that extensive clustering of telomeres occurs in mature GV stage oocytes, and in pre-implantation embryos. When calculating average telomere length by assuming that each signal presents one telomere, the calculated telomere length decreased from the oocyte to the cleavage stages, and increased between the cleavage stages and the blastocyst (11.12 vs 8.43 vs 12.22kb respectively, p<0.001). Other methods of calculation, based upon expected maximum and minimum numbers of telomeres, confirm that telomere length in blastocysts is significantly longer than cleavage stages. Individual blastomeres within an embryo showed substantial variation in calculated average telomere length. This study implies that telomere length changes according to the stage of pre-implantation embryo development

The Magnetic Field of the Irregular Galaxy NGC 4214

We examine the magnetic field in NGC 4214, a nearby irregular galaxy, using multi-wavelength radio continuum polarization data from the Very Large Array. We find that the global radio continuum spectrum shows signs that free-free absorption and/or synchrotron losses may be important. The 3cm radio continuum morphology is similar to that of the Halpha, while the 20cm emission is more diffuse. We estimate that 50% of the radio continuum emission in the center of the galaxy is thermal. Our estimate of the magnetic field strength is $30\pm 9.5$ \uG\ in the center and $10\pm3$ \uG\ at the edges. We find that the hot gas, magnetic, and the gravitational pressures are all the same order of magnitude. Inside the central star forming regions, we find that the thermal and turbulent pressures of the HII regions dominate the pressure balance. We do not detect any significant polarization on size scales greater than 200 pc. We place an upper limit of 8 \uG\ on the uniform field strength in this galaxy. We suggest that the diffuse synchrotron region, seen to the north of the main body of emission at 20cm, is elongated due to a uniform magnetic field with a maximum field strength of 7.6 \uG. We find that, while the shear in NGC 4214 is comparable to that of the Milky Way, the supernova rate is half that of the Milky Way and suggest that the star formation episode in NGC 4214 needs additional time to build up enough turbulence to drive an $\alpha-\omega$ dynamo.Comment: Accepted by ApJ. Version with high resolution figures at http://www.astro.virginia.edu/~aak8t/data/n4214/ms.pd

Cowdria ruminantium DNA is unstable in a SuperCos1 library

A Cowdria ruminantium genomic library was constructed in a cosmid vector to serve as a source of easily accessible and pure C. ruminantium DNA for molecular genetic studies. The cosmid library contained 846 clones which were arrayed into microtitre plates. Restriction enzyme digestion patterns indicated that these clones had an average insert size of 35 kb. Probing of the arrays did not detect any bovine clones and only one of the known C. ruminantium genes, pCS20, was detected. Due to the high AT content and the fact that C. ruminantium genes are active in the Escherichia coli host, the C. ruminantium clones were unstable in the SuperCos 1 vector and most clones did not grow reproducibly. The library was contaminated with E. coli clones and these clones were maintained with greater fidelity than the C. ruminantium clones, resulting in a skewed representation over time. We have isolated seven C. ruminantium clones which we were able to serially culture reproducibly; two of these clones overlap. These clones constitute the first large regions of C. ruminantium DNA to be cloned and represent almost 10% of the C. ruminantium genome.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Dynamic variation in cycling of hematopoietic stem cells in steady state and inflammation

Both fast-cycling and quiescent mouse hematopoietic stem cells (HSCs) can reconstitute lifelong hematopoiesis, and HSC cycling status can fluctuate over time in steady state and accelerate upon inflammation

Biofouling of crypts of historical and architectural interest at la Plata Cemetery (Argentina)

Cemeteries are part of the cultural heritage of urban communities, containing funerary crypts and monuments of historical and architectural interest. Efforts aimed at the conservation of these structures must target not only the abiotic stresses that cause their destruction, such as light and humidity, but also biofouling by biotic agents. The purpose of this study was to assess the development of biofouling of several historically and architecturally valuable crypts at La Plata Cemetery (Argentina). Samples obtained from the biofilms, lichens, and fungal colonies that had developed on the marble surfaces and cement mortar of these crypts were analyzed by conventional microbiological techniques and by scanning electron microscopy. The lichens were identified as Caloplaca austrocitrina, Lecanora albescens, Xanthoparmelia farinosa and Xanthoria candelaria, the fungi as Aspergillus sp., Penicillium sp., Fusarium sp., Candida sp. and Rhodotorula sp., and the bacteria as Bacillus sp. and Pseudomonas sp. The mechanisms by which these microorganisms cause the aesthetic and biochemical deterioration of the crypts are discussed