Ebola Virus Antibodies in Fruit Bats, Ghana, West Africa

10.3201/eid1807.111654Emerging Infectious Diseases1871207-120

A General Bayesian Approach to Analyzing Diallel Crosses of Inbred Strains

The classic diallel takes a set of parents and produces offspring from all possible mating pairs. Phenotype values among the offspring can then be related back to their respective parentage. When the parents are diploid, sexed, and inbred, the diallel can characterize aggregate effects of genetic background on a phenotype, revealing effects of strain dosage, heterosis, parent of origin, epistasis, and sex-specific versions thereof. However, its analysis is traditionally intricate, unforgiving of unplanned missing information, and highly sensitive to imbalance, making the diallel unapproachable to many geneticists. Nonetheless, imbalanced and incomplete diallels arise frequently, albeit unintentionally, as by-products of larger-scale experiments that collect F1 data, for example, pilot studies or multiparent breeding efforts such as the Collaborative Cross or the Arabidopsis MAGIC lines. We present a general Bayesian model for analyzing diallel data on dioecious diploid inbred strains that cleanly decomposes the observed patterns of variation into biologically intuitive components, simultaneously models and accommodates outliers, and provides shrinkage estimates of effects that automatically incorporate uncertainty due to imbalance, missing data, and small sample size. We further present a model selection procedure for weighing evidence for or against the inclusion of those components in a predictive model. We evaluate our method through simulation and apply it to incomplete diallel data on the founders and F1's of the Collaborative Cross, robustly characterizing the genetic architecture of 48 phenotypes

A methodology for the measurement of radiated noise from marine piling

This paper describes a methodology that has been developed for measuring marine piling noise, which is designed to record the temporal, spatial and spectral characteristics of the radiated sound field. Results are presented for measurements of two pile diameters, 2m and 4.74m, in a shallow water site off the east coast of the UK. Measurements of the entire piling sequence for several piles were conducted at ranges from 10 m to 22 km for piles in 10-20 m water depth. To assess variations in the temporal, spatial and spectral characteristics, a number of recording systems were simultaneously deployed at various ranges and depths, allowing the full piling sequence to be measured. This allowed assessment of source level variation at fixed locations, and the effect of propagation within the water column

The contribution to anthropogenic noise from marine aggregate extraction operation in UK waters

As of 2009, there were 75 licensed areas within UK waters for marine aggregate extraction. Each year, around 20 million tonnes of sand and gravel are extracted from these areas for use in the construction and building industry1. Extraction of marine aggregate has the potential to generate noise, and if at sufficient levels, this could have a negative impact on marine species in or around the dredging area. However, measurement of the noise generated during marine aggregate extraction has been limited, particularly in UK waters. The most extensive measurements were undertaken in the Beaufort Sea during oil exploration in the 1980s2,3. Other measurements around Sakhalin Island have been reported in the literature, which were compared by Ainslie et al4 to other vessels including the Overseas Harriette5. This paper presents the results of underwater noise measurements for six different dredgers measured in three locations around the UK, with aggregate type varying from sand to coarse gravel. From the measurements of radiated noise for dredgers under normal operation an estimate is made of the long term contributions to ambient noise levels from typical dredgers under normal operation, the contribution to the overall ambient noise budget, and the cumulative Sound Exposure Level for receptors in the vicinity

Measurement of underwater noise arising from marine aggregate dredging operations

This is the final report for project MALSF MEPF 09/P108, funded by the Aggregate Levy Sustainability Fund, the aim of which is to provide data for the typical underwater radiated noise levels from marine aggregate dredgers in the UK fleet during normal operations. The work is aligned with the stated aims of the ALSFMEPF to reduce the environmental footprint of marine extraction of aggregates, and follows directly from the key knowledge gap identified in the initial scoping study conducted in MEPF Project 08/P21 [Thomsen et al, 2009]. The key finding of the study is the noise output of dredging vessels is similar to a ‘noisy merchant vessel’ and is substantially quieter in terms of acoustic energy output than some other anthropogenic noise sources such as seismic airguns and marine pile driving. This project has been an extensive study of the noise generated by the UK’s fleet of trailing suction hopper dredgers during marine aggregate extraction. The objectives of the work were (i) to develop a suitable methodology for measuring underwater noise radiated by dredgers, (ii) undertake measurements on UK dredgers at up to four sites and report, whilst disseminating the results to the wider stakeholder community. In the report, data is presented for 6 vessels, measured across 3 different areas around the UK’s coast

The measurement of underwater noise radiated by dredging vessels during aggregate extraction operations

The total marine aggregate extracted from the seabed in UK waters can exceed 20 million tonnes each year, and there is a need to understand the noise generated during the extraction process in order to evaluate any potential impact on the marine environment. For aggregate extraction, the type of vessel used is a trailing suction hopper dredger, which lowers a drag head and suction pipe to the sea floor to extract the sand or gravel, depositing it in a hopper on the vessel, whilst returning unwanted material and water over the side of the vessel. There are a number of potential noise generation mechanisms during this type of dredging activity. This paper presents the results of underwater noise measurements for six different dredgers measured in three locations around the UK, with aggregate type varying from sand to coarse gravel. One vessel was measured in two different areas with different aggregate types. The methodology used to derive the source level for the dredgers is described, and the results of an investigation undertaken into the origin of the radiated noise is given. Measurements were made at frequencies up to 100 kHz, with limited data obtained up to 200 kHz. Noise levels are shown for the same dredger under different operational modes, illustrating that the noise output level is partially dependent upon the mode of operation and the aggregate type being extracted

Henipavirus Neutralising Antibodies in an Isolated Island Population of African Fruit Bats

Isolated islands provide valuable opportunities to study the persistence of viruses in wildlife populations, including population size thresholds such as the critical community size. The straw-coloured fruit bat, Eidolon helvum, has been identified as a reservoir for henipaviruses (serological evidence) and Lagos bat virus (LBV; virus isolation and serological evidence) in continental Africa. Here, we sampled from a remote population of E. helvum annobonensis fruit bats on Annobón island in the Gulf of Guinea to investigate whether antibodies to these viruses also exist in this isolated subspecies. Henipavirus serological analyses (Luminex multiplexed binding and inhibition assays, virus neutralisation tests and western blots) and lyssavirus serological analyses (LBV: modified Fluorescent Antibody Virus Neutralisation test, LBV and Mokola virus: lentivirus pseudovirus neutralisation assay) were undertaken on 73 and 70 samples respectively. Given the isolation of fruit bats on Annobón and their lack of connectivity with other populations, it was expected that the population size on the island would be too small to allow persistence of viruses that are thought to cause acute and immunising infections. However, the presence of antibodies against henipaviruses was detected using the Luminex binding assay and confirmed using alternative assays. Neutralising antibodies to LBV were detected in one bat using both assays. We demonstrate clear evidence for exposure of multiple individuals to henipaviruses in this remote population of E. helvum annobonensis fruit bats on Annobón island. The situation is less clear for LBV. Seroprevalences to henipaviruses and LBV in Annobón are notably different to those in E. helvum in continental locations studied using the same sampling techniques and assays. Whilst cross-sectional serological studies in wildlife populations cannot provide details on viral dynamics within populations, valuable information on the presence or absence of viruses may be obtained and utilised for informing future studies

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Novel Structural Components of the Ventral Disc and Lateral Crest in Giardia intestinalis

Giardia intestinalis is a ubiquitous parasitic protist that is the causative agent of giardiasis, one of the most common protozoan diarrheal diseases in the world. Giardia trophozoites attach to the intestinal epithelium using a specialized and elaborate microtubule structure, the ventral disc. Surrounding the ventral disc is a less characterized putatively contractile structure, the lateral crest, which forms a continuous perimeter seal with the substrate. A better understanding of ventral disc and lateral crest structure, conformational dynamics, and biogenesis is critical for understanding the mechanism of giardial attachment to the host. To determine the components comprising the ventral disc and lateral crest, we used shotgun proteomics to identify proteins in a preparation of isolated ventral discs. Candidate disc-associated proteins, or DAPs, were GFP-tagged using a ligation-independent high-throughput cloning method. Based on disc localization, we identified eighteen novel DAPs, which more than doubles the number of known disc-associated proteins. Ten of the novel DAPs are associated with the lateral crest or outer edge of the disc, and are the first confirmed components of this structure. Using Fluorescence Recovery After Photobleaching (FRAP) with representative novel DAP::GFP strains we found that the newly identified DAPs tested did not recover after photobleaching and are therefore structural components of the ventral disc or lateral crest. Functional analyses of the novel DAPs will be central toward understanding the mechanism of ventral disc-mediated attachment and the mechanism of disc biogenesis during cell division. Since attachment of Giardia to the intestine via the ventral disc is essential for pathogenesis, it is possible that some proteins comprising the disc could be potential drug targets if their loss or disruption interfered with disc biogenesis or function, preventing attachment

Experimental tests of CPT symmetry and quantum mechanics at CPLEAR

We review a phenomenological parametrization of an open quantum-mechanical formalism for CPT violation in the neutral kaon system, and constrain the parameters using fits to recent CPLEAR data.We review a phenomenological parametrization of an open quantum-mechanical formalism for CPT violation in the neutral kaon system, and constrain the parameters using fits to recent CPLEAR data