96 research outputs found
Genomic tools reveal complex social organization of an invasive large mammal (\u3ci\u3eSus scrofa\u3c/i\u3e)
A comprehensive understanding of sociality in wildlife is vital to optimizing conservation and management efforts. However, sociality is complicated, especially for widely distributed species that exhibit substantive behavioral plasticity. Invasive wild pigs (Sus scrofa), often representing hybrids of European wild boar and domestic pigs, are among the most adaptable and widely distributed large mammals. The social structure of wild pigs is believed to be similar to European wild boar, consisting of matriarchal groups (sounders) and solitary males. However, wild pig social structure is understudied and largely limited to visual observations. Using a hierarchical approach, we incorporated genomic tools to describe wild pig social group composition in two disparate ecoregions within their invaded range in North America. The most common social unit was sounders, which are characterized as the association of two or more breeding-aged wild pigs with or without dependent offspring. In addition to sounders, pseudo-solitary females and male-dominated bachelor groups were observed at a greater frequency than previously reported. Though primarily composed of close female kin, some sounders included unrelated females. Bachelor groups were predominantly composed of young, dispersal-aged males and almost always included only close kin. Collectively, our study suggests social organization of wild pigs in their invaded range is similar to that observed among wild boar but is complex, dynamic, and likely variable across invaded habitats
Whole-genome sequencing shows that patient-to-patient transmission rarely accounts for acquisition of Staphylococcus aureus in an intensive care unit
BACKGROUND
Strategies to prevent Staphylococcus aureus infection in hospitals focus on patient-to-patient transmission. We used whole-genome sequencing to investigate the role of colonized patients as the source of new S. aureus acquisitions, and the reliability of identifying patient-to-patient transmission using the conventional approach of spa typing and overlapping patient stay.
METHODS
Over 14 months, all unselected patients admitted to an adult intensive care unit (ICU) were serially screened for S. aureus. All available isolates (n = 275) were spa typed and underwent whole-genome sequencing to investigate their relatedness at high resolution.
RESULTS
Staphylococcus aureus was carried by 185 of 1109 patients sampled within 24 hours of ICU admission (16.7%); 59 (5.3%) patients carried methicillin-resistant S. aureus (MRSA). Forty-four S. aureus (22 MRSA) acquisitions while on ICU were detected. Isolates were available for genetic analysis from 37 acquisitions. Whole-genome sequencing indicated that 7 of these 37 (18.9%) were transmissions from other colonized patients. Conventional methods (spa typing combined with overlapping patient stay) falsely identified 3 patient-to-patient transmissions (all MRSA) and failed to detect 2 acquisitions and 4 transmissions (2 MRSA).
CONCLUSIONS
Only a minority of S. aureus acquisitions can be explained by patient-to-patient transmission. Whole-genome sequencing provides the resolution to disprove transmission events indicated by conventional methods and also to reveal otherwise unsuspected transmission events. Whole-genome sequencing should replace conventional methods for detection of nosocomial S. aureus transmission
People of the British Isles: preliminary analysis of genotypes and surnames in a UK control population
There is a great deal of interest in fine scale population structure in the UK, both as a signature of historical immigration events and because of the effect population structure may have on disease association studies. Although population structure appears to have a minor impact on the current generation of genome-wide association studies, it is likely to play a significant part in the next generation of studies designed to search for rare variants. A powerful way of detecting such structure is to control and document carefully the provenance of the samples involved. Here we describe the collection of a cohort of rural UK samples (The People of the British Isles), aimed at providing a well-characterised UK control population that can be used as a resource by the research community as well as
providing fine scale genetic information on the British population. So far, some 4,000 samples have been collected, the majority of which fit the criteria of coming from a rural area and having all four grandparents from approximately the same area. Analysis of the first 3,865 samples that have been geocoded indicates that 75% have
a mean distance between grandparental places of birth of 37.3km, and that about 70% of grandparental places of birth can be classed as rural. Preliminary genotyping of 1,057
samples demonstrates the value of these samples for investigating fine scale population structure within the UK, and shows how this can be enhanced by the use of surnames
Formation Flying and Change Detection for the UNSW Canberra Space ‘M2’ Low Earth Orbit Formation Flying CubeSat Mission
The University of New South Wales, Canberra (UNSW Canberra) embarked on an ambitious CubeSatellite research, development, and education program in 2017 through funding provided by the Royal Australian Air Force (RAAF). The program consisted of M1 (Mission 1), M2 Pathfinder, and concludes with the formation flying mission M2. M2 is the final mission comprising two 6U CubeSatellites flying in formation using differential aerodynamic drag control. The M2 satellites were launched in a conjoined 12U form factor on RocketLab’s ‘They Go Up So Fast’ launch in March 2021. On 10th September 2021 the spacecraft divided into two 6U CubeSats (M2-A and M2-B) under the action of a small spring force in their near-circular 550km, 45-degree inclination orbit. The formation is controlled by varying the spacecrafts’ attitude, which creates a large variation in the aerodynamic drag force due to the change in the cross-sectional area from the large, double-deployable, solar arrays located on the zenith face of the spacecraft.
This paper presents the outcomes of the Formation Flying and Change Detection primary mission objectives for the mission. The results are generated by collecting and analysing optical and RF (Radio Frequency) space domain awareness sensor data from the ground and validating them against GPS (Global Positioning System) and attitude data downlinked from the spacecraft. The outcomes of the broader mission objectives, which include increasing the Technology Readiness Level for a suite of intelligent on-board optical and RF sensor technologies, will be presented in subsequent publications.
The results presented here comprise two major campaigns: 1.) The spacecraft separation campaign when the original 12U form factor deployed following launch split in half to form the M2-A and M2-B satellites, and 2) the demonstration of active formation control of the spacecraft via differential aerodynamic drag.
M2-A and M2-B underwent several major configuration changes during the spacecraft separation campaign. The results from ground-based sensors detecting the 12U spacecraft separating into two distinct (6U) objects are presented. The effect of the double-deployable solar arrays deployment on the relative orbital motion of the M2-A and M2-B spacecraft is illustrated and compared to data from optical and RF ground-based measurements taken during this window. The formation control campaign involved actively controlling the spacecraft via differential aerodynamic drag in order to significantly alter the separation distance. The mission demonstrated the capability to switch the leading spacecraft’s position between M2-A and M2-B and to actively control separation distance ranging from 130km down to 1km. Formation control is achieved via open-loop, pre-scheduled, commands issued from the UNSW Canberra Space ground station. A two-stage modelling and simulation process is used to derive the scheduled attitude states.
Firstly, a batch least squares orbit determination algorithm is applied to GPS data from a steady-state differential drag actuation period (where one spacecraft is in maximum drag and the other in its minimum drag attitude configuration). The batch least squares orbit determination is conducted out using the NASA General Mission Analysis Tool (GMAT), resulting in precise state estimates for each spacecraft and drag coefficient (Cd) estimates for both the maximum and minimum drag configurations. Predictions of trajectory for various attitude profiles can be produced by tailoring the spacecraft’s drag coefficients between the maximum and minimum values generated by the batch least squares state estimation process.
Ground-based optical and RF space domain awareness (SDA) sensor measurements collected during the manoeuvre campaign are compared to the spacecraft’s GPS and attitude telemetry data. The SDA sensors are actively seeking to detect changes in the separation distance between the spacecraft. Initial results from an investigation into whether changes observed in photometric light curve signatures can signal the commencement of a differential drag manoeuvre are presented
An IL28B Genotype-Based Clinical Prediction Model for Treatment of Chronic Hepatitis C
BACKGROUND:Genetic variation in IL28B and other factors are associated with sustained virological response (SVR) after pegylated-interferon/ribavirin treatment for chronic hepatitis C (CHC). Using data from the HALT-C Trial, we developed a model to predict a patient's probability of SVR based on IL28B genotype and clinical variables. METHODS:HALT-C enrolled patients with advanced CHC who had failed previous interferon-based treatment. Subjects were re-treated with pegylated-interferon/ribavirin during trial lead-in. We used step-wise logistic regression to calculate adjusted odds ratios (aOR) and create the predictive model. Leave-one-out cross-validation was used to predict a priori probabilities of SVR and determine area under the receiver operator characteristics curve (AUC). RESULTS:Among 646 HCV genotype 1-infected European American patients, 14.2% achieved SVR. IL28B rs12979860-CC genotype was the strongest predictor of SVR (aOR, 7.56; p<.0001); the model also included HCV RNA (log10 IU/ml), AST:ALT ratio, Ishak fibrosis score and prior ribavirin treatment. For this model AUC was 78.5%, compared to 73.0% for a model restricted to the four clinical predictors and 60.0% for a model restricted to IL28B genotype (p<0.001). Subjects with a predicted probability of SVR <10% had an observed SVR rate of 3.8%; subjects with a predicted probability >10% (43.3% of subjects) had an SVR rate of 27.9% and accounted for 84.8% of subjects actually achieving SVR. To verify that consideration of both IL28B genotype and clinical variables is required for treatment decisions, we calculated AUC values from published data for the IDEAL Study. CONCLUSION:A clinical prediction model based on IL28B genotype and clinical variables can yield useful individualized predictions of the probability of treatment success that could increase SVR rates and decrease the frequency of futile treatment among patients with CHC
Prediction of cis-regulatory elements controlling genes differentially expressed by retinal and choroidal vascular endothelial cells
Cultured endothelial cells of the human retina and choroid demonstrate distinct patterns of gene expression. We hypothesized that differential gene expression reflected differences in the interactions of transcription factors and respective cis-regulatory motifs(s) in these two endothelial cell subpopulations, recognizing that motifs often exist as modules. We tested this hypothesis in silico by using TRANSFAC Professional and CisModule to identify cis-regulatory motifs and modules in genes that were differentially expressed by human retinal versus choroidal endothelial cells, as identified by analysis of a microarray data set. Motifs corresponding to eight transcription factors were significantly (p < 0.05) differentially abundant in genes that were relatively highly expressed in retinal (i.e., glucocorticoid receptor, high mobility group AT-hook 1, heat shock transcription factor 1, p53, vitamin D receptor) or choroidal (i.e., transcription factor E2F, Yin Yang 1, zinc finger 5) endothelial cells. Predicted cis-regulatory modules were quite different for these two groups of genes. Our findings raise the possibility of exploiting specific cis-regulatory motifs to target therapy at the ocular endothelial cells subtypes responsible for neovascular age-related macular degeneration or proliferative diabetic retinopathy
Seasonal and annual fluxes of nutrients and organic matter from large rivers to the Arctic Ocean and surrounding seas
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Estuaries and Coasts 35 (2012): 369-382, doi:10.1007/s12237-011-9386-6.River inputs of nutrients and organic matter impact the biogeochemistry of arctic
estuaries and the Arctic Ocean as a whole, yet there is considerable uncertainty about the
magnitude of fluvial fluxes at the pan-arctic scale. Samples from the six largest arctic
rivers, with a combined watershed area of 11.3 x 106 km2, have revealed strong seasonal
variations in constituent concentrations and fluxes within rivers as well as large
differences among the rivers. Specifically, we investigate fluxes of dissolved organic
carbon, dissolved organic nitrogen, total dissolved phosphorus, dissolved inorganic
nitrogen, nitrate, and silica. This is the first time that seasonal and annual constituent
fluxes have been determined using consistent sampling and analytical methods at the pan
arctic scale, and consequently provide the best available estimates for constituent flux
from land to the Arctic Ocean and surrounding seas. Given the large inputs of river water
to the relatively small Arctic Ocean, and the dramatic impacts that climate change is
having in the Arctic, it is particularly urgent that we establish the contemporary river
fluxes so that we will be able to detect future changes and evaluate the impact of the
changes on the biogeochemistry of the receiving coastal and ocean systems.This work was supported by the National Science Foundation through grants
OPP-0229302, OPP-0519840, OPP-0732522, and OPP-0732944. Additional support was
provided by the U. S. Geological Survey (Yukon River) and the Department of Indian
and Northern Affairs (Mackenzie River)
Anti-SARS-CoV-2 antibody responses are attenuated in patients with IBD treated with infliximab.
OBJECTIVE: Antitumour necrosis factor (anti-TNF) drugs impair protective immunity following pneumococcal, influenza and viral hepatitis vaccination and increase the risk of serious respiratory infections. We sought to determine whether infliximab-treated patients with IBD have attenuated serological responses to SARS-CoV-2 infections. DESIGN: Antibody responses in participants treated with infliximab were compared with a reference cohort treated with vedolizumab, a gut-selective anti-integrin α4β7 monoclonal antibody that is not associated with impaired vaccine responses or increased susceptibility to systemic infections. 6935 patients were recruited from 92 UK hospitals between 22 September and 23 December 2020. RESULTS: Rates of symptomatic and proven SARS-CoV-2 infection were similar between groups. Seroprevalence was lower in infliximab-treated than vedolizumab-treated patients (3.4% (161/4685) vs 6.0% (134/2250), p<0.0001). Multivariable logistic regression analyses confirmed that infliximab (vs vedolizumab; OR 0.66 (95% CI 0.51 to 0.87), p=0.0027) and immunomodulator use (OR 0.70 (95% CI 0.53 to 0.92), p=0.012) were independently associated with lower seropositivity. In patients with confirmed SARS-CoV-2 infection, seroconversion was observed in fewer infliximab-treated than vedolizumab-treated patients (48% (39/81) vs 83% (30/36), p=0.00044) and the magnitude of anti-SARS-CoV-2 reactivity was lower (median 0.8 cut-off index (0.2-5.6) vs 37.0 (15.2-76.1), p<0.0001). CONCLUSIONS: Infliximab is associated with attenuated serological responses to SARS-CoV-2 that were further blunted by immunomodulators used as concomitant therapy. Impaired serological responses to SARS-CoV-2 infection might have important implications for global public health policy and individual anti-TNF-treated patients. Serological testing and virus surveillance should be considered to detect suboptimal vaccine responses, persistent infection and viral evolution to inform public health policy. TRIAL REGISTRATION NUMBER: ISRCTN45176516
Analysis of protein-coding genetic variation in 60,706 humans
Large-scale reference data sets of human genetic variation are critical for the medical and functional interpretation of DNA sequence changes. We describe the aggregation and analysis of high-quality exome (protein-coding region) sequence data for 60,706 individuals of diverse ethnicities generated as part of the Exome Aggregation Consortium (ExAC). This catalogue of human genetic diversity contains an average of one variant every eight bases of the exome, and provides direct evidence for the presence of widespread mutational recurrence. We have used this catalogue to calculate objective metrics of pathogenicity for sequence variants, and to identify genes subject to strong selection against various classes of mutation; identifying 3,230 genes with near-complete depletion of truncating variants with 72% having no currently established human disease phenotype. Finally, we demonstrate that these data can be used for the efficient filtering of candidate disease-causing variants, and for the discovery of human “knockout” variants in protein-coding genes
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