1,563 research outputs found
Challenges in Collaborative HRI for Remote Robot Teams
Collaboration between human supervisors and remote teams of robots is highly
challenging, particularly in high-stakes, distant, hazardous locations, such as
off-shore energy platforms. In order for these teams of robots to truly be
beneficial, they need to be trusted to operate autonomously, performing tasks
such as inspection and emergency response, thus reducing the number of
personnel placed in harm's way. As remote robots are generally trusted less
than robots in close-proximity, we present a solution to instil trust in the
operator through a `mediator robot' that can exhibit social skills, alongside
sophisticated visualisation techniques. In this position paper, we present
general challenges and then take a closer look at one challenge in particular,
discussing an initial study, which investigates the relationship between the
level of control the supervisor hands over to the mediator robot and how this
affects their trust. We show that the supervisor is more likely to have higher
trust overall if their initial experience involves handing over control of the
emergency situation to the robotic assistant. We discuss this result, here, as
well as other challenges and interaction techniques for human-robot
collaboration.Comment: 9 pages. Peer reviewed position paper accepted in the CHI 2019
Workshop: The Challenges of Working on Social Robots that Collaborate with
People (SIRCHI2019), ACM CHI Conference on Human Factors in Computing
Systems, May 2019, Glasgow, U
Functional characterization of the Mycobacterium abscessus genome coupled with condition specific transcriptomics reveals conserved molecular strategies for host adaptation and persistence
Background: Mycobacterium abscessus subsp. abscessus (MAB) is a highly drug resistant mycobacterium and the most common respiratory pathogen among the rapidly growing non-tuberculous mycobacteria. MAB is also one of the most deadly of the emerging cystic fibrosis (CF) pathogens requiring prolonged treatment with multiple antibiotics. In addition to its âmycobacterialâ virulence genes, the genome of MAB harbours a large accessory genome, presumably acquired via lateral gene transfer including homologs shared with the CF pathogens Pseudomonas aeruginosa and Burkholderia cepacia. While multiple genome sequences are available there is little functional genomics data available for this important pathogen. Results: We report here the first multi-omics approach to characterize the primary transcriptome, coding potential and potential regulatory regions of the MAB genome utilizing differential RNA sequencing (dRNA-seq), RNA-seq, Ribosome profiling and LC-MS proteomics. In addition we attempt to address the genomes contribution to the molecular systems that underlie MABâs adaptation and persistence in the human host through an examination of MABs transcriptional response to a number of clinically relevant conditions. These include hypoxia, exposure to sub-inhibitory concentrations of antibiotics and growth in an artificial sputum designed to mimic the conditions within the cystic fibrosis lung. Conclusions: Our integrated map provides the first comprehensive view of the primary transcriptome of MAB and evidence for the translation of over one hundred new short open reading frames (sORFs). Our map will act as a resource for ongoing functional genomics characterization of MAB and our transcriptome data from clinically relevant stresses informs our understanding of MABâs adaptation to life in the CF lung. MABâs adaptation to growth in artificial CF sputum highlights shared metabolic strategies with other CF pathogens including P. aeruginosa and mirrors the transcriptional responses that lead to persistence in mycobacteria. These strategies include an increased reliance on amino acid metabolism, and fatty acid catabolism and highlights the relevance of the glyoxylate shunt to growth in the CF lung. Our data suggests that, similar to what is seen in chronically persisting P. aeruginosa, progression towards a biofilm mode of growth would play a more prominent role in a longer-term MAB infection. Finally, MABâs transcriptional response to antibiotics highlights the role of antibiotic modifications enzymes, active transport and the evolutionarily conserved WhiB7 driven antibiotic resistance regulon
Iron biogeochemistry across marine systems progress from the past decade
Based on an international workshop (Gothenburg, 14â16 May 2008), this review article aims to combine interdisciplinary knowledge from coastal and open ocean research on iron biogeochemistry. The major scientific findings of the past decade are structured into sections on natural and artificial iron fertilization, iron inputs into coastal and estuarine systems, colloidal iron and organic matter, and biological processes. Potential effects of global climate change, particularly ocean acidification, on iron biogeochemistry are discussed. The findings are synthesized into recommendations for future research areas
Microwave, infrared and Raman spectra, r0 structural parameters, ab initio calculations and vibrational assignment of 1-fluoro-1-silacyclopentanea)
The microwave spectrum (6500â18 500 MHz) of 1-fluoro-1-silacyclopentane, c-C4H8SiHF has been recorded and 87 transitions for the 28Si, 29Si, 30Si, and 13C isotopomers have been assigned for a single conformer. Infrared spectra (3050-350 cmâ1) of the gas and solid and Raman spectrum (3100-40 cmâ1) of the liquid have also been recorded. The vibrational data indicate the presence of a single conformer with no symmetry which is consistent with the twist form. Ab initio calculations with a variety of basis sets up to MP2(full)/aug-cc-pVTZ predict the envelope-axial and envelope-equatorial conformers to be saddle points with nearly the same energies but much lower energy than the planar conformer. By utilizing the microwaverotational constants for seven isotopomers (28Si, 29Si, 30Si, and four 13C) combined with the structural parameters predicted from the MP2(full)/6â311+G(d,p) calculations, adjusted r0 structural parameters have been obtained for the twist conformer. The heavy atom distances in Ă
are: r0(SiC2) = 1.875(3); r0(SiC3) = 1.872(3); r0(C2C4) = 1.549(3); r0(C3C5) = 1.547(3); r0(C4C5) = 1.542(3); r0(SiF) = 1.598(3) and the angles in degrees are: â CSiC = 96.7(5); â SiC2C4 = 103.6(5); â SiC3C5 = 102.9(5); â C2C4C5 = 108.4(5); â C3C5C4 = 108.1(5); â F6Si1C2 = 110.7(5); â F6Si1C3 = 111.6(5). The heavy atom ring parameters are compared to the corresponding rs parameters. Normal coordinate calculations with scaled force constants from MP2(full)/6â31G(d) calculations were carried out to predict the fundamental vibrational frequencies, infrared intensities, Raman activities, depolarization values, and infrared band contours. These experimental and theoretical results are compared to the corresponding quantities of some other five-membered rings
Characterization of the equine skeletal muscle transcriptome identifies novel functional responses to exercise training
<p>Abstract</p> <p>Background</p> <p>Digital gene expression profiling was used to characterize the assembly of genes expressed in equine skeletal muscle and to identify the subset of genes that were differentially expressed following a ten-month period of exercise training. The study cohort comprised seven Thoroughbred racehorses from a single training yard. Skeletal muscle biopsies were collected at rest from the <it>gluteus medius </it>at two time points: T<sub>1 </sub>- untrained, (9 ± 0.5 months old) and T<sub>2 </sub>- trained (20 ± 0.7 months old).</p> <p>Results</p> <p>The most abundant mRNA transcripts in the muscle transcriptome were those involved in muscle contraction, aerobic respiration and mitochondrial function. A previously unreported over-representation of genes related to RNA processing, the stress response and proteolysis was observed. Following training 92 tags were differentially expressed of which 74 were annotated. Sixteen genes showed increased expression, including the mitochondrial genes <it>ACADVL</it>, <it>MRPS21 </it>and <it>SLC25A29 </it>encoded by the nuclear genome. Among the 58 genes with decreased expression, <it>MSTN</it>, a negative regulator of muscle growth, had the greatest decrease.</p> <p>Functional analysis of all expressed genes using FatiScan revealed an asymmetric distribution of 482 Gene Ontology (GO) groups and 18 KEGG pathways. Functional groups displaying highly significant (<it>P </it>< 0.0001) increased expression included mitochondrion, oxidative phosphorylation and fatty acid metabolism while functional groups with decreased expression were mainly associated with structural genes and included the sarcoplasm, laminin complex and cytoskeleton.</p> <p>Conclusion</p> <p>Exercise training in Thoroughbred racehorses results in coordinate changes in the gene expression of functional groups of genes related to metabolism, oxidative phosphorylation and muscle structure.</p
Tracing differences in iron supply to the Mid-Atlantic Ridge valley between hydrothermal vent sites: implications for the addition of iron to the deep ocean
Supply of iron (Fe) to the surface ocean supports primary productivity, and while hydrothermal input of Fe to the deep ocean is known
to be extensive it remains poorly constrained. Global estimates of hydrothermal Fe supply rely on using dissolved Fe (dFe) to
excess He (xs3He) ratios to upscale fluxes, but observational constraints on dFe/xs3He may be sensitive to
assumptions linked to sampling and interpolation. We examined the variability in dFe/xs3He using two methods of estimation, for
four vent sites with different geochemistry along the Mid-Atlantic Ridge. At both Rainbow and TAG, the plume was sampled repeatedly and the range of
dFe/xs3He was 4 to 63 and 4 to 87ânmol:fmol, respectively, primarily due to differences in plume age. To account for background
xs3He and shifting plume position, we calibrated He values using contemporaneous dissolved Mn (dMn). Applying this
approach more widely, we found dFe/xs3He ratios of 12, 4â8, 4â44, and 4â86ânmolâfmolâ1 for the Menez Gwen, Lucky
Strike, Rainbow, and TAG hydrothermal vent sites, respectively. Differences in plume dFe/xs3He across sites were not simply
related to the vent endmember Fe and He fluxes. Within 40âkm of the vents, the dFe/xs3He ratios decreased to
3â38ânmolâfmolâ1, due to the precipitation and subsequent settling of particulates. The ratio of colloidal Fe to dFe was
consistently higher (0.67â0.97) than the deep N. Atlantic (0.5) throughout both the TAG and Rainbow plumes, indicative of Fe exchange
between dissolved and particulate phases. Our comparison of TAG and Rainbow shows there is a limit to the amount of hydrothermal Fe released
from vents that can form colloids in the rising plume. Higher particle loading will enhance the longevity of the Rainbow hydrothermal plume within
the deep ocean assuming particles undergo continual dissolution/disaggregation. Future studies examining the length of plume pathways required to
escape the ridge valley will be important in determining Fe supply from slow spreading mid-ocean ridges to the deep ocean, along with the
frequency of ultramafic sites such as Rainbow. Resolving the ridge valley bathymetry and accounting for variability in vent sources in global
biogeochemical models will be key to further constraining the hydrothermal Fe flux.</p
Tracing differences in iron supply to the Mid-Atlantic Ridge valley between hydrothermal vent sites: implications for the addition of iron to the deep ocean
Supply of iron (Fe) to the surface ocean supports primary productivity, and while hydrothermal input of Fe to the deep ocean is known to be extensive it remains poorly constrained. Global estimates of hydrothermal Fe supply rely on using dissolved Fe (dFe) to excess He (xsÂłHe) ratios to upscale fluxes, but observational constraints on dFe/xsÂłHe may be sensitive to assumptions linked to sampling and interpolation. We examined the variability in dFe/xsÂłHe using two methods of estimation, for four vent sites with different geochemistry along the Mid-Atlantic Ridge. At both Rainbow and TAG, the plume was sampled repeatedly and the range of dFe/xsÂłHe was 4 to 63 and 4 to 87ânmol:fmol, respectively, primarily due to differences in plume age. To account for background xsÂłHe and shifting plume position, we calibrated He values using contemporaneous dissolved Mn (dMn). Applying this approach more widely, we found dFe/xsÂłHe ratios of 12, 4â8, 4â44, and 4â86ânmolâfmolâ1 for the Menez Gwen, Lucky Strike, Rainbow, and TAG hydrothermal vent sites, respectively. Differences in plume dFe/xsÂłHe across sites were not simply related to the vent endmember Fe and He fluxes. Within 40âkm of the vents, the dFe/xsÂłHe ratios decreased to 3â38ânmolâfmolâ1, due to the precipitation and subsequent settling of particulates. The ratio of colloidal Fe to dFe was consistently higher (0.67â0.97) than the deep N. Atlantic (0.5) throughout both the TAG and Rainbow plumes, indicative of Fe exchange between dissolved and particulate phases. Our comparison of TAG and Rainbow shows there is a limit to the amount of hydrothermal Fe released from vents that can form colloids in the rising plume. Higher particle loading will enhance the longevity of the Rainbow hydrothermal plume within the deep ocean assuming particles undergo continual dissolution/disaggregation. Future studies examining the length of plume pathways required to escape the ridge valley will be important in determining Fe supply from slow spreading mid-ocean ridges to the deep ocean, along with the frequency of ultramafic sites such as Rainbow. Resolving the ridge valley bathymetry and accounting for variability in vent sources in global biogeochemical models will be key to further constraining the hydrothermal Fe flux
Coastal Ocean and Shelf-Sea Biogeochemical Cycling of Trace Elements and Isotopes: Lessons Learned from GEOTRACES
Continental shelves and shelf seas play a central role in the global carbon cycle. However, their importance with respect to trace element and isotope (TEI) inputs to ocean basins is less well understood. Here, we present major findings on shelf TEI biogeochemistry from the GEOTRACES programme as well as a proof of concept for a new method to estimate shelf TEI fluxes. The case studies focus on advances in our understanding of TEI cycling in the Arctic, transformations within a major river estuary (Amazon), shelf sediment micronutrient fluxes and basin-scale estimates of submarine groundwater discharge. The proposed shelf flux tracer is 228-radium (T1/2 = 5.75 yr), which is continuously supplied to the shelf from coastal aquifers, sediment porewater exchange and rivers. Model-derived shelf 228Ra fluxes are combined with TEI/ 228Ra ratios to quantify ocean TEI fluxes from the western North Atlantic margin. The results from this new approach agree well with previous estimates for shelf Co, Fe, Mn and Zn inputs and exceed published estimates of atmospheric deposition by factors of approximately 3-23. Lastly, recommendations are made for additional GEOTRACES process studies and coastal margin-focused section cruises that will help refine the model and provide better insight on the mechanisms driving shelf-derived TEI fluxes to the ocean.This article is part of the themed issue \u27Biological and climatic impacts of ocean trace element chemistry\u27
Biogeochemical cycling of dissolved zinc along the GEOTRACES South Atlantic transect GA10 at 40°S
The biogeochemical cycle of zinc (Zn) in the South Atlantic, at 40°S, was investigated as part of the UK
GEOTRACES program. To date there is little understanding of the supply of Zn, an essential requirement for
phytoplankton growth, to this highly productive region. Vertical Zn profiles displayed nutrient-like distributions
with distinct gradients associated with the watermasses present. Surface Zn concentrations are among the lowest
reported for theworldâs oceans (<50 pM). A strong Zn-Si linear relationshipwas observed (Zn (nM)= 0.065 Si (ÎŒM),
r2=0.97, n = 460). Our results suggest that the use of a global Zn-Si relationship would lead to an underestimation
of dissolved Zn in deeper waters of the South Atlantic. By utilizing Si* and a new tracer Zn* our data indicate that
the preferential removal of Zn in the Southern Ocean prevented a direct return path for dissolved Zn to the surface
waters of the South Atlantic at 40°S and potentially the thermocline waters of the South Atlantic subtropical gyre.
The importance of Zn for phytoplankton growth was evaluated using the Zn-soluble reactive phosphorus (SRP)
relationship. We hypothesize that the low Zn concentrations in the South Atlantic may select for phytoplankton
cells with a lower Zn requirement. In addition, a much deeper kink at ~ 500m in the Zn:SRP ratio was observed
compared to other oceanic regions
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