483 research outputs found
Semantic mapping for service robots: building and using maps for mobile manipulators in semi-structured environments
Although much progress has been made in the field of robotic mapping, many challenges remain including: efficient semantic segmentation using RGB-D sensors, map representations that include complex features (structures and objects), and interfaces for interactive annotation of maps. This thesis addresses how prior knowledge of semi-structured human environments can be leveraged to improve segmentation, mapping, and semantic annotation of maps. We present an organized connected component approach for segmenting RGB-D data into planes and clusters. These segments serve as input to our mapping approach that utilizes them as planar landmarks and object landmarks for Simultaneous Localization and Mapping (SLAM), providing necessary information for service robot tasks and improving data association and loop closure. These features are meaningful to humans, enabling annotation of mapped features to establish common ground and simplifying tasking. A modular, open-source software framework, the OmniMapper, is also presented that allows a number of different sensors and features to be combined to generate a combined map representation, and enabling easy addition of new feature types.Ph.D
Free-Viewpoint Facial Re-Enactment from a Casual Capture
We propose a system for free-viewpoint facial re-enactment from a casual video capture of a target subject. Our system can render and re-enact the subject consistently in all the captured views. Furthermore, our system also enables interactive free-viewpoint facial re-enactment of the target from novel views. The re-enactment of the target subject is driven by an expression sequence of a source subject, which is captured using a custom app running on an iPhone X. Our system handles large pose variations in the target subject while keeping the re-enactment consistent. We demonstrate the efficacy of our system by showing various applications.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 66599
Free-Viewpoint Facial Re-Enactment from a Casual Capture
We propose a system for free-viewpoint facial re-enactment from a casual video capture of a target subject. Our system can render and re-enact the subject consistently in all the captured views. Furthermore, our system also enables interactive free-viewpoint facial re-enactment of the target from novel views. The re-enactment of the target subject is driven by an expression sequence of a source subject, which is captured using a custom app running on an iPhone X. Our system handles large pose variations in the target subject while keeping the re-enactment consistent. We demonstrate the efficacy of our system by showing various applications.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 66599
Considerations for legal, ethical, and effective practice in dementia research
Dementia represents a potentially overwhelming health burden, both for the UK and worldwide. Addressing this fast-growing issue is a key priority for the government, health service and the public. Advances in care including the development of efficacious disease-modifying, and eventually curative, treatments can only be achieved through effective dementia research. Specifically, research directly involving participants with dementia is essential to further understanding. However, working with cognitively impaired participants with and without capacity to consent to research presents unique ethical and legal challenges. For clinicians and scientists on the frontline of dementia research, scenarios frequently arise that pose such challenges. A lack of guidance for a consistent approach in navigating these scenarios limits researchers’ ability to proceed with confidence. This represents a threat to the rights and wishes of research participants as well as the field at large, as it may lead to studies being unnecessarily terminated or, worse, poor practice. In this article, we take a multiprofessional approach, informed by carer input, to these issues. We review the relevant ethical and legal literature relating to the conduct of non-interventional research studies in patients with dementia. This includes a thorough recap of the Mental Capacity Act (2005), which provides a legal framework in England and Wales for conducting research with participants who lack capacity to consent. We also discuss the important, but sometimes incomplete, role of research ethics committees in guiding researchers. We then present and discuss a series of case vignettes designed to highlight areas of incomplete coverage by existing governance. These vignettes describe theoretical scenarios informed by our own real-word experiences of encountering ethical issues when conducting dementia research. They include scenarios in which participants demonstrate varying degrees of understanding of the research they are involved in and ability to communicate their wishes and feelings. Building on these vignettes, we then provide a checklist for researchers to work through when presented with similar scenarios. This checklist covers the key ethical, legal and practical considerations that we have argued for. Taken together, this article can act as a guide, previously lacking in the literature, for colleagues in the field to enable much needed ethical, legal and effective research
Using globally threatened pelagic birds to identify priority sites for marine conservation in the South Atlantic Ocean
The Convention on Biological Diversity aspires to designate 10% of the global oceans as Marine Protected Areas (MPAs), but so far, few MPAs protect pelagic species in the high seas. Transparent scientific approaches are needed to ensure that these encompass areas with high biodiversity value. Here we used the distribution of all globally threatened seabirds breeding in a centrally located archipelago (Tristan da Cunha) to provide guidance on where MPAs could be established in the South Atlantic Ocean. We combined year-round tracking data from six species, and used the systematic conservation-planning tool, 'Zonation', to delineate areas that would protect the largest proportion of each population. The areas used most intensively varied among species and seasons. Combining the sites used by all six species suggested that the most important areas of the South Atlantic are located south of South Africa, around the central South Atlantic between 30 degrees S and 55 degrees S, and near South America. We estimated that the longline fishing effort in these intensively used areas is around 11 million hooks on average each year, highlighting the need for improved monitoring of seabird bycatch rates and the enforcement of compliance with bird bycatch mitigation requirements by fisheries. There was no overlap between the identified areas and any of the existing MPAs in the South Atlantic. The conservation of these highly mobile, pelagic species cannot be achieved by single countries, but requires a multi-national approach at an ocean-basin scale, such as an agreement for the conservation of biodiversity beyond national jurisdiction under the United Nation Convention on the Law of the Sea
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Locus coeruleus pathology in progressive supranuclear palsy, and its relation to disease severity
Abstract: The locus coeruleus is the major source of noradrenaline to the brain and contributes to a wide range of physiological and cognitive functions including arousal, attention, autonomic control, and adaptive behaviour. Neurodegeneration and pathological aggregation of tau protein in the locus coeruleus are early features of progressive supranuclear palsy (PSP). This pathology is proposed to contribute to the clinical expression of disease, including the PSP Richardson’s syndrome. We test the hypothesis that tau pathology and neuronal loss are associated with clinical heterogeneity and severity in PSP. We used immunohistochemistry in post mortem tissues from 31 patients with a clinical diagnosis of PSP (22 with Richardson’s syndrome) and 6 control cases. We quantified the presence of hyperphosphorylated tau, the number of pigmented cells indicative of noradrenergic neurons, and the percentage of pigmented neurons with tau-positive inclusions. Ante mortem assessment of clinical severity using the PSP rating scale was available within 1.8 (±0.9) years for 23 patients. We found an average 49% reduction of pigmented neurons in PSP patients relative to controls. The loss of pigmented neurons correlated with disease severity, even after adjusting for disease duration and the interval between clinical assessment and death. The degree of neuronal loss was negatively associated with tau-positive inclusions, with an average of 44% of pigmented neurons displaying tau-inclusions. Degeneration and tau pathology in the locus coeruleus are related to clinical heterogeneity of PSP. The noradrenergic deficit in the locus coeruleus is a candidate target for pharmacological treatment. Recent developments in ultra-high field magnetic resonance imaging to quantify in vivo structural integrity of the locus coeruleus may provide biomarkers for noradrenergic experimental medicines studies in PSP
Use of a beta-lactam graded challenge process for inpatients with self-reported penicillin allergies at an academic medical center
BackgroundThe Antimicrobial Stewardship Program (ASP) at Nebraska Medicine collaborated with a board-certified allergist to develop a penicillin allergy guidance document for treating inpatients with self-reported allergy. This guidance contains an algorithm for evaluating and safely challenging penicillin-allergic patients with beta-lactams without inpatient allergy consults being available.MethodsFollowing multi-disciplinary review, an order set for beta-lactam graded challenges (GC) was implemented in 2018. This contains recommended monitoring and detailed medication orders to challenge patients with various beta-lactam agents. Inpatient orders for GC from 3/2018–6/2022 were retrospectively reviewed to evaluate ordering characteristics, outcomes of the challenge, and whether documentation of the allergy history was updated. All beta-lactam challenges administered to inpatients were included, and descriptive statistics were performed.ResultsOverall, 157 GC were administered; 13 with oral amoxicillin and 144 with intravenous (IV) beta-lactams. Ceftriaxone accounted for the most challenges (43%). All oral challenges were recommended by an Infectious Diseases consult service, as were a majority of IV challenges (60%). Less than one in five were administered in an ICU (19%). Almost all (n = 150, 96%) were tolerated without any adverse event. There was one reaction (1%) of hives and six (4%) involving a rash, none of which had persistent effects. Allergy information was updated in the electronic health record after 92% of the challenges.ConclusionBoth intravenous and oral beta-lactam graded challenges were implemented successfully in a hospital without a regular inpatient allergy consult service. They were well-tolerated, administered primarily in non-ICU settings, and were often ordered by non-specialist services. In patients with a self-reported penicillin allergy, these results demonstrate the utility and safety of a broadly adopted beta-lactam GC process
Planetary population synthesis
In stellar astrophysics, the technique of population synthesis has been
successfully used for several decades. For planets, it is in contrast still a
young method which only became important in recent years because of the rapid
increase of the number of known extrasolar planets, and the associated growth
of statistical observational constraints. With planetary population synthesis,
the theory of planet formation and evolution can be put to the test against
these constraints. In this review of planetary population synthesis, we first
briefly list key observational constraints. Then, the work flow in the method
and its two main components are presented, namely global end-to-end models that
predict planetary system properties directly from protoplanetary disk
properties and probability distributions for these initial conditions. An
overview of various population synthesis models in the literature is given. The
sub-models for the physical processes considered in global models are
described: the evolution of the protoplanetary disk, the planets' accretion of
solids and gas, orbital migration, and N-body interactions among concurrently
growing protoplanets. Next, typical population synthesis results are
illustrated in the form of new syntheses obtained with the latest generation of
the Bern model. Planetary formation tracks, the distribution of planets in the
mass-distance and radius-distance plane, the planetary mass function, and the
distributions of planetary radii, semimajor axes, and luminosities are shown,
linked to underlying physical processes, and compared with their observational
counterparts. We finish by highlighting the most important predictions made by
population synthesis models and discuss the lessons learned from these
predictions - both those later observationally confirmed and those rejected.Comment: 47 pages, 12 figures. Invited review accepted for publication in the
'Handbook of Exoplanets', planet formation section, section editor: Ralph
Pudritz, Springer reference works, Juan Antonio Belmonte and Hans Deeg, Ed
Reduced Cognitive Assessment Scores Among Individuals With Magnetic Resonance Imaging-Detected Vascular Brain Injury
Background and Purpose- Little is known about the association between covert vascular brain injury and cognitive impairment in middle-aged populations. We investigated if scores on a cognitive screen were lower in individuals with higher cardiovascular risk, and those with covert vascular brain injury. Methods- Seven thousand five hundred forty-seven adults, aged 35 to 69 years, free of cardiovascular disease underwent a cognitive assessment using the Digital Symbol Substitution test and Montreal Cognitive Assessment, and magnetic resonance imaging (MRI) to detect covert vascular brain injury (high white matter hyperintensities, lacunar, and nonlacunar brain infarctions). Cardiovascular risk factors were quantified using the INTERHEART (A Global Study of Risk Factors for Acute Myocardial Infarction) risk score. Multivariable mixed models tested for independent determinants of reduced cognitive scores. The population attributable risk of risk factors and MRI vascular brain injury on low cognitive scores was calculated. Results- The mean age of participants was 58 (SD, 9) years; 55% were women. Montreal Cognitive Assessment and Digital Symbol Substitution test scores decreased significantly with increasing age
Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.
Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis
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