1,669 research outputs found
Robotic Pick-and-Place of Novel Objects in Clutter with Multi-Affordance Grasping and Cross-Domain Image Matching
This paper presents a robotic pick-and-place system that is capable of
grasping and recognizing both known and novel objects in cluttered
environments. The key new feature of the system is that it handles a wide range
of object categories without needing any task-specific training data for novel
objects. To achieve this, it first uses a category-agnostic affordance
prediction algorithm to select and execute among four different grasping
primitive behaviors. It then recognizes picked objects with a cross-domain
image classification framework that matches observed images to product images.
Since product images are readily available for a wide range of objects (e.g.,
from the web), the system works out-of-the-box for novel objects without
requiring any additional training data. Exhaustive experimental results
demonstrate that our multi-affordance grasping achieves high success rates for
a wide variety of objects in clutter, and our recognition algorithm achieves
high accuracy for both known and novel grasped objects. The approach was part
of the MIT-Princeton Team system that took 1st place in the stowing task at the
2017 Amazon Robotics Challenge. All code, datasets, and pre-trained models are
available online at http://arc.cs.princeton.eduComment: Project webpage: http://arc.cs.princeton.edu Summary video:
https://youtu.be/6fG7zwGfIk
Summary report of work on ten tasks
There are no author-identified significant results in this report
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CD1a autoreactive T cells recognize natural skin oils that function as headless antigens
CD1a autoreactive T cells are common in human blood and skin, but the search for natural autoantigens has been confounded by background T cell responses to CD1 proteins and self lipids. After capturing CD1a-lipid complexes, we gently eluted ligands, while preserving unliganded CD1a for testing lipids from tissues. CD1a released hundreds of ligands of two types. Inhibitory ligands were ubiquitous membrane lipids with polar headgroups, whereas stimulatory compounds were apolar oils. CD1a autoantigens naturally accumulate in epidermis and sebum, where they were identified as squalene and skin waxes. T cell activation by skin oils suggests that headless mini-antigens nest within CD1a and displace non-antigenic resident lipids with large head groups. Oily autoantigens naturally coat the skin's surface, pointing to a new mechanism of barrier immunity
Content-based Filtering Recommendation Approach to Label Irish Legal Judgements
Machine learning approaches are applied across several domains to either simplify or automate tasks which directly result in saved time or cost. Text document labelling is one such task that requires immense human knowledge about the domain and efforts to review, understand and label the documents. The company Stare Decisis summarises legal judgements and labels them as they are made available on Irish public legal source www.courts.ie. This research presents a recommendation-based approach to reduce the time for solicitors at Stare Decisis by reducing many numbers of available labels to pick from to a concentrated few that potentially contains the relevant label for a given judgement. To solve this problem, traditional and state-of-the-art text feature representations along with K-Nearest Neighbour recommender using both cosine similarity and word mover\u27s distance are developed and compared. A series of experiments are designed starting from TF vectors and KNN recommender which is set as a baseline. Further experiments were designed after observing the results of the current experiment. Pre-trained word2vec was used in this experiment as a baseline for state-of-the-art approaches and domain specific embeddings were developed using data scraped from legal text sources
Impact of Actinobacillus pleuropneumoniae biofilm mode of growth on the lipid A structures and stimulation of immune cells
Actinobacillus pleuropneumoniae (APP), the etiologic agent of porcine pleuropneumonia, forms biofilms on biotic and abiotic surfaces. APP biofilms confers resistance to antibiotics. To our knowledge, no studies have examined the role of APP biofilm in immune evasion and infection persistence. This study was undertaken to (i) investigate biofilm-associated LPS modifications occurring during the switch to biofilm mode of growth; and (ii) characterize pro-inflammatory cytokines expression in porcine pulmonary alveolar macrophages (PAMs) and proliferation in porcine PBMCs challenged with planktonic or biofilm APP cells. Extracted lipid A samples from biofilm and planktonic cultures were analyzed by HPLC high-resolution, accurate mass spectrometry. Biofilm cells displayed significant changes in lipid A profiles when compared with their planktonic counterparts. Furthermore, in vitro experiments were conducted to examine the inflammatory response of PAMs exposed to UV-inactivated APP grown in biofilm or in suspension. Relative mRNA expression of pro-inflammatory genes IL1, IL6, IL8 and MCP1 decreased in PAMs when exposed to biofilm cells compared to planktonic cells. Additionally, the biofilm state reduced PBMCs proliferation. Taken together, APP biofilm cells show a weaker ability to stimulate innate immune cells, which could be due, in part, to lipid A structure modifications
Virulence-related Mycobacterium avium subsp hominissuis MAV_2928 gene is associated with vacuole remodeling in macrophages
<p>Abstract</p> <p>Background</p> <p><it>Mycobacterium avium </it>subsp <it>hominissuis </it>(previously <it>Mycobacterium avium </it>subsp <it>avium</it>) is an environmental organism associated with opportunistic infections in humans. <it>Mycobacterium hominissuis </it>infects and replicates within mononuclear phagocytes. Previous study characterized an attenuated mutant in which the PPE gene (MAV_2928) homologous to Rv1787 was inactivated. This mutant, in contrast to the wild-type bacterium, was shown both to have impaired the ability to replicate within macrophages and to have prevented phagosome/lysosome fusion.</p> <p>Results</p> <p>MAV_2928 gene is primarily upregulated upon phagocytosis. The transcriptional profile of macrophages infected with the wild-type bacterium and the mutant were examined using DNA microarray, which showed that the two bacteria interact uniquely with mononuclear phagocytes. Based on the results, it was hypothesized that the phagosome environment and vacuole membrane of the wild-type bacterium might differ from the mutant. Wild-type bacterium phagosomes expressed a number of proteins different from those infected with the mutant. Proteins on the phagosomes were confirmed by fluorescence microscopy and Western blot. The environment in the phagosome of macrophages infected with the mutant differed from the environment of vacuoles with <it>M. hominissuis </it>wild-type in the concentration of zinc, manganese, calcium and potassium.</p> <p>Conclusion</p> <p>The results suggest that the MAV_2928 gene/operon might participate in the establishment of bacterial intracellular environment in macrophages.</p
Raman scattering in pathology
Smith ZJ, Huser T, Wachsman-Hogiu S. Raman scattering in pathology. Analytical Cellular Pathology. 2012;35(3):145-163
An in vitro investigation of microbial volatile analysis for diagnosis of wound infection
Microorganisms produce a wide range of volatile compounds as a product of metabolism. As a result of their different metabolic capabilities, the profiles of volatiles produced will differ between species. This research investigates the detection of volatile profiles from bacterial species associated with wound infection, for species discrimination when cultured under wound like conditions.This work shows that by combing the analysis of bacterial culture headspace using Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS) with multivariate statistical analysis it is possible to discriminate wound-associated bacterial species in planktonic culture, in both complex culture media and a simulated wound fluid. Furthermore, this research demonstrates the detection of volatile profiles from discarded clinical wound dressings. To advance the use of volatile analysis of wound-associated bacteria for species discrimination, a novel collagen based biofilm model providing wound-like culture conditions was developed and characterised. Use of this model for the culture of reproducible steady-state biofilms, and analysis of biofilm headspace volatile profiles was successfully undertaken and subsequently employed in combination with SIFT-MS and multivariate statistical analysis. Results show that the discrimination of wound-associated bacterial biofilms based on headspace volatile profiles under wound like conditions was feasible. In addition, SIFT-MS analysis of multispecies biofilms was undertaken and the detected headspace profiles compared to those of single species biofilms. This indicated that identification of multispecies biofilms using detection of volatile metabolites is more complex, as the headspace was dominated by volatile compounds associated with only one of the species present.The results of this research indicate that application of volatile analysis to wound diagnostics may be of use for the identification of the cause of infection, particularly within acute wounds, which are often caused by a single species
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