248 research outputs found
Episodic encoding is more than the sum of its parts: An fMRI investigation of multifeatural contextual encoding
No full textEpisodic memories are characterized by their contextual richness, yet little is known about how the various features comprising an episode are brought together in memory. Here we employed fMRI and a multidimensional source memory procedure to investigate processes supporting the mnemonic binding of item and contextual information. Volunteers were scanned while encoding items for which the contextual features (color and location) varied independently, allowing activity elicited at the time of study to be segregated according to whether both, one, or neither feature was successfully retrieved on a later memory test. Activity uniquely associated with successful encoding of both features was identified in the intra-parietal sulcus, a region strongly implicated in the support of attentionally mediated perceptual binding. The findings suggest that the encoding of disparate features of an episode into a common memory representation requires that the features be conjoined in a common perceptual representation when the episode is initially experienced
Management of osteoarthritis at the base of the thumb: a multicentre service evaluation project
No full textAims
Base of thumb osteoarthritis (BTOA) is a common age-related disease which has a significant negative impact upon quality of life. Our aim was to assess current UK practice in secondary care with regard to the nature of non-surgical treatments, the surgical procedures most commonly performed, and factors influencing the surgical decision-making process.
Methods
Ten consecutive patients undergoing surgery for BTOA between March 2017 and May 2019 were prospectively identified in 15 UK centres. Demographic details, duration of symptoms, radiological grade, non-surgical management strategies, and surgery conducted were recorded. A supplementary consultant questionnaire consisting of four multiple-choice-questions (MCQ) based on hypothetical clinical scenarios was distributed.
Results
A total of 150 patients were identified with a mean age of 64 years (SD 9), comprising 119 females and 31 males. Median duration of symptoms prior to surgery was 24 months (Interquartile range (IQR) 12 to 40). Hand therapy was used in 67 patients (45%), splints in 80 (53%), and 121 patients (81%) received one or more intra-articular injections, of which 81 (67%) were image-guided (14 (12%) ultrasound and 67 (55%) fluoroscopic). Only 48 patients (32%) received all three non-surgical treatments. Simple trapeziectomy (79 patients) and trapeziectomy with ligament reconstruction and/or tendon interposition (69 patients) were the most commonly performed operations. One patient was treated with arthrodesis, and one with arthroplasty. The supplementary questionnaire revealed that no specific patient or disease characteristics significantly influenced the type of surgery undertaken.
Conclusion
We found considerable variation in practice of both non-surgical and surgical management of BTOA. The proportion of patients exhausting non-surgical strategies before being offered surgery is low. Surgeons tend to favour a single type of surgery irrespective of patient or disease characteristics
3DHD CityScenes: High-Definition Maps in High-Density Point Clouds
No full textOverview
3DHD CityScenes is the most comprehensive, large-scale high-definition (HD) map dataset to date, annotated in the three spatial dimensions of globally referenced, high-density LiDAR point clouds collected in urban domains. Our HD map covers 127 km of road sections of the inner city of Hamburg, Germany including 467 km of individual lanes. In total, our map comprises 266,762 individual items.
Our corresponding paper (published at ITSC 2022) is available here.
Further, we have applied 3DHD CityScenes to map deviation detection here.
Moreover, we release code to facilitate the application of our dataset and the reproducibility of our research. Specifically, our 3DHD_DevKit comprises:
Python tools to read, generate, and visualize the dataset,
3DHDNet deep learning pipeline (training, inference, evaluation) for
map deviation detection and 3D object detection.
The DevKit is available here:
https://github.com/volkswagen/3DHD_devkit.
The dataset and DevKit have been created by Christopher Plachetka as project lead during his PhD period at Volkswagen Group, Germany.
When using our dataset, you are welcome to cite:
@INPROCEEDINGS{9921866,
author={Plachetka, Christopher and Sertolli, Benjamin and Fricke, Jenny and Klingner, Marvin and
Fingscheidt, Tim},
booktitle={2022 IEEE 25th International Conference on Intelligent Transportation Systems (ITSC)},
title={3DHD CityScenes: High-Definition Maps in High-Density Point Clouds},
year={2022},
pages={627-634}}
Acknowledgements
We thank the following interns for their exceptional contributions to our work.
Benjamin Sertolli: Major contributions to our DevKit during his master thesis
Niels Maier: Measurement campaign for data collection and data preparation
The European large-scale project Hi-Drive (www.Hi-Drive.eu) supports the publication of 3DHD CityScenes and encourages the general publication of information and databases facilitating the development of automated driving technologies.
The Dataset
After downloading, the 3DHD_CityScenes folder provides five subdirectories, which are explained briefly in the following.
1. Dataset
This directory contains the training, validation, and test set definition (train.json, val.json, test.json) used in our publications. Respective files contain samples that define a geolocation and the orientation of the ego vehicle in global coordinates on the map.
During dataset generation (done by our DevKit), samples are used to take crops from the larger point cloud. Also, map elements in reach of a sample are collected. Both modalities can then be used, e.g., as input to a neural network such as our 3DHDNet.
To read any JSON-encoded data provided by 3DHD CityScenes in Python, you can use the following code snipped as an example.
import json
json_path = r"E:\3DHD_CityScenes\Dataset\train.json"
with open(json_path) as jf:
data = json.load(jf)
print(data)
2. HD_Map
Map items are stored as lists of items in JSON format. In particular, we provide:
traffic signs,
traffic lights,
pole-like objects,
construction site locations,
construction site obstacles (point-like such as cones, and line-like such as fences),
line-shaped markings (solid, dashed, etc.),
polygon-shaped markings (arrows, stop lines, symbols, etc.),
lanes (ordinary and temporary),
relations between elements (only for construction sites, e.g., sign to lane association).
3. HD_Map_MetaData
Our high-density point cloud used as basis for annotating the HD map is split in 648 tiles. This directory contains the geolocation for each tile as polygon on the map. You can view the respective tile definition using QGIS. Alternatively, we also provide respective polygons as lists of UTM coordinates in JSON.
Files with the ending .dbf, .prj, .qpj, .shp, and .shx belong to the tile definition as “shape file” (commonly used in geodesy) that can be viewed using QGIS. The JSON file contains the same information provided in a different format used in our Python API.
4. HD_PointCloud_Tiles
The high-density point cloud tiles are provided in global UTM32N coordinates and are encoded in a proprietary binary format. The first 4 bytes (integer) encode the number of points contained in that file. Subsequently, all point cloud values are provided as arrays. First all x-values, then all y-values, and so on. Specifically, the arrays are encoded as follows.
x-coordinates: 4 byte integer
y-coordinates: 4 byte integer
z-coordinates: 4 byte integer
intensity of reflected beams: 2 byte unsigned integer
ground classification flag: 1 byte unsigned integer
After reading, respective values have to be unnormalized. As an example, you can use the following code snipped to read the point cloud data. For visualization, you can use the pptk package, for instance.
import numpy as np
import pptk
file_path = r"E:\3DHD_CityScenes\HD_PointCloud_Tiles\HH_001.bin"
pc_dict = {}
key_list = ['x', 'y', 'z', 'intensity', 'is_ground']
type_list = ['<i4', '<i4', '<i4', '<u2', 'u1']
with open(file_path, "r") as fid:
num_points = np.fromfile(fid, count=1, dtype='<u4')[0]
# print(num_points)
# Init
for k, dtype in zip(key_list, type_list):
pc_dict[k] = np.zeros([num_points], dtype=dtype)
# Read all arrays
for k, t in zip(key_list, type_list):
pc_dict[k] = np.fromfile(fid, count=num_points, dtype=t)
# Unnorm
pc_dict['x'] = (pc_dict['x'] / 1000) + 500000
pc_dict['y'] = (pc_dict['y'] / 1000) + 5000000
pc_dict['z'] = (pc_dict['z'] / 1000)
pc_dict['intensity'] = pc_dict['intensity'] / 2**16
pc_dict['is_ground'] = pc_dict['is_ground'].astype(np.bool_)
fid.close()
print(pc_dict)
# Visualization
# Normalize (due to large UTM values)
x_utm = pc_dict['x'] - np.mean(pc_dict['x'])
y_utm = pc_dict['y'] - np.mean(pc_dict['y'])
z_utm = pc_dict['z']
xyz = np.column_stack((x_utm, y_utm, z_utm))
viewer = pptk.viewer(xyz)
viewer.attributes(pc_dict['intensity'])
viewer.set(point_size=0.03)
5. Trajectories
We provide 15 real-world trajectories recorded during a measurement campaign covering the whole HD map. Trajectory samples are provided approx. with 30 Hz and are encoded in JSON.
These trajectories were used to provide the samples in train.json, val.json. and test.json with realistic geolocations and orientations of the ego vehicle.
OP1 – OP5 cover the majority of the map with 5 trajectories.
RH1 – RH10 cover the majority of the map with 10 trajectories.
Note that OP5 is split into three separate parts, a-c. RH9 is split into two parts, a-b. Moreover, OP4 mostly equals OP1 (thus, we speak of 14 trajectories in our paper). For completeness, however, we provide all recorded trajectories here
Two epidemiologic patterns of norovirus outbreaks: surveillance in England and wales, 1992-2000.
No full textIn the period 1992-2000, the Public Health Laboratory Service Communicable Disease Surveillance Centre collected standardized epidemiologic data on 1,877 general outbreaks of Norovirus (formerly "Norwalk-like virus") infection in England and Wales. Seventy-nine percent of general outbreaks occurred in health-care institutions, i.e., hospitals (40%) and residential-care facilities (39%). When compared with outbreaks in other settings, those in health-care institutions were unique in exhibiting a winter peak (p<0.0001); these outbreaks were also associated with significantly higher death rates and prolonged duration but were smaller in size and less likely to be foodborne. These data suggest that Norovirus infection has considerable impact on the health service and the vulnerable populations residing in institutions such as hospitals and residential homes. A distinct outbreak pattern in health-care institutions suggests a combination of host, virologic, and environmental factors that mediate these divergent epidemiologic patterns
Systematic Review of Escalated Imatinib Doses Compared with Sunitinib or Best Supportive Care, for the Treatment of People with Unresectable/Metastatic Gastrointestinal Stromal Tumours Whose Disease has Progressed on the Standard Imatinib Dose
No full textPMID: 21971958 [PubMed - indexed for MEDLINE] PMCID: PMC3348468 Free PMC Article This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are creditedPeer reviewe
The rate of nonunion in the MRI-detected occult scaphoid fracture: a multicentre cohort study
No full textAims
There is a lack of published evidence relating to the rate of nonunion seen in occult scaphoid fractures, diagnosed only after MRI. This study reports the rate of delayed union and nonunion in a cohort of patients with MRI-detected acute scaphoid fractures.
Methods
This multicentre cohort study at eight centres in the UK included all patients with an acute scaphoid fracture diagnosed on MRI having presented acutely following wrist trauma with normal radiographs. Data were gathered retrospectively for a minimum of 12 months at each centre. The primary outcome measures were the rate of acute surgery, delayed union, and nonunion.
Results
A total of 1,989 patients underwent acute MRI for a suspected scaphoid fracture during the study period, of which 256 patients (12.9%) were diagnosed with a previously occult scaphoid fracture. Of the patients with scaphoid fractures, six underwent early surgical fixation (2.3%) and there was a total of 16 cases of delayed or nonunion (6.3%) in the remaining 250 patients treated with cast immobilization. Of the nine nonunions (3.5%), seven underwent surgery (2.7%), one opted for non-surgical treatment, and one failed to attend follow-up. Of the seven delayed unions (2.7%), one (0.4%) was treated with surgery at two months, one (0.4%) did not attend further follow-up, and the remaining five fractures (1.9%) healed after further cast immobilization. All fractures treated with surgery had united at follow-up. There was one complication of surgery (prominent screw requiring removal).
Conclusion
MRI-detected scaphoid fractures are not universally benign, with delayed or nonunion of scaphoid fractures diagnosed only after MRI seen in over 6% despite appropriate initial immobilization, with most of these patients with nonunion requiring surgery to achieve union. This study adds weight to the evidence base supporting the use of early MRI for these patients
Hundreds of variants clustered in genomic loci and biological pathways affect human height
No full textMost common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits(1), but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait(2,3). The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P<0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways
Common variants at 6p21.1 are associated with large artery atherosclerotic stroke
No full textGenome-wide association studies (GWAS) have not consistently detected replicable genetic risk factors for ischemic stroke, potentially due to etiological heterogeneity of this trait. We performed GWAS of ischemic stroke and a major ischemic stroke subtype (large artery atherosclerosis, LAA) using 1,162 ischemic stroke cases (including 421 LAA cases) and 1,244 population controls from Australia. Evidence for a genetic influence on ischemic stroke risk was detected, but this influence was higher and more significant for the LAA subtype. We identified a new LAA susceptibility locus on chromosome 6p21.1 (rs556621: odds ratio (OR) = 1.62, P = 3.9 × 10 -8) and replicated this association in 1,715 LAA cases and 52,695 population controls from 10 independent population cohorts (meta-analysis replication OR = 1.15, P = 3.9 × 10 -4; discovery and replication combined OR = 1.21, P = 4.7 × 10 -8). This study identifies a genetic risk locus for LAA and shows how analyzing etiological subtypes may better identify genetic risk alleles for ischemic stroke
Meta-analysis identifies 13 new loci associated with waist-hip ratio and reveals sexual dimorphism in the genetic basis of fat distribution
No full textWaist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻¹³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions
Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture
No full textApproaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups
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