Autostereoscopic 3D displays Dodgson, N.A.
Computer (Long Beach, Calif.),
08/2005, Letnik:
38, Številka:
8
Journal Article
Recenzirano
Most of the perceptual cues that humans use to visualize the world's 3D structure are available in 2D projections. This is why we can make sense of photographs and images on a television screen, at ...the cinema, or on a computer monitor. Such cues include occlusion, perspective, familiar size, and atmospheric haze. Four cues are missing from 2D media: stereo parallax - seeing a different image with each eye, movement parallax - seeing different images when we move our heads, accommodation - the eyes' lenses focus on the object of interest, and convergence - both eyes converge on the object of interest. All 3D display technologies (stereoscopic displays) provide at least stereo parallax. Autostereoscopic displays provide the 3D image without the viewer needing to wear any special viewing gear.
We present a new contrast enhancing color to grayscale conversion algorithm which works in real-time. It incorporates novel techniques for image sampling and dimensionality reduction, sampling color ...differences by Gaussian pairing and analyzing color differences by predominant component analysis. In addition to its speed and simplicity, the algorithm has the advantages of continuous mapping, global consistency, and grayscale preservation, as well as predictable luminance, saturation, and hue ordering properties.
S. Benton published a definitive taxonomy of the first one hundred and seventy years of 3D displays covering the field up to the year 2000. In this article we review how display technologies have ...advanced in the last ten years and update Benton's taxonomy to include the latest additions. Our aim is to produce a display taxonomy suitable for content producers highlighting which displays have common requirements for image delivery. We also analyze key technical characteristics of 3D displays and use these characteristics to suggest the future applications for each category of display.
Carbapenem-resistant
(CRE) represent a health threat, but effective control interventions remain unclear. Hospital wastewater sites are increasingly being highlighted as important potential ...reservoirs. We investigated a large
carbapenemase (KPC)-producing
outbreak and wider CRE incidence trends in the Central Manchester University Hospital NHS Foundation Trust (CMFT) (United Kingdom) over 8 years, to determine the impact of infection prevention and control measures. Bacteriology and patient administration data (2009 to 2017) were linked, and a subset of CMFT or regional hospital KPC-producing
isolates (
= 268) were sequenced. Control interventions followed international guidelines and included cohorting, rectal screening (
= 184,539 screens), environmental sampling, enhanced cleaning, and ward closure and plumbing replacement. Segmented regression of time trends for CRE detections was used to evaluate the impact of interventions on CRE incidence. Genomic analysis (
= 268 isolates) identified the spread of a KPC-producing
outbreak clone (strain A, sequence type 216 ST216;
= 125) among patients and in the environment, particularly on 2 cardiac wards (wards 3 and 4), despite control measures. ST216 strain A had caused an antecedent outbreak and shared its KPC plasmids with other
lineages and
species. CRE acquisition incidence declined after closure of wards 3 and 4 and plumbing replacement, suggesting an environmental contribution. However, ward 3/ward 4 wastewater sites were rapidly recolonized with CRE and patient CRE acquisitions recurred, albeit at lower rates. Patient relocation and plumbing replacement were associated with control of a clonal KPC-producing
outbreak; however, environmental contamination with CRE and patient CRE acquisitions recurred rapidly following this intervention. The large numbers of cases and the persistence of
in
, including pathogenic lineages, are of concern.
Carbapenemase-producing Enterobacterales (CPE) are an important public health threat, with costly operational and economic consequences for NHS Integrated Care Systems and NHS Trusts. UK Health ...Security Agency guidelines recommend that Trusts use locally developed risk assessments to accurately identify high-risk individuals for screening, and implement the most appropriate method of testing, but this presents many challenges.
A convenience sample of cross-specialty experts from across England met to discuss the barriers and practical solutions to implementing UK Health Security Agency framework into operational and clinical workflows. The group derived responses to six key questions that are frequently asked about screening for CPE.
Four patient groups were identified for CPE screening: high-risk unplanned admissions, high-risk elective admissions, patients in high-risk units, and known positive contacts. Rapid molecular testing is a preferred screening method for some of these settings, offering faster turnaround times and more accurate results than culture-based testing. It is important to stimulate action now, as several lessons can be learnt from screening during the COVID-19 pandemic, as well as from CPE outbreaks.
Further decisive and instructive information is needed to establish CPE screening protocols based on local epidemiology and risk factors. Local management should continually evaluate local epidemiology, analysing data and undertaking frequent prevalence studies to understand risks, and prepare resources- such as upscaled screening- to prevent increasing prevalence, clusters or outbreaks. Rapid molecular-based methods will be a crucial part of these considerations, as they can reduce unnecessary isolation and opportunity costs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Rapid identification of patients who are colonized with carbapenemase-producing organisms (CPO) is included in multiple national guidelines for containment of these organisms. In a multisite study, ...we evaluated the performance of the Cepheid Xpert Carba-R assay, a qualitative diagnostic test that was designed for the rapid detection and differentiation of the blaKPC, blaNDM, blaVIM, blaOXA-48, and blaIMP-1 genes from rectal swab specimens. A double rectal swab set was collected from 383 patients admitted at four institutions (2 in the United States, 1 in the United Kingdom, 1 in Spain). One swab was used for reference culture (MacConkey broth containing 1 mg/liter of meropenem and subcultured to a MacConkey agar plate with a 10-μg meropenem disk) and for sequencing of DNA obtained from carbapenem-nonsusceptible isolates for carbapenemase identification. The other swab was used for the Xpert Carba-R assay. In addition to the clinical rectal swabs, 250 contrived specimens (108 well-characterized CPO and 142 negative controls spiked onto negative rectal swabs) were tested. Overall, 149/633 (23.5%) samples were positive by the Xpert Carba-R assay. In 6 samples, multiple targets were detected (4 VIM/OXA-48, 1 IMP-1/NDM, and 1 NDM/KPC). The Xpert Carba-R assay detected 155 targets (26 IMP-1, 30 VIM, 27 NDM, 33 KPC, 39 OXA-48) within a time range of 32 to 48 min. The sensitivity, specificity, and positive and negative predictive values of the Xpert Carba-R assay compared to those of the reference culture and sequencing results were 96.6% (95% confidence interval CI, 92.2% to 98.9%), 98.6% (95% CI, 97.1% to 99.4%), 95.3%, and 99.0%, respectively. The Cepheid Xpert Carba-R assay is an accurate and rapid test to identify rectal colonization with CPO, which can guide infection control programs to limit the spread of these organisms.
Sophisticated video processing effects require both image and geometry information. We explore the possibility to augment a video camera with a recent infrared time‐of‐flight depth camera, to capture ...high‐resolution RGB and low‐resolution, noisy depth at video frame rates. To turn such a setup into a practical RGBZ video camera, we develop efficient data filtering techniques that are tailored to the noise characteristics of IR depth cameras. We first remove typical artefacts in the RGBZ data and then apply an efficient spatiotemporal denoising and upsampling scheme. This allows us to record temporally coherent RGBZ videos at interactive frame rates and to use them to render a variety of effects in unprecedented quality. We show effects such as video relighting, geometry‐based ion and stylisation, background segmentation and rendering in stereoscopic 3D.
Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae were first seen in the UK in 2003 and have been increasingly reported since 2010, largely owing to an ongoing outbreak in ...North-West England. We examined the role of clonal spread and plasmid transmission in their emergence.
Isolates comprised KPC-positive K. pneumoniae ( n = 33), Escherichia coli ( n = 7) and Enterobacter spp. ( n = 4) referred to the national reference laboratory between 2008 and 2010 from 17 UK centres, including three in North-West England. Isolates were typed by MLST. Plasmids were transferred by electroporation and characterized by PCR or sequencing. PCR screening assays were developed to distinguish plasmid pKpQIL variants.
The K. pneumoniae isolates included 10 STs, of which three belonged to clonal group (CG) 258. CG258 ( n = 19) isolates were detected in 13 centres but accounted for only 7/19 (36.8%) of those from North-West England. Most KPC-producers (37/44, 84.1%), including 16/19 CG258 K. pneumoniae , carried bla KPC on IncFII K2 plasmids. Sequencing of a subset of these plasmids ( n = 11) revealed similarities with published pKpQIL. One variant, pKpQIL-UK identified in K. pneumoniae CG258 ( n = 5) and ST468 ( n = 1) isolates from distinct centres had only a few nucleotide changes from classical pKpQIL, whereas pKpQIL-D1 ( n = 1) and pKpQIL-D2 ( n = 4), from isolates of various species in the North-West, harboured large variations, reflecting replacement of the partitioning and replication functions and potentially thereby facilitating spread. PCR revealed that 36/37 (97.3%) IncFII K2 -type plasmids in KPC-positive isolates had pKpQIL markers.
pKpQIL-like plasmids played a major role in the early dissemination of KPC enzymes in the UK.
Carbapenem resistance in Gram-negative bacteria is associated with severe infections in the hospital setting. No uniform screening policy or agreed set of criteria exists within the EU to inform ...treatment decisions for infections caused by carbapenem-resistant Gram-negative bacteria.
To develop a range of consensus statements to survey experts in carbapenem resistance, to identify potential similarities and differences across the EU and across specialties.
The survey contained 43 statements, covering six key topics relating to carbapenem-resistant organisms: microbiological screening; diagnosis; infection control implementation; antibiotic stewardship; use of resources; and influencing policy.
In total, 136 survey responses were received (66% infectious disease specialists, 18% microbiologists, 11% intensive care specialists, 4% other/unknown) from France, Germany, Greece, Italy, Spain, and the UK. High, or very high, levels of agreement were seen for all 43 consensus statements, indicating good alignment concerning early identification and optimal management of infection due to carbapenem-resistant organisms.
We offer the following recommendations: (1) screening is required when a patient may have been exposed to the healthcare system in countries/hospitals where carbapenem-resistant organisms are endemic; (2) rapid diagnostic tools should be available in every institution; (3) all institutions should have a specific policy for the control of carbapenem-resistant organisms, which is routinely audited; (4) clear strategies are required to define both appropriate and inappropriate use of carbapenems; (5) priority funding should be allocated to the management of infections due to carbapenem-resistant organisms; and (6) international co-operation is required to reduce country-to-country transmission of carbapenem-resistant organisms.
Carbapenemase-producing Enterobacteriaceae (CPE) are a growing problem in UK hospitals. Preventing transmission requires early detection. This study evaluates a new screening policy for patients with ...a history of blaKPC-associated CPE (KPC-CPE) in a higher incidence hospital. Previous policy assumed ‘once positive always positive’. New policy uses rapid screening and risk assessment. Results show that most (76.5%) patients with a history of KPC-CPE do not have detectable KPC-CPE on readmission or during their subsequent hospital stay but that repeat screening after an initial negative result is required. The new policy takes a risk-based approach while prioritizing isolation facilities in a higher incidence trust.
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