119 research outputs found
3DS-SLAM: A 3D Object Detection based Semantic SLAM towards Dynamic Indoor Environments
The existence of variable factors within the environment can cause a decline
in camera localization accuracy, as it violates the fundamental assumption of a
static environment in Simultaneous Localization and Mapping (SLAM) algorithms.
Recent semantic SLAM systems towards dynamic environments either rely solely on
2D semantic information, or solely on geometric information, or combine their
results in a loosely integrated manner. In this research paper, we introduce
3DS-SLAM, 3D Semantic SLAM, tailored for dynamic scenes with visual 3D object
detection. The 3DS-SLAM is a tightly-coupled algorithm resolving both semantic
and geometric constraints sequentially. We designed a 3D part-aware hybrid
transformer for point cloud-based object detection to identify dynamic objects.
Subsequently, we propose a dynamic feature filter based on HDBSCAN clustering
to extract objects with significant absolute depth differences. When compared
against ORB-SLAM2, 3DS-SLAM exhibits an average improvement of 98.01% across
the dynamic sequences of the TUM RGB-D dataset. Furthermore, it surpasses the
performance of the other four leading SLAM systems designed for dynamic
environments
Automated Speaker Independent Visual Speech Recognition: A Comprehensive Survey
Speaker-independent VSR is a complex task that involves identifying spoken
words or phrases from video recordings of a speaker's facial movements. Over
the years, there has been a considerable amount of research in the field of VSR
involving different algorithms and datasets to evaluate system performance.
These efforts have resulted in significant progress in developing effective VSR
models, creating new opportunities for further research in this area. This
survey provides a detailed examination of the progression of VSR over the past
three decades, with a particular emphasis on the transition from
speaker-dependent to speaker-independent systems. We also provide a
comprehensive overview of the various datasets used in VSR research and the
preprocessing techniques employed to achieve speaker independence. The survey
covers the works published from 1990 to 2023, thoroughly analyzing each work
and comparing them on various parameters. This survey provides an in-depth
analysis of speaker-independent VSR systems evolution from 1990 to 2023. It
outlines the development of VSR systems over time and highlights the need to
develop end-to-end pipelines for speaker-independent VSR. The pictorial
representation offers a clear and concise overview of the techniques used in
speaker-independent VSR, thereby aiding in the comprehension and analysis of
the various methodologies. The survey also highlights the strengths and
limitations of each technique and provides insights into developing novel
approaches for analyzing visual speech cues. Overall, This comprehensive review
provides insights into the current state-of-the-art speaker-independent VSR and
highlights potential areas for future research
A case study of a real-time evaluation of the risk of disease transmission associated with a failure to follow recommended sterilization procedures
Background Failures to follow recommendations for reprocessing of surgical instruments may place patients at risk for exposure to pathogenic microorganisms. When such failures occur, medical facilities often face considerable uncertainty and challenges in assessing the actual risks of disease transmission. Methods In 2011, staff at an Ohio hospital determined that surgical instruments inside a Steriset Container had inadvertently been autoclaved on a gravity cycle rather than on the recommended pre-vacuum cycle, potentially exposing 72 patients who underwent surgery with the instruments to risk of infection. To provide an assessment of the level of risk, we tested the effectiveness of the machine washer/disinfector step and of the sterilization process inside the Steriset Container on the gravity cycle for killing of Geobacillus stearothermophilus spores, Clostridium difficile spores, and methicillin-resistant Staphylococcus aureus (MRSA). Based on the test results, the risk of transmission of MRSA by the instruments was calculated and the risk of transmission of hepatitis B virus was estimated. Results The machine washer/disinfector consistently reduced MRSA recovery by a factor of 1:100,000. The sterilization process inside the Steriset Container consistently reduced MRSA concentrations by a factor of >1:10,000,000 and killed 105 C. difficile spores and 105 G. stearothermophilus spores. The risk of MRSA transmission due to the incident was calculated to be 1 in 100 trillion. Conclusions The risk for transmission of infection due to the failure to follow recommended sterilization processes was negligible based upon complete killing of G. stearothermophilus biological indicator spores, C. difficile spores, and MRSA under conditions that replicated the incident where proper procedures were not followed. Such real-time assessments of the risks associated with specific incidents may provide evidence-based information that can be used to inform decisions regarding disclosure of the incident to patients
Analysis of jak2 catalytic function by peptide microarrays: The role of the JH2 domain and V617F mutation
Janus kinase 2 (JAK2) initiates signaling from several cytokine receptors and is required for biological responses such as erythropoiesis. JAK2 activity is controlled by regulatory proteins such as Suppressor of Cytokine Signaling (SOCS) proteins and protein tyrosine phosphatases. JAK2 activity is also intrinsically controlled by regulatory domains, where the pseudokinase (JAK homology 2, JH2) domain has been shown to play an essential role. The physiological role of the JH2 domain in the regulation of JAK2 activity was highlighted by the discovery of the acquired missense point mutation V617F in myeloproliferative neoplasms (MPN). Hence, determining the precise role of this domain is critical for understanding disease pathogenesis and design of new treatment modalities. Here, we have evaluated the effect of inter-domain interactions in kinase activity and substrate specificity. By using for the first time purified recombinant JAK2 proteins and a novel peptide micro-array platform, we have determined initial phosphorylation rates and peptide substrate preference for the recombinant kinase domain (JH1) of JAK2, and two constructs comprising both the kinase and pseudokinase domains (JH1-JH2) of JAK2. The data demonstrate that (i) JH2 drastically decreases the activity of the JAK2 JH1 domain, (ii) JH2 increased the Kmfor ATP (iii) JH2 modulates the peptide preference of JAK2 (iv) the V617F mutation partially releases this inhibitory mechanism but does not significantly affect substrate preference or Kmfor ATP. These results provide the biochemical basis for understanding the interaction between the kinase and the pseudokinase domain of JAK2 and identify a novel regulatory role for the JAK2 pseudokinase domain. Additionally, this method can be used to identify new regulatory mechanisms for protein kinases that provide a better platform for designing specific strategies for therapeutic approaches
Carbon nanotubes for ultrafast fibre lasers
Carbon nanotubes (CNTs) possess both remarkable optical properties and high potential for integration in various photonic devices. We overview, here, recent progress in CNT applications in fibre optics putting particular emphasis on fibre lasers. We discuss fabrication and characterisation of different CNTs, development of CNT-based saturable absorbers (CNT-SA), their integration and operation in fibre laser cavities putting emphasis on state-of-the-art fibre lasers, mode locked using CNT-SA. We discuss new design concepts of high-performance ultrafast operation fibre lasers covering ytterbium (Yb), bismuth (Bi), erbium (Er), thulium (Tm) and holmium (Ho)-doped fibre lasers
WSES guidelines for management of Clostridium difficile infection in surgical patients
In the last two decades there have been dramatic changes in the epidemiology of Clostridium difficile infection (CDI), with increases in incidence and severity of disease in many countries worldwide. The incidence of CDI has also increased in surgical patients. Optimization of management of C difficile, has therefore become increasingly urgent. An international multidisciplinary panel of experts prepared evidenced-based World Society of Emergency Surgery (WSES) guidelines for management of CDI in surgical patients.Peer reviewe
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