10,223 research outputs found
Structured Light-Based 3D Reconstruction System for Plants.
Camera-based 3D reconstruction of physical objects is one of the most popular computer vision trends in recent years. Many systems have been built to model different real-world subjects, but there is lack of a completely robust system for plants. This paper presents a full 3D reconstruction system that incorporates both hardware structures (including the proposed structured light system to enhance textures on object surfaces) and software algorithms (including the proposed 3D point cloud registration and plant feature measurement). This paper demonstrates the ability to produce 3D models of whole plants created from multiple pairs of stereo images taken at different viewing angles, without the need to destructively cut away any parts of a plant. The ability to accurately predict phenotyping features, such as the number of leaves, plant height, leaf size and internode distances, is also demonstrated. Experimental results show that, for plants having a range of leaf sizes and a distance between leaves appropriate for the hardware design, the algorithms successfully predict phenotyping features in the target crops, with a recall of 0.97 and a precision of 0.89 for leaf detection and less than a 13-mm error for plant size, leaf size and internode distance
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A case series of primary cutaneous coccidioidomycosis after a record-breaking rainy season.
Percutaneous pulmonary valve implantation alters electrophysiologic substrate
BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) is firstāline therapy for some congenital heart disease patients with right ventricular outflow tract dysfunction. The hemodynamics improvements after PPVI are well documented, but little is known about its effects on the electrophysiologic substrate. The objective of this study is to assess the shortā and mediumāterm electrophysiologic substrate changes and elucidate postprocedure arrhythmias. METHODS AND RESULTS: A retrospective chart review of patients undergoing PPVI from May 2010 to April 2015 was performed. AĀ total of 106 patients underwent PPVI; most commonly these patients had tetralogy of Fallot (n=59, 55%) and pulmonary insufficiency (n=60, 57%). The median followāup time was 28Ā months (7ā63Ā months). PreāPPVI, 25 patients (24%) had documented arrhythmias: nonsustained ventricular tachycardia (NSVT) (n=9, 8%), frequent premature ventricular contractions (PVCs) (n=6, 6%), and atrial fibrillation/flutter (AF/AFL) (n=10, 9%). PostāPPVI, arrhythmias resolved in 4 patients who had NSVT (44%) and 5 patients who had PVCs (83%). New arrhythmias were seen in 16 patients (15%): 7 NSVT, 8 PVCs, and 1 AF/AFL. There was resolution at mediumāterm followāup in 6 (86%) patients with newāonset NSVT and 7 (88%) patients with newāonset PVCs. There was no difference in QRS duration preāPPVI, postāPPVI, and at mediumāterm followāup (P=0.6). The median corrected QT lengthened immediately postāPPVI but shortened significantly at midterm followāup (P<0.01). CONCLUSIONS: PPVI reduced the prevalence of NSVT. The majority of postimplant arrhythmias resolve by 6Ā months of followāup
Cynicism about change, work engagement, and job satisfaction of Public Sector Nurses
This paper uses the job demandsāresources theory to examine the consequences of changes on nursing work. Data were collected from 220 public sector nurses in Australia to test the model. We conducted a twoāwave data collection process where independent variables (organisational change, workload, job control, nursing administrative stressors, cynicism about organisational change, and demographic variables) were collected in Time 1. The dependent variables (nursing work engagement and job satisfaction) were collected 6 months later. Changes to nursing work were found to cause high workload and an increase of administrative stressors that leads to an increase in nursesā change cynicism. Job control was needed to cope with the increase in workload and reduction in cynicism about change. Cynicism about organisational change was found to have a direct negative effect on nursesā engagement which in turn was found to negatively impact job satisfaction. Our contribution to theory and practice arises from the discovery that the connections between organisational change, work environment variables, and job outcomes of nurses are more complicated than previous research suggests. Theoretical and practical implications will be discussed
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Isomeric triazines exhibit unique profiles of bioorthogonal reactivity.
Expanding the scope of bioorthogonal reactivity requires access to new and mutually compatible reagents. We report here that 1,2,4-triazines can be tuned to exhibit unique reaction profiles with biocompatible strained alkenes and alkynes. Computational analyses were used to identify candidate orthogonal reactions, and the predictions were experimentally verified. Notably, 5-substituted triazines, unlike their 6-substituted counterparts, undergo rapid [4 + 2] cycloadditions with a sterically encumbered strained alkyne. This unique, sterically controlled reactivity was exploited for dual bioorthogonal labeling. Mutually orthogonal triazines and cycloaddition chemistries will enable new multi-component imaging applications
No Need for a Lexicon? Evaluating the Value of the Pronunciation Lexica in End-to-End Models
For decades, context-dependent phonemes have been the dominant sub-word unit
for conventional acoustic modeling systems. This status quo has begun to be
challenged recently by end-to-end models which seek to combine acoustic,
pronunciation, and language model components into a single neural network. Such
systems, which typically predict graphemes or words, simplify the recognition
process since they remove the need for a separate expert-curated pronunciation
lexicon to map from phoneme-based units to words. However, there has been
little previous work comparing phoneme-based versus grapheme-based sub-word
units in the end-to-end modeling framework, to determine whether the gains from
such approaches are primarily due to the new probabilistic model, or from the
joint learning of the various components with grapheme-based units.
In this work, we conduct detailed experiments which are aimed at quantifying
the value of phoneme-based pronunciation lexica in the context of end-to-end
models. We examine phoneme-based end-to-end models, which are contrasted
against grapheme-based ones on a large vocabulary English Voice-search task,
where we find that graphemes do indeed outperform phonemes. We also compare
grapheme and phoneme-based approaches on a multi-dialect English task, which
once again confirm the superiority of graphemes, greatly simplifying the system
for recognizing multiple dialects
Visual Diagnosis: Pearling: a case study
We present the case of a patient who attempted to perform a type of body modification known as "pearling" or "genital beading" while in prison. This patient unfortunately caused severe trauma to his penis, requiring surgical intervention. Photographs of the traumatic injuries are presented
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EGFR is required for Wnt9a-Fzd9b signalling specificity in haematopoietic stem cells.
Wnt signalling drives many processes in development, homeostasis and disease; however, the role and mechanism of individual ligand-receptor (Wnt-Frizzled (Fzd)) interactions in specific biological processes remain poorly understood. Wnt9a is specifically required for the amplification of blood progenitor cells during development. Using genetic studies in zebrafish and human embryonic stem cells, paired with in vitro cell biology and biochemistry, we determined that Wnt9a signals specifically through Fzd9b to elicit Ī²-catenin-dependent Wnt signalling that regulates haematopoietic stem and progenitor cell emergence. We demonstrate that the epidermal growth factor receptor (EGFR) is required as a cofactor for Wnt9a-Fzd9b signalling. EGFR-mediated phosphorylation of one tyrosine residue on the Fzd9b intracellular tail in response to Wnt9a promotes internalization of the Wnt9a-Fzd9b-LRP signalosome and subsequent signal transduction. These findings provide mechanistic insights for specific Wnt-Fzd signals, which will be crucial for specific therapeutic targeting and regenerative medicine
Protein Delivery of an Artificial Transcription Factor Restores Widespread Ube3a Expression in an Angelman Syndrome Mouse Brain.
Angelman syndrome (AS) is a neurological genetic disorder caused by loss of expression of the maternal copy of UBE3A in the brain. Due to brain-specific genetic imprinting at this locus, the paternal UBE3A is silenced by a long antisense transcript. Inhibition of the antisense transcript could lead to unsilencing of paternal UBE3A, thus providing a therapeutic approach for AS. However, widespread delivery of gene regulators to the brain remains challenging. Here, we report an engineered zinc finger-based artificial transcription factor (ATF) that, when injected i.p. or s.c., crossed the blood-brain barrier and increased Ube3a expression in the brain of an adult mouse model of AS. The factor displayed widespread distribution throughout the brain. Immunohistochemistry of both the hippocampus and cerebellum revealed an increase in Ube3a upon treatment. An ATF containing an alternative DNA-binding domain did not activate Ube3a. We believe this to be the first report of an injectable engineered zinc finger protein that can cause widespread activation of an endogenous gene in the brain. These observations have important implications for the study and treatment of AS and other neurological disorders
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