1,375 research outputs found
Joint multicast routing and channel assignment in multiradio multichannel wireless mesh networks using simulated annealing
This is the post-print version of the article - Copyright @ 2008 Springer-VerlagThis paper proposes a simulated annealing (SA) algorithm based optimization approach to search a minimum-interference multicast tree which satisfies the end-to-end delay constraint and optimizes the usage of the scarce radio network resource in wireless mesh networks. In the proposed SA multicast algorithm, the path-oriented encoding method is adopted and each candidate solution is represented by a tree data structure (i.e., a set of paths). Since we anticipate the multicast trees on which the minimum-interference channel assignment can be produced, a fitness function that returns the total channel conflict is devised. The techniques for controlling the annealing process are well developed. A simple yet effective channel assignment algorithm is proposed to reduce the channel conflict. Simulation results show that the proposed SA based multicast algorithm can produce the multicast trees which have better performance in terms of both the total channel conflict and the tree cost than that of a well known multicast algorithm in wireless mesh networks.This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1
Intimate intergroup contact across the lifespan
Intergroup contact can be as casual as members of different groups walking past one another on the street or as intimate as developing cross‐group friendships or romantic relationships. To date, however, the majority of intergroup contact research has focused on examining the effects of contact through self‐report measures of interactions and friendships. While this research has made a substantial contribution to scientific understanding, less is known about how different forms of contact (casual vs. intimate) influence each other and are associated with outcomes across the lifespan. The present article focuses on intimate contact; a close and meaningful relationship or interaction with either an ingroup or outgroup member. We critically review the nature and consequences (good and bad) of intimate contact for children, youth and adults and for both majority and minority group members, focusing primarily on intimate intergroup contact. We also consider how intimate contact might be best measured in future research. Implications for research design, policy, and practice are considered
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Genetic variation in the SIM1 locus is associated with erectile dysfunction.
Erectile dysfunction affects millions of men worldwide. Twin studies support the role of genetic risk factors underlying erectile dysfunction, but no specific genetic variants have been identified. We conducted a large-scale genome-wide association study of erectile dysfunction in 36,649 men in the multiethnic Kaiser Permanente Northern California Genetic Epidemiology Research in Adult Health and Aging cohort. We also undertook replication analyses in 222,358 men from the UK Biobank. In the discovery cohort, we identified a single locus (rs17185536-T) on chromosome 6 near the single-minded family basic helix-loop-helix transcription factor 1 (SIM1) gene that was significantly associated with the risk of erectile dysfunction (odds ratio = 1.26, P = 3.4 × 10-25). The association replicated in the UK Biobank sample (odds ratio = 1.25, P = 6.8 × 10-14), and the effect is independent of known erectile dysfunction risk factors, including body mass index (BMI). The risk locus resides on the same topologically associating domain as SIM1 and interacts with the SIM1 promoter, and the rs17185536-T risk allele showed differential enhancer activity. SIM1 is part of the leptin-melanocortin system, which has an established role in body weight homeostasis and sexual function. Because the variants associated with erectile dysfunction are not associated with differences in BMI, our findings suggest a mechanism that is specific to sexual function
Parkinson Disease-Associated Protein α-Synuclein Blocks VDAC Providing New Insights into Mitochondrial Toxicity
Approximation Algorithm for Line Segment Coverage for Wireless Sensor Network
The coverage problem in wireless sensor networks deals with the problem of
covering a region or parts of it with sensors. In this paper, we address the
problem of covering a set of line segments in sensor networks. A line segment `
is said to be covered if it intersects the sensing regions of at least one
sensor distributed in that region. We show that the problem of finding the
minimum number of sensors needed to cover each member in a given set of line
segments in a rectangular area is NP-hard. Next, we propose a constant factor
approximation algorithm for the problem of covering a set of axis-parallel line
segments. We also show that a PTAS exists for this problem.Comment: 16 pages, 5 figures
The effect of socio-economic status on severity of periocular basal cell carcinoma at presentation
Purpose: To evaluate the influence of socio-economic factors on size of periocular basal cell carcinoma at presentation. Methods: All periocular basal cell carcinoma cases receiving treatment from the oculoplastics team in South Glasgow Hospitals NHS Trust, Glasgow, between 1999 and 2009, were identified retrospectively. Information collected included demographic details of patients, side and site of lesions, type of lesions, and size of lesions. The size of lesion was defined as small for any dimension not exceeding 5 mm, medium for dimensions between 6 mm and 10 mm, and large for dimensions exceeding 11 mm. Home address was used to determine the Scottish Index of Multiple Deprivation rank. The demographics, size of lesion, and Scottish Index of Multiple Deprivation rank were investigated using the general linear regression modelling. Results: Of the 67 cases, 24 were men and 43 were women. The mean age was 71.5 years. There were a total of 67 identified cases, of which 38 presented with small-size lesions, 24 with medium-size lesions, and 5 with large-size lesions. Scottish Index of Multiple Deprivation is related to the presenting incidence of basal cell carcinoma, with the lower ranks presenting more frequently. Conclusions: Socio-economic deprivation is associated with larger and more frequent presentation of periocular basal cell carcinoma. This highlights the importance of raising awareness among populations of the more deprived areas of the significance of lumps and bumps within the periocular regions
UIT-Saviors at MEDVQA-GI 2023: Improving Multimodal Learning with Image Enhancement for Gastrointestinal Visual Question Answering
In recent years, artificial intelligence has played an important role in
medicine and disease diagnosis, with many applications to be mentioned, one of
which is Medical Visual Question Answering (MedVQA). By combining computer
vision and natural language processing, MedVQA systems can assist experts in
extracting relevant information from medical image based on a given question
and providing precise diagnostic answers. The ImageCLEFmed-MEDVQA-GI-2023
challenge carried out visual question answering task in the gastrointestinal
domain, which includes gastroscopy and colonoscopy images. Our team approached
Task 1 of the challenge by proposing a multimodal learning method with image
enhancement to improve the VQA performance on gastrointestinal images. The
multimodal architecture is set up with BERT encoder and different pre-trained
vision models based on convolutional neural network (CNN) and Transformer
architecture for features extraction from question and endoscopy image. The
result of this study highlights the dominance of Transformer-based vision
models over the CNNs and demonstrates the effectiveness of the image
enhancement process, with six out of the eight vision models achieving better
F1-Score. Our best method, which takes advantages of BERT+BEiT fusion and image
enhancement, achieves up to 87.25% accuracy and 91.85% F1-Score on the
development test set, while also producing good result on the private test set
with accuracy of 82.01%.Comment: ImageCLEF2023 published version:
https://ceur-ws.org/Vol-3497/paper-129.pd
Axial-flexural coupled vibration and buckling of composite beams using sinusoidal shear deformation theory
A finite element model based on sinusoidal shear deformation theory is developed to study vibration and buckling analysis of composite beams with arbitrary lay-ups. This theory satisfies the zero traction boundary conditions on the top and bottom surfaces of beam without using shear correction factors. Besides, it has strong similarity with Euler–Bernoulli beam theory in some aspects such as governing equations, boundary conditions, and stress resultant expressions. By using Hamilton’s principle, governing equations of motion are derived. A displacement-based one-dimensional finite element model is developed to solve the problem. Numerical results for cross-ply and angle-ply composite beams are obtained as special cases and are compared with other solutions available in the literature. A variety of parametric studies are conducted to demonstrate the effect of fiber orientation and modulus ratio on the natural frequencies, critical buckling loads, and load-frequency curves as well as corresponding mode shapes of composite beams
Imaging biomarkers of adiposity and sarcopenia as potential predictors for overall survival among patients with endometrial cancer treated with bevacizumab
Objective:To examine associations of body mass index (BMI), subcutaneous fat area (SFA) and density (SFD), visceral fat area (VFA) and density (VFD) and total psoas area (TPA) to outcomes among patients receiving chemotherapy with or without bevacizumab for advanced or recurrent endometrial cancer (EC). Methods:This was a multi-institutional, retrospective study of patients with EC treated with and without bevacizumab as part of front-line, platinum based chemotherapy. Demographics and clinical characteristics were collected. SFA, VFA, SFD, VFD, and TPA were determined from pre-treatment CT scans using a deep learning algorithm. Data was compared with overall survival (OS) and progression free survival (PFS). Results:Seventy-eight patients were analyzed. The majority were Caucasian (87.2%) with a mean BMI of 34.7 kg/m2. PFS and OS did not differ between patients with BMI, SFA, VFA, SFD, VFD, or TPA ≥ the 50th percentile compared to <50th percentile (p = 0.91, 0.45, 0.71, 0.74, 0.60, and 0.74 respectively) and (p = 0.99, 0.59, 0.14, 0.77, and 0.85 respectively). When adjusting for prognostic factors, elevated VFA trended towards shorter OS (25.1 vs 59.5 months, HR = 1.68 [0.92-3.05]).Patients receiving bevacizumab had similar OS compared to those who did not (37.6 vs 44.5 months, p = 0.409). When stratified by adiposity markers, no subset demonstrated benefit from bevacizumab. Conclusion:Obesity has been associated with increased levels of vascular endothelial growth factor (VEGF), the main target for bevacizumab therapy. Imaging measurements of VFA may provide prognostic information for patients with EC but no adiposity marker was predictive of improved response to bevacizumab
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