32 research outputs found
Xqx Based Modeling For General Integer Programming Problems
We present a new way to model general integer programming (IP) problems with in- equality and equality constraints using XQX. We begin with the definition of IP problems folloby their practical applications, and then present the existing XQX based models to handle such problems. We then present our XQX model for general IP problems (including binary IP) with equality and inequality constraints, and also show how this model can be applied to problems with just inequality constraints. We then present the local optima based solution procedure for our XQX model. We also present new theorems and their proofs for our XQX model. Next, we present a detailed literature survey on the 0-1 multidimensional knapsack problem (MDKP) and apply our XQX model using our simple heuristic procedure to solve benchmark problems. The 0-1 MDKP is a binary IP problem with inequality con- straints and variables with binary values. We apply our XQX model using a heuristics we developed on 0-1 MDKP problems of various sizes and found that our model can handle any problem sizes and can provide reasonable quality results in reasonable time. Finally, we apply our XQX model developed for general integer programming problems on the general multi-dimensional knapsack problems. The general MDKP is a general IP problem with inequality constraints where the variables are positive integers. We apply our XQX model on GMDKP problems of various sizes and find that it can provide reasonable quality results in reasonable time. We also find that it can handle problems of any size and provide fea- sible and good quality solutions irrespective of the starting solutions. We conclude with a discussion of some issues related with our XQX model
Structured Mesh Generation along Louisiana-Mississippi Coastline for Simulation of Coastal Processes
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Comparative Analysis of Percutaneous Drainage versus Operative Drainage of Intra-Abdominal Abscesses in a Resource-Limited Setting: The Tanzanian Experience
Background: Intra-abdominal abscesses (IAAs) are a major cause of morbidity and mortality worldwide. While image-guided percutaneous abscess drainage (PAD) has become the standard of care in many countries, over half of the global population does not have access to interventional radiology (IR) and are left with surgery as the only option for source control. Objective: The purpose of this study is to evaluate the development, implementation, and role of a PAD service in a resource-limited setting. Method: A retrospective cohort study was performed on all patients who underwent percutaneous or surgical abscess drainage (SAD) of IAAs at Tanzania’s national referral hospital from 10/2018 to 4/2021. Patients were identified through a match case search of institutional records and inclusion was confirmed through manual chart review. Demographics, patient presentation, procedural data, and clinical outcomes were recorded in a password-encrypted database and compared between groups. Findings: Sixty-three patients underwent abscess drainage: 32 percutaneously and 31 surgically. In the PAD group, there was a 100% technical success rate and a 0% complication rate. In the SAD group, there was a 64.5% technical success rate and ten deaths within 30 days (32.3%), and one additional complication requiring major therapy (3.2%) (p < 0.001). Conclusion: Results from this study demonstrate that PAD can be performed with high technical success and without complication by trained IR physicians in Tanzania. The development of a successful PAD program exemplifies the drastic need to support the growth of IR services in this setting
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
Management of Obstructive Sleep Apnea secondary to TMJ Ankylosis by Distraction Osteogenesis
Mandibular retrognathism secondary to temporomandibular joint ankylosis has been a significant contributing factor for obstructive sleep apnea. Although several surgical methods including conventional osteotomies have been tried in the past, the intensive nature of the operation and its results which includes change in facial esthetics, occlusion and its long term effects on the TMJ preclude many individuals from undergoing osteotomy. Distraction osteogenesis, a less invasive surgical technique has been employed in our study on a routine basis in the management of sleep apnea, secondary to TMJ ankylosis, and the results have been gratifying
Fork-Hook encryption policy based secured Data Centric Routing Gateway for proactive trust ware data transmission in WBSN
A wireless body sensor network is a collection of sensor nodes interconnected to monitor the patient to collect data and make cooperative on-route communication to medical healthcare. Due to increasing security issue on the transmission path, the data get leaked or false injected. So the security on routing is essential to make centralized routing with secure data transmission and protection against malicious activities. To resolve this problem of the security issue, to propose a Fork-Hook Encryption Policy based on Secured Data Centric Routing Gateway Protocol (FHEP-SDCRGP) to ensure the security depends on crypto blockchain policy for proactive trust ware routing creates encrypted transmission in WBSN. This initially verifies the lookup transmission from neighbor nodes and creates a cluster head path that demonstrates transition containing hop count. Then routing approach gets validated through Trust aware controller node key aggregation. Begin on the transmission medium, the packets get hashed through blockchain principle to encrypt through Fork-Hook Encryption Policy (FHEP) to create Successive Hop Index (SHI), and the private Key to each transmission node gets verified. This removes the sleeper cell nodes on the path that get non-authenticated to secure the data packets through the Sleeper node threading protocol. Each node receives verified through master node aggregation by Hop Count Rollback Node Aggregator (HCRNA) to transmit the encrypted packet from the cooperative routing node. After ascertaining the hop count matched broadcasting cluster head on controller node aggregation, the Key gets received from the authenticator to decrypt the data. The proposed system performs better in secure routing and authentication based on secured proactive cluster head aggregation. This attains higher verification on each flow, and the aggregator rollback acknowledgment improves the security and other existing approaches
Computational experiment of critical event tabu search for the general integer multidimensional knapsack problem
In this paper, we propose a critical event tabu search meta-heuristic for the general integer multidimensional knapsack problem (GMDKP). Variations of GMDKP have enormous applications, and often occur as a sub-problem of more general combinatorial problems. For the special case of binary multidimensional knapsack problems (BMDKP) there are variety of heuristics, mostly sophisticated meta-heuristics, which provides good solutions to the problem. However, to date there is no method that can provide reasonable solutions to realistic size GMDKP. To the best of our knowledge there are only three heuristics published in the literature for GMDKP, and all three are simple greedy heuristics. There is no meta-heuristic available that effectively provides good solutions for large-scale GMDKP. One successful meta-heuristic that has proven to be highly effective in solving combinatorial optimization is a variation of tabu search known as the critical event tabu search (CETS). CETS was originally proposed for the BMDKP with considerable success afterwards. In CETS, clever use of surrogate programming is embedded as choice rules to obtain high quality solutions. The main purpose of this paper is to design the meta-heuristic CETS for the GMDKP using variety of different surrogate choice rules. Extensive computational experiment for large-scale problems are presented. Our procedures open the door for further applications of meta-heuristics to general integer programs
Interventional Approach to Portal Vein Thrombosis and Liver Transplantation: State of the Art
Porto-mesenteric vein thrombosis (PVT) is a well-recognized but uncommon disease entity in patients with and without cirrhosis. Given the complexity of these patients, there are many differing treatment algorithms depending on the individual circumstances of a given patient. The focus of this review is primarily patients with cirrhosis, with an emphasis on liver transplantation considerations. The presence of cirrhosis substantially affects work-up, prognosis, and management of these patients and will substantially affect the patient treatment and have additional implications for prognosis and long-term outcomes. Here, we review the incidence of portal vein thrombosis in known cirrhotic patients, medical and interventional treatment options that are currently used, and, in particular, how to approach cirrhotic patients with PVT who are awaiting liver transplantation
Time to conventional angiography in gastrointestinal bleeding: CT angiography compared to tagged RBC scan
Purpose To compare CT angiography (CTA) and tagged red blood cell (RBC) scan as a function of time from these initial imaging studies to subsequent conventional angiography and catheter-directed embolization in patients with gastrointestinal (GI) bleeding.Methods An IRB-approved retrospective study was conducted of 35 consecutive patients diagnosed with GI bleeding that received angiography for planned catheter-directed embolization. Of these patients, 20 were diagnosed with bleeding using a tagged RBC scan, whereas 15 were diagnosed using CTA. The lengths of time between diagnostic study order to study completion, diagnostic study completion to angiography, and total time from diagnostic study order to angiography were calculated. The results of both groups were compared using a t test with p value of < 0.05 considered statistically significant.Results The mean time from diagnostic study order to study completion was 3 h and 4 min for the CTA group and 5 h and 1 min for the tagged RBC scan group (p value = 0.0001). There was no statistically significant difference between the time to angiography after completion of the preceding diagnostic study. The total mean time from diagnostic study order to intervention was 6 h and 8 min for the CTA group and 9 h and 29 min for the tagged RBC scan group, a statistically significant difference (p value = 0.028).Conclusions In patients requiring conventional angiography for GI bleeding, CT angiography results in a faster time to angiography than tagged RBC scan, which appears to be due to the longer duration required to complete the tagged RBC scan. Decreasing time to angiography is vital, as GI bleeding can be fatal and earlier diagnosis and intervention has the potential to reduce morbidity and mortality, while also increasing sensitivity of angiography. These findings may assist ordering clinicians in deciding on the appropriate diagnostic study