Node Count Research Articles

Wildfire Monitoring Based on Energy Efficient Clustering Approach for FANETS

Forest fires are a significant threat to the ecological system’s stability. Several attempts have been made to detect forest fires using a variety of approaches, including optical fire sensors, and satellite-based technologies, all of which have been unsuccessful. In today’s world, research on flying ad hoc networks (FANETs) is a thriving field and can be used successfully. This paper describes a unique clustering approach that identifies the presence of a fire zone in a forest and transfers all sensed data to a base station as soon as feasible via wireless communication. The fire department takes the required steps to prevent the spread of the fire. It is proposed in this study that an efficient clustering approach be used to deal with routing and energy challenges to extend the lifetime of an unmanned aerial vehicle (UAV) in case of forest fires. Due to the restricted energy and high mobility, this directly impacts the flying duration and routing of FANET nodes. As a result, it is vital to enhance the lifetime of wireless sensor networks (WSNs) to maintain high system availability. Our proposed algorithm EE-SS regulates the energy usage of nodes while taking into account the features of a disaster region and other factors. For firefighting, sensor nodes are placed throughout the forest zone to collect essential data points for identifying forest fires and dividing them into distinct clusters. All of the sensor nodes in the cluster communicate their packets to the base station continually through the cluster head. When FANET nodes communicate with one another, their transmission range is constantly adjusted to meet their operating requirements. This paper examines the existing clustering techniques for forest fire detection approaches restricted to wireless sensor networks and their limitations. Our newly designed algorithm chooses the most optimum cluster heads (CHs) based on their fitness, reducing the routing overhead and increasing the system’s efficiency. Our proposed method results from simulations are compared with the existing approaches such as LEACH, LEACH-C, PSO-HAS, and SEED. The evaluation is carried out concerning overall energy usage, residual energy, the count of live nodes, the network lifetime, and the time it takes to build a cluster compared to other approaches. As a result, our proposed EE-SS algorithm outperforms all the considered state-of-art algorithms.

Sentinel lymph node biopsy compared with systematic lymphadenectomy in patients with uterine carcinosarcoma (536)

<b>Objectives:</b> To assess survival among patients with newly diagnosed uterine carcinosarcoma undergoing sentinel lymph node biopsy (SLN) alone and those undergoing systematic lymphadenectomy (LND). <b>Methods:</b> We identified all patients with newly diagnosed uterine carcinosarcoma who underwent primary surgical management at our institution from January 1996 to December 2019. Patients with gross extrauterine disease of any type were excluded. The SLN cohort underwent SLN biopsy alone, with bilateral SLNs identified. The systematic LND cohort did not undergo SLN biopsy. Progression-free survival (PFS) and overall survival (OS) were defined from the date of surgery to the event. Appropriate statistical testing was performed. <b>Results:</b> We identified 99 SLN and 100 LND patients. Median age and BMI were not different between the groups. Minimally invasive surgery was the approach in 56 (56.6%) SLN (56.6%) and 47 (47%) LND patients (p=0.2). There was no significant difference between cohorts with respect to the degree of myoinvasion (<50%, >50%), presence of lymphovascular space invasion (LVSI), stage, or positive washings. The median total node count was four (range: 1-13) for SLN and 19 (range: 2-50) for LN (p<0.001). Nodal metastasis was noted in 26 (26%) SLN and 21 (21%) LND (p=0.4). Postoperative therapy was given to 91 (92%) SLN and 87 (87%) LND (p=0.3). The type of postoperative therapy administered was as follows: none in eight (8%) SLN and 14 (14%) LND; chemotherapy with or without radiation (RT) in 86 (87%) SLN and 71 (71%) LND; RT alone in five (5%) SLN and 15 (15%) LND (p=0.02). Median follow-up was 51.3 months (range: 0.9-211.1) for the SLN cohort compared with 40.8 months (range: 0.5-269.1) for the LND cohort (p=0.3). The 4-year PFS was 62.4% (SE 5.3%) for SLN and 47.7% (SE 5.5%) for LND (p=0.07). The 4-year OS was 72.4% (SE 4.9%) for SLN and 62.2% (SE 4.2%) for LND (p=0.2). There was no difference in PFS or OS when adjusted for the type of postoperative therapy (chemotherapy with or without RT vs none/RT). An isolated nodal recurrence occurred in two (2%) SLN and four (4%) LND patients (p=0.2). <b>Conclusions:</b> There is no difference in PFS or OS among patients who have uterine carcinosarcoma and undergo SLN biopsy versus systematic LND. SLN biopsy adequately detects the presence of nodal metastasis in these patients. SLN biopsy alone does not compromise oncologic outcomes, and systematic LND is unnecessary in the setting of successful bilateral SLN mapping.

O090 The Sweet approach to oesophagectomy is still a valid surgical approach seldom used in the UK

Abstract Introduction The left thoracophrenotomy approach to oesophagectomy or Sweet Oesophagectomy (SO) for oesophageal cancer is performed by many centres worldwide but seldom used in UK, owing to concerns over extent of lymphadenectomy compared with Ivor-Lewis oesophagectomy (ILO) approach. This study aims to compare oncological and clinical outcomes following the Sweet approach with ILO. Methods A retrospective, single centre study was conducted, analysing all patient data following the SO approach and ILO for oesophageal cancer between August 2012 - March 2021. Results The total number who underwent the Sweet (SO) operation and ILO was 72 and 197 patients respectively.91.7% vs 80.2%, p=0.071 were distal oesophageal tumours. Median lymph node count were 22 and 23 respectively, p=0.980. The Sweet was associated with 69.4% circumferential, 94.4% proximal and 95.8% distal R0 resections compared with 72.6% (p=0.365, 98%(p=0.132) and 96%(p=0.330) with ILO resection, respectively. Median operative time was 169 vs. 301 minutes for Sweet and ILO respectively, p&amp;lt;0.001. The overall complication rate was 29.2% with the Sweet and 45.7% with ILO, p=0.015, including, Anastomotic leaks 0 vs. 11, p=0.041 And return to theatre 1 vs. 22, p=0.04. The 30, 90 day and 5-year survival was 100% vs. 99%(p=0.391), 98.6% vs. 95.9% (p=0.281) &amp; 51.4% vs. 50.3% (p=0.869), respectively. Conclusion The Sweet procedure was associated with comparable oncological efficacy and survival to ILO. Furthermore, was associated with significantly shorter operative time and lower complication rates, therefore should be considered in selected cases. Take-home message Left thoracotomy oesophagectomy remains an appropriate option with significantly better results in our centre, in the management of lower oesophageal and junctional carcinoma as compared to ILO. Having a reduced hospital stay and operative time may be more favourable in more frail patients with distal and junctional oesophageal tumours.

A Preoperative Scoring System to Predict the Risk of Inadequate Lymph Node Count in Rectal Cancer.

PurposeThe aim of this study was to develop and validate a preoperative scoring system to stratify rectal cancer (RC) patients with different risks of inadequate lymph node examination.MethodsA total of 1,375 stage I–III RC patients between 2011 and 2020 from the Second Affiliated Hospital of Harbin Medical University were included in the retrospective study and randomly divided into a development set (n = 688) and a validation set (n = 687). The logistic regression model was used to determine independent factors contributing to lymph node count (LNC) < 12. A preoperative scoring system was constructed based on beta (β) coefficients. The area under the receiver operating curve (AUC) was used to test model discrimination.ResultsPreoperative significant indicators related to LNC < 12 included age, tumor size, tumor location, and CEA. The AUCs of the scoring system for development and validation sets were 0.694 (95% CI = 0.648–0.741) and 0.666 (95% CI = 0.615–0.716), respectively. Patients who scored 0–2, 3–4, and 5–6 were classified into the low-risk group, medium-risk group, and high-risk group, respectively.ConclusionsThe preoperative scoring system could identify RC patients with high risk of inadequate lymphadenectomy accurately and further provide a reference to perform preoperative lymph node staining in targeted patients to reduce the difficulty of meeting the 12-node standard, with the purpose of accurate tumor stage and favorable prognosis.

Prognostic impact of examined mediastinal lymph node count in clinical N0 non-small cell lung cancer.

The number of examined mediastinal lymph nodes (mLNs) could represent the quality of mediastinal lymphadenectomy for non-small cell lung cancer (NSCLC). This study aimed to evaluate the prognostic impact of the number of examined individual mLNs in patients with resectable NSCLC. We retrospectively evaluated 1420 patients with clinical stage IA-IIB, N0 NSCLC who underwent complete resection by lobectomy, which involved hilar and mLN dissection, between 2008 and 2016. We investigated the threshold number of examined mLNs that had prognostic significance and evaluated their effects on the risk of mLN recurrence. In a respective multivariable analysis according to the number of examined mLNs, examining ≥3 mLNs [reference (ref.) mLNs ≤2] achieved statistical significance and had the best prognosis (hazard ratio, 0.68; P = 0.013). In the multivariable analyses for each pathological N (pN) stage, ≥3 examined mLNs (ref. mLNs ≤2) were an independent prognostic factor in pN1 disease (hazard ratio, 0.32, P = 0.002), but not in pN0 or pN2 disease. The cumulative incidence of mLN recurrence was significantly lower in patients with ≥3 examined mLNs (ref. mLNs ≤2, hazard ratio, 0.27; P = 0.008) in pN1 disease. Patients with ≥3 examined mLNs had higher upstaging rates to pN2 than those with ≤2 examined mLNs. Examining ≥3 mLNs contributed to a favourable prognosis and low mLN recurrence risk in patients with clinical stage I-II, N0 NSCLC. Our findings can serve as a benchmark for the number of required mLNs to be examined.

Universality of Nodal Count Distribution in Large Metric Graphs

An eigenfunction of the Laplacian on a metric (quantum) graph has an excess number of zeros due to the graph’s non-trivial topology. This number, called the nodal surplus, is an integer between 0 and the graph’s first Betti number β. We study the distribution of the nodal surplus values in the countably infinite set of the graph’s eigenfunctions. We conjecture that this distribution converges to Gaussian for any sequence of graphs of growing β. We prove this conjecture for several special graph sequences and test it numerically for a variety of well-known graph families. Accurate computation of the distribution is made possible by a formula expressing the nodal surplus distribution as an integral over a high-dimensional torus.

Assessment of the Use of Preoperative CT Scan Image for Predicting Lymph Nodes for Resection of Colorectal Cancer: A Retrospective Study

Introduction: Colorectal cancer (CRC) is the most common cancer that accounts for nearly 10% of the cancers, with 1.36 million people worldwide. Nodal status (N-stage) evaluation was inferior between observers, which considered CT scanning a good N-stage. We hypothesized that CRC patients’ preoperative CT scan imaging predicts the nodal and metastatic stage. Methods: This noninterventional retrospective study was carried out using patients’ medical records, including medical history and results of diagnostic tests, and preoperative clinical and pathological stages. All direct identifiers have been removed from all patient data. This study included 96 patients who underwent resection curative surgery for CRC at the Tertiary Hospital, Sudan, between March 2009 and December 2020. Results: The median age was 69 years (47–74 years), and 49 (51.04%) were female. The tumor stage of the patients was 4, 11, 74, and 7 as T1, T2, T3, and T4, respectively. A total of 38 patients with a malignant spread in lymph nodes were observed, and the median lymph node count was 11 (range 4–52). Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value (PPV), negative predictive value (NPV), and accuracy calculated for the malignant lymph nodes were 75.56% (95% CI: 60.46–87.12%), 45.10% (95% CI: 31.13–59.66%), 1.38 (95% CI: 1.02–1.86), 0.54 (95% CI: 0.30–0.98), 54.84% (95% CI: 47.38–62.09%), 67.65% (95% CI: 53.53–79.15%), and 59.38% (95% CI: 48.87–69.29%), respectively. Conclusion: The preoperative CT scan images were used to predict lymph nodes with a diagnostic accuracy of 59.38% for N-stage in patients with CRC.

Short-term outcome for high-risk patients after esophagectomy.

Transthoracic esophagectomy (TTE) for esophageal cancer facilitates mediastinal dissection; however, it has a significant impact on cardiopulmonary status. High-risk patients may therefore be better candidates for transhiatal esophagectomy (THE) in order to prevent serious complications. This study addressed short-term outcome following TTE and THE in patients that are considered to have a higher risk of surgery-related morbidity. This population-based study included patients who underwent a curative esophagectomy between 2011 and 2018, registered in the Dutch Upper GI Cancer Audit. The Charlson comorbidity index was used to assign patients to a low-risk (score ≤ 1) and high-risk group (score ≥ 2). Propensity score matching was applied to produce comparable groups between high-risk patients receiving TTE and THE. Primary endpoint was mortality (in-hospital/30-day mortality), secondary endpoints included morbidity and oncological outcomes. Additionally, a matched subgroup analysis was performed, including only cervical reconstructions. Of 5,438 patients, 945 and 431 high-risk patients underwent TTE and THE, respectively. After propensity score matching, mortality (6.3 vs 3.3%, P = 0.050), overall morbidity, Clavien-Dindo ≥ 3 complications, pulmonary complications, cardiac complications and re-interventions were significantly more observed after TTE compared to THE. A significantly higher mortality after TTE with a cervical reconstruction was found compared to THE (7.0 vs. 2.2%, P = 0.020). Patients with a high Charlson comorbidity index predispose for a complicated postoperative course after esophagectomy, this was more outspoken after TTE compared to THE. In daily practice, these outcomes should be balanced with the lower lymph node yield, but comparable positive node count and radicality after THE.

The Value of Lymph Node Dissection in Patients With Node-Positive Upper Urinary Tract Urothelial Cancer: A Retrospective Cohort Study.

PurposeThe value of lymphadenectomy during radical nephroureterectomy (RNU) remains unclear. This study aimed to determine the effects of the removed lymph node (RLN) counts, positive lymph node (pLN) counts, and pLN density (pLND) on survival outcomes in patients with node-positive upper urinary tract urothelial cancer (UTUC).MethodsA total of 306 patients with node-positive UTUC in the Surveillance, Epidemiology, and End Results database between 2004 and 2016 were identified. Multivariable Cox regression analyses were used to evaluate the effect of RLN counts, pLN counts, and pLND on survival outcomes. The maximally selected rank statistics were used to determine the most informative cutoff value for pLND on survival outcomes.ResultsThe RLN counts or pLN counts were not associated with survival outcomes, whereas higher pLND was associated with lower cancer-specific survival (CSS) and overall survival (OS) [hazard ratio (HR) 1.75, P = 0.014 and HR 1.62, P = 0.036, respectively]. The most informative cutoff value for pLND in relation to survival was 27%. Patients with pLND ≥27% had worse 5-year survival rates than those with pLND <27% (52.9% vs. 75.9% for CSS and 18.7% vs. 34.2% for OS, each P < 0.05). Furthermore, the multivariable Cox regression model with pLND could predict 5-year CSS (AUC 0.732 vs. 0.647) or OS (AUC 0.704 vs. 0.621) more accurately than the model without pLND.ConclusionsFor patients with node-positive UTUC, more lymph nodes removed do not offer a better therapeutic effect. However, pLND provides additional prognostic value.

A Pilot Study of Prognostic Value of Metastatic Lymph Node Count and Size in Patients with Different Stages of Gastric Carcinoma.

BackgroundThe correlation between the preoperative lymph node count (LNC) on multidetector computed tomography (MDCT) and the prognosis of gastric carcinoma (GC) remains to be defined. This research aims to evaluate the prognostic value of LNC on MDCT in GC patients based on tumor-node-metastasis (TNM) staging, using different size criteria for counting.MethodsThe clinical data of 126 patients with gastric adenocarcinoma undergoing gastrectomy were retrospectively analyzed. Lymph nodes greater than 8mm and 5mm on MDCT were counted and recorded. The prognostic implications of LNC on MDCT for patient survival were analyzed according to different size criteria for counting and tumor TNM staging.ResultsWhen 8mm was used as the counting criterion, LNC on MDCT had no significant effect on the overall survival (OS) of the entire cohort. In addition, the OS of T1–T2 GC patients with LNC on MDCT ≥1 was significantly worse than that of patients with LNC on MDCT <1. When 5mm was used as the counting criterion, LNC on MDCT was found to be significantly associated with the OS of the entire cohort. In the subgroup analysis, patients with relatively advanced (T3-T4, N+ and III) GC with LNC on MDCT >7 showed a significantly worse OS than those with LNC on MDCT ≤7. LNC on MDCT >7 with 5mm as the counting criterion and Stage III were independent risk factors for adverse prognosis.ConclusionThe prognostic value of LNC on MDCT based on different size criteria varies in patients with different stages of GC. LNC of a smaller size (5mm) on MDCT may be a prognostic factor for patients with relatively advanced GC.

Importance of HALP Score in Breast Cancer and its Diagnostic Value in Predicting Axillary Lymph Node Status.

To determine the diagnostic value of the haemoglobin, albumin, lymphocyte, and platelet (HALP) score in predicting axillary lymph node (ALN) involvement. Observational study. Department of General Surgery, Balıkesir University and Mersin City Hospital, Turkey from January 2016-December 2021. Included in the study were 307 patients who underwent surgical treatment for breast cancer. HALP values were calculated by multiplying the haemoglobin, albumin, and lymphocyte values and dividing the resulting value by the platelet number. The patients were divided in two groups, being those with low HALP (Group 1) and high HALP (Group 2) scores. We examined the potential of the HALP score for the prediction of ALN involvement. Group 1 had 65 patients and the Group 2 had 242 patients. At the cut-off point, a HALP score of <29.01 predicted the presence of axillary involvement with a sensitivity of 84.33% and a specificity of 26.1%. The sentinel lymph node sampling rate was similar in both groups (12.3% vs. 16.9% p=0.365). The presence of positive lymph nodes in the axilla was higher in group 1 (67.7% vs. 53.3% p=0.038). There was no correlation between HALP score, and the metastatic lymph node and total lymph node count. The use of HALP score alone for the prediction of axillary lymph node positivity in patients with breast cancer is not advised. In the present study, a low HALP score was associated with aggressive tumour activity, such as advanced tumour and axillary lymph node positivity. Breast cancer, Axillary lymph node involvement, Immunity, Nutrition.

Quality-of-Service-Linked Privileged Content-Caching Mechanism for Named Data Networks

The domain of information-centric networking (ICN) is expanding as more devices are becoming a part of connected technologies. New methods for serving content from a producer to a consumer are being explored, and Named Data Networking (NDN) is one of them. The NDN protocol routes the content from a producer to a consumer in a network using content names, instead of IP addresses. This facility, combined with content caching, efficiently serves content for very large networks consisting of a hybrid and ad hoc topology with both wired and wireless media. This paper addresses the issue of the quality-of-service (QoS) dimension for content delivery in NDN-based networks. The Internet Engineering Task Force (IETF) classifies QoS traffic as (prompt, reliable), prompt, reliable, and regular, and assigns corresponding priorities for managing the content. QoS-linked privileged content caching (QLPCC) proposes strategies for Pending Interest Table (PIT) and content store (CS) management in dedicated QoS nodes for handling priority content. QoS nodes are intermediately resourceful NDN nodes between content producers and consumers which specifically manage QoS traffic. The results of this study are compared with EQPR, PRR probability cache, and Least Frequently Used (LFU) and Least Fresh First (LFF) schemes, and QLPCC outperformed the latter-mentioned schemes in terms of QoS-node CS size vs. hit rate (6% to 47%), response time vs, QoS-node CS size (65% to 90%), and hop count vs. QoS-node CS size (60% to 84%) from the perspectives of priority traffic and overall traffic. QLPCC performed predictably when the NDN node count was increased from 500 to 1000, showing that the strategy is scalable.

Self-Stabilizing Capacitated Vertex Cover Algorithms for Internet-of-Things-Enabled Wireless Sensor Networks.

Wireless sensor networks (WSNs) achieving environmental sensing are fundamental communication layer technologies in the Internet of Things. Battery-powered sensor nodes may face many problems, such as battery drain and software problems. Therefore, the utilization of self-stabilization, which is one of the fault-tolerance techniques, brings the network back to its legitimate state when the topology is changed due to node leaves. In this technique, a scheduler decides on which nodes could execute their rules regarding spatial and temporal properties. A useful graph theoretical structure is the vertex cover that can be utilized in various WSN applications such as routing, clustering, replica placement and link monitoring. A capacitated vertex cover is the generalized version of the problem which restricts the number of edges covered by a vertex by applying a capacity constraint to limit the covered edge count. In this paper, we propose two self-stabilizing capacitated vertex cover algorithms for WSNs. To the best of our knowledge, these algorithms are the first attempts in this manner. The first algorithm is stabilized under an unfair distributed scheduler (that is, the scheduler which does not grant all enabled nodes to make their moves but guarantees the global progress of the system) at most step, where n is the count of nodes. The second algorithm assumes 2-hop (degree 2) knowledge about the network and runs under the unfair scheduler, which subsumes the synchronous and distributed fair scheduler and stabilizes itself after moves in step, which is acceptable for most WSN setups. We theoretically analyze the algorithms to provide proof of correctness and their step complexities. Moreover, we provide simulation setups by applying IRIS sensor node parameters and compare our algorithms with their counterparts. The gathered measurements from the simulations revealed that the proposed algorithms are faster than their competitors, use less energy and offer better vertex cover solutions.

Is increasing nodal count associated with improved recurrence-free and overall survival following standard right hemicolectomy for colon cancer?

Background and ObjectivesIncreasing lymph node harvest for right‐sided colon cancer is associated with improved overall survival (OS), but most relevant studies failed to report the extent of resection. We examined the association between increasing lymph node count with standard right hemicolectomy according to nodal status and prognostic outcomes in right‐sided tumors.MethodsRetrospective analysis of prospectively collected clinical data from patients with proximal colonic adenocarcinomas (n = 1390) following right hemicolectomy. Associations between lymph node counts (0–12 vs. 13–15, 16–20, and >20) and recurrence‐free survival (RFS) and OS were examined using multivariate Cox modeling adjusted for confounders.ResultsWe found no association between increasing nodal count and RFS, regardless of nodal status. In the absence of nodal metastases, increasing nodal count (16–20 and >20 vs. 0–12 nodes) was associated with 57% (95% confidence interval [CI]: 0.21–0.89) and 52% (95% CI: 0.24–0.95) improved OS, respectively. In the presence of nodal metastases, increasing nodal count was not associated with OS. Adjuvant chemotherapy did not modify this effect.ConclusionIncreasing nodal count (>15 nodes) with right hemicolectomy was not associated with improved RFS. Improved OS was only found for node‐negative tumors, casting some doubt on the benefits of resecting more lymph nodes in the presence of nodal metastases.

Design and analysis of a multiple collaborative beamforming scheme in the realm of Wireless Sensor Networks featuring 3-dimension node configuration

Collaborative Beamforming (CB) is an essential tool towards achieving long-range transmission in Wireless Sensor Networks (WSNs). In some instances, there may be multiple intended data destinations (sinks) in a WSN. This calls for multi-CB. In comparison to sink-by-sink CB, multi-CB implies improved data rates and decreased co-channel interference; and consequently increased network capacity. In current literature, there is no research in multi-CB particularly in 3-dimension WSNs. In this paper, a novel multi-CB mechanism is brought to the fore. This is from the point of view of a random arrangement of sensor nodes in a 3-dimension manner. It is assumed that all sinks' directions are known at the CB cluster head. Node transmit amplitude and phase are optimized using a Particle Swarm Optimization (PSO) algorithm variant to concurrently achieve balanced multiple narrow beams and minimal radiation in undesired directions. The performance of the proposed scheme is checked against that of a pure multiple beam steering approach (without beam power balancing and minimization of radiation in undesired directions). Moreover, an analysis of beam power, width and steering accuracy is done upon varying the number of collaborating nodes and the collaborating cluster radius. Increasing the count of collaborating nodes yields improved beam precision/accuracy, lower radiation in undesired directions and appreciable stability in beam power performance Increasing the collaborating nodes' cluster radius yields narrow beams, improved beam precision and appreciably lower radiation in undesired directions. The contributions of this work to current literature include: (i) formulation and analysis of a multiple beamforming scheme in the realm of 3-dimension WSNs; (ii) design of a multi-CB scheme taking into account minimization of radiation in undesired directions; (iii) a statistical multi-CB performance analysis upon varying collaborating nodes' cluster radius and collaborating node count.

Multivariate Network Layout Using Force-Directed Method with Attribute Constraints

Graph visualization with proper layout is widely applied to understand the relationship between entities in a complex system and the topological structure information is mainly used. Real-world graphs often have the community structures property which is ignored in many existing graph layout methods. Thus, we propose a multivariate network layout method using the force-directed method with attribute constraints. This method can effectively take into account the hierarchical structure, connection strength, and quantitative comparison between communities. First, the layout of community centers is generated by a force-directed algorithm in which node count of the community is taken as constraints to enable area balance of community; Second, community force based on node attribute is added in the force-directed algorithm to maintain the community clarity. A visualization system is also developed to allow users to interactively generate community structure-aware layout results. qualitative and quantitative evaluation of the results verifies the usability and effectiveness of the proposed method by comparing it with other methods.

Impact of Examined Lymph Node Count on Precise Staging and Long-term Survival After Neoadjuvant Therapy for Carcinoma of the Esophagus: A SEER Database Analysis.

PurposeTo identify the optimal number of lymph nodes dissected during esophagectomy following neoadjuvant therapy for carcinoma of the esophagus by using the Surveillance, Epidemiology and End Results Registry (SEER) database.Patients and MethodsPatients who underwent neoadjuvant Chemoradiotherapy (nCRT) plus esophagectomy with EC from 2001–2016 were analyzed retrospectively in the SEER database. We analyzed the correlation between the lymphadenectomy count and nodal stage migration and overall survival (OS) by using a binary logistic regression model and Cox proportional hazards regression. The curves of the odds ratios (ORs) of nodal stage migration and hazard ratios (HRs) of OS were smoothed using the LOWESS technique, and the cutoff points were determined by the Chow test. The OS curves were calculated with the Kaplan-Meier method.ResultsAmong the 4,710 patients analyzed in the SEER database, a median of 12 lymph nodes (IQR, 7–19) were harvested. There was a significantly proportional increase in nodal stage migration (OR, 1.017; 95% CI, 1.011 to 1.023; P < 0.001) and serial improvements in OS among node-negative patients (HR, 0.983; 95% CI, 0.977 to 0.988; P < 0.001) with an increased ELN count after adjusting for the T stage. The corresponding cutoff point of the 16 ELNs was calculated for the OR of stage migration by the Chow test. For those with node-negative and node-positive diseases, no significant trend of survival benefit that favored a more extensive lymphadenectomy was demonstrated (HR, 1.001; 95% CI, 0.989 to 1.012; P = 0.906; and HR, 0.996; 95% CI, 0.985 to 1.006; P = 0.405, respectively).ConclusionOn the basis of these results, we recommend that at least 16 ELNs be removed for accurate nodal staging as well as for obtaining a therapeutic benefit after nCRT for EC. Furthermore, once precise nodal staging has been achieved, patient survival does not improve with additional ELN dissection after nCRT, regardless of pathological nodal staging (negative or positive).

Partition detection and recovery by UAVs in damaged WSANs using N‐angle clustering

SummaryConnectivity is essential in wireless sensor and actor networks (WSANs) deployed for data collection and monitoring applications. WSANs serving in inhospitable environments are prone to damage, and sometimes, the concurrent multiple node failures in the same area may cause network partitioning. The autonomous network recovery in harsh environments is challenging because the nodes in different partitions cannot determine the scope of the damage. This paper proposes an approach called partition detection and recovery by unmanned aerial vehicles (UAVs) in damaged WSANs using N‐angle clustering (N‐anglePDRU), which consists of all the phases required to accumulate information about the network partitions and reconnect them successfully. The algorithm is evaluated for different randomly generated network topologies according to various state‐of‐the‐art parameters such as detection and recovery time, messages transmitted, relay node count, and distance traveled by UAVs. The proposed approach is also compared with the existing algorithms, and the obtained results demonstrate that N‐anglePDRU recovers the partitioned network in less recovery time with minimum relay nodes and distance traveled.

An improved Aquila optimization with fuzzy model based energy efficient cluster routing protocol for wireless sensor networks

Due to the latest advances in microelectronics, wireless sensor networking (WSN) has been introduced in many applications. The flow of event data in WSN applications requires timely and reliable distribution so that immediate response and appropriate action can be taken. However, the limited power supply to the sensor terminal causes a transmission between the delay on the way to the base station and the power consumption. Clustering techniques are essential in developing the WSN routing algorithm that improves network operating time and power efficiency. However, due to the unbalanced power consumption between the terminals, the WSN is the optimal, energy efficient routing. In this work, we propose an energy efficient cluster based routing protocol (EEC-HO) for WSN using hybrid optimization algorithm. We introduce an improved Aquila optimization with fuzzy (IAO-Fuzzy) model for optimal and efficient cluster formation and cluster head (CH) computation. The main objective of proposed IAO-Fuzzy model used to compute the trust degree of each node, the highest trust node is considered as CH. After that, the hybrid beetle search induced decision making (BSDM) algorithm for optimal path selection to transfer data transfer between two nodes. Finally, the simulation results of proposed EEC-HO routing protocol is compared with the existing routing protocols. For the impact of sensor node density case, we observed that the effectiveness of proposed EEC-HO routing protocol is 45.887%, 30.666%, 56.666%, 17.629% and 41.666% efficient than existing protocols in terms of energy consumption, network lifetime, average hop count, throughput and dead nodes respectively. For the impact of simulation rounds case, we observed that the effectiveness of proposed EEC-HO routing protocol is 21.216%, 35.417%, 41.667%, 18.568% and 40.000% efficient than existing protocols in terms of energy consumption, network lifetime, average hop count, throughput and number of dead nodes respectively.

Optimal cluster head selection for energy efficient wireless sensor network using hybrid competitive swarm optimization and harmony search algorithm

A Wireless Sensor Network (WSN) is a network made up of many sensor nodes that are geographically dispersed. Because the sensor nodes in WSN are battery-powered, energy efficiency is a major issue. As a result, it is critical to make effective use of available energy in order to avoid energy waste. The clustering system provides an energy-efficient method of data transfer. The existing clustering scheme utilises distinctive Low-Energy Adaptive Clustering Hierarchy (LEACH) and optimization approaches faces issues like complicated local search, trade off in exploration and exploitation. A combination of the Harmony Search Algorithm (HSA) and the Competitive Swarm Optimization (CSO) is developed for energy efficient selection of cluster head (CH) to provide a global search with quick convergence rate. The proposed method has a high HSA search efficiency and a dynamic CSO capability that extends the life of sensor nodes. The proportion of alive nodes, count of dead nodes, residual energy and throughput are used to measure the hybrid algorithm’s performance. In terms of throughput and residual energy, the suggested hybrid HSA-CSO algorithm surpasses the current methods.