Additional Nodes Research Articles

Continuous gap contact formulation based on the screened Poisson equation

We introduce a PDE-based node-to-element contact formulation as an alternative to classical, purely geometrical formulations. It is challenging to devise solutions to nonsmooth contact problem with continuous gap using finite element discretizations. We herein achieve this objective by constructing an approximate distance function (ADF) to the boundaries of solid objects, and in doing so, also obtain universal uniqueness of contact detection. Unilateral constraints are implemented using a mixed model combining the screened Poisson equation and a force element, which has the topology of a continuum element containing an additional incident node. An ADF is obtained by solving the screened Poisson equation with constant essential boundary conditions and a variable transformation. The ADF does not explicitly depend on the number of objects and a single solution of the partial differential equation for this field uniquely defines the contact conditions for all incident points in the mesh. Having an ADF field to any obstacle circumvents the multiple target surfaces and avoids the specific data structures present in traditional contact-impact algorithms. We also relax the interpretation of the Lagrange multipliers as contact forces, and the Courant–Beltrami function is used with a mixed formulation producing the required differentiable result. We demonstrate the advantages of the new approach in two- and three-dimensional problems that are solved using Newton iterations. Simultaneous constraints for each incident point are considered.

Revival of associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma: An international multicenter study with promising outcomes

BackgroundAssociating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma has been considered to be contraindicated due to the initial poor results. Given the recent reports of improved outcomes, we aimed to collect the recent experiences of different centers performing associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma to analyze factors related to improved outcomes. MethodsThis proof-of-concept study collected contemporary cases of associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma and analyzed for morbidity, short and long-term survival, and factors associated with outcomes. ResultsIn total, 39 patients from 8 centers underwent associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma from 2010 to 2020. The median preoperative future liver remnant volume was 323 mL (155–460 mL). The median future liver remnant increase was 58.7% (8.9% -264.5%) with a median interstage interval of 13 days (6–60 days). Post–stage 1 and post–stage 2 biliary leaks occurred in 2 (7.7%) and 4 (15%) patients. Six patients (23%) after stage 1 and 6 (23%) after stage 2 experienced grade 3 or higher complications. Two patients (7.7%) died within 90 days after stage 2. The 1-, 3-, and 5-year survival was 92%, 69%, and 55%, respectively. A subgroup analysis revealed poor survival for patients undergoing additional vascular resection and lymph node positivity. Lymph node–negative patients showed excellent survival demonstrated by 1-, 3-, and 5-year survival of 86%, 86%, and 86%. ConclusionThis study highlights that the critical attitude toward associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma needs to be revised. In selected patients with perihilar cholangiocarcinoma, associating liver partition and portal vein ligation for staged hepatectomy can achieve favorable survival that compares to the outcome of established surgical treatment strategies reported in benchmark studies for perihilar cholangiocarcinoma including 1-stage hepatectomy and liver transplantation.

Does Stage Migration Occur as a Consequence of Omitting Completion Lymph Node Dissection for Melanoma?

Completion lymph node dissection (CLND) is no longer recommended routinely in the treatment of melanoma. CLND omission may understage patients for whom the distinction between stage IIIA and IIIB-C could alter adjuvant therapy recommendations. The aim of this study is to determine if stage migration has occurred with the declining use of CLND. Patients with clinically node-negative ≥T1b cutaneous melanoma were identified from the National Cancer Database (NCDB) from 2012 to 2018. CLND utilization and changes in AJCC staging were analyzed. Patients undergoing sentinel lymph node biopsy (SLNB) alone were compared with those undergoing SLNB + CLND. Overall, 68,933 patients met inclusion criteria and 60,536 underwent SLNB, of which 9031 (14.9%) were tumor positive. CLND was performed in 3776 (41.8%). Patients undergoing CLND were younger (58 versus 62 years, p < 0.0001) and more likely male (61.5% versus 57.9%, p = 0.0005). Patients were more likely to have an N classification >N1a if they received SLNB + CLND (36.8%) versus SLNB alone (19.3%), p < 0.0001. This translated to a small difference in stage IIIA patients between groups (SLNB alone 34.0%, SLNB + CLND 31.8%, p < 0.0001). Of the patients with T1b/T2a tumors who would be upstaged from IIIA to IIIC with identification of additional positive nodes, IIIC incidence was only slightly higher after SLNB + CLND compared with SLNB alone (4.4% versus 1.1%, p < 0.0001). CLND utilization dramatically decreased from 59% in 2012 to 12.6% in 2018, p < 0.0001. However, the incidence of stage IIIA disease for all patients remained stable over the 7-year study period. While the utilization of CLND after positive SLNB has declined dramatically in the last 7 years, stage migration that may affect adjuvant therapy decisions has not occurred to a clinically meaningful degree.

FE-GAN: Fast and Efficient Underwater Image Enhancement Model Based on Conditional GAN

The processing of underwater images can vastly ease the difficulty of underwater robots’ tasks and promote ocean exploration development. This paper proposes a fast and efficient underwater image enhancement model based on conditional GAN with good generalization ability using aggregation strategies and concatenate operations to take full advantage of the limited hierarchical features. A sequential network can avoid frequently visiting additional nodes, which is beneficial for speeding up inference and reducing memory consumption. Through the structural re-parameterization approach, we design a dual residual block (DRB) and accordingly construct a hierarchical attention encoder (HAE), which can extract sufficient feature and texture information from different levels of an image, and with 11.52% promotion in GFLOPs. Extensive experiments were carried out on real and artificially synthesized benchmark underwater image datasets, and qualitative and quantitative comparisons with state-of-the-art methods were implemented. The results show that our model produces better images, and has good generalization ability and real-time performance, which is more conducive to the practical application of underwater robot tasks.

Lake testbed for mobile acoustic communications and networking

We present a lake testbed that can support mobile acoustic communications and networking research. The primary assets of the testbed are two autonomous underwater vehicles equipped with software-defined acoustic modems. The acoustic modems are integrated with the user-installed autonomy software on the vehicle, MOOS-IvP. Through this integration, vehicle information can be passed to the acoustic modem. Or the acoustic modem can receive remote instructions to modify vehicle missions. With additional stationary nodes, the testbed can support two types of acoustic experiments. First, it supports acoustic waveform transmissions from two synchronized mobile nodes. The acoustic transmissions can be recorded in a multi-element receiving array for offline data processing. Second, the testbed can perform real-time acoustic communication and networking tests for different vehicle trajectories. We will present the testbed instrument and capabilities, field deployments, sample acoustic data, and communication test results. [The research is supported by the national science foundation (NSF).]

Balanced neighbor exploration for semi-supervised node classification on imbalanced graph data

Graph neural networks (GNNs) are powerful models for node classification tasks. When the nodes exhibit a skew distribution, the imbalanced graph data and the message-passing way of GNNs may significantly influence the decision boundary. Existing methods, generating additional nodes and edges or assigning weights of nodes to balance the training scenario, generally have a complicated implementation and a high time complexity. To this end, we propose Balanced Neighbor Exploration (BNE), an algorithm to improve training efficiency and classification performance in a fundamentally different way without generating nodes and computing weights. Intuitively, nodes highly influenced by nodes in one class should have a higher probability of belonging to the class. Inspired by this intuition, BNE incorporates more nodes highly influenced by minority nodes into the minority set to provide a balanced training scenario. The neighbor exploration involves sum and sort operations whose time complexities are O(N) and O(Nlog⁡N), respectively, with a fast operation process. Moreover, BNE conducts the message-passing and neighbor exploration processes simultaneously, with a straightforward implementation. Experiments on real-world imbalanced graph data demonstrate that BNE vastly outperforms the state-of-the-art methods for semi-supervised node classification on imbalanced graph data.

Nonsentinel Axillary Lymph Node Status in Clinically Node-Negative Early Breast Cancer After Primary Systemic Therapy and Positive Sentinel Lymph Node: A Predictive Model Proposal

BackgroundIn clinically node-negative (cN0) early stage breast cancer (EBC) undergoing primary systemic treatment (PST), post-treatment positive sentinel lymph node (SLN+) directs axillary lymph node dissection (ALND), with uncertain impacts on outcomes and increased morbidities.Patients and MethodsWe conducted an observational study on imaging-confirmed cN0 EBC, who underwent PST and breast surgery that resulted in SLN+ and underwent ALND. The association among baseline/postsurgical clinic–pathological factors and positive nonsentinel additional axillary lymph nodes (non-SLN+) was analyzed with logistic regression. LASSO regression (LR) identified variables to include in a predictive score of non-SLN+ (ALND-predict). The accuracy and calibration were assessed, an optimal cut-point was then identified, and in silico validation with bootstrap was undertaken.ResultsNon-SLN+ were detected in 22.2% cases after ALND. Only progesterone receptor (PR) levels and macrometastatic SLN+ were independently associated to non-SLN+. LR identified PR, Ki67, and type and number of SLN+ as the most efficient covariates. The ALND-predict score was built based on their LR coefficients, showing an area under the curve (AUC) of 0.83 and an optimal cut-off of 63, with a negative predictive value (NPV) of 0.925. Continuous and dichotomic scores had a good fit (p = 0.876 and p = 1.00, respectively) and were independently associated to non-SLN+ [adjusted odds ratio (aOR): 1.06, p = 0.002 and aOR: 23.77, p < 0.001, respectively]. After 5000 bootstrap-adjusted retesting, the estimated bias-corrected and accelerated 95%CI included the aOR.ConclusionsIn cN0 EBC with post-PST SLN+, non-SLN+ at ALND are infrequent (~22%) and independently associated to PR levels and macrometastatic SLN. ALND-predict multiparametric score accurately predicted absence of non-SLN involvement, identifying most patients who could be safely spared unnecessary ALND. Prospective validation is required.

18F-DCFPyL PET in first BCR and initial staging: Concordance with conventional imaging.

58 Background: 18F-DCFPyL recently gained FDA approval for the staging of biochemically recurrent prostate cancer (PCa). After 18F-DCFPyL became available at our NCI-Designated Comprehensive Cancer Center, 164 PCa pts underwent imaging by 5/2022. Given its novelty, the clinical utility of 18F-DCFPyL versus conventional imaging (CI) is not well-defined. We evaluated the concordance and treatment impact of 18F-DCFPyL compared to CI in suspected first biochemical recurrence (BCR) and upstaging rates of 18F-DCFPyL in initial staging. Methods: The electronic medical record was queried to identify 18F-DCFPyL scans performed at our center. We selected patients (pts) with PSA recurrence after definitive frontline therapy or those undergoing initial staging. CI was within 3 months of 18F-DCFPyL. Concordance between CI and 18F-DCFPyL was assessed, with probable disease defined through assessments by the radiologist and treating oncologist and the clinical setting. Provider notes were used to capture anticipated treatment plans before and after 18F-DCFPyL. Results: For suspected BCR 30 pts had CI and 6 had two types of CI. The majority (n = 20) were MRIs of the prostate/pelvis. The remainder were nuclear bone scans (n = 4), body CTs (n = 4), 18F-fluciclovine scans (n = 3), FDG-PET (n = 1), and spinal imaging (n = 3). Discordant findings were present for 12/30 patients in shared imaging fields, of which 7 had likely disease captured solely on 18F-DCFPyL, 1 instance of disease missed on 18F-DCFPyL, and 4 instances where findings of uncertain malignant potential on CI were not tracer-avid on 18F-DCFPyL. The missed disease on 18F-DCFPyL was a PIRADS 4 prostate lesion captured on MRI. In this group, 4 cases of pelvic nodal lesions were identified on 18F-DCFPyL and not MRI. 18F-DCFPyL influenced treatment plans in 4/30 cases. Therapy was selected as follows: local salvage radiation (RT) was chosen after rule-out of systemic disease, RT was restricted to the prostate bed after a culprit lesion was found, and observation was chosen (n = 2) after disease was ruled out on PSMA-PET. For initial staging, 15 pts were thought to have prostate-only disease. On 18F-DCFPyL, 3/15 were upstaged to distant metastatic disease and 2/15 were upstaged to pelvic nodal disease. Three pts were thought to have extra-prostatic pelvic disease, of which 1/3 were upstaged to distant metastatic disease on 18F-DCFPyL. Conclusions: In the BCR setting, in which disease is often low volume, 18F-DCFPyL frequently adds valuable guidance. In our cohort 18F-DCFPyL captured additional pelvic nodal disease and helped clarify equivocal imaging, limiting unnecessary treatment. For initial staging, the 33% of pts upstaged is substantial, and further data will show whether subsequent changes in management affect outcomes. Limitations include inability to verify disease histologically and to forecast treatment decisions if PSMA-PET were not available.

Comparison of integrin αvβ3 expression with 68Ga-NODAGA-RGD PET/CT and glucose metabolism with 18F-FDG PET/CT in esophageal or gastroesophageal junction cancers

BackgroundThe primary aims of this study were to compare in patients with esophageal or esophagogastric junction cancers the potential of 68Ga-NODAGA-RGD PET/CT with that of 18F-FDG PET/CT regarding tumoral uptake and distribution, as well as histopathologic examination.MethodsTen 68Ga-NODAGA-RGD and ten 18F-FDG PET/CT were performed in nine prospectively included participants (1 woman; aged 58 ± 8.4 y, range 40–69 y). Maximum SUV (SUVmax) and metabolic tumor volumes (MTV) were calculated. The Mann–Whitney U test and Spearman correlation analysis (ρ) were used.Results68Ga-NODAGA-RGD PET/CT detected positive uptake in 10 primary sites (8 for primary tumors and 2 for local relapse suspicion), 6 lymph nodes and 3 skeletal sites. 18F-FDG PET/CT detected positive uptake in the same sites but also in 16 additional lymph nodes and 1 adrenal gland. On a lesion-based analysis, SUVmax of 18F-FDG was significantly higher than those of 68Ga-NODAGA-RGD (4.9 [3.7–11.3] vs. 3.2 [2.6–4.2] g/mL, p = 0.014). Only one participant showed a higher SUVmax in an osseous metastasis with 68Ga-NODAGA-RGD as compared to 18F-FDG (6.6 vs. 3.9 g/mL). Correlation analysis showed positive correlation between 18F-FDG and 68Ga-NODAGA-RGD PET parameters (ρ = 0.56, p = 0.012 for SUVmax, ρ = 0.78, p < 0.001 for lesion-to-background ratios and ρ = 0.58, p = 0.024 for MTV). We observed that 18F-FDG uptake was homogenous inside all the confirmed primary sites (n = 9). In contrast, 68Ga-NODAGA-RGD PET showed more heterogenous uptake in 6 out of the 9 confirmed primary sites (67%), seen mostly in the periphery of the tumor in 5 out of the 9 confirmed primary sites (56%), and showed slight extensions into perilesional structures in 5 out of the 9 confirmed primary sites (56%).ConclusionsIn conclusion, 68Ga-NODAGA-RGD has lower potential in the detection of esophageal or esophagogastric junction malignancies compared to 18F-FDG. However, the results suggest that PET imaging of integrin αvβ3 expression may provide complementary information and could aid in tumor diversity and delineation.Trial registration: Trial registration: NCT02666547. Registered January 28, 2016—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02666547.

Arousal Regulation by the External Globus Pallidus: A New Node for the Mesocircuit Hypothesis.

In the decade since its debut, the Mesocircuit Hypothesis (MH) has provided researchers a scaffolding for interpreting their findings by associating subcortical-cortical dysfunction with the loss and recovery of consciousness following severe brain injury. Here, we leverage new findings from human and rodent lesions, as well as chemo/optogenetic, tractography, and stimulation studies to propose the external segment of the globus pallidus (GPe) as an additional node in the MH, in hopes of increasing its explanatory power. Specifically, we discuss the anatomical and molecular mechanisms involving the GPe in sleep-wake control and propose a plausible mechanistic model explaining how the GPe can modulate cortical activity through its direct connections with the prefrontal cortex and thalamic reticular nucleus to initiate and maintain sleep. The inclusion of the GPe in the arousal circuitry has implications for understanding a range of phenomena, such as the effects of the adenosine (A2A) and dopamine (D2) receptors on sleep-wake cycles, the paradoxical effects of zolpidem in disorders of consciousness, and sleep disturbances in conditions such as Parkinson's Disease.

An anti-consensus strategy based on continuous perturbation updates in opposite directions

In modern society, multi-agent consensus is applied in many applications such as distributed machine learning, wireless sensor networks and so on. However, some agents might behave abnormally subject to external attack or internal faults, and thus fault-tolerant consensus problem is studied recently, among which Q-consensus is one of the state-of-the-art and effective methods to identify all the faulty agents and achieve consensus for normal agents in general networks. To fight against Q-consensus algorithm, this paper proposes a novel strategy, called split attack, which is simple but capable of breaking consensus convergence. By aggregating all the states of neighboring nodes with an extra perturbation, the normal nodes are split into sub-groups and converge to two separate values, so that consensus is broken. Two scenarios, including the introduction of additional faulty nodes and compromise of the original nodes, are considered. More specifically, in the former case, two additional faulty nodes are adopted, each of which is responsible to mislead parts of the normal nodes. While in the latter one, two original normal nodes are compromised to mislead the whole system. Moreover, the compromised nodes selection is fundamentally a classification problem, and thus optimized through CNN. Finally, the numerical simulations are provided to verify the proposed schemes and indicate that the proposed method outperforms other attack methods.

Measurement of extracapsular extension in sentinel lymph node as a possible predictor of residual axillary disease in breast cancer

BackgroundThe presence of Extracapsular Extension (ECE) in the Sentinel Lymph Node Biopsy (SLNB) is still a doubt in the literature. Some studies suggest that the presence of ECE may be related to a greater number of positive axillary lymph nodes which could impact Disease Free Survival (DFS) and Overall Survival (OS). This study searches for the clinical significance of the ECE. MethodsRetrospective cohort comparing the presence or absence of ECE in T1-2 invasive breast cancer with positive SLNB. All cases treated surgically at the Cancer Institute of the State of São Paulo (ICESP) between 2009 and 2013 were analyzed. All patients with axillary disease in SLNB underwent AD. OutcomesIdentify the association between the presence and length of ECE and additional axillary positive lymph nodes, OS and DFS between both groups. Results128 patients with positive SLNB were included, and 65 had ECE. The mean metastasis size of 0.62 (SD = 0.59) mm at SLNB was related to the presence of ECE (p < 0.008). The presence of ECE was related to a higher mean of positive sentinel lymph nodes, 3.9 (± 4.8) vs. 2.0 (± 2.1), p = 0.001. The median length of follow-up was 115 months. The OS and DFS rates had no differences between the groups. ConclusionThe presence of ECE was associated with additional positive axillary lymph nodes in this study. Therefore, the OS and DFS were similar in both groups after 10 years of follow-up. It is necessary for additional studies to define the importance of AD when SLNB with ECE.

Federated Learning Using Three-Operator ADMM

Federated learning (FL) has emerged as an instance of distributed machine learning paradigm that avoids the transmission of data generated on the users' side. Although data are not transmitted, edge devices have to deal with limited communication bandwidths, data heterogeneity, and straggler effects due to the limited computational resources of users' devices. A prominent approach to overcome such difficulties is FedADMM, which is based on the classical two-operator consensus alternating direction method of multipliers (ADMM). The common assumption of FL algorithms, including FedADMM, is that they learn a global model using data only on the users' side and not on the edge server. However, in edge learning, the server is expected to be near the base station and have direct access to rich datasets. In this paper, we argue that leveraging the rich data on the edge server is much more beneficial than utilizing only user datasets. Specifically, we show that the mere application of FL with an additional virtual user node representing the data on the edge server is inefficient. We propose FedTOP-ADMM, which generalizes FedADMM and is based on a three-operator ADMM-type technique that exploits a smooth cost function on the edge server to learn a global model parallel to the edge devices. Our numerical experiments indicate that FedTOP-ADMM has substantial gain up to 33\% in communication efficiency to reach a desired test accuracy with respect to FedADMM, including a virtual user on the edge server.

Priority based [formula omitted]-coverage hole restoration and [formula omitted]-connectivity using whale optimization scheme for underwater wireless sensor networks

Coverage hole restoration and connectivity is a typical problem for underwater wireless sensor networks. In underwater applications like underwater oilfield reservoirs, undersea minerals and monitoring etc., where nodes face many hurdles and are unable to cover the required region during a natural disaster such as tsunami, flood, earthquakes, and environmental interference. It creates a coverage hole and consumes high energy with bad network quality. This problem considered as an NP-complete problem where a set of sensor nodes is required to identify the k-coverage hole and m-connectivity. In the literature, researchers have not focused on k-coverage hole restoration and m-connectivity issues during natural disasters and environmental interference. To mitigate this problem, we proposed priority-based coverage hole restoration and -connection using a whale optimization scheme to restore coverage holes and extract relevant information for the construction of undersea oilfield reservoirs, minerals, and mines. In this scheme, we identified the list of k-coverage holes and addressed autonomous underwater vehicles (AUVs) to place the additional mobile nodes in an appropriate coverage hole. A novel multi-objective function is formulated to obtain the optimal path for AUVs. Furthermore, while restoring coverage holes, we checked the connectivity of nodes. In the network, each node coordinated sleep scheduling with neighbor nodes to maintain energy efficiency. Performance evaluation of the proposed scheme shows better results than the existing schemes under different network scenarios which provide maximum coverage and connectivity, less energy consumption with a high convergence rate.

Feasibility of seismic wave communication using electromagnetic vibrator under strong environmental noise interference: Field experimental research.

Although various wired or wireless communication facilities play a significant role in underground mine production monitoring and disaster warning, some communication nodes will be damaged when an accident occurs, resulting in unreliable emergency communications. Due to the excellent transmission characteristics of seismic waves in the earth channel, there is no need for the seismic wave communication system to set up relay nodes. Since seismic waves are not easily disturbed by the external environment, they can be used as a new type of emergency communication carrier to realize information transmission. However, under strong background noise interference in a real environment, the feasibility of seismic wave communication using an electromagnetic vibrator is not yet known. Therefore, a field experiment research on electromagnetic vibrator seismic wave communication was conducted. First, the model of electromagnetic vibrator seismic wave communication was established. In addition, the on-off keying modulation method, the cross-correlation segment threshold demodulation method, and the noise suppression method based on the time-frequency characteristics of the carrier were introduced. Finally, an electromagnetic vibrator seismic wave communication system was built, and binary data communication up to 72m without deploying additional relay nodes was achieved successfully. The experimental results illustrate the feasibility of the electromagnetic vibrator seismic wave communication under strong background noise interference in a real environment. Furthermore, combined with the characteristics of the seismic wave, the time-frequency slice filtering can significantly improve the signal-to-noise ratio of the seismic wave and can further increase the communication distance with respect to the traditional methods.

Leveraging Commonsense for Object Localisation in Partial Scenes.

We propose an end-to-end solution to address the problem of object localisation in partial scenes, where we aim to estimate the position of an object in an unknown area given only a partial 3D scan of the scene. We propose a novel scene representation to facilitate the geometric reasoning, Directed Spatial Commonsense Graph (D-SCG), a spatial scene graph that is enriched with additional concept nodes from a commonsense knowledge base. Specifically, the nodes of D-SCG represent the scene objects and the edges are their relative positions. Each object node is then connected via different commonsense relationships to a set of concept nodes. With the proposed graph-based scene representation, we estimate the unknown position of the target object using a Graph Neural Network that implements a sparse attentional message passing mechanism. The network first predicts the relative positions between the target object and each visible object by learning a rich representation of the objects via aggregating both the object nodes and the concept nodes in D-SCG. These relative positions then are merged to obtain the final position. We evaluate our method using Partial ScanNet, improving the state-of-the-art by 5.9% in terms of the localisation accuracy at a 8x faster training speed.

Взаимодействие залпа атакующих дронов и залпа зенитных дронов как компьютерная антагонистическая неньютоновская 2D-игра

The paper considers problem of the attacking drone avoiding interception at the final stage of its flight. Duration of this stage is a few seconds. Drones are flying to the target, explode and die. The literature traditionally considers the attack and the anti-aircraft drones independently. It is proposed to identify the attacking and the anti-aircraft drones as a single oscillatory system with the antagonistic components. Antagonistic components are connected using the non-Newtonian elastic element. Test game with a high-explosive drone, test game with a fragmentation drone and 2D salvo game were considered. The game in this case is not a traditional minimax optimization problem, but appears to be simulation of the compromise unstable motion mode. Salvo of three attack drones in the 2D games is aimed against three stationary targets. Anti-aircraft salvo includes two high-explosive and two fragmentation drones. The attacking drones “know nothing” about the anti-aircraft target distribution; thus, each of them “avoids” the anti-aircraft drones simultaneously. One operator is playing. Therefore, the game has only two parameters, i.e. two different stiffness coefficients of any non-Newtonian elastic element. The non-Newtonian oscillatory system under study is non-oscillatory. There are violations of the well-known oscillation theorems of the oscillations theory: with the increasing rigidity, the system oscillation frequency drops, the oscillation forms acquire additional nodes, etc.

Computing Connected Resolvability of Graphs Using Binary Enhanced Harris Hawks Optimization

In this paper, we consider the NP-hard problem of finding the minimum connected resolving set of graphs. A vertex set B of a connected graph G resolves G if every vertex of G is uniquely identified by its vector of distances to the vertices in B. A resolving set B of G is connected if the subgraph induced by B is a nontrivial connected subgraph of G. The cardinality of the minimal resolving set is the metric dimension of G and the cardinality of minimum connected resolving set is the connected metric dimension of G. The problem is solved heuristically by a binary version of an enhanced Harris Hawk Optimization (BEHHO) algorithm. This is the first attempt to determine the connected resolving set heuristically. BEHHO combines classical HHO with opposition-based learning, chaotic local search and is equipped with an S-shaped transfer function to convert the continuous variable into a binary one. The hawks of BEHHO are binary encoded and are used to represent which one of the vertices of a graph belongs to the connected resolving set. The feasibility is enforced by repairing hawks such that an additional node selected from V\B is added to B up to obtain the connected resolving set. The proposed BEHHO algorithm is compared to binary Harris Hawk Optimization (BHHO), binary opposition-based learning Harris Hawk Optimization (BOHHO), binary chaotic local search Harris Hawk Optimization (BCHHO) algorithms. Computational results confirm the superiority of the BEHHO for determining connected metric dimension.

MELANOME ACRAL: DU DIAGNOSTIC AU TRAITEMENT

Acro-lentiginous melanoma, a pigmented lesion of the extremities, especially the palms and soles, is defined by a malignant tumor proliferation with high metastatic potential, which develops at the expense of melanocytes. Its incidence is constantly increasing and varies according to country and ethnicity. Its diagnosis is primarily histopathological, and its management remains multidisciplinary, where surgery and the plastic surgeon occupy a very important place. Our study consists of a retrospective descriptive study of 25 cases of acro-lentiginous melanoma. The average age of our patients is 60 years, with a male predominance. Plantar localization is predominant. All patients underwent extension workup and management consisted of surgical resection with safety margins followed by additional lymph node dissection and coverage of the resulting tissue loss. Through this study, we highlight the aggressive nature of acro-lentiginous melanoma as well as the importance of protocolized management of these melanomas.

Standard pancreatoduodenectomy versus extended pancreatoduodenectomy with modified retroperitoneal nerve resection in patients with pancreatic head cancer: a multicenter randomized controlled trial.

The extent of pancreatoduodenectomy for pancreatic head cancer remains controversial, and more high-level clinical evidence is needed. This study aimed to evaluate the outcome of extended pancreatoduodenectomy (EPD) with retroperitoneal nerve resection in pancreatic head cancer. This multicenter randomized trial was performed at 6 Chinese high-volume hospitals that enrolled patients between October 3, 2012, and September 21, 2017. Four hundred patients with stage I or II pancreatic head cancer and without specific pancreatic cancer treatments (preoperative chemotherapy or chemoradiation) within three months were randomly assigned to undergo standard pancreatoduodenectomy (SPD) or EPD, with the latter followed by dissection of additional lymph nodes (LNs), nerves and soft tissues 270° on the right side surrounding the superior mesenteric artery and celiac axis. The primary endpoint was overall survival (OS) by intention-to-treat (ITT). The secondary endpoints were disease-free survival (DFS), mortality, morbidity, and postoperative pain intensity. The R1 rate was slightly lower with EPD (8.46%) than with SPD (12.56%). The morbidity and mortality rates were similar between the two groups. The median OS was similar in the EPD and SPD groups by ITT in the whole study cohort (23.0 vs. 20.2 months, P = 0.100), while the median DFS was superior in the EPD group (16.1 vs. 13.2 months, P = 0.031). Patients with preoperative CA19-9 < 200.0 U/mL had significantly improved OS and DFS with EPD (EPD vs. SPD, 30.8 vs. 20.9 months, P = 0.009; 23.4 vs. 13.5 months, P < 0.001). The EPD group exhibited significantly lower locoregional (16.48% vs. 35.20%, P < 0.001) and mesenteric LN recurrence rates (3.98% vs. 10.06%, P = 0.022). The EPD group exhibited less back pain 6 months postoperation than the SPD group. EPD for pancreatic head cancer did not significantly improve OS, but patients with EPD treatment had significantly improved DFS. In the subgroup analysis, improvements in both OS and DFS in the EPD arm were observed in patients with preoperative CA19-9 < 200.0 U/mL. EPD could be used as an effective surgical procedure for patients with pancreatic head cancer, especially those with preoperative CA19-9 < 200.0 U/mL.