Node Chain Research Articles

Toxicity and efficacy of salvage carbon 11-choline positron emission tomography/computed tomography-guided radiation therapy in patients with lymph node recurrence of prostate cancer.

To report the 3-year toxicity and outcomes of carbon 11 (11C)-choline-positron emission tomography (PET)/computed tomography (CT)-guided radiotherapy (RT), delivered via helical tomotherapy (HTT; Tomotherapy® Hi-Art II® Treatment System, Accuray Inc., Sunnyvale, CA, USA) after lymph node (LN) relapses in patients with prostate cancer. From January 2005 to March 2013, 81 patients with biochemical recurrence after surgery, with or without adjuvant/salvage RT or radical RT, and with evidence of LN 11C-choline-PET/CT pathological uptake, underwent HTT (median [range] prostate-specific antigen level 2.59 [0.61-187] ng/mL). Of the 81 patients, 72 were treated at the pelvic and/or lumbar-aortic LN chain with HTT at 51.8 Gy/28 fr and with simultaneous integrated boost to a median dose of 65.5 Gy on the pathological uptake sites detected by 11C-choline-PET/CT. Nine patients were treated without simultaneous integrated boost (50-65.5 Gy, 25-30 fr). With a median (range) follow-up of 36 (9-116) months, 91.4% of the patients had a PSA reduction 3 months after HTT. The 3-year overall, local relapse-free and clinical relapse-free survival rates were 80.0, 89.8 and 61.8%, respectively. The 3-year actuarial incidences of ≥grade 2 rectal and ≥grade 2 genitourinary toxicity were 6.6% (±2.9%) and 26.3% (±5.5%), respectively. A PSA nadir of ≥0.26 ng/mL (hazard ratio [HR] 3.6, 95% confidence interval [CI] 1.7-7.7; P = 0.001), extrapelvic 11C-choline-PET/CT-positive LN location (HR 2.4, 95% CI 0.9-6.4; P = 0.07), RT previous to HTT (HR 2.7; 95% CI 1.07-6.9, P = 0.04) and number of positive LNs (HR 1.13, 95% CI 1.04-1.22; P = 0.003) were the main predictors of clinical relapse after HTT. 11C-choline-PET/CT-guided HTT is safe and effective in the treatment of LN relapses of prostate cancer in previously treated patients.

Linear-size suffix tries

Suffix trees are highly regarded data structures for text indexing and string algorithms [MCreight 76, Weiner 73]. For any given string w of length n=|w|, a suffix tree for w takes O(n) nodes and links. It is often presented as a compacted version of a suffix trie for w, where the latter is the trie (or digital search tree) built on the suffixes of w. Here the compaction process replaces each maximal chain of unary nodes with a single arc. For this, the suffix tree requires that the labels of its arcs are substrings encoded as pointers to w (or equivalent information). On the contrary, the arcs of the suffix trie are labeled by single symbols but there can be Θ(n2) nodes and links for suffix tries in the worst case because of their unary nodes. It is an interesting question if the suffix trie can be stored using O(n) nodes. We present the linear-size suffix trie, which guarantees O(n) nodes. We use a new technique for reducing the number of unary nodes to O(n), that stems from some results on antidictionaries. For instance, by using the linear-size suffix trie, we are able to check whether a pattern p of length m=|p| occurs in w in O(mlog⁡|Σ|) time and we can find the longest common substring of two strings w1 and w2 in O((|w1|+|w2|)log⁡|Σ|) time for an alphabet Σ.

Weighing Efficiency-Robustness in Supply Chain Disruption by Multi-Objective Firefly Algorithm

This paper investigates various supply chain disruptions in terms of scenario planning, including node disruption and chain disruption; namely, disruptions in distribution centers and disruptions between manufacturing centers and distribution centers. Meanwhile, it also focuses on the simultaneous disruption on one node or a number of nodes, simultaneous disruption in one chain or a number of chains and the corresponding mathematical models and exemplification in relation to numerous manufacturing centers and diverse products. Robustness of the design of the supply chain network is examined by weighing efficiency against robustness during supply chain disruptions. Efficiency is represented by operating cost; robustness is indicated by the expected disruption cost and the weighing issue is calculated by the multi-objective firefly algorithm for consistency in the results. It has been shown that the total cost achieved by the optimal target function is lower than that at the most effective time of supply chains. In other words, the decrease of expected disruption cost by improving robustness in supply chains is greater than the increase of operating cost by reducing efficiency, thus leading to cost advantage. Consequently, by approximating the Pareto Front Chart of weighing between efficiency and robustness, enterprises can choose appropriate efficiency and robustness for their longer-term development.

Actin Automata with Memory

Actin is a globular protein which forms long polar filaments in eukaryotic. The actin filaments play the roles of cytoskeleton, motility units, information processing and learning. We model actin filament as a double chain of finite state machines, nodes, which take states “0” and “1”. The states are abstractions of absence and presence of a subthreshold charge on actin units corresponding to the nodes. All nodes update their state in parallel to discrete time. A node updates its current state depending on states of two closest neighbors in the node chain and two closest neighbors in the complementary chain. Previous models of actin automata consider momentary state transitions of nodes. We enrich the actin automata model by assuming that states of nodes depend not only on the current states of neighboring node but also on their past states. Thus, we assess the effect of memory of past states on the dynamics of acting automata. We demonstrate in computational experiments that memory slows down propagation of perturbations, decrease entropy of space-time patterns generated, transforms traveling localizations to stationary oscillators, and stationary oscillations to still patterns.

A Case Study in Low-Complexity ECG Signal Encoding: How Compressing is Compressed Sensing?

When transmission or storage costs are an issue, lossy data compression enters the processing chain of resource-constrained sensor nodes. However, their limited computational power imposes the use of encoding strategies based on a small number of digital computations. In this case study, we propose the use of an embodiment of compressed sensing as a lossy digital signal compression, whose encoding stage only requires a number of fixed-point accumulations that is linear in the dimension of the encoded signal. We support this design with some evidence that for the task of compressing ECG signals, the simplicity of this scheme is well-balanced by its achieved code rates when its performances are compared against those of conventional signal compression techniques.

Fast and robust self-organization for micro-electro-mechanical robotic systems

Microrobots are low-power and low-capacity memory devices that can sense and act. They perform various missions and tasks in a wide range of applications including odor localization, firefighting, medical service, surveillance and security, search and rescue. To achieve these tasks nodes should reconfigure their physical topology to another target organization. The self-organization is one of the most challenging tasks in MEMS applications. In this paper, we propose a distributed and efficient parallel self-organization protocol for chains of MEMS nodes. This protocol is memory-efficient because it does not use the predefined positions of the target shape, which reduces the memory usage to a constant complexity. Our algorithm is implemented in a real environment simulator called DPRSim, the Dynamic Physical Rendering Simulator.

Microscopic derivation of open quantum walks

Open quantum walks (OQWs) are exclusively driven by dissipation and are formulated as completely positive trace-preserving (CPTP) maps on underlying graphs. The microscopic derivation of discrete and continuous-in-time OQWs is presented. It is assumed that connected nodes are weakly interacting via a common bath. The resulting reduced master equation of the quantum walker on the lattice is in the generalized master equation form. The time discretization of the generalized master equation leads to the OQW formalism. The explicit form of the transition operators establishes a connection between dynamical properties of the OQWs and thermodynamical characteristics of the environment. The derivation is demonstrated for the examples of the OQW on a circle of nodes and on a finite chain of nodes. For both examples, a transition between diffusive and ballistic quantum trajectories is observed and found to be related to the temperature of the bath.

Analysis of dynamic path loss based on the RSSI model for rupture location analysis in underground wireless sensor networks and its implications for Earthquake Early Warning System (EEWS)

Sensors deployed in underground tunnels found that radio frequency signals suffer significant signal strength attenuation which can result in considerable variation of link quality on the receiving end. This study analyzes the received signal strength index (RSSI) based on the development of a theoretical wireless sensor model for data collection by enabling sensors to determine the location from which each data packet is obtained. To improve positioning accuracy, the complex radio wave propagation environment requires the use of a voronoi cell to minimize signal attenuation. A relatively simple calculation is used to predict the intensity and perception range of the received wireless signals to measure the extent of signal reduction in the attenuating rock medium. Simulation results show that RSSI-based localization and wireless network lifetime and throughput measurements are more accurate when the node concept is applied to the self-locating rupture zones than the maximum likelihood estimation method. The proposed minimum energy relay routing technique based on beacon node chain deployment is found to help correct localization errors resulting from interference caused by the underground tunnel environment. The extent of localization and power of the sensor nodes are determined based on the beacon node chain deployment of tunnel wireless sensor networks. The algorithm accounts for the distance and the corresponding RSSI between adjacent beacon nodes to calculate the actual path loss parameter in the tunnel. The proposed model can serve as the theoretical basis for locating ruptures in underground wireless sensor network nodes, thus maximizing the monitoring range of large scale tectonic environments while minimizing equipment cost. We recommend that this model can be field tested through a series of experiments by researchers and engineers working in seismology, telecommunication, and information technology.

SU‐E‐T‐73: A Robust Proton Beam Therapy Technique for High‐Risk Prostate Cancer Whole Pelvis Irradiation: Bilateral Opposed Single Field Uniform Dose (SFUD) Plan with Lateral Penumbra Gradient Matching

Purpose:To develop a clinical feasible and robust proton therapy technique to spare bowel, bladder and rectum for high‐risk prostate cancer patientsMethods:The study includes 3 high‐risk prostate cancer cases treated with bilateral opposed SFUD with lateral penumbra gradient matching technique prescribed to 5400cGyE in 30 fx in our institution. To treat whole pelvic lymph node chain, the complicated ‘H’ shape, using SFUD technique, we divided the target into two sub‐targets (LLAT beam treating ‘90 degree T‐shape’ and RLAT beam treating ‘: shape’) in Plan A and use lateral penumbra gradient matching at patient's left side. Vice verse in Plan B. Each plan deliver half of the prescription dose. Beam‐specific PTVs were created to take range uncertainty and setup error into account. For daily treatment, patient received four fields from both plan A and B per day. Robustness evaluation were performed in the worst case scenario with 3.5% range uncertainty and 1, 2, 3mm overlap or gap between LLAT and RLAT field matching in Raystation 4.0. All of cases also have a Tomotherapy backup plan approved by physician as a dosimetric comparison.Results:The total treatment time take 15–20mins including IGRT and four fields delivery on ProteusONE, a compact size PBS proton system, compared to 25–30min in traditional Tomotherapy. Robustness analysis shows that this plan technique is insensitive to the range uncertainties. With the lateral gradient matching, 1, 2, 3mm overlap renders only 2.5%, 5.5% and 8% hot or cool spot in the junction areas. Dosimetric comparisons with Tomotherapy show a significant dose reduction in bladder D50%(14.7±9.3Gy), D35%(7.3±5.8Gy); small bowel and rectum average dose(19.6±7.5Gy and 14.5±6.3Gy respectively).Conclusion:The bilateral opposed(SFUD) plan with lateral penumbra gradient matching has been approved to be a safe, robust and efficient treatment option for whole pelvis high‐risk prostate cancer patient which significantly spares the OARs.

Incidental radiation to uninvolved internal mammary lymph nodes in breast cancer.

Routine treatment of clinically uninvolved internal mammary nodes in breast cancer patients requiring post-mastectomy radiation therapy is controversial. The purpose of this study was to measure the incidental radiation dose to the internal mammary lymph nodes not included in the planning target volume (PTV) in women with breast cancer receiving post-mastectomy radiation therapy. This retrospective protocol utilized CT-based 3D conformal treatment plans. Fifty consecutive patients were included in the analysis: 25 left breast and 25 right breast patients. 3D conformal treatment plans chest wall tangent fields and matched supraclavicular were used. All plans were prescribed to a total dose of 50 Gy in 25 fractions to the chest wall and 46 Gy in 23 fractions to the supraclavicular field. The internal mammary node chain was intentionally not included in the target volume. For purposes of this study, internal mammary vessels were contoured following the Radiation Therapy Oncologist Group atlas with a 7-mm PTV expansion, utilizing original CT simulation images. The internal mammary nodes were contoured in between the first 3 and first 5 intercostal spaces for comparison. Percent volume of internal mammary node PTV receiving 95 % of the prescribed dose (47.5 Gy) with 7-mm expansion and first 5 intercostal spaces for all patients was 25.2 % (range 0.04-97.6 %, standard deviation (SD) 23.5). The mean internal mammary node dose for all patients was 24.98 Gy (range 3.54-55.93 Gy, SD 16). Results of this study suggest the incidental dose to the internal mammary nodes does not achieve clinically significant therapeutic levels in post-mastectomy breast cancer patients treated with standard 3D conformal radiation therapy chest wall irradiation. If risk factors for microscopic involvement are present, internal mammary nodes must be specifically included in target volumes in order to be adequately treated.

Developing and evaluating computational models of musical style

AbstractStylistic composition is a creative musical activity, in which students as well as renowned composers write according to the style of another composer or period. We describe and evaluate two computational models of stylistic composition, called Racchman-Oct2010 (random constrained chain of Markovian nodes, October 2010) and Racchmaninof-Oct2010 (Racchman with inheritance of form). The former is a constrained Markov model, and the latter embeds this model in an analogy-based design system. Racchmaninof-Oct2010 applies a pattern discovery algorithm called SIACT and a perceptually validated formula for rating pattern importance, to guide the generation of a new target design from an existing source design. A listening study is reported concerning human judgments of music excerpts that are, to varying degrees, in the style of mazurkas by Frédéric Chopin (1810–1849). The listening study acts as an evaluation of the two computational models and a third, benchmark system, called Experiments in Musical Intelligence. Judges' responses indicate that some aspects of musical style, such as phrasing and rhythm, are being modeled effectively by our algorithms. Judgments are also used to identify areas for future improvements. We discuss the broader implications of this work for the fields of engineering and design, where there is potential to make use of our models of hierarchical repetitive structure.

Response of CHOP therapy in the treatment of Non-Hodgkin’s Lymphoma - one year study in CMH, Dhaka

Introduction: The lymphoma’s are a group of malignant disease that originate from uninhibited growth of cellular elements normally found in lymphatic tissue. All forms of lymphoma have the potential to spread from their origin in a single node or chain of nodes to other nodes and eventually to disseminate to spleen, liver and bone marrow. Objective: To assess the response rate and to evaluate the toxicity and safety of CHOP regimen. Methods: In this study 50 cases were selected of all age irrespectively and both sexes diagnosed at Combined Military Hospital, Dhaka. A prescribed proforma was used for each patient. It included particulars of the patient, history, physical findings, laboratory investigations (biopsy, cytology, and bone marrow study), ultrasonography and CT-scan in appropriate cases. Results: In this study, starting from July 2009 to June 2010, 50 patients were included. Out of them, 30 patients (60.00%) achieved complete remission, 12 patients (24.00%) had partial remission. Overall responses were 84 percent and 8 patients (16.00%) were non-responder. Two patients (4%) of non-responder died during chemotherapy. Conclusion: In this study a significant number of patients achieved complete and partial remission. The response was rapid and most of the patients achieved complete or partial remission after receiving only 2-3 cycles of therapy. Considering the toxicities, the patients were well-tolerated to CHOP regimen. DOI: http://dx.doi.org/10.3329/jafmc.v10i1.22932 Journal of Armed Forces Medical College Bangladesh Vol.10(1) 2014

Dosimetric impact to organs at risk when the internal mammary node chain is included in irradiation of left breast

Dosimetric impact to organs at risk when the internal mammary node chain is included in irradiation of left breast

PO-1106 Dosimetric impact to organs at risk when the internal mammary node chain is included in irradiation of left breast

PO-1106 Dosimetric impact to organs at risk when the internal mammary node chain is included in irradiation of left breast

Chain-based communication in cylindrical underwater wireless sensor networks.

Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs). Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS) and Congestion adjusted PEGASIS (C-PEGASIS). Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate.

Comparison of Lymphedema Incidence Between 2 Lymphadenectomy Techniques in Patients With Uterine Cancer Undergoing Robotic Staging

This study aimed to compare the incidence of lower extremity lymphedema in patients with uterine cancer after robotic staging using the following 2 methods: standard and selective pelvic lymphadenectomy. Three hundred forty-four consecutive patients who presented with endometrial cancer from March 2007 to October 2012 underwent robotic staging. Surgeon A performed standard pelvic lymphadenectomy and surgeon B performed selective lymphadenectomy. Selective pelvic lymphadenectomy spared the lateral chain of the external iliac lymph nodes (LNs). The incidence of lymphedema and staging adequacy between the 2 groups were analyzed. Standard pelvic lymphadenectomy was performed in 238/344 (69.2%) patients and selective pelvic lymphadenectomy was performed in 106/344 (30.8%) patients. Conversion to laparotomy occurred in 2/344 cases (0.6%). Mean age for 344 patients was 63.6 (10) years and body mass index was 34.8 (10.1) kg/m(2). The mean operative time was 162.3 (54.6) minutes. Postoperative hospitalization was 1.62 (1.93) days. Histology included 80.8% endometrioid adenocarcinomas and 19.2% clear cell, serous, and carcinosarcomas. Mean pelvic LN counts for the standard and selective pelvic lymphadenectomy groups were 16 (8.6) and 15.5 (7.1), respectively (P = 0.31). Mean numbers of para-aortic LNs retrieved for the standard and selective lymphadenectomy groups were 3.1 (4.1) and 4.9 (4.5), respectively (P < 0.01).Median follow-up was 29.3 months (interquartile range, 15.6-43.1 months). The difference in the incidence of lower extremity lymphedema was statistically significant: 4.6% (11/238 patients) in the standard lymphadenectomy group versus 0.9% (1/106 patients) in the selective lymphadenectomy group (P = 0.03). When compared to the standard technique, selective pelvic lymphadenectomy with sparing of the lateral chain of the external iliac LNs is adequate and results in a lower incidence of lower extremity lymphedema.

Sentinel lymph node biopsy in breast cancer: a work in progress.

The sentinel lymph node biopsy is a safe, accurate operation for the initial staging of breast cancer. Over the last decade, there has been increasing literature supporting its use, and it is now considered a standard of care for the initial evaluation of metastatic spread to the axillary lymph node chain.

Cancer épidermoïde de la trachée : imagerie de l’atteinte ganglionnaire

The anatomy of the trachea lymphatics is poorly understood and the only researches date back to more than one century. Tracheal tumors are very rare, miscellaneous and variously lymphophilic. The cancers of the trachea have no TNM and their lymph node metastases are little studied despite their poor prognosis. We observed 2 cases of squamous cell carcinoma, one in the cervical and the other in the intrathoracic trachea. TDM-3D reformats demonstrated metastatic lymph nodes of the right para-tracheal lymph node chain (2R and 4R) in both patients and in the cervical lymph nodes (right recurrent nerve lymph node chain) in the patient with cervical tumor. Right location of the mediastinal metastases may be explained by the anatomy of the lymph node chain drainage of the lung segments, the right para-tracheal chain being the only one to regularly possess lymph nodes at that level. The right recurrent nerve lymph node metastases of the cervical tumor are explained by common lymph drainage of the cervical trachea towards larynx lymph centres. Besides lymph node metastases, cancers prognosis may also depends on its location in the trachea. Thus, the tracheal tumors are complex and constitute quite as many orphan tumors. Multicentric studies are mandatory to better understand their behavior. Means provided by new imaging techniques might permit establishing a veritable TNM lymph node mapping of these tumors.

Uterine lymphangiography: comparison of two methods for locating the medial iliac lymph node

Different methods for lymphatic mapping in dogs, such as infusing tissues with vital dyes or radioactive substances, have been studied, aiming at the early detection of lymph node metastasis. Thus, one could anticipate therapeutic measures and, consequently, prolong the survival and improve the quality of life of the patients. The objectives of this experiment were to locate the nodes responsible for draining the uterine body and horns and to try to establish the relationship between the uterus and the medial iliac lymph nodes to contribute to the early diagnosis and prognosis of uterine disorders. We studied 15 female dogs divided into two groups (5 dead and 10 intraoperative ovariohysterectomy bitches). The dye used was patent blue V (Patent Bleu V®). It was observed that the iliac lymph node chain receives much of the uterine (horns) drainage. This method should be considered for safer studies of uterine sanity. This information suggests that evaluating these lymph nodes will allow correlating changes in their physiological status with uterine pathologies.

A General Approach for Minimizing the Maximum Interference of a Wireless Ad-Hoc Network in Plane

The interference reduction is one of the most important problems in the field of wireless sensor networks. Wireless sensor network elements are small mobile receiver and transmitters. The energy of processor and other components of each device is supplied by a small battery with restricted energy. One of the meanings that play an important role in energy consumption is the interference of signals. The interference of messages through a wireless network, results in message failing and transmitter should resend its message, thus the interference directly affect on the energy consumption of transmitter. This paper presents an algorithm which suggests the best subgraph for the input distribution of the nodes in the plane how the maximum interference of the proposed graph has the minimum value. The input of the application is the complete network graph, which means we know the cost of each link in the network graph. Without any lose of generality the Euclidean distance could be used as the weight of each link. The links are arranged and ranked according to their weights, in an iterative process the link which imposition minimum increase on the network interference with some extra conditions which is proposed in future sections, is added to resulting topology and is eliminated from list until all nodes are connected together. Experimental results show the efficiency of proposed algorithm not only for one dimensional known distribution like exponential node chain, but also for two dimensional distributions like two Exponential node chains and alpha-Spiral node chains.