Properties of the Vascular Networks in Malignant Tumors

This work presents an analysis for real and synthetic angiogenic networks using a tomography image that obtains a portrait of a vascular network. After the image conversion into a binary format it is possible to measure various network properties, which includes the average path length, the clustering coefficient, the degree distribution and the fractal dimension. When comparing the observed properties with that produced by the Invasion Percolation algorithm (IPA), we observe that there exist differences between the properties obtained by the real and the synthetic networks produced by the IPA algorithm. Taking into account the former, a new algorithm which models the expansion of an angiogenic network through randomly heuristic rules is proposed. When comparing this new algorithm with the real networks it is observed that now both share some properties. Once creating synthetic networks, we prove the robustness of the network by subjecting the original angiogenic and the synthetic networks to the removal of the most connected nodes, and see to what extent the properties changed. Using this concept of robustness, in a very naive fashion it is possible to launch a hypothetical proposal for a therapeutic treatment based on the robustness of the network.

Download Full-text

ANALYTICAL INDICATOR. ANALYSIS OF THE REAL STATE OF DYNAMICS OF MORTALITY OF THE POPULATION OF RUSSIA FROM MALIGNANT TUMORS AND CHANGES IN ITS STRUCTURE

Problems in oncology ◽

10.37469/0507-3758-2019-65-2-205-219 ◽

2019 ◽

Vol 65 (2) ◽

pp. 205-219 ◽

Cited By ~ 1

Author(s):

V. Merabishvili

Keyword(s):

Malignant Tumors ◽

Specific Weight ◽

Mortality Rates ◽

Retirement Age ◽

Medium Term ◽

Age Composition ◽

The Real ◽

Indicator Analysis ◽

The Difference ◽

Real State

The mortality rate is one of the most important criteria for assessing the health of the population. However, it is important to use analytical indicators correctly, especially when evaluating time series. The value of the “gross” mortality is closely linked with a specific weight of persons of elderly and senile ages. All international publications (WHO, IARC, territorial cancer registers) assess the dynamics of morbidity and mortality only by standardized indicators that eliminate the difference in the age composition of the compared population groups. In Russia, from 1960 to 2017, the share of people of retirement age has increased more than 2 times. The structure of mortality from malignant tumors has changed dramatically. The paper presents the dynamics of gross and standardized mortality rates from malignant tumors in Russia and in all administrative territories. Shows the real success of the Oncology service. The medium-term interval forecast until 2025 has been calculated.

Download Full-text

Appendiceal cancer leading to intussusception detected incidentally during follow-up for Peutz–Jeghers syndrome

Clinical Journal of Gastroenterology ◽

10.1007/s12328-020-01200-w ◽

2020 ◽

Vol 13 (6) ◽

pp. 1136-1143

Author(s):

Kazuhiro Kurihara ◽

Takanori Suganuma

Keyword(s):

Malignant Tumors ◽

Endoscopic Examination ◽

Autosomal Dominant Disorder ◽

Tomography Image ◽

Elevated Lesion ◽

Poorly Differentiated ◽

Lower Endoscopy ◽

Peutz Jeghers Syndrome ◽

Computed Tomography Image

AbstractPeutz–Jeghers syndrome is an autosomal dominant disorder characterized by hamartomatous polyposis, pigmentation, and malignant tumors. We report a case of ileocecal carcinoma that was incidentally detected during follow-up for Peutz–Jeghers syndrome. A 39-year-old man with solitary Peutz–Jeghers syndrome had undergone three abdominal surgeries. He had been followed up via upper and lower gastrointestinal endoscopy and small intestinal endoscopy. In the endoscopic examination of the lower gastrointestinal tract, a 35 mm large, bumpy, elevated lesion was observed in the cecum. This lesion was not observed 9 months earlier during lower endoscopy. Biopsy of the specimen confirmed tubulovillous adenoma and carcinoma. This lesion was judged to be an indication for operation, and we performed ileocecectomy + D3 lymph node dissection. From the excised specimen, poorly differentiated carcinoma and adenoma components in contact with Peutz–Jeghers-type polyps in the appendix were recognized. A review of the computed tomography image obtained 2 years ago confirmed appendiceal swelling. We suspect that the ileocecal carcinoma in the appendix may have rapidly developed within the 9 months, and was incidentally detected on lower endoscopic examination during follow-up. For the prevention of appendicular tumorigenesis, prophylactic appendectomy may be considered in certain cases during follow-up for Peutz–Jeghers syndrome.

Download Full-text

Abstract 17426: Pulmonary Vein Isolation ‘Rewires’ Electrical Communications to Enhance Small-world Network Topology During Atrial Fibrillation

Circulation ◽

10.1161/circ.132.suppl_3.17426 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Hiroshi Ashikaga ◽

Jonathan Chrispin ◽

Degang Wu ◽

Joshua Garland

Keyword(s):

Atrial Fibrillation ◽

Communication Network ◽

Mutual Information ◽

Path Length ◽

Random Network ◽

Small World ◽

Clustering Coefficient ◽

Small World Network ◽

Z Score ◽

Network Properties

Recent evidence suggests that pulmonary vein isolation (PVI) may perturb the electrophysiological substrate for maintenance of atrial fibrillation (AF). Our previous work indicates that information theory metrics can quantify electrical communications during arrhythmia. We hypothesized that PVI ‘rewires’ the electrical communication network during AF such that the topology exhibits higher levels of small-world network properties, with higher clustering coefficient and lower path length, than would be expected by chance. Thirteen consecutive patients (n=6 with prior PVI and n=7 without) underwent AF ablation using a 64-electrode basket catheter in the left atrium. Multielectrode recording was performed during AF for 60 seconds, followed by PVI. Mutual information was calculated from the time series between each pair of electrodes using the Kraskov-Stögbauer-Grassberger estimator. The all-to-all mutual information matrix (64x64; Figure, upper panels) was thresholded by the median and standard deviations of mutual information to build a binary adjacency matrix for electrical communication networks. The properties of small-world network ( swn ; ‘small-world-ness’) were quantified by the ratio of the observed average clustering coefficient to that of a random network over the ratio of the observed average path length to that of a random network. swn was expressed in normal Z standard deviation units. As the binarizing threshold increased, the Z-score of swn decreased (Figure, lower panel). However, the Z-score at each threshold value was consistently higher with prior PVI than those without (p<0.05). In conclusion, electrical communication network during AF with prior PVI is associated with higher levels of small-world network properties than those without. This finding supports the concept that PVI perturbs the underlying substrate. In addition, swn of electrical communication network may be a promising metric to quantify substrate modification.

Download Full-text

Foreshocks and short-term hazard assessment of large earthquakes using complex networks: the case of the 2009 L'Aquila earthquake

Nonlinear Processes in Geophysics ◽

10.5194/npg-23-241-2016 ◽

2016 ◽

Vol 23 (4) ◽

pp. 241-256 ◽

Cited By ~ 10

Author(s):

Eleni Daskalaki ◽

Konstantinos Spiliotis ◽

Constantinos Siettos ◽

Georgios Minadakis ◽

Gerassimos A. Papadopoulos

Keyword(s):

Hazard Assessment ◽

Betweenness Centrality ◽

Small World ◽

Clustering Coefficient ◽

Earthquake Catalog ◽

Short Term ◽

2009 L’Aquila Earthquake ◽

Topological Measures ◽

Network Properties ◽

Large Earthquakes

Abstract. The monitoring of statistical network properties could be useful for the short-term hazard assessment of the occurrence of mainshocks in the presence of foreshocks. Using successive connections between events acquired from the earthquake catalog of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) for the case of the L'Aquila (Italy) mainshock (Mw = 6.3) of 6 April 2009, we provide evidence that network measures, both global (average clustering coefficient, small-world index) and local (betweenness centrality) ones, could potentially be exploited for forecasting purposes both in time and space. Our results reveal statistically significant increases in the topological measures and a nucleation of the betweenness centrality around the location of the epicenter about 2 months before the mainshock. The results of the analysis are robust even when considering either large or off-centered the main event space windows.

Download Full-text

OPTIMAL INTERCONNECTION OF AD HOC INJECTION NETWORKS

Journal of Interconnection Networks ◽

10.1142/s0219265908002278 ◽

2008 ◽

Vol 09 (03) ◽

pp. 277-297 ◽

Cited By ~ 5

Author(s):

GREGOIRE DANOY ◽

ENRIQUE ALBA ◽

PASCAL BOUVRY

Keyword(s):

Ad Hoc Networks ◽

Ad Hoc ◽

Small World ◽

Access Point ◽

Clustering Coefficient ◽

Mobility Patterns ◽

Characteristic Path Length ◽

Network Properties ◽

Hoc Networks ◽

Topology Control Problem

Multi-hop ad hoc networks allow establishing local groups of communicating devices in a self-organizing way. However, when considering realistic mobility patterns, such networks most often get divided in a set of disjoint partitions. This presence of partitions is an obstacle to communication within these networks. Ad hoc networks are generally composed of devices capable of communicating in a geographical neighborhood for free (e.g. using Wi-Fi or Bluetooth). In most cases a communication infrastructure is available. It can be a set of access point as well as a GSM/UMTS network. The use of such an infrastructure is billed, but it permits to interconnect distant nodes, through what we call “bypass links”. The objective of our work is to optimize the placement of these long-range links. To this end we rely on small-world network properties, which consist in a high clustering coefficient and a low characteristic path length. In this article we investigate the use of three genetic algorithms (generational, steady-state, and cooperative coevolutionary) to optimize three instances of this topology control problem and present initial evidence of their capacity to solve it.

Download Full-text

COMPLEX NETWORK ANALYSIS OF LITERARY AND SCIENTIFIC TEXTS

International Journal of Modern Physics C ◽

10.1142/s0129183112500519 ◽

2012 ◽

Vol 23 (07) ◽

pp. 1250051 ◽

Cited By ~ 21

Author(s):

IWONA GRABSKA-GRADZIŃSKA ◽

ANDRZEJ KULIG ◽

JAROSŁAW KWAPIEŃ ◽

STANISŁAW DROŻDŻ

Keyword(s):

English Language ◽

Quantitative Difference ◽

Clustering Coefficient ◽

Literary Texts ◽

Scaling Exponent ◽

Scientific Texts ◽

Scale Free ◽

Network Properties ◽

The One ◽

Zipf Law

We present results from our quantitative study of statistical and network properties of literary and scientific texts written in two languages: English and Polish. We show that Polish texts are described by the Zipf law with the scaling exponent smaller than the one for the English language. We also show that the scientific texts are typically characterized by the rank-frequency plots with relatively short range of power-law behavior as compared to the literary texts. We then transform the texts into their word-adjacency network representations and find another difference between the languages. For the majority of the literary texts in both languages, the corresponding networks revealed the scale-free structure, while this was not always the case for the scientific texts. However, all the network representations of texts were hierarchical. We do not observe any qualitative and quantitative difference between the languages. However, if we look at other network statistics like the clustering coefficient and the average shortest path length, the English texts occur to possess more clustered structure than do the Polish ones. This result was attributed to differences in grammar of both languages, which was also indicated in the Zipf plots. All the texts, however, show network structure that differs from any of the Watts–Strögatz, the Barabási–Albert, and the Erdös–Rényi architectures.

Download Full-text

Polymorphic Malware Detection by Image Conversion Technique

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.b4999.029320 ◽

2020 ◽

Vol 9 (3) ◽

pp. 2898-2903

Keyword(s):

Neural Networks ◽

Convolutional Neural Networks ◽

Training Module ◽

Dynamic Approach ◽

System A ◽

Image Conversion ◽

Binary Format ◽

Testing Data ◽

Hash Codes ◽

Polymorphic Malware

This model implements ways to detect polymorphic malware. This model uses a dynamic approach to detect the polymorphic malware. The objective is to increase the accuracy and efficiency of the detection as this malware can morph themselves, making it difficult to trace through anti-malware systems. As the tracing is going to be difficult the detection and classification system needs to be flexible that can able to detect the malware in every possible environment. This objective can be achieved by giving the system a superintelligence, this can be done by using the Convolutional Neural Networks (CNNs) in our system. This method records the pattern or the traces made by the polymorphic malware. The pattern is in the form of the image which is formed by converting the binary format of the hash codes. The generated images are then sent to the training module, based on this training module the Convolutional Neural Networks gives the result for any testing data.

Download Full-text

Longitudinal network theory approaches identify crucial factors affecting sporulation efficiency in yeast

10.1101/068270 ◽

2016 ◽

Cited By ~ 1

Author(s):

Camellia Sarkar ◽

Saumya Gupta ◽

Rahul Kumar Verma ◽

Himanshu Sinha ◽

Sarika Jalan

Keyword(s):

Gene Expression ◽

Network Theory ◽

Phenotypic Diversity ◽

Natural Populations ◽

Clustering Coefficient ◽

Regulatory Control ◽

Global Network ◽

Node Degree ◽

Developmental Processes ◽

Network Properties

ABSTRACTIntegrating network theory approaches over longitudinal genome-wide gene expression data is a robust approach to understand the molecular underpinnings of a dynamic biological process. Here, we performed a network-based investigation of longitudinal gene expression changes during sporulation of a yeast strain, SK1. Using global network attributes, viz. clustering coefficient, degree distribution of a node, degree-degree mixing of the connected nodes and disassortativity, we observed dynamic changes in these parameters indicating a highly connected network with inter-module crosstalk. Analysis of local attributes, such as clustering coefficient, hierarchy, betweenness centrality and Granovetter’s weak ties showed that there was an inherent hierarchy under regulatory control that was determined by specific nodes. Biological annotation of these nodes indicated the role of specifically linked pairs of genes in meiosis. These genes act as crucial regulators of sporulation in the highly sporulating SK1 strain. An independent analysis of these network properties in a less efficient sporulating strain helped to understand the heterogeneity of network profiles. We show that comparison of network properties has the potential to identify candidate nodes contributing to the phenotypic diversity of developmental processes in natural populations. Therefore, studying these network parameters as described in this work for dynamic developmental processes, such as sporulation in yeast and eventually in disease progression in humans, can help in identifying candidate factors which are potential regulators of differences between normal and perturbed processes and can be causal targets for intervention.

Download Full-text

CNTM-04. Alterations in structural connectomic properties associated with neurocognitive changes following glioma resection

Neuro-Oncology ◽

10.1093/neuonc/noab196.902 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi225-vi225

Author(s):

Kyle Noll ◽

Drew Mitchell ◽

Henry Chen ◽

Jeffrey Wefel ◽

Vinodh Kumar ◽

...

Keyword(s):

Verbal Memory ◽

Diffusion Tensor ◽

Rank Order ◽

Tumor Resection ◽

Receptive Language ◽

Clustering Coefficient ◽

Medium Effect ◽

Postoperative Changes ◽

Structural Network ◽

Network Properties

Abstract BACKGROUND Patients with brain tumors often experience decline in neurocognitive functioning (NCF) following surgical tumor resection. Connectomic studies have begun to uncover how abnormalities to underlying cerebral networks contribute to NCF deficits; however, few studies have investigated relationships between pre- to postoperative changes in structural connectomics and NCF. METHODS Fifteen right-handed adults with left perisylvian tumors underwent MRI of the brain with diffusion tensor imaging (DTI) and neuropsychological assessment before and after awake tumor resection. Graph theoretical analysis was applied to DTI-derived connectivity matrices to calculate structural network properties. Structural network properties and NCF measures were compared across the pre- to postoperative periods with matched pairs Wilcoxon signed-rank tests. Associations between pre- to postoperative change in network properties and change in NCF were determined with Spearman rank-order correlations (ρ). RESULTS Nearly 90% of the sample showed postoperative decline on 1 or more NCF measures. Significant postoperative NCF decline was found across measures of verbal memory, processing speed, executive functioning, receptive language, and the Clinical Trial Battery Composite (CTB COMP) index. Regarding connectomic properties, significant postoperative changes were observed in global and local efficiency, characteristic path length, clustering coefficient, betweenness centrality, and assortativity, with medium effect sizes. Significant associations (ρ = .59 to .62, all p < .05) were observed between changes in aspects of NCF and connectomic properties. CONCLUSIONS Decline in NCF was common following resection and some postoperative outcomes were associated with changes in structural connectomic properties following surgery.

Download Full-text

Disruption of Cortical Connectivity during Remifentanil Administration Is Associated with Cognitive Impairment but Not with Analgesia

Anesthesiology ◽

10.1097/aln.0000000000000510 ◽

2015 ◽

Vol 122 (1) ◽

pp. 140-149 ◽

Cited By ~ 14

Author(s):

Ahmad Khodayari-Rostamabad ◽

Søren S. Olesen ◽

Carina Graversen ◽

Lasse P. Malver ◽

Geana P. Kurita ◽

...

Keyword(s):

Reaction Time ◽

Functional Connectivity ◽

Path Length ◽

Experimental Pain ◽

Clustering Coefficient ◽

Cognitive Test ◽

Characteristic Path Length ◽

Network Properties ◽

Continuous Reaction ◽

Continuous Reaction Time

Abstract Background: The authors investigated the effect of remifentanil administration on resting electroencephalography functional connectivity and its relationship to cognitive function and analgesia in healthy volunteers. Methods: Twenty-one healthy male adult subjects were enrolled in this placebo-controlled double-blind cross-over study. For each subject, 2.5 min of multichannel electroencephalography recording, a cognitive test of sustained attention (continuous reaction time), and experimental pain scores to bone-pressure and heat stimuli were collected before and after infusion of remifentanil or placebo. A coherence matrix was calculated from the electroencephalogram, and three graph-theoretical measures (characteristic path-length, mean clustering coefficient, and relative small-worldness) were extracted to characterize the overall cortical network properties. Results: Compared to placebo, most graph-theoretical measures were significantly altered by remifentanil at the alpha and low beta range (8 to 18 Hz; all P < 0.001). Taken together, these alterations were characterized by an increase in the characteristic path-length (alpha 17% and low beta range 24%) and corresponding decrements in mean clustering coefficient (low beta range −25%) and relative small-worldness (alpha −17% and low beta range −42%). Changes in characteristic path-lengths after remifentanil infusion were correlated to the continuous reaction time index (r = −0.57; P = 0.009), while no significant correlations between graph-theoretical measures and experimental pain tests were seen. Conclusions: Remifentanil disrupts the functional connectivity network properties of the electroencephalogram. The findings give new insight into how opioids interfere with the normal brain functions and have the potential to be biomarkers for the sedative effects of opioids in different clinical settings.

Download Full-text