Information reliability in complex multitask networks

The emergence of distributed and complex networks has altered the field of information and data processing in the past few years. In distributed networks, the connected neighboring nodes can cooperate and share information with each other in order to solve particular tasks. However, in many applications the agents might be reluctant to share their true data with all their neighbors due to privacy and security constraints. In this paper, we study the performance of multitask distributed networks where sharing genuine information is subject to a cost. We formulate an information credibility model which results in the probability of sharing genuine information at each time instant according to the cost. Each agent then shares its true information with only a subset of its neighbors while sending fabricated data to the rest according to this probability. This behavior can affect the performance of the whole network in an adverse manner especially in cases where the cost is high. To overcome this problem, we propose an adaptive reputation protocol which enables the agents to evaluate the behavior of their neighbors over time and select the most reputable subset of neighbors to share genuine information with. We provide an extensive simulation-based analysis to compare the performance of the proposed method with several other distributed learning strategies. The results show that the proposed method outperforms the other learning strategies and enables the network to have a superior performance especially when the cost of sharing genuine information is high

Do Patients with Penetrating Abdominal Stab Wounds Require Laparotomy?

Background: The optimal management of hemodynamically stable asymptomatic patients with anterior abdominal stab wounds (AASWs) remains controversial. The goal is to identify and treat injuries in a safe cost-effective manner. Common evaluation strategies are local wound exploration (LWE), diagnostic peritoneal lavage (DPL), serial clinical assessment (SCAs) and computed tomography (CT) imaging. Making a decision about the right time to operate on a patient with a penetrating abdominal stab wound, especially those who have visceral evisceration, is a continuing challenge. Objectives: Until the year 2010, our strategy was emergency laparotomy in patients with penetrating anterior fascia and those with visceral evisceration. This survey was conducted towards evaluating the results of emergency laparotomy. So, better management can be done in patients with penetrating abdominal stab wounds. Patients and Methods: This retrospective cross-sectional study was performed on patients with abdominal penetrating trauma who referred to Al- Zahra hospital in Isfahan, Iran from October 2000 to October 2010. It should be noted that patients with abdominal blunt trauma, patients under 14 years old, those with lateral abdomen penetrating trauma and patients who had unstable hemodynamic status were excluded from the study. Medical records of patients were reviewed and demographic and clinical data were collected for all patients including: age, sex, mechanism of trauma and the results of LWE and laparotomy. Data were analyzed with PASW v.20 software. All data were expressed as mean ± SD. The distribution of nominal variables was compared using the Chi-squared test. Also diagnostic index for LWE were calculated. A two-sided P value less than 0.05 was considered to be statistically significant. Results: During the 10 year period of the study, 1100 consecutive patients with stab wounds were admitted to Al-Zahra hospital Isfahan, Iran. In total, about 150 cases had penetrating traumas in the anterior abdomen area. Sixty-three (42%) patients were operated immediately due to shock, visceral evisceration or aspiration of blood via a nasogastric tube on admission. Organ injury was seen in 78% of patients with visceral evisceration. Among these 87 cases, 29 patients’ (33.3%) anterior fascia was not penetrated in LWE. So, they were observed for several hours and discharged from the hospital without surgery. While for the remaining 58 patients (66.6%), whose LWE detected penetration of anterior abdominal fascia, laparotomy was performed which showed visceral injuries in 11 (18%) cases. Conclusions: All in all, 82 percent of laparotomies in patients with penetrated anterior abdominal fascia without visceral evisceration, who had no signs of peritoneal irritation, were negative. So, we recommended further evaluation in these patients. However, visceral evisceration is an indication for exploratory laparotomy, since in our study; the majority of patients had organ damages

Multiscale Fluctuation Dispersion Entropy of EEG as a Physiological Biomarker of Schizotypy

Altered electroencephalography (EEG) activity in schizotypal individuals is a powerful indicator of proneness towards psychosis. This alteration is beyond decreased alpha power often measured in resting state EEG. Multiscale fluctuation dispersion entropy (MFDE) measures the non-linear complexity of the fluctuations of EEGs and is a more effective approach compared to the traditional linear power spectral density (PSD) measures of EEG activity in patients with neurodegenerative disorders. In this study, we applied MFDE to EEG signals to distinguish high schizotypy (HS) and low schizotypy (LS) individuals. The study includes several trials from 29 participants psychometrically classified as HS (n=19) and LS (n=10). After preprocessing, MFDE was computed in frontal, parietal, central, temporal and occipital regions for each participant at multiple time scales. Statistical analysis and machine learning algorithms were used to calculate the differences in MFDE measures between the HS and LS groups. Our findings revealed significant differences in MFDE measures between LS and HS individuals in the delta frequency band (at time scale 100 ms). HS individuals exhibited increased complexity and irregularity compared to LS individuals in the delta frequency band particularly in the occipital region. Furthermore, the MFDE measures resulted in high accuracy (96.55%) in discriminating between HS and LS individuals and outperformed the models based on power spectrum, demonstrating the potential of MFDE as a neurophysiological marker for schizotypy traits. The increased non-linear fluctuation in delta frequency band in the occipital region of HS individuals implies the changes in cognitive functions, such as memory and attention, and has significant potential as a biomarker for schizotypy and proneness towards psychosis

Prevalence and risk factors of complication of endotracheal extubation in teaching hospitals affiliated with Jahrom University of medical science

Endotracheal intubation is to maintain a safe open airway to prevent pulmonary aspiration by administrating general anesthesia. Endotracheal tube, as a foreign body, can stimulate the patients’ airway during the emergence from general anesthesia and cause various reactions and complications immediately or within a multi-day delay.The present study intended to determine the prevalence and associated risk factors of the complications of endotracheal extubation (removal of endotracheal tube / ETT) within 24 hrs. since the surgery. To this end, a descriptive research was conducted on 200 adult candidates for elective and emergency surgery of endotracheal intubation by administrating general anesthesia. Data about the intended associated risk factors and complications were respectively collected in operating room (OR) and within 24 hrs. since surgery and were recorded in the questionnaire. The results indicated that the prevalent complications were sore throat (%21), cough (%12.5) and hoarseness (%15.5). There was not any case of dysphagia and bloody sputum (blood-streaked expectorant). Also, there was a significant relationship between sore throat and the type of surgery (P˂0.001). On the other hand, there was not any statistically significant relationship between sore throat and other associated risk factors (sex, age, weight, type of surgery and size of endotracheal tube). Likewise, not any significant relationship was observed between cough, hoarseness and the intended risk factors. To conclude, the present study found that the type of surgery has a significant effect on the incidence of sore throat within 24 hrs. since the surgical operation; thus, raising awareness of these risk factors and taking proper actions, particularly during intubation, can reduce the incidence of complications, in particular sore throat, and improve patients’ satisfaction.Keywords: General Anesthesia; Intubation; Complication

A robust adaptive estimation algorithm for Hamiltonian multi-agent networks

In this letter a robust incremental adaptation algorithm is presented to solve distributed estimation for a Hamiltonian network, where the measurements at each node may be corrupted by heavy-tailed impulsive noise. In the proposed algorithm, each node employs an error-nonlinearity into the update equation to mitigate the detrimental effects of impulsive noise. Moreover, the algorithm estimates both the optimal error non-linearity and the unknown parameter together, which in turn, obviates the requirement of prior knowledge about the statistical characteristics of measurement noise. In addition to algorithm development, its steady-state performance as well as convergence analysis have been provided. Simulation results validate the correctness of the analysis and reveal the superiority of the proposed algorithm over some existing algorithms

The decrease in NKG2D+ Natural Killer cells in peripheral blood of patients with metastatic colorectal cancer

Background: Natural killer (NK) cells play important roles in the immune defense against tumors such as colorectal cancer. In humans, NKG2D is an activating immune receptor constitutively expressed in most cytotoxic lymphocytes including NK and CD8+ T cells. In this study, the expression of NKG2D molecule was investigated in peripheral blood NK cells from colorectal cancer patients and compared with healthy subjects. Methods: We studied 21 non-metastatic (low-grade), 17 non-metastatic (high-grade), 16 metastatic colorectal cancer patients, and 24 healthy controls. Peripheral blood samples were obtained to isolate peripheral blood mononuclear cells (PBMCs) and the percentage of peripheral blood NKG2D+CD3-CD56+ NK cells was analyzed by flow cytometry. The expression of NKG2D at mRNA level was also measured by real-time PCR in both, patients and control subjects. Results: The results showed a significant reduction in the percentage of NKG2D+NK cells as well as NKG2D mRNA expression in peripheral blood of metastatic colon cancer patients. Conclusion: This result suggests that decreased expression of activating NKG2D receptor in metastatic colorectal cancer might compromise NK cell function and allow tumor to evade immunity (Tab. 3, Fig. 4, Ref. 33). Text in PDF www.elis.sk

Adaptive regularized diffusion adaptation over multitask networks

The focus of this paper is on multitask learning over adaptive networks where different clusters of nodes have different objectives. We propose an adaptive regularized diffusion strategy using Gaussian kernel regularization to enable the agents to learn about the objectives of their neighbors and to ignore misleading information. In this way, the nodes will be able to meet their objectives more accurately and improve the performance of the network. Simulation results are provided to illustrate the performance of the proposed adaptive regularization procedure in comparison with other implementations

Carbon cycle during the late Aptian–early Albian OAE 1b: A focus on the Kilian–Paquier levels interval

This is the final version. Available on open access from Elsevier via the DOI in this recordData availability: Data will be made available on request.The Oceanic Anoxic Event (OAE) 1b took place over a protracted time interval during the Aptian/Albian boundary interval, at the dawn of the mid-Cretaceous climatic optimum. OAE 1b is characterized by the occurrence of several sub-events recorded by organic matter-rich levels, which can be traced on regional-to-global scale. Previous studies have highlighted that the climax of the event occurred around the Kilian – Paquier interval, with this latter sub-event being the most extended and pronounced stratigraphic interval. Numerous studies on OAE 1b have however only focused on high-precision investigations of the Kilian and/or Paquier levels, leaving vast uncertainties about the environmental changes and their drivers during the entire OAE 1b, and hence also on the mechanisms leading to the formation of the sub-events themselves. In this study, we have performed a high-resolution multi-proxy analysis of the Briers section, a well-exposed section in the Blue Marls Formation of the SE France Vocontian Basin, continuously covering the Kilian – Paquier interval. Pyrolysis analyses show that most of the organic matter in this section is immature and of continental origin, averaging 1.5% TOC. The Kilian and Paquier levels are characterized by higher TOC values and a substantial increase in the amount of marine organic matter. Comparing TOC values with changes in Al or Ti concentration (proxies for continental weathering) and Hydrogen index (HI values, tracer for the type of organic matter) reveals that the background long-term change in TOC is linked to change in the continental organic matter delivery to the Vocontian Basin tied to changes in continental weathering rates. Sporadic increases in TOC values associated with the Kilian, HN 8, and Paquier levels, are most likely the result of short-lived events of increased marine primary productivity and organic matter preservation superimposed on the background influx of continental organic matter. A high-resolution bulk organic matter carbon isotope record shows that, apart from the Paquier level, all the fluctuations observed in the carbonate carbon isotope ratios are also mirrored in the organic matter record, although with higher amplitudes. This discrepancy in amplitude can be resolved by correcting the bulk organic matter carbon isotope record for fluctuations in the type of organic matter, demonstrating that both oceanic and atmospheric reservoirs were affected by similar carbon isotope fluctuations, which were hence of global extent. The abnormal bulk organic matter carbon isotope record of the Paquier level further confirms the large geographical expansion of unusual organic matter production and/or accumulation during this peculiar event. Overall, this study suggests that Milankovitch-paced (long eccentricity) changes in monsoonal activity and their effect on the accumulation of organic matter in continental wetlands best explains the rhythmic change in the global carbon isotope record across the OAE 1b interval.Aarhus Universitets Forskningsfon

Drug-related mutational patterns in hepatitis B virus (HBV) reverse transcriptase proteins from Iranian treatment-Naïve chronic HBV patients

Background: Immunomodulators and Nucleotide analogues have been used globally for the dealing of chronic hepatitis B virus (HBV) infection. However, the development of drug resistance is a major limitation to their long-term effectiveness. Objectives: The aim of this study was to characterize the hepatitis B virus reverse transcriptase (RT) protein variations among Iranian chronic HBV carriers who did not receive any antiviral treatments. Materials and Methods: Hepatitis B virus partial RT genes from 325 chronic in active carrier patients were amplified and directly sequenced. Nucleotide/amino acid substitutions were identified compared to the sequences obtained from the database. Results: All strains belonging to genotype D.365 amino-acid substitutions were found. Mutations related to lamivudine, adefovir, telbivudine, and entecavir occurred in (YMDD) 4% (n = 13), (SVQ) 17.23% (n = 56), (M204I/V + L180M) 2.45% (n = 8) and (M204I) 2.76% (n = 9) of patients, respectively. Conclusions: RT mutants do occur naturally and could be found in HBV carriers who have never received antiviral therapy. However, mutations related to drug resistance in Iranian treatment-naïve chronic HBV patients were found to be higher than other studies published formerly. Chronic HBV patients should be monitored closely prior the commencement of therapy to achieve the best regimen option. © 2013, KOWSAR Corp