1,399 research outputs found

    Incorporating Betweenness Centrality in Compressive Sensing for Congestion Detection

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    This paper presents a new Compressive Sensing (CS) scheme for detecting network congested links. We focus on decreasing the required number of measurements to detect all congested links in the context of network tomography. We have expanded the LASSO objective function by adding a new term corresponding to the prior knowledge based on the relationship between the congested links and the corresponding link Betweenness Centrality (BC). The accuracy of the proposed model is verified by simulations on two real datasets. The results demonstrate that our model outperformed the state-of-the-art CS based method with significant improvements in terms of F-Score

    Targeting colorectal cancer with anti-epidermal growth factor receptor antibodies: focus on panitumumab

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    Panitumumab is a fully humanized monoclonal antibody with a high degree of affinity for the extracellular domain of the epidermal growth factor receptor. Phase II clinical evaluation of this drug, when administered as a single agent, in patients with metastatic colorectal cancer refractory to chemotherapy, demonstrated a modest objective radiographic response rate with acceptable toxicity; the most frequently observed side effect is rash. A randomized phase III study in subjects with chemotherapy-refractory metastatic colorectal cancer documented a progression-free survival advantage in subjects treated with panitumumab plus best supportive care versus best supportive care alone; a difference in survival was not observed, likely due to the high cross over rate. Primary tumor KRAS mutation analysis performed in this study indicated that the benefit was confined to those patients whose tumors did not contain a KRAS mutation. Further studies with panitumumab will be required to develop biomarkers of response and to determine if panitumumab has a role in combination with cytotoxic chemotherapy. This article summarizes the current state-of-the-science knowledge on panitumumab therapy in the treatment of advanced colorectal cancer

    Salt Modulated Structure of Polyelectrolyte-Macroion Complex Fibers

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    The structure and stability of strongly charged complex fibers formed by complexation of a single long semi-flexible polyelectrolyte (PE) chain and many oppositely charged spherical macroions are investigated numerically at the ground-state level using a chain-sphere cell model. The model takes into account chain elasticity as well as electrostatic interactions between charged spheres and chain segments. Using a numerical optimization method based on a periodically repeated unit cell, we obtain fiber configurations that minimize the total energy. The optimal configurations exhibit a variety of helical structures for the arrangement of macroions including zig-zag, solenoidal and beads-on-a-string patterns. These structures are determined by a competition between attraction between spheres and the PE chain (which favors chain wrapping around the spheres), chain bending and electrostatic repulsion between chain segments (which favor unwrapping of the chain), and the interactions between neighboring sphere-chain complexes which can be attractive or repulsive depending on the system parameters such as medium salt concentration, macroion charge and chain length per macroion (linker size). At about physiological salt concentration, dense zig-zag patterns are found to be energetically most stable when parameters appropriate for the DNA-histone system in a chromatin fiber are adopted. In fact, the predicted fiber diameter in this regime is found to be around 30nm, which appears to agree with the thickness observed in in vitro experiments on chromatin. We also find a macroion density of 5-6 per 11nm which agrees with the zig-zag or cross-linker models of chromatin. Since our study deals primarily with a generic model, these findings suggest that chromatin-like structures should also be observable for PE-macroion complexes formed in solutions of DNA and synthetic nano-colloids of opposite charge.Comment: 18 pages, 15 figure

    Compensation and Culture: A Configurational Fit between Pay System and Culture Types

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    For most companies, compensation represents the largest single expenditure, and compensation is recognized as an important mechanism for organizational performance. Pay strategies also have the important role of underpinning and supporting organizational culture, and research suggests that failure to support organizational culture can precipitate a company’s failure. Understanding the convergence of these two domains represents an important area of research. We propose that four different culture classifications might each be supported by unique combinations of either an egalitarian or hierarchical pay distribution, in combination with or without pay-for-performance compensation strategies

    The mechanistic and prognostic implications of heart rate variability analysis in patients with cirrhosis

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    Chronic liver damage leads to scarring of the liver tissue and ultimately a systemic illness known as cirrhosis. Patients with cirrhosis exhibit multi-organ dysfunction and high mortality. Reduced heart rate variability (HRV) is a hallmark of cirrhosis, reflecting a state of defective cardiovascular control and physiological network disruption. Several lines of evidence have revealed that decreased HRV holds prognostic information and can predict survival of patients independent of the severity of liver disease. Thus, the aim of this review is to shed light on the mechanistic and prognostic implications of HRV analysis in patients with cirrhosis. Notably, several studies have extensively highlighted the critical role systemic inflammation elicits in conferring the reduction in patients’ HRV. It appears that IL-6 is likely to play a central mechanistic role, whereby its levels also correlate with manifestations, such as autonomic neuropathy and hence the partial uncoupling of the cardiac pacemaker from autonomic control. Reduced HRV has also been reported to be highly correlated with the severity of hepatic encephalopathy, potentially through systemic inflammation affecting specific brain regions, involved in both cognitive function and autonomic regulation. In general, the prognostic ability of HRV analysis holds immense potential in improving survival rates for patients with cirrhosis, as it may indeed be added to current prognostic indicators, to ultimately increase the accuracy of selecting the recipient most in need of liver transplantation. However, a network physiology approach in the future is critical to delineate the exact mechanistic basis by which decreased HRV confers poor prognosis

    Synthesis, structural characterization and biological activity of Cu(II), Co(II) and Ni(II) complexes derived from 2-(thiazol-2-ylimino)thiazolidin-4-one ligand

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    A novel series of metal complexes of 2-(thiazol-2-ylimino) thiazolidin-4-one ligand were prepared; the corresponding ligand was synthesized from reaction 2-Chloro-N-(thiazol-2-yl) acetamide with ammonium thiocyanate. The complexes are characterized by FTIR, UV-Vis, molar conductance and mass spectroscopy. The low molar conductance values indicate that the complexes are non-electrolytes.Spectroscopic studies confirmed that the ligand bonded to the metals through the sulphur atoms. Coordination number of copper and nickel complexes is four with square planar geometry, while the cobalt complex has octahedral geometry.In vitro antibacterial activity of ligand and its metal complexes was evaluated using well diffusion method and compared to the standard drug (tetracycline). The antibacterial activitywas examined against Escherichia coli, and pseudomonas aeruginosa, as gram negative bacteria and Staphylococcus aureus as gram positive bacteria. It was found that Nickel complex has the highest antibacterial activity among the synthesized compounds with Zone inhibition diameter in the range 25-29 mm

    Primjena umjetne toplinske stimulacije kao novi pristup za indukciju tendinopatije u magaraca

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    Animal models for tendonitis are essential for studying the disease’s mechanism and pathogenesis, and evaluating different therapeutic protocols. The temperature seems to play a significant role in tendinitis initiation. The aim of this study was the generation of a novel, safe and cheap tendinitis model, and validation of its reliability. The effect of microwave diathermy (30 watts for 30 min) on the flexor tendons of donkeys as animal models was investigated after 15, 30 and 60 days. The evaluation was based on geometric analysis, ultrasonography, histomorphometric analysis and scanning electron microscopy (SEM). Microwave diathermy was capable of successfully inducing well-defined lesions in the superficial digital flexor tendon (SDFT) as well as the deep digital flexor tendon (DDFT). The results showed that all the animals exhibited signs of lameness, starting on day 15 and reaching on maximum on day 30. A significant increase in limb circumference was also detected on day 30 (P<0.05). Furthermore, the geometrical analysis of the proportion of induced lesion (PIL) in correlation with the tendon diameter, revealed that PIL was at the maximum width on day 30 (20.6 ± 1.2% for SDFT and 15.7 ± 0.7% for DDFT), as detected by ultrasound. Moreover, a high number of rounded tenocytes, bleeding, severe matrix disruption, and an increase in fiber thickness were detected by histomorphometric analysis. Also, the matrix alignment was severely disrupted in both SDFT and DDFT by day 30, as confirmed by SEM. In conclusion, using microwave diathermy for induction of tendonitis in donkey is a reliable, minimally invasive, and cost-effective tendonitis model.Uporaba životinjskih modela je neophodna za proučavanje mehanizma bolesti, patogeneze i za procjenu protokola liječenje tendinitisa. Čini se da temperatura igra značajnu ulogu pri nastajanju tendinitisa. Cilj istraživanja bio je stvaranje novog, sigurnog i jeftinog modela za proučavanje tendinitisa te potvrda njegove pouzdanosti. Učinak mikrovalne dijatermije (30 vata tijekom 30 min) na tetive fleksora u magaraca kao životinjskih modela istraživan je nakon 15, 30 i 60 dana. Procjena se temeljila na geometrijskoj analizi, ultrazvuku, histomorfometrijskoj analizi i skenirajućoj elektronskoj mikroskopiji (SEM). Mikrovalna dijatermija uspješno je inducirala dobro definirane lezije u površinskoj digitalnoj tetivi fleksora (SDFT) kao i dubokoj digitalnoj tetivi fleksora (DDFT). Rezultati su pokazali da su sve životinje pokazivale znakove hromosti, počevši od 15. dana i dostižući maksimum 30. dana. Također, 30. dana je uočeno znakovito (P<0,05) povećanje opsega ekstremiteta. Nadalje, uporabom ultrazvuka i primjenom geometrijske analize udjela inducirane lezije (PIL) u korelaciji s promjerom tetive, ustanovljeno je da je PIL bio maksimalne širine 30. dana (20,6 ± 1,2% za SFT i 15,7 ± 0,7% za DDFT). Osim toga, histomorfometrijskom analizom otkriven je povećan broj zaobljenih tenocita, krvarenje, teži poremećaji u matriksu i povećanje debljine vlakana. Do 30. dana, SEM analiza je pokazala izražene poremećaje u poravnavanju matriksa i u SDFT i u DDFT. Zaključno, primjena mikrovalne dijatermije za indukciju tendinitisa kod magaraca je pouzdan, minimalno invazivan i troškovno učinkovit životinjski model za proučavanje ove bolesti
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