3,800 research outputs found
Thermodynamical Consistent Modeling and Analysis of Nematic Liquid Crystal Flows
The general Ericksen-Leslie system for the flow of nematic liquid crystals is
reconsidered in the non-isothermal case aiming for thermodynamically consistent
models. The non-isothermal model is then investigated analytically. A fairly
complete dynamic theory is developed by analyzing these systems as quasilinear
parabolic evolution equations in an -setting. First, the existence of
a unique, local strong solution is proved. It is then shown that this solution
extends to a global strong solution provided the initial data are close to an
equilibrium or the solution is eventually bounded in the natural norm of the
underlying state space. In these cases, the solution converges exponentially to
an equilibrium in the natural state manifold
Evaluation of bio-agent formulations to control Fusarium wilt of tomato
The ED50 value of antagonistic substance from Chaetomium globosum N0802 extracted with hexane was 157 μg/ml. This gave the highest inhibition of conidial production of Fusarium oxysporum f. sp. lycopersici causing tomato wilt var Sida. Crude hexane from Chaetomium lucknowense CLT and crude methanol from Trichoderma harzianum PC01 gave ED50 values of 188 and 192 μg/ml. It clearly demonstrated that antagonistic substances from all tested fungi could be deformed and this could break the conidial cells. The bio-agent formulations namely N0802, CLT and PC01 gave significantly highest disease reduction of tomato wilt which were 44.68, 36.28 and 41.01%, respectively, followed by prochoraz (21.95%). All tested bio-agent formulations could significantly increase the yield of tomato when compared to prochoraz and inoculated control. It is concluded that C. globosum, C. lucknowense and T. harzianumKeywords: Fusarium oxysporum f. sp. lycopersici, Chaetomium globosum, Chaetomium lucknowense, Trichoderma harzianum, bio-agent formulationsAfrican Journal of Biotechnology Vol. 9(36), pp. 5836-5844, 6 September, 201
Interdependent network reciprocity in evolutionary games
Besides the structure of interactions within networks, also the interactions between networks are of the outmost
importance. We therefore study the outcome of the public goods game on two interdependent networks that are
connected by means of a utility function, which determines how payoffs on both networks jointly influence the
success of players in each individual network. We show that an unbiased coupling allows the spontaneous
emergence of interdependent network reciprocity, which is capable to maintain healthy levels of public
cooperation even in extremely adverse conditions. The mechanism, however, requires simultaneous formation of
correlated cooperator clusters on both networks. If this does not emerge or if the coordination process is
disturbed, network reciprocity fails, resulting in the total collapse of cooperation. Network interdependence can
thus be exploited effectively to promote cooperation past the limits imposed by isolated networks, but only if the
coordination between the interdependent networks is not disturbe
Sequence variation in TgROP7 gene among Toxoplasma gondii isolates from different hosts and geographical regions
Toxoplasma gondii can infect a wide range of hosts including mammals and birds, causing toxoplasmosis which is one of the most common parasitic zoonoses worldwide. The present study examined sequence variation in rhoptry 7 (ROP7) gene among different T. gondii isolates from different hosts and geographical localities. Phylogenetic analysis of the examined T. gondii isolates was conducted using the maximum likelihood (ML) method. Sequence analysis revealed that 60 nucleotide positions were variable in the ROP7 gene sequences among the 19 examined T. gondii isolates, corresponding to sequence variations of 0 to 1.7%, which occurred at the first, second and third codons. Phylogenetic analysis indicated that sequence variation in ROP7 gene was low among the examined T. gondii isolates from different hosts and geographical localities, and that the ROP7 sequence was not suitable as genetic marker for the differentiation of T. gondii isolates. The results of the present study suggest that ROP7 gene may be a suitable vaccine candidate.Key words: Sequence variation, rhoptry 7 (ROP7) gene, Toxoplasma gondii, toxoplasmosis, phylogenetic analysis
Use Of Chinese Medicine Among Colorectal Cancer Patients: A Nationwide Population-Based Study.
Background: Traditional Chinese medicine (CM) appears to be used worldwide, especially by cancer patients. The aim of the present study was to explore CM uses and CM non-users by patients with colorectal cancer (CRC).Materials and methods: A retrospective study was conducted using registration and claims data sets for 2007 from the National Health Insurance Research Database. Patients with colorectal cancer were identified from the Registry for Catastrophic illness Patients. Binary logistic regression was used to estimate odds ratios as the measure of association with the use of CM.Results: A total of 61,211 CRC patients diagnosed in 2007 were analysis. Most CM users preferred to visit private clinics (46.9%) with 306,599 visits. In contrast, the majority of CM non-users preferred to visit private hospitals (42.2%) with 538,769 visits. Among all 176,707 cancer-specific CM visit, there were 66.6% visits to CM outpatient department (OPD) of private hospitals, while in 477,612 non-cancer-specific CM visits, 62.0% was for private clinics. The proportion of expenses for diagnostic fees for CM user in CM visits was much less than that for WM visits and CM non-users (US6.3 vs. 25.9 vs. 30.3). Female patients, younger age, and patients not living in the northern region, with higher EC or more comorbidities were more likely to receive CM treatment.Conclusion: The prevalence and costs of insurance-covered CM among CRC patients were low. Further longer longitudinal study is needed to follow up this trend.Key words: Chinese Medicine, Digestive System Neoplasms, Health Insuranc
Narrow superconducting window in LaFe1-x Nix AsO
We have studied Ni-substitution effect in LaFe1-x Nix AsO (0≤x≤0.1) by the measurements of x-ray diffraction, electrical resistivity, magnetic susceptibility, and heat capacity. The nickel doping drastically suppresses the resistivity anomaly associated with spin-density-wave ordering in the parent compound. Superconductivity emerges in a narrow region of 0.03≤x≤0.06 with the maximum Tc of 6.5 K at x=0.04, where enhanced magnetic susceptibility shows up. The upper critical field at zero temperature is estimated to exceed the Pauli paramagnetic limit. The much lowered Tc in comparison with LaFeAsO1-x Fx system is discussed. © 2009 The American Physical Society.published_or_final_versio
Changes in anti-viral effectiveness of interferon after dose reduction in chronic hepatitis c patients: a case control study
BACKGROUND: High dose interferon induction treatment of hepatitis C viral infection blocks viral production over 95%. Since dose reduction is often performed due to clinical considerations, the effect of dose reduction on hepatitis C virus kinetics was studied. METHODS: A new model that allowed longitudinal changes in the parameters of viral dynamics was used in a group of genotype-1 patients (N = 15) with dose reduction from 10 to 3 million units of interferon daily in combination with ribavirin, in comparison to a control group (N = 9) with no dose reduction. RESULTS: Dose reduction gave rise to a complex viral kinetic pattern, which could be only explained by a decrease in interferon effectiveness in blocking virion production. The benefit of the rapid initial viral decline following the high induction dose is lost after dose reduction. In addition, in some patients also the second phase viral decline slope, which is highly predictive of success of treatment, was impaired by the dose reduction resulting in smaller percentage of viral clearance in the dose reduction group. CONCLUSIONS: These findings, while explaining the failure of many induction schedules, suggest that for genotype-1 patients induction therapy should be continued till HCVRNA negativity in serum in order to increase the sustained response rate for chronic hepatitis C
Cognitive health in persons with human immunodeficiency virus: the impact of early treatment, comorbidities, and aging
With the advent of virally suppressive antiretroviral therapy (ART), life expectancy for persons with human immunodeficiency virus (HIV) with access to ART now approaches that of the general population. As persons with HIV age, noninfectious comorbidities occur more frequently compared with persons without HIV. Such comorbidities are likely to affect cognitive health, which may also be affected by lifestyle factors that may differ in persons with HIV. At the National Institutes of Health–supported meeting on Biotypes of Central Nervous System (CNS) Complications in persons with HIV, a session was devoted to early HIV treatment, noninfectious comorbidities, and aging as each pertains to cognitive health. Areas of consideration included acute and early HIV infection (presentation by Phillip Chan), drugs of abuse (Scott Letendre), stroke and cerebrovascular disease (Felicia Chow), mental health (John Joska), and aging (Julian Falutz). These presentations were followed by a discussion session led by Woody Lin, Jose A. Muñoz-Moreno, Paola Cinque, and Jeff Taylor. Alan Winston and Bruce Brew chaired the meeting with Jasmini Alagaratnam and Htein Linn Aung acting as rapporteurs. Here we present the main topics covered in the presentations, and the associated discussions highlighting knowledge gaps and future directions
Invariant Distribution of Promoter Activities in Escherichia coli
Cells need to allocate their limited resources to express a wide range of genes. To understand how Escherichia coli partitions its transcriptional resources between its different promoters, we employ a robotic assay using a comprehensive reporter strain library for E. coli to measure promoter activity on a genomic scale at high-temporal resolution and accuracy. This allows continuous tracking of promoter activity as cells change their growth rate from exponential to stationary phase in different media. We find a heavy-tailed distribution of promoter activities, with promoter activities spanning several orders of magnitude. While the shape of the distribution is almost completely independent of the growth conditions, the identity of the promoters expressed at different levels does depend on them. Translation machinery genes, however, keep the same relative expression levels in the distribution across conditions, and their fractional promoter activity tracks growth rate tightly. We present a simple optimization model for resource allocation which suggests that the observed invariant distributions might maximize growth rate. These invariant features of the distribution of promoter activities may suggest design constraints that shape the allocation of transcriptional resources
Quasi-Elliptic Bandpass Frequency Selective Surface Based on Coupled Stubs-Loaded Ring Resonators
© 2013 IEEE. In this paper, a novel design of frequency-selective surface (FSS) based on coupled stubs-loaded ring resonators (SLRRs) is proposed. The proposed FSS exhibits quasi-elliptic bandpass filtering characteristic at C-band. And each unit cell of the structure is composed of two SLRRs coupled by a circular aperture. A novel method of transmission line (TL) model is proposed to investigate the operating principle of a single SLRR under normal incidence plane wave. Moreover, the operating mechanism of the proposed FSS is further researched with the aid of the equivalent circuit model (ECM) analysis method. Due to the symmetric and low-profile physical structure, the FSS keeps stable frequency response under oblique incident plane wave for both transverse electric (TE) and transverse magnetic (TM) polarizations. Finally, the designed FSS is fabricated and measured. The measured results agree well with the simulated results. The measured results indicate that the proposed FSS exhibits a dual-polarized and stable bandpass frequency response with two transmission zeros (TZs) at around 5.71 and 6.87 GHz under different incident angles up to 40°
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