369 research outputs found

    Modelling Self-similar Traffic Of Multiservice Networks

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    Simulation modelling is carried out, which allows adequate describing the traffic of multiservice networks with the commutation of packets with the characteristic of burstiness. One of the most effective methods for studying the traffic of telecommunications systems is computer simulation modelling. By using the theory of queuing systems (QS), computer simulation modelling of packet flows (traffic) in modern multi-service networks is performed as a random self-similar process. Distribution laws such as exponential, Poisson and normal-logarithmic distributions, Pareto and Weibull distributions have been considered.The distribution of time intervals between arrivals of packages and the service duration of service of packages at different system loads has been studied. The research results show that the distribution function of time intervals between packet arrivals and the service duration of packages is in good agreement with the Pareto and Weibull distributions, but in most cases the Pareto distribution prevails.The queuing systems with the queues M/Pa/1 and Pa/M/1 has been studied, and the fractality of the intervals of requests arriving have been compared by the properties of the estimates of the system load and the service duration. It has been found out that in the system Pa/M/1, with the parameter of the form a> 2, the fractality of the intervals of requests arriving does not affect the average waiting time and load factor. However, when ≤2, as in the M/Pa/1 system, both considered statistical estimates differ.The application of adequate mathematical models of traffic allows to correctly assess the characteristics of the quality of service (QoS) of the network

    Sonolytic Oxidation of Tc(IV)O2nH2O Nanoparticles to Tc(VII)O4 in Aqueous Solution

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    Sonolysis of a hydrosol of TcO2nH2O was investigated in the Ar- or He- atmosphere. Colloidal TcO2nH2O nanoparticles were irradiated with a 200 kHz and 1.25 W/cm2 ultrasound. It was found that the TcO2nH2O colloids dispersed in an aqueous solution (under Ar or He atmosphere) was completely dissolved by ultrasonic irradiation (200 kHz, 200 W). The original brownish black color of the suspension slowly disappeared leaving behind a colorless solution. This change suggests that oxidation of Tc(IV) to Tc(VII) takes place. The oxidation was almost complete during 30 minutes sonication time under argon atmosphere for initial concentration of 6.0E-5 M. Addition of t-butyl alcohol, an effective radical scavenger which readily reacts with OH radicals, supressed the dissolution of TcO2nH2O colloids. This reaction indicates that TcO2nH2O molecules are oxidized by OH radicals produced in cavitation bubbles. Received: 20 November 2009; Revised:14 April 2010; Accepted: 18 April 201

    Sonolytic Oxidation of Tc(IV)O2nH2O Nanoparticles to Tc(VII)O4 in Aqueous Solution

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    Sonolysis of a hydrosol of TcO2nH2O was investigated in the Ar- or He- atmosphere. Colloidal TcO2nH2O nanoparticles were irradiated with a 200 kHz and 1.25 W/cm2 ultrasound. It was found that the TcO2nH2O colloids dispersed in an aqueous solution (under Ar or He atmosphere) was completely dissolved by ultrasonic irradiation (200 kHz, 200 W). The original brownish black color of the suspension slowly disappeared leaving behind a colorless solution. This change suggests that oxidation of Tc(IV) to Tc(VII) takes place. The oxidation was almost complete during 30 minutes sonication time under argon atmosphere for initial concentration of 6.0E-5 M. Addition of t-butyl alcohol, an effective radical scavenger which readily reacts with OH radicals, supressed the dissolution of TcO2nH2O colloids. This reaction indicates that TcO2nH2O molecules are oxidized by OH radicals produced in cavitation bubbles. Received: 20 November 2009; Revised:14 April 2010; Accepted: 18 April 201

    Transcription profiling reveals potential mechanisms of dysbiosis in the oral microbiome of rhesus macaques with chronic untreated SIV infection.

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    A majority of individuals infected with human immunodeficiency virus (HIV) have inadequate access to antiretroviral therapy and ultimately develop debilitating oral infections that often correlate with disease progression. Due to the impracticalities of conducting host-microbe systems-based studies in HIV infected patients, we have evaluated the potential of simian immunodeficiency virus (SIV) infected rhesus macaques to serve as a non-human primate model for oral manifestations of HIV disease. We present the first description of the rhesus macaque oral microbiota and show that a mixture of human commensal bacteria and "macaque versions" of human commensals colonize the tongue dorsum and dental plaque. Our findings indicate that SIV infection results in chronic activation of antiviral and inflammatory responses in the tongue mucosa that may collectively lead to repression of epithelial development and impact the microbiome. In addition, we show that dysbiosis of the lingual microbiome in SIV infection is characterized by outgrowth of Gemella morbillorum that may result from impaired macrophage function. Finally, we provide evidence that the increased capacity of opportunistic pathogens (e.g. E. coli) to colonize the microbiome is associated with reduced production of antimicrobial peptides

    Molecular and Phylogenetic Analysis of Thrips tabaci Lindeman (Thysanoptera: Thripidae) Infesting Chrysanthemum in Kashmir Region

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    Chrysanthemum (Dendranthema grandiflora L.), native to East Asia and cultivated for over 3,000 years, holds considerable economic significance, but is highly vulnerable to pests such as aphids, whiteflies, and thrips, resulting in substantial losses in both yield and quality. Accurate pest identification is crucial for developing effective management strategies. This study focuses on the molecular identification of thrips infesting this crop. Weekly field surveys were carried out from December 2022 to January 2025 in the polyhouse experimental fields of Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir. Molecular analysis involved DNA extraction, phylogenetic tree construction, and protein modeling. The study identified the thrips species as Thrips tabaci with 100% similarity, and the accession number is OR690649

    Quantitative analysis of prenylated RhoA interaction with its chaperone, RhoGDI

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    Small GTPases of the Rho family regulate cytoskeleton remodeling, cell polarity, and transcription, as well as the cell cycle, in eukaryotic cells. Membrane delivery and recycling of the Rho GTPases is mediated by Rho GDP dissociation inhibitor (RhoGDI), which forms a stable complex with prenylated Rho GTPases. We analyzed the interaction of RhoGDI with the active and inactive forms of prenylated and unprenylated RhoA. We demonstrate that RhoGDI binds the prenylated form of RhoA center dot GDP with unexpectedly high affinity (K-d = 5 pM). The very long half-life of the complex is reduced 25-fold on RhoA activation, with a concomitant reduction in affinity (K-d = 3 nM). The 2.8-angstrom structure of the RhoA center dot guanosine 5'-[beta,gamma-imido] triphosphate (GMPPNP)center dot RhoGDI complex demonstrated that complex formation forces the activated RhoA into a GDP-bound conformation in the absence of nucleotide hydrolysis. We demonstrate that membrane extraction of Rho GTPase by RhoGDI is a thermodynamically favored passive process that operates through a series of progressively tighter intermediates, much like the one that is mediated by RabGDI

    Studi dan Aplikasi Elektroda FeTiO3-TiO2/Ti untuk Degradasi Reactive Blue 160 dengan Metode Fotoelektrokatalisis: Study and Application of Photoelectrocatalytic FeTiO3-TiO2/ Ti Electrode to High-Degradation of Reactive Blue 160

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    The manufacture of titanium dioxide (TiO2) electrodes is made by anodizing method and coated with ilmenite (FeTiO3) through a dip-coating technique. The ilmenite (FeTiO3) coated TiO2/Ti plate electrode was developed for the degradation of the reactive blue 160 dye under photoelectrocatalytic UV and Visible light irradiation. The performance of FeTiO3-TiO2 / Ti composites degrades reactive blue 160 under UV irradiation and is visible photoelectrocatalytically compared to TiO2. The results of XRD characterization of TiO2 crystals in the form of anatase at 2θ, namely 35.1 ° (110), and the substitution of Fe dopant on TiO2 in the form of anatase and rutile crystals. FTIR data indicated the presence of Fe-O bonds at wave numbers <700 nm. SEM-EDX results showed a thin layer of FeTiO3 was formed, indicating that the dip-coating method was effective in the coating process. The performance of the FeTiO3-TiO2 / Ti electrode has the highest activity against the oxidation process under visible light than the TiO2/Ti electrode. The results of degradation of reactive blue 160 dye with a concentration of 0.5 ppm by photoelectrocatalytic showed that the TiO2 / Ti and FeTiO3-TiO2/Ti electrodes were active in visible irradiation with degradation rate constants of 48% and 69%. Keywords: Electrodes, ilmenite, TiO2 / Ti, degradation, reactive blue 160, photoelectrocatalysi

    Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

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    BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

    Biological nitrification inhibition (BNI) activity in sorghum and its characterization

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    Aims The ability to suppress soil nitrification through the release of nitrification inhibitors from plant roots is termed ‘biological nitrification inhibition’ (BNI). Here, we aimed at the quantification and characterization of the BNI function in sorghum that includes inhibitor production, their chemical identity, functionality and factors regulating their release. Methods Sorghum was grown in solution culture and root exudate was collected using aerated NH4Cl solutions. A bioluminescence assay using recombinant Nitrosomonas europaea was employed to determine the BNI activity. Activity-guided chromatographic fractionation was used to isolate biological nitrification inhibitors (BNIs). The chemical structure was analyzed using NMR and mass spectrometry; pH-stat systems were deployed to analyze the role of rhizosphere pH on BNIs release. Results Sorghum roots released two categories of BNIs: hydrophilic- and hydrophobic-BNIs. The release rates for hydrophilic- and hydrophobic- BNIs ranged from 10 to 25 ATU g−1 root dwt. d−1. Addition of hydrophilic BNIs (10 ATU g−1 soil) significantly inhibited soil nitrification (40 % inhibition) during a 30-d incubation test. Two BNI compounds isolated are: sakuranetin (ED80 0.6 μM; isolated from hydrophilic-BNIs fraction) and sorgoleone (ED80 13.0 μM; isolated from hydrophobic-BNIs fraction), which inhibited Nitrosomonas by blocking AMO and HAO enzymatic pathways. The BNIs release required the presence of NH4+ in the root environment and the stimulatory effect of NH4+ lasted 24 h. Unlike the hydrophobic-BNIs, the release of hydrophilic-BNIs declined at a rhizosphere pH >5.0; nearly 80 % of hydrophilic-BNI release was suppressed at pH ≥7.0. The released hydrophilic-BNIs were functionally stable within a pH range of 5.0 to 9.0. Sakuranetin showed a stronger inhibitory activity (ED50 0.2 μM) than methyl 3-(4-hydroxyphenyl) propionate (MHPP) (ED50 100 μM) (isolated from hydrophilic-BNIs fraction) in the in vitro culture-bioassay, but the activity was non-functional and ineffective in the soil-assay. Conclusions There is an urgent need to identify sorghum genetic stocks with high potential to release functional-BNIs for suppressing nitrification and to improve nitrogen use efficiency in sorghum-based production systems
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