61 research outputs found
An Adaptive Fuzzy Logic System for the Compensation of Nonlinear Distortion in Wireless Power Amplifiers
Computational intelligent systems are becoming an increasingly attractive solution for power amplifier (PA) behavioural modelling, due to their excellent approximation capability. This paper utilizes an adaptive fuzzy logic system (AFLS) for the modelling of the highly nonlinear MIMIX CFH2162-P3 PA. Moreover, PA’s inverse model based also on AFLS has been developed in order to act as a pre-distorter unit. Driving an LTE 1.4 MHz 64 QAM signal at 880 MHz as centre frequency at PA’s input, very good modelling performance was achieved, for both PA’s forward and inverse dynamics. A comparative study of AFLS and neural networks (NN) has been carried out to establish AFLS as an effective, robust, and easy-to-implement baseband model, which is suitable for inverse modelling of PAs and capable to be used as an effective digital pre-distorter. Pre-distortion system based on AFLS, achieved distortion suppression of 84.2%, compared to the 48.4% gained using the NN-based equivalent schem
Prospect and potential of Burkholderia sp. against Phytophthora capsici Leonian: a causative agent for foot rot disease of black pepper
Foot rot disease is a very destructive disease in black pepper in Malaysia. It is caused by Phytophthora capsici Leonian, which is a soilborne pathogenic protist (phylum, Oomycota) that infects aerial and subterranean structures of many host plants. This pathogen is a polycyclic, such that multiple cycles of infection and inoculum production occur in a single growing season. It is more prevalent in the tropics because of the favourable environmental conditions. The utilization of plant growth-promoting rhizobacteria (PGPR) as a biological control agent has been successfully implemented in controlling many plant pathogens. Many studies on the exploration of beneficial organisms have been carried out such as Pseudomonas fluorescens, which is one of the best examples used for the control of Fusarium wilt in tomato. Similarly, P. fluorescens is found to be an effective biocontrol agent against the foot rot disease in black pepper. Nowadays there is tremendous novel increase in the species of Burkholderia with either mutualistic or antagonistic interactions in the environment. Burkholderia sp. is an indigenous PGPR capable of producing a large number of commercially important hydrolytic enzymes and bioactive substances that promote plant growth and health; are eco-friendly, biodegradable and specific in their actions; and have a broad spectrum of antimicrobial activity in keeping down the population of phytopathogens, thus playing a great role in promoting sustainable agriculture today. Hence, in this book chapter, the potential applications of Burkholderia sp. to control foot rot disease of black pepper in Malaysia, their control mechanisms, plant growth promotion, commercial potentials and the future prospects as indigenous PGPR were discussed in relation to sustainable agriculture
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
Experimental study of flows over Block Ramps on stability of non-cohesive beds
Block ramps are ecofriendly drop structures, which ensure more stability in the downstream riverbed. The scouring in the stilling basin bed material generated by the rapidly varied flow transition affects the stability of the ramp structure. In the present study, a modified stilling basin bed configuration is tested along with the uniform conventional stilling basin bed arrangements to check the stability of non-cohesive beds downstream to block ramps. Uniform non-cohesive horizontal bed configurations and bed with sill arrangement are tested for varying block ramp slopes (20% ≤ i ≥ 30%). The critical particle densimetric Froude number (Fc*) is selected as the criteria to predict the hydraulic conditions for incipient sediment motion in the uniform beds and it is compared with the established literature formulations to estimate the stability of the beds under macroroughness conditions. Scour volumes from each experimental run is quantified and the intensity of sediment motion is determined and related with the critical particle densimetric Froude number. The findings of the paper also describe the effect of Fc* on dimensionless scour depth. Spatial shift in the maximum scour depth formation from the toe of the block ramp for the tested flows over the bed sill arrangement has been observed. Experimental observations and comparison of results show the effect of sill gradation pronounced for non-uniform bed configuration, which effectively reduce the scour depth henceforth it stabilizes the upstream block ramp structure relative to the uniform beds selected
Using mycorrhiza helper microorganisms (MHM) to improve the mycorrhizal efficiency on plant growth
In the context of the “New Green Revolution,” innovative agricultural practices have to be identified to sustainably improve the traditional cultural approaches already used in the green revolution and to apply efficient technologies to solve actual agricultural problems (more particularly in the developing countries) but without the use of chemical pesticides and fertilizers. To reach this objective, soil microbes represent a largely unexplored resource to promote agricultural yield and productivity in the context of sustainable farming practices. Among these beneficial microorganisms, arbuscular mycorrhizal fungi (AMF) form symbiotic association with ~80% of vascular plant species. These efficient symbionts are considered as a key group of soil microorganisms able to improve P uptake by plants. In addition, AMF have the potential to improve plant defense against plant pathogens and to promote plant tolerance against abiotic stresses. AMF are primary biotic soil components which, when missing or impoverished, e.g., due to anthropic input, can lead to a less efficient ecosystem functioning. Many environmental factors can affect the impact of AMF inoculation on the plant growth including the fungal species compatibility with soil characteristics and the interactions between the fungal inoculant and other soil microorganisms. Some microorganisms, named mycorrhiza helper bacteria (MHB), can facilitate the establishment and the functioning of the AMF symbiosis by stimulating spore germination, mycelial growth, root colonization, or sporulation but also by reducing stresses that could impact AMF symbiosis. The aim of this chapter is to review mechanisms implemented by MHB to promote the AMF establishment and to enhance the efficiency of the mycorrhizal effect on the plant growth. Using Mycorrhiza Helper Microorganisms (MHM) to Improve the Mycorrhizal Efficiency on Plant Growth
- …