Stability and maturity of thickened wastewater sludge treated in pilot-scale sludge treatment wetlands

Thickened wastewater activated sludge was treated in 13 pilot-scale sludge treatment wetlands of various configurations that operated continuously for three years in North Greece. Sludge was loaded for approximately 2.5 years, and the beds were left to rest for the remaining period. Three different sludge loading rates were used that represented three different population equivalents. Residual sludge stability and maturity were monitored for the last year. Sludge was regularly sampled and microbial respiration activity indices were measured via a static respiration assay. The phytotoxicity of sludge was quantified via a seed germination bioassay. Measurements of total solids, organic matter, total coliforms, pH and electrical conductivity were also made. According to microbial respiration activity measurements, the sludge end-product was classified as stable. The germination index of the final product exceeded 100% in most wetland units, while final pH values were approximately 6.5. The presence of plants positively affected the stability and maturity of the residual sludge end-product. Passive aeration did not significantly affect the quality of the residual sludge, while the addition of chromium at high concentrations hindered the sludge decomposition process. Conclusively, sludge treatment wetlands can be successfully used, not only to dewater, but also to stabilize and mature wastewater sludge after approximately a four-month resting phase.     

Detection of small bowel polyps and ulcers in wireless capsule endoscopy videos

Over the last decade, wireless capsule endoscopy (WCE) technology has become a very useful tool for diagnosing diseases within the human digestive tract. Physicians using WCE can examine the digestive tract in a minimally invasive way searching for pathological abnormalities such as bleeding, polyps, ulcers, and Crohn's disease. To improve effectiveness of WCE, researchers have developed software methods to automatically detect these diseases at a high rate of success. This paper proposes a novel synergistic methodology for automatically discovering polyps (protrusions) and perforated ulcers in WCE video frames. Finally, results of the methodology are given and statistical comparisons are also presented relevant to other works.     

Lipid-Modulating Treatments for Mixed Dyslipidemia Increase HDL-Associated Phospholipase A2 Activity with Differential Effects on HDL Subfractions

The effect of lipid-modulating treatments on modification of high density lipoprotein (HDL) subfractions remains unknown. In this study, mixed dyslipidemia patients (n = 100) inadequately controlled with a standard statin dose were randomized to switch to 40 mg of rosuvastatin or add-on extended release nicotinic acid/laropiprant (ER-NA/LRPT) or add-on fenofibrate. The cholesterol concentrations of HDL (HDL-C) subfractions and HDL-associated lipoprotein-associated phospholipase A₂ (HDL-Lp-PLA₂) activity were assessed at baseline and 3 months later. We observed that large HDL-C increased by 50 and 6 % in the add-on-ER-NA/LRPT and rosuvastatin groups, respectively, while it decreased by 20 % in the add-on-fenofibrate group (p < 0.01 vs baseline for all groups and p < 0.01 for all comparisons among groups). On the other hand, small HDL-C decreased by 17 % in the add-on-ER-NA/LRPT group (p < 0.01 vs baseline), while it increased by 25 % in the add-on-fenofibrate group (p < 0.01 vs baseline) without any change in the rosuvastatin group (p < 0.01 for all comparisons among groups). HDL-Lp-PLA₂ activity increased by 55, 33 and 18 % in add-on-ER-NA/LRPT, add-on-fenofibrate and rosuvastatin groups, respectively (p < 0.01 for all comparisons vs baseline and for all comparisons among groups). In conclusion, add-on-ER-NA/LRPT was associated with an increase in large HDL-C and a decrease in small HDL-C, while opposite effects were noticed in the add-on-fenofibrate group. Add-on-ER-NA/LRPT was associated with the most pronounced increase in HDL-Lp-PLA₂ activity.     

Decomposition of Cost Efficiency Into Persistent and Transient Efficiency in the Provision of Water Services: Evidence from England and Wales

Water Resources Management - Performance assessments of water utilities are essential to protect the interests of citizens, because utilities operate under natural monopolies and their costs are...     

Design of a modern automatic control system for the activated sludge process in wastewater treatment

The Activated Sludge Process (ASP) exhibits highly nonlinear properties. The design of an automatic control system that is robust against disturbance of inlet wastewater flow rate and has short process settling times is a chal enging matter. The proposed control method is an I-P modified controller automatic control system with state variable feedback and control canonical form simulation diagram for the process. A more stable response is achieved with this type of modern control. Settling times of 0.48 days are achieved for the concentration of microorganisms, (reference value step increase of 50 mg·L?1) and 0.01 days for the concentration of oxygen (reference value step increase of 0.1 mg·L?1). Fluctuations of concentrations of oxygen and microorganisms after an inlet disturbance of 5 × 103m3·d?1 are smal . Changes in the reference values of oxygen and microorganisms (increases by 10%, 20%and 30%) show satisfactory response of the system in al cases. Changes in the value of inlet wastewater flow rate disturbance (increases by 10%, 25%, 50%and 100%) are stabilized by the control system in short time. Maximum percent overshoot is also taken in consideration in all cases and the largest value is 25%which is acceptable. The proposed method with I-P controller is better for disturbance rejection and process settling times compared to the same method using PI control er. This method can substitute optimal control systems in ASP.     

The effect of hard and soft information and communication technologies investment on manufacturing business performance in Greece – A preliminary econometric study

This paper presents the results of the first empirical investigation of the effect of information and communication technologies (ICT) investment on business performance in Greece. It investigates the effect of both ‘hard’ ICT investment (in ICT hardware, software and networks) and ‘soft’ ICT investment (in ICT human resources, skills and organization) on firm output. It is based on data from big Greek industrial firms, which have been collected via a questionnaire-based survey conducted in cooperation with the Federation of Greek Industries (FGI). Using these data, econometric models of output have been constructed based on the microeconomic production theory. Our analysis shows that the Cobb–Douglas production function can adequately describe the output, as compared to the more general transcendental production function. Using this type of production function it has been found that hard ICT investment in Greece makes a positive and statistically significant contribution to firm output; however its output elasticity is lower than the one of the non-computer capital and much lower than the one of the labour. Also, from the dimensions-measures of the soft ICT investment we examined, it has been found that the existence of a separate ICT department has a positive and statistically significant effect on firm output, which is of considerable magnitude of about two thirds of the effect of the hard ICT investment. The possibility of an effect of firm size on the structural stability of the econometric models we employed was also investigated; it was found that for firms with total sales above about €20 million the structure of the models is reasonably stable, and therefore the conclusions drawn from them are valid, at least for the range of firm sizes that our data cover.     

Assessing the Use of the sGC Stimulator BAY-747, as a Potential Treatment for Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder, affecting one in 3500 to 5000 boys worldwide. The NO-sGC-cGMP pathway plays an important role in skeletal muscle function, primarily by improving blood flow and oxygen supply to the muscles during exercise. In fact, PDE5 inhibitors have previously been investigated as a potential therapy for DMD, however, a large-scale Phase III clinical trial did not meet its primary endpoint. Since the efficacy of PDE5i is dependent on sufficient endogenous NO production, which might be impaired in DMD, we investigated if NO-independent sGC stimulators, could have therapeutic benefits in a mouse model of DMD. Male mdx/mTR^G2 mice aged six weeks were given food supplemented with the sGC stimulator, BAY-747 (150 mg/kg of food) or food alone (untreated) ad libitum for 16 weeks. Untreated C57BL6/J mice were used as wild type (WT) controls. Assessments of the four-limb hang, grip strength, running wheel and serum creatine kinase (CK) levels showed that mdx/mTR^G2 mice had significantly reduced skeletal muscle function and severe muscle damage compared to WT mice. Treatment with BAY-747 improved grip strength and running speed, and these mice also had reduced CK levels compared to untreated mdx/mTR^G2 mice. We also observed increased inflammation and fibrosis in the skeletal muscle of mdx/mTR^G2 mice compared to WT. While gene expression of pro-inflammatory cytokines and some pro-fibrotic markers in the skeletal muscle was reduced following BAY-747 treatment, there was no reduction in infiltration of myeloid immune cells nor collagen deposition. In conclusion, treatment with BAY-747 significantly improves several functional and pathological parameters of the skeletal muscle in mdx/mTR^G2 mice. However, the effect size was moderate and therefore, more studies are needed to fully understand the potential treatment benefit of sGC stimulators in DMD.