3,698 research outputs found
Effect of dissolved oxygen and chemical oxygen demand to nitrogen ratios on the partial nitrification/denitrification process in moving bed biofilm reactors
Partial nitrification was reported to be technically feasible and economically favorable, especially for wastewater with high ammonium concentration or low C/N ratio. In this study, the effect of dissolved oxygen (DO) and influent ratio of chemical oxygen demand to nitrogen (COD/N) ratio on biological nitrogen removal from synthetic wastewater was investigated. Experiments were conducted in moving bed biofilm reactors (MBBRs) on partial nitrification process in pilot-plant configuration for 300 days. DO levels were changed from 0.04 to 0.12 and 0.42 to 3.4 mg/l in the anoxic (R1) and aerobic (R2) reactors, respectively. The optimum DO for partial nitrification was between 1-1.5 mg/l in the aerobic reactor (R2). Influent COD/N ratios between 20 and 2 g COD/g-N were tested by changing the nitrogen loading rate (NLR) supplied to the pilot plant. During operational conditions when the DO concentration in aerobic reactor was above 1 mg/l, near complete organic carbon removal occurred in the total MBBRs system. The effluent total nitrogen concentration in the operational conditions (1.7-2.1 mg O2/l and NH+ 4-N=35.7 mg N/l) was obtained in the range of 0.85-2 mg/l. The highest nitrite accumulation (50%- 52%) took place at the DO concentration of 1-1.5 mg/l and increased with decreasing COD/N ratio in aerobic reactor (R2). This study showed that the average nitrification rate at various COD/N ratios is about 0.96 gN/m2 per day while the maximum nitrification rate is about 2 gN/m2 per day at COD/N ratios lower than 6. The experimental COD/N ratio for denitrification was close to complete sum of NO2 - and NO3 - (NOx) removal efficiency (about 99%) at COD/N ratio equal 14 in the operational conditions in the anoxic reactor (R1)
Effects of date palm fruit extracts on skin mucosal immunity, immune related genes expression and growth performance of common carp (Cyprinus carpio) fry
The aim of this study was to investigate the effects of date palm fruit extracts (DPFE) on skin mucosal immunity, immune related genes expression and growth performance of fry common carp (Cyprinus carpio). One hundred and twenty specimens (4.06 ± 0.13 g) were supplied and allocated into six aquaria; specimens in three aquaria were fed non-supplemented diet (control) while the fish in the other 3 aquaria were fed with DPFE at 200 ml kg-1. At the end of feeding trial (8 weeks) skin mucus immune parameters (total immunoglobulins, lysozyme, protease and alkaline phosphatase activity) and immune related gene expression (tumor necrosis factor α [tnfa], lysozyme [ly] and interleukin-1-beta, [il1b]) in the head-kidney were studied. The results revealed that feeding carp fry with 200 ml kg-1 DPFE remarkably elevated the three skin mucus immune parameters tested (P 0.05) compared to control fish (fed control diet). Furthermore, growth performance parameters were significantly improved in fry fed DPFE (P < 0.05). More studies are needed to understand different aspects of DPFE administration in fry mucosal immunity. © 2015 Elsevier Ltd
Interleukin-1 alpha variation is associated with the risk of developing preeclampsia
Objective Preeclampsia is a syndrome that affects 5 of all pregnancies, producing substantial maternal and prenatal morbidity and mortality. Several studies have reported that cytokine genes are associated with the persistence of preeclampsia or the severity of the disease. The aim of this study is to investigate the relationships between the polymorphisms of interleukin-1 alpha-889 (IL-1A) gene and preeclampsia. Method Genomic DNA was extracted from the peripheral blood of 305 patients with preeclampsia and 325 normal controls from Sayyad Shirazi Hospital of Golestan University. Then subjected to SSP-PCR amplification. STATA software and the chi square test were used for statistic calculations. Results The frequencies of IL-1A -889 genotypes C/C, T/T and C/T in preeclampsia cases were 34.8, 8.2, 57 and in controls were 20.9, 7.6 and 71.3 respectively. There was a significant 1.5 fold excess frequency in genotype C/C in cases (CI = 1.44-3.07, OR = 2.1, P = 0.0001). There was a significant difference in the frequencies of alleles or genotypes in IL-1A promoter regions between patients with preeclampsia and the control group. Turkomans showed the highest frequency of the C allele and Sistanies had the lowest frequency of the C allele in preeclampsia compared to control groups (CI = 1.5-3.9, OR = 2.48, P = 0.0001). Conclusion Our findings suggest that the IL-1A-899C/C genotype and C allele are associated with susceptibility to preeclampsia. © 2015 Elsevier Ireland Ltd. All rights reserved
Interleukin-6-174 promoter polymorphism and susceptibility to hepatitis B virus infection as a risk factor for hepatocellular carcinoma in Iran
Background: Hepatitis B virus (HBV) is a major risk factor for hepatocellular carcinoma (HCC). Cytokines play an important role in the regulation of immune responses and defense against viral infections. Human interleukin 6 (IL6) is a multifunctional cytokine that participates in these processes. Objective: The aim of this study was to assess the IL6-174 gene polymorphism in patients with chronic hepatitis B virus (HBV) infection as compared with healthy controls in an Iranian population. Materials and Methods: Totals of 297 HBV patients and 368 control individuals were evaluated. Genomic DNA was extracted from peripheral blood and the SSPPCR (sequence specific primer-polymerase chain reaction) method was applied for genotyping. Results: The frequencies of genotypes C/C, G/G and C/G in HBV cases were 4.7, 34.3, 60.9 and in controls were 12.8, 39.7 and 47.6, respectively. The frequencies of G and C allele in patients and controls were 78.1, 21.9 and 67.4, 32.6 respectively. There was a significant difference in the frequencies of G/G genotype (CI=1.8-7.1, OR=3.47, P=0.00001) and G allele (CI=1.34-2.23, OR=1.72, P=0.0001) between HBV patients and the control group. Conclusions: These findings suggest that the IL6-174 C/G genotype and the G allele are strongly associated with susceptibility to HBV infection. Demographic information showed that most of the subjects were male (74.4). According to high frequency of G/G genotype in male participants (63.1) men probably are more susceptible to hepatitis than women
Effectiveness of chitosan as natural coagulant aid in removal of turbidity and bacteria from turbid waters
There has been considerable interest in the development of natural coagulants such as chitosan. By using natural coagulants, considerable savings in chemicals and sludge handling cost may be achieved. Chitosan, a natural linear biopolyaminosaccharide, is obtained by alkaline deacetylation of chitin. Present study is aimed to examine the effects of aluminium sulfate (alum) as coagulant in conjunction with chitosan as coagulant aid on removal of turbidity and bacteria from turbid waters. These tests were carried out using artificial water and kaoline as model suspensions to represent the wide range of natural turbid waters. A conventional jar test apparatus was employed for the tests. After determining of optimum mixing intensity and duration, alum suspensions were added to the samples and after one minute, the desired doses of natural chitosan were added. In optimum condition, residual Al+3 in treated water was less than 0.2 mg/l and meets the EPA guidelines. Turbidity removal efficiency was 74.3- 98.2% by chitosan at a pH 7.0-7.5 for all turbidities. In addition, chitosan significantly reduced the required dosage of primary coagulant 50-87.5%. Bacteria reduction of 2-4 log units (99 - 99.99%) was obtained within the first 1 to 2 h of treatment. Overall results indicate that E.coli was removed better than S. faecalis. The main effects of coagulation by chitosan on bacteria are enmeshment and stack on the microbial cell surface. We demonstrated that optimal design method is an efficient approach for optimization of coagulation-flocculation process and appropriate for raw water treatment
Global dynamic topography observations reveal limited influence of large-scale mantle flow
Convective circulation of the Earth’s mantle maintains some fraction of surface topography that varies with space and time. Most predictive models show that this dynamic topography has peak amplitudes of about ±2km, dominated by wavelengths of 10⁴km. Here, we test these models against our comprehensive observational database of 2,120 spot measurements of dynamic topography that were determined by analysing oceanic seismic surveys. These accurate measurements have typical peak amplitudes of ±1km and wavelengths of approximately 10³km, and are combined with limited continental constraints to
generate a global spherical harmonic model whose robustness has been carefully tested and benchmarked. Our power spectral analysis reveals significant discrepancies between observed and predicted dynamic topography. At longer wavelengths (such as 10⁴km), observed dynamic topography has peak amplitudes of about ±500m. At shorter wavelengths (such as 10³km), significant dynamic topography is still observed. We show that these discrepancies can be explained if short-wavelength dynamic topography is generated by temperature-driven density anomalies within a sub-plate asthenospheric channel. Stratigraphic observations from adjacent continental margins show that these dynamic topographic signals evolve quickly with time. More rapid temporal and spatial changes in vertical displacement of the Earth’s surface have direct consequences for fields as diverse as mantle flow, oceanic circulation and long-term climate change
Analisis Potensi dan Arahan Strategi Kebijakan Pengembangan Desa Ekowisata di Kecamatan Bumiaji Kota Batu
Kota Batu merupakan salah satu daerah otonom di Provinsi Jawa Timur yang mengandalkan sektor pariwisata untuk meningkatkan pendapatan asli daerah (PAD). Pengembangan pariwisata lebih mengarah pada objek wisata artifisial atau buatan yang dibangun oleh investor namun menimbulkan permasalahan lingkungan. Perlu alternatif lain pengembangan pariwisata yaitu obyek wisata yang mampu menekan dampak kerusakan lingkungan sekaligus meningkatkan peran masyarakat lokal dan kesejahteraannya yaitu pengembangan Desa Ekowisata berbasis Community Based Ecotourism (CBE). Penelitian ini bertujuan untuk melakukan penilaian potensi wisata dan obyek daya tarik wisata (ODTW) di desa desa wisata, menganalisis kesiapan terhadap pengembangan desa ekowisata, menganalisis desa wisata yang paling optimal untuk pengembangan desa ekowisata dan menentukan arahan strategi kebijakan pengembangan desa ekowisata di Kecamatan Bumiaji Kota Batu. Penelitian ini merupakan penelitian deskriptif. Pengumpulan data dengan survei primer dan sekunder. Pendekatan yang digunakan adalah Analisis potensi wisata dan obyek daya tarik wisata (ODTW), Penilaian kesiapan pengembangan Community Based Ecotourism (CBE), Analisis spasial dan Analisis SWOT. Hasil penelitian menunjukkan seluruh desa wisata di Kecamatan Bumiaji memiliki potensi wisata dan obyek daya tarik wisata (ODTW) berupa atraksi alam, sumberdaya pertanian dan budaya yang dapat lebih dikembangkan. Penilaian potensi wisata dan obyek daya tarik wisata (ODTW) menunjukkan Desa Tulungrejo dan Desa Sumberbrantas termasuk klasifikasi Sangat Baik; Analisis kesiapan terhadap pengembangan desa ekowisata berbasis masyarakat (CBE) menunjukkan Desa Tulungrejo dan Desa Bumiaji termasuk dalam klasifikasi Baik. Hasil analisis spasial menunjukkan Desa Tulungrejo merupakan desa yang paling optimal untuk pengembangan desa ekowisata di Kecamatan Bumiaji. Analisis Matrik Grand Strategy menunjukkan arahan strategi kebijakan pengembangan Desa Ekowisata di Desa Tulungrejo terletak pada kuadran 1, strategi yang digunakan bersifat agresif (SO). Kata Kunci : Kota Batu, pengembangan, potensi dan ODTW, Desa Ekowisat
Pilot-scale studies of combined clarification, filtration, and ultraviolet radiation systems for disinfection of secondary municipal wastewater effluent
Disinfection of municipal wastewater effluent was evaluated using three alternatives, including: (1) low-pressure (LP)+medium-pressure (MP) UV lamps; (2) clarifier+LP+MP; and (3) pressurized sand filter+ LP+MP. Total coliform (TC), fecal coliform (FC), fecal Streptococcus (FS), TSS, several physicochemical parameters, absorbtivity and UV transmittance (UVT; ) were tested. The UVT for secondary, clarified and filtered effluents were 3.5, 34 and 50, respectively. A 15 photo-reactivation in secondary effluent disinfected by LP lamp was observed, while it was limited to 0.03 by the MP lamp after filtration. Filtration to a surface overflow rate (SOR) of 1050 L/m2h, followed by MP irradiation at a dose of 230 mW s/cm2 was an effective alternative to reduce the TC, FC, and FS in the disinfected secondary effluent. Filtration+MP lamp met the standards of 1000 TC and 400 FC/100 mL for effluent discharge to receiving waters. This process can also inactivate FS, effecting a 6-log reduction. Among the evaluated alternatives, none of the other treatment systems performed as well as the pressurized sand filter+MP lamp, making this the best combination for post-treatment and disinfection of secondary effluent from a well-run wastewater treatment plant. © 2010 Elsevier B.V. All rights reserved
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Discrete wavelet transform based freezing of gait detection in Parkinson's disease
Wearable on body sensors have been employed in many applications including ambulatory monitoring and pervasive computing systems. In this work, a wearable assistant has been created for people suffering from Parkinson’s disease (PD), specifically with the Freezing of Gait (FoG) symptom. Wearable accelerometers were placed on the person’s body and used for movement measure. When FoG is detected, a rhythmic audio signal was given from the wearable assistant to motivate the wearer to continue walking. Long term monitoring results in collecting huge amounts of complex raw data; therefore, data analysis becomes impractical or infeasible resulting in the need for data reduction. In the present study, Discrete Wavelet Transform (DWT) has been used to extract the main features inherent in the key movement indicators for FoG detection. The discrimination capacities of these features were assessed using, i) Support Vector Machine (SVM) using a linear kernel function, and ii) Artificial Neural Network (ANN) with a two-layer feed-forward with hidden layer of 20 neurons that trained with conjugate gradient back- propagation. Using these two different machine learning techniques, we were capable of detecting FoG with an accuracy of 87.50% and 93.8%, respectively. Additionally, the comparison between the extracted features from DWT coefficients with those using Fast Fourier Transform (FFT) established accuracies of 93.8% and 81.3%, respectively. Finally, the discriminative features extracted from DWT yield to a robust multidimensional classification model compared to models in the literature based on a single feature. The work presented paves the way for reliable, real-time wearable sensors to aid people with PD
Procalcitonin Identifies Cell Injury, Not Bacterial Infection, in Acute Liver Failure
Background Because acute liver failure (ALF) patients share many clinical features with severe sepsis and septic shock, identifying bacterial infection clinically in ALF patients is challenging. Procalcitonin (PCT) has proven to be a useful marker in detecting bacterial infection. We sought to determine whether PCT discriminated between presence and absence of infection in patients with ALF. Method Retrospective analysis of data and samples of 115 ALF patients from the United States Acute Liver Failure Study Group randomly selected from 1863 patients were classified for disease severity and ALF etiology. Twenty uninfected chronic liver disease (CLD) subjects served as controls. Results
Procalcitonin concentrations in most samples were elevated, with median values for all ALF groups near or above a 2.0 ng/mL cut-off that generally indicates severe sepsis. While PCT concentrations increased somewhat with apparent liver injury severity, there were no differences in PCT levels between the pre-defined severity groups–non-SIRS and SIRS groups with no documented infections and Severe Sepsis and Septic Shock groups with documented infections, (p = 0.169). PCT values from CLD patients differed from all ALF groups (median CLD PCT value 0.104 ng/mL, (p ≤0.001)). Subjects with acetaminophen (APAP) toxicity, many without evidence of infection, demonstrated median PCT \u3e2.0 ng/mL, regardless of SIRS features, while some culture positive subjects had PCT values Summary/Conclusions While PCT appears to be a robust assay for detecting bacterial infection in the general population, there was poor discrimination between ALF patients with or without bacterial infection presumably because of the massive inflammation observed. Severe hepatocyte necrosis with inflammation results in elevated PCT levels, rendering this biomarker unreliable in the ALF setting
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