961 research outputs found

    Performance of a pilot-scale biofilters and constructed wetland with ornamental plants in greywater treatment

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    Partially treated black water from septic tanks and grey water from households in Kuching City were polluting the Sarawak River. A pilot scale ecological sanitation was implemented where blackwater was held in septic tanks and greywater was channeled to a grease trap, biofilters and a constructed wetland before discharge. The objectives of this study were to evaluate the efficiency of the biofilters and the constructed wetland with two species of terrestrial ornamental plants in greywater treatment. For the combined system, results indicated that the influent dissolved oxygen of below 1 mg/L improved to 3.4-4.6 mg/L. Removal of biochemical oxygen demand (BOD ) and chemical oxygen demand (COD) were the highest (99 and 95%). 5 Influent fecal coliform (FC) of 4.0x105 CFU/100mL dropped to 6.3x102 CFU/100mL at the effluent. More than 80% of ammonia-nitrogen (NH -N), total nitrogen (TN) and total suspended solids (TSS) were removed. Reactive 4 phosphorus (RP) and total phosphorus (TP) removals were 64 and 61% respectively. The biofilters contributed most of the total removal of BOD , COD, FC and NH -N. However, the wetland and biofillters were equally 5 4 efficient in TSS removal. The removal efficiency of the wetland in decreasing order was NO -N>FC> 3 TSS>BOD >TN>COD>NH -N>RP>TP and all removals exceeded 55% with the exception of P (38-39%). Both 5 4 species of plants grown on the wetland contained significantly higher weight and P content than the control. Tissue P content of F. microcarpa was significantly higher than S. campanulatum indicating F. microcarpa as a better accumulator of P. This indicates that constructed wetland with F. microcarpa could be potentially implemented in urban housing areas to reduce river pollution

    Physicochemical parameters of Bakun Reservoir in Belaga, Sarawak, Malaysia 13 months after reaching full supply level

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    Determining the water quality of Bakun Reservoir 13 months after it operates at full supply level is crucial for better understanding of changes in the physicochemical parameters, which may enable the prediction of its effects on the survival of aquatic life in the reservoir. This study determined 13 physicochemical parameters at six stations within the reservoir at fixed depths. The results showed that the minimum 5 mg/L of dissolved oxygen (DO) required for sensitive aquatic organisms was recorded at 6 m depth. However, DO was not detectable at depths exceeding 7 m. The water was acidic at depths of more than 10 m. Turbidity and total suspended solids increased corresponding with depth. Inorganic nitrogen were predominantly in the form of ammonia-nitrogen, creating an unhealthy environment for aquatic life. Concentration of Chl-a was significantly higher at the subsurface water than 30 m depth in four out of six stations. The present study shows changes in water quality as compared to the pre-impounded period and 15 months after the filling phase, in particular, stratification of dissolved oxygen, thermocline conditions and alkalinity. The changes varied according to the distance from the dam and may have been influenced by existing land developments within the area such as the construction of the Murum Hydroelectric Dam, oil palm plantations and timber concessionares. Though the water quality might have deteriorated, further study is needed to determine if this condition will prolong

    Ocular fundus pathology and chronic kidney disease in a Chinese population

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    <p>Abstract</p> <p>Background</p> <p>Previous study indicated a high prevalence of ocular fundus pathology among patients with chronic kidney disease (CKD), while the relationship between them has never been explored in a Chinese Population.</p> <p>Methods</p> <p>This cross-sectional study included 9 670 participants enrolled in a medical screening program. Ocular fundus examination was performed by ophthalmologists using ophthalmoscopes. The presence of eGFR less than 60 mL/min/1.73 m<sup>2 </sup>and/or proteinuria was defined as CKD.</p> <p>Results</p> <p>Compared to participants without CKD, participants with CKD had higher prevalence of retinopathy (28.5% vs. 16.3%, P < 0.001), glaucoma suspect (3.1% vs. 1.8%, P = 0.004), age-related macular degeneration (1.7% vs. 0.9%, P = 0.01) and overall eye pathology (32.0% vs. 19.4%, P < 0.001). After adjusting for potential confounders, the odds ratio of proteinuria for overall eye pathology and retinopathy was 1.29 (95% confidence interval [CI] 1.07-1.55) and 1.37 (95% CI 1.12-1.67), respectively. The results were robust after excluding participants with hypertension or with diabetes.</p> <p>Conclusions</p> <p>Ocular fundus pathology is common among Chinese patients with CKD. Regular eye exam among persons with proteinuria is warranted.</p

    Chinese version of the Global Youth Tobacco Survey: cross-cultural instrument adaptation

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    <p>Abstract</p> <p>Background</p> <p>Tobacco smoking poses public health concerns because of its high risk for many chronic diseases. Most smokers begin using tobacco in their teens and recent reports indicate that smoking prevalence is climbing among youth. The Global Youth Tobacco Survey (GYTS) is a worldwide, school-based, tobacco-specific survey, but cross-cultural differences limit its effectiveness in international studies. Specifically, the GYTS assesses not only the prevalence of smoking, but also tobacco-related attitudes, school curricula, and advertisements, which are culturally influenced. Therefore, we conducted this study to develop a Chinese version of the GYTS for both national surveillance and international comparison.</p> <p>Methods</p> <p>The original English GYTS was translated and back translated using a cross-cultural adaptation process. The comprehensiveness and feasibility of using the Chinese-version GYTS were reviewed by a panel of 6 tobacco-control experts. The understandability and cultural relevance of the Chinese-version GYTS were discussed in a focus group of 5 schoolteachers and 8 students. The expert and focus group feedback was incorporated into a final Chinese version of the GYTS, which was administered to 382 students throughout Taiwan by multi-stage sampling from 10 randomly selected schools.</p> <p>Results</p> <p>The internal consistency (Cronbach's alpha) for the GYTS subscales (smoking susceptibility, attitude toward smoking, and media messages about smoking) ranged from 0.70 to 0.94. The internal logical agreement of responses ranged from 85.3 to 99.2%.</p> <p>Conclusion</p> <p>The Chinese version of the GYTS has good reliability and validity and can serve as the foundation for international comparison and tobacco control in Chinese-speaking communities.</p

    PIPKIγ Regulates Focal Adhesion Dynamics and Colon Cancer Cell Invasion

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    Focal adhesion assembly and disassembly are essential for cell migration and cancer invasion, but the detailed molecular mechanisms regulating these processes remain to be elucidated. Phosphatidylinositol phosphate kinase type Iγ (PIPKIγ) binds talin and is required for focal adhesion formation in EGF-stimulated cells, but its role in regulating focal adhesion dynamics and cancer invasion is poorly understood. We show here that overexpression of PIPKIγ promoted focal adhesion formation, whereas cells expressing either PIPKIγK188,200R or PIPKIγD316K, two kinase-dead mutants, had much fewer focal adhesions than those expressing WT PIPKIγ in CHO-K1 cells and HCT116 colon cancer cells. Furthermore, overexpression of PIPKIγ, but not PIPKIγK188,200R, resulted in an increase in both focal adhesion assembly and disassembly rates. Depletion of PIPKIγ by using shRNA strongly inhibited formation of focal adhesions in HCT116 cells. Overexpression of PIPKIγK188,200R or depletion of PIPKIγ reduced the strength of HCT116 cell adhesion to fibronection and inhibited the invasive capacities of HCT116 cells. PIPKIγ depletion reduced PIP2 levels to ∼40% of control and PIP3 to undetectable levels, and inhibited vinculin localizing to focal adhesions. Taken together, PIPKIγ positively regulates focal adhesion dynamics and cancer invasion, most probably through PIP2-mediated vinculin activation

    The dependence of dijet production on photon virtuality in ep collisions at HERA

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    The dependence of dijet production on the virtuality of the exchanged photon, Q^2, has been studied by measuring dijet cross sections in the range 0 < Q^2 < 2000 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb^-1. Dijet cross sections were measured for jets with transverse energy E_T^jet > 7.5 and 6.5 GeV and pseudorapidities in the photon-proton centre-of-mass frame in the range -3 < eta^jet <0. The variable xg^obs, a measure of the photon momentum entering the hard process, was used to enhance the sensitivity of the measurement to the photon structure. The Q^2 dependence of the ratio of low- to high-xg^obs events was measured. Next-to-leading-order QCD predictions were found to generally underestimate the low-xg^obs contribution relative to that at high xg^obs. Monte Carlo models based on leading-logarithmic parton-showers, using a partonic structure for the photon which falls smoothly with increasing Q^2, provide a qualitative description of the data.Comment: 35 pages, 6 eps figures, submitted to Eur.Phys.J.

    Beauty photoproduction measured using decays into muons in dijet events in ep collisions at s\sqrt{s}=318 GeV

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    The photoproduction of beauty quarks in events with two jets and a muon has been measured with the ZEUS detector at HERA using an integrated luminosity of 110 pb1^{- 1}. The fraction of jets containing b quarks was extracted from the transverse momentum distribution of the muon relative to the closest jet. Differential cross sections for beauty production as a function of the transverse momentum and pseudorapidity of the muon, of the associated jet and of xγjetsx_{\gamma}^{jets}, the fraction of the photon's momentum participating in the hard process, are compared with MC models and QCD predictions made at next-to-leading order. The latter give a good description of the data.Comment: 32 pages, 6 tables, 7 figures Table 6 and Figure 7 revised September 200
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