Multivariate analysis of the sediment quality of a tropical coastal lake system

2014 ◽  
Vol 19 (4) ◽  
pp. 306-317 ◽  
Author(s):  
A. M. Sheela ◽  
J. Letha ◽  
S. Joseph ◽  
J. Joseph ◽  
J. Thomas
1993 ◽  
Vol 27 (5-6) ◽  
pp. 61-67 ◽  
Author(s):  
E. Jacobs ◽  
J. W. van Sluis

The surface water system of Amsterdam is very complicated. Of two characteristic types of water systems the influences on water and sediment quality are investigated. The importance of the sewer output to the total loads is different for both water systems. In a polder the load from the sewers is much more important than in the canal basin. Measures to reduce the emission from the sewers are much more effective in a polder. The effect of these measures on sediment quality is more than the effect on water quality. Some differences between a combined sewer system and a separate sewer system can be found in sediment quality.


2013 ◽  
Vol 27 (7) ◽  
pp. 2657-2670 ◽  
Author(s):  
A. M. Sheela ◽  
J. Letha ◽  
Joseph Sabu ◽  
K. K. Ramachandran ◽  
J. Justus

2021 ◽  
Author(s):  
Sonnia Nzilani Musyoka ◽  
Rita Nairuti

Semi-intensive aquaculture using ponds is among the most common practices of fish production, whose output depends highly on the ponds’ natural primary productivity. With the increased sustainability and health concerns with artificial fish feeds and chemical fertilizers, organic manure has been credited as a cheap, safe and sustainable alternative source of aquaculture nutrition. Apart from supplying nutrients to the phytoplankton, organic manures supply food directly to zooplankton and fish, provide substrate for microbes and improve water and pond sediment quality. Vermicompost fertilizer (excrete of earthworms) has been recognized as a potential pond fertilizer because it has superior nutritional quality (of up to five times), contains microbes, and is in ready-for-uptake form. Besides, the vermicompost contains humic acid, which has antibiotic properties, and promotes fish gut health, stress management, and immune systems. Nonetheless, the application of vermicompost fertilizer in aquaculture is still not a common practice. Therefore, this study reviews the concept of vermiculture vis-à-vis pond fertilization and the various utilizations of the vermicompost in fish farming. This is to enable fish farmers to make an informed decision on identifying and selecting proper biofertilizer, which can increase yields and cut costs of production, thus maximizing profits and improving resource utilization.


2020 ◽  
Vol 206 ◽  
pp. 02004
Author(s):  
Nianting Si ◽  
Liang Qu

Distribution of heavy metals (Hg, Cu, Pb, Zn, Cd and Cr) in the seawater and sediments were studied based on data from two oceanographic surveys carried out in Liaodong Bay in May and October 2016. The results showed that the values of heavy metals in seawater represent a uniform distribution, while no trends were detected for spatial distribution. High values of heavy metals in sediment were generally distributed nearshore areas in October. Concentrations of Pb, Zn, Hg in seawater were higher than the national guideline values of Mar. sediment quality of China. Values of Cu, Zn, Cd and Hg were higher than the national guideline values of Mar. sediment quality of China in October, while quality was in good condition in May. Correlation analysis showed that TOC was mainly contributed for the variations of heavy metals. The potential ecological risk analysis of heavy metals indicates that Hg, Cd and Cu should be listed as the priority contaminant metals in Liaodong Bay.


Author(s):  
Tania R. Prochnow ◽  
Bernardo Liberman ◽  
Nadia T. S. Pfeifer ◽  
Marilene G. Porawski ◽  
Norma Marroni ◽  
...  

This paper shows the results of air, water and sediment quality of Sapucaia stream, which belongs to Guafba Hydrographic Basin, in the State of Rio Grande do Sul, Southern Brazil. The correlations among the concentrations of Al, Cu, Fe, Mn, and Zn, present in the atmosphere, water and sediments, and their bioaccumulation in macrophytes are determined. Different degrees of pollution is characterized through the study of oxidative damage in fishes. The results indicate metal accumulation in macrophytes and fishes.


2019 ◽  
Vol 50 (2) ◽  
Author(s):  
Givanildo Zildo da Silva ◽  
Cibele Chalita Martins ◽  
Riselane de Lucena Alcântara Bruno ◽  
Francisco Elder Carlos Bezerra Pereira ◽  
Tatiane Sanches Jeromini

2019 ◽  
Vol 130 (5) ◽  
pp. 1692-1698 ◽  
Author(s):  
Mitchell P. Wilson ◽  
Andrew S. Jack ◽  
Andrew Nataraj ◽  
Michael Chow

OBJECTIVEReadmission to the hospital within 30 days of discharge is used as a surrogate marker for quality and value of care in the United States (US) healthcare system. Concern exists regarding the value of 30-day readmission as a quality of care metric in neurosurgical patients. Few studies have assessed 30-day readmission rates in neurosurgical patients outside the US. The authors performed a retrospective review of all adult neurosurgical patients admitted to a single Canadian neurosurgical academic center and who were discharged to home to assess for the all-cause 30-day readmission rate, unplanned 30-day readmission rate, and avoidable 30-day readmission rate.METHODSA retrospective review was performed assessing 30-day readmission rates after discharge to home in all neurosurgical patients admitted to a single academic neurosurgical center from January 1, 2011, to December 31, 2011. The primary outcomes included rates of all-cause, unplanned, and avoidable readmissions within 30 days of discharge. Secondary outcomes included factors associated with unplanned and avoidable 30-day readmissions.RESULTSA total of 184 of 950 patients (19.4%) were readmitted to the hospital within 30 days of discharge. One-hundred three patients (10.8%) were readmitted for an unplanned reason and 81 (8.5%) were readmitted for a planned or rescheduled operation. Only 19 readmissions (10%) were for a potentially avoidable reason. Univariate analysis identified factors associated with readmission for a complication or persistent/worsening symptom, including age (p = 0.009), length of stay (p = 0.007), general neurosurgery diagnosis (p < 0.001), cranial pathology (p < 0.001), intensive care unit (ICU) admission (p < 0.001), number of initial admission operations (p = 0.01), and shunt procedures (p < 0.001). Multivariate analysis identified predictive factors of readmission, including diagnosis (p = 0.002, OR 2.4, 95% CI 1.4–5.3), cranial pathology (p = 0.002, OR 2.7, 95% CI 1.4–5.3), ICU admission (p = 0.004, OR 2.4, 95% CI 1.3–4.2), and number of first admission operations (p = 0.01, OR 0.51, 95% CI 0.3–0.87). Univariate analysis performed to identify factors associated with potentially avoidable readmissions included length of stay (p = 0.03), diagnosis (p < 0.001), cranial pathology (p = 0.02), and shunt procedures (p < 0.001). Multivariate analysis identified only shunt procedures as a predictive factor for avoidable readmission (p = 0.02, OR 5.6, 95% CI 1.4–22.8).CONCLUSIONSAlmost one-fifth of neurosurgical patients were readmitted within 30 days of discharge. However, only about half of these patients were admitted for an unplanned reason, and only 10% of all readmissions were potentially avoidable. This study demonstrates unique challenges encountered in a publicly funded healthcare setting and supports the growing literature suggesting 30-day readmission rates may serve as an inappropriate quality of care metric in neurosurgical patients. Potentially avoidable readmissions can be predicted, and further research assessing predictors of avoidable readmissions is warranted.


2021 ◽  
Vol 34 (Supplement_1) ◽  
Author(s):  
David Liu ◽  
Mohamed Afzal ◽  
Tim Bright ◽  
David Watson ◽  
Peter Devitt ◽  
...  

Abstract   Surgery is the only effective treatment strategy for a symptomatic pharyngeal pouch. However, octo- and nonagenarians are often denied referral to a surgeon because of perceived increased risks. Here, we examine the perioperative outcomes of pharyngeal pouch surgery in octo- and nonagenarians in comparison to patients under 80 years-of-age. Methods Analysis of a prospectively maintained database of 113 patients (≥80 years-of-age: 27, &lt;80 years-of-age: 86) who underwent pharyngeal pouch surgery across seven hospitals from 1 January 2006 to 30 September 2020. Results Patients ≥80 years-of-age had comparable operative time, complication profile, intensive care admission, emergency reoperation, and revisional surgery as their younger counterparts. The severity of complications was not significantly different between the two age groups. No surgical mortality was recorded. Multivariate analysis demonstrated that diverticulectomy combined with cricopharyngeal myotomy independently predicted higher rates of complications (OR: 4.53, 95% CI: 1.43-14.33, p = 0.010), but also greater symptomatic improvement (OR: 4.36, 95% CI: 1.50-12.67, p = 0.007). Importantly, a greater proportion of octo- and nonagenarians experienced improved swallowing than patients &lt;80 years-of-age (96.3% vs. 74.4%, p = 0.013). Advanced age was not predictive of complications on multivariate analysis. Conclusion In appropriately selected patients, pharyngeal pouch surgery can be safely offered to patients above 80 years-of-age resulting in significant improvement in their quality-of-life. These patients should not be denied surgery on the basis of advanced age alone.


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2537 ◽  
Author(s):  
Mohamed K. Abdel-Fattah ◽  
Sameh Kotb Abd-Elmabod ◽  
Ali A. Aldosari ◽  
Ahmed S. Elrys ◽  
Elsayed Said Mohamed

Water scarcity and suitable irrigation water management in arid regions represent tangible challenges for sustainable agriculture. The current study aimed to apply multivariate analysis and to develop a simplified water quality assessment using principal component analysis (PCA) and the agglomerative hierarchical clustering (AHC) technique to assess the water quality of the Bahr Mouise canal in El-Sharkia Governorate, Egypt. The proposed methods depended on the monitored water chemical composition (e.g., pH, water electrical conductivity (ECiw), Ca2+, Mg2+, Na+, K+, HCO3−, Cl−, and SO42−) during 2019. Based on the supervised classification of satellite images (Landsat 8 Operational Land Imager (OLI)), the distinguished land use/land cover types around the Bahr Mouise canal were agriculture, urban, and water bodies, while the dominating land use was agriculture. The water quality of the Bahr Mouise canal was classified into two classes based on the application of the irrigation water quality index (IWQI), while the water quality was classified into three classes using the PCA and AHC methods. Temporal variations in water quality were investigated, where the water qualities in winter, autumn, and spring (January, February, March, April, November, and December) were classified as class I (no restrictions) based on IWQI application, and the water salinity, sodicity, and/or alkalinity did not represent limiting factors for irrigation water quality. On the other hand, in the summer season (May, June, July, August, and October), the irrigation water was classified as class II (low restrictions); therefore, irrigation processes during summer may lead to an increase in the alkalinity hazard. The PCA classifications were compared with the IWQI results; the PCA classifications had similar assessment results during the year, except in September, while the water quality was assigned to class II using the PCA method and class I by applying the IWQI. Furthermore, the normalized difference vegetation index (NDVI) around the Bahr Mouise canal over eight months and climatic data assisted in explaining the fluctuations in water quality during 2019 as a result of changing the crop season and agriculture management. Assessments of water quality help to conserve soil, reduce degradation risk, and support decision makers in order to obtain sustainable agriculture, especially under water irrigation scarcity and the limited agricultural land in such an arid region.


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