Environmental Impacts of Ship Breaking and Recycling Industry of Sitakunda, Chittagong, Bangladesh

Ship dismantling of Bangladesh is a reason of concern due to its economic values and environmental hazards. This study focuses on the Ship Breaking and Recycling Industry (SBRI) of Bangladesh to assess the environmental impacts. It was done by analyzing the water quality parameters like, Turbidity, Salinity, Electric conductivity (EC), Dissolved Oxygen (DO), pH, Total Dissolved Solids (TDS), Temperature, Ammonia-Nitrogen, Nitrate–Nitrogen, Phosphate concentrations of inside and surroundings of Ship Breaking Yard. Turbidity ranged from 7.71 to 119 FTU in and 4.07 to 41.74 FTU in inside and outside the ship breaking yard, respectively. Salinity ranged from 0.95 to 14.28 ppt and 0.06 to 0.79 ppt in insde and outside, respectively. Value of EC varied from1.75 to 1280 µs/cm in inside and 0.21 to 15.7 µs/cm in outside, DO ranged from 3.77 to 7.94 mg/l in inside and 1.95 to 5.34 mg/l in outside. TDS value ranged from1280 to 15340 mg/l in inside and 74 to 825 mg/l in outside of ship breaking yard. Ammonia-N value ranged from 0.46 to 7.046 mg/l, Nitrate-N value ranged from 0.10 to 6.9 mg/l and Phosphate value ranged from 0.175 to 4.75 mg/l in the analyzed water sample. Magnitude of environmental alteration by establishment of ship breaking industry was assessed by quantifying Environmental impact value of Study area and the value was found as -93, where ecological parameters value was found -72, Physico-chemical parameters value was -70 and human interest value was found +49 which indicate negative alteration on environment

Pseudomonas aeruginosa PAO1 Preferentially Grows as Aggregates in Liquid Batch Cultures and Disperses upon Starvation

In both natural and artificial environments, bacteria predominantly grow in biofilms, and bacteria often disperse from biofilms as freely suspended single-cells. In the present study, the formation and dispersal of planktonic cellular aggregates, or ‘suspended biofilms’, by Pseudomonas aeruginosa in liquid batch cultures were closely examined, and compared to biofilm formation on a matrix of polyester (PE) fibers as solid surface in batch cultures. Plankton samples were analyzed by laser-diffraction particle-size scanning (LDA) and microscopy of aggregates. Interestingly, LDA indicated that up to 90% of the total planktonic biomass consisted of cellular aggregates in the size range of 10–400 µm in diameter during the growth phase, as opposed to individual cells. In cultures with PE surfaces, P. aeruginosa preferred to grow in biofilms, as opposed to planktonicly. However, upon carbon, nitrogen or oxygen limitation, the planktonic aggregates and PE-attached biofilms dispersed into single cells, resulting in an increase in optical density (OD) independent of cellular growth. During growth, planktonic aggregates and PE-attached biofilms contained densely packed viable cells and extracellular DNA (eDNA), and starvation resulted in a loss of viable cells, and an increase in dead cells and eDNA. Furthermore, a release of metabolites and infective bacteriophage into the culture supernatant, and a marked decrease in intracellular concentration of the second messenger cyclic di-GMP, was observed in dispersing cultures. Thus, what traditionally has been described as planktonic, individual cell cultures of P. aeruginosa, are in fact suspended biofilms, and such aggregates have behaviors and responses (e.g. dispersal) similar to surface associated biofilms. In addition, we suggest that this planktonic biofilm model system can provide the basis for a detailed analysis of the synchronized biofilm life cycle of P. aeruginosa

Assessment of the quality of measures of child oral health-related quality of life

Background Several measures of oral health-related quality of life have been developed for children. The most frequently used are the Child Perceptions Questionnaire (CPQ), the Child Oral Impacts on Daily Performances (C-OIDP) and the Child Oral Health Impact Profile (COHIP). The aim of this study was to assess the methodological quality of the development and testing of these three measures. Methods A systematic search strategy was used to identify eligible studies published up to December 2012, using both MEDLINE and Web of Science. Titles and abstracts were read independently by two investigators and full papers retrieved where the inclusion criteria were met. Data were extracted by two teams of two investigators using a piloted protocol. The data were used to describe the development of the measures and their use against existing criteria. The methodological quality and measurement properties of the measures were assessed using standards proposed by the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) group. Results The search strategy yielded 653 papers, of which 417 were duplicates. Following analysis of the abstracts, 119 papers met the inclusion criteria. The majority of papers reported cross-sectional studies (n = 117) with three of longitudinal design. Fifteen studies which had used the original version of the measures in their original language were included in the COSMIN analysis. The most frequently used measure was the CPQ. Reliability and construct validity appear to be adequate for all three measures. Children were not fully involved in item generation which may compromise their content validity. Internal consistency was measured using classic test theory with no evidence of modern psychometric techniques being used to test unidimensionality of the measures included in the COSMIN analysis. Conclusion The three measures evaluated appear to be able to discriminate between groups. CPQ has been most widely tested and several versions are available. COHIP employed a rigorous development strategy but has been tested in fewer populations. C-OIDP is shorter and has been used successfully in epidemiological studies. Further testing using modern psychometric techniques such as item response theory is recommended. Future developments should also focus on the development of measures which can evaluate longitudinal change

Effect of pressure and infill density parameter setting on morphological and mechanical properties of polycaprolactone printed scaffold using desktop 3d bioprinter

Three dimensional (3D) bioprinting is the process of building a 3D construct containing biological cells. There are varies set of printing parameter involved in 3D bioprinting system that will affect the structure and the mechanical properties of the bioprinted construct. This study was done to investigated the effect of extrusion pressure and infill density on the polycaprolactone (PCL) 3D printed construct's morphology, printing accuracy and compressive strength. Based on morphological evaluations using scanning electron microscope, the printed scaffold was suggested to be at the best condition at pressure 60psi using 80% infill setting. Besides, the mechanical testing revealed the printed scaffold was successfully fabricated without losing its mechanical integrity. This is a good indication for PCL as structural host material to obtain functionalized 3D scaffold using bioprinting method

Spatial distribution and source identification of heavy metal pollution in roadside surface soil: a study of Dhaka Aricha highway, Bangladesh

Introduction In this study, metal pollution and their sources in surface soils were evaluated by pollution indices and multivariate statistical techniques in association with a geographical information system (GIS). Methods Surface soil samples were collected in dry season from different locations of Dhaka Aricha highway and analyzed by energy dispersive X-ray fluorescence (EDXRF). Results Thirteen different metals were found in the tested samples. Pollution indices are determined by enrichment factor in an order of Zr > Sn > P > Mn > Zn > Rb > Fe > Ba > Sr > Ti > K > Ca > Al. The resulting geoaccumulation index (I geo) value shows the following order: Sn > Zr > P > Mn > Zn > Rb > Fe > Ba > Ti > Sr > K > Ca > Al. Contamination factors (CFs) of the metals range from 1.422 to 3.979 (Fe); 0.213 to 1.089 (Al); 0.489 to 3.484 (Ca); 1.496 to 2.372 (K); 1.287 to 3.870 (Ti); 2.200 to 14.588 (Mn); 5.938 to 56.750 (Zr); 0.980 to 3.500 (Sr); 2.321 to 4.857 (Rb); 2.737 to 6.526 (Zn); 16.667 to 27.333 (Sn); 3.157 to 16.286 (P); and 0.741 to 3.328 (Ba). Pollution load index calculated from the CFs indicates that soils are strongly contaminated by Zr and Sn. Principal component analysis (PCA) of parameters exhibits three major components. R-mode cluster analysis reveals three distinct groups in both site and metal basis clustering that shows a similar pattern with the PCA. Conclusions These results might be helpful for future monitoring of further increase of heavy metal concentrations in surface soils along highways

Assessment of roadside surface water quality of Savar, Dhaka, Bangladesh using GIS and multivariate statistical techniques

Abstract In this study, multivariate statistical techniques in collaboration with GIS are used to assess the roadside surface water quality of Savar region. Nineteen water samples were collected in dry season and 15 water quality parameters including TSS, TDS, pH, DO, BOD, Cl−, F−, NO3 2−, NO2 −, SO4 2−, Ca, Mg, K, Zn and Pb were measured. The univariate overview of water quality parameters are TSS 25.154 ± 8.674 mg/l, TDS 840.400 ± 311.081 mg/l, pH 7.574 ± 0.256 pH unit, DO 4.544 ± 0.933 mg/l, BOD 0.758 ± 0.179 mg/l, Cl− 51.494 ± 28.095 mg/l, F− 0.771 ± 0.153 mg/l, NO3 2− 2.211 ± 0.878 mg/l, NO2 − 4.692 ± 5.971 mg/l, SO4 2− 69.545 ± 53.873 mg/l, Ca 48.458 ± 22.690 mg/l, Mg 19.676 ± 7.361 mg/l, K 12.874 ± 11.382 mg/l, Zn 0.027 ± 0.029 mg/l, Pb 0.096 ± 0.154 mg/l. The water quality data were subjected to R-mode PCA which resulted in five major components. PC1 explains 28% of total variance and indicates the roadside and brick field dust settle down (TDS, TSS) in the nearby water body. PC2 explains 22.123% of total variance and indicates the agricultural influence (K, Ca, and NO2 −). PC3 describes the contribution of nonpoint pollution from agricultural and soil erosion processes (SO4 2−, Cl−, and K). PC4 depicts heavy positively loaded by vehicle emission and diffusion from battery stores (Zn, Pb). PC5 depicts strong positive loading of BOD and strong negative loading of pH. Cluster analysis represents three major clusters for both water parameters and sampling sites. The site based on cluster showed similar grouping pattern of R-mode factor score map. The present work reveals a new scope to monitor the roadside water quality for future research in Bangladesh