Improving seabed classification from Multi-Beam Echo Sounder (MBES) backscatter data with visual data mining

Multi-Beam Echo Sounders are often used for classification of seabed type, as there exists a strong link between sonar backscatter and sediment characteristics of the seabed. Most of the methods for seabed classification from MBES backscatter create a highly-dimensional data set of statistical features and then use a combination of Principal Component Analysis and k-means clustering to derive classes. This procedure can be time consuming for contemporary large MBES data sets with millions of records. This paper examines the complexity of one of most commonly used classification approaches and suggests an alternative where feature data set is optimised in terms of dimensionality using computational and visual data mining. Both the original and the optimised method are tested on an MBES backscatter data set and validated against ground truth. The study found that the optimised method improves accuracy of classification and reduced complexity of processing. This is an encouraging result, which shows that bringing together methods from acoustic classification, visual data mining, spatial analysis and remote sensing can support the unprecedented increases in data volumes collected by contemporary acoustic sensors.     

Adaptation to climate change as resilience for urban extreme poor: lessons learned from targeted asset transfers programmes in Dhaka city of Bangladesh

This paper aims to identify how targeted asset transfers help to build adaptive capacity and adaptive actions of the urban extreme poor to climate change phenomena. This paper explores the theoretical debates of community-based adaptation approach and failure of such approach to address urban extreme poor. The empirical evidence of these theoretical debates will be drawn from two informal settlements of Dhaka city, where a targeted asset transfer project has been implementing since 2009. This paper explains that urban extreme poor usually work as unskilled labour and lack different livelihood capitals; and climate change is an increasingly important influence exacerbating an already vulnerable livelihood context. There is growing recognition in the literature that poor urban people and communities are adapting to climate change in physical and behavioural terms. But, in the case of urban extreme poor these adaptation approaches are delivering short-term survival strategies disregarding the notion of wellbeing in the medium to long-term perspectives. It is also evident that community level initiatives structurally reproduce the exclusion of the urban extreme poor. However, poverty literatures acknowledge that poverty-centred approaches could help to reduce vulnerability. As urban extreme poor are significantly more resource constrained, it is reasonable to assert that targeted asset transfers could be a poverty-centred adaptation approach in a changing climate. Targeted asset transfers approaches are the outcomes of recent social protection revolution that especially consider accumulation of physical, financial, human, and social capital in order to build adaptive capacity of the urban extreme poor. This adaptive capacity of the extreme poor may facilitate adjustments in assets, livelihoods, behaviours, and technologies in order to reduce future climate vulnerability. In this context, this paper seeks to answer whether targeted asset transfer approaches can be considered as effective poverty-centred adaptation approaches for the urban extreme poor or not.     

Volatility connectedness of GCC stock markets: how global oil price volatility drives volatility spillover in GCC stock markets?

Environmental Science and Pollution Research - The study investigated the volatility connectedness of GCC stock market return and S&P global oil index returns using Diebold and Yilmaz...     

Determination of sources of fine particles in different ambient atmospheres in South Korea using a chemical mass balance model

Abstract

To determine the sources of particulate matter less than 2.5?μm (PM_2.5 in different ambient atmospheres (urban, roadside, industrial, and rural sites), the chemical components of PM_2.5 such as ions (Cl^-, NO₃^-, SO₄^2-, NH₄⁺, Na⁺, K⁺, Ca²⁺, and Mg²⁺), carbonaceous species, and elements (Al, As, Ba, Cd, Cu, Fe, Mn, Ni, Pb, Se, V, and Zn) were measured. The average mass concentrations of PM_2.5 at the urban, roadside, industrial, and rural sites were 31.5?±?14.8, 31.6?±?22.3, 31.4?±?16.0, and 25.8?±?12.4?μg/m³, respectively. Except for secondary ammonium sulfate and ammonium nitrate, the model results showed that the traffic source (i.e., the sum of gasoline and diesel vehicle sources) was the most dominant source of PM_2.5 (17.1%) followed by biomass burning (13.8%) at the urban site. The major primary sources of PM_2.5 were consistent with the site characteristics (diesel vehicle source at the roadside site, coal-fired plants at the industrial site, and biomass burning at the rural site). Seasonal data from the urban site suggested that ammonium sulfate and ammonium nitrate were the most dominant sources of PM_2.5 during all seasons. Further, the contribution of road dust source to PM_2.5 increased during spring and fall seasons. We conclude that the determination of the major PM_2.5 sources is useful for establishing efficient control strategies for PM_2.5 in different regions and seasons.     

In vitro evaluation of the effect of dibutyl phthalate on electrogenic sodium-linked glucose transport in isolated rabbit ileum

Dibutyl phthalate, a known endocrine disruptor, is a commonly used plasticizer that influences the glucose homeostasis. The present study elucidates the effects of dibutyl phthalate (1 and 5 mmol/L) on electrogenic sodium-linked glucose transport in the isolated rabbit ileum with ‘Ussing chamber.’ Serosal addition of dibutyl phthalate has no effect on glucose-based electrogenic changes in short circuit current, and no effect of dibutyl phthalate is observed on ileal tissue conductance and catalase activity. However, mucosal addition of dibutyl phthalate in the presence of glucose shows a trend of decrease in short circuit current compared with the control. This indicates that dibutyl phthalate may have a deleterious effect on the electrogenic intestinal glucose transport.     

Air pollution and child health: the impact of brick kiln pollution on children's cognitive abilities and physical health in Pakistan

Environment, Development and Sustainability - This study explores the adverse impact of air pollution, caused by emissions from brick kilns, on the children’s cognitive ability and physical...     

Synthesis of BiVO4/TiO2 composites and evaluation of their photocatalytic activity under indoor illumination

BiVO₄/TiO₂ composites with different weight ratios have been prepared by coprecipitation-based reactions followed by either thermal or hydrothermal treatment with the aim of evaluating the TiO₂ photosensitization by BiVO₄. The obtained materials present in all cases the desired monoclinic phase of BiVO₄ and anatase phase of TiO₂. Visible light absorption increased with increasing amount of bismuth vanadate. XPS results reveal the surface enrichment of Ti with respect to the bulk composition in samples characterised by a higher content of BiVO₄. The photocatalytic activity of the prepared materials was tested for the degradation of isopropanol in the gas phase under indoor illumination conditions. Although none of the composites was able to improve the activity of TiO₂, the low BiVO₄ containing samples appear as more suitable for further synthesis tuning.     

Pb-induced changes in roots of two cultivated rice cultivars grown in lead-contaminated soil mediated by smoke

Environmental Science and Pollution Research - Nowadays, public concerns regarding deleterious effect of lead (Pb) is on rise due to its abundance and toxic effect on plants and other living...