26 research outputs found
NIR spectroscopy for personal screening
This work presents investigations into the use of the near-infrared (NIR) signals to
interrogate, detect and image specific chemical compounds of interest in a security
screening application, including when such compounds are hidden behind single layers
of clothing fabric.
In an initial set of experiments, the mechanisms governing the interaction of NIR
signals with clothing fabrics and similar materials has been studied, in order to account
for the influence of fabric layers when detecting hidden chemicals. Throughout the rest
of the work, NIR spectroscopy has been used as a means to perform qualitative and
quantitative analysis, in order to detect the presence of chemicals, and quantify the
concentration in aqueous solution of liquids.
It has been shown that, while the compounds can be identified on the basis of the
characteristic features that appear in the relevant NIR spectra, the origin and nature of
these spectra necessitate that such identification be performed with a chemometricsbased
approach. Accordingly, multivariate calibration models based on neural networks
and partial least squares regression (PLSR) have been developed to perform the
requisite analyses. Results of calibration and testing with a range of data are reported.
In order to facilitate operation in practical security screening, the development and
testing of a software-based lock-in amplifier is reported, as a mean to enhance the
signal-to-noise ratio (SNR) of the spectral data. It is shown that the amplifier can
process up to 40 wavelength channels in parallel, to extract the spectral data buried in
noise in each channel. Hence, with the SNR of the input signal set as low as -60 dB (by
introducing software-generated additive white noise in the spectra), adequate noise
suppression has been obtained, allowing the resulting spectral data to be used for
requisite chemical detection.
Finally, an integrated spectroscopic imaging application is developed to perform twodimensional
cross-sectional scans of chemical samples, carry out lock-in amplification
of the recorded intensity spectra, and plot the results of neural network-based chemical
detection in the form of intensity images colour-coded to depict the presence of the
pertinent chemicals at the scanned coordinates
NIR spectroscopy for personal screening
This work presents investigations into the use of the near-infrared (NIR) signals to interrogate, detect and image specific chemical compounds of interest in a security screening application, including when such compounds are hidden behind single layers of clothing fabric. In an initial set of experiments, the mechanisms governing the interaction of NIR signals with clothing fabrics and similar materials has been studied, in order to account for the influence of fabric layers when detecting hidden chemicals. Throughout the rest of the work, NIR spectroscopy has been used as a means to perform qualitative and quantitative analysis, in order to detect the presence of chemicals, and quantify the concentration in aqueous solution of liquids. It has been shown that, while the compounds can be identified on the basis of the characteristic features that appear in the relevant NIR spectra, the origin and nature of these spectra necessitate that such identification be performed with a chemometricsbased approach. Accordingly, multivariate calibration models based on neural networks and partial least squares regression (PLSR) have been developed to perform the requisite analyses. Results of calibration and testing with a range of data are reported. In order to facilitate operation in practical security screening, the development and testing of a software-based lock-in amplifier is reported, as a mean to enhance the signal-to-noise ratio (SNR) of the spectral data. It is shown that the amplifier can process up to 40 wavelength channels in parallel, to extract the spectral data buried in noise in each channel. Hence, with the SNR of the input signal set as low as -60 dB (by introducing software-generated additive white noise in the spectra), adequate noise suppression has been obtained, allowing the resulting spectral data to be used for requisite chemical detection. Finally, an integrated spectroscopic imaging application is developed to perform twodimensional cross-sectional scans of chemical samples, carry out lock-in amplification of the recorded intensity spectra, and plot the results of neural network-based chemical detection in the form of intensity images colour-coded to depict the presence of the pertinent chemicals at the scanned coordinates.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Role of Family Firms to Uplift the Financial Performance and Investment Opportunities of Listed Manufacturing Firms of Pakistan
This study is conducted to analyse the relationship of Ownership Structure with Firm Performance in non-financial companies listed at Pakistan Stock Exchange during the period 2008 to 2013. The basic focus of this study was related to the performance of family firms as compared to non-family firms. The distinction between both types has been explained in literature with the help of definitions given by different authors and scholars. Keeping in view the research aims and objectives the non-financial sector of Pakistan is taken as population. Simple random sampling technique is used in accordance to research requirements and extracted a sample of 120 firms for the purpose of analysis. All these firms are listed at Pakistan Stock Exchange (PSX). Investment Opportunities (Tobin’s Q), Return on Assets (ROA) and Return on Equity (ROE) have been used as a proxy variable to explore the firm value and firm’s financial performance. Sophisticated data analysis techniques such as descriptive, correlational, panel data regression analysis have been used. Results showed that Family firms are negatively correlated and Non-Family firms give better performance. On the basis of results obtained through data analysis it is concluded that Firm Performance critically depends on Managerial Ownership. Panel data analysis has shown that firm leverage and size has no relationship with proxy variables while remaining independent variables have significant relationship with performance variables. Agency problems arise due to increase in Managerial Shareholdings in Pakistani context, which ultimately affects the performance of the firms
Role of Family Firms to Uplift the Financial Performance and Investment Opportunities of Listed Manufacturing Firms of Pakistan
This study is conducted to analyse the relationship of Ownership Structure with Firm Performance in non-financial companies listed at Pakistan Stock Exchange during the period 2008 to 2013. The basic focus of this study was related to the performance of family firms as compared to non-family firms. The distinction between both types has been explained in literature with the help of definitions given by different authors and scholars. Keeping in view the research aims and objectives the non-financial sector of Pakistan is taken as population. Simple random sampling technique is used in accordance to research requirements and extracted a sample of 120 firms for the purpose of analysis. All these firms are listed at Pakistan Stock Exchange (PSX). Investment Opportunities (Tobin’s Q), Return on Assets (ROA) and Return on Equity (ROE) have been used as a proxy variable to explore the firm value and firm’s financial performance. Sophisticated data analysis techniques such as descriptive, correlational, panel data regression analysis have been used. Results showed that Family firms are negatively correlated and Non-Family firms give better performance. On the basis of results obtained through data analysis it is concluded that Firm Performance critically depends on Managerial Ownership. Panel data analysis has shown that firm leverage and size has no relationship with proxy variables while remaining independent variables have significant relationship with performance variables. Agency problems arise due to increase in Managerial Shareholdings in Pakistani context, which ultimately affects the performance of the firms
The Dynamics of International Political Economy Relationships and its Influence on the Process of Democratisation, Institution Building and National Governance Structure in Pakistan
The political history of Pakistan is strongly associated with the international political economy circumstances. Constrained due to the geographical location and her position in the regional political circumstances immediately after the independence, Pakistan opted for an alliance with the United States. The nature of Pakistan’s linkages with United States proved to be extremely counterproductive for the process of democratisation and prospects of institution-building. Various US administrations exploited the US-Pakistan’s asymmetrical relationships by taking advantage of Pakistani army’s alliance in pursuit of their imperialist policies in the Middle East, Cold War with USSR in Afghanistan and recently the War on Terror. Since, the authoritarian regimes continued to rule Pakistan under the auspices of US administrations, Pakistan remained stranded between the status of a complete autocracy and competitive authoritarianism since its independence till date. Pakistan has been one of the major recipients of foreign aid from US and other multilateral aid and development agencies but this aid has primarily been used to consolidate Pakistani army. The continuous inflow of development aid has had a negative rather than positive impact on Pakistan’s economy and political institutions
Impact of Authoritarianism on Democratisation and Local Governance in Pakistan: Historical Perspectives
This paper narrates the history of authoritarianism in the post-independence Pakistan and its effect on the process and prospects of democratisation and the possibilities of institutionalisation of local government reforms. The political history of Pakistan after the independence and other associated contextual factors highly differentiate her contemporary political organisation from other comparable countries in South Asia. For instance, India and Pakistan emerged as independent states from the colonial rule on the same day and both states inherited the almost similar administrative setups from the British rule nonetheless, the subsequent development of democratic credentials and the establishment of local governments as a regular third tier of government in India unequivocally distinguishes her case from that of Pakistan‟s. Pakistan‟s six decades of chaotic history has seen frequent changes in government including three major military regimes. The politically centralising factors have led Pakistan to become a security state where the apex twin institution i.e. the civil-military bureaucracy takes the lead in running the government and state‟s affairs at all levels. In such a context, the process of democratisation has remained precarious at larg
Unique Pakistani gut microbiota highlights population-specific microbiota signatures of type 2 diabetes mellitus
Biogeographic variations in the gut microbiota are pivotal to understanding the global pattern of host–microbiota interactions in prevalent lifestyle-related diseases. Pakistani adults, having an exceptionally high prevalence of type 2 diabetes mellitus (T2D), are one of the most understudied populations in microbiota research to date. The aim of the present study is to examine the gut microbiota across individuals from Pakistan and other populations of non-industrialized and industrialized lifestyles with a focus on T2D. The fecal samples from 94 urban-dwelling Pakistani adults with and without T2D were profiled by bacterial 16S ribosomal RNA gene and fungal internal transcribed spacer (ITS) region amplicon sequencing and eubacterial qPCR, and plasma samples quantified for circulating levels of lipopolysaccharide-binding protein (LBP) and the activation ability of Toll-like receptor (TLR)-signaling. Publicly available datasets generated with comparable molecular methods were retrieved for comparative analysis of the bacterial microbiota. Overall, urbanized Pakistanis’ gut microbiota was similar to that of transitional or non-industrialized populations, depleted in Akkermansiaceae and enriched in Prevotellaceae (dominated by the non-Westernized clades of Prevotella copri). The relatively high proportion of Atopobiaceae appeared to be a unique characteristic of the Pakistani gut microbiota. The Pakistanis with T2D had elevated levels of LBP and TLR-signaling in circulation as well as gut microbial signatures atypical of other populations, e.g., increased relative abundance of Libanicoccus/Parolsenella, limiting the inter-population extrapolation of gut microbiota-based classifiers for T2D. Taken together, our findings call for a more global representation of understudied populations to extend the applicability of microbiota-based diagnostics and therapeutics.Peer reviewe
Progress on the national action plan of Pakistan on antimicrobial resistance (AMR) : a narrative review and the implications
Introduction: The emergence of antimicrobial resistance (AMR) is a threat to public health. In 2015, the World Health Organization (WHO) introduced a global action plan to tackle AMR in the World Health Assembly. Pakistan’s national action plan (NAP) for AMR was released in May 2017 by the Ministry of National Health Services. Based on the NAP, strategies have been initiated on a national and provincial scale in Pakistan. Areas covered: This narrative review of the five components of the Pakistan NAP has been undertaken to discuss some of the challenges in implementation of the NAP for AMR in Pakistan including different opinions and views of key stakeholders, combined with suggestions on potential ways to reduce the burden of the AMR. Expert opinion: Going forward, healthcare authorities should focus on screening and monitoring of all the objectives of the NAP by establishing proper policies as well as promoting antimicrobial stewardship interventions and Infection prevention and control (IPC) practices. Overall, the comprehensive strengthening of the healthcare system is required to adequately implement the NAP, tackle continued inappropriate antimicrobial use and high AMR rates in Pakistan
The Dynamics of International Political Economy Relationships and its Influence on the Process of Democratisation, Institution Building and National Governance Structure in Pakistan
Abstract The political history of Pakistan is strongly associated with the international political economy circumstances. Constrained due to the geographical location and her position in the regional political circumstances immediately after the independence, Pakistan opted for an alliance with the United States. The nature of Pakistan's linkages with United States proved to be extremely counterproductive for the process of democratisation and prospects of institution-building. Various US administrations exploited the US-Pakistan's asymmetrical relationships by taking advantage of Pakistani army's alliance in pursuit of their imperialist policies in the Middle East, Cold War with USSR in Afghanistan and recently the War on Terror. Since, the authoritarian regimes continued to rule Pakistan under the auspices of US administrations, Pakistan remained stranded between the status of a complete autocracy and competitive authoritarianism since its independence till date. Pakistan has been one of the major recipients of foreign aid from US and other multilateral aid and development agencies but this aid has primarily been used to consolidate Pakistani army. The continuous inflow of development aid has had a negative rather than positive impact on Pakistan's economy and political institutions