Unified model for conductance through DNA with the Landauer-Buttiker formalism

In this work, we model the zero-bias conductance for the four different DNA strands that were used in conductance measurement experiment [A. K. Mahapatro, K. J. Jeong, G. U. Lee, and D. B. Janes, Nanotechnology 18, 195202 (2007)]. Our approach consists of three elements: (i) ab initio calculations of DNA, (ii) Green's function approach for transport calculations, and (iii) the use of two parameters to determine the decoherence rates. We first study the role of the backbone. We find that the backbone can alter the coherent transmission significantly at some energy points by interacting with the bases, though the overall shape of the transmission stays similar for the two cases. More importantly, we find that the coherent electrical conductance is tremendously smaller than what the experiments measure. We consider DNA strands under a variety of different experimental conditions and show that even in the most ideal cases, the calculated coherent conductance is much smaller than the experimental conductance. To understand the reasons for this, we carefully look at the effect of decoherence. By including decoherence, we show that our model can rationalize the measured conductance of the four strands, both qualitatively and quantitatively. We find that the effect of decoherence on G:C base pairs is crucial in getting agreement with the experiments. However, the decoherence on G:C base pairs alone does not explain the experimental conductance in strands containing a number of A:T base pairs. Including decoherence on A:T base pairs is also essential. By fitting the experimental trends and magnitudes in the conductance of the four different DNA molecules, we estimate for the first time that the deocherence rate is 6 meV for G:C and 1.5 meV for A:T base pairs.Comment: 12 pages, 9 figure

Climate Change and Non-Migration: Exploring Place Relations in Rural and Coastal Bangladesh

Increasing environmental stress are becoming a powerful driver of forced migration. Rural and coastal lives and livelihoods in many developing countries, including Bangladesh, are vulnerable to multiple sudden and gradual onset disasters. Growing research and policy interests are the disasters risk reduction and displaced population management. This qualitative research problematises and expands upon those who are unable and those who are unwilling to migrate through the multidimensionality of place relations. Through 60 semi-structured interviews from four at-risk communities in Kalapara, a rural and coastal hotspot in Bangladesh, the analysis of this study proffers four inter-related dimensions of place relation concerning a) livelihood opportunities, b) place obduracy, c) risk perceptions, and d) social-structural constraints. We introduce the multidimensionality of place relations to explain the human-place relationships under increasing environmental stress, which leads to diverse migratory and non-migratory behaviours. The result of this study represents a fundamental challenge to climate-induced migration approaches and demonstrates the value of voluntary and involuntary components of place relations in understanding migratory and non-migratory behaviour. Our discussion provides insight into how to best support non-migrant households' limits to adaptive capacity and well-being and build more climate and people-focused disaster risk reduction and displacement policies

Dynamic model for price of wheat in Bangladesh

Wheat is the second staple food of Bangladesh. In this paper we constructed a dynamic model for wheat price. Basically we constructed a single equation autoregressive integrated moving average (ARIMA) model of the price (quarterly wholesale wheat price). Standard ARIMA analysis rests on the simplifying assumption that the time series is stationary. So, at first stationary of the series is checked. An ARIMA (1,1,0) (2,1,1)4 model is constructed based on the autocorrelation and partial autocorrelation functions. Finally, forecasts are made based on the model developed

Farmer’s Level Motivation on Sunflower Cultivation in a Rice Based Cropping Pattern of Patuakhali District

The aim of the study was mainly to determine and describe the extent of the motivation on sunflower cultivation and also explore relationship between the 12 selected characteristics of the farmers with motivation on sunflower cultivation. The study was designed with mixed method approach where, both qualitative and quantitative analyses are blended in a rational way to have a deeper understanding about research problems. The study was conducted in Dumki and Patuakhali Sadar Upazilla of Patuakhali district, Bangladesh. The whole period of the study was six months from 01 January to 30 June 2016. Simple random sampling technique was used to select 110 farmers engaged in sunflower cultivation. In addition case study, focus group discussions, Key informant interviews were used to collect data. Data was collected by face to face interviews. Data was analyzed using descriptive statistical measures and computer software like SPSS. Pearson’s Product Moment coefficient of correlation results showed that out of 12 independent variables, the correlation coefficients of 7 variables had positive and significant relationship with their motivation on sunflower cultivation. Multiple regression analysis showed that training experience, innovativeness, and sunflower cultivation knowledge had significant contribution towards motivation on sunflower cultivation. Training, Contact with various sources of information, Organizational participation of the farmers was vital predictors. These predictors need further investigations

Determinants of Farmers’ Level Crop Productivity at Dumki Upazila under Patuakhali District

The major aims of this study were mainly to determine and describe the extent of farmers’ crop productivity and also explore the relationship between the 12 selected characteristics of the farmers with their crop productivity level. The study was designed with a mixed-method approach where both qualitative and quantitative analyses are blended in a rational way to have a deeper understanding of research problems. The study was conducted in Dumki Upazilla under Patuakhali district, Bangladesh. Simple random sampling technique was used to select 110 farmers except landless engaged in crop production. Data were collected by face to face interview using a pre-tested interview schedule during the period from March 10 to April 15, 2016. Data were analyzed using descriptive statistical measures and computer software like SPSS. Pearson's Product Moment coefficient of correlation results showed that out of 12 independent variables, the correlation coefficients of 7 variables had a positive and significant relationship with their level of crop productivity. The stepwise multiple regression analyses stated that only 4 variables such as communication exposure, innovativeness, risk orientation and training experience had a significant contribution to the farmers' crop productivity level and also accounted for 52.8 per cent of the total variation in productivity index. This study also showed some problems which were faced by the farmers during crop production. If these problems can be solved, the farmers’ crop productivity level will be increased

Financial Analysis of Textile Sector in Bangladesh: A Study on Selected Textile Companies

The Textile sector of Bangladesh has got a greater facet than any other sector in terms of growth and foreign exchange earnings. It makes a significant contribution to the national economy by creating generous employment opportunities and reducing poverty through socioeconomic development. The paper focuses on the financial strength of the textile sector in Bangladesh. And to know that up to what extent textile sector has used their available resources effectively. For this purpose profitability, liquidity and solvency position of textile companies has been examined. In this paper comparative ratio analysis technique has been used to know the financial soundness of textile companies. The result shows the profitability margins is slightly different due to volatile textiles market and volatility in raw material prices. The Liquidity and solvency position is almost the same in all the textile companies. Keywords: Textile Sector, profitability, liquidity, volatility and solvency

Climate change and non-migration - exploring the role of place relations in rural and coastal Bangladesh

Of growing research and policy interest are the experiences of people living under conditions of climate change–induced environmental stress, which either are unable to migrate (sometimes described as a ‘trapped population’) or are seemingly unwilling to do so (sometimes described as the ‘voluntarily immobile’). This paper problematises and expands upon these binary categories: examining the complex dimensionality of non-migration as a form of place relations, explored through qualitative study of rural and coastal Bangladeshi communities. Through 60 semi-structured interviews of individuals from four communities in the Kalapara region, the analysis proffers four qualitatively derived and inter-related dimensions of voluntary and involuntary non-migration framed as a form of place relations. These four dimensions concern the following: (1) livelihood opportunities, (2) place obduracy, (3) risk perceptions, and (4) social-structural constraints, with the interplay between these elements explaining diverse non-migratory experiences. In our analysis, ‘place obduracy’ is introduced as a concept to describe the differential speed of environmental change and socio-cultural adaptation responses to explain non-migratory experiences. Our discussion provides insight into how to best support non-migrant people’s adaptive capacity in the face of growing climate emergency

Assessing Empowerment of Farm Women: The Case of Barisal Sadar Upazila

The study was conducted to determine the extent of empowerment of the trained farm women and also to explore the influential factors of their empowerment status. The study was conducted at 5 villages of Kashipur union in Barisal Sadar upazila in Bangladesh. Data was collected from randomly selected 114 women from these villages using a pre-tested interview schedule during 2 February to 10 March 2016. The overall empowerment status scores of the farm women ranged from 28 to 83 against a possible range of 0 to 126. The sampled women had a low-medium level of empowerment (M = 48.23). Among the five dimensions of empowerment, psychological and economic empowerment dominated over the other dimensions. Coefficient of correlation showed that out of 10 selected characteristics of the farm women, education, family education, annual family income, savings, training experience and communication exposure had positive significant relationships with their empowerment status