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We explore the dynamic characteristics of positron acoustic multiple-solitons in an unmagnetized plasma containing mobile cold positrons, Kappa-distributed superthermal hot electrons and positrons, and stationary positive ions. This study investigates the overtaking collisional effects, various parametric impacts, and phase shifts in the electron–positron-ion (e-p-i) plasma. Through the reductive perturbation technique, we derived the Korteweg-de Vries (KdV) equation and the modified Korteweg-de Vries (mKdV) equation. The multiple-soliton solutions (MSS) are then obtained using the simplified Hirota method and Cole-Holf transformation. The investigation shows that the amplitudes and widths of multi-solitons decrease with the increasing hot positron concentration but increase with the increasing hot electron index parameter. The results are expected to help us understand the dynamics of waves propagation in the pulsar magnetosphere, the active galactic nuclei, the quasar's relativistic jet, the inner region of the accretion disk surrounding a black hole, etc. [ABSTRACT FROM AUTHOR]

Polyolefins are a widely accepted commodity polymer made from olefinic monomer consisting of carbon and hydrogen. This thermoplastic polymeric material is formed through reactive double bonds of olefins by the addition polymerization technique and it possesses a diverse range of unique features for a large variety of applications. Among the various types, polyethylene and polypropylene are the prominent classes of polyolefins that can be crafted and manipulated into diversified products for numerous applications. Research on polyolefins has boomed tremendously in recent times owing to the abundance of raw materials, low cost, lightweight, high chemical resistance, diverse functionalities, and outstanding physical characteristics. Polyolefins have also evidenced their potentiality as a fiber in micro to nanoscale and emerged as a fascinating material for widespread high-performance use. This review aims to provide an elucidation of the breakthroughs in polyolefins, namely as fibers, filaments, and yarns, and their applications in many domains such as medicine, body armor, and load-bearing industries. Moreover, the development of electrospun polyolefin nanofibers employing cutting-edge techniques and their prospective utilization in filtration, biomedical engineering, protective textiles, and lithium-ion batteries has been illustrated meticulously. Besides, this review delineates the challenges associated with the formation of polyolefin nanofiber using different techniques and critically analyzes overcoming the difficulties in forming functional nanofibers for the innovative field of applications. [ABSTRACT FROM AUTHOR]

Feature selection is an important step in the data science pipeline, and it is critical to develop efficient algorithms for this step. Mutual Information (MI) is one of the important measures used for feature selection, where attributes are sorted according to descending score of MI, and top-k attributes are retained. The goal of this work is to develop a new measure Attribute Average Conflict to effectively approximate top-k attributes, without actually calculating MI. Our proposed method is based on using the database concept of approximate functional dependency to quantify MI rank of attributes which to our knowledge has not been studied before. We demonstrate the effectiveness of our proposed measure with a Monte-Carlo simulation. We also perform extensive experiments using high dimensional synthetic and real datasets with millions of records. Our results show that our proposed method demonstrates perfect accuracy in selecting the top-k attributes, yet is significantly more efficient than state-of-art baselines, including exact methods for computing Mutual Information based feature selection, as well as adaptive random- sampling based approaches. We also investigate the upper and lower bounds of the proposed new measure and show that tighter bounds can be derived by using marginal frequency of attributes in specific arrangements. The bounds on the proposed measure can be used to select top-k attributes without full scan of the dataset in a single pass. We perform experimental evaluation on real datasets to show the accuracy and effectiveness of this approach. [ABSTRACT FROM AUTHOR]

This study intends to investigate the determinants of planting scale choice and its effect on rice farms' productivity and technical efficiency (TE) by using a national representative sample of 12,590 rice plots in Bangladesh. The stochastic production frontier approach has been employed separately for each planting scale to compare farm performances. It also addresses self-selection in the choice of planting scales by using multinomial endogenous switching regression that corrects potential selection biases for planting scale choice and TE. The empirical results show that the land elasticity was the highest (0.81) for the straight-line planting scale and the lowest (0.70) for the random scale. A critical finding from the self-selectivity variable was that the straight-line planting scale was an appropriate alternative for increasing rice farms' production and TE in Bangladesh. The straight-line planting scale had 2.8% and 2.0% higher efficiency than the semi-straight-line and random scales. In contrast, the random and semi-straight-line scales had negative associations with rice production. Household head education, land ownership, and improved rice varieties had positive effects, while land fragmentation, farm size, wage labour, and market distance negatively affected the adoption of a straight-line planting scale for rice production. A strong research-extension linkage is essential to motivating farmers to choose the appropriate planting scales and successfully diffuse information at the rural farm level. [ABSTRACT FROM AUTHOR]

In the last two decades, the extensive literature that has measured agricultural productivity and growth rate remains controversial and provides few strategies about its main determinants. The present study aims to find out the key determinants of food grain yield (FGY) and examine the role of climate change and agricultural subsidy (SUB) in the context of India using annually data spanning from 1991 to 2018. The current study applied the ARDL modelling to investigate the impacts of climatic factors (average rainfall (RF), mean temperature (AT), and carbon emission (CO2) and agricultural subsidy (SUB) on food grain yield (FGY) in the short-and long-term in India. The estimated outcomes indicate that climatic factors such as RF have a positive impact while AT and CO2 have a negative effect on FGY. Similarly, non-climate variables such as gross capital formation (GCF) and fertilizer usage (FERT) positively contributed to FGY, while the area under crop (LUC), SUB, and employment (AL) negatively affected FGY in India. The results from Granger causality divulge that climatic and non-climatic elements are the main determinants of food grain yield, which have been playing play a significant role in enhancing food grain production and ensuring food security in India. Based on empirical outcomes and findings, some key policy implications emerged. Precisely, government and policy developers should focus on technological innovation and precision agriculture to increase agriculture production and productivity. Government should create funds to curb the climate change problem and promote eco-friendly renewable energy. [ABSTRACT FROM AUTHOR]

Shrimp farming is fundamental to the national economy of Bangladesh, particularly through earning foreign currency. The nationwide lockdown and international cargo restriction jeopardized the sector and breaking its marketing chain. Assessing the degree of farming socio-economic peril from COVID-19 and suggesting early coping strategies and long-term mitigation measures are pressing to build resilience for this food production sector. To collect survey data, two key-informant face-to-face surveys with 51 shrimp farmers and 62 consumers in southwest Bangladesh were accomplished. As national lockdowns restricted access to export markets and movements within the country, farm incomes decreased against rising production costs. To compensate, farmers reduced their workforce (29.4%), but even with the sale of co-cultured finfish still suffered from large drops in revenue (42.8% average profit reduction). Furthermore, we present evidence that shrimp farmers should consider diversification of aquaculture product type as co-culture of additional shrimp species was a poor mitigation strategy against large market price fluctuations. Product price reductions were passed on to the consumer, who enjoyed falling product prices including more expensive shrimp products, but the markup for nearly all aquaculture products increased. The current jeopardy and consequences of shrimp farming future are discussed, including coping strategies to help policymakers in building resilience against future uncertainties. [ABSTRACT FROM AUTHOR]

Breast cancer was the commonest cancer among the female patients who attended Institute of Cancer Research & Hospital (NICRH), Dhaka, Bangladesh, which formed the second most common cancer worldwide. An expressive cross-sectional study was conceded out in NICRH. By convenience sampling, 322 female patients were selected. A design and well formatted pre-tested questionnaire was used to ask questions among the breast cancer patients. The objectives of the study was to investigate the distribution and determinants of breast cancer among the female patients admitted in NICRH. The period of the study was during July 2010 to June 2011. Majority (71 %) of the patients was in the age between 34 to 53 years and they were coming from rural areas. About 77%respondents had experienced first menstruation in the age between 12 to 13 years. It was found that 42 % respondents gave their first child birth in between 21 to 25 years age and among all the respondent 64%became pregnant up to 3 times. It also noted that 89%respondents had practice to use oral contraceptives. While trying to get their history of contraceptive use; it was found that 42 % used contraception in between 4 to 6 years. In this study we found that 90 % of the respondent's had the practice to breast fed their baby. But 24%of the respondent's have used HRTand among them 69 % had used it by =3 years. Around 56 % respondents had the parenchymal pattern of breast in mammography. Forty two percent respondent's had the history of disease on breast cancer and 25 % had the history of benign breast cancer and also 2 % had the experiences to use radiation. This study explored the overall scenario of breast cancer among the patients admitted to NICRH in Bangladesh context; understanding the different type of determinants, risk factors to developing breast cancer and the distribution of patients in different area which will help to build up the national awareness. Measure should be taken immediately to detect the factors that were associated with breast cancer. This study was a very little one in respect of the national situation in our country and the result reflected only a fraction of the original condition. Broad based study in large population with sound methodology is required to find out real situation about this matter in Bangladesh. [ABSTRACT FROM AUTHOR]

Community forest management (CFM) has received increasing worldwide attention from governments, researchers and educational institutions over the past two decades. Many governments, especially in developing countries, have prioritized CFM over traditional forest management systems. In Thailand, CFM is not recognized by the legal system; however, there are de facto CFM practices under common property resource regimes. CFM has in essence been practiced here for hundreds of years by local people, and represents an important aspect of Thai culture. This study aims at evaluating CFM in Thailand in the context of sustainable development. To meet the objective, the study gathered information through focus group discussions with various stakeholders: academics, Forest Department staff, and members of the Chang Tok Tay community forests. From the study, it emerged that forest resources are critical for the livelihoods and survival of rural people, and so they have protected forests to ensure sustainable livelihoods. This study identified that prospects for sustainable CFM in Thailand are bright because: (i) community members are highly motivated and are sufficiently interested to protect trees because they are well aware that their livelihoods are under threat from depleting forests; (ii) tradition and culture of rural people support their relation with nature; (iii) non-timber forest products (NTFPs) play a crucial role in local livelihoods for subsistence and necessitate protection of the forest watershed, which is vital to support their occupations; (iv) spiritual rituals such as those where Buddhist monks bind yellow cloth on trees play a vital role in protecting trees, something rare in other countries. The study further identified various hindrances to achieve sustainable CFM: (i) legal support for CFM is absent; (ii) the Royal Forest Department (RFD) cannot transfer appropriate technology to community people due to lack of legal support; (iii) scope for developing effective strategies for sustainable CFM by combining traditional knowledge with existing scientific knowledge is limited; (iv) a formal institutional arrangement for CFM does not exist; and (v) community members’ access to the hard technology of CFM is limited. Therefore, in addition to legalizing CFM, a formal institutional framework for elaboration, implementation and control of CFM is essential to achieve sustainable CFM in Thailand. [ABSTRACT FROM AUTHOR]

The balance of evidence suggests a perceptible human influence on global ecosystems. Human activities are affecting the global ecosystem, some directly and some indirectly. If researchers could clarify the extent to which specific human activities affect global ecosystems, they would be in a much better position to suggest strategies for mitigating against the worst disturbances. Sophisticated statistical analysis can help in interpreting the influence of specific human activities on global ecosystems more carefully. This study aims at identifying significant or influential human activities (i.e. factors) on CO2 emissions using statistical analyses. The study was conducted for two cases: (i) developed countries and (ii) developing countries. In developed countries, this study identified three influential human activities for CO2 emissions: (i) combustion of fossil fuels, (ii) population pressure on natural and terrestrial ecosystems, and (iii) land use change. In developing countries, the significant human activities causing an upsurge of CO2 emissions are: (i) combustion of fossil fuels, (ii) terrestrial ecosystem strength and (iii) land use change. Among these factors, combustion of fossil fuels is the most influential human activity for CO2 emissions both in developed and developing countries. Regression analysis based on the factor scores indicated that combustion of fossil fuels has significant positive influence on CO2 emissions in both developed and developing countries. Terrestrial ecosystem strength has a significant negative influence on CO2 emissions. Land use change and CO2 emissions are positively related, although regression analysis showed that the influence of land use change on CO2 emissions was still insignificant. It is anticipated, from the findings of this study, that CO2 emissions can be reduced by reducing fossil-fuel consumption and switching to alternative energy sources, preserving exiting forests, planting trees on abandoned and degraded forest lands, or by planting trees by social/agroforestry on agricultural lands. [ABSTRACT FROM AUTHOR]

The Hill Forests in Bangladesh have been depleted and degraded in volume, area, and quantity, thus requiring urgent forest protection by identifying the causes of forest loss. This study seeks to identify the fundamental causes of the shrinking forest cover in the Hill Forests in Bangladesh. The results indicate four sets of causes: (i) indigenous forest dwellers, having their own types of problems; (ii) migrants, who, because of problems in their places of origin, have decidedto move to the forests; (iii) the timber industry, which, legal or not, are cutting too many trees; and (iv) the government through its Forest Department which is not able or willing to implement suitable policies to regulate the cutting trees and to prevent illegal cutting.Because it is a time consuming task to mitigate the first and secondsets of factors, we recommend to involve forest dwellers in forestrypractices as much as possible and taking necessary steps to alleviate the third and fourth sets and thereby reduce the rate of forest depletion. Accordingly, a number of strategies that should be adopted tohalt the loss of remaining forest cover are discussed. [ABSTRACT FROM AUTHOR]