81 research outputs found

    Distributed Self-Concatenated Coding for Cooperative Communication

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    In this paper, we propose a power-efficient distributed binary self-concatenated coding scheme using iterative decoding (DSECCC-ID) for cooperative communications. The DSECCC-ID scheme is designed with the aid of binary extrinsic information transfer (EXIT) charts. The source node transmits self-concatenated convolutional coded (SECCC) symbols to both the relay and destination nodes during the first transmission period. The relay performs SECCC-ID decoding, where it mayor may not encounter decoding errors. It then reencodes the information bits using a recursive systematic convolutional (RSC) code during the second transmission period. The resultant symbols transmitted from the source and relay nodes can be viewed as the coded symbols of a three-component parallel concatenated encoder. At the destination node, three-component DSECCC-ID decoding is performed. The EXIT chart gives us an insight into operation of the distributed coding scheme, which enables us to significantly reduce the transmit power by about 3.3 dB in signal-to-noise ratio (SNR) terms, as compared with a noncooperative SECCC-ID scheme at a bit error rate (BER) of 10-5. Finally, the proposed system is capable of performing within about 1.5 dB from the two-hop relay-aided network’s capacity at a BER of 10-5 , even if there may be decoding errors at the relay

    Near-capacity iterative decoding of binary self-concatenated codes using soft decision demapping and 3-D EXIT charts

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    In this paper 3-D Extrinsic Information Transfer (EXIT) charts are used to design binary Self-Concatenated Convolutional Codes employing Iterative Decoding (SECCC-ID), exchanging extrinsic information with the soft-decision demapper to approach the channel capacity. Recursive Systematic Convolutional (RSC) codes are selected as constituent codes, an interleaver is used for randomising the extrinsic information exchange of the constituent codes, while a puncturer helps to increase the achievable bandwidth efficiency. The convergence behaviour of the decoder is analysed with the aid of bit-based 3-D EXIT charts, for accurately calculating the operating EbN0 threshold, especially when SP based soft demapper is employed. Finally, we propose an attractive system configuration, which is capable of operating within about 1 dB from the channel capacity

    Correlating CT Chest with RT-PCR in Diagnosing COVID-19: Experience at a Tertiary Health Care Hospital in Pakistan

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    Objective: To establish the accuracy of computed tomography(CT) chest in the diagnosis of COVID-19 pneumonia by taking reverse transcriptase-polymerase chain reaction(RT-PCR) as a reference standard and to analyze discordant CT chest and RT-PCR results. Materials and Methods: A retrospective cross-sectional study of patients presented to a tertiary health care hospital in Punjab, Pakistan for CT examination with suspicion of COVID-19 from April 1, to June 30, 2020. Each CT chest was categorized as positive/negative for COVID-19 pneumonia and the results were compared with the RT-PCR test. Discordant CT chest and PCR results were also investigated. Results: The study population had a mean age of 48 years ± 6.6 years with 54.5% males and 45.4% females. Sensitivity(Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of CT in diagnosing COVID-19 pneumonia taking RT- PCR as the gold standard was 92.5%, 46.6%%, 82.2%, 70%, and 80% respectively. Conclusion: CT chest has high sensitivity but modest specificity in the diagnosis of COVID-19 pneumonia. It can be employed as an adjunctive screening and diagnostic test for early diagnosis of disease in places where disease prevalence is high

    Increment of High-Grade Gliomas Among Pediatric and Young Adult Population

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    Background/Objective:  Glioblastomas are among the commonest primary brain cancers. This study aimed to assess the trend shift of high-grade glioma in our setting among the young and pediatric population. Materials and Methods:  This is a descriptive and cross-sectional study; it was carried out at the Department of Neurosurgery, Liaquat University of Medical and Health Sciences, between duration. All cases with suspected brain tumors, irrespective of age or gender were assessed for glioblastoma. Once a solid tumor was identified on imaging with consistent features of glioblastoma, a provisional diagnosis was established. After that, the patient underwent a brain biopsy. Patients' gender, demographics, clinical presentation, radiologic records, etc. were collected in a predefined proforma. Results:  22 patients were diagnosed with glioblastoma with a high frequency of patients between the age range of 20 to 30 years. The most common location of the tumor was subcortical near the midline. There was slight male predominance. 8 patients had levels of KPS at presentation < 70 and among those two were infants, four were in a vegetative state, and two had a loss of consciousness secondary to increased intracranial pressure. The recurrence rate among those who came back for follow-ups was 27.2%. Conclusion:  Though it is a short study with short follow-up results were astonishing due to perhaps trend shift among Glioblastoma patients, a further detailed workup is needed in different dimensions especially molecular level and genetics to know exactly about the disease and the national registry should be carried and alarmed to identify the problem at once, counter effectively and make a future strategy

    Success Rate of Endoscopic Third Ventriculostomy (ETV) in Non-Communicating Hydrocephalus in Pediatric Age Group

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    Objective:  To evaluate success rate of the endoscopic third Ventriculostomy (ETV) in non-communicating type of hydrocephalus in pediatric age group. Material and Methods:  This study was carried in the department of neurosurgery at Liaquat university hospital, Jamshoro in which an endoscopic third Ventriculostomy procedure was performed in patients (n = 55) with non-communicating hydrocephalus from October 2016 to April 2017. Post-operative follow-up was done on the 15th day post-operative to assess clinical and radiological improvement. Results:  55 patients were included in this study, 26 (47.27%) males and 29 (52.73%) females. The mean age was 3.96 years. The most common etiology was aqueductal stenosis 28 (50.90%) patients followed by posterior fossa tumors in 18 (32.72%) patients. The operative technique was successful in 41 (74.55%) patients. Out of 41 successful patients, 34 (82.92%) patients had clinical as well as radiological improvement whereas 7 (17.07%) patients had clinical improvement only. Conclusion:  The success rate of ETV was 74.55% in the non-communicating hydrocephalus in the pediatric age group in our study. Endoscopic third Ventriculostomy is an effective treatment for non-Communicating hydrocephalus in pediatric age groups by diversion of CSF intracranially. This procedure provides shunt freedom and can be used alternative to shunts in pediatric age groups with non-communicating hydrocephalus

    Impact of Web 2.0 on digital divide in AJ&K Pakistan

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    Abstract—Digital divide is normally measured in terms of gap between those who can efficiently use new technological tools, such as internet, and those who cannot. It was also hypothesized that web 2.0 tools motivate people to use technology i.e. social networking sites can play an important role in bridging digital gap. The study was conducted to determine the presence of digital divide in urban and rural areas of district Muzaffrabad, Azad Jammu & Kashmir. A cross-sectional community based survey was conducted involving 384 respondents from city Muzaffrabad and village Garhi Doppta. The existence of digital divide was assessed on the basis of the questionnaires given. Chi- square test was applied to find the association of different demographic and ICT related factors with internet usage. Despite the growing awareness there are possibilities of gender, age and area based digital divide. Outcomes of the survey affirmed that web 2.0 based web-sites are becoming popular and attracting people to use internet

    Effective extraction of cephalosporin C from whole fermentation broth of Acremonium chrysogenum utilizing aqueous two phase systems

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    The downstream processing of biotechnological products from fermentation broth is an important step of production and development of cost effective, efficient downstream processing of many biotechnological products. The present study was conducted by employing aqueous two phase systems (ATPSs) for the extraction of cephalosporin C (CPC) from whole fermentation broth of Acremonium chrysogenum. The biphasic system was prepared by mixing equal aliquots of 15% w/w polyethylene glycol (PEG) 3350 with 15% (NH4)2SO4. The effects of pH, neutral salts, temperature and centrifugal force on partitioning in ATPS to develop efficient extraction system for recovery of CPC from fermentation broth were also examined. The extraction efficiency was improved by enhancing the centrifugal force. Similarly centrifugation for 12.5 min also gave the maximum extraction. Improvement in the recovery yield was also observed by the addition of 0.1% NaCl. The concentration of CPC was determined by high performance liquid chromatography (HPLC). Slight modifications in the mobile phase from 10 to 5% MeOH improved CPC resolution. Further development of more inexpensive systems for extraction can be the future target of research.Keywords: Cephalosporin C, Acremonium chrysogenum, fermentation, aqueous two phase system (ATPS

    Spatial, temporal, and demographic patterns in prevalence of chewing tobacco use in 204 countries and territories, 1990-2019 : a systematic analysis from the Global Burden of Disease Study 2019

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    Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Findings In 2019, 273 center dot 9 million (95% uncertainty interval 258 center dot 5 to 290 center dot 9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 center dot 72% (4 center dot 46 to 5 center dot 01). 228 center dot 2 million (213 center dot 6 to 244 center dot 7; 83 center dot 29% [82 center dot 15 to 84 center dot 42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global agestandardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 center dot 21% [-1 center dot 26 to -1 center dot 16]), similar progress was not observed for chewing tobacco (0 center dot 46% [0 center dot 13 to 0 center dot 79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 center dot 94% [-1 center dot 72 to -0 center dot 14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Summary Background Chewing tobacco and other types of smokeless tobacco use have had less attention from the global health community than smoked tobacco use. However, the practice is popular in many parts of the world and has been linked to several adverse health outcomes. Understanding trends in prevalence with age, over time, and by location and sex is important for policy setting and in relation to monitoring and assessing commitment to the WHO Framework Convention on Tobacco Control. Methods We estimated prevalence of chewing tobacco use as part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 using a modelling strategy that used information on multiple types of smokeless tobacco products. We generated a time series of prevalence of chewing tobacco use among individuals aged 15 years and older from 1990 to 2019 in 204 countries and territories, including age-sex specific estimates. We also compared these trends to those of smoked tobacco over the same time period. Findings In 2019, 273 & middot;9 million (95% uncertainty interval 258 & middot;5 to 290 & middot;9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 & middot;72% (4 & middot;46 to 5 & middot;01). 228 & middot;2 million (213 & middot;6 to 244 & middot;7; 83 & middot;29% [82 & middot;15 to 84 & middot;42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global age standardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 & middot;21% [-1 & middot;26 to -1 & middot;16]), similar progress was not observed for chewing tobacco (0 & middot;46% [0 & middot;13 to 0 & middot;79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 & middot;94% [-1 & middot;72 to -0 & middot;14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Copyright (c) 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe
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