60 research outputs found

    Performance of BPSK subcarrier intensity modulation free-space optical communications using a log-normal atmospheric turbulence model

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    In this paper, we present simulation results for the bit error rate (BER) performance and the fading penalty of a BPSK - subcarrier intensity modulation (BPSK-SIM) free-space optical (FSO) communication link in a log-normal atmospheric turbulence model. The results obtained are based on the Monte-Carlo simulation. Multiple subcarrier modulation schemes offer increased system throughput and require no knowledge of the channel fading in deciding what symbol has been received. In an atmospheric channel with a fading strength 2 l ? of 0.1 obtaining a BER of 10-6 using a 2-subcarrier system will require a signal-tonoise (SNR) of 23.1 dB. The required SNR increases with the fading strength and at a BER of 10-9 the fading penalty due to the atmospheric turbulence is ~ 41 dB for 9 . 0 2 = l ? . The comparative studies of the OOK and BPSK-SIM schemes showed that for similar electrical SNR, BPSK-SIM offered improved performance across all range of turbulence variance

    Association of Wilms Tumor with Crossed Fused Renal Ectopia in Children: A Case Report

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    Introduction: Wilms tumor is the most common renal malignancy in children. The occurrence of Wilms tumor with various congenital genitourinary anomalies has been reported, particularly in horseshoe kidneys, hypospadias, disorder of sexual development, and double collecting system. However, Wilms tumor with crossed renal ectopia is a rare finding. Case Description: We are reporting a case report of Wilms tumor in a 3-year-old girl who presented with a huge left flank mass with cross-fused renal ectopia. After the initial workup and triphasic computed tomography (CT) scan of the chest, abdomen, and pelvis for confirmation of diagnosis and metastasis, the patient underwent image-guided tissue biopsy followed by neo-adjuvant chemotherapy, left radical nephrectomy with separation of fused right ectopic renal moiety and adjuvant chemoradiation. Practical Implication: This report shows an association of Wilms tumor with cross-fused renal ectopia, a rare combination. Unusual findings on imaging with unilateral flank mass should be considered as part of the differential diagnosis for this rare finding. Adjuvant chemotherapy and modern imaging helped delineate the anatomy and ease the surgery for safe resection, improving the overall outcome

    Emergency Angioembolization for Life-Threatening Haemorrhage in Wilms Tumour

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    Introduction: Renal artery embolization has been used in a palliative fashion for symptomatic relief of hematuria or flank pain in unresectable renal cell carcinoma in adults. There is limited data on using embolization for actively bleeding and unresectable tumours in the oncological pediatric population. Case description: A previously healthy, five-year-old boy with no significant past medical or surgical history presented to the clinic with gradually worsening abdominal distension associated with occasional abdominal pain, gross hematuria, and lethargy for four months. Diagnostic investigations showed an 18 cm left-sided metastatic (pulmonary) renal tumour (Wilms), which was deemed unresectable on imaging. Treatment was planned on SIOP-RTSG protocol. However, he became hemodynamically and vitally unstable with acute sudden distension of the abdomen on the left side after the first cycle of chemotherapy. Imaging showed active bleeding from an inferior branch of the left renal artery. Selective angioembolization was done, and chemotherapy was reinitiated with a patent left main renal artery. Following the fourth cycle of chemotherapy, he developed hemodynamic instability and abdominal pain; imaging revealed the resolution of pulmonary nodules and bleeding from the left renal artery (main); this was again embolized, and the patient was stabilized. The patient was operated on after optimization and complete resection of the mass was done with negative margins. On six months follow up, he is well. Practical implications: To the best of our knowledge, this is the first case where angioembolization has been done in conjunction with neoadjuvant chemotherapy to downsize a Wilms Tumor to achieve favourable outcomes. Continued research efforts are necessary to optimize strategies and improve the prognosis for pediatric patients, and this case is one of the prime examples

    Effect of bovine lactoferrin on seroconversion following polio vaccine administration in children: Protocol for a double-blinded randomised controlled trial

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    Introduction: The oral polio vaccine (OPV) has substantial results in eliminating wild poliovirus and the vaccine of choice in polio eradication. However, the mucosal immunity induced by the OPV is still uncertain. Literature has shown that bovine lactoferrin (BLF) is a safe and useful protein found in cow\u27s milk with extraordinary antimicrobial, antiviral, antiinflammatory and immune-modulatory functions that help children\u27s gut to fight against micro-organisms like poliovirus. However, limited data exist regarding the effect of BLF on polio vaccine immune response. The primary objective is to evaluate the effect of BLF in enhancing mucosal and humoral immunity in children following the administration of oral and inactivated polio vaccines.Methods and analysis: This is a two-arm double-blinded randomised controlled trial comparing 462 neonates (231 in both groups) receiving either BLF or placebo with breast milk. The intervention is administered from day 1 till 6 weeks of age to a full-term healthy singleton newborn born at the Aga Khan University Hospitals, Karachi, Pakistan. The primary outcome is the seroconversion, 1 month after the receipt of two doses of OPV (at 10 weeks). For descriptive statistical analysis, Stata will be used, the frequency with percentages will be reported to describe baseline characteristics of the participants. A χ2 test will be used to compare categorical variables and a simple t test to compare continuous variables. The proportion of seroconversion and shedding will be compared using χ2 test or Fisher\u27s exact test.Ethics and dissemination: The Ethics approval has been granted by the Ethics Review Committee (ERC) of Aga Khan University for the proposed trial (ID: 2019-1955-5013). Furthermore, the National Bioethics Committee (NBC) of Pakistan has also approved the study for human subject research (ID: 4-87/NBC-443/19/669). Study findings will be disseminated through presentations at scientific conferences and educational practice workshops and will be published in an international peer-reviewed scientific journal

    Outcome-Based Engineering Education: A Global Report of International OBE Accreditation and Assessment Practices

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    Outcome-based education (OBE) is a paradigm in which instructional and assessment/ evaluation are explicitly designed for ensuring the attainment and mastery of predefined learning outcomes. OBE is now the underlying paradigm followed by global accreditation efforts such as the Washington Accord (ratified in 1989). The shift to OBE is so pronounced that some education experts identify the shift to outcome-based education and accreditation as one of the top 5 major changes of the last 100 years. OBE is starkly different from the previous content-based educational approaches in shifting the aim from covering the content to a student-centric mastery that is driven by exit-outcomes and educational objectives. And while OBE is often criticized for straitjacketing education, and resisted by hesitant faculty members suspecting additional burden, studies show that the OBE movement, on the whole, has helped in improving the educational standards and outcomes by helping ensure proper planning of curriculum and assessment and their alignment with the program objectives and desired outcomes. OBE is also flexible in the sense that it does not dictate the choice of specific education strategies or teaching methods. New OBE schemes have also diversified in response to early misgiving about OBE (related to excessive paperwork, and bean-counting-like auditing) and now admit diverse types of evidence (including qualitative and quantitative, formative and summative, formal and informal assessments). In this paper, we present—as a geographically dispersed set of academics from Pakistan, United Kingdom, United States of America, Malaysia, Saudi Arabia—a global international perspective on OBE accreditation standards, practices, and attitudes. We will trace the historical development leading to the great shift to OBE in recent times and also synthesize insights from our diverse transnational experience in meeting accreditation requirements in different countries

    Community-based asthma assessment in young children:Adaptations for a multicentre longitudinal study in South Asia

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    BACKGROUND: Systematic assessment of childhood asthma is challenging in low- and middle-income country (LMIC) settings due to the lack of standardised and validated methodologies. We describe the contextual challenges and adaptation strategies in the implementation of a community-based asthma assessment in four resource-constrained settings in Bangladesh, India, and Pakistan. METHOD: We followed a group of children of age 6–8 years for 12 months to record their respiratory health outcomes. The study participants were enrolled at four study sites of the ‘Aetiology of Neonatal Infection in South Asia (ANISA)’ study. We standardised the research methods for the sites, trained field staff for uniform data collection and provided a ‘Child Card’ to the caregiver to record the illness history of the participants. We visited the children on three different occasions to collect data on respiratory-related illnesses. The lung function of the children was assessed in the outreach clinics using portable spirometers before and after 6-minute exercise, and capillary blood was examined under light microscopes to determine eosinophil levels. RESULTS: We enrolled 1512 children, 95.5% (1476/1512) of them completed the follow-up, and 81.5% (1232/1512) participants attended the lung function assessment tests. Pre- and post-exercise spirometry was performed successfully in 88.6% (1091/1232) and 85.7% (1056/1232) of children who attempted these tests. Limited access to health care services, shortage of skilled human resources, and cultural diversity were the main challenges in adopting uniform procedures across all sites. Designing the study implementation plan based on the local contexts and providing extensive training of the healthcare workers helped us to overcome these challenges. CONCLUSION: This study can be seen as a large-scale feasibility assessment of applying spirometry and exercise challenge tests in community settings of LMICs and provides confidence to build capacity to evaluate children’s respiratory outcomes in future translational research studies

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 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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