Comparative study on Maxwell and Navier stokes fluid equations with pressure gradient over a flat plate for convective boundary layer flow and heat transfer

In this article, Maxwell fluid over a flat plate for convective boundary layer flow with pressure gradient parameter is considered. The aim of this study is to compare and analyze the effects of the presence and absence of λ (relaxation time), and also the effects of m (pressure gradient parameter) and Pr (Prandtl number) on the momentum and thermal boundary layer thicknesses. An approximation technique namely Homotopy Perturbation Method (HPM) has been used with an implementation of Adam and Gear Method’s algorithms. The obtained results have been compared for zero relaxation time and also pressure gradient parameter with the published work of Fathizadeh and Rashidi. The current outcomes are found to be in good agreement with the published results. Physical interpretations have been given for the effects of the m, Pr and β (Deborah number) with λ. This study will play an important role in industrial and engineering applications

Two Stage Portfolio Selection and Optimization Model with the Hybrid Particle Swarm Optimization

The selection criteria play an important role in the portfolio optimization using any ratio model. In this paper, the authors have considered the mean return as profit and variance of return as risk on the asset return as selection criteria, as the first stage to optimize the selected portfolio. Furthermore, the sharp ratio (SR) has been considered to be the optimization ratio model. In this regard, the historical data taken from Shanghai Stock Exchange (SSE) has been considered. A metaheuristic technique has been developed, with financial tool box available in MATLAB and the particle swarm optimization (PSO) algorithm. Hence, called as the hybrid particle swarm optimization (HPSO) or can also be called as financial tool box particle swarm optimization (FTB-PSO). In this model, the budgets as constraint, where as two different models i.e. with and without short sale, have been considered. The obtained results have been compared with the existing literature and the proposed technique is found to be optimum and better in terms of profit

Macular Thickness by Age and Gender in Healthy Eyes Using Spectral Domain Optical Coherence Tomography

PURPOSE: To determine normal macular thickness and its variation by age and gender in healthy eyes using spectral-domain optical coherence tomography (SD-OCT). METHODS: In this cross-sectional analysis, two hundred and twenty eyes of 220 healthy subjects underwent raster scanning using Topcon SD-OCT system, at the Department of Ophthalmology, Dow University of Health Sciences and Civil Hospital Karachi, Pakistan. Macular thickness from all 9 regions of the ETDRS map was documented for each subject. Variations in macular thickness measurements by age and gender were determined. RESULTS: The 220 subjects had a mean age of 45.3 years (16-80 years). Using the ETDRS map, foveal thickness for all subjects was measured to be 229±20.46 µm. Mean macular thickness for all subjects was 262.8±13.34 µm. Male gender was associated with greater foveal (p<0.0001) and mean macular (p<0.0001) thickness compared to females. There was no association of mean macular thickness (r(2) = 0.01; p>0.05) and foveal thickness (r(2) = 0.00004; p>0.05) with age. CONCLUSION: We have provided normative data for macular thickness using Topcon SD-OCT system. Our results are comparable to some and vary from other reports using the similar OCT system. Our results suggest that male gender is associated with greater macular thickness, while macular thickness has no association with age in healthy eyes. This is the first normative data for macular thickness from Pakistan; benchmark for diagnosing and monitoring macular pathologies. The values obtained in this study may be useful for comparison with other populations, other SD-OCT systems and future imaging technologies

Brain abscess caused by lactococcus lactis in a young male

Lactococcus lactis cremoris is one of the gram positive cocci, not known to be pathogenic in humans. We report a case of brain abscess due to lactococcus lactis in an adolescent. An 18-year male with congenitally corrected transposition of great arteries and dextrocardia was admitted with fever, headache and right-sided numbness. Magnetic resonance imaging revealed a well circumscribed irregular heterogeneous abnormal signal intensity lesion in left temporo-parietal lobe having central area of diffusion restriction and peripheral wall enhancement on post-contrast images. He underwent mini-craniotomy for abscess drainage. Pus culture revealed growth of lactococcus lactis. He was treated with ceftriaxone and remained disability-free on six month follow-up. To our knowledge, this is one of the few reports of brain abscess caused by lactococcus lactis. Key Words: Brain abscess, Lactococcus lactis, Adolescent

Sociodemographic, clinical characteristics, and outcomes of influenza pneumonia patients admitted in a tertiary care hospital in Karachi, Pakistan: Findings from a cross-sectional study

Objective: To determine the sociodemographic, clinical characteristics, and outcomes of influenza pneumonia patients in tertiary care hospital, Karachi Pakistan.Study design: A cross-sectional study.Place and duration of study: The Aga Khan University Hospital Karachi Pakistan from January 2013 to December 2018. Methodology: All adult patients who were older than 18 years and suspected to have viral pneumonia were included in the study. Data were abstracted on 105 patients and were entered on preformed proforma after reviewing the files of patients.Results: Ninety-four (89.5%) patients were influenza positive and 15.2% (n=16) had been vaccinated. Around 92.4% (n=97), 81.9% (n=86) and 61.9% (n=65) patients had cough, fever and shortness of breath, respectively; and 63.8% (n=67), 16.2% (n=17), and 2.9% (n=3) patients had consolidation, nodules, and cavitation, respectively. Almost 91.4% (n=96) patients were given treatment and discharged home; however, 7.6% (n=8) died. Procalcitonin, creatinine, HCO3 , lactate, and bilirubin level were increased in 2nd group (mortality group) after 48 hours; however, the results were only significant for HCO3 (p = 0.035).Conclusion: Influenza pneumonia is very common in our population and older people are more likely to be affected by this disease. Patients can be prevented from adverse outcomes and complications, if diagnosed and treated in time

4convective heat transfer in the boundary layer flow of a maxwell fluid over a flat plate using an approximation technique in the presence of pressure gradient

In this study, the effect of pressure gradient have been included for heat transfer in the boundary layer flow of Maxwell fluid over a flat plate.The solution of the problem is obtained with an application of algorithms of Adams Method (AM) and Gear Method (GM) with Homotopy Perturbation Method (HPM) as an approximation technique. This technique shows the outcomes of pressure gradient (m), Deborah number (β) and Prandtl number (Pr) in the boundary layer flow on temperature and velocity profiles, also the momentum and thermal boundary layer thickness and discussed. To obtain this objective, the momentum and energy equations of Maxwell are solved. The outcomes of HPM in the absence of relaxation time (λ) or Deborah number (β) and pressure gradient (m) (i.e. λ = β = m = 0) at Prandtl number Pr = 1 are in closed relation with the numerical results having the value of η∞ is around 5. Also it is found that the system is convergent, as a whole momentum and thermal boundary layer thicknesses becomes thinner and thinner. Importantly, some cooling effects of the Maxwell fluid over a flat plate for energy profile have been observed

Cytomegalovirus and Tumors: Two Players for One Goal-Immune Escape

Cytomegalovirus (CMV) and the human tumor cell share the same objectives: escape the recognition and destruction by the immune system and establish a state of immune tolerance conducive for their development. For early tumor development, the escape of the first lines of defense of the immune surveillance is a critical step which determines survival or destruction. The presence of CMV on the tumor site and its involvement in carcinogenesis as initiator or promoter is increasingly documented. In this article, we highlight the similarity between mechanisms used by tumors and CMV to circumvent the immune defenses and evade from immune surveillance. We suggest that CMV and tumors help one another for their common objective. CMV gets shelter in immunologically poor environment of the tumor cells. In return CMV, by acting directly on the cancer cell and/or on the tumor microenvironment, provides the tumor cell the ways to promote its immune escape and development of immune tolerance

On the cache performance of the information centric network

The current Internet model has proved more sustainable then the provisioned capacity at the time when the architecture was designed.The voluminous growth of traffic over the Internet has brought challenges for the exiting networking architecture.The information centric paradigm appears to offer efficient solution towards content dissemination model.It is a content-focused networking paradigm rather than host-to-host communication. Caching is one of the major components of information centric networks.This paper is intended to explore the impact of cache on critical attributes of networks.We have made a comparative analysis of in-network and edge network caching mechanism using network simulation.The results proved that in-network caching mechanism is far better than network edge caching with improved throughout, increase link capacity to avoid congestion

Evaluation of quality of warfarin therapy by assessing patient\u27s time in therapeutic range at a tertiary care hospital in Pakistan

Objective: To assess the time in therapeutic range in patients on warfarin anti-coagulation therapy. Methods: The retrospective chart review was conducted at Aga Khan University Hospital, Karachi, and comprised data of patients having undergone anti-coagulation with warfarin from January 2013 to April 2015. To determine the mean time in therapeutic range, Rosendaal method was used. Association of time in therapeutic range with the composite outcome, bleeding and thromboembolic events was also assessed. Percentage of patients with time in therapeutic range \u3c60% was calculated. Results: There were 92 patients whose median time in therapeutic range was 34.9% (interquartile range: 20.0- 55.7). Overall, 71(77.2%) patients had time in therapeutic range below 60% which had statistically significant correlation with the composite outcome (p\u3c0.05). Number of comorbids was significant in predicting time in therapeutic range and patients with time in therapeutic range\u3c 60% (p\u3c0.05). Conclusion: Subjects had poor anti-coagulation quality. It might be prudent to move towards novel oral anticoagulant drugsas the first choice for therapeutic anti-coagulation