Análise de desenhos experimentais com outliers

Primary purpose of the article is to develop outlier robust designs. As a matter of fact, negative effect of outliers in any experimental settings is established where the outliers at any specific design point can destroy the features of the design for which it is being developed. It is attempted here in this article to develop a version of robustness for central composite designs which may protect it for outliers by introducing the idea of minimax outlying effect. This involves the calculation of the degree of outlying effect(s) outlier(s) may produce and then minimize the maximum of these outlying effects in an attempt to equalize the influence of all design points. On comparison, these outlier robust designs are proved to be more optimal, on the scales of A, D, and E optimalities, against existing conventional rotatable, orthogonal, and other such designs. The outlier robust designs, developed here, are suitable for settings prone to outliers where conventional designs fail to represent and analyze the processes and systems.El objetivo principal del artículo es desarrollar diseños robustos atípicos. De hecho, el efecto negativo de los valores atípicos en cualquier configuración experimental se establece donde los valores atípicos en cualquier punto de diseño específico pueden destruir las características del diseño para el que se está desarrollando. En este artículo se intenta desarrollar una versión de robustez para los diseños compuestos centrales que pueden protegerlo de los valores atípicos mediante la introducción de la idea del efecto periférico minimax. Esto implica el cálculo del grado de efecto (s) externo (s) que puede producir un valor atípico y luego minimizar el máximo de estos efectos externos en un intento de igualar la influencia de todos los puntos de diseño. En comparación, se demuestra que estos diseños robustos atípicos son más óptimos, en las escalas de las optimidades A, D y E, frente a los diseños convencionales existentes, ortogonales, rotativos y otros similares. Los diseños robustos atípicos, desarrollados aquí, son adecuados para configuraciones propensas a los valores atípicos en los que los diseños convencionales no representan ni analizan los procesos y sistemas.Objetivo principal do artigo é desenvolver projetos robustos outlier. De fato, o efeito negativo de outliers em qualquer ambiente experimental é estabelecido onde os outliers em qualquer ponto de design específico podem destruir os recursos do design para o qual ele está sendo desenvolvido. Neste artigo, tenta-se desenvolver uma versão de robustez para projetos compostos centrais que possam protegê-lo de outliers, introduzindo a ideia de efeito periférico minimax. Isso envolve o cálculo do grau de efeito (s) outlier (s) outlier (s) pode produzir e, em seguida, minimizar o máximo desses efeitos periféricos em uma tentativa de equalizar a influência de todos os pontos do projeto. Em comparação, esses designs robustos discrepantes são comprovadamente mais otimizados, nas escalas de otimalidades A, D e E, contra os designs convencionais rotacionais, ortogonais e outros existentes. Os designs robustos outlier, desenvolvidos aqui, são adequados para configurações propensas a outliers em que projetos convencionais não representam e analisam os processos e sistemas

An analysis of pattern and burden of patients Referred for nerve conduction study in a Tertiary care hospital in Pakistan

Background: To analyze the trend and load of neurological diseases in a university medical center for reffered electrophysiology. Methodology: From January 2016 to December 2018, this retrospective study was carried out in department of Neurology, Pakistan Institute of Medical Sciences (PIMS) Islamabad. A total of 4527 patients were evaluated during this time period in neurophysiology lab through computerized data

Obstructive sleep apnea in middle age male smokers

OBJECTIVE: Obstructive sleep apnea is the most common type of sleep apnea. This was designed to establish the relationship between smoking and obstructive sleep apnea. Methods:This cross-sectional study was conducted at the outpatient department of Pakistan Institute of Medical Sciences, Islamabad, Pakistan, from August 2018 to November 2018 (dates mentioned in methods are different) and comprised of males aged 30-50 years. Participants were divided into two groups of smokers and non-smokers and Berlin questionnaire was used to collect data employing systemic random sampling. SPSS 22 was used for analysis. Results:There were 768 male participants in the study equally split between smokers and non-smokers. Mean age was 39±5.76 years. Percentage of high-risk group among smokers was 36.5% and among non-smokers was 16.7%. Percentage of low risk group among smokers was 63.5% and among non-smokers was 83.3%. The odds ratio of obstructive sleep apnea was 2.87 times more in smokers than non-smokers. Conclusion:Long term smoking had a strong association with obstructive sleep apnea

Self-adapting security monitoring in Eucalyptus cloud environment

This paper discusses the importance of virtual machine (VM) scheduling strategies in cloud computing environments for handling the increasing number of tasks due to virtualization and cloud computing technology adoption. The paper evaluates legacy methods and specific VM scheduling algorithms for the Eucalyptus cloud environment and compare existing algorithms using QoS. The paper also presents a self-adapting security monitoring system for cloud infrastructure that takes into account the specific monitoring requirements of each tenant. The system uses Master Adaptation Drivers to convert tenant requirements into configuration settings and the Adaptation Manager to coordinate the adaptation process. The framework ensures security, cost efficiency, and responsiveness to dynamic events in the cloud environment. The paper also presents the need for improvement in the current security monitoring platform to support more types of monitoring devices and cover the consequences of multi-tenant setups. Future work includes incorporating log collectors and aggregators and addressing the needs of a super-tenant in the security monitoring architecture. The equitable sharing of monitoring resources between tenants and the provider should be established with an adjustable threshold mentioned in the SLA. The results of experiments show that Enhanced Round-Robin uses less energy compared to other methods, and the Fusion Method outperforms other techniques by reducing the number of Physical Machines turned on and increasing power efficienc

Convective Heat Transfer Study of ZnO Nanofluids and a Comparison with the Conventional Coolant Water

In this era, the utilization of automobiles is increasing rapidly. So, it is a task for the automobile industries to yield well-ordered cooling system, which is actually responsible to carry waste heat of engine to atmosphere for effective working of an internal combustion engines. In this research, car radiator was tested by the water based Nano fluids to increase its heat transfer capacity and new experimental results were reported. Zinc Oxide nanofluids were prepared and tested by adding their nanoparticles in water with different volume fractions (0.1, 0.2, 0.3 and 0.4)%. Experimentally, effect of these concentrations were observed by varying a fluid flow rate from 4 liter per minute to 1 liter per minute and inlet temperature of fluid entering in radiator was kept constant at 80oC and enhancement in heat transfer was observed  from 46% to 70% by using ZnO Nano Fluid having volumetric concentration 0.2%. Increase in volumetric concentration had shown the enhancement of heat transfer but up to 0.2% and it was seen that further increase in concentration was been reduced the heat transfer capacity.

Accuracy of procalcitonin levels for diagnosis of culture-positive sepsis in critically ill trauma patients: A retrospective analysis

Background: Abdominal trauma and intra-abdominal sepsis are associated with significant morbidity and mortality. Microcirculation in the gut is disrupted in hemorrhagic and septic shock leading to tissue hypoxia, and the damaged gut acts as a reservoir rich in inflammatory mediators and provides a continual source of inflammation to the systemic circulation leading to sepsis. Sepsis is defined as the presence (probable or documented) of infection together with a systemic inflammatory response to infection. Blood culture is commonly considered to be the preferred approach for diagnosing sepsis, although it is time-consuming, that is, reports are normally available only after 12-48 hours. Procalcitonin levels (PCT) have recently emerged as a promising biomarker in the diagnosis of sepsis. The aim of the present study is to determine the diagnostic accuracy of PCT levels in predicting sepsis in critically ill trauma patients.Methodology: This was designed as a validation study conducted in the Indoor Department of General Surgery, Liaquat National Hospital, Karachi. The sample size was calculated by taking the estimated frequency of sepsis in suspected patients at 62.13%, expected sensitivity of PCT at 70.83%, and specificity at 84.21% and the desired precision level of 12% for sensitivity; the calculated sample size was 96. The non-probability consecutive sampling method was used to recruit participants who were diagnosed with sepsis on clinical assessment. Blood culture samples were sent for the enrolled patients and a final diagnosis was made on the blood culture report. PCT levels were measured in these suspected patients on the same day of sending blood culture. Diagnostic accuracy of PCT size was measured using the receiver operating characteristic (ROC) curve. ROC curve was formulated for PCT levels against culture-proven sepsis to determine the ideal cut-off value of PCT levels. Two different cut-offs were determined to obtain the highest sensitivity and highest specificity accordingly.Results: A total of 97 individuals met the inclusion criteria with a mean age of 34.89 ± 10.52 years. Mean PCT levels were 0.96 ± 0.59, with a gender predilection towards females (p \u3c 0.001). No age difference was documented among gender (p = 0.655). The mean duration of intensive care unit stay was 11.73 ± 3.56 days. Culture-proven sepsis was identified in 67.0% of the study participants with a higher PCT level (p \u3c 0.001). Among the 52.6% males included in the study, half were reported to have culture-positive sepsis, but among the 47.4% females culture was positive in 87% (p \u3c 0.001). ROC revealed PCT was predictive for culture-positive sepsis at a cut-off value 0.47 ng/mL (p \u3c 0.001), with a sensitivity of 92.3%, specificity of 68.7%, positive predictive value (PPV) of 85.7%, and negative predictive value (NPV) of 81.5%. By increasing the cut-off value to 0.90 ng/mL at area under the curve of 0.816, the specificity increased to 81.3% and sensitivity became 66.2%, with a PPV of 87.8% and NPV of 54.2%.Conclusion: Our study determined two cut-values for PCT to predict sepsis, one with the highest sensitivity and the other with better specificity. Other than that, higher PCT levels were significant in female trauma patients. We conclude that PCT is a reliable marker for culture-proven diagnosis of sepsis and may aid physicians/surgeons to promptly manage patients accordingly

Can AI help in screening Viral and COVID-19 pneumonia?

Coronavirus disease (COVID-19) is a pandemic disease, which has already caused thousands of causalities and infected several millions of people worldwide. Any technological tool enabling rapid screening of the COVID-19 infection with high accuracy can be crucially helpful to healthcare professionals. The main clinical tool currently in use for the diagnosis of COVID-19 is the Reverse transcription polymerase chain reaction (RT-PCR), which is expensive, less-sensitive and requires specialized medical personnel. X-ray imaging is an easily accessible tool that can be an excellent alternative in the COVID-19 diagnosis. This research was taken to investigate the utility of artificial intelligence (AI) in the rapid and accurate detection of COVID-19 from chest X-ray images. The aim of this paper is to propose a robust technique for automatic detection of COVID-19 pneumonia from digital chest X-ray images applying pre-trained deep-learning algorithms while maximizing the detection accuracy. A public database was created by the authors combining several public databases and also by collecting images from recently published articles. The database contains a mixture of 423 COVID-19, 1485 viral pneumonia, and 1579 normal chest X-ray images. Transfer learning technique was used with the help of image augmentation to train and validate several pre-trained deep Convolutional Neural Networks (CNNs). The networks were trained to classify two different schemes: i) normal and COVID-19 pneumonia; ii) normal, viral and COVID-19 pneumonia with and without image augmentation. The classification accuracy, precision, sensitivity, and specificity for both the schemes were 99.7%, 99.7%, 99.7% and 99.55% and 97.9%, 97.95%, 97.9%, and 98.8%, respectively.Comment: 12 pages, 9 Figure

Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

Impact of Botoulinum Toxin-A on Complex Regional Pain Syndrome Type-2; A Case Report

CRPS is a very debilitating disorder. Pain (sensory) motor & autonomic changes are the main stream manifestation of this disorder. In this case study we employed Botoulinum Toxin-A along with routine pharmacotherapy to observe its Impact on patient’s pain intensity along with quality of life. On McGill pain scale and SF-36 QoL result showed improvement after 2nd week till 12th week. Change in each variable was significant over 12 weeks interval

Assessing The Reliability Of System Modules Used In Multiple Lifecycles

This paper presents a reliability assessment model for maintenance and reliability engineers to determine the reusability potential of system modules based on their operating lives and, the pre-determined lifecycle of the parent product. In the first phase, the paper considers the time-to-failure of system modules to determine their overall operating life under normal operating conditions. Then, it determines the maximum number of lifecycles of the modules under consideration, which is a function of the modules total functional life and the product lifecycle. The functional potential of the modules is then discussed with reference to the probability of their failure. The study employs Weibull analysis for carrying out this analysis. The methodology was validated by using lifecycle data from a consumer product. The findings show that some of the components/modules of the product have a remarkable amount of residual life, which can be utilized by reusing these components in the next generation of the product. The results demonstrate the effectiveness and practicality of this multiple-use strategy. The study provides more perspectives to future research in the field of reliability, and decision-making on maintenance management and value recovery through multiple uses of system modules