138 research outputs found

    Bilateral carotid body tumors: a case report And review

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    Carotid body tumors (CBTS) also known as chemodectomas are a type of paragangliomas which originate from the carotid body. Carotid body tumors present as a palpable mass in anterolateral aspect of the neck causing splaying of the external carotid artery (ECA) and internal carotid artery (ICA). Bilateral carotid body tumors are uncommon with a reported incidence of 5 - 10%. CBTs are commonly seen in 4th to 5th decades with female predilection. We report a case of 16 years old boy with bilateral carotid body tumors

    The Determinants of Corporate Dividend Policy: An Investigation of Pakistani Banking Industry

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    The paper investigates the impact of different firm specific factors on the dividend policy of companies by selecting a sample of 18 banks listed in KSE for the period 2006-2011. The dependent variable is dividend policy where as explanatory variables include, firm size and risk, profitability, firm’s growth and leverage. It was found that out of 18 banks 11 banks pay dividends whereas seven banks do not. The results have shown that the independent variables growth, profitability and firm size have positive coefficient of correlation when the dependent variable is dividend yield and Dividend Payout Ratio. However there is strong linear association between profitability and firm size with dividend policy but the variable growth rate has weak positive correlation with dividend policy. In contrast, the variables leverage and firm risk has inverse linear relationship with dividend policy. Banks that pay dividends were found, when we use method of correlation coefficient more profitable, stable and less risky as compare to banks that do not pay dividends. Keywords: Dividend Policy, Listed Banks, Pakista

    Effect of Phytobiocides in Controlling Soft Rot of Tomato

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    The effect of various phytobicides such as Oleander, Chili, Mint, Garlic, Turmeric, and Neem on the control of soft rot of tomato was made both in laboratory and screen house conditions. Significant (P ? 0.05) differences were found among different phytobiocides which were used to produce zone of inhibition (in mm) of Erwinia carotovora carotovora (on culture medium LB). Maximum zone of bacterial growth inhibition was achieved by turmeric (9.33 mm) followed by neem (7.33mm) and garlic (6.33mm). The screen house studies indicated that turmeric treated plants gave maximum height (61.67 cm), fresh shoot weight (35.68 g), fresh root weight (9.88 g), dry shoot weight (8.00 g), and dry root weight (3.25 g) followed by Neem and Garlic. These phytobiocides especially turmeric could serve as novel antibacterial agents. Key words: Phytobiocides, Erwinia, Turmeric, Zone of inhibition

    Ensemble Pruning for Glaucoma Detection in an Unbalanced Data Set

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    Background: Random forests are successful classifier ensemble methods consisting of typically 100 to 1000 classification trees. Ensemble pruning techniques reduce the computational cost, especially the memory demand, of random forests by reducing the number of trees without relevant loss of performance or even with increased performance of the sub-ensemble. The application to the problem of an early detection of glaucoma, a severe eye disease with low prevalence, based on topographical measurements of the eye background faces specific challenges. Objectives: We examine the performance of ensemble pruning strategies for glaucoma detection in an unbalanced data situation. Methods: The data set consists of 102 topographical features of the eye background of 254 healthy controls and 55 glaucoma patients. We compare the area under the receiver operating characteristic curve (AUC), and the Brier score on the total data set, in the majority class, and in the minority class of pruned random forest ensembles obtained with strategies based on the prediction accuracy of greedily grown sub-ensembles, the uncertainty weighted accuracy, and the similarity between single trees. To validate the findings and to examine the influence of the prevalence of glaucoma in the data set, we additionally perform a simulation study with lower prevalences of glaucoma. Results: In glaucoma classification all three pruning strategies lead to improved AUC and smaller Brier scores on the total data set with sub-ensembles as small as 30 to 80 trees compared to the classification results obtained with the full ensemble consisting of 1000 trees. In the simulation study, we were able to show that the prevalence of glaucoma is a critical factor and lower prevalence decreases the performance of our pruning strategies. Conclusions: The memory demand for glaucoma classification in an unbalanced data situation based on random forests could effectively be reduced by the application of pruning strategies without loss of performance in a population with increased risk of glaucoma

    Optimal trees selection for classification via out-of-bag assessment and sub-bagging

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    The effect of training data size on machine learning methods has been well investigated over the past two decades. The predictive performance of tree based machine learning methods, in general, improves with a decreasing rate as the size of training data increases. We investigate this in optimal trees ensemble (OTE) where the method fails to learn from some of the training observations due to internal validation. Modified tree selection methods are thus proposed for OTE to cater for the loss of training observations in internal validation. In the first method, corresponding out-of-bag (OOB) observations are used in both individual and collective performance assessment for each tree. Trees are ranked based on their individual performance on the OOB observations. A certain number of top ranked trees is selected and starting from the most accurate tree, subsequent trees are added one by one and their impact is recorded by using the OOB observations left out from the bootstrap sample taken for the tree being added. A tree is selected if it improves predictive accuracy of the ensemble. In the second approach, trees are grown on random subsets, taken without replacement-known as sub-bagging, of the training data instead of bootstrap samples (taken with replacement). The remaining observations from each sample are used in both individual and collective assessments for each corresponding tree similar to the first method. Analysis on 21 benchmark datasets and simulations studies show improved performance of the modified methods in comparison to OTE and other state-of-the-art methods

    Does courtesy bias affect how clients report on objective and subjective measures of family planning service quality? A comparison between facility- and home-based interviews

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    Purpose: Despite a general understanding that exit interviews being conducted at service providers\u27 facilities may influence clients\u27 responses favorably to health professionals, there is very little evidence available that demonstrates the extent to which this problem exists. This study aimed at assessing and comparing clients\u27 perceptions of the quality of family planning services and their satisfaction levels between facility- and home-based interviews.Methods: A cross-sectional survey was conducted among clients receiving family planning services across three service delivery channels - nongovernmental organization (NGO) clinics, social franchise (SF) centers, and outreach camps. The survey took place from December 2015 to January 2016 in 70 districts across all four provinces of Pakistan. A total of 2,807 clients were interviewed, of whom 1,404 clients were interviewed at health facilities after receiving services and 1,403 were interviewed at their homes within 3 days of method uptake.Results: Overall, we found no significant differences between the characteristics of study participants interviewed at health facilities or at home. The findings suggested that experiences reported in exit surveys at facilities were strongly biased positively. This was true for both experiential (service quality) and perception-based (satisfaction) questions in the context of SF centers, while at NGO clinics the interview location only affected clients\u27 responses regarding service quality. However, in outreach settings, clients are more likely to share bad experiences in exit interviews than in home-based interviews on objectively asked questions (service quality).Conclusion: Our study indicates signs of courtesy bias and possibly the Hawthorne effect in exit interviews. Program implementers could opt for home-based interviews for women receiving services at NGO clinics or SF center, whereas exit interviews could be used in outreach settings

    Pain Perception and Rate of Canine Retraction Through Self- Ligating Brackets and Conventional Elastomeric Ligation System: A Split Mouth Study

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    Objective: To evaluate the rate of tooth movement and the pain perception via self-ligating (SL) and conventional elastomeric ligation brackets (CB) system. Material and Methods: This study has been conducted at the Orthodontic Department of Baqai Dental College, Baqai Medical University. The sample size of this study comprised 40 patients, falling between the age of 12-30 years without any sex discrimination. Shapiro-Wilk was used to check the distribution of data. Non-parametric Mann Whitney U test was applied to evaluate the pain associated with SL and CB brackets system. To analysis the canine retraction Wilcoxon test was applied for the comparison of CB and SL brackets system. For all statistical analyses, the p-value of <0.05 was considered significant. Results: Pain level associated with retraction via CB and SL shows significant differences. However, the rate of canine retraction via CB and SL shows no significant differences at stages T0-T1 and T1-T2. However, stage T2-T3 shows a significant difference. Conclusion: As pain during orthodontic treatment is mostly associated with the level of compression of the periodontal ligament, it may be hypothesized that lower frictional forces generate less compression of the periodontal ligament and blood vessels, and so alter the type of pain experienced

    What influences family planning in rural Pakistan: Franchised service provider and community health worker perspective

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    Background: Pakistan has a low modern contraceptive prevalence rate, 26%, leading family planning (FP) programmes to explore partnerships with local private providers to improve access to quality FP services. This study aims to understand the socio-cultural and organizational factors that influence delivery of quality family planning services. Methods: This qualitative study was conducted with private service providers and community health workers (CHW) in Marie Stopes Society\u27s (MSS) social franchise network. A total of 31 providers and 28 CHWs from Sindh, Punjab, and Khyber Pakhtunkhwa provinces of Pakistan were purposively selected for in-depth interviews. The study used thematic content analysis to understand providers\u27 and health workers\u27 perspectives of family planning service provision. Results: This study found that normative environment, propagation of myths and misconceptions, and health concerns remain major barriers to service provision in rural communities. Findings showed that CHWs were instrumental in increasing awareness and positive attitudes towards family planning in the catchment areas. Moreover, social franchising was effective in increasing access to high-quality, subsidised family planning services amongst economically marginalised and low-awareness communities. Providers and health workers expressed satisfaction with the franchising approach, and revealed that being part of this network substantially increased their client volume and ability to serve poorer segments of the population. Conclusion: The study found that franchising private service providers in rural areas enhances their ability to serve clients, and when coupled with demand-generation elements, such as vouchers and community health workers, it substantially increases their client volume. Albeit effective, the franchising approach currently lacks the element of long-term service provision at the current scale, and may require further strategizing by the franchisor. Moreover, alternate strategies should be explored to ensure continued provision of FP services without vouchers and CHWs

    Ensemble of Optimal Trees, Random Forest and Random Projection Ensemble Classification

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    The predictive performance of a random forest ensemble is highly associated with the strength of individual trees and their diversity. Ensemble of a small number of accurate and diverse trees, if prediction accuracy is not compromised, will also reduce computational burden. We investigate the idea of integrating trees that are accurate and diverse. For this purpose, we utilize out-of-bag observations as a validation sample from the training bootstrap samples, to choose the best trees based on their individual performance and then assess these trees for diversity using the Brier score on an independent validation sample. Starting from the first best tree, a tree is selected for the final ensemble if its addition to the forest reduces error of the trees that have already been added. Our approach does not use an implicit dimension reduction for each tree as random project ensemble classification. A total of 35 bench mark problems on classification and regression are used to assess the performance of the proposed method and compare it with random forest, random projection ensemble, node harvest, support vector machine, kNN and classification and regression tree (CART). We compute unexplained variances or classification error rates for all the methods on the corresponding data sets. Our experiments reveal that the size of the ensemble is reduced significantly and better results are obtained in most of the cases. Results of a simulation study are also given where four tree style scenarios are considered to generate data sets with several structures

    Comparative efficacy of phosphate solubilizing bacteria and synthetic phosphate fertilizers on the growth of wheat

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    Wheat is recognized as one of the most important dietary elements due to its high nutritious content and thus, has become greatest food option all over the world. Phosphorus (P) being major plant food nutrient plays a vital role multiple functions of plant growth and development. The current study was carried out to compare the performance of phosphate solubilizing bacteria (PSB) as bio-fertilizer with commercially available phosphate fertilizers on wheat crop. The trial was designed in randomized complete block (RCB) replicated thrice. 6 different sources of phosphate fertilizers (Di-ammonium phosphate as DAP, Nitrophos as NP, Single super phosphate as SSP, Restore as PSB, Marathon as PSB, Nitrogen (N2) fixing bacteria as PSB) followed by control were evaluated for agronomic, physiological and quality attributes of wheat. The results showed that most of the qualitative traits were significantly influenced by different treatments. However, application of N2 fixing bacteria was more significant in all treatments. Highest total viable count of colony-forming units (14.63×106 at 3-WAS & 17.70×106 after harvest CFU g-1), maximum tillers’ count (337 m-2), grains’ count (45.57 spike-1), grain yield (2714.3 kg ha-1), LAI (0.67 & 1.16 at 56 & 112 DAS), CGR (13.59 g day-1 m-2), photosynthesis rate (26.13 µ mol m-2 sec-1) and flag leaf sugar content (0.24%) were recorded on account of using N2-fixing bacteria applied as PSB. Moreover, NPK content in shoot, grain as well as uptake of NPK by grain were also received as highest in the same treatment. Based on research findings, it is concluded that application of N2-fixing bacteria as PSB (7.5 kg ha-1) might be increasing wheat production in Dera Ismail Khan and other areas of similar environment in Pakistan
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